GB1597255A

GB1597255A - Warp knitting machine particularly a stitch-bonding machine

Info

Publication number: GB1597255A
Application number: GB1265178A
Authority: GB
Original assignee: Wirkmaschinenbau Karl Marx Veb
Current assignee: Wirkmaschinenbau Karl Marx Veb
Priority date: 1977-03-31
Filing date: 1978-03-31
Publication date: 1981-09-03
Also published as: DE2812032C2; FR2385831A1; DE2812032A1; JPS542454A; DD130263A1

Description

(54) A WARP KNITTING MACHINE, PARTICULARLY A STITCH-BONDING MACHINE (71) We, VEB WIRKMASCHINEN BAU KARL-MARX-STADT, of 73 Annaberger Strasse, Karl-Marx-Stadt, German Democratic Republic, a Corporation organised under the laws of the German Democratic Republic, 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: This invention relates to a device in a warp knitting machine, particularly a stitchbonding machine, for the feeding of threads, film, or other material in web form to a transverse laying means for said material.

For the production of stitch-bonded fabrics from films or other materials in web form, which hereinafter will be referred to as a film webs, in stitch-bonding machines it is also necessary for these film webs to be laid in zig-zag form.

Devices are already known for feeding film webs to the transverse laying means (U.

K. Patent Specification No. 1,410,153 and German Democratic Republic Patent Specification 110,904). A positive drive of the film web is employed in these devices, since the mass of the roll of film used prevents drawing-off in the same way as weft threads otherwise used in stitch-bonding machines.

In known devices driving is effected at constant speed. The film web is driven either by means of a pair of co-acting rollers or by a device in the form of a double endless belt.

Because of the transverse thrust crank working principle employed for the transverse laying means in stitch-bonding machines, the laying means effects on its path a movement which has a sinusoidal speed pattern. During one stroke of the transverse laying means there is produced in relation to the pair of driving rollers a path difference which has to be compensated by an additional storage device. Spring-loaded rockers or crank discs are, for example, used for this purpose. The disadvantages of this storage device consist in the first place of fluctuations of tension during a double stroke, and in the second place of the need to change the crank discs when the working width is changed. On the other hand storage devices of this kind have a large number of deflection points for the film web, so that lap formation is assisted.

It is an object of the invention to provide an uncomplicated and operationally reliable device for feeding threads, film, or other material in web form and to obviate the disadvantages of previously known devices having a positive drive.

The problem which the invention aims at solving consists in so arranging the guiding and driving of the threads, film, or other material in web form in a stitch-bonding machine that a separate storage device, which is always liable to fail, can be dispensed with.

Accordingly, the present invention consists in a warp knitting machine, particularly a stitch-bonding machine, a device for feeding threads, film, or other material in web form to a transverse laying means reciprocable away from and towards said device for laying said material, said device comprising a pair of co-acting driven rollers for engaging between them said threads, film, or other material and feeding it to the transverse laying means, and a guide roller arranged between said pair of rollers and said laying means for guiding the threads, film, or other web material parallel to the movement of the transverse laying means, the drive of the pair of rollers being connected to the drive of the transverse laying means by way of step-up gearing and a freewheel device, so that the pair of rollers is driven only during the movement of the laying means away from the feeding device.

Since in consequence of the lateral feeding of the threads, film, or other material to the laying means, the material is laid in loop form with a web length of double the working width during the away movement of the cross-folder, there is provided on the laying means drive shaft, which preferably also drives the pair of rollers with the aid of an infinitely variable transmission, a freewheel device which during the return movement of the laying means prevent the further delivery of threads, film, or other web material by the pair of rollers. According to this arrangement the transmission ratio between the pair of rollers and the drive shaft of the transverse laying means is so selected that the threads, film, or other web material have at least twice the speed of the laying means.

The device of the invention provides the advantage that while the threads or web of material travel over a very short path, the tension in the threads or web is relatively constant. The infinitely variable transmission permits single adaptation to different widths of web. Expensive storage devices can be dispensed with.

In order that the invention may be more readily understood, reference is made to the accompanying drawing which illustrates diagrammatically and by way of example one embodiment of the device of the invention in a stitch-bonding machine.

The stitch-bonding machine comprises frame walls 1 and 2. On the frame wall 1 on which is mounted a gearing (not shown) for the stroke movement of a transverse laying means 3, is arranged according to the invention a pair of rollers 4, 5 for feeding a film web 6 to the laying means 3. Instead of the film web 6 it is also possible to feed threads or groups of threads or other material in web form. It is expedient for the pair of rollers 4, 5 to be provided with a friction-increasing rubber covering. In order to achieve a satisfactory adhesion of the film to the rollers 4, 5, the film is guided over the pair of rollers 4, 5 in such a manner that it loops the rollers 4, 5 over an angle of 360 .

