Abstract:
A knitting instrumentality for use in a knitting machine and method of forming the same is provided and includes an elongate body member ( 10, 110, 210 ) stamped from sheet metal ( 11, 111, 211 ) in a predetermined shape and having a fine concave-and-convex pattern ( 12, 113, 114, 215 ) formed in the side faces thereof to reduce the contact area of such knitting instrumentality when placed in the knitting machine to reduce the static frictional forces thereon.

Description:
FIELD OF THE INVENTION 
     The present invention relates generally to knitting machines and more particularly to knitting instrumentalities for such knitting machines, in particular circular knitting machines and method of forming such knitting instrumentalities. 
     BACKGROUND OF THE INVENTION 
     Knitting machines, and in particular circular knitting machines, employ knitting instrumentalities to produce the knitted fabric. In a circular knitting machine, a rotating needle cylinder has a multiplicity of vertical grooves in the outer periphery formed by insert pieces which are stationary or fixed. These vertical grooves receive latch needles, intermediate jacks, patterning jacks and possibly other movable knitting instrumentalities for high speed reciprocation. A lubricating oil is sprayed in mist form onto these knitting instrumentalities to ensure smooth and uninterrupted reciprocation. 
     However, as knitting speed increases, these knitting instrumentalities tend to adhere to the insert pieces causing the lubricating oil to be expelled from the grooves and the movable knitting instrumentalities to move sluggishly. An abnormal load is applied to the knitting instrumentalities, particularly the butts of the latch needles and, if the condition persists, such abnormal loads frequently result in breakage of the knitting instrumentalities. Such breakage may cause a chain reaction of breakage of other knitting instrumentalities or peripheral parts of the knitting machine. 
     Attempts have been made to solve this problem with some success, but at substantially increased manufacturing costs because of the complicated processes required to produce the knitting instrumentalities. One example of such movable knitting instrumentalities is disclosed in Japanese Utility Model Laid-Open No.560-127387 (1985). Such knitting instrumentalities are provided with cutouts on opposite side faces with the cutouts on one face being positioned alternately with the cutouts on the other face. Another example is found in Japanese Utility Model Publication H-43419 (1989) in which the movable knitting instrumentalities are provided with projections on their side faces and bottoms. 
     SUMMARY OF THE INVENTION 
     With the foregoing in mind, it is an object of the present invention to provide knitting instrumentalities which are easy and less expensive to manufacture in large quantities while maintaining stable quality and which obviate the deficiencies and disadvantages of prior knitting instrumentalities. 
     This object of the present invention is accomplished by providing knitting instrumentalities that may be manufactured by stamping such instrumentalities from sheet metal in which a fine concave-and convex pattern has been formed to reduce the frictional forces on such knitting instrumentalities and substantially eliminate the tendency thereof to adhere to the insert pieces. In accordance with the present invention, such knitting instrumentalities include both movable and fixed elements capable of being formed by a metal stamping operation and which have surfaces rubbing against other surfaces. Examples of such movable elements are latch needles, intermediate jacks, patterning jacks, etc. and of such fixed elements are insert pieces, etc. Further, examples of such fine concave-and-convex patterns include multiple spaced-apart indentations on at least one surface of the knitting instrumentalities; several continuously formed indentations in at least one surface thereof; an undulating or sinuous shape for at least a portion of the length of the instrumentality; and a cross-sectional shape having thick and thin portions. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Some of the objects and advantages of the present invention having been stated, others will appear as the description proceeds when considered in conjunction with the accompanying drawings, in which: 
     FIG. 1 is a side elevational view of a knitting instrumentality, i.e. a patterning jack, formed in accordance with the present invention; 
     FIG. 2 is an enlarged sectional view taken substantially along line  2 — 2  in FIG. 1; 
     FIG. 3 is a side elevational view similar to FIG. 1 of another embodiment of a knitting instrumentality of the present invention; 
     FIG. 4 is an enlarged sectional view taken substantially along line  4 — 4  in FIG. 3; 
     FIG. 5 is a side elevational view similar to FIGS. 1 and 3 of a further embodiment of a knitting instrumentality of the present invention; 
     FIG. 6 is an elevational view of the knitting instrumentality of FIG. 6 looking in the direction of the arrows  6 — 6  in FIG. 6; and 
     FIG. 7 is a perspective view of a friction resistance apparatus used for testing and evaluating the knitting instrumentalities of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The present invention now will be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Like numbers refer to like elements throughout. 
     Referring now more specifically to the drawings and particularly to FIG. 1, there is illustrated a knitting instrumentality, generally indicated at  10 , in the form of a patterning jack. The knitting instrumentality  10  is formed of sheet metal  11  and is preferably formed by a stamping process by which large quantities can be produced easily and relatively inexpensively while maintaining stable quality. 
     As illustrated in FIGS. 1 and 2, the knitting instrumentality  10  is provided with a fine pattern of concave-and-convex areas in the form of indentations  12 . Indentations  12  are spaced apart with certain intervals therebetween, such as 0.5 mm for example. Indentations  12  are preferably concave polygons, such as triangles, squares, rectangles, etc. or of any other desired shape, such as dimples on a golf ball. 
     Indentations  12  may be formed on only one side of the knitting instrumentality  10  but are preferably formed on both sides thereof. Indentations  12  may be formed in the sheet metal  11  from which knitting instrumentality  10  is stamped, by passing the same through the nip of a pair of rolls having projections on the surface thereof corresponding to the desired pattern of indentations  12 . 
     The pattern of concave-and-convex areas result in thick and thin portions in the knitting instrumentality  10 . In the knitting instrumentality  10 , the indentations  12  define the thin portions  13  and the intervals between the indentations  12  define the thick portions  14 . The difference between the thick portion  14  and the thin portion  13  is preferably between about 0.01 mm and about 0.05 mm and most preferably about 0.02 mm. 
     Referring now to FIGS. 3 and 4, in which like reference characters with the prefix “1” added are used to refer to like elements, there is illustrated a knitting instrumentality, generally indicated at  110 , in the form of a patterning jack. Knitting instrumentality  110  is likewise formed of sheet metal  111  and is produced by a metal stamping operation. In cross-section, knitting instrumentality  110  has a thick center portion  114  and relatively thin outer or end portions  113 . The difference in thickness between portions  113  and  114  is preferably approximately 0.02 mm. The cross-sectional shape of knitting instrumentality  110  is preferably formed by passing the sheet metal  111  through the nip of a pair of rolls (not shown), the surfaces of which have profiles corresponding to the desired cross-sectional shape. 
     Referring now to FIGS. 5 and 6, in which like reference characters with the prefix “2” added are used to refer to like elements, there is illustrated a knitting instrumentality  210 , in the form of a patterning jack. Knitting instrumentality  210  is also formed of sheet metal  211  and has a medial or trunk portion  215  thereof formed in an undulating or sinuous shape longitudinally thereof. As illustrated, there are five (5) undulations  216  which are formed by pressing the stamped knitting instrumentality between upper and lower dies (not shown). In use, only the apogees of the undulation will contact the inserts and therefore the area of contact is substantially reduced. The reduced contact area permits lubricating oil to be supplied into the grooves between the inserts and other knitting instrumentalities  10 ,  110  or  210  so that the movable knitting instrumentalities can move smoothly. Heat generation is also reduced, as is abrasion on the butts of the knitting instrumentalities, thereby prolonging the useful life of the knitting instrumentalities. 
     The knitting instrumentalities  10 ,  110  or  210  of the present invention may be evaluated by a resistance tester  20  (FIG. 7) which measures the static frictional forces on the knitting instrumentalities  10 ,  110 , or  210  and, for comparison purposes, conventional knitting instrumentalities. The tester  20  includes a table, generally indicated at  21 , having a top  22  and legs  23  and  24 . Leg  23  has a horizontal guide  25  mounted thereon, which in turn mounts a spring scale  26  for sliding movement therealong. A weight  27  is connected to spring scale  26  by a line  28  trained about a pulley  29  to bias or move the spring scale  26  to the left as seen in FIG. 7 along an X axis. 
     A wand  30  extends upwardly from the top of the spring scale  26  and engages a knitting instrumentality  10 ,  110 , or  210  or a conventional knitting instrumentality (not shown). A reinforcing plate  31  is mounted on table top  22  in position to engage the opposite end portion of the knitting instrumentality  10 ,  110  and  210 . Plate  31  serves as a fulcrum about which the instrumentality pivots when the weight  27  is released and moves the spring scale  26  to the left for a predetermined distance and as a stop to stop pivoting movement of the knitting instrumentality at the predetermined distance from the starting position. 
     In conducting this evaluation, ten knitting instrumentalities  10 ,  110  and  210  of the present invention and ten conventional knitting instrumentalities of the same shape were selected. The table top  22  was first sprayed with lubricating oil and then a knitting instrumentality was placed thereon in the starting position along a Y axis (shown in FIG. 7) and the knitting instrumentality is then moved in a reciprocating sliding manner twenty (20) times along the Y axis while the knitting instrumentality is pressed downwardly at points A and B by the person conducting the test. The spring scale  26  is then moved to the right until the wand  30  engaged the right side edge of the knitting instrumentality and the weight  27  is released and permitted to fall freely until the knitting instrumentality is stopped by plate  31 . The scale  26  is then read and the amount shown thereon is recorded. Table 1 below lists the results recorded in tests on the ten conventional knitting instrumentalities and the ten knitting instrumentalities  10  (Example 1 in Table 1), the ten knitting instrumentalities  110  (Example 2 in Table 1) and the ten knitting instrumentalities  210  (Example 3 in Table 1). 
     
