Patent ID: 7648315

Claim:
A cutter holder to which a cutter is attached, the cutter defining a rotation axis, the cutter including an insertion portion, which is inserted in the cutter holder, and a central shaft, which is movable relative to the insertion portion in the direction of the rotation axis, the insertion portion including an outer surface, which extends along the rotation axis, the cutter holder comprising: a support cylinder in which the insertion portion is detachably inserted; a locking operation body, which is movable relative to the support cylinder, the locking operation body being movable between a locking position for locking the insertion portion in the support cylinder and an unlocking position where the insertion portion is permitted to be unlocked with respect to the support cylinder; a lock body located between the outer surface and the support cylinder, the lock body being switchable between a locked state and an unlocked state, the locking operation body in the locking position brings the lock body into the locked state, the locking operation body in the unlocking position brings the lock body into the unlocked state, the lock body in the locked state is located radially inward of the outer surface, and the lock body in the unlocked state is permitted to retract radially outward of the outer surface; a stopper body movable relative to the support cylinder, the stopper body being switchable between a contact state and a non-contact state, the stopper body in the contact state holds the lock body in the unlocked state, and the stopper body in the non-contact state is retracted from the lock body; a pressing body, the pressing body being switchable between a standby state and a retracted state, the pressing body in the standby state selectively contacts the central shaft when the insertion portion is inserted in the support cylinder, the pressing body in the retracted state is retracted from the stopper body; and an urging member, which urges the pressing body such that the pressing body is brought into the standby state and urges the stopper body such that the stopper body is brought into the contact state, and the urging member detachably engages the pressing body to the stopper body.