| 摘要 |
In a block for a rope or sheet: a pulley over which the rope moves, an eccentric cam which is pivotable to selectively clamp or release the rope against the pulley and a pivotably lever to which the cam is connected such that motion of the lever pivots the cam between its clamping and releasing position; bearing means to enable pivoting of the lever away from the cam clamping position; a spring to at least return the cam to its clamping position. |
