【０００１】
【発明の属する技術分野】
本発明は、物の包装や保管に使用する袋に関し、特に、袋の口を開閉するための開閉構造に関するものである。
【０００２】
【従来の技術】
従来、包装用袋の口部に２枚の板バネ材を組み合わせて装着し、その袋口を自在に開閉可能とする技術が知られている。例えば、特許文献１の包装用袋では、板状の合成樹脂製弾発体を重ね合わせ、その２枚の弾発体の両端部を一体として袋口を構成すると共に、それら弾発体の一方の内面に凸条を、他方の内面に凹溝を設けている。そして、弾発体のバネ弾性を利用して凸条と凹溝との相互係合を確実ならしめ、袋口を完全に封鎖できるようにしている。また、特許文献２のワンタッチ開閉式包装用袋では、その口部開閉手段を、合成樹脂製の弾発部材及び互いに重なり合った前後一対の合成樹脂製の板バネで構成している。そして、板バネの両側を内方に押圧することで、各板バネがそれぞれの外方に湾曲して袋体の口部が開き、押圧力を解除することで、板バネが元の状態に戻って袋体の口部が閉じるようにしている。
【０００３】
【特許文献１】実開昭５９−８７４５４号公報（請求の範囲及び各図）
【特許文献２】特開平９−３０１３８６号公報（要約）
【０００４】
【発明が解決しようとする課題】
しかしながら、上記従来の技術では、使用する板バネ材として真っ直ぐに延びる板バネ材を想定していたことから、板バネ材を２枚組み合わせて使用する必要があり、２枚重ねされた板バネ材により袋口の厚みが増すことが避けられなかった。特に袋の本体部分が比較的薄手の素材（例えば透明フィルム素材）で構成されている場合には、袋口が厚いことで袋全体が不格好に又は重々しく感じられ、意匠性に欠けていた。また、板バネ材を２枚使用することは、製造コストの増加要因ともなっていた。
【０００５】
本発明の目的は、単一の板バネ材で袋口の開閉構造を構築することにより、袋口の自在な開閉操作を確保しながら、従来よりも袋口を軽薄化することが可能な袋を提供することにある。
【０００６】
【課題を解決するための手段】
請求項１の発明は、互いに向き合う二つの袋面の左右の各端部同士がつながることで上端に袋口が構成された袋において、袋口を構成する二つの袋面のうちの一方に対し、弓形状又は円弧形状に付形された板バネ材をその袋面の左右方向に延びるように装着したことを特徴とする袋である。
【０００７】
請求項２の発明は、請求項１に記載の袋において、前記弓形状又は円弧形状に付形された板バネ材は、前記一方の袋面の外面側に対し全面接着状態で装着されており、当該板バネ材の両端部には折り返し部がそれぞれ設けられ、各折り返し部にて前記二つの袋面の左右の各端部が挟着されていることを特徴とする。
【０００８】
請求項３の発明は、請求項１に記載の袋において、前記弓形状又は円弧形状に付形された板バネ材は、前記一方の袋面の内面側に対し全面接着状態で装着されており、当該板バネ材が装着されている一方の袋面と向き合う他方の袋面の内面側には、袋口閉塞時に前記板バネ材と接触するシール材が設けられていることを特徴とする。
【０００９】
請求項４の発明は、請求項１又は３に記載の袋において、前記弓形状又は円弧形状に付形された板バネ材は、前記一方の袋面の内面側に対し全面接着状態で装着されており、袋口を構成する前記二つの袋面のうちの他方の袋面と向き合う前記板バネ材の表面には、袋口閉塞時に前記他方の袋面又は前記他方の袋面の内面側に設けられたシール材と接触するシール材が設けられていることを特徴とするものである。
【００１０】
（付記）請求項１において、「前記板バネ材の片側面が前記一方の袋面の外面側又は内面側に対し全面接着されていること」は好ましい。
【００１１】
（請求項１〜４に共通の作用）
本発明によれば、上端に袋口を構成する二つの袋面のうちの一方に対し、弓形状又は円弧形状に付形された板バネ材をその袋面の左右方向に延びるように装着することにより、袋口を自在に開閉操作可能な袋口の開閉構造が構築される。かかる袋口の開閉構造によれば、板バネ材に対し何の外力も及ぼされない自然状態では、板バネ材が装着されている一方の袋面と板バネ材が装着されていない他方の袋面の双方が、板バネ材の弓形又は円弧形の湾曲形状に沿って強制湾曲され、二つの袋面は共に湾曲しながら袋口の後又は前方向（左右方向と直交する方向）に張った状態となる。その結果、袋口付近において二つの袋面は互いに直接又は間接に接触した状態となり、袋口の閉塞が実現される。
【００１２】
これに対し、板バネ材の弓形状又は円弧形状が自然状態とは反対方向に反転するように板バネ材の中央を前又は後方向に押し（又は引っ張り）ながら、板バネ材の両端部をそれぞれの内方に向けて押圧する（即ち両端部を相互接近させる）ことで、板バネ材の湾曲形状が自然状態とは反対方向に反転した状態に板バネ材を反り返らせる。すると、板バネ材が装着されている一方の袋面は、板バネ材の反転動作に追従して反対方向に反り返るが、板バネ材が装着されていない他方の袋面は、必ずしも板バネ材の反転動作に追従しない。その結果、当該他方の袋面は板バネ材の張力による拘束から解放され、二つの袋面の接触状況が解除されて袋口の開放が実現される。尚、板バネ材の両端部をそれぞれの内方に向けて押圧する力を解除すると、板バネ材は再びその湾曲形状を反転させて元の弓形状又は円弧形状を取り戻し、二つの袋面が接近して袋口の閉塞が再現される。
【００１３】
【発明の実施の形態】
以下、本発明のいくつかの実施形態を図面を参照しながら説明する。
【００１４】
（基本となる実施形態）
