JP3755866B2

JP3755866B2 - Writing instrument shaft

Info

Publication number: JP3755866B2
Application number: JP2001019594A
Authority: JP
Inventors: 正広木暮
Original assignee: Pilot Corp
Current assignee: Pilot Corp
Priority date: 2001-01-29
Filing date: 2001-01-29
Publication date: 2006-03-15
Anticipated expiration: 2021-01-29
Also published as: JP2002219896A

Description

【０００１】
【発明の属する技術分野】
本発明は、軸筒の把持部にグリップ部材を、軸筒の小径に形成された把持部の後方の段部と、軸筒先端部に螺着した金属製の口金の後端面により、圧縮された状態で着脱自在に挟持してなる筆記具の軸筒に関する。
【０００２】
【従来の技術】
従来、図５に示すように、筆記具の軸筒２１の小径に形成された把持部３に、グリップ部材１４を把持部の後方段部（図示せず）と軸筒の先端部のねじ部１０に螺着した金属製の口金２８の後端面２９とで挟持して配設してなる筆記具の軸筒２１は知られている。
【０００３】
こうした筆記具の軸筒構造のほとんどは、グリップ部材を、把持部の後方段部と、軸筒先端部に螺着した口金２８の後端面２９とで挟持し、圧縮した状態で配設している。これは着脱自在に装着したグリップ部材の移動や、口金を螺着した際に、口金の端面とグリップ部材の先端面との間に隙間を形成するのを防止するためである。
【０００４】
しかしながら、グリップ部材を圧縮する場合には、口金の後端面とグリップ部材の先端面とが面接触するため、グリップ部材を圧縮しない場合に比べ、口金の螺着時の締め付け力が増大する。その結果、組立難くなったり、口金の締め不足により、口金が容易に外れ易くなり、移動や使用時に外れてしまうことがあった。特にグリップ部材の肉厚が厚い場合等、口金の端面とグリップ部材の先端面との接触面積が大きい場合には前記問題が生じ易かった。
【０００５】
こうした問題を解決する手段として、図４に示す筆記具の軸筒１１のように、口金１８の後端面１９に凹部１７を形成してグリップ部材１４の先端面１５との接触面積を減少させる方法もあるが、金属製の口金１８は切削加工にて製造するため、現実問題として凹部を形成する工程が付加されると、加工時間の増加に伴うコストアップになってしまうという問題があった。
【０００６】
【発明が解決しようとする課題】
本発明はこうした問題に鑑み、グリップ部材を、軸筒先端部に螺着した金属製の口金の後端面により圧縮した状態で配設する際に、口金の締め付け力を低減し、口金が容易に外れることがない筆記具の軸筒を、簡単な構造で、かつコストアップすることなく提供することにある。
【０００７】
【課題を解決するための手段】
本発明は、軸筒の把持部にグリップ部材を、後端面を軸筒の小径に形成された把持部の後方の段部に当接させ、先端面を軸筒先端部に螺着した金属製の口金の後端面に当接するとともに、口金の端面と把持部の段部の間隙をグリップ部材の長さより小さくすることにより、グリップ部材を圧縮された状態で着脱自在に挟持してなる筆記具の軸筒において、前記グリップ部材の先端面に凹部を形成し、口金の後端面とグリップ部材の先端面の接触面積を減少させたことを特徴とする
【０００８】
【発明の実施の形態】
本発明の実施の形態を図面を用いて説明する。同じ部材、同じ箇所を示すものは同じ符号を付す。図１から図３に示す第１の実施の形態を示す筆記具１は、先ず、軸筒２をアクリルニトリルスチレン樹脂（ＡＳ樹脂）で成形する。軸筒本体２の把持部３は、外径が小径に形成してある。その把持部３にグリップ部材４を着脱自在に装着するが、グリップ部材は予めシリコーンゴムにて成形しておく。その後、黄銅を切削加工することにより形成した口金８を、軸筒先端に形成したねじ部１０に螺着して筆記具の軸筒１を得る。図示はしていないが、筆記具として使用する場合には、例えば、軸筒内に、先端にボールペンチップを装着したボールペンレフィルを収納する。
【０００９】
グリップ部材４の長さＬ１は、口金８を螺着することにより、口金の端面９がグリップ部材の先端面５に面接触し、さらに完全に螺着すると、口金の端面９と把持部の段部６の間隙はＬ２は、グリップ部材の長さＬ１より小さく（Ｌ１＞Ｌ２）してあるので、グリップ部材４が圧縮した状態になる。このとき、グリップ部材の先端面５には、口金の後端面９との接触面積を減少させるため、凹部７を形成してあるので、グリップ部材の先端面５と面接触する面積が減少する。
【００１０】
前述したように、グリップ部材は成形品であるため、予め金型に凹部を形成しておけば、新たに凹部を形成する工程を付加する必要がないので、製造に係るコストがアップしない。また、凹部の形成場所は、グリップ部材の先端面に形成するとともに、口金の後端面との接触面積を減少するように形成してあれば、任意の数箇所あるいは周状に形成してあってもよい。
【００１１】
本実施の形態の筆記具の軸筒１の口金８と、図５に示す従来の実施の形態における筆記具の軸筒２１の口金２８の締め付け力を、株式会社東日製作所社製トルクメーターを用いて各３回測定した結果を表１に示す。
＊口金は黄銅のクロムメッキ製、グリップ部材の硬度７０（ショアーＡ硬度）を使用。
【００１２】
【表１】

