JP3756247B2

JP3756247B2 - Writing instrument caps

Info

Publication number: JP3756247B2
Application number: JP13572696A
Authority: JP
Inventors: 忠夫飯田
Original assignee: Pilot Ink Co Ltd
Current assignee: Pilot Ink Co Ltd
Priority date: 1996-05-02
Filing date: 1996-05-02
Publication date: 2006-03-15
Anticipated expiration: 2016-05-02
Also published as: JPH09295492A

Description

【０００１】
【発明の属する技術分野】
本発明は、筆記具等のキャップに関する。詳細には、有底筒体の周壁外周面に長手方向の縦リブを一体成形した合成樹脂の射出成形よりなる筆記具等のキャップに関する。
【０００２】
【従来の技術】
例えば、実開平４−８９３８８号公報には、誤って嚥下しても窒息を招くことのない筆軸用キャップとして、外周面に空気通路用の溝を軸方向に設け、前記溝端に臨み、溝上に端部を延長したリブをエアタイト嵌合部の外面近傍を避ける位置に設けた構成が開示され、それにより、エアタイト嵌合部の成形時のヒケを防止することが記載されている。
【０００３】
また、実開平６−２９８８６号公報には、誤飲による窒息防止と、気密保持部のヒケの防止を目的とする筆記具等のキャップとして、気密保持部の前方または後方に鍔部を設け、該鍔部に第一の溝を貫設し、前記気密保持部を除くキャップ本体外表面に第二の溝を設ける構成が開示されている。
【０００４】
【発明が解決しようとする課題】
前記実開平４−８９３８８号公報のキャップは、気密保持部のヒケを防止するとしても不格好なリブを突出させなければならず、キャップ全体の外観を損ねがちであり、デザインを考慮する上で制約がある。また、前記実開平６−２９８８６号公報のキャップも、気密保持部のヒケを防止するとしても、鍔部を有する外観形状に限定されがちであり、デザインを検討する上で自由度が小さい。さらに、両公報とも構造が複雑であり、金型等の製造コストを高くする。
【０００５】
本発明は、前記従来の問題点を解決するものであって、気密嵌合部の成形時のヒケを防止すると共に、シンプルな形状にして金型等の製造コストを低く抑え、さらに、キャップの外観形状をデザインする上での自由度を増加させることが可能な筆記具等のキャップを提供しようとするものである。尚、本発明において、「前方」とはキャップ閉塞側を示し、「後方」とはキャップ開口側を示す。
【０００６】
【課題を解決するための手段】
(1) 概要
本発明は、有底筒体の周壁２外周面に長手方向の縦リブ３を一体に設けた合成樹脂の射出成形よりなる筆記具等のキャップ１であって、前記周壁２に径方向外方へ膨出する環状の厚肉部４を一体に設け、前記厚肉部４の内周面に筆記具本体８と気密嵌合する環状のシール部６を一体に設け、さらに、前記厚肉部４の外周面に長手方向に延びる縦リブ３を一体に設け、前記厚肉部４後方には、薄肉部５が形成されると共にその外周面には前記厚肉部４から同外径で延びる縦リブ３が一体に設けられ、キャップ後端部外周面の通気路の横断面積が、厚肉部４の通気路の横断面積よりも増加したことを要件とする。
【０００７】
また、前記構成において、前記厚肉部４の横断面の肉厚寸法Ａと、前記縦リブ３の横断面の肉厚寸法Ｂとが、「１．５≦Ａ／Ｂ≦５．０」の関係を満足することが好ましい。
【０００８】
また、前記構成において、前記厚肉部４内周面の略中央部に前記シール部６を突設させることが有効である。
【０００９】
▲２▼ 縦リブ
前記周壁２（厚肉部４又は薄肉部５）外周面に設ける縦リブ３の本数は、一本であってもよいが、隣接する縦リブ３の間に窒息防止用の通気路を確実に形成する場合には、複数本（例えば、６本以上）が好ましい。
【００１０】
▲３▼ 厚肉部
前記厚肉部４は、有底筒体の周壁２の前部（すなわち閉塞側），後部（すなわち開口側），又は中央部のいずれの位置に配設してもよい。しかし、前記厚肉部４は、環状のシール部６を有するので、ペン先密閉空間を有効に形成させるよう、周壁２の中央部または後部に設けることが好ましい。また、前記厚肉部４によって、残りの他の周壁２は、薄肉部５が形成される。
【００１１】
厚肉部４の肉厚寸法Ａは、縦リブ３の肉厚寸法Ｂの１．５倍以上（即ち、関係式，Ａ／Ｂ≧１．５）が好ましい。このとき、シール部６を備えた厚肉部４の肉厚（即ち、シール部６及びシール部６近傍の周壁２の肉厚）が十分に厚くなるため、成形時、シール部６外周面の異形部（即ち、縦リブ３）の影響を全く受けず、シール部６にヒケを発生させることがない。これとは逆に、厚肉部４の肉厚寸法Ａの、縦リブ３の肉厚寸法Ｂに対する比率が１．５より小（即ち、関係式，Ａ／Ｂ＜１．５）の場合、成形時、シール部６外周面の異形部（即ち、縦リブ３）によってシール部６にヒケが発生してしまう。
【００１２】
