Search Images Maps Play YouTube News Gmail Drive More »
Sign in
Screen reader users: click this link for accessible mode. Accessible mode has the same essential features but works better with your reader.

Patents

  1. Advanced Patent Search
Publication numberUS3015203 A
Publication typeGrant
Publication dateJan 2, 1962
Filing dateDec 11, 1959
Priority dateDec 11, 1959
Publication numberUS 3015203 A, US 3015203A, US-A-3015203, US3015203 A, US3015203A
InventorsHeiberg Oernulf E
Original AssigneeWhitin Machine Works
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Torque controlled strand tensioning system and method
US 3015203 A
Abstract  available in
Images(4)
Previous page
Next page
Claims  available in
Description  (OCR text may contain errors)

0. E. HEIBERG Jan. 2, 1962 TORQUE CONTROLLED STRAND TENSIONING SYSTEM AND METHOD 4 Sheets-Sheet 1 Filed Dec.

we T E Na We N IE F m N E E O 3; 1 ATTORNEYS Jan. 2, 1962 Filed Dec. 11, 1959 I O. E. HEIBERG TORQUE CONTROLLED STRAND TENSIONING SYSTEM AND METHOD 4 Sheets-Sheet 2 ZNVENTOR.

OERNULF E. Heasewacr ATTORNEYS 0. E. HEIBERG Jan. 2, 1962 TORQUE CONTROLLED STRAND TENSIONING SYSTEM AND METHOD 4 Sheets-Sheet 3 Filed Dec.

NNN

INVENTOR: OEQNULF E. Ha BERG- BYaj'm,bil1A&mC}4W ATTORNEYS 0. E. HEIBERG Jan. 2, 1962 TORQUE CONTROLLED STRAND TENSIONING SYSTEM AND METHOD 4 Sheets-Sheet 4 Filed Dec.

INVENTOR: OERNULF- E. Henseae- BY ahfimM R ATTORNEYS United States Patent Office 3,015,203 Patented Jan. 2, 1962 3,0153% TQRQUE CGNTRGLLED STRAND TENEEEGNTNG dYSTEll/f AND METHUD Oernulf E. Heiherg, Charlottesville, Va, assignor to Whitin Machine Worlrs, Whitinsville, Masa, a corporation of Massachusetts Filed Dec. 11, 1959, Ser. No. S59,tl47 47 Claims. (Cl. 57-93) This invention relates to a novel apparatus and method for controlling tension in textile strands fed to rotating carriers or bobbins by a relatively rotating feeding ele ment. More particularly, the invention relates to a novel apparatus and method for maintaining predetermined uniform winding tension in roving or similar fibrous strands, coiled onto rotating bobbins or spools by relatively rotating flyers on roving frames, intermediates, slubbers and the like.

It is well known that a strand of roving normally contains just enough twist to keep the fibers together, and is, consequently, a loose structure of low strength. Exposed to longitudinal tension, a roving stretches to a sometimes considerable extent, varying with the amount of tension, with the radius of curvature of the surface which may be supporting the roving, and with other factors. As a suitable measure of this elongation, the stretch factor (7) may be defined as the ratio of a length of roving on the bobbin to the corresponding length delivered by the front drafting rolls of the roving frame.

Since the variations in the stretch factor inversely represent variations in the weight per unit length of the roving and, consequently, of the yarn spun from the roving, it is of utmost importance from a manufacturing viewpoint to maintain the smallest possible stretch factor variation in the strand as it is being wound on the bobbin. This is the primary object of the present invention.

Roving strands are wound on rotating bobbins by means of flyers rotating at lesser speed than the bobbins, the traversing of the strands onto the bobbins usually being effected by vertical reciprocation of the bobbins. The coils of roving thus wound on to the bobbin form cylindrical layers. The term lay spacing refers to the center'to-center distance between any two adjacent coils along the length of the bobbin, and is usually expressed in coils per inch. The lay speed is the linear velocity, usually expressed in inches per minute, of the vertical movement of the bobbin carriage. Since the flyers do not move either up or down, the lay speed is also the traversing velocity of the bobbins relative to the fiyers. The term r.p.m. as used hereinafter means revolutions per minute. The difference between the bobbin r.p.m. and the fiyer r.p.m. may be referred to as the winding r.p.m.

During a run or winding cycle, the fiver usuallv rotates at a constant r.p.m., while the diameter of the bobbin increases step by step with each add'tiona] layer of roving. To take the roving up at a constant rate as it emerges from the front drafting rolls, it thus becomes necessary to stepwise decrease the bobbin r.p.m. in such a manner that the winding r.p.m. will vary inversely to the momentary diameter of the bobbin. The decrease in winding r.p.m. is conventionally effected through the use of a pair of oppositely tapered cone pu leys, with a belt connecting them. One of the cone pulleys, usually the top cone, is driven at a constant r.p.m. The other cone pulley, usually the bottom cone, rotates at a gradually decreasing r.p.m., achieved by stepwise shifting of the belt.

The variation of the winding r.p.m. has heretofore taken place according to a mechanically predetermined program through the elements involved in driving the bobbins. Due to its inherent rigidity, such a system cannot take into account the many pertinent variables, such as the elastic properties of the fibers, the density of the package, the hank number, the condition of the ambient air, etc. A given pair of cone pulleys can therefore, in principle, be accurate only for a given set of these variables, and will otherwise be more or less inaccurate. As the cone pulleys are actually manufactured, their curvature is nearly always significantly inaccurate. The usual system of controlling the stretch factor of the roving by varying the winding r.p.m. stepwise during the run according to a predetermined program, is susceptible also to variations depending upon the judgment of the operating personnel. In many mills, the operators choose a starting point for the cone belt travel, which, unknown to them, causes the first few hundred yards of roving deposited on each bobbin to be as much as five to ten percent lighter than the average of subsequent lengths.

The variation in the weight of the roving resulting from the inaccuracies of the conventional roving frame adds materially to the cost of the yarn manufacturing process and tends to produce inferior products. The heavier sections of the roving may result in a waste of materials. The lighter sections tend to increase the amount of twist needed in the subsequent spinning opstation. The irregularities in the weight of the yarn frequently detracts from the commercial value of the final fabric.

In order to overcome the above-mentioned and other defects of conventional roving frames, it is an object of this invention to provide a novel method and apparatus for accurately controlling the stretch factor, which is effected by accurate control of the winding tension; i.e., the tension in the roving between the presserfoot of the fiyer or flyers and the bobbin or bobbins, this control being effected by sensing and regulating the torque transmitted from the bobbin or bobbins through the roving to the fiyer or flyers.

A preferred embodiment of apparatus for controlling the winding tension according to the present invention comprises a variable speed drive or winding speed variator, which may replace the conventional cone pulleys, and the output portion of which is connected to one of the two inlets of a conventional differential gear assembly, commonly known as a compound. The other inlet is driven by the main drive shaft, and the output of the compound drives the bobbins, as is well known. An auxiliary drive shaft, driven at a speed directly proportional to the speed of the main drive shaft, drives the input shaft of the variator at a constant r.p.m. through the medium of a torque balancing device which senses the torque of the input shaft of the variator and to which a predetermined, or controlled, external torque is applied. Since the torque in both the auxiliary shaft and the variator input shaft must remain equal, upon any tendency for the torque of the input shaft to vary, because the winding r.p.m. is such that the winding tension is not maintained at its prescribed value, the torque balancing device effects a change in the output speed of the variator sufficient to equalize the torque in the variator input shaft and the auxiliary shaft, and, thus, sufficient to produce a winding r.p.m. maintaining the winding tension at its prescribed value.

Although my new system for control of the winding tension may be used in conjunction with the conventional cone drive, it is contemplated that the usual cone pulleys may be eliminated and replaced by the aforementioned winding speed variator. The coils per inch of roving on the bobbin (lay spacing) are always equal to the ratio of the winding rip.m. to the linear traversing velocity (expressed in inches per minute) of the bobbin carriage. On the conventional roving frame, this ratio is usually constant, because both the winding rpm. and the velocity of the bobbin carriage are derived from the conventional variable speed cone pulley; i.e., the bottom cone shaft.

It is therefore another object of this invention to provide a novel method and means for varying the coils per inch during the run in any desired ratio to the winding r.p.m. A preferred embodiment of means for varying the coils per inch during the run comprises a second variable speed drive or lay speed variator for imparting traversing movement to the bobbin carriage whereby the ratio between the winding rpm. and the traversing velocity of the bobbin carriage may or may not be kept constant during the run. The two variators may be con trolled together, both actuated by the torque balancing device, but not necessarily according to the same program. By suitably interconnecting the control screws of the two variators, it is possible to vary the coils per inch during the run in any manner to suit the individual case.

A progressive reduction in the number of coils per inch during the run tends to provide the conical end surfaces of the bobbin with a more convex contour than is normally the case. The volume of each bobbin may thereby be increased and the tendency for the roving to slough off over the top of the bobbin near the end of the run, which otherwise might prevail, may be obviated.

Some of the objects of the invention having been stated, other objects will appear as the description proceeds when taken in connection with the accompanying drawings, in which FIGURE 1 is a diagram of a system for controlling the bobbin r.p.m. of a roving frame or similar machine relative to the flyer rpm. in response to variation in winding tension, and for correlating the speed of the traverse motion, in accordance with the present invention;

FIGURE 2 is an enlarged somewhat schematic view of the structure shown in the lower central portion of FIG- URE l, presenting the speed variators in greater detail and showing the torque balancing device partly in section;

FIGURE 3 is a schematic electrical diagram, includin means for locking the housing of the torque balancing device while the machine is idle, for the purpose of effectively preventing its rotation;

FIGURE 4 is a fragmentary detail of a bobbin, bolster, spindle, flyer and associated gears similar to that shown in the left-hand central portion of FIGURE 1, the elements of FIGURE 4 being representative of a plurality of such elements of a roving frame:

FIGURES 5 and 6 are schematic diagrams illustrating the relative positions of the presserfoot of the flyer with packages of different diameter;

FIGURE 7 is an enlar ed longitudinal sectional view through a differential compound illustrative of that shown in the left-hand upper portion of FIGURE 1;

FIGURE 8 is an enlarged fragmentary elevation, partially in section, taken substantially along line 8-8 in FIGURE 2 and showing an overriding clutch mechanism between the auxiliary drive shaft and one of a pair of sprocket wheels mounted thereon;

FIGURE 9 is a fragmentary sectional view taken sub stantially along line 99 in FIGURE 8;

FIGURE 10 is a View similar to FIGURE 8 taken substantially along line 101@ in FIGURE 2;

FIGURE 11 is a view similar to FIGURE 3 taken substantially along line 11-11 in FIGURE 2;

FIGURE 12 is a view similar to FIGURE 2, but showing a modified arrangement for controlling the lay speed variator in relation to the winding speed variator.

General synopsis of the invention As heretofore stated, the stretch factor and winding tension in the roving are accurately controlled, according to the present invention, by sensing and regulating the torque transmitted from the bobbin through the roving to the flyer. In order to maintain a constant stretch factor, the winding tension must either be kept constant during the run or it must be made to vary in a predetermined manner. In order that the winding tension is maintained constant, the torque transmitted from the bobbin to the fiyer through the roving must increase in direct proportion to the bobbin diameter.

Since, as mentioned above, the winding r.p.m. varies inversely to the bobbin diameter, the product of the winding torque and the winding rpm. is independent of the diameter, and consequently remains invariant during the run if the winding tension is constant. The product of the winding torque and the Winding r.p.rn. represents the power, expressible in watts or horsepower, consumed in the actual winding of the roving on the bobbin 31. This product may therefore be referred to as the winding power (Ev).

