JP2008068524A - Writing implement - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a writing implement which is provided with a double-tubular cap excellent in fitting-removing properties and further in productivity. <P>SOLUTION: The writing implement has a constitution that the double-tubular cap 20 composed of an outer cap 21 and an inner cap 22 is fitted removably to the front end side of a shaft tube 10. An outward projection 12b for fitting and removing the cap 20 is provided on the outer peripheral surface on the front end side of the shaft tube 10, while an inward projection 22b1 for fitting and removing the cap which can get over the outward projection 12b and can be fitted to this projection is provided on the inner peripheral surface of the inner cap 22, and a notch part 22b2 which is so disposed as to correspond to the position in the axial direction of the cap of the inward projection 22b1 and opens backward is provided in the peripheral wall of the inner cap 22. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a writing instrument such as a ballpoint pen, a mechanical pencil, a sign pen, and the like, in which a double cylindrical cap is mounted on the tip side of a shaft cylinder.

Some conventional writing instruments are equipped with a double cylindrical cap composed of an outer cap and an inner cap.
The reason for forming the cap in a double cylinder shape in this way is that the outer cap mainly has the function of fitting and holding the shaft cylinder, and the inner cap has the function of mainly maintaining the sealing property. There are various types according to the type and usage of the writing tool, such as providing the fitting holding function or the hermetic holding function to one of the caps.

By the way, when configuring a double cylindrical cap, it is also possible to integrally mold the outer cap and the inner cap, but in this case, the dimensional accuracy decreases due to molding sink marks, Airtightness and poor fitting are likely to occur.
Therefore, when a double cylindrical cap is configured, the outer cap (13) and the inner cap (5) are separately molded and assembled, for example, as a writing instrument described in Patent Document 1. Is preferred.

However, according to the prior art described in Patent Document 1, the sealing projection (fitting projection) 11 on the inner peripheral surface of the outer cap (13) is fitted over the entire outer periphery of the writing instrument body (15). Since it is set as the structure to match, the fitting force is comparatively large and it is easy to impair the detachability of the cap (1) with respect to a writing instrument main body (15).
Further, according to the prior art, in the manufacturing stage of the double cylindrical cap (1), the protrusion (7) on the outer peripheral surface of the inner cap (5) with respect to the locking projection (9) of the outer cap (13). ) Must be overcome and fitted. Therefore, in order to facilitate the over-fitting operation and prevent the inner cap (5) from easily falling off after assembly, the dimensions of the locking projection (9) and the convex portion (7) are increased. It is necessary to maintain the accuracy, and as a result, the productivity is likely to decrease.
Japanese Patent Laid-Open No. 11-32181

  The present invention has been made in view of the above-described conventional circumstances, and the subject of the present invention is to provide a writing instrument provided with a double cylindrical cap with good detachability, and further good productivity. Another object of the present invention is to provide a writing instrument having a double cylindrical cap.

  In order to solve the above-described problem, in the first invention, in a writing instrument in which a double cylindrical cap composed of an outer cap and an inner cap is detachably attached to a front end side of the shaft tube, A cap attaching / detaching outward projection for attaching / detaching the cap is provided on the outer peripheral surface of the front end side, and a cap attaching / detaching capable of getting over and fitting to the cap attaching / detaching outward projection is provided on the inner peripheral surface of the inner cap. Inward projections are provided, and the peripheral wall of the inner cap is arranged corresponding to the position of the cap mounting / detaching inward projection in the cap axial direction, and is provided with a notch opening rearward. It is characterized by.

  Further, in the second invention, an inward projection for assembling for assembling the inner cap is provided on the front end side inner peripheral surface of the outer cap, and the front end side outer peripheral surface of the inner cap is provided with the An outward projection for assembly that fits over and fits the inward projection for assembly is provided, and is arranged on the peripheral wall of the inner cap corresponding to the position of the inward projection for assembly in the cap axial direction. In addition, a notch that opens forward is provided.

