| 摘要 |
An extensible boom, particularly for mounting on a mobile rock breaking or mining machine, comprises an extensible member mounted for rotation about an axis extending in the direction of its length, a non-rotatable extensible member operative to impart extension to said rotatable member of the boom, means for extending the non-rotatable extensible member of the boom and means on said rotatable member of the boom for mounting a rock breaking or other tool thereon so that said tool operates on an axis which is different to said axis of the rotatable member of the boom and is movable relatively thereto. In one preferred arrangement the tool is supported on a tiltable turntable pivotally mounted on the forward end of the boom. |
