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:
Aug. 31, 1976
Filed:
Oct. 02, 1975
John D Muchow, Cerritos, CA (US);
Harry R Cove, Huntington Beach, CA (US);
Willis Oil Tool Co., Long Beach, CA (US);
Abstract
Reset means to advance a valve spool from a first valve seat to a second valve seat in opposition to exceedingly high biasing fluid pressure comprises a manually rotatable actuating means in screw threaded engagement with the body of the pilot valve. With the manually operable actuator at its retracted position, means is manually operated to operatively connect the manual actuator to the valve spool to permit advance of the manual actuator to drive the valve spool from the first valve seat to the second valve seat against the resistance of the biasing fluid pressure. In consequence of the advance of the valve spool to the second valve seat, an opposite fluid pressure progressively rises to a normal operating range at which it dominates the biasing fluid pressure to hold the spool against the second valve seat independently of the manual actuator and this rise of the opposite fluid pressure to the normal operating range automatically releases the connecting means to give the valve spool freedom for subsequent retraction by the biasing fluid pressure in the event that the dominating fluid pressure falls below its normal operating range.