       
         
               
             
               
               
               
               
               
               
               
               
               
               
               
               
             
               
               
               
               
               
               
               
               
               
               
               
               
             
           
               
                 TABLE 1 
               
             
             
               
                   
               
               
                 Unit: g 
               
             
          
           
               
                   
                 1 
                 2 
                 3 
                 4 
                 5 
                 6 
                 7 
                 8 
                 9 
                 10 
                 Average 
               
               
                   
                   
               
             
          
           
               
                 Conventional 
                 55 
                 85 
                 85 
                 60 
                 77 
                 93 
                 64 
                 64 
                 52 
                 70 
                 70.5 
               
               
                 Product 
               
               
                 Example 1 
                 20 
                  8 
                 16 
                  5 
                 11 
                 35 
                 28 
                 11 
                 16 
                 13 
                 16.3 
               
               
                 Example 2 
                 40 
                 20 
                 20 
                 29 
                 12 
                  5 
                 17 
                 16 
                 26 
                 11 
                 19.6 
               
               
                 Example 3 
                 21 
                 20 
                 17 
                  3 
                 15 
                 14 
                 15 
                 14 
                 10 
                  7 
                 13.9 
               
               
                   
               
             
          
         
       
     
     As is readily apparent, the knitting instrumentalities  10 ,  110  and  210  of the present invention are subject to significantly reduced static frictional forces compared to the conventional knitting instrumentalities. 
     Many modifications and other embodiments of the invention will come to mind to one skilled in the art to which this invention pertains having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is to be understood that the invention is not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.