Issued Patents All Time
Showing 26–29 of 29 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4905490 | Lock combination decoder | — | 1990-03-06 |
| 4722866 | Fire resistant gypsum board | Charles W. Lehnert | 1988-02-02 |
| 4664707 | Fire resistant gypsum composition | Charles W. Lehnert | 1987-05-12 |
| 4433563 | Lock decoder | — | 1984-02-28 |