JP3946340B2

JP3946340B2 - Mating structure of writing instrument cap

Info

Publication number: JP3946340B2
Application number: JP06233198A
Authority: JP
Inventors: 孝男稲葉; 秀之田中
Original assignee: Pilot Ink Co Ltd
Current assignee: Pilot Ink Co Ltd
Priority date: 1998-02-25
Filing date: 1998-02-25
Publication date: 2007-07-18
Anticipated expiration: 2018-02-25
Also published as: JPH11240290A

Description

【０００１】
【発明の属する技術分野】
本発明は筆記具のキャップ嵌合構造に関する。さらに詳細には、キャップ内面に二つの嵌合部を互いに前後に離した位置に設けた筆記具のキャップ嵌合構造に関する。
【０００２】
【従来の技術】
従来、この種のキャップ嵌合構造において、例えば、（ａ）実公平５−２４５５８号公報には、キャップの内孔に環状圧接部４ｂと、凹凸嵌合部４ｃとを、前後に離隔する位置に配在させてなる筆記具のキャップ嵌合構造が開示され、また、その実施例において、キャップ内孔又はキャップ開口端に、嵌合位置決定用の係止壁４ｄを設ける構成が開示されている。
しかし、前記公報（ａ）のものは、軸筒とキャップとの軸方向の当接箇所が係止壁４ｄの一箇所である。そのため、万が一、キャップを強い勢いで軸筒のペン先側に装着させた場合、前記当接箇所が変形または破壊され、軸筒をキャップ内の所定位置よりも深く差し入れて、ペン先をキャップの閉鎖壁に衝突させ破損させたり、キャップ開口端近傍内面の嵌合部を軸筒の肩部により押し広げたり、あるいは弾性体からなるペン先シール部材が配置されるタイプの筆記具では、ペン先の突き刺しによりペン先シール部材を破損させるおそれがある。
【０００３】
また、（ｂ）実開平４−７１２８８号公報には、キャップ内壁に、環状突起と振れ止め突起が適宜間隔をおいて配設された嵌合構造が開示され、その実施例において、軸筒の前方移動を停止させるストッパとして、軸筒肩部と当接するリブをキャップ内壁に設けた構成が開示されている。
ところが、前記公報（ｂ）のものは、キャップを軸筒ペン先側に装着した際、キャップ開口端と軸筒段部とは非接触状態にあり、キャップ開口端と軸筒段部との間に軸方向の比較的大きな隙間が存在する。そのため、前記公報（ａ）の構成と同様、勢い良くキャップ装着がなされた場合、軸筒とキャップの当接箇所が破壊され、軸筒の前側嵌合部をキャップ段部により損傷させるおそれがある。その上、前記公報（ｂ）の構成は、キャップ開口端と軸筒段部との間の比較的大きな隙間により、あたかもキャップ装着が不完全（いわゆるキャップ浮きの状態）のような印象をユーザーに与えることになり、筆記具全体の外観が損なわれる。
【０００４】
また、キャップ装着時、二つの軸方向の位置決めストッパを互いに軸方向に離した位置に設け、軸筒段部とキャップ開口端を当接させると同時に、軸筒肩部とキャップ内面の段部とを当接させる構成も考えられる。しかし、前記二つの位置決めストッパに同時に当接させるには、軸筒の段部から肩部までの長手寸法（本願の寸法Ｍに相当）と、キャップの段部から開口端までの長手寸法（本願の寸法Ｌに相当）とを完全に一致させる必要があり、そのためには、キャップ及び軸筒の高い寸法精度が要求され、製造上困難である。
【０００５】
【発明が解決しようとする課題】
本発明は、前記従来の問題点を解決するものであって、キャップを軸筒のペン先側に強い勢いで装着しても、軸筒がキャップ内の所定位置よりも深く差し込まれることを防止し、キャップ内面の嵌合部等の損傷を確実に回避でき、さらに、キャップ開口端と軸筒段部との間に大きな隙間を生じさせず、良好な外観を維持でき、しかも、高い精度を要さず製造が容易となる筆記具のキャップ嵌合構造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、キャップ閉塞側及び軸筒ペン先側を指し、「後方」とはキャップ開口側及び軸筒尾端側を指す。
【０００６】
【課題を解決するための手段】
本願発明は、ペン先３後方の軸筒１前部外面に肩部１２を設け、前記肩部１２後方の軸筒１外面に前記肩部１２より大径の段部１１を設け、一方、キャップ２の開口端２１近傍内面に、前記軸筒段部１１近傍外面と嵌合する後側嵌合部２３を設け、前記後側嵌合部２３前方のキャップ２内面に、前記軸筒肩部１２近傍外面と嵌合する前側嵌合部２４を設けた筆記具のキャップ嵌合構造であって、前記キャップ２内面の前側嵌合部２４前方に段部２２を設け、キャップ２を軸筒１のペン先３側に装着させた際、前記キャップ開口端２１と前記軸筒段部１１とを軸方向に当接させ、さらに、前記キャップ段部２２と前記軸筒肩部１２とを軸方向に非接触状態で対向させると共に、前記キャップ段部２２と前記軸筒肩部１２との軸方向の間隙寸法Ｃを１ｍｍ以下に設定してなること（請求項１）を要件とする（図１〜図６参照）。
【０００７】
（作用）
図１〜図３に示すように、キャップ２を軸筒１のペン先３側に通常に装着させると、キャップ２の開口端２１と軸筒１の段部１１が軸方向に当接し、キャップ装着は完了する。このとき、キャップ２内面に設けた段部２２と、軸筒１の肩部１２が軸方向に非接触状態で対面すると共に、前記キャップ段部２２と軸筒肩部１２との軸方向の間隙寸法Ｃが１ｍｍ以下に設定されている。