図１は板バネ材１０の一例を示し、図２は図１の板バネ材１０を用いた袋２０を示し、図３はその袋２０の口の開閉操作の概要を示す。図１（Ａ）及び（Ｂ）に示すように、板バネ材１０は、正面視で横長の長方形状、平面視でほぼ弓形状をなしている。この板バネ材１０は、図１（Ａ）の平面視で上に凸、下に凹となるような弓形状に予め付形されているため、その弓形状を反対方向に反り返らせるような（即ち板バネ材１０を平面視で上に凹、下に凸とするような）外力を及ぼしたときに、その外力に反発して元の弓形状に戻ろうとするバネ弾性を発揮する。かかるバネ弾性を持った板バネ材１０を構成する素材としては、合成樹脂や金属を例示できる。また、この板バネ材１０の左右両端部にはそれぞれ、フック形状をした折り返し部１１が設けられている。
【００１５】
図２に示すように、袋２０の本体は、透明な樹脂フィルム（例えばポリエチレンフィルム）で構成されている。具体的には、縦長な長方形状の樹脂フィルムを準備し、その縦方向中央部の仮想水平線を折り目線として樹脂フィルムを縦方向に折り曲げ、樹脂フィルムの下辺が上辺に重なるように樹脂フィルムの下半部を上半部に重ねる。そして、相互一致した樹脂フィルムの上半部左辺と下半部左辺とをラミネート接着して袋の左辺２３を形成すると共に、相互一致した樹脂フィルムの上半部右辺と下半部右辺とをラミネート接着して袋の右辺２４を形成して袋２０を構成している。この袋２０にあっては、互いに向き合う二つの袋面（第１袋面２１及び第２袋面２２）によって比較的薄手の袋本体が構成され、左辺２３、右辺２４及び下辺（下端）２５が完全に閉じられると共に、前記二つの袋面２１，２２の左右の各端部同士がつながることで上辺（上端）２６に袋口が形成されている。
【００１６】
前記弓形状に付形された板バネ材１０は、袋２０の上辺２６の袋口近傍であって第１袋面２１の外面側に対し、その左右方向（幅方向）に延びるように装着されている。この装着は、板バネ材１０の一方の側面（装着面１２）の全体に接着剤を施し、その装着面１２を第１袋面２１の外面に対して全面接着することにより行われている。従って、板バネ材１０と第１袋面２１とは、板バネ材の装着面１２と第１袋面２１の外面との間に隙間を残さない状態で一体化されている。こうして、第１及び第２の袋面２１，２２と、第１袋面２１の外面に装着された板バネ材１０とにより、袋口を自在に開閉操作可能な袋口の開閉構造が構築されている。
【００１７】
また、図２（Ａ）に示すように、二つの袋面２１，２２の左右の各端部は、板バネ材１０の各端部及びそこに設けられた折り返し部１１によって挟着されている。この挟着により、二つの袋面２１，２２に対して板バネ材１０が確実に一体化されている。尚、板バネ材１０の各折り返し部１１は、袋２０に対する取り付け補強部として機能するのみならず、板バネ材１０の両端部をそれぞれの内方に向けて押圧する際の手指の掛け部又は掛け代としても利用し得る。
【００１８】
さて、図３の上半部（閉塞時）に示すように、板バネ材１０に対して何の外力も及ぼさない自然状態では、板バネ材１０が装着されている第１袋面２１と、第２袋面２２の双方が、板バネ材１０の弓形状に沿って強制湾曲され、二つの袋面２１，２２は共に湾曲しながら袋口の前後方向（つまり各袋面の左右方向と直交する方向）に張った状態となる。その結果、板バネ材１０が設けられた位置において二つの袋面２１，２２が互いに接触し、袋口が閉塞状態となる。
【００１９】
これに対し、板バネ材１０の弓形状が自然状態とは反対方向に反転するように板バネ材１０の中央をその背後から前方向に押し（又は引っ張り）ながら、板バネ材１０の両端部をそれぞれの内方に向けて押圧して（即ち両端部を相互接近させて）、板バネ材１０の弓形状が自然状態とは反対方向に反転した状態に板バネ材１０を反り返らせる。すると、図３の下半部（開放時）に示すように、第１袋面２１は、板バネ材１０の反転動作に追従して反対方向に反り返るが、第２袋面２２は、必ずしも板バネ材１０の反転動作に追従しない。その結果、第２袋面２２は板バネ材１０の張力による拘束から解放され、二つの袋面２１，２２の接触状況が解除されて袋口が開放される。
【００２０】
なお、板バネ材１０の両端部をそれぞれの内方に向けて押圧する力を解除すると、板バネ材１０はその弓形状を反転させて元の弓形状を取り戻し、再び二つの袋面２１，２２が相互接触して袋口が閉塞される。このように本実施形態によれば、予め弓形状に付形された単一の板バネ材１０を第１袋面２１の左右方向に延びるように装着するという比較的簡単な工夫で、袋口の自在な開閉操作を可能とする袋口の開閉構造を構築することができる。そして、この開閉構造によれば、従来よりも袋口を軽薄化することができる。
【００２１】
（その他の実施形態）
図１〜図３の袋では板バネ材１０を第１袋面２１の外面側に装着したが、図４（Ａ）〜（Ｄ）及び図５（Ａ）〜（Ｃ）に示すように、弓形状に付形された各板バネ材１０ａ，１０ｂ及び１０ｃを、第１袋面２１の内面（即ち第２袋面２２の内面と対向する面）側に対し、前記同様、全面接着状態で装着してもよい。
【００２２】
図４（Ａ）の袋では、第２袋面２２の内面側であって板バネ材１０ａと対向する位置に、柔らかい素材でできた帯状のシール材３１を設けている。図４（Ｂ）の袋では、板バネ材１０ｂの横断面形状を略かまぼこ型にすると共に、第２袋面２２の内面側であって板バネ材１０ｂと対向する位置に帯状のシール材３２を設けている。図４（Ｃ）の袋では、板バネ材１０ｂの横断面形状を略かまぼこ型にすると共に、第２袋面２２の内面側であって板バネ材１０ｂと対向する位置に帯状のシール材３３を設け、更に、そのシール材３３の横断面形状を前記板バネ材１０ｂのかまぼこ断面形状に対応した凹形状としている。
【００２３】