This provides the further advantage that a satisfactory drawing-in of the threads or film is ensured. The pair of rollers 4, 5 is driven in the illustrated embodiment via an infinitely variable V-belt drive 7, 13, 14 by means of a freewheel device 8 which is mounted on a driving shaft 9 of the transverse laying means 3. The freewheel device 8 carries a toothed rim and with the aid of a sprocket wheel 11 a chain 10 drives an intermediate shaft 12 on which slidable cone pulleys 13 are mounted. The driving connection to the pair of rollers 4, 5 is made via the V-belt 14 and the V-belt pulley 7. As a result of a selected transmission ratio the pair of rollers 4, 5 has a peripheral speed which is twice as high as the speed of the laying means 3.

The pair of rollers 4, 5 may, however, also be driven direct by the transverse laying means 3, in which case the pair of rollers 4,5 is connected, by way of step-up gearing and a freewheel device, directly to one of guide rollers provided for parallel guiding on the guiding path 17 of the laying means 3. Since the guide rollers, over which the rope for the parallel guiding of the laying means 3 is guided, always work synchronously with the consumption of material fed, in contrast to a driving chain 22 of the laying means 3, complete synchronisation is achieved between the film delivered and film consumed.

With the aid of guide rollers 15, 16 the film web 6 moves parallel to the guide path 17 of the laying means 3. The jockey roller 15 is arranged at the free end of a level 18 which is pivotally mounted on the frame wall 1 and loaded by a compression spring 19 fastened on the frame wall 1, so that the lever 18 acts as a rocker arm and serves to adjust the tension in the film web 6 between the pair of rollers 4, 5 and holding means 20, 21 which are of known type for stitchbonding machines, for hooking on the film web 6.

During the movement of the laying means 3 away from the side near the frame wall 1 the pair of rollers 4, 5 is driven via the freewheel device 8 and V-belt drive 7, 13, 14 and the film web 6 is fed to the laying means 3.

After the film web 6 has been hooked on in the holding means 20 on the side near the frame wall 2, the driving shaft 9 reverses it direction of rotation in the usual manner for stitch-bonding machines and during rotation in this direction the freewheel device 8 keeps the pair of rollers 4, 5 stationary. The portion of the loop of film web 6 which is located between the laying means 3 and the guide roller 16 and which was drawn out during the forward movement of the laying means 3, is brought between the holding means 20 and 21 during the return movement of the laying means.

The laying means 3 is driven in known manner by the chain 22 with the aid of sprocket wheels 23 and 24, the sprocket wheel 24 being mounted on the driving shaft 9. With the aid of rollers 25, 26 and 27 the laying means 3 moves to-and-fro on the guide path 17.

WHAT WE CLAIM IS: 1. In a warp knitting machine, particularly a stitch-bonding machine, a device for feeding threads, film or other material in web form to a transverse laying means reciprocable away from and towards said device for laying said material, said device comprising a pair of co-acting driven rollers

