JP4610070B2

JP4610070B2 - Come buckle

Info

Publication number: JP4610070B2
Application number: JP2000350724A
Authority: JP
Inventors: 貴夫片山; 浩二郎山▲崎▼
Original assignee: Ashimori Industry Co Ltd; Combi Corp
Current assignee: Ashimori Industry Co Ltd; Combi Corp
Priority date: 2000-11-17
Filing date: 2000-11-17
Publication date: 2011-01-12
Anticipated expiration: 2020-11-17
Also published as: JP2002145008A

Description

【０００１】
【発明の属する技術分野】
この発明は、チャイルドシート等の物品等の被固定物を固定物に固定するために用いるカムバックルに関する。
【０００２】
【従来の技術】
従来、この種のカムバックルとして、特開平８−２６８２２２号公報にチャイルドシードに適用されたものが開示されている。
【０００３】
この種のカムバックルは、所定の挟持用部材を有する底蓋の両側に形成された一対の側壁間に、一側に波部を有するカムが回動自在に取付けられ、前記挟持用部材と波部間にウエビングを挟持する構成となっている。また、前記波部は、カム軸方向に沿って延びる複数の波条部によって構成され、各波条部の頂点とカム軸間の距離寸法は、カムの所定の締付け回転方向とは反対方向に向けて徐々に大きくなるように設定される。
【０００４】
そして、カムの波部とケースの底蓋側の所定の挟持用部材間に軽くウエビングを挟込んだ状態で当該ウエビングを所定方向に引張ると、カムが前記締付け回転方向に向けて従動回転して、波部とケース側の挟持用部材との離間距離が徐々に小さくなって、波部と前記挟持用部材間のウエビングの挟持力が大きくなっていく構成となっている。
【０００５】
【発明が解決しようとする課題】
しかしながら、上述のようなカムバックルでは、ウエビングを所定方向へ引張る力が大きくなればなる程、波部とケース側の挟持用部材間の離間距離が限りなく小さくなり、波部と前記挟持用部材間のウエビングの挟持力がほぼ際限なく大きくなっていく構成であるため、ウエビングを破断させてしまうおそれがあった。
【０００６】
これを防止するため、カムが一定以上回転しないようにケース側にカムストッパを設けることにより、ウエビングが過大な力で引張られた場合でも、波部と挟持用部材間の離間距離が所定以上に小さくならないようにして、波部と前記挟持用部材間のウエビングに作用する挟持力の上限を制限することも可能である。この場合、一定以上の力でウエビングが引張られると、ウエビングが波部とケースの底蓋側の所定の挟持用部材間から滑り出るようになる。
【０００７】
しかしながら、この場合、例えば、ウエビングの長期にわたる使用や繰り返し荷重等によってウエビングの厚みが薄くなってしまうと、当該ウエビングの挟持力が予め想定した初期値より著しく小さくなってしまうという問題がある。
【０００８】
そこで、この発明の目的は、ウエビングに過大な挟持力が加わることでウエビングが破断することを防止できると共に、長期にわたって安定した挟持力を維持できるカムバックルを提供することにある。
【０００９】
【課題を解決するための手段】
上記課題を解決すべく、請求項１記載のカムバックルは、基板部の両側に一対のカム支持部が相対向して立設されたフレーム部材と、前記カム支持部間に所定のカム軸周りに回転自在に支持され、前記基板部に対向する外周部分に、前記基板部との間に挿通されたウエビングを挟持可能なカム面を有し、前記ウエビングを挟持する所定の回転方向に回転付勢されたカム部材と、前記カム部材を前記回転方向と反対周りに回動操作するためのレバー部材と、を備え、前記カム面には、前記カム軸と平行な突条歯部が前記カム軸周りに並列形成されると共にそれら各突条歯部と前記カム軸との間隔寸法が前記回転方向の前方から後方に向けて前記カム軸と前記基板部間の離間寸法を越えるまで漸次大きくなるように設定され、かつ、前記各突条歯部のうち前記回転方向の最後列の突条歯部がそれよりも前列側の各突条歯部よりも変形強度が高く設定されたものである。
【００１０】
なお、請求項２記載のように、前記前列側の突条歯部の変形強度が、前記ウエビングに通常荷重よりも大きな所定の高荷重が作用したときに変形するように設定され、前記最後列の突条歯部の変形強度が、前記ウエビングに前記所定の高荷重が作用したときでも変形しないように設定されているとよい。
【００１１】
具体的には、請求項３記載のように、前記各突条歯部はそれぞれ横断面略三角形状に形成され、前記各突条歯部のうち前記回転方向の最後列の突条歯部の頂角は、それよりも前列側の各突条歯部の頂角よりも大きい構成を採用することができる。
【００１２】
また、請求項４記載のように、前記各突条歯部のうち前記回転方向最後列の突条歯部の突出寸法が、それよりも前列側の各突条歯部の突出寸法よりも大きいとよりよい。
【００１３】
【発明の実施の形態】
以下、この発明の実施の形態に係るカムバックルについて説明する。
【００１４】
このカムバックル１は、図１〜図３に示すように、フレーム部材２と、このフレーム部材２に回転自在に支持されたカム部材１０とを備える。
【００１５】
前記フレーム部材２は、基板部４の両側部に一対のカム支持部５が相対向して立設された正面視略コ字状の部材に形成される。このフレーム部材２は、例えば、厚板状金属部材を所定形状に打抜・屈曲形成することにより形成される。
【００１６】
上記基板部４は、平面視方形状の板状部材に形成され、その上面と前記カム部材１０との間でウエビングＷを挟持可能に形成される。
【００１７】
なお、本実施の形態では、基板部４の後端縁部（便宜上図２で示されるカムバックルの左方を前方、右方を後方とする）から後方斜め下に向けて、取付孔３ｈを有する取付片３を形成し、この取付片３を介して所定の部材（例えば後述するような乳児用チャイルドシード５１の被取付部分）に取付可能なようにしている。
【００１８】
各カム支持部５は、カム部材１０を所定のカム軸Ｃ周りに回転自在に支持するための部材であり、本実施の形態では、板状部材の略中央部に後述するカム軸部９を挿通可能なカム支持孔５ｈを形成した構成としている。
【００１９】
なお、本実施の形態では、各カム支持部５の後側上コーナ部５ａを所定の曲率半径を描く弧形状に形成して、後述するレバー部材２５がカム支持部５に干渉することなく円滑に回転するように形成している。また、各カム支持部５の前側上コーナ部に、切欠部５ｂが形成され、後述するコイルバネ部材２０の各係合端部２１ａがそれぞれ係合可能に形成される。
【００２０】
