JP3689789B2

JP3689789B2 - Chair

Info

Publication number: JP3689789B2
Application number: JP2000113406A
Authority: JP
Inventors: 智士管; 信治井上
Original assignee: Itoki Corp
Current assignee: Itoki Corp
Priority date: 1999-09-20
Filing date: 2000-04-14
Publication date: 2005-08-31
Anticipated expiration: 2020-04-14
Also published as: JP2001157616A

Description

【０００１】
【発明の属する技術分野】
本発明は、椅子に係わり、更に詳しくは背凭れ部の後傾動に伴って座部の後部が沈みながら後方へスライド変位する椅子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。尚、この種の椅子に用いられる前記ばねユニットは、座部の下板に上端を係止した軸体に背凭れ支持部材の中間部を挿通し、該軸体に圧縮コイルばねを巻装するとともに、該軸体の下部にノブの回転に伴って回転するナット部材を螺合し、背凭れ支持部材とノブ又はナット部材の間に圧縮コイルばねを圧縮状態で保持した構造のものである。
【０００３】
また、座部が前後方向へスライド移動するとともに、背凭れ部が背凭れ支持杆の中間部で弾性的に屈曲する椅子も公知である。
【０００４】
しかし、前者の椅子は、ばねユニット自体は構造が簡単で、しかも座部の下部に突出した状態で設けられているので組み付けが比較的簡単であり、安価な椅子を構成できるものの、背凭れ部が前後傾動しても脚部に対する座部の角度が一定であるのでリクライニング姿勢が取り難い。また、後者の椅子は、リクライニング姿勢が取れるものの、背凭れ部と座部の動作が連動してはなく、またそれぞれに設けたばね機構が構成部材の内部に組み込まれている構造であるので高価なものとなっている。
【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、背凭れ部の後傾動に伴って座部の後部が連動して沈みながら後方へスライド変位してリクライニング姿勢が取れるとともに、背凭れ部の後傾動に対して弾性付勢するためのばね機構が簡単であり、また安価である椅子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、背凭れ支持部材が前後傾動可能であるとともに、座支持部材が前後スライド可能且つ上下揺動可能であり、且つ前記背凭れ支持部材と座支持部材が連動して動作し、強さが調節可能な一つのばねユニットで前記取付体に対して背凭れ支持部材を前傾方向へ弾性付勢してなる椅子であって、前記取付体は、底板から立ち上がった前板と両側板を有し、前板両側部に係合孔を形成するとともに、両側板の前部上端にスライダーを設けたものであり、前記座支持部材は、両側部に沿って前記取付体の両側板をそれぞれ収容可能であり且つスライダーを摺接する下向き開放した案内溝を形成するとともに、前端両側部に前記係合孔にスライド係合する係合片を前方へ突設したものであり、座支持部材の前部を取付体の前部に前後スライド可能且つ上下揺動可能に連結してなる椅子を構成した。
【０００７】
更に具体的には、本発明は、脚部に取付けた取付体の中央部下部に背凭れ支持部材の下端部を第１枢着部にて前後傾動可能に取付け、前記取付体の上位に略水平に配した座支持部材の前部を該取付体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、座支持部材の後部と前記背凭れ支持部材の第１枢着部とは異なる部分とを第２枢着部にて回動可能に連結し、前記取付体の後部に対して背凭れ支持部材を強さが調節可能なばねユニットで前傾方向へ弾性付勢してなる椅子を構成した。
【０００９】
また、前記ばねユニットは、前記取付体の下部に突出したものであり、前記背凭れ支持部材の後傾動と座支持部材の後部の下動に対して弾性抵抗力を同時に付与するものであると、ばね機構の構造が簡単になって椅子のコスト低減化に寄与する。
【００１０】
【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５は椅子の機構部分の詳細図、図６〜図８はばね機構を示し、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。
【００１１】
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。
【００１２】
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。
【００１３】
前記取付体５は、底板１０から立ち上がった前板１１と両側板１２，１２を有し、前板１１の両側部に縦長の係合孔１３，１３を形成するとともに、両側板１２，１２の前部上端にスライダー１４，１４を設けたものである。
【００１４】
更に詳しくは、前記取付体５には、前記前板１１と両側板１２，１２の上縁にわたって外側方へ鍔部１５を形成し、両側板１２，１２の前部に対応する該鍔部１５に切欠部１６，１６を形成し、この切欠部１６を利用して該鍔部１５に側方から外嵌した前記スライダー１４を前後方向の移動を規制している。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。
【００１５】
前記背凭れ支持部材６は、側面視略へ字形に屈曲した形状であり、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の下部は斜め前下方へ延び、背面を構成する主板２６の両側縁に上方へ向いた補強板２７，２７を有し、該補強板２７，２７の基端側には上方へ略三角形状となして幅広となった連結部２８，２８を形成し、該連結部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２６の下端部、即ち前記両連結部２８，２８間に位置する部分には、前記ガスシリンダー１７を受け入れる切欠開口３２を形成している。
【００１６】
前記座支持部材７は、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り、両側部に沿って前記取付体５の両側板１２，１２をそれぞれ鍔部１５とともに収容可能であり且つスライダー１４を摺接する下向き開放した案内溝３３，３３を形成するとともに、前端両側部に前記係合孔１３，１３にスライド係合する係合片３４，３４を前方へ突設したものである。更に詳しくは、基板３５の両側部を上方へ断面倒コ字形に突出させ、その外側板３６，３６を前記基板３５よりも下方へ延長して前記案内溝３３，３３を形成している。また、前記案内溝３３，３３部分は前記基板３５よりも前方へ延長してあり、その前方突出部の内側に前記外側板３６，３６とそれぞれ対面するように内側板３７，３７を基板３５よりも下方へ延長して形成し、該内側板３７，３７の前縁に前記係合片３４，３４を突設している。更に、前記外側板３６，３６の後部には、前記支軸３０を挿通するための連結孔３８，３８を形成している。また、前記案内溝３３，３３に対応する後部上面には、前記背凭れ支持部材６の連結部２８，２８の上端を受け入れ可能なスリット孔３９，３９を形成している。
【００１７】
