Patent GB-996291-A (GB)
Title: Improvements in or relating to circular knitting machines including pattern mechanisms
IPC: D04B15/68
Filed: 1961-09-29
Abstract: 996,291. Knitting machines. A. PLANCK. Sept. 29, 1961, No. 35332/61. Heading D1C. In a circular knitting machine having knitting on transfer needles controlled by selector jacks, which jacks have both pattern butts and elimination butts, a pattern mechanism includes selector cams and eraser cams for co-operating with the pattern and elimination butts respectively and separate pattern control means for the selector and eraser cams which are driven independently of each other. As shown, needle cylinder 1, Fig. 1, has vertical grooves each of which contains a knitting needle 6 (or a transfer needle or the like) a needle operating swing jack 10 and a needle selector jack 15. Each needle 6 has a butt 6<SP>1</SP> which, when in working position, is guided in a cam groove 200, Fig. 6, in cam box 8 and an indentation to receive a hook-shaped head 10<SP>1</SP> on the associated jack 10. Each jack 10 has a butt 10<SP>2</SP> which in working position engages a cam track 201 in cam box 8. Lifting cams 202 in track 201 lift needles 6 through butts 10<SP>2</SP> of jacks 10 while lowering cams 203 in track 200 engage butts 61 to lower the needles. Alternatively needles 6 may be lowered by another cam in track 201 engaging butts 10<SP>2</SP> of jacks 10. A projection 10<SP>3</SP> on each jack 10 on the side opposite to butt 10<SP>2</SP> can withdraw into a groove 1<SP>1</SP> in cylinder 1 and prevents jack 10 from tipping sideways under the influence of frictional forces operating on butt 10<SP>2</SP>. The lower end 10<SP>4</SP> of each jack 10 projects between prongs 15<SP>1</SP>, 15<SP>2</SP> at the upper end of each selector jack 15 and forms a connection therewith. The jacks 15 are adapted to be selectively moved to the right at the top, to disengage butts 10<SP>2</SP> of swing jacks 10 from their lowering cam, by cam levers 32<SP>1</SP> controlled by a pattern drum 39<SP>1</SP> engaging butts 42 of the jacks. All the jacks 15 are returned to their normal position by means of a fixed cam 45<SP>1</SP>, Fig. 2, engaging butts 15<SP>3</SP> on the prongs 15<SP>2</SP> after the knitting operation ready for the next selection. The selector jacks 15 are also under over-riding control by long and short eraser cams 32<SP>2</SP>, 32<SP>3</SP> co-operating with elimination butts 43 on the jacks and controlled by a separate eraser drum 39<SP>2</SP>. These cams act to move the lower end of jacks 15 to the right to pivot them about projections 15<SP>4</SP> to return the top end of the jacks, which have been moved to the right by selector cams 32<SP>1</SP>, to the normal position. The lower ends of jacks 15 are returned to normal, by a cam 45 on a fixed track 20 acting on butts 15<SP>5</SP>, after the knitting operation. The long eraser cams 32<SP>2</SP> act when the butts 15<SP>5</SP> are not retained by cam 45 to return jacks 15 to normal position for needle operation. The short eraser cams 32<SP>3</SP> act when butts 15<SP>5</SP> are engaged by cam 45 to move jacks 15 from normal to take the needles out of operation. These short eraser cams engage with butts 43 at the same height on all the selector jacks over a certain section of the knitted article so that all the needles in this section can be kept out-of-action. The selector and eraser drums 39<SP>1</SP>, 39<SP>2</SP> are actuated by respective stepping gears 207, 208 which are operated through pawls and levers 214<SP>1</SP>, 214<SP>2</SP> from a common cam 225 on the cylinder driving ring 3. Over-running and back-running pawls are provided for these stepping gears and locking devices may be provided to prevent operation of the selector drum or eraser drum according to pattern requirements.