Patent US2273639A successfully refreshed from Google Patents.
Patent US3712122A successfully refreshed from Google Patents.
US3712122A
Expired / Lapsed
US
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Aircraft hard landing indicator
Assignee: ELECTRO DEV CORP
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Filing: 1971-02-08
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Granted: 1973-01-23
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Expires: 1991-02-08
Abstract
Abstract An apparatus for indicating when an aircraft has been subjected to an abnormal or ''''hard'''' impulse upon landing comprises a plurality of force sensors, each force sensor being disposed to provide an output signal proportional to the instantaneous ground contact force exerted upon one landing gear of the aircraft. The plurality of output signals provided by the sensors are amplified and supplied to a corresponding plurality of indicator circuits. Included in each indicator circuit is at least one level detector which provides an output to light an indicator lamp if the value of the output signal supplied thereto equals or exceeds a predetermined threshold value. In a preferred embodiment, each indicator circuit comprises a plurality of level detectors responsive to different threshold values. If a second, greater threshold value is exceeded during a predetermined time interval following traversal of a first, lesser threshold value, an output is provided by the indicator circuit to light the indicator lamp. The force threshold values and time interval which comprise an abnormal landing impulse are arrived at by structural analysis of the entire aircraft.
Inventors
- 👤 C Harris
- 👤 L Rama
- 👤 D Soward
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 18:51
CPC Classifications
G; G01; G01G; G01G19/00; G01G19/02; G01G19/07; G01L; G01L5/00; G01L5/0052; B; B64; B64D; B64D45/00; B64D2045/008
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
129 words
A system for indicating when an aircraft having at least one landing gear has been subjected to a predetermined impulse value upon landing, comprising: a. transducer means providing an output signal which is proportional to the ground contact force exerted on said landing gear, b. means producing a first signal when said output signal equals or exceeds a first threshold value, c. timing means producing an inhibit signal except for a predetermined time after the production of said first signal, d. means producing a second signal when said output signal equals or exceeds a second threshold value which is greater than said first threshold value, e. indicator means responsive to said second signal, and f. means inhibiting the operation of said indicator means in response to said inhibit signal.
Claim 2
Independent Claim
129 words
A system for indicating when an aircraft having at least one landing gear has been subjected to a predetermined impulse value upon landing, comprising: a. transducer means providing an output signal which is proportional to the ground contact force exerted on said landing gear, b. means producing a first signal when said output signal equals or exceeds a first threshold value, c. timing means producing an inhibit signal except for a predetermined time after the production of said first signal, d. means producing a second signal when said output signal equals or exceeds a second threshold value which is greater than said first threshold value, e. indicator means responsive to said second signal, and f. means inhibiting the operation of said indicator means in response to said inhibit signal.
Claim 3
Dependent Claim
61 words
A system as recited in claim 1, further comprising: a. means producing a third signal when said output signal equals or exceeds a third threshold value which is greater than said second threshold value, b. a second indicator means responsive to said third signal, and c. means inhibiting the operation of said second indicator means in response to said inhibit signal.
Claim 4
Dependent Claim
24 words
A system as recited in claim 2, further comprising means inhibiting the operation of said first indicator means in response to said third signal.
Claim 5
Dependent Claim
54 words
A system as recited in claim 1, further comprising: a. means producing a reset signal when said output signal drops below a threshold value which is less than said first threshold value, and b. means resetting said timer means in response to said reset signal to allow the production of said inhibit signal thereby.
Claim 6
Dependent Claim
44 words
A system as recited in claim 1, further comprising switch means coupled to said indicator means for latching said indicator means in an energized state in response to said second signal, and means for manually resetting said switch means to de-energize said indicator means.
Claim 7
Dependent Claim
30 words
The system as recited in claim 1, wherein said transducer means is of the type that measures ground contact force as a function of the landing gear''s shear deflection force.
Claim 8
Independent Claim
161 words
A system for indicating when an aircraft having a plurality of landing gear has been subjected to a predetermined impulse value upon landing, comprising: a. a plurality of transducer means, each transducer means providing an output signal which is proportional to the ground contact force exerted on one landing gear of the aircraft, b. a plurality of indicator circuits, one indicator circuit being provided for each transducer means, and each including i. means producing a first signal when the output signal from the associated transducer means equals or exceeds a first threshold value, ii. timing means producing an inhibit signal except for a predetermined time after the production of said first signal, iii. means producing a second signal once said output signal equals or exceeds a second threshold value which is greater than said first threshold value, iv. indicator means responsive to said second signal, and v. means inhibiting the operation of said indicator means in response to said inhibit signal.
Claim 9
Independent Claim
161 words
A system for indicating when an aircraft having a plurality of landing gear has been subjected to a predetermined impulse value upon landing, comprising: a. a plurality of transducer means, each transducer means providing an output signal which is proportional to the ground contact force exerted on one landing gear of the aircraft, b. a plurality of indicator circuits, one indicator circuit being provided for each transducer means, and each including i. means producing a first signal when the output signal from the associated transducer means equals or exceeds a first threshold value, ii. timing means producing an inhibit signal except for a predetermined time after the production of said first signal, iii. means producing a second signal once said output signal equals or exceeds a second threshold value which is greater than said first threshold value, iv. indicator means responsive to said second signal, and v. means inhibiting the operation of said indicator means in response to said inhibit signal.
Claim 10
Dependent Claim
32 words
The system as recited in claim 7, wherein each of said transducer means is of the type that measures ground contact force as a function of the landing gear''s shear deflection force.
Claim 11
Independent Claim
104 words
An apparatus for detecting when an aircraft having at least one landing gear has been subjected to an excessive impulse upon landing, comprising: a. means detecting the actual landing force exerted on said landing gear, b. means comparing said actual landing force over a given period of time with a first predetermined force value, c. means enabling said comparing means when said actual landing force exceeds a second predetermined force value which is less than said first predetermined force value, and d. means providing an output signal when said actual landing force equals or exceeds said first predetermined force value within said time period.
Claim 12
Independent Claim
104 words
An apparatus for detecting when an aircraft having at least one landing gear has been subjected to an excessive impulse upon landing, comprising: a. means detecting the actual landing force exerted on said landing gear, b. means comparing said actual landing force over a given period of time with a first predetermined force value, c. means enabling said comparing means when said actual landing force exceeds a second predetermined force value which is less than said first predetermined force value, and d. means providing an output signal when said actual landing force equals or exceeds said first predetermined force value within said time period.
Claim 13
Independent Claim
91 words
A method of obtaining an indication of whether an aircraft has been subjected to an abnormal impulse upon landing comprising the steps of: a. measuring the actual ground contact force exerted on at least one landing gear of the aircraft, b. comparing said actual ground contact force with a first predetermined value thereof during a predetermined period initiated when said actual ground contact force exceeds a second predetermined value thereof, said second value being less than said first value, and c. providing an indication when said first value has been exceeded.
Claim 14
Independent Claim
91 words
A method of obtaining an indication of whether an aircraft has been subjected to an abnormal impulse upon landing comprising the steps of: a. measuring the actual ground contact force exerted on at least one landing gear of the aircraft, b. comparing said actual ground contact force with a first predetermined value thereof during a predetermined period initiated when said actual ground contact force exceeds a second predetermined value thereof, said second value being less than said first value, and c. providing an indication when said first value has been exceeded.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-01-23 | 1976-07-24 | 1977-01-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-01-23 | 1980-07-24 | 1981-01-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-01-23 | 1984-07-24 | 1985-01-23 | $7700.00 | Window Closed / Lapsed |