US3756043A

US3756043A - Flat warp knitting machines

Info

Publication number: US3756043A
Application number: US00197682A
Authority: US
Inventors: H Kemter
Original assignee: Wirkmaschinenbau Karl Marx Veb
Current assignee: Wirkmaschinenbau Karl Marx Veb
Priority date: 1971-11-11
Filing date: 1971-11-11
Publication date: 1973-09-04
Anticipated expiration: 1990-09-04

Abstract

A flat warp knitting machine comprising two parallel endless chains mounted for continuous revolution in the same direction and at the same speed, a plurality of hooks mounted on the chains in a plane, a weft yarn layer mounted for traversal between the two chains in a plane spaced slightly from a plane in which the chains lie and adapted to engage in a plane at least one weft yarn, and means adjacent each of the chains for pressing each of the weft yarns under a respective hook of one of the chains when the weft yarn layer is adjacent the one chain, the improvement comprising adjacent each of the chains in proximity to the points of reversal of the traverse of the weft yarn layer means for retaining each weft yarn, the retaining means being stationary in the direction of movement of the chains and being mounted in a plane between the plane in which the weft yarn layer engages the weft yarns and the plane in which the chain hooks are mounted, and means adjacent each of the chains for casting off each weft yarn on the retaining means of one of the chains when the weft yarns are being fed to the hooks of the other chain.

Description

United States Patent [191 Kemter 1 Sept. 4, 1973 FLAT WARP KNITTING MACHINES Heinz Kemter, Karl-Marx-Stadt, Germany [75] Inventor:

[73] Assignee: Veb Wirkmaschinenbau Karl-Marx-Stadt, Karl-Marx-Stadt, Germany [22] Filed: Nov. 11, 1971 [21] Appl. No.: 197,682

3,523.432 8/1970 Vajoa et al. 66/85 A Primary ExaminerRonald Feldbaum Attorney-Albert C. Nolte et al.

[57} ABSTRACT A flat warp knitting machine comprising two parallel endless chains mounted for continuous revolution in the same direction and at the same speed, a plurality of hooks mounted on the chains in a plane, a weft yarn layer mounted for traversal between the two chains in a plane spaced slightly from a plane in which the chains lie and adapted to engage in a plane at least one weft yarn, and means adjacent each of the chains for pressing each of the weft yarns under a respective hook of one of the chains when the weft yarn layer is adjacent the one chain, the improvement comprising adjacent each of the chains in proximity to the points of reversal of the traverse of the weft yarn layer means for retaining each weft yarn, the retaining means being stationary in the direction of movement of the chains and being mounted in a plane between the plane in which the weft yarn layer engages the weft yarns and the plane in which the chain hooks are mounted, and means adjacent each of the chains for casting off each weft yarn on the retaining means of one of the chains when the weft yarns are being fed to the hooks of the other chain.

6 Claims, 15 Drawing Figures minnow 4 ma 3756043 sum s 0? 5 TE. 12A.

FLAT WARP KNITTING MACHINES The invention relates to improvements in a flat warp knitting machine, particularly a sewing knitting or Mali machine, having a weft yarn layer moving back and forth parallel to the stitch forming line and arranged behind the stitch forming line, and having two constantly revolving transfer chains leading to the stitch forming line, which chains are arranged under the weft yarn layer and provided with hooks in which at least one weft yarn .can be engaged by means of the weft yarn layer, weft yarn being pressed temporarily under the hooks of the transfer chains at the ends of traverse of the weft yarn layer.

A known warp knitting machine, particularly a sewing knitting machine of this type, serves for the production of a weft-warp knitting in which the wefts serve as the base and are woven between the sinker or needle stitches of the warp knitting. The wefts are formed by a group of weft yarns.

Also known is a similar warp knitting machine which can be considered a sewing knitting machine, which processes as a base a non-woven fabric which is fed to the stitch forming line together with a single weft yarn placed above and/or under it. This single weft yarn can be used for the production of patterns.

Due to the continuous drive of the transfer chains feeding the wefts to the stitch forming line, these machines are characterized by particular simplicity. In addition, the resultant working speed of the machine is considerable.

A disadvantage, however, is that the weft yarns can be engaged by the constantly revolving transfer chains principally only in zig-zag form, because the transfer chain carrying the weft yarns continues to run while the weft yarn layer moves toward the opposite transfer chain.

It is an object of the invention to provide a warp knitting machine, particularly a sewing knitting machine of the above-mentioned type, on which a textile fabric having wefts can be produced which extend according to the pattern of conventional weft-warp knittings in a right angle to the longitudinal axis of the fabric and which are, therefore, so-called parallel wefts.

