US 3492706 A
Description (OCR text may contain errors)
Feb. 3, 1970 c. A. LEE ETAL 3,492,766 METHOD AND APPARATUS FOR DISPOSING A CONTINUOUS FILAMENT ON A RACK FOR MAKING ENDLESS FABRIC Filed April 29. 1966 INVENTORS (Mass/1 455 mazes/v2 may! BY fidmiwwn J-M,
2m TM ATTORNEY$ U.S. Cl. 281 4 Claims ABSTRACT OF THE DISCLOSURE A single continuous filament is disposed in a plurality of substantially parallel loops upon a rack whereon the loops are sewn together to form an endless fabric. The filament is placed upon the rack by carrying one end repeatedly around the path defined by the rack there-by depositing successive turns of the rack filament upon the rack. The successive turns are separately guided across the rack to establish substantially parallel loops of the filament. The filament is then cut after the last loop and the two ends of the filament are fastened together over guides externally of the rack so that upon advancing the rack filaments over the predetermined path of the rack, the filament wound off at one side of the rack is wound back on at the other side. In winding the filament on the rack, one of the rolls defining the rack is moved at a rate slower than the end being carried around the path, to maintain tension in the filament. The tension in the filaments is equallized among the turns.
This invention relates to a method and apparatus for forming fabrics by sewing. More particularly, it relates to a method and apparatus for making endless fabrics in which sewn filaments are sewn in one direction across rack filaments running endlessly in another direction. Still more particularly it relates to a method and apparatus for disposing a single continuous filament upon a rack as a plurality of substantially parallel loops prior to their being sewn together to form the fabric.
This invention is directed to a method and apparatus for making fabrics such as the fabrics described in the copending application of Charles A. Lee, Ser. No. 431,030, filed Feb. 8, 1965 for Sewn Fabric and Method of Manufacture, now abandoned. Such fabrics are formed by stitching sewn filaments across a plurality of rack filaments, preferably with non-Woven filler filaments therebetween. The present invention is particularly directed to a method and apparatus for disposing a single continuous filament in a plurality of substantially parallel loops upon a rack Where the loops are sewn together to form an endless fabric by the method and apparatus described in the co-pending application of Charles A. Lee and Warren R. Furbeck, Ser. No. 546,380, filed Apr. 29, 1966, for Method and Apparatus for Making Endless Sewn Fabric, now U.S. Patent No. 3,459,612.
According to the present invention, a single continuous rack filament is carried a number of times over a predetermined path defined by a plurality of rolls disposed in predetermined relative position to form a rack. As the filament is wound on, each turn is captured, as between particular teeth of a comb, so that upon completion of the winding on, the loops of the rack filament are in predetermined laterally spaced relation upon the rack. The two ends of the rack filament may then be passed over pulleys and tied together so that the rack filament then passes in a multiloop closed path. Because the single filament is then itself endless, the tension in each loop is "United States Patent 3,492,766 Patented Feb. 3, 1970 ICC the same. If the tension is not equalized when the filament is first wound on, it can be equalized by moving the loops together several times about the predetermined path on the rack. The rack may then be squared and predetermined equalized tension placed in the loops of rack filament, as by pulling on one of the rolls. The filaments are then ready for the sewing operation, which may be carried out as described in the aforesaid application of Lee and Furbeck.
Prior to the actual sewing, non-woven filler filaments may be deposited upon the rack filaments so that the sewn filaments may sew the filler filaments to the rack filament.
The sewing operation may be performed at a sewing station disposed along the predetermined path, around which the loops are moved endlessly. The sewing operation may be performed automatically by sewing back and forth transversely of the rack filaments and advancing the loops of the rack filament a predetermined amount after each traverse. With the rack filament wound on the rolls, the loops may be advanced by driving one of the rolls, plus advancing the loops over the predetermined path. The fabric is thus formed as the loops are moved around the predetermined path. The sewing is continued until the first row of stitches returns to the sewing station. At this point, the sewing operation is completed.
