US3599446A - Terry knit fabric, machine and method of producing same - Google Patents

Abstract

The present invention is directed to a terry knit fabric having a plain jersey base with long warp yarns interknit in selected rows of needle loops running from course to course, a method and machine for knitting same wherein long lengths of warp yarns after being engaged with hooks in the needle bed are drawn to their desired long length, clamped and either cut or left in loop condition.

Description

United States Patent John B. Lawson Central Falls, R.I.;

Daniel Frishman, Andover, Mass. 809,078

Mar. 21, 1969 Aug. 17, 1971 Reid-Meredith, Inc.

Lawrence, Mass.

Inventors Appl. No. Filed Patented Assignee TERRY KNIT FABRIC, MACHINE AND METHOD OF PRODUCING SAME 11 Claims, 16 Drawing Figs.

US. Cl 66/61,

66/190, 66/191 Int. Cl D04b 7/ 12 Field of Search 66/61, 62,

[56] References Cited UNITED STATES PATENTS 1,978,412 10/1934 Carlson 66/135 2,034,869 3/1936 Holmes et al. 66/135 2,244,153 5/1941 l-lanisch 66/194 X 3,142,164 7/1964 Merritt 66/172 X Primary Examiner-Ronald Feldbaum Attorney-Wilkson, Mawhinney & Theibault PATENTEIJ met 7 I97! SHEEI 1 UF 8 INVENTOR JOHN B. LAWSON DANIEL FRISHMAN ATTORNEYS PATENTEI] mm 1 I9?! 3599, 146

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INVNKI JOHN B. LAWSO DANIEL FRISHMAN ATTORNEY TERRY KNIT FABRIC, MACHINE AND METHOD F PRODUCING SAME I sinkers, over bits, by a second set of needles or hooks, or with the aid of specially designed wheels. With these current techniques the maximum height of loop is highly restricted. With the progressive draw cam which is characteristic of all weft knitting the depth to which a yarn may be drawn (or measured out) is limited by the maximum cam angle, by the gauge of the machine, and by the coefficient of friction of the yarn. Since the stresses on the materials being measured increases rapidly with the depth of draw, an excessive draw will result in yarn fracture. Thus, the terry loop height is currently limited to from approximately 2 to times the needle spacing depending upon the limitations characterized above. For example, on a 10 gauge machine with the needles approximately one-tenth inch apart it is quite impractical to expect to draw a terry loop in excess of 1 inch even under the most favorable conditions.

An object of this invention is to both disclose a fabric of a terry type which has loops of unlimited length and a practical method for producing such a fabric. Further this invention describes a method of introducing warp threads into a basic weft knit structure where the warp threads comprise the terry loops in the fabric structure. Another object is to disclose a method for cutting the long terry loops produced by the methods of this invention.

These and other objects will be apparent from the following description:

FIGS. 1 through 10 are schematic perspective views of the elements of this invention througha sequence of moves.

FlG. II is a plan view of the knitting cams of this invention.

FIG. 12 is a partial perspective of the draw bar guide and drive.

FIG. 13 is a side section view of the machine of this invention.

FlG..14 is a fragmentary view of a draw bar and transfer hook assembly used when the terry loops are not to be cut.

FIG. 15 is a sectional taken through lines 15l5 of FIG. 14.

FIG. 16 is a magnified view of the fabric of this invention.

FIG. 17 is a vertical section taken on the lines 17ll7 in FIG. 16.

FABRIC and courses (weft threads) 100, 101, 102 and 103. lnterknit in each row of needle loops or in selected rows of needle loops as shown in loops 201 is a warp thread 300. This warp thread 300 produces a terry pile and differs from the normal terry pile in that it runs from course to course instead of from loop to loop within a course. It should be noted whether these terry loops 300 are cut ,or not the fabric of this invention may have the identical mechanical properties of a conventional short looped terry fabric. The fabric of this invention differs from short looped terry fabric in that the terry loops 300 are interconnected in a whale or warp series instead of in a course or weft series as is common practice in current weft knit terry fabrics, and may be many times longer than have hitherto been produced by existing methods, and the fabric of this invention may be characterized by the fact that its extended loops are not limited by the gauge length or needle spacing of the producing equipment.

