US3089985A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Safety circuit
Assignee: AT&T Inc
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Filing: 1960-10-27
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Granted: 1963-05-14
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Expires: 1980-10-27
Abstract
No abstract record available.
Inventors
- 👤 Eugene J Camfield
- 👤 William E Hauschild
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 15:47
CPC Classifications
F; F16; F16P; F16P3/00; F16P3/18; F16P3/20
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
195 words
ELECTRICAL CIRCUITRY FOR ACTUATING A LOAD DEVICE ONLY UPON SUBSTANTALLY SIMULTANEOUS ACTUATION OF TWO MANUALLY OPERABLE SWITCHES, COMPRISING TWO CONTROL CIRCUITS AND AN ASSOCIATED OUTPUT CIRCUIT, EACH OF SAID CONTROL CIRCUITS INCLUDING A CONTROL RELAY AND A TIME DELAY REALY ARRANGED IN PARALLEL, AND A NORMALLY OPEN MANUALLY CLOSABLE SWITCH ARRANGED IN SERIES WTH SAID RELAYS, EACH OF SAID TIME DELAY RELAYS HAVING NORMALLY CLOSED SWITCH CONTACTS ARRANGED IN SERIES WITH THE MANUALLY OPERABLE SWITCH AND THE RELAYS OF THE OTHER CONTROL CIRCUIT, WHEREBY EACH TIME DELAY RELAY, A PRESCRIBED PERIOD OF TIME AFTER CLOSING OF THE ASSOCIATED MANUALLY OPERABLE SWITCH, MAY PREVENT COMPLETION OF THE OTHER CONTROL CIRCUIT, EACH OF SAID CONTROL RELAYS HAVING NORMALLY OPEN SWITCH CONTACTS ARRANGED, WHEN CLOSED, TO BYPASS SAID TIME DELAY RELAY SWITCH CONTACTS OF ITS OWN CONTROL CIRCUIT, WHEREBY ACTUATION OF ONE OF SAID TIME DELAY RELAYS MAY NOT OPEN THE OTHER CONTROL CIRCUIT AFTER ACTUATION OF THE CONTROL RELAY THEREOF, SAID OUTPUT CIRCUIT INCLUDING, INSERIES ARRANGEMENT, A LOAD DEVICE AND TWO NORMALLY OPEN SWITCHES, EACH OF SAID SWITCHES BEING ASSOCIATED WITH ONE OF SAID CONTROL CIRCUITS AND BEING CLOSABLE BY ACTUATION OF ONE OF THE RELAYS THEREOF.
Claim 2
Dependent Claim
195 words
ELECTRICAL CIRCUITRY FOR ACTUATING A LOAD DEVICE ONLY UPON SUBSTANTALLY SIMULTANEOUS ACTUATION OF TWO MANUALLY OPERABLE SWITCHES, COMPRISING TWO CONTROL CIRCUITS AND AN ASSOCIATED OUTPUT CIRCUIT, EACH OF SAID CONTROL CIRCUITS INCLUDING A CONTROL RELAY AND A TIME DELAY REALY ARRANGED IN PARALLEL, AND A NORMALLY OPEN MANUALLY CLOSABLE SWITCH ARRANGED IN SERIES WTH SAID RELAYS, EACH OF SAID TIME DELAY RELAYS HAVING NORMALLY CLOSED SWITCH CONTACTS ARRANGED IN SERIES WITH THE MANUALLY OPERABLE SWITCH AND THE RELAYS OF THE OTHER CONTROL CIRCUIT, WHEREBY EACH TIME DELAY RELAY, A PRESCRIBED PERIOD OF TIME AFTER CLOSING OF THE ASSOCIATED MANUALLY OPERABLE SWITCH, MAY PREVENT COMPLETION OF THE OTHER CONTROL CIRCUIT, EACH OF SAID CONTROL RELAYS HAVING NORMALLY OPEN SWITCH CONTACTS ARRANGED, WHEN CLOSED, TO BYPASS SAID TIME DELAY RELAY SWITCH CONTACTS OF ITS OWN CONTROL CIRCUIT, WHEREBY ACTUATION OF ONE OF SAID TIME DELAY RELAYS MAY NOT OPEN THE OTHER CONTROL CIRCUIT AFTER ACTUATION OF THE CONTROL RELAY THEREOF, SAID OUTPUT CIRCUIT INCLUDING, INSERIES ARRANGEMENT, A LOAD DEVICE AND TWO NORMALLY OPEN SWITCHES, EACH OF SAID SWITCHES BEING ASSOCIATED WITH ONE OF SAID CONTROL CIRCUITS AND BEING CLOSABLE BY ACTUATION OF ONE OF THE RELAYS THEREOF.
References Cited (Backward Citations)
US2753493A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1966-05-13 | 1966-11-12 | 1967-05-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1970-05-13 | 1970-11-12 | 1971-05-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1974-05-13 | 1974-11-12 | 1975-05-14 | $7700.00 | Window Closed / Lapsed |