US3586460A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Rotor blade variable modulus trailing edge
Assignee: United States Department of the Air Force
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Filing: 1969-05-14
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Granted: 1971-06-22
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Expires: 1989-05-14
Abstract
Abstract A helicopter rotor blade is provided with a trailing edge of hollow construction to form a cavity in which materials of various weights and densities is contained. The structural and aerodynamic properties of the rotor blade are enhanced by controlling the mixture of the modulus fibrous materials contained in the trailing edge cavity.
Inventors
- 👤 Charles V Toner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 22:24
CPC Classifications
B; B64; B64C; B64C27/00; B64C27/32; B64C27/46; B64C27/473; Y; Y10; Y10S; Y10S416/00; Y10S416/50
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
122 words
In a rotary wing aircraft having a rotor blade with a variable modulus trailing edge to provide chordwise dynamic natural frequencies, a triangular-shaped container means having a rearwardly oriented apex portion and extending inside and longitudinally along the trailing edge of the rotor blade, a particulate material selectively positioned in said container means, said container means including upper, lower and forward wall sections, and fibrous material of a specific weight and density being selectively intermixed with said particulate material in said container means in varying amounts and concentrations so as to correspondingly vary the structural and aerodynamic properties of the rotary wing aircraft, thereby allowing overall design flexibility of the rotor blade to achieve optimum operational capability of the rotary wing aircraft.
Claim 2
Dependent Claim
122 words
In a rotary wing aircraft having a rotor blade with a variable modulus trailing edge to provide chordwise dynamic natural frequencies, a triangular-shaped container means having a rearwardly oriented apex portion and extending inside and longitudinally along the trailing edge of the rotor blade, a particulate material selectively positioned in said container means, said container means including upper, lower and forward wall sections, and fibrous material of a specific weight and density being selectively intermixed with said particulate material in said container means in varying amounts and concentrations so as to correspondingly vary the structural and aerodynamic properties of the rotary wing aircraft, thereby allowing overall design flexibility of the rotor blade to achieve optimum operational capability of the rotary wing aircraft.
Claim 3
Dependent Claim
22 words
In a rotor blade as defined in claim 1 wherein the material contained in said container means includes mixed modulus fibrous materials.
Claim 4
Dependent Claim
20 words
In a rotor blade as defined in claim 1 wherein the material contained in said container means includes fibrous glass.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-06-21 | 1974-12-21 | 1975-06-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-06-21 | 1978-12-21 | 1979-06-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-06-21 | 1982-12-21 | 1983-06-22 | $7700.00 | Window Closed / Lapsed |