GB1198985A - Improvements in or relating to Control Means for a Machine Tool - Google Patents

Abstract

1,198,985. Automatic speed control; programmed electric control. CARDING SPECIALISTS (CANADA) Ltd. July 26, 1967 [Aug. 5, 1966], No.35155/66. Headings G3N and G3R. [Also in Division B3] A reciprocable member of a machine carries a length of magnetic tape 16 past a pick-up head 17, the tape having as many parallel tracks as movements of the member are required in a machining cycle, the head being aligned with each track in turn. The member, such as a turret slide of a lathe, is driven by a double-acting hydraulic cylinder fed with pressure oil through a reversible valve and an adjustable valve 23. Each track on the tape comprises a frequency modulated waveform, the output from head 17 being fed to a discriminating network including two resonant circuits tuned respectively above and below a reference frequency. The outputs from the resonant circuits are amplified and applied to opposed electromagnets 24, 25, co-operating with armature 26 carrying nozzles 28, 29. Oil is bled off from each nozzle and supplied to opposite ends of cylinder 30 having piston 31 for actuating the valve 23. The turret slide is decelerated or accelerated when the detected frequency is greater or less than the reference frequency so that the speed of the slide is determined by the pitch of the recorded waveform. Each track may have amplitude modulation at its end to effect reversal of the slide, or a continuous track of constant frequency, extending along the tape, may be associated with another head, the slide being reversed when the additional head gives no output. The speed and direction of the spindle may be controlled by additional tracks, as well as indexing of the turret. The cross slide carries its own tape. The tapes may be replaced by drums.