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:
Aug. 27, 2002
Filed:
Aug. 24, 2000
Kenneth Edward Hart, Simi Valley, CA (US);
HR Textron, Inc., Valencia, CA (US);
Abstract
A control system utilizes hydraulic power only to control a fixed-wing aircraft horizontal stabilizer trim control surface with no electrical control devices except for a cockpit pilot/co-pilot initiated 3-position spring-centered toggle trim switch, a backup electrical motor and a standard electronic logic pilot interface. The toggle trim switch controls two solenoid valves which control the operation of a directional control valve. The control system also includes a hydraulic motor, a rate control valve, a blocking-bypass valve, a shutoff valve with an integrated position sensor and a gear set driving an acme threaded output shaft for elevating or lowering the horizontal stabilizer trim control surface on command by the pilot. The control system controls the horizontal stabilizer trim control surface angular displacement rate as a function of angular position by means of a mechanical feedback linkage between the spool of the rate control valve and the horizontal stabilizer trim control surface. The sleeve of the rate control valve has a variable outflow area slot to control the hydraulic flow rate to the motor ports of the hydraulic motor. The horizontal stabilizer trim control surface is automatically stopped at pre-determined maximum-up/maximum-down positions by means of a mechanical feedback linkage between the horizontal stabilizer trim control surface and the spool of the shutoff valve. If the mechanical feedback linkage between the rate control valve spool and the horizontal stabilizer trim control surface malfunctions, the rate control valve automatically reverts to a default fixed flow rate which translates into a corresponding fixed horizontal stabilizer trim control surface angular displacement rate.