The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 06, 1999
Filed:
Jun. 25, 1997
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Abstract
An electrical discharge machine for applying a pulsed voltage to a machining gap between an electrode and a workpiece disposed opposite thereto. An insulating dielectric fluid, such as oil or water mixed with a compound additive, is disposed in the gap. A positive polarity voltage and an opposite polarity voltage are applied via switches and respective impedances to the machining gap in order to generate a discharge for machining the workpiece. A pulse having a first polarity is applied to machine the workpiece and a pulse having a second polarity is applied when the first polarity pulse is not applied. A misfire pulse detector detects an undesired drop in the machining voltage by determining whether the first polarity voltage is in a range between two voltages, the first of which has a magnitude greater than the magnitude of the machining gap during discharge and the second of which has a magnitude greater than the magnitude of the first voltage.