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:
Jun. 24, 2014
Filed:
Apr. 14, 2011
Andrew Swift, Uttoxeter, GB;
Antony Morgan, Wolverhampton, GB;
Andrew Swift, Uttoxeter, GB;
Antony Morgan, Wolverhampton, GB;
Rolls-Royce PLC, London, GB;
Abstract
A pitch control mechanism for controlling the pitch of propeller assembly propellers has a hydraulic actuator, main hydraulic fluid supply lines, first back-up hydraulic fluid supply lines, and second back-up hydraulic fluid supply lines. The hydraulic actuator has first and second hydraulic cylinders that each angularly displace the propellers between fine and coarse positions. The main hydraulic fluid supply lines supply fluid to the first and second hydraulic cylinders for operating the hydraulic cylinders. The first back-up hydraulic fluid supply lines supply fluid to the hydraulic cylinder for displacing the propellers to a coarser position. The second back-up hydraulic fluid supply lines supply fluid to the second hydraulic cylinder for displacing the propellers to a coarser position. When the main hydraulic fluid supply lines supply inadequate fluid, the first and/or second back-up hydraulic fluid supply lines can supply fluid for displacing the propellers to a coarser position.