US3688524A

US3688524A - Warp knitting machine

Info

Publication number: US3688524A
Application number: US882671A
Authority: US
Inventors: Ervin Peschl; Jan Skrepek
Original assignee: Vyzkumny Ustav Pletarsky AS; W Schlafhorst AG and Co
Current assignee: Vyzkumny Ustav Pletarsky AS; Oerlikon Textile GmbH and Co KG
Priority date: 1968-12-06
Filing date: 1969-12-05
Publication date: 1972-09-05
Anticipated expiration: 1989-09-05
Also published as: FR2025555A1; GB1293167A; DE1960871A1

Abstract

In a warp knitting machine with bipartite knitting needles respectively having a hook part and a latch part and provided with at least one needle bar for the hook parts and at least one latch bar for the latch parts of the needles, there is included a control device for controlling movement of the latch bar, the control device comprising means for uniformly and non-uniformly varying movements of the latch parts in opening and closing the hook parts of the knitting needle, for each course knitted in the warp knitting machine.

Description

United States Patent Peschl et al.

[ 1 Sept. 5, 1972 [54] WARP KNITTING MACHINE [72] Inventors: Ervin Peschl, Ceska; Jan Skrepek,

Post Habrovany, both of Czechoslovakia [73] Assignee: W. Schlafhorst & Co., Monchengladbach, Germany, Vyzkumny Ustav Pletausky, Brno, C zechoslovakia [22] Filed: Dec. 5, 1969 [21] Appl. No.: 882,671

[30] Foreign Application Priority Data Dec. 6, 1968 Czechoslovakia ..832068 [52] US. Cl. ..66/86 R [51] Int. Cl. ..D04b 23/00 [58] Field of Search ..66/l20, 154, 86, 87

[56] References Cited UNITED STATES PATENTS 2,775,108 12/1956 Belli ..66/86 2,796,606 6/1957 Amidon ..66/120 Primary Examiner-Ronald Feldbaum Attorney-Curt M. Avery, Arthur E. Wilfond, Herbert L. Lerner and Daniel J. Tick 57 ABSTRACT In a warp knitting machine with bipartite knitting needles respectively having a hook part and a latch part and provided with at least one needle bar for the hook pans and at least one latch bar for the latch parts of the needles, there is included a control device for controlling movement of the latch bar, the control device comprising means for uniformly and non-uniformly varying movements of the latch parts in opening and closing the hook parts of the knitting needle, for each course knitted in the warp knitting machine.

11 Claims, 15 Drawing Figures PATENTEDSEP S19v2 3.688.524 snm 1 or i (AW L PATENTEBsEP 5 I972 SHEET 3 [1F 7 FIG.3

INVENTORS:

PAIENTEQSEP 6I972 3.688.524

SHEEI II III 7 F IGAO IROTATION OF THE MAIN SHAFT OF THE MACHINE NO STITCH FORMATION-TUCK BACKING OFF-STITCH FORMATION FIGAb IROTATION OF THE NEEDLE BAR CONTROL CAM I NO STITCH FORMATION-TUCK BACKING OFF-STITCH FORMATION IR OTATION OF THE LATCH BAR CONTROL CAM F|G.4c

STITCH FORMATION STITCH FORMATION ..s STITCH FORMATION TUCK T I IROTATION= ICOURSE OF STITCHES INVENTORS:

PATENTEB E 5 i972 SHEET 5 [IF 7 THREAD FILLING o a 6 OF THE DEVICE myENToRs- 5m? SHEET 6 OF 7 FIG.7Q

THREADFILLING o H I I I I I II In OFTHEDEVICE: :-T T-T-I.I.Tg

INVENTORS NPNDINDINPNPNP m FIG 10 WARP KNITTING MACHINE Our invention relates to warp knitting machine such as warp frame Raschel knitting machine, sewingknitting machine or the like, more particularly of the type having bipartite knitting needles respectively having a hook part and a latch part and provided with at least one needle bar for hook parts and at least one latch bar for the latch part of the needles.

