Issued Patents All Time
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4384624 | Earth boring head | John A. Duke | 1983-05-24 |
| 4306626 | Hydraulic earth boring machine | John A. Duke | 1981-12-22 |
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4384624 | Earth boring head | John A. Duke | 1983-05-24 |
| 4306626 | Hydraulic earth boring machine | John A. Duke | 1981-12-22 |