Abstract:
A warp knitting machine which includes a jacquard mechanism to control the pattern threads utilizes the jacquard mechanism to further control a thread breaking device and a thread tensioning device thereby providing an unusual thread pattern without the aid of a conventional pull thread.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to warp knitting machines, and in particular to a warp knitting machine which includes a jacquard mechanism that is used to control a thread tensioning and breaking means. 
     2. Description of the Prior Art 
     Warp knitting machines known in the prior art utilized a jacquard mechanism to steer or control the pattern threads in order to produce ware having smaller or larger openings therein, such as for example, in curtain material a thread in addition to the conventional pattern thread was utilized. This commonly called pull thread is controlled by the jacquard arrangement operating in conjunction with a jacquard bar in accordance with the pre-determined pattern. In a pre-determined manner the neighboring wales were pulled together over one or more stitch rows to create the desired design. It was thus possible to obtain openings of pre-determined size with pre-determined spacings in a pre-determined sequence. 
     According to the prior art, this type of stitch arrangement was only obtainable when a special pull thread and at least one additional jacquard bar was utilized. The additional pull thread, which in accordance with a pre-determined pattern was used to pull together the stitch wales, could not be utilized as a pattern thread. The use of an additional thread to create the desired pattern required the use of a large amount of material and has an undesirable affect in the final ware produced. The actual amount of additional thread used was directly related to the size of the machine which produced the material. 
     SUMMARY OF THE INVENTION 
     The present invention overcomes the shortcomings found in the prior art by providing means for utilizing the pattern thread to function as a pull thread. The pattern thread is controlled by the jacquard control mechanism and varies the tension on the pattern thread as it is led through a thread brake means and a thread tensioning means both of which are controlled by a jacquard mechanism. The jacquard mechanism activates the brake means prior to activating the tension means in order that the thread wales may be pulled together as will be explained hereinafter. Moreover, utilizing the jacquard mechanism to control the thread brake and thread tensioning means is simplified by use of electromagnets associated therewith. 
     Furthermore, in the present system the jacquard mechanism provides for individual steering of the pattern thread as well as individual control of the braking and tensioning of the pattern thread thereby having the capability of providing a maximum number of stitch variations. 
     A warp knitting machine, according to the principles of the present invention, wherein the pattern threads are controlled by a jacquard mechanism comprises, in combination; thread braking means operatively coupled to and controlled by the jacquard mechanism and adapted to receive the pattern threads therethrough, the thread tensioning means being activated at prescribed intervals by the jacquard mechanism after the thread braking means. 
     In a warp knitting machine, according to the principles of the present invention wherein the pattern thread is controlled by a jacquard mechanism, the process of pulling together the wales of knitted goods in a pre-determined pattern by utilizing only the pattern thread comprises; running the pattern thread through a braking mechanism and thread tensioning mechanism controlled by the jacquard mechanism, activating the braking mechanism prior to the activation of the tensioning mechanism at a pre-determined point along the wale to cause the pattern thread to have increased tension, and releasing the tensioning mechanism and the braking mechanism for a pre-determined number of wales before the reactivation thereof. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     In order that the invention may be more fully understood, it will now be described, by way of example, with reference to the accompanying drawings in which: 
     FIG. 1 is a pictorial representation of a warp knitting machine which includes a jacquard mechanism and a thread braking and thread tensioning means operatively coupled thereto, according to the principles of the present invention; 
     FIG. 2 is a side view in elevation of a thread braking and thread tensioning means with a pattern thread passing therethrough; 
     FIG. 3 is a perspective view of a plurality of thread braking and thread tensioning means according to the principles of the present invention; 
     FIG. 4a is a partial view in elevation of a thread braking means in its unactivated position; 
     FIG. 4b is a partial top plan view of the thread braking means in FIG. 4a; 
     FIG. 5a is a partial view in elevation of a thread braking means in its activated position; 
     FIG. 5b is a partial plan view of the thread braking means shown in FIG. 5a; 
     FIG. 6a shows the prior art stitch pattern without thread tensioning; 
     FIG. 6b shows the stitch pattern which provides thread tensioning, according to the principles of the present invention. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring now to the figures, and in particular to FIG. 1, which illustrates a warp knitting machine 10 which has disposed thereon, in a conventional manner, a jacquard mechanism 12 of the type described in U.S. Pat. No. 3,834,193 issued on Sept. 10, 1974, to C. P. Wilkens, a conventional warp beam 14 from which a ground thread 16 is pulled over a tension bar 18 to a ground thread guide bar 20 and a guide 22. Extending downwardly from the jacquard mechanism 12 are three thread harness wires 24, 26 and 28. The wire 24 is connected to a dropper 30 positioned in a dropper bar 32, in a conventional manner. The wire 26 is coupled, via an electromagnet 34, to a thread tensioning device 36. Wire 28 is coupled, via a spring 38, to a thread braking device 40. Spring 38 biases the thread braking device 40 to its open or inoperative condition. A spool 42 provides pattern thread 44 which is guided through a conventional thread brake 46, over guide rollers 48 to a tension bar 50, eyelets 52, provided in the thread braking device 40, through eyelets 54 and 56 provided in a bifurcated portion 58 of plate 60 of thread tensioning device 36, to guide bar 62, eyelets 64 of guide 66 to the needles 68 where the stitches are formed. 
