摘要 |
<p>The drive system for a motorised door (10) includes a drive (15) to move an associated door between open and closed positions, a disk (21) mounted for rotation by the drive means, the disk having multiple indicia (25) located at equal angular displacements around the axis of rotation of the disk, sensing means (30) for sensing the rotational movement of the disk by detecting passing of each successive indicium and for generating signals indicative of such rotational, movement, and a drive control (40) responsive to the signals from the sensing means and operative to monitor the rotational movement of the disk and<i/</p> |