For most applications of the sewn fabric, it is necessary that it then be stabilized. Stabilization may be effected in various ways, depending upon the materials of which the fabric is made and upon the particular use to which it is to be put. The stabilization may usually be effected by heat treatment or by adding a bonding agent or by both. As described in the aforesaid Lee and Fur'beck application, the heat stabilization may be effected on the same rack by continuing to advance the fabric about the predetermined path past at least one other station where it passes through an oven and is heated to a predetermined temperature as it passes endlessly through the oven.
For most purposes, it is desirable that the fabric be chemically stabilized as well as heat stabilized. To this end, some bonding agent is applied to the fabric, which bonding agent is then cured, preferably by running the fabric through the same oven as used in the heat treating, as described in the aforesaid Lee and Fur'beck application.
It is therefore a primary object of the present invention to provide a method and apparatus for making fabric by sewing loops or rock filaments together with sewn filaments to form an endless mesh fabric. Another object of the invention is to provide a method and apparatus for disposing a plurality of loops of a single continuous rack filament about a rack with the plurality of loops in predetermined relation to each other. Still another object of the invention is to provide a method and apparatus for disposing a plurality of loops of a single continuous rack filament upon a rack so that the loops of rack filament may be sewen together with sewn filaments transversely of the rack filament while the rack filament is on the rack, and the sewn fabric thus produced stabilized while the fabric remains upon the rack. Further objects and advantages of the present invention will become apparent from consideration of the following description taken in conjunction with the following drawings wherein:
PIGURE 1 is a perspective view of a rack for forming fabrics according to the present invention, illustrating in particular the winding on of a single continuous rack filament to form a plurality of laterally disposed loops;
FIGURE 2 is a side elevation of the apparatus as shown in FIGURE 1; and
FIGURE 3 is a partial end elevation of the apparatus shown in FIGURE 1, illustrating in particular the tying off of the filament upon completion of the winding on.
In FIGURES 1 and 2 there is illustrated a rack 11 upon which a single continuous filament 13 is Wound. As shown, the rack 11 includes two spaced frames 15 and 17 having means for mounting elongated support members in the form of rolls thereon. The frame 15 comprises a pair of spaced parallel uprights 19 and 21. The upright 19 and 21 may be constructed of wood or other suitable material. To maintain a spaced relation between the uprights a cross support member 23 is secured thereto. The lower ends of the uprights 19 and 21 are each secured to a respective fixed longitudinal member 25, 27 by a single bolt 29 which passes through the end of the upright and through the fixed member, thereby permitting limited rotary movement of the uprights about the fixed members. The fixed members 25 and 27 may be secured to the floor. To prevent the frame 15 from falling over as the apparatus is being placed in operation, support chains 31 are provided which are secured between the uprights 19 and 21 and the fixed members 25 and 27 as shown in FIGURE 1.
Journaled in the upright members and positioned slightly below the upper ends thereof is a stretch roll 33 which may be coupled by means of a pulley 34 and suitable belts 36 to a motor 35. The roll 33 is provided at one end thereof with a crowned portion 37 for receiving a flat belt 29.
Serving to guide the filament over the cross member 23 is an eye 40 through which the filament is passed and a rod bearing 42 providing a low friction surface for the filament as it passes over the member 23. To permit adjustment of the tension of the filament, a tension adjusting means 44 is provided as illustrated more particularly in FIGURE 3 and described in greater detail below.
Serving to maintain desired spacing between adjacent turns of the continuous filament 13 is a comb 41 which is detachably secured to the frame 15 and positioned so that the filament turns can fall in the recesses 43 between the teeth of the comb 41. (See FIGURE 3.)
The rear frame 17 includes spaced uprights 45 and 46 the lower ends of which are secured to fixed members 47 which in turn may be secured to the floor. The uprights 45 and 46 should be secured against motion as by bracing them or afiixing their upper ends to the ceiling. Rotatably mounted upon the uprights 45 and 46 are three rolls, an upper roll 49, an intermediate roll 51 and a lower roll 53.
