Issued Patents All Time
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4515832 | Method for coating the inside of pipe | William J. Siefert, Frederik Theijsmeijer | 1985-05-07 |
| 4262627 | Apparatus for coating the inside of pipe | William J. Siefert, Frederik Theijsmeijer | 1981-04-21 |