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:
Oct. 31, 1995
Filed:
Aug. 31, 1994
Charles H Covert, Manchester, NY (US);
Richard W Wagner, Albion, NY (US);
Kenneth W Turner, Webster, NY (US);
Karen M Meyer, Avon, NY (US);
General Motors Corporation, Detroit, MI (US);
Abstract
A refueling vapor recovery system for a vehicle utilizes recirculation of a portion of the displaced vapor and combines a vapor vent valve and a recirculation control into a single differential pressure valve assembly. A vapor vent conduit provides fuel tank vapor pressure to one side of a diaphragm and, through a restricted orifice, to the other side of the diaphragm, the other side being further connected by a recirculation conduit to the tank filler neck. When a gas cap closes the filler neck from the atmosphere, the orifice allows pressure to equalize across the diaphragm; and a spring biases the diaphragm to close a vapor vent valve. When the gas cap is removed, atmospheric pressure is provided through the recirculation conduit to the other side of the diaphragm, which can then be activated by a relatively small differential pressure to open the vent for relatively unrestricted vapor flow from the tank to a canister during refueling, with a small portion of the vapor recirculated in a controlled flow through the orifice and recirculation conduit to the filler neck for entrainment in incoming liquid fuel.