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US3705969A Expired / Lapsed US ⏱️ 0.0 years remaining

Cut-off protection system for electrical discharge machining power supply

Assignee: Colt Industries Inc
•
Filing: 1971-11-08
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Granted: 1972-12-12
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Expires: 1991-11-08
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Abstract

Abstract A SHORT CIRCUIT PROTECTION SYSTEM WHICH INCLUDES A CUTOFF MEANS OPERABLY CONNECTED TO THE OUTPUT SWITCH FOR INTERRUPTING OR OTHERWISE CONTROLLING ITS OPERATION. A CUTOFF MEANS RECIEVES ITS CONTROL SIGNAL AS THE RESULT OF A CONPARISON OF A GAP VOLTAGE SIGNAL FROM ONE OF THE GAP ELEMENTS AND A FLOATING REFERENCE VOLTAGE SIGNAL DERIVED FROM THE OTHER GAP ELEMENT WITH THE CUT-OFF MEANS BEING ACTIVATED RESPONSIVE TO A PREDETERMINED DIFFERENCE BETWEEN THESE SIGNALS. THE REFERENCE VOLTAGE NETWORK IS THUS CONNECTED DIRECTLY TO ONE OF THE GAP ELEMENTS AND INCLUDES A ZENER DIODE WITH ASSOCIATED POTENTIOMETER TO ALLOW ADJUSTING OF REFERENCE LEVEL. THE REFERENCE VOLTAGE ITSELF IS KEYED INTO OPERATION IN PHASE WITH THE OUTPUT SWITCH CONDUCTION AND THUS IN PHASE WITH EACH GAP DISCHARGE.

Inventors

  • 👤 Oliver A Bell Jr

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-02 15:52
CPC Classifications
B; B23; B23H; B23H1/00; B23H1/02; H; H02; H02H; H02H7/00

Claims Analysis

Total Claims: 0
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References Cited (Backward Citations)

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USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1975-12-12 1976-06-12 1976-12-12 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1979-12-12 1980-06-12 1980-12-12 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1983-12-12 1984-06-12 1984-12-12 $7700.00 Window Closed / Lapsed

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