Patent US4053258A successfully refreshed from Google Patents.
US4053258A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Tail-rotor arrangement for rotor crafts
Assignee: Airbus Group SAS
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Filing: 1975-08-27
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Granted: 1977-10-11
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Expires: 1995-08-27
Abstract
Abstract The invention relates to a two-bladed tail rotor arrangement for gyroplanes and helicopters, comprising two plates fixed to a rotary shaft, between which are embedded the median portion of a flat flexible spar. On the ends of the said spar are fitted two shells which form the rotor blades and whose cross-section evolves in the blade root area to become circular, whereby the said shells are terminated by cylindrical sleeves fixed by bonding to flanges which are connected by elastic blocks to two plates. The rotor boss assembly can be provided with a cylindrical fairing.
Inventors
- 👤 Rene Louis Mouille
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 17:36
CPC Classifications
B; B64; B64C; B64C27/00; B64C27/32; B64C27/33
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
148 words
A two-bladed tail rotor arrangement for lightweight moderately priced gryoplanes or helicopters comprising a strip-like flexible spar having a uniform rectangular cross-section, said spar being held at its median portion in a boss secured to the rotor shaft formed by a pair of plates having laterally opposed ends, a shaped blade shell surrounding each half of the spar and connected to the latter solely in the area of its outer end and extending freely up to the corresponding lateral end of the plates, each blade shell progressively evolving in cross-section from its outer end into a cylindrical blade root forming a sleeve surrounding the corresponding lateral end of the plates, a cylindrical flange inserted in and fixed to the sleeve of said blade root and an elastic contact interposed between the flange and the corresponding lateral end of said plates thereby connecting said blade root to said boss.
Claim 2
Dependent Claim
148 words
A two-bladed tail rotor arrangement for lightweight moderately priced gryoplanes or helicopters comprising a strip-like flexible spar having a uniform rectangular cross-section, said spar being held at its median portion in a boss secured to the rotor shaft formed by a pair of plates having laterally opposed ends, a shaped blade shell surrounding each half of the spar and connected to the latter solely in the area of its outer end and extending freely up to the corresponding lateral end of the plates, each blade shell progressively evolving in cross-section from its outer end into a cylindrical blade root forming a sleeve surrounding the corresponding lateral end of the plates, a cylindrical flange inserted in and fixed to the sleeve of said blade root and an elastic contact interposed between the flange and the corresponding lateral end of said plates thereby connecting said blade root to said boss.
Claim 3
Dependent Claim
35 words
The arrangement according to claim 1, wherein the elastic contacts are positioned in the plane containing the longitudinal axis of the spar, the rotation axis of the root and parallel to the said latter axis.
Claim 4
Dependent Claim
34 words
The arrangement according to claim 1, wherein the contacts are symmetrical revolution blocks having a progressive tapering towards their central portion, the diameter of their base circles being substantially the same as their height.
Claim 5
Dependent Claim
25 words
The arrangement according to claim 1, wherein the elastic contacts are mounted in compression between said flange and the associated lateral ends of the plates.
Claim 6
Dependent Claim
46 words
The arrangement according to claim 4, wherein the face of each base circle of said contacts is bonded to a thin member embedded in a corresponding recess in said root blade and in the corresponding portions of the lateral ends of the plates forming the boss.
Claim 7
Dependent Claim
16 words
The arrangement according to claim 1, wherein the elastic contacts comprise high elasticity silicone elastomer blocks.
Claim 8
Dependent Claim
27 words
The arrangement according to claim 1, wherein each sleeve portion of the blade root is fixed by bonding to the outer surface of the corresponding cylindrical flange.
Claim 9
Dependent Claim
15 words
The arrangement according to claim 1, wherein each cylindrical flange has a circular rigidifying collar.
Claim 10
Dependent Claim
21 words
The arrangement according to claim 1, wherein at least one flange has an integral lateral extension constituting a pitch control lever.
Claim 11
Dependent Claim
27 words
The arrangement according to claim 1, wherein the rotor boss assembly is enveloped by a fairing formed by two substantially cylindrical half shells covering the cylindrical flange.
References Cited (Backward Citations)
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Cited
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Cited
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Cited
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Cited
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Cited
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-10-10 | 1981-04-11 | 1981-10-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-10-10 | 1985-04-11 | 1985-10-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-10-10 | 1989-04-11 | 1989-10-11 | $7700.00 | Window Closed / Lapsed |