JP3775534B2

JP3775534B2 - Sewing machine differential feeder

Info

Publication number: JP3775534B2
Application number: JP18756597A
Authority: JP
Inventors: 信介長坂; 秀高稲垣; 克也渡会
Original assignee: Brother Industries Ltd
Current assignee: Brother Industries Ltd
Priority date: 1997-06-26
Filing date: 1997-06-26
Publication date: 2006-05-17
Anticipated expiration: 2017-06-26
Also published as: JPH119865A

Description

【０００１】
【発明の属する技術分野】
本発明は、ミシンの差動送り装置に関し、特に、差動送り歯部材が主送り歯部材と一体的に送り作動する第１状態と、差動送り歯部材が主送り歯部材の送り量に対して所定倍の送り量で送り作動する第２状態とに切換え可能に構成したものに関する。
【０００２】
【従来の技術】
従来、伸縮性のある布（伸縮地）を縫製可能なミシンには、針板上の縫製対象の布を押え脚と協働して布送り方向（前後方向）へ送る差動送り歯と主送り歯が、縫針の針落ち点を挟んで前後に配置され、伸縮地を縫製する場合、差動送り歯を主送り歯の送り量より大きな送り量で送り作動させ、主送り歯に対して差動送り歯で伸縮地の伸び量分を予め余分に送り、伸縮地に伸びが生じないようにして布送りする差動送り装置が設けられている。
【０００３】
例えば、特開平５−３１７５５０号公報に記載の差動送り装置においては、主送り歯と副送り歯（差動送り歯）が、前後方向へ移動自在に支持された主送り歯取付け軸と副送り歯取付け軸の先端部に設けられ、主送り駆動機構により主送り歯取付け軸に前後駆動力を伝達し、副送り駆動機構により副送り歯取付け軸に前後駆動力を伝達し、主送り歯と副送り歯を送り作動させるように構成してある。
【０００４】
前記主送り駆動機構は、駆動軸の回転運動を直線運動に変換してその駆動力を主送りスライドロッドに伝達し、主送りスライドロッドを前後へ揺動させることにより主送り歯取付け軸に前後駆動力を伝達する一般的な機構であり、主送りスライドロッドをその長さ方向へスライドさせることで、主送りスライドロッドの揺動量が変化し、主送り歯の送り量を調節できるようになっている。
【０００５】
一方、前記副送り駆動機構は、主送り歯取付け軸の前後移動による駆動力を、複数の駆動伝達部材を介して副送りスライドロッドに伝達し、副送りスライドロッドを前後へ揺動させることで、副送り歯取付軸に前後駆動力を伝達するように構成してある。副送りスライドロッドはその長さ方向へスライド自在に支持され、差動調整レバーを操作し副送りスライドロッドをスライドさせることで、副送りスライドロッドの揺動量が変化し、副送り歯取付け軸の前後移動ストローク、つまり副送り歯の送り量を調節できるように構成してある。
【０００６】
【発明が解決しようとする課題】
前記公報の差動送り装置では、主送り歯取付け軸と副送り歯取付け軸とを設け、これら１対の取付け軸を介して主送り歯と副送り歯を夫々支持する構造であり、しかも、主送り歯取付け軸の前後移動による駆動力を、複数の駆動伝達部材と副送りスライドロッド等を介して、副送り取付け軸に伝達する副送り駆動機構を設けなければならないため、差動送り装置が部品数の多い複雑且つ大型の構造になり、その製作コストも高価になる。
【０００７】
また、前記差動送り装置では、差動調整レバーを操作し、副送りスライドロッドの揺動量つまり副送り歯の送り量を無段階に調節できるものの、伸縮地の伸び量は押え脚の押え圧や伸縮地の生地等で異なるため、作業者が伸縮地の伸び量を推測し副送り歯の送り量を適正な値に調節するのは難しく、かえって使いにくくなるという問題がある。
【０００８】
本発明の目的は、構造を簡単化且つ小型化するとともに、差動送り歯の送り量を２段階に切換え可能に構成し、作業者が使い易いミシンの差動送り装置を提供することである。
【０００９】
【課題を解決するための手段】
請求項１のミシンの差動送り装置は、針板上の縫製対象の布を送る主送り歯と差動送り歯とを備え、差動送り歯と主送り歯を前後に配置してなるミシンの差動送り装置において、前記主送り歯を備えた主送り歯部材と、前記差動送り歯を備えた差動送り歯部材を、主送り歯部材と一体的に上下動させるとともに主送り歯部材に対して布送り方向へ所定ストローク相対移動自在に支持するスライド機構と、前記主送り歯部材に対して差動送り歯部材を前側へ弾性付勢するバネ部材と、前記差動送り歯部材が主送り歯部材と一体的に送り作動する第１状態と、差動送り歯部材が主送り歯部材の送り量の所定倍の送り量で送り作動する第２状態とに切換え可能に、差動送り歯部材と主送り歯部材とを作動的に連結する差動送り連結機構とを備えたものである。
【００１０】
差動送り連結機構を第１状態に切換えた状態では、主送り歯部材と主送り歯部にスライド機構を介して支持された差動送り歯部材が、バネ部材の弾性付勢力により所定の位置関係を保持し、主送り歯に前後駆動力が伝達され主送り歯部材が送り作動すると、差動送り歯部材は主送り歯部材と一体的に相等しい送り量で送り作動する。
【００１１】
差動送り連結機構を第２状態に切換えた状態では、主送り歯を駆動する前後駆動力が差動送り連結機構を介して差動送り歯部材に伝達され、差動送り歯部材が主送り歯部材の送り量の所定倍の送り量で送り作動し、伸縮性のある布（伸縮地）を縫製する場合、主送り歯に対して差動送り歯で伸縮地の伸び量分が予め余分に送られ、伸縮地に伸びが生じないように布送りが実行され、縫製の仕上がりが良好になる。
【００１２】
請求項２のミシンの差動送り装置は、請求項１の発明において、前記差動送り連結機構は、主送り歯部材に送り駆動力を伝達する主送り腕に高さ方向途中部が枢着され且つ上端部が差動送り歯部材に作動的に連結されたリンク部材を備え、前記リンク部材の下端部の係合部に係脱自在に係合するピン部材を含み、このピン部材を前記係合部に係脱させることにより差動送り連結機構を切換える切換え操作機構を設けたことを特徴とするものである。
【００１３】
主送り腕はその下端部が左右方向向きの水平な枢支軸に枢支され前後へ揺動駆動される。切換え操作機構によりピン部材をリンク部材の係合部から離脱させて、差動送り連結機構を第１状態に切換えると、主送り腕が前後へ揺動し主送り歯部材に前後駆動力が伝達され主送り歯部材が送り作動すると、差動送り歯部材が主送り歯部材と一体的に送り作動する。
【００１４】
ピン部材をリンク部材の係合部に係合させて、差動送り連結機構を第２状態に切換えると、主送り腕が前後へ揺動するとき、リンク部材がピン部材を中心として揺動し、このリンク部材を介して前後駆動力が差動送り部材へ伝達され、差動送り歯部材が主送り歯部材の送り量の所定倍の送り量で送り作動する。その他請求項１と同様の作用を奏する。
【００１５】
請求項３のミシンの差動送り装置は、請求項２の発明において、前記差動送り連結機構は、前記ピン部材が前記係合部に係合しない状態では第１状態になり、前記ピン部材が前記係合部に係合した状態では第２状態となることを特徴とするものである。それ故、切換え操作機構によりピン部材をリンク部材の係合部に係脱させ、差動送り連結機構を第１状態と第２状態とに切換えることができる。その他請求項２と同様の作用を奏する。
【００１６】
請求項４のミシンの差動送り装置は、請求項１〜３の何れか１項の発明において、前記所定倍は約２倍であることを特徴とするものである。それ故、差動送り連結機構を第２状態に切換えると、差動送り歯部材が主送り歯部材の送り量の約２倍の送り量で送り作動する。その他請求項１〜３の何れか１項と同様の作用を奏する。
【００１７】
請求項５のミシンの差動送り装置は、請求項３又は４の発明において、前記切換え操作機構は、前記ピン部材に作動的に連結され且つピン部材を係合部に係脱させるツマミ部材と、前記ピン部材が係合部へ係合したときにはその係合位置を保持し且つ係合部から離脱したときにはその離脱位置を保持するように、ピン部材を付勢するバネ部材とを備えたことを特徴とするものである。それ故、ツマミ部材を操作して、ピン部材をリンク部材の係合部に係脱させることができ、バネ部材の付勢力により、ピン部材を係合部へ係合した係合位置と係合部から離脱した離脱位置に夫々保持できる。その他請求項３又は４と同様の作用を奏する。
【００１８】
【発明の実施の形態】
以下、本発明の実施の形態について図面を参照しつつ説明する。本実施形態は、主に布の縁を縫製する為のロックミシンに本発明を適用した場合の一例である。但し、このロックミシンを操作する操作者を基準とし、手前側を前方、左右方向を左右方向として説明する。
【００１９】
図１〜図５に示すように、ロックミシンＭは、ベッド部８０と、ベッド部８０の右部に立設された脚柱部８１と、脚柱部８１上部から左方へ伸びるアーム部８２を有し、ベッド部８０の左端部分は片持ち状のフリーベッド部８３に構成されている。フリーベッド部８３上面部には針板８４が設けられ、この針板８４に布送り方向へ伸長して形成された長孔（図示略）から突出可能に、送り作動する差動送り歯３と主送り歯１とが前後に配置されている。アーム部８２には、主送り歯１と差動送り歯３との間に縫製対象の布を押さえる押え脚８５と、押え脚８５を下降位置と上昇位置とに切換える切換えレバー８６が装着され、下降位置に切換えられた押え脚８５と協働して、主送り歯１と差動送歯３により、針板８４上の縫製対象の布が布送り方向（前後方向）へ送られる。
【００２０】
アーム部８２には、下端に１対の縫針８８を装着し且つ針棒上下駆動機構（図示略）により上下動される針棒８７が支持されている。脚柱部８０の後端部には、複数本（例えば４本）の糸立９２と糸案内部材８９が立設され、脚柱部８１の前面部には糸調子調節ツマミ９０が設けられ、脚柱部８１の右側面部には、主送り歯１の送り量を調節する送り量調節ツマミ１０７と、駆動軸１０に連結された回動操作部材９１が設けられ、フリーベッド部８３の前面側には、差動送り装置６のツマミ部材４０の先端部分が突出している。