MACHINE AND METHOD The illustrations of FIGS. 1 through 10 show in sequence the moves required to produce the fabric of this invention. Before reviewing these illustrations we will first identify some of the elements employed. Referring to FIGS. 3 and 4!, a needle bed ll has slots 2 to receive slidable latch needles 3 with conventional butts 4 which are acted upon by cams which slide the needles in and out to produce a knit stitch in a conventional manner. The cams which move the needles 3 are fastened to the underside of a carriage 5 which reciprocates across the needle bed l in a conventional manner for a flat bed weft knitting machine. The cam path of this invention shown in FIG. 11 is slightly altered from the norm in that the needles 3 are cammed to a full clear position after the carriage 5 passes them by. Carriage 5 carries on its underside guard cams 6 and 6a, a double sided clearing cam 7 with an adjustable draw cam 8 nestled within the lobes of the clearing cam 7. The knitting cycle is activated by the carriage 5 moving across the needle bed l. The needle butts 4 are collected between a guard cam 6 or 6a, depending on the instant direction of carriage movement, and one lobe of clearing cam 7. Thence the needles 3 are drawn in to form a new stitch by the draw cam (stitch cam) 8. As the needles 3 are drawn in a yarn guide (carrier) 9 of a conventional design, traveling with the carrier guides a weft yarn 10 into the hooks of needles 3 so that new knitted loops may be found in the weft yarn 10 in the conven tional manner of weft knitting technology. Note: the yarn guide 9 will be shifted from its position 9 in FIG. 111 to a position 9a for the return stroke of carriage 5 by means well known in flat bed knitting. As the carriage 5 continues its traverse, the needles 3 are pushed out again to a full clear position by the opposite lobe of clearing cam 7. The needles may be of the well-known friction type so they will stay put following the cam engagement, and it should be noted the carriage should be equipped with suitable latch guard systems to prevent latch closing during the needle-clearing moves.

This conventional knitting frame just described is further equipped with a warp yarn system comprising a guide bar 11 which is mounted in an appropriate form so it may be moved in and away from the needles 3 in a parallel plane to the needle bed I and so it can also be moved (shogged) short distances sidewise with respect to the needle bed 1. Protruding from the guide bar 11 are short yarn fingers 12 which have thread holes 13 at their ends. These yarn fingers 12 are spaced along the guide bar 11 to match or to match multiples of the needle spacings in needle bed 1. Above the guide bar ll is a warp yarn clamp bar 14 which is mounted on appropriate slides on top of the guide bar 11 in such a manner as to allow it to be moved down on top of the guide bar 111 so as to clamp all yarns running under it. Warp yarns 15 are threaded from a suitable creel or beam through guides on the ends of a series of independent takeup arms 18 which arms may have electrical contracts suitable for connection to a stop motion system to arrest the machine operation if any of the warp yarns should break or become too slack. These takeup arms 18 are urged in a counterclockwise direction as shown by arrow Z in FIG. 3 by suitable springs to maintain a tension on all the warp yarns 15. From the takeup arms 18 the warp yarns l5 travel under the clamp 14 and through the hole 13 in yarn fingers 112 then down to the lower loop clamps l6 and I7 which will be described later, as shown in FlG. 1.

With the warp yarns l5 threaded as just described from a creel or beam to the loop clamps l6 and 117, with a weft yarn l0 in its yarn guide 9 FlG. 4, with fabric on the needles 3 as is standard practice in starting (picking up) a weft knitting machine, and with the fabric tensioned as will be subsequently described we can proceed to follow the moves of this invention through a complete cycle. First in FIG. 2 the guide bar ll is moved in towards the needle bed I (arrow A) to position the yarn guide fingers 12 over the needles 3 so as to move any ac tive warp yarns between a pair of needles 3. Thence the guide bar Ill is shifted sidewise (arrow B) to partially warp active warp yarns I5 around an adjacent needle.

