JP3994649B2 - Chair back tilting device - Google Patents

Description

【０００１】
【発明の属する技術分野】
本発明は、椅子の背凭れ傾動装置に係わり、更に詳しくは背凭れ部を前傾方向へ弾性付勢するためのばねユニットが合成樹脂と金属との異種材料で構成されていても廃棄処分の際に分別が容易な椅子の背凭れ傾動装置に関するものである。
【０００２】
【従来の技術】
従来、座部に対して背凭れ部が前後傾動し、座部と背凭れ部との間に設けた強さが調節可能なばねユニットにて該背凭れ部の後傾動に対して弾性抵抗力を付与してなる椅子は公知である。
【０００３】
即ち、この種の椅子の背凭れ傾動機構は、脚部に取付けた取付体に対して背凭れ支持部材を前傾方向へ弾性付勢するばねユニットが、合成樹脂製のノブに基端部を螺着した金属製のテンション杆を、前記背凭れ支持部材の背面に当止した当止体に挿通するとともに、ノブと当止体間に圧縮コイルばねを介装し、前記テンション杆の先端部を前記背凭れ支持部材に貫通し且つ先端に形成した係止片を前記取付体に係着した構造のものである。
【０００４】
ところで、前述のばねユニットにおいては、背凭れ部の後傾動に対する弾性抵抗力を調節するために、テンション杆の螺軸部をノブに螺着する必要があるが、従来の螺着構造は、金属製のナット部材を合成樹脂製のノブにインサート成形して埋設するか、又はナット部材をノブに回転規制状態で強固に嵌合するものであった。また、ノブを回転させて弾性力を調節する際に、螺軸部がナット部材から不意に抜けないように、ナット部材を螺合した後に、該螺軸部の先端をカシメていた。そのため、椅子を廃棄処分する際に、異種材料であるノブとテンション杆及びナット部材とを分解することが難しく、また分解できたとしても手間やコストがかかっていた。
【０００５】
【発明が解決しようとする課題】
そこで、本発明が前述の状況に鑑み、解決しようとするところは、脚部に取付けた取付体に対して背凭れ支持部材をばねユニットにて前傾方向へ弾性付勢する構造の椅子の背凭れ傾動装置において、ばねユニットの組立てが容易であるにも係わらず、組立て状態では十分な強度を備えるとともに、廃棄処分の際に異種材料の分別ができるように分解を容易となした椅子の背凭れ傾動装置を提供する点にある。
【０００６】
【課題を解決するための手段】
本発明は、前述の課題解決のために、脚部に取付けた取付体に対して背凭れ支持部材を前傾方向へ弾性付勢するばねユニットが、合成樹脂製のノブに基端部を螺着した金属製のテンション杆を、前記背凭れ支持部材の背面に当止した当止体に挿通するとともに、ノブと当止体間に圧縮コイルばねを介装し、前記テンション杆の先端部を前記背凭れ支持部材に貫通し且つ先端に形成した係止片を前記取付体に係着したものである椅子の背凭れ傾動装置であって、前記テンション杆の基端部に形成した螺軸部に、長形のフランジ部を有するフランジ付きナット部材を螺合するとともに、前記ノブに前記フランジ部と略同形で該フランジ部を通過可能な長形の装着孔を形成し、前記ナット部材をノブの装着孔の内部側から挿通し且つ９０度回転させてフランジ部を装着孔の外部側に係止するとともに、前記螺軸部を隠蔽するキャップに設けた一対の脚片を前記フランジ部の両側に残る装着孔内に嵌合係止し、前記ナット部材を回り止め状態でノブに取付けてなる椅子の背凭れ傾動装置を構成した。
【０００７】
ここで、前記ノブは、上方へ開放した筒状部材であり、中央部に前記ナット部材を保持するための下方開放した円筒形状の保持部を内部へ突出させて形成し、該保持部の底面板に前記装着孔を形成するとともに、内周面に軸方向へ延びた規制リブを複数突設したものであり、前記キャップは、前記保持部内に嵌合する形状に形成するとともに、外周面に前記規制リブを受け入れる複数の縦溝を形成し、更に前記両脚片間にナット部材のフランジ部を嵌合する凹段部を形成したものであることが好ましい。
【０００８】
更に、前記ばねユニットの当止体は、中心部に前記係止片が通過可能な円形孔を形成し、前記圧縮コイルばねの一端を当止し得る当止板と、前記テンション杆をスライド可能に挟持し、下部外周に前記当止板の円形孔に接合するテーパー面を形成し且つ前記背凭れ支持部材の背面に当止する当止部材とから構成され、前記当止板には、その周囲から延び、前記ノブとで前記圧縮コイルばねを外覆する筒状カバー部を有し、該カバー部は前記ノブを内挿できる内径を有するとともに、内周面に軸方向へ延びた複数の縦リブを形成し、一方前記ノブの外周面には前記縦リブを軸方向スライド可能に受け入れる複数の条溝を形成してなることも好ましい。
【０００９】
【発明の実施の形態】
次に本発明の実施の形態を添付図面に基づき更に詳細に説明する。図１は本発明に係る椅子の全体斜視図、図２〜図１３は椅子の機構部分の詳細図を示し、図中符号１は脚部、２は座部、３は背凭れ部、４はばねユニット、５は取付体、６は背凭れ支持部材、７は座支持部材をそれぞれ示している。
【００１０】
本発明に係る椅子は、脚部１に座部２を回転可能に取付けるとともに、背凭れ部３を前後傾動可能に取付け且つ該背凭れ部３の動作に連動して座部２の後部を上下動可能となすとともに、前後スライド可能となし、そして一つのばねユニット４にて前記背凭れ部３の後傾動と座部２の後部の下動に対して弾性抵抗力を同時に付与したものである。
【００１１】
つまり、本発明に係る椅子は、脚部１に取付けた取付体５の中央部下部に背凭れ支持部材６の下端部を第１枢着部８にて前後傾動可能に取付け、前記取付体５の上位に略水平に配した座支持部材７の前部を該取付体５の前部に前後スライド可能且つ上下揺動可能に連結するとともに、座支持部材７の後部と、前記背凭れ支持部材６の第１枢着部８とは異なる部分とを、第２枢着部９にて回動可能に連結し、前記取付体５の後部に対して背凭れ支持部材６を強さが調節可能なばねユニット４で前傾方向へ弾性付勢してなるものである。
【００１２】
前記取付体５は、スチール板材をプレス加工によって一体成形したものであり、底板１０から周囲が立ち上がった上方開放の箱状であり、少なくとも両側板１１，１１と底板１０の後部に後方上方へ傾斜した傾斜部１２を有し、上縁周囲には祖と向きに鍔部１３を形成したものである。
【００１３】
更に詳しくは、前記取付体５には、前記両側板１１，１１の前部に横長の開口１４，１４を形成するとともに、該開口１４の直上の鍔部１３を切起して当止片１５をそれぞれ両側に突設し、また両側板１１，１１の後部に鍔部１３にわたって切欠部１６，１６を形成している。また、前記底板１０の中央部やや後方寄り位置には、脚部１に立設したガスシリンダー１７の上端部を取付けるための円形孔１８を形成するとともに、取付体５の内部で前記底板１０とは間隔を置いて固着した固定部材１９の中央部にも円形孔２０を形成し、両円形孔１８，２０を貫通するように上方が縮径したテーパー状の固定筒２１を固着し、該固定筒２１に前記ガスシリンダー１７の先細上端部を嵌着するようになっている。更に、前記底板１０の下面で中央部やや後方寄り位置には、支持部材２２を固着し、該支持部材２２の両側縁に下向きに形成した支持板２３，２３には前記第１枢着部８を構成する支軸２４を挿通するための支持孔２５，２５を形成している。尚、前記支持部材２２に設けた支持孔２５，２５の位置は、前記ガスシリンダー１７よりも若干前方である。
【００１４】
前記背凭れ支持部材６は、後部に背凭れ杆２６を連設若しくは一体形成した部材であり、背凭れ杆２６の上部には図示しないクッション体を取付けて前記背凭れ部３を構成するものである。前記背凭れ支持部材６の前部は斜め前下方へ延び、背面を構成する主板２７の両側縁に上方へ向いた連結板２８，２８を有し、該連結板２８，２８の中央部側には上方へ略三角形状となして幅広となっており、該連結板２８の前下部には前記支軸２４を挿通するための支持孔２９を形成するとともに、後上部には前記第２枢着部９を構成する支軸３０を挿通するための連結孔３１を形成している。また、前記背凭れ支持部材６の主板２７の前下端部には、前記ガスシリンダー１７を受け入れる前方開放した切欠開口３２を形成している。
【００１５】
前記座支持部材７は、上面板３３の両側に側面板３４，３４を下方へ延設した断面略コ字形の部材であり、該上面板３３の上部に図示しないクッション体を取付けて前記座部２を構成するものである。前記座支持部材７は、前記側面板３４，３４間に取付体５を受け入れることが可能で且つ前記背凭れ支持部材６の両連結板２８，２８間に受け入れられることが可能な横幅を有し、該側面板３４，３４の前部下方へ張り出した部分に、前記取付体５の開口１４，１４に前後動可能に遊嵌するガイド軸３５を取付けるための通孔３６，３６を形成するとともに、側面板３４，３４の後部に前記支軸３０を受け入れる下方開放した切欠溝３７，３７を形成している。更に詳しくは、前記ガイド軸３５には、円筒状の合成樹脂製スリーブ３８が被嵌されており、前記取付体５の当止片１５の上端に当該座支持部材７の上面板３３が載支された状態で、前記開口１４内でスリーブ３８が自由に前後移動できるように該開口１４の上下幅を設定している。尚、前記ガイド軸３５は両側面板３４，３４からそれぞれ突設した突起であっても良い。また、前記切欠溝３７は前記支軸３０を挿通するのに必要最小限な幅の導入部３７Ａと、支軸３０に被嵌した円筒状の合成樹脂製スリーブ３９を回転可能に嵌合する軸受部３７Ｂとからなっている。そして、図４に示した最大負荷状態、即ち着座して背凭れ部３に凭れ掛かって前記背凭れ支持部材６が最も後傾して前記座支持部材７の後部が後方へ移動しながら沈んだ状態で、前記スリーブ３９又は該スリーブ３９が支軸３０の両端部のみに設けた場合には支軸３０が、前記固定部材１９の上面に取付けた緩衝板４０に当止するようになっている。
