Patent US5215092A successfully refreshed from Google Patents.
US3572928A
Expired / Lapsed
US
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Aircraft proximity warning system
Assignee: Comstock and Wescott Inc
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Filing: 1969-05-19
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Granted: 1971-03-30
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Expires: 1989-05-19
Abstract
Abstract An airborne system to be carried by each protected aircraft includes a pulsed, infrared emitting xenon flash lamp and a photoelectric circuit for sensing the flashes from other target aircraft controlling an alarm or display. The photocell is IR filtered to discriminate against light sources low in IR. The sensing circuits discriminate against light from steady and intermittent sources other than the xenon lamp. Reflections of flashes from the protected craft''s lamp are rejected by blocking the sensing circuit during the duration of the lamp flash, and to avoid coincidence of the protected and target craft flashes the flash repetition is randomly varied about the mean rate. An array of photoelectric cells viewing different zones ahead of the protected aircraft controls a visual display indicating the location and range of target aircraft.
Inventors
- 👤 John A Decker Jr
- 👤 Martin O Harwit
- 👤 Melvyn G Morris
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 22:40
CPC Classifications
G; G01; G01S; G01S11/00; G01S11/12
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
160 words
Aircraft proximity detection apparatus airborne on craft carrying a short rise time flash lamp pulsed for predetermined interval, comprising: a plurality of photoelectric means responsive to light to produce photoelectric signals following the appearance and duration of the light; a plurality of proximity alarm devices; a corresponding plurality of electronic circuits interconnecting respective photoelectric means and devices, each circuit including frequency selective means with a characteristic response only to short rise time signals of duration substantially the same as the predetermined interval of said lamp flash, said response actuating an alarm device such that steady light and intermittent light of longer duration than said lamp flash are rejected by said circuits, and respective alarms are actuated only by response of a corresponding circuit to light flashes from another aircraft; and said devices being disposed to view in different directions, and respective alarms being arranged in a corresponding disposition thereby to indicate both the proximity and direction of the other aircraft.
Claim 2
Dependent Claim
160 words
Aircraft proximity detection apparatus airborne on craft carrying a short rise time flash lamp pulsed for predetermined interval, comprising: a plurality of photoelectric means responsive to light to produce photoelectric signals following the appearance and duration of the light; a plurality of proximity alarm devices; a corresponding plurality of electronic circuits interconnecting respective photoelectric means and devices, each circuit including frequency selective means with a characteristic response only to short rise time signals of duration substantially the same as the predetermined interval of said lamp flash, said response actuating an alarm device such that steady light and intermittent light of longer duration than said lamp flash are rejected by said circuits, and respective alarms are actuated only by response of a corresponding circuit to light flashes from another aircraft; and said devices being disposed to view in different directions, and respective alarms being arranged in a corresponding disposition thereby to indicate both the proximity and direction of the other aircraft.
Claim 3
Dependent Claim
51 words
Apparatus according to claim 1 wherein each said electronic circuit includes a monostable oscillator connected to and triggered by said frequency selective means to supply power to its respective alarm device and including timing means limiting the period of said power supply to a fraction of the interval between lamp flashes.
Claim 4
Dependent Claim
86 words
Apparatus according to claim 1 wherein said frequency responsive means comprises a single shot flip-flop coupled to said photoelectric means and responsive to an electric signal produced to generate a pulse of the same order of length as said predetermined interval, a gating valve connected between the flip-flop and said alarm, and a second connection to said valve from said photoelectric means, said valve being responsive only to the application of said photoelectric signal during the interval of said generated pulse to actuate said alarm device.
Claim 5
Dependent Claim
37 words
Apparatus according to claim 1 characterized by a flash lamp, a pulse generator for flashing said lamp at an average repetition rate and including means randomly to vary the occurrence of successive pulses about said average rate.
Claim 6
Dependent Claim
26 words
Apparatus according to claim 4 characterized by a connection between said pulse generator and each said electric circuit for rendering said circuit nonresponsive during each pulse.
Claim 7
Dependent Claim
101 words
Apparatus according to claim 1 characterized by a plurality of alarms for each photoelectric means, each said electronic circuit for each photoelectric means including a plurality of coincidence gates each connected between said frequency selective means and a respective alarm, and a plurality of range channels each connected between said photoelectric means and respective gates, said range channels including threshold detectors of electric signals of different amplitude, and said gates being responsive respectively to the coincidence of said frequency selective means response and threshold signals of different amplitude to actuate different alarms, thereby to indicate the range of the other aircraft.
