Abstract: A method for mounting a casing shoe (4) around a cylindrical drilling apparatus (2), which shoe is used by drilling and pulled in the ground on drilling, whereby shoe (4) and drilling apparatus (2) can in the installed position rotate with respect to one another and move a certain distance axially with respect to one another, when shoulder (8) in the shoe is in transverse groove (9) on the periphery of the drilling apparatus and the groove is determining the length of the axial motion. The cylindrical shoe (2) is shrunk in order to make its diameter smaller around a spot in drilling apparatus (2) smaller than the outer diameter (Du), until through shrinking the outer diameter of the shoe has become smaller than the outer diameter (Du) of the drilling apparatus.

Abstract: A method to drill a hole in the soil by a bit assembly and a bit assembly comprising a ring-shaped bit (2) to drill the outer circle of the hole and to which a protection tube system (4), mounted in the hole while drilling, is coupled, and a cylindric inner bit (1) to drill the center portion of the hole, from which bit at least the rotative motion is transmitted to the outer bit (2). Drilling by the outer bit (2) and pulling out the protection tube (4) are disconnected upon need by reverse rotation of the inner bit, whereafter drilling is continued with the inner bit (1) only.

Abstract: Drilling apparatus which comprises support structure mounted guide tracks which extend in a drilling direction. A rotating and pushing unit is mounted on said guide tracks for movement in the drilling direction. The apparatus is provided with a series of members for adjusting the height of the rotating and pushing unit in relation to the guide tracks, the members extending in the drilling direction and allowing the rotating and pushing unit to glide in the drilling direction.

Abstract: A method for adjusting the impact force on a hammer operated by a compressible pressure medium utilizes a hammer including a working cylinder having a to-and-fro moving percussion piston and a spindle positioned therein for striking a tool. The working cylinder is positioned inside an outer shell and the spindle is attached to the outer shell. The working cylinder is movable relative to the outer shell and the spindle. A pressure chamber is formed between the working cylinder and the outer shell and pressure medium is fed into or removed from the chamber to adjust the position of the working cylinder relative to the outer shell. In making this adjustment, the strength and frequency of impact of the piston against the opposite end of the spindle is adjusted.

Abstract: An apparatus comprising a rotatable tool having a drill head and a method for regulating the penetration of the apparatus in rock or soil are disclosed. In particular, the apparatus and method of the invention are designed to prevent damage to drill bits mounted on the drill head when any one of the drill bits encounters an excessive opposing force as, for example, would result if the drill bits impacted a rock when drilling in soil. The apparatus includes mechanism for detecting the excessive force acting on one or more drill bits and automatically restricts the driving force which moves the tool forward.

Abstract: An apparatus and a method for drilling a tunnel utilize hydraulic means comprising a cylinder and a piston to enable independent adjustment of the driving force acting on the protecting tubes and the driving force acting on the drilling tool/conveying tubes. The hydraulic means acts as a thrust bearing and moves freely in the longitudinal direction of the drilling apparatus in response to forces acting on the drilling tool which are detected as changes in pressure in the hydraulic means.

Abstract: A method for drilling a tunnel in rock which utilizes a drilling apparatus comprising a drill head having tools therein and at least one conveying tube is disclosed. The method utilizes roller units which support the conveying tube to transmit the forward driving force from a power unit at the rear end of the apparatus to the drill head.

Abstract: A method for controlling advancement of a drilling apparatus comprising a drill head having tools therein and at least one conveying tube is disclosed. The method utilizes changes in pressure sensed in the drill head or the conveying tube as a means for assessing forces acting on tools in the drill head. The measured pressure information is transmitted to control equipment which adjusts the driving force applied by a power unit to the apparatus to effect the drilling operation. The method thereby provides an effective means of preventing damage to the tools.

Abstract: A drill head for drilling a tunnel in rock or soil comprises a rotatable drill bit assembly and a cylindrical protecting tube. The bit assembly comprises a bit holder and a cylindrical drill bit. The bit assembly has a cylindrical surface which forms a continuous cylindrical lap joint with the protecting tube. The bit assembly also has at least one opening for removing, through the bit assembly, drill cuttings from the face of the drill bit. In use, the lap joint allows rotation of the drill bit assembly relative to the protecting tube and prevents access of the drill cuttings to the outside of the drill head.

Abstract: A method for mounting pipelines (8) or outer walls of a tunnel in the ground where one after another joined polygon or round cylinders are forced to penetrate into the ground when the soil cut by the front edge of the first cylinder (2) moves into the said cylinders during tunnelling. The cylinders (2, 3, 4, 15) containing soil are replaced by the final pipe/piping (8) meant for the ground, by forcing and/or pulling said pipe/piping in the place of said cylinders and the soil excavated from the tunnel is removed from the tunnel inside the said cylinders when said cylinders are forced out of the tunnel.

Abstract: A drilling apparatus and a method for its control maintains the alignment of a drill head while driving a tunnel. The control is achieved by manipulating the center of gravity of a drill bit unit with respect to a line determined by two supporting points of a protecting tube which are the sole points of the protecting tube supported against the tunnel bottom.

Abstract: A method and apparatus for producing an underground pipeline from an excavated hole uses a drill head with a suitable tool attached thereto. Loosened soil is transported out of the drilled tunnel with a transportation drum containing an internal spiral. The drum is supported by a roll devices fixed to outer pipes. Rotating movement is transmitted to the rotating drill head from the transportation drum which is driven by a motor. Cylinders push the whole system and force is transmitted by the outer pipes to the drill head. Guiding of the drill head is accomplished with fluid actuators. Attachment and removal of the drill tool is accomplished through a free hole in the transportation drum and a central hole in the drill head, and the free hole and central hole also allow observation of the drill tool and tunnel face during drilling.