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:
Apr. 29, 1980
Filed:
Dec. 21, 1977
Andrew H Logan, Rancho Palos Verdes, CA (US);
Richard E Moore, Los Angeles, CA (US);
Summa Corporation, Las Vegas, NV (US);
Abstract
An antitorque system for use in a helicopter produces antitorque moments with efficiency comparable to that of the tail rotor it is designed to replace. The antitorque forces are generated mainly from the main rotor downwash by the circulation control effect. The downwash is deflected laterally as it passes around the tail boom by a sheet of air continuously discharged tangentially to the surface of the tail boom on one side of it at velocities in the range 30 to 120 meters per second from slots extending longitudinally along the tail boom and having a width in the range 4 to 20 millimeters. The discharged air is supplied by a relatively low-pressure-ratio fan within the fuselage which directs a stream of air rearwardly into the tail boom. The tail boom is provided at its rear end with a laterally disposed aperture through which some of the fan-supplied air is discharged to create a direct jet thrust. The flow through the aperture is throttled to vary the antitorque moment for trim and maneuvering.