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. 23, 1992
Filed:
Sep. 06, 1989
Frank N Piasecki, Haverford, PA (US);
Piasecki Aircraft Corporation, Essington, PA (US);
Abstract
An improved control system for a rotary wing aircraft having a tail assembly comprising an annular duct within the interior of which a variable pitch propeller is concentrically mounted for rotation forwardly of movable surfaces for deflecting the slip stream generated by the propeller transversely of the duct as will provide transversely directed thrust forces for amounts required to counteract rotor torque and provide directional control of the aircraft in azimuth. The improvement comprises a collective pitch torque compensation unit connected between the pilot's rotor collective pitch control and the pitch control actuator of the propeller in which the compensation unit establishes changes in the pitch of the tail propeller that are proportional to changes in the rotor collective pitch in amounts that vary dependent upon the high or low range pitch setting of a pilot operable propeller pitch adjusting switch, whereby compensating thrust forces are automatically generated in counteracting changes in rotor torque created by changes in rotor collective pitch.