In the heretofore known warp knitting machines of this type, each two-part knitting needle is formed of a hook part having a shaft that is hollow or that is formed with a groove and a latch part which is displaceably mounted in the hollow or groove of the hook part. By means of a controlled reciprocal motion of the needle bar and the latch bar, the hooks of the knitting needles are alternately opened and closed as required by the cycle of the stitch forming and the production of a related warp knitted fabric or web. In the heretofore known warp knitting machines or the like provided with bipartite knitting needles, all hook parts are secured on a needle bar and all latch parts on a latch bar. Owing to this structure, all of the knitting needles operate simultaneously. All machines of this type are furnished with a displacement mechanism which controls the mutual reciprocatory movement of the needle bar and the latch bar so that the hooks of the bipartite knitting needles, when forming each course of the knitted fabric, are closed in the knocking-over position and are opened in the position in which the thread is to be filled.

The number of patterns that are possible to be knitted with such warp knitting machines or the like is consequently considerably reduced. It is in fact known, by employing various auxiliary patterning mechanisms, such as drop plates, patterning presses and the like, to attain a greater number of possible patterns on such machines; however, these mechanisms are relatively complex and costly and furthermore place increased demands on survicing of the machine.

It is accordingly an object of our invention to provide a warp knitting machine which avoids the foregoing disadvantages of the heretofore known machines of this general type and which more particularly affords a considerable increase in the possible number of patterns attainable with warp knitting machines or the like without requiring auxiliary patterning mechanisms.

With the foregoing and other objects in view we provide according to our invention, in a warp knitting machine with bipartite knitting needles respectively having a hook part and a latch part and provided with at least one needle bar for the hook parts and at least one latch bar for the latch parts of the needles, control device for controlling movement of the latch bar, the control device comprising means for uniformly and non-uniformly varying movements of the latch parts in opening and closing the hook parts of the knitting needle, for each course knitted in the warp knitting machine. It is thereby possible to control the movements of the bipartite knitting needles during the production of courses in such a way that the knitting needles form stitches in one course and form no stitches in another course.

In accordance with further features of our invention, the control device comprises at least two control cams rotatable at the same rotary speed for actuating the latch parts on the one hand and the hook parts on the other hand, the control cam for controlling the displacements of the hook parts being formed with a greater number of lifter lobes than the control cam for controlling the displacements of the latch parts. If, for example, in such a construction according to the invention, the control cam for controlling displacements of the latch parts is provided with a single lifter lobe and the control cam for the hook parts of the needles is provided with two lifter lobes, the hook parts are twice reciprocatingly displaced and the latch parts only once for one rotation of the control cams, that is during the formation of one course. The hook parts are thereby at the knocking-over location and then also form only one stitch. In accordance with an added feature of the invention, the control device comprises control cams rotatable at varying rotary speeds, the control cam for controlling the displacements of the latch parts being rotatable at a lower rotary speed than the control cam for controlling the displacements of the hook parts.

ln accordance with yet another feature of the invention, the control device is formed of a control chain having individual control members instead of a control cam.

In accordance with concomitant features of our invention we provide another embodiment thereof wherein the control device comprises at least one patterning disc or wheel having a periphery divided into a plurality of control fields or domains, each of the control fields controlling the displacement of the latch parts for each course being knitted. In accordance with other features of the invention included in another embodiment thereof which affords the attainment of a greater number of patterning possibilities, the latch bar is divided into two parts along the length of the working width thereof, the displacements of each part of the latch bar being controllable individually and independently of one another by means of control device such as control eccentrics, control cams, chains or patterning discs or wheels.

The control device of our invention is advantageous both for warp knitting machines as well as for sewingknitting machines. In the latter case, when the knitting needles are displaced into the position wherein thread is filled or drawn in, the knitting needles interweave the base material such as for example a fibrous fleece, a web, a foil and the like, and the hook parts are provided with points.

In addition, a warp knitting machine or similar machine constructed in accordance with the invention permits the production without auxiliary devices of warp fabrics with patterns or designs formed by blind filling, with patterns similar to pressed patterns and drop plate patterns, and with crepe patterns, and also the production of looping plush as well as combinations of the aforementioned patterns or designs in a knitted fabric.

Other features which are considered as characteristic for the invention are set forth in the appended claims.

Although the invention is illustrated and described herein as embodied in warp knitting machine, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.

