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:
Aug. 29, 1995
Filed:
Mar. 15, 1994
Ronald S Plantan, Charlotte, NC (US);
Echlin Inc., Branford, CT (US);
Abstract
A unitary full-function valve is used to control the operation of a service brake system and a spring brake system. The valve includes a valve body that has multiple ports, including separate ports for providing fluid communication to a spring brake chamber, a service brake chamber, a fluid reservoir and an exhaust port. The valve body also has ports for receiving pressurized supply fluid and control fluid. The supply fluid inhibits the activation of the spring brakes so that the spring brakes are activated when no supply fluid is present. The control fluid is used to activate the service brakes on demand. A biased one-way pressure protection valve is disposed in the valve body to isolate fluid in the service brake system from fluid in the spring brake system when the pressure in the service brake system falls below a variable pressure level. A passageway within the valve body connects the fluid in the spring brake system with the biased pressure protection valve to increase the variable pressure level in proportion to the pressure level in the spring brake system.