The winding power, being determined by the tension under which the roving R (FIGURE 1) is being wound on the bobbin 31 and also by the rate at which it is taken up, is essentially independent of the mechanism employed. An accurate theoretical analysis, as applied to the conventional roving frame, leads to the formula:

wherein Ev is the total winding power for the whole machine expressed in horsepower units (1 hp.746 watts); for a roving frame with m spindles; the roving is being wound on the bobbins under a tension of W grams; the diameter of the front bottom drafting roll is d inches; this roll rotates at the constant rate of 1' rpm; and the stretch factor is f.

Equation I shows that, assuming the stretch factor (f) to be constant; the winding tension (W) and the winding power (Ev) are strictly proportional, one to the other. Constancy of either of these two quantities depends on constancy of the other.

On the conventional roving frame, the traversing motion of the bobbin carriage is driven from the variable speed cone pulley, i.e., from the bottom cone shaft. The same shaft is also connected to one of the two inlets of a differential gear assembly, commonly referred to as the compound. The output of the compound drives the bobbins. The gear ratios are usually chosen so that the cone pulleys provide the winding r.p.m. A component of the bobbin r.p.m., equal to the flyer rpm, is introduced directly from the main shaft of the machine into the compound through the second of the two inlets. Since all the winding motion comes from the cone drive, the winding r.p.m. will be zero if the cone drive is disconnected. The bobbin r.p.m. will in that case be equal to the flyer rpm, and no winding will take place.

Referring to the conventional roving frame as described above, the preferred apparatus for carrying out the invention can make use of a variable speed drive of any of the known types, instead of the conventional cone pulleys. For the purpose of brevity, such a variable speed drive may be termed as a variator. Since I wish to reserve one variator 1125 exclusively for the transmission of the winding power, a second variator 245 is needed to transmit the power for the traverse motion. As heretofore stated, the two variators are termed as the winding speed variator and the lay speed variator, respectively.

Disregarding frictions, the winding speed variator transmits nothing but the winding power. From what already has been said, it may be understood that the winding tension under those conditions will be strictly proportional to the power transmitted by the winding aoiaaoa speed variator 125. The winding tension will remain constant if the transmitting power is constant.

If frictions again are disregarded, the power transmitted by the winding speed variator 125 will be equal to the rpm. of the input shaft 132 of the variator 125 multiplied by the torque in the same shaft. Since the input shaft 132 of the winding speed variator 125 ro tates at a constant r.p.m., we finally arrive at the conclusion that the total winding tension for all the bobbins 31 on the frame will be strictly proportional to the torque transmitted by the input shaft 132 of the Winding speed variator 125. The average Winding tension on each bobbin 21 may therefore be kept constant, or it may be varied during the run according to any prescribed program, by corresponding control of the torque transmitted by the input shaft 132 of the winding speed variator 125.

The torque of the input shaft of the winding speed variator may be sensed or measured by transmitting it through a device which I shall refer to as a torque balancer, torque sensing device, or torque measuring device 131 (FIGURES 1 and 2).

The winding speed variator 125 is shown to the left in FIGURE 2. The power input passes from left to right through the torque balancer 131, consisting of a simple bevel gear differential assembly shown in the middle of FIGURE 2. The planetary bevel gear 150 rotates on the stub shaft 147 attached to an external housing 133, held essentially stationary by the application of a controlled external torque. The torque needed to prevent rotation of the housing 133 is exactly twice the torque transmitted from right to left through the differential gear assembly. An accurate analysis shows that the torque in gram-inches which must be applied to the torque balancer housing to prevent its rotation is where, as in Equation 1, W is the winding tension in grams for each individual bobbin; d is the diameter in inches of the front bottom drafting roll; m is the number of spindles on the frame, and f is the stretch factor. F is the constant ratiofixed by the permanent gearing of the machineof the rpm. of the front bottom drafting roll to the rpm. of the input shaft 132 of the winding speed variator 125.

In Equation II, F, d, and m are constants, because their values have been built into the machine. The stretch factor f may be assumed to be at least approximately constant. Equation'II therefore shows that the average winding tension (W) for each bobbin and the external control torque (Q which must be applied to the torque balancer housing to prevent its rotation, are proportional one to the other, and that the fixed ratio between these two quantities can be accurately predetermined by calculations based on the gearing of the machine.

The controlled external torque (Q applicable to the torque balancer housing 133 to prevent its rotation, may in principle be provided by means of a weight B suspended by a string 151 wrapped around a drum 152 attached to the torque balancer housing 133. The drum may, or may not, be cylindrical. To produce a programmed variation of the Winding tension during the run, the leverage upon which the weight B is acting may be made to change during the run, for example by letting the string follow a spur in a non-cylindrical drum. Or, there may be two drums of different shape, each with its own weight and string, and the other to compensate for the torques resulting from friction. The controlled torque may also be obtained by springs, or by electrical, h draulic or pneumatic means, without departing from the spirit of the invention.

If the torque passing from the right to left through the torque balancer momentarily should exceed the value determined by the external control torque, for example, because the winding rpm. is slightly too high to maintain the winding tension at its prescribed value, then the torque balancer housing 133 with the drum attached to it will turn in such a direction that the weight B is raised. The rotation of the housing is transferred to the control shaft 143 of the winding speed variator in such a direction that the output shaft 124- of the variator is made to slow down enough to bring the torque passing through the torque balancer back to its prescribed value, and thereby reestablish equilibrium.

Detaiz'ed description Referring more specifically to the drawings, and to FIGURE 1 in particular, an apparatus for carrying out the method of the present invention is shown in association with a conventional compound for the bobbin drive and a conventional traverse motion of a roving frame, ail of the parts being shown somewhat schematically in a diagram of Well-known form. With the exception of the particular elements of the present invention, the illustration of FEGURE 1 corresponds to a roving frame of the type manufactured by a well-known American textile machinery manufacturer, but roving frames made by other machinery builders are not essentially different. The illustration of FIGURE 1 is similar to illustrations provided in many catalogues and instruction booklets issued by the manufacturers of roving frames and which are well-known in most textile mills. Thus, the conventional elements illustrated in FIGURE 1 may be readily recognized by those familar with the art.

Referring to FIGURE 1 more in detail, the numeral lit indicates the main drive shaft of the roving frame which has a pulley 11 thereon driven by an electric motor 12 through the medium of an endless belt 13 and a pulley id fixed on the shaft of the motor 12. Drive shaft I10 has a gear i5 fixed thereon which is connected, by a diagrammatically illustrated gear train 16, to a gear 17 fixed on a spindle haft Zii. Spindle shaft 26 drives a plurality of conventoinal spindles 21 on each of which is mounted a strand traversing means embodied in a fiyer .22. Only one of the spindles 2?. and fiyers 22 are shown in the drawings, although it is well-known that a plurality of such spindles and fiyers are provided on each machine.

Spindle shaft 29 imparts rotation to each spindle 21 by means of beveled gears 23 and 24. Roving or a similar strand of textile strand material R is fed to each fiyer 22 from the usual drafting rolls D. As shown in FIG- URE 4-, the strand R passes through an opening 25 in the upper end of the flyer 22, then passes partially around said upper end of the flyer and through one of its arms 26, which arm is hollow, as is usual. The roving strand R then passes out of the iower end of the hollow arm 26 and passes around the conventional presser finger 27 and then through the usual opening provided in the presserfoot or paddle 28 to be wound in the form of coils around an axially reciprocal carrier or bobbin 31.

Each bobbin or carrier 31 is positioned on a bolster or other support 32 having a gear 33 on its lower end which rests upon a bracket 3 (FIGURE 4) carried by the conventional bolster rail 35. The bolster rail 35, frequently called the bobbin carriage, is common to all the spindles and bolsters on the machine. Each gear 3-3 meshes with a bevel gear 3-6 fixed on a bobbin shaft 37 which is also common to all the spindles and bolsters on the machine. Bobbin shaft 3'7 is connected to the output portion of a conventional differential compound, broadly designated at A9, by means of gears 41 and 42 and an intervening gear train 53. The differential compound 40 is conventional and is mounted on the main drive shaft in as will be later described in more detail.

The constant speed main drive shaft lit opposite from drive pulley lll has a direct drive connection to the top cone shaft 50 which is substituted for the usual top cone shaft, or the usual top cone shaft may be used in this instance. For purposes of clarity hereinafter, the shaft will be termed as the top cone shaft, although the usual top cone may be omitted. A twist change gear 4-5 fixed on main shaft 14 is one of a plurality of gears forming a gear train, generally designated at 46. The twist gear train also includes a gear 47 fixed on top cone shaft 50.

The direct drive is also transmitted through gears 48, 49 to the front roll shaft 4%, and thereby to the drafting rolls D. Top cone shaft '1) also imparts intermittent rotation to contact 51, sometimes called a tumbler shaft, which is a part of the conventional rack mechanism 52. and is instrumental in reversing the direction of traverse of bolster rail 35 and bobbins 31. The conventional rack mechanism 52 is shown in part in FIGURE 1. However, the usual belt shifter may be omitted from the rack mechanism, since it is not required with the illustrated embodiment of the present invention.

The bobbins 31 are raised and lowered by means of a conventional traverse motion, certain elements of which will now be described. A traverse drive shaft 55 (PI URES 1 and 2) may be driven by means peculiar to the present invention and which will be later described. Traverse drive shaft 55 has a bevel gear 56 fixed thereon which is alternately engaged by a pair of spaced twin bevel gears 57, 58. Gears 57, 58 are fixed on a common. sleeve 6% keyed for axial movement on an auxiliary traverse drive shaft 61.

Auxiliary traverse drive shaft 61 has a bevel gear 62 fixed thereon which meshes with a bevel gear 63 fixed on a jack shaft 64. Shaft 64 also has a spur gear 65 fixed thereon which meshes with a gear 66 fixed on a lay shaft 67. Lay shaft 67 has a lay change gear 71 fixed thereon which meshes with one of a lay train of gears generally designated at '72. The lay train 72 also includes a gear 73 which is fixed on a conventional lifter shaft 74 having one or more pinions 75 fixed thereon, each of which meshes with an arcuate lift rack 7'6 which is formed integral with a bobbin lifter arm '77. Through conventional means, not shown, the lifter arm 77 is connected with bolster rail 35 for imparting vertical reciprocation thereto.

As is well known, twin gears 57, 58 are alternately shifted into engagement with cone gear 56 on the traverse drive shaft 55 by means of reversing lever se. Lever 811 is shifted to and fro by means of an eccentric cam 81 fixed on the lower end of contact shaft 51. Contact shaft 51 has a dog 82 fixed thereon which is provided with a pair of vertically spaced and oppositely directed arms or abutments 83, 84 which alternately engage a pair of interconnected, but relatively adjustable builder jaws 85, 86 which are guided against a stationary plate 87 and are penetrated by respective oppositely threaded portions of a builder screw 90. Builder jaws 85, 86 are raised and lowered with bolster rail 35 (FIGURE 4).

As builder jaw 86 moves below and out of engagement with the upper abutment 84. on builder dog 82, conven tional resilient means, not shown, but associated with cam 81, causes the teeth of a missing-tooth gear 11, on the upper end of contact shaft 51, to engage a bevel gear 92 fixed on top cone shaft 511. Since top cone shaft 50 and bevel gear 92 are continuously driven during each winding cycle, a half revolution is imparted to shaft 51 to cause the other arm or abutment 83 of builder dog 82 to engage builder jaws 85, 86 as an area of missing teeth on gear 91 registers with gear 92. In so doing, the eccentric cam 31 in the lower right-hand portion of FIG- URE 1 moves reversing lever 80 and shifts sleeve as and gears 57, 53 in the corresponding direction, thus reversing the direction of movement of bobbin carriage 35. This procedure is reversed as the bottom builder jaw 85 moves above the level of the abutment 33 on the builder dog 82.