  In the third invention, an inner protrusion for preventing the inner cap from being removed from the inner cap on the rear end side of the outer cap is provided to prevent the inner cap from coming off the outer cap. An inner cap retainer is provided on the outer peripheral surface of the rear end so that the inner cap can be brought into contact with the inward projection for retaining the inner cap from the front when the inner cap is enlarged by fitting with the shaft cylinder. An outward projection is provided.

Since the present invention is configured as described above, the following effects can be obtained.
According to the first aspect of the present invention, in order to mount the double cylindrical cap on the shaft cylinder, when the cap-removing inward projection of the inner cap gets over the cap-removing outward protrusion of the shaft cylinder, The inner cap is flexibly expanded by the notch.
Similarly, in order to remove the double cylindrical cap from the shaft cylinder, the inner cap cap attaching / detaching inward projection may be reversed over the shaft cylinder cap attaching / detaching outward projection. The diameter of the cap is flexibly expanded by a notch portion opened rearward.
Therefore, the cap can be attached and detached with respect to the shaft tube.

Further, according to the second invention, when the inner cap is mounted on the outer cap, the inner cap is mounted on the inner cap when the inner cap is mounted on the inner cap. The cap is flexibly reduced in diameter by the notch.
Therefore, the operation | work at the time of attaching an inner cap to an outer cap can be performed favorably, and productivity of a double cylindrical cap can be improved by extension.

Further, according to the third aspect of the invention, the outward protrusion for retaining the inner cap expands in diameter by fitting with the shaft tube, and can come into contact with the inward protrusion for retaining the outer cap from the front. Position.
Therefore, it is possible to prevent the inner cap from being detached from the outer cap due to the tensile force when removing the double cylindrical cap from the shaft tube.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
The writing instrument A includes a shaft cylinder 10 in which a writing portion 31 of a ballpoint pen refill 30 protrudes from the front end, and a double cylindrical cap 20 that is detachably mounted on the front end side of the shaft cylinder 10 ( (Refer FIG. 1 (a) (b)).
In addition, in this specification, the front shall mean the writing part 31 side (in other words, cap 20 front end side) in the axial direction of the opening / closing body 10. The term “rear” means the side opposite to the writing portion 31 in the coaxial direction.

  The shaft tube 10 has a front end portion 12 screwed to a front end side of a long tubular main body portion 11. As another example of the shaft tube 10, a configuration in which the main body portion 11 and the tip portion 12 are integrally formed may be used.

  The main body 11 has a cylindrical shape extending over substantially the entire length of the writing instrument A, and has a ball-point pen refill 30 inside thereof, and a grip portion 13 made of an elastic material is annularly mounted on the outer peripheral surface thereof.

Further, the front end portion 12 has a substantially conical inclined surface 12a on the front end side thereof, and has a cap attaching / detaching outward projection 12b for attaching / detaching the cap 20 slightly behind the inclined surface.
Further, the front end portion 12 has an annular convex portion 12c that abuts a rear end portion of an inner cap 22 described later on the rear end side slightly from the cap attaching / detaching outward projection 12b. The rear portion also has an annular groove 12d (see FIG. 1B).
And this tip part 12 makes the writing part 31 of the ball-point pen refill 30 inserted in the inside protrude from the front end.

  The outward projection 12b for attaching / detaching the cap includes an inclined surface 12a that forms the outer peripheral surface on the front end side of the front end portion 12, a cylindrical flat surface 12b1 connected to the rear end of the inclined surface 12a, and the flat surface 12b1. It consists of an inclined surface 12b2 having a reduced diameter from the rear end toward the rear, and is continuous in an annular shape over the entire circumference of the front opening 12 (see FIG. 1 (a)).

The flat surface 12b1 is a surface pressed against an inner cap 22 of the cap 20 described later.
In addition, the inclination angle of the inclined surface 12b2 is appropriately set so that the attached cap 20 can be removed smoothly.

