# US 11,306,541 B2 · Drill bit > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,306,541 B2 - Document ID: US11306541B2 - Status: Granted - Kind: B2 - Application number: 16/338,151 - Filed: 2016-10-10 - Published: 2019-09-12 - Granted: 2022-04-19 - Earliest claimed: 2016-10-10 - Assignees: Tmt Tapping-Measuring-Technology Sarl - Applicants: Tmt Tapping-Measuring-Technology Sarl - Inventors: Romain Clesen; Gerhard Meier - Web page: https://patentgrep.com/patent/US11306541B2 ## CPC - E21B 10/38: characterised by conduits or nozzles for drilling fluids - C21B 7/12: Opening or sealing the tap holes - E21B 10/36: Percussion drill bits ({with helical conveying portion E21B10/445;} characterised by wear resisting parts E21B10/46) - E21B 10/54: the bit being of the rotary drag type, e.g. fork-type bits - E21B 10/56: Button-type inserts (E21B10/52 takes precedence) - E21B: EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS - C21B: MANUFACTURE OF IRON OR STEEL (preliminary treatment of ferrous ores or scrap C22B1/00) ## Abstract A drill bit (11) for the drilling, in particular the rotary percussive drilling, of a hole, in particular a tap hole of a melting furnace, the drill bit (11) comprising a drill head (10), which has at least one hard material insert (16), and a base body (12) for connecting the drill bit to a driving element, the hard material insert (16) being inserted into a seat, which is formed in an axial end face (13) of the drill head (10), in such a manner that at least a head cutting edge (18) of the hard material insert (16) protrudes beyond the axial end face (13), wherein the seat has a flank portion and a mating flank portion located opposite the flank portion, between which the hard material insert (16) is disposed, the flank portion, which is disposed opposite a recess formed in the hard material insert (16), being provided with a material projection (35) which is at least partially made of a welding material, is bonded to the drill head (10) via the welding material and protrudes into the recess so as to establish a form-fitting connection with the hard material insert (16). ## Claims ### Claim 1 A drill bit (11, 41) for the drilling, in particular the rotary percussive drilling, of a hole, in particular a tap hole of a melting furnace, the drill bit (11, 41) comprising a drill head (10, 42), which has at least one hard material insert (16, 43), and a base body (12) for connecting the drill bit to a driving element, the hard material insert (16, 43) being inserted into a seat (14, 44), which is formed in an axial end face (13) of the drill head (10, 42), in such a manner that at least a head cutting edge (18, 46, 47) of the hard material insert (16, 43) protrudes beyond the axial end face (13), characterized in that the seat (14, 44) has a flank portion (29, 54) and a mating flank portion (30, 51) located opposite the flank portion, between which the hard material insert (16, 43) is disposed, the flank portion (29, 54), which is disposed opposite a recess (33, 49) formed in the hard material insert (16, 43), being provided with a material projection (35, 36, 53) which is at least partially made of a welded material (37), is bonded to the drill head (10, 42) via the welded material (37) and protrudes into the recess (33, 49) so as to establish a form-fitting connection with the hard material insert (16, 43); wherein the hard material insert (16) has at least one retaining extension (21) which is substantially parallel to an axis of rotation R of the drill head (10) and which engages into a bottom clearance (22) formed in a seat bottom (23) of the seat (14). ### Claim 2 (depends on 1) The drill bit (11, 41) according to claim 1, characterized in that the material projection (35, 53) protruding into the recess (33, 49) of the hard material insert (16, 43) is made entirely of welded material (37). ### Claim 3 (depends on 2) The drill bit (11, 41) according to claim 2, characterized in that the material projection (35, 53) is a weld spot. ### Claim 4 (depends on 2) The drill bit (11) according to claim 2, characterized in that the material projection (35) at least partially fills both a clearance (40) formed adjacent to the recess in the hard material insert (16) and a clearance (34) formed in the opposite flank portion (29) of the seat (14). ### Claim 5 (depends on 1) The drill bit (11) according to claim 1, characterized in that the length of the seat (14) in the drill head (10) extends substantially radially with respect to an axis of rotation R of the drill head (10) and the seat (14) has an opening (26) at the radially outer end, the hard material insert (16), whose length extends in the same radial direction, being accommodated in the seat (14) in such a manner that the hard material insert (16) protrudes beyond a circumferential surface (28) of the drill head (10) by a protrusion (27) which extends radially with respect to the axis of rotation R. ### Claim 6 (depends on 5) The drill bit (11) according to claim 5, characterized in that the radial protrusion (27) of the hard material insert (16) forms a circumferential cutting edge (19) which extends substantially parallel to the axis of rotation R of the drill head (10). ### Claim 7 (depends on 6) The drill bit (11) according to claim 6, characterized in that starting from the head cutting edge (18), which protrudes beyond the axial end face (13) of the drill head (10), the circumferential cutting edge (19) extends beyond the seat bottom (23) of the seat (14) in such a manner that a cutting edge leg (24) of the circumferential cutting edge (19) is accommodated in a second bottom clearance (25) in the seat bottom (23) of the seat (14). ### Claim 8 (depends on 1) The drill bit (11) according to claim 1, characterized in that multiple hard material inserts (16), each inserted into a seat (14), are distributed across the circumference of the end face (13) of the drill head (10). ### Claim 9 (depends on 8) The drill bit (11) according to claim 8, characterized in that the lengths of at least two hard material inserts (16) extend differently in the radial direction with respect to the axis of rotation R of the drill head (10) in such a manner that