US3558998A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Reversible polarity universal electrical discharge machining power supply with current cut-off
Assignee: Amsted Industries Inc
•
Filing: 1968-05-07
•
Granted: 1971-01-26
•
Expires: 1988-05-07
Abstract
Abstract A REVERSIBLE POLARITY ELECTRICAL DISCHARGE MACHINING POWER SUPPLY WHICH IS SELECTIVELY OPERABLE IN A CAPACITOR DISCHARGE-TYPE OR A PULSE-TYPE MODE FOR PROVIDING MACHINING DISCHARGES THROUGH ONE OR MORE IONIZABLE GAPS EACH OF WHICH IS DEFINE BETWEEN A RESPECTIVE ELECTRODE AND A WORKPIECE. FOR EACH OF THE ELECTRODES THERE IS A PAIR OF OPPOSITELY POLARIZED POWER SWITCHES TO INTERMITTENTLY PROVIDE CURRENT FLOW BETWEEN THE ELECTRODE AND A POWER SOURCE, AND FOR EACH OF THE POWER SWITCHES THERE IS A CURRENT CUT-OFF CIRCUIT TO INTERRUPT AN EXCESSIVE CURRENT FLOW THERETHROUGH WITHOUT AFFECTING THE OPERATION OF THE OTHER POWER SWITCHES.
Inventors
- 👤 Robert B Bertolasi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 22:22
CPC Classifications
B; B23; B23H; B23H1/00; B23H1/02
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-01-25 | 1974-07-27 | 1975-01-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-01-25 | 1978-07-27 | 1979-01-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-01-25 | 1982-07-27 | 1983-01-26 | $7700.00 | Window Closed / Lapsed |