【００２１】
図４〜図１０に示すように、ロックミシンＭの内部には、主送り歯１を備えた主送り歯部材２と、差動送り歯３を備えた差動送り歯部材４と、主送り歯部材２と差動送り歯部材４に前後駆動力を伝達する前後駆動機構５と、主送り歯部材２に対する差動送り歯部材４の布送り量を２段階に切換え可能な差動送り装置６と、可動刃５５と主送り歯部材２と差動送り歯部材４に上下駆動力を伝達する上下駆動機構７と、差動送り歯３と主送り歯１の高さ位置を夫々微調節可能な高さ位置調節装置（第１調節機構８と第２調節機構９）等が設けられている。
【００２２】
主送り歯部材２は、主送り腕１４の上端部に左右方向向きのピン部材１６に枢着された取付け部材１７に、第２調節機構９を介して高さ位置調節可能に連結され、差動送り歯部材４は、その後端部において差動送り装置６のスライド機構２０を介して主送り歯部材２に支持され、その前端部において、引張りコイルバネ１８で下方へ付勢されて、揺動伝達部材６０の伝達部６２に摺動自在に支持されている。
【００２３】
前後駆動機構５について説明する。
前後駆動機構５は、ベッド部８０内のミシンモータ（図示略）により回転駆動される駆動軸１０と、駆動軸１０に固着された前後駆動用カム１１と、前後駆動用カム１１に上下方向略中段部が摺接された前後駆動力伝達部材１２と、下端部においてフレームに回転自在に支持された左右方向向きの水平な枢支軸１３に枢支された主送り腕１４とを有し、前後駆動力伝達部材１２の下端部が主送り腕１４のレバー部１４ｂに揺動可能にピン結合されている。
【００２４】
前後駆動力伝達部材１２は駆動軸１０の後側に配設され、一端部をフレームに連結した引張りコイルバネ１５により前斜め上方へ付勢され、前後駆動力伝達部材１２の中段部分前端の摺動面１２ａが前後駆動用カム１１に摺動自在に当接している。主送り腕１４は左右両端部分に１対の屈曲部１４ａを有し、これら屈曲部１４ａの下端部が枢支軸１３に枢支され、右側の屈曲部１４ａの下端部からレバー部１４ｂが前方へ延びている。前記取付け部材１７を枢支するピン部材１６は左右１対の屈曲部１４ａの上端部にスライド不可で且つ揺動可能に架着されている。
【００２５】
前後駆動力伝達部材１２の上端部には送り量調節機構１００の角駒１０１が回転自在に連結され、この角駒１０１はフレームに水平軸心回りに支持された係合部材１０２の係合溝１０２ａに摺動自在に係合している。前後駆動力伝達部材１２が前後駆動用カム１１により前後に駆動されると、角駒１０１が係合溝１０２ａで案内されて移動し、この角駒１０１の移動方向に応じて主送り腕１４の前後揺動角が決まり、取付け部材１７と主送り歯部材２の送り量が決まる。
【００２６】
図６、図７の状態において、駆動軸１０が矢印方向へ回動され、前後駆動用カム１１で前後駆動力伝達部材１２がコイルバネ１５の付勢力に抗して押動されると、角駒１０１は係合部材１０２の係合溝１０２ａに案内されて矢印α方向へ移動し、主送り腕１４が後方へ揺動する。ここで、主送り歯部材２の送り量を調節可能な布送り量調節機構１００ついて、図５〜図７を参照して簡単に説明する。布送り量調節機構１００は、角駒１０１及び係合溝１０２ａを有する係合部材１０２と、フレームに回動自在に支持された軸部材１０５の左端部に固着された円板１０４であって、係合部材１０２の先端部のピン１０３が係合する溝カム１０４ａを有する円板１０４と、軸部材１０５の右端部に固着された送り量調節ツマミ１０７等で構成されている。
【００２７】
送り量調節ツマミ１０７を回動操作し、軸部材１０５を介して円板１０４を回転させ、角駒１０１が矢印β方向へ移動するようにすると、前後駆動力伝達部材１２が前後駆動用カム１１により前後に駆動されても、主送り腕１４の前後へ揺動しなくなり、取付け部材１７と主送り歯部材２が送り作動しなくなり、角駒１０１の移動方向と矢印β方向の角度が大きくなると、主送り歯部材２の送り量も大きくなる。図１に示すように、例えば、送り量調節ツマミ１０７を回動操作し、揺動量０を含めて４段階に調節できるようになっている。尚、軸部材１０５には板バネ１０６が摺接している。
【００２８】
差動送り装置６について説明する。
図６〜図１２に示すように、差動送り装置６は、差動送り歯部材４を主送り歯部材２と一体的に上下動させるとともに主送り歯部材２に対して前後方向へ所定ストローク相対移動自在に支持するスライド機構２０と、主送り歯部材２に対して差動送り歯部材４を前側へ弾性付勢する圧縮コイルバネ２１（バネ部材：図８では略））と、差動送り歯部材４が主送り歯部材２と一体的に送り作動する第１状態（図１０、図１１参照）と、差動送り歯部材４が主送り歯部材２の送り量ａ（例えば８mm）の約２倍の送り量２ａで送り作動する第２状態（図１２、図１３参照）とに切換え可能に、差動送り歯部材４と主送り歯部材２とを作動的に連結する差動送り連結機構２２を有する。
【００２９】
スライド機構２０は、差動送り歯部材４に固定された平面視逆コ字型（図８参照）の連結金具２６を有し、この連結金具の１対の支持部２６ａを、主送り歯部材２を貫通し前後に突出し且つ主送り歯部材２に止めネジ２５ａで固定された軸部材２５に摺動自在に外嵌させるとともに、連結金具に形成された長孔２６ｂに、主送り歯部材２から左方へ突出したピン２ａを係合させることにより、差動送り歯部材４が主送り歯部材２と一体的に上下動し、主送り歯部材２に対して相対的に回転せずに前後方向へ所定ストローク相対移動自在に支持されている。圧縮コイルバネ２１は、主送り歯部材２と連結金具の前側の支持部２６ａの間において前側の軸部材２５に外装されている。
【００３０】
差動送り連結機構２２は、主送り腕１４に高さ方向途中部が枢着され且つ上端部が連結金具２６（つまり、差動送り歯部材４）に作動的に連結されたリンク部材３０と、リンク部材３０の下端部の係合部３０ａに係脱自在に係合するピン部材４２を含み、このピン部材４２を前記係合部３０ａに係脱させることにより差動送り連結機構２２を第１状態と第２状態とに切換える切換え操作機構３１を有する。主送り腕１４左側の屈曲部１４ａから軸部材３５が左方へ突設され、この軸部材３５にリンク部材３０の高さ方向途中部が揺動可能に枢着されている。差動送り歯部材４が固着された連結金具の左端部からピン３６が左方へ突設され、このピン３６にリンク部材３０の上端部のＵ形の係合部３０ｂが回動自在に係合して連結されている。
【００３１】
切換え操作機構３１は、ピン部材４２に揺動体４３を介して作動的に連結され且つピン部材４２を係合部３０ａに係脱させるツマミ部材４０と、ピン部材４２が係合部３０ａへ係合したときにはその係合位置を保持し且つ係合部３０ｂから離脱したときにはその離脱位置を保持するように、ピン部材４２を揺動体４３を介して付勢する捩じりバネ４４を有する。ピン４２は揺動体４３の後端部に固着されており、揺動体４３は左右方向向きのピン４３ｂによりフレームに枢着され、揺動体４３の前端部には長孔４３ａが形成され、この長孔４３ａにツマミ部材４０の後端部のピン４０ａが挿入され連結されている。ツマミ部材４０の前端部分は、ガイド部材４１によりガイドされ、フリーベッド部８３の前方へ突出し、ツマミ部材４０の前端部には把持部４０ｂが形成されている。
【００３２】
図１０、図１１は、ピン部材４２がリンク部材３０の係合部３０ａに係合していない差動送り連結機構２２の第１状態を示している。この第１状態から、ツマミ部材４０の把持部４０ｂを下方へ操作すると、揺動体４３が揺動し、ピン部材４２がリンク部材３０の下端部のガイド部３０ｃにガイドされて係合部３０ａに係合し、差動送り連結機構２２が第２状態になる（図１２、図１３参照）。
【００３３】
前記捩じりバネ４４は、その一端部を揺動体４３の後部に連結し他端部をフレームに連結して設けられ、差動送り連結機構２２が第１状態になると、図１０に鎖線で示すように、捩じりバネ４４による揺動体４３の付勢方向が、揺動体４３の支軸４３ｂより下側に指向するため、揺動体４３は図１０において反時計回り（図１０の一点鎖線矢印方向）に回転付勢され、ピン部材４２が離脱位置に保持される。差動送り連結機構２２が第２状態になると、図１２に鎖線で示すように、捩じりバネ４４による揺動体４３の付勢方向が、揺動体４３の支軸４３ｂより上側に指向するため、揺動体４２は図１２において時計回り（図１２の一点鎖線矢印方向）に回転付勢され、ピン部材４２は結合位置に保持される。
【００３４】
ここで、主送り歯１に対して差動送り歯３を差動送りさせる原理について説明する。ピン部材４２が係合部３０ａに係合しない第１状態では、リンク部材３０の回動が規制されないので、スライド機構２０の圧縮コイルバネ２１の付勢力を介して主送り歯１と差動送り歯３とが一体的に相等しい送り量で布送りを行う。これに対して、ピン部材４２が係合部３０ａに係合した第２状態では、主送り歯１の送り量ａのときに差動送り歯３の送り量が約２ａになる。
【００３５】
即ち、図１０に示すように、枢支軸１３から軸部材３５までの距離ｂ２が枢支軸１３からピン部材１６までの距離ｂ１の約０．６５倍であり、図１２に示すように、ピン部材４２からピン部材３６までの距離ｃ２がピン部材４２から軸部材３５までの距離ｃ１の約３．０倍であるので、主送り歯１の送りａ（枢支軸１６の前後移動量）が約３．０位であるので、主送り歯１の送り量ａ（枢支軸１６の前記移動量）が約０．６５×３．０だけ増幅された送り量約２ａが差動送り歯３の送り量になる。つまり、図１４に示すように、第１状態では、主送り歯部材２と差動送り歯部材４は送り量ａで一体的に送り作動し、第２状態では、差動送り歯部材４が主送り歯部材２の送り量ａの約２倍の送り量２ａで送り作動する。
