GB1599624A

GB1599624A - Warp knitting machine particularly a stitch-bonding machine having a device for laying weft material consisting of plastics film

Info

Publication number: GB1599624A
Application number: GB2116678A
Authority: GB
Original assignee: Wirkmaschinenbau Karl Marx Veb
Current assignee: Wirkmaschinenbau Karl Marx Veb
Priority date: 1977-06-15
Filing date: 1978-05-22
Publication date: 1981-10-07
Also published as: DE2811986A1; DE2811986C2; FR2394628B3; DD131655A1; FR2394628A1

Description

(54) WARP KNITTING MACHINE, PARTICULARLY A STITCH-BONDING MACHINE, HAVING A DEVICE FOR LAYING WEFT MATERIAL CONSISTING OF PLASTICS FILM (71) We, VEB WIRKMASCHINENBAU 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 warp knitting machine, particularly a stitch-bonding machine, having a device for laying webs, particularly plastics film serving as weft material.

It is known, on stitch-bonding machines, to use, instead of a ground fabric or a system of groups of threads spread out flat between two transport means, a weft material consisting of webs of plastics film which is supplied to the knotting or loop-forming stations of the machine where the film is pierced by the knitting needles and processed into a planar product in known manner.

The transport means are in general two substantially parallel chains, moving in the same direction, fitted on the sides facing one another, at equal intervals, with hooks to receive the ground fabric, or the system of groups of threads, or the webs of film which have to be transported.

In a known stitch-bonding machine strips of plastics film and the groups of threads are inserted alternately into the hooks of the transport means by a transversely reciprocating weft laying means and so are laid out between the transport means.

To ensure an orderly and reliable insertion or suspension of the weft material in the hooks of the transport means, the weft laying carriage ofthe laying means remains above the transport means for a short time until they have covered a distance of at least one or two hook spacings so that a predetermined offset appears between the delivery point of the weft laying carriage and the point of insertion of the weft material on the transport means and the weft material can be laid round the individual hooks. For this it is necessary that the weft material be held back in the delivery position of the weft laying carriage in relation to the movement of the transport means. When groups of weft threads are being laid this is effected by means of a perforated rail disposed in the weft laying carriage, into the holes of which rail the individual threads are drawn.

Since this perforated rail cannot be used in laying webs of plastics film it had already been proposed to provide on the weft laying carriage two hold-back devices disposed on a linkage, which could be brought alternately into the operative position. The linkages are set in motion at the required moments by suitable means.

The disadvantage here is that the, sometimes heavy loading of the hold-back devices which occur during the attainment of the above-described offset, especially when unsplit film webs are being dealt with, is transmitted by constraint to the linkage and also to other components of the weft laying carriage. This results in wear which appear in particular in the form of an increase in the play of the linkage parts and the other components of the weft laying carriage relative to one another and thus to a shortening of the life of the device.

Consequently there are also defects in the insertion of the film webs in the hooks on the transport chains.

A further disadvantage is that the film web has to be pierced by the hooks on the transport means as it is inserted This results in considerable stressing of the hooks and of the transport means.

Finally, the provision of the above-described hold-back device is in itself a disadvantage as it leads to a very complicated construction of the weft laying carriage and so it is not possible to employ a weft laying carriage which is used for the laying of groups of threads. The consequences are higher construction costs, increased susceptibility of the device and a restriction of the field of application of the stitch-bonding machine in question.

The invention aims, therefore, in the process of laying film webs as weft material on warp-knitting and particularly stitch-bonding machines, by means of the maximum avoidance of wear, to increase the life of the operative parts such as the weft laying means and the transport means and to reduce the functional inaccuracies caused by this wear.

The problem which the invention aims at solving is to provide a warp knitting machine, particularly a stitch-bonding machine, with a device for laying weft material in the form of film having a reciprocating weft laying means, the latter to be of simple construction with a small number of moving parts, and means to be provided for holding the film web to support the transfer to the transport means, separately from the weft laying means, acting simultaneously as means for the partial splitting of the film web.