In order to vary the displacement between the distal surfaces of the builder jaws 85, 8d and to, consequently, vary the length of stroke of the traverse of the bobbin rail 35 and the bobbin 31, the builder screw 90 is rotated in a stepwise manner, each time a half revolution is imparted to builder dog 82 in the manner heretofore described. The conventional rack mechanism 52 is used for this purpose, and it will be noted that contact shaft 51 has a worm 95 fixed thereon which meshes with a worm gear 96 connected through a gear train 97 to a rack 102.

Rack 102 is engaged by a pinion 183 having another pinion 16 i integral therewith, or connected thereto, which meshes with a gear 1G5 keyed on the upper portion of builder screw 90 so the builder screw 91 may move vertically relative to the gear 105. It is apparent that, each time a step in rotation is imparted to contact shaft 51, a step in movement is imparted to rack 102 to thus impart a step in rotation to builder screw 90 and to thus move builder jaws 85, 86 toward each other at the end of each stroke of bobbin carriage 35 (FIGURE 4) in each direction. A hand wheel 106 is usually provided on the upper end of builder screw 90 for resetting builder jaws 85, 36 at the end of each winding cycle or run.

Difierential compound Although the differential compound 40 is not peculiar to the present invention, it will now be described in detail in order that the invention may be clearly understood. Generally, the compound performs an addition of a variable r.p.m. component derived from the bottom cone shaft and a constant rpm. component coming directly from the main shaft 10 of the frame, making the sum of the two components available for the drive of the bobbins. The gear ratios are usually selected so that the variable r.p.m. component provides the winding rpm, and the constant r.p.m. component provides a component of the bobbin r.p.m. equal to the flyer rpm.

The differential compound 40 is best shown in FIG- URES 1 and 7 wherein it will be observed that it comprises a housing 110 (first or constant speed input element) fixed on main shaft 10 and provided with an internal or ring gear 111 which is engaged by a planetary gear 112. The planetary gear 112 also engages a sun gear or sleeve gear 113 fixed on the inner end of an inner sleeve 114 (second or variable speed input element) loosely journaled on the main shaft 10. Another outer sleeve 115 (variable speed output element) is loosely journaled in the sleeve 114 and has a pair of diametrically opposed arms 116, 117 extending therefrom. Planetary gear 112 is journaled on arm 116 and a counterweight 12-9 is journaled or fixed on the other arm 117. The speed of output sleeve 115 may be calculated by the formula:

where,

n =r.p.m. of outer sleeve 115 n =r.p.m. of sun gear 113 and inner sleeve 114 M=r.p.m. of internal gear 111 t =Number of teeth in sun gear 113 i Number of teeth in internal gear 111 Gear 42, described heretofore, is fixed on the outer portion of outer sleeve 115 and another gear 121 is fixed on the outer portion of inner sleeve 114. Gear 121 is connected, by a gear train 122, to a gear 123 (FIGURE 1) fixed on the output shaft 124 of the winding speed variator broadly designated at 125, and which constitutes one of the most important elements of the present invention. The output shaft 124 may be termed as an intermediate bobbin drive shaft. Shaft 124 may be continuous, but is shown in the form of two interconnected sections 12 1a, 12% for purposes to be later described.

It might be stated that conventional roving frames are usually provided with a common shaft extending from the traverse reversing bevel gear 56 to gear 123, and the equivalent of shaft 124 is then driven by the usual bottom cone. In effect, therefore, the winding speed variator 125 Torque controlled bobbin drive and tension regulator An accurate analysis of the interaction of the various parts of the conventional roving frame leads to the following exact equation:

where,

D=Effective winding diameter of the bobbin at any given layer of roving,

R Momentary ratio of the bottom cone r.p.m. to the top cone r.p.m.,

f=ivlomentary value of the stretch factor,

K specific constant for the individual roving frame, de-

rivable from the gearing.

Although the variations in the value of the stretch factor (f) are very important, they are relatively small. Equation IV therefore shows that the bobbin diameter (D) is essentially determined by the cone drive ratio (R).

Due to the difference in radial pressure, the fiber material nearest to the core of the bobbin is usually more compressed than that in the outer layers. A bobbin where the stretch factor has exactly the same value in every yard of roving, may be referred to a a perfect" bobbin. if, by any means at all, such a bobbin had been made, an analysis of it would show the density of the fiber material to decrease from the inside to the outside of the bobbin according to some definite mathematical law. Conversely, the conventional roving frame will only produce a perfect bobbin if the cone drive controls the diameter increase according to a program that reproduces the law governing the density distribution in a perfect bobbin.

This law, unfortunately, differs with the density level, with the elastic propertie of the fiber material, and with other variables. in no case, is it accurately known. A given pair of conventional cone pulleys can therefore in principle be accurate only for a given set of the pertinent variables, and will otherwise be more or less inaccurate. As actually manufactured, the cone drives are significantly inaccurate, and may differ considerably between any two presumably identical machines.

The conventional means for controlling the stretch factor of the roving are therefore unsatisfactory, both because they never are entirely accurate and also because they lack the flexibility necessary to adapt themselves antornatically to differing conditions.

According to the present invention the stretch factor of the roving is controlled, not by a pre-set program of relative speeds, but through control of the winding tension. As far as is known, a bobbin wound under constant winding tension will be perfect in the sense that the stretch factor will have the same value for every yard of roving on the bobbin. Even if more refined measurements sometime in the future should show that this is not always entirely accurate, a slight gradual change in the winding tension may be effected to keep the stretch factor constant during the run.

The method of this invention is carried out by controlling the torque transmitted from the bobbin through the roving strand to the fiyer. This torque is usually much greater than the torque required to overcome the friction in the flyers and connected elements, so that the gears ill which are supposedly meant to drive the flyers are actually holding them back.

At constant winding tension, the torque transmitted from a single bobbin to the corresponding fiyer is proportional to the winding diameter, and, thus, the transmitted torque increases during the run, and reaches its maximum as the last layer of roving is being wound on the bobbin.

in actual practice, the magnitude of these torques and the flow of energy which they represent, has been calculated wherein the winding cycle was carried out on a conventional roving frame having the conventional type of cone drive for the bobbins. For example, a conventional roving frame with 108 spindles was winding 1.00 hank roving. The average density of the cotton on the full 10" x 5" bobbin was 0.45 grams per cubic centimeter, which was found to correspond to an average winding tension of 750 grams. The machine was operated at a flyer speed of 926 revolutions per minute. The average stretch factor was 1.04. Calculations showed that, when the last layer of roving on the bobbin had a diameter of 4.75 inches the torque transmitted from the bobbin to the flyer through the roving represented 6.6 horsepower. ()nly a relatively small percentage of this power was lost by friction. Most of it was returned to the main shaft through the flyer drive. Further, calculations showed that out of the total power transmitted from the bobbins to the flyers, only 0.39 horsepower passed through the cone drive.

On the conventional roving frame, the variable speed cone pulley, i.e.. the bottom cone, i geared to the shaft referred to as 124 in FIGURE 1. Shaft 124 i further connected through gears 123, 122, 121 to the inner sleeve 114 in the differential compound carrying the sun gear 113. The winding r.p.m. is therefore directly proportional to the bottom cone r.p.m.

in the present invention, the winding speed variator 125 replaces the cone drive of the conventional frame in pro viding the Winding r.p.m. The variator 125 receives its motion from the auxiliary drive shaft 139 and delivers it to shaft 124, from which it is further transmitted to the inner sleeve 114 of the differential compound. Auxiliary drive shaft 139 is driven at a constant r.p.m. in fixed ratio to the constant r.p.m. of the front bottom drafting roll on shaft 4%. As already explained, the winding tension will remain constant if the winding speed variator 125 is regulated so that the winding power (Ev) remains constant.

The power transmitted by any shaft is proportional to the torque multiplied by the r.p.m. Since, in the present case, constant winding tension and constant winding power go together, it follows that the winding tension will be constant if the torque in the input shaft 132 of the winding speed variator 125 is constant. The problem of maintaining a constant winding tension in the roving is thereby reduced to the problem of maintaining a constant torque in input shaft 132 of winding speed variator 125.

To this end, the torque balancing device is provided and is embodied in a differential gear assembly, broadly indicated at 131, which also acts as a torque sensing and torque transmitting device. The torque balancing device 131 is interposed between auxiliary drive shaft 131 and the input shaft 132 of winding speed variator 12.5. The torque balancer 131 comprises a housing 133 journaled on the proximal ends of shafts 13-0, 132, and being yieldably restrained from rotation by an externally applied control torque.

The combined torques in shafts 13%), 132 are transferred to housing 133 as will be later described. Since the torques in the last-mentioned two shafts 13-h, 132 are exactly equal and act upon housing 133 in the same direction, an external control torque, equal to twice the torque transmitted through the torque balancer 131 from shaft to shaft 132, must be applied to housing 133 to prevent its rotation.

The value of the external control torque (Q required to obtain a given winding tension (W) may be calculated from Equation II. Whenever the torques acting internally upon housing 133 get out of balance with the external control torque, housing 133 will turn one way or the other. Through gears 145, 144, carried by housing 133 and a speed regulator or control shaft 143, respectively, this movement of housing 133 is transmitted to the regulator shaft 143 of winding speed variator 125 thereby changing the speed ratio of the variator 125 in such a manner that the various torques acting upon housing 133 get back into balance. It will be understood that a higher r.p.m. of output shaft 124 of Winding speed variator 125 increases the torques acting internally on housing 133, while a lower r.p.m. of shaft 124 has the opposite effect. The torque control is accurate in principle. The only inaccuracies are caused by friction and similar mechanical imperfections.

The winding speed variator 125 may be a variable speed drive of any desired or conventional construction as long as the r.p.m. of the output shaft 124 may be infinitely varied relative to the r.p.m. of the input shaft 132 through adjustment of an element thereof. In this instance, the winding speed variator 125 is shown as being of a wellknown type including expansible cone pulleys 135, 136 mounted on the respective input and output shafts 132, 124.

An endless belt 137 is entrained about pulleys 135, 136, and the displacement between the cones of respective pulleys 135, 136 is varied by means of a pair of levers 140 (FIGURE 2), corresponding ends of which are pivotally connected to respective collars 142 penetrated by oppositely threaded portions of control shaft 143. As is well known, adjustment of control shaft 143 in one direction imparts movement to levers 140 to move the cones of one of the pulleys 135, 136 toward each other while moving the cones of the other of the pulleys away from each other, and the pulley cones move in the opposite direction with adjustment of shaft 14-3 in the opposite direction.

In this instance, control shaft 143 has a gear 144 fixed thereon which meshes with a gear 145 suitably secured to or formed integral with housing 133 of the torque sensing device 131. As heretofore stated, housing 133 contains differential gearing which is embodied in a pair of relatively large differential bevel gears or sun gears 148, 149 (FIGURE 2) fixed on proximal, axially, alined ends of shafts 130, 132. A stub shaft 147 is journaled in housing 133 and has a planetary bevel gear 150 fixedly mounted thereon which meshes with the two large differential gears 148, 149.

Auxiliary drive shaft 130 is driven at a constant speed through direct connections with main drive shaft 10. The r.p.m. of shaft 130 may correspond to the fastest or starting r.p.m. of the conventional bottom cone which is omitted in this instance and replaced by shaft 130.

Housing 133 may be yieldably restrained from rotation by means of torque controlling weight B depending from pliable element or cable 151 which is wound about drum 152. Drum 152 may be in axial relationship to shafts 134), 132. The end of the pliable element 151 remote from weight B is suitably attached to the drum 152.

The mass of the weight B should be chosen such that it will exert a torque on the housing 133 at the torque balancer, equal to twice the torque to be transmitted through the torque balance from shaft 130 to shaft 132. Further, the position of the variator speed control shaft 143 and the gear 144 thereon should be such that the r.p.m. of output shaft 124 will cause rotation of the bobbins 31 at exactly the correct r.p.m. to establish the desired winding tension in the strand of roving R between the presserfoot 28 of each ilyer 22 and the respective bobbin 31 as the first layer of roving is deposited thereon, at which stage the weight member B will occupy its lowermost position spaced substantially from the drum 152 of torque balancer 131.

