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:
Feb. 02, 1999
Filed:
Feb. 24, 1997
Applicant:
Inventors:
Assignee:
Illinois Tool Works Inc., Glenview, IL (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
B23K / ;
U.S. Cl.
CPC ...
21912139 ; 21912157 ; 21912144 ; 21912154 ;
Abstract
A method and apparatus for controlling and maintaining a continuous flow of pilot arc current in a plasma cutting torch includes a pilot circuit, a current sensing circuit, and a control circuit. The control circuit maintains a continuous flow of pilot current through the pilot circuit both before and after a cutting arc has been generated. The control circuit further controls the magnitude of the pilot current in response to the sensing circuit indicating the absence or presence of the cutting arc.