JPH0223420Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention uses a small tube and a rod that is slidably disposed inside the small tube as a pen tip, and an elastic body interposed between the rod and an ink relay core allows the rod to be The purpose of this is to prevent variations in the ink ejection capacity of small tube writing implements that have been given a sliding force due to production problems, and to stabilize the quality.

An example of the conventional structure of this type of writing instrument will be explained with reference to FIG. 1. A holding member for fixing a small tube 1 made of metal or other appropriate material and having wear-resistant protrusions attached or surface treated as necessary. 2 includes a hollow hole 21 into which a rod 3 made of synthetic resin or metal is inserted and which has an ink groove on the side wall if necessary; an elastic body 4 made of rubber, porous urethane, etc.; and a fiber bundle or resin sintered body. A rear hole 22 into which an ink relay core 5 made of a body or the like is fitted is formed.
A narrow rod body 3 with a nailhead-shaped bulge 31 formed at its rear end.
is loosely fitted into the inner hole 21 of the holding member 2 and the center hole 11 of the small tube 1, and the bulging portion 31
has a larger diameter than the diameter of the medium hole 21 and comes into contact with the end 23 of the medium hole 21, so that the thin rod body 3 does not come out of the small tube 1, and moreover, the elastic body 4 absorbs the sliding force back and forth. Granted.

The rod 3 mentioned above is extremely thin, for example,
In some cases, the thickness is about 0.2 mm or less, and therefore, considerable effort is required to form the bulge 31. A particular problem is that by forming bulges 31 of the same shape on multiple rods 3, even with advances in mechanization and automation, bulges 31 that are too small or too large are often formed. Become. The bulge 31 is too small or too large because the space A formed between the end 23 of the hollow 21 of the holding member 2 and the elastic body 4
This means that variations occur in the volume of the ink, which results in variations in ink discharge. That is, space A
Depending on the initial settings, it doesn't really matter if it exists or not, but if it exists, it will become an ink pool, and the volume of this ink pool will inevitably affect the ink discharge. This affects the amount of ink discharged, and the initially set ink discharge amount cannot be determined.

The present invention was devised in view of the above, and uses a small tube and a rod slidably arranged inside the small tube as a pen tip, and an elastic body interposed between the rod and an ink relay core. In the small tube type writing instrument in which a sliding force is applied to the rod, recesses into which the rear end of the rod can be inserted are formed in the front and rear parts of the elastic body, and the rear end of the rod is in the recess on the front side. The gist of the present invention is a small tube type writing instrument characterized in that the end portion is inserted so as to be supported at the bottom of the recess. The embodiments shown in the drawings will be explained below.

FIG. 2 shows an embodiment of the present invention, and the same parts as in the embodiment shown in FIG. Also, as the elastic body 401, the third
As shown in FIG.
1, insert the rear end 311 of the rod 301 into the recess 411 on the front side, and insert the rod 301 into the recess 411.
It is supported at the bottom of 11.

The elastic body 401 shreds the long cylindrical object and creates the recess 4.
11,421 or by molding using a mold such as press molding, and
As mentioned above, the rod can be formed by simply extrusion molding and then cut into pieces, so molding of both is relatively easy and dimensional variations can be minimized. Therefore, the rod body 301 and the elastic body 401
The external shape formed by both of the rods 3 and the elastic body 4 can be made into a desired shape compared to the external shape formed by both the rod body 3 and the elastic body 4 shown in FIG. As a result, even when forming the space A shown in FIG. 1, the setting becomes easy and the problem of variations in ink discharge amount can be reduced.

In addition, the recess 4 on the rear side of the elastic body 401 in FIG.
21 is an ink reservoir whose volume changes as the rod 301 slides;
The rear end 311 of the rod 301 can be inserted in the same way as the recess 411 on the front side, and it can also be used as a recess on the front side. It is also possible to form a section and fit into the recess 421 for convenience when assembling the writing instrument.

