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:
Mar. 06, 1990
Filed:
Apr. 18, 1989
Applicant:
Inventor:
William F Esthimer, Walpole, MA (US);
Assignee:
Bird-Johnson Company, Walpole, MA (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
B63H / ;
U.S. Cl.
CPC ...
440 50 ; 416 27 ; 4161 / ; 440 86 ;
Abstract
The pitch of a marine controllable pitch propeller is detected by a motion/DC current transducer in the propeller hub. Circuitry rotating with the propeller shaft converts an AC power signal to DC for energization of the transducer and converts a DC output signal from the transducer to AC. The AC power and output signals are transferred from the rotating circuit to a stationary circuit in the vessel hull by rotary transformers. There are no contacts between relatively moving parts of the transducer or rotary transformers, thus ensuring long life for the pitch detection system.