GB1583473A

GB1583473A - Methods and machines for knitting plush fabrics

Info

Publication number: GB1583473A
Application number: GB35197/77A
Authority: GB
Original assignee: Moody & Co Ltd Tom
Current assignee: Moody & Co Ltd Tom
Priority date: 1977-08-23
Filing date: 1977-08-23
Publication date: 1981-01-28

Description

(54) METHODS AND MACHINES FOR KNITTING PLUSH FABRICS (71) We, TOM MOODY AND COMPANY LIMITED, a British company, of Stonebridge Works, Stonebridge, Leicester, do hereby declare the invention for which we pray that a patent may be granted to us and the method by which it is to be performed to be particularly described in and by the following statement : - The invention relates to methods .and machines for knitting plush fabrics.

-The invention generally provides a method for knitting plush fabric on a knitting machine having a' first set of needles in tricks in one cylinder and a second set of needles in tricks in another opposed cylinder, which method includes the step of feeding first, plush yarn at a first knitting station into hooks of both sets of needles to form ground and plush loops respectively, timing the needle movement so that 'the movement for drawing of the plush loops proceeds at least partly in advance of the movement for drawing of the ground loops, and feeding a second, binding yarn at that first knitting station into the hooks of needles about to draw the ground loops from a position where the binding yarn just misses the hooks of the needles for forming the plush loops.

This may be effected by off-setting a stitch cam for drawing ground loops circumferentially from the stitch cam for drawing the plush loops and holding down the needles which carry plush loops whilst the ground loops are being subsequently drawn. Such a cam arrangement may however not be suitable for other forms of knitting without, ,major cam re-arrange ments.

Preferably the movement of the needles for drawing the plush loops is started in advance of starting, of the movement of needles for ,drawing the ground loops and the "drawing' of both sets of loops is continued simultaneously in the same cylinder sector. To complete the knitting of a plush fabric the method may further comprises feeding a locking yarn at a second knitting station'to the' needles car- rying the ground loops whilst holding the needles carrying the 'plush loops at an inactive level; and at some stage thereafter pressing off the plush loops. Such a method may be performed by modifying only a few cams on a knitting machine for knitting non-plush fabric.

The invention also pro.vides a knitting machine for performing the method. The movement of needles for drawing the ground and plush loops is controlled by stitch cams. The number of needles whose movement is controlled by any one stitch cam at any one time varies depending of the gauge of the machine. Advantageously cam faces of the stitch cams forming the ground and plush loops respectively are off-set circumferentially in such a way that the leading part of the inclined cam face of the stitch cam. fo'r forming the ground loops is less than half-way, conveniently less than one quarter, along the inclined face of the stitch cam for forming the plush loops.Thus on a 10 - gauge machine (10 needles per inch) having a normal cam slope, the wave of needles drawing ,the plush loops starts 1.5 to 3 needle tricks in advance of the wave drawing the ground loops, the total number of needles in both waves being from 6 to 8.

,The vital operation' takes place at the first knitting station. By drawing plush and ground loops simultaneously, a low plush yarn tension can be utilized which may result after press-off in plush loops having substantially irregularly varying lengths and a fabric which has.no pronounced stripeeffect.The draw movement of the different sets of needles also enables long plush loops to be produced and the ground loops are not knitted with yarn "robbed" from the plush loops, Preferably the binding yarn is fed from a feed Dosition downstream, of the plush yarn aid'at a greater angle ,than the plush yarn so that the feeding of the plush yarn and binding yarn to the needles drawing the ground.loops is completed at approximately ,the same time and before any snbstantial length of plush loop has been drawn. The feed position can be selected so that the landing of the locking yarn on the latches closes the latches in such a way as to lick in the binding yarn from a position outside the tip of the needle hooks into the needle hooks. Thus a steep feeding angle can be used for the binding yarn.

A reliable licking in operation can be created by placing the binding yarn feed pdsition close to the needles and just behind a plush yarn feed position inside the sector swept by latches of the ground loop drawing needles. Surprisingly no latch damage results and it is possible then to commence closing the latches whilst they are in front of the binding yarn feed position after having emerged from latch guard surfaces of a plush yarn feeder. This arrangement has the advantage that the additional space required for the binding yarn introduction is very small.

The start of the drawing movement for the plush loops in advance of that for the ground loops, combined with the licking in action enables the binding yarn to be fed reliably to the ground loop forming needles only and and without substantially increasing the cylinder sector required for drawing of the ground and plush loops.

As a consequence the second knitting station can be arranged close to the first and need not be displaced downstream so that the usual cam systems can be used for the second knitting station. The cam systems for the second knitting station may be the same and located in the same sector as for normal non-plush forms of knitting on a double cylinder knitting machine.

