Abstract: A drilling device has a frame (1) with a feed device (2) for carrying a drilling device (3) movable to-and-fro for rotating a drill string (4). The drilling device includes a sensor (6) for sensing an end (7) of a drill string element (8) in the drill string (4), and a register for the position of the end (7) along the feed device (2) and for the displacement of the drilling device (3) along the feed device (2).

Abstract: A method of providing a substantially leakproof shielding layer in the ground. The method includes the following steps: a) making a plurality of substantially parallel holes (H) in the ground by means of a guided drill head (4) which ejects ground-decomposing liquid mainly in the advance direction of the head, and b) passing through each hole an injection head (6) which ejects injection liquid essentially transversely to the advance direction thereof, so that the injection liquid will penetrate into the ground material and mix therewith and after transition to a solid state, together with injection liquid in an adjacent hole, which has also penetrated into and mixed with the ground material and has been transformed into a solid state, will form part of the shielding layer. The invention further includes a device for performing the method.

Abstract: A casing tube formed from plastic and a casing shoe formed from metal are provided for drilling in layers of earth or rock. The casing shoe is locked to the casing tube by threads, grooves or flanges provided on a reduced diameter portion of the casing shoe. A tube-formed extension is provided in the casing shoe for protecting the casing tube from damage during a drilling operation.

Abstract: A rock or ground-drilling machine includes a gear housing (14) in which there is journalled a shaft (31) which surrounds a drill string (23) in the manner of a sleeve and which is affixed to the drill string by means of a chuck (7) connected to the shaft (31). the chuck is operated by means of pressure fluid delivered to the chuck (27) through the medium of a commutator (36) acting between the gear housing (14) and the shaft (31). the shaft (31) is journalled in the gear housing (14) by means of one single rolling bearing (39). the commutator (36) lies resiliently against the gear housing (14) and is flexible in response to sideways movement of the shaft (31).

Abstract: A device for permanent joining of plastic tubes intended for use as covering or lining tubes when drilling holes in the ground including a female portion on a first tube and a male portion interacting therewith on a second tube. The male portion being provided with annular projections and recesses round its outer circumference and the female portion being provided with annular projections and recesses round its inner circumference with the recesses and projections on one tube interengaging with the projections and recesses on the other tube in such a fashion that at least one of the tubes is radially deformed and the joint can withstand axial and torsional forces.