【００１６】
そして、前記脚部１のガスシリンダー１７の上端に前記取付体５を取付けた状態で、前記背凭れ支持部材６を取付体５の後部下方からあてがい、前記支持部材２２の支持板２３，２３を両連結板２８，２８間に位置させ、支持板２３，２３の支持孔２５，２５と連結板２８，２８の支持孔２９，２９とに前記支軸２４を挿通して連結する。この際、それぞれ両側部で両支持孔２５，２９に合成樹脂製のスリーブ４１を嵌挿し、該スリーブ４１に前記支軸２４を挿通して回動時の金属音が発生しないようにしている。また、前記前記背凭れ支持部材６が最も後傾した場合に、それ以上の後傾を制限するために、前記支持板２３，２３の下端部にストッパー片４２を突設し、前記背凭れ支持部材６の主板２７の両側先端が該ストッパー片４２に当止するようになっている。
【００１７】
それから、前記座支持部材７を取付体５に被せて、前部は前記当止片１５，１５に上面板３３を載支するとともに、前記ガイド軸３５を開口１４，１４を貫通させて取付け、後部は前記背凭れ支持部材６の連結孔３１，３１に貫通させた支軸３０を前記切欠溝３７，３７内に受け入れるとともに、支軸３０に外嵌したスリーブ３９を切欠溝３７の軸受部３７Ｂに嵌合して上下方向へ抜け止め状態で連結する。つまり、前記座支持部材７の前部は取付体５の前部に前後スライド可能且つ上下揺動可能に連結されている。
【００１８】
前記ガイド軸３５と開口１４との係合部、第１枢着部８を構成する支軸２４、第２枢着部９を構成する支軸３０とは、逆三角形の頂点に位置し、図３に示した状態から背凭れ支持部材６が後方へ傾動すると、その動作に伴って座支持部材７の後部が下動するとともに、座支持部材７が全体的に後方へ移動して図４に示した状態となる。この場合、前記当止片１５が上面板３３の下面に接触した状態を維持しながら、前記ガイド軸３５が開口１４内を後方へ移動することになる。
【００１９】
次に、本発明に係る椅子の背凭れ傾動装置におけるばねユニット４の構造及び該ばねユニット４の椅子本体への取付構造について説明する。ここで、前記背凭れ支持部材６を前傾方向へ弾性付勢するためのばねユニット４は、図２〜図１３に詳しく示されているように、取付体５の底板１０に対して背凭れ支持部材６の主板２７を引き付ける方向に弾性力を付与し、またその弾性力の強さを調節できるものである。また、当該ばねユニット４は、一つの構成部品として組み立てた後、所定位置に簡単に装着できるにも係わらず、容易に外れないようになし、しかも異種材料毎に容易に分解できるようにして分別廃棄を可能としたことを特徴としている。
【００２０】
つまり、前記ばねユニット４は、脚部１に取付けた取付体５の後部に対して背凭れ支持部材６を前傾方向へ弾性付勢するものであり、合成樹脂製のノブ４３に基端部を螺着した金属製のテンション杆４４を当止体４５に挿通するとともに、ノブ４３と当止体４５間に圧縮コイルばね４６を介装し、前記テンション杆４４の先端に係止片４７を略Ｔ字形となるように形成したものである。
【００２１】
更に詳しくは、前記テンション杆４４の基端部に形成した螺軸部４８に、長形、例えば小判型のフランジ部５０を有する金属製のフランジ付きナット部材４９を螺合するとともに、前記ノブ４３に前記フランジ部５０と略同形で該フランジ部５０を通過可能な長形の装着孔５１を形成し、前記ナット部材４９をノブ４３の装着孔５１の内部側から挿通し且つ９０度回転させてフランジ部５０を装着孔５１の外部側に係止するとともに、前記螺軸部４８を隠蔽するキャップ５２に設けた一対の脚片５３，５３を前記フランジ部５０の両側に残る装着孔５１内に嵌合係止し、前記ナット部材４９を回り止め状態でノブ４３に取付けている。つまり、前記ナット部材４９は、前記ノブ４３に嵌合構造のみにより回り止め状態で取付けられており、該ノブ４３を回転することにより、ノブ４３とともに進退して弾性付勢力を調節できるようになっている。尚、前記ナット部材４９は、ノブ４３に組み付ける前に、予めテンション杆４４の螺軸部４８に螺合した後に、該螺軸部４８の先端をカシメることにより抜けないようにしている。図中符号５４は、螺軸部４８のカシメ部を示している。
【００２２】
更に、前記ノブ４３は、上方へ開放した筒状部材であり、中央部に前記ナット部材４９を保持する円筒形状の保持部５５を内部側へ突出するように形成するとともに、その周囲に前記圧縮コイルばね４６の一端を保持する環状凹部５６を形成している。また、前記保持部５５の内部側に位置する底面板５７には前記装着孔５１を形成している。
【００２３】
また、前記ノブ４３の保持部５５の内周面には、軸方向へ延びた規制リブ５８，…を複数突設し、前記キャップ５２は、前記保持部５５内に嵌合する形状に合成樹脂で形成するとともに、外周面に前記規制リブ５８を受け入れる複数の縦溝５９，…を形成し、更に前記両脚片５３，５３間にナット部材４９のフランジ部５０を嵌合する凹段部６０を形成している。また、前記キャップ５２の脚片５３の先端外面には爪部６１が形成されており、該爪部６１が前記装着孔５１の内部側孔縁に抜け止め係合する。ここで、前記キャップ５２の両脚片５３，５３は、内外に弾力性を有するように成形されているため、この脚片５３，５３が、フランジ部５０の両側の装着孔５１に嵌合されていても、ナット部材４９の回転を完全に規制することはできず、極端に回転力が強い場合には脚片５３，５３が変形、若しくは分断してキャップ５２が保持部５５内から外れ、それに伴ってフランジ部５０が回転し、装着孔５１から抜けることも想定される。そこで、本発明では、保持部５５の規制リブ５８に、キャップ５２の縦溝５９が嵌合することで、ノブ４３に対するキャップ５２の回転を規制し、更にキャップ５２の凹段部６０にフランジ部５０が嵌合することで、キャップ５２に対するフランジ部５０の回転を規制したのである。尚、前記ノブ４３から、テンション杆４４とナット部材４９を分離するには、前記爪部６１，６１をドライバーの先端などで内側に押し込めばキャップ５２が保持部５５内から外れるので、この状態になればフランジ部５０を９０度回転させて装着孔５１から抜けるのである。
【００２４】
一方、前記取付体５には前記係止片４７が通過可能な長形孔６２とそれに交叉する係合凹部６３からなる係止部６４を形成し、前記背凭れ支持部材６には前記係止片４７が通過可能且つ前記当止体４５が通過不能な開口６５を形成し、前記テンション杆４４の先端部を開口６５と長形孔６２に挿通し且つ前記当止体４５を背凭れ支持部材６の背面に当止した後、テンション杆４４を回転させて前記係止片４７を係合凹部６３に係合するとともに、前記長形孔６２内に規制体６６の一部を嵌合保持して前記テンション杆４４を回転止めしてなるものである。
【００２５】
更に詳しくは、前記ばねユニット４の当止体４５は、中心部に前記係止片４７が通過可能な円形孔６７を形成するとともに、前記圧縮コイルばね４６の一端を当止し得る当止板６８と、二つ割り部材であり、重合面に前記テンション杆４４をスライド可能に挟持する縦溝７０を形成するとともに、下部外周に前記当止板６８の円形孔６７に接合するテーパー面７１を形成し且つ重合状態で上端が前記背凭れ支持部材６の開口６５の縁部に当止可能である当止部材６９，６９とから構成されている。ここで、前記二つ割り当止部材６９，６９は、硬質ゴム等の弾性変形可能な素材で成形し、重合状態で上端部に前記取付体５の長形孔６２に遊挿可能である。更に、前記当止板６８には、その周囲から延びた筒状カバー部７２を有し、該カバー部７２と前記ノブ４３とで前記圧縮コイルばね４６を外覆している。前記カバー部７２は、前記ノブ４３を内挿できる内径を有し、常にノブ４３の上部が内挿された状態となっている。尚、本実施形態では、前記円形孔６７は、テーパー面７１に面接合するテーパー孔で形成している。
【００２６】
前記当止板６８に一体形成した前記カバー部７２の内周面には、軸方向へ延びた複数の縦リブ７３，…を形成し、一方前記ノブ４３の外周面には前記縦リブ７３を軸方向スライド可能に受け入れる複数の条溝７４，…を形成している。これにより、前記縦リブ７３と条溝７４との係合によって、ノブ４３とカバー部７２は回転に対して一体化し、ノブ４３とカバー部７２のどちらを持っても弾性抵抗力を調節することができる。尚、前記ノブ４３の下部の角部は、丸みを持たせているが、ノブ４３を回転させて圧縮コイルばね４６を押し縮めると、該ノブ４３はカバー部７２に深く進入する。このとき、ノブ４３の丸みを持たせた下部周囲部とカバー部７２の開口縁の間に隙間が生じるが、前記縦リブ７３，…が存在するので、この隙間に指先が挟まれる恐れがないのである。
