Issued Patents 1989
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4888089 | Process of making an electrical resistance device | John A. Marstiller, Frederick G. J. Grise | 1989-12-19 |
| 4849255 | Electric resistance heater | Frederick G. J. Grise, John A. Martstiller | 1989-07-18 |