The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings, in which:

FIG. 1 is a diagrammatic elevational view partly in section of a warp knitting machine constructed in accordance with our invention wherein the latch bar is controlled by control cams;

FIG. 2 is a view similar to that of FIG. I of another embodiment of the warp knitting machine of our invention wherein displacement of the latch bar is controlled by a control cam rotatable at one half the rotary speed at which the control cam for controlling the displacement of the needle bar is rotatable;

FIG. 3 is another view similar to that of FIGS. 1 and 2 of a further embodiment of the invention wherein displacement of the latch bar is controlled by a chain;

FIGS. 4a to 4c show characteristic curves of the displacements of the needle bar and the latch bar;

FIGS. 5 and 5a respectively show a pattern and the thread filling for a knitted fabric with a four guide bar pattern;

FIG. 6 shows a four guide bar design or pattern with foundation weaves in a fringed pattern;

FIGS. 7 and 7a respectively show a pattern and the thread filling for a two-bar three guide bar pattern;

FIG. 8 shows a smooth warp knitted pattern combined with a looped pattern;

FIGS. 9 and 9a respectively show a pattern and the thread filling for a thread guide bar pattern with tricot foundation pattern; and

FIG. 10 is a sewn fabric with warp knitted pattern.

Referring now to the drawings and first particularly to FIG. 1 thereof, there is shown therein an embodiment of the warp knitting machine of our invention having bipartite knitting needles I, referred to hereinafter merely as knitting needles. The knitting needles I are respectively formed of a hook part 2 having a hollow stem in which a latch part 3 is guidingly displaceable. The hook parts 2 (only one shown in FIG. 1) are cast in lead members 4 which are fastened by screws 5 to a needle bar 6 which is in turn mounted by means of screws 7 on two guide pins 8 which are slidably displaceable in bearings 9 fastened by screws 10 to a support 11. The needle bar 6 performs an upward and downward reciprocatory movement in the direction of a double headed arrow S and S The latch parts 3 of the knitting needles 1 are cast in lead members 12 that are fastened by screws 13 to a latch bar 14 which is in turn mounted by means of screws 15 to guiding pins 16 that are slidably displaceable in bearings 17 fastened by screws 18 to the support 11. The latch bar 14 also performs a reciprocatory movement upwards and downwards in direction of the double headed arrow S and S Each guide pin 8 is connected by a pin 19 with a pull rod 20 which is in turn connected by a pin 21 with a rocking lever 22. The rocking lever 22 swings or rocks about a bar or shaft 23 carried by holders 24 (only one of which is shown in FIG. 1) which are fastened by screws 25 to a support 26. The rocking lever 22 carries a pin 27 on which a roller 28 is rotatably mounted. The roller 28 is controlled by and follows the surface of a control cam 81 provided with two

lifter lobes

82 and 83. The cam 81 is fastened on to a shaft 30 which is mounted in bearings 31 screwed by screws 32 to the support 26.

The guide pin 16 is connected by the pin 33 to the pull rod 34 which is in turn secured by a pin 35 to an oscillating or rocking lever 36 which rocks or swings about the fixedly'mounted rod or pivot 23. A roller 37 is rotatably mounted on the pin 35 and is controlled or follows the surface of a control cam 38 mounted on the shaft 30.

Warp threads

39 and 40 are unwound from the warp beams 41 and 42 respectively and are guided over back rests 43 and 414 to eye needles 45 and 46 which are cast in

lead members

47 and 48 and which are secured on guide bars 49 and 50 respectively.

The knitting needles 1 are guided in sinkers 51 of a knocking-over bar. Knitted fabric 53 is withdrawn by three draw-off

rollers

54, 55 and 56 and are wound into a package 57. Side walls 58 (only one shown in FIG. I) of the knitting machine are connected by the supports 1 I and 26 which extend transversely therebetween.

In the embodiment of FIG. 2, the displacement mechanism of the warp knitting machine which controls the latch bar M differs from the displacement mechanism of the warp knitting machine shown in FIG. I in that the control cam 38 which controls the roller or follower 37 is mounted on and firmly connected to its own shaft 59 which is rotatably mounted in bearings 60 which are in turn fastened by screws 61 to connecting supports 62 extending transversely between and secured to the side walls 58 of the knitting machine. In FIG. 2 the roller 37 is rotatably mounted on the pin 35, as in the embodiment of FIG. 1, the pin 35 being carried by the oscillating lever 36 which differs in the embodiment of FIG. 2 by the fact that it is longer than the oscillating lever 36 of FIG. 1. A gear 63 is fixedly connected to the shaft 30 and meshes with a gear 64 fixedly mounted on the shaft 59.

