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. 21, 1994
Filed:
Feb. 04, 1993
Steven D Wallestad, Kansas City, MO (US);
Midland Brake, Inc., Kansas City, MO (US);
Abstract
A valve assembly for use with spring-set air-release vehicle parking brakes comprises a particular arrangement of conventional components providing desired spring brake operational characteristics heretofore requiring costly, complex specially-designed units. The valve assembly typically employs a plurality of interconnected check valves in combination with pressure protection and quick release valves to provide the desired characteristics. These include a system whereby at startup pressurized air from the tractor fills the trailer reservoir tanks and the spring brake chambers simultaneously. The valve assembly also assures that if during tractor-trailer operation the supply air from the tractor is severed or otherwise lost, service brake air in the trailer reservoir tanks is retained at a sufficient pressure to provide adequate service brake operation. Similarly, if pressurized air in the trailer reservoir tanks is lost, sufficient pressure is maintained in the system to keep the spring brakes released for safe parking of the tractor-trailer combination.