| 摘要 |
<p>CONVERTIBLE RAISED DRILL APPARATUS A raise drill apparatus includes a ground-engaging base, a support and guide structure projecting from the base, and a drill pipe-engaging and rotating mechanism slidingly connected to the support and guide structure. Hydraulic thrust cylinders are connected between the base and the engaging and rotating mechanism for supplying force axially to the drill pipe and moving the engaging and rotating mechanism back and forth along the support and guide structure. The engaging and rotating mechanism is supported by and cantilevered from the support and guide structure and a supplemental ground-engaging support member is connected to the support and guide structure on the side opposite the engaging and rotating mechanism. The ground-engaging base engages the ground surface only on the same side of the drill pipe as the support and guide structure. The base includes an extended portion which projects to the other side of the drill pipe and a removable supplemental ground-engaging base is connected between the extended base portion and ground on said other side of the drill pipe for providing supplemental support during up-reaming and being removable so that the drill hole can be completed by the apparatus.</p> |