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を両連結部２８，２８間に位置させ、支持板２３，２３の支持孔２５，２５と連結部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４０を嵌挿し、該スリーブ４０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。
【００１８】
それから、前記座支持部材７を取付体５に斜め後方から乗せ、座支持部材７の両案内溝３３，３３内に取付体５の両側板１２，１２、鍔部１５及びスライダー１４，１４をそれぞれ受け入れると同時に、座支持部材７の前記係合片３４，３４を取付体５の係合孔１３，１３にスライド係合させた後、背凭れ支持部材６の連結孔３１，３１と座支持部材７の連結孔３８，３８とに前記支軸３０を挿通して連結する。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。この際、それぞれ両側部で支持孔３１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３０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、前記両スリーブ４１，４１は内方へ延びており、図４に示した最大負荷状態、即ち着座して背凭れ部３に凭れ掛かって最も後傾した状態でスリーブ４１の下端が前記取付体５の固定部材１９の上面に当接するようになっている。この際、スリーブ４１は合成樹脂製であるので、各金属部材と接触しても金属音は発生しない。
【００１９】
前記係合片３４と係合孔１３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、座支持部材７の前後幅よりも前記係合片３４と係合孔１３との係合深さを深く設定しているので、その係合が外れることはない。また、座支持部材７の前後移動は、両案内溝３３，３３に摺接するスライダー１４，１４によって円滑に行われる。
【００２０】
そして、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３、図４、図６〜図８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２６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ようになしたことを特徴としている。
【００２１】
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、ノブ４２から延びたテンション杆４３を当止体４４に挿通するとともに、ノブ４２と当止体４４間に圧縮コイルばね４５を介装し、前記テンション杆４３の先端に係止片４６を略Ｔ字形となるように固着してなり、前記取付体５には前記係止片４６が通過可能な長形孔４８とそれに交叉する係合凹部４９からなる係止部４７を形成し、前記背凭れ支持部材６には前記係止片４６が通過可能且つ前記当止体４４が通過不能な開口５０を形成し、前記テンション杆４３の先端部を開口５０と長形孔４８に挿通し且つ前記当止体４４を背凭れ支持部材６の背面に当止した後、テンション杆４３を回転させて前記係止片４６を係合凹部４９に係合してなるものである。
【００２２】
更に詳しくは、前記ばねユニット４の当止体４４は、中心部に前記係止片４６が通過可能な円形孔５２を形成するとともに、前記圧縮コイルばね４５の一端を当止し得るリング板５１と、二つ割り部材であり、重合面５４に前記テンション杆４３をスライド可能に挟持する縦溝５５を形成するとともに、下部外周に前記リング板５１の円形孔５２に接合するテーパー面５６を形成し且つ重合状態で上部が前記背凭れ支持部材６の開口５０の縁部に当止可能な肩部５７を形成してなる当止部材５３，５３とから構成されている。尚、本実施形態では、前記円形孔５２は、テーパー面５６に面接合するテーパー孔で形成している。
【００２３】
更に、前記二つ割り当止部材５３，５３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４８に遊挿可能で、重合面５４に沿った方向に長形の突部５８を形成するとともに、該突部５８の上面に重合面５４に直交する方向に前記係止片４６を一時的に係止する凹溝５９Ａを形成し且つ両突部５８，５８の間に重合面５４に沿って前記係止片４６を収容する凹溝５９Ｂを形成している。
【００２４】
そして、前記テンション杆４３の下部に形成した螺軸部６０にナット部材６１を螺合するとともに、該ナット部材６１を前記ノブ４２に回り止め状態で保持し、該ノブ４２を回転することにより、弾性付勢力を調節できるようになっている。更に、前記ノブ４２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６１を保持する円筒形状の保持部６２を形成するとともに、その周囲に前記圧縮コイルばね４５の一端を保持する環状凹部６３を形成している。また、前記保持部６２の上面には前記係止片４６が通過可能で前記ナット部材６１のフランジ部６４が通過不能な装着孔６５を形成している。
【００２５】
そこで、前記ばねユニット４を組み立てるには、図６に示すように、先ずテンション杆４３の螺軸部６０にナット部材６１を螺合した後、該螺軸部６０の先端を潰して抜け止め部６６を形成する（図６（ａ）参照）。次に、テンション杆４３を先端部の係止片４６からノブ４２の下方より前記装着孔６５に挿通し、ナット部材６１を保持部６２に保持すると、ノブ４２から上方へテンション杆４３が突出した状態となる。そして、前記テンション杆４３に圧縮コイルばね４５を巻装し、その下端部を前記環状凹部６３に保持し、前記リング板５１の円形孔５２にテンション杆４３の係止片４６を遊挿して、圧縮コイルばね４５の上端に当止するとともに、圧縮コイルばね４５をリング板５１で圧縮しながら、リング板５１から突出したテンション杆４３の上部を前記二つ割り当止部材５３，５３で挟み込んで両縦溝５５，５５で挟持すると同時に、当止部材５３，５３のテーパー面５６，５６を前記円形孔５２に嵌合する（図６（ｂ），（ｃ）参照）。更に、前記テンション杆４３を回転させて、係止片４６を突部５８，５８の長手方向に向けその上面の凹溝５９Ａ，５９Ａで保持する（図６（ｃ）参照）。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。
【００２６】
そして、図７に示すように、図６（ｃ）の状態のばねユニット４の係止片４６を突部５８，５８とともに前記背凭れ支持部材６の開口５０に挿入し、更に取付体５の長形孔４８に挿入し、前記係止片４６を取付体５の底板１０の上面に出現させる。それから、テンション杆４３のみを回転させて前記係止片４６を突部５８，５８の上端から外して凹溝５９Ｂに収容すると同時に係合凹部４９に係合させるのである（図８参照）。
【００２７】
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の圧縮コイルバネ４５の弾性付勢力によって背凭れ支持部材６の主板２６が取付体５の底板１０に最も接近し、当止体４４に該底板１０が接触している。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４１の下端が前記取付体５の固定部材１９の上面に当接する。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。
【００２８】
