JP3948132B2

JP3948132B2 - Sewing presser lifting device

Info

Publication number: JP3948132B2
Application number: JP26673898A
Authority: JP
Inventors: 雅夫小川
Original assignee: Brother Industries Ltd
Current assignee: Brother Industries Ltd
Priority date: 1998-09-21
Filing date: 1998-09-21
Publication date: 2007-07-25
Anticipated expiration: 2018-09-21
Also published as: JP2000093677A

Description

【０００１】
【発明の属する技術分野】
本発明は、ミシンの布押え昇降装置に関し、特に布押えを手動操作レバー以外に、操作者の膝操作や足踏み操作による操作レバーにより、或いはボタン操作などによる動力源により昇降するようにした技術に関する。
【０００２】
【従来の技術】
従来、家庭用の電子制御式ミシンにおいては、その頭部に、縫針を下端に取付けた針棒と、布押えを下端に取付けた押え棒とが配設され、この布押えを上下動させる布押え昇降装置が設けられている。即ち、この布押え昇降装置においては、押え棒の途中部に押え棒抱きが設けられ、押え棒に接近させて設けられた手動操作レバーを手動操作することで、押え棒抱きを介して押え棒が下降位置から上昇して布押えが上昇位置に切換えられて保持されるようになっている。そして、この状態のときに、縫製する加工布をセットしたり、縫製した加工布を取り出すようにしている。
【０００３】
ところで、手動操作レバーにより布押えを昇降させる場合、手動操作レバーを必ず手で操作するので、布押えの昇降操作が面倒なことから、最近では、工業用ミシンのように、操作者の膝で操作する膝操作レバーを介して布押えを昇降操作できるようにした家庭用ミシンが実用に供されている。例えば、図２０に示すように、手動操作レバー１２８に加えて、膝操作レバー１４８により布押え１２１を昇降操作する家庭用ミシンの布押え昇降装置１２０について説明する。
【０００４】
アーム部３の頭部４には、押え棒１２２がフレームＦに上下動可能に支持され、この押え棒１２２の途中部に押え棒抱き１２６が固着され、押え棒１２２は押えバネ１２３により下方に弾性付勢され、下端に取付けられた布押え１２１を介して加工布を押圧する。この押え棒抱き１２６に糸緩め作動部材１３２が固着され、この糸緩め作動部材１３２には糸調子機構１３０を張力解放状態に切換える糸緩め板１００が連結されている。そして、フレームＦに回動可能に設けられた手動操作レバー１２８を手で上側に回動操作することにより、手動操作レバー１２８のカム部により押え棒抱き１２６を介して押え棒１２２が上昇位置に上昇してロックされるのと同時に、糸緩め作動部材１３２を介して糸緩め板１００により糸調子機構１３０が張力解放状態に切換えられる。
【０００５】
一方、ミシンのベッド部１には、前後方向向きの回動軸１４５がフレームに回動可能に枢支され、回動軸１４５の後端部に固着した連結部材１０１の２つの端部１０１ａ，１０１ｂがフレームＦに当接することで、回動軸１４５の回動範囲が規制されている。アーム部３には揺動レバー１０２が配設され、この揺動レバー１０２は枢支ピン１０３により揺動可能であり、その左端部において糸緩め作動部材１３２に連結されるとともに、その右端部において連結ロッド１０４の上端部に連結されている。
【０００６】
更に、この連結ロッド１０４の下端部は、回動部材１０５の一端部に連結され、回動部材１０５の他端部は連結部材１０１の一方の端部１０１ｂに上側から当接し、この回動部材１０５は引っ張りコイルバネ１０６により正面視反時計回りに付勢されている。そして、前記回動軸１４５の前端部に膝操作レバー１４８の基端部が着脱可能に装着されている。即ち、この状態においては、膝操作レバー１４８は、押えバネ１２３と引っ張りコイルバネ１０６のバネ力により、連結部材１０１の端部１０１ｂがフレームＦに当接する通常位置Ｌ１に保持されている。
【０００７】
そして、膝でその膝操作レバー１４８の操作部１４８ａを右方に押圧することにより、膝操作レバー１４８が操作位置Ｌ２まで回動するときに、回動軸１４５が正面視反時計回りに回動し、連結部材１０１と回動部材１０５とを介して連結ロッド１０４の下方への移動で揺動レバー１０２の左端部が上昇するのと同時に、糸緩め作動部材１３２が上昇するので、手動操作レバー１２８のときと同様に、押え棒抱き１２６を介して押え棒１２２が上昇するので、糸緩め板１００により糸調子機構１３０が張力解放状態に切換えられる。
【０００８】
ここで、膝で膝操作レバー１４８を回動操作する場合に、押えバネ１２３や引っ張りコイルバネ１０６のバネ力に抗して回動させるので、回動操作量が大きくなる程、つまり押え棒１２２をより高く上昇させる程、そのバネ力が大きくなり操作性に欠けることから、特公昭５５−４４３４号公報においては、電動アクチュエータで押え棒を上昇駆動する電動式押え上げ装置が記載されている。また、特公平６−４０９１７号公報においては、この電動式押え上げ装置の欠点を解消するように、押え棒を付勢する押えバネのバネ力を電動アクチュエータで軽減させるようにし、押え棒の高さ位置を任意に変更可能にした電動式押え上げ装置が記載されている。
【０００９】
【発明が解決しようとする課題】
図２０に示す従来の家庭用ミシンの布押え昇降装置１２０においては、操作者の操作性を考慮して、ミシンモータを駆動する起動スイッチや返し縫いスイッチなどがミシン操作し易い頭部４に設けられている。そして、手動操作レバー１２８を操作して布押え１２１を上昇位置に切換えて保持したときには、押え棒１２２のこのときの高さ位置を検出してミシンモータの駆動を禁止するようになっているが、ミシン停止中のときに、膝操作レバー１４８を操作して押え棒１２２を上昇させて加工布を布押え１２１の下側にセットするときに、細かい布の取扱い作業が多い場合には、布押え１２１を上昇位置まで上昇させるようなことがなく、このときに、誤って手が起動スイッチに触れてミシンモータが駆動されることがあり、縫針が折損するなどの事故が発生し易いという問題がある。
【００１０】
また、布厚が数ミリもある厚手の生地を縫製している場合には、押えバネ１２３のバネ力が回動軸１４５に及ばないことから、膝操作レバー１４８は、通常位置Ｌ１から布押え１２１の布押え位置に対応する操作位置Ｌ２までの範囲において、引っ張りコイルバネ１０６が作用するだけのほぼフリー状態になっているので、操作者の膝が縫製中に膝操作レバー１４８をうっかりと押すようなときには、布押え１２１が上昇して加工布を押圧しなくなって縫目不良になり、しかも糸緩め板１００により糸調子機構が張力解放状態に切換えられて糸調子不良になること、などの問題がある。
【００１１】
そこで、膝操作レバー１４８を常に通常位置Ｌ１に保持するように、回動軸１４５を常に正面視で時計回りに付勢する付勢バネを別途設ける場合、或いは引っ張りコイルバネ１０６のバネ力を強くする場合には、操作者の膝にこの付勢バネのバネ力が作用して、膝操作レバー１４８をうっかりと押すような間違いが起こりにくいが、布押え１２１を上昇させる為に膝操作レバー１４８を操作するときには、押えバネ１２３や引っ張りコイルバネ１０６に加えて、別途設けた付勢バネのバネ力が同時に作用することになり、膝操作レバー１４８の操作性が悪くなるという問題がある。
【００１２】
本発明の目的は、ミシン停止中に膝操作レバーで押え棒を上昇操作したときにミシンモータの起動を禁止すること、縫製中に膝操作レバーを操作したときにミシンモータの駆動を停止すること、膝操作レバーの操作性を向上させること、ミシン操作の安全性を高めること、等である。
【００１３】
【課題を解決するための手段】
請求項１のミシンの布押え昇降装置は、ミシンモータにより上下動される縫針と、押え棒の下端に取付けられた布押えと、この布押えを加工布を押える押圧位置と上昇位置とに切換える布押え上下動機構と、糸駒から縫針の目孔に至る上糸に張力を付与する糸調子機構と、この糸調子機構を張力解放状態に切換える張力解放機構と、手動操作により布押え上下動機構を操作する手動操作レバーと、手動操作以外の操作により布押え上下動機構を操作する第２の操作部材とを備えたミシンの布押え昇降装置において、第２の操作部材が布押え上昇側へ操作されていることを検出して操作検出信号を出力するスイッチ手段と、ミシンモータの停止状態においてスイッチ手段から検出信号を受けたときミシンモータの駆動を禁止する駆動禁止制御手段とを備えたものである。
【００１４】
第２の操作部材を布押え上昇側へ操作することにより、布押え上下動機構により布押えが上昇する。ところで、ミシンモータの停止状態のときに、第２の操作部材が布押え上昇側へ操作されたとき、スイッチ手段はその第２の操作部材の操作を検出して操作検出信号を出力する。その結果、駆動禁止制御手段は、スイッチ手段から検出信号を受けると直ぐにミシンモータの駆動を禁止する。即ち、第２の操作部材が膝操作レバーのときに、この膝操作レバーを膝で間違って操作したときには、スイッチ手段から出力される操作検出信号によりミシンモータの駆動が確実に禁止される。
【００１５】
請求項２のミシンの布押え昇降装置は、請求項１の発明において、前記押え棒の高さ位置をリアルタイムで検出する高さ検出手段と、縫製中に高さ検出手段とスイッチ手段からの検出信号を受け、スイッチ手段が操作検出信号を出力中であり、且つ押え棒の高さ位置が操作検出信号の出力開始時の高さよりも高くなったことを条件としてミシンモータの駆動を停止する駆動停止制御手段とを備えたことを特徴とするものである。
【００１６】
この場合、高さ検出手段は、例えばポテンショメータなどの電気的な信号を出力可能なアクチュエータを有し、押え棒の高さ位置をリアルタイムで検出する。そして、駆動停止制御手段は、縫製中に高さ検出手段とスイッチ手段からの検出信号を受け、スイッチ手段が操作検出信号を出力中であり、しかも押え棒の高さ位置が操作検出信号の出力開始時の高さよりも高くなったことを条件として、つまり第２の操作部材の操作量が大きくなって、布押えが縫製中の加工布の布厚に対応する高さ以上に上昇するときには、ミシンモータの駆動を停止する。その他請求項１と同様の作用を奏する。
【００１７】