In the embodiment of FIG. 3, there is shown a warp knitting machine wherein the displacement mechanism which controls the latch bar 14 includes a rotatable drum 65 that is mounted on and fixedly connected to a shaft 66. This rotatable drum 65 carries control members 67 which are connected to one another by pins 68 in a manner conventional with the connection of the links of a chain. As can be readily seen in FIG. 3, the control members 67 differ from the remaining conventional links of the chain carried by the drum 65 in that they are formed with raised lobe-like parts which cause the roller 37 to lift as the lobe-like parts pass thereunder. The shaft 66 is rotatably mounted in bearings 69 which are fastened by means of screws 70 to a support 71 which extends transversely between and connects the side walls 58 of the warp knitting machine. The oscillating or rocking lever 36 carrying the roller 37 oscillates about a bar or pivot 72 which is fixedly mounted and which is carried by a support 73. The support 73 is fastened by screws 74 to a connecting support 75 extending transversely between and secured to the side walls 58 of the knitting machine. Supports 77 (only one shown in FIG. 3) are also mounted on the connecting support 75 by screws 76 and carry a nonrotatably mounted rod or pivot 78 about which arms 73 (only one of which is shown in FIG. 3) oscillate. The

arms 79 are provided at an end thereof with respective pins 80 on which rollers 28 (only one of which is shown in FIG. 3) are rotatably mounted and are controlled by and follow the control cam 29.

The embodiment of the warp knitting machine shown in FIG. 1 operates in the following manner:

The starting position for the formation of a course of knitted fabric is the phase wherein the needle bar 6 furnished with hook parts 2 and the latch bar 14 provided with latch parts 3 are located in the lower knocking-over position. The displacement mechanism of the warp knitting machine controlled by the control cam 81 which is provided with two

lifter lobes

82 and 83 lifts the needle bar 6 from the lower knocking-over position in direction of the arrow S into the upper position for thread laying wherein the eye needles 45 and 46

lay warp threads

39 and 40 into the hooks of the hook parts 2 of the knitting needles 1. Thereafter, the needle bar 6 drops to the lower knocking-over position. The latch bar 14 remains in the lower knocking-over position because the rotatable control cam 38 does not lift the roller 37 in this phase. Consequently, the hook part 2 of the knitting needle 1 remains open during knocking-over so that the knitting needle 1 forms a tuck. The needle bar 6 is then lifted again by the further-rotating control cam 81 into the position for thread-laying wherein laying of the

warp threads

39 and 40 into the hook parts 2 of the knitting needles 1 takes place, whereafter the needle bar 6 is again lowered into the knocking-over position. Meanwhile, the latch bar 14 is raised by the control cam 37 upwardly into the closed position of the knitting needles 1 wherein the latch parts 3 close the hook parts 2 of the knitting needles 1 whereupon knocking-over occurs and the knitting needles 1 form stitches.

In FIG. 4a there are shown the displacements of the needle bar 6 and the latch bar 14. During one rotation of the main shaft of the warp knitting machine, the control cam 81 with both

lifter lobes

82 and 83 thereof effects two liftings of the needle bar 6 represented by the characteristic curve A, and the control cam 38 effects one lifting of the latch parts 3, as shown by the characteristic curve B, which closes the hook parts 2 of the knitting needles 1 only for each second lifting of the needle bar 6.

In the embodiment shown in FIG. 2, the displacement of the needle bar 6 is controlled by the simple control cam 29 so that for each rotation of the main shaft, a lifting of the needle bar 6 is effected. Nevertheless, the rotations of the control cam 38 for the latch bar 14 are only half the number of rotations of the control cam 29, due to the fact that the gear ratio of the

gears

63 and 64 is 1:2, so that the latch bai 14 is lifted only for each second lifting of the knitting needles 1, the hook parts 2 consequently being closed only in each second knitted course during knocking-over.

In FIG. 4b there are shown by characteristic curves similar to those of FIG. 4a, the displacements of the needle bar 6 and the latch bar 14 for the embodiment of the warp knitting machine of FIG. 2.