また、厚肉部４の肉厚寸法Ａが、縦リブ３の肉厚寸法Ｂの５倍以下（即ち、関係式，Ａ／Ｂ≦５．０）が好ましい。このとき、射出成形時の成形サイクルを短くでき、量産に最適となる。これとは反対に、厚肉部４の肉厚寸法Ａの、縦リブ３の肉厚寸法Ｂに対する比率が５より大（即ち、関係式，Ａ／Ｂ＞５．０）の場合、厚肉部４の肉厚が極端に厚くなり、材料である合成樹脂の量が増加するばかりか、射出成形時の金型の冷却時間（即ち、成形サイクル）が長くなり、製造コストが高くなる。
【００１３】
▲４▼ シール部
前記シール部６は、環状凸部として突設される構成が有効であり、その縦断面形状は、Ｒ曲面またはテーパ面が好ましい。また、前記シール部６は、厚肉部４の略中央部（即ち、厚肉部４の前端と後端の中間部）に設けることが好ましい。そのとき、前記シール部６の縦断面の肉厚寸法Ｍは、前記厚肉部４の縦断面の肉厚寸法Ｌよりも小さくなる。それにより、薄肉部５に縦リブ３（又は縦リブ３１）を設けたとき、その薄肉部５の縦リブ３（３１）端部と、前記シール部６との間に適宜な距離が生じ、前記シール部６は、前記薄肉部５の縦リブ３（３１）によるヒケの発生が抑えられる。さらに詳細には、前記厚肉部４の縦断面の肉厚寸法Ｌと、前記シール部６の縦断面の肉厚寸法Ｍとが、「Ｌ／Ｍ≧２．０」の関係を満足するとき、薄肉部５の縦リブ３（３１）によるシール部６におけるヒケの発生が十分に抑制される。
【００１４】
▲５▼ 合成樹脂
キャップ１を構成する合成樹脂材料として、例えば、ポリエチレン、ポリプロピレン、ポリアセタール、ポリエチレンテレフタレート、ポリブチレンテレフタレート等が挙げられる。
【００１５】
▲６▼ 作用
厚肉部４内周面にシール部６を設けたことによって、シール部６を備えた周壁２の外周面に縦リブ３を設けたにもかかわらず、シール部６に成形時のヒケを生じさせず、筆記具本体８と気密嵌合可能な適正な環形状のシール部６を形成することができる。それにより、シール部６外周面に縦リブ３を設けないように考慮する必要がなくなるので、金型の製造コストを低く抑えたシンプルな形状にすることができ、また、デザイン上の自由度が広がる。
【００１６】
それに加え、幼児等の誤飲による窒息事故を防止するキャップ（いわゆる通気キャップ）とする場合、前記作用効果（即ち、製造コストを低く抑え、デザイン上の制約を減少させる）を有する通気キャップを提供することができる。
【００１７】
【発明の実施の形態】
本発明の実施の形態を図面に従って説明する。
【００１８】
【実施例１】
図１〜図４に本発明の第１実施例を示す。詳細には、図１は本発明のキャップ１の第１実施例を示す縦断面図である。図２は、図１のＸ−Ｘ線断面図である。図３は図１のＹ−Ｙ線断面図である。図４は図１のキャップ１を筆記具本体８に装着した状態の説明図である。
【００１９】
（厚肉部，薄肉部）
キャップ本体は、合成樹脂の射出成形よりなる有底円筒体である。キャップ本体の周壁２の後部（後端部よりわずかに前方）には、径方向外方に環状に膨出する厚肉部４が一体成形され、さらに、残りの周壁２の前方及び後方には、薄肉部５が形成されている。
【００２０】
（縦リブ，シール部）
前記周壁２（即ち、厚肉部４及び薄肉部５）には、その開口端から閉塞端に連続して８本の縦リブ３が一体に突設されている。隣合う縦リブ３と縦リブ３の間には、溝状の通気路４１，５１が形成されそれにより、幼児等の誤飲による窒息事故を防止する。前記厚肉部４の前後方向の略中央部には、縦断面円弧状に突出する環状のシール部６が一体形成されている。
【００２１】
また、前記厚肉部４後方には、薄肉部５が形成されると共にその外周面には前記厚肉部４から同外径で延びる縦リブ３が一体に設けられる。それにより、キャップ後端部外周面の通気路の横断面積が、厚肉部４の通気路４１の横断面積よりも増加し、それにより、キャップ後端縁外周が、幼児等の喉内壁に食いついたとしても、十分な空気流量を確保することができる。
【００２２】
（肉厚寸法）
前記縦リブ３は、軸方向に均一な横断面の肉厚のまま延設され、実際には、その肉厚寸法Ｂは、０．６ｍｍに設定されている。また、前記厚肉部４は、その横断面の肉厚寸法Ａが、１．０ｍｍ〜１．２ｍｍに設定され、その縦断面の肉厚寸法Ｌが、３．３ｍｍに設定されている。また、前記シール部６の縦断面の肉厚寸法Ｍは、０．９ｍｍに設定された。すなわち、縦リブ３の肉厚寸法Ｂに対する、厚肉部４の肉厚寸法Ａの比率（Ａ／Ｂ）は、「１．５≦Ａ／Ｂ≦５．０」の関係を満足し、シール部６の縦断面の肉厚寸法Ｍに対する、厚肉部４の縦断面の肉厚寸法Ｌの比率（Ｌ／Ｍ）は、「Ｌ／Ｍ≧２．０」の関係を満足している。
【００２３】
【実施例２】
図５〜図７に本発明の第２実施例を示す。キャップ本体は、第１実施例同様、合成樹脂の射出成形よりなる有底筒体である。キャップ本体の周壁２の後部（後端部よりわずかに前方）には、径方向外方に環状に膨出する厚肉部４が一体成形される。前記厚肉部４の前方には、前記縦リブ３より肉厚の縦リブ３１を備えた薄肉部５（即ち、溝状の通気路５１を有する異形断面の厚肉部３１）が設けられる。前記溝状の通気路５１は、厚肉部４の通気路４１と、シ−ル部６より前方位置で接続される。尚、肉厚寸法Ａ，Ｂ，Ｌ，Ｍ及び他の構成は、第１実施例と同じである。
