| 摘要 |
<p>A pressurized medium actuated gripping device which is included in a rock or earth drilling machine for rotary drilling, and is adapted for gripping a drill rod for transmitting rotation and/or axial movement to a string of drill rods, said gripping device including a rotatable housing (22) in which gripping jaws (34) arranged around the drill rod are movable substantially radially relative said rod, and also a sleeve-shaped piston element (29) of elastomeric material, which is sealingly arranged in the housing for separating a pressure chamber (33), arranged for the supply of pressurized medium and between the housing and the piston element, from a central space wherein the gripping jaws are arranged, and which is adapted for actuating the gripping jaws into engagement with the drill rod when the pressure chamber is supplied with pressurized medium. The piston element is provided with surfaces (29b) which are substantially radially displaceable relative walls (31, 32) surrounding the pressure chamber (33) inside the housing (22) and seal against these walls.</p> |