この２つの送り歯のうち、後側に位置する主送り歯１の前後移動範囲が主に針落ち点の近傍であって使用者の望む縫目のピッチに影響し、前側に位置する差動送り歯３の前後移動範囲が主に主送り歯１の前後移動範囲の手間側にある。そのため、縫製中の布は押さ足８５によって押さえつけられ、布の移動がある程度制限された状態であり、伸縮性の大きい布が押さえられた状態で主送り歯１で後方へ移動されると伸びるが、第２状態のように、主送り歯１の送り量に対して差動送り歯３の送り量が大きい場合には、同時に差動送り歯３によって主送り歯１より多く送られるので、その主送り歯１による引っ張りが解消された後の縮みが吸収され、縫製後の布縮みが防止できるのである。特に伸縮性の大きいニット地やジャージ地等ではこのような差動送り縫いは有効である。尚、主送り歯１及び差動送り歯３は、駆動軸１０によって縫い針が布から抜けた所定のタイミングで布送り作動を行う。
【００３６】
上下駆動機構７について説明する。
図６〜図９に示すように、上下駆動機構７は、駆動軸１０と、駆動軸１０に固着された上下駆動用カム５０と、上下駆動用カム５０に係合する上下駆動力伝達部材５１と、前後駆動機構５と共通の枢支軸１３であって上下駆動力伝達部材５１の下端部が固着された枢支軸１３と、枢支軸１３の左端部に固着された揺動リンク部材５２と、揺動リンク部材５２にピン５４にて連結された縦向きの可動部材５３を有する。
【００３７】
駆動軸１０の右端部には、脚柱部８１の右側へ突出し手動にて駆動軸１０を回動させることのできる回動操作部材９１が連結されている。上下駆動力伝達部材５１は、上下駆動用カム５０に係合する二股カム従動部５４を有し、主送り腕１４の１対の屈曲部１４ａの間に配設され、上下駆動力伝達部材５１の上下方向中段部に形成された円弧状の長孔５１ａに、主送り腕１４のピン部材１６が挿通している。
【００３８】
図６、図７に示すように、二股カム従動部５４は、相対向する第１従動部５４ａと第２従動部５４ｂからなり、上下駆動用カム５０により、第１従動部５４ａが押動され、上下駆動力伝達部材５１が後方へ揺動すると、揺動リンク部材５２が枢支軸１３を中心として上方へ揺動し、可動刃５５と差動送り歯部材４が上昇駆動され、第２従動部５４ｂが押動される。上下駆動力伝達部材５１が前方へ揺動すると、可動刃５５と差動送り歯部材４が下降駆動される。
【００３９】
可動部材５３は鉛直姿勢の板状フレーム９５（図８参照）の左側に位置し、可動部材５３の上端部には左右方向向きの軸部５７（ピン部材）が一体形成されている。この軸部５７と前記ピン５４は、可動部材５３から右方へ突出し、板状フレーム９５に形成された縦向きの長孔５８，５９に挿通して上下方向へガイドされている。尚、軸部５７の前後量端面は面取りされて、長孔５８の鉛直面に夫々摺接している。
【００４０】
図８に示すように、軸部５７は可動部材５３から左方へも長く伸び、軸部５７には軸部材５７ａが摺動自在に挿通し、この軸部材５７ａに板状フレーム９５の右側において可動刃５５が固着されている。一方、固定刃５６は板状フレーム９５の上端に針板８４の上方へ僅かに突出するように取付けられている。軸部材５７ａの左端部には止め輪５７ｂが取付けられ、止め輪５７ｂと軸部５７の左端間において軸部材５７ｂに圧縮コイルバネ５７ｃが外装され、このコイルバネ５７ｃの付勢力で可動刃５５が固定刃５６と摺接状態を保持し、上下動する可動刃５５と固定刃５６との協働により、後方へ送られる縫製直前の布端部を切断するようになっている。
【００４１】
板状フレーム９５には、揺動伝達部材６０の前端部が枢支ピン６１により枢着され、揺動伝達部材６０の途中部の上端近傍部に、差動送り歯部材４の前端下面部を摺動自在に支持して、差動送り歯部材４に上下駆動力を伝達する軸状の伝達部６２が左方突出状に形成されている。揺動伝達部材６０の他端部には、長軸が枢支ピン６１の方に向く長孔６３が形成され、この長孔６３に可動部材５３の軸部５７が係合している（図１６〜図１９参照）。
【００４２】
前記枢支ピン６１には偏心ピン部６６が一体形成され、この偏心ピン部６６に揺動伝達部材６０の前端部が枢支されている。図１６は可動刃５５と差動送り歯部材４が上昇限界位置に位置した状態を示し、図１７は可動刃５５及び差動送り歯部材４が下降限界位置に位置した状態を示し、伝達部６２と差動送り歯部材４は、可動刃５５の上下ストロークｈの約２／３のストロークで上下動する。
【００４３】
前記高さ位置調節装置について説明する。
高さ位置調節装置は、前記上下駆動機構７に含まれ差動送り歯３の高さ位置を微調節する為の第１調節機構８と、前記前後駆動機構５に含まれ主送り歯１の高さ位置を微調節する為の第２調節機構９からなる。
【００４４】
第１調節機構８は、図１５〜図１９に示すように、揺動伝達部材６０を板状フレーム９５に枢支する枢支ピン６１に一体形成された偏心ピン部６６を含み、揺動伝達部材６０の伝達部６２の高さ位置を微調節可能な偏心機構６５を有する。枢支ピン６１の軸心６１ａに対して偏心ピン部６６の軸心６６ａは、偏心量ｅ（例えば１．５mm）だけ偏心しているので、偏心ピン部６６をスクリュードライバで回動させることで、全方向へ偏心量ｅで偏心させ、伝達部６２の高さ位置を微調節し、差動送り歯部材４の高さ位置を微調節することができる。尚、上述した微調整においては、フレームに螺合した止めビスをスクリュードライバーで緩めて偏心ピン部６６を所望の位置に回転させ、微調整後に止めビスを締め偏心ピン部６６の位置を固定する。
【００４５】
図１６、図１８、図１９は可動刃５５を上昇限界位置に上昇させた際の第１調節機構８の状態を示し、図１６の第１調節機構８の状態から、例えば、偏心ピン部６６を図において反時計回りに９０度回転させ、図１８に示すように、枢支ピン６１の軸心６１ａに対して偏心ピン部６６の軸心６６ａを偏心させ、偏心ピン部６６の高さ位置がｅだけ高くなると、揺動伝達部材６０が略軸部５７の軸心５７ａを中心として図において時計回りに回転し、伝達部６２の高さは約ｅ／２高くなる。
【００４６】
図示していないが、図１６の第１調節機構８の状態から、例えば、偏心ピン部６６を図において時計回りに９０度回転させ、枢支ピン６１の軸心６１ａに対して偏心ピン部６６の軸心６６ａを偏心させ、偏心ピン部６６の高さ位置がｅだけ高くなると、揺動伝達部材６０が略軸部５７の軸心５７ａを中心として図において反時計回りに回動し、伝達部６２の高さは約ｅ／２低くなる。
【００４７】
また、図１６の第１調節機構８の状態から、例えば、偏心ピン部６６を図において１８０度回転させ、図１９に示すように、枢支ピン６１の軸心６１ａに対して偏心ピン部６６の軸心６６ａを偏心させ、偏心ピン部６６を左方へ２ｅ移動すると、偏心ピン部６６の軸心６６ａの高さ位置は変化しないが、長孔６３の案内作用により、偏心ピン部６６の軸心６６ａと軸部５７の軸心５７ａ間の距離が短くなるため、伝達部６２の高さも低くなる。
【００４８】
このように、伝達部６２の高さ位置は、偏心ピン部６６の高さ位置の変化だけでなく、偏心ピン部６６の軸心６６ａと軸部５７の軸心５７ａ間の距離の変化によっても調節される。このように、偏心ピン部６６を回動させることにより、伝達部６２の高さ位置つまり差動送り歯３の高さ位置を微調節できる。
【００４９】
第２調節機構９は、図１５、図２０〜図２２に示すように、主送り腕１４のピン部材１６に枢支された取付け部材１７に昇降自在にガイドされ、主送り歯部材２がビス７１で固定されたた昇降部材７０を有し、昇降部材７０は取付け部材１７に１対のビス７２で締結解除可能に締結されている。
【００５０】
取付け部材１７は断面コの字型に形成され、取付け部材１７の間に昇降部材７０が配設されている。昇降部材７０には鉛直向きのガイドピン７３が挿通され、止め輪７３ａで固定されている。ガイドピン７３の上下両端部分は取付け部材１７の上下両端部を挿通し昇降自在にガイドされている。取付部材１７の後端部には上下に長い左右１対の長孔７５が形成されており、取付部材１７の後側から１対のビス７２が１対の長孔７５を挿通し昇降部材７０に螺着されている。つまり、１対のビス７２を緩めて、主送り歯部材２を、図２１に示す上昇限界位置と図２２に示す下降限界位置の間の所望の位置へ移動させ、１対のビス７２を締めると、その高さ位置に主送り歯部材２を固定することができる。
【００５１】
このロックミシンＭの作用・効果について説明する。
差動送り装置６において、主送り歯部材２に差動送り歯部材４をスライド機構２０を介して支持し、圧縮コイルバネ２１により前側へ付勢し、差動送り連結機構２２により差動送り歯部材４と主送り歯部材２とを作動的に連結し、差動送り連結機構２２を第１状態に切換えて、主送り歯部材２と差動送り歯部材４とを一体的に送り作動させ、差動送り歯部材を第２状態に切換えて、差動送り歯部材４を主送り歯部材２の送り量ａの約２倍の送り量２ａで送り作動させることができるため、差動送り装置６の構造が簡単且つ小型になりその製作コストを低減でき、且つ、差動送り歯部材４の送り量を２段階に調節するように構成したので、ユーザーにとって非常に使い易いものになる。
【００５２】
差動送り連結機構２２は、主送り歯部材２に送り駆動力を伝達する主送り腕１４に高さ方向途中部が軸部材３５を介して枢着され、且つ上端部が連結金具２６つまり差動送り歯部材２に作動的に連結されたリンク部材３０を備えたので、リンク部材３０の係合部３０ａに係脱自在に係合するピン部材４２を含み、このピン部材４２を係合部３０ａに係脱させることにより差動送り連結機構２２を切換える切換え操作機構３１を設けたので、差動送り連結機構２２を第１状態と第２状態に非常に簡単且つ確実に切換えることが可能になる。
【００５３】
切換え操作機構３１は、ピン部材４２に作動的に連結され且つピン部材４２をリンク部材３０の係合部３０ａに係脱させるツマミ部材４０と、ピン部材４２が係合部３０ａへ係合したときにはその係合位置を保持し且つ係合部３０ａから離脱したときにはその離脱位置を保持するように、ピン部材４２を付勢する捩じりバネ部材４４を備えたので、ツマミ部材４０を操作してピン部材４２を係合部３０ａに簡単に係脱させることができ、ツマミ部材４０を操作しないときには、ピン部材４２を前記係合位置又は離脱位置に確実に保持できる。
【００５４】
尚、枢支軸１３から軸部材３５までの距離ｂ２と枢支軸１３からピン部材１６までの距離ｂ１の比率と、ピン部材４２からピン部材３６までの距離ｃ２とピン部材４２から軸部材３５までの距離ｃ１の比率を適宜変更することで、差動送り連結機構２２を第２状態に切換えたとき、主送り歯１の送り量ａに対する差動送り歯部材４は送り量を変更することができる。また、切換え操作機構３１においては、本実施形態にの構造に限らず、種々の構造のもを採用することができる。
