| 摘要 |
The present rock drilling bit comprises along its shaft portions of asymmetrical cross sectional areas for strengthening the drilling bit. These asymmetrical portions are distributed along and around the central axis of the shaft in such a manner that a curve which interconnects the surface centers of gravity of these portions which are located off said central axis, forms a spiral helix. These portions may be located in preferred sections of the drill bit shaft, especially in a transitionary section between the tip of the drill bit and the shaft proper or in another transitionary section between the shaft and a shank of the drilling bit.
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