JP5496046B2 - Writing instrument - Google Patents

Description

  The present invention relates to a writing instrument in which one core can be extended by rotating a shaft cylinder.

  Conventionally, there is a utility model registration No. 2555673 as a technology in such a field. The writing instrument described in this gazette is a rotary feed-out type, and when the rear shaft is rotated with respect to the front shaft, the driving member arranged in the rear shaft moves back and forth while rotating the refill holder, The tip of the refill held in the refill holder is configured to protrude from the tip of the front shaft. As a writing mechanism for the writing instrument, the cam and the cam chassis are non-rotatably connected by a protrusion provided on the outer periphery of the cam, and a spiral cam groove is formed by the cam and the cam chassis. On the other hand, an actuator for engaging with the spiral cam groove is formed on the outer peripheral surface of the refill holder. Then, by rotating the rear shaft, the cam groove follows and rotates, and the refill holder advances and retreats in the shaft cylinder through the actuator inserted in the cam groove. Since the refill (center core) is fixed to the refill holder, the front end of the refill can be projected and retracted from the front end of the front shaft by rotating the rear shaft forward or backward.

Utility Model Registration No. 2555673

  However, since the conventional writing instrument described above is equipped with a refill feeding mechanism in the rear shaft, for example, the rear shaft has a complicated shape or the clip provided on the rear shaft is changed. When changing the design, there is a problem that the degree of freedom in designing the rear shaft is low because it depends on the size and shape of the refill feeding mechanism.

  An object of the present invention is to provide a writing instrument that increases the degree of freedom in designing the rear shaft.

The present invention relates to a writing instrument that is capable of feeding out one core inserted in a shaft cylinder composed of a front shaft and a rear shaft.
The front shaft unit that is rotatably connected to the rear shaft has a cam surface that extends in the circumferential direction on the inner wall surface, and the front shaft that is rotatably connected to the rear shaft; A follower portion that is inserted into the front shaft and protrudes on the outer wall surface and slides on the cam surface is formed, and the center core holder that reciprocates in the axial direction within the front shaft, and the follower portion of the center core holder in front And a spring portion to be pressed against the cam surface of the shaft.

  This writing instrument employs a front shaft unit in which a center core feeding mechanism is provided in the front shaft. With this writing instrument, when the front shaft is rotated relative to the rear shaft, the cam surface extending in the circumferential direction on the inner wall surface of the front shaft rotates. Then, the follower portion provided in the core holder urged by the spring portion reciprocates in the axial direction following the cam surface moving in the circumferential direction, and reciprocates the core holder in the axial direction. By reciprocating the center core holder, the tip end of the center core can be projected and retracted from the tip end of the front shaft. Therefore, by adopting the front shaft unit provided with the center feeding mechanism to the writing instrument, the design of the rear shaft can be easily changed, and the degree of freedom in designing the rear shaft can be increased.

Further, it is preferable to further include a connecting ring that is fitted to the inner wall surface of the rear shaft and is rotatably mounted in the circumferential direction at the rear end of the outer wall surface of the front shaft.
Such a connecting ring can stably rotate the front shaft, and can also be used as a component that reliably connects the front shaft unit and the rear shaft.

The front shaft is composed of a front opening portion that can be divided into two parts by screw connection and a holder housing portion, and a coil spring as a spring portion is provided around the center core loaded in the center core holder, and the front end of the coil spring is It is preferable that the coil spring is locked to the front opening, the rear end of the coil spring is locked to the center core, and the rear end of the center core is regulated in the center core holder.
In such a configuration, the core can be pulled out from the core holder together with the coil spring by turning the front opening of the front shaft and separating it from the holder housing. Thus, this structure can exchange a core from the front side of a writing instrument, and replacement | exchange of a core is easy.

  According to the present invention, the degree of freedom in designing the rear shaft can be increased.

It is a perspective view which shows one Embodiment of the writing instrument which concerns on this invention. It is a perspective view which shows the state which isolate | separated the front shaft unit and the rear shaft. It is sectional drawing of the writing instrument shown by FIG. FIG. 2 is an exploded perspective view of the writing instrument shown in FIG. 1. (A) is sectional drawing of the holder accommodating part which has a cam surface, (b) is a development view of a cam surface.

  Hereinafter, preferred embodiments of a writing instrument according to the present invention will be described in detail with reference to the drawings. In the following description, the pen tip side is referred to as “front side”.