【００２７】
更には、前記規制体６６は、本実施形態では同一形状で互いに１８０度回転させた状態で嵌合して一体化する二つ割りの規制小体７５，７５から構成されている。ここで、前記規制体６６の二つ割り構造は、特に限定されないが、図８〜図１０に示した規制小体７５で構成すれば、互いに無理嵌め状態で一体化できるので好ましく、また予め一端に係止片４７が固定され且つ他端に抜け止め状態でナット部材４９が螺合されている前記テンション杆４４の軸部に外挿するためには必要であるが、ナット部材４９を後で螺合して組み立てる場合には、一体成形したものであっても良いのである。つまり、図１０に示した本実施形態の規制体６６は、前記背凭れ支持部材６の背面に係止し且つ前記開口６５を通して前記当止体４５に接触可能であるとともに、中心部に前記テンション杆４４を挿通する挿通孔７６を形成したフランジ部７７と、該フランジ部７７の挿通孔７６を挟んだ位置から延び前記テンション杆４４の両側に残る前記長形孔６２内に嵌入可能であるとともに、前記係止片４７の上端に係止可能な一対の嵌合片７８，６９とを有するものである。
【００２８】
更に詳しくは、前記規制体６６の両嵌合片７８，７８の先端に、前記テンション杆４４の係止片４７を渡した状態で係止可能な凹溝７９，７９を形成し、両嵌合片７８，７８の凹溝７９，７９に係止片４７を係止した状態で前記長形孔６２に下方から両嵌合片７８，７８及び係止片４７を共に挿入可能となしている。また、前記両嵌合片７８，７８の先端部内側には、当該嵌合片７８，７８の間に落とし込んだ係止片４７の上端に係止できるように係止爪部８０，８０を突設している。また、前記テンション杆４４の係止片４７は、棒体の上面を水平面でカットした断面倒Ｄ字形となして、前記嵌合片７８，７８の間に落とし込み易く、しかも係止爪部８０，８０を確実に係止できるようにしている。
【００２９】
前述の規制体６６を構成する規制小体７５は、図８及び図９に示すように、下部に半割のフランジ部７７Ａを有し、該フランジ部７７Ａから両嵌合片７８Ａ，７８Ａを立設するとともに、両嵌合片７８Ａ，７８Ａ間に対応するフランジ部７７Ａの内縁部には前記挿通孔７６を形成する凹部７６Ａを形成し、更に一方の嵌合片７８Ａの上部内側に係止爪部８０Ａを突設している。そして、一方の嵌合片７８Ａの外側一側に嵌合凹部８１Ａを上下に形成するとともに、他方の嵌合片７８Ａの内側他側に前記嵌合凹部８１Ａと凹凸嵌合し得る形状の嵌合凸部８２Ａを形成している。このように「Ａ」を付した一方の規制小体７５と、図９に示すように［Ｂ］を付した他方の規制小体７５とを、前記テンション杆４４の軸部を挟んで両側から互いに嵌合し、それぞれのフランジ部７７Ａ，７７Ｂで前記フランジ部７７を形成し、内外に接合された嵌合片７８Ａ，７８Ｂで前記嵌合片７８を形成するのである。また、前記フランジ部７７の上面は周囲が薄肉となった円錐形状とし、前記係合凹部６３の下面に対応する部分には凹溝８３を形成している。
【００３０】
そこで、前記ばねユニット４を組み立てるには、図２及び図５〜図７に示すように、先ず螺軸部４８にナット部材４９を螺合し、その先端にカシメ部５４を形成したテンション杆４４を、ナット部材４９側からノブ４３の装着孔５１に上方より挿通し、ナット部材４９を９０度回転させてフランジ部５０を保持部５５の装着孔５１の外側孔縁部に係止する。次に、前記キャップ５２を保持部５５内に嵌合し、その両脚片５３，５３をフランジ部５０の両側に残った装着孔５１内に挿入し、爪部６１を装着孔５１の内側孔縁部に弾性的に抜け止め係合する。そして、前記係止片４７側から圧縮コイルばね４６をテンション杆４４に巻装し、その一端を環状凹部５６に嵌合した後、前記カバー部７２を有する当止板６８の円形孔６７に係止片４７側からテンション杆４４を挿通し、圧縮コイルばね４６の一端を当止板６８に当止する。それから、テーパー状の円形孔６７の外部に、同じくテーパー面７１を有する二つ割りの当止部材６９，５５をその縦溝７０，７０でテンション杆４４の軸部を挟み込んで装着し、前記圧縮コイルばね４６を圧縮しながら、当止部材６９，６９と係止片４７との間に前記規制体６６を装着するとともに、両嵌合片７８，７８の凹溝７９，７９に係止片４７を係止する。この状態で、圧縮コイルばね４６に加えていた圧縮力を除いても、ばねユニット４はそのままの状態を維持する。これで、ばねユニット４の組み立てと所定部位への装着前の設定を完了する。
【００３１】
そして、図１１に示すように、前記テンション杆４４の係止片４７を、規制体６６の両嵌合片７８，７８とともに前記背凭れ支持部材６の開口６５に下方より挿入し、更に取付体５の長形孔６２に挿入し、前記係止片４７を取付体５の底板１０後部の傾斜部１２上面に出現させる。それから、前記係止片４７をテンション杆４４を中心として強制的に回転させて該係止片４７を凹溝７９，７９から外せば、前記圧縮コイルばね４６の弾性復元力によって、該係止片４７が両嵌合片７８，７８間に落ち込み、前記係合凹部６３に係合すると同時に係止爪部８０，８０によって抜止状態となる（図１２及び図１３参照）。ここで、抜止状態とは、前記規制体６６の両嵌合片７８，７８が取付体５の長形孔６２に嵌合した状態を維持することを意味し、両嵌合片７８，７８で前記係止片４７の中央部を挟んで該係止片４７の回転を強制的に制限することにより、該係止片４７が長形孔６２から抜けることがなくなるのである。
【００３２】
次に、本発明に係る椅子の動作について説明する。図３に示した無負荷状態、即ち着座しない初期状態では、前記ばねユニット４の圧縮コイルばね４６の弾性付勢力によって背凭れ支持部材６の主板２７が取付体５の底板１０後部の傾斜部１２に最も接近し、当止体４５の当止部材６９と底板１０が接触している。また、取付体５の傾斜部１２と当止部材６９との間には、背凭れ支持部材６の開口６５を貫通した規制体６６のフランジ部７７が挟まれている。それから、座部２に着座して背凭れ部３に凭れ掛かかると、前記背凭れ支持部材７は第１枢着部８を中心に後傾するとともに、それに伴って前記座支持部材７の後部が若干後方へ変位しながら沈み、遂には図４に示した最大負荷状態となって、前記スリーブ３９の下端が前記取付体５の固定部材１９の上面に設けた緩衝体４０に当接する。つまり、前記背凭れ支持部材６と座支持部材７の動作変化の両極端を規定している。
【００３３】
また、前記二つ割り当止部材６９，６９の両縦溝７０，７０でテンション杆４４の上部を挟持し、しかもテーパー面７１，７１を当止板６８のテーパー状円形孔６７に嵌合していることから、両縦溝７０，７０とテンション杆４４との間には常に摺動摩擦力が働き、背凭れ支持部材６の前後方向の傾動動作時にその摩擦力が制動力となって急激な変化を規制するのである。更に、この制動力は、背凭れ支持部材６が後傾するにつれて圧縮コイルばね４６の弾性力が大きくなって両縦溝７０，７０をテンション杆４４に押し付ける力が増大するので徐々に大きくなる。従って、背凭れ支持部材６の後傾に対する抵抗力は、圧縮コイルばね４６の弾性力と、両縦溝７０，７０とテンション杆４４との間に生じる制動力との和になる。一方、着座者が後傾状態から立起状態に起き上がる際には、背凭れ支持部材６に作用する後傾方向の負荷が急激に小さくなって、圧縮コイルばね４６の弾性力によって背凭れ支持部材６が初期状態に速やかに復帰しようとするが、前述の両縦溝７０，７０とテンション杆４４との間に生じる制動力によってその復帰動作が緩やかになる。
【００３４】
【発明の効果】
以上にしてなる請求項１に係る発明の椅子の背凭れ傾動装置によれば、背凭れ部を前傾方向へ弾性付勢するためのばねユニットが合成樹脂と金属との異種材料で構成されていても廃棄処分の際に分別が容易である。つまり、キャップの脚片をドライバーの先端などで押し込めばキャップが保持部内から外れるので、この状態になればフランジ部を９０度回転させて装着孔から簡単に抜くことができ、合成樹脂製のノブと金属製のテンション杆とナット部材を分別廃棄することができる。
【００３５】
請求項２によれば、前記効果に加えて、保持部の規制リブにキャップの縦溝が嵌合しているので、ノブに対するキャップの回転が規制され、更にキャップの凹段部にフランジ部が嵌合しているので、キャップに対するフランジ部の回転が規制され、ノブにナット部材を回転規制した状態で確実に取付けることができ、また脚片の強度が弱くても該脚片に捩れの負荷がかからないので、該脚片が損傷することもないのである。
【００３６】
請求項３によれば、前記効果に加えて、縦リブと条溝との係合によって、ノブとカバー部は回転に対して一体化し、ノブとカバー部のどちらを持ってもナット部材を回転させることができ、もってばねユニットの弾性抵抗力を調節することができる。尚、ノブを回転させて圧縮コイルばねを押し縮めると、該ノブはカバー部に深く進入し、前記ノブの下部の角部に丸みを持たせた場合には、ノブの下部周囲部とカバー部の開口縁の間に隙間が生じるが、前記縦リブが存在するので、この隙間に指先が挟まれる恐れがないのである。