In FIG. 3 the guide bar 11 has been moved back .from the needles (arrow C) drawing each warp yarn 15 into the hook of its adjacent needle. As the guide bar 11 withdraws it may shift back (arrow D) to its original starting position as in FIG. 1.

Above the web of threads running from the thread fingers 12 to the needles 3 just formed is a drawbar 20. This drawbar 20 is mounted between a pair of endless chains 23 with suitable guide rails as shown in FIG. 12 so the drawbar 20 can be driven up and down as will be described subsequently. The drive chains 23 are wrapped around fixed pulleys 24 on top and movable pulleys 25 at the lower ends. By moving the lower pulleys 25in an arc whose radius reaches back to the center of pulleys 24 the whole chain drive and therefore the draw bar 20 could be shifted to a position 26 when needed as will be described later. The draw bar 20 is constructed of a pair of side plates 19 with smooth rounded edges 27 between which are a pair of narrow spacers 21 and a toothed divider In FIG. 4 the drawbar 20 has come down to the web of warp yarns 15, engaged same, and continued down (arrow E) to start drawing the warp threads 15 into lengthening loops. Once the drawbar 20 has started drawing the warp yarns 15 thecarriage starts across the needle bed 1 (arrow F) carrying the weft yarn into the hooks of the needles 3, activating said needles as previously described to create a new row of knitted loops (stitches) 28 which include the warp yarns 15. Also during the movement of drawbar 20 a knife 29 is pulled between the transfer hooks 31 and 32 of hook bar 30 (arrow G) to cut the warp yarns which had been drawn in the previous cycle and had been hooked in transfer hooks 31 and 32 and clamped by clamps 16 and 17 as will be subsequently described. 7

When the drawbar completes its draw, the clamp 14 on guide bar 11 is closed (arrow H) to lock the warp yarns 15 against further advancement or pull back as in FIG. 5.

With the warp yarns 15 held by clamp 14 at one end and with the other end knitted (looped) into the fabric the lower clamps 17 and 16 open (arrows .I K) FIG. 6 and the previously drawn and cut yarns are blown clear of the clamps 16 and 17'and the transfer hooks 31 and 32 towards the fabric by a suitable series of air jets symbolized by 33 in'fIG. 6.

The drawbar drive system as shown in FIG. 12 is then swung over (arrow M) to position the drawbar 20 over the transfer hook assembly 30 as in FIG. 7. v

' Thetransfer hook assembly 30 is mounted in a suitabl frame which allows for movements to, and away from, the drawbar 20 and sideways for reasons to follow. This transfer hook assembly 30, best seen in FIG. 7, is constructed of two angle plates 34 in which a series of hooked transfer bits 31 and 32 are mounted opposite one another and spaced lengthwise to match the tooth pattern in divider 22 so there is one pair of transfer bits 31 and 32 for each tooth in divider 22. Angle plates 34 are fastened to slide rails 35 which provide guides for the knife block 36 in FIGS. 3 and 4 to travel on.

With the drawbar 20 positioned over the transfer hook assembly 30, the transfer hook assembly moves up (arrow 0) in FIG. 8 so the transfer bits 31 and 32, FIG. 7, pass on either side of the divider bar 22 and up between the warp yarns 15 which cross sideplates 19 of drawbar 20 and which are grouped by the teeth of divider 22. When the hook portions of the transfer bits 31 and 32 are fully through the warp yarns then the whole transfer bar assembly 30 is shogged sidewise (arrow P) to gather the warp yarns 15 within the envelope of the hooks of said transfer bits 31 and 32.