In the embodiment of the warp knitting machine of our invention shown in FIG. 3, the displacements of the needle bar 6 are controlled by the simple control cam 29 and the displacements of the latch bar 14 by a chain, each control member 67 of the chain controlling the displacement of the latch bar 14 when forming a knitted course. The desired ratio of the rotary speed of the control cam 29 to the rotary speed of the drum 65 is provided by a conventional non-illustrated transmission system. The sequence of displacements of the needle bar 6 and the latch bar 14 in the corresponding sequential courses is represented by characteristic curves in FIG. 40. During a course in which boththe hook part 2 as well as the latch part 3 are lifted, stitching is formed. In courses wherein only hook parts 2 are lifted, only tucks are formed. The

control cams

29 and 81 of the needle bar 6 and the control earns 38 of the latch bar 14 as well as the control chain having the control members 67 can be replaced by patterning discs or wheels for specific types of knitted fabrics.

A sewn fabric can also be produced in the aforementioned warp knitting machines or similar machines if the hook parts 2 of the knitting needle 1 are provided with points and the needles interweave a fibrous fleece or a similar foundation material.

FIGS. 5 and 5a show respectively the pattern and the drawing-in or thread filling for a fabric with four guide bar pattern. In this case, as shown in FIG. 5a, the first guide bar I is provided with a basic drawing-in or thread filling of 1:1 i.e., one eye needle is full and one is empty, and forms an open fringed pattern in each second row or course. The second guide bar II similarly has a drawing-in or thread filling 1:1 i.e., one eye needle full and one empty, alternately efi'ecting weft filling and blind or blank filling so that this guide bar II forms no stitches but rather fills weft in each uneven course and forms loops in every even course. In FIG. 5, the courses in which stitches are formed are denoted by the letter P and the courses wherein the knitting needles form no stitches are denoted by the letter N. The warp threads of the second guide bar II form the thread system for the foundation pattern. The third and fourth guide bars III and IV lay, by lateral displacement, stationary threads in longitudinal direction in the foundation weave.

The four guide bar weave in FIG. 6 shows a foundation weave in fringed pattern which is joined or connected in one row by weft and in the second row by loops. The stationary threads in longitudinal direction are interwoven through the connecting weft of the foundation weave, in fact alternately on the upper and lower side of the fabric.

FIGS. 7 and 7a show respectively a pattern and the drawing-in or thread filling for a two-bar three guide bar pattern. As shown in FIG. 7a, the first guide bar I has a drawing-in or a thread filling ratio of 1:1 i.e., one eye needle is full and one empty, and the second and third guide bars II and III have patterning drawing-in or thread filling. The first guide bar I of FIG. 7a carries out the foundation pattern and forms on the forward needle bar an Atlas pattern wherein each reverse course forms loops by blind or blank drawing-in or filling while the other courses are formed of stitches. In FIG. 7, the letters P denote that the stiching needles form stitches, and the letters N denote that they form no stitches in the respective courses. The second guide bar II with the patterning drawing-in or thread filling thereof, as shown in FIG. 7a, lays stationary threads in longitudinal direction in conformity with the foundation weave. The third guide bar I lays the threads drawn-in or filled in a pattern thereby into the stitching needles of the referred needle bar, where it forms loops, while the same guide bar III lays weft on the forward needle bar.

The blind or blank drawing-in or filling and the conforming displacement of the stationary threads permit the production of a warp knitted weave combined with looping patterns, this combined weave being interwoven on the underside thereof uniformly in transverse direction by weft-forming threads of the loops, and on the upper and lower sides thereof in the longitudinal direction by stationary threads between the small rods of the stitches, as shown especially clearly in FIG. 8. In diagonal and transverse direction, firmness is imparted to this weave by the loops that are drawn-in or filled blind. FIGS. 9 and 9a show respectively a pattern and the drawing-in or thread filling for a three guide bar pattern. As shown in FIG. 9a, the first guide bar I provides a drawing-in or thread filling at a 1:1 ratio i.e., one eye needle is full and one empty, the second and third guide bars II and III having drawing-in or thread filling ratios of 1:3 i.e., one eye needle full and three eye needles empty. The first guide bar 1 produces the foundation pattern, forming a tricot pattern wherein closed and open courses or rows alternate. The open filling is blind, the closed forms stitches. In FIG. 9, the letters P accordingly denote the formation of stitches by the stitching needles and the letters N denote, on the other hand, no formation of stitches by the stitching needles in the respective courses. The second and third guide bars II and III alternately interweave stationary threads through the tricot pattern. The conformed displacement of the stationary threads and the blind drawing-in or thread filling of the foundation weave permit the production of a smooth warp knitted weave, ash shown in FIG. 10, on a foundation material by the application of a sewing-knitting machine constructed in accordance with our invention. In this case, stationary or standing threads are alternately interwoven with the foundation weave on the upper side of the sewn fabric. The knitted fabric patterns shown for example in FIGS. through 10 demonstrate quite clearly the advantage attainable by the device of our invention over warp knitting machines or the like known heretofore.

