Issued Patents All Time
Showing 1–1 of 1 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4924512 | Method and apparatus for preventing recognition of a telephone dialing signal | Rudolf Gerritsen | 1990-05-08 |
Showing 1–1 of 1 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4924512 | Method and apparatus for preventing recognition of a telephone dialing signal | Rudolf Gerritsen | 1990-05-08 |