| 摘要 |
<p>Drilling apparatus which comprises a frame operating as an underlay having in the drilling direction mounted guide tracks (4), a rotating and pushing unit which is moved on said guide tracks in the drilling direction and in which unit the devices (9, 11) have been formed for adjusting the height level of the unit in relation to the tracks (4) and of needed force generating devices and a control unit. Different height levels are arranged for the rotating and pushing unit according to different pipe diameters (1) so that the lower surfaces of the pipes take a place essential at the same height level in relation to the guide tracks (4) when it is drilled holes which correspond to different pipe diameters.</p> |
