Abstract: A percussion bores for forming borer in a stone material and including a chisel stem (2) having a prismatic cross-section and provided with a chiseling head (3) and at least one radial opening (4), a twist drill (6) extending through the cylindrical through-bore (3) of the chisel stem and projecting beyond the chiseling head (7), a drilling head (10) with cutting elements (9) provided at the projecting end of the twist drill and a shank (12) provided at another end of the twist drill, and a stop (13) provided between the shank (12) and the chisel stem (2), with a drill stem being offset radially inwardly with respect to an outer diameter of the shank in the region of the stop.

Abstract: A percussion bores for forming borer in a stone material and including a chisel stem (2) having a prismatic cross-section and provided with a chiseling head (3) and at least one radial opening (4), a twist drill (6) extending through the cylindrical through-bore (3) of the chisel stem and projecting beyond the chiseling head (7), a drilling head (10) with cutting elements (9) provided at the projecting end of the twist drill and a shank (12) provided at another end of the twist drill, and a stop (13) provided between the shank (12) and the chisel stem (2), with a drill stem being offset radially inwardly with respect to an outer diameter of the shank in the region of the stop.

Abstract: A tool for setting self-cutting undercut anchors (6) in boreholes (B) in a receiving material (G) includes anchors (6) formed of an axially extending anchor rod (7) with a conically shaped surface at a leading end of the rod widening in the setting direction, and an axially extending rotatable sleeve (9) laterally enclosing the anchor rod and which is axially displaceable against the conically shaped surface for effecting radially outward spreading of cutting tabs located at the leading end of the sleeve. The cutting tabs form an undercut (U) in the inner surface of the borehole (B) as the sleeve is rotated. The tool has a rotatable propelling part (2) for the sleeve (9) of the undercut anchor (6) and a trailing end (3) of the propelling part is arranged for insertion into a chuck of a rotary hammer drill. The propelling part (2) cooperates with a support element (4) arranged to be supported by the surface of the receiving material (G) in which the borehole (B) is formed.

Abstract: A drive-in dowel including an inner sleeve (2) having a load application element (3), a cone-shaped widening section (5) formed at a front, in a setting direction (S), end of the inner sleeve (2), and a substantially cylindrical support section (6) adjoining the cone-shaped widening section (5) and having an outer diameter (w) which is smaller than a largest diameter (d) of the cone-shaped widening section (5), and an outer sleeve (7) arranged coaxially with the inner sleeve (2) and having, in its front, in the setting direction (s), region, a plurality of expansion tabs (8) separated from each other by longitudinal slots and radially expandable upon the outer sleeve (7) being impact driven over the cone-shaped widening section (5) of the inner sleeve (2), with the expansion tabs (8) being provided with annularly arranged, chisel-like cutters (11).

Abstract: A spreading anchor including an anchor rod having a stem (2) provided at its front end with a cone (3) which widens toward its free end, and a sleeve (5) which surrounds the stem (2), is axially displaceable along the anchor rod, and has a plurality of cutting tabs (6) separated from each other by axially extending slots (70, extending from a hinge point (9) in a direction of the cone (3), and having cutters (10), in regions of their free front ends, with the cutting tabs expanding radially upon the sleeve (5) being pushed onto the cone (3), with the sleeve (5) having at its free end in a region of the cutting tabs (6), and axially extending folded-over section (8) having an axial length (1) corresponding approximately to the length of the axial slots, and with the hinge (9) being located in the transition region between the folded-over section (8) and the sleeve outer surface.

Abstract: A spreading anchor including an anchor rod (2) having a stem (12) provided at its front end, when viewed in a setting direction, with a cone (3) widening outwardly towards its free end and a longitudinally displaceable sleeve (4) pushed over the anchor rod (2) and having at a front end (8) cutting tabs (5) which are provided with cutters, are separated from each other by gaps, extend from a plastic hinge (11) toward the cone (3), and are spread radially upon sliding of the sleeve (4) over the cone (3), the sections of the cutting tabs (5), which extend from free ends thereof in a direction toward the plastic hinge (11), having an outer surface (6) remote from the cone (3) and formed at least in their cutting region thereof as a substantially toroidal surface.

Abstract: A cutting tool for forming undercuts in boreholes includes a cutting member pivotally and rotatably supported in a tubular drive shaft. The combination of the drive shaft and cutting tool provide a ball joint so that the cutting tool is pivotally supported relative to the drive shaft axis. The drive shaft has an guidance bore for the cutting tool. Guidance stop faces in the guidance bore transmit rotational movement to a head forming a cutting member on the cutting tool. The head forms the undercut. The head rolls over the surface to be undercut.