The flat surface 12b1 may be omitted, and the cap attaching / detaching outward projection 12b may be formed in an acute angle shape including only the inclined surface 12a and the inclined surface 12b2. In this configuration, the inclined surface 12a is formed. And the inclined surface 12b2 may be worn by friction with the inner cap 22 and the cap fitting force may be reduced.
Therefore, according to a preferred aspect of the present embodiment, by providing the flat surface 12b1 between the inclined surface 12a and the inclined surface 12b2, the wear as described above is reduced, and the cap fitting force is appropriately adjusted over a long period of time. To be maintained.

  Further, the annular convex portion 12c is formed so as to be contacted in the axial direction by an inner cap retaining outward projection 22b3, which will be described later, and to be covered by the projection 22b3.

  The annular groove portion 12d is formed between the annular convex portion 12c and the grip portion 13 on the shaft tube 10 side by reducing the diameter of the rear side of the annular convex portion 12c. An elastic annular member 14 is fitted in the annular groove 12d.

  The elastic annular member 14 is formed of rubber or an elastic synthetic resin material that is harder than the grip portion 13, and improves the grip feeling particularly for a user who grips the vicinity of the front end portion 12 on the distal end side of the shaft tube. It acts to prevent the gripping hand from shifting forward due to writing pressure.

  The cap 20 includes an outer cap 21 and an inner cap 22 mounted in the outer cap 21 (see FIGS. 2A and 2B).

  The outer cap 21 has a substantially bottomed cylindrical shape that closes the front end side and opens the rear end side, and has a small cylindrical portion 21a for mounting the inner cap 22 on the inner front end side thereof. On the inner rear end side, an inward projection 21b for retaining the inner cap is provided.

The small cylinder part 21a has an inward projection 21a1 for assembly for assembling the inner cap 22 on its inner peripheral surface (see FIG. 2 (a)).
The inward projection 21a1 for assembly has a substantially mountain shape in cross section, and is provided in an annular shape over the entire inner peripheral surface of the small tube portion 21a.

A plurality of inward projections 21b for retaining the inner cap are disposed at predetermined intervals on the inner peripheral surface of the rear end side of the outer cap 21 in the circumferential direction.
The inward projection 21b for retaining the inner cap is a projection having a substantially mountain shape in section protruding from the inner peripheral surface of the outer cap 21 in the centripetal direction, and abuts against the rear end of the inner cap 22 when the diameter is increased. The inner cap 22 is prevented from coming off the outer cap 21.

A guide protrusion 21c is disposed between the inner cap retaining inward protrusions 21b and 21b adjacent in the circumferential direction.
The guide protrusion 21c has a top portion formed substantially parallel to the axis of the outer cap 21.
As shown in FIG. 2 (a), the guide protrusion 21c is brought into close contact or sliding contact with the large cylindrical portion 22b on the rear end side of the inner cap 22 when the inner cap 22 is assembled to the outer cap 21. While guiding the forward movement of the cap 22 in the axial direction, the inner cap 22 is aligned with the outer cap 21.
Further, as shown in FIG. 1A, the guide projection 21c is close to or slides on the outer peripheral surface of the elastic annular member 14 on the shaft tube 10 side when the cap 20 is mounted on the front end side of the shaft tube 10. The contact guides the cap 20 to move rearward in the axial direction and aligns the cap 20 with the shaft tube 10.

Further, the inner cap 22 has a substantially conical shape having a top portion penetrated so as to loosely insert the writing portion 31.
On the front end side of the inner cap 22, a substantially cylindrical small tube portion 22 a that fits with the small tube portion 21 a of the outer cap 21 is formed. An outer protrusion 22a1 for assembly and a notch 22a2 are provided on the outer peripheral surface of the small tube portion 22a (see FIG. 2A).

  The assembly outward projection 22a1 is a projection for getting over and fitting to the assembly inward projection 21a1 on the outer cap 21 side, and is formed across the circumferential direction of the small tube portion 22a.

