BOPI 08 BR/2023 REPERTOIRE NUMERIQUE 47 (30) EP n° 20192805.8 du 26/08/2020 (54) Carved out drill bit. (72) HAMMARGREN, John (SE) (73) SANDVIK MINING AND CONSTRUCTION TOOLS AB, 81181 SANDVIKEN (SE) (74) S.C.P AKKUM, AKKUM & Associates, n° 1777, Rue 6.261, Auditorium Jean Paul II, Quartier Mbankolo, B.P. 4966, YAOUNDE (CM). (57) A drill bit comprising a shank and drill bit head which are both centred on a longitudinal axis; wherein the drill bit head has a gauge and a front face with a peripheral edge which is adjacent to the gauge, the peripheral edge having a diameter Dl, the area within the peripheral edge defining the total area of the front face; wherein the front face having a central island at its radially innermost section, a plurality of peripheral platforms at its the radially outermost section adjacent to the peripheral edge and a recessed section positioned radially between the central island and the peripheral platforms; wherein the central island and the peripheral platforms are axially raised in comparison to the recessed section; wherein a plurality of inner front inserts are positioned on the central island and at least one outer front insert is positioned on each of the peripheral platforms; characterized in that: the area of the recessed section is > 62% of the area of the total area of the front face. Consulter le mémoire
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