Claim 8
Dependent Claim
179 words
Aircraft proximity detection apparatus airborne on each aircraft comprising: a short rise time flash lamp pulsed for predetermined interval; a pulse generator for flashing said lamp at an average repetition rate including means randomly to vary the occurrence of successive pulses about said average rate; photoelectric means responsive to light to produce a photoelectric signal following the appearance and duration of the light; a proximity alarm device; an electronic circuit interconnecting the photoelectric means and device including frequency selective means with a characteristic response only to short rise time signals of duration substantially the same as said predetermined interval, said response actuating said alarm device; whereby steady light and intermittent light of longer duration than said lamp flash are rejected by said circuit and said alarm is actuated only by response of said circuit to lamp flashed from another aircraft, thereby to indicate the proximity of said other aircraft; and said random pulse generator varying the flash rates of respective aircraft lamps thereby to reduce to negligible portions the possibility of coincidence of successive lamp flashes on different aircraft.
Claim 9
Dependent Claim
179 words
Aircraft proximity detection apparatus airborne on each aircraft comprising: a short rise time flash lamp pulsed for predetermined interval; a pulse generator for flashing said lamp at an average repetition rate including means randomly to vary the occurrence of successive pulses about said average rate; photoelectric means responsive to light to produce a photoelectric signal following the appearance and duration of the light; a proximity alarm device; an electronic circuit interconnecting the photoelectric means and device including frequency selective means with a characteristic response only to short rise time signals of duration substantially the same as said predetermined interval, said response actuating said alarm device; whereby steady light and intermittent light of longer duration than said lamp flash are rejected by said circuit and said alarm is actuated only by response of said circuit to lamp flashed from another aircraft, thereby to indicate the proximity of said other aircraft; and said random pulse generator varying the flash rates of respective aircraft lamps thereby to reduce to negligible portions the possibility of coincidence of successive lamp flashes on different aircraft.
Claim 10
Dependent Claim
24 words
Apparatus according to claim 7 characterized by a connection between said pulse generator and electronic circuit for rendering said circuit nonresponsive during each pulse.
Claim 11
Dependent Claim
167 words
Aircraft proximity detection apparatus airborne on craft carrying a short rise time flash lamp pulsed for a predetermined interval, comprising; photoelectric means responsive to light to produce a photoelectric signal following the apparatus and duration of the light; a proximity alarm device; an electronic circuit interconnecting the photoelectric means and device including frequency selective means with a characteristic response only to short rise time signals of duration substantially the same as said predetermined interval, said response actuating said alarm device, said electronic circuit including a monostable oscillator connected to and triggered by said frequency selective means to supply power to said alarm device and timing means limiting the period of said power supply to a fraction of the interval between lamp flashes; and whereby steady light an intermittent light of longer duration than said lamp flash are rejected by said circuit and said alarm is actuated only by response of said circuit to lamp flashes from another aircraft, thereby to indicate the proximity of said other aircraft.
Claim 12
Dependent Claim
167 words
Aircraft proximity detection apparatus airborne on craft carrying a short rise time flash lamp pulsed for a predetermined interval, comprising; photoelectric means responsive to light to produce a photoelectric signal following the apparatus and duration of the light; a proximity alarm device; an electronic circuit interconnecting the photoelectric means and device including frequency selective means with a characteristic response only to short rise time signals of duration substantially the same as said predetermined interval, said response actuating said alarm device, said electronic circuit including a monostable oscillator connected to and triggered by said frequency selective means to supply power to said alarm device and timing means limiting the period of said power supply to a fraction of the interval between lamp flashes; and whereby steady light an intermittent light of longer duration than said lamp flash are rejected by said circuit and said alarm is actuated only by response of said circuit to lamp flashes from another aircraft, thereby to indicate the proximity of said other aircraft.
Claim 13
Dependent Claim
87 words
Apparatus according to claim 9 wherein said frequency responsive means comprises a single shot flip-flop coupled to said photoelectric means and responsive to an electric signal produced thereby to generate a pulse of the same order of length as said predetermined interval, a gating valve connected between the flip-flop and said alarm, and a second connection so said valve from said photoelectric means, said valve being responsive only to the application of said photoelectric signal during the interval of said generated pulse to actuate said alarm device.
Claim 14
Dependent Claim
96 words
Apparatus according to claim 9 characterized by a plurality of alarms for each photoelectric means, said electronic circuit including a plurality of coincidence gates each connected between said frequency selective means and a respective alarm, and a plurality of range channels each connected between said photoelectric means and respective gates, sAid range channels including threshold detectors of electric signals of different amplitude, and said gates being responsive respectively to the coincidence of said frequency selective means response and threshold signals of different amplitude to actuate different alarms, thereby to indicate the range of the other aircraft.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-03-29 | 1974-09-28 | 1975-03-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-03-29 | 1978-09-28 | 1979-03-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-03-29 | 1982-09-28 | 1983-03-30 | $7700.00 | Window Closed / Lapsed |