Issued Patents All Time
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 6660199 | Pipe structure and method of manufacture | Roger Siferd, Matthew C. Ankrom | 2003-12-09 |
| 6565350 | Apparatus for forming a reinforcing structure on an end of a pipe | Roger Siferd, Matthew C. Ankrom | 2003-05-20 |
| 6199592 | Pipe structure and method of manufacture | Roger Siferd, Matthew C. Ankrom | 2001-03-13 |