【００５５】
【発明の効果】
請求項１のミシンの差動送り装置によれば、差動送り歯部材を主送り歯部材にスライド機構を介して支持し、バネ部材により前側へ付勢し、差動送り連結機構により差動送り歯部材と主送り歯部材とを作動的に連結し、差動送り連結機構を第１状態に切換えて、主送り歯部材と差動送り歯部材とを一体的に送り作動させ、差動送り連結機構を第２状態に切換えて、差動送り歯部材を主送り歯部材の送り量の所定倍の送り量で送り作動させることができるため、差動送り装置の構造が簡単且つ小型になりその製作コストも安価になり、且つ、差動送り歯部材の送り量を２段階に調節するように構成したので、ユーザーにとって非常に使い易いものになる。
【００５６】
請求項２のミシンの差動送り装置によれば、請求項１と同様の効果を奏するが、前記差動送り連結機構は、主送り歯部材に送り駆動力を伝達する主送り腕に高さ方向途中部が枢着され且つ上端部が差動送り歯部材に作動的に連結されたリンク部材を備え、リンク部材の下端部の係合部に係脱自在に係合するピン部材を含み、このピン部材を前記係合部に係脱させることにより差動送り連結機構を切換える切換え操作機構を設けたので、差動送り連結機構を第１状態と第２状態に非常に簡単且つ確実に切換えることが可能になる。
【００５７】
請求項３のミシンの差動送り装置によれば、請求項２と同様の効果を奏するが、前記差動送り連結機構は、前記ピン部材が前記係合部に係合しない状態では第１状態になり、前記ピン部材が前記係合部に係合した状態では第２状態となるように構成したので、差動送り連結機構を前記第１状態と第２状態とに簡単且つ確実に切換えることができる。
【００５８】
請求項４のミシンの差動送り装置によれば、請求項１〜３の何れか１項と同様の効果を奏するが、前記所定倍を約２倍に構成したので、差動送り連結機構を第２状態に切換えると、差動送り歯部材を主送り歯部材の送り量の約２倍の送り量で送り作動させ、縫製に良好な差動送りを行うことができる。
【００５９】
請求項５のミシンの差動送り装置によれば、請求項３又は４と同様の効果を奏するが、前記切換え操作機構は、前記ピン部材に作動的に連結され且つピン部材を係合部に係脱させるツマミ部材と、前記ピン部材が係合部へ係合したときにはその係合位置を保持し且つ係合部から離脱したときにはその離脱位置を保持するように、ピン部材を付勢するバネ部材とを備えたので、ツマミ部材を操作してピン部材をリンク部材の係合部に簡単に係脱させることができ、ツマミ部材を操作しないときには、ピン部材を前記係合位置又は離脱位置に確実に保持できる。
【図面の簡単な説明】
【図１】本発明の実施形態お係るロックミシンの斜視図である。
【図２】ロックミシンの正面図である。
【図３】ロックミシンの左側面図である。
【図４】ロックミシンの左側面透視図である。
【図５】ロックミシンの正面透視図である。
【図６】ロックミシン内部の要部左側面図である。
【図７】ロックミシン内部の要部右側面図である。
【図８】ロックミシン内部の要部平面図である。
【図９】ロックミシン内部の要部正面図である。
【図１０】差動送り装置（第１状態）の作動説明図である。
【図１１】差動送り装置（第１状態）の作動説明図である。
【図１２】差動送り装置（第２状態）の作動説明図である。
【図１３】差動送り装置（第２状態）の作動説明図である。
【図１４】主送り歯部材と差動送り歯部材の送り量を示す図である。
【図１５】高さ位置調節機構（第１、第２調節機構）を示す図である。
【図１６】上下駆動機構の作動説明図である。
【図１７】上下駆動機構の作動説明図である。
【図１８】第１調節機構の作動説明図である。
【図１９】第１調節機構の作動説明図である。
【図２０】図１５のXX−XX線断面図である。
【図２１】第２調節機構の作動説明図である。
【図２２】第２調節機構の作動説明図である。
【符号の説明】
Ｍロックミシン
１主送り歯
２主送り歯部材
３差動送り歯
４差動送り歯部材
５前後駆動機構
６差動送り装置
７上下駆動機構
８第１調節機構
９第２調節機構
１０駆動軸
１１前後駆動用カム
１２前後駆動力伝達部材
１３枢支軸
１４主送り腕
１６ピン部材
２０スライド機構
２１圧縮コイルバネ
２２差動送り連結機構
３０リンク部材
３０ａ係合部
３１切換え操作機構
４０ツマミ部材
４２ピン部材
４４捩じりバネ
５０上下駆動用カム
５１上下駆動力伝達部材
５２揺動リンク部材
５４二股カム従動部
５５可動刃
５７軸部（ピン部材）
６０揺動伝達部材
６１枢支ピン
６２伝達部
６３長孔
６５偏心機構
６６偏心ピン部
８４針板[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a differential feed device for a sewing machine, and more particularly, to a first state in which a differential feed dog member feeds and operates integrally with a main feed dog member, and a differential feed dog member to a feed amount of a main feed dog member. In contrast, the present invention relates to a structure that can be switched to a second state in which a feed operation is performed with a feed amount of a predetermined multiple.
[0002]
[Prior art]
Conventionally, a sewing machine that can sew stretchable cloth (stretchable fabric) has a differential feed dog and a main feed that feed the cloth to be sewn on the needle plate in the cloth feed direction (front-rear direction) in cooperation with the presser foot. When the feed dog is placed before and after the needle drop point of the sewing needle and the stretch ground is sewn, the differential feed dog is fed with a feed amount larger than the feed amount of the main feed dog, There is provided a differential feeding device that feeds the amount of stretch of the stretchable ground in advance with the differential feed teeth and feeds the fabric so that the stretchable ground does not stretch.
[0003]
For example, in the differential feeding device described in Japanese Patent Application Laid-Open No. 5-317550, the main feed dog and the sub feed dog (differential feed dog) are supported by the main feed dog mounting shaft and the sub feed shaft supported so as to be movable in the front-rear direction. Provided at the tip of the feed dog mounting shaft, the main feed drive mechanism transmits the front / rear driving force to the main feed dog mounting shaft, the sub feed drive mechanism transmits the front / rear drive force to the sub feed dog mounting shaft, and the main feed dog And the auxiliary feed dog is operated to feed.
[0004]
The main feed drive mechanism converts the rotational motion of the drive shaft into linear motion, transmits the driving force to the main feed slide rod, and swings the main feed slide rod back and forth to move back and forth to the main feed dog mounting shaft. This is a general mechanism that transmits the driving force. By sliding the main feed slide rod in its length direction, the swing amount of the main feed slide rod changes and the feed amount of the main feed dog can be adjusted. ing.
