| 摘要 |
Controllable drill head containing an elongated body of which one end is attached to a bore pipe and a spout element is mounted in a turnable manner on the other, foremost end of the body, in and opposite to an opening in this body, wherein the head contains an elongated, elastic, bendable element which at one end carries the spout element and which has been mounted in the body in such a manner that when being in a rest position the movable element stretches out in the longitudinal direction of the body, but which is elastically bendable in the cross direction of the body so as to alter the direction of the spout element through bending, a mechanism for (3) stopping the foremost end of the bendable element with the spout element in the forward direction without the element bending through and to keep the spout element from changing direction, and a mechanism for exerting forward pressure on a part of the bendable element which is situated further away from the foremost end of the body than the foremost end thereof which is stopped by the body so as to provoke bending through of the bendable element.
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