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:
Oct. 31, 2000
Filed:
Feb. 10, 1999
Yuji Kaneko, Kanagawa, JP;
Yoshihiro Watanabe, Kanagawa, JP;
Sodick Co., Ltd., Kanagawa, JP;
Abstract
An electric discharge machining apparatus including a first power source for applying machining voltage to a machining gap to generate an electric discharge, a second power source for applying voltage of equal to or lower than 20 V to the machining gap, a transistor switching bridge connected to both the workpiece and the tool electrode, a switch for selectively connecting one of the first and second power sources to the transistor switching bridge, a transistor controller for controlling on/off switching operation of the transistor switching bridge to alternatively change polarity of voltage being applied to the machining gap, a contact detector for electrically detecting the contact between the workpiece and the tool electrode when output of the second power source is applied across the machining gap, and an NC device which controls the switch so that the first power source is connected to the transistor switching bridge when the application of the machining power is required while the second power source is connected to the transistor switching bridge when detecting the contact by the contact detector is required.