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:
Jul. 29, 1980
Filed:
Oct. 04, 1978
Robert J Price, Peoria, IL (US);
Caterpillar Tractor Co., Peoria, IL (US);
Abstract
An element (12) having a chamber (28) such as, for example, a boom (12) of an excavator (10) or a draft tube of a scraper is subject to torsional loading during use of the element (12). Torsional loading creates tensile stresses (T) on the welds (22) of the excavator boom (12), which can lead to weld failure. A method for controllably treating the metal of the element (12) includes heating the element (12) and pressurizing the chamber (28), maintaining the element (12) and chamber (28) at a preselected temperature and pressure (P.sub.1), respectively, and cooling the element (12) and depressurizing the chamber (28). The method produces residual compressive stresses (C.sub.2) in the metal, such as in the root area (23) of the welds (22) of the excavator boom (12), for increasing fatigue life under torsional loading of the boom (12).