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:
Sep. 18, 2001
Filed:
Sep. 14, 2000
Yukihiko Takeuchi, Handa, JP;
Yasunori Kobayashi, Toyohashi, JP;
Denso Corporation, , JP;
Abstract
A valve controlling a fuel tank pressure is disposed in a passage connecting the fuel tank and a canister that communicates with atmosphere. The control valve includes a first valve for introducing an atmospheric pressure into the fuel tank when the fuel tank pressure becomes negative and a second valve for releasing an excessively high pressure in the fuel tank. The first valve opens when the fuel tank pressure drops below a predetermined level and closes again when the fuel tank pressure is recovered. To prevent a vibrating operation of the first valve between its open and closed positions, the closing operation of the once opened valve is delayed by an orifice formed through a diaphragm of the valve. The orifice alleviates a quick change of the pressure applied to one surface of the valve. A magnet to restrict the quick movement of the valve may be used in place of the orifice. Preferably, an electromagnetic driver for forcibly opening the first valve, irrespective of the fuel tank pressure, is connected to the first valve.