Issued Patents All Time
Showing 1–23 of 23 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 6167329 | Dual microprocessor electronic trip unit for a circuit interrupter | Joseph C. Engel, Richard A. Johnson | 2000-12-26 |
| 5627718 | Apparatus providing protection and metering in an ac electrical system utilizing a multi-function sampling technique | Joseph C. Engel, Richard A. Johnson | 1997-05-06 |
| 5600527 | Circuit interrupter providing protection and waveform capture for harmonic analysis | Joseph C. Engel, Richard A. Johnson | 1997-02-04 |
| 5559719 | Digitally controlled circuit interrupter with improved automatic selection of sampling interval for 50 Hz and 60 Hz power systems | Richard A. Johnson, Joseph C. Engel, Alan B. Shimp | 1996-09-24 |
| 5493468 | Electrical contactor system with transfer of scaled overload information | Patrick J. Hunter, Robert T. Elms, Denis A. Mueller | 1996-02-20 |
| 5428495 | Electrical switching apparatus with digital trip unit and automatic frequency selection | William J. Murphy, Joseph C. Engel, Alan B. Shimp | 1995-06-27 |
| 5367427 | Overcurrent trip unit with indication of dependency of trip functions | Joseph J. Matsko | 1994-11-22 |
| 5325315 | Process for auto calibration of a microprocessor based overcurrent protective device and apparatus | Joseph C. Engel, Marlan L. Winter, Edward C. Prather | 1994-06-28 |
| 5050172 | Microcomputer controlled electric contactor with power loss memory | Robert T. Elms | 1991-09-17 |
| 4940391 | Compressor surge detection system | Robert T. Elms, Clyde O. Peterson | 1990-07-10 |
| 4827369 | Circuit interrupter apparatus with a selectable display means | Joseph J. Matsko | 1989-05-02 |
| 4819118 | Electromagnetic contactor tandem control system for thermal protection of a bidirectional motor drive | Denis A. Mueller | 1989-04-04 |
| 4809125 | Circuit interrupter apparatus with a style saving rating plug | Joseph J. Matsko | 1989-02-28 |
| 4794484 | Circuit interrupter apparatus with a style saving override circuit | Joseph J. Matsko, William E. Beatty, Jr., Raymond O. D. Whitt | 1988-12-27 |
| 4757420 | Electromagnetic contactor with wide range overload current relay board utilizing left shifting and method | Joseph C. Engel, John Leddy | 1988-07-12 |
| 4751606 | Circuit interrupter apparatus with a battery backup and reset circuit | Joseph J. Matsko | 1988-06-14 |
| 4734639 | Master metering module with voltage selector | Daniel P. Orange, Joseph C. Engel, Denis A. Mueller, Robert T. Elms | 1988-03-29 |
| 4720761 | Electromagnetic contactor with current regulated electromagnetic coil for holding the contacts closed | Joseph C. Engel, John Leddy | 1988-01-19 |
| 4525650 | Starting and operating method and apparatus for discharge lamps | John M. Hicks, Joseph C. Engel, Robert J. Spreadbury, Robert T. Elms | 1985-06-25 |
| 4476511 | Circuit interrupter with front panel numeric display | Robert T. Elms, Joseph C. Engel | 1984-10-09 |
| 4377836 | Circuit interrupter with solid state digital trip unit and positive power-up feature | Robert T. Elms, Bernard Mercier | 1983-03-22 |
| 4351012 | Circuit interrupter with digital trip unit and means to enter trip settings | Robert T. Elms, Joseph C. Engel, Bernard Mercier, John T. Wilson | 1982-09-21 |
| 4331999 | Circuit interrupter with digital trip unit and power supply | Joseph C. Engel, John A. Wafer, Robert T. Elms | 1982-05-25 |