Once the warp yarns 15 are engaged in the hooks of bits 31 and 32 the transfer bar assembly 30 is lowered slightly (arrow R) as in FIG. 9 to tension and secure a hold on all the warp yarns 15. Then the drawbar 20 will start its ascent (arrow S) to its upper stop.

When the drawbar 20 has moved up (arrow V) in FIG. 10 above the plane of the lower clamps 16 and 17, said clamps move back (arrows W and X) to secure the newly formed warp yarn loops. When the new warp loops are secured by clamps 16 and 17, the warp clamp 14 is once again raised as in FIG. 1, and when the drawbar 20 returns to its position above the plane of the guide bar 11, the next cycle may commence as just described.

The above description has concerned itself with cut loops; however, if one should wish to draw warp loops, without cutting them, then the transfer hook system, and drawbar assembly would be altered as shown in FIGS. 14 and 15.

An alternative drawbar 20a would consist of two sideplates 60 with teeth for collecting the warp yarns 15 separated by a spacer 61 all forming a deep channel shape inside which the transfer hook assembly 30a can collect the warp yarns 15 as previously described. The alternative transfer hook assembly 30a consists of a single row of hooked transfer bits 62 spaced to match the teeth of plates 60 set into a bar 65. On either side of each bit 62 is a stripper cam 63 which is mounted in a channel structure 64 inside of which is the hook bar 65. The stripper cams 63 are so shaped as to form an inclined plane 67 which will shed any warp yarn in a hook 62 if the hook were to be raised. The transfer bits (hooks) 62 may be raised by raising bar 64 inside channel structure 64 by means of an air cylinder 66 mounted on channel structure 64 by means 64.

The release of the warp yarns loops as just described would occur in place of the cutting cycle disclosed earlier (see FIG. 4), and all other moves as previously stated for drawbar 20a and transfer bar 30a would follow the earlier descriptions for drawbar 20 and transfer hook bar 30.

Having described the moves of the key elements of our machines we call attention to the arrangement of these elements within a frame as shown in FIG. 13 and in particular we may examine the tensioning (take down) of the fabric which presents a unique problem because long yarns may extend therefrom. In order to avoid the long hair entanglement, the mechanism for transporting and tensioning the fabric comprises a pair of driven conveyor belts between which the fabric is gripped.

This take down system is constructed and driven as follows. The top belt 40 is stretched between an idler roll 41 and a drive roll 42. Roll 42 has a rack wheel 52 fastened to one end which rack wheel 52 is acted upon by a spring loaded pawl 53 which locks the rack wheel 52 from clockwise rotation. Said rack wheel 52 is driven in a counterclockwise rotation by a spring loaded system comprising a pawl 43 hooked to a crank 44 which crank 44 may be rotated in a counterclockwise rotation through the action of the push' rod 45 working off an eccentric cam 46 on the main drive shift 55 of the machine. The action of cam 46, and rod 45 cocks the crank 44 against an adjustable spring 47 and it is the action of this spring 47 which rotates crank 44 clockwise to pull the rack wheel 52 in a counterclockwise rotation through the interaction of pawl 43. By adjusting spring 47 a selected degree of torque may be applied to the belt 40 to advance the fabric under a desired tension, since the reaction of spring 47 will only function as fabric is knit and will not cycle if there is a balance between the fabric tension and spring 47. When there is a fabric to take up, spring 47 via crank 44 and pawl 43 will turn rack wheel 52 to the next tooth on pawl 53 thence cam 46 will react to recock crank 44 to repeat a cycle. Such fabric-tensioning drive systems are quite common on weft knitting frames. Below the top belt 40 is the second belt 49 which is stretched between a fixed roll 50, and a spring-loaded roll 51. Spring loaded roll 51 provides the grip on the fabric required to assure transportation by clamping said fabric between itself and roll 42 of the top belt 40. From the belts 40 and 49 the fabric falls away to a suitable receptacle underneath.

