Issued Patents All Time
Showing 1–8 of 8 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 5899629 | Manhole | Martin C. Pettesch | 1999-05-04 |
| 5785452 | Manhole | Martin C. Pettesch | 1998-07-28 |
| 5511898 | Moveable manhole cover | Martin C. Pettesch, Michael P. Breheny, Christopher M. Andrews, Thomas G. Nelson | 1996-04-30 |
| D321928 | Combination ball valve and check valve | — | 1991-11-26 |
| D306482 | Manhole cover | — | 1990-03-06 |
| 4706718 | Containment manhole having spillage sealing means | — | 1987-11-17 |
| D284887 | Offset coupling | — | 1986-07-29 |
| 4194530 | Restrictive vent | — | 1980-03-25 |