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:
Dec. 08, 1987
Filed:
Sep. 02, 1986
Dennis C Eckhardt, Saginaw, MI (US);
General Motors Corporation, Detroit, MI (US);
Abstract
A check valve for disposition between a vacuum operated device and the intake of an auxiliary vacuum pump of an automobile which discharges into the crankcase of the engine of the vehicle. The check valve includes an elastomeric umbrella valve having a flexible lip which is self-biased to a closed position preventing backflow of air to the vacuum operated device and which is flexed to a normal open position by a pressure difference corresponding to pump operation with the integrity of the auxiliary vacuum system intact. A larger pressure difference corresponding to operation of the vacuum pump with the integrity of the auxiliary vacuum system breached flexes the lip of the umbrella valve to a control open position wherein airflow is restricted to only a control orifice of the valve the flow area of which orifice is predetermined to limit airflow to less than the rate at which air is scavenged from the crankcase of the engine.