| 摘要 |
A gate (1) can be moved in front of an opening (3) in a wall along a lower guide track (2). The top of the gate is guided by an attachment to the central post (5). A motor (8) is mounted on a stand (9) in the centre of the track and its drive shaft (10) has a rotating pulley (11) attached to it, with a supplementary pulley (16) below it. The opposite ends of wire (21) are attached to the gate, the wire passes round a notch in pulley (11), then around pulley (16) so that it does not foul itself, and then around a second notch in pulley (11), so that when the motor turns the gate moves. |