【００２４】
（ヒケ）
前記第１，第２実施例において、肉厚寸法Ａ、Ｂ、Ｌ、Ｍが、前記関係式を満足しているため、シール部６の内周面にはヒケが発生せず、筆記具本体８と十分な気密嵌合がなされる（図４）。尚、前記薄肉部５内周面には、図２，図６に示すように、縦リブ３（異形部）の存在によってヒケ７が生じているが、ペン先を気密に保持するキャップの機能を何ら損ねるものではない。
【００２５】
（適用可能な筆記具等）
尚、本発明のキャップ（図１，図５）は、例えば、マーキングペン、サインペン、ボールペン、パイプペン、万年筆等の筆記具、あるいは、修正液、化粧液、接着剤等の塗布具に適用可能である。
【００２６】
【発明の効果】
本発明の筆記具等のキャップは前記構成にしたことにより、気密嵌合部の成形時のヒケを防止すると共に、シンプルな形状にして金型等の製造コストを低く抑え、さらに、キャップの外観形状をデザインする上での自由度が増す。
【図面の簡単な説明】
【図１】本発明の筆記具等のキャップの第１実施例を示す縦断面図である。
【図２】図１のＸ−Ｘ線断面図である。
【図３】図１のＹ−Ｙ線断面図である。
【図４】図１のキャップを筆記具本体に装着した状態の説明図である。
【図５】本発明の筆記具等のキャップの第２実施例を示す縦断面図である。
【図６】図５のＸ−Ｘ線断面図である。
【図７】図５のＹ−Ｙ線断面図である。
【符号の説明】
１キャップ
２周壁
３縦リブ
４厚肉部
４１通気路
５薄肉部
５１通気路
６シール部
７ヒケ
８筆記具本体
Ａ厚肉部の横断面の肉厚寸法
Ｂ縦リブの横断面の肉厚寸法
Ｌ厚肉部の縦断面の肉厚寸法
Ｍシール部の縦断面の肉厚寸法[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a cap such as a writing instrument. Specifically, the present invention relates to a cap such as a writing instrument made of synthetic resin injection molding in which a longitudinal rib in the longitudinal direction is integrally formed on the outer peripheral surface of a peripheral wall of a bottomed cylindrical body.
[0002]
[Prior art]
For example, in Japanese Utility Model Publication No. 4-89388, as a brush shaft cap that does not cause suffocation even if swallowed by mistake, an air passage groove is provided in the axial direction on the outer peripheral surface, facing the groove end, Further, there is disclosed a structure in which ribs having extended end portions are provided at positions avoiding the vicinity of the outer surface of the air tight fitting portion, thereby preventing sink marks during molding of the air tight fitting portion.
[0003]
Japanese Utility Model Laid-Open No. 6-29886 discloses a cap for a writing instrument or the like for the purpose of preventing suffocation due to accidental ingestion and preventing sinking of the hermetic retaining part, and has a collar part in front or rear of the hermetic retaining part, A configuration is disclosed in which a first groove is provided in the collar portion and a second groove is provided on the outer surface of the cap body excluding the airtight holding portion.
[0004]
[Problems to be solved by the invention]
