JPS644540Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a fixing structure for a tail plug that is attached to the end face of the main body or cap of a writing instrument.

A tail plug is attached to the end face of the main body or cap of a writing instrument for functional and aesthetic reasons, and in the past, this tail plug was fixed by screw fitting, press-fitting, etc. However, screw fitting requires time and effort to assemble and has the problem that the screws tend to loosen during use.Furthermore, press-fit fitting also has the problem that the fitting force becomes unstable due to slight variations in the dimensions of the fitting part, and vibrations etc. There were problems such as falling off.

Therefore, the fixing structure of the tail plug for a writing instrument of the present invention has an annular inward protrusion at the tip, and an engagement tube with a plurality of cuts from the tip surface is provided inward from the end surface of the main body of the writing instrument or the cap. At the same time, an engaging element having an annular groove is protruded from the inner surface of the elastic synthetic resin hemispherical tail plug near its tip,
This engaging element is inserted into the engaging cylinder, and the annular end face of the tail plug is pressed and deformed by the main body of the writing instrument or the end face of the cap, and the engaging element is urged outward by the elastic force generated. It is characterized by the above-mentioned annular inner protrusion being engaged with the annular groove of the engaging element, and it is very easy to assemble and is firmly fixed so that there is no risk of it falling off during use. can also be resolved.

Embodiments of the present invention will be specifically described below with reference to the drawings.

An engagement tube 2 is provided on the end surface 1a of the writing instrument body 1 to protrude inward, and the tip of the engagement tube 2 is provided with an annular inward protrusion 2a, and three slits 2c are provided from the tip surface 2b. The tip is notched to make it easier to expand. In addition, writing instrument body 1
It goes without saying that the present invention will work even if the cap is replaced by a cap. The tail plug 3 is a hemispherical shell-shaped body made of highly elastic synthetic resin, and its annular end surface 3a has a size equal to the outer diameter of the writing instrument body 1. When the center part of the tail plug 3 is pressed against the end surface 1a and deformed very slightly, a large elastic force is generated. An engagement element 4 having an inner diameter equal to the inner diameter of the engagement tube 2 projects from the inner center of the tail plug 3. An annular groove 4 having a vertical step portion 4a in the vicinity of the tip of the engaging element 4
b is provided, but this annular groove 4b is connected to the tail plug 3.
When the annular end surface 3a abuts the end surface 1a of the writing instrument main body 1 and further deforms slightly and moves inward, the annular inner protrusion 2a engages, and the distal end surface 2b of the engagement tube 2 forms a step. 4a.

In order to fix this tail plug 3 to the writing instrument main body 1, first insert the engaging element 4 into the engaging tube 2,
When the distal end of the engaging member 4 comes into contact with the annular inner protrusion 2a, it expands because of the cutout 2c and can move further, bringing the annular end surface 3a into contact with the end surface 1a. At this time, as described above, the annular inner projection 2a is not yet engaged with the annular groove 4b. Next, when the center part of the tail plug 3 is pressed, the tail plug 3 is slightly deformed and the engaging element 4 moves forward by that amount, causing the annular inner protrusion 2 to move forward.
a engages with the annular groove 4b, and the distal end surface 2b of the engagement tube 2
comes into contact with the stepped portion 4a and the fixation is completed.

In this way, the tail plug of the present invention can be fixed very easily, and since the tail plug has a hemispherical shell shape, it is not only attractive from a design standpoint, but also has high rigidity, and can generate a large elastic force with a small amount of deformation. This occurs, and the engaging element is strongly urged outward, so that it can firmly engage with the engaging cylinder. Therefore, there is no risk of the tail plug shaking in the axial direction or even falling off, and since the engaging element is inserted into the engaging tube in the direction perpendicular to the axis, there is no shaking, but there may be variations in dimensions. Therefore, even if the fit is a little loose, the axial direction is very firmly fixed, so there will be no wobbling.

As explained above, according to the present invention, the tail plug can be securely fixed with a simple structure, and the fear of it falling off can be eliminated.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of an embodiment of the present invention, and FIG. 2 is a perspective view of the tail plug. DESCRIPTION OF SYMBOLS 1...Writing instrument body, 1a...End face, 2...Engagement tube, 2a...Annular inward projection, 2c...Cut,
3... Tail plug, 3a... Annular end surface, 4... Engagement element, 4b... Annular groove.

Claims (1)

[Scope of utility model claims] A hemispherical shell-shaped tail plug made of elastic synthetic resin, which has an annular inward protrusion at its tip and an engagement tube with a plurality of cuts from the tip surface, which is provided inward from the end surface of the writing instrument body or cap. An engaging element having an annular groove is provided protruding from the inner surface near the tip thereof, and this engaging element is inserted into the engaging cylinder so that the annular end face of the tail plug is pressed against the end face of the writing instrument body or the cap and deforms. 1. A fixing structure for a tail plug for a writing instrument, characterized in that the annular inner protrusion is engaged with the annular groove while the engaging element is urged outward by an elastic force generated by the engagement.