Patent US3974987A successfully refreshed from Google Patents.
US3974987A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Cascade effect blown flap
Assignee: Northrop Grumman Systems Corp
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Filing: 1975-05-07
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Granted: 1976-08-17
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Expires: 1995-05-07
Abstract
Abstract A control airfoil such as a wing flap is provided adjacent its leading edge with a plurality of parallel blowing slots extending spanwise of the flap and leading from a plenum in the interior of the flap, the plenum being supplied with high pressure air and the slots being so arranged in airtight relationship with the trailing edge of the wing that the slots are serially uncovered in a cascade arrangement, as the flap is deflected continuously downward from its neutral position, to blow a cascade of high pressure air rearwardly in successively small angle increments over the upper surface of the flap to continuously re-energize the boundary layer air thereon and thereby increase the coefficient of lift during landing of the aircraft by permitting extreme flap angles to be used.
Inventors
- 👤 Melvin Shorr
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 07:47
CPC Classifications
B; B64; B64C; B64C21/00; B64C21/02; B64C21/04; B64C2230/00; B64C2230/04; B64C2230/06; Y; Y02; Y02T; Y02T50/00; Y02T50/10
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
182 words
An aircraft wing and trailing edge cascade-effect blowing flap combination comprising: a. an aircraft wing having a trailing edge adapted to mount a blowing flap within a sealable recess provided therein, said flap being deflectable downwardly from a neutral position relative to said wing to a deflection angle substantially greater than 60° thereto, b. means connecting the interior of said flap to a source of high pressure air, c. a plurality of blowing means in said flap operable to blow a cascade of high pressure air from the interior of said flap rearwardly over the upper surface thereof, and arranged in series to incrementally increase the volume of said high pressure air as said flap is deflected from said neutral position to said deflection angle greater than 60°, and an additional blowing slot in the trailing edge thereof between upper and lower springy, preloaded surface skins terminating in a normally closed slot, said slot being operable to open when the high pressure air in said flap exceeds a predetermined value, to blow said high pressure air therethrough to define a jet flap.
Claim 2
Dependent Claim
182 words
An aircraft wing and trailing edge cascade-effect blowing flap combination comprising: a. an aircraft wing having a trailing edge adapted to mount a blowing flap within a sealable recess provided therein, said flap being deflectable downwardly from a neutral position relative to said wing to a deflection angle substantially greater than 60° thereto, b. means connecting the interior of said flap to a source of high pressure air, c. a plurality of blowing means in said flap operable to blow a cascade of high pressure air from the interior of said flap rearwardly over the upper surface thereof, and arranged in series to incrementally increase the volume of said high pressure air as said flap is deflected from said neutral position to said deflection angle greater than 60°, and an additional blowing slot in the trailing edge thereof between upper and lower springy, preloaded surface skins terminating in a normally closed slot, said slot being operable to open when the high pressure air in said flap exceeds a predetermined value, to blow said high pressure air therethrough to define a jet flap.
Claim 3
Dependent Claim
262 words
An aircraft wing and trailing edge cascade-effect blowing flap combination comprising: a. an aircraft wing having a portion of its trailing edge constructed to define a substantially air tight generally arcuate planar surface, the upper surface of said wing extending rearwardly beyond the lower surface of said wing and terminating in a relatively thin edge overlying said arcuate planar surface, b. a flap pivotally mounted on said wing to deflect downwardly with respect to said wing, the leading edge of said flap being recessed in said arcuate planar surface and complementally shaped to form a mutually sealable surface therewith, c. enclosure means defining a plenum in the interior of said flap adjacent the leading edge thereof, d. flexible duct means connecting said plenum to a source of high pressure air, e. a plurality of spanwise extending blowing slots arranged in parallel series adjacent the leading edge of said flap and communicating with the interior of said plenum, the major portion of said slots underlying said edge on the trailing upper surface of said wing, f. a seal mounted between said arcuate planar surface and said leading edge of said flap below said slots, and g. flexible sealing means between said flap and the lower surface of said wing, whereby said blowing slots are serially uncovered by said edge on the upper surface of said wing as said flap is deflected downwardly to incrementally increase the volume of high pressure air blown in a cascade from said slots as said flap is deflected to its maximum angle of deflection relative to said wing.
Claim 4
Dependent Claim
262 words
An aircraft wing and trailing edge cascade-effect blowing flap combination comprising: a. an aircraft wing having a portion of its trailing edge constructed to define a substantially air tight generally arcuate planar surface, the upper surface of said wing extending rearwardly beyond the lower surface of said wing and terminating in a relatively thin edge overlying said arcuate planar surface, b. a flap pivotally mounted on said wing to deflect downwardly with respect to said wing, the leading edge of said flap being recessed in said arcuate planar surface and complementally shaped to form a mutually sealable surface therewith, c. enclosure means defining a plenum in the interior of said flap adjacent the leading edge thereof, d. flexible duct means connecting said plenum to a source of high pressure air, e. a plurality of spanwise extending blowing slots arranged in parallel series adjacent the leading edge of said flap and communicating with the interior of said plenum, the major portion of said slots underlying said edge on the trailing upper surface of said wing, f. a seal mounted between said arcuate planar surface and said leading edge of said flap below said slots, and g. flexible sealing means between said flap and the lower surface of said wing, whereby said blowing slots are serially uncovered by said edge on the upper surface of said wing as said flap is deflected downwardly to incrementally increase the volume of high pressure air blown in a cascade from said slots as said flap is deflected to its maximum angle of deflection relative to said wing.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-08-17 | 1980-02-16 | 1980-08-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-08-17 | 1984-02-16 | 1984-08-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-08-17 | 1988-02-16 | 1988-08-17 | $7700.00 | Window Closed / Lapsed |