The cap disclosed in Japanese Utility Model Laid-Open No. 4-89388 has to project an unpleasant rib even if it prevents the airtight holding portion from sinking, which tends to impair the appearance of the entire cap, and restricts the design. There is. Further, the cap disclosed in Japanese Utility Model Laid-Open No. 6-29886 tends to be limited to an external shape having a collar even if it prevents the airtight holding portion from sinking, and has a low degree of freedom in considering the design. Furthermore, both publications have a complicated structure, which increases the manufacturing cost of molds and the like.
[0005]
The present invention solves the above-mentioned conventional problems, prevents sink marks during the molding of the airtight fitting portion, and reduces the manufacturing cost of the mold and the like with a simple shape. An object of the present invention is to provide a cap such as a writing instrument capable of increasing the degree of freedom in designing the external shape. In the present invention, “front” indicates the cap closing side, and “rear” indicates the cap opening side.
[0006]
[Means for Solving the Problems]
(1) Outline The present invention is a cap 1 such as a writing instrument made of synthetic resin injection molding in which a longitudinal rib 3 in the longitudinal direction is integrally provided on an outer peripheral surface of a peripheral wall 2 of a bottomed cylindrical body. An annular thick portion 4 that bulges outward in the direction is integrally provided, and an annular seal portion 6 that is airtightly fitted to the writing instrument main body 8 is integrally provided on the inner peripheral surface of the thick portion 4. A longitudinal rib 3 extending in the longitudinal direction is integrally provided on the outer peripheral surface of the thick portion 4, and a thin portion 5 is formed behind the thick portion 4, and the outer diameter of the outer peripheral surface is the same as that of the thick portion 4. It is a requirement that the vertical ribs 3 extending in the above are integrally provided, and that the cross-sectional area of the air passage on the outer peripheral surface of the rear end of the cap is larger than the cross-sectional area of the air passage of the thick portion 4 .
