US3853424A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Labyrinth air valve for rotor hub
Assignee: Individual
•
Filing: 1973-07-18
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Granted: 1974-12-10
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Expires: 1993-07-18
Abstract
Abstract An air valve for a circulation control helicopter rotor. The valve comprises an inner member and a rotating blade-carrying outer member with an air passage between the two; the inner member can be translated to a position that is eccentric with respect to the rotating outer member to cause a cyclic variation in the amount of air received by each blade. Sealing means are provided at the entrance to each rotor blade, the preferred form being a labyrinth structure on both the inner and outer members.
Inventors
- 👤 H Bernaerts
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 12:29
CPC Classifications
B; B64; B64C; B64C27/00; B64C27/32; B64C27/325
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
56 words
A rotor hub for a circulation control helicopter rotor comprising: an inner member; a rotating outer member surrounding said inner member and spaced therefrom to form a fluid flow passage; fluid receiving means in said rotating member; and sealing means between said inner member and said fluid receIving means, said sealing means comprising a labyrinth seal.
Claim 2
Dependent Claim
56 words
A rotor hub for a circulation control helicopter rotor comprising: an inner member; a rotating outer member surrounding said inner member and spaced therefrom to form a fluid flow passage; fluid receiving means in said rotating member; and sealing means between said inner member and said fluid receIving means, said sealing means comprising a labyrinth seal.
Claim 3
Dependent Claim
17 words
A rotor hub as in claim 1 wherein said sealing means is on said inner member only.
Claim 4
Dependent Claim
17 words
A rotor hub as in claim 1 wherein said sealing means is on said rotating member only.
Claim 5
Dependent Claim
25 words
A rotor hub as in claim 1 wherein said sealing means comprises cooperating seals, one on said inner member and one on said rotating member.
Claim 6
Dependent Claim
15 words
A rotor hub as in claim 4 wherein said cooperating seals comprise interdigitated labyrinth seals.
Claim 7
Dependent Claim
14 words
A rotor hub as in claim 1 having means for by-passing said sealing means.
Claim 8
Dependent Claim
26 words
A rotor hub as in claim 6 wherein said by-pass means comprises passages through said inner member, said passages communicating directly with said fluid receiving nozzles.
Claim 9
Dependent Claim
60 words
A hub for a circulation control rotor helicopter comprising: a rotating outer member carrying a plurality of hollow blades; means to direct collective pitch control fluid to the blades; means to direct cyclic pitch control fluid to the blades, said means comprising a translatable inner member; and means to prevent the admission of cyclic pitch control fluid to the blades.
Claim 10
Dependent Claim
60 words
A hub for a circulation control rotor helicopter comprising: a rotating outer member carrying a plurality of hollow blades; means to direct collective pitch control fluid to the blades; means to direct cyclic pitch control fluid to the blades, said means comprising a translatable inner member; and means to prevent the admission of cyclic pitch control fluid to the blades.
Claim 11
Dependent Claim
25 words
A hub as in claim 8 wherein the means to direct collective pitch control fluid comprises a plurality of passages in said translatable inner member.
Claim 12
Dependent Claim
28 words
A hub as in claim 9 wherein the means to prevent the admission of cyclic pitch control fluid comprises a seal between said inner and said outer members.
Claim 13
Dependent Claim
17 words
A hub as in claim 10 wherein said seal comprises a labyrinth seal on said inner member.
Claim 14
Dependent Claim
17 words
A hub as in claim 10 wherein said seal comprises a labyrinth seal on said outer member.
Claim 15
Dependent Claim
24 words
A hub as in claim 10 wherein said seal comprises interdigitated labyrinth seals, one on said inner member and one on said outer member.
Claim 16
Dependent Claim
19 words
A hub as in claim 10 wherein said inner member is mounted for rotation independently of said outer member.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-12-09 | 1978-06-10 | 1978-12-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-12-09 | 1982-06-10 | 1982-12-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-12-09 | 1986-06-10 | 1986-12-10 | $7700.00 | Window Closed / Lapsed |