Issued Patents All Time
Showing 1–8 of 8 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 5639384 | Apparatus and method for improving gas backwash in lateral underdrains | Eugen O. Bergmann, Richard Hsieh | 1997-06-17 |
| 5489388 | Apparatus and method for improving gas backwash in lateral underdrains | Eugen O. Bergmann, Richard Hsieh | 1996-02-06 |
| 5328608 | Mutli-lateral filter underdrain block | Eugen O. Bergmann | 1994-07-12 |
| 5269920 | Cap system for underdrains in gravity filters | Richard P. Beverly | 1993-12-14 |
| 5232592 | Cap for underdrains in gravity filters | Gerald D. Wolfe, Richard P. Beverly | 1993-08-03 |
| 5160614 | Air duct block for air/water underdrain systems in gravity filters | — | 1992-11-03 |
| 5149427 | Cap for underdrains in gravity filters | Gerald D. Wolfe, Richard P. Beverly | 1992-09-22 |
| 5087362 | Flume distribution system with removable block | — | 1992-02-11 |