【０００８】
そのため、万が一、キャップ２が通常より極めて強い装着力で強い勢いで軸筒１のペン先３側に装着され、キャップ開口端２１が軸筒段部１１を乗り越えようとしても、キャップ段部２２と軸筒肩部１２が当接するので、キャップ２の深差しが防止され、ペン先３やキャップ２の後側嵌合部２３の損傷が回避できる。
【０００９】
前記間隙寸法Ｃが１ｍｍ以下である構成のため、強い勢いのキャップ装着の際、キャップ開口端２１が軸筒段部１１を乗り越えようとしても、キャップ２の後側嵌合部２３を軸筒段部１１が押し広げてしまう前に、キャップ段部２２と軸筒肩部１２が軸方向に確実に当接し、前記後側嵌合部２３の変形又は損傷が防止され、後側嵌合部２３の内径寸法及び形状が維持できる。仮に、前記間隙寸法Ｃが１ｍｍより大きい場合、軸方向の寸法ばらつきは十分に吸収できるとしても、強い勢いでキャップ装着がなされた場合、キャップ段部２２と軸筒肩部１２が当接する前に、キャップ開口端２１が軸筒段部１１を乗り越え、キャップ開口端２１近傍内面の後側嵌合部２３を軸筒１の段部１１が押し広げてしまうおそれがある。前記間隙寸法Ｃは、０．５ｍｍ以下（即ち、０＜Ｃ≦０．５ｍｍ）が、より一層キャップの深差し防止がなされる点で好ましい。
【００１０】
その上、キャップ装着完了時、キャップ開口端２１と軸筒１の段部１１が軸方向に当接しているため、キャップ開口端２１と軸筒段部１１との間に隙間が生じず、あたかもキャップ装着が不完全のような印象をユーザーに与えることがなく、商品としての筆記具の良好な外観を維持できる。さらに、キャップ装着完了時、軸筒段部１１とキャップ開口端２１とが衝止するため、前記衝止時に発生する嵌合音（いわゆるパッチン音）が、キャップ開口端２１から発生するため、クリアな嵌合音となり、気持ちのよい嵌合感を味わうことができる。逆に、キャップ２と軸筒１との軸方向の当接箇所がキャップ内奥である場合、発生する嵌合音は籠もった鈍い音となりがちである。
【００１１】
また、キャップ装着の際、キャップ開口端２１と軸筒段部１１とを当接させると同時に、キャップ段部２２と軸筒肩部１２とを軸方向に非接触状態で対向させた構成、即ち、キャップ２の開口端２１から段部２２までの長手寸法（図４の寸法Ｌ）が、軸筒１の段部１１から肩部１２までの長手寸法（図６の寸法Ｍ）より僅かに大きく設定した構成（即ち、Ｌ＞Ｍ）により、キャップ２及び軸筒１の長手寸法（即ち、寸法Ｍ、寸法Ｌ）が多少ばらついたとしても、前記構成Ｌ＞Ｍの関係を維持することは容易である。即ち、前記構成Ｌ＞Ｍの関係により、長手寸法のばらつきを吸収することができ、その結果、キャップ２及び軸筒１の製造において高い寸法精度が不要となり、製造が極めて容易となり、安価な筆記具に最適となる。
【００１２】
特に、キャップ２内面の前後に離した位置に、二つの嵌合部（即ち、後側嵌合部２３、及び前側嵌合部２４）を設ける本願のタイプのキャップ嵌合構造の場合、キャップ２全体は比較的長い形状のものとなって、長手方向の寸法ばらつきがより一層大きくなりがちであり、精度よく製造するには不利である。しかし、前記構成（即ち、長手寸法の関係Ｌ＞Ｍを満たす構成）は、キャップ２及び軸筒１の長手方向の寸法ばらつきを吸収するため、本願タイプのキャップ嵌合構造に採用する場合、製造が容易になる点でたいへん有効である。
【００１３】
また、前記軸筒段部１１と前記キャップ開口端２１の材質がどちらか一方が合成樹脂の場合、及び前記軸筒肩部１２と前記キャップ段部２２の材質がどちらか一方が合成樹脂の場合、当接時の強度に不安があるが、請求項１乃至２の構成にすることにより、当接時の強度不足の不安を解消できる。
【００１４】
・接触長さＤ
前記筆記具のキャップ嵌合構造（請求項１）において、キャップ２を軸筒１のペン先３側に装着させた際、キャップ開口端２１と軸筒段部１１との径方向の接触長さＤを１ｍｍ以下に設定すること（請求項２）が好ましい（図３参照）。
【００１５】
（作用）
前記キャップ開口端２１と前記段部１１との径方向の接触長さＤが１ｍｍ以下の場合、比較的小さい軸筒段部１１となり外観性が維持でき且つ使用時に指が引っ掛かる不快を解消できるとしても、径方向の当接量が比較的小さく、キャップ２が強い勢いで装着されると、キャップ開口端２１が軸筒段部１１を乗り越えてしまうおそれがあり、軸方向の当接機能にとって不利である。しかし、前記接触長さＤが１ｍｍ以下の場合において、前記請求項１の構成のキャップ深差し防止効果が特に有効に作用する。
【００１６】
【００１７】
【００１８】
【００１９】
【００２０】
【００２１】
【００２２】
【００２３】
【００２４】
【００２５】
【００２６】
・構成要素の説明（図１〜図６参照）
（軸筒）
軸筒１は、前端にペン先３を有する。前記ペン先３は、軸筒１前部外面へのキャップ２の被着により、保護される。また、ペン先３からインキを吐出させるタイプの場合、キャップ２の装着によりペン先３が密封され、インキの蒸発が抑制される。
【００２７】
前記ペン先３は、筆記機能を有するペン先であればいずれでもよく、例えば、ボールペンチップ、合成樹脂の押出成形によりなるペン体、繊維束の樹脂加工ペン体、パイプ状ペン体、先端にスリットを有する板状ペン体、毛筆ペン体、多孔質ペン体、及び鉛芯等を挙げることができる。
【００２８】
（肩部）