Accordingly, the present invention con liStS in a warp knitting machine, particularly a stitch-bonding machine, having a device for laying weft material, in the form of a plastics film, by means of a reciprocating weft laying carriage, the film supplied in the form of a web being spread out flat and inserted in hooks of two approximately parallel transport means carrying the weft material to a loop-forming station, characterized in that immediately above each transport means in the direction of the path of movement of the weft laying carriage, there is disposed a respective fixed, comb-like holding means provided with prongs, of which the prongs are directed toward the other transport means and project beyond the hooks of the associated transport means in this direction, the prongs of the holding means serving to engage, at least in the zone of its outer edges, the film web to be inserted by the weft laying carriage in the hooks of the transport means.

Conveniently, the distances between the prongs of the holding means are less than the width of the film web to be laid out. Moreover the prongs of the holding means are preferably disposed symmetrically in relation to the middle of the path of motion of the weft laying carriage.

In a preferred form of construction the holding means are in the form of gripper plates with gripper pins disposed in the manner of a comb on their end faces, running to a point at the front.

In order that the invention may be more readily understood, reference is made to the accompanying drawings which illustrate diagrammatically and by way of examples an embodiment thereof, and in which: Fig. 1 shows a weft laying station in a stitch-boding machine for producing a stitchbonded fabric, which has a ground consisting of film strips spread out flat, Fig. 2 shows the weft laying carriage of Fig. 1 in greater detail, Fig. 3 shows the means of controlling some functional parts of the weft laying carriage, and Fig. 4 shows a gripper plate in its association with a transport means and some components of the weft laying carriage.

As shown in Fig. 1 a plastics film web 1 which is supplied from a stock (not shown) is laid out in zig-zag fashion between two endless transport chains 6 by means of a weft laying carriage 2 and inserted alternately in upwardly bent hooks 7 on one of the two transport chains. Above and within the weft laying carriage 2 the film web 1 is guided respectively by two pairs of guide rollers 4 and 5. While the weft laying carriage 2 effects a reciprocating movement along two guide bars 3, parallel to the loop-forming station 27 of the machine, the endless transport chains 6 move toward said station, so that if the two movements are matched suitably the already described zig-zag spreading of the film web 1 becomes possible.

The weft laying carriage 2 (see Figs. 2 and 3) comprises two fiat side members 10 and 11 and struts 12 and 13 which interconnect them. Further connections between the side members 10 and 11 are provided by the guide rollers 5 and guide plates 20 and 21 which form a gap for the passage of the film web 1.

The reciprocating movement of the weft laying carriage 2 is obtained by means of a chain 28 (Fig. 2).

In a manner which is known, means are disposed on the weft laying carriage 2 which press temporarily under the hooks 7 the weft material pierced by the hooks 7, in order to secure a satisfactory transfer of the material to the hooks. These means are two pushers 14 and 15 which can be brought into engage- ment with the web 1 by a gear drive consisting of a connecting rod 19, two arms 16 and a rocker 17 which can rotate round the shaft 18. To increase the accuracy of movement, such gear drive is disposed both on the side member 10 and on the side member 11. By virtue of the connection effected by the pushers 14 and 15 the two gear drives operate synchronously.

To bring the appropriate pusher 14 or 15 into engagement with the web 1 at the reversal positin of the weft laying carriage 2, the two arms 16 on the gear drive associated with the front side member 11 are fitted with pins 23 and 24 which project through apertures in the side member 11 and come into engagement with a cam 25 at both ends of the movement path of the weft laying carriage 2.

These cams 25 are mounted by means of sleeves 26 on the front guide bar 3 at both reversal points of the weft laying carriage 2.

According to the invention holding means provided with prongs in the form of a comb are disposed immediately above each transport chain 6 (See Fig. 4). In the present embodiment these are constituted by plates 9 fitted with holding pins 8 which plates are connected to the machine frame 22 in a rigid manner, for example by means of a screw connection. However, to permit adaptation to various operating conditions the connection between the plates 9 and the machine frame 22 may be made adjustable vertically and in the direction in which the pins 8 extend.

Similarly, it is also possible to fix the plates 9 to adjusting spindles (not shown) of the warp frame.

The plates 9 are preferably disposed in such a way that the pins 8 extend between the hooks 7 of the transport chain 6 and the delivery point of the weft laying carriage 2, that is to say on the underside of the gap formed by the guide plates 20 and 21, in the direction of the opposite transport chain 6.

In particular it is essential for the pins 8 to project clearly beyond the hooks 7. Moreover, it is convenient if they are pointed.

