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:
Jun. 02, 1998
Filed:
Sep. 03, 1996
Elizabeth B Hackett, Lebanon, NH (US);
Timothy M Brewer, Lebanon, NH (US);
Zhipeng Lu, Hanover, NH (US);
Richard W Couch, Jr, Hanover, NH (US);
Hypertherm, Inc., Hanover, NH (US);
Abstract
A plasma arc torch apparatus and method for cutting or marking a workpiece includes a torch having an electrode and a nozzle coupled to a power supply, and a plasma gas source coupled to a fluid line for delivering plasma gas to the torch. A flow restriction member is disposed in the fluid line adjacent the torch and causes the pressure of the plasma gas in the torch to gradually increase during start up thus creating a stable plasma arc. A three-way valve is disposed in the fluid line downstream of the flow restriction member and has an inlet, a torch outlet, and a vent outlet. The inlet is in fluid communication with the torch outlet for delivering plasma gas to the torch when the valve is in the open position, and the torch outlet is in fluid communication with the vent outlet when the valve is in the vent position, for rapidly dissipating the gas in the plasma chamber of the torch to atmosphere after the arc has been extinguished. The rapid reduction of the gas pressure in the torch reduces the cycle time, enabling the torch to be restarted more quickly after completion of a prior cutting cycle.