Issued Patents All Time
Showing 1–9 of 9 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4730767 | Letter sheet with return envelope | — | 1988-03-15 |
| 4730768 | Remailable envelope | — | 1988-03-15 |
| 4597591 | Envelope with concealed message window | Frank T. Knapp | 1986-07-01 |
| 4579277 | Detachable tip-on envelope | — | 1986-04-01 |
| 4566627 | Tamper detection envelope | — | 1986-01-28 |
| 4487360 | Two way envelope | Harland S. Fisher, Gregory Georgiades | 1984-12-11 |
| 4462538 | Door hanger envelope | — | 1984-07-31 |
| 4294400 | Non-gusseted expansible envelope | — | 1981-10-13 |
| 4190161 | Compartmented envelope | — | 1980-02-26 |