US3866202A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Alarm circuitry
Assignee: Gulf and Western Manufacturing Co
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Filing: 1973-10-29
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Granted: 1975-02-11
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Expires: 1993-10-29
Abstract
Abstract The alarm circuitry employs a plurality of pressure responsive sensors interconnected by conductor means to detection circuitry including an alarm relay, display panel, or other alarm indicating means. One sensor may be associated with each door, window or other entrance means of the protected premises and all sensors are preferably closed when the premises are secured. In one embodiment the sensors are coupled in series and the detection circuitry is voltage responsive, while in another embodiment the sensors are coupled in parallel and the detection circuitry is current responsive. In both embodiments the detection circuitry senses an alarm condition when a sensor is activated or when the conductor means becomes open or short circuited. In addition, the detection circuitry includes one or more test switches actuable by an authorized person prior to leaving the premises to determine if all entrance means are in a safe closed position, and to check the operability of the alarm circuitry itself prior to enabling it for possible energization by an unauthorized person.
Inventors
- 👤 Martin H Reiss
- 👤 James R Adams
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 18:13
CPC Classifications
G; G08; G08B; G08B13/00; G08B13/02; G08B13/08
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
131 words
Alarm circuitry for use in a structure having entrance means, comprising; current detection means, a plurality of sensors each operatively associated with an entrance means and responsive to an activation thereof to change said sensor from a first state to a second state, conductor means intercoupling said sensors in parallel to an input of said current detection means, each said sensor including a current source for drawing a predetermined amount of current whereby each current source draws a different amount of current, said detection means including means for registering a first condition when all said sensors are drawing current and means for registering a plurality of alarm conditions, each such alarm condition corresponding to activation of one of said sensors, and an additional current source connected in parallel with said sensors.
Claim 2
Dependent Claim
131 words
Alarm circuitry for use in a structure having entrance means, comprising; current detection means, a plurality of sensors each operatively associated with an entrance means and responsive to an activation thereof to change said sensor from a first state to a second state, conductor means intercoupling said sensors in parallel to an input of said current detection means, each said sensor including a current source for drawing a predetermined amount of current whereby each current source draws a different amount of current, said detection means including means for registering a first condition when all said sensors are drawing current and means for registering a plurality of alarm conditions, each such alarm condition corresponding to activation of one of said sensors, and an additional current source connected in parallel with said sensors.
Claim 3
Dependent Claim
26 words
Alarm circuitry as defined in claim 1 wherein each said current source includes a field effect transistor and resistor coupled in series between said conductor means.
Claim 4
Dependent Claim
44 words
Alarm circuitry as defined in claim 1 wherein said detection means includes a meter and a limiting resistor and means coupling the meter and limiting resistor in series, the input of said current detection means being defined at one end of the limiting resistor.
Claim 5
Dependent Claim
23 words
Alarm circuitry as defined in claim 1 wherein said additional current source draws a different amount of current than any of said sensors.
Claim 6
Dependent Claim
21 words
Alarm circuitry as defined in claim 4 wherein said additional current source draws less current than any one of said sensors.
Claim 7
Dependent Claim
22 words
Alarm circuitry as defined in claim 1 wherein said current detection means distinguishes a short circuit condition by a maximum current detection.
Claim 8
Dependent Claim
21 words
Alarm circuitry as defined in claim 5 wherein said additional current limiting means is added for distinguishing between two fault conditions.
Claim 9
Dependent Claim
149 words
Alarm circuitry for use in a structure having a plurality of ways through which access may be gained, comprising; current detection means, a plurality of sensor switch means each operatively associated with an access way and responsive to an activation thereof to change from a first state to a second state, a plurality of constant current elements each arranged to draw a different amount of current, means coupling each sensor switch means in series with an associated constant current element, and means intercoupling the series connected constant current elements and sensor switch means in parallel to an input of said current detection means, said current detection means including means for registering a first condition when all said sensor switch means are drawing current, and for registering a plurality of alarm conditions, each such alarm condition corresponding to activation of one of said sensor switch means to its second state.
Claim 10
Dependent Claim
149 words
Alarm circuitry for use in a structure having a plurality of ways through which access may be gained, comprising; current detection means, a plurality of sensor switch means each operatively associated with an access way and responsive to an activation thereof to change from a first state to a second state, a plurality of constant current elements each arranged to draw a different amount of current, means coupling each sensor switch means in series with an associated constant current element, and means intercoupling the series connected constant current elements and sensor switch means in parallel to an input of said current detection means, said current detection means including means for registering a first condition when all said sensor switch means are drawing current, and for registering a plurality of alarm conditions, each such alarm condition corresponding to activation of one of said sensor switch means to its second state.
Claim 11
Dependent Claim
24 words
The alarm circuitry of claim 8 wherein each said constant current element comprises an active semiconductor device and a limiting resistor coupled in series.
Claim 12
Dependent Claim
15 words
The alarm circuitry of claim 9 wherein said means intercoupling includes two different voltage lines.
Claim 13
Dependent Claim
45 words
The alarm circuitry of claim 10 wherein said semiconductor device comprises a field effect transistor having one electrode coupled to the sensor switch means, a second electrode coupled to the limiting resistor and a third electrode coupled to one of the two different voltage lines.
Claim 14
Dependent Claim
115 words
Alarm circuitry for use in a structure having a plurality of ways through which access may be gained comprising; current detection means, a plurality of sensors each operatively associated with an access way and each including a current source comprising a field effect transistor coupled in series with a current limiting resistor, each said current source drawing a different predetermined amount of current, and conductor means intercoupling said sensors in parallel to an input of said current detection means, said current detection means including means for registering a first condition when all said sensors are drawing current and for registering a plurality of different alarm conditions each corresponding to activation of one of said sensors.
Claim 15
Dependent Claim
115 words
Alarm circuitry for use in a structure having a plurality of ways through which access may be gained comprising; current detection means, a plurality of sensors each operatively associated with an access way and each including a current source comprising a field effect transistor coupled in series with a current limiting resistor, each said current source drawing a different predetermined amount of current, and conductor means intercoupling said sensors in parallel to an input of said current detection means, said current detection means including means for registering a first condition when all said sensors are drawing current and for registering a plurality of different alarm conditions each corresponding to activation of one of said sensors.
References Cited (Backward Citations)
US2556363A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-02-10 | 1978-08-12 | 1979-02-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-02-10 | 1982-08-12 | 1983-02-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-02-10 | 1986-08-12 | 1987-02-11 | $7700.00 | Window Closed / Lapsed |