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:
May. 25, 1993
Filed:
Dec. 09, 1991
Vincent F Troiani, New Florence, PA (US);
Westinghouse Air Brake Company, Wilmerding, PA (US);
Abstract
A piston valve assembly for a freight brake control valve device in which axial displacement of a piston member is provided relative to its slide valve in response to slide valve friction creating excessive resistance to movement of the piston assembly from lap to release position. This relative movement between the piston member and slide valve causes a graduating valve that is carried fast with the piston member to open a release insuring passage in the slide valve and thereby exhaust auxiliary reservoir pressure from one side of the piston member. Accordingly, a relatively high pressure differential is created across the piston member to quickly overcome the slide valve resistance and assure prompt movement of the piston valve assembly and thereby obtain brake release without delay.