【図面の簡単な説明】
【図１】本発明に係る椅子の全体斜視図である。
【図２】背凭れ支持部材と座支持部材の傾動機構及びばねユニットを示す分解断面図である。
【図３】無負荷状態の要部の縦断面図である。
【図４】最大負荷状態の要部の縦断面図である。
【図５】ばねユニットの分解斜視図である。
【図６】ノブの斜視図である。
【図７】ノブにフランジ付きナット部材を取付けた状態を示し、（ａ）は上面から見た部分省略断面図、（ｂ）は下から見た断面図である。
【図８】規制体を構成する規制小体を示し、（ａ）は平面図、（ｂ）は側面図、（ｃ）は（ａ）のＸ−Ｘ線断面図である。
【図９】規制体の分解斜視図である。
【図１０】同じく規制体の斜視図である。
【図１１】ばねユニットを背凭れ支持部材と取付体に装着する状態を示す部分斜視図である。
【図１２】同じくばねユニットを背凭れ支持部材と取付体に装着した状態を示す部分斜視図である。
【図１３】同じくばねユニットを背凭れ支持部材と取付体に装着した状態を示す部分平面図である。
【符号の説明】
１ 脚部 ２ 座部
３ 背凭れ部 ４ ばねユニット
５ 取付体 ６ 背凭れ支持部材
７ 座支持部材 ８ 第１枢着部
９ 第２枢着部 １０ 底板
１１ 側板 １２ 傾斜部
１３ 鍔部 １４ 開口
１５ 当止片 １６ 切欠部
１７ ガスシリンダー １８ 円形孔
１９ 固定部材 ２０ 円形孔
２１ 固定筒 ２２ 支持部材
２３ 支持板 ２４ 支軸
２６ 背凭れ杆 ２７ 主板
２８ 連結板 ２９ 支持孔
３０ 支軸 ３１ 連結孔
３２ 切欠開口 ３３ 上面板
３４ 側面板 ３５ ガイド軸
３６ 通孔 ３７ 切欠溝
３７Ａ 導入部 ３７Ｂ 軸受部
３８ スリーブ ３９ スリーブ
４０ 緩衝体 ４１ スリーブ
４２ ストッパー片 ４３ ノブ
４４ テンション杆 ４５ 当止体
４７ 係止片 ４８ 螺軸部
４９ ナット部材 ５０ フランジ部
５１ 装着孔 ５２ キャップ
５３ 脚片 ５４ カシメ部
５５ 保持部 ５６ 環状凹部
５７ 底面板 ５８ 規制リブ
５９ 縦溝 ６０ 凹段部
６１ 爪部 ６２ 長形孔
６３ 係合凹部 ６４ 係止部
６５ 開口 ６６ 規制体
６７ 円形孔 ６８ 当止板
６９ 当止部材 ７０ 縦溝
７１ テーパー面 ７２ カバー部
７３ 縦リブ ７４ 条溝
７５ 規制小体 ７６ 挿通孔
７６Ａ 凹部 ７７ フランジ部
７８ 嵌合片 ７９ 凹溝
８０ 係止爪部 ８１Ａ 嵌合凹部
８２Ａ 嵌合凸部 ８３ 凹溝[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a chair back tilting device, and more particularly, even if a spring unit for elastically urging the backrest in a forward tilting direction is made of a different material of synthetic resin and metal, it can be disposed of. The present invention relates to a chair back tilting device that can be easily separated.
[0002]
[Prior art]
Conventionally, the backrest part tilts back and forth with respect to the seat part, and an elastic resistance force against the back tilt of the backrest part by a spring unit that can adjust the strength provided between the seat part and the backrest part. A chair provided with is known.
[0003]
In other words, the backrest tilting mechanism of this type of chair has a spring unit that elastically biases the backrest support member in the forward tilt direction with respect to the attachment body attached to the leg portion, and the base end portion of the knob made of synthetic resin. The screwed metal tension rod is inserted into a retaining body that is abutted against the back surface of the backrest support member, and a compression coil spring is interposed between the knob and the retaining member, and the tip of the tension rod And a locking piece formed at the tip of the back support member and engaged with the mounting body.
[0004]
By the way, in the above-mentioned spring unit, in order to adjust the elastic resistance force against the backward tilting of the backrest portion, it is necessary to screw the screw shaft portion of the tension rod to the knob. A nut member made of synthetic resin is insert-molded and embedded in a knob made of synthetic resin, or the nut member is firmly fitted to the knob in a rotation restricted state. Further, when the elastic force is adjusted by rotating the knob, the tip of the screw shaft portion is crimped after the nut member is screwed so that the screw shaft portion does not come out of the nut member unexpectedly. Therefore, when disposing of the chair, it is difficult to disassemble the knob, the tension rod and the nut member, which are different materials, and even if it can be disassembled, it takes time and cost.
[0005]
[Problems to be solved by the invention]
Therefore, in view of the above-described situation, the present invention intends to solve the problem of the back of a chair having a structure in which a backrest support member is elastically biased forwardly by a spring unit with respect to an attachment body attached to a leg portion. Despite the ease of assembling the spring unit in the tilting and tilting device, the back of the chair has sufficient strength in the assembled state and is easily disassembled so that different materials can be separated during disposal. The point is to provide a tilting and tilting device.