Auxiliary drive shaft 1311 is gear-driven from top cone shaft 50. Referring to FIGURE 2, it is apparent that input shaft 132 of the winding speed variator will rotate in the opposite direction from shaft 135. Therefore, in this particular embodiment, auxiliary drive shaft 136 is driven in the opposite direction from that at which the usual bottom cone is driven. However, it is to be understood that other elements of the roving frame may be so arranged that shafts 130, 132 may rotate in directions opposite from those indicated herein.

In this instance, top cone shaft 55 has a gear 153 fixed thereon and engaging a gear 154 integral with or rotatable in fixed relation to a sprocket wheel 155. Sprocket wheel 155 is engaged by an endless sprocket chain 156. Chain 156 also engages a sprocket wheel 157 mounted on auxiliary drive shaft 130. Sprocket wheel 157 may be fixed on auxiliary drive shaft 130, but it is preferably connected with shaft by means of a suitable overriding clutch mechanism as best shown in FIGURE 10. This overriding clutch mechanism may be provided in order to permit shaft 130 to be rotated independently of sprocket wheel 157, as will be more fully described hereinafter.

To illustrate the principles of this invention, the derivation of Equations I and II will now be shown.

In general, the power (E) in HP. units (1 H.P.=746 watts) transmitted by a shaft rotating at a rate of n r.p.m. carrying a torque of Q gram inches is The torque acting between a bobbin and a flyer as a result of the winding tension in the roving is W D/ 2 gram inches, where W is the winding tension in grams, and D' is the momentary value of the effective winding diameter of the bobbin in inches. The winding power (Ev) is the power consumed when this torque acts against the winding r.p.m., which may be referred to by the symbol V. The winding r.p.m. is the difference between the bobbin r.p.m. and the flyer r.p.m.

In analogy with Equation V, the winding power (Ev) in a roving frame with m spindles is Since the yardage of roving taken up by the bobbin must be equal to the yardage delivered by the front drafting rolls multiplied by the stretch factor f, we have where is the r.p.m. of the front bottom drafting roll having a diameter of d inches.

Substitution of Equation VII in VI gives As heretofore stated, Equation I shows the total wind ing power (Ev) in HP. units in a roving frame with "m spindles, operating under a winding tension of W grams in each strand of roving, Where the front bottom drafting roll has a diameter of d inches and rotates at a rate 0; r r.p.m., and where the stretch factor has a value 0 C M It is of interest to note that Equation I could have been developed without reference to any particular Winding mechanism. 1r d r is the rate in inches per minute at which the roving is delivered from the front rolls for any one winding spindle. If this is multiplied by f and by m, it becomes the rate in inches per minute at which the roving is taken up by all the spindles combined. W 1r d r f m is therefore the total winding power in gram inches per minute for the whole machine. The numerical factor 1.748 10"* includes 1r and transforms the winding power (Ev) into horsepower units.

If we assume that the input shaft 132 to the winding speed variator 125 is rotating at a rate of n r.p.m. carrying a torque of Q gram inches, then the power in HP. units (E) transmitted by that shaft is given by Equation V.

1.3 Since the external control torque Q acting upon the torque balance housing 133 must be twice the torque transmitted by shaft 132, we have Introducing Equation VIII in V, we get another expression for the total winding power in the machine; i.e.,

By F we shall understand the ratio between the r.p.m. (r) of the front bottom drafting roll shaft 4% and the r.p.m. (n) of shaft 132; i.e.,

r=F n From Equations I, IX, X, follows by substitution Qn F W f (II) The significance of Equation II and the meaning of the symbols has already been discussed.

When the automatic tension regulator of the present invention is used, Equation II provides a simple method for calculating the control torque (Q which must be applied externally to housing 133 of torque balance 131 to produce the desired value of the winding tension (W). Since these relationships are exact, there is no other uncertainty involved than that resulting from the frictions between intervening mechanical elements of the machine. This uncertainty is usually negligible and need not be considered. Accordingly, the torque balance 131 and weight B, producing the control torque (Q in the embodiment set forth herein, sense a torque proportional to the torque between the relatively rotating bobbins and flyers to thus give a measure of the torque therebetween, so that the automatic tension regulator of the present invention is also a measuring instrument, whereby the winding tension can be accurately determined. Furthermore, the automatic regulator limits the winding tension effectively to the chosen value, thus preventing excessive winding tension which could damage the machine. The need for such a protection has become considerable due to the high winding tensions that recently have come into use.

The following is an example of how the tension regulato? of the present invention may be used with an otherwise conventional roving frame. Referring to FIGURE 1 we may assume that the designated gear and sprocket elements have the following number of teeth:

(Element) (Number of teeth) 48 66T 49 921 153 301 154 30T 155 ZOT 157 5ST We may further assume that the front bottom drafting roll has a diameter of d=1.125 inches, and that, driven by gear 49, this roll rotates at a rate of r=234 r.p.m. The frame has m=108 spindles. Making a relatively dense package of 1.00 hank roving, the average winding tension is W=750 grams. The stretch factor has an average value of f=l.04.

The ratio (F) between the r.p.m. of the front bottom drafting roll (r) and the r.p.m. (n) of input shaft 132 is then From the Equation 1, it follows that the total winding power (Ev) is From Equation II, it follows that the required control 1 a torque (Q which must be applied externally to housing 133, is

186600 gram inches.

These calculations show that in order to obtain the desired winding tension of W :750 grams, the control torque must be Q =186600 gram inches. The power transmitted by the winding speed variator is 0.39 HP.

The control torque (Q must act in the same direction as top cone shaft 50 rotates. Assuming drum 152 to have a diameter of 2.49 inches, weight B must be kilograms. In fact, with the design details as given above, weight 13 must always be 200 times as heavy as the desired winding tension in the individual strand of roving (w). By varying the weight B, any desired winding tension can conveniently and accurately be obtained. The winding tension may be adjusted to suit the individual case, and its actual value will always be exactly known.

Since the diameter of drum 152 influences the torque (Q caused by weight B, it follows that the winding tension can be made to vary during the run according to a predetermined program by giving drum 1% a noncylindrical contour. To compensate for the torques resulting from frictions, an additional non-cylindrical drum, with an additional string and an additional Weight, may be axially attached to drum 1152.

Drive for auxiliary drive shaft The overriding clutch mechanism shown in FIGURE 10 is of a well-known type and comprises a polygonally or triangularly shaped internal block which is fixed on shaft 130 and whose fiat peripheral surfaces are each engaged by a ball or roller 161 normally biased toward the desired direction of rotation of sprocket wheel 157, as by a tension spring 162. Each ball 161 is adapted to engage the inner surface of a circular cavity 163 formed in sprocket wheel 157. Thus, counterclockwise rotation of sprocket wheel 157 in FIGURE 10 imparts corresponding rotation to auxiliary drive shaft 130. On the other hand, shaft 130 may be driven while sprocket wheel 157 remains stationary in order to perform a resetting operation to be later described.

It will be noted that shaft 130 also has a sprocket wheel 165 mounted thereon by means of a suitable overriding clutch mechanism (FIGURE 8) which may be identical to the overriding clutch mechanism (FIGURE 10) shown in association with the sprocket wheel 157. Since the clutches of FIGURES 8 and 10 may be identical, the parts of the clutch shown in FIGURE 8 shall bear the same reference characters as like parts in FIGURE 10 with the prime notation added. Accordingly, a further detailed description of the overriding clutch mechanism shown in FIGURE 8 is deemed unnecessary.

Sprocket wheel 165 is engaged by an endless sprocket chain 167 which also engages a sprocket wheel 1'70 (FIGURE 1) mounted on the shaft of a slow speed auxiliary electric motor 172. Motor 172 serves to reset the tension regulator before the start of each winding cycle, as will be later described. Motor 172 drives auxiliary drive shaft 130 independently of sprocket wheel 157 and imparts relatively slow rotation to the bobbins 31, in the normal direction of rotation during the resetting operation, without imparting motion to many other elements of the machine.

Braking device Since the weight B is relatively heavy, locking means are provided to restrain housing 133 from movement under influence of weight B when the machine is not operating. Any suitable restraining means may be provided for this purpose and, in the present embodiment of the invention, it will be observed in FIGURES 2 and 3 that gear 145 is spaced from the body of housing 133 sufficiently to provide a brake drum 175, of a braking or locking device 179, on housing 133.

Braking drum 175 is adapted to be engaged by a brake band or shoe 176 carried by a brake lever 177. Brake lever 177 is pivoted, as at 181), and is normally biased toward brake drum 75, as by a spring 181. A solenoid plunger 182, connected to the other end of lever 177, is surrounded by a solenoid coil 1% to which electrical conductors 184, 185 are connected. Conductor 185 leads to one side of a normally closed switch g of a time-delay-relay 138, from the other side of which a conductor 139 extends.

Relay 188 may be of any desired or conventional construction, such as is disclosed in United States Patent No. 2,751,621, just so long as relay 188 is capable of delaying energization of solenoid 183 for a predetermined interval following energization of the main drive motor 12, so that main drive motor 12 may reach full speed before the brake shoe 176 is moved away from brake 175.

In this instance, time-delay-relay 188 comprises a housing a having an adjustable air escapement valve 12 thereon and a diaphragm c therein. Diaphragm c is engaged by a solenoid plunger e having switch bar g thereon and being encircled by a solenoid coil p. Switch bar g normally establishes contact between conductors 185, 189. Conductors r, s are connected to opposite ends of coil p, conductor 1' being connected to a lead wire or conductor L-1, and conductor s extending to a normally open double-pole, push-button start switch 202. Corresponding ends of conductors L-1, L2 are connected to a suitable source of electrical energy embodied in a plug P.

Conductor 184 is connected to a conductor 184a by means of a normally closed relay switch 1114b. Conductors 186, 187 extend from the respective conductors 184a, L-1 to opposite sides of the main drive electrical motor 12. Conductors 184a, L-2 lead to a relay 192 having a pair of switches 193, 194 therein which are normally open to the main drive circuit, but which are closed upon energization of a relay coil 1%.

One end of relay coil 1% is connected to lead conductor L-1 and the other end of coil 1% is connected, by a conductor t, to a normally closed push-button stop switch 1%. The side of switch 197 opposite from conductor t has a conductor 2% leading therefrom to one side of the normally open side of switch 193 in relay 192, and the other side of switch 193 has lead conductor L2 connected thereto.

Conductor L-2 is also connected to switch 1%. Conductor L-2 has a conductor 261 leading therefrom to the side of start switch 292 opposite conductor s. When switch 2412 is depressed, it establishes contact between conductors 201 and s. At the same time, switch 202 establishes contact between a conductor 20 2- and a conductor 2%. Conductor 2414 leads to conductor 2111 and conductor 2115 leads to coil 1% of relay 192 through conductor t.

It is apparent that when start switch 262 is depressed, it energizes relay coil 196 to move switches 193, 1% downwardly and also energizes coil p of time-delay-relay 188, thus breaking the normally closed circuit to the brake solenoid 183 practically simultaneously with the closing of the circuit thereto so that the brake actually remains locked; that is, brake shoe 176 remains against the drum 175 as the main drive electric motor 12 is energized.

Since start switch 2112 is released shortly after it is depressed by the operator, stop switch 197 maintains the flow of current through the coil 1% of relay 122, but coil p of time-delay-relay 188 is de-energized. Accordingly, after a predetermined interval established by adjustment of valve b, the switch bar g returns to closed position to energize coil 183 and move brake shoe 176 out of engagement with brake band 175, thus providing an interval of time suflicient for the motor 12 to reach full speed before brake shoe 176 is released and moved out of 15 engagement with brake band 175. Otherwise, the torque developed by the auxiliary drive shaft 131 would be insufiicient to maintain the weight in raised position if it happened to be in raised position at the time the roving machine had been previously stopped.

