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:
Jun. 03, 1997
Filed:
May. 21, 1996
Gary D Dawson, Rochester, MI (US);
William B Blomquist, Clarkston, MI (US);
John Cook, Chatham, CA;
Murray Busato, Chatham, CA;
Chrysler Corporation, Auburn Hills, MI (US);
Abstract
An assembly for testing an evaporative emission control system of an automotive vehicle which controls emission of volatile fuel vapors. The assembly is used to determine if a leak is present in a portion of the system which includes a vapor collection canister. The leak detection assembly incorporates a vacuum actuated canister vent control valve which seals the evaporative system so the leak detection test can be performed. A vacuum actuated pump which performs a leak detection test. An engine control unit initializes the pump by drawing air into a pump cavity and also closes the vent control valve. After the initialization period, the pump is activated to pressurize the evaporative emission control system. Once a control pressure is achieved, the cycle rate starts to drop off. If no leak exists in the system, the pump will eventually stop pumping. If there is a leak, the pump will continue to pump at a rate that will be representative of the flow characteristics of the size of the leak. After the test has been concluded, the vent control valve will unseal the system after the vacuum has been bled out through the orifice/check valve that has been holding the seal during the test.