Patent GB-191514606-A (GB)
Title: Improvement in Circular Knitting Machines.
Inventor: SCOTT ROBERT WALTER
IPC: D04B9/00
Filed: 1915-10-15
Abstract: 14,606. Scott, R. W. Dec. 19, 1914, [Convention date]. Circular machines; knitted fabrics.-Relates to machines of the kind described in Specification 12,722/13, and comprises means whereby the needles may be selectively operated to cause certain needles to retain their loops or to knit whilst other needles are caused to knit or cast off, for example in the production of welts knit upon as relatively large a number of needles as the attached fabric, or for knitting successive sections of fabric each having the same number of knit wales, one section having needle wales corresponding to sinker wales of a succeeding section. The needles are selected by long and short jacks j<3>, j<1> provided with butts engaging grooves 364, 365, which are raised by cams 366, 367 arranged in advance of the stitch cams 8, the long-jack needles being raised to clear whilst the short-jack needles are raised only to the tuck level. In advance of the movable 'depressing-cam 382, are arranged supplementary depressing and advancing cams 2<a>, 2<b> carried by a movable pattern-controlled member. When the cam 382 is advanced into operative position and the cams 2<a>, 2<b> are withdrawn, the longjack needles pass above the cam 382 and knit, whilst the short-jack needles are depressed to enter the non-knitting track 10. When the cams 2<a>, 2<b> are advanced, all needles are depressed by the cam 2<a>, but the short-jack needles are again raised by their jacks j<1> and are advanced by the cam 2<b> to clear and pass into the stitch cams; the long-jack needles, previously cleared by the action of the cam 366, pass into the track 10 and cast off their loops. In forming an article, a selvedge as described in Specification 12,727/13 may be first formed from a course of yarn run on the long-jack needles during the withdrawal of the short-jack needles, followed by a course of yarn fed to all needles; then a welt may be formed upon the long-jack needles, followed by a locking- course knitted on all the needles, after which plain fabric may be knitted upon the shortjack needles. By making a suitable set-up on the long-jack needles and knitting a section of fabric on these needles only, and then introducing the short-jack needles and withdrawing the long-jack needles, plain fabric may be produced, composed of successive sections having the same number of needle wales, in which the needle wales of one section correspond to sinker wales of the succeeding section. As shown in Fig. 16, the jacks j<1>, j<3> are arranged alternately, whereby a fabric is produced having in the welt the same number of needle wales as in the attached plain fabric. Fig. 17 shows a modification in which the loops are cast off from part only of the needles forming the welt. As shown, the short jacks j<1> occupy every alternate needle groove, whilst the long jacks j<3> every fourth groove; the remaining grooves are occupied by jacks j<2> controlled by the groove 365, of such a length as to raise their respective needles always above the cam 382. When the cam 382 is operative, the needles operated by jacks j<1> are depressed to retain their loops; but when the cams 2<a>, 2<b> are advanced, only those needles corresponding to the long jacks j<3> are caused to cast off loops. The cams 382, 2<a>, 2<b> are preferably inserted and withdrawn in two stages corresponding to the passage of the long-butted needles. Figs. 14 and 15 show suitable jacks, the jacks j<1>, j<2> having a central butt and a lower bevelled portion. To prevent articles from clinging to the needles when cast off, a stationary friction device consisting of a tube 405, Fig. 2, supported by a stationary arm 406. or an arm such as 406 extending within the needle cylinder 260 may be provided.