[0006]
[Means for Solving the Problems]
In order to solve the above-described problems, the present invention provides a spring unit that elastically biases a backrest support member in a forward tilt direction with respect to an attachment body attached to a leg portion, and a base end portion is screwed onto a synthetic resin knob. The attached metal tension rod is inserted into a stopper that is stopped against the back of the back support member, and a compression coil spring is interposed between the knob and the stopper, and the tip of the tension rod is A backrest tilting device for a chair, wherein the backrest support member is formed by engaging a locking piece that penetrates the backrest support member and is formed at the tip thereof, and a screw shaft portion formed at a base end portion of the tension rod. A nut member with a flange having a long flange portion is screwed together, and a long mounting hole having substantially the same shape as the flange portion and passing through the flange portion is formed in the knob. Insert it from the inside of the mounting hole and rotate it 90 degrees The flange portion is locked to the outside of the mounting hole, and a pair of leg pieces provided on the cap for concealing the screw shaft portion are fitted and locked in the mounting holes remaining on both sides of the flange portion, and the nut member A backrest tilting device for the chair, which is attached to the knob in a non-rotating state, is constructed.
[0007]
Here, the knob is a cylindrical member that is open upward, and is formed by projecting a cylindrical holding portion that opens downward to hold the nut member at the center, and is formed at the bottom of the holding portion. The mounting hole is formed in the face plate, and a plurality of restriction ribs extending in the axial direction are provided on the inner peripheral surface, and the cap is formed in a shape that fits in the holding portion, and is formed on the outer peripheral surface. It is preferable that a plurality of vertical grooves for receiving the restriction ribs are formed, and a concave step portion for fitting a flange portion of a nut member is formed between the both leg pieces.
[0008]
Further, the stopper of the spring unit is formed with a circular hole through which the locking piece can pass at the center, and a stopper plate that can stop one end of the compression coil spring and the tension rod can be slid. And a stopper member that forms a tapered surface that joins the circular hole of the stopper plate on the outer periphery of the stopper plate and that contacts the back surface of the backrest support member. A cylindrical cover portion extending from the periphery and covering the compression coil spring with the knob; the cover portion having an inner diameter into which the knob can be inserted; and a plurality of axially extending inner peripheral surfaces It is also preferable that a vertical rib is formed, and a plurality of grooves are formed on the outer peripheral surface of the knob so as to receive the vertical rib in an axially slidable manner.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments of the present invention will be described in more detail with reference to the accompanying drawings. FIG. 1 is an overall perspective view of a chair according to the present invention, FIGS. 2 to 13 are detailed views of a mechanism part of the chair, in which 1 is a leg, 2 is a seat, 3 is a backrest, 4 is The spring unit, 5 is a mounting body, 6 is a back support member, and 7 is a seat support member.
[0010]
In the chair according to the present invention, the seat 2 is rotatably attached to the leg 1, the backrest 3 is attached to be tiltable back and forth, and the back of the seat 2 is moved up and down in conjunction with the operation of the backrest 3. It is configured to be movable, to be slidable back and forth, and with one spring unit 4, an elastic resistance force is simultaneously applied to the rearward tilting of the backrest portion 3 and the downward movement of the rear portion of the seat portion 2. .
[0011]
That is, in the chair according to the present invention, the lower end portion of the back support member 6 is attached to the lower portion of the center portion of the attachment body 5 attached to the leg portion 1 so as to be able to tilt forward and backward at the first pivotal attachment portion 8. The front portion of the seat support member 7 disposed substantially horizontally above the front of the attachment body 5 is connected to the front portion of the mounting body 5 so as to be slidable back and forth and swingable up and down, and the rear portion of the seat support member 7 and the backrest support member A portion different from the first pivoting portion 8 of 6 is rotatably connected by the second pivoting portion 9, and the strength of the backrest support member 6 can be adjusted with respect to the rear portion of the mounting body 5. The spring unit 4 is elastically biased in the forward tilt direction.
[0012]
The mounting body 5 is formed by integrally forming a steel plate material by press working, and has a box shape with an open top that rises from the bottom plate 10, and is inclined rearward and upward at least at the rear portions of the side plates 11 and 11 and the bottom plate 10. In this example, a flange portion 13 is formed around the upper edge so as to face the ancestor.
[0013]
More specifically, the attachment body 5 is formed with horizontally long openings 14 and 14 at the front portions of the side plates 11 and 11, and a collar 13 immediately above the opening 14 is cut up to form a stopper piece 15. Are formed on both sides, and notches 16 and 16 are formed on the rear portions of the side plates 11 and 11 over the flange 13. In addition, a circular hole 18 for attaching the upper end portion of the gas cylinder 17 erected on the leg portion 1 is formed at a position slightly rearward of the center portion of the bottom plate 10, and the bottom plate 10 and the inside of the attachment body 5 are formed. Is formed with a circular hole 20 in the central portion of the fixing member 19 fixed at intervals, and a fixed fixing tube 21 having a tapered diameter whose upper part is reduced so as to penetrate both the circular holes 18 and 20 is fixed. A tapered upper end portion of the gas cylinder 17 is fitted into the cylinder 21. Further, a support member 22 is fixed to the lower surface of the bottom plate 10 at a position slightly rearward of the center, and the first pivoting portion 8 is formed on the support plates 23 and 23 formed downward on both side edges of the support member 22. Support holes 25, 25 for inserting the support shaft 24 constituting the. Note that the positions of the support holes 25, 25 provided in the support member 22 are slightly in front of the gas cylinder 17.
[0014]
The backrest support member 6 is a member in which a backrest collar 26 is continuously or integrally formed at a rear portion, and a cushion body (not shown) is attached to an upper portion of the backrest collar 26 to constitute the backrest section 3. is there. The front portion of the backrest support member 6 extends obliquely forward and downward, and has connection plates 28 and 28 facing upward on both side edges of the main plate 27 constituting the back surface, and on the center side of the connection plates 28 and 28. Is formed in a generally triangular shape upward and wide, and a support hole 29 for inserting the support shaft 24 is formed in the front lower portion of the connecting plate 28, and the second pivot attachment is formed in the rear upper portion. A connecting hole 31 for inserting the support shaft 30 constituting the portion 9 is formed. Further, a notch opening 32 that is open forward to receive the gas cylinder 17 is formed at the front lower end of the main plate 27 of the back support member 6.
[0015]
The seat support member 7 is a member having a substantially U-shaped cross section in which side plates 34, 34 are extended downward on both sides of the upper surface plate 33, and a cushion body (not shown) is attached to the upper portion of the upper surface plate 33. 2 is constituted. The seat support member 7 has a lateral width that can receive the mounting body 5 between the side plates 34 and 34 and can be received between the connecting plates 28 and 28 of the back support member 6. In addition, through holes 36, 36 for attaching guide shafts 35 that are loosely fitted to the openings 14, 14 of the attachment body 5 are formed in the portions of the side plates 34, 34 that project downward from the front part. In the rear portions of the side plates 34, 34, notched grooves 37, 37 that open downward to receive the support shaft 30 are formed. More specifically, a cylindrical synthetic resin sleeve 38 is fitted on the guide shaft 35, and the upper surface plate 33 of the seat support member 7 is mounted on the upper end of the stopper piece 15 of the mounting body 5. In this state, the vertical width of the opening 14 is set so that the sleeve 38 can freely move back and forth within the opening 14. The guide shaft 35 may be protrusions protruding from both side plates 34, 34, respectively. The notch groove 37 is a bearing for rotatably fitting an introduction portion 37A having a minimum width necessary for inserting the support shaft 30 and a cylindrical synthetic resin sleeve 39 fitted on the support shaft 30. Part 37B. Then, in the maximum load state shown in FIG. 4, that is, sitting and leaning on the backrest 3, the backrest support member 6 tilts most backward and the rear portion of the seat support member 7 sinks while moving backward. In this state, when the sleeve 39 or the sleeve 39 is provided only at both ends of the support shaft 30, the support shaft 30 comes into contact with the buffer plate 40 attached to the upper surface of the fixing member 19. .
[0016]
Then, with the attachment body 5 attached to the upper end of the gas cylinder 17 of the leg 1, the back support member 6 is applied from below the rear of the attachment body 5, and the support plates 23, 23 of the support member 22 are attached. The support shaft 24 is inserted between and connected to the support holes 25 and 25 of the support plates 23 and 23 and the support holes 29 and 29 of the connection plates 28 and 28, which are positioned between the connection plates 28 and 28. At this time, synthetic resin sleeves 41 are fitted into the support holes 25 and 29 on both sides, respectively, and the support shaft 24 is inserted into the sleeve 41 so that no metallic noise is generated during rotation. Further, when the backrest support member 6 is most tilted backward, a stopper piece 42 is provided at the lower end of the support plates 23 and 23 so as to limit the further backward tilt, thereby supporting the backrest. Both ends of the main plate 27 of the member 6 are brought into contact with the stopper pieces 42.