図４（Ａ）〜（Ｃ）の袋にあっては、板バネ材１０ａ，１０ｂに対し何の外力も及ぼされない自然状態では、各板バネ材１０ａ，１０ｂの表面がそれと対向するシール材３１〜３３に直接接触して袋口が閉塞されると共に、各板バネ材１０ａ，１０ｂとシール材３１〜３３との相互密着により、袋口のシール性が高められ袋内部の密閉性が向上する。なお、シール材３１〜３３の構成素材としては、ゴム、軟質樹脂、発泡樹脂等を例示できる。
【００２４】
図４（Ｄ）の袋は、図４（Ｃ）の袋に対して一対のタブ部２７，２８を付与したものである。即ち、第１袋面２１の内側であって板バネ材１０ｂの直下には、第１袋面の幅方向全体に延びる横長帯状の第１タブ部２７が設けられている。同様に、第２袋面２２の内側であってシール材３３の直下には、第２袋面の幅方向全体に延びる横長帯状の第２タブ部２８が設けられている。第１及び第２タブ部２７，２８にあっては、それぞれの上端部が各袋面との連結部（根元）となっており、その連結部（根元）を中心として、図中矢印で示す方向に自在に回動可能となっている。これら一対のタブ部２７，２８は、袋内部において一種の逆止弁を構成する。例えば、袋内に小麦粉などの粉体が収容されている場合に、板バネ材１０ｂを自然状態から反対方向に反り返らせた反動で、粉体が袋の中から外に飛び出しそうになったときでも、各タブ部２７，２８が袋口を閉じる方向に回動して袋内の粉体が袋口の方向（即ち上方向）に吸い出される事態を防止する。
【００２５】
図５（Ａ）の袋では、板バネ材１０ｃの横断面形状を三角形状にすると共に、第２袋面２２の内面側であって板バネ材１０ｃと対向する位置に帯状のシール材３４を設け、更に、そのシール材３４の横断面形状を前記板バネ材１０ｃの三角形状に呼応した三角溝型の凹形状としている。シール材３４の構成素材としてはゴム、軟質樹脂、発泡樹脂等を例示できる。この袋にあっては、板バネ材１０ｃに対し何の外力も及ぼされない自然状態では、板バネ材１０ｃの表面がそれと対向するシール材３４に直接接触して袋口が閉塞されると共に、板バネ材１０ｃとシール材３４との相互密着により袋口のシール性が高められ、袋内部の密閉性が向上する。
【００２６】
図５（Ｂ）の袋では、第１袋面２１の内面側に装着された板バネ材１０ａの表面に対し該第１袋面の幅方向全体に延びるチューブ（又はパイプ）３５を固着すると共に、第２袋面２２の内面側であって前記チューブ３５と対向する位置に、同じく第２袋面の幅方向全体に延びるチューブ（又はパイプ）３６を固着している。シール材としてのチューブ３５，３６は、例えば軟質樹脂からなる中空で細長い部材であり、該チューブを押し潰そうとする押圧作用に対してある程度の反発弾性を示す。この袋にあっては、板バネ材１０ａに対し何の外力も及ぼされない自然状態では、板バネ材表面のチューブ３５と、第２袋面側のチューブ３６とが相互接触して袋口が閉塞されると共に、板バネ材１０ａが両チューブ３５，３６を押し潰す方向に押圧することによって両チューブ３５，３６が変形しながら相互密着し、袋口のシール性が高められて袋内部の密閉性が向上する。
【００２７】
図５（Ｃ）に示すように、第１袋面２１の内面側に二つの板バネ材１０ａを上下に並べて設けてもよい。また、図５（Ｄ）に示すように、第１袋面２１の外面側に二つの板バネ材１０を上下に並べて設けてもよい。
【００２８】
図１〜図５に示した板バネ材１０，１０ａ，１０ｂ及び１０ｃはいずれも、平面視で弓形状をなすものであったが、図６に示すように、板バネ材１０ｄを平面視で円弧形状となるように構成してもよい。「円弧形状」には、図６に示すような楕円形状のほかに、円形状、半円形状、三日月形状、渦巻き形状等の湾曲形状も含まれる。図６の袋では、円弧形状の板バネ材１０ｄの外側に、第１及び第２の袋面２１，２２（破線で示す）が配置される。
【００２９】
図７（Ａ）に示すように、第１及び第２袋面２１，２２の各々の上端部２６に取っ手部となる突片４１を突出形成してもよい。また図７（Ｂ）に示すように、第１及び第２袋面２１，２２の各々の上端部中央を波形状又はシワ形状に加工することで取っ手部４２としてもよい。かかる取っ手部としての突片４１や取っ手部４２を設けることで、そこを手指でつまむことができ、板バネ材１０ａを自然状態と反対方向に反り返らせたときに、袋口を構成している二つの袋面２１，２２を離間させ易くなる。
【００３０】
図４（Ａ）〜（Ｄ）及び図５（Ａ）では、板バネ材１０ａ，１０ｂ又は１０ｃが装着されている第１袋面２１と向き合う第２袋面２２の内面側に、袋口閉塞時に当該板バネ材と接触するシール材３１〜３４を設けたが、その構成に代えて、前記板バネ材１０ａ，１０ｂ又は１０ｃの表面に、袋口閉塞時に第２袋面２２と接触するシール材を設けてもよい。あるいは、図４（Ａ）〜（Ｄ）及び図５（Ａ）の構成に追加して、前記板バネ材１０ａ，１０ｂ又は１０ｃの表面に、袋口閉塞時に第２袋面２２の内面側に設けられたシール材３１〜３４と接触するシール材を設けてもよい。
【００３１】
なお、この明細書において、「シール材」には、例えばシリコンゴム皮膜のようなシール性皮膜やシール性コーティングも含まれる。
【００３２】
【発明の効果】
請求項１によれば、上端に袋口を構成する二つの袋面のうちの一方に対し、弓形状又は円弧形状に付形された板バネ材をその袋面の左右方向に延びるように装着することにより、単一の板バネ材で袋口の開閉構造を構築でき、板バネ材の湾曲状態変化に伴う袋口の自在な開閉操作を確保しながら、従来よりも袋口を軽薄化することができる。
【００３３】
請求項２によれば、板バネ材が一方の袋面の外面側に対し全面接着状態で装着されることにより、板バネ材に対し何の外力も及ぼされない自然状態では、板バネ材が装着されている一方の袋面の内面側と、板バネ材が装着されていない他方の袋面の内面側とが互いに接触して、袋口の閉塞が実現される。更に、板バネ材の両端部にそれぞれ設けられた折り返し部にて二つの袋面の左右の各端部を挟着することで、板バネ材と二つの袋面との一体化が確実になる。また、板バネ材の各折り返し部を、板バネ材の両端部をそれぞれの内方に向けて押圧する際の手指の掛け部又は掛け代として利用することが可能となり、板バネ材の湾曲状況の反転操作がし易くなる。
