Patent US3721950A successfully refreshed from Google Patents.
US3721950A
Expired / Lapsed
US
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Responsive navigation beacon
Assignee: Lockheed Martin Corp
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Filing: 1969-08-13
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Granted: 1973-03-20
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Expires: 1989-08-13
Abstract
Abstract A navigation beacon is provided which does not emit a continuous signal. Instead, it has a pair of responsive devices rotating at different angular velocities related in the ratio 2:1. The responsive devices may be either passive reflectors or active transponders, and the signal may be subsonic, sonic, or supersonic acoustic energy, or infrared, visible, ultraviolet or microwave radiation or combinations of any of these forms of energy. In any case, an observer having any bearing relative to the beacon will receive two distinct responses from the pair of reflectors or transponders. The time interval between these two responses will be a calculable function of that bearing. In addition, the interval between interrogation and response will be a calculable function of the observer''s range from the beacon. Various refinements may be added to make the beacon easier to locate for friendly forces, or to make it difficult for enemy forces to locate. The beacon can even be turned off entirely except when activated by a predetermined command and the command can be in coded form to prevent activation by an enemy.
Inventors
- 👤 S Jorgensen
- 👤 W Kearsley
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 11:07
CPC Classifications
G; G01; G01S; G01S13/00; G01S13/74; G01S13/76; G01S13/78; G01S13/785; G01S1/00; G01S1/02; G01S13/75
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
182 words
A responsive navigation beacon comprising: A. a pair of directional responders each having an axis of colinear response and responding to and transmitting acoustic signals anywhere in the range from subsonic through supersonic frequencies inclusive; B. each of said transponders arranged to 1. respond only to a signal arriving along a narrow path, and 2. to transmit a response only along said narrow path in the opposite direction and only while said signal is being received; C. motive means being normally off and arranged to rotate both said directional responders about a common axis at angular velocities of omega and 1/C times omega respectively, where C is substantially a constant; D. means for directionally orienting said beacon so that said colinear response axes periodically rotate into mutually parallel relationship when pointed in a predetermined direction; E. an omni-directional hydrophone on said beacon responsive to acoustic signals in said frequency range; F. means for turning said motive means on in response to reception of a predetermined acoustic signal by said omnidirectional hydrophone; G. and means for turning said motive means off again thereafter.
Claim 2
Dependent Claim
182 words
A responsive navigation beacon comprising: A. a pair of directional responders each having an axis of colinear response and responding to and transmitting acoustic signals anywhere in the range from subsonic through supersonic frequencies inclusive; B. each of said transponders arranged to 1. respond only to a signal arriving along a narrow path, and 2. to transmit a response only along said narrow path in the opposite direction and only while said signal is being received; C. motive means being normally off and arranged to rotate both said directional responders about a common axis at angular velocities of omega and 1/C times omega respectively, where C is substantially a constant; D. means for directionally orienting said beacon so that said colinear response axes periodically rotate into mutually parallel relationship when pointed in a predetermined direction; E. an omni-directional hydrophone on said beacon responsive to acoustic signals in said frequency range; F. means for turning said motive means on in response to reception of a predetermined acoustic signal by said omnidirectional hydrophone; G. and means for turning said motive means off again thereafter.
Claim 3
Dependent Claim
34 words
A beacon as in claim 1 further comprising: a decoder responsive to said omni-directional hydrophone and arranged to recognize a predetermine coded signal and to turn on said motive means in selective response thereto.
Claim 4
Dependent Claim
127 words
to transmit a response only along said narrow path in the opposite direction and only while said signal is being received; C. motive means being normally off and arranged to rotate both said directional responders about a common axis at angular velocities of omega and 1/C times omega respectively, where C is substantially a constant; D. means for directionally orienting said beacon so that said colinear response axes periodically rotate into mutually parallel relationship when pointed in a predetermined direction; E. an omni-directional hydrophone on said beacon responsive to acoustic signals in said frequency range; F. means for turning said motive means on in response to reception of a predetermined acoustic signal by said omnidirectional hydrophone; G. and means for turning said motive means off again thereafter.
Claim 5
Dependent Claim
127 words
to transmit a response only along said narrow path in the opposite direction and only while said signal is being received; C. motive means being normally off and arranged to rotate both said directional responders about a common axis at angular velocities of omega and 1/C times omega respectively, where C is substantially a constant; D. means for directionally orienting said beacon so that said colinear response axes periodically rotate into mutually parallel relationship when pointed in a predetermined direction; E. an omni-directional hydrophone on said beacon responsive to acoustic signals in said frequency range; F. means for turning said motive means on in response to reception of a predetermined acoustic signal by said omnidirectional hydrophone; G. and means for turning said motive means off again thereafter.
Claim 6
Dependent Claim
37 words
A beacon as in claim 2 further comprising: means responsive to said decoder to activate said turn-off means to turn off said motive means in response to reception of a second predetermined coded signal by said hydrophone.
Claim 7
Dependent Claim
56 words
A beacon as in claim 3 further comprising: a timer in said beacon arranged to A. start in response to reception of said predetermined signal by said hydrophone, B. measure out a predetermined time interval after starting, and C. activate said turn-off means to turn off said motive means at the end of said time interval.
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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) | 1976-03-19 | 1976-09-18 | 1977-03-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-03-19 | 1980-09-18 | 1981-03-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-03-19 | 1984-09-18 | 1985-03-20 | $7700.00 | Window Closed / Lapsed |