[0007]
Moreover, in the said structure, the thickness dimension A of the cross section of the said thick part 4 and the thickness dimension B of the cross section of the said vertical rib 3 are "1.5 <= A / B <= 5.0". It is preferable to satisfy the relationship.
[0008]
Moreover, in the said structure, it is effective to project the said seal part 6 in the approximate center part of the said thick part 4 internal peripheral surface.
[0009]
(2) Vertical ribs The number of the vertical ribs 3 provided on the outer peripheral surface of the peripheral wall 2 (thick wall portion 4 or thin wall portion 5) may be one, but for preventing suffocation between adjacent vertical ribs 3. In the case where the air passage is reliably formed, a plurality (for example, 6 or more) is preferable.
[0010]
(3) Thick part The thick part 4 may be disposed at any position of the front part (that is, the closing side), the rear part (that is, the opening side), or the central part of the peripheral wall 2 of the bottomed cylindrical body. . However, since the said thick part 4 has the cyclic | annular seal | sticker part 6, it is preferable to provide in the center part or rear part of the surrounding wall 2 so that a nib sealing space may be formed effectively. In addition, the remaining thick peripheral portion 2 forms a thin portion 5 by the thick portion 4.
[0011]
The wall thickness dimension A of the thick wall portion 4 is preferably 1.5 times or more the wall thickness dimension B of the vertical rib 3 (that is, relational expression, A / B ≧ 1.5). At this time, the thickness of the thick portion 4 provided with the seal portion 6 (that is, the thickness of the seal portion 6 and the peripheral wall 2 in the vicinity of the seal portion 6) is sufficiently thick. There is no influence of the deformed portion (that is, the vertical rib 3), and no sink marks are generated in the seal portion 6. On the contrary, when the ratio of the thickness dimension A of the thick portion 4 to the thickness dimension B of the vertical rib 3 is smaller than 1.5 (that is, relational expression, A / B <1.5), At the time of molding, sink marks are generated in the seal portion 6 due to the deformed portion (that is, the vertical rib 3) on the outer peripheral surface of the seal portion 6.
[0012]
Further, the thickness A of the thick portion 4 is preferably 5 times or less than the thickness B of the vertical rib 3 (that is, relational expression, A / B ≦ 5.0). At this time, the molding cycle at the time of injection molding can be shortened, which is optimal for mass production. On the other hand, when the ratio of the thickness A of the thick portion 4 to the thickness B of the vertical rib 3 is greater than 5 (ie, relational expression, A / B> 5.0), The thickness of the portion 4 becomes extremely thick and the amount of the synthetic resin as the material increases, and the cooling time (that is, the molding cycle) of the mold at the time of injection molding becomes long and the manufacturing cost increases.
[0013]
(4) Seal portion The seal portion 6 is effective to project as an annular convex portion, and the longitudinal cross-sectional shape thereof is preferably an R curved surface or a tapered surface. Moreover, it is preferable to provide the said seal part 6 in the approximate center part (namely, intermediate part of the front end and rear end of the thick part 4) of the thick part 4. FIG. At that time, the thickness dimension M of the longitudinal section of the seal portion 6 is smaller than the thickness dimension L of the longitudinal section of the thick section 4. Thereby, when the vertical rib 3 (or vertical rib 31) is provided in the thin portion 5, an appropriate distance is generated between the end of the vertical rib 3 (31) of the thin portion 5 and the seal portion 6, The seal portion 6 can be prevented from sinking due to the vertical ribs 3 (31) of the thin portion 5. More specifically, when the thickness dimension L of the longitudinal section of the thick section 4 and the thickness dimension M of the longitudinal section of the seal section 6 satisfy the relationship “L / M ≧ 2.0”. The occurrence of sink marks in the seal portion 6 due to the vertical ribs 3 (31) of the thin portion 5 is sufficiently suppressed.
