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. 11, 2007
Filed:
Jun. 03, 2003
James Hart, Trafford, PA (US);
Thomas Engle, Clayton, NY (US);
James Hart, Trafford, PA (US);
Thomas Engle, Clayton, NY (US);
Westinghouse Air Brake Technologies Corporation, Wilmerding, PA (US);
Abstract
A release graduating valve for freight brake control is provided for a railcar having a pneumatic control valve, emergency and auxiliary reservoirs each normally charged with pressurized fluid from a brake pipe and a fluid pressure activated brake cylinder device for applying the brakes on the railcar. A selectively operable release graduating valve can include a graduated release valve and a changeover valve which selectively interposes the graduated release valve to exhaust brake cylinder pressure in a graduated manner responsive to brake pipe pressure. Alternatively, the changeover valve can isolate the graduated release valve and direct the pneumatic control valve to exhaust brake cylinder pressure in a conventional manner. The changeover valve can be operated responsive to the pressure in an air pipe supplied with pressurized fluid from a remote source. A permanent release graduating valve can be provided wherein the changeover valve is omitted, in which case the brake cylinder exhaust is always controlled by the graduated release valve. Either configuration of the release graduating valve could be also be utilized in an ECP freight brake control system.