| 摘要 |
<p>The key is pivotally mounted on one end of the foot, a roller being mounted on the foot inwardly of the other end for rotation about an axis transverse to the longitudinal axis of the foot. A second roller is mounted on the foot adjacent the other end for rotation about an axis parallel to axis of the rotation of the first roller. The rollers are located relative to each other that they function as a rolling fulcrum. The first roller functions initially as a pivot for lifting the manhole cover. The secon roller functions as a trolley to enable the lifted cover to be transported. An operating lever has one end connected to the foot adjacent the end with the lever projecting at an angle.</p> |
