Issued Patents All Time
Showing 1–4 of 4 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4969670 | Large diameter corrugated plastic pipe | James L. Fouss | 1990-11-13 |
| 4946206 | Bidirectional corrugated pipe-rib seal | Stephen L. Roe, John L. Seehausen | 1990-08-07 |
| 4913473 | Large diameter double-walled plastic pipe | James L. Fouss | 1990-04-03 |
| 4726490 | Safety lid | Donald J. Smith | 1988-02-23 |