It is a more specific object of the invention to engage every weft in two transfer chain hooks which oppose each other on a line extending at least substantially perpendicularly to the transfer chains.

Other objects and advantages of the invention will become apparent from the following description of the invention.

According to the invention, means for retaining each weft yarn is arranged at both reversing points of the weft yarn layer between the yarn delivery line of the weft yarn layer and the transfer chain hooks, extends in the same direction as the hooks and is immovable in the direction of motion of the transfer chains. By means of this retaining means, a length of weft yarn between the transfer chain hooks and the delivery point of the weft yarn layer can be retained alternately at the ends of traverse of the weft yarn layer. By means likewise provided at the two reversing points of the weft yarn layer and in association with the retaining means, the

length of the weft yarn retained by the retaining means on one side can be cast off alternately onto the adjacent transfer chain hook, when the weft yarn layer feeds the weft yarn to the hook of the transfer chain of the other side.

The retaining means are preferably provided with hooks extending toward the hooks of the transfer chains.

The cast-off means consist preferably of raisable and lowerable pressers which are held by springs in their upper inoperative position and which can be lowered by solenoids into their operating position. The lowering of the cast-off means into the operating positions can be started by means of the weft yarn layer. It is advisable to arrange the cast-off means on swivel arms and to turn them laterally to the outside by means of the weft yarn layer when the pressers are not in use.

The means according to the invention for parallelizing the wefts are characterized by particular simplicity which ensures great reliability. This is due primarily to the fact that the retaining means are stationary.

The cast-off means cooperating with the retaining means must be movable, but it is only necessary that they be set in motion at a certain time. To this end the weft yarn layer can act at the same time as an impulse transmitter, so that no special control means are required.

The invention will now be further described by reference to two specific embodiments thereof as illustrated in the drawings in which:

FIG. 1 is a partly schematic isometric view of a weft layer of a sewing knitting machine for the production of a weft-warp knitting the base of which consists of parallel wefts;

FIG. 2 is a partly schematic isometric view of a weft yarn layer of a sewing knitting machine for the production of a weft-warp knitting the base of which consists of overlapping zig-zag wefts and of pattern wefts which are parallel wefts;

FIG. 3 is a detail isometric view of the weft yarn layer of FIG. 1 with the pressers which bring the weft yarns under the hooks of the transfer chains;

FIG. 4 is a detail isometric view of the means for controlling the pressers of FIG. 3;

FIG. 5 is a partly schematic isometric view of the transfer of the wefts to the retaining means on the right side of the machine;

FIG. 6 is a simplified elevation view in the direction of arrow VI of FIG. 5; FIG. 7 corresponds to FIG. 5 but illustrates the start of the deflection of the weft yarns;

FIG. 8 is a simplified elevation view in the direction of arrow VIII of FIG. 7;

FIG. 9 corresponds to FIGS. 5 and 7 but illustrates the end of the deflection of the weft yarns;

FIG. 10 is a simplified elevation view in the direction of arrow X of FIG. 9;

FIG. 11 is a partly schematic isometric view of the transfer of the weft yarns at the retaining means on the left side of the machine with simultaneous use of the presser associated with the retaining means on the right side of the machine;

FIG. 12 is a partly schematic isometric view of the presser with its driving means associated with the retaining means on the left side of the machine;

FIG. 13 is a partly schematic front elevation of the two pressers associated with the retaining means in cooperation with the weft yarn layer;

FIG. 14 is a partly schematic plan view of the front side of a weft-warp knitting formed with the weft yarn layer according to FIG. 2 and provided with pattern wefts on the front side; and

FIG. 15 is a partly schematic plan view of the back of a similar weft-warp knitting with pattern wefts on both sides.

According to FIG. 1, the weft yarns 1 are engaged alternately by means of the weft yarn layer 2 in the hooks 3 of two

endless transfer chains

4 and 5.

The weft yarn layer 2 consists of a carriage which has two side plates 6 and 7 and a perforated bar 8 forming the yarn delivery line. Struts 9 and 10, along with the perforated bar 8, connect the side plates 6 and 7 to each other.

The weft yarn layer 2 is guided on rods 11 and is moved back and forth by means of a chain 12 parallel to the stitch forming line 13 (indicated by broken line) of the machine. The two transfer chains 4 and lead to the stitch forming line 13 behind which is the weft yarn layer 2 which is arranged above the

transfer chains

4 and 5. The hooks 3 of the

transfer chains

4 and 5 point upward.

