US 3606769 A
Description (OCR text may contain errors)
Sept. 2t, 1971 R. L. WALFORD commuous WEFT FEED FOR WARP xumme mcnmms Filed June' '16; 1969 L4"Sheets-Sheet 1 w wm Q 32 mm wx wn 5 M23 math: Q TM h HI I I I .1 l I m j 5 m I I I} m m-3k 5 m@ $3 33 L I kkmfis Edam 0 mm in INVIz'N'l'OR. RICHARD L. '41. FORD ATTORNEY Sept-21,1971 R. WALFORD 3,606,769
' commuous WEFT.FEED FOR WARP KNITTING Mommas Filed June 1 1969 4 Sheets-Sheet l x/wrmva EL mmrs I" INVEN'I'OR. RICHARD L. WALFORD fIE. if
ATTORNEY "'Spi'l R. L. WALFORD 5 5 I CONTINUOUS WEFT FEED FOR WARP KNITTING MACHINES Filed June 16, 1969 Y 4 Sheets-Sheet 3 #vsmr YARN DELAY HOOKICAM 0PERA7'E0}[ KN/TT/NEELEMENTS PULLEY HA 7' INSERT YARN INVIiN'I'OR. RICHARD L. mum/90 BY 10/ i 210/2, ATTORNEY Sept. 21; 1.971 R. L. WALFORD com'nwous WEFT FEED FOR WARP KNITTING wwmmas Filed June 16, 1969 4 Sheets-Sheet 4 Q \h \2 u Wm N m m r L A v v w 6 u M c i Q r m a w 5 \E 3 553m whim 559B 9 5 w ems. kmww United States Patent 3,606,769 CONTINUOUS WEFT FEED FOR WARP KNITTING MACHINES Richard L. Walford, Bloomfield, N.J., assignor to J. P. Stevens & Co., Inc., New York, N.Y. Ifiled June 16, 1969, Ser. No. 833,402 Int. Cl. D04b 23/12 US. Cl. 66-84 14 Claims ABSTRACT OF THE DISCLOSURE A continuous insert yarn feed for warp knitting machines is provided with two inclined chains leading to the ends of the knitting line, each chain carrying pulleys With tops or hats having a pointed extension. Insert yarn is fed from one or more packages to a reciprocating arm which carries the yarn around the pulleys on the outside of the chains in a zig-zag fashion. The yarn is around the pulley underneath the hat until it reaches a bottom sprocket in each chain, these sprockets being adjacent to the knitting line of the machine. As the pulleys on the chains turn around the bottom sprocket, the insert yarn is lifted onto the hat and on further turning slips off. The last motion around the right or left hand lower sprockets releases tension on the insert yarn as it is laid at the knitting line heside the warps. Knitting of the warps is by conventional means, including warp thread guides, needles, sinker bars, and the like. Brakes may be provided, for example a flat bar with a soft rubber lining which bears against the pulleys near the bottom of each chain. This prevents the pulleys from overrunning, particularly when a machine is slowing to a stop. With very fragile insert yarns or those which can stretch very easily, the brake can, if desired, be normally kept out of contact with the pulleys when the machine is operating and only engage them when it is slowing down.
BACKGROUND OF THE INVENTION Warp knitting machines have been known for many years, the knitting being effected with the warp threads and with insert or weft threads laid in and incorporated into the fabric by the knitting stitches of the warp yarns. The enormous potential speed of the knitting machines themselves, for example 1200 courses per minute or more, has imposed severe operating conditions on the mechanism for feeding the insert yarn because the tremendous speed can produce unwanted or non-uniform tension. No problem is presented if feeds are used in which the insert yarns are cut to length and fed in by carrying chains with pins which release the yarn as soon as it has been inserted. The Carman Pat. No. 3,364,701, Jan. 23, 1968, describes such a machine. These machines have been extremely successful and can be operated at very high speeds. However, they do require additional elements and increase the complication at the feed.