The support rolls 33, 49, 51 and 53 generally define an endless path over which the loops of rack filament 13 are disposed in performing the first operation of disposing loops or rock filament 13 on the rack 11 and over which the rack filaments 13 are moved in the subsequent sewing and stabilizing operations. The stretch roll 33 is mounted for movement about the bolts 29 in order to adjust the length of the path and maintain proper tension in the rack filament 13 after it has been disposed on the rack 11. To provide a means for adjusting the position of the stretch roll 33 and the tension within the filament 13, a tensioning means 57 is provided. In the illustrated embodiment, the tensioning means 57 comprises a pair of upright support members 59 the lowermost ends of which are rigidly secured to the fixed members 25 and 27. The support members 59 should be secured against movement as by appropriate bracing or by securing their upper ends to a ceiling. The frame 15 is provided with two bolts 61 positioned opposite books 63 provided upon the uprights 59. Secured between the bolts 61 and hooks 63 are chains 65 each having a turnbuckle 67 serving as a means for adjusting the distance between the fixed uprights 59 and respective movable uprights 19 and 21 and for placing proper tension in the wound filament 13.
It is generally desirable that the finished fabric be of uniform length across its entire width. To this end, it is preferable that the lengths of the paths taken by the respective filament all be substantially the same. The uprights 19 and 21 are therefore adjusted to provide equal path lengths at both ends of the roll 33. This adjustment may be by any suitable method as by trial and error or accurate measurement. This adjustment may be etfected by use of the turnbuckles 67. At the same time, it is contemplated that the tension in the loops of filament 13 or in the sewn fabric may be adjusted from time to time during the fabrication process. Since this adjustment of tension is also effected by use of the turnbacks 67, and since the turnbuckles 67 are independently adjusted, means is provided for assuring that the rack remains square during such adjustment of the turnbuckles 67.
As illustrated, a simple means for keeping the rack square comprises a pair of cords 68 each attached at one end to a respective one of uprights 19', 21 as by an eye 69. The other ends of the cords 68 are passed over guides 70 to an indicating means 71, which may comprise a carpenters level 72 disposed on a support 73 in turn supported at each end by a respective one of cords 68. With the rack initially square, the cords 68 are tied at such lengths that the level 72 is horizontal. Then any relative difference in the distances between the uppermost ends of the uprights 19 and 21 and the respective support members 59 will be readily detected by the indicating means 71. If the respective turnbuckles 67 are adjusted while keeping the level 72 horizontal, the rack 11 is kept square.
The first operation, that of disposing loops of rack filament 13 in predetermined laterally spaced relation upon the rack 11, may now be described in a preferred embodiment by reference to FIGURES l to 3. The filament may be made of any of a number of materials used in textiles. For example, it may be made of synthetic fibers such as polyester fibers sold under the trademark Dacron. However, many other materials such as other synthetic fibers, natural fibers, metal and even paper can be used, depending upon the use to which the finished fabric is to be put. The number of loops and the size of the filament 13 depend both upon the material of which the filament 13 is made as well as upon the desired properties of the finished fabric. The rack filament 13 provides strength to the finished fabric and must therefore be large enough for the purpose; at the same time it must not diminish other desirable properties of the fabric, such as its permeability. For making one type of filter fabric, it has been found suitable to use a Dacron filament of 220 denier with 16 loops per inch.
The free end of the rack filament is passed from the storage spool 75 through the eye 40 and the adjustable tension means 44 and over the low friction bearing 42. The free end of the rack filament 13 is then secured to the belt 39 as by tying the free end of the rack filament 1a to the belt 39.
The belt 39 is disposed on the rolls 33, 49, 53 and 51 in the path along which it is desired to dispose loops of rack filament 13. The belt may be of any suitable flexible material and may even be a turn of the rack filament 13 itself. That is, rather than tying the free end of the filament 13 to a separate belt 39, the free end may be hand carried over a complete loop, following the desired path, and may then be tied to itself, forming a closed loop comprising the belt 39. The motor 35 is actuated to drive the roll 33 which in turn drives the belt 39 about the path defined by the rolls 33, 49, 53 and 51.