【００３４】
請求項３によれば、板バネ材が一方の袋面の内面側に対し全面接着状態で装着されることにより、板バネ材に対し何の外力も及ぼされない自然状態では、板バネ材が装着されている一方の袋面の内面側と、板バネ材が装着されていない他方の袋面の内面側とが互いに、板バネ材及びシール材を間に挟んで間接的に接触して、袋口の閉塞が実現される。更に袋口閉塞時には、一方の袋面の内面側に対し全面接着状態で装着された板バネ材と、他方の袋面の内面側に設けられたシール材とが直接又は間接に接触することで袋口のシール性が高められ、袋内部の密閉性が向上する。
【００３５】
請求項４によれば、板バネ材が一方の袋面の内面側に対し全面接着状態で装着されることにより、板バネ材に対し何の外力も及ぼされない自然状態では、板バネ材が装着されている一方の袋面の内面側と、板バネ材が装着されていない他方の袋面の内面側とが互いに、板バネ材及びシール材を間に挟んで間接的に接触して、袋口の閉塞が実現される。更に袋口閉塞時には、一方の袋面の内面側に対し全面接着状態で装着された板バネ材の表面に設けられたシール材と、他方の袋面又は他方の袋面の内面側に設けられたシール材とが直接又は間接に接触することで袋口のシール性が高められ、袋内部の密閉性が向上する。
【図面の簡単な説明】
【図１】板バネ材の一例を示し、（Ａ）は平面図、（Ｂ）は正面図。
【図２】図１の板バネ材を用いた袋を示し、（Ａ）は平面図、（Ｂ）は正面図、（Ｃ）はＡ−Ａ線での拡大断面（端面）図。
【図３】図２の袋における袋口の開閉操作の概要を示す斜視図。
【図４】（Ａ）〜（Ｄ）は袋口の構造の各種態様を示す部分断面図。
【図５】（Ａ）〜（Ｄ）は袋口の構造の各種態様を示す部分断面図。
【図６】板バネ材の変更例を示す平面図。
【図７】（Ａ）及び（Ｂ）は袋の変更例を示す概略斜視図。
【符号の説明】
１０，１０ａ，１０ｂ，１０ｃ，１０ｄ…板バネ材、１１…折り返し部、１２…板バネ材の装着面、２０…袋、２１…第１袋面、２２…第２袋面、２６…袋の上辺（上端）、３１，３２，３３，３４…帯状のシール材、３５，３６…チューブ（シール材を構成する）。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a bag used for packaging and storing goods, and more particularly, to an opening and closing structure for opening and closing the mouth of the bag.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, there has been known a technique in which two leaf spring materials are combined and attached to a mouth portion of a packaging bag and the bag mouth can be freely opened and closed. For example, in the packaging bag of Patent Literature 1, plate-shaped synthetic resin springs are overlapped, and both ends of the two springs are integrated to form a bag mouth, and one of the springs is used. Have a ridge on the inner surface and a concave groove on the other inner surface. Then, by utilizing the spring elasticity of the resilient body, mutual engagement between the ridge and the concave groove is ensured, so that the bag mouth can be completely closed. Further, in the one-touch opening / closing type packaging bag of Patent Document 2, the mouth opening / closing means is constituted by a synthetic resin resilient member and a pair of front and rear synthetic resin leaf springs overlapping each other. Then, by pressing both sides of the leaf spring inward, each leaf spring bends outward and the mouth of the bag opens, and by releasing the pressing force, the leaf spring returns to its original state. Return to close the mouth of the bag.