[0017]
Then, the seat support member 7 is put on the attachment body 5 and the front part supports the upper plate 33 on the stopper pieces 15 and 15 and the guide shaft 35 is attached through the openings 14 and 14. The rear portion receives the support shaft 30 that has passed through the connecting holes 31, 31 of the back support member 6 in the notch grooves 37, 37, and a sleeve 39 that is externally fitted to the support shaft 30 is a bearing portion 37 </ b> B of the notch groove 37. And is connected in a vertically locked state. That is, the front portion of the seat support member 7 is connected to the front portion of the attachment body 5 so as to be slidable back and forth and swingable up and down.
[0018]
The engaging portion between the guide shaft 35 and the opening 14, the support shaft 24 constituting the first pivot attachment portion 8, and the support shaft 30 constituting the second pivot attachment portion 9 are located at the apex of the inverted triangle. When the backrest support member 6 tilts backward from the state shown in FIG. 3, the rear portion of the seat support member 7 moves downward along with the movement, and the seat support member 7 moves rearward as a whole, as shown in FIG. It will be in the state shown. In this case, the guide shaft 35 moves backward in the opening 14 while maintaining the contact piece 15 in contact with the lower surface of the upper surface plate 33.
[0019]
Next, the structure of the spring unit 4 and the structure of attaching the spring unit 4 to the chair main body in the chair back tilting apparatus according to the present invention will be described. Here, the spring unit 4 for elastically urging the backrest support member 6 in the forward tilt direction is backrested with respect to the bottom plate 10 of the mounting body 5 as shown in detail in FIGS. An elastic force is applied in the direction in which the main plate 27 of the support member 6 is attracted, and the strength of the elastic force can be adjusted. In addition, the spring unit 4 is separated as a single component so that it cannot be easily detached even though it can be easily mounted at a predetermined position, and can be easily disassembled for different materials. It is characterized by the fact that it can be discarded.
[0020]
That is, the spring unit 4 elastically biases the back support member 6 in the forward tilt direction with respect to the rear portion of the attachment body 5 attached to the leg portion 1, and has a base end portion on the knob 43 made of synthetic resin. A metal tension bar 44 with a screw is inserted into the stopper body 45, a compression coil spring 46 is interposed between the knob 43 and the stopper body 45, and a locking piece 47 is attached to the tip of the tension bar 44. It is formed so as to be substantially T-shaped.
[0021]
More specifically, a metal flanged nut member 49 having a long, for example, oval flange portion 50 is screwed into a screw shaft portion 48 formed at the base end portion of the tension rod 44, and the knob 43 A long mounting hole 51 that is substantially the same shape as the flange portion 50 and can pass through the flange portion 50 is formed, and the nut member 49 is inserted from the inside of the mounting hole 51 of the knob 43 and rotated by 90 degrees. The flange portion 50 is locked to the outside of the mounting hole 51, and a pair of leg pieces 53, 53 provided on the cap 52 that conceals the screw shaft portion 48 are placed in the mounting hole 51 remaining on both sides of the flange portion 50. The nut member 49 is attached to the knob 43 in a locked state. That is, the nut member 49 is attached to the knob 43 in a non-rotating state only by a fitting structure, and by rotating the knob 43, the nut member 49 can move forward and backward together with the knob 43 to adjust the elastic biasing force. ing. The nut member 49 is screwed into the screw shaft portion 48 of the tension rod 44 in advance before being assembled to the knob 43, and then the tip end of the screw shaft portion 48 is prevented from being pulled out. Reference numeral 54 in the drawing indicates a caulking portion of the screw shaft portion 48.
[0022]
Further, the knob 43 is a cylindrical member opened upward, and a cylindrical holding portion 55 for holding the nut member 49 is formed in the central portion so as to protrude to the inner side, and the compression is formed around it. An annular recess 56 that holds one end of the coil spring 46 is formed. The mounting hole 51 is formed in the bottom plate 57 located on the inner side of the holding portion 55.
[0023]
Further, a plurality of restriction ribs 58 extending in the axial direction are provided on the inner peripheral surface of the holding portion 55 of the knob 43, and the cap 52 is formed of a synthetic resin in a shape that fits into the holding portion 55. Are formed on the outer peripheral surface, and a plurality of vertical grooves 59 for receiving the regulating ribs 58 are formed on the outer peripheral surface, and a recessed step portion 60 for fitting the flange portion 50 of the nut member 49 between the leg pieces 53 is formed. Forming. Further, a claw portion 61 is formed on the outer surface of the tip end of the leg piece 53 of the cap 52, and the claw portion 61 is engaged with the inner side hole edge of the mounting hole 51 to prevent it from coming off. Here, since both the leg pieces 53 and 53 of the cap 52 are formed so as to have elasticity inside and outside, the leg pieces 53 and 53 are fitted in the mounting holes 51 on both sides of the flange portion 50. However, the rotation of the nut member 49 cannot be completely controlled, and when the rotational force is extremely strong, the leg pieces 53 and 53 are deformed or divided so that the cap 52 is detached from the holding portion 55, Accordingly, it is assumed that the flange portion 50 rotates and comes out of the mounting hole 51. Therefore, in the present invention, the vertical groove 59 of the cap 52 is fitted to the restriction rib 58 of the holding portion 55, thereby restricting the rotation of the cap 52 relative to the knob 43, and further to the concave step portion 60 of the cap 52. The rotation of the flange portion 50 with respect to the cap 52 is regulated by fitting 50. In order to separate the tension rod 44 and the nut member 49 from the knob 43, the cap 52 is detached from the holding portion 55 by pushing the claw portions 61 and 61 inward with the tip of a screwdriver. If this is the case, the flange portion 50 is rotated 90 degrees so as to come out of the mounting hole 51.
[0024]
On the other hand, the attachment body 5 is formed with an elongated hole 62 through which the engagement piece 47 can pass and an engagement recess 63 intersecting with the elongated hole 62, and the backrest support member 6 has the engagement portion 64. An opening 65 through which the piece 47 can pass and the stopper 45 cannot pass is formed, the tip end of the tension rod 44 is inserted into the opening 65 and the elongated hole 62, and the stopper 45 is supported on the backrest. 6, the tension rod 44 is rotated to engage the locking piece 47 with the engaging recess 63, and a part of the regulating body 66 is fitted and held in the elongated hole 62. Thus, the tension rod 44 is prevented from rotating.
[0025]
More specifically, the stopper body 45 of the spring unit 4 forms a circular hole 67 through which the locking piece 47 can pass in the center, and a stopper plate that can stop one end of the compression coil spring 46. 68, and a longitudinal groove 70 that slidably holds the tension rod 44 on the overlapping surface, and a tapered surface 71 that joins the circular hole 67 of the stopper plate 68 on the outer periphery of the lower portion. The upper end of the backrest support member 6 in the overlapped state is constituted by stop members 69 and 69 which can stop at the edge of the opening 65 of the back support member 6. Here, the bipartitioning stop members 69 and 69 are formed of an elastically deformable material such as hard rubber, and can be loosely inserted into the elongated hole 62 of the mounting body 5 at the upper end portion in a superposed state. Further, the stopper plate 68 has a cylindrical cover portion 72 extending from the periphery thereof, and the cover portion 72 and the knob 43 cover the compression coil spring 46. The cover portion 72 has an inner diameter that allows the knob 43 to be inserted therein, and the upper portion of the knob 43 is always inserted therein. In the present embodiment, the circular hole 67 is a tapered hole that is surface-bonded to the tapered surface 71.
[0026]
A plurality of longitudinal ribs 73 extending in the axial direction are formed on the inner peripheral surface of the cover portion 72 formed integrally with the stopper plate 68, while the vertical rib 73 is formed on the outer peripheral surface of the knob 43. A plurality of grooves 74,... That are slidable in the axial direction are formed. Thereby, the engagement between the vertical rib 73 and the groove 74 makes the knob 43 and the cover part 72 integrated with respect to rotation, and the elastic resistance force is adjusted regardless of which of the knob 43 and the cover part 72 is held. Can do. The lower corner of the knob 43 is rounded, but when the knob 43 is rotated to compress and compress the compression coil spring 46, the knob 43 enters the cover portion 72 deeply. At this time, a gap is formed between the rounded lower peripheral portion of the knob 43 and the opening edge of the cover portion 72. However, since the vertical ribs 73 are present, there is no possibility that the fingertip is caught in the gap. It is.