[0005]
On the other hand, the sub-feed drive mechanism transmits the driving force due to the back-and-forth movement of the main feed dog mounting shaft to the sub-feed slide rod via a plurality of drive transmission members, and swings the sub-feed slide rod back and forth. The front / rear driving force is transmitted to the auxiliary feed dog mounting shaft. The sub-feed slide rod is slidably supported in its length direction, and by operating the differential adjustment lever and sliding the sub-feed slide rod, the swing amount of the sub-feed slide rod changes, and the auxiliary feed dog mounting shaft The forward / backward movement stroke, that is, the feed amount of the auxiliary feed dog can be adjusted.
[0006]
[Problems to be solved by the invention]
In the differential feed device of the above publication, a main feed dog mounting shaft and a sub feed dog mounting shaft are provided, and the main feed dog and the sub feed dog are respectively supported via the pair of mounting shafts. Since it is necessary to provide a sub-feed drive mechanism that transmits the driving force generated by the forward / backward movement of the main feed dog mounting shaft to the sub-feed mounting shaft via a plurality of drive transmission members and sub-feed slide rods, a differential feed device However, it becomes a complicated and large structure with a large number of parts, and its manufacturing cost is also expensive.
[0007]
In the differential feeding device, the amount of extension of the expansion and contraction can be adjusted by pressing the pressure of the presser foot, although the differential adjustment lever can be operated to adjust the swing amount of the auxiliary feed slide rod, that is, the feed amount of the secondary feed dog steplessly. Therefore, it is difficult for the operator to estimate the stretch amount of the stretch fabric and adjust the feed amount of the auxiliary feed dog to an appropriate value, which makes it difficult to use.
[0008]
SUMMARY OF THE INVENTION An object of the present invention is to provide a differential feed device for a sewing machine that is easy and easy for an operator to make the structure simple and downsized, and to be configured so that the feed amount of a differential feed dog can be switched in two stages. .
[0009]
[Means for Solving the Problems]
A differential feed device for a sewing machine according to claim 1 is provided with a main feed dog and a differential feed dog that feed a cloth to be sewn on a needle plate, and the differential feed dog and the main feed dog are arranged at the front and back. In the differential feed device, the main feed dog member provided with the main feed dog and the differential feed dog member provided with the differential feed dog are moved up and down integrally with the main feed dog member and the main feed dog A slide mechanism that supports the member so as to be movable in a predetermined stroke relative to the cloth feed direction; a spring member that elastically biases the differential feed dog member forward relative to the main feed dog member; and the differential feed dog member Can be switched between a first state in which the feed feed member integrally feeds with the main feed dog member and a second state in which the differential feed dog member feeds at a feed amount that is a predetermined multiple of the feed amount of the main feed dog member. A differential feed coupling mechanism for operatively coupling the dynamic feed dog member and the main feed dog member; It is.
[0010]
When the differential feed coupling mechanism is switched to the first state, the differential feed dog member supported by the main feed dog member and the main feed dog portion via the slide mechanism is moved to a predetermined position by the elastic biasing force of the spring member. When the relationship is maintained and the front / rear driving force is transmitted to the main feed dog and the main feed dog member feeds, the differential feed dog member feeds at the same feed amount integrally with the main feed dog member.
[0011]
In the state where the differential feed coupling mechanism is switched to the second state, the longitudinal driving force for driving the main feed dog is transmitted to the differential feed dog member via the differential feed linkage mechanism, and the differential feed dog member is moved to the main feed. When the feed operation is performed with a feed amount that is a predetermined multiple of the feed amount of the tooth member and a stretchable cloth (stretchable area) is sewn, the extension amount of the stretchable area is preliminarily extraneous with the differential feed dog relative to the main feed dog. The cloth is fed so that the stretch fabric does not stretch, and the sewing finish is improved.
[0012]
According to a second aspect of the present invention, there is provided a differential feed device for a sewing machine according to the first aspect, wherein the differential feed coupling mechanism is pivotally attached to a main feed arm that transmits a feed driving force to a main feed dog member. And a pin member operably connected to the differential feed dog member, and including a pin member detachably engaged with an engagement portion at the lower end portion of the link member. A switching operation mechanism for switching the differential feed connecting mechanism by engaging with and disengaging from the engaging portion is provided.
[0013]
The lower end of the main feed arm is pivotally supported by a horizontal pivot shaft in the left-right direction and is driven to swing back and forth. When the pin member is disengaged from the engaging portion of the link member by the switching operation mechanism and the differential feed coupling mechanism is switched to the first state, the main feed arm swings back and forth, and the longitudinal drive force is transmitted to the main feed dog member. When the main feed dog member feeds, the differential feed dog member feeds integrally with the main feed dog member.
[0014]
When the pin member is engaged with the engaging portion of the link member and the differential feed coupling mechanism is switched to the second state, when the main feed arm swings back and forth, the link member swings around the pin member. The longitudinal driving force is transmitted to the differential feed member via this link member, and the differential feed dog member is fed at a feed amount that is a predetermined multiple of the feed amount of the main feed dog member. Other effects similar to those of the first aspect are achieved.
[0015]
A differential feed device for a sewing machine according to a third aspect is the sewing machine according to the second aspect, wherein the differential feed coupling mechanism is in a first state when the pin member is not engaged with the engagement portion. Is in the second state when engaged with the engaging portion. Therefore, the pin member can be engaged with and disengaged from the engaging portion of the link member by the switching operation mechanism, and the differential feed coupling mechanism can be switched between the first state and the second state. Other effects similar to those of the second aspect are achieved.
[0016]
A differential feeding device for a sewing machine according to a fourth aspect of the invention is characterized in that, in the invention according to any one of the first to third aspects, the predetermined multiple is about double. Therefore, when the differential feed coupling mechanism is switched to the second state, the differential feed dog member feeds at a feed amount that is approximately twice the feed amount of the main feed dog member. In addition, the same effect as any one of claims 1 to 3 is exhibited.
[0017]
According to a fifth aspect of the present invention, there is provided the differential feeding device for the sewing machine according to the third or fourth aspect, wherein the switching operation mechanism is operatively connected to the pin member and engages / disengages the pin member with the engaging portion. And a spring member that biases the pin member so that the engagement position is maintained when the pin member is engaged with the engagement portion and the disengagement position is maintained when the pin member is disengaged from the engagement portion. It is characterized by. Therefore, by operating the knob member, the pin member can be engaged with and disengaged from the engaging portion of the link member, and the engaging position where the pin member is engaged with the engaging portion is engaged by the biasing force of the spring member. Each can be held at the disengagement position where it is disengaged from the part. Other effects similar to those of the third or fourth aspect are achieved.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings. This embodiment is an example in the case where the present invention is applied to a lock sewing machine for mainly sewing the edge of a cloth. However, on the basis of an operator who operates the lock sewing machine, the front side will be described as the front, and the left-right direction will be described as the left-right direction.
[0019]
As shown in FIGS. 1 to 5, the lock sewing machine M includes a bed portion 80, a leg column portion 81 standing on the right side of the bed portion 80, and an arm portion 82 extending leftward from the upper portion of the leg column portion 81. The left end portion of the bed portion 80 is configured as a cantilevered free bed portion 83. A needle plate 84 is provided on the upper surface of the free bed 83, and a differential feed dog 3 that feeds the needle plate 84 so that it can project from a long hole (not shown) formed by extending in the cloth feed direction. The main feed dog 1 is arranged forward and backward. The arm portion 82 is provided with a presser foot 85 for pressing the cloth to be sewn between the main feed dog 1 and the differential feed dog 3 and a switching lever 86 for switching the presser foot 85 between the lowered position and the raised position. In cooperation with the presser foot 85 switched to the lowered position, the main feed dog 1 and the differential feed dog 3 feed the cloth to be sewn on the needle plate 84 in the cloth feed direction (front-rear direction).
[0020]
A pair of sewing needles 88 is attached to the lower end of the arm portion 82 and a needle bar 87 that is vertically moved by a needle bar vertical drive mechanism (not shown) is supported. A plurality of (for example, four) thread guides 92 and a thread guide member 89 are erected on the rear end portion of the pedestal portion 80, and a thread tension adjusting knob 90 is provided on the front surface of the pedestal portion 81. A feed amount adjustment knob 107 that adjusts the feed amount of the main feed dog 1 and a rotation operation member 91 connected to the drive shaft 10 are provided on the right side surface portion of the pedestal portion 81, and the front side of the free bed portion 83 is provided. The tip portion of the knob member 40 of the differential feeder 6 protrudes.
[0021]
As shown in FIGS. 4 to 10, the lock sewing machine M includes a main feed dog member 2 having a main feed dog 1, a differential feed dog member 4 having a differential feed dog 3, and a main feed. A front / rear drive mechanism 5 for transmitting a front / rear drive force to the tooth member 2 and the differential feed dog member 4, and a differential feed device capable of switching the cloth feed amount of the differential feed dog member 4 with respect to the main feed dog member 2 in two stages. 6, the vertical driving mechanism 7 for transmitting the vertical driving force to the movable blade 55, the main feed dog member 2 and the differential feed dog member 4, and the height positions of the differential feed dog 3 and the main feed dog 1 are finely adjusted. Possible height position adjusting devices (first adjusting mechanism 8 and second adjusting mechanism 9) and the like are provided.
[0022]
The main feed dog member 2 is connected to an attachment member 17 pivotally attached to the upper end portion of the main feed arm 14 via a pin member 16 oriented in the left-right direction via a second adjustment mechanism 9 so that the height position can be adjusted. The moving feed dog member 4 is supported by the main feed dog member 2 via the slide mechanism 20 of the differential feed device 6 at its rear end, and is urged downward by a tension coil spring 18 at its front end to swing. The transmission part 60 of the transmission member 60 is slidably supported.
[0023]
The front-rear drive mechanism 5 will be described.