When the weft laying carriage 2 is in motion the portion of the film web 1 which is firmly suspended in the hooks of the transport chain 6, from which the weft laying carriage 2 is moving away, is drawn, in consequence of the movement of the weft laying carriage 2, over the pairs of guide rollers 4 and 5 from its stock and spread out flat between the two transport chains 6 as shown in Fig. 1.

When the weft laying carriage 2 approaches a reversal point in its movement and hence also a transport chain 6, the pin 23 or 24 comes into engagement in a known manner with the respective cam 25 so that, as in Fig.

4 for example, the pusher 14 moves against the film web 1. The web 1 thus assumes an almost perpendicular position between the pusher 14 or 15 and the guide plates 20 and 21 in relation to the hooks 7 and the holding pins 8.

As the weft laying carriage 2 continues to move the film web 1 is first engaged by the prongs of the holding means. In the preferred embodiment this is effected by the holding pins 8 piercing the film web 1. The advantage of this appears mainly when unsplit film webs 1 are being dealt with. The pins 8 penetrate the film web 1 and partly split it so that the hooks 7 can penetrate it easily, which saves wear on the hooks 7.

The pusher 14 or 15 ensures that the film web 1 is pushed far enough on to the holding pins 8 and the hooks 7 so that it becomes properly inserted.

The weft laying carriage 2 remains in its reversal position until the transport chains 6 have moved at least one to two hook spacings towards the loop-forming station 27. The film web is thereby drawn further off its stock and slit by the pins 8, but owing to the rigid disposition of the plates 9 relative to the frame 22, the film web 1 is held back in the direction of movement of the transport chains 6 and, when the weft laying carriage 2 has moved away from the reversal point, becomes securely suspended in the hooks 7.

It is obvious that, apart from unsplit film webs 1, it is also possible to deal with those which, for example, have already been split up partly or completely by means of a porcupine roller. These then have a net-like structure thus ensuring the cohesion of the film web. In this connection it is possible that the film web 1 is already held adequately by two holding pins 8 which act in the zone of the film web 1. It is also convenient if the pins 8 and in general the prongs of the holding means are disposed symmetrically about the middle of the path of movement of the weft laying carriage 2.

With the invention it becomes possible to process film webs as weft material on warp knitting machines, especially stitch-bonding machines, using a weft laying carriage which is distinguished from the known industrial arrangement by a substantially simpler construction. The forces resulting from the insertion of the film in the hooks of the transport means no longer have to be absorbed by the weft laying carriage but are cushioned by the holding means. Thus an important source of the susceptibility of the weft laying carriage to breakdown is obviated.

A further advantage is the splitting of the film before it comes into contact with the hooks of the transport means. This leads to lighter loading of these hooks and hence also to a longer life.

WHAT WE CLAIM IS: 1. A warp knitting machine, particularly a stitch-bonding machine, having a device for laying weft material, in the form of a plastics film, by means of a reciprocating weft laying carriage, the film supplied in the form of a web being spread out flat and inserted in hooks of two approximately parallel transport means carrying the weft material to a loop-forming station, characterized in that immediately above each transport means in the dirction of the path of movement of the weft laying carriage, there is disposed a respective fixed, comb-like holding means provided with prongs, of which the prongs are directed toward the other transport means and project beyond the hooks of the associated transport means in this direction, the prongs of the holding means serving to engage, at least in the zone of its outer edges, the film web to be inserted by the weft laying carriage in the hooks of the transport means.

2. A warp knitting machine according to claim 1, wherein the spacing between the prongs of the holding means is less than the width of the film web which is to be laid.

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

Claims

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

According to the invention holding means provided with prongs in the form of a comb are disposed immediately above each transport chain 6 (See Fig. 4). In the present embodiment these are constituted by plates 9 fitted with holding pins 8 which plates are connected to the machine frame 22 in a rigid manner, for example by means of a screw connection. However, to permit adaptation to various operating conditions the connection between the plates 9 and the machine frame 22 may be made adjustable vertically and in the direction in which the pins 8 extend.

Similarly, it is also possible to fix the plates 9 to adjusting spindles (not shown) of the warp frame.

