GB1039504A - Method of regulating the feed in electro-erosive machining - Google Patents

Abstract

1,039,504. Electro-erosion. BETEILIGUNGSUND PATENTVERWALLUNGSGESELLSCHAFT. April 30, 1965 [May 2, 1964], No. 18370/65. Heading B3V. [Also in Division G3] In spark erosion apparatus, movement of the tool electrode is controlled by a circuit including an AND gate 1 having two inputs 9 and 10 at least one of which is dependent upon the spacing between the tool and workpiece electrodes; the output from the AND gate is applied as one input to a bi-stable circuit 2 having a second input connected to a regulating unit 3 which delivers a signal at regular intervals of time. The two outputs 4 and 5 of the bi-stable circuit 2 are connected to the drive mechanism of the tool electrode, a signal on 4 producing a " forwards " movement and a signal on 5 producing a " backwards " movement. The signal on output 5 is produced only when two signals are present at 9 and 10, and the signal on output 5 is produced at regular intervals through the operation of unit 3; the inputs to 9 and 10 are dependent on the operating conditions and are derived from the current pulses, the no-load voltage pulses, the forming voltage pulses or the control voltage pulses which occur during the operation of the apparatus. Arrangements, some of which include two AND gates, suitable for the various combinations of output signals are described with reference to Figs. 1 and 3 to 14 (not shown). The outputs 4 and 5 may be applied to the electrode drive mechanism by way of further logic circuits, including AND or OR gates (Figs. 15 to 17, not shown).