BLADE CHANGE MECHANISM FOR POWER TOOL

Disclosed is a blade replacement apparatus of an electric instrument, which is used to replace blades connected by a bolt, the bolt extending along a first axis, the blade replacement apparatus comprising a nut that fits the bolt to fix the blade, a nut loosening/tightening member, a locking member, and an operating member, one of the nut loosening/tightening member and the operating member having a first matching portion, the locking member having a second matching portion, wherein the operating member is movable between an operating position and a non-operating position, the operating member allowing a user to perform an operation by hand without using any instruments; when the operating member is in the non-operating position, the first matching portion engages with the second matching portion, and the rotation of the nut loosening/tightening member around the first axis is obstructed by the locking member; when the operating member is in the operating position, the first matching portion is disengaged from the second matching portion, and the rotation of the nut loosening/tightening member around the first axis tightens or loosens the nut.