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:
Nov. 02, 2004
Filed:
Mar. 19, 2002
David V. Arel, Granby, CT (US);
Robert Perkinson, Somers, CT (US);
David Danielson, Suffield, CT (US);
Hamilton Sundstrand, Windsor Locks, CT (US);
Abstract
A propeller control system provides for actuation through supply pressure only. A transfer bearing thereby requires only a single land. The supply pressure is metered at a pitch change valve within the rotating propeller shaft downstream of the transfer bearing to provide hydraulic pressure for actuation and control. A feather override mode is provided by energizing a feathering solenoid. The increased supply pressure changes the hydraulic force balance of the pitch change valve to allow the increased supply pressure into a Coarse Pitch chamber and simultaneously allow fluid within the Fine Pitch chamber to flow to drain pressure. The flow to drain changes the hydraulic balance on the Pitch Change Actuator Piston to drive a pitch link attached to each propeller blade and thereby change the pitch thereof towards coarse pitch.