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. 31, 1994
Filed:
Jan. 14, 1992
Richard W Couch, Jr, Hanover, NH (US);
Nicholas A Sanders, Norwich, NH (US);
Lifeng Luo, Lebanon, NH (US);
John Sobr, Enfield, NH (US);
Patrik Backander, Lebanon, NH (US);
Hypertherm, Inc., Hanover, NH (US);
Abstract
In a plasma arc cutting torch a flow of plasma gas is bypassed out of a plasma chamber, preferably at an annular gap between a pre-orifice in an inner nozzle piece and an exit nozzle orifice in an outer nozzle piece. A bypass channel formed between the inner and outer nozzle pieces directs the bypass flow to atmosphere. A metering valve or restricting orifice remote from the gap controls the amount of the bypass flow and delays the response of changes in the flow parameters in the plasma chamber to changes in the bypass flow. The pre-orifice and nozzle orifice are positioned and dimensioned to optimize the mass flow velocity and the strength of a vortex-type flow at the pre-orifice, thereby creating a virtual nozzle immediately below the electrode. The gas flow in the plasma chamber is highly uniform and very steady.