Issued Patents All Time
Showing 1–3 of 3 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4842062 | Hydraulic lock alleviation device, well cementing stage tool, and related methods | David E. Schneider | 1989-06-27 |
| 4442736 | Power pipe tong rotary plunger inserter | Martin E. True | 1984-04-17 |
| 4437646 | Discharge valve for concrete pumping apparatus | David E. Bigelow | 1984-03-20 |