カム部材１０は、柱状ブロック体の外周部に前記基板部４の上面に対向して配設可能なカム面１１が形成されてなる。本実施の形態では、一例として、略円柱状ブロック体の外周部の一部を外方に向けて張出し、その張出した外周部にカム面１１を形成した構成としている。
【００２１】
このカム部材１０には、その側面視形状の略中央部の位置にその幅方向に沿って、カム軸部９を挿通可能なカム軸挿通孔１０ｈが形成される。
【００２２】
ここで、カム軸部９は、細長い棒状部９ａの一端に円盤状の頭部９ｂが形成された構成とされる。そして、カム軸挿通孔１０ｈを各カム支持孔５ｈの位置に合わせるようにしてカム部材１０を各カム支持部５間に配設した状態で、カム軸部９をその先端側から一方側のカム支持孔５ｈ，カム軸挿通孔１０ｈ，他方側のカム支持孔５ｈに挿通させることにより、カム部材１０がカム支持部５間に所定のカム軸Ｃ周りに回転自在に支持されることになる。
【００２３】
また、このカム部材１０は、所定のカム付勢手段により前記カム軸Ｃ周りの所定の締付け回転方向Ｐ（図２参照）に向けて付勢される。
【００２４】
本実施の形態では、カム付勢手段としてコイルバネ部材２０を用いている（図２及び図３参照）。このコイルバネ部材２０は、鋼線等の弾性を有する線材が、略Ｕ字状に屈曲され、その両側部分２１の長手方向略中央部がそれぞれ前記カム軸部９の棒状部９ａを挿通可能なリング状部２０ａに曲成されると共に、その両側部分２１の端部が折返すように略Ｕ字状に屈曲されて係合端部２１ａに形成された構成とされる。そして、コイルバネ部材２０をカム部材１０に抱持状に取付けて、カム部材１０の両外側面と各カム支持部５の内面との各間においてカム軸部９の棒状部９ａを各リング状部２０ａ内に挿通させるようにし、さらに、各係合端部２１ａをカム支持部５の切欠部５ｂに係合させると共に、コイルバネ部材２０の横杵部２２をカム部材１０の外周面にその後方より当接可能に配設する。このコイルバネ部材２０の弾性力により、カム部材１０が締付け回転方向Ｐに向けて付勢されるように構成される。
【００２５】
また、カム面１１は、図２〜図４に示すように、前記カム軸Ｃと平行な突条歯部１２Ａ１〜１２Ａ８，１２Ｂが当該カム軸Ｃ周りに並列形成されると共に、そのカム軸Ｃと各突条歯部１２Ａ１〜１２Ａ８，１２Ｂ（より厳密には各突条歯部１２Ａ１〜１２Ａ８，１２Ｂの突出頂点）との間隔寸法（Ｄ１〜Ｄ９）が、締付け回転方向Ｐの前方から後方に向けて、前記カム軸Ｃと基板部５間の間隔寸法Ｄ（図２参照）を超えるまで漸次大きくなるように設定されてなる。本実施の形態では、カム軸Ｃと締付け回転方向Ｐの最後列の突条歯部１２Ｂ間の間隔寸法だけが、前記間隔寸法Ｄを越えるように設定される。なお、図４に、カム軸Ｃを中心としかつ締付け回転方向Ｐの最前列の突条歯部１２Ａ１の突出頂点を通過する円Ｃ１を２点鎖線で、各突条歯部１２Ａ１〜１２Ａ８，１２Ｂが形成される仮想曲面の所定断面での弧状曲線Ｃ２を破線で、弧状曲線Ｃ２と同心でかつ突条歯部１２Ｂの突出頂点を通る弧状曲線Ｃ３を破線でそれぞれ示す。
【００２６】
そして、カム面１１が基板部４よりも前記締付け回転方向Ｐの後方よりの位置にあって、基板部４とカム軸Ｃとを最短距離で結ぶ直線上に、各突条歯部１２Ａ１〜１２Ａ８，１２Ｂのうち締付け回転方向Ｐ前方よりのものが位置している場合には、カム部材１０のカム面１１と基板部４間にウエビングＷが挿通可能な程度の比較的大きな距離があいた状態となる。また、かかる状態から、コイルバネ部材２０の付勢力等によりカム部材１０が締付け回転方向Ｐに向けて回転すると、その回転に伴って基板部４とカム軸Ｃとを最短距離で結ぶ直線上に、各突条歯部１２Ａ１〜１２Ａ８，１２Ｂのうち締付け回転方向Ｐ後方よりのものが位置して、カム部材１０のカム面１１と基板部４間の間隔寸法が徐々に小さくなり、それらの間にウエビングＷを挟持可能となる。
【００２７】
また、このようにウエビングＷを挟持した状態で、ウエビングＷが締付け方向Ｑ（図２参照）に向けて引張られると、ウエビングＷとカム面１１との摩擦により、カム部材１０が締付け回転方向Ｐに向けて従動回転して、カム部材１０のカム面１１と基板部４間の間隔寸法がさらに小さくなり、ウエビングＷの挟持力が大きくなっていく。
【００２８】
また、各突条歯部１２Ａ１〜１２Ａ８，１２Ｂのうち、締付け回転方向Ｐの最後列の突条歯部１２Ｂの変形強度は、それよりも前列側の各突条歯部１２Ａ１〜１２Ａ８の変形強度よりも高く設定される。具体的には、本カムバックルの使用時において、ウエビングＷに通常範囲の引張り力（使用用途により異なる）が作用している場合には、各突条歯部１２Ａ１〜１２Ａ８，１２Ｂが変形せず、ウエビングＷに通常範囲以上の引張り力が作用している場合に、突条歯部１２Ｂが変形せず、各突条歯部１２Ａ１〜１２Ａ８が変形する程度に形成されている（これによる効果については後述）。
【００２９】
本実施の形態では、かかる構成を実現するために、各突条歯部１２Ａ１〜１２Ａ８，１２Ｂを、締付け回転方向Ｐの前方側の辺が長辺で締付け回転方向Ｐの後方の辺が短辺である断面略三角形状に形成し、突条歯部１２Ｂの頂角αを、各突条歯部１２Ａ１〜１２Ａ８の頂角β（図４で突条歯部１２Ａ８の頂角βだけ図示）よりも大きな値となるように設定している。なお、各突条歯部１２Ａ１〜１２Ａ８の頂角βは同じでもよい。この場合、突条歯部１２Ｂの先端近傍での肉厚は、各突条歯部１２Ａ１〜１２Ａ８の先端近傍での肉厚よりも厚いため、各突条歯部１２Ａ１〜１２Ａ８，１２ＢがウエビングＷに強い力で押し当てられた際に、突条歯部１２Ｂは、それよりも前列側の各突条歯部１２Ａ１〜１２Ａ８よりも変形し難くなる。なお、本実施の形態では、カム軸Ｃに対する各突条歯部１２Ａ１〜１２Ａ８，１２Ｂの頂点間の中心角θを同一となるようにし、各頂点を僅かに角取りしている。
【００３０】
なお、各突条歯部１２Ａ１〜１２Ａ８がウエビングＷに強く押し当てられた際にそれらが容易に変形できるようにするため、カム部材１０の全体又はカム面１１の部分をアルミニウムやアルミニウム合金等比較的柔らかい材料で形成することが好ましい。
【００３１】
なお、突条歯部１２Ｂの変形強度を、それよりも前列側の各突条歯部１２Ａ１〜１２Ａ８のそれよりも高く設定する構成としては、上述の他、突条歯部１２Ｂを、各突条歯部１２Ａ１〜１２Ａ８を形成した材料よりも変形強度の高い材料で形成する構成等を採用することができる。
【００３２】
また、本カムバックルには、図１〜図３に示すように、カム部材１０を、締付け回転方向Ｐと反対周りに回動させるためのレバー部材２５が設けられる。
【００３３】
レバー部材２５は、樹脂等により形成されるもので、フレーム部材２の一対のカム支持部５に支持されたカム部材１０をそのカム支持部５と共に覆うカバー部２６と、そのカバー部２６の後方に連設された操作部２９とを備える。
【００３４】
