Abstract: The invention relates to a threaded plug on an elongated body for a threaded connection to a threaded bushing, wherein the threaded plug has a conical external thread, in which a section of a flank of the external thread can be represented as a section of a function which has a curvature, wherein the section of the function has an angle to a connecting line of adjacent thread bases or thread tips that is greater than 45° over a height of at least 0.3 times the thread height.

Abstract: The invention relates to a threaded bushing on an elongated body for a threaded connection with a threaded plug, wherein the threaded bushing has a conical internal thread, in which adjacent flanks of the internal thread are designed as sections of two identical ellipses offset from one another.

Abstract: The invention relates to a control for at least one retainer of a transfer device for a rod section of a ground drilling device, wherein the ground drilling device is configured for moving a drill string, and the transfer device is configured for transferring the received rod section from a position in a rod magazine to a position on the drill string or vice versa, and the control is configured to move the retainer between a position above the rod magazine and the position on the drill string while the drill string is still moving.

Abstract: A rod section of a ground drilling rod configured at its end to form at least one plug connection and having at one end (a) a connecting plug with an outer contour; or (b) a connecting socket with an inner contour, the outer contour or the inner contour being essentially sinusoidal in cross section.

Abstract: The invention relates to a control for at least one retainer of a transfer device for a rod section of a ground drilling device, wherein the ground drilling device is configured for moving a drill string, and the transfer device is configured for transferring the received rod section from a position in a rod magazine to a position on the drill string or vice versa, and the control is configured to move the retainer between a position above the rod magazine and the position on the drill string while the drill string is still moving.

Abstract: A ground drilling device for cable-guided drilling comprising a drive for connecting and/or moving rod sections of a drill string along a drill string axis, wherein a cable reserve for receiving a cable with a length of at least two rod sections is provided and a contact device for electrical contacting of one end of the cable of the cable reserve is provided.

Abstract: A ground drilling device has a drilling carriage which defines a drill string axis, a drill rod magazine for a plurality of rod sections, and a transfer device for the transfer of a rod section between the drill rod magazine and a position of the rod section in the direction of the drill string axis. The ground drilling device also has a guide on a top of the drill rod magazine that is configured to guide movement of the transfer device.

Abstract: A rod section of a ground drilling rod configured at its end to form at least one plug connection and having at one end (a) a connecting plug with an outer contour; or (b) a connecting socket with an inner contour, the outer contour or the inner contour being essentially sinusoidal in cross section.

Abstract: A ground drilling device having a drilling carriage, which defines a drill string axis, a first drill rod magazine for a plurality of rod sections and a transfer device for the transfer of a rod section between the first drill rod magazine and a position of the rod section along the drill string axis, wherein at least a first connection element is arranged at the first rod magazine and/or at the drilling carriage for the connecting of the first rod magazine to a second rod magazine such that the second rod magazine is arranged next to the first rod magazine.

Abstract: A ground drilling device having a drilling carriage, which defines a drill string axis, a first drill rod magazine for a plurality of rod sections and a transfer device for the transfer of a rod section between the first drill rod magazine and a position of the rod section along the drill string axis, wherein at least a first connection element is arranged at the first rod magazine and/or at the drilling carriage for the connecting of the first rod magazine to a second rod magazine such that the second rod magazine is arranged next to the first rod magazine.

Abstract: A ground drilling device for cable-guided drilling comprising a drive for connecting and/or moving rod sections of a drill string along a drill string axis, wherein a cable reserve for receiving a cable with a length of at least two rod sections is provided and a contact device for electrical contacting of one end of the cable of the cable reserve is provided.

Abstract: A ground drilling device having a drilling carriage, which defines a drill string axis, a drill rod magazine for a plurality of rod sections and a transfer device for the transfer of a rod section between the drill rod magazine and a position of the rod section in the direction of the drill string axis, wherein a guide for a movement of the transfer device is present on the drill rod magazine.

Abstract: A rod section of a ground drilling rod, wherein the rod section is configured at its end as a plug connection and comprises at one end (a) a connection plug or (b) a connection socket, wherein the connection plug on the outside or the connection socket on the inside comprises nonround segments along a cross section, wherein the cross section is constant in configuration.

Abstract: A threaded plug for a threaded connection includes a core having an exterior thread. At least one flank of the exterior thread forms a segment of an ellipse, wherein the segment of the ellipse extends continuously from a root of the thread to a corresponding crest of the thread. A threaded connection can be formed by combining the threaded plug with a threaded bushing having an interior thread constructed to engage with the exterior thread of the threaded plug.

Abstract: In a method for introducing a geothermal probe into the earth, a geothermal probe is introduced in a radiating manner with the drill head into the earth. After the drilling operation, the drill head remains in the earth. The drill head is introduced into the earth with the assistance of a rod linkage.

Abstract: In a method of installing a borehole heat exchanger in the earth, a channel is formed in the earth by means of a pushing device, thereby causing a compression of the earth as a result of earth being displaced, and inserting a borehole heat exchanger in the channel, causing an elastic component of the earth to move toward the heat exchanger as the earth relaxes in order to provide an intimate contact between the earth and the heat exchanger. Installation of the borehole heat exchanger in elastically displaced earth ensures not only a stable and lasting securement of the heat exchanger in the earth but also the intimate contact between earth and heat exchanger wall so important for heat exchanger.

Abstract: The invention relates to a screw connector for a screw engagement, comprising an external thread applied to a core and flanks of the external thread form an ellipse.

Abstract: An apparatus for overdrilling a buried line includes a rotatably driven thrust linkage and/or traction linkage, and has a forward end which is connected to a ring-shaped to hollow cylindrical overdrilling head which embraces the line. The overdrilling head is provided interiorly with a centering protrusion for spontaneous centering of the overdrilling head in concert with the line.

Abstract: In a method for introducing a geothermal probe into the earth, a geothermal probe is introduced in a radiating manner with the drill head into the earth. After the drilling operation, the drill head remains in the earth.

Abstract: In a method of installing a borehole heat exchanger in the earth, a channel is formed in the earth by means of a pushing device, thereby causing a compression of the earth as a result of earth being displaced, and inserting a borehole heat exchanger in the channel, causing an elastic component of the earth to move toward the heat exchanger as the earth relaxes in order to provide an intimate contact between the earth and the heat exchanger. Installation of the borehole heat exchanger in elastically displaced earth ensures not only a stable and lasting securement of the heat exchanger in the earth but also the intimate contact between earth and heat exchanger wall so important for heat exchanger.