軸筒肩部１２は、ペン先３後方の軸筒１前部外面に、一体又は別部材の取り付けにより設けられる。前記軸筒肩部１２前面は、キャップ段部２２と当接可能に、軸方向に対向している。前記軸筒肩部１２の縦断面形状は、直角形状、Ｒ曲面形状、テーパ形状等適宜であるが、キャップ段部２２との当接面は、軸線に対して垂直面であることが、十分な当接衝止力を有する点で好ましい。また、前記軸筒肩部１２のキャップ段部２２との対向面に、溝や突起等を設けることもできる。
【００２９】
（段部）
軸筒段部１１は、前記軸筒肩部１２後方の軸筒１外面に、一体または別部材の取り付けにより設けられる。前記軸筒段部１１は、その前方の軸筒肩部１２よりも大径であるため、キャップ２の装着の際、キャップ開口端２１が軸筒肩部１２に引っ掛かることを防止し、キャップ装着を円滑にする。前記軸筒段部１１の形状は、直角形状、Ｒ曲面形状、テーパ形状等適宜であるが、キャップ２の開口端２１との当接面は、軸線に対して垂直面であることが、十分な当接衝止力を有する点で好ましい。また、前記軸筒段部１１のキャップ２の開口端２１との当接面に、溝や突起等を設けることもできる。
【００３０】
（後側嵌合部、前側嵌合部）
キャップ２内面に形成される後側嵌合部２３、及び前側嵌合部２４としては、例えば、気密嵌合用の環状突起、あるいは周状に分散配置される複数の点状突起等が挙げられる。また、前記キャップ２の後側嵌合部２３、及び前側嵌合部２４の軸筒１外面（即ち、後側嵌合部１３、及び前側嵌合部１４）との嵌合構造は、乗り越え嵌合又は摺接嵌合（圧入嵌合ともいう）のいずれの嵌合構造でもよい。また、後側嵌合部２３の内径は、前側嵌合部２４の内径より大きく設定され、それにより、キャップ装着の過程で、キャップ開口端２１内面の後側嵌合部２３を軸筒肩部１２に引っかけて円滑なキャップ２の装着を阻害することが防止される。また、前記後側嵌合部２３、及び前側嵌合部２４が嵌合する軸筒１外面には、面状の摺接嵌合部や突起状の乗り越え嵌合部が形成される。
【００３１】
（段部）
キャップ２内面に形成される段部２２は、軸筒肩部１２前面が当接可能であればいずれの形状でもよく、例えば、キャップ２内周面に設けた一般的な段形状の他、突起形状のものでもよい。前記キャップ段部２２の軸筒肩部１２との当接面は、軸方向に対して垂直面であることが十分な当接衝止力を有する点で好ましい。
【００３２】
前記キャップ段部２２が、前記キャップ２内周面より突出する軸方向に延びる複数本のリブの中間部又は後端部に設けた段形状である場合、前記キャップ段部２２の前方位置で、ペン先密封部（例えば、弾性体よりなるペン先シール部材、繊維や多孔質体等よりなる吸液部材、合成樹脂製有底筒体よりなるインナーキャップ等）を、キャップ２内に支持することもできる。前記ペン先密封部を支持する前記リブが段部２２を兼ねる構成により、簡易な構造となって製造が容易となる。
【００３３】
【発明の実施の形態】
本発明の実施の形態について図面に従って説明する。本発明の実施例を図１〜図６に示す。
【００３４】
（軸筒）
図６に示すように、軸筒１は、円筒状の合成樹脂（例えば、ポリプロピレン樹脂）の射出成形体であり、その前端には、直接またはホルダー部材等を介して間接的にペン先３（ここではボールペンチップ）が取り付けられている。前記ペン先３の後方の軸筒１前部外周面には、複数の環状突起よりなる滑り止め機能を有する凹凸状の把持部１５が一体に形成されている。
【００３５】
さらに、前記軸筒１外面の把持部１５の前方且つペン先３後方（即ち把持部１５とペン先３の間）には、テーパ状に面取りされた肩部１２が一体に形成されている。また、軸筒１外面の前記把持部１５の後方には、前記肩部１２より大きい外径の段部１１が形成される。前記段部１１は、軸筒１外面に取り付けた別部材（例えば、ポリプロピレン樹脂製）の前端面により構成されている。
【００３６】
また、軸筒１外面の前記肩部１２後方且つ把持部１５前方（即ち肩部１２と把持部１５の間）には、キャップ２の前側嵌合部２４と摺接嵌合可能な環状平滑部よりなる前側嵌合部１４が一体に形成され、前記把持部１５後方且つ段部１１前方（即ち把持部１５と段部１１の間）には、キャップ２の後側嵌合部２３と乗り越え嵌合可能な環状凸部よりなる後側嵌合部１３が一体に形成されている。尚、前記軸筒１の肩部１２から段部１１までの軸方向の長さＭは、ここでは２８．０ｍｍに設定されている。
【００３７】
（キャップ）
図４及び図５に示すように、キャップ２は、有底円筒状の透明性合成樹脂（例えば、ポリカーボネート樹脂）の射出成形体である。
【００３８】
キャップ２の開口端２１近傍内面には、周状に分散配置された複数（ここでは４個）の点状突起よりなる後側嵌合部２３が一体に形成される。そして、前記キャップの後側嵌合部２３は、キャップ装着時、前記軸筒段部１１近傍の環状凸部よりなる後側嵌合部１３と乗り越え嵌合する。
【００３９】
また、前記後側嵌合部２３前方のキャップ２の内面には、後側嵌合部２３同様、周状に分散配置された複数（ここでは４個）の点状突起よりなる前側嵌合部２４が一体に形成されている。そして、前記前側嵌合部２４は、キャップ装着時、前記軸筒肩部１２近傍の環状平滑部よりなる前側嵌合部１４と摺接嵌合する。
【００４０】
前記前側嵌合部２４の前方のキャップ２内面には、軸方向に延設された複数本（ここでは６本）のリブが一体に形成され、その後端部が、軸方向に対して垂直な段形状の段部２２が形成されている。キャップ２の開口端２１から段部２２までの軸方向の長さＬは、ここでは２８．２ｍｍに設定されている（図４参照）。
