Issued Patents All Time
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 6080981 | Apparatus for controlling the operation of a door movable in a door opening to prevent contact between the door and an obstruction in the door opening | — | 2000-06-27 |
| 5424717 | Laser light transmitter and proximity detector | Terence Christopher Platt | 1995-06-13 |
| 5075632 | Automatic control using proximity sensors | Terence Christopher Platt | 1991-12-24 |
| 4506765 | Proximity detector circuitry especially for lift doors | John Trett | 1985-03-26 |
| 4427095 | Monitoring and controlling lift positions | John Trett | 1984-01-24 |