| 摘要 |
The drive mechanism consists of a cable drum (4) driven by an electric motor and possessing a thread-like guide groove for at least one pulley-cable (14). The cable drum is in the form of a sphere contained inside a tubular piece (7) whose enclosing walls it barely touches. The tubular piece is swivel mounted on the cable drum's pivot axle (6). The tubular piece has a spring (9) and at least one end switch (11,12) operated by the tubular piece in a preset pivot position. The tubular piece has at least one control cam or lever (10). |