The plates 9 are preferably disposed in such a way that the pins 8 extend between the hooks 7 of the transport chain 6 and the delivery point of the weft laying carriage 2, that is to say on the underside of the gap formed by the guide plates 20 and 21, in the direction of the opposite transport chain 6.

In particular it is essential for the pins 8 to project clearly beyond the hooks 7. Moreover, it is convenient if they are pointed.

When the weft laying carriage 2 is in motion the portion of the film web 1 which is firmly suspended in the hooks of the transport chain 6, from which the weft laying carriage 2 is moving away, is drawn, in consequence of the movement of the weft laying carriage 2, over the pairs of guide rollers 4 and 5 from its stock and spread out flat between the two transport chains 6 as shown in Fig. 1.

When the weft laying carriage 2 approaches a reversal point in its movement and hence also a transport chain 6, the pin 23 or 24 comes into engagement in a known manner with the respective cam 25 so that, as in Fig.

4 for example, the pusher 14 moves against the film web 1. The web 1 thus assumes an almost perpendicular position between the pusher 14 or 15 and the guide plates 20 and 21 in relation to the hooks 7 and the holding pins 8.

As the weft laying carriage 2 continues to move the film web 1 is first engaged by the prongs of the holding means. In the preferred embodiment this is effected by the holding pins 8 piercing the film web 1. The advantage of this appears mainly when unsplit film webs 1 are being dealt with. The pins 8 penetrate the film web 1 and partly split it so that the hooks 7 can penetrate it easily, which saves wear on the hooks 7.

The pusher 14 or 15 ensures that the film web 1 is pushed far enough on to the holding pins 8 and the hooks 7 so that it becomes properly inserted.

The weft laying carriage 2 remains in its reversal position until the transport chains 6 have moved at least one to two hook spacings towards the loop-forming station 27. The film web is thereby drawn further off its stock and slit by the pins 8, but owing to the rigid disposition of the plates 9 relative to the frame 22, the film web 1 is held back in the direction of movement of the transport chains 6 and, when the weft laying carriage 2 has moved away from the reversal point, becomes securely suspended in the hooks 7.

It is obvious that, apart from unsplit film webs 1, it is also possible to deal with those which, for example, have already been split up partly or completely by means of a porcupine roller. These then have a net-like structure thus ensuring the cohesion of the film web. In this connection it is possible that the film web 1 is already held adequately by two holding pins 8 which act in the zone of the film web 1. It is also convenient if the pins 8 and in general the prongs of the holding means are disposed symmetrically about the middle of the path of movement of the weft laying carriage 2.

With the invention it becomes possible to process film webs as weft material on warp knitting machines, especially stitch-bonding machines, using a weft laying carriage which is distinguished from the known industrial arrangement by a substantially simpler construction. The forces resulting from the insertion of the film in the hooks of the transport means no longer have to be absorbed by the weft laying carriage but are cushioned by the holding means. Thus an important source of the susceptibility of the weft laying carriage to breakdown is obviated.

A further advantage is the splitting of the film before it comes into contact with the hooks of the transport means. This leads to lighter loading of these hooks and hence also to a longer life.

WHAT WE CLAIM IS: 1. A warp knitting machine, particularly a stitch-bonding machine, having a device for laying weft material, in the form of a plastics film, by means of a reciprocating weft laying carriage, the film supplied in the form of a web being spread out flat and inserted in hooks of two approximately parallel transport means carrying the weft material to a loop-forming station, characterized in that immediately above each transport means in the dirction of the path of movement of the weft laying carriage, there is disposed a respective fixed, comb-like holding means provided with prongs, of which the prongs are directed toward the other transport means and project beyond the hooks of the associated transport means in this direction, the prongs of the holding means serving to engage, at least in the zone of its outer edges, the film web to be inserted by the weft laying carriage in the hooks of the transport means.
2. A warp knitting machine according to claim 1, wherein the spacing between the prongs of the holding means is less than the width of the film web which is to be laid.
3. A warp knitting machine according to

claim 1 or 2, wherein the prongs of the holding means are disposed symmetrically about the middle of the path of movement of the weft laying carriage.
4. A warp knitting machine according to claims 1 to 3, wherein the holding means are plates having forwardly tapering holding pins disposed on their end faces in the form of a comb.
5. A warp knitting machine, particularly a stitch-bonding machine, substantially as herein described with reference to and as shown in the accompanying drawings.