As can be seen from FIGS. 3 and 4, the weft yarn layer 2 is also provided with two alternately raisable and lowerable pressers l4 and 15, the function of which is to press the weft yarn layer 2 temporarily under the hooks 3 of the

respective transfer chain

4 or 5 at the respective ends of traverse of the weft yarn layer 2, so that the weft yarns 1 cross the shafts of the hooks 3 of the

respective transfer chain

4 or 5 between the

respective presser

14 or 15 and the perforated bar 8. This assures a satisfactory transfer of the weft yarns l to the hooks 3 of the

respective transfer chain

4 or 5.

In the case of FIGS. 3 and 4 the weft yarn layer 2 is at its right moving end, at which the left presser 14 is effective.

The

pressure

14 and 15 are suspended at both ends on rocker arms 17 which are secured on a shaft 18 mounted in the side plates 6 and 7. To each rocker arm 17 are articulated two arms 16 to the other ends of which is articulated an arm 19 to form a parallelogram.

On the front rocker arm 17 (not shown) are secured two

bolts

20 and 21 which cooperate with stop cams 22 (FIG. 4). A cam 22 is arranged on each machine side. The stop cams 22 are carried each by a sleeve 23 which is secured against rotation and arranged at the front rod 11.

The weft yarn layer of FIG. 1 is provided for the production of a weft-warp knitting the base of which, consisting of the weft yarns 1, is thus woven between the needle and sinker stitches of the warp knitting, the wefts being so-called parallel wefts. In order to make this possible, a respective retaining means 24 and 25 is provided on each machine side. The retaining means 24 and 25 are arranged between the perforated bar 8 and the hooks 3 of the

transfer chains

4 and 5, as shown on the right hand looper 25 in FIG. 3. The retaining means 24 and 25 are immovable at least in the direction of motion of the

transfer chains

4 and 5 and have books 26 directed toward the hooks 3 of the

transfer chains

4 and 5. The shafts of the hooks 26 are, therefore, so-to-speak crossed by the weft yarns 1 at the reversing points of the weft yarn layer 2.

When the weft yarn layer moves, for example, into its right hand end position, the weft yarns 1, bent upwardly, are inserted by means of the presser 14 between a hook 3 of the transfer chain 5 and a hook 26 of the retaining means 25 (FIGS. 5 and 6). Since the retaining means 25 stands still while the

transfer chains

4 and 5 move toward the stitch forming line, the hooks 26 of the retaining means 25 retain the weft yarns I over a yarn length 27 between the perforated bar 8 and the hooks 3 of the transfer chain 5 and deflect the weft yarns 1 in this way increasingly to the rear, as can be seen from FIGS. 7 to 10.

The same process takes place between the hooks 26 of the left hand retaining means 24 and the hooks 3 of the left transfer chain 4 during the leftward motion of the weft yarn layer 2.

The weft yarns 1 are cast off from the retaining means 24 and 25 by means of

pressers

28 and 29, of which one is arranged on each machine side (FIGS. 1 and 13). As can be seen particularly from FIG. 12, the

pressers

28 and 29 can be raised and lowered, and they are secured for this purpose to the bottom end of a bar 30 which is held in its upper position by means of a tension spring 31. The lowering of the

pressers

28 and 29 is effected by means of a solenoid, the core 32a of which is surrounded by a coil 32 and secured at the upper end of the bar 30. The coils 32 of the

pressers

28 and 29 at the respective machine sides are energized alternately. According to FIG. 13, respective stationary contacts 33 and 34 are provided to this end for each coil 32. Two additional contacts 35 and 36 are arranged on the weft yarn layer 2.

In FIG. 13, the weft yarn layer 2 is in its left end position. Then the contacts 33, 35 are closed activating the coil 32 of the right hand presser 29 so that the presser 29 descends.

The lowering of the left hand presser 28 is effected by the contacts 36 and 34.

It can thus be seen that the yarn length 27 is cast off from the right hand retaining means 25 to the hooks 3 of the right hand transfer chain 5 by means of the right hand presser 29 when the weft yarn layer 2 feeds the weft yarns 1 to the hooks 3 of the left hand transfer chain 4 (FIG. 11).

Conversely, the yarn length 27 is cast off from the left hand retaining means 24 to the hooks 3 of the left hand transfer chain 4 when the weft yarn layer 2 feeds the weft yarns 1 to the hooks 3 of the right hand transfer chain 5.

The offering of the weft yarns 1 to the hooks 3 of the

transfer chains

4 or 5 of one machine side thus coincides with the casting off of the yarn length 27 to the hooks 3 of the

transfer chains

4 or 5 of the other machine side, which means that each weft yarn 1 is engaged by two transfer chain hooks which oppose each other in a line which extends at least substantially perpendicularly to the

transfer chains

4 and 5.

