Patent Publication Number: US-3879962-A

Title: Fabric hold-down blade for circular hosiery knitting machines

Description:
[451 Apr. 29, 1975 1 1 FABRIC HOLD-DOWN BLADE FOR CIRCULAR HOSIERY KNITTING MACHINES [75] Inventor: Peter A. Mahler, High Point, N.C.  
 [73] Assignee: H. E. Crawford Co., Inc.,  
 Kernersville, N.C.  
 [22] Filed: Mar. 25, 1974 [21] Appl. N0.: 454,330  
 I5 I If I5 14 5O Tia IO 1,936,166 2/1970 Germany 66/9 R 4,568 l/1895 United Kingdom 66/104 268,796 6/1964 Netherlands 66/90 Primary Examiner-Wm. Carter Reynolds Attorney, Agent, or FirmParrott, Bell, Seltzer, Park &amp; Gibson [57] ABSTRACT The fabric hold-down blade is positioned opposite the yarn feeding position and is supported on the dial for vertical movement between the outer periphery of the dial and the circle of cylinder needles. Pattern control means is provided for lowering the fabric hold-down blade so that the lower end engages the fabric when the fabric is being formed on the cylinder needles only and for raising the fabric hold-down blade upwardly so that the lower end is above the level of and will not interfere with the operation of the dial needles when the fabric is being formed on the dial and cylinder needles.  
 6 Claims, 3 Drawing Figures FABRIC HOLD-DOWN BLADE FOR CIRCULAR HGSIERY KNITTING MACHINES The invention relates generally to a fabric hold-down blade for a circular hosiery knitting machine and more particularly to a fabric hold-down blade for a circular hosiery knitting machine of the type adapted to knit socks of the type having a ribbed cuff with terry loops on the inside of the foot portion.  
  In the knitting of this type of sock on a circular hosiery knitting machine having a set of dial and cylinder needles, it is the usual practice to knit this type of sock with three yarns, at least in those portions having terry loops. Two of these yarns are usually referred to as body yarns and are fed to the needles at a relatively low position while the third or terry yarn is fed to the needles at a high position so that it may be laid over the nibs of the sinkers. In order to provide a relatively wide separation between the terry yarn and the body yarns, it is the usual practice to provide a drop throat plate at the yarn feeding station. In order to avoid engagement of the downwardly extending portion of the throat plate by the sinkers, it is necessary to move the sinkers outwardly at the yarn feeding station so that they do not hold the fabric down on the needles as they pass the yarn feeding station. If the fabric is not held down to the normal level, during both rotary anti reciprocatory knitting, the relatively wide separation between the terry yarn and the body yarn is not maintained and this results in the improper positioning of the yarns relative to the nibs of the sinkers.  
  With the foregoing in mind, it is an object of the present invention to provide a fabric hold-down blade which is adapted to be moved downwardly so that its lower end engages and holds the fabric down in the normal position on the needles when the fabric is being formed during both rotation and reciprocation of the cylinder needles so that the proper separation of the terry and body yarns is maintained. The fabric holddown blade is also raised upwardly so that its lower end is above the level of and will not interfere with the op eration of the dial needles when the fabric is being formed on both the dial and cylinder needles.  
  In accordance with the present invention, the fabric hold-down blade is positioned opposite the throat plate and between the dial and the cylinder needles and its upper end is fixed on a slide block which is supported for vertical movement on a pair of slide posts, the lower ends of which are fixed in the dial. A compression spring is supported between the slide posts and normally urges the slide block and the fabric hold-down blade to an uppermost position. Pattern control means is provided for lowering the slide block and the fabric hold-down blade when the fabric is being formed on the cylinder needles only and for raising the slide block and the fabric hold-down blade upwardly to an inoperative position and above the level of the dial needles when the fabric is being formed on both the dial and cylinder needles.  
  Other objects and advantages will appear as the description proceeds when taken in connection with the accompanying drawings, in which FIG. l is a fragmentary top plan view of a portion of the latch ring and dial of the knitting machine, with parts in section, and with the fabric hold-down blade of the present invention being supported on the dial;  
  FIG. 2 is a vertical sectional view taken substantially along t e line 2-2 in FIG. 1 and illustrating the fabric hold-down blade in solid lines in the position it assumes in engagement with the fabric as it is being formed on the cylinder needles, and showing the fabric hold-down blade in dotted lines in the position it assumes when it is raised to an inoperative position; and  
  FIG. 3 is a fragmentary isometric view of the fabric hold-down blade, looking in the direction of the arrow 3 in FIG. 1, and showing the fabric hold-down blade in the raised position.  
