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:
Jan. 18, 1994
Filed:
Apr. 24, 1992
Robert E Shelhart, Adrian, MI (US);
Carl J Klug, Lyons, OH (US);
Wickes Manufacturing Company, Charlotte, NC (US);
Abstract
A vehicle convertible top has hydraulic cylinders for moving the top between extreme raised and lowered positions. The cylinders each have a pair of fluid translating ports each connected to ports in an elongated housing. A reversible hydraulic pump is in one end of the housing, while a reservoir is in the other end, separated by a pump cap. The pump cap houses two fluid circuits each connected to a housing port and each including an end of cycle hydraulic locking device which comprises a normally-closed valve and a valve actuator in each circuit. In one direction of pump operation, one of the valves is opened by pressure fluid in the one circuit to enable the outflow of the pressure fluid to the cylinders. The other valve is forced open by its actuator, in response to pressure in the one circuit, to enable the return flow of fluid to the pump through the other circuit. The one valve closes when the pump ceases operation, preventing fluid backflow through the one circuit to the pump. Reverse operation is similar. The pump cap includes makeup valving connected to the reservoir to accommodate fluid requirements due to cylinder displacement differential. At both cycle ends, the top is hydraulically locked in extreme raised and lowered positions to facilitate top latching and top stowage. A manually-operated bypass is provided in the pump cap to vent both circuits to the reservoir to enable manual top operation in the event of a pump failure.