The two

pressers

28 and 29 must not be in the way of the weft yarn layer 2 when the latter moves into its two end positions. To this end the

pressers

28 and 29 can be lifted out by an appropriate amount. in order to make this unnecessary, the

pressers

28 and 29 are provided on

arms

37 and 38 which can be turned about axes 39 extending parallel to the transfer chains 4 and 5 (FIGS. 1, l2 and 13). The inner rest position of each of the

arms

37 and 38 is limited by respective thumbs 40. The deflection of the

arms

37 and 38 is effected alternately by means of the weft yarn layer 2, which presses the

arm

37 or 38 to the outside by means of the respective strut 9 or 10.

The invention is not limited to the production of a weft-warp knitting with parallel wefts as a base. It is also possible, for example, to produce with the invention a textile fabric which is provided with parallel pattern wefts. The base of the textile fabric can consist in this case, for example, likewise of wefts but alternatively of a non-woven fabric or the like. If the base of the textile fabric is formed of wefts, these can be, according to the invention, either parallel wefts or wefts overlapping in zig-zag form according to German Patent l,059,608. The production of the last-mentioned textile fabric is possible with the embodiment of FIG. 2. To this end the perforated bar 8 of the weft yarn layer 2 is designed for guiding two groups of weft yarns. The rear group 41 of weft yarns forms the base in the weft-warp knitting to be produced. The weft yarns of the group 41 are alternately engaged in known manner in the hooks 3 of the two

transfer chains

4 and 5. The front group 42 of weft yarns, however, serves for the formation of the pattern and its weft yarns are laid by means of the invention as parallel wefts. Only for the group 42 is the machine, therefore, provided with the retaining means 24 and 25 and the

pressers

28 and 29.

The construction of such a weft-warp knitting is illustrated in FIG. 14.

Since the pattern group 42 of weft yarns is guided in the perforated bar 8 ahead of the group 41 forming the base, the pattern wefts 42 lie on the front side of the base wefts 41. Similarly, the pattern group 42 of weft yarns could also be fed into the perforated bar 8 behind the group 41 forming the base in which case the pattern group 42 comes to lie on the back of the base wefts 41. It is even possible to feed two pattern groups into the perforated bar 8 respectively in front of and behind the base weft group 41. The result is then a weft-warp knitting as shown in FIG. 15. The base wefts 41 are arranged in this case between the pattern weft group 42 and the pattern weft group 43.

The invention also offers the possibility of making use of the

pressers

28 and 29 independent in time of the feeding of the weft threads to the hooks 3 of the

transfer chains

4 and 5. In this case diagonal wefts can be produced, the angle of which differs from the angle of the base weft group 41.

What is claimed is:

1. In a flat warp knitting machine comprising two parallel endless chains mounted for continuous revolution in the same direction and at the same speed, a plurality of hooks mounted on the chains in a plane, a weft yarn layer mounted for traversal between the two chains in a plane spaced slightly from a plane in which the chains lie and adapted to engage at least one weft yarn and lay said at least one weft yarn between said chains in a plane parallel to the plane of traversal of the weft yarn layer, and means adjacent each of said chains for pressing each of said weft yarns under a respective hook of one of said chains when the weft yarn layer is adjacent said one chain, the improvement comprising adjacent each of the chains in proximity to the points of reversal of the traverse of the weft yarn layer means for looping each weft yarn, said looping means being stationary in the direction of movement of the chains and each including means for retaining one of the weft yarns, each of said retaining means being positioned, when the weft yarn layer reaches the point of reversal in proximity to the retaining means, in a plane between the plane in which the weft yarn layer lays the weft yarns and the plane in which the chain hooks are mounted, and means adjacent each of said chains for casting off each weft yarn on the retaining means of one of said chains when the weft yarns are being fed to the hooks of the other transfer chain.

2. A machine according to claim 1, in which the retaining means comprise hooks and the hooks of the retaining means and the hooks of the chains are oriented with the free ends thereof in mutual opposition.

3. A machine according to claim 2, in which the casting off means comprise means for pressing the weft yarns adjacent the points of engagement thereof by the hooks of the retaining means so as to urge the weft yarns out of engagement with the hooks of the retaining means.

4. A machine according to claim 3, in which each of said casting off means further includes a spring for holding the pressing means thereof out of engagement with the weft yarns and a solenoid operatively connected to the pressing means of each of the casting off means for moving the pressing means into engagement with the weft yarns upon actuation of the solenoid.

5. A machine according to claim 4, further comprising means for actuating the solenoid, a part of said actuating means being carried by the weft yarn layer.

6. A machine according to claim 5, in which the pressing means of each of the casting off means is mounted on a respective arm pivotally mounted for rotation in a plane transverse to the plane of the chains and the arm is so located relative to the weft yarn layer as to be engaged by the weft yarn layer at the ends of the traversal path of the weft yarn layer and thereby be pushed out of the way.