Device for producing a plush-like surface structure

Abstract

Assembly in a double needle-row knitting machine for producing a plush-like surface structure includes a pair of knitting needle rows spaced from one another, a pair of knocking-over bars disposed adjacent the needle rows, respectively, within the space therebetween and spaced, in turn, from one another, the needle rows and the knocking-over bars being actuable for knitting respective individual webs located adjacent the respective knocking-over bars and connected by pile threads extending therebetween to form a base fabric web, the knocking-over bars having respective edges for firmly holding stitches knitted by the needles, and a severing device located in the space between the knocking-over bars directly below the edges of the knocking-over bars for severing the pile threads to separate the individual webs.

Description

The invention relates to device or assembly for producing plush-like surface structures, and more particularly, in a double needle-row knitting machine, such as a Raschel knitting machine, for example, having a severing device which separates the base fabric web into individual webs.

In devices or assemblies of the foregoing general type, a base fabric or cloth web is first knitted which is made up of two individual webs that are connected to one another or interwoven by so-called pile threads. Thereafter, the pile threads are severed by a cutting device so that two individual webs are formed which, depending upon the spacing of both needle rows from one another, have a greater or lesser high pile. Each individual cloth web is passed over a transport roller and finally wound on separate winding mandrels.

It has been known heretofore to separate the base cloth web beforehand within the knitting machine into two individual webs and for this purpose, for example, to dispose between the transport rollers a rotary knife-blade, which is displaceable along the width of the cloth web.

When cutting apart the base fabric web with this heretofore known device, there is, however, no assurance that the pile threads forming the pile will be severed exactly in the middle thereof and that both individual fabric webs will have the same pile height.

It is accordingly an object of the invention to provide in a double needle-row knitting machine, an assembly for producing a plush-like surface structure which avoids the foregoing disadvantages of the heretofore known assemblies of this general type. More specifically, it is an object of the invention to provide such assembly which will avoid the formation of plush-like surface structures having non-uniform pile heights.

With the foregoing and other objects in view, in accordance with the invention, there is provided in a double needle-row knitting machine, an assembly for producing a plush-like surface structure comprising a pair of knitting needle rows spaced from one another, a pair of knocking-over bars disposed adjacent the needle rows, respectively, within the space therebetween and spaced, in turn, from one another, the needle rows and the knocking-over bars being actuable for knitting respective individual webs located adjacent the respective knocking-over bars and connected by pile threads extending therebetween to form a base fabric web, the knocking-over bars having respective edges for firmly holding the stitches knitted by the needles, and a severing device located in the space between the knocking-over bars directly below the edges of the knocking-over bars for severing the pile threads to separate the individual webs. By the term "directly" there is meant a location of the severing edge so close to the edges of the knocking-over bars as to permit the pile threads to be severed almost immediately or, at most, shortly after they are formed between the individual fabric webs. The spacing between the severing edge and the edge of the knocking-over bars should only be large enough for the base fabric web to be held together over a few courses by the yet-unsevered pile threads connecting the individual fabric webs. Since the base fabric web need not thereby be passed for very long distances to the severing location at the transport rollers, there is no possibility that the pile threads would be relieved of tension in different manner before the severing thereof and thereby be of different length. Furthermore, the harmful influence of unavoidable production inaccuracies on the take-up rollers, such as off-centering thereof or the like, are avoided because they now no longer determine the pile height at the severing location but rather only fulfill reversing functions in direction toward the respective take-up mandrel. In consideration of the foregoing data, it will be generally advantageous to select the spacing between the severing edge and the upper edges of the knocking-over bars so that it corresponds to the width of five courses at most.

In order to be able to determine in an optimal manner the number of the pile threads still holding together the base fabric web before the severing thereof into individual webs, there is provided in accordance with a further feature of the invention, a severing device that is vertically adjustable. In accordance with yet another feature of the invention the severing device is in the form of a revolving band blade which is advantageously operatively connected to a sharpening device.

