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. 25, 1988
Filed:
Jul. 13, 1987
Applicant:
Inventors:
Probir K Chatterjea, Mt. Prospect, IL (US);
Steven C Kirkham, McHenry, IL (US);
Assignee:
Dresser Industries, Inc., Dallas, TX (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
F16D / ; F15B / ;
U.S. Cl.
CPC ...
60429 ; 60468 ; 60484 ; 60486 ; 91461 ;
Abstract
A control system for the boom and bucket operation system on a front end loader that includes an unloader valve responsive to pilot valve pressure to bypass hydraulic fluid pumped by an auxiliary pump to the reservoir while maintaining the primary pump supply to a loader valve which supplies pressure to the boom and bucket cylinders in response to the operation of pilot valves. The unloader valve bypasses the auxiliary pump flow when the pressure is below a predetermined value and when the pressure is above a second higher predetermined value.