また、前記二つ割り当止部材５３，５３の両縦溝５５，５５でテンション杆４３の上部を挟持し、しかもテーパー面５６，５６をリング板５１のテーパー状円形孔５２に嵌合していることから、両縦溝５５，５５とテンション杆４３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バネ４５の弾性力が大きくなって両縦溝５５，５５をテンション杆４３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、圧縮コイルバネ４５の弾性力と、両縦溝５５，５５とテンション杆４３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、圧縮コイルバネ４５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５５，５５とテンション杆４３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。
【００２９】
また、図9に示した変形例は、前記ばねユニット４の当止体４４の構造が異なり、それに伴って前記背凭れ支持部材６の開口５０の形状を変えたものであり、前述の実施形態のものより構造を簡単にしたものである。つまり、前記当止体４４は、中心部に前記係止片４６が通過可能な段落ち円形孔５２を形成するとともに、前記圧縮コイルばね４５の一端を円形孔５２の周囲の突出段部６８に外嵌状態で当止し得るリング板６７と、前記同様に二つ割り部材であり、重合面５４に前記テンション杆４３をスライド可能に挟持する縦溝５５を形成するとともに、下部外周に前記リング板５１の円形孔５２に接合するテーパー面５６を形成してなる当止部材６９，６９とから構成されている。ここで、前記ナット部材６１は、通常のナットであり、更に螺軸部６０の先端は潰すことなく、そのままの状態にしているので、前記装着孔６５は螺軸部６０を貫通するだけの小孔にしている。また、前記背凭れ支持部材６の開口５０は、単に係止片４６を挿通するだけであるので、必要最小限の長形の形状になっている。この場合、前記長形孔４８と開口５０を直交する方向に形成すれば、両者の重なり部分にテンション杆４３が位置するので、テンション杆４３の保持が確実である。
【００３０】
【発明の効果】
以上にしてなる請求項１に係る発明の椅子は、脚部に取付けた取付体に対して、背凭れ支持部材が前後傾動可能であるとともに、座支持部材が前後スライド可能且つ上下揺動可能であり、且つ前記背凭れ支持部材と座支持部材が連動して動作し、強さが調節可能な一つのばねユニットで前記取付体に対して背凭れ支持部材を前傾方向へ弾性付勢してなる椅子であって、前記取付体は、底板から立ち上がった前板と両側板を有し、前板両側部に係合孔を形成するとともに、両側板の前部上端にスライダーを設けたものであり、前記座支持部材は、両側部に沿って前記取付体の両側板をそれぞれ収容可能であり且つスライダーを摺接する下向き開放した案内溝を形成するとともに、前端両側部に前記係合孔にスライド係合する係合片を前方へ突設したものであり、座支持部材の前部を取付体の前部に前後スライド可能且つ上下揺動可能に連結してなるので、一つのばねユニットによって、前記背凭れ支持部材の後傾動と座支持部材の後部の下動に対して弾性抵抗力を同時に付与することができ、背凭れ部と座部の変化に対して弾性付勢するためのばね機構が簡単になり、コスト低減化を図ることができ、更に取付体に対する座支持部材の連結が極めて簡単であり、更に背凭れ支持部材の後傾動に伴って座支持部材の後部が連動して沈みながら後方へスライド変位させることができ、しかもその動作が極めて円滑である。
【００３１】
請求項２によれば、背凭れ部の後傾動に伴って座部の後部が連動して沈みながら後方へスライド変位してリクライニング姿勢が取れるとともに、背凭れ部の後傾動に対して弾性付勢するためのばね機構が簡単であり、コスト低減化を図ることができる。
【００３３】
請求項３によれば、一つのばねユニットによって、前記背凭れ支持部材の後傾動と座支持部材の後部の下動に対して弾性抵抗力を同時に付与することができ、しかも前記取付体の下部にばねユニットが突出した状態で取付けるので組み立てが簡単であり、椅子全体の更なるコスト低減化を図ることができる。
【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を示す分解斜視図である。
【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】背凭れ支持部材と座支持部材の傾動機構を示す平面図である。
【図６】ばねユニットの組み立て工程を示した説明用斜視図である。
【図７】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８】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９】ばねユニットを含む弾性付勢機構の変形例を示す要部の縦断面図である。
【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前板１２側板
１３係合孔１４スライダー
１５鍔部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
２５支持孔２６主板
２７補強板２８連結部
２９支持孔３０支軸
３１支持孔３２切欠開口
３３案内溝３４係合片
３５基板３６外側板
３７内側板３８連結孔
３９スリット孔４０スリーブ
４１スリーブ４２ノブ
４３テンション杆４４当止体
４５圧縮コイルバネ４６係止片
４７係止部４８長形孔
４９係合凹部５０開口
５１リング板５２円形孔
５３当止部材５４重合面
５５縦溝５６テーパー面
５７肩部５８突部
５９Ａ，５９Ｂ凹溝６０螺軸部
６１ナット部材６２保持部
６３環状凹部６４フランジ部
６５装着孔６６抜け止め部
６７リング板６８突出段部
６９当止部材[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a chair, and more particularly to a chair that slides backward while the rear portion of a seat portion sinks as the backrest tilts backward.
[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. The spring unit used in this type of chair is such that the middle part of the back support member is inserted into a shaft body whose upper end is locked to the lower plate of the seat portion, and a compression coil spring is wound around the shaft body. In addition, a nut member that rotates with the rotation of the knob is screwed into the lower portion of the shaft body, and a compression coil spring is held in a compressed state between the backrest support member and the knob or nut member.
[0003]
