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:
Jul. 08, 1986
Filed:
Jun. 20, 1985
Applicant:
Inventors:
Rickie A Young, Cedar Rapids, IA (US);
David L Willard, Cedar Rapids, IA (US);
Gerald P Berger, Cedar Rapids, IA (US);
Assignee:
FMC Corporation, Chicago, IL (US);
Attorneys:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
B66C / ;
U.S. Cl.
CPC ...
212149 ; 212151 ; 212159 ;
Abstract
A hydraulic circuit for a crane having both lift and boom hoist pumps driven by the same engine with appropriate control valves to independently control the lift hooks and the boom angle. An unloading valve is interposed in the boom hoise circuit and dumps the boom hoise pump directly to reservoir when the pressure in the left pump circuit becomes excessive. A boom limit valve, actuated as the boom reaches both upper and lower limits, also causes the unloading valve to dump the boom hoise pump to reservoir.