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. 06, 2011
Filed:
Apr. 27, 2009
Eugenio Ferreira Cunha, São Paulo, BR;
Jason Sicotte, Bristol, CT (US);
Fabio Rodrigo Geib, São Paulo, BR;
Eugenio Ferreira Cunha, São Paulo, BR;
Jason Sicotte, Bristol, CT (US);
Fabio Rodrigo Geib, São Paulo, BR;
Barnes Group Inc., Bristol, CT (US);
Abstract
A method for residual stress enhancement for a coil spring includes radially expanding at least a select axial portion of the coil spring to remove residual tensile stress from the spring inner diameter and induce residual compressive stress in the spring inner diameter. The spring is expanded by radial force on the inner diameter and/or by a helical unwinding force induced by rotating at least one end of the spring relative to the other end of the spring. A tool includes a spring expansion portion and, optionally, a diameter control portion. Cylindrical, conical and/or beehive springs are processed to enhance residual stress.