Patent ID: 6250856
Filing Date: 2001-06-26
Classification: B23B,Y10T

Abstract:
A shank attaching structure in which an engagement member is provided on an inner peripheral face of an opening portion formed on a tip of an arbor so as to freely retreat in a direction of an outside diameter, and a shank provided on a base end of a cutter is detachably attached to the opening portion of the arbor with one touch,wherein the shank is formed to have such an outside diameter as to pass in a state in which the engagement member provided on the arbor retreats in the direction of the outside diameter, a diameter of a base end portion of the shank is further reduced to form a stepped portion for abutment, and a concave portion(s) for accommodating a projected portion of the engagement member projected in a direction of an inside diameter is/are formed on a tip side portion of the stepped portion,a first sleeve is provided on the inner peripheral face of the opening portion of the arbor in such a manner that a tip of the first sleeve can abut against the stepped portion of the shank to retreat toward a base end side and the state in which the engagement member is caused to retreat in the direction of the outside diameter can be kept by an outer peripheral face of the first sleeve,a holding hole for holding the engagement member in a slide operation region of the first sleeve is formed in a wall portion of the arbor,the state in which the engagement member retreats in the direction of the outside diameter is kept until a tip of the first sleeve pressed toward an open end by an elastic member to be abut by the stepped portion of the shank,a second sleeve is provided on the outer peripheral face of the arbor for being moved in at least one of directions of an axial tip and a base end, pressing the engagement member in the direction of the inside diameter by the inner peripheral face of the second sleeve with the movement in one of the directions, and accommodating the engagement member in the direction of the outside diameter without the movement in one of the directions, andthe second sleeve is pressed in one of the directions by an elastic member, thereby keeping a state in which the engagement member is accommodated in the concave portion of the shank, and the second sleeve is moved in a direction opposite to the one of the directions against elastic force of the elastic member, thereby causing the engagement member to retreat in the direction of the outside diameter.