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. 07, 1998
Filed:
Mar. 20, 1996
Thomas Haley Gardner, Englewood, OH (US);
General Motors Corporation, Detroit, MI (US);
Abstract
A rotary drive unit powers a double-acting cam and a Geneva drive. The cam actuates two double-acting pumps which supply pressurized hydraulic fluid to a double-acting motor. A punch is reciprocated by the motor to punch sectors from a sheet material. The Geneva drive rotates a carrier which is indexed to receive material punched from the sheet. The hydraulic fluid is maintained in the system by a pair of check valves which deliver fluid as required from a pressurized reservoir to the pumps during a low pressure portion of the pumping cycle. Also provided are bleed and fill valves and pressure relieve valves which further assist in filling the system and controlling the maximum system pressure.