US3637168A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Flexible blade retractable rotor aircraft
Assignee: Teledyne Ryan Aeronautical Corp
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Filing: 1970-02-11
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Granted: 1972-01-25
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Expires: 1990-02-11
Abstract
Abstract A compound helicopter-type aircraft with a fixed wing and forward propulsion means, and incorporating a rotor having flexible blades which are wound up on reels and enclosed in the aircraft when not in use. The blades are composed of flexible straps with segmented leading edge portions of airfoil shape, and flexible rear filler portions to complete the airfoil, the segmented portions being designed to prevent the strap from being stretched beyond its elastic limit. The rotor blades are synchronized in extension and retraction and controlled in accordance with rotational speed by an automatic brake means, which also causes retraction of the blades when power is shut off, unless intentionally overridden.
Inventors
- 👤 T Claude Ryan
- 👤 Peter F Girard
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 02:52
CPC Classifications
B; B64; B64C; B64C27/00; B64C27/32; B64C27/46
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
149 words
In an aircraft having an airframe, fixed aerodynamic lifting surfaces and a source of propulsive power, a flexible blade retractable rotor, comprising, a hub mounted in said airframe for rotation about a substantially vertical axis and having a drive shaft coupled to said source of power, a pair of reels coaxially rotatably mounted on said hub, with coupling means interconnecting said reels to rotate synchronously in opposite directions, a longitudinal flexible rotor blade attached to and wound on each of said reels, a pair of booms extending from said hub on opposite sides thereof, with a rotor blade guiding trunnion pivotally mounted on the outer end of each boom to swing in the direction of pitch change of the blade, pitch control means on said hub connected to said trunnions, and, rotational speed responsive brake means connected to said coupling means for selective retarding and release of said reels.
Claim 2
Dependent Claim
149 words
In an aircraft having an airframe, fixed aerodynamic lifting surfaces and a source of propulsive power, a flexible blade retractable rotor, comprising, a hub mounted in said airframe for rotation about a substantially vertical axis and having a drive shaft coupled to said source of power, a pair of reels coaxially rotatably mounted on said hub, with coupling means interconnecting said reels to rotate synchronously in opposite directions, a longitudinal flexible rotor blade attached to and wound on each of said reels, a pair of booms extending from said hub on opposite sides thereof, with a rotor blade guiding trunnion pivotally mounted on the outer end of each boom to swing in the direction of pitch change of the blade, pitch control means on said hub connected to said trunnions, and, rotational speed responsive brake means connected to said coupling means for selective retarding and release of said reels.
Claim 3
Dependent Claim
84 words
An aircraft according to claim 1, wherein said brake means includes, a brake shaft concentric within said drive shaft and on which said pinion is secured, a brakedrum fixed in said airframe, a base plate secured to said brake shaft and rotatable in said brakedrum, arms pivotally mounted on and extending outwardly from said base plate, with flyweights on the outer ends thereof, brakeshoes on the inner ends of said arms, and pressure spring means biasing said brakeshoes into engagement with said brake drum.
Claim 4
Dependent Claim
23 words
An aircraft according to claim 2, and including override actuators connected to said arms for selective engagement and release of said brake means.
Claim 5
Dependent Claim
21 words
An aircraft according to claim 3, and including torque-adjusting means connected to said arms in opposition to said pressure spring means.
Claim 6
Dependent Claim
52 words
An aircraft according to claim 1, wherein each of said trunnions has substantially horizontal upper and lower blade guiding rollers, and substantially vertical leading and trailing edge rollers, the leading and trailing edge rollers having circumferential channels shaped to conform generally to the leading and trailing edge configurations of the rotor blade.
Claim 7
Dependent Claim
33 words
An aircraft according to claim 1, wherein each of said booms is pivotally attached to said hub to swing substantially vertically, said hub having stop means limiting the downward travel of the boom.
Claim 8
Dependent Claim
105 words
An aircraft according to claim 1, wherein said rotor blades each comprise, a flexible longitudinal strap member, a plurality of longitudinal pivotally interconnected leading edge members secured to one edge of said strap member, a flexible filler material bonded to said strap member, forming an airfoil body from said leading edge members to the other edge of the strap member, each of said leading edge members having a chordal tongue projecting from one side, and a chordal slot in the other side to receive the tongue of the next adjacent leading Edge member in a pivotal connection with a limited range of spanwise angular displacement.
Claim 9
Dependent Claim
51 words
An aircraft according to claim 7, wherein each of said leading edge members has a spanwise slot in which said strap member is held, the lower face of each slot having a spanwise curvature with a radius substantially equal of the radius of the rolled rotor blades on the respective reel.
Claim 10
Dependent Claim
36 words
An aircraft according to claim 7, wherein said strap member has perforations through which said filler material extends, certain of said leading edge members having rearwardly extending ribs secured to and chordally stiffening said strap member.
References Cited (Backward Citations)
US2172333A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-01-24 | 1975-07-26 | 1976-01-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-01-24 | 1979-07-26 | 1980-01-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-01-24 | 1983-07-26 | 1984-01-25 | $7700.00 | Window Closed / Lapsed |