In accordance with an additional feature of the invention, the revolving band blade is supported in a guide member corresponding to the width of the fabric web.

According to a concomitant feature of the invention, the guide member is constructed as a profile rod braced or supported through the individual webs of the fabric at the knocking-over bars. Due to this construction, all of threads of the individual webs act as a vibration-damping member between the rear sides of the needle bars and the rear side of the guide member constructed as a profile rod and supporting the revolving band blade. In this way, accuracy in the severing operation can be additionally improved.

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 device for producing a plush-like surface structure, 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 single FIGURE of the drawing showing diagrammatically and in sectional view an embodiment of the assembly for producing a plush-like surface structure according to the invention.

Referring now to the drawing, there is shown therein an assembly for producing a plush-like surface structure in a double needle-row knitting machine. In the interest of clarity, only those features of the knitting machine necessary for an understanding of the invention are shown in the figure. Thus, guide needles 1 and 2 are shown with warp threads 3 and 4, and a guide needle 5 with a pile thread 6, which is formed with the warp threads 3 and 4 by means of knitting needles 7 and 8 into a closed base fabric web 9. Knocking-over bars 10 and 11 are separated by a spacing a which determines the length of the pile threads and thereby the height of the pile of the individual webs 12 and 13 of which the base fabric web 9 is formed. Exactly in the middle between the knocking-over bars 10 and 11, there is located a severing device 14 made up of a revolving band blade 15 and a guide member constructed as a profile rod 16 which guides and supports the band blade 15. It is clearly apparent that the cutting edge 17 of the bank blade 15 is located directly below the edges 18 and 19 of the knocking-over bars 10 and 11 which firmly hold the stitches so that in the illustrated embodiment, only a single unsevered pile thread 6' still forms or holds together the base fabric web 9. The smallest possible spacing is simultaneously shown between the cutting edge 17 and the edges 18 and 19 of the knocking-over bars 10 and 11. Below the cutting edge 17, the pile threads 9 have all been severed and form the pile 20 and 21 of the individual webs 12 and 13. It is further apparent how the individual webs 12 and 13 with the piles 20 and 21, respectively, fill out the spaces between the knocking-over bars 10 and 11 and the profile rod 16 and thereby serve additionally as vibration-damping member for the guide member 16 of the severing device 14. The individual webs 12 and 13 are passed over transport rollers 22 and 23 and are wound up on non-illustrated take-up mandrels in a conventional manner.

As mentioned hereinbefore, the scope of the invention in this application is not limited to the illustrated embodiment. Thus, for example, instead of a revolving band blade or other mechanical severing devices, such as rotary circular blades that are displaceable along the width of the fabric web or reciprocatingly swinging band blades, thermoelectrically or chemically active severing devices can also be used.

Claims

I claim:

1. In a double needle-row knitting machine, an assembly for producing a plush-like surface structure comprising a pair of knitting needle rows spaced from one another, a pair of knocking-over bars disposed adjacent said needle row, respectively, within said space therebetween, and spaced in turn, from one another, said needle rows and said knocking-over bars being actuable for knitting respective individual webs located adjacent the respective knocking-over bars and connected by pile threads extending therebetween to form a base fabric web, said knocking-over bars having respective edges for firmly holding the stitches knitted by the needles, and a severing device located in the space between said knocking-over bars directly below said edges of said knocking-over bars for severing said pile threads to separate said individual webs, whereby said pile threads are severed just after being formed before the tension is relieved to provide for severance substantially at the middle of the pile threads and resulting in individual fabric webs of substantially the same pile height.

2. Assembly according to claim 1, wherein said severing device is a revolving band blade.

3. Assembly according to claim 2 including a guide member having a length corresponding to the width of the fabric web, said revolving band blade being supported by said guide member.

4. Assembly according to claim 3 wherein said guide member is constructed as a profile rod engageable through the individual webs of the fabric with the knocking-over bars.