A ballpoint pen is provided in which the width of the drawing line can be changed, wherein responsiveness can be improved when distinguishing between drawing thin lines and thick lines. A ballpoint pen 1 provided at the pen tip side with a first writing part having a writing ball 25, wherein the ballpoint pen 1 is characterized by being provided with a writing part at the pen tip side with which it is possible to write a thicker line than the line written with the first writing part, only the first writing part being used when the writing weight is 1 g and the writing angle is 90, and the second writing part being used when the writing weight is 200 g, and the writing angle is 40-90.

The present disclosure relates to a system comprising a writing instrument. The writing instrument comprises a ceramic writing ball. The ceramic writing ball comprises relative to the total weight of the ceramic writing ball about 1.0 wt.-% to about 14.6 wt.-% of one or more metal oxides selected from Y.sub.2O.sub.3, HfO, MgO, CaO and/or Ce.sub.2O.sub.3, about 0.15 wt.-% to about 3.0 wt.-% Al.sub.2O.sub.3, and ZrO.sub.2 as balance.

A ballpoint pen bends at the pen tip, that can be changed by the force applied when writing. Wobbling does not occur, and a stable writing feel can be obtained. The ballpoint pen makes it possible to clearly change the thickness of the drawn line by the force applied when writing, so that lines of different thickness can be written with a single writing tip using the angle of the ballpoint pen tip. The ballpoint pen includes: a writing ball; a holder for holding the writing ball; an ink supply section; a shaft body inside which the ink supply section is held; and a tip shaft, which is connected to the tip of the shaft body and from which the holder protrudes during writing. The tip shaft is formed by two-color molding in which a front half and a back half are interdigitated in a saw tooth form.

A ballpoint pen bends at the pen tip, that can be changed by the force applied when writing. Wobbling does not occur, and a stable writing feel can be obtained. The ballpoint pen makes it possible to clearly change the thickness of the drawn line by the force applied when writing, so that lines of different thickness can be written with a single writing tip using the angle of the ballpoint pen tip. The ballpoint pen includes: a writing ball; a holder for holding the writing ball; an ink supply section; a shaft body inside which the ink supply section is held; and a tip shaft, which is connected to the tip of the shaft body and from which the holder protrudes during writing. The tip shaft is formed by two-color molding in which a front half and a back half are interdigitated in a saw tooth form.

A writing implement in which a joint connecting an ink supply section and a ballpoint pen tip together is configured from three members. The three members configuring the joint are a substantially cylindrical center member, a substantially cylindrical surrounding member formed at the outer periphery of the center member, and an interposing member that is molded by a soft member molded so as to cover the outer periphery of the center member and the surrounding member. An annular gap section is provided between the center member and the surrounding member. The leading end of the ink supply section is fitted into the gap section. The joint is formed by two color molding. The center member and the surrounding member are molded by primary molding, and the interposing member is integrally molded onto the center member and the surrounding member by secondary molding.

A writing implement in which a joint connecting an ink supply section and a ballpoint pen tip together is configured from three members. The three members configuring the joint are a substantially cylindrical center member, a substantially cylindrical surrounding member formed at the outer periphery of the center member, and an interposing member that is molded by a soft member molded so as to cover the outer periphery of the center member and the surrounding member. An annular gap section is provided between the center member and the surrounding member. The leading end of the ink supply section is fitted into the gap section. The joint is formed by two color molding. The center member and the surrounding member are molded by primary molding, and the interposing member is integrally molded onto the center member and the surrounding member by secondary molding.

Provided is a ballpoint pen refill including: an ink storage tube made of a synthetic resin and storing an ink thereinside; a ball holder made of a synthetic resin and attached to a distal end of the ink storage tube; a ball pressing rod mounted inside the ball holder; and a writing ball stored in a distal end of the ball holder and having a rear end side held by the ball pressing rod, in which the ball pressing rod includes: a fixing portion fixed to the ball holder; a movable portion slidable in a front-rear direction with respect to the ball holder; a compression portion connecting the fixing portion and the movable portion; and a rearward movement restricting portion protruding from a distal end of the fixing portion and provided with a gap from a rear end of the compression portion.

In order to provide a writing ball capable of suppressing wear of a ball seat of a ballpoint pen tip and obtaining stable ink outflow, a writing ball that is a sphere, the sphere comprising, at least: a first hard component containing a first metal; a second hard component containing a second metal; and a binding component, the writing ball comprising: a first outer surface from which the first hard component is exposed, the first outer surface being an outermost surface of the sphere; and a recess including, as a bottom surface, a second outer surface from which the second hard component is exposed, the second outer surface being recessed inward from the first outer surface, wherein the first outer surface includes a smooth surface is provided.

To make it possible to easily change a writing line width.

A ballpoint pen chip that brings a front half part side of a transfer ball into contact with an inward annular protrusion on a front end side in a chip body from a backward side of the inward annular protrusion and receives a rear half part side of the transfer ball with a front end part of a receiving member. The receiving member includes, on a front end side thereof, a reduction part gradually reduced in a cross-sectional area forward. A front-most end part of the reduction part is disposed backward from the transfer ball. A portion of the receiving member further on a rear side than the reduction part is unretreatably fixed to the chip body and configured to elastically contract when a pressing force is received from the transfer ball.

A writing instrument includes a shaft barrel and a grip provided at part of the shaft barrel. The grip has a cylindrically shaped inside shaft part and a cylindrically shaped outside shaft part arranged at the outside of the inside shaft part, thinner than the inside shaft part, and made of a nonviscoelastic plastic. A space part is provided between the inside shaft part and the outside shaft part.