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:
Jul. 25, 1978
Filed:
Mar. 08, 1976
Lyle F Martz, Penn Hills, PA (US);
Westinghouse Electric Corp., Pittsburgh, PA (US);
Abstract
This disclosure relates to a system for protecting pneumatic cylinders and diaphragm valves against failure of both electrical and pneumatic supplies. In the event of a failure of the air supply, the loss of air pressure is detected and all drives are locked in position. The position pneumatic feedback signal from the pneumatic cylinder diaphragm valve is then connected directly to a pneumatic memory. Thus when the air supply recovers, the pneumatic memory will be equal to the instantaneous position of the pneumatic cylinder or diaphragm valve. In the event of an electrical failure, a solenoid valve interrupts the flow of the pneumatic signal from an electropneumatic transducer to the pneumatic memory, so that the air cylinder or valve is directly connected to the pneumatic memory. By selectively energizing a pair of solenoid valves connected to the memory, the operator using an emergency d.c. source can then slue the memory up or down as required for control purposes until the restoration of the electrical supply.