Advantageously, the cam system area preceding the first knitting station has a press off cam for pressing off needles with plush loops and latches of the empty needles are cammed open by sliders in the opposite cylinder before the plush yarn is fed. Using such an arrangement a complete plush knitting method of the invention can be performed on two successive knitting stations and the needle latches are guarded and opened as required throughout without leading to the need for more space than that usually occupied by two knitting stations.

The needles may be arranged in a 1 x 1 set-out and the plush loops may be pressed off immediately after the knitting of the locking yarn. The plush and binding yarn are generally knitted in a top cylinder. The fabric may be treated to give a cut pile. The plush yarn may be formed by two or more separate yarns combined at the first knitting station.

The invention is illustrated by reference to the drawings in which: Figure 1 is a developed view of the inside of a cam system for two successive knitting stations of a knitting machine operating according to the method of the invention; Figure 2 is a perspective view from the outside at a first knitting station of the knitting machine of Figure 1; Figure 3 is a plan view from the outside of the knitting machine of Figure 1 with feeders in dotted lines removed; Figure 4 is a side view of the feeders at the first knitting station of the machine of Figure 1; and Figure 5 is a view from above of the feeder at the first knitting station of the machine of Figure 1.

The knitting machine With reference to Figure 1, a l0-gauge Wildt Mellor Bromley 22 inch diameter double cylinder knitting machine type SPJ has its cam systems arranged to provide three systems with two feeding station as shown in Figure 1 around the cylinder periphery. The cam system is that conventional for SPJ machines except: that (I) a press-off cam 2 and associated lower ing cam 3 are provided in the bottom cylinder cam system in a settling area 4 preceding a first knitting station 6 having the usual clearing cams 8 and transfer cam 10; and (2) a stitch cam ila of the first knitting station 6 in the bottom cylinder is arranged to commence a draw movement from 11 to 3 needle pitches, approximately 2 needle pitches in advance of the draw movement at the opposite stitch cam 1 lib in the top cylinder.The other stitch cams lib are conventional.

The total draw movement extends over 6-7 needle pitches so that the top and bottom draw movements take place simultaneously over a sector corresponding to 4 to 5 needle pitches. The top cylinder cam system is thus unchanged. The feeders are arranged as usual except that an extra, easily adjustable rod-like feeder 18 is placed behind a feeder 20 at the first knitting station 6.

To perform a particular method of plush knitting, double ended latch needles are set out in a 1 x 1 arrangement in alternate tricks in the top and bottom cylinder..

The needles are controlled by sliders having bevelled tips (See Figure 5) so that the empty sliders open any closed latches of needles held by other sliders in the opposite cylinder. The transfer cams 10 are withdrawn. The sliderbutts pass along path 14 in the top cylinder and path 16 in the bottom cylinder.

The knitting method With reference to Figure 1, at stage 0, all needles in the bottom cylinder ca,rry,, ing plush ,loops formed during a previous knitting operation are pressed off by the press-off cam 2.

.A.t stage I thi: sliders pass up their clearing. cams. The empty needles in the bottom cylinder which have. been pressedoff by the press-off cam 2, have their'latches opened by the .sliders iri the top cylinder prior to passing behind the a latch guarding surface of the feeder 20.

At stage II, the hooks of the bottom cylinder needles are just above the slot 21 in the feeder 20 and the latches are below.

The.hooks of the top cylinder needles are just. below, the slot 21 with their latches above. (See also Figure 3).

At stage III, a pair of plush yarns 22.

has been laid between the hooks of the top, and bottom cylinder needles and the bottom cylinder needles are .moved downward by the modified stitch cam 11 a to start drawing plush loops 24. The bottom cylinder needles have no old, loops on their stems and those needles continue to descend without their latches closing. The needle heads : pass just in front of the feeder 18. The top cylinder needles remain at .a high level. The tension exerted by old loops 34 on the .top cylinder needle stem (See Figure 4) causes their latches to start closing gently. The feeder 18 is directly behind the feeder 20'and the closing latches pass .over the. end of the feeder 18: At stage IV, the top cylinder needles commence to move up whilst the bottom cylinder needles' continue to move down.

The old loops 34 on the top cylinder needles are restrained by take down tension and top' cylinder verge and cause the latches of the top ' cylinder needles to close rapidly. (See Figure 2). These latches in so doing engage a binding '.yarn 26 from the feeder 18 and Iick- or swipe that yarn into the top cylinder needle hooks at a time.

when the butts of the sliders associated with the'' bottom cylinder needles are less than half-way "'down the stitch cam lla.

In Figure 2 top5, the top cylinder needles marked 28 have latches' which are just about to close. The needles marked 30 are in the process of licking in the binding yarn 26. The needles marked 32 have completed the subsequent knockover and are continuing to draw loops of the yarns 22.

At stage V, the slider butts in the top and bottom cylinders leave the associated stitch cams 1 la and 1 Ib simultaneously.

