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:
Jun. 13, 2006
Filed:
Feb. 24, 2004
Peter C. Sun, Rochester Hills, MI (US);
Pei-chung Wang, Troy, MI (US);
Peter C. Sun, Rochester Hills, MI (US);
Pei-Chung Wang, Troy, MI (US);
General Motors Corporation, Detroit, MI (US);
Abstract
A method of spot welding a sheet overlapped to a tube with a servomotor-driven electrode applying a clamping force to the sheet. Over a first clamping time interval, the clamping force is increased to a first force level, at which point a welding current is applied to weld the sheet and tube together for a welding time interval. The first force level is maintained for a second clamping time interval, after which the clamping force is reduced to a second force level over a third clamping time interval and is maintained for a fourth clamping time interval. The welding current is removed upon expiration of the welding time interval and the clamping force is simultaneously reduced over a fifth clamping time interval, after which the electrode is disengaged from the sheet. The reduction in clamping force during the welding cycle reduces cracking of the spot weld.