A rock drill including a drill stem (2), major cutting edges (5, 6) extending substantially over a diameter of the drill stem (2) and projecting beyond the end face (3) of the drill stem, and at least one minor cutting edge (9, 10) extending substantially in a radial direction and provided on at least one elongate cutting body (7, 8) which projects beyond the end face (3), with the minor cutting edge (9, 10) being located, at a contemplated rotational direction (R) of the drill (1) about the drill axis (A), in front of a corresponding major cutting edge (5, 6) adjacent to a main discharge groove (13) for drilling dust, and with the elongate cutting body (7, 8) having a cutting surface (11) tapering from the minor cutting edge (9) toward the end face (3) of the drill stem (2) and having at least one inclination surface (12) adjacent to the circumference of the drill stem (2) and inclined toward the circumference of the drill stem and with respect to a radial extension of the minor cutting edge (9), in a direction opposite the drill rotational direction (R).
A drill including a stem (2) having at least two discharge grooves (3,4) for discharging drilling dust and helically circumscribing the stem (2), a drill head (5) provided at an of the stem (2) opposite the end provided with the shank and having a plurality of bits (7-9), which are formed of hard metal and project radially beyond the drill head (5), with the drill head having a plurality of drilling dust grooves (10-12) which separate the bits and number of which exceeds a number of the discharge grooves (3,4), with at least one pair of the drilling dust grooves (10,12) passing into a common discharge groove (4), and with the drill further having a helical groove section (13) forming a common transitional region between the at least one pair of the drilling dust grooves (10,12) and the common discharge groove and the passing cross-section of which is smaller than the passing cross-section of the common discharge groove.
A drilling tool (1), especially a rock drilling tool, has an axially extending shaft (2) with one end arranged to seat in a chuck of a drilling device and the opposite end securely connected to a drilling head (5). The drilling head has at least three hard metal cutting members (7, 8 and 9) with at least two adjacent cutting members located at the outer circumferential surface of the drilling head and preferably projecting radially outwardly from the circumferential surface. The cutting members are spaced circumferentially apart at an angle in the range of about 100.degree. to about 150.degree.. Drilled material grooves (10, 11 and 12) separate the cutting members (7, 8 and 9) in the circumferential direction. In turn the drilled material grooves (10, 11 and 12) discharge into at least one discharge groove extending helically around the shaft. A circle (E) encircling the drilling head (5) is formed by the radially outer edges of the outwardly projecting cutting members. The circle (E) has a diameter (e) at least equal to 15 mm and preferably at least equal to 18 mm. The drilled material grooves located between the cutting members (7, 8 and 9) are spaced apart by an angle (.beta.) in a range of about 100.degree. to about 150.degree.. The drilled material grooves (10, 11 and 12) are located in a region (15) of the outer circumferential surface with an opening to the grooves having an aperture angle .alpha. in the circumferential direction with a value .alpha..ltoreq.100-e and an axial extent (f) with a value of >0.
A rotary hammerdrill bit for use with a percussion drilling device or a hammer drilling device, with a shank and a drill head attached to or configured on the shank, wherein a front side pointing in the advance direction of the drill head has a main cutting plate forming a main cutting axis. The main cutting plate extends over the diameter of the drill head and has a tip or tip-edge lying in the longitudinal axis of the drill bit and forms drill blades that are substantially roof-shaped and are inclined radially from the tip or tip-edge. The front side of the drill head has at least one pair of cutting pins, wherein the cutting pins are arranged on the drill head in essentially the same radial positions.
A drill including a stem (2,22) having at least one discharge groove (3) helically circumscribing the stem (2,22), and a drill head (4,24) provided at the end of the stem (2,22) opposite the end at which a shank is provided and having at least two hard metal bits (5,25) projecting radially beyond a drill head circumference, with the drill head further having drilling dust grooves (7,27) extending at least partially between the bits (5,25) and opening into the at least one discharge groove (3) and having, at least in a region of the at least two hard metal bits (5,25), an extended circumferential profile (8,28) projecting radially beyond a circumference (9,29) of the stem (2,22).
A rock drill head including a radially extending groove (2a) formed in a head body, a recess (5) formed inside the groove (2a); and at least two, substantially plate-shaped, hard-material inserts located in the groove (2a) and having each a radially extending, segment (4a, 4b) engaging in the recess (5).
