US4082479A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Overspeed spoilers for vertical axis wind turbine
Assignee: National Research Council Canada
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Filing: 1976-07-21
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Granted: 1978-04-04
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Expires: 1996-07-21
Abstract
Abstract An overspeed spoiler for vertical axis wind turbines of the type having straight or curved airfoil blades attached to a vertical shaft formed by a relatively thin flat blade shaped spoiler element hinge mounted on the trailing edge, leading edge, or at a central position of a portion of the airfoil section with the element having two portions one of which is held flush or against a surface by spring means with a surface of the blade towards the turbine rotor axis and the other lies substantially parallel to the chordline of the airfoil, the weight and configuration of the element being such that a predetermined turbine rotor speed the element rotates against the spring force because of centrifugal action and takes up a position generally transverse to the air flow direction such as to cause much increased drag and control overspeeding of the rotor.
Inventors
- 👤 Rajindar S. Rangi
- 👤 Peter South
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 21:14
CPC Classifications
F; F03; F03D; F03D7/00; F03D7/06; Y; Y02; Y02E; Y02E10/00; Y02E10/70; Y02E10/74
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
185 words
An overspeed spoiler for vertical axis wind turbines of the type having airfoil blades attached to and mounted outwardly of a vertical turbine rotor shaft comprising: (a) a relatively thin spoiler element hinge mounted at a position along the span-wise length of the airfoil blade, said element having two portions the first of which is held in a closed position generally flush against the surface of the airfoil blade towards the turbine rotor axis and the second extends outwardly from the hinge mounting and generally parallel to the center line of the said airfoil blade, (b) spring means attached to said element and to the airfoil blade and biased such as to hold the spoiler element in the closed position, and (c) the weight and configuration of the element and the spring strength being such that at a predetermined rotor speed the element rotates against the spring bias force because of centrifugal action and takes up an open position with both portions generally transverse to the air flow direction such as to cause much increased drag and provide control of overspeeding of the turbine rotor.
Claim 2
Dependent Claim
185 words
An overspeed spoiler for vertical axis wind turbines of the type having airfoil blades attached to and mounted outwardly of a vertical turbine rotor shaft comprising: (a) a relatively thin spoiler element hinge mounted at a position along the span-wise length of the airfoil blade, said element having two portions the first of which is held in a closed position generally flush against the surface of the airfoil blade towards the turbine rotor axis and the second extends outwardly from the hinge mounting and generally parallel to the center line of the said airfoil blade, (b) spring means attached to said element and to the airfoil blade and biased such as to hold the spoiler element in the closed position, and (c) the weight and configuration of the element and the spring strength being such that at a predetermined rotor speed the element rotates against the spring bias force because of centrifugal action and takes up an open position with both portions generally transverse to the air flow direction such as to cause much increased drag and provide control of overspeeding of the turbine rotor.
Claim 3
Dependent Claim
26 words
An overspeed spoiler for vertical axis wind turbines as in claim 1 wherein the spoiler element is mounted on the trailing edge of the airfoil blade.
Claim 4
Dependent Claim
26 words
An overspeed spoiler for vertical axis wind turbines as in claim 1 wherein the spoiler element is mounted on the leading edge of the airfoil blade.
Claim 5
Dependent Claim
26 words
An overspeed spoiler for vertical axis wind turbines as in claim 1 wherein the spoiler element is mounted at a central position in the airfoil blade.
Claim 6
Dependent Claim
70 words
An overspeed spoiler for vertical axis wind turbines as in claim 1 wherein the first portions of the spoiler element has a curved shape to conform to the surface shape of the airfoil blade and the second has a generally flat, straight shape such that the center of gravity of the complete spoiler element lies inwardly of the airfoil blade towards the rotor shaft when in the said closed position.
Claim 7
Dependent Claim
15 words
An overspeed spoiler as in claim 1 wherein the two portions have substantially equal areas.
Claim 8
Dependent Claim
34 words
An overspeed spoiler as in claim 1 wherein one of the portions of the spoiler element has a generally flat blade shape and the other is an extended arm with a balance weight attached.
References Cited (Backward Citations)
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GB206160A
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US1786057A
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GB252461A
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US2076520A
Cited
US2148921A
Cited
FR990595A
Cited
US3038543A
Cited
US3348806A
Cited
US3812812A
Cited
US3918839A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-04-03 | 1981-10-03 | 1982-04-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-04-03 | 1985-10-03 | 1986-04-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-04-03 | 1989-10-03 | 1990-04-04 | $7700.00 | Window Closed / Lapsed |