Issued Patents 1989
Showing 1–1 of 1 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4833697 | Writing instrument for electronic counting and gravity switch reset | Fred P. Perna | 1989-05-23 |
Showing 1–1 of 1 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4833697 | Writing instrument for electronic counting and gravity switch reset | Fred P. Perna | 1989-05-23 |