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:
Oct. 13, 1987
Filed:
Nov. 01, 1984
Jerry B Tomlin, Sugar Land, TX (US);
Ronald L Loup, Clarkston, MI (US);
Koomey, Inc., Brookshire, TX (US);
Abstract
A fail-safe system for use on a hydraulic piloted pressure reducing and regulating valve for holding the valve at the last selected operating pressure in the event of loss of control signals. A pressure regulating valve having a body and a control piston therein is provided with a pilot piston in the body which is adapted to be connected to and responsive to a hydraulic signal pilot pressure. A segmented locking ring surrounds the assembly and coacting concentric V-shaped locking grooves are provided between the locking ring and the assembly for locking the assembly. The segmented ring is biased towards an unlocked position. An annular cam ring engages the exterior of the locking ring. Coacting wedge surfaces between the cam ring and the locking ring are provided for locking and releasing the locking ring. The cam ring is biased for urging the coacting wedge surfaces into engagement. A release piston engages the cam ring for moving the cam ring in a direction to disengage the coacting wedge surfaces upon the application of release pressure.