[0014]
(5) Examples of the synthetic resin material constituting the synthetic resin cap 1 include polyethylene, polypropylene, polyacetal, polyethylene terephthalate, polybutylene terephthalate, and the like.
[0015]
(6) When the seal portion 6 is provided on the inner peripheral surface of the working thick portion 4, the vertical rib 3 is provided on the outer peripheral surface of the peripheral wall 2 provided with the seal portion 6. Thus, an appropriate ring-shaped seal portion 6 that can be airtightly fitted to the writing instrument body 8 can be formed without causing the above-described sink marks. As a result, there is no need to consider not to provide the vertical rib 3 on the outer peripheral surface of the seal portion 6, so that a simple shape can be achieved while keeping the manufacturing cost of the mold low, and the degree of freedom in design is also high. spread.
[0016]
In addition, in the case of a cap (so-called ventilation cap) that prevents suffocation accidents caused by accidental ingestion of infants, etc., a ventilation cap having the above-described effects (ie, reducing manufacturing costs and reducing design constraints) is provided. can do.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described with reference to the drawings.
[0018]
[Example 1]
1 to 4 show a first embodiment of the present invention. Specifically, FIG. 1 is a longitudinal sectional view showing a first embodiment of the cap 1 of the present invention. 2 is a cross-sectional view taken along line XX of FIG. 3 is a cross-sectional view taken along line YY of FIG. FIG. 4 is an explanatory diagram of a state in which the cap 1 of FIG.
[0019]
(Thick part, thin part)
The cap body is a bottomed cylindrical body made of synthetic resin injection molding. A thick portion 4 bulging annularly outward in the radial direction is integrally formed at the rear portion (slightly forward from the rear end portion) of the peripheral wall 2 of the cap body, and further, at the front and rear of the remaining peripheral wall 2 A thin portion 5 is formed.
[0020]
(Vertical rib, seal part)
Eight vertical ribs 3 are integrally projected from the open end to the closed end of the peripheral wall 2 (that is, the thick portion 4 and the thin portion 5). Groove-shaped air passages 41 and 51 are formed between the adjacent vertical ribs 3 and 3, thereby preventing suffocation accidents caused by accidental ingestion of infants and the like. An annular seal portion 6 that protrudes in an arc shape in the longitudinal section is integrally formed at a substantially central portion in the front-rear direction of the thick portion 4.
[0021]
Further, a thin portion 5 is formed behind the thick portion 4, and a vertical rib 3 extending from the thick portion 4 with the same outer diameter is integrally provided on the outer peripheral surface thereof. Thereby, the cross-sectional area of the air passage of the cap rear end outer peripheral surface, an increase than the cross-sectional area of the air passage 4 1 of the thick portion 4, whereby the cap rear edge outer circumference, throat inner wall of such infants Even if there is a meal, a sufficient air flow rate can be secured.
[0022]
(Thickness dimension)
The vertical ribs 3 are extended in the axial direction with a uniform cross-sectional thickness, and the thickness dimension B is actually set to 0.6 mm. Further, the thick portion 4 has a thickness A of a transverse cross section set to 1.0 mm to 1.2 mm, and a thickness L of a vertical cross section set to 3.3 mm. The thickness M of the longitudinal section of the seal portion 6 was set to 0.9 mm. That is, the ratio (A / B) of the thickness A of the thick portion 4 to the thickness B of the vertical rib 3 satisfies the relationship of “1.5 ≦ A / B ≦ 5.0”, and the seal The ratio (L / M) of the thickness dimension L of the vertical section of the thick section 4 to the thickness dimension M of the vertical section of the section 6 satisfies the relationship of “L / M ≧ 2.0”.
