Issued Patents All Time
Showing 1–3 of 3 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4991893 | Manhole cover lifting device | Russell B. Gordon, Bill Beach | 1991-02-12 |
| 4982653 | Method and apparatus for ventilating an enclosure accessed by a manhole | Russell B. Gordon, Marion W. Smith | 1991-01-08 |
| 4794956 | Air conduit for manhole | Russell B. Gordon, Marion W. Smith | 1989-01-03 |