US4727359A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Analog fire sensor
Assignee: Hochiki Corp
•
Filing: 1986-03-28
•
Granted: 1988-02-23
•
Expires: 2006-03-28
Abstract
Abstract An analog fire detecting system in which a plurality of sensors produce analog data corresponding to a physical state such as temperature, smoke density, etc. relevant to a fire condition. The values of such analog data are compared with a predetermined threshold level, and if the threshold level is exceeded the analog data is transmitted to a central station in response to a polling signal therefrom. A CPU in the central station determines, from the analog data from the sensors, if there is a possibility of a fire and if so makes a predictive calculation of the remaining time until a fire condition will be reached. An alarm is given when such predicted time falls below a preset interval.
Inventors
- 👤 Sadataka Yuchi
- 👤 Masaki Maruyama
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 07:54
CPC Classifications
G; G08; G08B; G08B26/00; G08B26/001; G08B26/002
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
111 words
A fire detection system for detecting a fire condition in any of a plurality of supervised regions, comprising: a plurality of sensors respectively located in such regions and which produce analog data corresponding to a physical state relevant to a fire condition, each such sensor transmitting the analog data produced thereby in response to a polling signal received thereby only if such data exceeds a predetermined threshold level; and a central signal station adapted to poll said sensors sequentially and to receive the analog data transmitted thereby, and which makes a predictive calculation of the time remaining until outbreak of a fire on the basis of the analog data so received.
Claim 2
Dependent Claim
111 words
A fire detection system for detecting a fire condition in any of a plurality of supervised regions, comprising: a plurality of sensors respectively located in such regions and which produce analog data corresponding to a physical state relevant to a fire condition, each such sensor transmitting the analog data produced thereby in response to a polling signal received thereby only if such data exceeds a predetermined threshold level; and a central signal station adapted to poll said sensors sequentially and to receive the analog data transmitted thereby, and which makes a predictive calculation of the time remaining until outbreak of a fire on the basis of the analog data so received.
Claim 3
Dependent Claim
51 words
A fire detection system as claimed in claim 1, wherein each of said sensors comprises a data signal transmission section for transmitting the analog data and a calling discriminating section which enables the transmission section to transmit the analog data when a polling signal is received from the central signal station.
Claim 4
Dependent Claim
46 words
A fire detection system as claimed in claim 1, in which the central signal station comprises a CPU for making the predictive fire calculation, and does not initiate such calculation for analog data received from a sensor unless such data exceeds a predetermined calculation starting level.
Claim 5
Dependent Claim
22 words
A fire detection system as claimed in claim 3, in which said sensor threshold level is lower than said calculation starting time.
Claim 6
Dependent Claim
87 words
An analog fire sensor for use in a fire detection system as claimed in claim 1, comprising: an analog sensor section for producing analog data corresponding to the magnitude of a physical state relevant to a fire condition; a comparing section for comparing the value of the analog data output from the analog sensor section with a predetermined sensor threshold level; and a data signal transmission section for transmitting the analog data in response to a polling signal received thereby when such data exceeds said threshold level.
Claim 7
Dependent Claim
60 words
An analog fire sensor as claimed in claim 5, further comprising an average calculating section which samples the analog data at a predetermined sampling period and calculates the average value of the sampled data; and wherein said signal transmission section transmits the average sampled data in response to a polling signal only when such average exceeds said predetermined threshold level.
Claim 8
Dependent Claim
25 words
An analog fire sensor as claimed in claim 6, wherein said average calculating section sequentially calculates the moving average values of the sampled analog data.
Claim 9
Dependent Claim
26 words
An analog fire sensor as claimed in claim 7, wherein said average calculating section further calculates a simple average value from the plural moving average values.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-02-22 | 1991-08-24 | 1992-02-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-02-22 | 1995-08-24 | 1996-02-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-02-22 | 1999-08-24 | 2000-02-23 | $7700.00 | Window Closed / Lapsed |