The front-rear drive mechanism 5 includes a drive shaft 10 that is rotationally driven by a sewing machine motor (not shown) in the bed 80, a front-rear drive cam 11 that is fixed to the drive shaft 10, and a front-rear drive cam 11 that is substantially vertical. A front / rear driving force transmission member 12 in which the middle portion is slidably contacted, and a main feed arm 14 pivotally supported by a horizontal pivot shaft 13 in the left-right direction and rotatably supported by the frame at the lower end portion; A lower end portion of the front / rear driving force transmission member 12 is pin-coupled to the lever portion 14b of the main feed arm 14 so as to be swingable.
[0024]
The front / rear driving force transmission member 12 is disposed on the rear side of the drive shaft 10 and is biased forward and obliquely upward by a tension coil spring 15 having one end connected to the frame, so that the front end of the middle portion of the front / rear driving force transmission member 12 slides. The surface 12a is slidably in contact with the front and rear drive cam 11. The main feed arm 14 has a pair of bent portions 14a at both left and right end portions, the lower ends of the bent portions 14a are pivotally supported by the pivot shaft 13, and the lever portion 14b is moved forward from the lower end of the right bent portion 14a. It extends to. The pin member 16 that pivotally supports the mounting member 17 is attached to the upper end portions of the pair of left and right bent portions 14a so as not to slide and to swing.
[0025]
A square piece 101 of the feed amount adjusting mechanism 100 is rotatably connected to the upper end portion of the front / rear driving force transmission member 12, and the square piece 101 is engaged with an engagement groove of an engagement member 102 supported around the horizontal axis by the frame. 102a is slidably engaged with 102a. When the front / rear driving force transmission member 12 is driven back and forth by the front / rear driving cam 11, the square piece 101 is guided and moved by the engagement groove 102 a, and the main feed arm 14 moves according to the moving direction of the square piece 101. The forward / backward swing angle is determined, and the feed amounts of the attachment member 17 and the main feed dog member 2 are determined.
[0026]
In the state of FIGS. 6 and 7, when the drive shaft 10 is rotated in the direction of the arrow and the front / rear drive force transmission member 12 is pushed against the biasing force of the coil spring 15 by the front / rear drive cam 11, 101 is guided in the engagement groove 102a of the engagement member 102 and moves in the direction of the arrow α, and the main feed arm 14 swings backward. Here, the cloth feed amount adjusting mechanism 100 capable of adjusting the feed amount of the main feed dog member 2 will be briefly described with reference to FIGS. The cloth feed amount adjusting mechanism 100 includes an engagement member 102 having a square piece 101 and an engagement groove 102a, and a disc 104 fixed to the left end portion of a shaft member 105 that is rotatably supported by a frame. A disc 104 having a groove cam 104a with which a pin 103 at the tip end portion of the engaging member 102 is engaged, a feed amount adjusting knob 107 fixed to the right end portion of the shaft member 105, and the like.
[0027]
When the feed amount adjusting knob 107 is rotated to rotate the disk 104 via the shaft member 105 so that the square piece 101 moves in the arrow β direction, the front / rear driving force transmitting member 12 is moved to the front / rear driving cam 11. The main feed arm 14 does not swing back and forth even when driven by the front and rear, the attachment member 17 and the main feed dog member 2 do not feed, and the angle of the square piece 101 and the direction of the arrow β increase. The feed amount of the main feed dog member 2 is also increased. As shown in FIG. 1, for example, the feed amount adjusting knob 107 can be rotated and adjusted in four stages including a swing amount of zero. A leaf spring 106 is in sliding contact with the shaft member 105.
[0028]
The differential feeder 6 will be described.
As shown in FIGS. 6 to 12, the differential feed device 6 moves the differential feed dog member 4 up and down integrally with the main feed dog member 2 and has a predetermined stroke in the front-rear direction with respect to the main feed dog member 2. A slide mechanism 20 that is supported so as to be relatively movable, a compression coil spring 21 (spring member: omitted in FIG. 8) that elastically biases the differential feed dog member 4 forward relative to the main feed dog member 2, and a differential feed The first state (see FIGS. 10 and 11) in which the tooth member 4 is fed integrally with the main feed dog member 2, and the differential feed dog member 4 is of the feed amount a (for example, 8 mm) of the main feed dog member 2. A differential feed that operatively connects the differential feed dog member 4 and the main feed dog member 2 so as to be switchable to a second state (see FIGS. 12 and 13) in which the feed operation is performed at about twice the feed amount 2a. It has a coupling mechanism 22.
[0029]
The slide mechanism 20 includes a connecting metal fitting 26 having a reverse U-shape in plan view (see FIG. 8) fixed to the differential feed dog member 4, and a pair of support portions 26a of the connecting metal fitting is connected to the main feed dog member. 2, is slidably fitted to a shaft member 25 that protrudes forward and backward and is fixed to the main feed dog member 2 with a set screw 25 a, and the main feed dog member 2 is inserted into a long hole 26 b formed in the connecting metal fitting. The differential feed dog member 4 moves up and down integrally with the main feed dog member 2 by engaging the pin 2a protruding to the left from the main feed dog member 2 without rotating relative to the main feed dog member 2. It is supported so as to be movable in a predetermined stroke relative to the front-rear direction. The compression coil spring 21 is externally mounted on the front shaft member 25 between the main feed dog member 2 and the front support portion 26a of the connection fitting.
[0030]
The differential feed coupling mechanism 22 includes a link member 30 having a middle portion in the height direction pivoted on the main feed arm 14 and an upper end portion operatively coupled to the coupling fitting 26 (that is, the differential feed dog member 4). The link member 30 includes a pin member 42 that is detachably engaged with the engagement portion 30a at the lower end portion of the link member 30, and the differential feed coupling mechanism 22 is moved to the engagement portion 30a by engaging and disengaging the pin member 42 with the engagement portion 30a. A switching operation mechanism 31 for switching between the first state and the second state is provided. A shaft member 35 protrudes leftward from the bent portion 14a on the left side of the main feed arm 14, and a midway in the height direction of the link member 30 is pivotally attached to the shaft member 35. A pin 36 protrudes leftward from the left end portion of the connecting bracket to which the differential feed dog member 4 is fixed, and a U-shaped engaging portion 30b at the upper end portion of the link member 30 is rotatably engaged with the pin 36. Connected together.
[0031]
The switching operation mechanism 31 is operatively connected to the pin member 42 via the swinging body 43, and a knob member 40 that engages and disengages the pin member 42 with the engaging portion 30a, and the pin member 42 engages with the engaging portion 30a. The torsion spring 44 that biases the pin member 42 via the swinging body 43 is provided so that the engagement position is maintained when the pin member 42 is released and the disengagement portion 30b is released. The pin 42 is fixed to the rear end portion of the rocking body 43. The rocking body 43 is pivotally attached to the frame by a pin 43b oriented in the left-right direction, and a long hole 43a is formed in the front end portion of the rocking body 43. A pin 40a at the rear end of the knob member 40 is inserted into and connected to the hole 43a. The front end portion of the knob member 40 is guided by the guide member 41 and protrudes forward of the free bed portion 83, and a grip portion 40 b is formed at the front end portion of the knob member 40.
[0032]
10 and 11 show a first state of the differential feed connecting mechanism 22 in which the pin member 42 is not engaged with the engaging portion 30a of the link member 30. FIG. When the grip portion 40b of the knob member 40 is operated downward from the first state, the swinging body 43 swings, and the pin member 42 is guided by the guide portion 30c at the lower end portion of the link member 30 to be engaged with the engaging portion 30a. Engage and the differential feed coupling mechanism 22 enters the second state (see FIGS. 12 and 13).
[0033]
The torsion spring 44 is provided with one end connected to the rear part of the rocking body 43 and the other end connected to the frame. When the differential feed connecting mechanism 22 is in the first state, the torsion spring 44 is shown by a chain line in FIG. As shown in FIG. 10, since the urging direction of the oscillating body 43 by the torsion spring 44 is directed downward from the support shaft 43b of the oscillating body 43, the oscillating body 43 rotates counterclockwise in FIG. The pin member 42 is held at the disengaged position by being urged to rotate in the direction of the arrow. When the differential feed coupling mechanism 22 is in the second state, the urging direction of the oscillating body 43 by the torsion spring 44 is directed upward from the support shaft 43b of the oscillating body 43 as shown by a chain line in FIG. The oscillating body 42 is urged to rotate clockwise in FIG. 12 (in the direction of the one-dot chain line in FIG. 12), and the pin member 42 is held at the coupling position.
[0034]
Here, the principle of differentially feeding the differential feed dog 3 with respect to the main feed dog 1 will be described. In the first state in which the pin member 42 is not engaged with the engaging portion 30a, the rotation of the link member 30 is not restricted, and therefore the main feed dog 1 and the differential feed dog via the biasing force of the compression coil spring 21 of the slide mechanism 20. Cloth feed is performed with a feed amount which is integrally equal to 3. On the other hand, in the second state in which the pin member 42 is engaged with the engaging portion 30a, the feed amount of the differential feed dog 3 is about 2a when the feed amount a of the main feed dog 1 is reached.
[0035]
That is, as shown in FIG. 10, the distance b2 from the pivot shaft 13 to the shaft member 35 is about 0.65 times the distance b1 from the pivot shaft 13 to the pin member 16, and as shown in FIG. Since the distance c2 from the pin member 42 to the pin member 36 is about 3.0 times the distance c1 from the pin member 42 to the shaft member 35, the feed a of the main feed dog 1 (the amount of forward and backward movement of the pivot shaft 16). Is about 3.0, so that the feed amount about 2a obtained by amplifying the feed amount a of the main feed dog 1 (the movement amount of the pivot shaft 16) by about 0.65 × 3.0 is the differential feed dog. The feed amount is 3. That is, as shown in FIG. 14, in the first state, the main feed dog member 2 and the differential feed dog member 4 are integrally fed at a feed amount a, and in the second state, the differential feed dog member 4 is The feed operation is performed at a feed amount 2a that is approximately twice the feed amount a of the main feed dog member 2.
