Patent GB-1235134-A (GB)
Title: Circular warp knitting machine
IPC: D04B25/02
Filed: 1968-10-15
Abstract: 1,235,134. Knitting. RENFRO HOSIERY MILLS CO. 15 Oct., 1968 [18 Oct., 1967; 6 Aug., 1968], No. 48790/68. Headings D1C and D1K. A stocking tube is produced and shaped on a circular warp knitting machine by feeding sets of warp yarns W-1, W-2 through apertures in separate guide rings 140, 142 to the needles 31 contained in a cylinder 30 and which are reciprocated to cause them to knit the yarns. A warp knitted structure is achieved by oscillating the guide rings 140, 142 about the needle cylinder during the continuous and repeated movement of the needles so that an openwork or patterned warp knitted structure is produced, Figs. 15, 27 and 32. Each stitch may consist of single or double loop structure and an ornamental effect can be achieved by providing a heavy pattern design yarn (H-1<SP>11</SP>, H-2<SP>11</SP>) at desired intervals, Fig. 32 not shown. The needles are reciprocated to effect knitting by a needle operating ring 34 engaging their butts and which is reciprocated by an eccentric on a drive shaft of the machine. The yarn guide rings 140, 142 have a suitable profiled edge 144, 155 which is engaged by rollers 146 to guide the rings during their oscillating movement imposed by links 160, 162 coupled to them and driven by a pair of cam wheels 173, 174. The cam wheels are rotated in timed relation to the machine speed and have the desired contour to effect the necessary laying and lapping of the yarns about the needles to produce the warp knitted structure. In addition the yarns are fed from a creel to the guide rings after passing around a grooved feed roller which is driven through a variable speed drive from the drive shaft of the machine. A pair of fabric take-down rollers 46, 47 are also driven from the variable speed drive and at a rate corresponding to the rate of feed of the yarns. Variation in the rate of feed of the yarns alters the stitch length or quality of the fabric whereby shaping of the knitted stocking tube is achieved. The take-down rollers are likewise adjusted to compensate for the variation in the amount of fabric produced. Associated with the take-down rollers is a cutter 93 which under the control of the links 99 on a pattern chain slits the fabric tube longitudinally as it passes over a flattened guide member 92. The slit portion is to provide edges which can be joined to corresponding edges of another tube when manufacturing tights. On completion of each tubular portion each portion is separated from the next by a cutter 51 between the blades 100, 101 of which the fabric tube passes after it has been delivered from between the take-down rollers 46, 47. The top blade 101 is movable and is controlled by a solenoid which is energized at desired intervals. The yarns from the creel each support a dropper of a stop motion after the yarns have passed around the feed roller. The wrap yarns are divided into the two sets prior to feeding to the rings 140, 142 one group W-1 being fed direct to the apertures in the guide ring 140 and the other set being subdivided into three groups and passed round guiding springs 154 prior to entering the apertures in the guide ring 142. Two or more than two guide rings may be used and the rings may be threaded up to produce various patterned designs and wrap knitted structures using similar or dissimilar yarns including stretch yarns.