Abstract: This invention is to a writing tool such as mechanical pencil or a ballpoint pen in which a writing shaft having a head member is inserted in an outer sleeve in such a manner that the head member projects from the outer sleeve. A stair or step and a spiral groove are provided on the forward inner surface and the rearward inner surface of a tubular cap, respectively, with an inside diameter of the rear part of the spiral groove being larger. A bearing part is brought into contact with a lead tank provided inside a forward art of the tubular part so that the forward part of the outer sleeve is movable in the axial direction and is locked in the turning direction against a rearward inner surface of the outer sleeve. The rearward part of the tubular body is provided with a slit, holding pieces of a stick-shaped object holder slidably inserted in said slit. A stick-shaped object is held by the holding pieces, and the projection is provided on each holder engaged with the spiral groove of the tubular cap.

Abstract: Mechanism for putting the head of a shaft into and out of the head of an outer sleeve comprised of an outer sleeve (1), a long hole (2) formed in the outer sleeve (1), and a clip (3) to be put into and out of the outer sleeve (1) through the long hole (2). A shaft (4) is inserted in the outer sleeve (1), and a cam mechanism (8) cooperates with the clip (3) in a manner that causes the cam mechanism (8) to move forward and backward in an axial direction according to in and out movement of the clip (3). A spring (6) spring-biases the shaft (4) toward the cam mechanism.

Abstract: This invention is to a writing tool such as mechanical pencil or a ballpoint pen in which a writing shaft having a head member is inserted in an outer sleeve in such a manner that the head member projects from the outer sleeve. A stair or step and a spiral groove are providd on the forward inner surface and the rearward inner surface of a tubular cap, respectively with an inside diameter of the rear part of the spiral groove being larger. A bearing part is brought into contact with a lead tank provided inside a forward art of the tubular part so that the forward part of the outer sleeve is movable in the axial direction and is locked in the turning direction against a rearward inner surface of the outer sleeve. The rearward part of the tubular body is provided with a slit, holding pieces of a stick-shaped object holder slidably inserted in said slit. A stick-shaped object is held by the holding pieces, and the projection is provided on each holder engaged with the spiral groove of the tubular cap.