US4137007A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Rotor blade structure
Assignee: Individual
•
Filing: 1976-12-20
•
Granted: 1979-01-30
•
Expires: 1996-12-20
Abstract
Abstract A system of spars, each having a rectangular cross-section, is provided by placing the spars in lateral juxtaposition to one another like a plank to form a rotor blade. A skin of plastic foam is provided on the blade. The cross-sections of the spars, and the corresponding cross-sections of the blade, are varied in accordance with aerodynamic requirements. The spars are kept in position by means of clamps and/or connections and/or rings, forming an integral unit similar to a plank; and the integrated spars are directly attached to a hub or an electric generator.
Inventors
- 👤 Walter Schonball
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 02:28
CPC Classifications
B; B64; B64C; B64C27/00; B64C27/32; B64C27/46; B64C27/473; Y; Y02; Y02E; Y02E10/00; Y02E10/70; Y02E10/72
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
131 words
A rotor blade for a wind generator, comprising; a plurality of straight spars each having a longitudinally uniform, rectangular cross-section, and all secured to one another in lateral contact with one another to provide an integral unit thereof, similar to a plank; a skin of synthetic plastic foam embedding the unit of spars and defining a rotor blade having an exterior, aerodynamic profile, the number of the spars, transverse of the rotor blade, diminishing longitudinally from a hub end of the rotor blade, and the uniform cross-section of each spar having an area corresponding to the cross-sectional area of a directly embedding portion of the rotor blade; and means for attaching the hub end of the rotor blade to a hub, whereby the rotor blade has maximum strength near the hub.
Claim 2
Dependent Claim
131 words
A rotor blade for a wind generator, comprising; a plurality of straight spars each having a longitudinally uniform, rectangular cross-section, and all secured to one another in lateral contact with one another to provide an integral unit thereof, similar to a plank; a skin of synthetic plastic foam embedding the unit of spars and defining a rotor blade having an exterior, aerodynamic profile, the number of the spars, transverse of the rotor blade, diminishing longitudinally from a hub end of the rotor blade, and the uniform cross-section of each spar having an area corresponding to the cross-sectional area of a directly embedding portion of the rotor blade; and means for attaching the hub end of the rotor blade to a hub, whereby the rotor blade has maximum strength near the hub.
Claim 3
Dependent Claim
22 words
A rotor blade according to claim 1 in which the spars are glued to one another for their securing to one another.
Claim 4
Dependent Claim
26 words
A rotor blade according to claim 1 in which the spars are of aluminum and are welded to one another for their securing to one another.
References Cited (Backward Citations)
US1304102A
Cited
US22696A
Cited
US1419180A
Cited
US2362301A
Cited
US2589316A
Cited
US2674327A
Cited
US2863513A
Cited
US3028292A
Cited
US3105557A
Cited
US3229935A
Cited
US3566493A
Cited
US3519228A
Cited
US3713753A
Cited
US3743440A
Cited
US3607600A
Cited
US3784322A
Cited
US3706511A
Cited
US3779487A
Cited
US3967996A
Cited
US3962506A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-01-29 | 1982-07-31 | 1983-01-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-01-29 | 1986-07-31 | 1987-01-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-01-29 | 1990-07-31 | 1991-01-30 | $7700.00 | Window Closed / Lapsed |