It is apparent that, at the end of the run, or at any time during operation of the machine, stop switch 197 may be depressed and, since switch 202 is then out of contact with the proximal ends of conductors 294, 205, this will break the circuit to the coil 196 of relay 192, thus releasing switches 1%, 194 and breaking the circuit to electric motor 12 and solenoid 183 to stop the machine and simultaneously cause brake shoe 176 to move against brake band 175.

From the foregoing, it is apparent that brake band 176 engages drum 175 and prevents unintentional rotation of housing 133 of the torque sensing device 131 Whenever main drive electrical motor 12 is de-energized and the roving frame is not operating. it is apparent that motor 12 may be controlled by a circuit independent of those remaining elements of the main circuit of FIGURE 3 heretofore described, and switch 197 may then be disposed in the path of the usual shipper so as to break the circuit to solenoid coil 183 whenever the roving frame is stopped, even though the main drive motor 12 may continue to rotate. Since the latter is the equivalent of the circuit of FIGURE 3 thus far described, an illustration thereof is deemed unnecessary.

Resetting means for tension regulator At the end of a run, the various operating elements of the automatic tension regulator must be reset; that is, control shaft 143 for speed variators 125, 245 must be rotated to return the cones of pulleys 135, 136 to starting position, and weight B must be lowered to starting position. As heretofore stated, this resetting operation is effected by auxiliary motor 172.

Referring again to FIGURE 3, it will be observed that auxiliary motor 172 has conductors 210, 211 connected to opposite sides thereof. Conductor 216 extends from auxiliary motor 172 to one end of the coil u of relay 1841;. The other end of the coil u has a conductor 212 leading therefrom to conductor 184.

Conductor 211 extends from auxiliary motor 172 to one side of a normally open relay switch 213, the other side of which has a conductor 214 leading therefrom to one side of a normally open manual push-button reset switch 215. The other side of reset switch 215 has a conductor 216 leading therefrom to the switch 193 associated with relay 192. Switch 193 establishes contact between conductor 216 and a conductor 217 when relay coil 196 is deenergized. The other end of conductor 217 leads to a medial portion of conductor 210.

One end of the coil y of relay 213 is connected to conductor 214 and its other end has a conductor 220 leading therefrom to one side of a normally closed reset stop switch 221. The other side of switch 221 has a conductor 222 leading therefrom to conductor L2. The switch 221 may be positioned at any desired location so as to break the circuit to auxiliary motor 172 when the resetting operation has been completed; that is, when the Weight B has been returned to its lowermost position. In this instance, switch 221 is shown suitably supported so as to be engaged by weight B when it reaches lowermost position at the end of the resetting operation.

As heretofore stated, motor 172 serves to reset torque sensing device 131 following each winding cycle and prior to the next succeeding cycle. It follows, therefore, that main drive motor 12 remains de-energized during the energization of electric motor 172 or, at least, during the resetting operation.

Since the overriding clutch (FIGURE l0) is provided in sprocket wheel 157, and sprocket chain 156 is not driven during the resetting operation, electric motor 172 drives shaft in the same direction in which it is driven during normal operation of the roving machine, but at a considerably slow speed. This shaft must be driven during the resetting operation in order to rotate the pulleys 135, 136 of variable speed drive 125. Of course, shaft 133 also drives the pulleys of the auxiliary or second variable speed drive 245 in a like manner. Thus, this avoids placing the threads on the opposed ends of the control shaft 14-3 under excessive pressure.

As will be explained more in detail hereinafter, brake shoe 176 is released relative to drum 175; that is, brake shoe 176 is moved away from drum 175, during the resetting operation so that housing 133 of torque sensing device 131 may be moved solely by the weight of weight 8. However, since the weight B is relatively heavy, a suitable torque absorbing means should preferably be employed in order to prevent housing 133 from placing gear 14 d and control shaft 143 under excessive torque. In other words, the control shaft 143 should not be relied upon as the sole means to absorb the torque produced in the housing 133 by the weight B in the absence of suiiicient torque between shafts 131i, 132 to support weight B. Otherwise, the control shaft 143 and the threaded members 142 of variable speed drive 245 would have to be excessively large.

Accordingly, I have provided a simple torque absorbing apparatus which is effective only during the resetting operation. Said torque absorbing apparatus is broadly designated at 233 and comprises a pair of interconnected coaxial gears 231, 232. Gear 231 engages gear 145 and is fixed on a shaft 233 on which gear 232 is also secured. Shaft 233 may be journaled for free rotation in any desired manner, such as by hearing means carried by the frame of variable speed drive 125. Gear 232 meshes with a gear 234- which is preferably of substantially the same diameter as gear 145 and which is mounted on shaft 132 by means of a suitable overriding clutch mechanism similar to that shown in FIGURES 8 and 10, and as is shown in FIGURE 11. Since the clutch mechanism associated with gear 23-:- and shaft 132 is substantially the same as the clutch mechanism of FIGURE 10, except being effective in the opposite direction, those elements of FIGURE 11 which correspond to like elements of FIGURE 10 shall bear the same reference characters with the double-prime notation thereafter to avoid repetitive description.

it is apparent that, when a balanced torque exists between shafts 133, 132 and housing 133, shaft 132 is the driver in FIGURE 11 and is, thus, free to rotate independently of the gear 233. On the other hand, during the resetting operation, shaft 132 rotates relatively slowly and there is no appreciable torque between shafts 130, 132 so that housing 133 is free to rotate in the opposite direction from auxiliary drive shaft 130 and in the same direction as shaft 132. However, since shaft 132 is then rotating at a substantially slower speed than that at which the gear 234- would rotate; if it were free to do so, gear 233 would become the driver relative to shaft 132 and,

- thus, housing 133 cannot rotate, during the resetting operation, at a speed any greater than that of the shaft 132, thus relieving gear 144- and control shaft 143 from excessive torque during the resetting operation.

Operation of bobbin drive it is to be assumed that the resetting operation has been completed so that weight B occupie lowermost position and variator 125 is so arranged that, upon starting the machine, the highest desired rate of output speed will be imparted to the shaft 124 in the lower left-hand portion of FIGURES l and 2, since the output speed of variator 125 gradually decreases as the bobbin diameter or package diameter increases. In other words, the flyer speed is constant throughout the wind and the bobbin speed gradually diminishes as the diameter of the bobbin increases.

The roving R is threaded through flyers 22, wrapped around presserfeet 28 thereof a few times, and then a few turns are wrapped around the bobbins by the operator. Thereupon, start switch 202 is depressed by the operator to establish contact between respective conductors 201, t and 264, 205. As heretofore stated, this energizes the coil 2 of time-delay-relay 188 and the coil 196 of relay 192 to energize main drive electric motor 12 and also insures that coil 183 associated with the braking device 179 (FIGURE 3) remains de-energized until electric motor 12 has reached full speed. Thereupon, switch bar g establishes contact between conductors 185, 189 to release said braking device 179. It is to be understood that relay 18 5b occupies closed position at this time primarily because relay 213 occupies open position. Even though reset switch 215 might accidentally be pressed while electric motor 12 is energized, switch bar 193 will then be spaced from the proximal ends of conductors 216, 217 so that electric motor 172 and the coil of relay 1841; will remain de-energized.

As already mentioned, weight B applies a predetermined control torque (Q to housing 133 of the torque balancer 131, equal to twice the torque transmitted by either shaft 130 or shaft 132.

If the regulator were inactive, the winding tension would increase steeply with increasing bobbin diameter. But the higher winding tension causes an increased torque in shafts 130, 132 whereby housing 133 carrying drum 152 is made to turn in the positive direction; i.e., clockwise when seen from the right, raising the weight B. Through gears 145, 144 the rotation of housing 133 is transmitted to the common control shaft 143 of the two variators 125,

245, causing their output shafts, respectively 124 and 246, to slow down. The reduced r.p.m. of output shaft 124 from variator causes a proportional reduction in the winding r.p.m., whereby the excessive winding tension is relieved, and the regulator is again returned to equilibrrum.

By keeping friction losses to a minimum, the regulator can be made very sensitive. Since it acts continuously, the movements are very slow and gradual.

As the bobbin diameter increases the r.p.m. of output shafts 124, 246 from variators 125, 245 respectively continues to decrease, and weight B continues to rise. The total traverse of weight B from the beginning to the end of the run obviously depends on various design details, such as the number of revolutions that shaft 143 must make to cover the required speed range, the relativ number of teeth in gears 145, 144, and the diameter of drum 152.

At the end of the winding cycle, the circuit to electric motor 12 may be broken automatically by conventional means well known in the art, but not shown in the present drawings, or the manual stop switch 197 may be depressed, to also stop further rotation of electric motor 12. Referring to FIGURE 3, it is apparent that, when stop switch 197 is depressed, the contact between conductors 200, t is interrupted, and the circuit to coil 1% is broken, so that switches 193, 194 break the circuit between conductor L-2 and conductors 200, 184a.

At the end of each winding cycle, and immediately before electric motor 12 is de-energized in the manner described, it is necessary to produce sufficient slack in the roving between the drafting rolls and the flyers to facilitate lifting the flyers 22 off the respective spindles 21 and removing or dofling the filled bobbins from the spindles and bolsters associated with the usual bolster rail 35. In order to produce sufficient slack between the drafting rolls and the flyers for the doffing operation, the fiyers 22 and bobbins 31 should preferably be rotated at the same speed for a relatively short period so that the roving is not taken up by the bobbin, but accumulated on top of the flyer.

Accordingly, shaft 124 preferably is split into two coaxial sections 124a, 12411, and a suitable manually operable clutch 243 may be interposed between and connected to the proximal ends of said sections of shaft 124. Thus, main drive shaft 11} then drives compound 49 and, since sleeve 114 thereof (FIGURE 7) is not driven at this time, this effectually interlocks the sleeves 114 and 115 relative to housing 11% so the bobbins are driven directly by the main shaft 10. Thus, bobbins 31 and flyers 32 operate at the same speed. When sufficient slack has been produced in the roving, the stop switch 197 (FIGURE 3) is depressed by the operator, and clutch mechanism 240 is released to again establish a fixed relationship between the two sections 124a, 1241) of shaft 124.

It is apparent that, since the flow of current between conductors 185, 189 at switch g is also interrupted when stop switch 197 is depressed, spring 181 will also actuate the brake device 179; that is, spring 181 will return brake shoe 176 into engagement with brake band 175 at the same time that main drive electric motor 12 is tie-energized.

After the dofi'ing operation, empty bobbins, along with the flyers 22, are mounted on the spindles 21 and the resetting operation is effected in the manner heretofore described. It will be noted in FIGURE 3 that electric motor 172 is energized for the resetting operation by depressing the normally open manual reset switch 215. Thereupon, current flows from lead wire L-2, through switch 221, conductor 220 and the coil y of relay 213. It might be stated that, at the time reset switch 215 is depressed, weight B is spaced substantially above switch 221 so that switch 221 then occupies closed position.

Current flows from the end of coil y remote from conductor 220, through conductor 214, reset switch 215, conductor 2116, relay switch 193, conductors 217 and 210, the coil u of relay 184b, conductors 212, 184, through the solenoid 183, conductors 185, 189 and lead conductor L-1. This opens relay 18412 and closes relay 213.

Relay 1841) is provided so as to prevent current from flowing through main drive electric motor 12 during the resetting operation.