At stage IV, the loops formed by the plush yarns 22 and the binding yarn 26 on the top cylinder needles are about to be knocked over after introduction of a locking yarn 34 from a feeder 36. The needles carrying the plush loops 24 are kept,, .low whilst the locking yarn 34 is being .drawn'to to form the old loop 34 pre- viously referred to by the stitch cam 1 lb in the bottom cylinder.

With reference to Figures 2 to 5, the position of the feeder 18 is critical. The binding yarn 26 is supplied at a steeper angle than the yarns 22 so that the yarn 26 misses the hook of the bottom cylinder needles which descend in front of feeder 18 but sufficiently close to ensure that the binding yarn 26 is licked into hooks of the top cylinder needles by their closing latches (See Figures 2 and 5). The feeder 18 is located with respect to the. paths of the top and bottom cylinder needle hooks (shown in chain dotted lines in Figure 3) as shown in Figure 3. The feeder 18 must be easily adjustable so that it can place the yarn accurately with respect to the needle and latch movement. The. drawing movement of the top cylinder needles can be delayed further but this offers no advantages and increases the risk of wrong feeding needlessly.

Advantages Using the invention, it is firstly possible' to quickly convert a Wildt SPJ machine or machines of similar type to knit plush.

fabric. The conversion is simple, avoids latch guarding problems or the need -for general cam re-arrangement and enables knitting to be performed at every knitting station.

Using the invention fabrics may be obtained superior to those produced on dial and cylinder, plush ' knitting machines on which first a plush yarn is fed and pulled by cylinder needles and then a binding yarn is fed to the dial' needles to be knitted into loops later jointly: with the plush ya'rns. The invention permits long plush loops to be obtained and knitting to proceed at low tension whilst stripeeffects in the fabric can be substantially reduced.

The stitch cam 1 la can 'be' adjusting to vary the plush loop length. The inventfon works- best if the plush loops are slack and the stitch cam 1 lla is adjusted as low as possible. However shorter plush loops may be produced if required.

WHAT WE CLAIM IS: 1. A method for knitting plush fabric on a knitting machine having a first set of needles in tricks in one cylinder and a second set of needles in tricks in another opposed cylinder, which method includes the step of feeding first, plush yarn at a first knitting station into hooks at both sets of needles to form ground and plush loops respectively, timing the needle movement so that the movement for drawing of the plush loops proceeds at least partly in advance of the movement for drawing of the

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. ing plush ,loops formed during a previous knitting operation are pressed off by the press-off cam 2. .A.t stage I thi: sliders pass up their clearing. cams. The empty needles in the bottom cylinder which have. been pressedoff by the press-off cam 2, have their'latches opened by the .sliders iri the top cylinder prior to passing behind the a latch guarding surface of the feeder 20. At stage II, the hooks of the bottom cylinder needles are just above the slot 21 in the feeder 20 and the latches are below. The.hooks of the top cylinder needles are just. below, the slot 21 with their latches above. (See also Figure 3). At stage III, a pair of plush yarns 22. has been laid between the hooks of the top, and bottom cylinder needles and the bottom cylinder needles are .moved downward by the modified stitch cam 11 a to start drawing plush loops 24. The bottom cylinder needles have no old, loops on their stems and those needles continue to descend without their latches closing. The needle heads : pass just in front of the feeder 18. The top cylinder needles remain at .a high level. The tension exerted by old loops 34 on the .top cylinder needle stem (See Figure 4) causes their latches to start closing gently. The feeder 18 is directly behind the feeder 20'and the closing latches pass .over the. end of the feeder 18: At stage IV, the top cylinder needles commence to move up whilst the bottom cylinder needles' continue to move down. The old loops 34 on the top cylinder needles are restrained by take down tension and top' cylinder verge and cause the latches of the top ' cylinder needles to close rapidly. (See Figure 2). These latches in so doing engage a binding '.yarn 26 from the feeder 18 and Iick- or swipe that yarn into the top cylinder needle hooks at a time. when the butts of the sliders associated with the'' bottom cylinder needles are less than half-way "'down the stitch cam lla. In Figure 2 top5, the top cylinder needles marked 28 have latches' which are just about to close. The needles marked 30 are in the process of licking in the binding yarn 26. The needles marked 32 have completed the subsequent knockover and are continuing to draw loops of the yarns 22. At stage V, the slider butts in the top and bottom cylinders leave the associated stitch cams 1 la and 1 Ib simultaneously. At stage IV, the loops formed by the plush yarns 22 and the binding yarn 26 on the top cylinder needles are about to be knocked over after introduction of a locking yarn 34 from a feeder 36. The needles carrying the plush loops 24 are kept,, .low whilst the locking yarn 34 is being .drawn'to to form the old loop 34 pre- viously referred to by the stitch cam 1 lb in the bottom cylinder. With reference to Figures 2 to 5, the position of the feeder 18 is critical. The binding yarn 26 is supplied at a steeper angle than the yarns 22 so that the yarn 26 misses the hook of the bottom cylinder needles which descend in front of feeder 18 but sufficiently close to ensure that the binding yarn 26 is licked into hooks of the top cylinder needles by their closing latches (See Figures 2 and 5). The feeder 18 is located with respect to the. paths of the top and bottom cylinder needle hooks (shown in chain dotted lines in Figure 3) as shown in Figure 3. The feeder 18 must be easily adjustable so that it can place the yarn accurately with respect to the needle and latch movement. The. drawing movement of the top cylinder needles can be delayed further but this offers no advantages and increases the risk of wrong feeding needlessly. Advantages Using the invention, it is firstly possible' to quickly convert a Wildt SPJ machine or machines of similar type to knit plush. fabric. The conversion is simple, avoids latch guarding problems or the need -for general cam re-arrangement and enables knitting to be performed at every knitting station. Using the invention fabrics may be obtained superior to those produced on dial and cylinder, plush ' knitting machines on which first a plush yarn is fed and pulled by cylinder needles and then a binding yarn is fed to the dial' needles to be knitted into loops later jointly: with the plush ya'rns. The invention permits long plush loops to be obtained and knitting to proceed at low tension whilst stripeeffects in the fabric can be substantially reduced. The stitch cam 1 la can 'be' adjusting to vary the plush loop length. The inventfon works- best if the plush loops are slack and the stitch cam 1 lla is adjusted as low as possible. However shorter plush loops may be produced if required. WHAT WE CLAIM IS:

