Issued Patents All Time
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 5006144 | Melting glass with oxidation control and lowered emissions | Leonard A. Knavish | 1991-04-09 |
| 4544396 | Method and apparatus for controlling currents in glass melter | John F. Krumwiede, William G. Hilliard, James E. Harris | 1985-10-01 |
| 4536205 | Method for controlling currents in glass melter | John F. Krumwiede, William G. Hilliard, James E. Harris | 1985-08-20 |