US4253091A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for detection of alarm conditions
Assignee: Mobil Oil AS
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Filing: 1977-01-05
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Granted: 1981-02-24
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Expires: 1997-01-05
Abstract
Abstract Method and apparatus for a condition-sensing system including features of checking the integrity of the system and detecting the presence of an alarm condition. Condition-sensing system is described as a fire alarm system for a central station employing a modification of the McCulloh circuit. A plurality of fire detection loops including normally open circuit detectors are each powered at opposite ends. Each leg of each loop is sequentially checked for integrity and then the detectors are checked for alarm conditions. A switching system is employed for the sequential operations. A programmable controller is disclosed as a switching system.
Inventors
- 👤 Jehuda Frydman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 04:13
CPC Classifications
G; G08; G08B; G08B25/00; G08B25/01; G08B25/04; G08B25/045; G08B26/00; G08B26/001; G08B26/002; G08B29/00; G08B29/12; G08B29/123; G08B29/14
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
69 words
The method of sensing conditions in a system including sensors and also including channels having legs communicating with each of the sensors comprising the steps of scanning in a first direction one leg of a channel to determine its integrity, later scanning in a second direction another leg of the same channel to determine its integrity, and subsequently scanning across both legs to determine the condition of the sensor.
Claim 2
Independent Claim
69 words
The method of sensing conditions in a system including sensors and also including channels having legs communicating with each of the sensors comprising the steps of scanning in a first direction one leg of a channel to determine its integrity, later scanning in a second direction another leg of the same channel to determine its integrity, and subsequently scanning across both legs to determine the condition of the sensor.
Claim 3
Dependent Claim
144 words
A condition sensing system including at least one open circuit type environmental sensor having at least two terminals, means for sensing the status of said sensor and including at least two inputs and two outputs, a first conductor extending over a first path from a first of said inputs to a terminal on said sensor and thence by way of a second path to a first of said outputs, a second conductor extending over said second path from a second of said inputs to another of said terminals on said sensor and thence by way of said first path to a second of said outputs, and means for intermittently energizing said first output to sense at said first input the continuity of said first conductor and for intermittently energizing said second output to sense at said second input the continuity of said second conductor.
Claim 4
Dependent Claim
144 words
A condition sensing system including at least one open circuit type environmental sensor having at least two terminals, means for sensing the status of said sensor and including at least two inputs and two outputs, a first conductor extending over a first path from a first of said inputs to a terminal on said sensor and thence by way of a second path to a first of said outputs, a second conductor extending over said second path from a second of said inputs to another of said terminals on said sensor and thence by way of said first path to a second of said outputs, and means for intermittently energizing said first output to sense at said first input the continuity of said first conductor and for intermittently energizing said second output to sense at said second input the continuity of said second conductor.
Claim 5
Dependent Claim
27 words
The system of claim 2 in which means is provided for intermittently energizing said first output to sense at said second input the condition of said sensor.
Claim 6
Dependent Claim
131 words
The system of claim 3 in which there are included third and fourth conductors, a second normally open environmental sensor having two terminals, said means for sensing the status including third and fourth inputs, said third conductor extending along said second path from said first output to a terminal of said second sensor and thence along said first path to said third input, said fourth conductor extending along said second path from said fourth input to another terminal of said second sensor and thence along said first path to said second output, and means for intermittently energizing said first output to sense at said third input the continuity of said third conductor and for intermittently energizing said second output to sense at said fourth input the continuity of said fourth conductor.
Claim 7
Dependent Claim
28 words
The system of claim 4 in which means is provided for intermittently energizing said first output to sense at said fourth input the condition of said second sensor.
Claim 8
Dependent Claim
131 words
The system of claim 3 in which there are included third and fourth conductors, a second normally open environmental sensor having two terminals, said means for sensing the status including third and fourth outputs, said third conductor extending along said second path from said third output to a terminal of said second sensor and thence along said first path to said first input, said fourth conductor extending along said first path from said fourth output to another terminal of said second sensor and thence along said second path to said second input, and means for intermittently energizing said third output to sense at said first input the continuity of said third conductor and for intermittently energizing said fourth output to sense at said second input the continuity of said fourth conductor.
Claim 9
Dependent Claim
42 words
The system of claim 5 including means for storing representations of sensor conditions, and means responsive to the complete scan of inputs associated with the last output to be turned on for scanning the representations to provide an indication of alarm conditions.
Claim 10
Dependent Claim
31 words
The system of claim 4 wherein the number of pairs of conductors, inputs, and outputs bears the relationship: Z=(XY)/4 where: Z=number of pairs of conductors, X=number of inputs, Y=number of outputs.
Claim 11
Dependent Claim
25 words
The system of claim 5 wherein isolating diodes are connected in series with each conductor at its connection to an input and to an output.
Claim 12
Dependent Claim
42 words
The system of claim 9 including means for storing representations of sensor conditions, and means responsive to the complete scan of inputs associated with the last output to be turned on for scanning the representations to provide an indication of alarm conditions.
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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) | 1984-02-24 | 1984-08-25 | 1985-02-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-02-24 | 1988-08-25 | 1989-02-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-02-24 | 1992-08-25 | 1993-02-24 | $7700.00 | Window Closed / Lapsed |