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:
Jul. 17, 1990
Filed:
Oct. 30, 1989
Wabco Westinghouse Fahrzeugbremsen GmbH, Hanover, DE;
Abstract
A valve including a housing in which is disposed a relay piston. The relay piston has an upper control surface adjacent a control chamber leading to a control connection. The underside of the relay piston is in communication with a reaction chamber leading to a working pressure connection. An outlet valve seat is formed on the lower extremity of the relay piston. A multistage hollow graduated piston disposed within a graduated bore formed in the housing. The graduated piston has a tapered edge extending downwardly to form an inlet valve seat. A hollow valve element is cooperatively associated with the inlet and outlet valve seats to form inlet and outlet valves. The underside of the graduated piston a reaction chamber which is connected to a second control pressure connection. A supply pressure connection is connected to an annular chamber which is in communication with the inlet valve so the working pressure is gradually increased in steps until a predetermined pressure value representing an emergency situation is exceeded which causes the working pressure to immediately rise to the full pressure value of the supply pressure.