Patent GB-946889-A (GB)
Title: Improvements in or relating to elastic yarn feeders for knitting machines
IPC: D04B15/48
Filed: 1962-03-20
Abstract: 946,889. Knitting-machines. SCOTT & WILLIAMS Inc. March 20, 1962 [April 13, 1961], No. 10699/62. Heading D1C. During the incorporation of an elastic yarn into the fabric being knitted on a circular machine the elastic yarn is positively fed at a rate slower than that at which it is consumed to cause it to be extended. However, just prior to it ceasing to be fed to the needles the rate at which it is positively fed is increased to the rate at which it is being consumed so that the elastic yarn is relieved of any tension, whereafter the yarn is severed and clamped as it is withdrawn and simultaneously the positive feeding of it is stopped. When the elastic yarn is reintroduced it is fed at the slower rate to provide its normal extension. For this purpose the elastic yarn passes from its supply to a number of helically grooved spindles 50 around which it is wrapped and which are both individually rotated and collectively revolve about a central axis to positively feed the elastic yarn to a yarn feeder. The drive for the spindles comprises a central shaft 34 carrying at one end a carrier supporting a gear-wheel for each spindle 50 and which gear-wheels engage a fixed central gear through which the shaft 34 projects so that the rotation of the carrier by the shaft 34 revolves the spindles about the shaft 34 and simultaneously causes the spindles to individually rotate. The other end of shaft 34 carries a wheel 32 having a tyre 30 in engagement with a disc 28 which is continuously rotated by gearing from the drive of the machine. The shaft 34 is mounted in a bearing 36 supported by an arm 60 adjustably secured to a rod 58 slidable in bearings 52, 54 of a bracket 56. A collar 86 is secured at one end of rod 58 and is engaged by one arm 88 of a bell crank lever the other arm of which is attached to a wire 94 so that when the lever is pivoted by the wire 94 the rod 58 is moved to cause the bearing 36 and thereby the wheel 32 to move radially with respect to the disc 28 to increase the effective radial position of contact of wheel and disc to increase the speed of feeding the yarn. The reverse movement is achieved by a spring 80 attached to arm 60. The arm 60 also carries a rod 70 in a lug 68 which is engaged by pivoted lever 72 under control of a wire 76 to cause the arm 60 to pivot about rod 58 and thereby lift the wheel out of engagement with disc 28 to cause the feeding of the elastic yarn to cease. The wire 94 is controlled by the pattern chain of the machine through a pneumatic arrangement whereby at the desired moment the wheel 32 is caused to increase its position of radial contact with disc 28 so that the speed at which the yarn is fed is increased just before removal of the elastic yarn guide. The pattern chain also serves to initiate actuation of the pawl and ratchet mechanism controlling the cams for actuating the yarn guides and is so constructed that after it has caused the speed of the feeding mechanism to increase it then causes the pawl and ratchet mechanism to function for withdrawing the elastic yarn feeder and for severing and clamping the yarn. The pawl and ratchet mechanism also actuates a cam wheel which operates the wire 76 so that as the guide is withdrawn the wheel 32 is disengaged from driving disc 28.