Many years ago, for example in Pat. No. 2,743,596, May 1, 1956, it was proposed to feed a single uncut insert yarn. One early proposal utilized hooks alternately bent in and out, around which a single end of yarn was laid. These hooks were moved and resulted, of course, in a zigzag of the insert yarn until it reached the knitting line, at which point it jumped off the hooks. Friction and tension rendered this simple mechanism useful only if a knitting machine was run at much lower speeds than the knitting machine is capable of. The zig-zag from a single feed point, of course, became longer and longer, with increasing tension, and it Was thought necessary to then slant them in slightly so that the zig-zag was not quite so long when it reached the knitting line. This helped somewhat, but still the tension caused by the friction over the bent 3,606,769 Patented Sept. 21, 1971 books forced the machines to operate at very greatly reduced speeds. The problem, therefore, was not satisfactorily solved.
In general, probably the most successful high speed machine used cut insert yarns which can be fed from a relatively large number of packages moving around a chain This form of mechanism, shown in the Carman patent, permitted use of different colored yarns in successive courses, high speed, and in general is one of the most successful modern machines. There is some additional complexity and a problem is sometimes presented because if packages moved rapidly, when a package becomes exhausted transfer to a fresh package is not readily effected with conventional transfer mechanisms. Nevertheless, since a large number of packages can be used, for example twelve or more, the machine could be run for quite considerable times without stoppage.
There remained still a need for reliable and uniform feed of a continuous end of insert yarn from a stationary package which can be transferred to a fresh package in the conventional manner when the yarn has been used up. This possibility of rapid transfer without stopping the machine is of real importance because an extremely high speed, very wide warp knitting machine can use up yarn at the rate of a good many miles a hour.
SUMMARY OF THE INVENTION The present invention is a feed which lays a continuous end of insert yarn at high speed. It is also attachable to standard Warp knitting machines or other machines having similar requirements, such as machines for yarn reinforced paper. It is an advantage of the invention that it can be used with standard warp knitting machines without any significant change in the mechanism. One may consider that once the insert yarn has been applied to the knitting line, the present invention ceases and the rest of the knitting operation proceeds in normal, conventional manner. However, as will be pointed out below, a variant of the present invention permits inserting yarn only every other course or every three or more courses where this type of fabric is desired.
An important feature of the present invention is that the pulleys around which the single end is fed to form a zig-zag are on the outside of each chain as it moves toward the knitting line and not on the inside, as Was formerly thought necessary. The pulleys on any one chain are spaced at uniform intervals. The intervals, however, need not necessarily be identical on both chains, and where the chains have different lengths and/or diiferent speeds, the intervals on the two chains will not be the same although uniform on each chain. Also, a particular form of top or hat on the pulleys is provided with a projection and lifting tab which when it turns around the bottom sprockets of the feed chains points at the knitting line and permits the insert yarn to slip oif without any change in tension.
Another important feature of the present invention is a brake which may be applied to the pulleys near the bottom sprockets. These pulleys are rotating at tremendous speed in a high speed machine and, although they are light, have sufficient inertia so they will continue to spin when a machine is shut down. This can cause snarling of insert yarn and other problems. Accordingly, in the present invention a brake, such as a bar with a soft rubber braking surface, is applied to the peripheries of the pulleys for a reasonable distance before they reach the bottom drive sprocket of the chains carrying them. The drag of the brake is not very great, but it is sufiicient to slow down and stop rotation of the pulleys almost instantly when the machine is shut down. With reasonably strong insert yarn the brakes may remain continuously in operating position, and their gentle braking action, that is to say gentle in terms of the tension put on the insert yarn, also assures a uniformity of tension as the insert yarn is released.
With very fragile insert yarns and/ or highly stretchable insert yarns, such as, for example certain core spun yarns, the continuous braking may be undesirable, and in such a case simple means, such as solenoids, may be provided which interlock with the machine starting mechanisms so that the brakes are only applied as the machine stops and there is no braking when it is operating at full speed. Such interlocking brake-applying means are conventional in a very wide variety of different machines for a number of different purposes and, therefore, they are not specifically illustrated in the present application as their exact design forms no part of the invention even in the more specific modification where a releasable brake is present. In some machines the preferred brakes may be dispensed with, for example on some smaller or slower machines.
