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:
May. 05, 1998
Filed:
Mar. 20, 1996
Frank Richard Chiappetta, Berwyn, PA (US);
Fran Rich Chi Associates, Inc., Berwyn, PA (US);
Abstract
A ducted fan 20 provides lift to a flying vehicle 10. The ducted fan includes direction control vanes (1, 2, 3, 4) for controlling torques applied to the vehicle, and also includes lift negation vanes (305, 306, 307, 308), which control the available lift. The lift negation vanes are oriented with their longitudinal axes parallel to the forward-aft axis (9) of the vehicle in order to reduce drag at high forward velocities. The thrust negation vanes include fixed (305) and movable (305M) portions, with the movable portions rotatable so as to extend into the duct airflow to cause turbulence. The direction control vanes are airfoils arranged for rotation about their quarter-chord axes (410), which reduces the amount of torque required for rotation of the direction-control vanes. This, in turn, allows stepper motors (924a) to be used to drive the vanes. The effects of forward velocity on the ducted fan also creates effects which tend to pitch the vehicle nose-down. A pair of conventional-type horizontally disposed airfoils (44a, 44b) is rotatable for pitch control, and a control system (700) senses airspeed, and provides a compensating rotation of the airfoils.