Patent ID: 11396203

Abstract:
A knock type writing tool is provided, in which an appropriate amount of air can be taken in depending on an amount of a thermochromic ink discharged from a pen tip, so that the thermochromic ink can be smoothly discharged from the pen tip, and in which a writing body can rotate surely in conjunction with a rotation of a rotating member. An air hole 63a and a plurality of projection pieces 63b are provided at a rear end portion of a writing body 6. A front surface of a projection and retraction rotating member 7 is provided with a plurality of abutment parts 73, on which respective rear ends of the plurality of projection pieces 63b are to abut, and with a plurality of protrusion parts 72, each of which is formed between the plurality of abutment parts 73 and protruded more forward than the plurality of abutment parts 73. The protrusion parts 72 are respectively inserted in gaps 63c between the projection pieces 63b. An axial length of each projection piece 63b is longer than an axial length of each protrusion part 72, so that a portion of the gap 63c is left more forward than a front end of each protrusion part 72.