[0003]
[Patent Document 1] Japanese Utility Model Application Laid-Open No. 59-87454 (Claims and Figures)
[Patent Document 2] JP-A-9-301386 (abstract)
[0004]
[Problems to be solved by the invention]
However, in the above-mentioned conventional technology, since a leaf spring material that extends straight is assumed as a leaf spring material to be used, it is necessary to use two leaf spring materials in combination, and the two leaf spring materials are stacked. This inevitably increased the thickness of the bag mouth. In particular, when the main body portion of the bag is made of a relatively thin material (for example, a transparent film material), the whole bag feels unnatural or heavy due to the thick mouth of the bag, and lacks design. In addition, the use of two leaf spring materials has been a factor in increasing the manufacturing cost.
[0005]
SUMMARY OF THE INVENTION An object of the present invention is to construct a bag opening / closing structure with a single leaf spring material, thereby ensuring a flexible opening / closing operation of the bag opening and making the bag opening thinner than before. Is to provide.
[0006]
[Means for Solving the Problems]
The invention according to claim 1 is a bag in which a bag mouth is formed at an upper end by connecting left and right ends of two bag surfaces facing each other to one of two bag surfaces constituting the bag mouth. , Wherein a leaf spring material shaped like a bow or an arc is attached so as to extend in the left-right direction of the bag surface.
[0007]
According to a second aspect of the present invention, in the bag according to the first aspect, the leaf spring material shaped in the bow shape or the arc shape is attached to the outer surface side of the one bag surface in a state of being entirely adhered. A folded portion is provided at each of both ends of the leaf spring material, and left and right ends of the two bag surfaces are sandwiched between the folded portions.
[0008]
According to a third aspect of the present invention, in the bag according to the first aspect, the leaf spring material shaped in the bow shape or the arc shape is attached to the inner surface side of the one bag surface in a state of being entirely adhered. A seal member is provided on the inner surface side of the other bag surface facing the one bag surface on which the leaf spring material is mounted, and is in contact with the leaf spring material when the bag mouth is closed.
[0009]
According to a fourth aspect of the present invention, in the bag according to the first or third aspect, the plate spring material shaped in the bow shape or the arc shape is attached to the inner surface side of the one bag surface in a state of being entirely adhered. The surface of the leaf spring material facing the other bag surface of the two bag surfaces constituting the bag mouth, the other bag surface or the inner surface side of the other bag surface when the bag mouth is closed. It is characterized in that a sealing material that comes into contact with the provided sealing material is provided.
[0010]
(Supplementary Note) In claim 1, it is preferable that "one side surface of the leaf spring material is entirely adhered to an outer surface side or an inner surface side of the one bag surface".
[0011]
(Functions Common to Claims 1 to 4)
According to the present invention, a leaf spring material formed in an arc shape or an arc shape is attached to one of the two bag surfaces forming the bag mouth at the upper end so as to extend in the left-right direction of the bag surface. Thus, a bag mouth opening / closing structure capable of freely opening / closing the bag mouth is constructed. According to the opening / closing structure of the bag mouth, in a natural state where no external force is applied to the leaf spring material, one bag surface on which the leaf spring material is mounted and the other bag surface on which the leaf spring material is not mounted. Are forcibly curved along the curved or arcuate shape of the leaf spring material, and the two bag surfaces are stretched in the rear or front direction (in the direction perpendicular to the left-right direction) while being curved together. State. As a result, the two bag surfaces come into direct or indirect contact with each other near the bag mouth, and the bag mouth is closed.
[0012]
On the other hand, while pushing (or pulling) the center of the leaf spring material forward or backward so that the bow shape or arc shape of the leaf spring material is reversed in the direction opposite to the natural state, both ends of the leaf spring material are By pressing them inward (that is, bringing both ends closer to each other), the leaf spring material is warped in a state in which the curved shape of the leaf spring material is reversed in a direction opposite to the natural state. Then, the one bag surface on which the leaf spring material is attached is warped in the opposite direction following the reversing operation of the leaf spring material, but the other bag surface on which the leaf spring material is not attached is not necessarily a leaf spring material. Does not follow the inversion operation of. As a result, the other bag surface is released from the restraint by the tension of the leaf spring material, the contact state between the two bag surfaces is released, and the opening of the bag mouth is realized. When the force for pressing both ends of the leaf spring material inward is released, the leaf spring material reverses its curved shape again to return to the original bow shape or arc shape, and the two bag surfaces are removed. The closeness of the bag mouth is reproduced by approaching.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, some embodiments of the present invention will be described with reference to the drawings.
