JP2001246893A - Casing of writing implement having two kinds of formed parts - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inexpensive casing of a writing implement by forming a grip and a decorative part, or a clip and another functional component or the like, in two kinds simultaneously on the casing of the writing implement such as a mechanical pencil or a ball-point pen or on the casing of a cap or the like. SOLUTION: In regard to the casing of the casing of the writing implement having two kinds of formed parts, secondary-side formed parts independent of each other are formed in a plurality of places of a primary-side formed part.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a barrel for a writing instrument such as a sharp pencil or a ball pen or a barrel for a cap.
The present invention relates to a structure in which a grip, a decorative portion, a clip, and other functional components are formed by two types of molding.

[0002]

2. Description of the Related Art Conventionally, many writing instruments provided with grip rubber, which is an elastic body, have been developed in order to reduce the burden of writing. In particular, when the rubber grip is mounted on the barrel, it is necessary to apply an aqueous solution or the like to the barrel, and press-fit the rubber grip. Therefore, in order to omit the process of attaching the grip rubber to the barrel, 2
There is known a writing instrument in which a rubber grip is formed at a portion to be gripped by a barrel of a writing instrument. Also, the decoration part etc.
Those formed by seed molding are also known. However, the above-mentioned conventional one is provided with only one secondary-side molded part on the primary-side molded part. For example, when a grip is provided by secondary molding, a tail plug, a clip, etc. A process of attaching with a separate member is required, which is troublesome.

[0003]

Normally, a barrel of a writing instrument is provided with a rubber stopper, a tail plug, a clip or other decorative members in addition to a rubber grip. For example, specifically, in the case of a ballpoint pen, in many cases, a transparent shaft cylinder is provided with a grip, a tail plug, a clip, and the like in the same color as the ink. A low-cost writing instrument is often formed by integrally molding the barrel and the clip, but has a problem in that the performance, strength and decorativeness of the clip are inferior. Therefore, there is a case in which a separate clip made of a resin molded product having excellent mechanical properties is attached to the shaft cylinder, but there is a problem that the cost increases. The present invention provides functional characteristics by forming grips, decorative parts, clips, and other functional parts at a time on a barrel of a writing instrument such as a sharp pencil or a ball pen or a barrel of a cap by molding. Another object of the present invention is to reduce the cost as much as the decorativeness.

[0004]

The present invention has the following arrangement to achieve the above object. According to the first aspect of the invention, there is provided a shaft barrel of a writing instrument having two types of molded portions, wherein independent secondary side molded portions are formed at a plurality of locations of the primary side molded portion.

According to a second aspect of the present invention, there is provided a writing instrument barrel having two types of molded portions, wherein the primary side molded portion has the same shape as the first aspect of the writing instrument barrel having two types of molded portions. An engaging portion is formed between the contact portions of the secondary-side molded portion in a state in which the concave portion is filled with the convex portion, and the axial cross-sectional dimension of the concave portion is 0 ° ≦ α ≦ 45 ° or 0.1 mm. 5mm ≦ a ≦
The relationship is set to b ≧ 2a at 2.0 mm.

[0006]

FIG. 1 shows a barrel 1 of a writing instrument having two types of molded portions according to a first embodiment of the present invention. In many cases, the shaft portion 2 is formed of a transparent shaft in which the color and the remaining amount of the contained ink are visible. A grip 3 serving as a grip for writing is provided on a front outer peripheral portion of the shaft portion 2, and a tail plug 4 is provided on a rear end of the shaft portion 2.

The barrel 1 is formed by two types of injection molding, and includes a primary molding step of molding the shaft portion 2 and a secondary molding step of molding the grip 3 and the tail plug 4 at the same time. Shaft 2
A hole-shaped concave portion 1a is formed at a required portion (usually at two positions) on the side surface near the rear end of the shaft portion 2 and the convex portion 4b is filled in the concave portion 1a. Shaft 4a to be in contact
The tail plug 4 provided with is formed by secondary molding. In addition, the axial cross-sectional dimension of the concave portion is formed in the range of 0 ° ≦ α ≦ 45 ° from the standpoint of molding and die. Although the embodiment shows a state in which the shaft portion of the tail plug engages with the rear end hole of the shaft portion of the barrel, the above-described concave portion and convex portion are used when the tail plug is fitted on the outer peripheral portion of the barrel. The relationship may be interchanged. Further, not only the tail plug but also the grip and other parts can be formed with the engaging part at a predetermined position of the shaft part in a relationship between the concave part and the convex part. The engaging portion is not always provided, but is formed at a position where positioning and strong fixing are required.