【００４１】
また、前記キャップ段部２２前方のリブの内面では、合成ゴムよりなる円筒状外面を有するペン先シール部材４が圧入保持される。また、前記ペン先シール部材４は、インキ色に着色されており、透明性キャップ２であることと相まって、外部よりインキ色を視認することができる。
【００４２】
（キャップ装着状態）
図１〜図３に示すように、キャップ装着後、前記キャップ開口端２１は、軸筒段部１１と軸方向に当接していると同時に、前記キャップ段部２２は、軸筒肩部１２と軸方向に非接触状態で対峙している。前記キャップ段部２２と前記軸筒肩部１２との軸方向の間隙寸法Ｃは、前記長手寸法ＬとＭの差であり、ここでは０．２ｍｍに設定されている（図２参照）。一方、キャップ２の開口端２１と軸筒１の段部１１との径方向の接触長さＤは、ここでは０．３ｍｍに設定されている（図３参照）。
【００４３】
また、本実施例において、キャップ段部２２と軸筒肩部１２との当接面は、両者ともに軸方向に対して垂直面となっており、キャップ開口端２１と軸筒段部１１の当接面も、両者ともに軸方向に対して垂直面となっている。
【００４４】
また、本実施例では、軸筒１のペン先３側にキャップ２を装着させた際、軸筒１前部外面の把持部１５が、キャップ２により覆われている。前記把持部１５をキャップ２が覆うことにより、前記滑り止め把持部１５への埃の付着等の汚れを避けることができる。また、キャップ２が把持部１５を覆う場合、キャップ２の長手寸法は比較的長くなるため、軸方向の寸法ばらつきは大きくなり、製造上不利であるが、キャップ装着時、段部２２と軸筒１の肩部１２とを軸方向に非接触状態で対向させると同時、キャップ２開口端２１を軸筒１の段部１１に軸方向に当接させる構成により、軸方向の寸法ばらつきが十分吸収でき、製造が容易となる。
【００４５】
【００４６】
【００４７】
【００４８】
【００４９】
【００５０】
【００５１】
【００５２】
【００５３】
【００５４】
【００５５】
【００５６】
【発明の効果】
本発明筆記具のキャップ嵌合構造は、請求項１の構成により、キャップを軸筒のペン先側に強い勢いで装着しても、軸筒がキャップ内の所定位置よりも深く差し込まれることを防止し、キャップ内面の嵌合部等の損傷を確実に回避できると共に、キャップ開口端と軸筒段部との間に隙間を生じさせず良好な外観を維持でき、しかも、高い精度を要さず製造が容易となる。また、キャップの後側嵌合部を軸筒段部が押し広げてしまう前に、キャップ段部と軸筒肩部が当接するため、前記後側嵌合部の変形又は損傷が抑止され、後側嵌合部の内径寸法及び形状が維持できる。
【００５７】
また、請求項２の構成は、前記請求項１の構成と相まって、キャップ深差し防止効果が有効に発揮される。
【００５８】
【００５９】
【図面の簡単な説明】
【図１】本発明の実施例のキャップ装着状態を示す縦断面図である。
【図２】図１のＰ部拡大図である。
【図３】図１のＱ部拡大図である。
【図４】図１のキャップの縦断面図である。
【図５】図４のＡ−Ａ線断面図である。
【図６】図１の軸筒の縦断面図である。
【符号の説明】
１軸筒
１１段部
１２肩部
１３後側嵌合部（環状凸部）
１４前側嵌合部（環状平滑部）
１５把持部
２キャップ
２１開口端
２２段部
２３後側嵌合部（点状突起）
２４前側嵌合部（点状突起）
３ペン先
４ペン先シール部材
Ｃ間隙寸法
Ｄ当接長さ
Ｌキャップの段部から開口端までの長手寸法
Ｍ軸筒の段部から肩部までの長手寸法[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a cap fitting structure for a writing instrument. More specifically, the present invention relates to a writing instrument cap fitting structure in which two fitting portions are provided on the inner surface of the cap at positions separated from each other.
[0002]
[Prior art]
Conventionally, in this type of cap fitting structure, for example, (a) Japanese Utility Model Publication No. 5-24558 discloses a position in which the annular press-contact portion 4b and the concave-convex fitting portion 4c are separated in the front-rear direction in the inner hole of the cap. A cap fitting structure for a writing instrument arranged on the cap is disclosed, and in the embodiment, a configuration in which a locking wall 4d for determining a fitting position is provided at the cap inner hole or the cap opening end is disclosed. .