The system for producing the fabric of this invention as described makes a plain jersey fabric with interknit loops or ends of controlled length. It should be understood from this description that manyvariations on the stitching and construction just described could be employed. For example, the camming could be arranged so that after the carriage has passed, the extended needles could be at a tuck position instead of a clear position. Then after hooking the warp threads on the needles and starting the draw, selected needles might be cleared for knitting, leaving the unselected needles to produce tuck stitches in the particular course. Such a setup would produce a fancy fabric with the hairs interknit. 7

In another variation the warp thread mechanisms could be made selectively inactive producing bands of plain or fancy fabric without hairs and bands of fabric with hairs interknit. Another alternative would be to introduce the warp threads across two or more needles instead of one to produce a stronger locking of the warp threads in the fabric. Further, one could shog the warp threads from one set of needles to another on a programmed basis to produce patterns with respect to the introduction of different colored or different textured warp yarns. Multiple warp guide bars could be employed or multiple ends could be introduced to the needles at either the warp or weft feeds. The machine could be constructed with transfer hooks which were designed to shed their warp ends when the cycle called for the release so a fabric could be produced with long loops instead of cut ends. The machine is constructed so the transfer hook bar and lower clamps may be moved up or down to facilitate a range of warp length selections. It is even possible to contemplate a programming of the draw to produce varied hair lengths within a continuous fabric. In short this concept is acceptable to most of the flexibilities of weft knitting such as needle selection, yarn changing, and so on.

What we claim is:

l. The method of knitting a fabric having a plain jersey base and a loop terry pile comprising a. presenting a plurality of warp yarns between spaced-apart adjacent needles of a series of raised needles,

b. shogging the warp yarns to partially wrap the warp yarns around adjacent needles, 4

c. drawing each warp yarn into the book of its adjacent needle,

d. drawing the thus hooked warp yarns into lengthening loops e. knitting a weft yarn into the hooks of the needles containing the warp yarns to create a new row of knitted loops which include the warp yarns,

. engaging the loops of the thus drawn warp yarns in transfer hooks spaced from the needle bed the distance of the desired length of the warp yarn loops,

g. clamping the thus engaged loops and repeating the cycle ofsteps (a) through (f).

2. The method of knitting of claim 1 further comprising the step of cutting the drawn loops of the clamped warp yarns to produce a knitjersey base fabric having a long hairylike face.

3. The method of knitting of claim 1 wherein the warp yarns are drawn different lengths for each course to produce varied hair lengths within a continuous fabric.

4. The method of knitting of claim 1 wherein the drawn warp yarns are cut at their looped ends in some courses and not cut in other courses.

5. The method of knitting of claim 1 wherein after hooking the warp yarns on the needles and starting the draw selected needles are cleared for knitting leaving the unselected needles to produce tuck stitches in the particular course to produce a fabric with the hairs interknit.

6. A flat-bed-type knitting machine comprising a. a bed of adjacently spaced knitting needles mounted to be moved toward and from a knit point,

b. means for feeding a plurality of warp yarns to the needles of said bed,

c. means associated with said feed means and knitting needles causing hooked engagement of said warp yarns with said knitting needles,

d. drawing means positioned to engage the hooked warp yarns and to draw same into long loops,

e. means positioned to engage the knitting needles on said bed and carrying a weft yarn into the hooks of the needles having the warp yarns engaged in their hooks to create a new row of knitted loops which include the warp yarns, f. engaging means carried by said machine and being positioned to be engaged by the loops of said warp yarns drawn in step (d).

g. and means associated with said drawing means to withdraw said means and recycle means (a) through 0) to knit another course of fabric having looped warp yarns.

7. The machine of claim 6 further comprising clamping means and loop incising means operatively associated with said engaging means to cut the loops of warp yarns engaged by said loop-engaging means and being clamped above same to produce courses of a long hairylike faced fabric.