請求項３のミシンの布押え昇降装置は、請求項２の発明において、前記第２の操作部材の操作により押え棒を上昇させる押え上げ回動部材と、この押え上げ回動部材の回動に連動して張力解放機構を作動させる糸緩め部材の為の作動制御部材と、スイッチ手段の作動制御部材とを設け、糸緩め部材は押え上げ回動部材の回動作動の後期に張力解放機構を作動させるように構成されたことを特徴とするものである。
【００１８】
この場合、第２の操作部材を操作することで押え上げ回動部材が回動して押え棒を上昇させるが、糸緩め板はこの押え上げ回動部材の回動作動の後期において、押え上げ回動部材に連動して張力解放機構を作動させる。また、押え上げ回動部材の回動初期にスイッチ手段を作動させる。即ち、第２の操作部材である膝操作レバーを膝により誤って操作する場合、押え棒が上げられる前にミシンの駆動は禁止されて布操作の安全性が確保され、そして押え上げ回動部材の回動作動の後期に対応するまで、第２の操作部材を誤って大きく操作することは滅多にないので、糸調子機構による上糸への張力付与を確保でき、糸調子不良を防止できる。これら３つの作用が１つの押え上げ回動部材に集約され、一層確実に実行される。その他請求項２と同様の作用を奏する。
【００１９】
請求項４のミシンの布押え昇降装置は、請求項３の発明において、前記押え上げ回動部材の回動中心から押え上げ回動部材の回動時に押え棒を上昇させる回転コロの中心作動部までの水平方向レバー長が、回動角の増大に応じて減少するように構成されたことを特徴とするものである。
この場合、第２の操作部材を操作することで押え上げ回動部材が回動して押え棒を上昇させるときに、押え上げ回動部材の回動中心から、押え上げ回動部材の回動時に押え棒を上昇させる回転コロの中心作動部までの水平方向レバー長は、回動角の増大に応じて、つまり押え棒を上昇させる程減少する。即ち、押え棒が上昇するに応じて、第２の操作部材による操作力を一層軽くできる。その他請求項３と同様の作用を奏する。
【００２０】
請求項５のミシンの布押え昇降装置は、請求項２〜４の何れか１項の発明において、前記駆動禁止制御手段は、ミシンモータの停止状態において高さ検出手段で検出した高さ位置が布押えの最上位置付近に対応する所定値以上のときにも、ミシンモータの駆動を禁止することを特徴とするものである。
この場合、例えば手動操作レバーを操作するなどして、布押えを最上位置付近の上昇位置まで上昇させたときには、高さ検出手段はこのときに検出した高さ位置が所定値以上であるとしてミシンモータの駆動を禁止する。即ち、布押えが上昇位置に保持されているときには、操作者の両手を使えるようになり、誤って起動スイッチを操作した場合でも、ミシンの起動を確実に阻止できる。その他請求項２〜４の何れか１項と同様の作用を奏する。
【００２１】
請求項６のミシンの布押え昇降装置は、請求項１〜５の何れか１項の発明において、前記手動操作レバーに形成された係合部を介して布押えをその上昇位置にロックするように構成され、第２の操作部材の操作により布押えの上昇位置におけるロック状態を解除可能に構成されたことを特徴とするものである。
この場合、手動操作レバーを操作して布押えを上昇させるときに、手動操作レバーに形成された係合部を介して布押えが上昇位置にロックされた場合でも、第２の操作部材を大きく操作することで、手動操作レバーの上昇位置におけるロック状態を確実に解除できる。その他請求項１〜５の何れか１項と同様の作用を奏する。
【００２２】
【００２３】
【００２４】
【００２５】
【００２６】
【００２７】
【００２８】
【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に基いて説明する。本実施形態は、実用模様やワンポイントマーク等の種々の模様縫いが可能な電子制御式ミシンに本発明を適用した場合の例である。
電子制御式ミシンＭは、図１に示すように、ミシンベッド部１と、ベッド部１の右端部から立設された脚柱部２と、脚柱部２の上端からベッド部１に対向するように左方へ延びるアーム部３を有する。
ベッド部１には、送り歯を上下動させる送り歯上下動機構（図示略）及び前後動させる送り歯前後動機構（図示略）、下糸ボビンを収容し縫針１８と協働する糸輪捕捉器（例えば、水平釜）等が設けられている。
【００２９】
アーム部３には、下端に縫針１８を装着した針棒１５を上下動させる針棒駆動機構１０、針棒１５を布送り方向と直交する方向に揺動させる針棒揺動機構（図示略）、天秤１３を針棒１５の上下動に調時して上下動させる天秤駆動機構（図示略）等が設けられている。尚、送り歯上下動機構と針棒駆動機構と天秤駆動機構とはミシンモータ１６で駆動され、針棒揺動機構は針棒揺動用モータ８４で駆動され、送り歯前後動機構は送り歯前後駆動用モータ８５で駆動される（図１７参照）。アーム部３の頭部４には、縫製作業の起動と停止を指令する起動・停止スイッチ７、返し縫いスイッチ８などが設けられている。
【００３０】
アーム部３の前面には大型の液晶ディスプレイ５が設けられ、このディスプレイ５の前面には、複数の模様や機能を示す機能名の表示位置の各々に対応させて、透明電極からなるタッチキー６がマトリックス状に設けられている。即ち、所望の模様の選択や機能の指示を、これら模様や機能名に対応するタッチキー６を押圧操作することで実現することができる。
【００３１】
ここで、針棒駆動機構１０について、図２に基づいて簡単に説明すると、アーム部３に配設された主軸１１の左端部にはクランク部材１２が固着され、そのクランク部材１２には天秤１３が設けられるとともに、クランクレバー１４の上端部がピン結合され、クランクレバー１４の下端部が針棒１５の中断部に連結されている。これにより、ミシンモータ１６でベルト１７を介して主軸１１が回転駆動されると、クランク部材１２とクランクレバー１４を介して針棒１５が上下に駆動されるのと同時に、天秤１３も上下駆動され、縫針１８と糸輪捕捉器とにより、後述する布押え２１で押圧された加工布に縫目が形成される。
【００３２】
次に、押え棒２２の下端部に着脱可能に装着された布押え（押え足）２１を手動操作レバー２８又は膝操作レバー４８（第２操作部材に相当する）で昇降駆動させる布押え昇降装置２０について、図３〜図６に基づいて説明する。
前記頭部４には、下端部に布押え２１を取付けた押え棒２２が上下方向向きに配設され、ミシンフレームＦに上下動可能に支持されている。そして、圧縮コイルバネからなる押えバネ２３の上端をこのミシンフレームＦに固定し且つその下端を押え棒２２に固定することで、押え棒２２が下方に弾性付勢されている。
【００３３】
次に、手動操作レバー２８の操作により、布押え２１を押圧位置と上昇位置とに切換える布押え上下動機構２５について説明する。
この押え棒２２の中段部には、左右方向に長い押え棒抱き２６が固着されている。一方、頭部４の右下隅部には、前後方向向きの枢支軸２７により手動操作レバー２８がミシンフレームＦに回動可能に枢支され、図３に示すように、下側の非操作位置２８（Ｌ）と、略水平な第１操作位置２８（Ｈ）と、これよりも上側の第２操作位置２８（Ｔ）とに切換え操作可能になっている。
【００３４】
この手動操作レバー２８には図６に示すように、押え棒抱き２６の左端部の下側の傾斜状端面２６ａ（図７、図９参照）に係合する係合部２８ａと、後述する糸緩め部材３２を押圧作動する第１作動部２８ｂが形成されるとともに、後述する作動板６７を押圧作動する第２作動部２８ｃが形成されている。即ち、図９に示すように、手動操作レバー２８が非操作位置２８（Ｌ）のときには、布押え２１が針板９の上面の押圧位置であり、押え棒抱き２６は実線で示す２６（Ｌ）の高さ位置である。
【００３５】
そして、手動操作レバー２８を第１操作位置２８（Ｈ）に切換えたときには、押え棒抱き２６は係合部２８ａのカム形状により鎖線で示す２６（Ｈ）の高さ位置に上昇し、更に、手動操作レバー２８を第２操作位置２８（Ｔ）に切換えたときには、押え棒抱き２６は鎖線で示す２６（Ｔ）の高さ位置に更に上昇する。但し、手動操作レバー２８を第２操作位置２８（Ｔ）に切換えるのは、厚手の生地を布押え２１の下側にセットするような場合である。ここで、手動操作レバー２８を第１操作位置２８（Ｈ）に切換えたとき、その係合部２８ａが押え棒抱き２６の傾斜状端面２６ａに係合することで、手動操作レバー２８はその第１操作位置２８（Ｈ）にロックされる。
【００３６】
次に、上糸に張力を付与する糸調子機構３０を張力解放状態に切換える張力解放機構３１について説明する。
この糸調子機構３０は、上糸を挟持する１対の糸調子皿をバネ力で付勢することで、上糸に張力を付与するように構成された一般的なものである。
図８、図１３に示すように、前記手動操作レバー２８の直ぐ上側には、糸緩め部材３２が枢支ピン３３でミシンフレームＦに回動自在に枢支されている。この糸緩め部材３２の右端部に糸緩めロット３４の下端部が連結され、この糸緩めロット３４の上端部は、図４に示すように、糸調子機構３０の可動調子皿（図示略）に連結され、糸緩めロット３４が下方移動することにより、糸調子機構３０を張力解放状態に切換えるようになっている。
【００３７】
即ち、手動操作レバー２８を非操作位置２８（Ｌ）から第１操作位置２８（Ｈ）に切換えたときには、図１０に示すように、手動操作レバー２８の第１作動部２８ｂで糸緩め部材３２を正面視にて時計回りに回動させるので、糸緩めロット３４を下方に移動して、糸調子機構３０が張力解放状態に切換えられる。
次に、膝操作レバー４８を操作して、布押え２１を押圧位置と上昇位置とに切換える布押え上下動機構４０について説明する。
図３〜図５に示すように、前記手動操作レバー２８の後側には、平面視略コ字状の押え上げ回動部材４１が、手動操作レバー２８の枢支軸２７により回動自在に枢支されている。
【００３８】
図１３に示すように、この押え上げ回動部材４１の前壁の突起部４１ａには、コロ４２（回転コロに相当する）が回転可能に枢着され、前壁のその突起部４１ａから回動中心方向に戻る上端面に形成された段差部にリフトカム（これが、糸緩め部材の作動制御部材に相当する）４１ｄが形成されている。また、図１５に示すように、押え上げ回動部材４１の後壁の下側には、膝操作レバー４８の操作を検出する操作検出スイッチ６６を作動（ＯＮ状態）させる作動突起部（これが、スイッチ手段の作動制御部材に相当する）４１ｂが形成されるとともに、上側突起部４１ｃには、後述するリンク機構５０の連結リンク５１の左端部が連結されている。
【００３９】
