Patent EP0073681A2 successfully refreshed from Google Patents.
EP0073681A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Improvements relating to position detection devices
Assignee: Individual
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Filing: 1982-09-01
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Granted: —
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Expires: 2002-09-01
Abstract
Abstract An out of proximity alarm system useful for indicating when the distance between two bodies has increased beyond a predetermined distance is disclosed. In the preferred embodiment, the system comprises a radio transmitter attachable to one of the bodies, such as a personal article such as a briefcase and having a pulsed R.F. output. A radio receiver carried by a second body, such as a person, receives the transmitted signal when the two bodies are within range of each other. The receiver incorporates a time delay stage which is kept disabled by the received pulsed signal. Should the distance between the two bodies increase beyond a predetermined amount the pulsed signal will have insufficient strength to keep the time delay stage disabled, thus activating an alarm and alerting the carrier of the receiver that he has left the personal article behind.
Inventors
- 👤 Kunwar Chander Jeet Singh
- 👤 Sandor Goldner
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-03 18:25
CPC Classifications
G; G08; G08B; G08B21/00; G08B21/02; G08B21/0202; G08B21/023; G08B13/00; G08B13/02; G08B13/14; G08B13/1427; G08B13/22; G08B21/0241; G08B21/0247
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
93 words
An out of proximity alarm system comprising: a transmitter attachable to a first body, including means for generating a radiated signal; and a receiver attachable to a second body, comprising: means for receiving said radiated signal; means for demodulating said radiated signal and producing a demodulated signal; alarm means; and means responsive to said demodulated signal for activating said alarm means when the level of said demodulated signal falls below a threshold level; whereby when the distance between said first and second bodies increases beyond a predetermined amount, said alarm means is activated.
Claim 2
Dependent Claim
93 words
An out of proximity alarm system comprising: a transmitter attachable to a first body, including means for generating a radiated signal; and a receiver attachable to a second body, comprising: means for receiving said radiated signal; means for demodulating said radiated signal and producing a demodulated signal; alarm means; and means responsive to said demodulated signal for activating said alarm means when the level of said demodulated signal falls below a threshold level; whereby when the distance between said first and second bodies increases beyond a predetermined amount, said alarm means is activated.
Claim 3
Dependent Claim
54 words
The out of proximity alarm system recited in claim 1 wherein said means for generating a radiated signal includes ultrasonic frequency oscillator means, means for pulse modulating said ultrasonic frequency oscillator means and ultrasonic transducer transmitting means coupled to said ultrasonic frequency oscillator means and said means for receiving includes ultrasonic transducer receiving means.
Claim 4
Dependent Claim
22 words
The out of proximity alarm system recited in claim 2 wherein said means responsive to said demodulated signal comprises time delay means.
Claim 5
Dependent Claim
27 words
The out of proximity alarm system recited in claim 3 wherein said means for receiving further comprises passband amplifier means coupled to said ultrasonic transducer receiving means.
Claim 6
Dependent Claim
19 words
The out of proximity alarm system recited in claim 4 wherein said means for demodulating comprises tone decoder means.
Claim 7
Dependent Claim
20 words
The out of proximity alarm system recited in claim 5 wherein said time-delay means comprises resistor- capacitor charge storage means.
Claim 8
Dependent Claim
25 words
The out of proximity, alarm system recited in claim 6 wherein said first body is a person and said second body is a personal article.
Claim 9
Dependent Claim
25 words
The out of proximity alarm system recited in claim 6 wherein said second body is a person and said first body is a personal article.
Claim 10
Dependent Claim
96 words
9 An out of proximity alarm system comprising: a transmitter attachable to a first body, including means for generating a radio frequency signal; and a receiver attachable to a second body, comprising: means for receiving said radio frequency signal; means for demodulating said radio frequency signal and producing a demodulated signal; and alarm means responsive to said demodulated signal; one of said bodies being a person and the other of said bodies being a personal article; whereby when the distance between said first and second bodies increases beyond a predetermined amount, said alarm means is activated.
