EP3760828

• Sandvik Mining and Construction Tools ABseit 4. Dez. 2020

The present invention relates to a drill bit (100) for percussion drilling comprising: a drill bit body (101) intended to extend along an axis A and comprising a front surface (105), said front surface comprises a first circular area (110) arranged transverse and coaxially to axis A, a second area surface (111) surrounding said first area surface (110), said second area surface (111) is extending in an angle α in relation to a plane transverse to axis A, and a third area surface (112) surrounding said second area surface (111), said third area surface (112) is extending in an angle β in relation to a plane transverse to axis A such that the front surface (105) will have a substantially convex shape; and a number (n) of buttons (200) arranged in said second area surface (111) and third area surface (112), said buttons (200) have a button body (201) extending along an axis B and a length L along axis B, said button body (201) has a circular cross-sectional shape transverse to axis B, a rear end surface (203) and a forward end surface (204), wherein the angle α is within the range of 5 -15°, the angle β is within the range of 30 - 45° and the buttons 200 are arranged in circular recesses (120) extending substantially transverse from the second surface (111) and third area surface (112) into the drill bit body (101), said recesses (120) have a radius corresponding to the button body radius (Rb) and a depth corresponding to the length L of the button body (201) such that the button bodies (201) are fitted within the drill bit body (101) with the forward end surface (204) exposed in the second area surface (111) and third area surface (112).