即ち、膝操作レバー４８の操作時に、押え上げ回動部材４１が回動して、このリフトカム４１ｄが後述する糸緩めピン３５に係合するとき、つまり布押え２１の上昇位置以上に上昇するときに、糸緩め部材３２による糸緩め解放量がその最大値に維持される。
一方、図３、図１１に示すように、ベッド部１には、前後方向向きの回動軸４５がミシンフレームＦに回動自在に枢支され、回動軸４５の前端部は、上下１対のスロット４５ａを有する筒状に形成されている。
【００４０】
前記回動軸４５の後端部には、引っ張りコイルバネ４６のバネ力で正面視にて時計回り方向に付勢された連結腕４７の基端部が固着されている。ここで、この回動軸４５には、後述する膝操作レバー４８の回動範囲を規定する為に、図示外のボルトが取付けられている。
膝操作レバー４８は、金属製のロッドを屈曲形成し、連結部４８ａに係合ピン４９を固定するとともに、操作者の膝で操作する幅広の操作部４８ｂを設けたものである。そして、必要に応じて、膝操作レバー４８の連結部４８ａを回動軸４５の前端部に挿入することで、係合ピン４９が回動軸４５のスロット４５ａに係合され、膝操作レバー４８が回動軸４５に連結される。
【００４１】
次に、この膝操作レバー４８の操作で前記押え上げ回動部材４１を回動させて布押え２１を昇降させるリンク機構５０について、図３、図８に基づいて説明する。
前記連結リンク５１の右端部は、ミシンフレームＦに固着した枢支ピン５２により回動可能に枢支された第１連結板５３の端部に連結されている。一方、連結腕４７の他端部には、所定形状に屈曲されたリンク板５４の下端部が連結され、このリンク板５４の上端部は、枢支ピン５２により回動可能に枢支された第２連結板５５の端部に連結されている。
【００４２】
ここで、これら第１及び第２連結板５３，５５について簡単に説明すると、第１連結板５３は、第２連結板５５に対して枢支ピン５２を回動中心として微動調節可能になっており、膝操作レバー４８の位置に対する押え上げ回動部材４１の回動位置を微調節できるようになっている。
ここで、図３において、膝操作レバー４８を操作しないときには、非操作位置（P0）であり、第１操作位置（P1）は、リンク機構５０により発生する遊び代に対応する位置である。
【００４３】
即ち、図３において、膝操作レバー４８を非操作位置（P0）から反時計回り方向、つまり布押え上昇側へ操作したときには、連結腕４７とリンク板５４と第１及び第２連結板５３，５５と連結リンク５１とを介して押え上げ回動部材４１が、図１４、図１６に示すように、正面視にて時計回りに回動するので、コロ４２が押え棒抱き２６を下側から上向きに持ち上げ、押え棒２２と布押え２１とが同時に上昇する。
【００４４】
ところで、前記糸緩め部材３２には、図５、図１４に示すように、押え上げ回動部材４１の前壁に上側から当接する糸緩めピン３５が後向きに固着されているので、押え上げ回動部材４１の時計回りへの回動時に、この糸緩めピン３５を介して糸緩め部材３２も時計回りに回動され、糸緩めロット３４を介して前述したように、糸調子機構３０を張力解放状態に切換えるようになっている。ここで、図１４に示すように、膝操作レバー４８を操作したときの押え上げ回動部材４１の回動位置４１（p1）において、押え上げ回動部材４１の前壁のリフトカム４１ｄと糸緩めピン３５との間に所定の隙間寸法が設けられているので、糸緩め部材３２による張力解放状態への切換えは、押え上げ回動部材４１の回動作動の後期において糸緩め部材３２が回動するときに実行される。
【００４５】
次に、押え棒２２の高さ位置を検出する高さ検出機構６０について、図５、図７、図１２、図１３に基づいて説明する。
前記押え棒抱き２６の後側には、ミシンケースに固定された板状の補助フレームＳＦに取付けられたホルダー板６１が配設され、このホルダー板６１の前側にポテンショメータからなる高さ検出器６２が取付けられ、この高さ検出器６２の軸６２ａに固着された作動アーム６３の先端に作動ピン６４が固着され、この作動ピン６４の先端部が押え棒抱き２６の一端部に上側から当接している（図５参照）。ここで、このホルダー板６１に位置調節可能に連結された取付け板６５に、押え上げ回動部材４１の作動突起部４１ｂで作動される操作検出スイッチ６６（スイッチ手段に相当する）が取付けられている。
【００４６】
即ち、押え棒抱き２６（布押え２１）の高さ位置に応じて、作動ピン６４と作動アーム６３とを介して軸６２ａが回動するので、高さ検出器６２から出力される高さ検出信号に基づいて、布押え２１の縫製中における布押え２１の高さ位置を検出することができる。
一方、図７、図５に示すように、押え棒抱き２６の後端面には、略横向きで且つ裏返しＪ字状の作動板６７が一端部においてピン６８で回動可能に枢支されている。
【００４７】
これにより、手動操作レバー２８を操作して第１操作位置２８（Ｈ）に切換えたときには、図６、図１０に示すように、手動操作レバー２８の第２作動部２８ｃで作動板６７を時計回りに回動させるので、作動板６７の先端部の作動部６７ａで作動ピン６４を、押え棒抱き２６の高さよりも高く押し上げることになり、高さ検出器６２からは、布押え２１が上昇位置であることを示す所定値の高さ検出信号が出力される。
【００４８】
ところで、この作動板６７には後方向きの係合ピン６９が固着され、この係合ピン６９は糸緩め部材３２に左側から係合可能になっている。即ち、図１０に示すように、手動操作レバー２８を第１操作位置２８（Ｈ）に切換えたときには、前述したように、布押え２１が上昇位置にロックされるが、このとき、膝操作レバー４８を布押え上昇側に大きく操作したときには、押え上げ回動部材４１により糸緩め部材３２が時計回りに回動するときに、糸緩め部材３２の押圧面３２ａ（図１３参照）で係合ピン６９を左方に押圧するので、作動板６７が更に時計回りに回動することになる。
【００４９】
その結果、押え上げ回動部材４１がより大きく回動し、コロ４２で押え棒抱き２６をより上昇させることにより、手動操作レバー２８の係合部２８ａと押え棒抱き２６の傾斜状端面２６ａとの係合が解除され、また手動操作レバー２８の第１作動部２８ｂと糸緩め部材３２との間に隙間が生じ、更に第２作動部２８ｃと作動板６７との間にも隙間が生じるので、手動操作レバー２８は、何れの箇所においても支持されなくなり、その自重で非操作位置２８（Ｌ）に落下し、そのロック状態が解除されることになる。
【００５０】
次に、電子制御式ミシンＭの制御系について説明する。
図１７に示すように、制御装置７５は、入力インターフェース７６と、ＣＰＵ７７とＲＯＭ７８及びＲＡＭ７９とを含むコンピュータと、出力インターフェース８０と、これらを接続するデータバスなどのバス８１とを有する。入力インターフェース７６には、起動・停止スイッチ７と、タッチキー６と、ミシン主軸の複数の回転位相を検出するエンコーダセンサ８２、操作検出スイッチ６６と、高さ検出器６２に接続されたＡ／Ｄ変換器８３などが接続されている。
【００５１】
出力インターフェース８０には、これらモータ１６、８４〜８５と、液晶ディスプレイ５の為のディスプレイコントローラ（ＬＣＤＣ）８６とが接続されている。
ＲＯＭ７８には、後述する本案特有の駆動禁止制御や駆動停止制御の制御プログラムを含むミシン制御に関する種々の制御プログラムが予め格納されている。前記ＲＡＭ７９には、前述した各種の制御に必要なメモリ類（フラグやポインタやカウンタ等のメモリ、レジスタやバッファ等）が設けられている。
【００５２】
次に、制御装置Ｃで実行される駆動禁止制御のルーチンについて、図１８のフローチャートに基づいて説明する。但し、図中符号Ｓｉ（ｉ＝１０、１１、１２・・・）は各ステップを示すものである。
ミシンＭに電源が投入されて初期化処理が実行された後、ミシン停止中において所定微小時間毎に駆動禁止制御が実行される。即ち、この制御が開始されると、先ず、高さ検出器６２から出力される高さ検出信号が読み込まれ（Ｓ10）、この高さ検出信号に基づいて押え棒２２の実際の高さ位置がリアルタイムで求められる（Ｓ11）。
【００５３】
次に、この押え棒２２の高さが上昇位置に対応する駆動禁止位置でないときで（Ｓ12：No）、しかも操作検出スイッチ６６からＯＦＦ状態の操作検出信号を受けているときには（Ｓ13：No）、ミシンモータ１６の起動が可能なので、ミシン駆動が許可され（Ｓ14）、この制御を終了してメインルーチンにリターンする。しかし、押え棒２２の高さが上昇位置に対応する駆動禁止位置のとき（Ｓ12：Yes ）、又は操作検出スイッチ６６からＯＮ状態の操作検出信号を受けているときには（Ｓ13：Yes ）、ミシン駆動を禁止するように指令され（Ｓ15）、同様にリターンする。
【００５４】
一方、縫製中においては、図１９に示す駆動停止制御が所定微小時間毎に実行される。
即ち、この制御が開始されたときに、操作検出スイッチ６６からＯＦＦ状態の操作検出信号を受けているとき、つまり膝操作レバー４８が膝で操作されていないときには（Ｓ20：No）、高さ検出器６２から出力される高さ検出信号が読み込まれ（Ｓ21）、この高さ検出信号に基づいて押え棒２２の実際の高さ位置H1が求められる（Ｓ22）。そして、この新規に求めた高さ位置H1が停止の為のしきい値Ｊとして更新され（Ｓ23）、この制御を終了してメインルーチンにリターンする。
【００５５】
一方、膝で膝操作レバー４８が操作されたことにより、操作検出スイッチ６６からＯＮ状態の操作検出信号を受けているときには（Ｓ20：Yes ）、高さ検出器６２から出力される高さ検出信号が読み込まれ（Ｓ24）、この高さ検出信号に基づいて押え棒２２の実際の高さ位置H1が求められる（Ｓ25）。そして、この新規に求めた高さ位置H1が停止用しきい値Ｊ以下のとき、つまり膝操作レバー４８が操作されているが、縫製中の布押え２１の高さが布厚よりも高くなっていないときには、ミシンモータ１６の駆動を停止させることがなく（Ｓ26：No）、同様にリターンする。
【００５６】
ところで、新規に求めた高さ位置H1が停止用しきい値Ｊよりも大きくなったとき、つまり縫製中に膝操作レバー４８が操作されて、縫製中の布押え２１の高さが布厚よりも高くなったときには（Ｓ26：Yes ）、ミシンモータ１６の駆動を停止するように指令され（Ｓ27）、同様にリターンする。これにより、布押え２１で加工布を押圧しなくなった時点でミシンの駆動が停止されるので、縫目不良の発生を未然に防止することができる。
【００５７】
次に、このように構成されたミシンＭの作動及び効果について説明する。
