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:
Dec. 08, 1998
Filed:
Mar. 18, 1997
Joseph Allen Daniel, Mentor, OH (US);
The Lincoln Electric Company, Cleveland, OH (US);
Abstract
A circuit for providing D.C. current from a power source having a current regulating input to a plasma system including an electrode and a nozzle with a plasma arc opening exposing the electrode to a juxtapositioned workpiece, which circuit has a first circuit branch for creating a pilot arc across the electrode and nozzle, a second circuit branch for creating an operative plasma arc across the electrode and the workpiece, a current sensor in the second circuit branch for sensing the workpiece current in the second circuit branch, a switch for opening the first circuit branch when the sensed workpiece current exceeds a preselected current to transfer the pilot arc to the operative plasma arc, a system for regulating the current in the first circuit branch until the arc transfer and a circuit for increasing the pilot current supplied from said power source to first circuit branch when sensed workpiece current exceeds a low threshold value.