Issued Patents All Time
Showing 1–3 of 3 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 5880440 | Electrical coil insulator | Charles T. Whitfield, Ronald R. Barnes, Herbert G. Ray | 1999-03-09 |
| 4900897 | Sheathed electric heating element assembly | Donald M. Cunningham, Mark A. Bartels | 1990-02-13 |
| 4687905 | Electric immersion heating element assembly for use with a plastic water heater tank | Donald M. Cunningham, Mark A. Bartels | 1987-08-18 |