先ず、ミシン停止中において、手動操作レバー２８を操作して非操作位置２８（Ｌ）から水平な第１操作位置２８（Ｈ）に切換えることにより、手動操作レバー２８は上昇位置にロックされ、押え棒抱き２６が係合部２８ａのカム形状により２６（Ｈ）の高さ位置に上昇する。このとき、手動操作レバー２８の第１作動部２８ｂで糸緩め部材３２が時計回りに回動され、糸緩めロット３４が下方に移動して糸調子機構３０が張力解放状態に切換えられる。
【００５８】
更に、手動操作レバー２８の第２作動部２８ｃで作動板６７が時計回りに回動され、作動板６７の作動部６７ａで作動ピン６４が高く押し上げられ、高さ検出器６２から出力される、布押え２１が上昇位置であることを示す所定値の高さ検出信号に基づいて、ミシン駆動が禁止される。そして、この状態で加工布が布押え２１の下側にセットされ、手動操作レバー２８が非操作位置２８（Ｌ）に切換える。その結果、布押え２１は加工布の布厚だけ針板９から高い縫製位置で加工布を押圧するようになり、高さ検出器６２からは、この布厚に応じた高さ位置信号が出力される。
【００５９】
ところで、ミシン停止中において、膝操作レバー４８を操作して布押え２１を上昇させて加工布をセットする為に、膝操作レバー４８を非操作位置（P0）から第１操作位置（P1）まで操作したとき、操作検出スイッチ６６がＯＮ状態に切り換わり、同様にミシン駆動が禁止されるので、両手で加工布をセットするときなどに、起動スイッチ７を間違って操作した場合でもミシンモータ１６が起動しないので、安全性を高めることができる。
【００６０】
更に、この膝操作レバー４８を第２操作位置(P2)の位置まで回動操作したときには、連結腕４７とリンク板５４と第１及び第２連結板５３，５５と連結リンク５１とを介して押え上げ回動部材４１が時計回りに回動して、コロ４２が押え棒抱き２６を持ち上げるので、押え棒２２は手動操作レバー２８を第１操作位置２８（Ｈ）に切換えたのと同様の高さ位置に上昇し、更に膝操作レバー４８を第３操作位置(P3)の位置まで大きく回動操作したときには、手動操作レバー２８を第２操作位置２８（Ｔ）に切換えたのと同様の高さ位置である。ここで、図１０、図１４、図１６において、膝操作レバー４８の位置(P0)〜(P3)に対応する作動ピン６４、押え上げ回動部材４１の回動位置を、(p0)〜(p3)で示すものとする。
【００６１】
ところで、縫製中に、膝操作レバー４８を(P2)や(P3)の操作位置まで誤って操作したとき、操作検出スイッチ６６がＯＮ状態に切り換わり、押え棒２２の実際の高さ位置H1が縫製中の布厚よりも高くなったときに、ミシンモータ１６の駆動が停止されるので、安全性を高めることができるとともに、縫目不良を確実に防止することができる。
また、前記押え上げ回動部材４１の回動中心から押え上げ回動部材４１の回動時に押え棒２２を上昇させるコロ４２までの水平方向レバー長が、回動角の増大に応じて減少するように構成されたので、膝操作レバー４８を操作して押え棒２２を上昇させるに応じて、膝操作レバー４８による操作力を軽くでき、膝操作レバー４８の操作性を高めることができる。
【００６２】
膝操作レバー４８で押え上げ操作するときに、糸緩め部材３２は、押え上げ回動部材４１の回動作動の後期に張力解放機構３１を作動させるように構成されたので、押え上げ回動部材４１の回動作動の後期に対応するまで、膝操作レバー４８を誤って大きく操作することは滅多になく、糸調子機構３０による上糸への張力付与を確保でき、糸調子不良を確実に防止することができる。
そして、押え上げ回動部材４１と手動操作レバー２８とは同一の枢支軸２７を中心に回動可能に構成されるとともに、押え上げ回動部材４１のリフトカム４１ｄにより、張力解放機構３１を作動させるので、糸緩め部材３２を手動操作と膝操作とに共通化して使用でき、コスト的に有利である。
【００６３】
また、リフトカム４１ｄのカム形状如何により、これら両操作レバー２８，４８による糸緩めタイミングの調整を不要にできる。
更に、押え上げ回動部材４１に、布押え２１の押え上げ機能と、糸緩め機能と、操作検出スイッチ６６を作動させる作動突起部４１ｂとを集約して構成したので、各々のタイミング調整が不要となり、組付け作業を簡単化できる。
ここで、駆動禁止制御の制御プログラムや制御装置７５などで駆動禁止制御手段が構成され、駆動停止制御の制御プログラムや制御装置７５などで駆動停止制御手段が構成されている。
【００６４】
尚、縫製中に駆動停止制御によりミシンモータ１６の駆動を停止するに際して、高さ検出器６２から出力される高さ位置信号の増加率が所定値よりも大きいときに駆動停止するようにしたり、縫製中の布厚を設定するようにし、縫製中に布押え２１の高さがこの布厚よりも高くなったときに駆動停止するようにしてもよい。また、膝操作レバー４８を操作して押え棒２２を上昇したときに、ベッド部１内に設けたドロップフィード機構を作動させることにより、送り歯を針板９の上側に下降させるようにしてもよい。
【００６５】
また、本発明は前記実施形態に限定して解釈されるべきではなく、本発明の技術的思想を逸脱しない範囲において、前記実施形態の各部の構成に、既存の技術や当業者に自明の技術に基いて種々の変更を加えることもあり得る。更に、刺繍ミシンや本縫いミシンなどの種々のミシンの布押え昇降装置に本発明を適用し得ることは勿論である。
【００６６】
【発明の効果】
請求項１の発明によれば、縫針と布押えと布押え上下動機構と糸調子機構と張力解放機構と手動操作レバーと第２の操作部材とを備えたミシンの布押え昇降装置において、スイッチ手段と、駆動禁止制御手段とを設けたので、ミシン停止中に、膝や足などで第２の操作部材を間違って操作したときには、ミシンモータの駆動が確実に禁止され、起動スイッチを間違って操作した場合でもミシンモータが起動しないので、安全性を高めることができる。
【００６７】
請求項２の発明によれば、請求項１と同様の効果を奏するが、高さ検出手段と、駆動停止制御手段とを設けたので、縫製中に膝で第２の操作部材を誤って操作し、その操作量が大きくなって、布押えが縫製中の加工布の布厚に対応する高さ以上に上昇するときには、縫製動作を即座に中止でき、縫目不良を確実に防止することができる。
【００６８】
請求項３の発明によれば、請求項２と同様の効果を奏するが、押え上げ回動部材と、作動制御部材とを設け、糸緩め部材は押え上げ回動部材の回動作動の後期に張力解放機構を作動させるように構成されたので、スイッチ手段の作動制御部材により、押え棒が上昇する前にミシンの駆動を禁止して、布操作の安全性を確保できる。また、糸緩め部材の作動制御部材による糸緩めは、押え上げ回動部材の回動作動の後期に対応して実行されるので、押え上げ回動部材の回動作動の後期まで、第２の操作部材を誤って大きく操作することは滅多になく、糸調子機構による上糸への張力付与を確保でき、糸調子不良を確実に防止することができる。
【００６９】
請求項４の発明によれば、請求項３と同様の効果を奏するが、前記押え上げ回動部材の回動中心から押え上げ回動部材の回動時に押え棒を上昇させる回転コロ中心作動部までの水平方向レバー長が、回動角の増大に応じて減少するように構成されたので、第２の操作部材を操作して押え棒を上昇させるに応じて、第２の操作部材による操作力をより一層軽くでき、第２の操作部材の操作性を高めることができる。
【００７０】
請求項５の発明によれば、請求項２〜４の何れか１項と同様の効果を奏するが、前記駆動禁止制御手段は、ミシンモータの停止状態において高さ検出手段で検出した高さ位置が布押えの最上位置付近に対応する所定値以上のときにも、ミシンモータの駆動を禁止するので、例えば手動操作レバーを操作して布押えをその上昇位置に保持したときには、操作者の両手が使えるようになり、起動スイッチを誤って操作した場合でも、ミシンの起動を確実に阻止することができる。
【００７１】
請求項６の発明によれば、請求項１〜５の何れか１項と同様の効果を奏するが、前記手動操作レバーに形成された係合部を介して布押えをその上昇位置にロックするように構成され、第２の操作部材の操作により布押えの上昇位置におけるロック状態を解除可能に構成されたので、手動操作レバーの上昇位置におけるロック状態を手で手動操作レバーを操作して解除することなく、第２の操作部材を大きく操作することで解除でき、縫製作業性を高めることができる。
【００７２】
【００７３】
【００７４】
【図面の簡単な説明】
【図１】本発明の実施形態に係る電子制御式ミシンの正面図である。
【図２】電子制御式ミシンの針棒駆動に関する内部機構を部分的に示す正面図である。
【図３】電子制御式ミシンの押え棒に関する図２相当図である。
【図４】布押え昇降装置の側面図である。
【図５】布押え昇降装置の平面図である。
【図６】手動操作レバーの拡大正面図である。
【図７】作動板を設けた押え棒抱きの背面図である。
【図８】電子制御式ミシンのアーム部内の部分拡大正面図である。
【図９】アーム部のうちの頭部の部分拡大正面図である。
【図１０】押え棒や押え棒抱きを含む要部部分拡大正面図である。
【図１１】膝操作レバー及び回動軸の拡大側面図である。
【図１２】アーム部のうちの頭部の部分拡大背面図である。
【図１３】押え棒や押え棒抱きを含む要部部分拡大正面図である。
【図１４】押え棒や押え棒抱きの昇降動作を説明する図１３相当図である。
【図１５】図５Ｏ−Ｏ線縦断正面図である。
【図１６】押え上げ回動部材の動作を説明する図１５相当図である。
【図１７】電子制御式ミシンの制御系のブロック図である。
【図１８】駆動禁止制御のフローチャートである。
【図１９】駆動停止制御のフローチャートである。
【図２０】従来の技術に係る布押え昇降機構の概略斜視図である。
【符号の説明】
Ｍ電子制御式ミシン
１６ミシンモータ
１８縫針
２１布押え
２５布押え上下動機構
２８手動操作レバー
２８ａ係合部
３０糸調子機構
３１張力解放機構
３２糸緩め部材
４０布押え上下動機構
４１押え上げ回動部材
４２コロ
４８膝操作レバー
６２高さ検出器
６６操作検出スイッチ[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a presser foot lifting device for a sewing machine, and more particularly, to a technique for lifting a presser foot by means of an operation lever by an operator's knee operation or stepping operation, or by a power source by button operation, in addition to a manual operation lever. .