From the foregoing, it is apparent that when relay 213 is closed, current flows from the coil y of relay 213, through the switch portion of relay 213 and conductor 211 to electric motor 172. Current flows from the other side of electric motor 172 through conductor 210, through the coil u of relay 184b, conductors 212, 184, solenoid 183 and thence to the lead wire or conductor L-l in the manner heretofore described. It is thus seen that, although switch 215 may be released following energization of the coil relay 213, the coil of relay 213 remains energized and, therefore, electric motor 172 remains energized.

As heretofore stated, since the main drive electric motor 12 is then de-energized, shaft 130 is rotated solely by electric motor 172, and the overriding clutch in the sprocket wheel 157 (FIGURES 2 and 8) permits shaft 130 to rotate in its normal direction without irnparting rotation to sprocket whee-l 157. Therefore, the bobbins 31 are rotated relatively slowly while the flyers 22 remain stationary.

Since solenoid 183 is also energized at the time of energization of electric motor 172, brake shoe 176 is moved away from brake band 175 during the resetting operation so that the housing 133 of torque sensing device 131 is free to rotate by the weight of weight B, with the exception of the effect produced by the torque limiting device 239 interposed between the shaft 132 and the housing 133.

Once the resetting operation has commenced, the operator need no longer be concerned with it, since, upon completion of the resetting operation, the weight B will open switch 221 to break the circuit to the coil of relay 213 and, thus, to the electric motor 172 and the coil of relay 184k. After the resetting operation has been 2i) completed, the strands of roving extending from the drafting rolls D are then threaded through the flyers 22 and then wrapped around the bobbins 31 in the manner heretofore described to thus complete a cycle in the operation of the torque sensing device 131 and the associated winding tension regulator.

Traverse motion drive The bottom cone shaft on a conventional roving frame provides the winding r.p.m. (V), and it also provides the vertical traverse motion of the bobbin carriage. By the lay speed (L) we mean the linear traversing velocity of the bobbin carriage, expressed in inches per minute.

Since the coils per inch (U) are equal to the ratio of the winding r.p.m. (V) to the lay speed (L), we have U: V/L (Xi) The r.p.m. of the bottom cone diminishes during the run, but since both the winding r.p.m. (V) and the lay speed (L) are derived from the bottom cone of prior roving frames, the ratio between them; i.e., the coils per inch (U), remains constant.

In the method of the present invention, it is no longer practical to draw both the winding rpm. (V) and the lay speed (L) from the same variator. To obtain effective regulation of the winding tension, the winding power (Ev) must be isolated in a separate variator.

In addition to the winding speed variator 125, I have, therefore, provided the separate lay speed variator 24 5. For descriptive purposes, assume that the two variators are of identical design. Further assume that variators 125, 245 are actuated together by the rotation of the torque balance housing 133, transmitted through gears 145, 144 to variator control shaft 143.

If the two variators are of identical design and they are actuated together in identical manners, the ratio of the winding r.p.m. (V) to the lay speed (L), i.e., the coils per inch (U), may still remain constant during the run, if this should be desirable. It has long been known, however, that the independent regulation of the winding rpm. and the lay speed, for example, by means of two sets of cone pulleys, offers important advantages, but also that it introduces additional difiiculties. It is therefore not generally done.

On the other hand, the flexibility of the automatic tension control according to the present invention makes it possible to obtain the full advantages of a non-uniform lay spacing adapted to fit the individual case, without any related difficulties. Since this is a major advantage of the present method, it will now be explained in detail why this is so.

A perfect roving bobbin was defined above as a bobbin where every yard of roving has exactly the same stretch factor. It was explained that when such a bobbin is analyzed, the density of the fibrous material is found to decrease along any radius from the core to the outside of the bobbin. The density gradient is non-uniform and follows a definite mathematical law, which, unfortunately, differs somewhat with fiber properties, density levels, etc., and in no case has been accurately determined.

For the present purpose, it is sufficient to be aware of the fact that the density distribution in a perfect bob-- bin is given by nature. It is something which must be accepted as it is, because it cannot be changed. An old, and as yet largely unsolved, problem is to give the conventional cone pulleys such a curvature that they will reproduce the density distribution of a perfect bobbin.

It is necessary to distinguish clearly between the coils per inch measured in the axial direction of the bobbin, and the layers per inch measured along a radius. The weight of a small unit volume of the fibrous material anywhere in the bobbin is under otherwise equal conditions proportional to the product of the coils per inch and the layers per inch. Both quantities have therefore an equal influence upon the density at any given location in the bobbin. But, a given density distribution can be produced by many different combinations in the spacing of the coils and the layers. This applies also to the density distribution in a perfect bobbin. It is the density distribution itself that matters. It does not matter how it is produced.

A conventional roving frame normally operates with constant coils per inch. The radial density gradient is achieved by gradually allowing each new layer of roving more space in the radial direction as the run proceeds. The curvature of the cones has been designed for that purpose.

Suppose that such a roving frame actually is producing a perfect bobbin, but then a change is made so that the coils per inch now are decreasing during the run. The layers will then be spaced as they were before, but due to the progressively fewer coils per inch the density will diminish in the radial direction more rapidly than it should. The winding tension will fall off towards the end of the run, the roving in the outer layers of the bobbin will be heavier than it should be, and an assortment of operating difficulties will be encountered.

The variations in the coils per inch are therefore interrelated to the variations in the layers per inch through the required density gradient. Due to this inherent relationship, any attempt to control these two quantities separately by the usual inflexible means, such as two pairs of cone pulleys, is likely to prove impractical.

The present invention eliminates these limitations entirely. The coils per inch may be varied during the run according to any program. The automatic tension regulator will space the layers accordingly, so that a perfeet bobbin with the correct density distribution will be obtained in any case.

To obtain the conical shape of the end surfaces of the bobbin, the length of the traverse stroke is usually shorterred by a constant increment for each new layer of roving. On the other hand, on a conventional frame operating with constant coils per inch, the diameter increments per layer are gradually increasing during the run. The constant increments in the vertical direction combined with the increasing increments in the horizontal direction tend to give the end surfaces of the bobbin a more or less concave contour. This is disadvantageous, both because it reduces the volume of the bobbin and because it increases the tendency of the roving to overrun or slough off at the two ends of the bobbin towards the end of the run. The overruns are a constant problem in roving frame operations.

From what has been stated above regarding the interrelation of the coils per inch and the layers per inch through the radial density gradient of the bobbin, it will be understood that, through a progressive decrease in the coils per inch during the run it is possible to diminish, or even reverse, the negative progression in the layers per inch; i.e., by placing the coils progressively farther apart during the run it is possible to make the layers become progressively closer together. The conical end surfaces of such a bobbin will have a convex, rather than a concave, contour. By suitable adjustment of the progression in the coils per inch, it is thus possible in principle to give the end surfaces of the bobbin almost any contour.

This is fortunate. While a convex contour of the end surfaces of the bobbin is generally desirable, the best contour curve can, as a rule, only be found by the trial method. The curve will differ with the fiber material, the hank number, the density level, the mechanical condition of the machine, and with other variables. There are no definite applicable rules for determining the desired curvature.

From the foregoing, it may be understood that, in the method of the present invention, it is usually desirable to control the coils per inch and the layers per inch simultaneously in an interconnected manner from the 22 movement of an element equivalent to the torque balance housing 133, but the two regulations do not necessarily need to follow the same pattern. Consequently, the variators 125, 245 need not be of the same design.

In FIGURES l and 2, the variators 125, 245 are shown to be of the same design, and it is indicated that they are controlled in identical manners through the common control shaft 143 which derives its rotation from torque balancer housing 133.

As far as the traverse motion is concerned, lay speed variator 245 takes the place of the conventional cone drive. It obtains its input power from auxiliary drive shaft which rotates at the same r.p.m., but in the opposite direction as compared to shaft 132, which serves as input shaft for winding speed variator 125. Corresponding parts of the two variators therefore rotate in opposite directions. Output shaft 246 of lay speed variator 245 is connected, by sprocket wheels 2'47, 248 and chain 251, to the same train of gears, 56,. 57, 58, 62, 63*, etc., which conventionally is connected to the bottom cone shaft as previously described.

As indicated in FIGURE 12, variators 125, 245 may be controlled together but in an adjustable interrelation to each other. As shown in FIGURE 12, this may be achieved by dividing control shaft 143 in two parts or sections, 143a, 14%, each serving a separate variator. interposed between sections 143a, 1439b is a normal change gear assembly, comprising gears 260, 262, 263, 261. By changing one or more of these gears, the gear ratio between shafts 143a, 143b can be given any desired value. It should be understood, however, that instead of the illdicated change gear assembly, other means with other characteristics may be used for the interconnection of shafts 143a, 1431;.

Conclusion The method of tension control of the present invention differs radically from those of any known prior art, par ticularly because there is an automatic adjustment to many uncontrollable variables which otherwise would influence the final result.

Although a particular type of torque sensing and controlling mechanism and a particular type of variable speed transmission have been disclosed, it is apparent that many different types of such devices may readily be adapted to existing or new roving frames for the purpose of controlling what I have referred to as the winding power, without departing from the spirit of the invention.

Although the method of the present invention, and the functions of the tension regulating system, have as their immediate object the control of the winding tension, the controlled winding tension is not in itself particularly important, because it seems that the elongation of the roving between the presserfoot and the bobbin is limited to about 3 to 4 percent, and this elongation appears to have low sensitivity to changes in winding tension particuiarly when the tension already is high.

The elongation of greatest significance seems to occur somewhere between the nip of the front drafting rolls and the presserfoot, probably mostly between the nip of the rolls and the top of the flyer. This elongation, which may be as low as 2% and as high as 10% with the frame still running, depends upon a complex interaction of several factors, including the nature of the fiber material, the amount of real or false twist in the roving, the amount of tension, etc. The operator conventionally tries to control the elongation at this stage by controlling the tension as he sees it and feels it, but this method of control is highly unsatisfactory. Various attempts have been made to control the roving frame automatically by means actuated from the tension in the roving between the front roll nip and the top of the flyer, but so far without practical success.

The tension in the roving at the top of the fiyer is proportional to the winding tension. Since the present invention permits an accurate control of the winding tension, it also accurately controls the tension at the top of the flyers. The elongation of the roving at that point is thereby kept under control.

Thus, the invention eliminates weight variations in the roving which have occurred heretofore due to faulty cone curvature and other mechanical shortcomings, and it also makes it possible to deal effectively with weight variations due to the human factor.

In most mills, there is a tendency to start each run with too much tension in the roving. The first few layers of roving on the bobbin may thereby be stretched to percent more than the average of subsequent layers, and the difference may still be measurable after several hundred yards of roving have been put on the bobbin. Due to the recent trend of spinning all yarn from a single strand of roving, the resulting variations in the weight of the roving are fully reflected in the weight of the yarn.

There are many reasons why the start of each run with excessive winding tension is, to some extent, unavoidable. Unless the first layer of roving deposited on the smooth surface of the wooden bobbin is wound under adequate tension, the fiber material will not remain stationary, but will gradually creep over the top of the wooden bobbin, making it necessary to put the material into waste.

By means of adjusting screw b of time-delayrelay, or by suitable modification of the electrical control system for the automatic tension regulator, the first layer of roving may be wound against the bare wooden bobbin under relative high tension. Action of the automatic tension regulator could thus be delayed until the traverse motion has been reversed the first time. The roving deposited directly on the bare Wooden bob-bin could thereby be overstretched, but since this is a relative small length and it generally is not used anyway, it does not matter. The rest of the roving on the bobbin would then have the correct weight.

Recently, there has been a trend to achieve higher bobbin densities by wrapping the roving one or two additional times around the presser finger 27 and simultaneously make appropriate changes in the lay and tension gears. Research on these questions has brought out the fact that, for any given hank roving, there is a definite relationship between the average bobbin density and the Winding tension. The tension increases very steeply when the average density of a 10" x 5 bobbin exceeds 0.450.48 grams per cubic centimeter whereby the frame may thus become mechanically overloaded.