Also known is a chair in which the seat portion slides in the front-rear direction and the backrest portion elastically bends at the middle portion of the backrest support rod.
[0004]
However, in the former chair, the spring unit itself has a simple structure, and it is provided in a state protruding from the lower part of the seat part, so that it is relatively easy to assemble and can constitute an inexpensive chair. Even if it tilts back and forth, the angle of the seat with respect to the leg is constant, so it is difficult to take a reclining posture. Although the latter chair can be in a reclining posture, the backrest and seat do not operate in conjunction with each other, and the spring mechanism provided for each of them is a structure that is built into the components, and is expensive. It has become a thing.
[0005]
[Problems to be solved by the invention]
Therefore, in view of the above situation, the present invention intends to solve the problem that the rear part of the seat part sinks in conjunction with the backward tilt of the backrest part and slides backward to take a reclining posture. A spring mechanism for urging elastically against the rearward tilting of the bent part is simple and inexpensive.
[0006]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, the present invention is such that the backrest support member can tilt back and forth with respect to the attachment body attached to the leg, and the seat support member can slide back and forth and swing up and down. chairs and the work in conjunction is backrest carrier and the seat supporting member, formed by elastically urging the backrest carrier to forward tilting direction with respect to the attachment body with adjustable one spring unit strength The mounting body has a front plate and both side plates rising from the bottom plate, and has an engagement hole on both sides of the front plate and a slider on the upper end of the front portion of both side plates, The seat support member can accommodate both side plates of the mounting body along both side portions, and forms a downwardly opened guide groove that slides on the slider, and slide-engages with the engagement hole on both side portions of the front end. With an engaging piece protruding forward There were constructed chair comprising slidably and linked vertically swingably back and forth the front of the seat support member to the front of the mounting body.
[0007]
More specifically, the present invention attaches the lower end portion of the backrest support member to the lower portion of the center portion of the attachment body attached to the leg portion so as to be able to tilt forward and backward at the first pivotally attached portion, and is substantially above the attachment body. The front part of the seat support member arranged horizontally is connected to the front part of the mounting body so as to be slidable back and forth and swing up and down, and the rear part of the seat support member and the first pivot part of the back support member Different parts are connected to each other by a second pivoting portion, and the backrest support member is elastically biased in a forward tilt direction by a spring unit whose strength can be adjusted with respect to the rear portion of the mounting body. Made up a chair.