【００１３】
グリップ部材の硬度を５０（ショアーＡ硬度）に変更し、本実施の形態の筆記具の軸筒１の口金８と、図５に示す従来の実施の形態における筆記具の軸筒２１の口金２８の締め付け力を、株式会社東日製作所社製トルクメーターを用いて各３回測定した結果を表２に示す。
【００１４】
【表２】

【００１５】
本発明の実施の形態では、便宜上、グリップ部材をシリコーンゴムで形成しているが、本発明のグリップ部材は、弾性変形可能な天然ゴム、ブチルゴム、フッ素ゴム、塩化ビニル樹脂、ブタジエンゴム、ウレタンゴム、ポリエチレン樹脂、その他合成ゴム等、グリップ部材として一般的に知られている弾性体のなかから適宜選定すればよい。また、金属製の口金も黄銅に限定されるものでなく、ステンレス鋼やアルミニウム等、口金として一般的に知られている金属のなかから適宜選定すればよい。
【００１６】
【発明の効果】
本発明の筆記具は前述したような構造なので、グリップ部材を、軸筒先端部に螺着した金属製の口金の後端面により圧縮した状態で配設する際に、口金の締め付け力を低減し、口金が容易に外れることがない筆記具の軸筒を、簡単な構造で、かつコストアップすることなく提供することができた。
【図面の簡単な説明】
【図１】本発明の第１の実施の形態を示す、筆記具の要部を断面とした図である。
【図２】本発明の第１の実施の形態における、組立工程をしめす図である。
【図３】図１における要部拡大断面図である。
【図４】口金の後端面に凹部形成した例を示す、筆記具の軸筒要部を断面とした図である。
【図５】従来の実施の形態を示す、筆記具の要部を断面とした図である。
【符号の説明】
１、１１、２１筆記具
２軸筒
３把持部
４、１４グリップ部材
５、１５グリップ先端面
６段部
７、１７凹部
８、１８、２８口金
９、１９、２９口金の後端面
１０ねじ部[0001]
BACKGROUND OF THE INVENTION
In the present invention, a grip member is compressed in a gripping portion of a shaft tube, and a stepped portion behind the gripping portion formed in a small diameter of the shaft tube and a rear end surface of a metal base screwed to a tip portion of the shaft tube. It is related with the axial cylinder of the writing instrument formed so that it can be detachably pinched in the state.
[0002]
[Prior art]
Conventionally, as shown in FIG. 5, a grip member 14 is attached to a gripping portion 3 formed in a small diameter of a shaft cylinder 21 of a writing instrument, and a rear step portion (not shown) of the gripping portion and a screw portion 10 at a tip end portion of the shaft cylinder. An axial tube 21 of a writing instrument is known which is sandwiched and disposed between a rear end surface 29 of a metal base 28 screwed onto the shaft.
[0003]
In most of the shaft tube structures of such writing instruments, the grip member is disposed between the rear stepped portion of the gripping portion and the rear end surface 29 of the base 28 screwed to the tip of the shaft tube, and is compressed. . This is to prevent a gap from being formed between the end surface of the base and the front end surface of the grip member when the grip member is detachably mounted or when the base is screwed.
[0004]
However, when the grip member is compressed, the rear end surface of the base and the front end surface of the grip member are in surface contact with each other, and therefore, the tightening force when the base is screwed is increased as compared with the case where the grip member is not compressed. As a result, it becomes difficult to assemble, or due to insufficient tightening of the base, the base can be easily detached, and it may come off during movement or use. In particular, when the thickness of the grip member is large, the above problem is likely to occur when the contact area between the end face of the base and the tip face of the grip member is large.
[0005]
As a means for solving such a problem, there is a method of reducing the contact area with the front end surface 15 of the grip member 14 by forming a recess 17 in the rear end surface 19 of the base 18 as in the case 11 of the writing instrument shown in FIG. However, since the metal base 18 is manufactured by cutting, there is a problem that if a step of forming a concave portion is added as a practical problem, the cost increases with an increase in processing time.
[0006]
[Problems to be solved by the invention]
In view of these problems, the present invention reduces the clamping force of the base when the grip member is disposed in a compressed state by the rear end surface of the metal base screwed to the tip of the shaft tube, and the base can be easily formed. An object of the present invention is to provide a writing cylinder that does not come off with a simple structure and without increasing costs.
[0007]
[Means for Solving the Problems]
The present invention is a metal member in which a grip member is attached to a grip portion of a shaft tube, a rear end surface thereof is brought into contact with a stepped portion behind a grip portion formed in a small diameter of the shaft tube, and a tip surface is screwed to the tip portion of the shaft tube. A shaft of a writing instrument that is detachably held in a compressed state by abutting the rear end surface of the base and making the gap between the end surface of the base and the stepped portion of the gripping portion smaller than the length of the grip member. In the cylinder, a concave portion is formed on the front end surface of the grip member to reduce a contact area between the rear end surface of the base and the front end surface of the grip member.
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described with reference to the drawings. The same code | symbol is attached | subjected to what shows the same member and the same location. In the writing instrument 1 showing the first embodiment shown in FIG. 1 to FIG. 3, first, the shaft cylinder 2 is formed of acrylonitrile styrene resin (AS resin). The grip portion 3 of the shaft cylinder body 2 is formed with a small outer diameter. A grip member 4 is detachably attached to the grip portion 3, and the grip member is previously formed of silicone rubber. Thereafter, the base 8 formed by cutting brass is screwed onto the screw portion 10 formed at the tip of the shaft tube to obtain the shaft tube 1 of the writing instrument. Although not shown, when used as a writing instrument, for example, a ball-point pen refill with a ball-point pen tip attached to the tip is stored in the shaft tube.
[0009]
The length L1 of the grip member 4 is such that when the base 8 is screwed, the end surface 9 of the base comes into surface contact with the tip surface 5 of the grip member, and when the screw is completely screwed, the end surface 9 of the base and the step of the gripping portion. Since the gap L2 of the portion 6 is smaller than the length L1 of the grip member (L1> L2), the grip member 4 is in a compressed state. At this time, since the concave portion 7 is formed on the front end surface 5 of the grip member in order to reduce the contact area with the rear end surface 9 of the base, the area in surface contact with the front end surface 5 of the grip member is reduced.
[0010]
As described above, since the grip member is a molded product, if a recess is formed in the mold in advance, it is not necessary to add a process for forming a new recess, so that the manufacturing cost does not increase. Moreover, as long as the recessed portion is formed on the front end surface of the grip member and is formed so as to reduce the contact area with the rear end surface of the base, it is formed in any number of locations or in a circumferential shape. Also good.
[0011]
The fastening force of the base 8 of the shaft cylinder 1 of the writing instrument of the present embodiment and the base 28 of the shaft cylinder 21 of the writing instrument in the conventional embodiment shown in FIG. 5 is measured using a torque meter manufactured by Tohnichi Corporation. Table 1 shows the results of three measurements.
* The base is made of brass chrome plating and uses a grip member hardness of 70 (Shore A hardness).
[0012]
[Table 1]