  The circular hosiery knitting machine includes a circle of cylinder needles 10 which are supported for vertical sliding movement in a slotted needle cylinder 11. A dial bed 12 is fixed on the lower end of a dial drive shaft 13 and the dial bed 12 is radially grooved to receive dial needles 14 for radial sliding movement therein. Dial needle control cams 15 are supported on the lower surface of a dial plate 16 and control the inward and outward radial movement of the dial needles 14. A latch ring 20 surrounds the circle of cylinder needles 10 and is pivotally supported on a shaft 21. A drop throat plate 22 is supported in the latch ring 20 and at the yarn feeding station.  
  Yarn feed means, illustrated as a single yarn feed finger 24, is positioned for movement into and out of operative position in the throat plate 22 for selectively feeding yarn to the dial needles 14 and the cylinder needles 10 to form either rib or plain knit fabric, as indicated at F. Although only one yarn feed finger 24 is illustrated, it is to be understood that there are usually three or more yarn fingers positioned for movement into and out of operative position in the throat plate 22. The finger 24 is at times raised to inoperative position by a thrust rod 25, the lower end of which is adapted to engage and be operated by cams on a main pattern drum, not shown, in the usual manner.  
  A sinker bed 30 is supported on the upper end of the needle cylinder 1 l and is grooved to support sinkers 31 for radial movement between the cylinder needles 10. A sinker cap 32 is supported on the sinker bed 31 and contains suitable cams for moving the sinkers 31 inwardly and outwardly in a radial direction. As the sinkers 31 approach the yarn feeding station, they are moved outwardly so that the nibs pass outside of the downwardly extending portion of the drop throat plate 22. The sinkers 31 are then moved inwardly between the cylinder needles 10 so that the nibs of the sinkers pass between the yarns being fed at a low position and the yarn being fed at a high position to form terry loops of the upper yarn. As illustrated in FIG. 2, body yarns Y-l and Y-2 are fed to the needles at a low position by the yarn feed finger 24 while the terry yarn Y-3 is fed to the needles at a relatively high position by the feed finger 24. The yarns pass downwardly through yarn guide eyes 35 which are fixed in a plate 36 supported on a bridging portion 37 of the latch ring 20.  
  Since the sinkers are in an outermost position at the throat plate, the fabric has a tendency to ride up on the cylinder needles so that the normal separation between the terry yarn Y-3 and the body yarns Y-l and Y-2 is reduced. The fabric has a greater tendency to ride up the cylinder needles 1D when the needles are reciprocated in the clockwise direction, as when kitting heel and toe pockets. When the direction of movement of the needle cylinder is reversed to move clockwise, the yarn take-up wires provide additional tension on the yarns and this tends to pull the fabric up on the cylinder needles.  
  To maintain the fabric in its normal position on the cylinder needles. a fabric hold-down blade is positioned opposite the throat plate 22 and its lower end portion is positioned between the outer periphery of the dial l6 and the circle of cylinder needles 10. Support means is positioned on the dial 16 for supporting the blade 40 for vertical movement between the operative position shown in solid lines in FIG. 2 and the inoperative position shown in dotted lines in FIG. 2. The fabric hold-down blade support means includes a pair of spaced apart slide posts 41, 42 which are threadably supported at their lower ends in the upper surface of the dial l6 and extend upwardly therefrom. A slide bracket or block 43 is provided with a pair of vertically extending bores 45, 46 (FIG. 3) which are adapted to engage and slideably support the slide block 43 on the slide posts 41, 42.  
  Resilient means. in the form of a compression spring 50, is provided for normally urging the slide block 43 upwardly so that the fabric hold-down blade 40 is raised to the upper or inoperative position shown in FIG. 3 with its lower end above the level of the dial needles 14. The lower end of the compression spring 50 is supportedin a hole in the upper surface of the dial plate 16 and the upper end of the compression spring 50 extends up inside of a hole in the slide block 43. The upper end of the fabric hold-down blade 40 is fixed on the slide block 43, as by screws 52 (FIG. 3).  
