Device preventing outlet of injection material and ground water

摘要

The device also prevents the outlet of ground water and earth when bore tube (1, 2) extensions are coupled together when the boring is being carried out. The device comprises an elongated box (3) with two apertures at the ends through which the bore tube is guided. The apertures are provided with seals (7) which locate on the tube and thereby seal the interior of the box (3) against the exterior. Centrally in the box is a rotary slide, a push slide or a flap. The rotary slide (5) is formed as a disc or a disc segment with a hole (8). The hole is sufficiently large, that the bore tube can easily fit through it at its greatest diameter.