Patent ID: 8366366

Claim:
A device for fixing a rotary blade to a spindle of a rotary tool, comprising: an outer flange and an inner flange for clamping the rotary blade; and a screw body having a screw shaft portion and a screw flange, the screw shaft portion being tightened into a screw hole of the spindle, the screw flange being extended from a head side of the screw shaft portion to a circumference of the screw shaft portion and pressed against an outer surface side of the outer flange; wherein: the screw flange has a truncated cone shape having a larger diameter on a side of the outer flange and has an operating lever on its outer surface, the operating lever being operable to pivot between a received position and a use position by a pivotal operation in front and back reverting directions, the operating lever having a shape bent into a V configuration conforming to the truncated cone shape of the screw flange and provided with a receiving cross section around its bent leading edge; and when the operating lever is pivoted to the received position, the operating lever is received within a lever receiving concave part provided at the outer surface of the truncated cone-shaped screw flange and is received in a state where its leading end side does not protrude from a peripheral edge of the screw flange, and when the operating lever is pivoted to the use position, the receiving base of the operating lever closely fits into a receiving concave part having a V configuration and formed at the bottom of the lever receiving concave part, the operating lever being brought into a state where the leading end side protrudes from the peripheral edge of the screw flange in a radial direction, and the rotary blade can be fixed to the spindle by rotating the operating lever in a direction such that the screw shaft portion is tightened into a screw hole of the spindle.