  Adjustment means is carried by the slide block 43 for adjustably limiting the amount of downward movement of the slide block to thereby limit the downward movement of the lower end of the fabric hold-down plate 40 against the fabric F. This adjustment means is illustrated as a screw 53 which is threaded in the upper end of the slide block 43 and extends downwardly through the center of the compression spring 50. The lower end of the screw 53 is adapted to engage the dial plate 16, as illustrated in dotted lines in FIG. 2, when the slide block 43 is moved to the lower or operative position. A control arm 54 is supported at one end on the upper surface of the slide block 43 by means of a lock nut 55 and extends outwardly therefrom.  
  Pattern control means is provided for lowering the slide block 43 and the fabric hold-down blade 40 to engage the fabric F when the fabric is being formed on only the cylinder needles l0 and to allow the compression spring 50 to raise the slide block 43 and the fabric hold-down blade 40 upwardly so that the lower end of the fabric hold-down blade 40 is positioned above the level of the dial needles 14 when the fabric is being formed on both the dial and cylinder needles. This pattern control means includes a control lever 60, the forward end of which is adapted to overlie and engage the control arm 54 and a medial portion of which is pivotally supported on a shaft 61 (FIG. 2) fixed in the bridging portion 37 of the latch ring 20. The upper end of a thrust rod 62 engages the outer end of the control lever and the lower end of the thrust rod 62 is adapted to be raised and lowered by suitable cams on a main pattern drum, not shown, for moving the control lever 60 between the solid and dotted lines positions shown in FIG. 2.  
  The fabric hold-down blade of the present invention is thus adapted to be moved downwardly to the solid line position shown in FIG. 2 when the fabric is being knit on the cylinder needles only to maintain the fabric at a low position on the cylinder needles as they are raised to pick up and knit the yarn at the yarn feeding station. The fabric hold-down blade 40 maintains the fabric F at the proper level during both rotary and reciprocatory knitting so that the proper separation between the terry and body yarns is maintained. When rib fabric is being knit on both the dial and cylinder needles. the fabric hold-down blade 40 is raised to the dotted line position shown in FIG. 2 so that the lower end is above the level of the dial needles l4 and the blade 40 will not interfere with the radial movement of the dial needles as they are projected outwardly at the yarn feeding station to pick up and knit yarn in cooperation with the cylinder needles.  
  In the drawings and specification there has been set forth a preferred embodiment of the invention, and although specific terms are employed, they are used in a generic and descriptive sense only and not for purposes of limitation.  
 That which is claimed is:  
  1. In a circular hosiery knitting machine including a circle of cylinder needles. a dial positioned within said circle of cylinder needles. dial needles supported for radial movement in said dial. a latch ring surrounding said circle of cylinder needles, a throat plate positioned in said latch ring, and yarn feed means positioned for movement into and out of operative position in said throat plate for selectively feeding yarn to&#39;said dial and cylinder needles to form fabric thereon; the combination therewith of fabric hold-down means comprising a. a fabric hold-down blade positioned opposite said throat plate and between said dial and said circle of cylinder needles,  
 b. support means positioned on said dial and supporting said blade for vertical movement between the outer periphery of said dial and said circle of cylinder needles. and  
 c. pattern control means for lowering said support means and said fabric hold-down blade to engage the fabric when the fabric is being formed on said cylinder needles only and to raise said support means and said fabric hold-down blade upwardly so that the lower end of said fabric hold-down blade is above the level of said dial needles when the fabric is being formed on said dial and cylinder needles.  
  2. In a knitting machine according to claim 1 wherein said support means comprises a pair of slide posts supported in spaced apart relationship on the upper surface of said dial and extending upwardly therefrom, a slide block supporting the upper end of said fabric hold-down blade and including a pair of vertically extending holes adapted to engage and slideably support said slide block on said slide posts for vertical movement. and resilient means normally urging said slide block upwardly on said slide posts.  
  3. In a knitting machine according to claim 2 including adjustment means carried by said slide block for adjustably limiting the amount of downward movement of said slide block to thereby limit the downward movement of the lower end of said fabric hold-down plate.  
  4. In a knitting machine according to claim 2 wherein said resilient means comprises a compression spring supported in a vertical position between said slide posts and having upper and lower ends. the lower end of said compression spring being seated against said dial and the upper end of said compression spring being seated against said slide block.  
  5. ln a knitting machine according to claim 3 wherein said adjustment means comprises a screw threadably supported in said slide bracket and extending downwardly therefrom so that the lower end thereof engages said dial to limit the downward movement of said slide 5 said cylinder needles only.  
 bracket.  
  6. In a knitting machine according to claim 1 wherein said pattern control means includes a lever engageable with the upper portion of said support means for imparting downward movement thereto when knitting on