However, in the publication (a), the axial contact portion between the shaft tube and the cap is one place of the locking wall 4d. Therefore, in the unlikely event that the cap is attached to the pen tip side of the shaft tube with a strong force, the contact portion is deformed or destroyed, the shaft tube is inserted deeper than a predetermined position in the cap, and the pen tip is inserted into the cap. In a writing instrument of the type in which the pen tip is made to collide with the closed wall and break, or the fitting portion of the inner surface near the cap opening end is expanded by the shoulder of the shaft tube, or the pen tip seal member made of an elastic body is arranged. There is a possibility that the pen point seal member may be damaged by the piercing.
[0003]
Further, (b) Japanese Utility Model Laid-Open No. 4-71288 discloses a fitting structure in which an annular protrusion and an anti-rest protrusion are disposed at an appropriate interval on the inner wall of the cap. As a stopper for stopping the forward movement, a configuration is disclosed in which a rib that contacts the shoulder of the shaft cylinder is provided on the inner wall of the cap.
However, in the publication (b), when the cap is mounted on the shaft pen point side, the cap opening end and the shaft tube stepped portion are not in contact with each other, and the gap between the cap open end and the shaft tube stepped portion is not. There is a relatively large gap in the axial direction. For this reason, as in the configuration of the above-mentioned publication (a), when the cap is attached vigorously, the contact portion between the shaft tube and the cap may be destroyed, and the front fitting portion of the shaft tube may be damaged by the cap step portion. . In addition, the configuration of the publication (b) gives the user the impression that the cap is not completely installed (so-called cap floating state) due to the relatively large gap between the cap opening end and the shaft tube step. The appearance of the entire writing instrument is impaired.
[0004]
In addition, when the cap is mounted, two axial positioning stoppers are provided at positions separated from each other in the axial direction so that the shaft tube step and the cap opening end are in contact with each other, and at the same time, the shaft tube shoulder and the step on the inner surface of the cap It is also possible to adopt a configuration in which the abutment is brought into contact. However, in order to simultaneously contact the two positioning stoppers, the longitudinal dimension from the step portion of the shaft tube to the shoulder portion (corresponding to the dimension M of the present application) and the longitudinal dimension from the step portion of the cap to the open end (this application) For this purpose, high dimensional accuracy of the cap and the shaft tube is required, which is difficult to manufacture.
[0005]
[Problems to be solved by the invention]
The present invention solves the above-mentioned conventional problems, and prevents the shaft tube from being inserted deeper than a predetermined position in the cap even if the cap is attached to the pen tip side of the shaft tube with a strong momentum. In addition, it is possible to reliably avoid damage to the fitting part on the inner surface of the cap, and to maintain a good appearance without creating a large gap between the cap opening end and the shaft tube step part, and with high accuracy. It is an object of the present invention to provide a writing instrument cap fitting structure that is easy to manufacture.
In the present invention, “front” refers to the cap closing side and shaft barrel pen tip side, and “rear” refers to the cap opening side and shaft barrel tail end side.
[0006]
[Means for Solving the Problems]
The present application onset bright, a shoulder 12 is provided, the large-diameter stepped portion 11 from the shoulder 12 provided on the shaft tube 1 the outer surface of the shoulder portion 12 rearward barrel 1 front outer surface of the pen tip 3 backward, whereas, A rear fitting portion 23 is provided on the inner surface in the vicinity of the opening end 21 of the cap 2 so as to be fitted to the outer surface in the vicinity of the shaft tube step portion 11, and the shaft cylinder shoulder portion is provided on the inner surface of the cap 2 in front of the rear fitting portion 23. 12 is a cap fitting structure of a writing instrument provided with a front fitting portion 24 fitted to the outer surface in the vicinity, and a step portion 22 is provided in front of the front fitting portion 24 on the inner surface of the cap 2, and the cap 2 is attached to the shaft tube 1. When mounted on the pen tip 3 side, the cap opening end 21 and the shaft tube step portion 11 are brought into contact with each other in the axial direction, and the cap step portion 22 and the shaft tube shoulder portion 12 are moved in the axial direction. It is made to oppose in a non-contact state, and the axial gap dimension C between the cap step portion 22 and the shaft tube shoulder portion 12 1mm be set below (claim 1) and requirement (see FIGS. 1 to 6).
[0007]
(Function)
As shown in FIGS. 1 to 3, when the cap 2 is normally mounted on the pen tip 3 side of the shaft tube 1, the opening end 21 of the cap 2 and the step portion 11 of the shaft tube 1 abut on each other in the axial direction. Installation is complete. At this time, the step portion 22 provided on the inner surface of the cap 2 and the shoulder portion 12 of the shaft tube 1 face each other in a non-contact state in the axial direction, and the axial gap between the cap step portion 22 and the shaft tube shoulder portion 12. The dimension C is set to 1 mm or less.
[0008]
Therefore, even if the cap 2 is mounted on the pen tip 3 side of the shaft tube 1 with a much stronger mounting force than usual and the cap opening end 21 tries to get over the shaft tube step portion 11, Since the shaft tube shoulder portion 12 abuts, deep insertion of the cap 2 is prevented, and damage to the pen tip 3 and the rear fitting portion 23 of the cap 2 can be avoided.
[0009]
Since the gap dimension C is 1 mm or less, even when the cap opening end 21 tries to get over the shaft tube step portion 11 when the cap is attached with a strong momentum, the rear fitting portion 23 of the cap 2 is connected to the shaft tube step. Before the portion 11 is spread out, the cap step portion 22 and the shaft tube shoulder portion 12 are securely in contact with each other in the axial direction, so that the deformation or damage of the rear fitting portion 23 is prevented, and the rear fitting portion 23 is prevented. Can maintain the inner diameter size and shape. If the gap dimension C is larger than 1 mm, the dimensional variation in the axial direction can be sufficiently absorbed, but if the cap is attached with a strong momentum, before the cap step 22 and the shaft tube shoulder 12 abut. There is a possibility that the cap opening end 21 gets over the shaft tube step portion 11, and the step portion 11 of the shaft tube 1 pushes and spreads the rear side fitting portion 23 in the vicinity of the cap opening end 21. The gap dimension C is preferably 0.5 mm or less (that is, 0 <C ≦ 0.5 mm) from the viewpoint of further preventing deep cap insertion.
