Issued Patents All Time
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| RE33690 | Level sensor | Harold P. Adams, Jr., Andrew B. Maitland, David R. Hill, Lee M. Richey, David Taylor | 1991-09-17 |
| 4747451 | Level sensor | Harold P. Adams, Jr., David R. Hill, Lee M. Richey, Andrew B. Maitland, David Taylor | 1988-05-31 |