PROBLEM TO BE SOLVED: To provide a screw-type writing utensil which can be obtaind through high yield working as a screw-type kind, assembled comparatively easily and stretchable by a simple rotary operation.;SOLUTION: This twist-type stretchable writing utensil comprises a barrel part; a rotary barrel which is fixed in the rear part of a sheath slidably fitted to the rear slender barrel part of the barrel part through a crown and inserted inside the barrel part; a lead tank which has a writing utensil loaded at the apex and is inserted in the rotary barrel; and a fitting case fitted to a rear slender tank of the lead tank. In addition, the lead tip of the writing utensil is freely projectable from the apex of a mouthpiece by changing the rotating motion of the rotary barrel to the straight line motion of the lead tank and the fitting case by the operation of the barrel part and the sheath. At the same time, an auxiliary fitment such as an eraser attached to the apex of the fitting case is set to be freely projectable from an opening of the crown and also the rotation of the rotary barrel is stopped during the projection of the lead tip from the mouthpiece. Thus the free regulation of a projecting length of the lead in a mechanical pencil can be made by the reciprocating ejection operation of the lead tank fitting case.;COPYRIGHT: (C)2006,JPO&NCIPI
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