Appearing and disappearing core type writing utility

摘要

The present invention relates to an appearing and disappearing core type writing instrument capable of appearing and disappearing a core based on a rotation operation. The writing instrument includes a hollow cylindrical body having an opened front end, a driving member which is engaged at an intermediate portion of the body in such a manner that the driving member is not rotated with respect to the body, a hollow cylindrical guide inserted into the front end of the body and rotatably engaged to the body, and a moving rod which is threadedly engaged with the driving member and is forwardly and backwardly moved by the driving member which is integrally rotated with the body for thereby appearing and disappearing the core through a front end portion of the guide in a state that the core is engaged to the front end of the moving rod and is inserted into the guide and is inserted into the non-rotational through hole formed at the rear end of the guide in such a manner that the moving rod is movable in the forward and backward directions.