前記カバー部２６の両側壁部２７には、カム軸部９の棒状部９ａを挿通可能な挿通孔部２７ｈが形成される。そして、挿通孔部２７ｈをカム支持孔５ｈと対応する位置に配設するようにして、各側壁部２７をカム支持部５の外側に配設した状態で、カム軸部９の棒状部９ａが、一方側の挿通孔部２７ｈ，カム支持孔５ｈから、カム部材１０のカム軸挿通孔１０ｈを通って、他方側のカム支持孔５ｈ，挿通孔部２７ｈに挿通され、こうして、レバー部材２５がカム軸Ｃ周りに回転自在に取付けられる。この際、カム部材１０の周方向の一部に外方に向けて突設された係止片１３が、カバー部２６の内周部に形成された係合凹部２８に係合され、カム部材１０及びレバー部材２５が共回りするように構成される。これにより、カム部材１０が締付け回転方向Ｐに向けて回転された状態で、操作部２９を上方へ持上げるように回動させると、それに伴ってカム部材１０が締付け回転方向Ｐの逆方向へ向けて回転されて、カム部材１０のカム面１１と基板部４間に挟持されるウエビングＷの挟持を開放可能なようにしている。
【００３５】
以上のように構成されたカムバックルの動作について説明する。
【００３６】
まず、通常の使用状態では、レバー部材２５の操作部２９を上方に持上げるようにして、コイルバネ部材２０の付勢力に抗してカム部材１０を締付け回転方向Ｐの逆方向に回転させる。すると、基板部４とカム部材１０間の間隔寸法が大きくなって、それらの間にウエビングＷを挿通自在な状態となるので、これらの間にウエビングＷを所望量挿通させる。次に、操作部２９を離すと、コイルバネ部材２０の付勢力によりカム部材１０が締付け回転方向Ｐに向けて回転する。これにより、カム部材１０のカム面１１と基板部４間の間隔寸法が小さくなって、各突条歯部１２Ａ１〜１２Ａ８，１２Ｂのうち締付け回転方向Ｐの比較的前列側のものと基板部４の間にウエビングＷが軽く挟持される。この状態から、ウエビングＷが所定の許容範囲内の力で締付け方向Ｑに向けて引張られると、図５に示すように、カム部材１０が従動回転して、カム部材１０のカム面１１と基板部４間の間隔寸法が小さくなって、ウエビングＷの挟持力が大きくなる。通常は、この状態で使用されており、この使用状態から、操作部２９を上方に持上げるようにしてカム部材１０を締付け回転方向Ｐの逆方向に回転させると、ウエビングＷを開放可能な状態となる。また、この通常状態では、突条歯部１２Ａ１〜１２Ａ８，１２Ｂは変形しないし、しかも、ウエビングＷが繰返し荷重等で薄くなったときにも、それに応じてカム部材１０が回転するので、当該ウエビングＷを所定の挟持力で挟持できる。
【００３７】
一方、上述の使用状態で、ウエビングＷが通常範囲以上の大きな力で引張られると、カム部材１０がさらに従動回転し、そして、図５に示すように、締付け回転方向Ｐの最後列の突条歯部１２ＢがウエビングＷを押込むように当接した状態で、当該カム部材１０の回転が停止される。この状態からウエビングＷがより過大な力で引張られると、図６に示すように、各突条歯部１２Ａ１〜１２Ａ８の先端部が過大な力でウエビングＷに押付けられて潰れるように変形して、主として突条歯部１２Ｂと基板部４間の挟持力によってウエビングＷが挟持される状態となり、ウエビングＷの挟持力が低下し、徐々にウエビングＷが滑りだすようになる。つまり、各突条歯部１２Ａ１〜１２Ａ８の先端部の変形により、複数の突条歯部１２Ａ１〜１２Ａ８，１２ＢによりウエビングＷを挟持している状態から、単一の突条歯部１２ＢによりウエビングＷを挟持している状態に移行して、当該ウエビングＷの挟持力を低下させて、ウエビングＷに過大な挟持力が加わらないようにしている。このとき、ウエビングＷは、一気にカムバックル１から抜出すことなく、単一の突条歯部１２Ｂにより所定の力で挟持された状態で滑り出す。
【００３８】
なお、このようにウエビングＷに過大な引張力が加わった際に、突条歯部１２Ｂ以外の突条歯部１２Ａ１〜１２Ａ８によるウエビングＷの挟持力を可及的に排除するため、各突条歯部１２Ａ１〜１２Ａ８，１２Ｂのうち締付け回転方向Ｐの最後列の突条歯部１２Ｂの突出寸法（各突条歯部１２Ａ１〜１２Ａ８，１２Ｂが形成される仮想曲面に対する突出寸法）を、それよりも前列側の各突条歯部１２Ａ１〜１２Ａ８の突出寸法（同上）よりも大きくしておくことが好ましい（図４で、突条歯部１２Ｂの頂点が弧状曲線Ｃ３上にあるのに対し、突条歯部１２Ａ１〜１２Ａ８の頂点が弧状曲線Ｃ３より僅かに内側にある）。この場合、突条歯部１２ＢとウエビングＷとの当接により、カム軸部９とカム軸挿通孔１０ｈ及びカム支持孔５ｈ間の遊び寸法やカム周辺部の僅かな変形分、カム部材１０の全体が上方へわずかに持上げられるようになるので、他の突条歯部１２Ａ１〜１２Ａ８から上方へ離隔する方向へ移動して、それら突条歯部１２Ａ１〜１２Ａ８によるウエビングＷの挟持力を可及的に排除でき、従って、ウエビングＷがより滑り出し易くなる。
【００３９】
以上のように構成されるカムバックルの使用例を図７〜図９に示す。
【００４０】
図７はクッション材等を省略した乳児用チャイルドシート５１の斜視図を示しており、チャイルドシート５１の座部５２の前側中央に股ウエビング５３の一端部が固定され、この股ウエビング５３の他端部にバックル本体５４が取り付けられている。また、チャイルドシート５１の座部５２に座った年少者の左右の肩にまたがってそれぞれ装着される肩ウエビング５５、５６の端部には、タング部材５７、５８がそれぞれ取り付けられている。そして、これらタング部材５７、５８をバックル本体５４内に挿入することにより、互いに係脱自在に係止するように構成されている。
【００４１】
また、両肩ウエビング５５、５６はチャイルドシート５１の背もたれ部５９で、背面側に引き出され互いに連結状とされている。そして、その連結状とされた部分に長さ調整用ウエビング５０の一端部が連結され、長さ調整用ウエビング５０の他端部が座部５２の下側を通じてチャイルドシート５１前部の引出部５１ａから引出される。
【００４２】
本カムバックル１は、上記引出部５１ａに設置固定され、上記長さ調整用ウエビング５０が当該カムバックル１を介して引出される。そして、長さ調整用ウエビング５０の引出量を調整した後、カムバックル１が長さ調整用ウエビング５０を所定箇所で解除自在に挟持固定することにより、背もたれ部５９の前側に引き出される両肩ウエビング５５、５６の長さを所望に調整できる構成となっている。
【００４３】
なお、本カムバックル１は、上記チャイルドシード５１以外にも、例えば、トラックの荷台で荷物を締付け固定する場合等、帯状部材であるウエビングＷを解除自在に挟持固定する各種用途に用いることができる。
【００４４】
以上のように構成されたカムバックル１によると、各突条歯部１２Ａ１〜１２Ａ８，１２Ｂのうち締付け回転方向Ｐの最後列の突条歯部１２Ｂの変形強度がそれよりも前列側の各突条歯部１２Ａ１〜１２Ａ８の変形強度よりも高く設定されているため、ウエビングＷに過大な引張力が加わった場合には、突条歯部１２Ａ１〜１２Ａ８を変形させることにより、それら突条歯部１２Ａ１〜１２Ａ８によるウエビングＷの挟持力を小さくして、ウエビングＷに過大な挟持力が加わり、ウエビングＷが破断することを防止できる。