[0010]
In addition, since the cap opening end 21 and the step portion 11 of the shaft tube 1 are in contact with each other in the axial direction when the cap is completely installed, no gap is generated between the cap opening end 21 and the shaft tube step portion 11, as if Without giving the user an impression that the cap is incomplete, it is possible to maintain a good appearance of the writing instrument as a product. Further, when the cap is completely attached, the shaft tube step portion 11 and the cap opening end 21 come into contact with each other, so that a fitting sound (a so-called patching sound) generated at the time of the stop is generated from the cap opening end 21. And a pleasant fitting feeling can be enjoyed. Conversely, when the axial contact portion between the cap 2 and the shaft tube 1 is in the back of the cap, the generated fitting noise tends to be a dull sound.
[0011]
Further, when the cap is attached, the cap opening end 21 and the shaft tube step portion 11 are brought into contact with each other, and at the same time, the cap step portion 22 and the shaft tube shoulder portion 12 are opposed to each other in a non-contact state in the axial direction. The longitudinal dimension from the opening end 21 of the cap 2 to the step portion 22 (dimension L in FIG. 4) is slightly larger than the longitudinal dimension from the step portion 11 to the shoulder portion 12 (dimension M in FIG. 6) of the shaft tube 1. Even if the longitudinal dimension (that is, dimension M, dimension L) of the cap 2 and the shaft tube 1 varies slightly depending on the set structure (that is, L> M), it is easy to maintain the relationship of the structure L> M. It is. That is, due to the relationship of the configuration L> M, variations in the longitudinal dimension can be absorbed. As a result, high dimensional accuracy is not required in the production of the cap 2 and the shaft tube 1, and the production becomes extremely easy and an inexpensive writing instrument. Ideal for.
[0012]
In particular, in the case of the cap fitting structure of this type in which two fitting portions (that is, the rear fitting portion 23 and the front fitting portion 24) are provided at positions separated from the front and rear of the inner surface of the cap 2, the cap 2 The whole becomes a relatively long shape, and the dimensional variation in the longitudinal direction tends to become even larger, which is disadvantageous for accurate production. However, the configuration (that is, the configuration satisfying the relationship L> M in the longitudinal dimension) absorbs the dimensional variation in the longitudinal direction of the cap 2 and the shaft tube 1, and therefore, when employed in the cap fitting structure of the present application type, It is very effective in that it becomes easy.
[0013]
Further, when one of the material of the shaft tube step portion 11 and the cap opening end 21 is a synthetic resin, and when the material of the shaft tube shoulder portion 12 or the cap step portion 22 is a synthetic resin Although there is anxiety about the strength at the time of contact, by adopting the structure according to claims 1 and 2, anxiety about insufficient strength at the time of contact can be solved.
[0014]
・ Contact length D
In the cap fitting structure of the writing instrument (Claim 1), when the cap 2 is mounted on the pen tip 3 side of the shaft tube 1, the contact length D in the radial direction between the cap opening end 21 and the shaft tube step portion 11 is provided. Is preferably set to 1 mm or less (claim 2) (see FIG. 3).
[0015]
(Function)
When the contact length D in the radial direction between the cap opening end 21 and the step portion 11 is 1 mm or less, it becomes a relatively small shaft tube step portion 11 so that the appearance can be maintained and the discomfort that a finger gets caught during use can be eliminated. However, if the amount of contact in the radial direction is relatively small and the cap 2 is attached with a strong momentum, the cap opening end 21 may get over the shaft tube step portion 11, which is disadvantageous for the axial contact function. It is. However, in the case where the contact length D is 1 mm or less, the cap deep penetration preventing effect of the configuration of the first aspect is particularly effective.
[0016]
[0017]
[0018]
[0019]
[0020]
[0021]
[0022]
[0023]
[0024]
[0025]
[0026]
・ Description of components (see FIGS. 1-6 )
(Shaft tube)
The shaft cylinder 1 has a nib 3 at the front end. The nib 3 is protected by attaching the cap 2 to the outer surface of the front portion of the shaft cylinder 1. In the case of a type in which ink is ejected from the nib 3, the nib 3 is sealed by the cap 2 being attached, and ink evaporation is suppressed.
[0027]
The pen nib 3 may be any pen nib having a writing function, for example, a ball pen tip, a pen body formed by synthetic resin extrusion molding, a fiber bundle resin processing pen body, a pipe-shaped pen body, and a slit at the tip. A plate-shaped pen body, a brush pen body, a porous pen body, a lead core, and the like can be mentioned.
[0028]
(Shoulder)
The shaft tube shoulder portion 12 is provided on the outer surface of the front portion of the shaft tube 1 at the rear of the nib 3 by being integrated or attached by another member. The front surface of the shaft tube shoulder portion 12 is opposed to the cap step portion 22 in the axial direction so as to be in contact with the cap step portion 22. The vertical cross-sectional shape of the shaft tube shoulder portion 12 is appropriate as a right-angle shape, an R curved surface shape, a tapered shape, etc., but it is sufficient that the contact surface with the cap step portion 22 is a surface perpendicular to the axis. It is preferable in that it has a sufficient abutment stopping force. Further, a groove, a protrusion, or the like can be provided on a surface of the shaft tube shoulder portion 12 facing the cap step portion 22.
