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:
Feb. 18, 1986
Filed:
Sep. 08, 1982
David J Wickham, Chippenham, GB;
Westinghouse Brake & Signal Company, Chippenham, GB;
Abstract
A control valve arrangement adapted to produce and maintain a pilot signal comprises a number of standard modules. The basic element has two standard modules, each of which includes a diaphragm-controlled on-off valve. An input signal is applied to a first valve against a reference pressure such that when the valve is on, a signal is generated and held as a pilot pressure. A second valve responds to a fall in input signal pressure to cancel out pilot pressure. The two valves together constitute a bistable operator. A particular use of this operator is in a railway braking system in which the first valve is used as an application valve and the second valve is used as a release valve. A third module may be used as a pilot pressure-maintaining valve. The pneumatically-operated diaphragm assembly shown in FIG. 1, comprises three modules, 1, 2 and 3. Module 1 is the brake application module, module 2 is the release module and module 3 is an optional pilot pressure-maintaining module. Each module includes a ball valve 8, 21, 30, operated by respective diaphragms 5, 19, 26. Modules 1 and 2 act as a bistable operator producing the pilot pressure and module 3 acts to maintain the pilot pressure.