By the way, in FIG. 2, if the elastic body 401 is impermeable to ink, it may be suspected that the ink conduction path is not secured, but in such a case, the rear hole 22 or the center of the holding member 2 It is sufficient to form a groove in the end 23 of the hole 21, to form a groove in the outer wall of the elastic body 401, or to make the shape of the elastic body 401 small. Examples are also included in FIGS. 5 to 10, which show examples.

5 and 6 show an elastic body 402 having concave portions 412 and 422, which serve as the diameter-reducing front and rear portions and the diameter-expanding openings. The front and rear portions of the diameter reduction facilitate insertion into the holding member 2, and the recesses 412 and 422 facilitate insertion of the rod 301.

Elastic bodies 403, 404, 4 in FIGS. 7 to 9
05 is an example showing that the front and rear recesses do not have to be hole-shaped, FIG. 7 is an example of slit-shaped recesses 413, 423, and FIG. 8 is an example of slit-shaped recesses 414, 424. FIG. 9 shows an example in which the recesses 415 and 425 are formed at different angles from each other, and the recesses 415 and 425 have a "+"-shaped cross section. Further, in the example shown in FIG. 9, a recess 435 is also formed, and the recess 435 is an example of forming a groove in the outer wall of the elastic body as described above.

Other than these, various modifications can be made without departing from the gist of the present invention. For example, projections or circumferential ribs 446 are formed in the recesses 416 and 426 like the elastic body 406 in FIG.
1 can be positively press-fitted, or it can be used to form a bulge at the rear end of the rod so that it can fit over the rod. Here, it will be easily understood that even if a bulge is formed at the rear end of the rod, the problem as shown in FIG. 1 can be ignored. The reason for forming the protrusion 446 is
This shows that if the elastic body is made symmetrical, it can be used without worrying about the front or back of the elastic body. Furthermore, regarding the positional relationship of the elastic body, as long as it is satisfied that the elastic body is located between the ink relay core and the rod and applies a sliding force to the rod, the intervening state of the elastic body is appropriate.

As mentioned above, the small tube type writing instrument of the present invention is
A small tube type writing instrument in which the pen tip is a small tube and a rod arranged so as to be slidable inside the small tube, and a sliding force is applied to the rod by an elastic body interposed between the rod and an ink relay core. , a recess into which the rear end of the rod can be inserted is formed in the front and rear parts of the elastic body, and the rear end of the rod is inserted into the recess on the front side so as to be supported at the bottom of the recess. Therefore, by stabilizing the overall shape of the rod and the elastic body, it is possible to suppress variations in ink discharge.In addition, a recess is provided not only at the front part of the elastic body but also at the rear part, and both of these are located at the rear end of the rod. Since the part can be inserted, assembly efficiency is also satisfied.In addition, since the rear end of the rod is supported at the bottom of the recess, even if it is a soft elastic body, the rod can be inserted in a well-positioned state. It can be made into a mass-produced product with good quality.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional view of the main part showing a conventional example, Fig. 2 is a longitudinal sectional view of the main part showing an embodiment of the present invention, Fig. 3,
FIG. 4 is a vertical sectional view and a perspective view showing an example of an elastic body, FIGS. 5 and 6 are a vertical sectional view and a perspective view showing other examples of an elastic body, and FIGS. 7 to 9 are a longitudinal sectional view and a perspective view showing an example of an elastic body. FIG. 10 is a perspective view showing another example of the elastic body, and FIG. 10 is a longitudinal sectional view showing another example of the elastic body. 1: tubule, 3,301: rod, 4,401...4
06: Elastic body, 411, 412...416: Front side recess, 421, 422...426: Rear side recess,
5: Ink relay core.

Claims (1)

[Scope of utility model registration request] A small tube type writing instrument in which the pen tip is a small tube and a rod arranged so as to be slidable inside the small tube, and a sliding force is applied to the rod by an elastic body interposed between the rod and an ink relay core. , forming recesses into which the rear end of the rod can be inserted in the front and rear parts of the elastic body, and inserting the rear end of the rod into the recess on the front side;
A small tube type writing instrument, characterized in that it is inserted so as to be supported at the bottom of the recess.