     For convenience the pattern thread 44 is shown in a bolder line than the ground thread 16 to enable one to understand the operation of the present invention. 
     Referring now to FIG. 2 which shows an enlarged view in elevation of a thread tensioning device 36 and the thread braking device 40, according to the principles of the present invention. For ease in understanding the operation of the present invention the pattern thread 44 is shown entering the eyelet 52 provided on plate 60 of thread tensioning device 36 directly from the thread guide 28. The normal or unenergized position of the thread tension device is shown in the dotted lines of FIG. 2. When the thread tensioning device 36 is activated by means of electromagnet 34 under control of the jacquard mechanism 12, it is moved into a position shown in the solid lines of FIG. 2. The pattern thread is caused to interact with the remote pivot points or guides 70, 72 and 74 causing loops 76 and 78 to form, thereby increasing the tension on thread 44 each time a jacquard mechanism 12 activates electromatnet 34. 
     Spring 38 normally biases plate 80 of thread braking device 40 to its normally inoperative condition (applying no restraint to thread 44). Pattern thread 44 is fed through eyelet 82 of plate 80 as well as eyelet 52 in end plate 60. With the thread tensioning device 36 and the thread braking device 40 unactivated eyelets 52 and 82 are in line and therefore thread 44 may pass readily therethrough. 
     The operation of the thread braking device is more clearly shown with reference to the FIGS. 4a and 4b which shows the braking device 40 in its unactivated condition. FIGS. 5a and 5b show the position of plates 60 and 80 when the thread braking device 40 is activated by the jacquard mechanism 12. The movement of plate 80 about pivot point 84 forces eyelets 52 and 82 to move out of alignment thereby causing additional resistance or drag to the pattern thread 44 passing therethrough. 
     FIG. 3 shows a plurality of thread tensioning devices 36 and thread braking devices 40 in tandum and adjusted to operate on a plurality of pattern threads. As shown, one tensioning device 84 has been activated by the jacquard mechanism, not shown. Movement of the thread tensioning device activated by the jacquard mechanism is performed only after the thread braking device 36 has been activated on each of the pattern threads. This enables the portion of the pattern thread in the vicinity of the needles to be tightened, its tension increased, without affecting the thread taken off the spool 42. 
     FIG. 6a discloses a conventional stitch pattern which is accomplished without any tension on the pattern thread 44. 
     FIG. 6b discloses the pattern accomplished by providing thread braking and thread tensioning to the pattern thread at pre-determined intervals in the stitching cycle. The thread wales 86, 88 and 90 are drawn together as the thread brake device 40 and thread tensioning device 36 are activated by the jacquard mechanism 12. 
     Hereinbefore has been disclosed a warp kniting machine wherein the pattern threads are controlled by a jacquard mechanism which activates a thread braking device and thread tensioning device at various points in the knitting cycle. It will be understood that various changes in the details, materials, arrangement of parts and operating conditions which have been herein described and illustrated in order to explain the nature of the invention may be made by those skilled in the art within the principles and scope of the present invention.