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.:

US 6521864 B1

Date of Patent:

Feb. 18, 2003

Filed:

Jan. 08, 2001

Method and apparatus for the laser cutting of mild steel or structural steel with a multifocus optical component

Applicant:

Inventors:

Christophe Bertez, Vaureal, FR;

Jean Hamy, Montigny Les Cormeille, FR;

Olivier Matile, Paris, FR;

Assignee:

L'Air Liquide Societe Anonyme a Directoire et Conseil de Surveillance pour l'Etude et L'Exploitatiion des Procedes Georges Claude, Paris, FR;

Attorney:

Young & Thompson

Primary Examiner:

M Alexandra Elve

Int. Cl.

CPC ...

B23K 2/600 ;

U.S. Cl.

CPC ...

B23K 2/600 ;

Abstract

Method and apparatus for cutting a workpiece made of structural steel or mild steel, i.e. alloy or non-alloy steels, by the use of a transparent or reflecting optical unit for focusing a laser beam, and of an assist gas for the laser beam. The optical unit is of the multifocus type and is chosen from lenses, mirrors and combinations thereof. The assist gas is nitrogen or a nitrogen/oxygen mixture. The method of the invention makes it possible to obtain a low or almost zero oxidation of the cut face and to do so while increasing the cutting performance by about 40% compared with a laser cutting method using nitrogen or a nitrogen/oxygen mixture.

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