Twist drill bit for rock drilling
AssigneeHilti Aktiengesellschaft
InventorsWerner Kleine, Hans-Werner Bongers-Ambrosius
Life of this patent
Estimating the term…
Abstract
A twist drill bit (1) for use in rock has a helical land (7) arranged between a chuck insert end (2) and a tool head (3), and extends helically around a rotational axis (A) extending along a shaft (5). The radially outer surface (8) of the land (7) has its width (x) increasing as it approaches the tool head (3).
Claims4
A twist drill bit for use in drilling rock and rock-like materials comprises an axially extending shaft (5) having a tool head (3) at a leading end and a chuck insert end (2) at a trailing end, at least one land (7) extending helically around said shaft from said tool head to said chuck insert end and forming a helical groove (11) between adjacent turns of said land, said land having a radially outer surface (8) increasing in axial width in the direction from said chuck insert end (2) to said tool head (3), a pitch (α) of said land (7) varies along the axial length of said shaft (5) and decreases in the direction from said tool head to said chuck insert end (2).
Dependencies are inferred from the claim text.