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:
Jan. 16, 2001
Filed:
May. 07, 1999
Michael A. A'Hearn, Shorewood, IL (US);
Thomas J. Hajek, Jr., Lockport, IL (US);
Srikrishnan T. Tolappa, Aurora, IL (US);
Caterpillar Inc., Peoria, IL (US);
Abstract
A fluid control circuit providing a float capability for a double-acting actuator having first and second actuating chambers is provided. The fluid circuit includes signal controlled load check valves disposed between the actuating chambers and a directional control valve. The directional control valve is movable from a centered, neutral position towards first and second operative positions and a float position. The directional control valve and the load check valves are cooperatively operable in one operable position to allow fluid flow from the first actuating chamber to the exhaust port, and fluid flow from the pump port to the second actuating chamber. In the float position of the directional control valve, both of the signal controlled load check valves are opened to allow open fluid flow between the first and second actuating chambers thus allowing the tool attached to the actuator to float.