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:
Feb. 18, 2014
Filed:
Oct. 02, 2009
Robert E. Wilson, Derby, GB;
Jonathan E. Holt, Derby, GB;
Antony Morgan, Wolverhampton, GB;
Rolls-Royce PLC, London, GB;
Abstract
A engine such as a gas turbine engine has a bladed rotorhaving variable pitch blades. In normal operation, the pitch angle of the bladesis controlled by a primary pitch control system. A back-up system is provided for controlling the blades, for example to displace them to a feathered condition, in the event of failure of the primary pitch control system. The back-up system comprises a pumpmounted on the rotor, and driven by relative rotation between the rotorand a contra-rotating rotor. In response to a failure signal on a conduit, the pump delivers hydraulic fluid under pressure to a secondary actuator, which acts on the blade