We claim:

1. In a warp knitting machine with bipartite knitting needles respectively having a hook part and a latch part, and provided with at least one needle bar for the latch part, and provided with at least one needle bar for the hook parts and at least one latch bar for the latch parts of the needles, control device for controlling movement of the latch bar, said control device comprising means for uniformly and non-uniformly varying movements of said latch parts in opening and closing the hook parts of the knitting needle, so as to selectively form stitches in one course knitted in the warp knitting machine and no stitches in another.

2. Control device according to claim 1 comprising at least two rotary control members rotatable at given speed for respectively actuating the latch parts, on the one hand, and the hook parts, on the other hand, the control member for actuating the hook parts having more lifting lobes than the control member for actuating the latch parts.

3. Control device according to claim 2 wherein at least one of said rotary control members comprises a control chain having individual control links formed with lifting lobes.

4. Control device according to claim 3 wherein at least another of said rotary control members comprises a control cam.

5. In a warp knitting machine with bipartite knitting needles respectively having a hook part and a latch part, and provided with at least one needle bar for the hook parts and at least one latch bar for the latch parts of the needles, control device for controlling movement of the latch bar, said control device comprising means for uniformly and nonuniformly varying movements of said latch parts in opening and closing the hook parts of the knitting needle, for each course knitted in the warp knitting machine, and at least two rotary control members rotatable at different speeds for respectively actuating the latch parts, on the one hand, and the hook parts, on the other hand, the control member for actuating the latch parts being rotatable at a slower speed than the control member for actuating the hook parts.

6. Control device according to claim 5 wherein at least one of said rotary control members comprises a control chain having individual control links.

7. Control device according to claim 6 wherein at least another of said rotary control members comprises a control cam.

8. Control device according to claim 1 comprising at least one patterning disc having a peripheral surface divided into a plurality of control fields, each of said control fields being adapted to control displacement of the latch parts for each course knitted.

9. Warp knitting machine according to claim I wherein the latch bar is divided into at least two parts along the length of the operating width thereof, said control device comprising separate control members for respectively controlling displacement of each of the parts of the latch bar individually and independently of one another.

10. In a warp knitting machine with bipartite knitting needles respectively having a hook part and a latch part, and provided with at least one needle bar for the hook parts and at least one latch bar for the latch parts of the needles, control device for controlling movement of the latch bar, said control device comprising means for uniformly and non-uniformly varying movements of said latch parts in opening and closing the hook parts of the knitting needle, for each course knitted in the warp knitting machine, and at least two control cams rotatable at the same speed for respectively actuating the latch parts, on the one hand, and the hook parts, on the other hand, the control cam for actuating the hook parts having more lifting lobes than the control cam for actuating the latch parts.

11. In a warp knitting machine with bipartite knitting needles respectively having a hook part and a latch part, and provided with at least one needle bar for the hook parts and at least one latch bar for the latch parts of the needles, control device for controlling movement of the latch bar, said control device comprising means for uniformly and non-uniformly varying movements of said latch parts in opening and closing the hook parts of the knitting needle, for each course knitted in the warp knitting machine, and at least two control cams rotatable at different speeds for respec-

Claims

9. Warp knitting machine according to claim 1 wherein the latch bar is divided into at least two parts along the length of the operating width thereof, said control device comprising separate control members for respectively controlling displacement of each of the parts of the latch bar individually and independently of one another.

11. In a warp knitting machine with bipartite knitting needles respectively having a hook part and a latch part, and provided with at least one needle bar for the hook parts and at least one latch bar for the latch parts of the needles, control device for controlling movement of the latch bar, said control device comprising means for uniformly and noN-uniformly varying movements of said latch parts in opening and closing the hook parts of the knitting needle, for each course knitted in the warp knitting machine, and at least two control cams rotatable at different speeds for respectively actuating the latch parts, on the one hand, and the hook parts, on the other hand, the control cam for actuating the latch parts being rotatable at a slower speed than the control cam for actuating the hook parts.