Title of Invention

AN ELECTRIC DISCHARGE MACHINE.

Abstract

An electrical discharge machine comprising an electrode tool and a workpiece spaced apart by a machining gap bathed in dielectric liquid, said electrode tool and #orkpiece being connected, via a polarity means, to an erosive pulse generator means for generating a succession of rectangular erosive current pulses in the machining gap, the erosive pulse generator comprising a d.c. voltage source, a current limiting means and an oscillator controlled by an electronic switch which controls the duration and intervals'of the erosive pulse, is disclosed. The electrical discharge machine is characterised in that it includes a circuit ifor generating non-erosive pulses, for controlling the ignition of the electric discharge of the said erosive pulses and thereby reducing electrode tool wear; said'circuit consisting of a step-up transformer, the primary winding of which is connected across the said erosive pulse generator means through a capacitor and a resistor connected in series and the secondary.winding of which is connected to the machining gap through a series combinator of a diode and a resistor and the polarity changer means, and a diode connected in series between the output of the erosive pulse generator means and the said polarity changer means to isolate the said step up transformer from the erosive pulse generator means.

Full Text

Documents:

134-BOM-1991-CANCELLED PAGES.pdf

134-BOM-1991-CORRESPONDENCE(IPO).pdf

134-BOM-1991-CORRESPONDENCE(RECEIVED).pdf

134-BOM-1991-FORM 2(COMPLETE).pdf

134-BOM-1991-FORM 2(GRANTED).pdf

134-BOM-1991-FORMS.pdf

134-BOM-1991-SPECIFICATION(AMENDED).pdf