Patent US3806936A successfully refreshed from Google Patents.
US3806936A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Personal locator
Assignee: AERO ELECTRONICS DEV CO Inc
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Filing: 1972-08-14
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Granted: 1974-04-23
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Expires: 1992-08-14
Abstract
Abstract A tone modulated transmitter and a pair of radio receiver circuits provide a personal locator which can transmit emergency distress signals and can receive signals which are used to indicate the direction from which the signals are being received. The locator is small enough to be carried in a pocket or connected to the pants belt of a user.
Inventors
- 👤 C Koster
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 15:26
CPC Classifications
G; G01; G01S; G01S1/00; G01S1/02; G01S1/68
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
118 words
A personal locator comprising: a tone modulated radio transmitter; first and second radio receiver circuits, each having an input lead and an output lead; first and second directional antennas, said first directional antenna being coupled to said input lead of said first receiver circuit, and said second directional antenna being coupled to said input lead of said second receiver circuit; an indicating device, said device being connected between said output leads of said first and said second receiver circuits, said device indicating the difference in signal between the output leads of said first and said second receiver circuits; a source of electrical potential; and means for selectively connecting said source to said transmitter and to said receiver circuit.
Claim 2
Dependent Claim
118 words
A personal locator comprising: a tone modulated radio transmitter; first and second radio receiver circuits, each having an input lead and an output lead; first and second directional antennas, said first directional antenna being coupled to said input lead of said first receiver circuit, and said second directional antenna being coupled to said input lead of said second receiver circuit; an indicating device, said device being connected between said output leads of said first and said second receiver circuits, said device indicating the difference in signal between the output leads of said first and said second receiver circuits; a source of electrical potential; and means for selectively connecting said source to said transmitter and to said receiver circuit.
Claim 3
Dependent Claim
32 words
A personal locator as defined in claim 1 including: an audio amplifier; and a loudspeaker, said audio amplifier being connected between said output lead of said first receiver circuit and said speaker.
Claim 4
Dependent Claim
35 words
A personal locator as defined in claim 1 including: means for generating a rapidly changing audio frequency, said means for generating being coupled to said transmitter to provide a distinctive emergency signal from said transmitter.
Claim 5
Dependent Claim
33 words
A personal locator as defined in claim 1 including: means for shielding said first and said second directional antennas to eliminate error indication in the direction of a radio frequency signal being received.
Claim 6
Dependent Claim
39 words
A personal locator as defined in claim 4 including: means for orienting said first and said second directional antennas to aid said means for shielding in eliminating error indication in the direction of a radio frequency signal being received.
Claim 7
Dependent Claim
102 words
A personal locator comprising: a tone modulated radio transmitter; first and second radio receiver circuits each having an R.F. stage, a mixer, an IF amplifier and an audio detector; first and second directional antennas, said first directional antenna being coupled to said R. F. stage of said first receiver circuit, said second directional antenna being coupled to said R. F. stage of said second receiver circuit; an indicating device, said device being coNnected between said audio detectors of said first and said second receiver circuits; a battery; and means for selectively connecting said battery to said transmitter and to said receiver circuits.
Claim 8
Dependent Claim
102 words
A personal locator comprising: a tone modulated radio transmitter; first and second radio receiver circuits each having an R.F. stage, a mixer, an IF amplifier and an audio detector; first and second directional antennas, said first directional antenna being coupled to said R. F. stage of said first receiver circuit, said second directional antenna being coupled to said R. F. stage of said second receiver circuit; an indicating device, said device being coNnected between said audio detectors of said first and said second receiver circuits; a battery; and means for selectively connecting said battery to said transmitter and to said receiver circuits.
Claim 9
Dependent Claim
115 words
A personal locator as defined in claim 6 wherein said tone modulated transmitter includes: a crystal controller oscillator; an RF amplifier, said crystal controlled oscillator being coupled to said RF amplifier; a unijunction transistor oscillator circuit; a free running multivibrator, said oscillator circuit being coupled to said multivibrator, said oscillator circuit providing a signal to said multivibrator to cause the frequency of said multivibrator to change over an audio frequency range at a predetermined rate, said multivibrator being coupled to said RF amplifier to cause the amplitude of an RF signal of said RF amplifier to change at the audio frequency rate; and a transmitting antenna, said transmitting antenna being coupled to said RF amplifier.
Claim 10
Dependent Claim
33 words
A personal locator as defined in claim 7 including: means for shielding said first and said second directional antennas to eliminate error indication in the direction of a radio frequency signal being received.
Claim 11
Dependent Claim
41 words
A personal locator as defined in claim 7 including: means for orienting said first and said second directional antennas to aid said means for shielding in eliminating a 180* error indication in the direction of a radio frequency signal being received.
Claim 12
Dependent Claim
32 words
A personal locator as defined in claim 7 including: an audio amplifier; and a loudspeaker, said audio amplifier being connected between said output lead of said first receiver circuit and said speaker.
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) | 1977-04-22 | 1977-10-22 | 1978-04-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-04-22 | 1981-10-22 | 1982-04-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-04-22 | 1985-10-22 | 1986-04-23 | $7700.00 | Window Closed / Lapsed |