Nikken Kosakusho Works, Ltd.

Eisaku Nakai

Suguru Maemura

Masahiro Taguchi

Susumu Mikado

Steve Eckersall

Yusaku Yamamoto

In a shank portion of an end mill which is chucked by a tool holder, flat surfaces are formed at a plurality of circumferential positions in the outer periphery of the shank portion so that the flat surfaces abut on side lock bolts attached to a body of the tool holder.

Tool holder

End mill and shank structure of end mill

A tool holder includes a drawing screw and a stopper member. The drawing screw is positioned in an intermediate hole. A rear end face of a head of the drawing screw faces a boundary wall surface, and a top end of a shaft of the drawing screw is screwed in a rear end of a collet. The stopper member is positioned in an annular space between an outer peripheral surface of the shaft of the drawing screw and an inner peripheral surface of the intermediate hole. The stopper member faces a front end face of the head of the drawing screw, and limits movement of the head toward a top end of the tool holder. The drawing screw and the stopper member are inserted and assembled from a top end opening of a collet holding hole.

Tool holder and method for assembling the same

In order to provide a tool holder which greatly reduces frictional resistance between a locknut and a taper collet, and eliminates a twisting of the taper collet during tightening of the locknut, in a tool holder comprising a locknutwhich pushes a taper colletinto a tapered holeof a collet chuck bodyto chuck a cutting tool, between a reference endof the tape colletand a collet supporting portionopposed thereto, interposed is a bearing washerto reduce frictional resistance between both contact surfaces. To both surfaces of this bearing washer, namely, to the respective surfaces which come into contact with the reference endand collet supporting portion, surface treatment by any of ion nitriding, DLC (Diamond-Like Carbon) coating, and TiN coating is applied.

Growing community of inventors

Daito, Japan

Eisaku Nakai