| 摘要 |
<p>The grab or excavating device for operating in confined spacers has jaws (2, 2') with pairs of arms (15) attached to their inside faces, swinging about hinge pins (3, 3') offset from the centre line of the housing. The arms on one jaw overlap the arms on the other jaw. On the top of each jaw is a further hinge pin (9) also connected to a longer arm (10) along the outside of the housing, attached to a yoke (12) higher up. The whole can be operated by a block and pulley system (22, 23, 30) inside the housing, operated from above. Each jaw has an inner face (7, 7') which slopes upwards from its pointed lower tip (6) to about the level of the lower hinge pins (3, 3').</p> |