The above generally described operation of the insert yarn feed of the present invention is useful where an insert yarn is laid in every course. However, it is a further advantage of the present invention that it is possible to have an insert yarn only every other course or every third course, etc. In this modification of the present invention holding or delay pins or hooks catch the insert yarn as it comes down to the bottom sprockets of the two chains carrying the pulleys. This delay hook or pin is rocked into and out of holding position in synchronism with the knitting machine drive, the operating ratio being determined by whether an insert yarn is to be laid in every other course or less often. Various means for lifting such delay hooks out of contact with the yarn can be used, and in broader aspects of this variant of the present invention it is not limited to any particular synchronous actuation. However, in a still more specific aspect, a very simple, rugged and efficient drive is a rocking delay hook or pin which is rocked in and out by lobes of a cam on each of the lower sprockets. This requires no additional elements; its synchronism is rigidly maintained; its actuation is positive, and so it constitutes the preferred actuation.
When an insert yarn is to be laid in every course, of course the delay hooks do not come into play and they can be permanently kept out of operative position when the machine is operating in this mode. This can also be effected by a circular cam, i.e., a disc which has a circular periphery, attached to the lower sprockets. Since it is very simple to change cams and they mount on the sprockets in a definite predetermined position with respect to the pulleys, this form of operation has a number of advantages, but the invention, of course, is not limited thereto. It is also possible to have a plurality of cams on the bottom sprockets, for example one which is a circular disc which holds the delay pin out of action or cam which brings the delay pin into action every other course and another one every third course combined with a cam follower which can be slid up vertically to contact one or other of the cams. It is usually preferable to provide the two chains each with upper and lower sprockets, and in such a construction cams turning with the sprocket shaft are preferable. However, the bottom of the chains may pass around idler devices and other means may be provided for raising the delay pins into contact with the yarn.
BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a plan view of the yarn feed;
FIG. 2 is a side elevation looking from the left of FIG. 1;
FIG. 3 is an enlarged detail of a piece of the drive chain, a pulley and its top or hat, as shown in FIG. 1;
FIG. 4 is an elevation of FIG. 3 looking from the left or outside of the chain;
FIG. 5 is a diagrammatic showing of the lower sprockets and portion of the chain with pulleys in different positions as a pulley is moving around the lower sprocket, nine positions on the left hand sprocket and a smaller number on the right;
FIG. 6 is an elevation of a knitting line showing nine positions corresponding to the nine positions of the left hand lower sprocket of FIG. 5;
FIG. 7 is a detail of the drive of the chains, and
FIG. 8 is a detail of the cam and linkage for moving delay pins.
DESCRIPTION OF THE PREFERRED EMBODIMENTS FIGS. 1 and 2 show in plan view and side elevations, respectively, the feed of a single end of insert yarn to the knitting line. Only so much of the conventional warp knitting machine is shown as illustrates where the mechanism of the present invention fastens in. In general, the rest of the warp knitting machine is not affected at all.
A three-package transfer arrangement 1 is shown in FIG. 1 from which an insert yarn is coming. The mportant advantage of transfer can be enjoyed. With a high speed machine, for example one knitting 1200 or more courses a minute, normal sized packages last for only five minutes or less with a large machine.
The yarn from the supply cones or packages 1 is led through the eye 4 in an oscillating arm 3 which threads the insert yarn in a zig-zag direction down to the knitting line 11. The construction of the arm is best shown in FIG. 2, but FIG. 1 shows the actual movement of the arm in the form of a curved double arrow. Oscillation of the arm, which is in synchronism with the knitting machine, is effected from the knitting machine cam shaft 21 through chains 22, 23 to a shaft 24 which drives a reciprocating mechanism 25. As this is of standard design, it is shown diagrammatically and not in structural detall. The yarn threading mechanism is shown mounted on the top of a support 20. Portions of the main supports for the knitting machine are shown at 32 in FIG. 1. It will be seen that the oscillation of the arm 3 threads the insert yarn around pulleys 8L and SR for left hand and right hand chains, the chains themselves being numbered 5L and SR. The chains are driven by upper sprockets 6L and GR and supported by lower sprockets 7L and 7R. In general, with a number of elements which are repeated on the two chains the same letter designation will be used.
