| 摘要 |
Rock and earth drilling aggregate for rotary drilling comprising an axially fixedly arranged pressure medium actuated tube holder (21) and an axially movably arranged and mechanically rotatable pressure medium actuated chuck (27) which is arranged to be moved forwards or backwards along a feed beam (11) through actuation of a reversible pressure medium actuated feed motor (17), the tube holder (21) and the chuck (27) being arranged to alternatingly grip one of a number of, by means of thread couplings (99) connected, string elements composed drill string (23), so that by means of the tube holder and the chuck can be achieved withdrawal of the drill string (23) from a drill hole or insertion of the drill string (23) into a drill hole, whereby the tube holder (21) is arranged to release when loaded with pressure medium and to grip at pressure medium unloading and that the chuck (27) is arranged to grip at pressure medium loading and release at pressure medium unloading. The aggregate comprises a means (101) in form of a valve which is activated for preventing pressure medium loading of said tube holder (21) when said chuck (27) is rotated for disconnecting said thread coupling (99) and that said means (101) is reset when said feed motor (17) feeds said chuck (27) forwards.
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