JPS5916229Y2 - Fitting device for barrel and cap in writing instrument - Google Patents

Description

[Detailed description of the invention] This design has a simple structure that maintains the airtightness of the writing tip for a long period of time, and also allows for a comfortable feeling when attaching and detaching the cap and barrel. The present invention relates to a cap fitting device.

There have been various devices for fitting the barrel and cap in consideration of maintaining airtightness, but most of them involve a sealing member interposed at the tip of the cap, and the writing tip is press-fitted from the opening. It is something that makes you

However, in the case of this type of press-fitting method, complete airtightness cannot be expected, and furthermore, the presence of special inclusions inevitably causes inconvenience in processing and assembly.

There is also a structure in which one end is sealed and the barrel is inserted through an opening at the other end, but in this case, if you try to achieve smooth operation during the process of inserting the barrel into the cap, the inner surface of the cap Close contact with the barrel must be avoided as much as possible. Therefore, in order to maintain airtightness between the cap and the barrel, special consideration must be given to the fitting part between the two, making the airtight structure complicated. It had become.

As mentioned above, this design has a simple structure that maintains the airtightness of the writing tip completely for a long period of time, and also allows for smooth attachment and detachment of the cap and barrel. The aim is to provide an integrated device.

Hereinafter, embodiments of the present invention will be described based on the drawings.

The core 1 is made of an elastic material such as polyethylene or polypropylene, and has a bottomed cylindrical shape having a thick part 2 and a thin part 3.
It is fixed to the cap 4 via.

Reference numeral 5 denotes an annular groove formed at the boundary 2b between the thick part 2 and the thin part 3, into which a protrusion 7 having an outer diameter larger than the inner diameter of the thin part 3 is fitted. At this point, the cap 4 is fitted onto the shaft cylinder 6, and the airtightness within the thick walled portion 2 is maintained.

A deformed part 8 for exhaust is formed on the inner surface of the thin part 2.

1 and 2 illustrate an example in which a groove 8a is formed on the inner surface of the thin wall portion 3 to form the irregularly shaped portion 8. The groove 8a extends from the vicinity of the annular groove 5 to the end surface of the thin wall portion 3. It extends and opens there.

The reason why the irregularly shaped part 8 is extended to the end face of the thin walled part 3 is for processing convenience, and the protrusion 7 of the shaft cylinder neck part, which has an outer diameter larger than the inner diameter of the thin walled part 3, is press-fitted into the thin walled part 3. The four stripes 8a do not necessarily need to extend to the end face of the thin wall portion 3 if the air compressed during the process can escape to the outside.

Moreover, the number of formations may be one or two or more.

FIG. 3 shows an example in which a protruding strip 8b is formed to form the irregularly shaped portion 8. In the case of this protruding strip 8b as well, it is preferable that the protruding strip 8b extends from the vicinity of the annular groove 5 to the end surface of the thin wall portion 3. Also, the number of grooves formed may be one or more than two, as in the case of the above-mentioned grooved grooves 8a.

FIG. 4 shows another modification of the irregularly shaped portion 8, in which the inner surface of the thin wall portion 3 is made polygonal to form the irregularly shaped portion 8.

Reference numeral 9 denotes a gap formed between the inner surface of the cap 4 and the outer surface of the thin-walled portion 3 of the core, and the thin-walled portion 3 Allows for radial deformation.

In the process of fitting the protrusion 7 of the barrel neck into the annular groove 5 of the core, the thin wall portion 3 of the valve expands in the radial direction, and the compressed air flows through the protrusion 7 and the irregularly shaped inner surface of the thin wall portion 3. The air is discharged outside the core 1 through the gap between the core 1 and the core 1, ensuring smooth operation.

Thus, when the protrusion 7 fits into the annular groove 5, the expanded thin part 3 returns to its original state, and the fit between the two becomes even tighter.

As described above, the present invention has an irregularly shaped part such as a concave line, a convex line, or a polygon in the thin part of the elastic material core with one end closed, extending to the vicinity of the annular groove formed at the boundary between the thick part and the thin part. Because of this feature, the axial length of the thin wall part can be adjusted and maintained at an appropriate length, and the airtightness at the writing tip can be completely maintained for a long period of time. At the same time, it has become extremely easy to obtain a fitting device for the barrel and the sleeve that ensures smooth operation when inserting the barrel into the cap.

[Brief explanation of the drawing]

FIG. 1 is a side sectional view of a cap in which the present invention is implemented, FIG. 2 is a sectional view taken along line A-A in FIG. The illustrated diagram, FIG. 5, is an explanatory diagram of the shaft cylinder neck. 1...core, 2...thick part, 3...
・・・Thin wall part, 4... Cap, 5...
- Annular groove, 7... protrusion, 8... oddly shaped part, 8a... grooved line, 8b... convex line.

Claims (1)

[Scope of utility model registration request] A shaft cylinder having a fitting part with the shaft cylinder, and an elastic core having one end closed and the other end open, which is mounted inside the cap, so that the cap is fitted to the shaft cylinder through the core. and a cap fitting device, a thick part 2 and a thin part 3 are attached to the core 1.
At the same time, an annular groove 5 is formed at the boundary between the thick part 2 and the thin part 3, and the annular groove 5 is formed on the inner surface of the thin part 3.
A deformed part 8 for exhaust that extends to the side is formed, and a protrusion 7 of the shaft cylinder neck having an outer diameter larger than the inner diameter of the thin core part 3 fits into the annular groove 5 of the core. Features a fitting device for the barrel and cap of a writing instrument.