[0009]
Further, the spring unit protrudes from the lower part of the attachment body, and simultaneously applies an elastic resistance force to the back tilt of the back support member and the downward movement of the rear portion of the seat support member. The structure of the spring mechanism is simplified, which contributes to the cost reduction of the chair.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments of the present invention will be described in more detail with reference to the accompanying drawings. 1 is an overall perspective view of a chair according to the present invention, FIGS. 2 to 5 are detailed views of a mechanism portion of the chair, FIGS. 6 to 8 show a spring mechanism, reference numeral 1 is a leg portion, and 2 is a seat portion. 3 is a backrest part, 4 is a spring unit, 5 is a mounting body, 6 is a backrest support member, and 7 is a seat support member.
[0011]
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. .
[0012]
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.
[0013]
The mounting body 5 includes a front plate 11 and both side plates 12, 12 rising from the bottom plate 10, and longitudinally engaging holes 13, 13 are formed on both sides of the front plate 11. Sliders 14 are provided at the upper end of the front part.
[0014]
More specifically, a flange 15 is formed on the mounting body 5 outwardly over the upper edges of the front plate 11 and the side plates 12, 12, and the flange 15 corresponding to the front portions of the side plates 12, 12. Notches 16 and 16 are formed in the upper and lower portions, and the slider 14 that is externally fitted to the flange 15 is restricted from moving in the front-rear direction by using the notches 16. 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.
[0015]
The backrest support member 6 has a substantially bent shape when viewed from the side. A cushion body (not shown) is attached to the upper portion to constitute the backrest portion 3. The lower part of the back support member 6 extends obliquely forward and downward, and has reinforcing plates 27 and 27 directed upward on both side edges of the main plate 26 constituting the back surface, and on the base end side of the reinforcing plates 27 and 27. The connecting portions 28 and 28 are formed in a generally triangular shape and widened upward, and a support hole 29 for inserting the support shaft 24 is formed in the lower front portion of the connecting portion 28 and in the upper rear portion. Is formed with a connecting hole 31 through which the support shaft 30 constituting the second pivot attachment portion 9 is inserted. Further, a notch opening 32 for receiving the gas cylinder 17 is formed at the lower end of the main plate 26 of the backrest support member 6, that is, at a portion located between the connecting portions 28 and 28.
[0016]
The seat support member 7 constitutes the seat portion 2 by attaching a cushion body (not shown) to the upper portion, and can accommodate both side plates 12 and 12 of the attachment body 5 together with the flange portion 15 along both side portions. In addition, the guide grooves 33 and 33 that are open downward to slidably contact the slider 14 are formed, and the engagement pieces 34 and 34 that are slidably engaged with the engagement holes 13 and 13 are provided on both sides of the front end so as to project forward. It is. More specifically, both side portions of the substrate 35 are projected upward in an inverted U-shaped cross section, and the outer plates 36 and 36 are extended downward from the substrate 35 to form the guide grooves 33 and 33. Further, the guide grooves 33 and 33 extend forward from the substrate 35, and the inner plates 37 and 37 are arranged from the substrate 35 so as to face the outer plates 36 and 36, respectively, inside the front projecting portion. The engaging pieces 34 and 34 project from the front edges of the inner plates 37 and 37. Further, connection holes 38 and 38 for inserting the support shaft 30 are formed in the rear portions of the outer plates 36 and 36. In addition, slit holes 39 and 39 that can receive the upper ends of the connecting portions 28 and 28 of the back support member 6 are formed on the rear upper surface corresponding to the guide grooves 33 and 33.
[0017]
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 into 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 portions 28 and 28. At this time, sleeves 40 made of synthetic resin are fitted into both support holes 25 and 29 on both sides, respectively, and the support shaft 24 is inserted into the sleeve 40 so as not to generate metal sound during rotation.
[0018]
Then, the seat support member 7 is put on the mounting body 5 from the oblique rear side, and both side plates 12, 12, the flange 15 and the sliders 14, 14 of the mounting body 5 are placed in both guide grooves 33, 33 of the seat support member 7, respectively. At the same time as receiving, the engaging pieces 34, 34 of the seat support member 7 are slidably engaged with the engagement holes 13, 13 of the mounting body 5, and then the connection holes 31, 31 of the back support member 6 and the seat support member The support shaft 30 is inserted into and connected to the seven connection holes 38, 38. 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. At this time, a sleeve 41 made of a synthetic resin is fitted into the support holes 31 on both sides, and the support shaft 30 is inserted into the sleeve 41 so that no metallic noise is generated during rotation. The sleeves 41 and 41 extend inward, and the lower end of the sleeve 41 is attached to the mounting position in the maximum load state shown in FIG. The upper surface of the fixing member 19 of the body 5 is brought into contact with the upper surface. At this time, since the sleeve 41 is made of synthetic resin, no metal sound is generated even if it comes into contact with each metal member.