[0002]
[Prior art]
Conventionally, in an electronically controlled sewing machine for home use, a needle bar with a sewing needle attached to the lower end and a presser bar with a presser foot attached to the lower end are disposed on the head, and the cloth that moves the presser foot up and down. A presser lifting device is provided. That is, in this presser foot lifting device, a presser bar hug is provided in the middle of the presser bar, and a manual operation lever provided close to the presser bar is manually operated, so that the presser bar is held via the presser bar hug. Ascends from the lowered position, and the presser foot is switched to the raised position and held. In this state, the work cloth to be sewn is set or the sewn work cloth is taken out.
[0003]
By the way, when raising and lowering the presser foot using the manual operation lever, the manual operation lever is always operated by hand, so the lifting and lowering operation of the presser foot is cumbersome, and recently, with the operator's knee like an industrial sewing machine. Household sewing machines that allow the presser foot to be lifted and lowered via a knee control lever to be operated have been put into practical use. For example, as shown in FIG. 20, a presser lifting device 120 for a household sewing machine that moves the presser foot 121 up and down with a knee control lever 148 in addition to the manual operation lever 128 will be described.
[0004]
A presser bar 122 is supported by the frame F so as to be movable up and down on the head 4 of the arm unit 3, and a presser bar holder 126 is fixed to the middle part of the presser bar 122. The presser bar 122 is moved downward by a presser spring 123. The work cloth is pressed through a cloth presser 121 that is elastically biased and attached to the lower end. A thread loosening operation member 132 is fixed to the presser bar clamp 126, and a thread loosening plate 100 for switching the thread tension mechanism 130 to a tension releasing state is connected to the thread loosening operation member 132. Then, by manually turning the manual operation lever 128 provided on the frame F so as to be turned upward by hand, the presser bar 122 is moved to the raised position by the cam portion of the manual operation lever 128 via the presser bar holder 126. At the same time as being raised and locked, the thread tension mechanism 130 is switched to the tension release state by the thread release plate 100 via the thread release operation member 132.
[0005]
On the other hand, on the bed portion 1 of the sewing machine, two end portions 101a of the connecting member 101 fixed to the rear end portion of the rotation shaft 145 are pivotally supported by the frame so that the rotation shaft 145 is oriented in the front-rear direction. When 101b abuts on the frame F, the rotation range of the rotation shaft 145 is restricted. The arm portion 3 is provided with a swing lever 102. The swing lever 102 can be swung by a pivot pin 103, and is connected to a thread loosening operation member 132 at the left end thereof and at the right end thereof. The upper end of the connecting rod 104 is connected.
[0006]
Further, the lower end portion of the connecting rod 104 is connected to one end portion of the rotating member 105, and the other end portion of the rotating member 105 abuts on one end portion 101 b of the connecting member 101 from above, and this rotating member 105 is biased counterclockwise by a tension coil spring 106 when viewed from the front. And the base end part of the knee operation lever 148 is detachably attached to the front end part of the rotating shaft 145. That is, in this state, the knee operation lever 148 is held at the normal position L1 where the end portion 101b of the connecting member 101 contacts the frame F by the spring force of the presser spring 123 and the tension coil spring 106.
[0007]
Then, by pressing the operation portion 148a of the knee operation lever 148 with the knee to the right, the rotation shaft 145 rotates counterclockwise when the knee operation lever 148 rotates to the operation position L2. Since the left end portion of the swing lever 102 is raised by the downward movement of the connecting rod 104 via the connecting member 101 and the rotating member 105, the thread loosening actuating member 132 is raised at the same time. As in the case of 128, the presser bar 122 is lifted through the presser bar holding 126, so that the thread tension mechanism 130 is switched to the tension release state by the thread loosening plate 100.
[0008]
Here, when the knee operation lever 148 is rotated with the knee, it is rotated against the spring force of the presser spring 123 and the tension coil spring 106. Therefore, the greater the amount of rotation operation, that is, the presser bar 122 is moved. Japanese Patent Publication No. 55-4434 describes an electric presser lifting device that lifts a presser bar with an electric actuator, because the spring force increases and the operability is lacking as it is raised higher. In Japanese Patent Publication No. 6-40917, the spring force of the presser spring that urges the presser bar is reduced by the electric actuator so as to eliminate the disadvantages of the electric presser lifting device. An electric presser foot lifting device that can arbitrarily change the position is described.
[0009]
[Problems to be solved by the invention]
In the conventional presser foot lifting device 120 for a home sewing machine shown in FIG. 20, in consideration of the operability for the operator, a start switch for driving the sewing machine motor, a reverse stitching switch, and the like are provided on the head 4 where the sewing machine is easily operated. ing. When the manual operation lever 128 is operated and the presser foot 121 is switched to the raised position and held, the height position of the presser bar 122 at this time is detected and the driving of the sewing machine motor is prohibited. When the sewing machine is stopped and the knee operating lever 148 is operated to raise the presser bar 122 and the work cloth is set on the lower side of the work clamp 121, if there is a lot of work for handling fine cloth, The presser 121 is not raised to the raised position. At this time, the hand may accidentally touch the start switch and the sewing machine motor may be driven, so that an accident such as breakage of the sewing needle is likely to occur. There is.
[0010]
Further, when a thick fabric having a fabric thickness of several millimeters is being sewn, since the spring force of the presser spring 123 does not reach the rotation shaft 145, the knee operation lever 148 is pressed from the normal position L1. Since the tension coil spring 106 is almost free in the range up to the operation position L2 corresponding to the presser foot position 121, the knee of the operator may inadvertently press the knee operation lever 148 during sewing. In such a case, the presser foot 121 is raised and the work cloth is not pressed, resulting in poor stitching, and the thread tension mechanism is switched to the tension release state by the thread loosening plate 100, resulting in poor thread tension. There is.
[0011]
Therefore, in order to always hold the knee operation lever 148 at the normal position L1, a biasing spring that always biases the rotating shaft 145 clockwise in front view is provided, or the spring force of the tension coil spring 106 is increased. In this case, the spring force of the urging spring acts on the operator's knee, and it is unlikely that a mistake such as inadvertently pressing the knee operation lever 148 will occur, but in order to raise the presser foot 121, the knee operation lever 148 is When operating, in addition to the presser spring 123 and the tension coil spring 106, the spring force of the separately provided biasing spring acts simultaneously, and there is a problem that the operability of the knee operating lever 148 is deteriorated.
[0012]
An object of the present invention is to prohibit the start of the sewing machine motor when the presser bar is lifted with the knee operating lever while the sewing machine is stopped, and to stop the driving of the sewing machine motor when the knee operating lever is operated during sewing. Improving the operability of the knee control lever, increasing the safety of the sewing machine operation, and the like.
[0013]
[Means for Solving the Problems]
According to another aspect of the sewing machine presser lifting apparatus of the present invention, the sewing needle is moved up and down by the sewing machine motor, the presser foot is attached to the lower end of the presser bar, and the presser foot is switched between the press position for pressing the work cloth and the lift position. The presser foot up / down mechanism, the thread tension mechanism that applies tension to the upper thread from the thread spool to the stitch hole, the tension release mechanism that switches the thread tension mechanism to the tension release state, and the presser foot up / down operation manually. In a presser foot lifting / lowering device for a sewing machine including a manual operation lever for operating a mechanism and a second operation member for operating a presser foot vertical movement mechanism by an operation other than manual operation, the second operation member is on the presser foot raising side. Switch means for detecting the operation of the sewing machine and outputting an operation detection signal; and a drive prohibition control means for prohibiting the driving of the sewing machine motor when the detection signal is received from the switch means when the sewing machine motor is stopped. It is those with a door.
[0014]
By operating the second operation member to the presser foot raising side, the presser foot is lifted by the presser foot vertical movement mechanism. By the way, when the second operating member is operated to the presser foot raising side while the sewing machine motor is stopped, the switch means detects the operation of the second operating member and outputs an operation detection signal. As a result, the drive prohibition control unit prohibits the driving of the sewing machine motor as soon as the detection signal is received from the switch unit. In other words, when the second operating member is the knee operating lever, if the knee operating lever is erroneously operated with the knee, the operation detection signal output from the switch means reliably inhibits the driving of the sewing machine motor.
[0015]
According to a second aspect of the present invention, there is provided a sewing machine presser lifting device according to the first aspect of the present invention. The height detection means for detecting the height position of the presser bar in real time, and the detection from the height detection means and the switch means during sewing. Drive that stops driving the sewing machine motor on condition that the switch means is outputting the operation detection signal and the height position of the presser bar is higher than the height at the start of output of the operation detection signal. And a stop control means.
[0016]
In this case, the height detection means includes an actuator capable of outputting an electrical signal such as a potentiometer, and detects the height position of the presser bar in real time. The drive stop control means receives the detection signals from the height detection means and the switch means during sewing, the switch means is outputting the operation detection signal, and the height position of the presser bar outputs the operation detection signal. On condition that the height is higher than the starting height, that is, when the amount of operation of the second operating member increases, and the presser foot rises above the height corresponding to the thickness of the work cloth being sewn, Stop driving the sewing machine motor. Other effects similar to those of the first aspect are achieved.
