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:
Aug. 23, 1994
Filed:
Apr. 19, 1993
Sanjay M Shah, Rochester Hills, MI (US);
Michael H Lovell, Leonard, MI (US);
General Motors Corporation, Detroit, MI (US);
Abstract
A method of forming an elongated box shape tubular frame member from a round tube includes the steps of: providing a lower die member having a cavity submerged substantially below the top surface of the lower die and having a cavity width equal to the width of the desired box shape frame member and less than the diameter of the tube. The lower die has an entry opening which opens to the top surface of the die and is defined by angularly disposed funnel walls which converge to intersect with the cavity. The round tubular blank is placed onto the lower die so that the blank rests on the angularly disposed funnel walls above the cavity. The upper die is lowered onto the lower die and has a lid wall which forces the tubular blank downwardly into the cavity while the angularly disposed funnel walls guide the blank to collapse in a manner preventing pinching of the blank between the upper and lower dies. The application of internal hydraulic pressure then expands the collapsed tube outwardly to the shape defined by the cavity of the lower die and the lid wall of the upper die.