Patent GB-1194785-A (GB)
Title: Improved Draw Mechanism for Straight-Bar Knitting Machines
Inventor: SWANWICK BARRY FREDERICK
IPC: D04B11/06
Filed: 1968-03-22
Abstract: 1,194,785. Knitting. S. A. MONK (SUTTON IN ASHFIELD) Ltd. 14 March, 1969 [22 March, 1968], No. 13911/68. Headings D1C and D1K. When producing garments of an asymmetrical nature, e.g. ASG<SP>1</SP>, ASG<SP>2</SP> in addition to producing garments of a symmetrical nature, e.g., SG, on the divisions of a straight-bar machine, additional control is superimposed on the usual adjustable draw mechanism such that the traverse of the carriers C corresponds to the width KW of the garment being knitted irrespective of its shape. The traverse ST of the slurcocks SC is correspondingly adjusted to ensure that they maintain a constant lead over the carriers In effect the centre line CL and SOL of the traverse of the carriers and slurcocks over the whole length of the garment corresponds with the centre line of the garment. As described the carrier drive is via a chain 58 and roller 16 engageable in a carrier slide 60 driving the carrier bar of the division. The carrier traverse is adjustable by nuts 2, 42 on lead screws 1, 35 which are adjustable to vary the position of the chain end sprockets 54 .. 57 to determine the point of engagement of the roller 16 and slide 60 in the usual way. The drive to the chain 58 is from the usual draw mechanism and comprises draw cam 65 coupled to draw lever 33 through a pitman 34 and driving rack 13. The rack 13 is coupled by pinion 12 and bevel gears 14, 17 to shaft 18 which transmits its drive through bevel gears 19, 20 to chain sprocket 23 to drive the carrier chain 58 and also to chain sprocket 22 to slurcock drive 79. A coupling 80 operated from a cam 86 on the cam shaft 66 serves to maintain the lead of the slurcock SC over the carrier C constant. In normal circumstances and knitting a symmetrical pattern the draw mechanism transmits its motion to the carriers and slurcocks and adjustment of the nuts to vary the width of the fabric causes a unit DSU to vary the length of draw. This is achieved by rotating a shaft 5 or 89 which rotates spindles 26, 46 to raise or lower a nut 27 coupled to a lever 28 supporting the fulcrum point of the draw lever 33 to raise or lower it and correspondingly the block 32 which is the point of connection of it with the pitman 34. The effective leverage being varied causes the draw to be correspondingly varied. In the event of an asymmetrical garment being knitted the nuts 2 and 41 are adjusted accordingly. However the movement of the two is summated by an asymmetric differential unit ADU which adjusts the position of the driving pinion 12 along the rack 13 by permitting the unit to slide along the splined shaft 18. In effect the unit ASD centralises the draw motion in relation to the end control nuts 2 and 41 and the unit DSU controls the length of traverse of the carriers and slurcocks. The DSU unit comprises a screwed spindle on which a pinion 42 is mounted and a splined spindle 46 on which a pinion 43 is mounted. The respective spindles are coupled to the end nuts 2 and 40. Movement of one or both nuts causes the spindles to rotate and depending on whether the spindles rotate a different amount or in the same or opposite directions the spur gears rotate or remain stationary and are raised or lowered on the spindles to raise or lower nut 27 and effect control of the draw lever. The asymmetric differential unit ADU comprises two screws 8, 10 coupled to the corresponding end nuts and housed in a slipper 11 slidable along the screws and vertically supporting the shaft bearing the pinion 12 and bevel gear 14. Freely supported midway on the shaft and within the slipper is a worm wheel 9 which engages on either side with the screw 8, 10. Consequently adjustment of one nut to an extent differing from the other causes the screws 8, 10 to turn to different extents. The worm 9 is thereby rotated and the slipper 11 caused to slide along the screws with the result that the bevel gears 14, 17 move along splined shaft 18 and pinion 12 is repositioned along rack 13. The effect is to alter the mid position of the carrier and slurcock traverse by adjustment of the drive from the draw mechanism. Alternatively instead of a chain drive to the carriers a friction box may be used. Also by the use of two carriers and slurcocks for each division and corresponding bars driving them which can be coupled together two blanks of narrow width may be knitted on each division of the machine.