JPH0627432Y2 - Small tube pen tip mounting structure - Google Patents

Description

[Detailed Description of the Invention] (Industrial field of application) The present invention relates to a small-tube pen tip in a small-tube writing instrument in which a writing portion is composed of a small-tube nib and a needle body loosely inserted in the small-tube nib. It relates to a mounting structure.

(Prior art and its problems) Conventionally, in most cases, the small-tube pen tip of the small-tube writing instrument is fixed by press-fitting to the attachment hole at the tip of the synthetic resin holder. , Because the holder that press-fits the small tube nib is made of synthetic resin due to its force during writing, it is liable to be deformed, so the tip of the small tube nib may be slightly decentered or extremely pulled out. As a result, it includes problems such as hindering the subsequent writing. Further, in this case, generally, in order to improve the efficiency of press-fitting work of the small tube pen tip into the holder, as shown in FIG. 4, a small sliding needle-like guide hole H is formed in the small tube pen tip attachment hole opening of the holder. However, with the presence of this guide hole, the microscopic gap between the pen tip and the holder, which occurs intermittently due to the deformation of the synthetic resin holder during writing, and the vibration of the booth pen tip during writing, As a result, the unpleasant sound is generated as a result of being complicatedly related to each other, and the vibration is transmitted to the hand, which makes the writing work unpleasant.

Therefore, in order to solve these problems, generally, a metal tip is placed on the outside of the tip of the synthetic resin holder so that the synthetic resin holder is deformed as much as possible. However, in this case, it is not possible to expect a sufficient improvement in accuracy due to the design dimension of the tip metal, and in addition to the variation in the outer diameter of the holder and the plating thickness when the metal tip is plated, the tip metal eventually becomes It was difficult to cover it, or it was difficult to remove it, making it difficult to achieve the intended purpose, and there was a risk that the above problems would recur.

(Means for Solving the Problems) The present invention has been made in view of the above-mentioned circumstances, and a small tube nib is press-fitted and fixed in a pen tip attachment hole at the tip of a synthetic resin holder, and a metal tip is formed on the outside of the tip of the holder. A small tube nib mounting structure in which a tip is fitted, wherein a plurality of fitting projections are provided on an outer wall portion corresponding to the pen tip fixing portion of the holder, and the fitting projection is pressed against the inner surface of the tip. The various problems described above are solved by making the gist of the small tube pen tip mounting structure characterized by the above.

(Operation) In the present invention, since a plurality of fitting projections are provided on the outer wall portion corresponding to the small tube nib fixing portion of the synthetic resin holder to which the metal tip is fitted, the metal tip and the holder are attached. Even if there are variations in design dimensions between the two, or even if there is a change in the dimensions of the tip metal due to various plating treatments on the surface of the tip metal, these are absorbed by the soft elasticity due to the resin due to the protrusions, and the tip metal is held in the holder. In this case, it is firmly fixed to the tip, so that the problem of eccentricity of the tip of the small tube nib and the generation of unpleasant noise during writing can be prevented as much as possible.

(Example) Hereinafter, the present invention will be described in detail based on an example.

FIGS. 1 and 2 show an embodiment of the present invention. A holder 1 made of a synthetic resin such as polyacetal or polypropylene has a small tube nib 2 made of metal such as stainless steel which is press-fitted and fixed to the tip thereof. It has an attachment hole 1a and an intermediate hole 1b at the rear portion thereof. The needle body 3 loosely inserted into the small tube nib 2 with its tip slightly protruded first in the intermediate hole 1b. A weight 4 included in the portion is arranged to be movable back and forth.

A tip 5 made of metal plated with stainless steel or brass is attached to the outside of the tip of the holder 1. Here, the small pen tip 2 of the holder 1 is attached.
A plurality of fitting projections 1c are provided in the longitudinal direction (eight projections in the figure) on the outer wall portion corresponding to the fixed portion 2a, and the inner surface of the tip metal 5 is pressed against each of the fitting projections 1c. Protrusion 1
Because of this, c is slightly deformed due to the resin, so that the tip 5 can be securely fixed to the holder 1 even if there is a dimensional deviation. Therefore, the inner diameter of the tip portion of the tip 5 is preferably set in advance to be slightly smaller than the outermost diameter including the fitting projection 1c of the outer wall portion corresponding to the pen tip fixing portion 2a of the holder 1.

In the present invention, in addition to those shown in the above-mentioned embodiment, for example, as shown in FIG.
A plurality of annular fitting projections 1c 'may be provided on the outer wall portion corresponding to a, and various modes can be adopted without departing from the scope of the present invention.

As the needle means sliding means in the present invention, in addition to the type using the weight in the above description, various elastic bodies can be adopted, and further, as a mechanism for guiding ink, a comb-shaped cross section is used. A so-called bellows, a fiber bundle, or the like can be used.

(Effect) As described in detail above, the present invention is a small tube pen in which a small tube nib is press-fitted and fixed in a pen tip attachment hole at the tip of a synthetic resin holder, and a metal tip is fitted to the outside of the tip of the holder. In the tip mounting structure, a plurality of fitting projections are provided on the outer wall portion corresponding to the pen tip fixing portion of the holder, and the fitting projections are pressed against the inner surface of the tip metal. As a result of being able to fit securely and firmly, the pen tip is slightly decentered by the writing pressure, or the pen tip is pulled out, and furthermore, the unpleasant noise during writing can be prevented as much as possible, which is a practically small size. A tubular writing instrument can be provided.

[Brief description of drawings]

1 and 3 of the drawings are longitudinal sectional views of a main part of a small tube type writing instrument showing an embodiment of the present invention, and FIG. 2 is a sectional view taken along the line AA in FIG. 1 and FIG. FIG. 7 is an enlarged view of a main part for explaining a conventional example. 1 ... Holder, 1a ... Pen tip mounting hole, 2 ... Small tube pen tip, 2a ... Fixed part, 5 ... Tip metal

Claims (1)

[Scope of utility model registration request] 1. A small-tube nib mounting structure in which a small-tube nib is press-fitted and fixed in a pen-nip mounting hole at the tip of a synthetic resin holder, and a metal tip is fitted to the outside of the tip of the holder. 2. A small tube nib attachment structure, wherein a plurality of fitting projections are provided on an outer wall portion corresponding to the pen tip fixing portion, and the fitting projections are pressed against the inner surface of the tip metal.