US3861065A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for simulating the effects of aerodynamic forces on aircraft control
Assignee: Northrop Grumman Properties Ltd
•
Filing: 1973-01-08
•
Granted: 1975-01-21
•
Expires: 1993-01-08
Abstract
Abstract An apparatus for simulating the effects of aerodynamic forces on aircraft controls comprises means for generating first and third pressures, and means for generating second and fourth pressures, the difference between said first and third pressures being normally equal to the difference between said second and fourth pressures. A first and second piston can abut and have the first pressure applied between them and the third pressure applied to their other faces. An output member is movable by the first piston in response to the first pressure. A third piston is subjected to the second and fourth pressures and can coact with the second piston to urge the latter to abut the first piston. In normal conditions output force is derived from said first piston and otherwise from said third piston.
Inventors
- 👤 Jerzy Leon Courtenay
- 👤 Donald Craven
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 23:01
CPC Classifications
G; G09; G09B; G09B9/00; G09B9/02; G09B9/08; G09B9/28
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
309 words
An apparatus for providing, on a manually operated part of a power driven control for an aircraft, a simulated effect of aerodynamic forces on the aircraft control surfaces, comprising a pair of means for generating respective first and second fluid pressures each of which is dependent on pitot and static air pressures on the aircraft, a first cylinder, first and second pistons slidable in said first cylinder, means for applying said first pressure to a zone within said first cylinder between said first and second pistons, an abutment on one of said pistons and engageable with the other of said pistons, a thrust member coacting with said first piston and providing an output member for the apparatus, a second cylinder aligned with said first cylinder at an end thereof remote from said first piston, a third piston slidable in said second cylinder, means for applying said second pressure to a side of said third piston remote from said second piston, means for applying a third pressure to the sides of said first and second pistons remote from the first pressure, means for applying a fourth pressure to the side of said third piston remote from said second pressure, means coacting with said second and third pistons such that movement of said second piston in response to said third pressure is opposed by movement of the third piston in response to said second pressure, whereby when said third and fourth pressures are lower than said first and second pressures respectively and the resultant pressure force on the second piston is equal to or greater than the resultant pressure force on the third piston, thrust on the output member is derived from the first piston, and when the resultant pressure force on said third piston is greater than that on said first piston said thrust is derived from the third piston.
Claim 2
Independent Claim
309 words
An apparatus for providing, on a manually operated part of a power driven control for an aircraft, a simulated effect of aerodynamic forces on the aircraft control surfaces, comprising a pair of means for generating respective first and second fluid pressures each of which is dependent on pitot and static air pressures on the aircraft, a first cylinder, first and second pistons slidable in said first cylinder, means for applying said first pressure to a zone within said first cylinder between said first and second pistons, an abutment on one of said pistons and engageable with the other of said pistons, a thrust member coacting with said first piston and providing an output member for the apparatus, a second cylinder aligned with said first cylinder at an end thereof remote from said first piston, a third piston slidable in said second cylinder, means for applying said second pressure to a side of said third piston remote from said second piston, means for applying a third pressure to the sides of said first and second pistons remote from the first pressure, means for applying a fourth pressure to the side of said third piston remote from said second pressure, means coacting with said second and third pistons such that movement of said second piston in response to said third pressure is opposed by movement of the third piston in response to said second pressure, whereby when said third and fourth pressures are lower than said first and second pressures respectively and the resultant pressure force on the second piston is equal to or greater than the resultant pressure force on the third piston, thrust on the output member is derived from the first piston, and when the resultant pressure force on said third piston is greater than that on said first piston said thrust is derived from the third piston.
Claim 3
Dependent Claim
20 words
An apparatus as claimed in claim 1 in which said first, second and third pistons have substantially equal effective areas.
Claim 4
Dependent Claim
55 words
An apparatus as claimed in claim 1 in which said first and second pressure generating means are substantially identical and respectively include means connecting said third and fourth pressure-applying means to a low pressure, whereby the difference between said first and third pressures is substantially equal to the difference between said second and fourth pressures.