[0017]
According to a third aspect of the present invention, there is provided a presser foot lifting / lowering device according to the second aspect of the present invention, wherein the presser foot turning member for raising the presser bar by the operation of the second operation member, and the rotation of the presser foot lifting member. An operation control member for a thread loosening member that operates the tension release mechanism in conjunction with each other and an operation control member for the switch means are provided, and the tension release mechanism is provided later in the rotation operation of the presser lifting rotation member. It is characterized by being configured to operate.
[0018]
In this case, by operating the second operating member, the presser lifting rotary member rotates to raise the presser bar. The thread release plate is lifted by the presser lifter later in the rotation operation of the presser lifting rotary member. The tension release mechanism is operated in conjunction with the rotating member. Further, the switch means is operated at the initial stage of rotation of the presser lifting rotation member. That is, when the knee operating lever which is the second operating member is erroneously operated by the knee, the sewing machine is prohibited from being driven before the presser bar is lifted to ensure the safety of the cloth operation, and the presser lifting rotary member. The second operating member is rarely erroneously operated largely until it corresponds to the later stage of the rotation operation, so that it is possible to ensure the tension applied to the upper thread by the thread tension mechanism and to prevent the thread tension failure. These three actions are integrated into one presser-lifting rotation member and executed more reliably. Other effects similar to those of the second aspect are achieved.
[0019]
According to a fourth aspect of the present invention, there is provided a sewing machine presser lifting / lowering device according to the third aspect of the present invention, wherein the presser bar is lifted from the center of rotation of the presser lifting rotary member while the presser bar is lifted. The horizontal lever length up to is configured to decrease as the rotation angle increases.
In this case, when the presser lifting rotation member rotates to raise the presser bar by operating the second operation member, the presser lifting rotation member rotates from the rotation center of the presser lifting rotation member. The horizontal lever length to the central operating part of the rotating roller that sometimes raises the presser bar decreases with increasing rotation angle, that is, as the presser bar is raised. That is, as the presser bar moves up, the operation force by the second operation member can be further reduced. Other effects similar to those of the third aspect are achieved.
[0020]
According to a fifth aspect of the present invention, there is provided the sewing machine presser foot lifting device according to any one of the second to fourth aspects, wherein the drive prohibition control means has a height position detected by the height detection means when the sewing machine motor is stopped. The driving of the sewing machine motor is also prohibited when the predetermined value or more corresponding to the vicinity of the uppermost position of the presser foot is exceeded.
In this case, for example, when the work clamp is raised to the raised position near the uppermost position by operating a manual operation lever, the height detection means determines that the height position detected at this time is equal to or greater than a predetermined value. Prohibit motor drive. That is, when the presser foot is held at the raised position, both hands of the operator can be used, and even if the start switch is operated by mistake, the start of the sewing machine can be reliably prevented. Other effects similar to those of any one of claims 2 to 4 are achieved.
[0021]
A cloth presser lifting / lowering device for a sewing machine according to a sixth aspect of the present invention is the invention according to any one of the first to fifth aspects, wherein the presser foot is locked to its raised position via an engaging portion formed on the manual operation lever. It is comprised so that the locked state in the raising position of the presser foot can be released by the operation of the second operation member.
In this case, when operating the manual operation lever to raise the presser foot, even if the presser foot is locked at the raised position via the engaging portion formed on the manual operation lever, the second operation member is enlarged. By operating, the locked state at the raised position of the manual operation lever can be reliably released. Other effects similar to those of any one of claims 1 to 5 are achieved.
[0022]
[0023]
[0024]
[0025]
[0026]
[0027]
[0028]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. This embodiment is an example when the present invention is applied to an electronically controlled sewing machine capable of sewing various patterns such as a practical pattern and a one-point mark.
As shown in FIG. 1, the electronically controlled sewing machine M is opposed to the sewing machine bed portion 1, a pedestal column portion 2 erected from the right end portion of the bed portion 1, and the bed portion 1 from the upper end of the pedestal column portion 2. Thus, it has the arm part 3 extended to the left.
In the bed portion 1, a feed dog vertical movement mechanism (not shown) that moves the feed dog up and down, a feed dog forward / backward movement mechanism (not shown) that moves back and forth, and a bobbin bobbin that accommodates the needle 18 A vessel (for example, a horizontal hook) is provided.
[0029]
The arm portion 3 includes a needle bar drive mechanism 10 that moves the needle bar 15 with a sewing needle 18 attached to the lower end thereof up and down, and a needle bar swing mechanism that swings the needle bar 15 in a direction perpendicular to the cloth feed direction (not shown). A balance driving mechanism (not shown) for moving the balance 13 up and down in time with the up and down movement of the needle bar 15 is provided. The feed dog vertical movement mechanism, the needle bar drive mechanism, and the balance drive mechanism are driven by the sewing machine motor 16, the needle bar swing mechanism is driven by the needle bar swing motor 84, and the feed dog forward and backward movement mechanism is the front and rear feed teeth. It is driven by a driving motor 85 (see FIG. 17). The head 4 of the arm 3 has a start / stop switch 7 for commanding start and stop of the sewing work, a reverse stitching switch 8 and the like. But Is provided.
[0030]
A large liquid crystal display 5 is provided on the front surface of the arm 3, and touch keys 6 made of transparent electrodes are provided on the front surface of the display 5 in correspondence with display positions of function names indicating a plurality of patterns and functions. Are provided in a matrix. That is, a desired pattern can be selected and a function instruction can be realized by pressing the touch key 6 corresponding to the pattern or function name.
[0031]
Here, the needle bar drive mechanism 10 will be briefly described with reference to FIG. 2. A crank member 12 is fixed to the left end portion of the main shaft 11 disposed in the arm portion 3, and a balance 13 is attached to the crank member 12. Are provided, the upper end of the crank lever 14 is pin-coupled, and the lower end of the crank lever 14 is connected to the interrupting portion of the needle bar 15. Thus, when the main shaft 11 is rotationally driven by the sewing machine motor 16 via the belt 17, the needle bar 15 is vertically driven via the crank member 12 and the crank lever 14, and at the same time, the balance 13 is also vertically driven. The stitches are formed on the work cloth pressed by the presser foot 21 described later by the sewing needle 18 and the thread catcher.
[0032]
Next, a presser lifting device that lifts and lowers the presser foot (presser foot) 21 detachably attached to the lower end portion of the presser bar 22 with a manual operation lever 28 or a knee operation lever 48 (corresponding to a second operation member). 20 will be described with reference to FIGS.
A presser bar 22 having a presser foot 21 attached to the lower end thereof is disposed on the head 4 in the vertical direction and is supported by the sewing machine frame F so as to be movable up and down. The presser bar 22 is elastically biased downward by fixing the upper end of the presser spring 23 formed of a compression coil spring to the sewing machine frame F and fixing the lower end to the presser bar 22.
[0033]
Next, the presser foot up-and-down moving mechanism 25 that switches the presser foot 21 between the pressed position and the raised position by operating the manual operation lever 28 will be described.
A presser bar hanger 26 that is long in the left-right direction is fixed to the middle part of the presser bar 22. On the other hand, a manual operation lever 28 is pivotally supported on the sewing machine frame F by a pivot shaft 27 extending in the front-rear direction at the lower right corner of the head 4, and as shown in FIG. Switching operation can be performed between a position 28 (L), a substantially horizontal first operation position 28 (H), and a second operation position 28 (T) above the first operation position 28 (H).
[0034]
As shown in FIG. 6, the manual operation lever 28 includes an engaging portion 28 a that engages with an inclined end surface 26 a (see FIGS. 7 and 9) on the lower side of the left end portion of the presser bar clamp 26, and a thread that will be described later. A first operating portion 28b that presses the loosening member 32 is formed, and a second operating portion 28c that presses an operating plate 67 described later is formed. That is, as shown in FIG. 9, when the manual operation lever 28 is in the non-operation position 28 (L), the presser foot 21 is the pressing position on the upper surface of the needle plate 9, and the presser bar clamp 26 is indicated by a solid line 26 (L ) Height position.
[0035]
When the manual operation lever 28 is switched to the first operation position 28 (H), the presser bar clamp 26 is raised to a height position of 26 (H) indicated by a chain line by the cam shape of the engaging portion 28a. When the manual operation lever 28 is switched to the second operation position 28 (T), the presser bar clamp 26 is further raised to a height position of 26 (T) indicated by a chain line. However, the manual operation lever 28 is switched to the second operation position 28 (T) when a thick fabric is set below the presser foot 21. Here, when the manual operation lever 28 is switched to the first operation position 28 (H), the engaging portion 28 a engages with the inclined end surface 26 a of the presser bar holding 26, so that the manual operation lever 28 has its first position. 1 It is locked at the operation position 28 (H).
[0036]
Next, the tension release mechanism 31 that switches the thread tension mechanism 30 that applies tension to the upper thread to the tension release state will be described.
The thread tension mechanism 30 is generally configured to apply tension to the upper thread by urging a pair of thread tension trays that sandwich the upper thread with a spring force.
As shown in FIGS. 8 and 13, a thread loosening member 32 is pivotally supported on the sewing machine frame F by a pivot pin 33 immediately above the manual operation lever 28. The lower end portion of the yarn loosening lot 34 is connected to the right end portion of the yarn loosening member 32, and the upper end portion of the yarn loosening lot 34 is connected to a movable tension tray (not shown) of the thread tension mechanism 30 as shown in FIG. When the thread loosening lot 34 is connected and moved downward, the thread tension mechanism 30 is switched to the tension release state.
[0037]
That is, when the manual operation lever 28 is switched from the non-operation position 28 (L) to the first operation position 28 (H), the thread loosening member 32 is moved by the first operating portion 28b of the manual operation lever 28 as shown in FIG. Is rotated clockwise as viewed from the front, and the thread loosening lot 34 is moved downward to switch the thread tension mechanism 30 to the tension release state.
Next, the presser foot up-and-down moving mechanism 40 that operates the knee operation lever 48 to switch the presser foot 21 between the pressed position and the raised position will be described.
As shown in FIGS. 3 to 5, on the rear side of the manual operation lever 28, a presser lifting rotation member 41 having a substantially U shape in plan view is rotatable by a pivot shaft 27 of the manual operation lever 28. It is pivotally supported.
