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:
Mar. 25, 1980
Filed:
Apr. 10, 1978
Applicant:
Inventor:
Lowell R Hall, Elwood, IL (US);
Assignee:
Caterpillar Tractor Co., Peoria, IL (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
F58 / ;
U.S. Cl.
CPC ...
137596 ; 91447 ; 91451 ; 91454 ;
Abstract
A valve controls fluid flow to a fluid jack by movement of a single valve spool to a first position. A check valve and bypass valve cooperate to pass fluid exhausted from the fluid jack to a tank bypassing the single valve spool. Movement of the bypass valve is controlled by developing a controlled pressure drop between the fluid in the fluid jack and the fluid between the check valve and the single valve spool in response to the valve spool being moved to a second position.