Patent ID: 8172236

Claim:
A bit mounting device for mounting a tool bit on a spindle of a rotary tool, comprising: a mount shaft having an axis and constructed to be mounted to the spindle; a holder defining a bit receiving hole, the bit receiving hole having the same axis as the mount shaft; a stop ring attached to an inner circumference of an inlet portion of the bit receiving hole and directly engageable with the tool bit for preventing the tool bit from being removed from the bit receiving hole; a bit push member positioned within the bit receiving hole on the side of a bottom of the bit receiving hole and movable in a bit mounting direction and a bit removing direction opposite to the bit mounting direction; and an operation sleeve attached to the holder and movable in opposite directions parallel to the axis of the mount shaft, wherein a force of the movement of the operation sleeve in one of the opposite directions is converted into a movement of the bit push member in the bit removing direction, so that the tool bit is disengaged from the stop ring.