US4588355A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Flexible swashplate centering member
Assignee: RTX Corp
•
Filing: 1984-08-23
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Granted: 1986-05-13
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Expires: 2004-08-23
Abstract
Abstract Centering and stabilizing against rotation of a helicopter swashplate stationary ring are provided by spokes that are attached between the airframe and the stationary ring. When the swashplate tilts for cyclic control, the spokes bend and twist. When the swashplate translates for collective control, the spokes are required to lengthen and skew with respect to the swashplate. An elastomeric bearing having a cylindrical component to allow for skew and a shear pad to allow for lengthening attaches each spoke to the swashplate. The invention eliminates the need for the ball joint, standpipe and scissors associated with traditional swashplate centering techniques.
Inventors
- 👤 Donald L. Ferris
- 👤 Michael J. Marchitto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 18:07
CPC Classifications
B; B64; B64C; B64C27/00; B64C27/54; B64C27/58; B64C27/59; B64C27/605
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
54 words
A centering member attaching the stationary ring of a helicopter swashplate concentrically about the rotorshaft to the airframe, comprising: flexible elongated members disposed radially to the rotorshaft, each attached at one end to the airframe; and attachment means for attaching the other end of each elongated member articuably and elongatably to the stationary ring.
Claim 2
Dependent Claim
54 words
A centering member attaching the stationary ring of a helicopter swashplate concentrically about the rotorshaft to the airframe, comprising: flexible elongated members disposed radially to the rotorshaft, each attached at one end to the airframe; and attachment means for attaching the other end of each elongated member articuably and elongatably to the stationary ring.
Claim 3
Dependent Claim
49 words
A centering member according to claim 1, wherein each attachment means comprises: a laminated elastomeric shear pad allowing for elongation of the attachment means in response to swashplate translation; and a cylindrical bearing allowing for skewing of the elongated member relative to the swashplate in response to swashplate translation.
Claim 4
Dependent Claim
64 words
A centering member according to claim 1, wherein each attachment means comprises: a laminated elastomeric shear pad allowing for elongation of the attachment means in response to swashplate translation; and a spherical bearing allowing for skewing of the elongated member relative to the swashplate in response to swashplate translation and twisting of the elongated member relative to the swashplate in response to swashplate tilt.
References Cited (Backward Citations)
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Cited
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Cited
US2410545A
Cited
US3558082A
Cited
US3933324A
Cited
US3952546A
Cited
US4326834A
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US4297080A
Cited
US4323332A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-05-12 | 1989-11-11 | 1990-05-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-05-12 | 1993-11-11 | 1994-05-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-05-12 | 1997-11-11 | 1998-05-13 | $7700.00 | Window Closed / Lapsed |