| 摘要 |
PCT No. PCT/SE89/00452 Sec. 371 Date Nov. 16, 1989 Sec. 102(e) Date Nov. 16, 1989 PCT Filed Aug. 29, 1989 PCT Pub. No. WO90/02242 PCT Pub. Date Mar. 8, 1990.A device for forming an elongated hole in the ground, comprising a hollow, flexible conduit, a head (2') which is connected to one end of the conduit and which is fitted with at least one nozzle (5') through which fluid passing along the conduit under pressure is delivered in such a direction and under such pressure that when the head is not in rotation, the head will form a hole of curved configuration and such that when the head rotates about its longitudinal axis and the conduit is moved forwards in the hole-forming direction the head will form a substantially straight hole, the end of the head facing towards the hole-forming direction being provided with a surface which is positioned obliquely to the longitudinal axis of the head and which assists the head in forming a curved hole. The oblique surface is formed on a member (6') which is mounted on the head, the member being adjustably attached to the head in a manner to enable adjustments to be made to the angle of said member relative to the longitudinal axis of the head. |
