| 摘要 |
Crawler mounted jumbo for mines consists of a rigid frame with crawlers either side. A height adjustable boom (8) at the endface of the frame (1) between the side crawlers projects beyond the frame crawlers and supports a carriage at right angles to the boom for the guided drill itself (28). Pref. the boom should be secured to the frame and capable of movement under power round a horizontal and vertical axis. The carriage should pivot round a swivel bearing (17) at the end of the boom round an axis at right angles to the boom between first and second end settings so as to lie above, and below, the end of the boom supporting it. The boom should be powered by a piston and cylinder (13) in which the rod is hinged to the boom and the cylinder is hinged to a vertical bolt (11) fixed in the frame and with the boom mounted to it. |
