Issued Patents All Time
Showing 1–4 of 4 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 5398783 | Elevator hall call device with integral indicator display element | — | 1995-03-21 |
| 5001459 | Escalator handrail guard warning device | David Steel | 1991-03-19 |
| 4647921 | Alphanumeric display | John C. Doane, Joe K. Koe | 1987-03-03 |
| 4261440 | Automatically compensating object detection circuit | — | 1981-04-14 |