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:
May. 04, 1999
Filed:
Jun. 06, 1997
Applicant:
Inventors:
Dennis Borowy, Hanover, NH (US);
Jon Lindsay, West Lebanon, NH (US);
Assignee:
Hypertherm, Inc., Hanover, NH (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
B23K / ;
U.S. Cl.
CPC ...
21912157 ; 21912154 ; 21912402 ; 21913033 ; 21912159 ;
Abstract
A safety circuit is utilized in a blow forward contact start plasma arc torch to extinguish the current to the torch upon determination of an unsafe operating condition. The torch includes a torch body, an electrode and a translatable conductive nozzle biased into contact with the electrode. The safety circuit receives a reference signal a signal indicative of the arc voltage and a mode status signal. The torch current is extinguished when the signal indicative of the arc voltage is less than the reference signal and the mode status signal indicates the torch is operating in the transferred arc mode.