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

Claims

**WARNING** start of CLMS field may overlap end of DESC **. laying means away from the feeding device. Since in consequence of the lateral feeding of the threads, film, or other material to the laying means, the material is laid in loop form with a web length of double the working width during the away movement of the cross-folder, there is provided on the laying means drive shaft, which preferably also drives the pair of rollers with the aid of an infinitely variable transmission, a freewheel device which during the return movement of the laying means prevent the further delivery of threads, film, or other web material by the pair of rollers. According to this arrangement the transmission ratio between the pair of rollers and the drive shaft of the transverse laying means is so selected that the threads, film, or other web material have at least twice the speed of the laying means. The device of the invention provides the advantage that while the threads or web of material travel over a very short path, the tension in the threads or web is relatively constant. The infinitely variable transmission permits single adaptation to different widths of web. Expensive storage devices can be dispensed with. In order that the invention may be more readily understood, reference is made to the accompanying drawing which illustrates diagrammatically and by way of example one embodiment of the device of the invention in a stitch-bonding machine. The stitch-bonding machine comprises frame walls 1 and 2. On the frame wall 1 on which is mounted a gearing (not shown) for the stroke movement of a transverse laying means 3, is arranged according to the invention a pair of rollers 4, 5 for feeding a film web 6 to the laying means 3. Instead of the film web 6 it is also possible to feed threads or groups of threads or other material in web form. It is expedient for the pair of rollers 4, 5 to be provided with a friction-increasing rubber covering. In order to achieve a satisfactory adhesion of the film to the rollers 4, 5, the film is guided over the pair of rollers 4, 5 in such a manner that it loops the rollers 4, 5 over an angle of 360 . This provides the further advantage that a satisfactory drawing-in of the threads or film is ensured. The pair of rollers 4, 5 is driven in the illustrated embodiment via an infinitely variable V-belt drive 7, 13, 14 by means of a freewheel device 8 which is mounted on a driving shaft 9 of the transverse laying means 3. The freewheel device 8 carries a toothed rim and with the aid of a sprocket wheel 11 a chain 10 drives an intermediate shaft 12 on which slidable cone pulleys 13 are mounted. The driving connection to the pair of rollers 4, 5 is made via the V-belt 14 and the V-belt pulley 7. As a result of a selected transmission ratio the pair of rollers 4, 5 has a peripheral speed which is twice as high as the speed of the laying means 3. The pair of rollers 4, 5 may, however, also be driven direct by the transverse laying means 3, in which case the pair of rollers 4,5 is connected, by way of step-up gearing and a freewheel device, directly to one of guide rollers provided for parallel guiding on the guiding path 17 of the laying means 3. Since the guide rollers, over which the rope for the parallel guiding of the laying means 3 is guided, always work synchronously with the consumption of material fed, in contrast to a driving chain 22 of the laying means 3, complete synchronisation is achieved between the film delivered and film consumed. With the aid of guide rollers 15, 16 the film web 6 moves parallel to the guide path 17 of the laying means 3. The jockey roller 15 is arranged at the free end of a level 18 which is pivotally mounted on the frame wall 1 and loaded by a compression spring 19 fastened on the frame wall 1, so that the lever 18 acts as a rocker arm and serves to adjust the tension in the film web 6 between the pair of rollers 4, 5 and holding means 20, 21 which are of known type for stitchbonding machines, for hooking on the film web 6. During the movement of the laying means 3 away from the side near the frame wall 1 the pair of rollers 4, 5 is driven via the freewheel device 8 and V-belt drive 7, 13, 14 and the film web 6 is fed to the laying means 3. After the film web 6 has been hooked on in the holding means 20 on the side near the frame wall 2, the driving shaft 9 reverses it direction of rotation in the usual manner for stitch-bonding machines and during rotation in this direction the freewheel device 8 keeps the pair of rollers 4, 5 stationary. The portion of the loop of film web 6 which is located between the laying means 3 and the guide roller 16 and which was drawn out during the forward movement of the laying means 3, is brought between the holding means 20 and 21 during the return movement of the laying means. The laying means 3 is driven in known manner by the chain 22 with the aid of sprocket wheels 23 and 24, the sprocket wheel 24 being mounted on the driving shaft 9. With the aid of rollers 25, 26 and 27 the laying means 3 moves to-and-fro on the guide path 17. WHAT WE CLAIM IS:

1. In a warp knitting machine, particularly a stitch-bonding machine, a device for feeding threads, film or other material in web form to a transverse laying means reciprocable away from and towards said device for laying said material, said device comprising a pair of co-acting driven rollers

for engaging between them said threads, film, or other material and feeding it to the transverse laying means, and a guide roller arranged between said pair of rollers and said laying means for guiding the threads, film, or other web material parallel to the movement of the transverse laying means, the drive of the pair of rollers being connected to the drive of the transverse laying means by way of step-up gearing and a freewheel device, so that the pair of rollers is driven only during the movement of the laying means away from the feeding device.

2. In a warp-knitting machine a device according to claim 1, wherein the pair of rollers is mounted on the drive side for the reciprocating movement of the transverse laying means and the drive of the pair of rollers is connected to the driving shaft of the laying means.

3. In a warp-knitting machine a device according to claim 1, wherein the drive of the pair of rollers is connected to a guide roller for the parallel guiding of the transverse laying means and is driven by said guide roller by way of step-up gearing and a freewheel device.

4. In a warp-knitting machine a device according to claims 1 to 3, wherein the feeding speed of the pair of rollers during the movement of the transverse laying means away from the feeding device is equal to twice the speed of the laying means.

5. In a warp-knitting machine a device according to any of claims 1 to 4, wherein the threads, film, or other web material loop the rollers of the pair of rollers over an angle of 360".

6. In a warp-knitting machine a device according to any of claims 1 to 5, wherein the rollers of the pair of rollers have a friction-increasing rubber covering.

7. In a warp-knitting machine particularly a stitch-bonding machine, a device for feeding threads, film or other material in web form to a reciprocating transverse laying means, substantially as herein described with reference to and as shown in the accompanying drawing.