Claim 11
Dependent Claim
96 words
9 An out of proximity alarm system comprising: a transmitter attachable to a first body, including means for generating a radio frequency signal; and a receiver attachable to a second body, comprising: means for receiving said radio frequency signal; means for demodulating said radio frequency signal and producing a demodulated signal; and alarm means responsive to said demodulated signal; one of said bodies being a person and the other of said bodies being a personal article; whereby when the distance between said first and second bodies increases beyond a predetermined amount, said alarm means is activated.
Claim 12
Dependent Claim
36 words
10 . The out of proximity alarm system recited in claim 9 wherein said means for generating a radio frequency signal includes radio frequency oscillator means and means for pulse modulating said radio frequency oscillator means.
Claim 13
Dependent Claim
23 words
11 . The out of proximity alarm system recited in claim 10 wherein said receiver further comprises means for amplifying said demodulated signal.
Claim 14
Dependent Claim
26 words
The out of proximity alarm system recited in claim wherein said means for amplifying includes gain adjusting means for varying the reception range of said receiver.
Claim 15
Dependent Claim
40 words
13 .. The out of proximity alarm system recited in claim12 wherein said receiver further comprises time-delay means responsive to said demodulated signal for activating said alarm means when the level of said demodulated signal falls below a threshold level.
Claim 16
Dependent Claim
39 words
The out of proximity alarm system recited in claim 13 wherein said means for receiving comprises: means for converting said radio frequency signal to an intermediate frequency signal; and intermediate frequency amplifier means coupled to said means for converting.
Claim 17
Dependent Claim
70 words
The out of proximity alarm system recited in claim 13 wherein: said means for receiving includes a radio frequency amplifier; said radio frequency oscillator means includes oscillator means tuned to the center frequency of said radio frequency amplifier; and said means for receiving further includes inductor capacitor tuned circuit means coupled to the input of said radio frequency amplifier and tuned to the center frequency of said radio frequency amplifier.
Claim 18
Dependent Claim
21 words
The out of proximity alarm system recited in claim 14 or 15 wherein said means for demodulating comprises envelope detection means.
Claim 19
Dependent Claim
37 words
The out of proximity alarm system recited in claim 16'wherein said alarm means comprises: sub-audio frequency oscillator means; and audio frequency oscillator means coupled to said sub-audio frequency oscillator means for producing a pulsating audio alarm signal.
Claim 20
Dependent Claim
35 words
The out of proximity alarm system recited in claim'17 wherein said transmitter further includes means for digitally encoding said radio frequency signal and said receiver further includes means for digitally decoding said radio frequency signal.
Claim 21
Dependent Claim
21 words
The out of proximity alarm system recited in claim 13 wherein said time delay means comprises resistor- capacitor charge storage means.
Claim 22
Dependent Claim
139 words
An out of proximity alarm system for determining when a first body has separated from a second body by a predetermined distance comprising: transmitting means mounted on one of said bodies comprising radio frequency oscillation means and means for pulse modulating said radio frequency oscillation means; receiving means mounted on the other of said bodies comprising radio frequency reception means tuned to the frequency of said radio frequency oscillation means, radio frequency amplifier means, demodulation means coupled to said radio frequency amplifier means, low frequency amplifier means coupled to said demodulation means, alarm means and time delay means responsive to the demodulated signal from said demodulation means for activating said alarm means when said demodulated signal falls below a threshold level; wherein one of said bodies is a person and the other of said bodies is a personal article.
Claim 23
Dependent Claim
139 words
An out of proximity alarm system for determining when a first body has separated from a second body by a predetermined distance comprising: transmitting means mounted on one of said bodies comprising radio frequency oscillation means and means for pulse modulating said radio frequency oscillation means; receiving means mounted on the other of said bodies comprising radio frequency reception means tuned to the frequency of said radio frequency oscillation means, radio frequency amplifier means, demodulation means coupled to said radio frequency amplifier means, low frequency amplifier means coupled to said demodulation means, alarm means and time delay means responsive to the demodulated signal from said demodulation means for activating said alarm means when said demodulated signal falls below a threshold level; wherein one of said bodies is a person and the other of said bodies is a personal article.
Claim 24
Dependent Claim
28 words
The system recited in claim 22 wherein said radio frequency amplifier means comprises intermediate frequency amplifier means and said radio frequency reception means further comprises frequency conversion means.
References Cited (Backward Citations)
No citation records indexed.
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