Issued Patents 1989
Showing 1–6 of 6 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4881083 | Homing technique for an in-ground boring device | John E. Mercer | 1989-11-14 |
| 4867255 | Technique for steering a downhole hammer | Glen Baker, Dmitry Feldman, Shiu S. Ng, John E. Mercer | 1989-09-19 |
| 4864293 | Inground boring technique including real time transducer | — | 1989-09-05 |
| 4856600 | Technique for providing an underground tunnel utilizing a powered boring device | Glen Baker, James A. Fikse, John E. Mercer | 1989-08-15 |
| 4821815 | Technique for providing an underground tunnel utilizing a powered boring device | Glen Baker, James A. Fikse, John E. Mercer | 1989-04-18 |
| 4806869 | An above-ground arrangement for and method of locating a discrete in ground boring device | John E. Mercer | 1989-02-21 |