FIG. 7 illustrates a typical drive for the chains 5L and SR in synchronism with the main machine drive. This main drive, which is connected to shaft 24, as has been described above, causes this shaft to turn a bevel gear 35'. In order to be able to see the gears, the top of the housing 25 has been removed, and in order not to confuse this detailed drawing the arm 3 is also not shown, but it is, of course, present, as appears from FIG. 1. Each of the gears 36L and 36R drive sprockets, which in turn, through chains 37L and 37R, turn sprockets 38L and 38R on the shafts of the sprockets 6L and 6R, which turn the chains 5L and SR, only portions of these chains being shown in FIG. 7; and in order not to complicate the drawings the pulleys on the chains, which are referred to below, are omitted. The purpose of FIG. 7 is merely to show in generally diagrammatic form one typical drive of the chains 5L and SR. These chains are driven in synchronism with the main drive of the machine. The relative sizes of the sprockets are not significant as they will depend on the synchronism of the operations of a particular knitting machine. The drive illustrated is simple but is only one typical drive as carrier chains such as 5L and SR have been used in other machines. It will be noted that the two chains 5L and SR are moving in a plane which is parallel to the knitting line 11, which will be described in more detail below.
Turning now to FIGS. 3 and 4, which show two different views of the pulleys, it will be seen that they are attached to the chains and comprise a pulley proper 9 and a top or hat 10 which comes to a point in a definite direction at a small angle to the chain. A slanted tab 33 lifts the thread out of the groove in a pulley as its chain goes around the lower sprocket. It will be noted that the cap 10 with its tab 33 are fastened to the chain by the threaded bolt 39 and do not turn. The pulleys 9, however, rotate about this bolt as an axle.
The two chains are turned by their sprockets at quite high speed in synchronism with the knitting machine drive as shown; and as a result, as the pulleys 8 approach the lower sprocket 7 they'are turning at a high rate of speed and, light though they are, buildup a considerable momentum. When a machine is stopped, this can cause them to keep spinning and to pull out insert yarn, which can then snarl. It is therefore desirable to slow them down at stop and start of the machine, and this is effected by the brakes 12L and 12R, which are bars with a soft rubber under surface contacting the pulley portions 9.
Where fairly strong insert yarn is used, the brakes can be continuously in braking position as the additional amount of friction, while very large in comparison to the momentum of a light spinning pulley when the machine is being stopped, is negligible as far as the tension of the insert yarn is concerned. However, in addition to the braking when starting and stopping the machine, the continuous gentle braking has a beneficial effect in as suring an even more perfect uniformity of tension in the insert yarn, and so where the strength of the yarn permits, it may be desirable to keep the brakes in braking contact even when the machine is operating. With certain insert yarns, for example such as certain core spun yarns which are either fragile or quite stretchable or both, continuous braking is undesirable, and so means can be provided for applying the brakes only at the start and stop of the machine. Such mechanisms are shown as solenoids 34 interlocked with the starting and stopping switches, are of conventional design and are therefore shown diagrammatically.
FIG. 2 also illustrates in purely diagrammatic form warp 26 and beams 27. It will be seen that the chains as they approach the knitting line 11, shown in FIG. 1, are outside of the warps. In the same figure there is shown a guide bar drive 28, guides 29, and knitting needles 18. As these are conventional devices and are not changed by the present invention, they are shown purely diagrammatically both in this figure and FIG. 6.