[0027]
Further, in the present embodiment, the restricting body 66 is composed of two split restricting bodies 75 and 75 that are fitted and integrated with each other in the state of being rotated 180 degrees with each other. Here, the split structure of the restricting body 66 is not particularly limited, but it is preferable that the restricting body 66 is constituted by the restricting body 75 shown in FIGS. Although it is necessary for extrapolation to the shaft portion of the tension rod 44 in which the stopper 47 is fixed and the nut member 49 is screwed with the other end being prevented from coming off, the nut member 49 is screwed later. In the case of assembling, it may be integrally molded. That is, the restricting body 66 of the present embodiment shown in FIG. 10 is locked to the back surface of the backrest support member 6 and can contact the stopper 45 through the opening 65 and has the tension at the center. A flange portion 77 in which an insertion hole 76 for inserting the flange 44 is formed, and the flange portion 77 extends from a position sandwiching the insertion hole 76 and can be fitted into the elongated hole 62 remaining on both sides of the tension rod 44. And a pair of fitting pieces 78 and 69 that can be locked to the upper end of the locking piece 47.
[0028]
More specifically, concave grooves 79, 79 that can be locked in a state where the locking piece 47 of the tension rod 44 is passed are formed at the tips of both the fitting pieces 78, 78 of the restricting body 66. Both the fitting pieces 78 and 78 and the locking piece 47 can be inserted into the elongated hole 62 from below while the locking piece 47 is locked in the concave grooves 79 and 79 of the pieces 78 and 78. Further, locking claw portions 80, 80 project inside the front end portions of the fitting pieces 78, 78 so that they can be locked to the upper ends of the locking pieces 47 dropped between the fitting pieces 78, 78. Has been established. In addition, the locking piece 47 of the tension rod 44 has a cross-sectionally inverted D shape in which the upper surface of the rod body is cut in a horizontal plane, and can be easily dropped between the fitting pieces 78, 78. 80 can be securely locked.
[0029]
As shown in FIGS. 8 and 9, the regulation body 75 constituting the regulation body 66 has a halved flange portion 77A in the lower portion, and both fitting pieces 78A and 78A are raised from the flange portion 77A. In addition, a recess 76A for forming the insertion hole 76 is formed in the inner edge of the flange portion 77A corresponding to both the fitting pieces 78A, 78A, and a locking claw is formed on the inner side of the upper portion of the one fitting piece 78A. The portion 80A is projected. A fitting recess 81A is formed up and down on one outer side of one fitting piece 78A, and the fitting has a shape capable of engaging with the fitting recess 81A on the other inner side of the other fitting piece 78A. A convex portion 82A is formed. In this way, one regulation body 75 with “A” and the other regulation body 75 with [B] as shown in FIG. 9 are inserted from both sides across the shaft portion of the tension rod 44. The flange portions 77A and 77B are fitted to each other to form the flange portion 77, and the fitting pieces 78A and 78B joined inside and outside form the fitting piece 78. The upper surface of the flange portion 77 has a conical shape with a thin periphery, and a concave groove 83 is formed in a portion corresponding to the lower surface of the engaging concave portion 63.
[0030]
Therefore, in order to assemble the spring unit 4, as shown in FIGS. 2 and 5 to 7, first, a tension member 44 in which a nut member 49 is screwed to the screw shaft portion 48 and a crimping portion 54 is formed at the tip thereof. Is inserted from above into the mounting hole 51 of the knob 43 from the nut member 49 side, and the nut member 49 is rotated 90 degrees to engage the flange portion 50 with the outer hole edge of the mounting hole 51 of the holding portion 55. Next, the cap 52 is fitted into the holding portion 55, both leg pieces 53, 53 are inserted into the mounting holes 51 remaining on both sides of the flange portion 50, and the claw portion 61 is inserted into the inner hole edge of the mounting hole 51. It is elastically engaged with the part. Then, after the compression coil spring 46 is wound around the tension rod 44 from the side of the locking piece 47 and one end thereof is fitted into the annular recess 56, the compression spring 46 is engaged with the circular hole 67 of the stopper plate 68 having the cover portion 72. The tension rod 44 is inserted from the stop piece 47 side, and one end of the compression coil spring 46 is stopped against the stop plate 68. Then, a split member 69, 55 having a tapered surface 71 is mounted on the outside of the tapered circular hole 67 with the longitudinal groove 70, 70 sandwiching the shaft portion of the tension rod 44, and the compression coil spring. While the compression member 46 is compressed, the restricting body 66 is mounted between the stopper members 69, 69 and the locking piece 47, and the locking piece 47 is engaged with the concave grooves 79, 79 of the fitting pieces 78, 78. Stop. In this state, even if the compressive force applied to the compression coil spring 46 is removed, the spring unit 4 maintains the state as it is. This completes the assembly of the spring unit 4 and the setting before mounting to the predetermined part.
[0031]
Then, as shown in FIG. 11, the locking piece 47 of the tension rod 44 is inserted into the opening 65 of the backrest support member 6 together with the fitting pieces 78 and 78 of the restricting body 66 from below, and further the attachment body 5 and the locking piece 47 is made to appear on the upper surface of the inclined portion 12 at the rear portion of the bottom plate 10 of the mounting body 5. Then, if the locking piece 47 is forcibly rotated around the tension rod 44 to remove the locking piece 47 from the concave grooves 79, 79, the locking piece 47 is moved by the elastic restoring force of the compression coil spring 46. 47 falls between the fitting pieces 78 and 78 and engages with the engaging recess 63, and at the same time, the locking claw portions 80 and 80 are brought into the removal state (see FIGS. 12 and 13). Here, the removal-prevented state means that both the fitting pieces 78 and 78 of the restricting body 66 are kept in the state of being fitted into the elongated holes 62 of the attachment body 5. By forcibly restricting the rotation of the locking piece 47 across the center portion of the locking piece 47, the locking piece 47 will not come out of the elongated hole 62.
[0032]
Next, the operation of the chair according to the present invention will be described. In the unloaded state shown in FIG. 3, i.e., the initial state in which the seat is not seated, the main plate 27 of the backrest support member 6 is inclined by the elastic biasing force of the compression coil spring 46 of the spring unit 4. The stopper member 69 of the stopper body 45 and the bottom plate 10 are in contact with each other. Further, between the inclined portion 12 of the attachment body 5 and the stopper member 69, a flange portion 77 of the restricting body 66 that passes through the opening 65 of the backrest support member 6 is sandwiched. Then, when sitting on the seat portion 2 and leaning on the backrest portion 3, the backrest support member 7 tilts backward about the first pivotal attachment portion 8, and accordingly, the rear portion of the seat support member 7. 4 sinks while being slightly displaced rearward, and finally reaches the maximum load state shown in FIG. 4, and the lower end of the sleeve 39 comes into contact with the buffer body 40 provided on the upper surface of the fixing member 19 of the mounting body 5. That is, the extremes of the movement change of the backrest support member 6 and the seat support member 7 are defined.
[0033]
Further, the upper portion of the tension rod 44 is sandwiched between the longitudinal grooves 70 and 70 of the two split-stop members 69 and 69, and the tapered surfaces 71 and 71 are fitted into the tapered circular holes 67 of the stop plate 68. Therefore, a sliding frictional force always acts between the longitudinal grooves 70 and 70 and the tension rod 44, and the frictional force becomes a braking force when the backrest support member 6 is tilted in the front-rear direction, and a sudden change occurs. It regulates. Further, this braking force gradually increases because the elastic force of the compression coil spring 46 increases as the backrest support member 6 tilts backward, and the force pressing both the longitudinal grooves 70, 70 against the tension rod 44 increases. Therefore, the resistance force against the backward tilting of the backrest support member 6 is the sum of the elastic force of the compression coil spring 46 and the braking force generated between the longitudinal grooves 70 and 70 and the tension rod 44. On the other hand, when the seated person rises from the rearward tilted state to the standing-up state, the load in the rearward tilt direction acting on the backrest support member 6 is rapidly reduced, and the backrest support member is caused by the elastic force of the compression coil spring 46. 6 attempts to quickly return to the initial state, but the return operation is moderated by the braking force generated between the two longitudinal grooves 70, 70 and the tension rod 44.
[0034]
【The invention's effect】
According to the chair backrest tilting device of the invention according to claim 1 as described above, the spring unit for elastically urging the backrest portion in the forward tilt direction is made of different materials of synthetic resin and metal. However, separation is easy at the time of disposal. In other words, if the cap leg is pushed in with the tip of a screwdriver, the cap will be removed from the inside of the holding part. In this state, the flange part can be rotated 90 degrees and easily removed from the mounting hole. The metal tension rod and the nut member can be separated and discarded.
