| 摘要 |
The invention relates to a telescopically extensible drill comprising a drill barrel (1) and a drill bit (3) connected to the barrel. The drill further includes a drill rod (2) which can be displaced between two mutually different functional positions in relation to the drill barrel (1) and the drill bit (3). The drill rod (2) is configured with means (23, 24, 21) operative to fixate the rod in its two functional positions relative to the drill barrel (1) and the drill bit (3). In one of these functional positions, a retracted functional position (Fig. 5), a forwardly located screw thread (21) on the drill rod (2) engages with a screw thread (33) on the drill bit (3). In the other of these functional positions, the extended functional position of the drill (Fig. 6), shoulders (23, 24) on the drill rod (2) engage in recesses (14, 15) on the drill barrel (1). This adjustment of the drill between the two functional positions can be readily automated. The inventive drill enables relatively deep holes to be drilled, without needing to splice additional barrels or rods to the drill. |
