Patent GB-865178-A (GB)
Title: Improvements in or relating to knitting machines
IPC: D04B9/02
Filed: 1957-06-25
Abstract: 865,178. Knitting-machines. SCOTT & WILLIAMS Inc. June 25, 1957 [July 19, 1956], No.20038/57. Class 74 (2). Stitch control means for a circular knitting- machine having needles and sinkers co-operating therewith for the formation of stitches comprises sensing means responsive to the size of stitches produced and means responsive to said sensing means controlling the size of stitches being formed, the last-mentioned means including pneumatic motor means and controlling means therefor operated by said sensing means. A cam 150, pivoted at 152, feels and follows backs of sinkers and, as the position of the sinker varies as a result of small deviations from the predetermined loop size, causes the opening of one and closing of the other of nozzles 184, 186, which control pneumatic motor means operative to correct the stitch length by raising or lowering of the needle cylinder, or by varying the time of dwell of needles at their lowest point, or by allowing the needles to fire to a lower point, or both, or by variation in the effective tension applied by a grab take-up. Movements of the cam 150 rock a lever 156 which, in turn, causes rocking of levers 164, 166, carrying baffles 168, 170, so that one nozzle may be opened to atmosphere and the other closed. The nozzles control relays 64, 66, supplied with compressed air through pipe 58 and patterncontrolled valve 63; and the outlets from the relays are connected, the one to an oil reservoir 82 feeding one end of an oil cylinder 84 and the other to the other end of the cylinder. Thus, a piston in the cylinder is moved up or down and, acting through rod 94, links 96, 98, and arm 122, rotates a cam 110 to raise or lower the needle cylinder, through a screw 114. Resultant normalization of sinker movement will bring the mechanism to the position in which both nozzles are open and the cylinder height fixed for the time being. The basic cylinder height corresponding to the loop length for each of the parts of the stocking is determined by rocking about its pivots a stirrup 106 on which the cam 110 is mounted, the position of the stirrup being determined by screws 130, 132 carried on an extension thereof and co-operating with cams 134, 136 on the fashioning drum. A third screw 126 may abut against a fixed stop, as shown, to limit descent of the cylinder, or may coact with a third cam, to provide for further lowering of the cylinder. The levers 156, 164, 166 are carried on a slide 160 urged radially inwardly of the needle cylinder by a spring 200 until an adjustable screw 198 abuts against a wedge 188; and the position of this slide is adjusted in correspondence with the basic height of the needle cylinder by cams on the cam drum, acting through a Bowden wire 190. The pneumatic control may be disabled by a cam rotating with the main pattern drum. Variation of loop length for leg fashioning is provided by step-by-step small upward movements of wedge 188. In Fig. 16, the stitch cam 384 is fixed and the boxing-in cam 386 is vertically slidable relatively thereto under control of the pneumatic means. In Fig. 18, the pneumatic means, through cylinder 490 and link 484, traverses a counterweight 472 along a lever 444 to vary, through a cord 412, the effective weight of a grab take-up. Specifications 753,213, 764,694, 865,179, 856,180, 865,181 and 865,182 are referred to.