Patent GB-1427577-A (GB)
Title: Control equipment for circular knitting machines
IPC: D04B15/94
Filed: 1973-07-10
Abstract: 1427577 Knitting-machines BILLI SpA 10 July 1973 32831/73 Heading D1C [Also in Divisions F2 and G3] A circular knitting machine includes a control enabling the core drum to be successively advanced after predetermined numbers of cylinder revolutions. The control comprises first programming means for presetting the extent of cam drum advance, second programming means to receive pulses from a cylinder revolution counter and produce outputs after predetermined numbers of revolutions whereby a control signal initiates angular advance of the cam drum. A control pulse generator 1, e.g. a rotating disc 51 and a stationary contact 53, Fig. 4, associated with the needle cylinder 3 feeds pulses to a digital counter 5 and a decoder 7. Coincidence circuits 14 are connected to a first programmer comprising a disc 10 and co-operating arm 12 rotating with the cam drum. The disc carries a continuous ring 10B to which a fixed voltage is applied and sectors 10C. Contacts on the arm apply voltage to the sectors in turn, their circumferential extent determining the period of drum advance. Second programmer 9 arranged between the decoder 7 and circuits 14 consists of rotary switches and terminals which can be set at predetermined numbers of revolutions. The intervals between drum advances can thereby be set. Coincidence circuits 14 comprise NAND gates and are connected to circuit 16 to control mechanism for connecting the drum to the cylinder. A speed selector unit 18 ensures that the cylinder rotates at the desired speed, particularly that it runs at a low speed when the drum is advanced. When counter 5 reaches a predetermined value as set by programmer 9 a signal is transmitted from circuits 14 to activate the cam drum and vary the motor speed. The value set is usually one less than required to compensate for delays. The counter remains locked while the drum rotates as set by the relevant sector 10C. As the arm leaves one sector a signal initiates resetting of the counter and a new count begins with the cylinder rotating at the selected speed. As the drum becomes stationary the arm 12 just reaches the next sector, activating one input of the corresponding coincidence circuit. The drum is next advanced when the appropriate count is reached in that part of the programmer 9 corresponding to this circuit. The machine may be set to run at a single speed only, or to produce a single stocking and then stop. An oscillator may be provided to produce a rapid chain of pulses and advance the drum to the start of a new cycle. A coupling between a member 47 coupled to the cylinder drive and a shaft 55 of the drum drive is shown in Figure 9. The shaft 55 is driven by via gears 59A, B from a shaft 61 one end of which is journalled in member 47. A body 65 fixed to the shaft 61 projects into a recess of member 47. It has flats 65A above which are supported rollers held by a cage 69. If the drum is to remain stationary the rollers are above the centre of the flats; when the rollers are wedged between the flats and the member 47 drive is transmitted to shaft 61.