[0014]
(Basic embodiment)
1 shows an example of the leaf spring material 10, FIG. 2 shows a bag 20 using the leaf spring material 10 of FIG. 1, and FIG. 3 shows an outline of the opening / closing operation of the mouth of the bag 20. As shown in FIGS. 1A and 1B, the leaf spring material 10 has a horizontally long rectangular shape in a front view, and a substantially bow shape in a plan view. Since the leaf spring material 10 is previously formed in an arch shape that is convex upward and concave downward in plan view of FIG. 1 (A), it is possible to warp the bow shape in the opposite direction. When an external force is applied (that is, the leaf spring material 10 is concave upward and convex downward in a plan view), the spring exerts a spring elasticity to return to the original bow shape by repelling the external force. As a material constituting the leaf spring material 10 having such spring elasticity, a synthetic resin or a metal can be exemplified. A hook-shaped folded portion 11 is provided at each of the left and right ends of the leaf spring material 10.
[0015]
As shown in FIG. 2, the main body of the bag 20 is formed of a transparent resin film (for example, a polyethylene film). Specifically, a vertically long rectangular resin film is prepared, and the resin film is vertically bent using a virtual horizontal line at the center in the vertical direction as a fold line, and the lower side of the resin film is overlapped with the upper side. Lay half on top. Then, the upper left portion and the lower left portion of the resin film which are mutually matched are laminated and bonded to form the left side 23 of the bag, and the upper right portion and the lower right portion of the mutually matched resin film are laminated. The bag 20 is formed by bonding to form the right side 24 of the bag. In the bag 20, a relatively thin bag body is constituted by two bag surfaces (a first bag surface 21 and a second bag surface 22) facing each other, and a left side 23, a right side 24 and a lower side (lower end) 25 are formed. A bag mouth is formed on the upper side (upper end) 26 by being completely closed and connecting the left and right ends of the two bag surfaces 21 and 22 to each other.
[0016]
The leaf spring material 10 shaped like the bow is mounted on the outer side of the first bag surface 21 near the bag mouth on the upper side 26 of the bag 20 so as to extend in the left-right direction (width direction). ing. This mounting is performed by applying an adhesive to the entire one side surface (mounting surface 12) of the leaf spring material 10 and bonding the entire mounting surface 12 to the outer surface of the first bag surface 21. Therefore, the leaf spring material 10 and the first bag surface 21 are integrated without leaving a gap between the mounting surface 12 of the leaf spring material and the outer surface of the first bag surface 21. In this way, the opening and closing structure of the bag mouth which can freely open and close the bag mouth is constructed by the first and second bag surfaces 21 and 22 and the leaf spring material 10 attached to the outer surface of the first bag surface 21. ing.
[0017]
Further, as shown in FIG. 2A, the left and right ends of the two bag surfaces 21 and 22 are sandwiched by the ends of the leaf spring material 10 and the folded portion 11 provided thereon. . By this sandwiching, the leaf spring material 10 is securely integrated with the two bag surfaces 21 and 22. Each folded portion 11 of the leaf spring material 10 not only functions as an attachment reinforcing portion for the bag 20, but also a hook portion of a finger when pressing both ends of the leaf spring material 10 inward. It can also be used as a credit.
[0018]
Now, as shown in the upper half of FIG. 3 (at the time of closing), in a natural state in which no external force is exerted on the leaf spring material 10, a first bag surface 21 on which the leaf spring material 10 is mounted, Both of the second bag surfaces 22 are forcibly curved along the bow shape of the leaf spring material 10, and the two bag surfaces 21 and 22 are both curved and orthogonal to the front-back direction of the bag mouth (that is, the right-left direction of each bag surface). Direction). As a result, the two bag surfaces 21 and 22 contact each other at the position where the leaf spring material 10 is provided, and the bag mouth is closed.
[0019]
On the other hand, while pushing (or pulling) the center of the leaf spring material 10 forward from behind so that the bow shape of the leaf spring material 10 is reversed in the direction opposite to the natural state, both ends of the leaf spring material 10 Are pressed inward (that is, the both ends are brought closer to each other), and the leaf spring material 10 is warped in a state where the bow shape of the leaf spring material 10 is reversed in a direction opposite to the natural state. Then, as shown in the lower half of FIG. 3 (when opened), the first bag surface 21 warps in the opposite direction following the reversing operation of the leaf spring material 10, but the second bag surface 22 does not necessarily It does not follow the reversing operation of the spring material 10. As a result, the second bag surface 22 is released from the restraint by the tension of the leaf spring material 10, the contact state between the two bag surfaces 21, 22 is released, and the bag mouth is opened.
[0020]
When the force of pressing both ends of the leaf spring material 10 inwardly is released, the leaf spring material 10 reverses its bow shape to recover the original bow shape, and again returns to the two bag surfaces 21, 22 contact each other and the bag mouth is closed. As described above, according to the present embodiment, the opening of the single leaf spring material 10 shaped in a bow shape in advance so as to extend in the left-right direction of the first bag surface 21 is improved. It is possible to construct a bag mouth opening / closing structure that allows free opening / closing operation. And according to this opening / closing structure, the bag mouth can be made thinner than before.