Each time the belt makes a complete turn around the predetermined path, a loop of rack filament 13 is disposed on the rack in this same path. The comb 41 serves as guide means for guiding successive turns of the rack filament 13 into predetermined spaced relation. As illustrated, each turn of the belt deposits a turn of filament 13 near the belt. This turn may then be deposited in the empty recess 43 nearest the far end of the comb. This turn may be hand carried to the proper recess or mechanical means may be provided. Alternatively, the comb 41 may be movably mounted and driven in synchronism with the belt 39 so that the proper recess is disposed at the belt 39 to receive each turn of rack filament as it is wound on, moving ultimately to its final position as shown in FIGURE 3. As another alternative, the comb 41 may be made in the formof a screw turned in synchronism with the belt 39; each successive turn may then fall in the groove 43 between screw threads nearest the belt 39 and drawn longitudinally of the roll 33 to the same final position, when the screw is stopped.
Irrespective of how the filament 13 is placed in the recesses 43, successive turns of the filament are moved longitudinally of the roll 33 into predetermined substantially parallel laterally spaced relation on the rack 11. As the turns move through the predetermined path around the rolls 33, 49, 51 and 53, they naturally assume substantially parallel relations with a lateral distribution determined by the relative disposition of the recesses 43.
When all of the desired number of turns of rack filament 13 have been wound on the rack 11, the two ends of the filament may be cut and tied together as shown in FIGURE 3. The end cut from the belt 39 is brought down from the roll 33 and passed over a pulley 77 mounted on the cross piece 23. The end cut from the spool 75 is brought up and around the roll 33, then down over a pulley 79. The two ends may then be tied into a knot 81.
If the loops of rack filament 13 are not substantially parallel, the roll 33 may be driven one way or the other or preferably back and forth for a number of turns. The loops will tend to assume a disposition more nearly parallel. Of course, the loops are never truly closed, and the continuous filament in fact gradually moves in a spiral toward one end or the other, the part that is thus wound off at one end of the roll 3.3 'being returned by way of the pulleys 77 and 79 to the other end, where it is wound on. Movement of the loops also serves to equalize the tension in the loops. The loops are all laid down under comparable conditions, but because of friction, the tension is not necessarily the same in each loop. Further it may be desirable to modify the tension or change the length of the predetermined path. This may be achieved by adjusting the turnbuckles 67 and adding or removing a length of filament 13 at the knot 81. In any event, since there is but a single continuous filament, the tension is readily equalized by a few turns of the roll 33.
The rack 11 is thereby set up for the sewing operation. It is often desirable however to hold the loops of rack filament in the proper relationship during the sewing operation. To this end, additional combs may be inserted at appropriate locations around the predetermined path.
It may be noted that the diameter of the crowned portion 37 of the roll 33 is somewhat larger in diameter than the roll 33 itself. This drives the belt 39 and hence. the free end of the filament 13 somewhat faster than the roll 33 advances the filament 13 from the spool 75. This keeps the filament 13 tight as it is wound on, thus avoiding slack that might entangle the filament. The tension means 44 also serves to keep the filament 13 taut. The tension means 44 may, as shown, comprise a pair of washers 83 between which the filament 13 is drawn from the spool 75. The friction thus created keeps the filament taut. The amount of friction is determined by the compression in a spring 85 which is urging the washers 83 together. The spring compression may be adjusted by a nut 87 mounted on a screw 89, thus controlling the tension in the filament 13 as its wound on the rack.
With the rack filament 13 so disposed upon the rack 11, the sewing and finishing operations may be performed.
They may be performed on this same rack 11 in the manner described in the aforesaid co-pending application of Lee and Furbeck.
Although various preferred embodiments of the present invention have been herein described, numerous modifications may be made therein within the scope of the present invention. The invention is limited only by the claims.
What is claimed is.
