Issued Patents All Time
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 7090771 | Filtration system underdrain | John Dyson, Harold W. Johnson, Louis U. Brittingham, Jr., Gregory Matanoski | 2006-08-15 |
| 6921481 | Automatic backwash filter system | Harold W. Johnson | 2005-07-26 |