[0038]
As shown in FIG. 13, a roller 42 (corresponding to a rotating roller) is pivotally attached to the protrusion 41a on the front wall of the presser lifting rotation member 41, and rotates from the protrusion 41a on the front wall. Lift cam (this is the stepped part formed on the upper end surface returning to the moving center direction. yarn Operation control member for loosening member In (Corresponding) 41d is formed. Further, as shown in FIG. 15, on the lower side of the rear wall of the presser-lifting rotation member 41, an operation protrusion (which is an ON state) that operates (ON state) an operation detection switch 66 that detects the operation of the knee operation lever 48. 41b (corresponding to an operation control member of the switch means) is formed, and a left end portion of a connection link 51 of a link mechanism 50 described later is connected to the upper protrusion 41c.
[0039]
Immediately That is, when the knee-operating lever 48 is operated, the presser-lifting rotation member 41 is rotated, and when the lift cam 41d is engaged with a thread-relaxation pin 35 described later, that is, when the presser foot 21 is raised above the raised position. In addition, the amount of yarn loosening released by the yarn loosening member 32 is maintained at its maximum value.
On the other hand, as shown in FIGS. 3 and 11, the bed portion 1 has a pivot shaft 45 in the front-rear direction pivotally supported by the sewing machine frame F, and the front end portion of the pivot shaft 45 is vertically 1 It is formed in a cylindrical shape having a pair of slots 45a.
[0040]
A proximal end portion of a connecting arm 47 that is urged clockwise in front view by the spring force of the tension coil spring 46 is fixed to the rear end portion of the rotating shaft 45. Here, a bolt (not shown) is attached to the rotation shaft 45 in order to define a rotation range of a knee operation lever 48 described later.
The knee operating lever 48 is formed by bending a metal rod, fixing the engaging pin 49 to the connecting portion 48a, and providing a wide operating portion 48b operated by the operator's knee. Then, if necessary, the engaging pin 49 is engaged with the slot 45a of the rotating shaft 45 by inserting the connecting portion 48a of the knee operating lever 48 into the front end portion of the rotating shaft 45, and the knee operating lever 48 is engaged. Is coupled to the pivot shaft 45.
[0041]
Next, the link mechanism 50 for moving the presser foot lifting member 41 and moving the presser foot 21 up and down by operating the knee operation lever 48 will be described with reference to FIGS.
The right end of the connection link 51 is connected to the end of a first connection plate 53 that is pivotally supported by a pivot pin 52 fixed to the sewing machine frame F. On the other hand, the other end of the connecting arm 47 is connected to the lower end of a link plate 54 bent in a predetermined shape, and the upper end of the link plate 54 is pivotally supported by a pivot pin 52. It is connected to the end of the second connecting plate 55.
[0042]
Here, the first and second connecting plates 53 and 55 will be briefly described. The first connecting plate 53 can be finely adjusted with respect to the second connecting plate 55 with the pivot pin 52 as a rotation center. Thus, the rotation position of the presser lifting rotation member 41 with respect to the position of the knee operation lever 48 can be finely adjusted.
Here, in FIG. 3, when the knee operation lever 48 is not operated, it is the non-operation position (P0), and the first operation position (P1) is a position corresponding to the allowance generated by the link mechanism 50.
[0043]
That is, in FIG. 3, when the knee operation lever 48 is operated in the counterclockwise direction from the non-operation position (P0), that is, the presser foot ascending side, the connecting arm 47, the link plate 54, the first and second connecting plates 53, As shown in FIGS. 14 and 16, the presser lifting rotation member 41 rotates clockwise through the connecting link 51, as shown in FIGS. 14 and 16, so that the roller 42 moves the presser bar holder 26 from the lower side. Lifting upward, the presser bar 22 and the presser foot 21 rise simultaneously.
[0044]
By the way, as shown in FIGS. 5 and 14, the thread loosening member 32 is fixed with a thread loosening pin 35 that comes in contact with the front wall of the presser lifting rotation member 41 from the upper side. When the moving member 41 is rotated clockwise, the thread loosening member 32 is also rotated clockwise via the thread loosening pin 35, and the thread tension mechanism 30 is tensioned via the thread loosening lot 34 as described above. Switch to the released state. Here, as shown in FIG. 14, the lift cam 41d on the front wall of the presser lifting rotary member 41 and the thread loosening at the rotary position 41 (p1) of the presser lifting rotary member 41 when the knee operating lever 48 is operated. Since a predetermined gap is provided between the pin 35 and the pin 35, the thread releasing member 32 is switched to the tension release state in a later stage of the turning operation of the presser lifting turning member 41. When executed.
[0045]
Next, the height detection mechanism 60 that detects the height position of the presser bar 22 will be described with reference to FIGS. 5, 7, 12, and 13.
A holder plate 61 attached to a plate-like auxiliary frame SF fixed to the sewing machine case is disposed on the rear side of the presser bar holder 26, and a height detector 62 composed of a potentiometer is disposed on the front side of the holder plate 61. Is attached, and the operating pin 64 is fixed to the tip of the operating arm 63 fixed to the shaft 62a of the height detector 62, and the tip of the operating pin 64 comes into contact with one end of the presser bar holder 26 from above. (See FIG. 5). Here, an operation detection switch 66 (corresponding to a switch means) that is operated by the operation protrusion 41b of the presser lifting rotation member 41 is attached to the attachment plate 65 that is connected to the holder plate 61 so that the position thereof can be adjusted. Yes.
[0046]
That is, since the shaft 62a rotates via the operating pin 64 and the operating arm 63 according to the height position of the presser bar clamp 26 (cloth presser 21), the height detection output from the height detector 62 is detected. Based on the signal, the height position of the presser foot 21 during sewing of the presser foot 21 can be detected.
On the other hand, as shown in FIG. 7 and FIG. 5, a substantially horizontal J-shaped operation plate 67 is pivotally supported at one end by a pin 68 on the rear end surface of the presser bar holder 26. .
[0047]
As a result, when the manual operation lever 28 is operated to switch to the first operation position 28 (H), the operation plate 67 is moved by the second operation portion 28c of the manual operation lever 28 as shown in FIGS. Since it rotates around, the operating pin 64 is pushed up higher than the height of the presser bar clamp 26 by the operating portion 67a at the tip of the operating plate 67, and the presser foot 21 is lifted from the height detector 62. A height detection signal having a predetermined value indicating the position is output.
[0048]
By the way, a rearward-facing engagement pin 69 is fixed to the operating plate 67, and the engagement pin 69 can be engaged with the thread loosening member 32 from the left side. That is, as shown in FIG. 10, when the manual operation lever 28 is switched to the first operation position 28 (H), the presser foot 21 is locked at the raised position as described above. When 48 is greatly operated to the presser foot raising side, when the thread loosening member 32 is rotated clockwise by the presser foot lifting rotating member 41, the engagement pin is engaged with the pressing surface 32a (see FIG. 13) of the thread loosening member 32. Since 69 is pressed to the left, the operation plate 67 is further rotated clockwise.
[0049]
As a result, the presser lifting rotation member 41 is further rotated, and the presser bar clamp 26 is further lifted by the roller 42, whereby the engaging portion 28a of the manual operation lever 28 and the inclined end surface 26a of the presser bar clamp 26 are connected. Is released, and a gap is created between the first actuating portion 28b of the manual operation lever 28 and the thread loosening member 32, and a gap is also created between the second actuating portion 28c and the actuating plate 67. The manual operation lever 28 is not supported at any location, and falls to the non-operation position 28 (L) by its own weight, and the locked state is released.
[0050]
Next, a control system of the electronically controlled sewing machine M will be described.
As shown in FIG. 17, the control device 75 includes an input interface 76, a computer including a CPU 77, a ROM 78, and a RAM 79, an output interface 80, and a bus 81 such as a data bus connecting them. The input interface 76 includes a start / stop switch 7, a touch key 6, an encoder sensor 82 that detects a plurality of rotational phases of the sewing machine spindle, an operation detection switch 66, and an A / D connected to the height detector 62. A converter 83 or the like is connected.
[0051]
These motors 16 and 84 to 85 and a display controller (LCDC) 86 for the liquid crystal display 5 are connected to the output interface 80.
The ROM 78 stores in advance various control programs related to sewing machine control including control programs for drive prohibition control and drive stop control that are specific to the present invention, which will be described later. The RAM 79 is provided with memories (memory such as flags, pointers, counters, registers, buffers, etc.) necessary for the various controls described above.
[0052]
Next, a drive prohibition control routine executed by the control device C will be described based on the flowchart of FIG. In the figure, reference sign Si (i = 10, 11, 12,...) Indicates each step.
After power is turned on to the sewing machine M and initialization processing is executed, drive prohibition control is executed every predetermined minute time while the sewing machine is stopped. That is, when this control is started, first, the height detection signal output from the height detector 62 is read (S10), and the actual height position of the presser bar 22 is determined based on this height detection signal. It is obtained in real time (S11).
[0053]
Next, when the height of the presser bar 22 is not the drive prohibition position corresponding to the raised position (S12: No), and when the operation detection signal in the OFF state is received from the operation detection switch 66 (S13: No). Since the sewing machine motor 16 can be started, sewing machine driving is permitted (S14), this control is terminated, and the process returns to the main routine. However, when the height of the presser bar 22 is the drive prohibition position corresponding to the raised position (S12: Yes), or when the operation detection signal of the ON state is received from the operation detection switch 66 (S13: Yes), the sewing machine is driven. Is commanded to be prohibited (S15), and the process returns in the same manner.
[0054]
On the other hand, during sewing, the drive stop control shown in FIG. 19 is executed every predetermined minute time.
That is, when this control is started, when an operation detection signal in the OFF state is received from the operation detection switch 66, that is, when the knee operation lever 48 is not operated with the knee (S20: No), the height detection is performed. The height detection signal output from the device 62 is read (S21), and the actual height position H1 of the presser bar 22 is obtained based on the height detection signal (S22). Then, the newly obtained height position H1 is updated as a threshold value J for stopping (S23), this control is terminated, and the process returns to the main routine.
[0055]
On the other hand, when the operation detection signal in the ON state is received from the operation detection switch 66 due to the operation of the knee operation lever 48 with the knee (S20: Yes), the height detection signal output from the height detector 62. Is read (S24), and the actual height position H1 of the presser bar 22 is obtained based on the height detection signal (S25). When the newly obtained height position H1 is equal to or less than the stop threshold value J, that is, the knee operation lever 48 is operated, the height of the presser foot 21 during sewing becomes higher than the fabric thickness. If not, the drive of the sewing machine motor 16 is not stopped (S26: No), and the process returns in the same manner.