Of these two feed dogs, the forward / backward movement range of the main feed dog 1 located on the rear side is mainly in the vicinity of the needle drop point, affecting the stitch pitch desired by the user, and the differential located on the front side. The longitudinal movement range of the feed dog 3 is mainly on the labor side of the longitudinal movement range of the main feed dog 1. Therefore, the cloth being sewn is pressed by the pressing foot 85, and the movement of the cloth is restricted to some extent. If the cloth having high elasticity is pressed and moved backward by the main feed dog 1, the cloth is stretched. When the feed amount of the differential feed dog 3 is larger than the feed amount of the main feed dog 1 as in the second state, the differential feed dog 3 feeds more than the main feed dog 1 at the same time. The shrinkage after the pulling by the main feed dog 1 is eliminated is absorbed, and the fabric shrinkage after sewing can be prevented. Such differential feed stitching is particularly effective for knit fabrics and jersey fabrics that are highly stretchable. The main feed dog 1 and the differential feed dog 3 perform a cloth feed operation at a predetermined timing when the sewing needle is removed from the cloth by the drive shaft 10.
[0036]
The vertical drive mechanism 7 will be described.
As shown in FIGS. 6 to 9, the vertical drive mechanism 7 includes a drive shaft 10, a vertical drive cam 50 fixed to the drive shaft 10, and a vertical drive force transmission member 51 that engages with the vertical drive cam 50. A pivot shaft 13 common to the front-rear drive mechanism 5 and having the lower end portion of the vertical drive force transmission member 51 secured thereto, and a swing link member secured to the left end portion of the pivot shaft 13 52 and a vertically movable member 53 connected to the swing link member 52 by a pin 54.
[0037]
A rotation operation member 91 that protrudes to the right side of the pedestal column 81 and can manually rotate the drive shaft 10 is connected to the right end portion of the drive shaft 10. The vertical drive force transmission member 51 has a bifurcated cam driven portion 54 that engages with the vertical drive cam 50, and is disposed between the pair of bent portions 14 a of the main feed arm 14. The pin member 16 of the main feed arm 14 is inserted into an arc-shaped long hole 51a formed in the middle part in the vertical direction.
[0038]
As shown in FIGS. 6 and 7, the bifurcated cam follower 54 includes a first follower 54 a and a second follower 54 b that are opposed to each other, and the first follower 54 a is pushed by the vertical drive cam 50. When the vertical driving force transmission member 51 swings backward, the swing link member 52 swings upward about the pivot shaft 13, and the movable blade 55 and the differential feed dog member 4 are driven upward, and the second The follower 54b is pushed. When the vertical driving force transmission member 51 swings forward, the movable blade 55 and the differential feed dog member 4 are driven downward.
[0039]
The movable member 53 is located on the left side of the plate-like frame 95 (see FIG. 8) in the vertical posture, and a shaft portion 57 (pin member) facing in the left-right direction is integrally formed at the upper end portion of the movable member 53. The shaft portion 57 and the pin 54 protrude rightward from the movable member 53, and are inserted vertically through elongated holes 58 and 59 formed in the plate-like frame 95 to be guided in the vertical direction. Note that the front and rear end faces of the shaft portion 57 are chamfered and are in sliding contact with the vertical surfaces of the long holes 58, respectively.
[0040]
As shown in FIG. 8, the shaft portion 57 extends to the left from the movable member 53, and a shaft member 57 a is slidably inserted into the shaft portion 57, and is inserted into the shaft member 57 a on the right side of the plate frame 95. The movable blade 55 is fixed. On the other hand, the fixed blade 56 is attached to the upper end of the plate-like frame 95 so as to slightly protrude above the needle plate 84. A retaining ring 57b is attached to the left end portion of the shaft member 57a, and a compression coil spring 57c is externally mounted on the shaft member 57b between the retaining ring 57b and the left end of the shaft portion 57, and the movable blade 55 is fixed by the urging force of the coil spring 57c. The cloth end portion just before sewing sent to the rear side is cut by the cooperation of the movable blade 55 and the fixed blade 56 which are in sliding contact with each other and move up and down.
[0041]
The front end portion of the swing transmission member 60 is pivotally attached to the plate-like frame 95 by the pivot pin 61, and the front end lower surface portion of the differential feed dog member 4 is disposed in the vicinity of the upper end of the middle portion of the swing transmission member 60. A shaft-shaped transmission portion 62 that is slidably supported and transmits the vertical driving force to the differential feed dog member 4 is formed to project leftward. A long hole 63 whose long axis faces the pivot pin 61 is formed at the other end of the swing transmitting member 60, and the shaft 57 of the movable member 53 is engaged with the long hole 63 (see FIG. 16 to 19).
[0042]
An eccentric pin portion 66 is integrally formed on the pivot pin 61, and the front end portion of the swing transmission member 60 is pivotally supported on the eccentric pin portion 66. 16 shows a state where the movable blade 55 and the differential feed dog member 4 are located at the ascent limit position, and FIG. 17 shows a state where the movable blade 55 and the differential feed dog member 4 are located at the descending limit position. 62 and the differential feed dog member 4 move up and down with a stroke of about 2/3 of the up and down stroke h of the movable blade 55.
[0043]
The height position adjusting device will be described.
The height position adjusting device is included in the vertical drive mechanism 7 and includes a first adjustment mechanism 8 for finely adjusting the height position of the differential feed dog 3 and the front and rear drive mechanism 5 of the main feed dog 1. It comprises a second adjustment mechanism 9 for finely adjusting the height position.
[0044]
As shown in FIGS. 15 to 19, the first adjusting mechanism 8 includes an eccentric pin portion 66 integrally formed with a pivot pin 61 that pivotally supports the swing transmission member 60 on the plate frame 95, and transmits the swing transmission. An eccentric mechanism 65 capable of finely adjusting the height position of the transmission portion 62 of the member 60 is provided. Since the shaft center 66a of the eccentric pin portion 66 is eccentric by the amount of eccentricity e (for example, 1.5 mm) with respect to the shaft center 61a of the pivotal support pin 61, by rotating the eccentric pin portion 66 with a screw driver, It is possible to finely adjust the height position of the differential feed dog member 4 by decentering in all directions by the eccentric amount e and finely adjusting the height position of the transmission portion 62. In the fine adjustment described above, the locking screw screwed into the frame is loosened with a screwdriver to rotate the eccentric pin portion 66 to a desired position, and after the fine adjustment, the locking screw is tightened to fix the position of the eccentric pin portion 66. .
[0045]
16, 18 and 19 show the state of the first adjustment mechanism 8 when the movable blade 55 is raised to the ascent limit position. From the state of the first adjustment mechanism 8 in FIG. As shown in FIG. 18, the shaft center 66 a of the eccentric pin portion 66 is eccentric with respect to the shaft center 61 a of the pivot support pin 61, and the height position of the eccentric pin portion 66 is rotated. Is increased by e, the rocking transmission member 60 is rotated clockwise in the drawing about the axial center 57a of the shaft portion 57, and the height of the transmission portion 62 is increased by about e / 2.
[0046]
Although not shown, from the state of the first adjustment mechanism 8 of FIG. 16, for example, the eccentric pin portion 66 is rotated 90 degrees clockwise in the drawing, and the eccentric pin portion 66 is rotated with respect to the axis 61a of the pivot pin 61. When the shaft center 66a is decentered and the height position of the eccentric pin portion 66 is increased by e, the rocking transmission member 60 is rotated counterclockwise in the drawing about the shaft center 57a of the shaft portion 57, and transmitted. The height of the part 62 is reduced by about e / 2.
[0047]
Further, for example, the eccentric pin portion 66 is rotated 180 degrees in the drawing from the state of the first adjusting mechanism 8 in FIG. 16, and the eccentric pin portion 66 with respect to the axis 61 a of the pivot pin 61 as shown in FIG. 19. When the eccentric pin portion 66 is moved 2e to the left, the height position of the eccentric pin portion 66 does not change, but the guide action of the long hole 63 causes the eccentric pin portion 66 to move. Since the distance between the shaft center 66a and the shaft center 57a of the shaft portion 57 is shortened, the height of the transmission portion 62 is also lowered.
[0048]
Thus, the height position of the transmission portion 62 is not only due to the change in the height position of the eccentric pin portion 66 but also due to the change in the distance between the shaft center 66a of the eccentric pin portion 66 and the shaft center 57a of the shaft portion 57. Adjusted. Thus, by rotating the eccentric pin portion 66, the height position of the transmission portion 62, that is, the height position of the differential feed dog 3 can be finely adjusted.
[0049]
As shown in FIGS. 15 and 20 to 22, the second adjusting mechanism 9 is guided by an attachment member 17 pivotally supported by the pin member 16 of the main feed arm 14 so that the main feed dog member 2 is screwed. The elevating member 70 is fixed to the fixing member 71, and the elevating member 70 is fastened to the mounting member 17 with a pair of screws 72 so that the fastening can be released.
[0050]
The attachment member 17 is formed in a U-shaped cross section, and an elevating member 70 is disposed between the attachment members 17. A vertically oriented guide pin 73 is inserted into the elevating member 70 and fixed by a retaining ring 73a. The upper and lower end portions of the guide pin 73 are guided through the upper and lower end portions of the mounting member 17 so as to be movable up and down. A pair of left and right elongated holes 75 that are vertically long are formed in the rear end portion of the mounting member 17, and a pair of screws 72 are inserted from the rear side of the mounting member 17 through the pair of elongated holes 75. It is screwed on. That is, the pair of screws 72 are loosened, the main feed dog member 2 is moved to a desired position between the rising limit position shown in FIG. 21 and the lowering limit position shown in FIG. 22, and the pair of screws 72 are tightened. The main feed dog member 2 can be fixed at the height position.