[0029]
(Step)
The shaft tube step portion 11 is provided on the outer surface of the shaft tube 1 behind the shaft tube shoulder portion 12 by being attached integrally or by attaching another member. Since the shaft tube step portion 11 has a larger diameter than the shaft tube shoulder portion 12 in front thereof, the cap opening end 21 is prevented from being caught by the shaft tube shoulder portion 12 when the cap 2 is mounted, and the cap is mounted. To make it smooth. The shape of the cylindrical tube step portion 11 is appropriate as a right-angle shape, an R curved surface shape, a tapered shape, etc., but it is sufficient that the contact surface with the opening end 21 of the cap 2 is a surface perpendicular to the axis. It is preferable in that it has a sufficient abutment stopping force. Moreover, a groove | channel, a protrusion, etc. can also be provided in the contact surface with the opening end 21 of the cap 2 of the said axial cylinder step part 11. FIG.
[0030]
(Rear mating part, front mating part)
Examples of the rear-side fitting portion 23 and the front-side fitting portion 24 formed on the inner surface of the cap 2 include an annular projection for airtight fitting, or a plurality of dot-like projections distributed in a circumferential shape. Further, the fitting structure of the cap 2 with the rear fitting portion 23 and the front fitting portion 24 with the outer surface of the shaft cylinder 1 (that is, the rear fitting portion 13 and the front fitting portion 14) is an over-fit. Either fitting structure or sliding contact fitting (also referred to as press fitting fitting) may be used. Further, the inner diameter of the rear fitting portion 23 is set to be larger than the inner diameter of the front fitting portion 24, so that the rear fitting portion 23 on the inner surface of the cap opening end 21 is connected to the shaft cylinder shoulder portion in the process of mounting the cap. 12 to prevent the smooth cap 2 from being hindered. Further, on the outer surface of the shaft tube 1 to which the rear fitting portion 23 and the front fitting portion 24 are fitted, a planar sliding contact fitting portion and a protruding climbing fitting portion are formed.
[0031]
(Step)
The step portion 22 formed on the inner surface of the cap 2 may have any shape as long as the front surface of the shaft tube shoulder portion 12 can come into contact. For example, in addition to a general step shape provided on the inner peripheral surface of the cap 2, a projection The shape may be sufficient. The contact surface of the cap step portion 22 with the shaft cylinder shoulder portion 12 is preferably a surface perpendicular to the axial direction from the viewpoint of sufficient contact and stopping force.
[0032]
When the cap step portion 22 has a step shape provided at an intermediate portion or a rear end portion of a plurality of ribs extending in the axial direction protruding from the inner peripheral surface of the cap 2, at the front position of the cap step portion 22, Supporting a nib sealing part (for example, a nib seal member made of an elastic body, a liquid absorbing member made of a fiber or a porous body, an inner cap made of a synthetic resin bottomed cylindrical body, etc.) in the cap 2. You can also. Due to the configuration in which the rib supporting the pen point sealing portion also serves as the step portion 22, the structure becomes simple and the manufacture becomes easy.
[0033]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described with reference to the drawings. An embodiment of the present invention is shown in FIGS .
[0034]
( Shaft tube)
As shown in FIG. 6, the shaft tube 1 is an injection-molded body of a cylindrical synthetic resin (for example, polypropylene resin), and a pen tip 3 (directly through a holder member or the like directly on the front end thereof. Here, a ballpoint pen tip) is attached. On the outer peripheral surface of the front portion of the shaft cylinder 1 behind the pen tip 3, an uneven gripping portion 15 having a non-slip function made up of a plurality of annular protrusions is integrally formed.
[0035]
Further, a tapered chamfered shoulder 12 is integrally formed in front of the grip 15 on the outer surface of the shaft tube 1 and behind the pen tip 3 (that is, between the grip 15 and the pen tip 3). Further, a step portion 11 having an outer diameter larger than that of the shoulder portion 12 is formed behind the grip portion 15 on the outer surface of the shaft tube 1. The step portion 11 is constituted by a front end surface of another member (for example, made of polypropylene resin) attached to the outer surface of the shaft tube 1.
[0036]
In addition, an annular smooth portion that can be slidably fitted to the front side fitting portion 24 of the cap 2 is provided behind the shoulder portion 12 and on the front side of the grip portion 15 (that is, between the shoulder portion 12 and the grip portion 15). The front fitting portion 14 is integrally formed, and is fitted over the rear fitting portion 23 of the cap 2 on the rear side of the grip portion 15 and in front of the step portion 11 (that is, between the grip portion 15 and the step portion 11). A rear fitting portion 13 made of an annular convex portion that can be joined is formed integrally. The axial length M from the shoulder portion 12 to the step portion 11 of the shaft tube 1 is set to 28.0 mm here.
[0037]
(cap)
As shown in FIGS. 4 and 5, the cap 2 is an injection-molded body of a bottomed cylindrical transparent synthetic resin (for example, polycarbonate resin).
[0038]
On the inner surface near the opening end 21 of the cap 2, a rear fitting portion 23 made up of a plurality of (in this case, four) point-like projections distributed in a circumferential manner is integrally formed. The cap rear fitting portion 23 gets over and fits with the rear fitting portion 13 formed of an annular convex portion in the vicinity of the shaft tube step portion 11 when the cap is mounted.
[0039]
In addition, the rear fitting portion 23 includes a plurality of (four in this case) dotted protrusions arranged on the inner surface of the cap 2 in front of the rear fitting portion 23 in a circumferentially distributed manner, like the rear fitting portion 23. 24 is integrally formed. And the said front side fitting part 24 is slidably fitted with the front side fitting part 14 which consists of a cyclic | annular smooth part near the said shaft cylinder shoulder part 12 at the time of cap mounting.
