| 摘要 |
<p>The invention refers to a device for carrying out drilling in earth-layers and rocks during a simultaneous forcing downwards of a casing pipe (5) into the ground, whereby strokes from a countersink hammer via a bore crown or a guide (3) belonging to a bore crown (1) is provided to cooperate against a shoulder (6) situated at the lower most portion (7) of the casing pipe (5) in driving downwards of the casing pipe (5) into the bore hole made together with the bore crown (1) used. Said shoulder (6) is formed by a wearing ring (10) placed into position against an edge portion (8) within the inner mantle surface (9) of the casing pipe (5) for a direct or indirect cooperation against a shoulder surface (11) faced in a direction to the free end portion (7) of the casing pipe (5) and which is situated on the bore crown (1) or the guide (3) belonging to the bore crown (1) and also to a boring string (4) rotary connected to a drilling machine.</p> |