【００４５】
同時に、カム軸Ｃと各突条歯部１２Ａ１〜１２Ａ８，１２Ｂとの間隔寸法が締付け回転方向Ｐの前方から後方に向けてカム軸Ｃと基板部４間の離間寸法を越えるまで漸次大きくなるように設定されると共に、突条歯部１２Ｂの変形強度がそれよりも前列側の各突条歯部１２Ａ１〜１２Ａ８の変形強度よりも高く設定されているため、長期にわたる使用により薄くなったウエビングＷでも、所定の挟持力で挟持でき、ウエビングＷの破断を防止できる。
【００４６】
さらに、カム部材１０を締付け回転方向Ｐと反対周りに回動させるためのレバー部材２５を備えているので、ウエビングＷの挟持の解除を容易に行える。
【００４７】
しかも、カム部材１０を締付け回転方向Ｐに向けて付勢するコイルバネ部材２０等のカム付勢部材を備えているので、ウエビングＷをより確実に挟持することができる。
【００４８】
特に、突条歯部１２Ｂの変形強度をそれよりも前列側の各突条歯部１２Ａ１〜１２Ａ８の変形強度よりも高く設定するための構成として、各突条歯部１２Ａ１〜１２Ａ８，１２Ｂをそれぞれ横断面略三角形状に形成し、締付け回転方向Ｐの最後列の突条歯部１２Ｂの頂角αを、それよりも前列側の各突条歯部１２Ａ１〜１２Ａ８の頂角βよりも大きく仕上げた場合には、例えば、カム部材１０の全体又はカム部材１０のカム面１１の部分を、アルミニウム又はアルミニウム合金の押出成形により容易かつ大量迅速に成形することができるという利点がある。
【００４９】
また、各突条歯部１２Ａ１〜１２Ａ８，１２Ｂのうち締付け回転方向Ｐの最後列の突条歯部１２Ｂの突出寸法を、それよりも前列側の各突条歯部１２Ａ１〜１２Ａ８の突出寸法よりも大きくすると、過大な力でウエビングＷが引張られた場合に、突条歯部１２Ａ１〜１２Ａ８によるウエビングＷの挟持力を可及的に排除することができるので、ウエビングＷがより滑り出し易くなる。
【００５０】
なお、実施の形態では、最後列の突条歯部１２Ｂを一枚で構成しているが、複数で構成することもでき、この場合、荷重を分散してより変形強度を高く設定できる上、複数のうち最初の突条歯部が変形しても続く突条歯部で同じ効果を維持できる。
【００５１】
【発明の効果】
以上のように、この発明の請求項１〜請求項４記載のカムバックルによると、各突条歯部のうち回転方向の最後列の突条歯部がそれよりも前列側の各突条歯部よりも変形強度が高く設定されているため、ウエビングに過大な引張力が加わった場合でも、前列側の突条歯部を変形させることにより、それら突条歯部によるウエビングの挟持力を小さくして、ウエビングに過大な挟持力が加わることを防止でき、ウエビングの破断を防ぐことができる。
【００５２】
しかも、各突条歯部と前記カム軸との間隔寸法が前記回転方向の前方から後方に向けて前記カム軸と前記基板部間の離間寸法を越えるまで漸次大きくなるように設定されていて、前記各突条歯部のうち前記回転方向の最後列の突条歯部がそれよりも前列側の各突条歯部よりも変形強度が高く設定されているため、長期にわたって安定した挟持力を維持できる。
【００５３】
さらに、カム部材を所定の回転方向と反対周りに回動操作するためのレバー部材を備えているため、ウエビングの挟持の解除を容易に行える。
【００５４】
また、請求項３記載のように、各突条歯部がそれぞれ横断面略三角形状に形成され、前突条歯部のうち所定の回転方向の最後列の突条歯部の頂角が、それよりも前列側の各突条歯部の頂角よりも大きく形成されたものにあっては、カム部材の全体又はカム部材のカム面の部分全体を、所定の材料の押出成形により容易かつ大量迅速に成形することができるという利点がある。
【００５５】
さらに、請求項４記載のように、各突条歯部のうち所定の回転方向最後列の突条歯部の突出寸法が、それよりも前列側の各突条歯部の突出寸法よりも大きいものにあっては、過大な力でウエビングが引張られた場合に、最後列の突条歯部以外の各突条歯部によるウエビングＷの挟持力を可及的に排除することができ、ウエビングがより容易に滑り出る。
【図面の簡単な説明】
【図１】この発明の実施の形態に係るカムバックルを示す斜視図である。
【図２】同上のカムバックルを示す断面図である。
【図３】同上のカムバックルの分解斜視図である。
【図４】カム部材を示す要部拡大側面図である。
【図５】ウエビングが挟持された状態を示す要部拡大断面図である。
【図６】ウエビングが挟持された他の状態を示す要部拡大断面図である。
【図７】カムバックルの一使用対象例である乳児用チャイルドシートを示す斜視図である。
【図８】同上の乳児用チャイルドシートを示す背面図である。
【図９】同上の乳児用チャイルドシートを示す断面図である。
【符号の説明】
１カムバックル
２フレーム部材
４基板部
５カム支持部
９カム軸部
１０カム部材
１１カム面
１２Ａ１〜１２Ａ８突条歯部
１２Ｂ突条歯部
２０コイルバネ部材
２５レバー部材
Ｃカム軸
Ｗウエビング
α 頂角
β 頂角[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a cam buckle used for fixing an object to be fixed such as an article such as a child seat to a fixed object.
[0002]
[Prior art]
Conventionally, this type of cam buckle is disclosed in Japanese Patent Application Laid-Open No. 8-268222, which is applied to a child seed.
[0003]
In this type of cam buckle, a cam having a wave portion on one side is rotatably attached between a pair of side walls formed on both sides of a bottom lid having a predetermined holding member. The webbing is sandwiched between the parts. The corrugated portion is constituted by a plurality of corrugated portions extending along the cam shaft direction, and the distance dimension between the apex of each corrugated portion and the cam shaft is opposite to the predetermined tightening rotation direction of the cam. It is set so that it gradually becomes larger.
