1534

Item 1534

OTHER: Aircraft - Gyrocopter - Collective and Cyclic Control

A rotorhead for gyrocopters that has collective for jump take-offs, plus full collective and cyclic controls as per helicopters if wanted..

An idea that may, or may not, have been previously considered.

Sketch:

Composite Hub Bar:

Replace the conventional aluminum hub bar with an identical fiberglass/carbon composite hub bar. The composite hub bar would be made from unidirectional tape and the direction of the tape would be lengthwise, from blade grip to blade grip.

The result will be a hub bar that has high strength in;
~ tension (centrifugal blade forces)
~ inplane bending (lead/lag)
~ out-of-plane bending (flapping)
However, this hub bar will offer little resistance to rotation about it's longitudinal axis (pitch axis).

The pitches of the two blades will now be capable of change. This will allow for both blades to have their pitches increased; which will provide collected for jump-takeoffs. And/Or, allow one blade's pitch to be increased while the other blade's pitch is being decreased; which will provide cyclic control.

This hub bar should cost very little more than the aluminum hub bar that it replaces, particularly if made in some quantity. In addition, the composite hub bar can be both lighter and stronger than the aluminum one.

Flight Control:

A simple flight control for collective only might be the Seibel S-3, but modified to work with the conventional gyrocopter cyclic control.
His cyclic control might also be considered. The information can be 'picked' out of here.

A slightly more advanced flight control would be where two rods come up the inside a stub mast.

Dennis Fetters has a patent for the Mini-500 [5,163,815] that describes this method.

References Cited ~ U.S. Patent Documents


2499314	February 1950	Hunt
2511687	June 1950	Andrews
2810443	October 1957	Doman
2946390	July 1960	Pozgay
3109496	November 1963	Ellis, III et al.
3577616	March 1971	Ulisnik
3637321	January 1972	Nekrasov et al.
3756743	September 1973	Robertson
3885887	May 1975	Desjardins
4432696	February 1984	Stephan et al.
4534704	August 1985	McArdle
4681511	July 1987	Glatfelter

A very similar patent by Cicare for the CH-7 [5,165,854].

References Cited ~ U.S. Patent Documents


2748876	June 1956	Daland et al.
2599690	June 1952	Buivid et al.
2978037	April 1961	Focke
3199601	August 1965	Dean et al.
3217809	November 1965	Bossler
3589831	June 1971	Lemnios

Possible Concern:

Hopefully, the forces coming back to the polot will not be too strong. Doesn't the light 2-seat Russian helicopter have composite straps, in lieu of pitch bearings?

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Last Revised: August 27, 2006