The shaft 2 is made of AS resin, ABS resin, P
S resin, PC resin, PET resin, PBT resin, PP resin and the like are applied. The grip is not limited to an elastic body, but various elastomers, such as styrene and butadiene elastomers, which are suitable for the material of the shaft member of the shaft cylinder are usually selected. In addition, when the grip and the tail plug are formed of an elastic body, not only the burden at the time of writing can be reduced, but also the shock due to the trailing end drop is absorbed, and the backflow of the ink and the blurring due to the ink running out are prevented. .

FIG. 2 shows a shaft cylinder 5 of a writing implement having two types of molded portions according to a second embodiment of the present invention. Example 1
, And only the differences will be described. As in the previous example, a stepped hole-shaped recess 5a is formed at a required portion (usually two places) on the side surface near the rear end of the shaft portion 6, and the recess 5a is formed.
The tail plug 8 having the shaft portion 8a that comes into contact with the inner peripheral surface of the rear end hole of the shaft portion 6 in a state where the inside is filled with the convex portion 8b is secondarily formed.
Further, from the standpoint of molding and mold, the recess is formed in a relationship of 0.5 mm ≦ a ≦ 2.0 mm and b ≧ 2a in the axial section.

FIG. 3 shows a shaft cylinder 9 of a writing implement having two types of molded portions according to a third embodiment of the present invention. Example 1
Are basically the same, and only the differences will be described. The clip 12 is formed at the rear end of the shaft portion 10 of the shaft cylinder in the same configuration as the tail plug of the previous example. The clip 12 is made of a resin having excellent spring properties and creep resistance. Therefore, grip 1
No. 1 is not an elastic body, and is expected to have a non-slip effect and decorativeness due to unevenness.

FIG. 6 shows a shaft cylinder 13 of a writing instrument having two types of molded parts according to a conventional example. Although the shaft cylinder 13 has the grip 15 formed by secondary molding, the tail plug 16 is fixed to the rear end hole of the shaft portion 14 by press-fitting means or the like. Therefore, it is troublesome and increases the cost.

[0012]

In the shaft cylinder, a shaft portion is formed by primary molding by injection molding, and a plurality of portions such as a grip and a tail plug are formed simultaneously by secondary molding. In addition, at a predetermined position where a grip, a tail plug, and the like are formed by secondary molding, a concave portion of a required portion is formed on the circumferential side surface of the shaft portion, and the grip or the tail is filled with the convex portion in the concave portion. Multiple parts such as tail plugs can be molded. Therefore, even when the rubber grip and the rubber tail plug are formed by secondary molding, the rubber grip and the rubber tail plug can be firmly fixed to the shaft portion of the barrel.

[0013]

According to the present invention, the barrel of a writing instrument having two types of molded parts can be formed simultaneously with a grip, a tail plug, a clip, or another decorative part by secondary molding. Can be provided. For example, in the case of a ballpoint pen, a rubber grip and a rubber tail plug are simultaneously molded in the same color as the color of the ink on the transparent barrel, and can be firmly fixed. In addition, a functional member requiring a spring property or strength, such as a clip, can be simultaneously molded with another member.

[Brief description of the drawings]

FIG. 1 is a longitudinal half sectional view showing a shaft cylinder of a writing instrument that is Embodiment 1 of the present invention.

FIG. 2 is a longitudinal half sectional view showing a shaft cylinder of a writing instrument that is Embodiment 2 of the present invention.

FIG. 3 is a longitudinal half sectional view showing a shaft cylinder of a writing instrument that is Embodiment 3 of the present invention.

FIG. 4 is a sectional view taken along line AA in FIG. 1;

FIG. 5 is a sectional view taken along the line BB in FIG. 3;

FIG. 6 is a longitudinal half sectional view showing a shaft cylinder of a conventional writing instrument.

[Explanation of symbols]

 Reference Signs List 1 shaft cylinder 1a recess 2 shaft 3 grip 4 tail plug 4a shaft 4b protrusion 5 barrel 5a recess 6 shaft 7 grip 8 tail plug 8a shaft 8b protrusion 9 shaft 10 shaft 11 grip 12 clip 12a shaft Part 12b Convex part 13 Shaft tube 14 Shaft part 15 Grip 16 Tail plug

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) // B29C 45/16 B29L 31:00 B29L 9:00 B43K 23/00 B 31:00 25/00 A

Claims (2)

[Claims] 1. A writing implement having two types of forming parts, wherein independent secondary side forming parts are respectively formed at a plurality of locations of the primary side forming part in a barrel of a writing implement having two types of forming parts. Shaft tube. 2. An engaging portion in which a concave portion is filled with a convex portion is formed between the contact portions of the primary molded portion and the secondary molded portion, and the concave portion has an axial cross-sectional dimension. 0 ゜ ≦ α ≦
45 ° or b ≧ 2a with 0.5mm ≦ a ≦ 2.0mm
2. A shaft barrel for a writing instrument having two types of molded portions according to claim 1, wherein the relationship is set as follows.