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. 08, 1985
Filed:
Dec. 24, 1981
William W Blake, Kewanee, IL (US);
Caterpillar Tractor Co., Peoria, IL (US);
Abstract
A fluid control system (10) for two independent actuators or clutches (11,12) has a pair of normally open solenoid valves (44,46) for controlling fluid pressure in a pair of actuating chambers (31,32). This controls actuation of a pair of directional spools (26,27) which in turn controls engagement and disengagement of the clutches (11,12) such that failure of one of the solenoid valves to close properly would not cause unexpected engagement of the associated clutch. A shuttle spool (59) is movable in response to pressurization of one of the actuating chambers (31,32) to a position for venting the other actuating chamber (31,32) thereby preventing simultaneous engagement of both clutches.