[0023]
[Example 2]
5 to 7 show a second embodiment of the present invention. The cap main body is a bottomed cylindrical body made of synthetic resin injection molding as in the first embodiment. A thick portion 4 bulging annularly outward in the radial direction is integrally formed at the rear portion (slightly forward of the rear end portion) of the peripheral wall 2 of the cap body. In front of the thick portion 4, a thin portion 5 (that is, a thick portion 31 having a modified cross section having a groove-like air passage 51) having a vertical rib 31 thicker than the vertical rib 3 is provided. The groove-shaped air passage 51 is connected to the air passage 41 of the thick portion 4 at a position ahead of the seal portion 6. The thickness dimensions A, B, L, M and other configurations are the same as those in the first embodiment.
[0024]
(Sink)
In the first and second embodiments, since the wall thickness dimensions A, B, L, and M satisfy the relational expression, there is no sink on the inner peripheral surface of the seal portion 6, and the writing instrument body 8 And a sufficient hermetic fit (FIG. 4). As shown in FIGS. 2 and 6, sink marks 7 are formed on the inner peripheral surface of the thin portion 5 due to the presence of the vertical ribs 3 (deformed portions), but the cap functions to keep the pen tip airtight. There is no loss of anything.
[0025]
(Applicable writing instruments, etc.)
The cap of the present invention (FIGS. 1 and 5) can be applied to, for example, a writing instrument such as a marking pen, a sign pen, a ballpoint pen, a pipe pen, and a fountain pen, or an applicator such as a correction liquid, a cosmetic liquid, and an adhesive. .
[0026]
【The invention's effect】
The cap of the writing instrument or the like of the present invention has the above-described configuration to prevent sink marks at the time of forming the airtight fitting portion, to keep the manufacturing cost of the mold and the like simple and to further reduce the appearance shape of the cap. Increases the degree of freedom in designing
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view showing a first embodiment of a cap such as a writing instrument of the present invention.
2 is a cross-sectional view taken along line XX of FIG.
3 is a cross-sectional view taken along line YY in FIG.
4 is an explanatory view showing a state in which the cap of FIG. 1 is attached to the writing instrument body. FIG.
FIG. 5 is a longitudinal sectional view showing a second embodiment of the cap of the writing instrument of the present invention.
6 is a cross-sectional view taken along line XX of FIG.
7 is a cross-sectional view taken along line YY in FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Cap 2 Perimeter wall 3 Vertical rib 4 Thick part 41 Ventilation path 5 Thin wall part 51 Ventilation path 6 Seal part 7 Sink 8 Writing instrument body A Thickness dimension of the cross section of the thick part B Thickness dimension L of the cross section of the vertical rib Thickness M of the vertical section of the thick section M Thickness of the vertical section of the seal section

Claims

A cap of a writing instrument or the like made of synthetic resin injection molding, in which a longitudinal rib (3) in the longitudinal direction is integrally provided on an outer peripheral surface of a peripheral wall (2) of a bottomed cylindrical body, and radially outward on the peripheral wall (2) An annular thick portion (4) that bulges out is provided integrally, and an annular seal portion (6) that is airtightly fitted to the writing instrument body (8) is provided integrally on the inner peripheral surface of the thick portion (4). Furthermore, a longitudinal rib (3) extending in the longitudinal direction is integrally provided on the outer peripheral surface of the thick part (4), and a thin part (5) is formed at the rear of the thick part (4). A longitudinal rib (3) extending from the thick part (4) with the same outer diameter is integrally provided on the outer peripheral surface, and the cross-sectional area of the air passage on the outer peripheral surface of the rear end of the cap is the ventilation of the thick part (4). Cap for writing instruments, etc., characterized by an increase over the cross-sectional area of the road .

The thickness dimension (A) of the cross section of the thick part (4) and the thickness dimension (B) of the cross section of the vertical rib (3) are:
1.5 ≦ A / B ≦ 5.0
The cap for a writing instrument or the like according to claim 1 that satisfies the above relationship.

The cap of a writing instrument or the like according to claim 1 or 2, wherein the seal portion (6) protrudes from a substantially central portion of the inner peripheral surface of the thick portion (4).