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:
Sep. 19, 1978
Filed:
Apr. 12, 1974
Applicant:
Inventors:
Jan M Drees, Dallas, TX (US);
Walter G Sonneborn, Fort Worth, TX (US);
Jing G Yen, Arlington, TX (US);
Assignee:
Textron, Inc., Providence, RI (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
B64C / ;
U.S. Cl.
CPC ...
4161 / ; 244 1727 ;
Abstract
A method and system which isolates two-per-rev hub spring moment vibrations while providing control power during zero-g flight in a two-bladed teetering rotor helicopter. Hub spring structure is connected between the rotor and the pylon to resist rotor flapping about the teeter axis and thus provide control during zero-g flight. To isolate from the fusilage the hub spring moment two-per-rev vibrations, the rotor is coupled to the pylon below the rotor center of gravity at a distance related to both the hub spring rates and the in-plane frequency of the helicopter blades.