  As shown in FIG. 1 and FIG. 2, the writing instrument 1 is a rotation feeding type, and the center core 2 can be moved in and out by the rotation of the shaft cylinder 5. The shaft cylinder 5 includes a front shaft 3 and a rear shaft 4, and a clip 6 is integrally formed on the rear shaft 4.

  The front shaft unit 10 rotatably connected to the rear shaft 4 is equipped with a center feeding mechanism in the front shaft 3. In the front shaft unit 10, the core 2 is stored, and the core 2 can be exchanged from the front side of the writing instrument 1.

  As shown in FIGS. 2 to 4, the front shaft unit 10 includes a front shaft 3 that can be divided into two parts, and a cylindrical core holder 11 into which the core 2 is loaded. The front shaft 3 includes a conical tip 12 having a male thread 12a formed at the rear and a holder housing 13 having a female thread 13a formed at the front, and the front 12 is removed. Thus, the core 2 can be taken out and the core 2 can be replaced.

  A female screw portion 13a and a cam surface 14 extending in the circumferential direction are formed on the inner wall surface 13b of the substantially cylindrical holder accommodating portion 13 whose both ends are open. The cam surface 14 protrudes in a step shape over substantially the entire circumference of the inner wall surface 13b, and a boundary surface that is one step higher on the rear side than the front side is used as the cam surface 14 on the inner wall surface 13b.

  The cylindrical holder accommodating portion 13 includes a large diameter portion 13c located on the front side and a small diameter portion 13d located on the rear side. The large-diameter portion 13 c is formed with a female screw portion 13 a, and the outer surface of the large-diameter portion 13 c is continuous with the outer surface of the leading end portion 12 and is exposed to the outside of the writing portion 1. On the other hand, the small diameter portion 13d is inserted into the rear shaft 4 and is not exposed to the outside of the writing portion 1.

  A follower portion 16 that slides on the cam surface 14 is formed on the outer wall surface 11 a of the core holder 11 that passes through the holder housing portion 13. A flange portion 11 b is formed at the front end of the core holder 11, and the follower portion 16 extends from the flange portion 11 b in a key shape in the axis L direction on the outer wall surface 11 a of the core holder 11. Two follower portions 16 are formed with a phase angle of 180 degrees in the circumferential direction.

  A semicircular sliding contact portion 16a is formed on the end surface of the follower portion 16 in order to improve the sliding performance on the cam surface 14 (see FIG. 5). Then, the core holder 11 reciprocates in the direction of the axis L in accordance with the movement of the follower portion 16.

  Further, in order to keep pressing the sliding contact portion 16a of the follower portion 16 against the cam surface 14, a compression coil spring (spring portion) 17 is provided around the center core 2, and the front end of the compression coil spring 17 has a leading end. The compression coil spring 17 is engaged with a spring contact portion (crimp) 2 a formed in the middle of the core 2, and is engaged with a spring contact portion 12 b formed in a step shape on the mouth portion 12. The rear end is restricted from moving rearward by the rear end wall 11 c of the core holder 11. Therefore, the compression coil spring 17 continues to apply a biasing force toward the rear to the core holder 11, so that the sliding contact portion 16 a of the follower portion 16 can be constantly pressed against the cam surface 14.

  Further, the front shaft unit 10 is provided with a connecting ring 18, and the connecting ring 18 enables the front shaft unit 10 and the rear shaft 4 to be freely connected. The connecting ring 18 is locked by a retaining claw 22 formed at the rear end of the small diameter portion 13d of the holder accommodating portion 13, and on the rear end side of the outer wall surface of the small diameter portion 13d of the holder accommodating portion 13, It is fitted from the front end side of the retaining claw 22 and is rotatably mounted in the circumferential direction.

  As shown in FIG. 2, on the outer surface of the connecting ring 18, a ring-shaped convex portion 18a for fitting into a ring-shaped concave portion 4b formed on the inner wall surface 4a of the rear shaft 4 is provided side by side. . When the writing instrument 1 is assembled, when the front shaft unit 10 is inserted into the rear shaft 4 in the direction of the axis L, the convex portion 18a of the connecting ring 18 is fitted to the concave portion 4b with one touch.

  Such a connecting ring 18 can stably rotate the front shaft 3 and can also be used as a component that reliably connects the front shaft unit 10 and the rear shaft 4. A ring-shaped spacer portion 19 is integrally formed on the front side of the small-diameter portion 13d of the holder accommodating portion 13 in order to prevent the front shaft unit 10 from rattling in the rear shaft 4.

