| 摘要 |
The motion of mechanically moved ropes, chains, or rods has to be frequently adjusted to varying situations such as the motion of a rope holding a boat and compensate the changes created by the tide. In some cases the adjustment has to be made in a confined or awkward space. A pulley (11) is moved clockwise by a strong force (16) created by a rope (12) pulling at a lever joined to a spring (23) with one end and to the pulley (11) with the opposite end. The motion is changed to anti-clockwise when the forces are reduced (15). |