FIG. illustrates eight positions at the lower sprockets for a pair of pulleys. This constitutes a full fabric pattern. As the same thing is repeated on the right, only four positions are shown. Delay hooks or pins 16L and 16R are shown diagrammatically in FIG. 5. The cam and cam drive are shown for the lower left hand chain sprocket 7L in FIG. 8. It will be seen that in position 1 of FIG. 5 the insert yarn is lifted by the non-rotating tab 33 onto the hat and grasped by the pin 16L, which causes the yarn in positions 2 to 4 to be held, and as the pulley turns around the lower sprocket, yarn tension is reduced, which is one of the advantages of the invention. In position 4 the pin 16L has been disengaged from the yarn, which is now held on the top of hat 10 but cannot slip oif in this position because of the projection on the hat. At position 5 the yarn has slipped off the hat 10 of the pulley and is inserted across the knitting line, the knitting elements and diversion plate being represented at the left diagrammatically as a rectangle. It will be seen that on the right side when the yarn has been inserted at position 5, the delay pin 16R has engaged the next yarn zig-zag and is holding it through the next four positions. In other words, on the right hand side positions 5 to 8 correspond to the positions 1 to 4 on the left hand side. In position 4 the delay pin 16L has been retracted, which of course permits the yarn in position 5 to slide off the hat 101.. In effect, the staggered operation of the pins 16L and 16R results in there being only a single inserted yarn for each two courses. If fabric is desired with an inserted yarn every course, the delay pins 16L and 16R would be absent or would be permanently retracted. It can be seen from 'FIG. 1 that the actuation of the delay pins 16L and 16R is through cam followers 15L and 15R. These followers ride on cams 14L and 14R, of which only cam 14L is shown in FIG. 2.
FIG. 6 shows the knitting elements at the same positions corresponding to the left hand side of FIG. 5. Only the first warp thread guide and knitting needle is shown, the needle being in purely diagrammatic form. In an actual machine, of course, the needle is latched or, if the machine is of this type, a bearded needle is used. The needle 18 moves in its holder with a diversion plate 19 adjacent a stationary trick plate 31. The thickness of the inserted yarn 2 is enormously exaggerated for clarity. At position 9 another inserted yarn is shown coming into contact with a warp thread, as in position 1. This represents one full pattern of the fabric which is produced with four complete knitting machine cycles. Each cycle is represented in positions 1-2, 3-4, etc. The fabric is moved between courses by the conventional take-up roll 13, which appears diagrammatically in FIG. 1.
The knitting is effected in conventional manner, the sinkers 17L being moved in and out in the normal manner. This portion of the machine is not changed at all by the present invention, which is directed only to a feed mechanism for the insert yarn.
There has been illustrated chains in the form of a symmetrical V with chains of the same length. The chains move at the same speed. In this case pulley spacings are the same on each chain. If the chains are not symmetrically arranged, speed and pulley spacings are not identical but must still be uniform on any one chain.
In the drawings the machine is illustrated as extending up vertically and in this case the chains are also inclined with respect to the vertical and horizontal. This is not the only position in which the machine may be placed and, in general, it is required only that the inclination of the plane of the chains be such that they avoid any knitting machine elements and deposit the inserted yarn on the knitting line.
In the illustrated warp knitting machine an insert yarn is fed. Other machines, such as those for producing reinforced papers or laminates, may feed a filamentary element which is not always technically a yarn. Therefore, the more general term filamentary element will sometimes be used and includes yarn proper and also other similarly shaped elements, such as strings, threads, and
other fibrous material. Even where a filamentary element could properly be called a yarn is fed, the nature of the yarn may vary. It may be spun or continuous filament, multiple or single filament, and the like.
1. A device for inserting a filamentary element onto a predetermined line, which comprises in combination,
(a) a source of the filamentary element,
(b) endless chains extending from adjacent the filamentary element source to the ends of the predetermined line, the chains moving in a plane parallel to the predetermined line,
(c) pulleys attached to the top of each endless chain and extending outwardly therefrom, the pulleys being spaced at intervals which are uniform on any one chain,
(d) means for moving the chains in synchronism and in a direction so that the outer portions of each chain move from adjacent the source of filamentary element to the predetermined line,
(e) non-rotating means for lifting the filamentary element from the pulleys as they approach the predetermined line, said means attached to each chain for movement therewith and positioned above each pulley,
(f) means driven in synchronism with movement of the chains to thread the filamentary element around pulleys on the outer loops of the endless chains, whereby the filamentary element forms a zig-zag series from adjacent its source to the predetermined line.
