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:
Apr. 07, 1992
Filed:
Dec. 20, 1990
Andrew Paredes, Northville, MI (US);
Robert C Roethler, Howell, MI (US);
Ford Motor Company, Dearborn, MI (US);
Abstract
A scavenging system for a hydraulic circuit includes a sump passage connecting the sump to a reservoir, a solenoid-operated switching valve, a logic control circuit controlling operation of the switching valve and a passage connecting the reservoir to the inlet of a hydraulic pump that supplies the hydraulic circuit. A vacuum source, such as the intake manifold of an internal combustion engine or a vacuum pump, is connected through a ball check valve and vacuum regulator to a space in the reservoir above the fluid. Fluid level sensing switches sense the level of fliud within the reservoir and produce electronic signals used by the logic circuit to control the solenoid-operated switching valve. An oil filter cap allows the reservoir to be filled while maintaining vacuum within the reservoir. A heat exchanger located within the reservoir draws excess heat from the fluid by passing engine coolant through the exchanger. A float valve located within the sump closes the connection between the sump and the reservoir when fluid level within the sump is low and opens that connection when fluid level in the sump is high.