Title: Helicopter rotor hub provided with flexible elements such as virtual hinges

Abstract: A helicopter rotor hub is provided with a center plate and a plurality of arms projecting from the center plate. Each of the projecting arms has a slot for receiving a flexible element that is connected to a spindle and grip that supports the rotor blades. The rotor blades can accomplish the movements of flapping and lag by allowing the center plate to have a low stiffness in the vertical plane when the center plate lies in a horizontal plane, and the flexible element a low stiffness in the horizontal plane when the flexible elements lie in the vertical plane, thereby acting as virtual hinges. This allows for the possibility of locating the vertical hinges at an equal distance from the rotor axis, and the pitch variation hinge a small distance from the other hinges, allowing for a relatively small dimension of the hub.

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Inventors: Bruel, Andre (Cascina Costa, IT)

Application Number: 472458
Filing Date: 1974-05-24
Publication_date: 1976-03-02
Assignee: Costruzioni Aeronautiche Giovanni Agusta S.p.A. (Cascina Costa, IT)
Primary Class(es): 416/141 416/138
Other Classes:
US Patent Ref:

2949967	Aug, 1960	Jovanovich	416/141.
3026942	Mar, 1962	Cresap	416/135.
3280918	Oct, 1966	Drees et al.	416/135.
3520637	Jul, 1970	Tobey	416/135.
3606575	Sep, 1971	Lermusiaux	416/141.
3695779	Oct, 1972	Kastan et al.	416/141.
3762834	Oct, 1973	Bourquardez et al.	416/140.

Other Refs: 1,051,476

Dec, 1966	UK

Primary Examiner: Powell, Jr., Everette A.
Assistant Examiner:
Attorney: Toren, McGeady and Stanger