BIT MOUNTING DEVICE FOR ROTARY TOOL

摘要

PROBLEM TO BE SOLVED: To improve mounting and dismounting operation property of a bit in a bit mounting device for a rotary tool and provide steady technique of the bit being effective for increasing steady effect of the bit. SOLUTION: In this bit mounting device 20 for attaching the bit 14 to a tip of an anvil 8, an annular spring mounting groove 27c is formed at outer periphery of a spring holder 27, and a substantially C-shaped spring member 26 is fitted in the spring mounting groove 27c while energizing force (spring force) is given in the direction of the reduction of diameter. An opening part 27d communicating with a corner part of a hexagonal hole 27b in which a terminal part of the bit 14 is inserted is provided in a bottom of the spring mounting groove 27c. A spring member 26 is engaged with a corner part of the bit 14 inserted into the hexagonal hole 27b through the opening part 27d to regulate the movement of the bit 14 in the radial direction.