[0019]
The engagement portion between the engagement piece 34 and the engagement hole 13, the support shaft 24 constituting the first pivot attachment portion 8, and the support shaft 30 constituting the second pivot attachment portion 9 are positioned 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. The state shown in FIG. 4 is obtained. In this case, the engagement depth between the engagement piece 34 and the engagement hole 13 is set deeper than the front-rear width of the seat support member 7, so that the engagement is not released. The seat support member 7 is smoothly moved back and forth by the sliders 14 and 14 that are in sliding contact with the guide grooves 33 and 33.
[0020]
The spring unit 4 for elastically urging the backrest supporting member 6 in the forward tilt direction includes a bottom plate 10 of the mounting body 5 as shown in detail in FIGS. 3, 4, and 6 to 8. On the other hand, an elastic force is applied in the direction in which the main plate 26 of the backrest support member 6 is attracted, and the strength of the elastic force can be adjusted. Further, the spring unit 4 is characterized in that it can be easily mounted at a predetermined position after being assembled as one component.
[0021]
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 applies the tension rod 43 extending from the knob 42. The stopper 44 is inserted into the stopper 44, and a compression coil spring 45 is interposed between the knob 42 and the stopper 44, and the locking piece 46 is fixed to the tip of the tension rod 43 so as to be substantially T-shaped. The attachment body 5 is formed with an elongated hole 48 through which the engagement piece 46 can pass and an engagement recess 49 intersecting with the elongated hole 48, and the backrest support member 6 has the engagement piece 46. An opening 50 through which the stopper body 44 cannot pass is formed, the tip end portion of the tension rod 43 is inserted into the opening 50 and the elongated hole 48, and the stopper body 44 of the back support member 6 is inserted. After stopping against the back, rotate the tension rod 43 to stop 46 in which engage comprising the engaging recess 49.
[0022]
More specifically, the stopper body 44 of the spring unit 4 forms a circular hole 52 through which the locking piece 46 can pass in the center, and a ring plate 51 that can stop one end of the compression coil spring 45. A longitudinal groove 55 that slidably holds the tension rod 43 on the overlapping surface 54, and a tapered surface 56 that joins the circular hole 52 of the ring plate 51 on the outer periphery of the lower part, and The upper part of the backrest support member 6 in a superposed state is constituted by stopper members 53 and 53 formed with shoulder portions 57 that can stop against the edge of the opening 50 of the back support member 6. In the present embodiment, the circular hole 52 is a tapered hole that is surface-bonded to the tapered surface 56.
[0023]
Further, the bipartitioning stop members 53, 53 are formed of an elastically deformable material such as hard rubber and can be loosely inserted into the elongated hole 48 of the mounting body 5 at the upper end portion in a superposed state. A long protrusion 58 is formed in the extending direction, and a concave groove 59A is formed on the upper surface of the protrusion 58 to temporarily lock the locking piece 46 in a direction perpendicular to the overlapping surface 54. A concave groove 59 </ b> B that accommodates the locking piece 46 is formed between the protrusions 58 and 58 along the overlapping surface 54.
[0024]
Then, the nut member 61 is screwed to the screw shaft portion 60 formed in the lower part of the tension rod 43, and the nut member 61 is held in a non-rotating state by the knob 42, and the knob 42 is rotated, The elastic biasing force can be adjusted. Further, the knob 42 is a cylindrical member opened upward, and a cylindrical holding portion 62 for holding the nut member 61 is formed at the center portion, and one end of the compression coil spring 45 is held around the cylindrical holding portion 62. An annular recess 63 is formed. Further, a mounting hole 65 through which the locking piece 46 can pass and the flange portion 64 of the nut member 61 cannot pass is formed on the upper surface of the holding portion 62.
[0025]
Therefore, in order to assemble the spring unit 4, as shown in FIG. 6, first, the nut member 61 is screwed onto the screw shaft portion 60 of the tension rod 43, and then the tip end of the screw shaft portion 60 is crushed to prevent the spring unit 4 from coming off. 66 is formed (see FIG. 6A). Next, when the tension rod 43 is inserted from the locking piece 46 at the tip portion into the mounting hole 65 from below the knob 42 and the nut member 61 is held by the holding portion 62, the tension rod 43 protrudes upward from the knob 42. It becomes a state. Then, the compression coil spring 45 is wound around the tension rod 43, the lower end portion thereof is held in the annular recess 63, the locking piece 46 of the tension rod 43 is loosely inserted into the circular hole 52 of the ring plate 51, The upper end of the tension spring 43 protruding from the ring plate 51 is sandwiched between the two split stop members 53 and 53 while being pressed against the upper end of the compression coil spring 45 and compressed with the ring plate 51. At the same time as being sandwiched by the grooves 55, 55, the tapered surfaces 56, 56 of the stopper members 53, 53 are fitted into the circular holes 52 (see FIGS. 6B and 6C). Further, the tension rod 43 is rotated to hold the locking piece 46 in the longitudinal direction of the projections 58, 58 by the concave grooves 59A, 59A on the upper surface thereof (see FIG. 6C). This completes the assembly of the spring unit 4 and the setting before mounting to the predetermined part.
