Abstract: A coupling for anchor bolts, includes a sleeve having an internal screw thread and two anchor pipes having an external screw thread, the ends of the pipes being screwed into the sleeve. The sleeve is provided with an annular rib in the longitudinal centre thereof, the rib having a cylindrical inner end surface. The ends of the anchor pipes sealingly engage in the annular rib, and have cylindrical thread-free circumferential surfaces. In order to improve the tightness of the coupling and ensure that the transfer of impact energy from the first anchor pipe to the second anchor pipe does not engender much loss, the annular front surfaces of the anchor pipes are sealingly arranged against each other in the annular rib region. A leak-free coupling for anchor bolts which prevents the discharge of rinsing medium and/or setting mass is provided.

Abstract: A drill bit has, on its face, a combination of at least one straight cutting edge and at least two curved cutting edges arranged in a Y-shape. The cutting edges on the face of the drill bit are arranged such that they start from the axis of the drill bit or end directly adjacent thereto. The straight cutting edge is symmetrical with respect to the curved cutting edges, which are curved in opposite directions.

Abstract: A drill bit comprises, on its face, either only curved cutting edges or a combination consisting of at least one straight cutting edge and at least two curved cutting edges. The cutting edges on the face of the drill bit are arranged such that they start from the axis of the drill bit or end directly adjacent thereto. Three channels start from a blind hole serving to attach the drill bit to an anchor rod of an injection boring anchor, and their openings are not located in the area of the face of the drill bit but are situated in the area of the lateral surface of the same, said lateral surface conically expanding toward the cutting edges. The openings of the channels are placed in the area of concave recesses of the lateral surface of the drill bit in such a manner that they are recessed with regard to the periphery of the face of the drill bit.

Abstract: A coupling for anchor bolts, includes a sleeve having an internal screw thread and two anchor pipes having an external screw thread, the ends of the pipes being screwed into the sleeve. The sleeve is provided with an annular rib in the longitudinal centre thereof, the rib having a cylindrical inner end surface. The ends of the anchor pipes sealingly engage in the annular rib, and have cylindrical thread-free circumferential surfaces. In order to improve the tightness of the coupling and ensure that the transfer of impact energy from the first anchor pipe to the second anchor pipe does not engender much loss, the annular front surfaces of the anchor pipes are sealingly arranged against each other in the annular rib region. A leak-free coupling for anchor bolts which prevents the discharge of rinsing medium and/or setting mass is provided.

Abstract: An anchoring rod for rock anchoring (self-drilling injection bolts), includes an outer thread for connecting the anchoring rod to a drilling tool via a coupling sleeve. The end of the anchoring rod, which is screwed into the coupling sleeve, comprises a section which has a reduced diameter in comparison with the outer diameter of the anchoring rod. The free end of the section of the anchoring rod with the reduced diameter comprises a bevel. An open space is thus formed between the inner surface of the coupling sleeve and the reduced diameter end of the anchoring rod. The space stops the anchoring rod from becoming stuck in the coupling sleeve, even when the end of the rod is plastically deformed during the drilling process, so that the anchoring rod can be unscrewed from the coupling sleeve without applying significant force.

Abstract: A drill bit comprises, on its face, either only curved cutting edges or a combination consisting of at least one straight cutting edge and at least two curved cutting edges. The cutting edges on the face of the drill bit are arranged such that they start from the axis of the drill bit or end directly adjacent thereto. Three channels start from a blind hole serving to attach the drill bit to an anchor rod of an injection boring anchor, and their openings are not located in the area of the face of the drill bit but are situated in the area of the lateral surface of the same, said lateral surface conically expanding toward the cutting edges. The openings of the channels are placed in the area of concave recesses of the lateral surface of the drill bit in such a manner that they are recessed with regard to the periphery of the face of the drill bit.

Abstract: An anchoring rod for rock anchoring (self-drilling injection bolts), includes an outer thread for connecting the anchoring rod to a drilling tool via a coupling sleeve. The end of the anchoring rod, which is screwed into the coupling sleeve, comprises a section which has a reduced diameter in comparison with the outer diameter of the anchoring rod. The free end of the section of the anchoring rod with the reduced diameter comprises a bevel. An open space is thus formed between the inner surface of the coupling sleeve and the reduced diameter end of the anchoring rod. The space stops the anchoring rod from becoming stuck in the coupling sleeve, even when the end of the rod is plastically deformed during the drilling process, so that the anchoring rod can be unscrewed from the coupling sleeve without applying significant force.

Abstract: A drill bit (1) comprises, on its face, either only curved cutting edges (2) or a combination consisting of at least one straight cutting edge (2′) and at least two curved cutting edges (2). The cutting edges (2,2′) on the face of the drill bit (1) are arranged such that they start from the axis (4) of the drill bit (1) or end directly adjacent thereto. Three channels (10) start from a blind hole (5) serving to attach the drill bit (1) to an anchor rod of an injection boring anchor, and their openings (11) are not located in the area of the face of the drill bit (1) but are situated in the area of the lateral surface (13) of the same, said lateral surface conically expanding toward the cutting edges (2, 2′). The openings (11) of the channels (10) are placed in the area of concave recesses (12) of the lateral surface (13) of the drill bit (1) in such a manner that they are recessed with regard to the periphery of the face of the drill bit (1).