[0004]
Then, when the webbing is pulled in a predetermined direction with the webbing lightly sandwiched between the cam wave portion and the predetermined clamping member on the bottom lid side of the case, the cam is driven to rotate in the tightening rotation direction. The separation distance between the wave portion and the holding member on the case side is gradually reduced, and the webbing holding force between the wave portion and the holding member is increased.
[0005]
[Problems to be solved by the invention]
However, in the cam buckle as described above, the greater the force that pulls the webbing in a predetermined direction, the smaller the separation distance between the wave portion and the holding member on the case side, and the wave portion and the holding member Since the webbing pinching force between them increases almost indefinitely, the webbing may be broken.
[0006]
In order to prevent this, a cam stopper is provided on the case side so that the cam does not rotate more than a certain amount, so that even when the webbing is pulled with an excessive force, the separation distance between the wave portion and the clamping member is smaller than a predetermined value. It is also possible to limit the upper limit of the clamping force acting on the webbing between the wave portion and the clamping member. In this case, when the webbing is pulled with a force of a certain level or more, the webbing slides out between the predetermined sandwiching member on the wave lid and the bottom lid side of the case.
[0007]
However, in this case, for example, when the thickness of the webbing becomes thin due to long-term use of the webbing or repeated load, there is a problem that the clamping force of the webbing becomes significantly smaller than the initial value assumed in advance.
[0008]
Therefore, an object of the present invention is to provide a cam buckle that can prevent the webbing from being broken by applying an excessive clamping force to the webbing and can maintain a stable clamping force over a long period of time.
[0009]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, the cam buckle according to claim 1 is a frame member in which a pair of cam support portions are erected on opposite sides of the base plate portion, and a predetermined cam shaft between the cam support portions. And a cam surface capable of sandwiching a webbing inserted between the substrate part and an outer peripheral part facing the substrate part, and rotating in a predetermined rotation direction for sandwiching the webbing. A biased cam member and a lever member for rotating the cam member in a direction opposite to the rotation direction, and a protruding tooth portion parallel to the cam shaft is provided on the cam surface. They are formed in parallel around the shaft, and the distance between each of the protruding tooth portions and the cam shaft gradually increases from the front to the rear in the rotational direction until the distance between the cam shaft and the substrate portion exceeds the distance between them. And each said protruding tooth In which the last column deformation strength than the protrusion teeth ridge toothing front row side than that of the rotational direction is set to be higher among.
[0010]
In addition, as described in claim 2, the deformation strength of the front row side protrusion teeth portion is set to be deformed when a predetermined high load larger than a normal load is applied to the webbing, and the last row It is preferable that the deformation strength of the protruding tooth portion is set so as not to be deformed even when the predetermined high load is applied to the webbing.
[0011]
Specifically, as described in claim 3, each of the protruding tooth portions is formed in a substantially triangular shape in cross section, and of the protruding tooth portions of the last row in the rotation direction among the protruding tooth portions. The apex angle may be larger than the apex angle of each protruding tooth portion on the front row side.
[0012]
In addition, as described in claim 4, the protruding dimension of the protruding tooth part of the last row in the rotation direction among the protruding tooth parts is larger than the protruding dimension of each protruding tooth part on the front row side. And better.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a cam buckle according to an embodiment of the present invention will be described.
[0014]
As shown in FIGS. 1 to 3, the cam buckle 1 includes a frame member 2 and a cam member 10 that is rotatably supported by the frame member 2.
[0015]
The frame member 2 is formed in a substantially U-shaped member in a front view in which a pair of cam support portions 5 are erected on opposite sides of the substrate portion 4. The frame member 2 is formed, for example, by punching and bending a thick plate-like metal member into a predetermined shape.
[0016]
The substrate portion 4 is formed as a plate-like member having a rectangular shape in plan view, and is formed so that the webbing W can be sandwiched between the upper surface thereof and the cam member 10.
[0017]
In the present embodiment, the mounting hole 3h is formed from the rear edge of the base plate portion 4 (for convenience, the left side of the cam buckle shown in FIG. The attachment piece 3 is formed, and can be attached to a predetermined member (for example, a portion to be attached to an infant child seed 51 as described later) through the attachment piece 3.
[0018]
Each cam support portion 5 is a member for rotatably supporting a cam member 10 around a predetermined cam axis C. In the present embodiment, a cam shaft portion 9 described later is provided at a substantially central portion of the plate-like member. The cam support hole 5h that can be inserted is formed.
[0019]
In the present embodiment, the rear upper corner portion 5a of each cam support portion 5 is formed in an arc shape having a predetermined radius of curvature so that a lever member 25, which will be described later, is smooth without interfering with the cam support portion 5. It is formed to rotate. Further, a notch portion 5b is formed in the front upper corner portion of each cam support portion 5, and each engagement end portion 21a of a coil spring member 20 described later is formed to be engageable.
[0020]
The cam member 10 is formed with a cam surface 11 that can be disposed on the outer peripheral portion of the columnar block body so as to face the upper surface of the substrate portion 4. In the present embodiment, as an example, a part of the outer peripheral portion of the substantially cylindrical block body is extended outward and the cam surface 11 is formed on the extended outer peripheral portion.
[0021]
A cam shaft insertion hole 10h through which the cam shaft portion 9 can be inserted is formed in the cam member 10 along the width direction at a substantially central portion of the side view shape.
[0022]
Here, the cam shaft portion 9 is configured such that a disk-shaped head portion 9b is formed at one end of the elongated rod-shaped portion 9a. Then, with the cam member 10 disposed between the cam support portions 5 so that the cam shaft insertion holes 10h are aligned with the positions of the cam support holes 5h, the cam shaft portion 9 is connected to the cam on one side from the tip side. By inserting the support hole 5h, the cam shaft insertion hole 10h, and the cam support hole 5h on the other side, the cam member 10 is supported between the cam support portions 5 so as to be rotatable around a predetermined cam axis C.
[0023]
Further, the cam member 10 is urged toward a predetermined tightening rotation direction P (see FIG. 2) around the cam shaft C by a predetermined cam urging means.
[0024]
In this embodiment, the coil spring member 20 is used as the cam biasing means (see FIGS. 2 and 3). The coil spring member 20 is a ring in which a wire having elasticity such as a steel wire is bent in a substantially U shape, and the center portions in the longitudinal direction of both side portions 21 can be inserted through the rod-like portions 9a of the cam shaft portion 9, respectively. In addition to being bent into the shape portion 20a, the end portions of both side portions 21 are bent into a substantially U shape so that the end portions of the both side portions 21 are folded back. Then, the coil spring member 20 is attached to the cam member 10 in a holding shape, and the rod-shaped portion 9a of the cam shaft portion 9 is connected to each ring-shaped portion between the outer surface of the cam member 10 and the inner surface of each cam support portion 5. The engaging end portions 21a are engaged with the cutout portions 5b of the cam support portion 5, and the lateral flange portion 22 of the coil spring member 20 is fitted to the outer peripheral surface of the cam member 10 from the rear side. It arrange | positions so that contact | abutment is possible. The cam member 10 is configured to be biased in the tightening rotation direction P by the elastic force of the coil spring member 20.
