Patent US3757319A successfully refreshed from Google Patents.
US3757319A
Expired / Lapsed
US
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Security alarm system with bypass
Assignee: Eaton Corp
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Filing: 1971-04-05
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Granted: 1973-09-04
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Expires: 1991-04-05
Abstract
Abstract A battery operated alarm system including a more or less conventional closed circuit burglar alarm loop in which are sensors that may open the circuit so as to actuate a bell or other signaling device. In this system, a resistor limits the current passing in the normally closed loop, conserving battery power and also permitting further control of the loop by an electronic door lock. One of the sensors is a door switch that will be bypassed when a key is inserted into the lock, and there is a time delay holding the switch bypassed for a time that will permit a person to pass the door. The system also includes normally open circuit loops such as may be closed by operation of an electric floor mat, and one of those loops may be utilized for a fire sensor and will remain in operation at times when a switch has been actuated to place the other loops out of operation.
Inventors
- 👤 R Hedin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 20:39
CPC Classifications
G; G08; G08B; G08B13/00; G08B13/22
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
266 words
A security alarm system comprising a signaling device for indicating the presence of an alarm condition, control circuitry including a power supply for actuating said signaling device, first sensing means associated with said control circuitry and responsive to the presence of an alarm condition for effecting the actuation of said signaling device, a first normally closed control loop associated with said control circuitry and energized by said power supply, means limiting the flow of current from said power supply through said normally closed loop, said first sensing means being series connected in said first control loop and having a normally closed condition and assuming an open condition upon the occurrence of an alarm condition, latching means responsive to said first sensing means having a latched condition for effecting energization of said signaling means and an unlatched condition preventing the energization of said signaling means, said latching means assuming said latched condition in response to said first sensing means sensing the occurrence of an alarm condition, code receptive means offering a first signal when presented with a predetermined code and a second signal when presented with a code other than said predetermined code and bypass means connected in parallel to said sensing means and responsive to said first signal of said code receptive means to conduct the limited flow of current past said sensing means to render said sensing means ineffective for actuation of said signaling device and responsive to said second signal to prevent the conduction of the limited flow of current past said sensing means to allow said sensing means to actuate said signaling device.
Claim 2
Dependent Claim
266 words
A security alarm system comprising a signaling device for indicating the presence of an alarm condition, control circuitry including a power supply for actuating said signaling device, first sensing means associated with said control circuitry and responsive to the presence of an alarm condition for effecting the actuation of said signaling device, a first normally closed control loop associated with said control circuitry and energized by said power supply, means limiting the flow of current from said power supply through said normally closed loop, said first sensing means being series connected in said first control loop and having a normally closed condition and assuming an open condition upon the occurrence of an alarm condition, latching means responsive to said first sensing means having a latched condition for effecting energization of said signaling means and an unlatched condition preventing the energization of said signaling means, said latching means assuming said latched condition in response to said first sensing means sensing the occurrence of an alarm condition, code receptive means offering a first signal when presented with a predetermined code and a second signal when presented with a code other than said predetermined code and bypass means connected in parallel to said sensing means and responsive to said first signal of said code receptive means to conduct the limited flow of current past said sensing means to render said sensing means ineffective for actuation of said signaling device and responsive to said second signal to prevent the conduction of the limited flow of current past said sensing means to allow said sensing means to actuate said signaling device.
Claim 3
Dependent Claim
85 words
A security system as defined in claim 1, in which said control circuitry includes switch means that are electrically actuated for actuating said signaling device, and said means that limit the current flow through said normally closed loop being connected in common to said loop and to said switch means, said switch means being actuated by a rise in the potential of the limited current flow thereto affected when thE current flow in said loop is interrupted by an open condition of said sensing means.
Claim 4
Dependent Claim
49 words
A security alarm system as defined in claim 1 further including time delay means responsive to said first signal of said code receptive means to maintain said bypass means effective for a time after said first signal is removed to prevent actuation of said signaling device during that time.
Claim 5
Dependent Claim
201 words
A security system as defined in claim 1 further including second and third normally open control loops associated with said control circuitry and energized by said power supply, second and third sensing means each series connected in the corresponding second or third control loop and having a normally open condition and assuming a closed condition upon the occurrence of an alarm condition for effecting actuation of said signaling means and switch means for controlling the flow of current through the first mentioned control loop and said second control loop, said switch means having an on condition providing for current flow through said first and second control loops to enable said first and second sensing means to sense the presence of an alarm condition, said switching means having an off condition preventing the flow of current through said first and second control loops to prevent said first and second sensing means from sensing the presence of an alarm condition, said switch means being inneffective to control current flow through said third control loop to enable said third sensing means to be effective to effect actuation of said signaling means when said switch means is in an off condition or an on condition.
Claim 6
Dependent Claim
26 words
A security alarm system as defined in claim 1 including means responsive to said second signal for actuating said signaling device independently of said sensing means.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-09-03 | 1977-03-05 | 1977-09-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-09-03 | 1981-03-05 | 1981-09-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-09-03 | 1985-03-05 | 1985-09-04 | $7700.00 | Window Closed / Lapsed |