Patent US3823899A successfully refreshed from Google Patents.
US3823899A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Actuation system for angularly positioning aircraft landing gear wheels
Assignee: Lockheed Martin Corp
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Filing: 1972-10-20
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Granted: 1974-07-16
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Expires: 1992-10-20
Abstract
Abstract This device positions an airplane''s landing gear wheels to a selected angle from the straight-ahead position relative to the longitudinal line of the aircraft or the direction of movement to compensate for crosswind landing and take-off. It comprises an axle for each such wheel, which axle is pivoted about a vertically oriented pin so that when the several axles are rotated by actuator means the desired wheel angle is effected. Such actuator means may be a linear type, pushing or pulling a bellcrank arm made as part of the axle, or it may be a rotary type turning about the vertical axis.
Inventors
- 👤 N Currey
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 18:29
CPC Classifications
B; B64; B64C; B64C25/00; B64C25/32; B64C25/50; B64C25/505
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
255 words
In an aircraft having a tricycle landing gear arrangement consisting of a pair of main wheel units and a nose wheel unit, an actuation system for the angular adjustment of said several wheel units relative to the long dimension of said aircraft comprising: a pilot''s control lever; a hydraulic drive actuator operatively connected to each of said main and nose wheel units for the rotation thereof in the horizontal plane, the drive actuators of each main wheel unit including a screwjack and a bellcrank connection between the end of said screwjack and its associated main wheel unit; an electrohydraulic valve connected between each said drive actuator and said pilot''s control lever; a linear voltage displacement transducer operatively connected to each said drive actuator; an indicator visible to the pilot connected to each said transducer and operative to register the angular adjustment of each of said main and nose wheel units at all times; and a control unit interposed between said pilot''s control lever and all of said electrohydraulic valves and operative upon movement of said control lever to concurrently operate said valves and thereby energize said actuators whereby said main and nose wheel units are angularly adjusted equally and in unison, said control unit including a servo amplifier individual to each said valve and a comparator operatively connected to all of said transducers and between said pilot''s control lever and said valves, said comparator being operative to de-energize said control unit upon an asymmetric operation of said drive actuators in excess of a predetermined amount.
Claim 2
Dependent Claim
255 words
In an aircraft having a tricycle landing gear arrangement consisting of a pair of main wheel units and a nose wheel unit, an actuation system for the angular adjustment of said several wheel units relative to the long dimension of said aircraft comprising: a pilot''s control lever; a hydraulic drive actuator operatively connected to each of said main and nose wheel units for the rotation thereof in the horizontal plane, the drive actuators of each main wheel unit including a screwjack and a bellcrank connection between the end of said screwjack and its associated main wheel unit; an electrohydraulic valve connected between each said drive actuator and said pilot''s control lever; a linear voltage displacement transducer operatively connected to each said drive actuator; an indicator visible to the pilot connected to each said transducer and operative to register the angular adjustment of each of said main and nose wheel units at all times; and a control unit interposed between said pilot''s control lever and all of said electrohydraulic valves and operative upon movement of said control lever to concurrently operate said valves and thereby energize said actuators whereby said main and nose wheel units are angularly adjusted equally and in unison, said control unit including a servo amplifier individual to each said valve and a comparator operatively connected to all of said transducers and between said pilot''s control lever and said valves, said comparator being operative to de-energize said control unit upon an asymmetric operation of said drive actuators in excess of a predetermined amount.
Claim 3
Dependent Claim
31 words
The actuation system of claim 1 wherein said predetermined amount of asymmetric operation is equal to a misalignment corresponding to approximately a 5* angle of one wheel unit relative to another.
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) | 1977-07-15 | 1978-01-14 | 1978-07-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-07-15 | 1982-01-14 | 1982-07-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-07-15 | 1986-01-14 | 1986-07-16 | $7700.00 | Window Closed / Lapsed |