US3695779A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Rotor system including a blade retention member
Assignee: Lockheed Martin Corp
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Filing: 1970-05-18
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Granted: 1972-10-03
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Expires: 1990-05-18
Abstract
Abstract In a helicopter rotor system, a hub assembly including a blade retention member which is compressible and torsionable in installation and operation of such rotor system, the torsional stiffness of the member decreasing with increasing rotor blade speed, the compressible stress not exceeding the strength of the material out of which the member is fabricated. Its inboard end is fixedly connected to either the rotor blade or a movable hub enveloping it at its inboard end, while its outboard end is fixedly connected to the fixed hub or extension thereof in the rotor system. Means are also provided in the system for isolating bearing means supporting the blade from the blade retention member. The member itself comprises a plurality of rails spacedly disposed radially equidistant from a common centerline coincident with the feathering axis for the blade.
Inventors
- 👤 Howard Kastan
- 👤 Joe C Pena
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 21:18
CPC Classifications
B; B64; B64C; B64C27/00; B64C27/32; B64C27/33; B64C27/327; B64C27/46; B64C27/473; B64C27/48
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
90 words
In combination with a hub and a blade mounted to said hub, a compressible and torqueable blade retention member comprising in combination a plurality of spaced elongate flexible elements each having ends, each of such elements being disposed radially from and arcuately about a common centerline for said member, and inboard and outboard end fitting portions being mounted on the corresponding ends of said elements, said blade being connected to the inboard end fitting portion and said hub being connected to the outboard end fitting portion of said retention member.
Claim 2
Dependent Claim
90 words
In combination with a hub and a blade mounted to said hub, a compressible and torqueable blade retention member comprising in combination a plurality of spaced elongate flexible elements each having ends, each of such elements being disposed radially from and arcuately about a common centerline for said member, and inboard and outboard end fitting portions being mounted on the corresponding ends of said elements, said blade being connected to the inboard end fitting portion and said hub being connected to the outboard end fitting portion of said retention member.
Claim 3
Dependent Claim
121 words
A helicopter rotor system comprising in combination a hub having a plurality of radially extending arms each including a central portion, a plurality of rotor blades corresponding in number to said plurality of arms, a cuff-like member for an connected to each of said rotor blades and enveloping each of said arms, a non-elastomeric compression-torsion member disposed within said cuff-like member and having a plurality of elongate flexible elements disposed radially equidistant from a common centerline for said member and having an inboard end portion connected to said cuff-like member and an outboard end portion connected to each of said arms, and bearing means mounted on each of said arms for feathering each of said rotor blades through said cuff-like member.
Claim 4
Dependent Claim
121 words
A helicopter rotor system comprising in combination a hub having a plurality of radially extending arms each including a central portion, a plurality of rotor blades corresponding in number to said plurality of arms, a cuff-like member for an connected to each of said rotor blades and enveloping each of said arms, a non-elastomeric compression-torsion member disposed within said cuff-like member and having a plurality of elongate flexible elements disposed radially equidistant from a common centerline for said member and having an inboard end portion connected to said cuff-like member and an outboard end portion connected to each of said arms, and bearing means mounted on each of said arms for feathering each of said rotor blades through said cuff-like member.
Claim 5
Dependent Claim
15 words
The system of claim 2 in which each of said elements is H-configurated in cross-section.
Claim 6
Dependent Claim
19 words
The system of claim 2 in which said member is forged and machined from type 300 Maraging steel material.
Claim 7
Dependent Claim
129 words
A helicopter rotor system comprising in combination, a hub having a plurality of radially extending arms each including a central portion, a plurality of rotor blades corresponding in number to said plurality of arms, a cuff-like member for and included with each of said rotor blades and enveloping each of said arms, a non-elastomeric compression-torsion member disposed within said cuff-like member and having an elongate flexible element disposed in axial alignment with a common centerline for said compression-torsion member and having an inboard end portion connected to said cuff-like member and an outboard end portion connected to each of said arms, said elongate flexible element being H-configured in cross-section, and bearing means mounted on each of said arms for feathering each of said rotor blades through said cuff-like member.
Claim 8
Dependent Claim
129 words
A helicopter rotor system comprising in combination, a hub having a plurality of radially extending arms each including a central portion, a plurality of rotor blades corresponding in number to said plurality of arms, a cuff-like member for and included with each of said rotor blades and enveloping each of said arms, a non-elastomeric compression-torsion member disposed within said cuff-like member and having an elongate flexible element disposed in axial alignment with a common centerline for said compression-torsion member and having an inboard end portion connected to said cuff-like member and an outboard end portion connected to each of said arms, said elongate flexible element being H-configured in cross-section, and bearing means mounted on each of said arms for feathering each of said rotor blades through said cuff-like member.
Claim 9
Dependent Claim
19 words
The system of claim 5 in which said member is forged and machined from type 300 Maraging steel material.
Claim 10
Dependent Claim
37 words
In the combination of claim 1, said rotor blade including a cuff-like member which envelops said retention member, the inboard end fitting portion of said retention member being attached to said cuff-like member of said rotor blade.
Claim 11
Dependent Claim
18 words
In the combination of claim 1, each of said elongate flexible elements including the characteristic of being non-elastomeric.
Claim 12
Dependent Claim
16 words
The combination of claim 1 including bearing means mounted on said hUb for feathering each blade.
Claim 13
Dependent Claim
18 words
In the combination of claim 9, each of said elongate flexible elements including the characteristic of being non-elastomeric.
Claim 14
Dependent Claim
18 words
In the combination of claim 7, each of said elongate flexible elements including the characteristic of being non-elastomeric.
Claim 15
Dependent Claim
16 words
The combination of claim 7 including bearing means mounted on said hub for feathering said blade.
Claim 16
Dependent Claim
16 words
The combination of claim 11 including bearing means mounted on said hub for feathering said blade.
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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) | 1975-10-03 | 1976-04-03 | 1976-10-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-10-03 | 1980-04-03 | 1980-10-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-10-03 | 1984-04-03 | 1984-10-03 | $7700.00 | Window Closed / Lapsed |