[0025]
As shown in FIGS. 2 to 4, the cam surface 11 has protrusions 12 A 1 to 12 A 8 and 12 B parallel to the cam shaft C formed in parallel around the cam shaft C, and the cam shaft C And the distances (D1 to D9) between the protruding tooth portions 12A1 to 12A8 and 12B (more strictly, the protruding vertices of the protruding tooth portions 12A1 to 12A8 and 12B) from the front to the rear in the tightening rotation direction P. On the other hand, the distance between the cam shaft C and the substrate 5 is set so as to gradually increase until the distance D (see FIG. 2) is exceeded. In the present embodiment, only the spacing dimension between the camshaft C and the last row of teeth 12B in the tightening rotation direction P is set to exceed the spacing dimension D. In FIG. 4, a circle C1 centering on the camshaft C and passing through the protrusion vertex of the protrusion tooth 12A1 in the forefront row in the tightening rotation direction P is indicated by a two-dot chain line, and the protrusion teeth 12A1 to 12A8, 12B. An arcuate curve C2 in a predetermined cross section of the virtual curved surface formed by the broken line is indicated by a broken line, and an arcuate curve C3 concentric with the arcuate curve C2 and passing through the protruding vertex of the protruding tooth portion 12B is indicated by a broken line.
[0026]
Then, the cam surface 11 is located behind the base plate portion 4 in the tightening rotation direction P, and each of the protruding tooth portions 12A1 to 12A8 is on a straight line connecting the base plate portion 4 and the cam shaft C with the shortest distance. , 12B from the front in the tightening rotation direction P is located at a relatively large distance so that the webbing W can be inserted between the cam surface 11 of the cam member 10 and the substrate portion 4; Become. Further, from this state, when the cam member 10 rotates in the tightening rotation direction P due to the urging force of the coil spring member 20, etc., along the rotation, on the straight line connecting the substrate portion 4 and the cam shaft C at the shortest distance, Among the projecting tooth portions 12A1 to 12A8, 12B, the one from the rear of the tightening rotation direction P is positioned, and the distance between the cam surface 11 of the cam member 10 and the substrate portion 4 is gradually reduced. The webbing W can be clamped.
[0027]
When the webbing W is pulled in the tightening direction Q (see FIG. 2) with the webbing W sandwiched in this way, the cam member 10 is tightened in the tightening rotation direction P due to the friction between the webbing W and the cam surface 11. , The distance between the cam surface 11 of the cam member 10 and the substrate portion 4 is further reduced, and the clamping force of the webbing W is increased.
[0028]
Further, the deformation strength of the last row of tooth portions 12B in the tightening rotation direction P among the respective tooth portions 12A1 to 12A8, 12B is the deformation strength of each of the tooth portions 12A1 to 12A8 on the front row side. Higher than. Specifically, when the cam buckle is used and the tensile force in the normal range (depending on the use application) is acting on the webbing W, the protruding tooth portions 12A1 to 12A8 and 12B are not deformed. When the tensile force exceeding the normal range is applied to the webbing W, the protruding tooth portion 12B is not deformed, and the protruding tooth portions 12A1 to 12A8 are deformed (about the effect by this). Will be described later).
[0029]
In the present embodiment, in order to realize such a configuration, each of the protruding tooth portions 12A1 to 12A8, 12B has a long side on the front side in the tightening rotation direction P and a short side on the rear side in the tightening rotation direction P. The apex angle α of the ridge tooth portion 12B is determined from the apex angle β of each ridge tooth portion 12A1 to 12A8 (only the apex angle β of the ridge tooth portion 12A8 is shown in FIG. 4). Is set to a large value. In addition, apex angle (beta) of each protrusion tooth part 12A1-12A8 may be the same. In this case, since the thickness in the vicinity of the tip of the ridge tooth portion 12B is thicker than the thickness in the vicinity of the tip of each ridge tooth portion 12A1 to 12A8, each ridge tooth portion 12A1 to 12A8, 12B is webbing W. When pressed with a strong force, the protruding tooth portion 12B is less likely to deform than the protruding tooth portions 12A1 to 12A8 on the front row side. In the present embodiment, the central angle θ between the vertices of the protruding tooth portions 12A1 to 12A8, 12B with respect to the cam shaft C is made the same, and the vertices are slightly rounded.
[0030]
In addition, when each protrusion tooth part 12A1 to 12A8 is strongly pressed against the webbing W, the entire cam member 10 or the part of the cam surface 11 is compared with aluminum or an aluminum alloy so that they can be easily deformed. It is preferable to form with a soft material.
[0031]
In addition to the above, as the configuration for setting the deformation strength of the protruding tooth portion 12B higher than that of the protruding tooth portions 12A1 to 12A8 on the front row side, the protruding tooth portion 12B The structure etc. which form with the material whose deformation strength is higher than the material which formed the tooth-tooth part 12A1-12A8 are employable.
[0032]
Further, as shown in FIGS. 1 to 3, the cam buckle is provided with a lever member 25 for rotating the cam member 10 in the direction opposite to the tightening rotation direction P.
[0033]
The lever member 25 is formed of resin or the like, and includes a cover portion 26 that covers the cam member 10 supported by the pair of cam support portions 5 of the frame member 2 together with the cam support portion 5, and a rear portion of the cover portion 26. And an operation unit 29 provided continuously.
[0034]
The side wall portions 27 of the cover portion 26 are formed with insertion hole portions 27h through which the rod-shaped portions 9a of the cam shaft portion 9 can be inserted. Then, the rod-shaped portion 9a of the cam shaft portion 9 is formed in a state where the side wall portions 27 are disposed outside the cam support portion 5 so that the insertion hole portions 27h are disposed at positions corresponding to the cam support holes 5h. From the insertion hole portion 27h on one side and the cam support hole 5h, the cam shaft insertion hole 10h of the cam member 10 is passed through the cam support hole 5h and insertion hole portion 27h on the other side, and thus the lever member 25 is moved. The cam shaft C is rotatably mounted around the cam shaft C. At this time, the locking piece 13 protruding outward from a part of the circumferential direction of the cam member 10 is engaged with an engagement recess 28 formed in the inner peripheral portion of the cover portion 26, and the cam member 10 and the lever member 25 are configured to rotate together. Thus, when the cam member 10 is rotated in the tightening rotation direction P and is rotated so as to lift the operation portion 29 upward, the cam member 10 is moved in the direction opposite to the tightening rotation direction P accordingly. The webbing W held between the cam surface 11 of the cam member 10 and the substrate portion 4 can be released.
[0035]
The operation of the cam buckle configured as described above will be described.
