Patent US3762834A successfully refreshed from Google Patents.
US3762834A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Helicopter rotors comprising a reinforced plastics hub
Assignee: Airbus Group SAS
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Filing: 1972-02-02
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Granted: 1973-10-02
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Expires: 1992-02-02
Abstract
Abstract A helicopter rotor has a reinforced plastics hub. Arms extend radially outwardly from the hub each arm carrying through, the intermediary of a sleeve, a blade. The arms are reinforced with fibres.
Inventors
- 👤 G Bourquardez
- 👤 M Gouzien
- 👤 R Mercier
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 18:23
CPC Classifications
B; B64; B64C; B64C27/00; B64C27/51; B64C27/32; B64C27/33
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
147 words
A rotor construction comprising a one-piece star-shaped moulded rotor hub substantially made of bundles of mineral filaments agglomerated by a polymerized synthetic resin, each bundle extending from the end of one star arm to the end of the next one, each star arm having near the hub axis, in the star plane, a flattened cross-section merging into a cylindrical substantially radial end portion; a sleeve, surrounding each said cylindrical portion and secured thereto, having at least a lateral lug at the end directed towards the hub axis; an elongated drag damper in said star plane, one end of which is secured to said lug and the other to the hub towards one of the next star arm; a blade having a bushing engaging each said sleeve; roller means between said bushing and sleeve and means adapted to withstand centrifugal force for securing said blade to said arm.
Claim 2
Dependent Claim
147 words
A rotor construction comprising a one-piece star-shaped moulded rotor hub substantially made of bundles of mineral filaments agglomerated by a polymerized synthetic resin, each bundle extending from the end of one star arm to the end of the next one, each star arm having near the hub axis, in the star plane, a flattened cross-section merging into a cylindrical substantially radial end portion; a sleeve, surrounding each said cylindrical portion and secured thereto, having at least a lateral lug at the end directed towards the hub axis; an elongated drag damper in said star plane, one end of which is secured to said lug and the other to the hub towards one of the next star arm; a blade having a bushing engaging each said sleeve; roller means between said bushing and sleeve and means adapted to withstand centrifugal force for securing said blade to said arm.
Claim 3
Dependent Claim
34 words
The improved rotor of claim 1 wherein the said end cylindrical portion is thickened by the inclusion of shapes in strong fibre cloths coaxially of the group of axial Fibres of the cylindrical portion.
Claim 4
Dependent Claim
56 words
The improved rotor of claim 1, wherein said means to withstand centrifugal force is a straight element which withstands tension but which can twist and which is disposed axially in the cylindrical portion and whose ends are secured, on either side of the cylindrical portion which bears the sleeve, to the arm and to the blade.
Claim 5
Dependent Claim
34 words
The improved rotor of claim 1, wherein one of the two ends of said drag damper is secured to a casing containing the central part of the hub in the gap between two blades.
Claim 6
Dependent Claim
30 words
The improved rotor of claim 2, wherein said means to withstand centrifugal force is a straight element embodied by a group of strong fibres encased in a flexible vulcanized elastomer.
Claim 7
Dependent Claim
18 words
The improved rotor of claim 5, wherein the group is a terminal portion of the hub-reinforcing fibre groups.
Claim 8
Dependent Claim
22 words
The improved rotor of claim 5, wherein the fibre group is isolated from the cylindrical portion by a flexible antifriction plastics sheath.
Claim 9
Dependent Claim
26 words
The improved rotor of claim 6, wherein the outer end of the group is encased in hardened synthetic resin and shaped for connection to the blade.
Claim 10
Dependent Claim
26 words
The improved rotor of claim 6, wherein the terminal part of the group has a length substantially equal to half the total length of the arm.
Claim 11
Dependent Claim
28 words
The improved rotor of claim 6, wherein the terminal part of the group extends mainly in the arm part comprising the cylindrical portion around which the sleeve extends.
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) | 1976-10-01 | 1977-04-02 | 1977-10-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-10-01 | 1981-04-02 | 1981-10-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-10-01 | 1985-04-02 | 1985-10-02 | $7700.00 | Window Closed / Lapsed |