Twist-drill bit
AssigneeHilti Aktiengesellschaft
InventorsWerner Kleine, Hans-Werner Bongers-Ambrosius
Life of this patent
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Abstract
A helical drill bit (1) for rock has an axially extending shank (2) located between a chuck insert end (3) and an opposite drilling head (4) with at least one axially extending helical discharge groove (7) extending radially inwardly from the outer circumferential surface of the shank. A radially projecting groove reinforcement (9) is arranged in the base of the radial groove (8), with the reinforcement changing its geometric form or its position within the discharge groove (7) along the discharge groove (7).
Claims10
A helical drill bit for drilling in rock comprising an axially extending shank (2) with a chuck insert and (3) at one end and a drilling head (4) at the other end, said shank having at least one axially extending helical discharge groove (7), said groove (7) having a base (8) spaced radially inward from an outer circumferential surface of said shank with a groove reinforcement extending radially outwardly from the groove base (8), and the position and geometric form of said groove reinforcement (9) varying in the axial direction of said discharge groove (7).
A helical drill bit, as set forth in claim 6, wherein the rib height (H) of said discharge groove (7) increases towards the chuck insert end (3).
Dependencies are inferred from the claim text.