Appts. for extn. of sample of material from workpiece

摘要

The appts. takes a boat-shaped sample (2) from the interior wall of a pipe (40) by two frontal milling tools (4,6) which are relatively tilted and rotated by their motors (8,10) on a drive spindle (12) mounted in bearings (18,20) on parallel plates (14,16). A transmission motor (22) and spring coupling (24) set the spindle in rotation about the axis of advance (26). The plates are stabilised by a strut (42). The tool axes each describe half of a double cone with their tips at different points on the common base circle.