8. The machine of claim 6 further comprising clamp means positioned between said engaging means and said bed of knitting needles to retain the drawn warp yarns taut while recycling the machine to knit another course of drawn warp yarns,

9. The machine of claim 6 wherein said drawing means is a bar extending over the width of the warp yarns and positioned to engage the yarns between the yarn feed means and the bed of knitting needles to draw elongated loops of the warp yarns between the needle bed and the engaging means.

10. The machine of claim 9 wherein the bar is mounted on an endless chain the axis of opposed runs of the chains of which may be shifted to cause engagement of the loop of warp yarns with the engaging means and then removed from the engaging means,

11. The machine of claim 6 further comprising knit fabric take up means for maintaining an even tension on the fabric issuing from the knitting bed.

Claims (11)

1. The method of knitting a fabric having a plain jersey base and a loop terry pile comprising a. presenting a plurality of warp yarns between spaced-apart adjacent needles of a series of raised needles, b. shogging the warp yarns to partially wrap the warp yarns around adjacent needles, c. drawing each warp yarn into the hook of its adjacent needle, d. drawing the thus hooked warp yarns into lengthening loops e. knitting a weft yarn into the hooks of the needles containing the warp yarns to create a new row of knitted loops which include the warp yarns, f. engaging the loops of the thus drawn warp yarns in transfer hooks spaced from the needle bed the distance of the desired length of the warp yarn loops, g. clamping the thus engaged loops and repeating the cycle of steps (a) through (f).

2. The method of knitting of claim 1 further comprising the step of cutting the drawn loops of the clamped warp yarns to produce a knit jersey base fabric having a long hairylike face.

3. The method of knitting of claim 1 wherein the warp yarns are drawn different lengths for each course to produce varied hair lengths within a continuous fabric.

4. The method of knitting of claim 1 wherein the drawn warp yarns are cut at their looped ends in some courses and not cut in other courses.

5. The method of knitting of claim 1 wherein after hooking the warp yarns on the needles and starting the draw selected needles are cleared for knitting leaving the unselected needles to produce tuck stitches in the particular course to produce a fabric with the hairs interknit.

6. A flat-bed-type knitting machine comprising a. a bed of adjacently spaced knitting needles mounted to be moved toward and from a knit point, b. means for feeding a plurality of warp yarns to the needles of said bed, c. means associated with said feed means and knitting needles causing hooked engagement of said warp yarns with said knitting needles, d. drawing means positioned to engage the hooked warp yarns and to draw same into long loops, e. means positioned to engage the knitting needles on said bed and carrying a weft yarn into the hooks of the needles having the warp yarns engaged in their hooks to create a new row of knitted loops which include the warp yarns, f. engaging means carried by said machine and being positioned to be engaged by the loops of said warp yarns drawn in step (d), g. and means associated with said drawing means to withdraw said means and recycle means (a) through (f) to knit another course of fabric having looped warp yarns.

7. The machine of claim 6 further comprising clamping means and loop incising means operatively associated with said engaging means to cut the loops of warp yarns engaged by said loop-engaging means and being clamped above same to produce courses of a long hairylike faced fabric.

8. The machine of claim 6 further comprising clamp means positioned between said engaging means and said bed of knitting needles to retain the drawn warp yarns taut while recycling the machine to knit another course of drawn warp yarns.

9. The machine of claim 6 wherein said drawing means is a bar extending over the width of the warp yarns and positioned to engage the yarns between the yarn feed means and the bed of knitting needles to draw elongated loops of the warp yarns between the needle bed and the engaging means.

10. The machine of claim 9 wherein the bar is mounted on an endless chain the axis of opposed runs of the chains of which may be shifted to cause engagement of the loop of warp yarns with the engaging means and then removed from the engaging means.

11. The machine of claim 6 further comprising knit fabric take up means for maintaining an even tension on the fabric issuing from the knitting bed.

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