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:
May. 23, 1995
Filed:
Nov. 08, 1993
Robert P Benjey, Dexter, MI (US);
G.T. Products, Inc., Ann Arbor, MI (US);
Abstract
A head valve for maintaining a desired pressure head in a vehicle fuel tank which responds automatically to pressure changes in the filler pipe corresponding to a change from normal vehicle operation to a refueling operation to adjust the pressure head maintained by the head valve. In a vehicle fuel system including a filler pipe selectively opened and closed by a cap, the valve of the present invention responds to pressure changes near the filler pipe inlet upon removal of the cap to increase the pressure head it maintains in fuel tank 10 and prevent the fuel tank from being overfilled. When the refueling operation is completed and the cap is replaced, the change in pressure near the filler pipe inlet operates the valve to decrease its head valve closing force and reduce the pressure head maintained in the tank for normal vehicle operation. In one embodiment the valve includes a spring-biased diaphragm control element operated by the pressure changes in the filler pipe to move against and away from a spring-biased head valve element, resulting in a corresponding decrease and increase in the closing bias of the head valve element and the resulting pressure head maintained in fuel tank 10.