Claim 5
Dependent Claim
43 words
An apparatus as claimed in claim 1 which includes a linkage connecting said thrust member to said manually-operated part of the aircraft control, and a pair of opposed biasing means acting on said linkage to urge the latter to a central, equilibrium position.
Claim 6
Dependent Claim
19 words
An apparatus as claimed in claim 4 in which said biasing means are compression springs of substantially equal rate.
Claim 7
Dependent Claim
24 words
An apparatus as claimed in claim 5 which includes a third spring acting on said linkage to bias the latter towards said central position.
Claim 8
Dependent Claim
70 words
An apparatus as claimed in claim 6, in which said pair of compression springs have substantially equal free lengths and engage said linkage so as to have substantially equal compressed lengths in said central position of said linkage, whereby, when said linkage has moved a predetermined distance from said central position, said thrust member is Acted upon only by one of said pair of springs and by said third spring.
Claim 9
Dependent Claim
32 words
An apparatus as claimed in claim 4 which includes a damper arrangement coupled to said thrust member by means of said linkage and opposing movement of said thrust member in either direction.
Claim 10
Dependent Claim
38 words
An apparatus as claimed in claim 8 in which said damper arrangement comprises a piston and cyclinder unit, portions of the cylinder of said unit on opposite saides of the associated piston being interconnected by a flow restrictor.
Claim 11
Dependent Claim
50 words
An apparatus as claimed in claim 1 in which said first pressure generating means comprises a fluid pressure source, a return line and a valve responsive to a difference between said pitot and static pressures to provide said first pressure intermediate the pressure at said source and said return line.
Claim 12
Dependent Claim
56 words
An apparatus as claimed in claim 10 in which said first pressure generating means includes a housing, a first diaphragm subjected on opposite sides to said pitot and static pressures, a first lever pivotally movable in said housing by said diaphragm, and a control element for said valve, said control element being movable by said lever.
Claim 13
Dependent Claim
64 words
An apparatus as claimed in claim 11 in which said first pressure generating means includes a second lever pivotally mounted in said housing and operatively connected to said valve control member and a coupling member engaged between said first and second levers, said coupling member being movable to vary movement of said second lever in response to a given movement of said first lever.
Claim 14
Dependent Claim
27 words
An apparatus as claimed in claim 12 which includes a mechanism for moving said coupling member in response to the configuration of variable-geometry wings on said aircraft.
Claim 15
Dependent Claim
35 words
An apparatus as claimed in claim 13 in which said mechanism comprises a cam pivotally movable in response to variation of the postions of said wings, and a cam follower linked to said coupling memeber.
Claim 16
Dependent Claim
164 words
An apparatus as claimed in claim 11 in which said first pressure generating means includes a second diaphragm subjected on opposite sides to said pitot and static pressures, a pressure-sensitive device responsive to said pitot pressure and coupled to said second diaphragm so as to oppose movement of the latter in response to an increase in said pitot pressure, a third lever pivotally mounted in the housing and movable by said second diaphragm, and a further coupling element engaging said third and first levers so as to oppose movement of the latter by said first diaphragm, said further coupling element being positioned so as to be able to apply to said first lever a moment which is greater than that applied by said first diaphragm, and the arrangement being such that, below predetermined ratio of pitot to static pressure, the force applied by said pressure-sensitive element exceeds that applied by said second diaphragm, and said first levers thereby operated only by said first diaphragm.
Claim 17
Dependent Claim
22 words
An apparatus as claimed in claim 1 in which said first and second means for generating said fluid pressures are substantially identical.
References Cited (Backward Citations)
US3529365A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-01-20 | 1978-07-22 | 1979-01-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-01-20 | 1982-07-22 | 1983-01-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-01-20 | 1986-07-22 | 1987-01-21 | $7700.00 | Window Closed / Lapsed |