  A slit 20 extending in the direction of the axis L is formed at the rear end of the core holder 11, and a rotation stopper piece 21 protruding in the radial direction is formed on the inner wall surface 4 a of the rear shaft 4. . Then, the rotation stopper piece 21 enters the slit 20 of the core holder 11 so that the rotation prevention of the core holder 11 and the linear movement in the direction of the axis L are possible.

  As shown in FIG. 5, a cam surface 14 extending in the circumferential direction is formed on the inner wall surface 13 b of the holder accommodating portion 13. The cam surface 14 includes a guide surface 14c extending obliquely from a valley bottom 14a at the lowest position (center buried position) to a top 14b at the uppermost position (core protruding position), and a top 14b of the guide surface 14c. A locking recess 14d that is formed and enables the sliding contact portion 16a of the follower portion 16 to be dropped is provided. Such cam surfaces 14 are formed at two locations on the inner wall surface 13b of the holder accommodating portion 13 with a phase angle of 180 degrees in the circumferential direction, and the follower portion 16 also corresponds to the outer wall surface of the core holder 11 so as to correspond to this. Two locations are formed in 11a with a phase angle of 180 degrees in the circumferential direction.

  In the writing instrument 1 having such a configuration, as shown by an arrow A in FIG. 1, when the front shaft 3 is rotated with respect to the rear shaft 4 so as to be twisted, it is formed on the inner wall surface of the front shaft 3. The cam surface 14 is rotated together with the front shaft 3. And the follower part 16 provided in the core holder 11 urged by the compression coil spring 17 follows the cam surface 14 moving in the circumferential direction and reciprocates in the axis L direction. Reciprocates in the direction of the axis L. By reciprocating the core holder 11, the tip of the core 2 can be projected and retracted from the tip of the front shaft 3.

  When the user twists the front shaft 3, the follower portion 16 moves in the axial direction from the valley bottom 14 a toward the top portion 14 b along the guide surface 14 c forming an inclined surface. At this time, the compression coil spring 17 continues to be compressed, and finally the sliding contact portion 16a of the follower portion 16 is dropped into the locking recess 14d beyond the top portion 14b, and the tip of the core 2 is moved to the front shaft 3 Protrusively and ready for writing. Next, when the front shaft 3 is twisted in the opposite direction and the sliding portion 16a of the follower portion 16 gets over the locking recess 14d, the follower portion 16 slides down the guide surface 14c at a stroke by the spring force of the compression coil spring 17, The tip of the core 2 can be quickly hidden in the front shaft 3.

  Thus, by employing the front shaft unit 10 including the front shaft 3, the core holder 11, and the compression coil spring 17, the center of gravity at the time of writing can be brought to the front shaft 3 side, and the rear shaft 4 The design can be easily changed, and the degree of freedom in designing the rear shaft 4 can be increased.

  Further, when exchanging the core 2, the center core 2 can be pulled out from the core holder 11 together with the compression coil spring 17 by turning the front end portion 12 of the front shaft 3 and separating it from the holder housing portion 13. Thus, the core 2 can be exchanged from the front side of the writing instrument 1, and the workability of exchanging the core 2 is facilitated.

  DESCRIPTION OF SYMBOLS 1 ... Writing instrument, 2 ... Center core, 3 ... Front shaft, 4 ... Rear shaft, 5 ... Shaft cylinder, 10 ... Front shaft unit, 11 ... Center core holder, 12 ... Front opening part, 13 ... Holder accommodation part, 14 ... Cam surface, 16 ... follower part, 17 ... compression coil spring (spring part), 18 ... connecting ring, L ... axis.

Claims (3)

In a writing instrument that allows one core inserted in a cylinder composed of a front shaft and a rear shaft to be extended,
The front shaft unit rotatably connected to the rear shaft is
The front shaft having a cam surface extending in the circumferential direction on the inner wall surface and rotatably connected to the rear shaft;
A core holder which is inserted into the front shaft and protrudes on the outer wall surface and slides on the cam surface, and reciprocates in the axial direction within the front shaft;
A writing instrument comprising: a spring portion that presses the follower portion of the core holder against the cam surface of the front shaft.   2. The coupling ring according to claim 1, further comprising a coupling ring that is fitted to an inner wall surface of the rear shaft and is rotatably mounted in a circumferential direction at a rear end of the outer wall surface of the front shaft. Writing instruments.   The front shaft includes a front opening portion that can be divided into two parts by screw connection and a holder housing portion, and a coil spring as the spring portion is provided around the core loaded in the core holder, and the coil spring The front end of the coil spring is locked to the front opening, the rear end of the coil spring is locked to the center core, and the rear end of the center core is regulated in the center core holder. The writing instrument according to Item 1 or 2.

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