Density determinations, being somewhat cumbersome, are not customarily made. The operator therefore does not usually know anything about the load carried by the various parts of the frame. In some cases he may be overcautious. In other cases, he may unknowingly go far beyond the safety limits. My invention eliminates all uncertainty in this respect, because the winding tension is always accurately known.

In the drawings and specification, there have been set forth preferred embodiments of the invention and, although specific terms are employed, they are used in a generic and descriptive sense only and not for purposes of limitation, the scope of the invention being defined in the claims.

I claim:

1. A method of controlling the winding speed in a roving frame having rotating flyers for traversing roving onto rotating bobbins which comprises sensing at least a measure of the torque between the flyers and the bobbins, and varying the relative speed between the flyers and the bobbins in response to variations in the torque so sensed.

2. A method of maintaining a constant predetermined winding tension in a strand of roving as it passes from drafting rolls through a rotating flyer and as it is wound on a corresponding rotating bobbin, which comprises continuously detecting relative changes in the torque between the flyer and the bobbin during continuous rotation of the fiyer and the bobbin and simultaneously regulating the 2 irelative speed between the bobbin and the flyer in response to the relative changes in the torque between the flyer and the bobbin.

3. A method of controlling the Winding speed in a roving frame having rotating flyers for trasversing roving onto relatively rotating bobbins which comprises sensing at least a measure of the average torque between all the flyers and all the bobbins on the roving frame, and varying the relative speed between the flyers and the bobbins during rotation of the flyers and the bobbins in response to variation in the torque so sensed.

4. In a roving frame having rotating flyers driven at a constant speed for directing roving from drafting rolls to respective relatively rotating bobbins; the method of controlling the winding speed between the flyers and the bobbins which comprises sensing the torque between the flyers and the bobbins, applying a predetermined amount of opposing torque between the flyers and the bobbins, and varying the speed of the bobbins in response to any variations sensed in the torque relative to the opposing torque so applied.

5. A method of controlling the winding speed and lay speed in a roving frame having rotating flyers for traversing roving onto relatively rotating and axially reciprocating bobbins which comprises sensing at least a measure of the torque between the flyers and the bobbins, and producing relative changes in the relative speed between the flyers and the bobbins in response to variations in the torque so sensed while producing relative changes in the lay speed in direct proportion to the relative changes in the relative speed between the flyers and the bobbins.

6. A method of controlling the winding speed and lay speed in a roving frame having rotating flyers for traversing roving onto relatively rotating and axially reciproeating bobbins which comprises sensing at least a measure of the torque between the flyers and the bobbins, and producing relative changes in the speed of the bobbins in response to variations in the torque so sensed while producing relative changes in the lay speed at progressively changing proportions to the relative changes in the speed of the bobbins.

7. A method of controlling the winding speed and lay speed in a roving frame having rotating flyers for traversing roving onto relatively rotating bobbins which comprises sensing at least a measure of the torque between the flyers and the bobbins, and varying the speed of the bobbins in response to variations in the torque so sensed while varying the lay speed in response to the varying speed of the bobbins and in direct proportion to variations in the bobbin speed.

8. A method of controlling the winding speed and lay speed in a roving frame having rotating flyers for traversing roving onto relatively rotating bobbins which comprises sensing at least a measure of the torque between the flyers and the bobbins, and varying the relative speed of the flyers and the bobbins in response to variations in the torque so sensed while varying the lay speed in response to the varying relative speed of the flyers and the bobbins but at progressively changing proportions with respect to the variations in the relative speed of the flyers and the bobbins.

9. A method of controlling the winding speed and the lay speed in a roving frame having constant speed rotating flyers for traversing roving onto axially reciprocating and variable speed rotating bobbins which comprises sensing at least a measure of the torque transmitted from the rotating bobbins through the roving to the flyers, progressively producing relative changes in the speed of the bobbins in response to relative changes in the torque so sensed, and producing relative changes in the lay speed in direct proportion to the relative changes in the bobbin speed.

10. A method of controlling the winding speed and the lay speed in a roving frame having constant speed rotating flyers for traversing roving onto axially reciproeating and variable speed rotating bobbins which comprises sensing at least a measure of the torque transmitted from the rotating bobbins through the roving to the flyers, progressively producing relative changes in the speed of the bobbins in response to relative changes in the torque so sensed, and producing relative changes in the lay speed at a predetermined ratio to the relative changes in the bobbin speed.

11. A method of controlling the winding speed in a roving frame having rotating flyers for traversing roving onto rotating bobbins which comprises sensing at least a measure of the power transmitted between the flyers and the bobbins, and varying the relative speed of the flyers and the bob-bins in response to variations in the power so sensed.

12. Apparatus for producing a constant winding tension in a strand of roving passing from drafting rolls through a flyer to a bobbin comprising mean to drive the fiver, means operatively associated with the ilyer driving means for driving said bobbin at a variable speed, means to control the bobbin driving means including means for sensing at least a measure of the relative changes in the torque transmitted from the bobbin through the strand to the flyer, and means to vary the speed of the bobbin driving means in response to the sensed relative changes in the torque so transmitted.

13. In a roving frame having driven drafting rolls and flyers wherein roving passes from the drafting rolls and through the flyers, variable-speed rotating bobbins for receiving roving from the flyers, and driving connections between the bobbins and the flyers; means for maintaining the peripheral speed of the bobbins and roving wound thereon at a speed producing a predetermined constant winding tension in the roving between the flyers and the bobbins comprising a power measuring device interposed in the drive connections between the livers and the bobbins, and means responsive to any variation in the power measured by said device for compensatively regulating the variable speed of the bobbins to maintain said power constant.

14. In a structure according to claim 13 having a traverse motion for raising and lowering said bobbins relative to said flyers; means for driving said traverse motion, and means for progressively changing the speed of said traverse motion in direct proportion to the changes in the speed of the bobbins effected by said power measuring device.

15. In a structure according to claim 13 having a traverse motion for raising and lowering said bobbins relative to said flyers progressively decreasing distances; means for driving said traverse motion, and means producing successive relative changes in the speed of the traverse motion at a predetermined ratio with respect to successive relative changes effected in the speed of the bobbins by said power measuring device.

16. In a roving frame having constant-speed driven drafting rolls and flyers wherein roving passes from the drafting rolls and through the flyers, variable-speed rotating bobbins for receiving roving from the flyers, means for maintaining the peripheral speed of the bobbins and roving wound thereon at a speed producing a predetermined winding tension in the roving between the flyers and the bobbins comprising a variable speed drive mechanically interconnecting the flyers and the bobbins, and means maintaining a constant predetermined torque balance between the input of the variable speed drive and the flyers, said last-named means serving to adjust the output speed of the variable speed drive in accordance with changes in the amount of torque between the flyers and bobbins resulting from variations in the roving and the increasing diameter of the mass of roving wound on the bobbins.

17. Apparatus for producing a constant winding tension in each of a plurality of strands of roving passing from drafting rolls, through constant-speed rotating flyers to variable-speed rotating bobbins in a roving frame, said roving frame including a constant-speed main shaft, 21 variable-speed shaft, a compound having two input elements for receiving power from the main. shaft and said variable speed shaft, and said compound having a variable output element for driving said bobbins; the combination therewith of a variable speed drive having an input shaft and an output portion connected to said variable speed shaft, an auxiliary shaft driven in direct relation with said main shaft, a torque sensing device interposed between said auxiliary shaft and the input shaft of said variable speed drive, pressure means applying a predetermined balancing torque to said sensing device, and said device including means responsive to variation sensed in the torque between the auxiliary shaft and the input shaft relative to said balancing torque for regulating said drive to change the speed of the variable speed shaft and to balance the torque between said auX- iliary shaft and said input shaft with said pressure means.

18. Apparatus according to claim 17 wherein said roving frame includes a traverse motion for transmitting vertical reciprocation to said bobbins relative to the flyers, and means operatively associated with said sensing device for driving the traverse motion at relatively changing speeds at a predetermined ratio to the relative changes in the speed of the variable speed shaft.

19. Apparatus according to claim 17 wherein said roving frame includes a traverse motion for transmitting vertical reciprocation to said bobbins relative to the flyers, and means operatively associated with said sensing device for driving the traverse motion at relatively changing speeds in direct relation to relative changes in the speed of the variable speed shaft.

20. A structure according to claim 19 wherein said last-named means comprises a second variable speed drive having a second input portion and a second output portion, said auxiliary shaft being connected to the second input portion, said second output portion being connected in direct driving relation with said traverse motion, and the responsive means of said device being operable to regulate the second variable speed drive in direct relation to its regulation of said first-named variable speed drive.

21. In a roving frame having a plurality of rotating flyers and respective relatively rotating bobbins to which roving is directed by the flyers, first means to drive said flyers at a constant speed, a top cone shaft driven in direct relation to said flyers, a compound differential having a first constant-speed input element driven in direct relation to said flyers and a second variable-speed input element and an output element, and mechanical connections between the output element and the bobbins for varying the speed thereof; the combination of a variable speed shaft for driving the second input element, a variable speed drive connecting said variable speed shaft with said top cone shaft, a torque sensing device interposed between said top cone shaft and said variable speed drive, said device including means responsive to variations in torque between said top cone shaft and said variable speed shaft for regulating said variable speed drive to change the speed of the variable speed shaft and thereby maintain a predetermined constant torque between the top cone shaft and the variable speed shaft.

22. Apparatus for producing a constant winding tension in each of a plurality of strands of roving passing from drafting rolls, through constant-speed rotating flyers to variable-speed rotating bobbins in a roving frame, said roving frame including a constant-speed main shaft, means transmitting rotation from the main shaft to the flyers, a bobbin drive shaft, and means transmitting rotation from the bobbin drive shaft to the bobbins; said apparatus comprising an auxiliary shaft driven in direct relation with said main shaft, a variable speed drive having a constant-speed input portion and a variable speed output portion, means connecting the output portion to said bobbin drive shaft, a torque sensing device interposed between said auxiliary shaft and the input portion of said variable speed drive, means applying a predetermined torque to said sensing device, and means responsive to variation in the torque between the auxiliary shaft and the input portion of said variable speed drive either side of said predetermined torque for regulating said drive to change the speed of the bobbin drive shaft and to balance the torque between said auxiliary shaft and said input shaft with said predetermined torque.

23. Apparatus for producing a constant winding tension in each of a plurality of strands of roving passing from drafting rolls through constant-speed rotating flyers to variable-speed rotating bobbins in a roving frame, said roving frame including a constant-speed main shaft, direct driving connections between the main shaft, the drafting rolls and the flyers, and a compound interposed between the main shaft and the bobbins and having a variable speed input element; the combination therewith of a speed variator having a variable speed output portion and a constant speed input shaft, means connecting said variable speed output portion to said input element, an auxiliary shaft driven in direct relation with said main shaft, a torque sensing device interposed between said auxiliary shaft and the input shaft of said speed variator, means applying a predetermined opposing torque to said sensing device, and said device including means responsive to variation in the torque between the auxiliary shaft and the input shaft of said speed variator, either side of the applied torque, for regulating said variator to change the speed of the variable speed output portion and to balance the torque between said auxiliary shaft and said input shaft with the applied torque.

24. A structure according to claim 23 in which said torque sensing device comprises a pair of gears fixed on the proximal ends of the auxiliary and input shafts, a housing journaled adjacent the proximal ends of said auxiliary and input shafts, a planetary gear disposed between and engaging said first-named gears and journaled in said housing, and said means applying a predetermined torque being operatively associated with said housing and applying said torque in a direction opposite from the direction of rotation of said auxiliary shaft.

25. A structure according to claim 24 wherein said torque applying means comprises a pliable member attached to and at least partially encircling said housing, and a pressure member attached to said pliable element.

26 A structure according to claim 25 in which said pressure member is a Weight and the torque produced by said weight is approximately twice the torque transmitted through the auxiliary and input shafts.