2. A device according to claim 1 in which the means for lifting the filamentary element from the pulleys comprises non-rotating inclined lifting tabs on the pulley attachments to the chains.
3. A device according to claim 2 in which each inclined lifting taib includes a non-rotating cap immediately above each pulley and the lifting tab lifts the filamentary ele ments onto the pulley cap.
4. In a warp knitting machine which comprises means for inserting weft yarn along a knitting line, the improvement in a yarn inserting device comprising in combination,
(a) a source of insert yarn,
(b) two endless chains extending from adjacent the insert yarn source to the ends of the knitting line and slanting sufficiently to avoid knitting machine elements, the chains moving in a plane parallel to the knitting line,
(c) pulleys mounted on the tops of each endless chain and extending outwardly therefrom, said pulleys being mounted on the chains at intervals which are uniform on any one chain,
((1) non-rotating means for lifting the yarn from the pulleys as they approach the knitting line, said means attached to each chain for movement therewith and positioned above each pulley,
(e) means for driving the two chains in synchronism with the knitting machine in a direction so that the outer portions of each chain move from adjacent the source of insert yarn to the knitting line, the chain speed and pulley intervals being adjusted so that weft yarn inserted at the knitting line is substantially parallel thereto, and
(f) means driven in synchronism with the knitting machine to thread the insert yarn around the pulleys on the outer loops of the two chains, whereby the yarn forms a zig-zag series from adjacent the insert yarn source to the knitting line.
5. An improved warp knitting machine according to claim 4 in which the means for lifting the insert yarn from the pulleys comprise tabs on the non-rotating means.
6. An improved knitting machine according to claim'5 in which the non-rotating means comprises caps immediately above the pulleys, the caps being in a plane par allel to but slightly above the plane of the chains and the yarn lifting tabs being positioned to lift the insert yarn onto the caps as the pulleys approach the knitting line.
7. An improved yarp knitting machine according to claim 6 in which movable delay hooks, one associated with each chain, are provided adjacent the ends of the knitting line and means are provided for moving the hooks to grasp the insert yarn as a pulley approaches an end of the knitting line.
8. An improved warp knitting machine according to claim 4 in which movable delay hooks, one associated with each chain, are provided adjacent the ends of the knitting line and means are provided for moving the hooks to grasp the insert yarn as a pulley approaches an end of the knitting line.
9. An improved warp knitting machine according to claim 8 in which the chains are provided with upper driving sprockets and lower sprockets adjacent the ends of the knitting line and the means for causing the delay hooks to grasp the yarn comprise cam members on each lower sprocket and cam follower means connecting the cam profile to the delay hooks to cause them to be moved up by a rocking motion.
10. An improved warp knitting machine according to claim 9 in which bottom sprocket rotation and cam contour are synchronized to cause the delay hooks to hold yarn during at least one knitting course, whereby the knitting machine knits in a pattern with at least one course knit without an insert yarn.
11. An improved warp knitting machine according to claim 4 in which the means for threading the insert yarn around the pulleys comprise an oscillating arm driven in synchronism with the knitting machine and having an insert yarn guide at its end.
12. An improved warp knitting machine according to claim 11 in which braking means are provided contacting the peripheries of the pulleys on the outer loop of each chain as they approach the knitting line and means for causing said braking means to engage the pulleys with gentle braking force at least during periods of stopping the knitting machine.
13. An improved warp knitting machine according to claim 4 in which braking means are provided contacting the peripheries of the pulleys on the outer loop of each chain as they approach the knitting line and means for causing said braking means to engage the pulleys with gentle braking force at least during periods of stopping the knitting machine.
14. A warp knitting machine according to claim 13 in which the braking means are movable bars provided with resilient braking surfaces Where they contact pulley peripheries.
References Cited UNITED STATES PATENTS 2,000,643 5/1935 Morton 66-85 2,962,080 11/1960 Hirsch 281 (CL) (UX) 3,364,701 1/1968 Carman 66-84 ROBERT R. MACKEY, Primary Examiner US. Cl. X.R.