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. 27, 1979
Filed:
Aug. 01, 1977
Applicant:
Inventors:
William C Swanson, Clarendon Hills, IL (US);
Imre Galos, Downers Grove, IL (US);
Assignee:
International Harvester Company, Chicago, IL (US);
Primary Examiner:
Int. Cl.
CPC ...
F15B / ; F16K / ;
U.S. Cl.
CPC ...
91461 ; 251 28 ; 251 635 ; 251122 ; 251 63 ;
Abstract
An unloading valve spool with a tapered nose section is urged across a pair of unloading ports at a controlled rate eliminating violent upstream pressure generation. The unloading valve is subjected to equal system fluid pressure on each side of it as the spool is provided with a through passage that is dead headed on the back side of the unloading spool. A return spring urges the unloading spool to a normally closed position. An unloading piston prevents the unloading spool from closing too rapidly preventing the generation of a significant upstream pressure spike.