radially inner ends of the head cutting edges (18) have different distances from the axis of rotation R of the drill head (10). ### Claim 10 (depends on 1) The drill bit (41) according to claim 1, characterized in that the seat (44) is cylindrical, in particular a drill hole, and the hard material insert (43) has a retaining extension (45) which is substantially complementary to the seat (44) and inserted into the seat (44). ### Claim 11 (depends on 10) The drill bit (41) according to claim 10, characterized in that the hard material insert (43) has first and second head cutting edges (46, 47) which are disposed parallel to each other and extend radially to the axis of rotation R of the drill bit (41). ### Claim 12 (depends on 10) The drill bit (41) according to claim 10, characterized in that the clearance (48) formed in the hard material insert (43) has a flat portion (50) adjacent to a shoulder for forming the recess (49), said flat portion (50) extending as far as to a head cutting edge (46, 47). ### Claim 13 (depends on 12) The drill bit (41) according to claim 12, characterized in that the flat portion (50) is disposed in a plane that is disposed at a right angle to the head cutting edge (46, 47). ### Claim 14 (depends on 13) The drill bit (41) according to claim 13, characterized in that opposite the flat portion (50) and above the retaining extension (45), the hard material insert (43) has a radial protrusion (52) which extends in the direction of the head cutting edge (46, 47) and protrudes beyond the mating flank portion (51). ### Claim 15 (depends on 10) The drill bit (41) according to claim 10, characterized in that multiple hard material inserts (16, 43), each inserted into a seat (44), are distributed across the axial end face of the drill head (42). ### Claim 16 A drill bit (11, 41) for the drilling, in particular the rotary percussive drilling, of a hole, in particular a tap hole of a melting furnace, the drill bit (11, 41) comprising a drill head (10, 42), which has at least one hard material insert (16, 43), and a base body (12) for connecting the drill bit to a driving element, the hard material insert (16, 43) being inserted into a seat (14, 44), which is formed in an axial end face (13) of the drill head (10, 42), in such a manner that at least a head cutting edge (18, 46, 47) of the hard material insert (16, 43) protrudes beyond the axial end face (13), characterized in that the seat (14, 44) has a flank portion (29, 54) and a mating flank portion (30, 51) located opposite the flank portion, between which the hard material insert (16, 43) is disposed, the flank portion (29, 54), which is disposed opposite a recess (33, 49) formed in the hard material insert (16, 43), being provided with a material projection (35, 36, 53) which is at least partially made of a welded material (37), is bonded to the drill head (10, 42) via the welded material (37) and protrudes into the recess (33, 49) so as to establish a form-fitting connection with the hard material insert (16, 43); wherein the seat (44) is cylindrical, in particular a drill hole, and the hard material insert (43) has a retaining extension (45) which is substantially complementary to the seat (44) and inserted into the seat (44); wherein the clearance (48) formed in the hard material insert (43) has a flat portion (50) adjacent to a shoulder for forming the recess (49), said flat portion (50) extending as far as to a head cutting edge (46, 47); wherein the flat portion (50) is disposed in a plane that is disposed at a right angle to the head cutting edge (46, 47); and wherein opposite the flat portion (50) and above the retaining extension (45), the hard material insert (43) has a radial protrusion (52) which extends in the direction of the head cutting edge (46, 47) and protrudes beyond the mating flank portion (51). ### Claim 17 A drill bit (11, 41) for the drilling, in particular the rotary percussive drilling, of a hole, in particular a tap hole of a melting furnace, the drill bit (11, 41) comprising a drill head (10, 42), which has at least one hard material insert (16, 43), and a base body (12) for connecting the drill bit to a driving element, the hard material insert (16, 43) being inserted into a seat (14, 44), which is formed in an axial end face (13) of the drill head (10, 42), in such a manner that at least a head cutting edge (18, 46, 47) of the hard material insert (16, 43) protrudes beyond the axial end face (13), characterized in that the seat (14, 44) has a flank portion (29, 54) and a mating flank portion (30, 51) located opposite the flank portion, between which the hard material insert (16, 43) is disposed, the flank portion (29, 54), which is disposed opposite a recess (33, 49) formed in the hard material insert (16, 43), being provided with a material projection (35, 36, 53) which is at least partially made of a welded material (37), is bonded to the drill head (10, 42) via the welded material (37) and protrudes into the recess (33, 49) so as to establish a form-fitting connection with the hard material insert (16, 43); wherein the length of the seat (14) in the drill head (10) extends substantially radially with respect to an axis of rotation R of the drill head (10) and the seat (14) has an opening (26) at the radially outer end, the hard material insert (16), whose length extends in the same radial direction, being accommodated in the seat (14) in such a manner that the hard material insert (16) protrudes beyond a circumferential surface (28) of the drill head (10) by a protrusion (27) which extends radially with respect to the axis of rotation R; wherein the radial protrusion (27) of the hard material insert (16) forms a circumferential cutting edge (19) which extends substantially parallel to the axis of rotation R of the drill head (10); and wherein starting from the head cutting edge (18), which protrudes beyond the axial end face (13) of the drill head (10), the circumferential cutting edge (19) extends beyond the seat bottom (23) of the seat (14) in such a manner that a cutting edge leg (24) of the circumferential cutting edge (19) is accommodated in a second bottom clearance (25) in the seat bottom (23) of the seat (14).