[0021]
(Other embodiments)
In the bags of FIGS. 1 to 3, the leaf spring material 10 is mounted on the outer surface side of the first bag surface 21, but as shown in FIGS. 4 (A) to (D) and FIGS. 5 (A) to (C), Each of the leaf spring members 10a, 10b and 10c shaped like a bow is adhered to the inner surface of the first bag surface 21 (ie, the surface facing the inner surface of the second bag surface 22) in the same manner as described above. May be worn.
[0022]
In the bag shown in FIG. 4A, a band-shaped sealing material 31 made of a soft material is provided on the inner surface side of the second bag surface 22 and at a position facing the leaf spring material 10a. In the bag shown in FIG. 4B, the leaf spring material 10b has a substantially semi-cylindrical cross-sectional shape, and a band-like sealing material 32 is provided on the inner surface side of the second bag surface 22 so as to face the leaf spring material 10b. Is provided. In the bag shown in FIG. 4C, the leaf spring member 10b has a substantially semi-cylindrical cross-sectional shape, and a band-shaped sealing member 33 is provided on the inner side of the second bag surface 22 so as to face the leaf spring member 10b. Further, the cross-sectional shape of the sealing material 33 is formed in a concave shape corresponding to the kamaboko cross-sectional shape of the leaf spring material 10b.
[0023]
In the bags shown in FIGS. 4A to 4C, in a natural state where no external force is applied to the leaf spring materials 10a and 10b, the surface of each leaf spring material 10a and 10b has the sealing material 31 opposed thereto. 33, the bag mouth is closed, and the leaf spring members 10a, 10b and the sealing members 31 to 33 are in close contact with each other, so that the sealing property of the bag mouth is enhanced and the airtightness inside the bag is improved. . In addition, as a constituent material of the sealing materials 31 to 33, rubber, soft resin, foamed resin and the like can be exemplified.
[0024]
The bag shown in FIG. 4D is obtained by adding a pair of tab portions 27 and 28 to the bag shown in FIG. That is, the first tab portion 27 in the shape of a horizontally long strip is provided inside the first bag surface 21 and directly below the leaf spring material 10b, and extends in the entire width direction of the first bag surface. Similarly, inside the second bag surface 22 and immediately below the sealing material 33, a horizontally long strip-shaped second tab portion 28 extending in the entire width direction of the second bag surface is provided. In each of the first and second tab portions 27 and 28, the upper end thereof is a connecting portion (root) with each bag surface, and the connecting portion (root) is indicated by an arrow in the drawing. It is freely rotatable in the direction. The pair of tab portions 27 and 28 constitute a kind of check valve inside the bag. For example, when powder such as flour is stored in the bag, the powder is likely to jump out of the bag due to the recoil that caused the leaf spring material 10b to warp in the opposite direction from the natural state. Even at this time, the tab portions 27 and 28 rotate in the direction to close the bag mouth to prevent the powder in the bag from being sucked in the bag mouth direction (that is, upward).
[0025]
In the bag of FIG. 5A, the cross-sectional shape of the leaf spring material 10c is triangular, and a band-shaped sealing material 34 is provided on the inner side of the second bag surface 22 and at a position facing the leaf spring material 10c. Further, the seal member 34 has a triangular groove-shaped concave shape corresponding to the triangular shape of the leaf spring material 10c. Examples of the constituent material of the seal member 34 include rubber, soft resin, foamed resin, and the like. In this bag, in a natural state where no external force is exerted on the leaf spring material 10c, the surface of the leaf spring material 10c directly contacts the sealing material 34 facing the leaf spring material 10c, and the bag mouth is closed. The close contact between the spring material 10c and the sealing material 34 enhances the sealing performance of the bag mouth, and improves the airtightness inside the bag.
[0026]
In the bag shown in FIG. 5B, a tube (or pipe) 35 extending in the entire width direction of the first bag surface is fixed to the surface of the leaf spring material 10a mounted on the inner side of the first bag surface 21. A tube (or pipe) 36 extending in the entire width direction of the second bag surface is also fixed to a position on the inner surface side of the second bag surface 22 opposite to the tube 35. The tubes 35 and 36 as sealing materials are hollow and elongated members made of, for example, a soft resin, and exhibit a certain degree of rebound resilience to a pressing action to crush the tubes. In this bag, in a natural state where no external force is applied to the leaf spring material 10a, the tube 35 on the surface of the leaf spring material and the tube 36 on the second bag surface side contact each other, and the bag mouth is closed. At the same time, when the leaf spring material 10a presses the tubes 35 and 36 in the direction of crushing the tubes 35 and 36, the tubes 35 and 36 are deformed and adhere to each other while being deformed. Is improved.
[0027]
As shown in FIG. 5C, two leaf spring members 10 a may be provided on the inner surface side of the first bag surface 21 so as to be vertically arranged. Further, as shown in FIG. 5D, two leaf spring members 10 may be provided on the outer surface side of the first bag surface 21 so as to be vertically arranged.
[0028]
Each of the leaf spring materials 10, 10a, 10b and 10c shown in FIGS. 1 to 5 has an arc shape in plan view, but as shown in FIG. 6, the leaf spring material 10d is seen in plan view. It may be configured to have an arc shape. The “arc shape” includes a curved shape such as a circular shape, a semicircular shape, a crescent shape, and a spiral shape, in addition to the elliptical shape shown in FIG. 6. In the bag shown in FIG. 6, first and second bag surfaces 21, 22 (shown by broken lines) are arranged outside the arc-shaped leaf spring material 10d.
