Patent GB-492057-A (GB)
Title: Improvements in or relating to circular knitting machines
IPC: D04B9/16
Filed: 1937-04-08
Abstract: 492,057. Knitting. SCOTT & WILLIAMS, Inc. April 8, 1937, No. 10043. Convention date, April 8, 1936. [Class 74 (ii)] A circular machine having a dial with instruments for holding and transferring loops in the knitting of a welt, as described in Specification 102,711, [Class 74 (ii)], has means whereby an elastic yarn R is interlaced with the needles, so as to be incorporated in the fabric without being knitted, during the knitting of the welt and the transfer of the welt loops to the needles. The elastic yarn may also be incorporated in the stocking top at spaced courses as shown in Fig. 29. The needles are positioned in the path of their operating cams by pattern jacks 381 operated by a cam 366 and by a cam 100 which forces the lower ends of the jacks into the path of a make-up selector lever 102 or reader cams 765 operated from a trick wheel or auxiliary pattern drum 106 as described in Specification 383,840. The rubber yarn is supplied by a slidably mounted guide 110, Fig. 1, controlled by connections 116, 118 from a yarn finger F<7> which is operated by a push rod from a cam 122, Fig. 6 (not shown), on the main pattern drum. The cams 12, 12a are slidably mounted in a bracket 386 on the base plate B and are moved inwardly against spring action by a lever 200 operated by a push rod 462 and a stepped cam 124, Fig. 8 (not shown), on the main pattern drum. The cam 12a is operated to a limited extent only through a spring plunger 383, Fig. 2, from the slide 384 of the cam 12 so that it can engage long butt needles only. The cam 12a is so positioned with respect to the cam 12 that when the rod 462 moves from the face of the main pattern drum to the first level of the cam 124 the cam 12a engages the long butt needles before the cam 12, and when the rod moves to the second and third levels of the cam 124, the cam 12 is moved in to engage the long and short butt needles respectively. When the rod 462 is raised, a pin 462b thereon operates a lever 210 and depresses a lever 214 carrying a sinker cam 189. The rod 462 is also provided with a cam portion 462c, Fig. 3, which engages a finger 239 on a lever 238. and brings a cam 244 into position to force the partly raised jacks 381 off the cam 366 and prevent their associated needles being moved clear of the cam 12. The cam 382, Figs. 2 and 13, is movable radially in a bracket 388 by a lever 220, having one arm engaging an adjustable abutment 223 on the cam and the other arm positioned to engage a stepped cam 461a on a push rod 461 operated from a stepped cam on the main pattern drum, both cams being so shaped that the cam 382 can engage or miss all the needles or engage long butted needles only. The make up selector 102, Fig. 1, 3, 13, is pivoted on the same pin 246 as the reader cams 765 and is operated by a cam on the pattern drum which may carry further cams 123, 123a, Fig. 7 (not shown), to operate clamp and cutter mechanism 230 through a push rod 464. In operation, the selvedge edge is first produced by forming one course on every other needle followed by a course on all the needles, the selection of the needles for the first course being effected by the action of cams 100, 102 on the pattern jacks and by the introduction of the cam 382 which lowers unselected needles before they reach the stitch cam 361. At the second course the cam 12a is inserted to raise all the long butt needles not raised by the pattern jacks and the cam 382 partly withdrawn to allow short butt needles to pass over the stitch cam. The cam 12a is withdrawn at the end of the second course. On the third course the partly withdrawn cam 382 lowers alternate long butt needles and is then advanced to lower alternate short butt needles left at tucking level. At the same time the transfer bits T, Fig. 17, are pushed out at the knitting point to occupy the positions of the inactive cylinder needles and the yarn is drawn over the bits so that in this course alternate loops are taken by the needles and the remaining loops taken and held by the bits T till the completion of the welt. When clamp and cutting mechanism is not used the rubber yarn guide, with the yarn extending to the previous stocking, is lowered just before the leading high butt needle reaches the guide in the third course thus permitting the rubber yarn being engaged with the needles below the latches in advance of the projecting bits. The rubber yarn R is laid on the loops at the back of the fabric during initial courses without being interlaced so that it will be between the walls of the finished welt. On withdrawal of the cam 382 however and insertion of cam 12 selected needles are operated and pull the rubber yarn on to the sinkers which are then operated by retracting and advancing cams so that the yarn, caught in the throats, is pushed inwardly to allow previously unselected needles to pass in front thereof, when the whole of the needles are subsequently raised to take body yarn. When the rubber yarn is cast off at the knitting point it is interlaced between the loops forming the welt as shown in Fig. 29. In order to obtain a clearly defined ribbed appearance the sinkers on each side of the tying on needles advance earlier and to a greater extent at the knitting point than the other sinkers so as to lengthen the loops at wales where the yarn R passes through the sinkers thus operated being provided with high butts 399, Fig. 27, for operation by a cam 312. When the cutter and clamp are used the guide 110 is kept out of action during the knitting of the selvedge and for one or more courses thereafter till a convenient main rack serves to operate the guide, when the yarn is fed and needles operated as before. On completion of the transfer the bits T are withdrawn and reader cam 765 brought into operation for jack selection so as to cause the rubber yarn to be taken by three of every four needles at spaced courses and cast off so that it floats in front of one loop and behind three loops. U.S.A. Specification 1,189,220 also is referred to.