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. 06, 1980
Filed:
Jul. 11, 1977
Applicant:
Inventor:
Robert J Martin, Hutchinson, KS (US);
Assignee:
The Cessna Aircraft Company, Wichita, KS (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
F15B / ;
U.S. Cl.
CPC ...
91387 ; 91365 ; 13762564 ; 251 30 ; 335266 ;
Abstract
A conventional control valve hydraulically powered by a double acting cylinder and controlled electrically through a double acting solenoid supplied by a variable D.C. supply. The solenoid transmits varying forces to a four-way pilot valve which in turn controls the positioning of the double acting cylinder. The de-energized solenoid, control valve spool and pilot spool are neutrally balanced between two springs equally loaded with differing spring rates so that a small movement of the solenoid core will cause a proportionally larger movement of the main control valve spool proportioned to the different spring rates.