US3665445A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Detection system
Assignee: SCIENT SECURITY SYSTEMS Inc
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Filing: 1970-12-22
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Granted: 1972-05-23
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Expires: 1990-12-22
Abstract
Abstract An intruder detection system wherein vibrations generated by an intruder are detected apart from normal environmental noise and are utilized to set off an alarm. The system detects activity rate rather than total generated energy by measuring duration, frequency and amplitude of generated sound. Detected vibrations having a predetermined frequency range provide an input signal for both legs of a differential amplifier. The output signal of the differential amplifier is analyzed for presence of characteristics typical for intruder-generated vibrations.
Inventors
- 👤 Robert E Riley Jr
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 18:36
CPC Classifications
G; G08; G08B; G08B13/00; G08B13/16; G08B13/1654; G08B13/1672
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
315 words
Solid state detection system which comprises transducer means for producing an electrical signal in response to vibrations impinging thereon; bandpass amplifier means coupled to said transducer means, responsive to a signal output from said transducer means, and adapted to provide an amplified output signal in response to a signal from said transducer means having a frequency within a predetermined range; differential comparator means coupled to said bandpass amplifier means, responsive to an amplified output signal from said amplifier means, and adapted to establish a background signal level and to pass an output signal which exceeds in magnitude said background signal; first monostable multivibrator means having a predetermined time constant coupled to said differential comparator means and adapted to measure the duration of an output signal passed by said comparator means; first gate means coupled to said differential comparator means and said first monostable vibrator means and adapted to generate an event signal in response to an input from said differential comparator means of a relatively shorter duration than a predetermined time period and a signal from said first monostable multivibrator means; second gate means coupled to said differential comparator means and said first monostable vibrator means and adapted to generate a reject signal in response to an input from said differential comparator means of a relatively longer duration than a predetermined time period and a signal from said first monostable multivibrator means; second monostable multivibrator means having a predetermined time duration coupled to said first gate means and responsive to an event signal therefrom; counter means coupled to said second monostable multivibrator means, adapted to be energized by said second monostable vibrator means, responsive to an event signal from said first gate means, and adapted to store said event signal; and an alarm means coupled to said counter means and energized in response to a predetermined number of event signals stored by said counter means.
Claim 2
Dependent Claim
315 words
Solid state detection system which comprises transducer means for producing an electrical signal in response to vibrations impinging thereon; bandpass amplifier means coupled to said transducer means, responsive to a signal output from said transducer means, and adapted to provide an amplified output signal in response to a signal from said transducer means having a frequency within a predetermined range; differential comparator means coupled to said bandpass amplifier means, responsive to an amplified output signal from said amplifier means, and adapted to establish a background signal level and to pass an output signal which exceeds in magnitude said background signal; first monostable multivibrator means having a predetermined time constant coupled to said differential comparator means and adapted to measure the duration of an output signal passed by said comparator means; first gate means coupled to said differential comparator means and said first monostable vibrator means and adapted to generate an event signal in response to an input from said differential comparator means of a relatively shorter duration than a predetermined time period and a signal from said first monostable multivibrator means; second gate means coupled to said differential comparator means and said first monostable vibrator means and adapted to generate a reject signal in response to an input from said differential comparator means of a relatively longer duration than a predetermined time period and a signal from said first monostable multivibrator means; second monostable multivibrator means having a predetermined time duration coupled to said first gate means and responsive to an event signal therefrom; counter means coupled to said second monostable multivibrator means, adapted to be energized by said second monostable vibrator means, responsive to an event signal from said first gate means, and adapted to store said event signal; and an alarm means coupled to said counter means and energized in response to a predetermined number of event signals stored by said counter means.
Claim 3
Dependent Claim
38 words
The detection system of claim 1 wherein a third monostable vibrator means is provided coupled to said second gate means, responsive to a reject signal therefrom, and energizing a reject indicator means in response to said reject signal.
Claim 4
Dependent Claim
26 words
The detection system of claim 1 wherein an indicator means is provided coupled to said second monostable vibrator and is energized when the vibrator is energized.
Claim 5
Dependent Claim
23 words
The detection system of claim 1 wherein the counter means comprises a counting unit and a decoding unit responsive to said counting unit.
Claim 6
Dependent Claim
32 words
The detection system of claim 1 wherein the alarm means is additionally coupled to the differential comparator means and is adapted to be energized when the background signal exceeds a predetermined level.
References Cited (Backward Citations)
US3261009A
Cited
US3585581A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-05-23 | 1975-11-22 | 1976-05-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-05-23 | 1979-11-22 | 1980-05-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-05-23 | 1983-11-22 | 1984-05-23 | $7700.00 | Window Closed / Lapsed |