| 摘要 |
Percussion drill bit with several lobes, which are formed by grooves formed in the outer circumferential surface, are preferably arranged in a cross shape or X-shape relative to one another and have cutting edges formed by the roof-shaped end faces of inserted carbide pins, and in each case at least two carbide pins are inserted in each lobe and are arranged in a row in such a way that the cutting edges formed by the roof-shaped end faces of the carbide areas form a straight line running to the axis of rotation of the percussion drill bit, in which arrangement the carbide pins forming the cutting edges of the lobes with their roof-shaped end faces are inserted into end blind bores of the truncated-roof-shaped faces of the lobes, and the side surfaces of the roof-shaped end faces of each carbide pin run approximately in the same plane with the side surfaces of the lobe face of truncated roof shape, the blind bores accommodating the carbide pins run at an incline to the axis of rotation of the percussion drill bit, the carbide pins, in each case with their roof-shaped end faces, lie further away from the axis of rotation than the carbide-pin ends remote from the roof-shaped end faces, and the inner ends of the side surfaces of the truncated-roof-shaped face of each lobe, with a half, roughly frustoconical, circumferential surface, in each case enclosing the inner carbide pin of each lobe, ... Original abstract incomplete.
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