Further, the notch portion 22a2 is arranged corresponding to the position of the assembling outward projection 22a1 in the cap axial direction so as to intersect the assembling outward projection 22a1, and the peripheral wall of the small tube portion 22a is formed. It is formed so as to penetrate in the radial direction and open forward.
If it demonstrates in detail about the preferable example shown in figure, the dimension of the cap axial direction of the notch part 22a2 is set a little longer than the dimension of the cap axial direction of the outward protrusion 22a1 for assembly | attachment.
According to such an arrangement and shape of the notch 22a2, the small cylindrical portion 22a of the inner cap 22 is easily elastically reduced in diameter, and as a result, the outer cap 21 and the inner cap 22 are assembled as will be described in detail later. Workability can be improved.
Note that, according to the illustrated preferred example, the two notches 22a2 are provided so as to face each other in the circumferential direction of the small tube portion 22a, but may be one or three or more.

  Further, a substantially cylindrical large tube portion 22 b is provided on the rear end side of the inner cap 22. The large cylinder portion 22b is provided with an inward projection 22b1 for cap attachment / detachment, a notch portion 22b2, and an outward projection 22b3 for retaining the inner cap.

The cap attaching / detaching inward protrusions 22b1 are protrusions having a substantially mountain-shaped cross section protruding in the centripetal direction, and a plurality of inward protrusions 22b1 are provided at predetermined intervals over the inner peripheral surface of the large cylinder portion 22b in the circumferential direction.
When the cap 20 is mounted on the front end side of the shaft tube 10, the cap attaching / detaching inward projection 22 b 1 gets over and fits over the cap attaching / detaching outward projection 12 b on the outer peripheral surface of the tip portion 12.

Further, the notch 22b2 is arranged corresponding to the position of the cap attaching / detaching inward protrusion 22b1 in the cap axial direction, and is formed so as to penetrate the peripheral wall of the large cylindrical portion 22b in the radial direction and open backward. .
If it demonstrates in detail about the illustrated preferable example, the dimension of the notch part 22b2 in the cap axial direction is set to be slightly longer than the dimension in the cap axial direction of the outward projection 22b3 for inner cap retaining.
According to such an arrangement and shape of the notch portion 22b2, the large tube portion 22b of the inner cap 22 is easily elastically expanded in diameter. As a result, the cap 20 is attached to and detached from the front end side of the shaft tube 10 as will be described in detail later. Can be made easier.
Note that, according to the illustrated preferred example, the two notches 22b2 are provided so as to face each other in the circumferential direction of the large cylinder portion 22b, but may be one or three or more.

Further, the inner cap retaining outward projection 22b3 is formed so as to protrude in the centrifugal direction from the outer peripheral surface of the rear end portion of the inner cap 22 and to extend in the circumferential direction.
More specifically, the inner cap retaining outward projection 22b3 covers the annular convex portion 12c of the front end portion 12 in the circumferential direction when fitted to the front end portion 12, and the annular convex portion 12c. It is formed in a substantially L-shaped cross section so as to abut against.
When the inner cap 22 is expanded in diameter by fitting the inner cap 22 to the front opening 12, the outer cap 22 b 3 for preventing the inner cap from being removed is disposed on the outer cap of the outer cap 21. It is made to contact | abut from the front with respect to the inward protrusion 21b for retaining.

Next, the effect of the writing instrument A having the above configuration will be described in detail.
First, in the manufacturing stage of the writing instrument A, when the inner cap 22 is assembled to the outer cap 21, the small cylindrical portion 22a on the front end side of the inner cap 22 is inserted into the small cylindrical portion 21a on the inner front end side of the outer cap 21. When pressed, the outer cap 21 and the inner cap 22 are fitted so that the outer projection 22a1 for assembly on the inner cap 22 side gets over the inward projection 21a1 for assembly on the outer cap 21 side ( (Refer FIG. 2 (a) (b)).
At the time of this fitting, the small tube portion 22a on the inner cap 22 side is easily elastically deformed and reduced in diameter by the cutout portion 22a2 of the peripheral wall. Therefore, the assembly work is performed smoothly.

