US3791586A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Combination clamshell thrust reverser & variable nozzle area ramp
Assignee: Boeing Co
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Filing: 1972-12-26
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Granted: 1974-02-12
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Expires: 1992-12-26
Abstract
Abstract A failsafe thrust reverser for a jet aircraft engine wherein the reverser unit comprises a pair of clamshell blocker doors pivotally mounted about vertical axes for rotational actuation. The reverser unit is positioned within a D-shaped or twodimensional exhaust nozzle duct that has a variable area ramp on its bottom planar surface. The failsafe feature is provided by the variable ramp being positioned within the rotational arc of the clamshell blocker doors such that when the ramp is in its raised or high cruise speed position, the ramp through a blocking action, mechanically jams the blocker doors so that they can not rotate to the reverse thrust position.
Inventors
- 👤 J Moorehead
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 20:32
CPC Classifications
F; F02; F02K; F02K1/00; F02K1/54; F02K1/56; F02K1/60; B; B64; B64D; B64D27/00; B64D27/02; B64D27/16
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
53 words
In combination with a jet engine exhaust nozzle system: a variable ramp for controlling the size of the nozzle opening, means for reversing the jet engine exhaust flow, and said variable ramp being adapted to prevent movement of said thrust reversing means when said ramp is displaced from its maximum sized opening position.
Claim 2
Dependent Claim
53 words
In combination with a jet engine exhaust nozzle system: a variable ramp for controlling the size of the nozzle opening, means for reversing the jet engine exhaust flow, and said variable ramp being adapted to prevent movement of said thrust reversing means when said ramp is displaced from its maximum sized opening position.
Claim 3
Dependent Claim
87 words
In combination with a jet engine exhaust duct and nozzle system: a planar surface within the exhaust duct and extending beyond the exhaust nozzle exit, a ramp mounted in the planer surface of the exhaust duct and inwardly movable for forming a variable throat area in the exhaust nozzle, means for reversing the jet engine exhaust flow, said means being positioned adjacent to the ramp such that inward displacement of the ramp to a minimum throat area position prevents the jet engine exhaust flow from being reversed.
Claim 4
Dependent Claim
87 words
In combination with a jet engine exhaust duct and nozzle system: a planar surface within the exhaust duct and extending beyond the exhaust nozzle exit, a ramp mounted in the planer surface of the exhaust duct and inwardly movable for forming a variable throat area in the exhaust nozzle, means for reversing the jet engine exhaust flow, said means being positioned adjacent to the ramp such that inward displacement of the ramp to a minimum throat area position prevents the jet engine exhaust flow from being reversed.
Claim 5
Dependent Claim
108 words
In combination with a variable exhaust nozzle for a jet propulsion engine, a thrust reverser unit, said exhaust nozzle having an internal duct wherein one side of which forms a planar surface, an adjustable ramp forming a portion of the planer surface and movable between a retracted position and an extended portion for forming a variable throat section within the exhaust nozzle duct, said thrust reverser unit comprising an exhaust flow deflecting member positioned adjacent to the adjustable ramp and mounted for rotation within the duct such that the deflecting member is prevented from movement to the thrust reversal position when the ramp is in an extended position.
Claim 6
Dependent Claim
108 words
In combination with a variable exhaust nozzle for a jet propulsion engine, a thrust reverser unit, said exhaust nozzle having an internal duct wherein one side of which forms a planar surface, an adjustable ramp forming a portion of the planer surface and movable between a retracted position and an extended portion for forming a variable throat section within the exhaust nozzle duct, said thrust reverser unit comprising an exhaust flow deflecting member positioned adjacent to the adjustable ramp and mounted for rotation within the duct such that the deflecting member is prevented from movement to the thrust reversal position when the ramp is in an extended position.
Claim 7
Dependent Claim
131 words
A fail-safe thrust reversing system for a jet engine exhaust nozzle having a D-shaped flat bottomed duct comprising: an adjustable ramp mounted in the bottom planer surface of the duct and movable vertically for forming a variable area throat section in the exhaust nozzle; a pair of clamshell doors pivotally mounted in the duct for rotation about a vertical axis and for reversing the jet engine exhaust flow when the ramp is down at its maximum throat area position; the ramp being positioned within the rotational arc of the clamshell doors such that when the ramp is displaced upwardly toward a minimum throat area position, the clamshell doors mechanically abut the upwardly displaced ramp and thereby provide the fail-safe feature by preventing movement of the clamshell doors to their reverse position.
Claim 8
Dependent Claim
131 words
A fail-safe thrust reversing system for a jet engine exhaust nozzle having a D-shaped flat bottomed duct comprising: an adjustable ramp mounted in the bottom planer surface of the duct and movable vertically for forming a variable area throat section in the exhaust nozzle; a pair of clamshell doors pivotally mounted in the duct for rotation about a vertical axis and for reversing the jet engine exhaust flow when the ramp is down at its maximum throat area position; the ramp being positioned within the rotational arc of the clamshell doors such that when the ramp is displaced upwardly toward a minimum throat area position, the clamshell doors mechanically abut the upwardly displaced ramp and thereby provide the fail-safe feature by preventing movement of the clamshell doors to their reverse position.
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) | 1977-02-11 | 1977-08-13 | 1978-02-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-02-11 | 1981-08-13 | 1982-02-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-02-11 | 1985-08-13 | 1986-02-12 | $7700.00 | Window Closed / Lapsed |