[0026]
Then, as shown in FIG. 7, the locking piece 46 of the spring unit 4 in the state of FIG. 6C is inserted into the opening 50 of the backrest support member 6 together with the protrusions 58 and 58, and The locking piece 46 is inserted into the long hole 48 and appears on the upper surface of the bottom plate 10 of the mounting body 5. Then, only the tension rod 43 is rotated so that the locking piece 46 is removed from the upper ends of the projections 58, 58 and accommodated in the concave groove 59B, and at the same time engaged with the engagement concave portion 49 (see FIG. 8).
[0027]
Next, the operation of the chair according to the present invention will be described. In the unloaded state shown in FIG. 3, that is, the initial state in which the seat is not seated, the main plate 26 of the backrest support member 6 comes closest to the bottom plate 10 of the mounting body 5 by the elastic biasing force of the compression coil spring 45 of the spring unit 4. The bottom plate 10 is in contact with the stop body 44. 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 41 contacts 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.
[0028]
Further, the upper part of the tension rod 43 is sandwiched between the longitudinal grooves 55 and 55 of the bipartitioning members 53 and 53, and the tapered surfaces 56 and 56 are fitted into the tapered circular hole 52 of the ring plate 51. Therefore, a sliding frictional force always acts between the longitudinal grooves 55 and 55 and the tension rod 43, and the frictional force acts as a braking force when the backrest support member 6 is tilted in the front-rear direction to restrict a sudden change. To do. Further, this braking force gradually increases because the elastic force of the compression coil spring 45 increases as the backrest support member 6 tilts backward, and the force pressing the both longitudinal grooves 55, 55 against the tension rod 43 increases. Therefore, the resistance force against the backward tilt of the backrest support member 6 is the sum of the elastic force of the compression coil spring 45 and the braking force generated between the longitudinal grooves 55, 55 and the tension rod 43. 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 6 is supported by the elastic force of the compression coil spring 45. Tries to quickly return to the initial state, but the return operation is moderated by the braking force generated between the two longitudinal grooves 55, 55 and the tension rod 43.
[0029]
Further, in the modification shown in FIG. 9, the structure of the stopper 44 of the spring unit 4 is different, and the shape of the opening 50 of the back support member 6 is changed accordingly. The structure is simpler than the one. That is, the stopper 44 has a stepped circular hole 52 through which the locking piece 46 can pass at the center, and one end of the compression coil spring 45 is formed on the protruding step 68 around the circular hole 52. A ring plate 67 that can be stopped in an externally fitted state, and a split member similar to the above, and a vertical groove 55 that slidably holds the tension rod 43 is formed on the overlapping surface 54, and the ring plate 51 on the outer periphery of the lower portion. It is comprised from the stop member 69 and 69 which form the taper surface 56 joined to the circular hole 52 of this. Here, the nut member 61 is a normal nut, and the tip of the screw shaft portion 60 is not crushed and is left as it is. Therefore, the mounting hole 65 is small enough to penetrate the screw shaft portion 60. It is a hole. Further, the opening 50 of the backrest support member 6 is simply inserted through the locking piece 46, and thus has a minimum required long shape. In this case, if the elongated hole 48 and the opening 50 are formed in a direction orthogonal to each other, the tension rod 43 is positioned at the overlapping portion between the two, so that the tension rod 43 is reliably held.
[0030]
【The invention's effect】
In the chair according to the first aspect of the present invention, the backrest support member can tilt back and forth with respect to the attachment body attached to the leg, and the seat support member can slide back and forth and can swing up and down. The backrest support member and the seat support member operate in conjunction with each other, and the backrest support member is elastically biased forwardly with respect to the attachment body by one spring unit whose strength can be adjusted. The mounting body has a front plate and both side plates raised from the bottom plate, and has an engagement hole in both side portions of the front plate and a slider at the upper end of the front portion of both side plates. The seat support member can accommodate both side plates of the mounting body along both side portions, and forms a downwardly opened guide groove that slides on the slider, and slides into the engagement hole on both side portions of the front end. Engaging engagement pieces project forward And is intended, therefore formed by connecting the front of the seat support member movably backward slidable and vertically swinging the front of the mounting member, by a single spring unit, tilt the seat support after said backrest carrier An elastic resistance force can be simultaneously applied to the downward movement of the rear part of the member, and the spring mechanism for elastically urging against the change of the backrest part and the seat part becomes simple, and the cost can be reduced. In addition, the seat support member can be easily connected to the mounting body, and the rear part of the seat support member can be slid backward while sinking in conjunction with the back tilt of the back support member. Its operation is extremely smooth.
[0031]
According to the second aspect of the present invention, the rear part of the seat part sinks in conjunction with the backward tilt of the backrest part and slides backward to take a reclining posture, and is elastically biased against the backward tilt of the backrest part. The spring mechanism for doing so is simple, and the cost can be reduced.
[0033]
According to the third aspect of the present invention, an elastic resistance force can be simultaneously applied to the back tilting of the back support member and the downward movement of the rear portion of the seat support member by one spring unit, and the lower part of the mounting body. Since the spring unit is mounted in a protruding state, the assembly is easy, and the cost of the entire chair can be further reduced.