1. A method for knitting plush fabric on a knitting machine having a first set of needles in tricks in one cylinder and a second set of needles in tricks in another opposed cylinder, which method includes the step of feeding first, plush yarn at a first knitting station into hooks at both sets of needles to form ground and plush loops respectively, timing the needle movement so that the movement for drawing of the plush loops proceeds at least partly in advance of the movement for drawing of the

ground loops, and feeding a second, binding yarn at that first knitting station into the hooks of needles about to draw the ground loops from a position where the binding yarn just misses the hooks of the neeedles for forming the plush loops.

2. A method according to claim 1 in which the movement of the needles for drawing the plush loops is started in advance of starting of the movement of needles for drawing the ground loops and the drawing of both sets of loops is continued simultaneously in the same cylinder sector.

3. A method according to claim 1 or claim 2 in which a locking yarn is fed at a second knitting station to the needles carrying the ground loops whilst holding the needles carrying the plush loops at an inactive leyel; and at some stage thereafter pressing off the plush loops.

4. A method according to claim 2 or claim 2 and claim 3 in which the binding yarn is fed from a feed position downstream of the plush yarn and at a greater angle than the plush yarn so that the feeding of the plush yarn and binding yarn to the needles drawing the ground loops is completed at approximately the same time and before any substantial length of plush loop has been drawn.

5. A method according to claim 4 in which the feed position is selected so that the landing of the locking yarn on the latches, closes the latches in such a way as to lick in the binding yarn from a position outside the tip of the needle hooks into the needle hooks.

A method according to claim 4 or claim 5 in which cam faces of stitch cams forming the ground and plush loops respectively are circumferentially off-set in such a way that the leading part of the inclined cam face of the stitch cam for forming the ground loops is less than half way along the inclined face of the stitch cam for forming the plush loops.

7. A method according to any of the preceding claims 2 to 6 in which the cam system area preceding the first knitting station has a press off cam for pressing off cam for pressing off needles with plush loops and latches of the empty needles are cammed open by sliders in the. opposite cylinder before the plush yarn is fed.

8. A method substantially as described with reference to the drawings.

9. A double cylinder knitting machine having double ended latch needles arranged in sets in the top and bottom cylinder and sliders adapted to open the needle latches comprising one or more cam systems and yarn feeders arranged so as to perform a method comprising feeding first, plush yarn at a first knitting station into hooks of both sets of needles to form ground loops and plush loops respectively, starting movement of needles for drawing the plush loops in advance of starting movement of needles for drawing the ground loops and feeding a second, binding yarn at that first knitting station into the hooks of the needles about to draw the ground loops from a position where the binding yarn just misses the hooks of the needles for forming the plush loops, feeding a locking yarn at a second knitting station to the needles carrying the ground loops whilst holding the needles carrying the plush loops at an inactive level; and at some stage thereafter pressing off the plush loops.

10. A knitting machine according to claim 9 arranged so that after starting the movement of needles for drawing plush loops in advance of starting movement of needles for drawing the ground loops, the movement for drawing both sets of loops is continued simultaneously in the same cylinder sector.

11. A double cylinder knitting machine substantially as described with reference to the drawings.

12. Plush fabric produced by a method or knitting machine according to any of the preceding claims.