1. A method of forming an endless belt having substantially parallel laterally spaced turns of filaments comprising carrying one end of a continuous rack filament around a predetermined closed path defined by a plurality of parallel elongated support members mounted in fixed spaced relationship to each other to form a rack, at least one of said support members being a roll, said one end being carried repeatedly around said path at a location longitudinally fixed along said support members thereby depositing successive turns of the continuous rack filament upon said support members at said fixed location, rotating said roll to move the surface thereof more slowly than the movement of said one end thereby maintaining tension in said rack filament, and separately guiding successive turns of the continuous rack filament longitudinally of said support members from said fixed location into predetermined substantially parallel laterally spaced relation on said rack.
2. An apparatus for the manufacture of an endless mesh fabric comprising a rack including a plurality of parallel elongated members mounted in fixed spaced relationship to each other for receiving rack filaments thereupon and supporting said filaments for movement longitudinally of said filaments and transversely of said members about a predetermined closed path, at least One of said members being a roll, means for rotating said roll, means coupled to said roll for carrying one end of a continuous rack filament around said path repeatedly thereby depositing successive turns of the continuous rack filament upon said members, said last named means carrying said one end at a rate exceeding the rate of movement of the surface of said roll thereby maintaining tension in said rack filament, and guide means for separately guiding successive turns of the continuous rack filament into predetermined substantially parallel laterally spaced relation on said rack.
3. An apparatus for the manufacture of an endless mesh fabric comprising a rack including a plurality of parallel elongated members mounted in fixed spaced relationship to each other for receiving rack filaments thereupon and supporting said filaments for movement longitudinally of said filaments and transversely of said members about a predetermined closed path, at least one of said members being a roll, means for rotating said roll, carrier means coupled to said roll for carrying one end of a continuous rack filament upon said members, said carrier means including a continuous elongated flexible member mounted about said members for motion along a path substantially parallel to said path, means coupled to said means for rotating for moving said flexible member along said path at a rate exceeding the rate of movement of the surface of said roll thereby maintaining tension in said rack filament, and guide means for separately guiding successive turns of the continuous rack filament into predetermined substantially parallel laterally spaced relation on said rack.
4. A method of forming an endless belt having substantially parallel laterally spaced turns of filaments comprising carrying one end of a continuous rack filament around a predetermined closed path defined by a plurality of elongated support members mounted in fixed spaced relationship to each other to form a rack, said one end being repeatedly carried around said path at a location longitudinally fixed along said support members, thereby depositing successive turns of the continuousrack filament upon said support members at said fixed location, and separately guiding successive turns of the continuous rack filament longitudinally of said support members from said fixed location into predetermined substantially parallel laterally spaced relation on said rack, the rack filament at the first of said turns being thereafter fastened to the rack filament at the last of said turns, thereby making said rack filament endless, and said endless rack filament being thereafter guided between said first and 7 8 last turns externally of said rack, whereby upon advanc- 2,239,635 4/1941 Walton 156-137 ing the rack filament over said predetermined path the 2,805,540 9/1957 Thompson 5721 X rack filament wound 01f at one side of the rack is Wound on at the other side. F REIGN PATENTS 5 185,401 10/1936 Switzerland.
References Cited 452,469 10/1949 Italy.
U D E PATE T NITE STAT S N S MERVIN STEIN, Primary Examiner 1,389,699 9/1921 Rivett 5721 1,412,309 4/1922 Lambert 156137 10 us. 01. X.R.
Column 2, line line Column 3, line line line Column 4, line Column 5, line UNITED STATES PATENT OFFICE 53, 68, 33, may 67,
change change change change change CERTIFICATE OF CORRECTION Patent No. 3,492, 706
Dated February 3, 1970 e Charles A. Lee and Warren R. Furbeck It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:
"or rock" to --of rack--; "sewen" to --sewn--.
"or rock" to --of rack-; "books" to --hooks--.
after the period insert --The filament 13 be drawn from a spool or bobbin 75.". change "its" to --it is--.
SIGNED AND SEALED JUL281970 WIHIHRII'JR- Comisaionn at hunt! I FORM PO-105O (10-69) UScOMM-DC COSTS-P08 us. novmnultm nmmnc OF'ICE nu o-au-nn