[0036]
First, in a normal use state, the cam member 10 is rotated in the direction opposite to the tightening rotation direction P against the urging force of the coil spring member 20 by lifting the operation portion 29 of the lever member 25 upward. Then, the distance between the substrate portion 4 and the cam member 10 is increased, and the webbing W can be inserted between them, so that a desired amount of webbing W is inserted between them. Next, when the operation unit 29 is released, the cam member 10 rotates in the tightening rotation direction P by the biasing force of the coil spring member 20. Thereby, the space | interval dimension between the cam surface 11 of the cam member 10 and the board | substrate part 4 becomes small, and the thing of the comparatively front row | line | column side of the rotation direction P among each protrusion tooth part 12A1-12A8, 12B and the board | substrate part 4 are included. The webbing W is lightly held between the two. From this state, when the webbing W is pulled in the tightening direction Q with a force within a predetermined allowable range, the cam member 10 is driven to rotate as shown in FIG. 5, and the cam surface 11 and the substrate of the cam member 10 are rotated. The space | interval dimension between the parts 4 becomes small, and the clamping force of webbing W becomes large. Normally, the webbing W is used in this state. When the cam member 10 is rotated in the direction opposite to the tightening rotation direction P so as to lift the operation unit 29 upward from the use state, the webbing W can be opened. It becomes. Further, in this normal state, the projecting tooth portions 12A1 to 12A8, 12B are not deformed, and even when the webbing W becomes thin due to repeated load or the like, the cam member 10 rotates accordingly. W can be clamped with a predetermined clamping force.
[0037]
On the other hand, when the webbing W is pulled with a large force exceeding the normal range in the above-described use state, the cam member 10 is further driven to rotate, and the protrusions in the last row in the tightening rotation direction P as shown in FIG. The rotation of the cam member 10 is stopped in a state where the tooth portion 12B is in contact with the webbing W so as to push it in. When the webbing W is pulled with an excessive force from this state, as shown in FIG. 6, the tip portions of the protruding tooth portions 12A1 to 12A8 are deformed so as to be pressed against the webbing W with an excessive force. The webbing W is sandwiched mainly by the sandwiching force between the protruding tooth portion 12B and the substrate portion 4, the sandwiching force of the webbing W is lowered, and the webbing W gradually begins to slide. That is, from the state in which the webbing W is sandwiched by the plurality of projecting tooth portions 12A1 to 12A8, 12B due to the deformation of the tip portion of each projecting tooth portion 12A1 to 12A8, the webbing W is formed by the single projecting tooth portion 12B. Is shifted to a state where the webbing W is clamped, and the clamping force of the webbing W is reduced so that an excessive clamping force is not applied to the webbing W. At this time, the webbing W slides out without being pulled out from the cam buckle 1 in a state of being sandwiched with a predetermined force by the single protruding tooth portion 12B.
[0038]
In addition, when excessive tensile force is applied to the webbing W in this way, in order to eliminate as much as possible the pinching force of the webbing W by the protruding tooth portions 12A1 to 12A8 other than the protruding tooth portion 12B, From the tooth portions 12A1 to 12A8 and 12B, the protruding dimension of the protruding tooth portion 12B in the last row in the tightening rotation direction P (the protruding dimension with respect to the virtual curved surface on which the protruding tooth portions 12A1 to 12A8 and 12B are formed) Is preferably larger than the protruding dimension (same as above) of the respective protruding tooth portions 12A1 to 12A8 on the front row side (in FIG. 4, the vertex of the protruding tooth portion 12B is on the arcuate curve C3, The apex of the protruding tooth portions 12A1 to 12A8 is slightly inside the arcuate curve C3). In this case, due to the contact between the ridge tooth portion 12B and the webbing W, the play size between the cam shaft portion 9 and the cam shaft insertion hole 10h and the cam support hole 5h, the slight deformation of the cam peripheral portion, Since the whole is slightly lifted upward, it moves in a direction away from the other protruding tooth portions 12A1 to 12A8, and the holding force of the webbing W by the protruding tooth portions 12A1 to 12A8 is made possible. Therefore, the webbing W becomes easier to slide out.
[0039]
Examples of use of the cam buckle configured as described above are shown in FIGS.
[0040]
FIG. 7 is a perspective view of an infant child seat 51 in which a cushioning material or the like is omitted. One end portion of a crotch webbing 53 is fixed to the front center of the seat portion 52 of the child seat 51, and the other end portion of the crotch webbing 53 is fixed to the child seat 51. A buckle body 54 is attached. Further, tongue members 57 and 58 are respectively attached to the end portions of the shoulder webbings 55 and 56 which are respectively mounted on the left and right shoulders of the young person sitting on the seat portion 52 of the child seat 51. The tongue members 57 and 58 are inserted into the buckle body 54 so as to be detachably engaged with each other.
[0041]
Both shoulder webbings 55 and 56 are backrests 59 of the child seat 51 and are drawn out to the back side to be connected to each other. Then, one end portion of the length adjusting webbing 50 is connected to the connected portion, and the other end portion of the length adjusting webbing 50 is passed through the lower side of the seat portion 52 from the leading portion 51a of the front portion of the child seat 51. Withdrawn.
[0042]
The cam buckle 1 is installed and fixed to the drawer 51a, and the length adjusting webbing 50 is pulled out via the cam buckle 1. Then, after adjusting the pull-out amount of the length adjustment webbing 50, the cam buckle 1 clamps and fixes the length adjustment webbing 50 at a predetermined position so as to be releasable so that both shoulder webbings are pulled out to the front side of the backrest part 59. The lengths 55 and 56 can be adjusted as desired.
[0043]
In addition to the child seed 51, the cam buckle 1 can be used for various applications in which the webbing W that is a belt-like member is releasably clamped and fixed, for example, when a luggage is fastened and fixed on a truck bed. .
[0044]
According to the cam buckle 1 configured as described above, the deformation strength of the ridge tooth portion 12B in the last row in the tightening rotation direction P among the ridge tooth portions 12A1 to 12A8, 12B is greater than each protrusion on the front row side. Since it is set higher than the deformation strength of the tooth portions 12A1 to 12A8, when an excessive tensile force is applied to the webbing W, the protrusion tooth portions 12A1 to 12A8 are deformed to deform the tooth portions. The pinching force of the webbing W by 12A1 to 12A8 can be reduced, and an excessive pinching force is applied to the webbing W, and the webbing W can be prevented from breaking.
[0045]
At the same time, the distance between the camshaft C and the protruding tooth portions 12A1 to 12A8, 12B gradually increases from the front to the rear in the tightening rotation direction P until the distance between the camshaft C and the substrate portion 4 is exceeded. Since the deformation strength of the ridge tooth portion 12B is set to be higher than the deformation strength of each ridge tooth portion 12A1 to 12A8 on the front row side, the webbing W that has been thinned by long-term use is set. However, it can be clamped with a predetermined clamping force, and the webbing W can be prevented from breaking.
[0046]
Furthermore, since the lever member 25 for rotating the cam member 10 in the direction opposite to the tightening rotation direction P is provided, the nipping of the webbing W can be easily released.
[0047]
In addition, since the cam urging member such as the coil spring member 20 that urges the cam member 10 toward the tightening rotation direction P is provided, the webbing W can be more securely held.
[0048]
In particular, as the configuration for setting the deformation strength of the ridge tooth portion 12B higher than the deformation strength of the ridge tooth portions 12A1 to 12A8 on the front row side, the ridge tooth portions 12A1 to 12A8 and 12B are respectively set. It is formed in a substantially triangular cross section, and the apex angle α of the last row of teeth 12B in the tightening rotation direction P is finished larger than the apex angle β of each of the teeth 12A1 to 12A8 on the front row side. In this case, for example, there is an advantage that the entire cam member 10 or the portion of the cam surface 11 of the cam member 10 can be easily and rapidly formed by extrusion molding of aluminum or aluminum alloy.