[0051]
The operation and effect of the lock sewing machine M will be described.
In the differential feed device 6, the differential feed dog member 4 is supported by the main feed dog member 2 via the slide mechanism 20, is urged forward by the compression coil spring 21, and is differentially fed by the differential feed coupling mechanism 22. The member 4 and the main feed dog member 2 are operatively connected, the differential feed connection mechanism 22 is switched to the first state, and the main feed dog member 2 and the differential feed dog member 4 are fed together. Since the differential feed dog member can be switched to the second state and the differential feed dog member 4 can be operated at a feed amount 2a that is approximately twice the feed amount a of the main feed dog member 2, the differential feed Since the structure of the device 6 is simple and small, the manufacturing cost can be reduced, and the feed amount of the differential feed dog member 4 is adjusted in two stages, so that it is very easy for the user to use.
[0052]
The differential feed coupling mechanism 22 is pivotally attached to the main feed arm 14 that transmits the feed driving force to the main feed dog member 2 via a shaft member 35 and the upper end thereof is a coupling fitting 26, that is, a difference. Since the link member 30 operatively connected to the moving feed dog member 2 is provided, the pin member 42 includes a pin member 42 that is detachably engaged with the engagement portion 30a of the link member 30. Since the switching operation mechanism 31 for switching the differential feed connecting mechanism 22 by engaging / disengaging with 30a is provided, the differential feed connecting mechanism 22 can be switched between the first state and the second state very easily and reliably. Become.
[0053]
The switching operation mechanism 31 is operatively connected to the pin member 42, and engages and disengages the pin member 42 with the engaging portion 30a of the link member 30, and when the pin member 42 engages with the engaging portion 30a. Since the torsion spring member 44 that urges the pin member 42 is provided so that the engagement position is maintained and the disengagement position 30a is retained when the disengagement portion 30a is disengaged, the knob member 40 is operated. The pin member 42 can be easily engaged and disengaged with the engaging portion 30a, and when the knob member 40 is not operated, the pin member 42 can be reliably held at the engagement position or the disengagement position.
[0054]
The ratio of the distance b2 from the pivot shaft 13 to the shaft member 35 and the distance b1 from the pivot shaft 13 to the pin member 16, the distance c2 from the pin member 42 to the pin member 36, and the distance c2 from the pin member 42 to the shaft member 35. When the differential feed coupling mechanism 22 is switched to the second state by appropriately changing the ratio of the distance c1 until the differential feed dog member 4 with respect to the feed amount a of the main feed dog 1 changes the feed amount. Can do. Further, the switching operation mechanism 31 is not limited to the structure of the present embodiment, and various structures can be employed.
[0055]
【The invention's effect】
According to the differential feed device of the sewing machine of the first aspect, the differential feed dog member is supported on the main feed dog member via the slide mechanism, biased to the front side by the spring member, and the differential feed coupling mechanism is used to perform the differential feed. The feed dog member and the main feed dog member are operatively connected, the differential feed connection mechanism is switched to the first state, and the main feed dog member and the differential feed dog member are fed together to perform differential operation. By switching the feed coupling mechanism to the second state, the differential feed dog member can be fed with a feed amount that is a predetermined multiple of the feed amount of the main feed dog member, so the structure of the differential feed device is simple and compact. Therefore, the manufacturing cost is also low, and the feed amount of the differential feed dog member is adjusted in two steps, which makes it very easy for the user to use.
[0056]
According to the differential feeding device of the sewing machine of the second aspect, the same effect as that of the first aspect is obtained, but the differential feeding coupling mechanism has a height on the main feeding arm that transmits the feeding driving force to the main feeding tooth member. A pin member that includes a link member that is pivotally attached in the middle of the direction and that has an upper end portion that is operatively connected to the differential feed dog member, and that engages and disengages with an engagement portion at the lower end portion of the link member; Since a switching operation mechanism for switching the differential feed connecting mechanism is provided by engaging / disengaging the pin member with the engaging portion, the differential feed connecting mechanism is switched between the first state and the second state very easily and reliably. It becomes possible.
[0057]
According to the differential feeding device for a sewing machine of the third aspect, the same effect as in the second aspect is obtained, but the differential feeding coupling mechanism is in the first state when the pin member is not engaged with the engaging portion. Since the pin member is configured to be in the second state when the pin member is engaged with the engaging portion, the differential feed coupling mechanism can be easily and reliably switched between the first state and the second state. Can do.
[0058]
According to the differential feed device for a sewing machine of claim 4, the same effect as in any one of claims 1 to 3 is obtained, but the predetermined multiple is configured to be about double, so that the differential feed coupling mechanism is When switched to the second state, the differential feed dog member can be operated with a feed amount that is approximately twice the feed amount of the main feed dog member, and good differential feed can be performed for sewing.
[0059]
According to the differential feeding device for a sewing machine of the fifth aspect, the same effect as in the third or fourth aspect is obtained, but the switching operation mechanism is operatively connected to the pin member and the pin member is used as an engaging portion. A knob member that engages and disengages, and a spring that biases the pin member so that the engagement position is maintained when the pin member is engaged with the engagement portion and the disengagement position is maintained when the pin member is disengaged from the engagement portion. The pin member can be easily engaged and disengaged with the engaging portion of the link member by operating the knob member. When the knob member is not operated, the pin member is moved to the engagement position or the disengaged position. It can be held securely.
[Brief description of the drawings]
FIG. 1 is a perspective view of a lock sewing machine according to an embodiment of the present invention.
FIG. 2 is a front view of the lock sewing machine.
FIG. 3 is a left side view of the lock sewing machine.
FIG. 4 is a left side perspective view of the lock sewing machine.
FIG. 5 is a front perspective view of the lock sewing machine.
FIG. 6 is a left side view of the main part inside the lock sewing machine.
FIG. 7 is a right side view of an essential part inside the lock sewing machine.
FIG. 8 is a plan view of an essential part inside the lock sewing machine.
FIG. 9 is a front view of an essential part inside the lock sewing machine.
FIG. 10 is an operation explanatory diagram of the differential feeding device (first state).
FIG. 11 is an operation explanatory diagram of the differential feeding device (first state).
FIG. 12 is an operation explanatory diagram of the differential feeding device (second state).
FIG. 13 is an operation explanatory diagram of the differential feeder (second state).
FIG. 14 is a diagram showing feed amounts of a main feed dog member and a differential feed dog member.
FIG. 15 is a view showing a height position adjusting mechanism (first and second adjusting mechanisms).
FIG. 16 is an operation explanatory diagram of the vertical drive mechanism.
FIG. 17 is an operation explanatory diagram of the vertical drive mechanism.
FIG. 18 is an operation explanatory diagram of the first adjustment mechanism.
FIG. 19 is an operation explanatory diagram of the first adjustment mechanism.
20 is a cross-sectional view taken along line XX-XX in FIG.
FIG. 21 is an operation explanatory diagram of the second adjustment mechanism.
FIG. 22 is an operation explanatory diagram of the second adjustment mechanism.
[Explanation of symbols]
M lock sewing machine
1 Main feed dog
2 Main feed dog members
3 Differential feed dog
4 Differential feed dog members
5 Front-rear drive mechanism
6 Differential feeder
7 Vertical drive mechanism
8 First adjustment mechanism
9 Second adjustment mechanism
10 Drive shaft
11 Longitudinal drive cam
12 Front / rear driving force transmission member
13 pivot axis
14 Main feed arm
16 Pin member
20 Slide mechanism
21 Compression coil spring
22 Differential feed coupling mechanism
30 Link member
30a Engagement part
31 Switching operation mechanism
40 Knob member
42 Pin member
44 Torsion spring
50 Vertical drive cam
51 Vertical drive force transmission member
52 Swing link member
54 Forked cam follower
55 Movable blade
57 Shaft (pin member)
60 Oscillating transmission member
61 pivot pin
62 Transmitter
63 Slotted hole
65 Eccentric mechanism
66 Eccentric pin
84 Needle plate

Claims

In the differential feed device of the sewing machine comprising the main feed dog and the differential feed dog that feed the cloth to be sewn on the needle plate, and the differential feed dog and the main feed dog arranged at the front and back,
A main feed dog member comprising the main feed dog;
A slide mechanism that moves the differential feed dog member having the differential feed dog up and down integrally with the main feed dog member, and supports the main feed dog member so as to be movable in a predetermined stroke relative to the cloth feed direction;
A spring member that elastically biases the differential feed dog member forward relative to the main feed dog member; a first state in which the differential feed dog member feeds and operates integrally with the main feed dog member; and differential feed A differential feed connection that operatively connects the differential feed dog member and the main feed dog member so that the tooth member can be switched to a second state in which the feed operation is performed at a feed amount that is a predetermined multiple of the feed amount of the main feed dog member. Mechanism,
A differential feeding device for a sewing machine comprising:

The differential feed coupling mechanism is a link member in which a middle portion in the height direction is pivotally attached to a main feed arm that transmits a feed driving force to the main feed dog member, and an upper end portion is operatively connected to the differential feed dog member. With
There is provided a switching operation mechanism including a pin member that is detachably engaged with an engaging portion at a lower end portion of the link member, and switching the differential feed connecting mechanism by engaging and disengaging the pin member with the engaging portion. The differential feeding device for a sewing machine according to claim 1, wherein:

The differential feed coupling mechanism is in a first state when the pin member is not engaged with the engaging portion, and is in a second state when the pin member is engaged with the engaging portion. The differential feeding device for a sewing machine according to claim 2.

The differential feed device for a sewing machine according to any one of claims 1 to 3, wherein the predetermined multiple is approximately double.

The switching operation mechanism is operatively connected to the pin member and holds the engaging position when the pin member is engaged with the engaging portion; 5. The differential feeding device for a sewing machine according to claim 3, further comprising a spring member that biases the pin member so as to hold the disengaged position when the engaging portion is disengaged.