Patent US3592559A successfully refreshed from Google Patents.
US3592559A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Variable geometry rotor system
Assignee: National Aeronautics and Space Administration
•
Filing: 1969-08-28
•
Granted: 1971-07-13
•
Expires: 1989-08-28
Abstract
Abstract This rotor system is designed to control the nonuniform wake shed from a given rotor blade impinging upon the other blades of the rotor system. The rotor system utilizes blade sets which are of a different diameter than another blade set in the system. The azimuth spacing between the blade sets can be varied while the aircraft is in flight. The vertical spacing between the blade sets can also be changed. Mechanism is provided for collective pitch control of the blade sets. The plan form of blade sets, as well as the configuration of their tips, are varied.
Inventors
- 👤 John F Ward
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 23:30
CPC Classifications
B; B64; B64C; B64C27/00; B64C27/32; B64C27/46
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
60 words
A variable geometry rotor assembly for aircraft comprising: blade means for a helicopter or similar vehicle having liftproducing blades; said blade means being arranged in sets; one set of said blade means having a greater diameter than another set; and means for varying the angular relationship between said sets to control the wake vortex interaction effect from the blade means.
Claim 2
Dependent Claim
60 words
A variable geometry rotor assembly for aircraft comprising: blade means for a helicopter or similar vehicle having liftproducing blades; said blade means being arranged in sets; one set of said blade means having a greater diameter than another set; and means for varying the angular relationship between said sets to control the wake vortex interaction effect from the blade means.
Claim 3
Dependent Claim
29 words
A variable geometry rotor assembly for aircraft as in claim 1 wherein the tips of one blade set have a different configuration than the tips of another blade set.
Claim 4
Dependent Claim
22 words
A variable geometry rotor assembly for aircraft as in claim 1 including means for varying the vertical distance between said blade sets.
Claim 5
Dependent Claim
41 words
A variable geometry rotor assembly for aircraft as in claim 1 wherein one set of blades is carried by a drive shaft; and said other set of blades being carried by another drive shaft concentric with said first mentioned drive Shaft.
Claim 6
Dependent Claim
41 words
A variable geometry rotor assembly for aircraft as in claim 4 wherein said shafts are clutched together, nd means for releasing said clutch to enable said shafts and sets to move relative to each other while said aircraft is in flight.
Claim 7
Dependent Claim
26 words
A variable geometry rotor assembly for aircraft as in claim 1 wherein the blade planform of one set differs from the blade planform of another set.
Claim 8
Dependent Claim
24 words
A variable geometry rotor assembly for aircraft as in claim 1 wherein means is included to change the pitch of said blade sets collectively.
Claim 9
Dependent Claim
24 words
A variable geometry rotor assembly for aircraft as in claim 1 wherein means is included to change the pitch of a blade set cyclically.
Claim 10
Dependent Claim
44 words
A variable geometry rotor assembly for aircraft as in claim 1 wherein means is included to vary the vertical distance between blade sets; means for collectively changing the pitch of the blade sets; and means for cyclically changing the pitch of a blade set.
Claim 11
Dependent Claim
56 words
A variable geometry rotor assembly as in claim 1 wherein the wing planform of said blade sets differ; said blade sets'' tips having different configurations; means for varying the vertical spacing between said blade sets; means for collectively changing the pitch of the blade sets, and means for cyclically changing the pitch of a blade set.
References Cited (Backward Citations)
US1467537A
Cited
US1788307A
Cited
US1771654A
Cited
US2126221A
Cited
US2192469A
Cited
US2684723A
Cited
US2982361A
Cited
US3232348A
Cited
US3153454A
Cited
US3369610A
Cited
US3482552A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-07-12 | 1975-01-11 | 1975-07-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-07-12 | 1979-01-11 | 1979-07-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-07-12 | 1983-01-11 | 1983-07-13 | $7700.00 | Window Closed / Lapsed |