[0049]
Further, of the protruding tooth portions 12A1 to 12A8 and 12B, the protruding dimension of the protruding tooth portion 12B in the last row in the tightening rotation direction P is larger than the protruding dimensions of the protruding tooth portions 12A1 to 12A8 on the front row side. If the webbing W is pulled with an excessive force, the holding force of the webbing W by the protruding tooth portions 12A1 to 12A8 can be eliminated as much as possible, so that the webbing W is more easily slid out.
[0050]
In the embodiment, the last row of protruding teeth 12B is configured as a single sheet, but it can also be configured as a plurality, and in this case, the load can be dispersed and the deformation strength can be set higher. Even if the first protruding tooth portion of the plurality is deformed, the same effect can be maintained in the continuing protruding tooth portion.
[0051]
【The invention's effect】
As described above, according to the cam buckle according to the first to fourth aspects of the present invention, among the protruding tooth portions, the protruding tooth portion in the last row in the rotational direction is the protruding tooth on the front row side. Since the deformation strength is set higher than the part, even if an excessive tensile force is applied to the webbing, the webbing pinching force by the projecting tooth part can be reduced by deforming the projecting tooth part on the front row side. Thus, an excessive clamping force can be prevented from being applied to the webbing, and the webbing can be prevented from being broken.
[0052]
Moreover, the interval dimension between each protruding tooth portion and the cam shaft is set to gradually increase from the front to the rear in the rotational direction until it exceeds the separation dimension between the cam shaft and the substrate portion, Since the last row of tooth portions in the rotation direction is set to have a higher deformation strength than that of each row tooth portion on the front row side, a stable clamping force over a long period of time. Can be maintained.
[0053]
Further, since the lever member for rotating the cam member in the direction opposite to the predetermined rotation direction is provided, it is possible to easily release the webbing.
[0054]
Further, as described in claim 3, each ridge tooth portion is formed in a substantially triangular cross section, and the apex angle of the ridge tooth portion in the last row in the predetermined rotation direction among the front ridge tooth portions, In the case where it is formed larger than the apex angle of each protruding tooth portion on the front row side, the entire cam member or the entire cam surface portion of the cam member can be easily formed by extrusion molding of a predetermined material. There is an advantage that a large amount can be rapidly formed.
[0055]
Furthermore, as described in claim 4, the protruding dimension of the protruding tooth part in the last row in the predetermined rotational direction among the protruding tooth parts is larger than the protruding dimension of each protruding tooth part on the front row side. If the webbing is pulled with an excessive force, the pinching force of the webbing W by each protruding tooth part other than the protruding tooth part in the last row can be eliminated as much as possible. Will slide out more easily.
[Brief description of the drawings]
FIG. 1 is a perspective view showing a cam buckle according to an embodiment of the present invention.
FIG. 2 is a cross-sectional view showing the cam buckle of the above.
FIG. 3 is an exploded perspective view of the cam buckle.
FIG. 4 is an enlarged side view of a main part showing a cam member.
FIG. 5 is an enlarged cross-sectional view of a main part showing a state where the webbing is sandwiched.
FIG. 6 is an enlarged cross-sectional view of a main part showing another state in which the webbing is sandwiched.
FIG. 7 is a perspective view showing an infant child seat which is an example of a use object of a cam buckle.
FIG. 8 is a rear view showing the above-described infant child seat.
FIG. 9 is a cross-sectional view showing the above-described infant child seat.
[Explanation of symbols]
1 Come Buckle
2 Frame members
4 Board part
5 Cam support
9 Cam shaft
10 Cam member
11 Cam surface
12A1-12A8 ridge tooth part
12B protruding tooth part
20 Coil spring member
25 Lever member
C Camshaft
W Webbing
α vertical angle
β apex angle

Claims

基板部の両側に一対のカム支持部が相対向して立設されたフレーム部材と、
前記カム支持部間に所定のカム軸周りに回転自在に支持され、前記基板部に対向する外周部分に、前記基板部との間に挿通されたウエビングを挟持可能なカム面を有し、前記ウエビングを挟持する所定の回転方向に回転付勢されたカム部材と、
前記カム部材を前記回転方向と反対周りに回動操作するためのレバー部材と、を備え、
前記カム面には、前記カム軸と平行な突条歯部が前記カム軸周りに並列形成されると共にそれら各突条歯部と前記カム軸との間隔寸法が前記回転方向の前方から後方に向けて前記カム軸と前記基板部間の離間寸法を越えるまで漸次大きくなるように設定され、かつ、前記各突条歯部のうち前記回転方向の最後列の突条歯部がそれよりも前列側の各突条歯部よりも変形強度が高く設定されたカムバックル。A frame member in which a pair of cam support portions are erected opposite to each other on both sides of the substrate portion;
A cam surface supported between the cam support portions so as to be rotatable around a predetermined cam shaft and capable of sandwiching a webbing inserted between the cam portion and an outer peripheral portion facing the substrate portion; A cam member that is urged to rotate in a predetermined rotation direction to sandwich the webbing;
A lever member for rotating the cam member in a direction opposite to the rotation direction,
On the cam surface, protruding tooth portions parallel to the cam shaft are formed in parallel around the cam shaft, and the distance between each protruding tooth portion and the cam shaft is changed from the front to the rear in the rotation direction. And is set so as to gradually increase until the distance between the camshaft and the substrate portion is exceeded, and among the protruding tooth portions, the protruding tooth portion in the last row in the rotation direction is in front of it. A cam buckle with higher deformation strength than each protruding tooth.

請求項１記載のカムバックルであって、
前記前列側の突条歯部の変形強度が、前記ウエビングに通常荷重よりも大きな所定の高荷重が作用したときに変形するように設定され、
前記最後列の突条歯部の変形強度が、前記ウエビングに前記所定の高荷重が作用したときでも変形しないように設定されたカムバックル。The cam buckle according to claim 1,
The deformation strength of the front row side protrusion teeth portion is set so as to be deformed when a predetermined high load larger than a normal load is applied to the webbing,
A cam buckle in which the deformation strength of the last row of teeth is set so as not to be deformed even when the predetermined high load is applied to the webbing.

請求項１又は請求項２記載のカムバックルであって、
前記各突条歯部はそれぞれ横断面略三角形状に形成され、前記各突条歯部のうち前記回転方向の最後列の突条歯部の頂角は、それよりも前列側の各突条歯部の頂角よりも大きいカムバックル。The cam buckle according to claim 1 or 2,
Each of the protruding tooth portions is formed in a substantially triangular cross section, and the apex angle of the protruding tooth portion of the last row in the rotational direction among the protruding tooth portions is the protruding row on the front row side than that. A cam buckle larger than the apex angle of the tooth.

請求項１〜請求項３のいずれかに記載のカムバックルであって、
前記各突条歯部のうち前記回転方向最後列の突条歯部の突出寸法が、それよりも前列側の各突条歯部の突出寸法よりも大きいカムバックル。The cam buckle according to any one of claims 1 to 3,
The cam buckle in which the projecting dimension of the projecting tooth part in the last row in the rotational direction among the projecting tooth parts is larger than the projecting dimension of each projecting tooth part on the front row side.