GB817083A - A circular knitting machine - Google Patents

Abstract

817,083. Knitting-machines. FIDELITY MACHINE CO. Inc. Jan. 23, 1957 [Feb. 1, 1956], No. 2419/57. Class 74 (2). Means controlling the speed of an electric motor driving a circular knitting-machine is operatively associated with pattern means governing predetermined operations of the machine, in such manner that any shift by the patterning means from one operation to another is automatically preceded by a change in motor speed. The motor speed is controlled by a potentiometer 22 when a solenoid switch 36 is not energized and by a potentiometer 23 when the switch is energized, the potentiometer 22 being controlled from the pattern drum 1 to set the motor at a high or a low speed and the potentiometer 23 being set manually to provide an intermediate speed. The machine normally runs at the high speed corresponding to the fullline position of the arm of the potentiometer 22. When a change of machine function is to occur, a lug 15, on a pattern chain 8 advanced by a pawl 11, is brought under a lever 17 to bring a bluff 19 from under a drum-racking pawl 3. The pawls 11, 3 work in alternation, being at opposite ends of a continuously operated bellcrank 6, and the succeeding stroke of the pawl 3 will thus be effective. The rocking of lever 17 has, however, closed a switch 33 to energize the solenoid switch and so set the motor at the intermediate speed under control of the potentiometer 23. The ensuing stroke of the pawl 3 brings a cam 29 on the drum 1 under a lever 31 and so, first swings the arm of the potentiometer 22, through gearing 25, 24, to the dottedline slow-speed position and secondly, through an arm 28, opens a switch 41 in series with switch 33 to de-energize switch 36 and bring the motor to slow speed under control of potentiometer 22. The length of the lug 15 is such that it remains under the lever 17 despite the next advance of the chain; and a second advance of the drum therefore occurs. During the first part of this second advance of the drum, the change of machine function is effected (e.g. change to oscillatory knitting) the length of cam 29 being sufficient to hold the lever 31 displaced during this operation; but during the second part of this second advance of the drum, the lug 29 moves from under the arm 31 so that, first the switch 41 is allowed to close to reimpose the intermediate speed, and then the arm of the potentiometer 22 is swung to high-speed position. The next advance of the chain brings the lug 15 from under the lever 17, allowing switch 33 to open; and the machine now runs at high speed again. Where it is required merely to separate two successive high-speed operations by a period of intermediate speed, the changespeed operation may be controlled by the chain without recourse to the drum. Racking of the drum may be effected in part, independently of the pawl 3, by auxiliary indexing pawls.