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:
Oct. 06, 2020
Filed:
Jun. 02, 2017
Applicant:
Pratt & Whitney Canada Corp., Longueuil, CA;
Inventor:
David Waddleton, Candiac, CA;
Assignee:
PRATT & WHITNEY CANADA CORP., Longueuil, CA;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
B64C 11/38 (2006.01); B64C 11/40 (2006.01); B64C 11/42 (2006.01); F01M 5/00 (2006.01); F02C 3/04 (2006.01);
U.S. Cl.
CPC ...
B64C 11/38 (2013.01); B64C 11/385 (2013.01); B64C 11/40 (2013.01); B64C 11/42 (2013.01); F01M 5/002 (2013.01); F02C 3/04 (2013.01); F05D 2220/323 (2013.01);
Abstract
A control circuit for changing the angle of propeller blades includes a propeller pitch change mechanism, and a fixed-displacement pump providing the supply of oil from an engine oil return system. A valve has an outlet port to direct oil from a cavity of the valve, and a pitch port in fluid communication with the pitch change mechanism. A spool of the valve is operable between a first position and a second position to respectively open and close the outlet port, and direct oil flow away from or to the pitch change mechanism.