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. 24, 2002
Filed:
Oct. 20, 2000
Barry Aher, Grantham, NH (US);
Kevin Horner-Richardson, Cornish, NH (US);
Roger Hewett, Plainfield, NH (US);
Thermal Dynamics Corporation, West Lebanon, NH (US);
Abstract
A plasma torch and method for cutting a workpiece under water directs a primary gas through a primary gas flow path in the torch to a central exit opening of the torch disposed on a longitudinal axis of the torch for exhaustion from the torch onto the workpiece in the form of an ionized plasma. The workpiece is submerged in water while the plasma torch is operated in closely spaced relationship with the workpiece to direct the ionized plasma upon the workpiece. A secondary gas flow path in the torch receives a secondary gas separate from the primary gas and directs it through the torch. Concentrically arranged first and second sets of secondary exit openings are disposed in the torch separate from the central exit opening and in generally radially spaced relationship with the longitudinal axis of the torch. The secondary exit openings exhaust secondary gas from the torch in a direction generally toward the workpiece. The secondary gas is exhausted from the first and second secondary exit openings at a flow rate sufficient to displace water surrounding the ionized plasma exiting the central exit opening of the torch to inhibit quenching of the ionized plasma.