[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 perspective view showing a tilting mechanism 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 a plan view showing a tilting mechanism of a backrest support member and a seat support member.
FIG. 6 is an explanatory perspective view showing an assembly process of the spring unit.
FIG. 7 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. 8 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. 9 is a longitudinal sectional view of an essential part showing a modified example of an elastic biasing mechanism including a spring unit.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Leg part 2 Seat part 3 Back part 4 Spring unit 5 Attachment body 6 Back support member 7 Seat support member 8 1st pivot part 9 2nd pivot part 10 Bottom board 11 Front board 12 Side board 13 Engagement hole 14 Slider 15 flange part 16 notch part 17 gas cylinder 18 circular hole 19 fixing member 20 circular hole 21 fixed cylinder 22 support member 23 support plate 24 support shaft 25 support hole 26 main plate 27 reinforcement plate 28 connection part 29 support hole 30 support shaft 31 support hole 32 Notch opening 33 Guide groove 34 Engagement piece 35 Substrate 36 Outer plate 37 Inner plate 38 Connection hole 39 Slit hole 40 Sleeve 41 Sleeve 42 Knob 43 Tension bar 44 Stopping body 45 Compression coil spring 46 Locking piece 47 Locking part 48 Long Shaped hole 49 Engaging recess 50 Opening 51 Ring plate 52 Circular hole 53 Stopping member 54 Superposition surface 55 Vertical groove 56 Tapered surface 57 Shoulder 58 Projection 59A, 59B recessed groove 60 threaded shaft portion 61 a nut member 62 exits the holding portion 63 annular recess 64 flange portion 65 mounting hole 66 stop portion 67 the ring plate 68 protruding step 69 abutting-stops member

Claims

脚部に取付けた取付体に対して、背凭れ支持部材が前後傾動可能であるとともに、座支持部材が前後スライド可能且つ上下揺動可能であり、且つ前記背凭れ支持部材と座支持部材が連動して動作し、強さが調節可能な一つのばねユニットで前記取付体に対して背凭れ支持部材を前傾方向へ弾性付勢してなる椅子であって、前記取付体は、底板から立ち上がった前板と両側板を有し、前板両側部に係合孔を形成するとともに、両側板の前部上端にスライダーを設けたものであり、前記座支持部材は、両側部に沿って前記取付体の両側板をそれぞれ収容可能であり且つスライダーを摺接する下向き開放した案内溝を形成するとともに、前端両側部に前記係合孔にスライド係合する係合片を前方へ突設したものであり、座支持部材の前部を取付体の前部に前後スライド可能且つ上下揺動可能に連結してなることを特徴とする椅子。The backrest support member can be tilted back and forth with respect to the mounting body attached to the leg, and the seat support member can slide back and forth and swing up and down, and the backrest support member and the seat support member are interlocked. The chair is formed by elastically urging the backrest supporting member in the forward tilt direction with respect to the mounting body with a single spring unit that can be adjusted in strength and the mounting body rises from the bottom plate. A front plate and both side plates, engaging holes are formed on both side portions of the front plate, and a slider is provided on the upper end of the front portion of each side plate. Each of the side plates of the mounting body can be accommodated, and a downwardly opening guide groove that slides on the slider is formed, and engaging pieces that slide-engage with the engaging holes on both sides of the front end project forward. Yes, the front part of the seat support member Chair and characterized by being linked to slidably and vertically swung back and forth parts.

前記脚部に取付けた取付体の中央部下部に前記背凭れ支持部材の下端部を第１枢着部にて前後傾動可能に取付け、前記取付体の上位に略水平に配した前記座支持部材の前部を該取付体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、座支持部材の後部と前記背凭れ支持部材の第１枢着部とは異なる部分とを第２枢着部にて回動可能に連結し、前記取付体の後部に対して背凭れ支持部材を強さが調節可能なばねユニットで前傾方向へ弾性付勢してなる請求項１記載の椅子。 The seat support member is attached to the lower part of the center part of the attachment body attached to the leg part so that the lower end of the back support member can be tilted back and forth at the first pivotally attached portion, and is arranged substantially horizontally above the attachment body. The front part of the seat support member is connected to the front part of the mounting body so as to be slidable back and forth and swingable up and down, and a rear part of the seat support member and a part different from the first pivot part of the back support member are connected to the second pivot. The chair according to claim 1, wherein the chair is connected to the wearing portion so as to be rotatable, and the backrest supporting member is elastically biased in a forward tilt direction by a spring unit capable of adjusting the strength with respect to the rear portion of the attachment body.

前記ばねユニットは、前記取付体の下部に突出したものであり、前記背凭れ支持部材の後傾動と座支持部材の後部の下動に対して弾性抵抗力を同時に付与するものである請求項１又は２何れかに記載の椅子。2. The spring unit projects from a lower portion of the attachment body, and simultaneously applies an elastic resistance force to a backward tilt of the back support member and a downward motion of a rear portion of the seat support member. Or the chair in any one of 2 .