Patent US3371254A successfully refreshed from Google Patents.
US3371254A
Expired / Lapsed
US
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Safety control system
Assignee: HAROLD T HAGFORS
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Filing: 1965-10-01
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Granted: 1968-02-27
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Expires: 1985-10-01
Abstract
No abstract record available.
Inventors
- 👤 Harold T Hagfors
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 09:49
CPC Classifications
F; F16; F16P; F16P3/00; F16P3/18; F16P3/20
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
114 words
A SAFETY CONTROL SYSTEM COMPRISING A MAIN CIRCUIT AND A CONTROL CIRCUIT THEREFOR, SWITCH MEANS IN SAID MAIN CIRCUIT FOR ACTUATING A LOAD, SAID SWITCH MEANS INCLUDING A FIRST MANUALLY OPERATED SWITCH AND A CONTROL RELAY HAVING ITS COIL CONNECTED IN SAID CONTROL CIRCUIT, A SECOND MANUALLY OPERATED SWITCH IN SAID CONTROL CIRCUIT FOR ENERGIZING SAID CONTROL RELAY, A TRANSISTOR CONNECTED IN SERIES WITH THE COIL OF SAID CONTROL RELAY TO PERMIT CURRENT TO FLOW THEREIN WHEN SAID TRANSISTOR CONDUCTS, AND MEANS FOR BIASING SAID TRANSISTOR TO CONDUCT UPON ACTUATION OF EITHER OF SAID MANUALLY OPERATED SWITCHES AND FOR BIASING SAID TRANSISTOR OUT OF CONDUCTION UPON THE EXPIRATION OF A PREDETERMINED TIME INTERVAL THEREAFTER.
Claim 2
Dependent Claim
114 words
A SAFETY CONTROL SYSTEM COMPRISING A MAIN CIRCUIT AND A CONTROL CIRCUIT THEREFOR, SWITCH MEANS IN SAID MAIN CIRCUIT FOR ACTUATING A LOAD, SAID SWITCH MEANS INCLUDING A FIRST MANUALLY OPERATED SWITCH AND A CONTROL RELAY HAVING ITS COIL CONNECTED IN SAID CONTROL CIRCUIT, A SECOND MANUALLY OPERATED SWITCH IN SAID CONTROL CIRCUIT FOR ENERGIZING SAID CONTROL RELAY, A TRANSISTOR CONNECTED IN SERIES WITH THE COIL OF SAID CONTROL RELAY TO PERMIT CURRENT TO FLOW THEREIN WHEN SAID TRANSISTOR CONDUCTS, AND MEANS FOR BIASING SAID TRANSISTOR TO CONDUCT UPON ACTUATION OF EITHER OF SAID MANUALLY OPERATED SWITCHES AND FOR BIASING SAID TRANSISTOR OUT OF CONDUCTION UPON THE EXPIRATION OF A PREDETERMINED TIME INTERVAL THEREAFTER.
References Cited (Backward Citations)
US2962633A
Cited
US3260898A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1971-02-26 | 1971-08-28 | 1972-02-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1975-02-26 | 1975-08-28 | 1976-02-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1979-02-26 | 1979-08-28 | 1980-02-27 | $7700.00 | Window Closed / Lapsed |