US3421156A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Self-checking detector
Assignee: TECHNICAL MARKETING ASSOCIATES
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Filing: 1964-12-18
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Granted: 1969-01-07
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Expires: 1984-12-18
Abstract
No abstract record available.
Inventors
- 👤 William G Rowell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 22:37
CPC Classifications
F; F23; F23N; F23N5/00; F23N5/02; F23N5/08; F23N5/082; F23N5/24; F23N5/242; G; G07; G07C; G07C3/00; G07C3/005; G08; G08B; G08B23/00; G08B29/00; G08B29/02; G08B29/04; F23N2227/00; F23N2227/12; F23N2227/18; F23N2231/00; F23N2231/10
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
119 words
A CONDITION MONITORING APPARATUS COMPRISING A SINGLE POLE DOUBLE THROW RELAY, A DC POWER SOURCE AND A PHOTOTRANSISTOR HAVING ITS COLLECTOR SERIES CONNECTED THROUGH THE RELAY COIL TO THE NEGATIVE TERMINAL OF THE POWER SOURCE, ITS EMITER CONNECTED TO THE POSITIVE TERMINAL OF THE POWER SOURCE AND ITS BASE CONNECTED TO A NORMALLY OPEN CONTACT OF THE RELAY SUCH THAT UPON APPLICATION OF ENERGY CAUSING SAID PHOTOTRANSISTOR TO REDUCE ITS INTERNAL RESISTANCE AND RELAY COIL CLOSES SAID CONTACT AND APPLIES A POSITIVE VOLTAGE PULSE TO SAID BASE SHUTTING OFF SAID PHOTOTRANSISTOR AND INCREASING ITS INTERNAL RESISTANCE WHICH IN TURN OPENS SAID CONTACT WHEREBY THE DESCRIBED CYCLE CONTINUES TO REPEAT SO LONG AS SAID ENERGY IS APPLIED TO SAID PHOTOTRANSISTOR.
Claim 2
Dependent Claim
119 words
A CONDITION MONITORING APPARATUS COMPRISING A SINGLE POLE DOUBLE THROW RELAY, A DC POWER SOURCE AND A PHOTOTRANSISTOR HAVING ITS COLLECTOR SERIES CONNECTED THROUGH THE RELAY COIL TO THE NEGATIVE TERMINAL OF THE POWER SOURCE, ITS EMITER CONNECTED TO THE POSITIVE TERMINAL OF THE POWER SOURCE AND ITS BASE CONNECTED TO A NORMALLY OPEN CONTACT OF THE RELAY SUCH THAT UPON APPLICATION OF ENERGY CAUSING SAID PHOTOTRANSISTOR TO REDUCE ITS INTERNAL RESISTANCE AND RELAY COIL CLOSES SAID CONTACT AND APPLIES A POSITIVE VOLTAGE PULSE TO SAID BASE SHUTTING OFF SAID PHOTOTRANSISTOR AND INCREASING ITS INTERNAL RESISTANCE WHICH IN TURN OPENS SAID CONTACT WHEREBY THE DESCRIBED CYCLE CONTINUES TO REPEAT SO LONG AS SAID ENERGY IS APPLIED TO SAID PHOTOTRANSISTOR.
References Cited (Backward Citations)
US2798213A
Cited
US3202976A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1972-01-07 | 1972-07-08 | 1973-01-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1976-01-07 | 1976-07-08 | 1977-01-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1980-01-07 | 1980-07-08 | 1981-01-07 | $7700.00 | Window Closed / Lapsed |