[0035]
According to the second aspect, in addition to the above-described effect, since the vertical groove of the cap is fitted to the restriction rib of the holding portion, the rotation of the cap with respect to the knob is restricted, and the flange portion is further provided in the concave step portion of the cap. Since it is fitted, the rotation of the flange with respect to the cap is restricted, and the nut member can be securely attached to the knob in a state where the rotation of the nut is restricted, and even if the strength of the leg piece is weak, the torsional load is applied to the leg piece. The leg pieces are not damaged because they are not damaged.
[0036]
According to the third aspect, in addition to the above-described effect, the knob and the cover portion are integrated with respect to the rotation by the engagement of the vertical rib and the groove, and the nut member can be rotated regardless of whether the knob or the cover portion is held. Thus, the elastic resistance of the spring unit can be adjusted. When the knob is rotated and the compression coil spring is pushed and shrunk, the knob enters the cover part deeply, and when the corner part of the lower part of the knob is rounded, the lower peripheral part of the knob and the cover part There is a gap between the opening edges of the two, but since the vertical rib exists, there is no fear that the fingertip is caught in the gap.
[Brief description of the drawings]
FIG. 1 is an overall perspective view of a chair according to the present invention.
FIG. 2 is an exploded cross-sectional view showing a tilting mechanism and a spring unit of a backrest support member and a seat support member.
FIG. 3 is a longitudinal sectional view of a main part in an unloaded state.
FIG. 4 is a longitudinal sectional view of a main part in a maximum load state.
FIG. 5 is an exploded perspective view of a spring unit.
FIG. 6 is a perspective view of the knob.
7A and 7B show a state where a nut member with a flange is attached to a knob, where FIG. 7A is a partially omitted cross-sectional view seen from the top, and FIG. 7B is a cross-sectional view seen from below.
8A and 8B show a regulation body constituting the regulation body, in which FIG. 8A is a plan view, FIG. 8B is a side view, and FIG. 8C is a sectional view taken along line XX of FIG.
FIG. 9 is an exploded perspective view of a regulating body.
FIG. 10 is a perspective view of the regulating body.
FIG. 11 is a partial perspective view showing a state in which the spring unit is mounted on the back support member and the attachment body.
FIG. 12 is a partial perspective view showing a state in which the spring unit is similarly mounted on the back support member and the attachment body.
FIG. 13 is a partial plan view showing a state in which the spring unit is similarly mounted on the back support member and the attachment body.
[Explanation of symbols]
1 Leg 2 Seat
3 Backrest 4 Spring unit
5 Mounting body 6 Back support member
7 seat support member 8 first pivot part
9 Second pivot part 10 Bottom plate
11 Side plate 12 Inclined part
13 buttock 14 opening
15 Stopping piece 16 Notch
17 Gas cylinder 18 Round hole
19 Fixing member 20 Circular hole
21 Fixed cylinder 22 Support member
23 support plate 24 spindle
26 Backrest 27 Main plate
28 Connecting plate 29 Support hole
30 Support shaft 31 Connection hole
32 Notch opening 33 Top plate
34 Side plate 35 Guide shaft
36 through hole 37 notch
37A introduction part 37B bearing part
38 sleeve 39 sleeve
40 shock absorber 41 sleeve
42 Stopper piece 43 Knob
44 Tension bar 45 Stopper
47 Locking piece 48 Screw shaft
49 Nut member 50 Flange
51 Mounting hole 52 Cap
53 Leg piece 54 Caulking part
55 Holding part 56 Annular recess
57 Bottom plate 58 Regulating rib
59 Longitudinal groove 60 Concave step
61 Claw 62 Long hole
63 engaging recess 64 locking portion
65 Opening 66 Regulator
67 Circular hole 68 Stop plate
69 Stopping member 70 Vertical groove
71 Tapered surface 72 Cover part
73 Vertical ribs 74 Strip grooves
75 Regulated body 76 Insertion hole
76A Concave part 77 Flange part
78 Fitting piece 79 Concave groove
80 Locking claw part 81A Fitting recess
82A Fitting convex part 83 Concave groove

Claims (3)

脚部に取付けた取付体に対して背凭れ支持部材を前傾方向へ弾性付勢するばねユニットが、合成樹脂製のノブに基端部を螺着した金属製のテンション杆を、前記背凭れ支持部材の背面に当止した当止体に挿通するとともに、ノブと当止体間に圧縮コイルばねを介装し、前記テンション杆の先端部を前記背凭れ支持部材に貫通し且つ先端に形成した係止片を前記取付体に係着したものである椅子の背凭れ傾動装置であって、前記テンション杆の基端部に形成した螺軸部に、長形のフランジ部を有するフランジ付きナット部材を螺合するとともに、前記ノブに前記フランジ部と略同形で該フランジ部を通過可能な長形の装着孔を形成し、前記ナット部材をノブの装着孔の内部側から挿通し且つ９０度回転させてフランジ部を装着孔の外部側に係止するとともに、前記螺軸部を隠蔽するキャップに設けた一対の脚片を前記フランジ部の両側に残る装着孔内に嵌合係止し、前記ナット部材を回り止め状態でノブに取付けてなることを特徴とする椅子の背凭れ傾動装置。A spring unit that elastically biases the back support member in a forward tilt direction with respect to the attachment body attached to the leg portion, and a metal tension rod having a base end screwed to a synthetic resin knob, It is inserted into the stop that is stopped against the back of the support member, and a compression coil spring is interposed between the knob and the stop, and the tip of the tension rod penetrates the back support member and is formed at the tip. A backrest tilting device for a chair, wherein the locking piece is engaged with the mounting body, and a nut with a flange having a long flange portion on a screw shaft portion formed at a base end portion of the tension rod The member is screwed, and a long mounting hole that is substantially the same shape as the flange portion and can pass through the flange portion is formed in the knob, and the nut member is inserted from the inner side of the mounting hole of the knob and is 90 degrees. Rotate to lock the flange to the outside of the mounting hole In addition, a pair of leg pieces provided on a cap that conceals the screw shaft portion are fitted and locked in mounting holes remaining on both sides of the flange portion, and the nut member is attached to the knob in a non-rotating state. Chair backrest tilting device characterized by 前記ノブは、上方へ開放した筒状部材であり、中央部に前記ナット部材を保持するための下方開放した円筒形状の保持部を内部へ突出させて形成し、該保持部の底面板に前記装着孔を形成するとともに、内周面に軸方向へ延びた規制リブを複数突設したものであり、前記キャップは、前記保持部内に嵌合する形状に形成するとともに、外周面に前記規制リブを受け入れる複数の縦溝を形成し、更に前記両脚片間にナット部材のフランジ部を嵌合する凹段部を形成したものである請求項１記載の椅子の背凭れ傾動装置。The knob is a cylindrical member opened upward, and a cylindrical holding portion opened downward to hold the nut member is formed in the center portion so as to protrude inside, and the bottom plate of the holding portion The mounting hole is formed, and a plurality of restriction ribs extending in the axial direction are provided on the inner peripheral surface, and the cap is formed in a shape that fits in the holding portion, and the restriction rib is formed on the outer peripheral surface. The backrest tilting device for a chair according to claim 1, wherein a plurality of longitudinal grooves for receiving the flange are formed, and a concave step portion for fitting a flange portion of the nut member is formed between the both leg pieces. 前記ばねユニットの当止体は、中心部に前記係止片が通過可能な円形孔を形成し、前記圧縮コイルばねの一端を当止し得る当止板と、前記テンション杆をスライド可能に挟持し、下部外周に前記当止板の円形孔に接合するテーパー面を形成し且つ前記背凭れ支持部材の背面に当止する当止部材とから構成され、前記当止板には、その周囲から延び、前記ノブとで前記圧縮コイルばねを外覆する筒状カバー部を有し、該カバー部は前記ノブを内挿できる内径を有するとともに、内周面に軸方向へ延びた複数の縦リブを形成し、一方前記ノブの外周面には前記縦リブを軸方向スライド可能に受け入れる複数の条溝を形成してなる請求項１又は２記載の椅子の背凭れ傾動装置。The stopper of the spring unit is formed with a circular hole through which the locking piece can pass at the center, and a stopper plate capable of stopping one end of the compression coil spring and the tension rod are slidably held. And a stopper member that forms a tapered surface that joins the circular hole of the stopper plate on the outer periphery of the stopper plate and stops against the back surface of the backrest support member. A cylindrical cover portion extending and covering the compression coil spring with the knob, the cover portion having an inner diameter capable of inserting the knob, and a plurality of vertical ribs extending in the axial direction on the inner peripheral surface The chair backrest tilting device according to claim 1 or 2, wherein a plurality of grooves are formed on the outer peripheral surface of the knob so as to be slidable in the axial direction.

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