JPS60193699A - Method of joining part in writing utensil - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for joining components having joints in a writing instrument, such as a cap, an intermediate ring, and a barrel.

2. Description of the Related Art Conventionally, methods for joining a barrel and an internal mechanism, a front shaft and a rear shaft, or a shaft and a clip in a writing instrument generally include bonding, press-fitting, or screwing. However, adhesion has the drawback that depending on the state of pretreatment, the presence or absence of a gap, or the amount of adhesive, the bond may not be perfect, the adhesive may protrude, or the barrel may be stained. In addition, press-fitting has drawbacks such as difficulty in controlling the press-fitting allowance and the occurrence of bulges, cracks, and buckling during press-fitting.

Further, screwing has drawbacks such as the necessity of adhesion to prevent loosening, increased costs in processing parts, and the occurrence of poor screwing due to plating. Furthermore, these bonding methods have a common drawback in that they cannot be removed after bonding. Therefore, even if a defect is found in the internal structure or shaft cylinder after assembly, it cannot be disassembled and replaced and the entire assembly must be discarded, resulting in a reduction in safety and an increase in costs.

The present invention solves the above-mentioned drawbacks, enables easy joining, reduces costs, and allows for easy disassembly and replacement of parts even after joining. The purpose is to provide a method.

In order to achieve the above object, the present invention uses a shape memory alloy for the joint parts of a writing instrument, takes a predetermined fitting dimension at room temperature, and then holds it at an appropriate temperature in a high or low temperature range relative to room temperature. The dimensions are memorized to be smaller or larger than the dimensional values at room temperature, and the assembly is performed by insertion or light press-fitting in this reduced or enlarged state, and then the temperature is returned to room temperature by cooling or heating and the specified fit is achieved. This completes the joining. When parts are disassembled, assembly can be easily carried out by heating or cooling the parts from the normal temperature state to a contracted or enlarged state.

Next, examples of the present invention will be described. The figure is a longitudinal cross-sectional view of a rotary-feeding ballpoint pen assembled using the conventional joining method (the upper half shows the writing body in the state where the writing body is stored, and the lower half shows the writing body in the state where the writing body protrudes). An intermediate ring (2) that supports the rotary feeding mechanism is screw-bonded, a mechanism stopper (3) and a cap (4) are screw-bonded inside the front shaft tip opening, and a clip (6) is screw-bonded at the rear end of the rear shaft (5). ) and the rear end side of the clip spring (7).
5), and this tail plug mounting screw (8)
On the other hand, the tail plug aI is screwed and glued with the decorative ring (9) in between.

In the figure, aη indicates the screw bonding location. Therefore, these screw bonding points A and 2 have the disadvantage of poor threading, poor adhesion, or dirt from the adhesive, and furthermore, even if there is a defect in a part of the internal mechanism after assembly, the joint cannot be disassembled. Therefore, there is a waste of having to discard everything.

Therefore, as an embodiment of the present invention, the above mouth! & (4),
The intermediate ring (2) and the tail plug mounting screw (8) are made of shape memory alloy, and are attached to the mechanism stopper (3), front shaft (1), rear shaft (5), and tail plug (10) respectively at room temperature. Measure the dimensions for the fitted state, memorize it so that it will shrink more than the dimension value at room temperature at an appropriate high temperature above room temperature, and assemble it by light press-fitting in the state of shrinkage at this high temperature, and then return to room temperature. It shall be cooled and fitted.

Moreover, when decomposing it, it shall be done by heating and shrinking it. In addition, the above cap (4), intermediate ring (2)
), instead of the tail plug mounting screw (8), it is also possible to use a mechanism stopper (3), front shaft (1), rear shaft (5), or tail plug (II) made of shape memory alloy, and it is also possible to use a clip. It is also possible to join (6) with a shape memory alloy.

As described above, according to the present invention, parts can be easily assembled by insertion or light press-fitting, so automatic assembly, which has been difficult in the past, becomes possible and costs are reduced. In addition, even after joining, it can be easily disassembled by changing the temperature, so if there is a defect in a part of the internal mechanism, the part can be replaced, and there is no need to discard everything as in the past. can also be improved, contributing to cost reduction.

[Brief explanation of drawings]

The figure is a longitudinal cross-sectional view of a rotary retractable ballpoint pen assembled using a conventional connection method. (1)...Front shaft, (2)...Middle ring, (3)...
...mechanism stop, (4)...cap, (5)...rear shaft,
(6)...Clip, (7)...Clip spring, (
8)... Tail plug installation screw, (9)... Decorative ring, Q
ω...Tail plug, αυ...Screw attachment point. Patent Applicant Mitsubishi Pencil Co., Ltd. Procedural Amendment (Method) August 28, 1980 Director General of the Patent Office Gakudono Shiga 1, Case Description 1982 Patent Application No. 497oo 2, Title of Invention Components in Writing Instruments Connection method 3, relationship with the case of the person making the amendment Patent applicant President Yoji Kazuhara 4, agent 5 Date of amendment order Revised June 26, 1988
The following corrections are made in the attached specification of the application. Note 1, *) In the third line of the page, next to "Ballpoint pen", insert the following phrase: "Figure 1 is a sectional view of the first half, and Figure 2 is the second half."

Claims (1)

[Claims] A method for joining parts in a writing instrument, characterized in that a shape memory alloy is used for a part having a joining part, and the part is joined to a part to be joined by heating or cooling treatment.