[0029]
As shown in FIG. 7A, a protrusion 41 serving as a handle may be formed at the upper end 26 of each of the first and second bag surfaces 21 and 22 so as to protrude. Also, as shown in FIG. 7B, the handle portion 42 may be formed by processing the center of the upper end of each of the first and second bag surfaces 21 and 22 into a wavy shape or a wrinkle shape. By providing the protruding piece 41 or the handle portion 42 as such a handle portion, it can be pinched by a finger, and when the leaf spring material 10a is warped in a direction opposite to the natural state, a bag opening is formed. The two bag surfaces 21 and 22 can be easily separated.
[0030]
4 (A) to 4 (D) and FIG. 5 (A), the bag mouth is closed on the inner side of the second bag surface 22 facing the first bag surface 21 on which the leaf spring material 10a, 10b or 10c is mounted. At this time, the seal members 31 to 34 that come into contact with the leaf spring material are provided. A material may be provided. Alternatively, in addition to the configuration of FIGS. 4A to 4D and FIG. 5A, on the surface of the leaf spring material 10a, 10b or 10c, the inner surface of the second bag surface 22 when the bag mouth is closed. A sealing material that comes into contact with the provided sealing materials 31 to 34 may be provided.
[0031]
In this specification, the “sealant” includes a sealable film such as a silicone rubber film and a sealable coating.
[0032]
【The invention's effect】
According to the first aspect, a leaf spring material shaped like an arc or an arc is attached to one of the two bag surfaces forming the bag mouth at the upper end so as to extend in the left-right direction of the bag surface. By doing so, the opening / closing structure of the bag mouth can be constructed with a single leaf spring material, and the bag mouth can be made thinner than before while ensuring the free opening / closing operation of the bag mouth due to the change in the curved state of the leaf spring material. be able to.
[0033]
According to the second aspect, the leaf spring material is attached to the outer surface side of one of the bag surfaces in a completely adhered state, so that the leaf spring material is attached in a natural state where no external force is exerted on the leaf spring material. The inner surface of the one bag surface and the inner surface of the other bag surface on which the leaf spring material is not attached come into contact with each other, and the bag mouth is closed. Further, the left and right ends of the two bag surfaces are sandwiched between the folded portions provided at both ends of the leaf spring material, whereby the integration of the leaf spring material and the two bag surfaces is ensured. . In addition, it becomes possible to use each folded portion of the leaf spring material as a hook portion or a margin for a finger when pressing both ends of the leaf spring material inward, and the bending state of the leaf spring material. Becomes easy to reverse.
[0034]
According to the third aspect, the leaf spring material is attached to the inner surface side of the one bag surface in a completely adhered state, so that the leaf spring material is attached in a natural state where no external force is applied to the leaf spring material. The inner surface of the one bag surface and the inner surface of the other bag surface on which the leaf spring material is not attached come into indirect contact with each other with the leaf spring material and the seal material interposed therebetween, and Mouth obstruction is achieved. Furthermore, when the bag mouth is closed, the leaf spring material attached to the inner surface of one of the bag surfaces in a completely adhered state and the sealing material provided on the inner surface side of the other bag surface come into direct or indirect contact. The sealing performance of the bag mouth is improved, and the sealing performance inside the bag is improved.
[0035]
According to the fourth aspect, the leaf spring material is attached to the inner surface side of one of the bag surfaces in a completely adhered state, so that the leaf spring material is attached in a natural state where no external force is exerted on the leaf spring material. The inner surface of one bag surface and the inner surface of the other bag surface on which the leaf spring material is not attached come into indirect contact with each other with the leaf spring material and the seal material interposed therebetween, and Mouth obstruction is achieved. Further, at the time of closing the bag mouth, a sealing material provided on the surface of a leaf spring material attached in a state of being entirely adhered to the inner surface of one bag surface, and a sealing material provided on the inner surface side of the other bag surface or the other bag surface. The sealing property of the bag mouth is improved by directly or indirectly contacting the sealed material, and the sealing property inside the bag is improved.
[Brief description of the drawings]
FIG. 1 shows an example of a leaf spring material, wherein (A) is a plan view and (B) is a front view.
2A and 2B show a bag using the leaf spring material of FIG. 1, wherein FIG. 2A is a plan view, FIG. 2B is a front view, and FIG. 2C is an enlarged cross-sectional view (end face) taken along line AA.
FIG. 3 is a perspective view showing an outline of an opening / closing operation of a bag mouth in the bag of FIG. 2;
4 (A) to 4 (D) are partial cross-sectional views showing various aspects of the structure of the bag mouth.
FIGS. 5A to 5D are partial cross-sectional views showing various aspects of the structure of the bag mouth.
FIG. 6 is a plan view showing a modified example of a leaf spring material.
FIGS. 7A and 7B are schematic perspective views showing a modified example of a bag.
[Explanation of symbols]
10, 10a, 10b, 10c, 10d: leaf spring material, 11: folded portion, 12: mounting surface of leaf spring material, 20: bag, 21: first bag surface, 22: second bag surface, 26: bag of Upper side (upper end), 31, 32, 33, 34 ... band-shaped sealing material, 35, 36 ... tube (constituting sealing material).
