US4090177A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Early fire compound sensing system and apparatus
Assignee: Yuwa Industries Co Ltd
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Filing: 1976-12-10
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Granted: 1978-05-16
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Expires: 1996-12-10
Abstract
Abstract An early fire product sensing system and apparatus has at least one earlier fire stage sensor and at least one later fire stage sensor. At least two of such sensors are coupled so that the earlier stage sensor output raises the sensitivity of the later stage sensor. The system is characterized by reducing the fire sensing period without reducing the sensing accuracy.
Inventors
- 👤 Kenrokuro Urata
- 👤 Yoshiyuki Sasai
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 20:05
CPC Classifications
G; G08; G08B; G08B17/00; G08B17/10; G08B17/117; G08B17/06
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
77 words
A fire sensing system comprising at least one first sensor providing an output responsive to an early fire stage at least one second sensor providing an alarm output responsive to a later fire stage, each such second sensor having a variable sensitivity and a coupling means therebetween enabling the output of any of said first sensors to raise the sensitivities of said second sensor, characterised by elevation of the overall sensitivity of said system with minimum errors.
Claim 2
Dependent Claim
77 words
A fire sensing system comprising at least one first sensor providing an output responsive to an early fire stage at least one second sensor providing an alarm output responsive to a later fire stage, each such second sensor having a variable sensitivity and a coupling means therebetween enabling the output of any of said first sensors to raise the sensitivities of said second sensor, characterised by elevation of the overall sensitivity of said system with minimum errors.
Claim 3
Dependent Claim
77 words
A fire sensing apparatus comprising at least one first sensor providing an output responsive to an early fire stage at least one second sensor providing an alarm output responsive to a later fire stage, each such second sensor having a variable sensitivity and a coupling means therebetween enabling the output of any of said first sensors to raise the sensitivities of said second sensor characterised by elevation of the overall sensitivity of said apparatus with minimum errors.
Claim 4
Dependent Claim
77 words
A fire sensing apparatus comprising at least one first sensor providing an output responsive to an early fire stage at least one second sensor providing an alarm output responsive to a later fire stage, each such second sensor having a variable sensitivity and a coupling means therebetween enabling the output of any of said first sensors to raise the sensitivities of said second sensor characterised by elevation of the overall sensitivity of said apparatus with minimum errors.
Claim 5
Independent Claim
90 words
A method for sensing fire comprising the steps of sensing in a first sensor an early fire stage and providing a first output responsive thereto, sensing in a second sensor having an input for controlling the sensitivity thereof a later fire stage and providing a second output responsive thereto for sounding an alarm; and coupling the output of said first sensor to the sensitivity control input of said second sensor for raising the sensitivity of said second sensor upon the sensing of an early fire stage by said first sensor.
Claim 6
Independent Claim
90 words
A method for sensing fire comprising the steps of sensing in a first sensor an early fire stage and providing a first output responsive thereto, sensing in a second sensor having an input for controlling the sensitivity thereof a later fire stage and providing a second output responsive thereto for sounding an alarm; and coupling the output of said first sensor to the sensitivity control input of said second sensor for raising the sensitivity of said second sensor upon the sensing of an early fire stage by said first sensor.
References Cited (Backward Citations)
US4027302A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-05-15 | 1981-11-14 | 1982-05-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-05-15 | 1985-11-14 | 1986-05-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-05-15 | 1989-11-14 | 1990-05-16 | $7700.00 | Window Closed / Lapsed |