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:
Nov. 07, 2000
Filed:
Dec. 21, 1998
Applicant:
Inventor:
Francedilla.ois Valentin Toulmay, Vitrolles, FR;
Assignee:
Eurocopter, , US;
Primary Examiner:
Int. Cl.
CPC ...
B64C / ; B64C / ;
U.S. Cl.
CPC ...
416228 ; 4162 / ; 416237 ; 416238 ;
Abstract
A blade for a rotary wing aircraft includes a blade tip winglet intended to reduce the blade-vortex interaction noise during descending flight. The winglet has, in plan view, an at least approximately trapezoidal shape, and the mean value of a chord C.sub.1 of the winglet is between 25% and 40% of a chord C.sub.0 of the main part of the blade. Compared with a conventional rectangular tip, and for the same aerodynamic thrust, the reduction in noise associated with use of the blade tip winglet can be as much as 40%.