[0040]
A plurality of (here, six) ribs extending in the axial direction are integrally formed on the inner surface of the cap 2 in front of the front-side fitting portion 24, and the rear end portion is perpendicular to the axial direction. A stepped step portion 22 is formed. The axial length L from the open end 21 of the cap 2 to the stepped portion 22 is set to 28.2 mm here (see FIG. 4).
[0041]
A nib seal member 4 having a cylindrical outer surface made of synthetic rubber is press-fitted and held on the inner surface of the rib in front of the cap step portion 22. Further, the pen point seal member 4 is colored in ink color, and coupled with the transparency cap 2, the ink color can be visually recognized from the outside.
[0042]
(With cap attached)
As shown in FIGS. 1 to 3, after the cap is mounted, the cap opening end 21 is in axial contact with the shaft tube step portion 11, and at the same time, the cap step portion 22 is connected to the shaft tube shoulder portion 12. They are facing each other in a non-contact state in the axial direction. A gap C in the axial direction between the cap step portion 22 and the shaft cylinder shoulder 12 is a difference between the longitudinal dimensions L and M, and is set to 0.2 mm (see FIG. 2). On the other hand, the contact length D in the radial direction between the open end 21 of the cap 2 and the stepped portion 11 of the shaft cylinder 1 is set to 0.3 mm (see FIG. 3).
[0043]
In this embodiment, the contact surface between the cap step portion 22 and the shaft shoulder portion 12 is a surface perpendicular to the axial direction, and the contact between the cap opening end 21 and the shaft tube step portion 11 is the same. Both contact surfaces are also perpendicular to the axial direction.
[0044]
Further, in this embodiment, when the cap 2 is mounted on the pen tip 3 side of the shaft tube 1, the grip portion 15 on the outer surface of the front portion of the shaft tube 1 is covered with the cap 2. By covering the grip portion 15 with the cap 2, it is possible to avoid contamination such as adhesion of dust to the anti-slip grip portion 15. Further, when the cap 2 covers the gripping part 15, the longitudinal dimension of the cap 2 is relatively long, so that the dimensional variation in the axial direction is large, which is disadvantageous in manufacturing. The configuration in which the cap 2 opening end 21 is in contact with the step portion 11 of the shaft tube 1 in the axial direction at the same time that the shoulder portion 1 is opposed to the shoulder portion 12 in the axial direction is sufficiently absorbed in the axial direction. Can be manufactured easily.
[0045]
[0046]
[0047]
[0048]
[0049]
[0050]
[0051]
[0052]
[0053]
[0054]
[0055]
[0056]
【The invention's effect】
The cap fitting structure of the writing instrument according to the present invention prevents the shaft tube from being inserted deeper than a predetermined position in the cap even if the cap is attached to the pen tip side of the shaft tube with a strong momentum. In addition, it is possible to reliably avoid damage to the fitting part on the inner surface of the cap, maintain a good appearance without creating a gap between the cap opening end and the shaft tube step, and do not require high accuracy. Manufacturing is easy. In addition, the cap stepped portion and the shaft tube shoulder contact each other before the shaft tube step portion spreads the rear fitting portion of the cap, so that deformation or damage of the rear fitting portion is suppressed, and the rear The inner diameter size and shape of the side fitting portion can be maintained.
[0057]
Moreover, the structure of Claim 2 combined with the structure of Claim 1 effectively exhibits the effect of preventing the cap deep penetration.
[0058]
[0059]
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view showing a cap mounting state of an embodiment of the present invention.
FIG. 2 is an enlarged view of a portion P in FIG.
FIG. 3 is an enlarged view of a Q part in FIG. 1;
4 is a longitudinal sectional view of the cap of FIG. 1. FIG.
5 is a cross-sectional view taken along line AA in FIG.
6 is a longitudinal sectional view of the shaft tube of FIG. 1. FIG.
[Explanation of symbols]
1 Shaft 11 Step 12 Shoulder 13 Rear fitting part (annular convex part)
14 Front fitting part (annular smooth part)
15 Grasping part 2 Cap 21 Open end 22 Step part 23 Rear side fitting part (dot-like projection)
24 Front fitting part (dot-like projection)
3 Pen nib 4 Pen nib seal member C Gap dimension D Contact length L Longitudinal dimension from step of cap to open end M Longitudinal dimension from step of shoulder to shoulder

Claims

The nib (3) is provided with a shoulder (12) on the rear outer surface of the shaft cylinder (1), and has a diameter larger than that of the shoulder (12) on the outer surface of the shaft cylinder (1) behind the shoulder (12). On the other hand, on the inner surface near the opening end (21) of the cap (2), a rear fitting portion (23) that fits with the outer surface near the shaft tube step portion (11) is provided, and the rear A side fitting portion (23) is a cap fitting structure for a writing instrument in which a front fitting portion (24) for fitting with the outer surface in the vicinity of the shaft tube shoulder portion (12) is provided on the inner surface of the front cap (2). When the step (22) is provided in front of the front fitting portion (24) on the inner surface of the cap (2) and the cap (2) is mounted on the pen tip (3) side of the shaft tube (1), the cap opening The end (21) and the shaft tube step portion (11) are contacted in the axial direction, and the cap step portion (22) and the shaft tube shoulder portion (12) are not moved in the axial direction. Cap fitting for a writing instrument, wherein the cap step (22) and the axial shoulder portion (12) are set to have an axial gap dimension (C) of 1 mm or less. Combined structure.

When the cap (2) is mounted on the pen tip (3) side of the shaft tube (1), the contact length (D) in the radial direction between the cap opening end (21) and the shaft tube step (11) The cap fitting structure for a writing instrument according to claim 1, wherein is set to 1 mm or less.