Issued Patents All Time
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 5984668 | Sparking device for promoting avoidance of short-circuiting | David L. Hansen | 1999-11-16 |
| 5924821 | Apparatus and method for gas and/or liquid exchange between an area outside and an area inside a bulk material pile | David L. Hansen | 1999-07-20 |