27. Apparatus for producing a constant winding tension in each of a plurality of strands of roving passing from drafting rolls through constant-speed rotating flyers to variable speed rotating bobbins in a roving frame, said roving frame including a constant-speed main shaft, direct driving connections between the main shaft, the drafting rolls and the flyers, and a compound interposed between the main shaft and the bobbins and having a variable speed input element; the combination therewith of a speed variator having a variable-speed output portion and a constant-speed input shaft, driving connections between said output portion and said input element, an auxiliary shaft, direct driving connections between the main shaft and the auxiliary shaft, means maintaining a constant predetermined torque in the auxiliary shaft and the input shaft comprising a housing journaled adjacent the proximal ends of the auxiliary and input shafts, a planetary gear journaled in said housing, a pair of sun gears on the proximal ends of said auxiliary and input shafts and engaging said planetary gear, means applying a predetermined opposing torque to said housing relative to said auxiliary shaft and causing said housing to rotate upon variation in the torque in the auxiliary and input shafts, and means responsive to rotation of the housing for regulating the speed of the output portion of the 2% speed variator to return the auxiliary and input shafts to balanced condition relative to the opposing torque applied to said housing.

28. A structure according to claim 27 including a braking device associated with said housing, and means rendering said braking device effective to lock said housing against rotation when the torque in said auxiliary and input shafts is less than the opposing torque applied by said torque applying means.

29. In a structure according to claim 27, means for resetting the torque maintaining means, comprising auxiliary means for driving said auxiliary shaft at a relatively slow speed independently of said main shaft whereby the torque between said auxiliary and input shafts is substantially less than said opposing torque and whereby said opposing torque imparts reverse rotation to said housing.

30. A structure according to claim 29 including mechanical connections between the housing and the input shaft of the speed variator for limiting the extent of rotative speed imparted to said housing by said opposing torque during the resetting operation, and overriding clutch means in said last-named mechanical connections being so arranged that said input shaft may rotate at a relatively fast operating speed without imparting rotation to said housing.

31. A structure according to claim 29 including a braking device for locking said housing against rotation during intervals in which the roving frame is not operating, and means for releasing said braking means during intervals of operation of said auxiliary means for driving said auxiliary shaft.

32. A structure according to claim 31 in which said roving frame is equipped with means for starting rotation of said main shaft, and means for delaying the releasing of said braking means for a predetermined interval following the starting of said main shaft.

33. A structure according to claim 27 wherein said means for regulating the speed of the output portion of the speed variator comprises a control shaft connected to the speed variator, and gear means connecting the housing to said control shaft whereby rotation of the housing imparts rotation to the control shaft.

34. A structure according to claim 33 wherein said roving frame includes a traverse motion, a second speed variator having an input portion connected to said auxiliary shaft and a second variable speed outlet portion connected to said traverse motion, and said control shaft being operatively connected to said second speed variator for regulating the same in direct relation to regulation of said first-named speed variator.

35. A structure according to claim 33 wherein said roving frame includes a traverse motion, a second speed variator having an input portion connected to said auxiliary shaft and a second variable speed outlet portion connected to said traverse motion, means connecting said control shaft to said second speed variator comprising a second control shaft for regulating the speed of the second variator, and means for transmitting rotation from the first-named control shaft to the second control shaft at a different speed than that of the first-named control shaft.

36. A structure according to claim 35 wherein said last-named means comprises a speed-reducing gear train.

37. Apparatus for producing a constant stretch factor and constant winding tension in each of a plurality of strands of roving passing from front bottom drafting rolls, through constant-speed rotating flyers to variable-speed rotating bobbins in a roving frame, said roving frame including a constant-speed main shaft, means transmitting rotation from the main shaft to the flyers, a bobbin drive shaft, and means transmitting rotation from the bobbin drive shaft to the bobbins; said apparatus comprising an auxiliary shaft driven in direct relation with said main shaft, a speed variator having a constant speed input shaft and a variable speed output portion, means connecting the output portion to said bobbin drive shaft, a torque measuring device interposed between said auxiliary shaft and the input portion of said variable speed drive, said measuring device comprising a housing journaled adjacent proximal ends of said auxiliary and input shafts, a planetary gear journaled in the housing, a pair of sun gears on proximal ends of the auxiliary and input shafts, means for applying to said housing a given torque equal to the product derived from multiplication of the transmission ratio from the auxiliary shaft to the front bottom drafting rolls times the Winding tension in grams times the diameter of the front bottom rolls in inches times the number of bobbins on the roving frame times the stretch factor, said torque being applied to said housing in the opposite direction from that of rotation of said auxiliary shaft, whereby said torque applying means rotates said housing upon the torque in said auxiliary and input shafts varying relative to said given torque, and means responsive to rotation of said housing for regulating said drive to change the speed of the bobbin drive shaft and to balance the torque in said auxiliary and input shafts with said given torque.

38. Apparatus for producing a constant winding tension in each of a plurality of strands of roving passing from drafting rolls through rotating flyers to rotating bobbins in a roving frame, said roving frame including a main shaft, first electrical means for starting and maintaining rotation of said shaft, direct driving connections between the main shaft, the drafting roHs and the flyers, and a compound interposed between the main shaft and the bobbins and having a variable speed input element; the combination therewith of a speed variator having a variable output and a constant input shaft, driving connections between said output and said input element, an auxiliary shaft, direct driving connections between the main and the auxiliary shafts, means maintaining a constant predetermined torque between the auxiliary and input shafts comprising a housing journaled on the proximal ends in the auxiliary and input shafts, a planetary gear journaled in said housing, a pair of sun gears on the proximal ends of said auxiliary and input shafts and engaging said planetary gear, means applying a predetermined opposing torque to said housing relative to said auxiliary shaft and causing said housing to rotate upon variation in the torque in the auxiliary and input shafts, means responsive to rotation of the housing for regulating the speed of the output of the speed variator to return the auxiliary and input shafts to balanced condition relative to the opposing torque applied to said housing, an electrically deactivated braking device for said housing located in a parallel electrical circuit to said first electrical means, and means actuating said device to brake said housing when the circuit to said first electrical means is open.

39. A structure according to claim 38 including means to delay deactivation of said braking device upon initial energization of said first electrical means substantially until said main shaft reaches said constant speed.

40. A structure according to claim 38 including means to delay deactivation of said braking device for a predetermined interval following initial energization of said first electrical means.

41. A structure according to claim 38 wherein said first electrical means comprises an electric motor, a timedelay-relay having a switch thereon interposed in the electrical circuit to said braking device, but being disposed in parallel with said electric motor, and said timedelay-relay being operable to close the circuit to the braking device and deactivate the same a predetermined interval after the closing of the electrical circuit to said electric motor.

42. A structure according to claim 41 including a second electric motor, means connecting the second electric motor with said auxiliary shaft, an overriding clutch means whereby said auxiliary shaft may be rotated by the sec- 0nd electric motor at a slower speed than the speed irnparted thereto by said main shaft, said second electric motor being arranged in said circuit parallel with said first electric motor and in series with said electrically deactivated braking device for deactivating the braking device during energization of the second electric motor, and said second electric motor being adapted to drive said auxiliary shaft at a relatively slow speed whereby the opposing torque effected by said torque applying means imparts reverse rotation to said housing for resetting said housing while the main shaft is stopped.

43. A structure according to claim 42 including means operable automatically upon completion of the resetting of said housing for breaking the circuit to the auxiliary motor.

44. In a roving frame having driven drafting rolls and flyers wherein roving passes from the drafting rolls and through the flyers, variable-speed rotating bobbins for receiving roving from the flyers, a vertically reciprocating carriage for the bobbins, a traverse motion for imparting reciprocating movement to the carriage; means for driving said traverse motion comprising a speed variator mechanically interconnecting the flyers and the traverse motion, means for sensing a torque proportional to the torque transmitted from the bobbins through the roving to the flyers, and means responsive to said sensing means to adjust the output speed of the speed variator in direct rela tion to relative changes in the torque so sensed.

45. In a roving frame having constant-speed driven drafting rolls and flyers wherein roving passes from the drafting rolls and through the flyers, variable-speed rotating bobbins for receiving roving from the flyers, a vertically reciprocating carriage for the bobbins, and a traverse motion for imparting reciprocating movement to the carriage; means for driving said traverse motion comprising a speed variator mechanically interconnecting the flyers and the traverse motion, means for sensing at least a measure of the torque transmitted from the bobbins through the roving to the flyers, and means responsive to said sensing means to adjust the output speed of the speed variator at a predetermined ratio to relative changes in the torque so sensed.

46. In a roving frame having constant speed driven drafting rolls and flyers wherein roving passes from the drafting rolls and through the flyers, rotating bobbins for receiving roving from the flyers, a main shaft for driving said flyers, means for transmitting rotation from the main shaft to the bobbins at progressively decreasing speeds of predetermined relatively changing relationship, a vertically reciprocating carriage for said bobbins, and a traverse motion for transmitting vertical reciprocatory movement to said carriage; the combination of a speed variator interposed between said main shaft and said traverse motion, means for sensing at least a measure of any variation in torque between the main shaft and the bobbins, and means automatically operable in response to variation in the torque so sensed for regulating said variator to produce relative changes in the speed of the traverse mo tion which differ from the relative changes in the speed of the bobbins.

47. Apparatus for producing constant winding tension in textile strands passing from drafting rolls through rotating flyers and rotating bobbins comprising: means for drving said flyers and bobbins at relative speeds, means for sensing at least a measure of any relative changes in the torque transmitted between the flyers and the bobbins, and means controlling said drive means to vary the relative speed between said flyers and said bobbins in response to the sensed relative changes in the torque so transmitted.

References Cited in the file of this patent UNITED STATES PATENTS 2,901,882 Granberry Sept. 1, 1959 2,901,883 Granberry Sept. 1, 1959 2,925,704 Noda Feb. 23, 1960

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US2901882 *Nov 5, 1956Sep 1, 1959West Point Mfg CoFly frame with independently variable speed drives and method
US2901883 *Nov 5, 1956Sep 1, 1959West Point Mfg CoHydraulic fly frame drive and method
US2925704 *Sep 10, 1957Feb 23, 1960Howa Machinery LtdApparatus for the back motion of the cone drum belt in a flyer frame
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3316700 *Nov 9, 1964May 2, 1967Whitin Machine WorksBuilder motion for roving frame
US3316701 *Nov 9, 1964May 2, 1967Whitin Machine WorksWinding apparatus with electric control circuit
US3332224 *Nov 17, 1964Jul 25, 1967Burlington Industries IncPneumatic spinning frame drive regulator
US3336739 *Mar 26, 1965Aug 22, 1967Deering Milliken Res CorpSpinning frame apparatus
US3662531 *Apr 21, 1970May 16, 1972Logan Inc JonathanMethod and apparatus for protecting production of textured textile yarn
US3693340 *Aug 7, 1969Sep 26, 1972Kanai HiroyukiSpindle speed controlling device for ring spinning and twisting machines
US4196572 *Sep 8, 1978Apr 8, 1980James Mackie & Sons LimitedTextile winding apparatus
US4370850 *Sep 26, 1980Feb 1, 1983Rieter Machine Works, Ltd.Roving frame and a method of packaging roving
US4409785 *May 6, 1981Oct 18, 1983Kabushiki Kaisha Toyoda Jidoshokki SeisakushoMethod of starting a flyer frame
EP2784195A1 *Mar 25, 2014Oct 1, 2014Rieter Ingolstadt GmbHDrive assembly for a spinning preparation machine
Classifications
U.S. Classification57/93, 57/98
International ClassificationD01H1/00, D01H13/14, D01H13/16, D01H1/36
Cooperative ClassificationD01H1/365, D01H13/16
European ClassificationD01H13/16, D01H1/36B