Further, when the cap 20 is mounted on the front end side of the barrel 10 in a normal use state, the cap opening / removal inward projection in the inner cap 22 can be achieved by inserting and pressing the front opening 12 into the inner cap 22. The inner cap 22 and the front end portion 12 are fitted with each other so that 22b1 gets over the cap attaching / detaching outward projection 12b on the outer periphery of the front end portion 12 (see FIGS. 1A and 1B).
During the overcoming, the inner cap 22 is elastically expanded in diameter by the notch 22b2 on the rear end side, so that the cap 20 can be easily attached.

Further, when the cap 20 is removed from the front end side of the shaft tube 10, the inner cap 22 is moved when the cap attaching / detaching inward projection 22b1 in the inner cap 22 gets over the cap attaching / detaching outward projection 12b on the outer periphery of the front end portion 12. The rear end of the inner cap 22 is elastically expanded in diameter so that the inner cap retaining outward projection 22b3 at the rear end of the inner cap 22 can abut against the inner cap retaining inward projection 21b on the inner peripheral surface of the outer cap 21. It becomes a state.
Accordingly, the fact that the inner cap 22 is removed from the outer cap 21 due to the pulling force when the cap 20 is removed from the shaft tube 10 indicates that the inner cap retaining outward projection 22b3 and the inner cap retaining feature. This can be prevented by contact with the inward projection 21b.
It should be noted that the inner cap retaining outward projection 22b3 contacts the inner cap retaining inward projection 21b when the inner cap 22 is elastically expanded by fitting with the shaft tube 10 as described above. Since it is in a contactable state, when assembling the inner cap 22 to the outer cap 21, there is no interference with the inward projection 21b for retaining the inner cap.

It is principal part sectional drawing of the writing instrument concerning this invention, (a) shows the state before mounting | wearing with the cap at the front end side of a axial cylinder, (b) shows the state which mounted | wore the front end side of the axial cylinder. . It is sectional drawing which shows the cap of the writing instrument, (a) shows the state before attaching an inner cap with respect to an outer cap, (b) shows the state after attaching an inner cap with respect to an outer cap.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10: Shaft cylinder 12: Tip part 12b: Outward protrusion for cap attachment / detachment 20: Cap 21: Outer cap 21a1: Inward protrusion for assembly 21b: Inward protrusion for inner cap removal 22: Inner cap 22a1: Assembly Outward projection 22b1: Inward projection for cap attachment / detachment 22a2, 22b2: Notch 22b3: Outward projection for inner cap removal

Claims (3)

In a writing instrument in which a double cylindrical cap consisting of an outer cap and an inner cap is detachably attached to the front end side of the shaft cylinder,
A cap attaching / detaching outward projection for attaching / detaching the cap is provided on the outer peripheral surface of the front end side of the shaft tube,
The inner peripheral surface of the inner cap is provided with an inward projection for cap attachment / detachment that can be fitted over and fitted to the outward projection for cap attachment / detachment,
The writing instrument, wherein a notch portion opened rearward is provided on the peripheral wall of the inner cap in correspondence with the position in the cap axial direction of the inward projection for attaching and detaching the cap. An inward projection for assembly for assembling the inner cap is provided on the inner peripheral surface of the front end side of the outer cap,
On the outer peripheral surface on the front end side of the inner cap is provided an outward projection for assembly that fits over the inward projection for assembly,
2. A peripheral wall of the inner cap is provided corresponding to a position in the cap axial direction of the inward projection for assembly, and is provided with a notch that opens forward. Writing instruments. On the rear end side inner peripheral surface of the outer cap, an inward projection for preventing the inner cap from being detached from the outer cap is provided,
On the rear end side outer peripheral surface of the inner cap, when the inner cap is expanded in diameter by fitting with the shaft tube, it can come into contact with the inward projection for retaining the inner cap from the front. The writing instrument according to claim 1 or 2, further comprising an outward projection for preventing the inner cap from being removed.

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