[0013]
The grip member hardness is changed to 50 (Shore A hardness), and the base 8 of the shaft cylinder 1 of the writing instrument according to the present embodiment and the base 28 of the shaft cylinder 21 of the writing instrument according to the conventional embodiment shown in FIG. Table 2 shows the results of measuring the force three times each using a torque meter manufactured by Tohnichi Corporation.
[0014]
[Table 2]

[0015]
In the embodiment of the present invention, the grip member is formed of silicone rubber for convenience, but the grip member of the present invention is elastically deformable natural rubber, butyl rubber, fluoro rubber, vinyl chloride resin, butadiene rubber, urethane rubber. It may be appropriately selected from elastic bodies generally known as grip members such as polyethylene resin and other synthetic rubbers. Further, the metal base is not limited to brass, and may be appropriately selected from metals generally known as bases such as stainless steel and aluminum.
[0016]
【The invention's effect】
Since the writing instrument of the present invention has the structure as described above, when the grip member is disposed in a compressed state by the rear end surface of the metal base screwed to the tip of the shaft tube, the clamping force of the base is reduced, It was possible to provide a writing instrument shaft tube that does not easily come off the base with a simple structure and without increasing costs.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a main part of a writing instrument according to a first embodiment of the present invention.
FIG. 2 shows an assembly process in the first embodiment of the present invention.
FIG. 3 is an enlarged cross-sectional view of a main part in FIG.
FIG. 4 is a cross-sectional view of a main portion of a writing cylinder, showing an example in which a recess is formed on the rear end surface of the base.
FIG. 5 is a cross-sectional view showing a main part of a writing instrument according to a conventional embodiment.
[ Explanation of symbols]
DESCRIPTION OF SYMBOLS 1, 11, 21 Writing implement 2 Shaft cylinder 3 Grip part 4, 14

Grip member

5, 15 Grip front end surface 6

Step part

7, 17

Recess

8, 18, 28

Base

9, 19, 29 29 Rear end face 10 of base

Claims

After the metal base with the gripping member on the gripping part of the shaft tube, the rear end surface abutting on the stepped part behind the gripping part formed in the small diameter of the shaft tube, and the tip surface screwed to the tip part of the shaft tube In the shaft cylinder of the writing instrument, wherein the grip member is detachably held in a compressed state by contacting the end surface and making the gap between the end surface of the base and the stepped portion of the grip portion smaller than the length of the grip member. A shaft of a writing instrument, wherein a concave portion is formed on the front end surface of the grip member to reduce a contact area between the rear end surface of the base and the front end surface of the grip member .