US3246311A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for fire detection and alarm
Assignee: Westinghouse Electric Corp
•
Filing: 1962-05-09
•
Granted: 1966-04-12
•
Expires: 1982-05-09
Abstract
No abstract record available.
Inventors
- 👤 Edgar A Sack
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 16:29
CPC Classifications
G; G08; G08B; G08B17/00; G08B17/06
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
113 words
FIRE ALARM APPARATUS RESPONSIVE TO AMBIENT TEMPERATURE COMPRISING, IN COMBINATION; AN ELECTROAUDIO TRANSDUCER HAVING AN INDUCTANCE ELEMENT; A TUNNEL DIODE; TEMPERATURE GRADIENT RESPONSIVE POWER SUPPLY MEANS AND A PAIR OF HEAT SINKS DISPOSED AT A DISTANCE APART, SAID POWER SUPPLY MEANS BEING DISPOSED BETWEEN SAID PAIR OF HEAT SINKS TO SENSE THE AMBIENT TEMPERATURE DIFFERENTIAL THEREBETWEEN; A SERIES OF CIRCUIT COMBINATION INCLUDING SAID INDUCTANCE ELEMENT, SAID TUNNEL DIODE AND SAID POWER SUPPLY MEANS; SAID CIRCUIT COMBINATION HAVING AN EFFECTIVE POSITIVE RESISTANCE MAGNITUDE GREATER THAN THE NEGATIVE RESISTANCE MAGNITUDE OF SAID TUNNEL DIODE SO THAT SAID CIRCUIT COMBINATION WILL OSCILLATE TO ACTIVATE SAID TRANSDUCER WHEN A PREDETERMINED TEMPERATURE DIFFERENTIAL EXISTS BETWEEN SAID HEAT SINKS.
Claim 2
Dependent Claim
113 words
FIRE ALARM APPARATUS RESPONSIVE TO AMBIENT TEMPERATURE COMPRISING, IN COMBINATION; AN ELECTROAUDIO TRANSDUCER HAVING AN INDUCTANCE ELEMENT; A TUNNEL DIODE; TEMPERATURE GRADIENT RESPONSIVE POWER SUPPLY MEANS AND A PAIR OF HEAT SINKS DISPOSED AT A DISTANCE APART, SAID POWER SUPPLY MEANS BEING DISPOSED BETWEEN SAID PAIR OF HEAT SINKS TO SENSE THE AMBIENT TEMPERATURE DIFFERENTIAL THEREBETWEEN; A SERIES OF CIRCUIT COMBINATION INCLUDING SAID INDUCTANCE ELEMENT, SAID TUNNEL DIODE AND SAID POWER SUPPLY MEANS; SAID CIRCUIT COMBINATION HAVING AN EFFECTIVE POSITIVE RESISTANCE MAGNITUDE GREATER THAN THE NEGATIVE RESISTANCE MAGNITUDE OF SAID TUNNEL DIODE SO THAT SAID CIRCUIT COMBINATION WILL OSCILLATE TO ACTIVATE SAID TRANSDUCER WHEN A PREDETERMINED TEMPERATURE DIFFERENTIAL EXISTS BETWEEN SAID HEAT SINKS.
References Cited (Backward Citations)
US666737A
Cited
US856162A
Cited
US2429466A
Cited
US2857446A
Cited
US2854660A
Cited
US2929968A
Cited
US3071495A
Cited
US3041588A
Cited
US3050684A
Cited
US3005860A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1969-04-11 | 1969-10-11 | 1970-04-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1973-04-11 | 1973-10-11 | 1974-04-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1977-04-11 | 1977-10-11 | 1978-04-12 | $7700.00 | Window Closed / Lapsed |