A thermochromic writing instrument, comprising: a writing body, storing a thermochromic ink therein, stored in a barrel; an operation body provided in the barrel to be operated to longitudinally move the writing body; a nib of the writing body configured to be capable of appearing from a front end of the writing instrument, wherein the writing instrument further includes a friction unit, rubbing handwriting in the thermochromic ink and capable of thermally changing the color of the handwriting by frictional heat generated at that time, and at least one clip body as the operation body, the friction unit is provided at a rear end of the barrel, and the clip body is provided in an area other than the rear end of the barrel.

A clip attaching structure includes a clip supporting portion which protrudes on an outer circumferential surface of a main body, a clip, and a coil spring. The clip is configured to be rotatable with respect to a fulcrum at which the clip is engaged with the clip supporting portion. The convex portion is inserted into an inside of one end portion of the coil spring, and the other end portion of the coil spring abuts against the outer circumferential surface of the main body. A base portion of the convex portion has an outer diameter greater than an inner diameter of the coil spring, and a tip end portion of the convex portion has an outer diameter smaller than the inner diameter of the coil spring.

A multicolor writing instrument with an automatic return function includes a lower housing having a hollow cylindrical shape; an upper housing connected to an upper portion of the lower housing and formed with locking steps; a clip member hingedly provided on the upper housing so as to be movable about a hinge shaft; a coil spring resiliently installed between the clip member and the upper housing; pen cores filled with at least two different color inks; knobs having ends fitted into the respective pen cores; return springs resiliently installed between the pen cores and the knobs; and a return member formed integrally with the clip member on one side of the hinge shaft and toward the respective knobs.

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.

A thermochromic writing instrument including a writing body, storing a thermochromic ink therein, stored in a barrel; an operation body provided in the barrel to be operated to longitudinally move the writing body; a nib of the writing body configured to be capable of appearing from a front end of the writing instrument, wherein the writing instrument 1 further includes a friction unit, for rubbing handwriting in the thermochromic ink and capable of thermally changing the color of the handwriting by frictional heat generated at that time, and at least one clip body as the operation body, the friction unit 10 is provided at a rear end of the barrel, and the clip body is provided in an area other than the rear end of the barrel.

A thermochromic writing instrument including a writing body, storing a thermochromic ink therein, stored in a barrel; an operation body provided in the barrel to be operated to longitudinally move the writing body; a nib of the writing body configured to be capable of appearing from a front end of the writing instrument, wherein the writing instrument 1 further includes a friction unit, for rubbing handwriting in the thermochromic ink and capable of thermally changing the color of the handwriting by frictional heat generated at that time, and at least one clip body as the operation body, the friction unit 10 is provided at a rear end of the barrel, and the clip body is provided in an area other than the rear end of the barrel.

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.

A multifunction pen includes plural refills including an electromagnetic induction touch pen. A knock operation to one of knock rods each of which is connected to a rear end of each of the plural refills causes a tip of one refill of the plural refills to move from a standby position in which the tip stays inside a shaft tube to an in-use position in which the tip projects from a tip end opening of the shaft tube. At least one refill from writing refills other than the electromagnetic induction touch pen is provided with a metal writing tip, and a tip of the electromagnetic induction touch pen at the in-use position is separated from the tips of the writing refills at the standby position by a distance such that electromagnetic induction by the electromagnetic induction touch pen is not affected by the tips of the writing refills.

A pressurized writing implement includes a shaft tube capable of housing therein a refill filled with a writing implement ink composition. The pressurized writing implement further includes a pressurizing mechanism that applies a pressure to the writing implement ink composition, the pressurized writing implement being capable of switching a writing state in which a front end part of the refill projects from a front end opening of the shaft tube, and a not-writing state in which the front end part of the refill is retracted from the front end opening of the shaft tube. The pressurized writing implement further includes a pressurizing-force adjusting mechanism that adjusts the pressure.

Provided is a retractable writing instrument including a pen point, a barrel, and a clip. The pen point is configured to be in a state of projecting from the barrel or a state of being retracted into the barrel by sliding the clip in a longitudinal direction of the barrel. The clip includes a clip body extending in the longitudinal direction of the barrel, a ball portion provided on a front side of the clip body and projecting in a direction of a surface of the barrel, and a clip base provided on a rear side of the clip body and is configured to produce a biasing force in a direction of a surface of the barrel. The surface of the barrel includes a guide groove extending in the longitudinal direction of the barrel and provided with a pair of side surfaces to restrict lateral movement of the ball portion, and the guide groove has a through groove capable of causing the ball portion to be in a noncontact state in a direction of the biasing force at least when the pen point is in the retracted state.