Deep hole forming tool using plastic deformation - has rotatable bit on axle inclined to axis of support shaft and defining imaginary sphere

摘要

The appts. is used to machine deep holes in metal pieces by a process of plastic deformation. The tool has a rotatable bit (1) mounted on an axle (4) projecting from the end of a shaft (5), the axle being inclined to the axis of the shaft and the active surface of the bit defining an imaginary sphere. The active surface may comprise elements projecting from the general surface, being arranged in plane sections angled to the axis of the head. The elements may be arranged to form a helicoidal line, being rigidly or elastically mounted on the head. Alternatively the active surface may be smooth band defining an imaginary sphere, or may comprise a series of independently rotatable discs (11). The head mounting may permit its radial displacement relative to the shaft.