| 摘要 |
In the manufacture of a bit body by a powder metallurgy process, a hollow mold is formed in the configuration of at least a portion of the outer surface of the bit body, and elongate pockets of generally V-section are then formed in the interior surface of the mold, to receive portions of thermally stable cutting elements, each of which is of generally triangular cross-section with a flat front face. Each pocket is machined from the mold material by means of a conical tool rotating about its axis, the axis being inclined to the perpendicular in a plane containing the required longitudinal axis of the pocket. The main elongate part of the pocket is formed by translatory movement of the tool along the axis of the pocket, and a flat, generally triangular, end face is then formed by translatory movement of the tool transversely of the axis of the pocket. |
