US3659289A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Alarm device
Assignee: Individual
•
Filing: 1969-09-23
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Granted: 1972-04-25
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Expires: 1989-09-23
Abstract
Abstract This invention relates to a monitoring device comprising a generator for generating longitudinal compressive waves of ultrasonic frequency and a receiver unit for monitoring the amplitude of the waves at the ultrasonic frequency received by a receiver. The receiver unit includes an oscillator for generating a signal train at a given carrier frequency and first switch means for controlling the transmission of the signal train at that carrier frequency to a remote detector unit, said first switch means being actuated in response to a change in the amplitude of the signal received by the receiver. The detector unit is tuned to the carrier frequency and has a further switch means under the control of the signal train (preferably transmitted via the power lines wiring) for actuating an alarm and/or recording device to indicate when the amplitude of waves received by the receiver has changed.
Inventors
- 👤 Kenneth John Everitt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 11:19
CPC Classifications
G; G08; G08B; G08B13/00; G08B13/16; G08B13/1609; G08B13/1618; G08B13/1627
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
218 words
A monitoring device comprising a generator, a receiver and a detector unit, the generator having an emitter for generating longitudinal compressive waves of ultrasonic frequency the receiver having means for receiving longitudinal compressive waves at said frequency, means for monitoring the amplitude of the waves received by said receiving means, an oscillator for generating a signal train at a given carrier frequency, a power line connection cord and first switch means for controlling the transmission of the signal train at said carrier frequency to the power line connection cord in response to a change in the amplitude of the signal received by said receiving means the detector unit having a further power line connection cord, an amplifier tuned to said carrier frequency, a further switch means controlled by the amplifier and indicating means controlled by the further switch means whereby the indicating means is under control of the signal train and indicates when the amplitude of waves received by said receiving means in the receiver has changed; said detector unit further including a second tuned amplifier only one of the two amplifiers being tuned to receive the signal train, said further switch means including discriminating means which actuates the indicating means only when an output is received solely from said one amplifier tuned to receive the signal train.
Claim 2
Dependent Claim
218 words
A monitoring device comprising a generator, a receiver and a detector unit, the generator having an emitter for generating longitudinal compressive waves of ultrasonic frequency the receiver having means for receiving longitudinal compressive waves at said frequency, means for monitoring the amplitude of the waves received by said receiving means, an oscillator for generating a signal train at a given carrier frequency, a power line connection cord and first switch means for controlling the transmission of the signal train at said carrier frequency to the power line connection cord in response to a change in the amplitude of the signal received by said receiving means the detector unit having a further power line connection cord, an amplifier tuned to said carrier frequency, a further switch means controlled by the amplifier and indicating means controlled by the further switch means whereby the indicating means is under control of the signal train and indicates when the amplitude of waves received by said receiving means in the receiver has changed; said detector unit further including a second tuned amplifier only one of the two amplifiers being tuned to receive the signal train, said further switch means including discriminating means which actuates the indicating means only when an output is received solely from said one amplifier tuned to receive the signal train.
Claim 3
Dependent Claim
85 words
A monitoring device as claimed in claim 1, in which the generator and the receiver are proximately housed having a single power line connection cord which serves both to supply electric power to the generator and receiver from a power line and for impressing the output of the oscillator on the power line, said further connection cord of the detector unit serving to supply electric power to the detector unit and to transmit the signal train impressed on the power line to said tuned amplifier.
Claim 4
Dependent Claim
52 words
A monitoring device as claimed in claim 1, in which said first switch means in said receiver stops the transmission of a signal train to the detector unit when the amplitude of the waves received by said receiving means changes by more than a predetermined amount in less than a predetermined time.
Claim 5
Dependent Claim
52 words
A monitoring device as claimed in claim 2, in which said first switch means in said receiver stops the output of said oscillator from reaching said connection cords when the amPlitude of the waves received by said receiving means changes by more than a predetermined amount in less than a predetermined time.
Claim 6
Dependent Claim
50 words
A monitoring device as claimed in claim 1, in which the oscillator in said receiver only impresses a signal train on said power line connection cords when the amplitude of the waves received by said receiving means changes by more than a predetermined amount in less than a predetermined time.
Claim 7
Dependent Claim
41 words
A monitoring device as claimed in claim 2, in which the receiver oscillator only impresses a signal train on the power line connection cords when there is a change in the wave pattern received by said receiving means in said receiver.
Claim 8
Dependent Claim
21 words
A monitoring device as claimed in claim 1, in which said emitter generates waves at a frequency greater than 30 kiloHertz.
Claim 9
Dependent Claim
21 words
A monitoring device as claimed in claim 1, in which said emitter generates waves at a frequency greater than 30 kiloHertz.
References Cited (Backward Citations)
US2071933A
Cited
US2400309A
Cited
US2655645A
Cited
US3191124A
Cited
US3287722A
Cited
US3135951A
Cited
US3388389A
Cited
US3378829A
Cited
US3513463A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-04-25 | 1975-10-25 | 1976-04-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-04-25 | 1979-10-25 | 1980-04-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-04-25 | 1983-10-25 | 1984-04-25 | $7700.00 | Window Closed / Lapsed |