GB865179A - Improvements in or relating to knitting machines - Google Patents

Abstract

865,179. Circular knitting-machines. SCOTT & WILLIAMS Inc. June 25, 1957 [July 19, 1956], No. 20039/57. Class 74 (2). Associated with each of a plurality of feedpoints there is provided means influenced by the sinkers to sense the size of stitches produced thereat and separately reversible operating- means responsive to the sensing means for controlling the size of such stitches. The heights of main stitch cam 8 and auxiliary stitch cam 10 are controlled by reversible electric motors 40, 82, the direction of rotation of each of which is determined by contact of an associated blade 186 carried in a lever 180 with one or other of contact screws 188, 190, the lever being rocked through intermediate levers 172, by levers 148, 1481 at the two feeds as these levers 148, 1481 are rocked about their pivots by the sinkers, against which they bear. Each lever 180 and associated contacts 188, 190 are carried on a slide 162. The main stitch cam 8 and associated end cam are mounted on a rod 16 and are urged upwardly by a spring to a position, determined by a nut, which they occupy when the automatic stitch controls are ineffective. The motor 40 carries on its shaft a cam 32 by which this stitch cam assembly can be lowered, through a rocking lever 26 which is effective only when its fulcrum 28 has been lowered, by a cam 52 carried on the main cam drum 54 and acting through linkwork including a lever 64. The rotation of the motor shaft is controlled by limit switches acted on by another cam on the motor shaft. The auxiliary stitch cam 10 is carried by a slide and is also spring-urged to an uppermost position under control of a rockshaft 90, a fork at the end of one arm on which embraces a pin 86 projecting from the slide, whiist a second arm 92 carries four screw followers 94, one or other of which cooperates with the appropriate one of cams 96. An aperture extending through these cams embraces an eccentric which may be rotated by a lever 102 to raise or lower the effective cam axis. The extent of counterclockwise rotation of the lever 102, and thus the lower limit of the cam axis, is limited by engagement of an extension 104 of the lever with an adjustable eccentric 106; thus the uppermost position of the cam 10 is limited. A spring 110 urges one end of lever 102 to engage beneath one end of a lever 114, the other end 120 of which follows a cam 122 rotated through worm 128 and worm-wheel 126 by the motor 82. The fulcrum 116 of the lever 114 is borne by a plunger 130, a pin 138 at the bottom of which is overlain by the free end of the lever 64. Thus, when the cam 52 initiates motor control of the main stitch cam, it also causes rod 130 to be depressed, lowering fulcrum 116 until the ends of the lever 114 engage cam 122 and lever 102 and the motor 82 controls cam 10. Extent of movement of the lever 102 is controlled by adjustable limit switches 140, 142. When automatic stitch control is to be inactive, as in heel and toe formation, the slides 162 are moved outwardly and a switch in the electrical supply is opened. The innermost position of each slide 162 is controlled by a wedge 204 movable downwardly by a Bowden wire 208 against the action of a spring 206. These wedges may be adjusted by the main fashioning cam, without control of cylinder height; but, preferably, the wires 208 are connected to a lever through which the needle cylinder is raised or lowered for fashioning, so that when the cylinder is moved to alter the stitch length, the slides are moved to substantially the positions demanded by the new sinker positions and the automatic control is required to correct for small variations only. The motor 40 may raise or lower the needle cylinder and the motor 82 control the auxiliary feed-stitch cam to compensate both for changes controlled from the main feed and also for improper length of stitches produced at the auxiliary feed. The motors may control individually different or similar stitch length affecting operations such as sinker radial motions, aligned timing of sinker or needle waves; or one motor may control fabric tension in the use of a grab take-up. More than two feeds may be controlled. Specifications 704,843, 722,473, 764,694, 865,178, 865,180, 865,181 and 865,182 are referred to.