Patent GB-614308-A (GB)
Title: Improvements in circular knitting machines and methods of operating same
IPC: D04B9/54
Filed: 1944-11-24
Abstract: 614,308. Knitting. SCOTT & WILLIAMS, Inc. Nov. 24, 1944, No. 23427. Convention date, Nov. 27, 1943. [Class 74(ii)] Each of such transfer elements T in a dial D as hold loops to be transferred to needles in the needle cylinder, is centred over the associated needle by raising the adjacent needles, the needle spacing being such that the element, when advanced with its loop, is wedged between and positioned by these raised needles. The raised needles are, in consequence, somewhat deflected. The arrangement is described in connection with the formation of the inturned welt of Fig. 1, forming the subject of Specification 632,145; the loops 21, 21<1> are those held by the transfer elements. One element is provided over every third cylinder needle, these needles having no jacks associated therewith. The remaining needles are, in alternation, provided with long and short butt jacks. Half the needles are long butt "instep needles" and half are short butt "heel needles." The transfer bits are first projected to receive their loops by a cam 186, Fig. 46, which is advanced in two stages to act first on long butted bits and then on short butted bits also; and are later projected and retracted, to transfer the loops to the associated needles, by cams 195, 196, Fig. 47, which are moved in unison. All these cams are controlled from the main pattern drum. The cams 195, 196 may remain operative during four courses, in order to conserve space on the pattern drum and to ensure the transfer of all the loops. By means of a disc cam, a radially movable jack cam 5, Fig. 4, can be withdrawn to miss all jack butts; partly inserted, as shown, to engage long butts; or fully inserted to act on all butts. The leading edge of the cams is shrouded in a depression in the top of a stationary jack cam 366. A needle lowering cam 382, controlled from the main pattern drum, can be withdrawn or inserted partly or fully to act on long butt needles or all needles. Radially movable lowering and raising cams 8, 20 are also controlled from the main pattern drum, through common connections which act on a slide 143, Fig. 27, carrying the cam 8, to move this radially inwards to operative position. A plate 147 carried on the slide 143 lies behind the outer end of a slide 144 carrying the cam 20 and, through a resilient connection 151, 152, carries the cam 20 in with the cam 8 until a screw 153 on slide 144 engages a fixed upright 141; thereafter, continued movement of the lever moves cam 8 only. Upon release of the cams, both are retracted by a spring. In knitting the first course of the welt, Fig. 1, the cam 5 is inserted half-way, so raising the needles associated with long butt jacks (every third needle) to such a height that they are cleared, ride over the leading stitch cam 361, take yarn and pass down under the following stitch cam 360. Cams 8 and 20 are retracted; but cam 382 is fully advanced and lowers the remaining needles below cam 361. For the second course, cam 5 is fully inserted (and remains so until after the knitting of the transfer course X) cam 382 is retracted or partly retracted (so that it may be fully inserted for later courses without missing half a course or breaking needle butts). Cam 20 is partly inserted to clear all long butt needles not already cleared by cams, and all remaining needles are raised by cam 271. For the third to the sixth courses cam 20 is withdrawn and the jackless needles, which are to hold their loops, are lowered by fully inserting cam 382, the remaining needles being raised to clear and knit. During the sixth course, while short butt needles are passing, cam 20 is partly inserted and remains so until withdrawal of cam 382 during the first part of the seventh course, so that this withdrawal may not cause depression of long butt jackless needles. During the succeeding courses, up to the transfer course. cams 8, 20 and 382 are all retracted and all the needles knit. In knitting of the transfer course, cam 382 remains retracted, but cam 8 is inserted to lower the jackless needles so that the transfer bits can be projected above them. These needles are then raised by cams 271 and 361 to a level where they are cleared through the bits, take the loops therefrom and take yarn and knit. The usual rocking means moves the main pattern drum once every four courses. An auxiliary rocking mechanism which operates during knitting of the selvage courses comprises a segment 69, Fig. 11, and a pawl 66 pivoted to an arm 68 which is in turn pivoted to a fixed point on the machine. The arm 68 is rocked by a cam 91 on the main drive shaft. A more varied needle selection may be obtained by the use of rockable pattern jacks 736, Fig. 56. Specifications 12722/13 and 102,711, [both in Class 74(ii)], and U.S.A. Specification 1,969,853 also are referred to.