[0056]
By the way, when the newly obtained height position H1 becomes larger than the stop threshold value J, that is, the knee operating lever 48 is operated during sewing, the height of the presser foot 21 during sewing is greater than the fabric thickness. Is also higher (S26: Yes), an instruction is given to stop driving the sewing machine motor 16 (S27), and the process returns in the same manner. Accordingly, since the sewing machine is stopped when the work presser 21 stops pressing the work cloth, it is possible to prevent the occurrence of a stitch failure.
[0057]
Next, the operation and effect of the sewing machine M configured as described above will be described.
First, when the sewing machine is stopped, the manual operation lever 28 is operated to switch from the non-operation position 28 (L) to the horizontal first operation position 28 (H), so that the manual operation lever 28 is locked at the raised position and is pressed. The rod holder 26 is raised to a height position of 26 (H) by the cam shape of the engaging portion 28a. At this time, the thread loosening member 32 is rotated clockwise by the first operating portion 28b of the manual operation lever 28, the thread loosening lot 34 is moved downward, and the thread tension mechanism 30 is switched to the tension release state.
[0058]
Further, the operating plate 67 is rotated clockwise by the second operating portion 28 c of the manual operation lever 28, the operating pin 64 is pushed up by the operating portion 67 a of the operating plate 67, and output from the height detector 62. Sewing machine driving is prohibited based on a predetermined height detection signal indicating that the presser foot 21 is in the raised position. In this state, the work cloth is set below the work clamp 21 and the manual operation lever 28 is switched to the non-operation position 28 (L). As a result, the cloth presser 21 presses the work cloth at a high sewing position from the needle plate 9 by the cloth thickness of the work cloth, and the height detector 62 outputs a height position signal corresponding to the cloth thickness. Is done.
[0059]
By the way, when the sewing machine is stopped, the knee operating lever 48 is moved from the non-operating position (P0) to the first operating position (P1) in order to operate the knee operating lever 48 to raise the work clamp 21 and set the work cloth. When the operation is performed, the operation detection switch 66 is switched to the ON state, and the sewing machine driving is similarly prohibited. Therefore, even when the start switch 7 is mistakenly operated when setting the work cloth with both hands, the sewing machine motor 16 is not operated. Since it does not start, safety can be improved.
[0060]
Further, when the knee operation lever 48 is turned to the second operation position (P2), the connection arm 47, the link plate 54, the first and second connection plates 53 and 55, and the connection link 51 are used. Since the presser lifting rotation member 41 rotates clockwise and the roller 42 lifts the presser bar clamp 26, the presser bar 22 is the same as when the manual operation lever 28 is switched to the first operation position 28 (H). When the knee operating lever 48 is further moved to the third operating position (P3) by raising it to the height position, and the manual operating lever 28 is switched to the second operating position 28 (T). It is the height position. 10, 14, and 16, the rotation positions of the operating pin 64 and the presser lifting rotation member 41 corresponding to the positions (P0) to (P3) of the knee operation lever 48 are (p0) to (p It shall be shown in p3).
[0061]
By the way, when the knee operation lever 48 is mistakenly operated to the operation position (P2) or (P3) during sewing, the operation detection switch 66 is turned ON, and the actual height position H1 of the presser bar 22 is set. Since the drive of the sewing machine motor 16 is stopped when it becomes higher than the thickness of the cloth being sewn, safety can be improved and a stitch failure can be reliably prevented.
Further, the horizontal lever length from the center of rotation of the presser lifting rotation member 41 to the roller 42 that raises the presser bar 22 when the presser lifting rotation member 41 is rotated decreases as the rotation angle increases. Thus, as the knee operating lever 48 is operated to raise the presser bar 22, the operating force by the knee operating lever 48 can be reduced, and the operability of the knee operating lever 48 can be improved.
[0062]
Since the thread loosening member 32 is configured to operate the tension release mechanism 31 at a later stage of the rotation operation of the presser lifting rotating member 41 when the presser lifting operation is performed by the knee operation lever 48, the presser lifting rotating member is operated. Until the later stage of the 41 rotation operation, it is rare that the knee operation lever 48 is mistakenly operated greatly, the tension on the upper thread can be secured by the thread tension mechanism 30, and the thread tension failure is reliably prevented. can do.
The presser lifting rotation member 41 and the manual operation lever 28 are configured to be rotatable around the same pivot shaft 27, and the tension release mechanism 31 is operated by the lift cam 41d of the presser lifting rotation member 41. Therefore, the thread loosening member 32 can be used in common for manual operation and knee operation, which is advantageous in terms of cost.
[0063]
Further, depending on the cam shape of the lift cam 41d, it is possible to eliminate the need for adjusting the yarn loosening timing by the operation levers 28 and 48.
Furthermore, since the presser foot lifting member 41 is configured by integrating the presser foot lifting function of the presser foot 21, the thread loosening function, and the operation protrusion 41b for operating the operation detection switch 66, each timing adjustment is unnecessary. Thus, the assembly work can be simplified.
Here, the drive prohibition control means is configured by the control program for drive prohibition control, the control device 75, and the like, and the drive stop control means is configured by the control program for drive stop control, the control device 75, and the like.
[0064]
When stopping the drive of the sewing machine motor 16 by the drive stop control during sewing, the drive is stopped when the increasing rate of the height position signal output from the height detector 62 is larger than a predetermined value, The cloth thickness during sewing may be set, and the driving may be stopped when the height of the cloth presser 21 becomes higher than the cloth thickness during sewing. Further, when the presser bar 22 is lifted by operating the knee operation lever 48, the feed dog is lowered to the upper side of the needle plate 9 by operating the drop feed mechanism provided in the bed portion 1. Good.
[0065]
Further, the present invention should not be construed as being limited to the above-described embodiments, and within the scope not departing from the technical idea of the present invention, the configuration of each part of the above-described embodiments is not limited to existing techniques or techniques obvious to those skilled in the art. Various modifications may be made based on the above. Furthermore, it goes without saying that the present invention can be applied to various presser lifting devices for sewing machines such as an embroidery sewing machine and a lockstitch sewing machine.
[0066]
【The invention's effect】
According to the first aspect of the present invention, there is provided a sewing machine presser lifting device including a sewing needle, a presser foot, a presser foot vertical movement mechanism, a thread tension mechanism, a tension release mechanism, a manual operation lever, and a second operation member. And a drive prohibition control means, so that if the second operating member is operated by mistake with the knee or foot while the sewing machine is stopped, the drive of the sewing machine motor is reliably prohibited and the start switch is Since the sewing machine motor does not start even when operated, safety can be improved.
[0067]
According to the second aspect of the present invention, the same effect as in the first aspect is obtained, but since the height detecting means and the drive stop control means are provided, the second operating member is erroneously operated with the knee during sewing. However, when the amount of operation increases and the presser foot rises above the height corresponding to the cloth thickness of the work cloth being sewn, the sewing operation can be stopped immediately, and stitch defects can be reliably prevented. it can.
[0068]
According to the invention of claim 3, the same effect as that of claim 2 is obtained, but the presser lifting rotation member and the operation control member are provided, and the thread loosening member is provided at a later stage of the rotation operation of the presser lifting rotation member. Since the tension release mechanism is configured to operate, the operation control member of the switch means prohibits the sewing machine from being driven before the presser bar is lifted, thereby ensuring the safety of the cloth operation. Further, since the thread loosening by the operation control member of the thread loosening member is executed corresponding to the latter stage of the turning operation of the presser lifting turning member, the second operation is performed until the later stage of the turning action of the presser lifting turning member. It is rare that the operating member is mistakenly operated largely, and it is possible to ensure the tension applied to the upper thread by the thread tension mechanism, and to reliably prevent a thread tension failure.
[0069]
According to the fourth aspect of the present invention, the same effect as that of the third aspect is achieved, but the rotary roller center actuating portion lifts the presser bar from the rotation center of the presser lifting rotation member when the presser lifting rotation member rotates. Since the horizontal lever length until is decreased as the rotation angle increases, the operation by the second operation member is performed according to the operation of the second operation member to raise the presser bar. The force can be further reduced and the operability of the second operating member can be enhanced.
[0070]
According to the invention of claim 5, the same effect as in any one of claims 2 to 4 is obtained, but the drive prohibition control means is the height position detected by the height detection means when the sewing machine motor is stopped. Since the sewing machine motor is prohibited from being driven even when is more than a predetermined value corresponding to the vicinity of the uppermost position of the presser foot, for example, when the manual presser is operated and the presser foot is held in its raised position, both hands of the operator Can be used, and even if the start switch is operated by mistake, the start of the sewing machine can be reliably prevented.
[0071]
According to the sixth aspect of the present invention, the same effect as in any one of the first to fifth aspects is obtained, but the presser foot is locked at its raised position via the engaging portion formed on the manual operation lever. Since the lock state at the raised position of the presser foot can be released by operating the second operation member, the locked state at the raised position of the manual operation lever can be released by operating the manual operation lever by hand. Without doing so, it can be released by operating the second operating member largely, and the sewing workability can be improved.
[0072]
[0073]
[0074]
[ Brief Description of Drawings]
FIG. 1 is a front view of an electronically controlled sewing machine according to an embodiment of the present invention.
FIG. 2 is a front view partially showing an internal mechanism related to needle bar driving of an electronically controlled sewing machine.
FIG. 3 is a view corresponding to FIG. 2 relating to a presser bar of an electronically controlled sewing machine.
FIG. 4 is a side view of the presser foot lifting device.
FIG. 5 is a plan view of the presser foot lifting device.
FIG. 6 is an enlarged front view of a manual operation lever.
FIG. 7 is a rear view of a presser bar holding provided with an operation plate.
FIG. 8 is a partially enlarged front view in the arm portion of the electronically controlled sewing machine.
FIG. 9 is a partially enlarged front view of a head portion of an arm portion.
FIG. 10 is an enlarged front view of a main part including a presser bar and a presser bar hug.
FIG. 11 is an enlarged side view of a knee operation lever and a rotation shaft.
FIG. 12 is a partially enlarged rear view of the head portion of the arm portion.
FIG. 13 is an enlarged front view of a main part including a presser bar and a presser bar hug.
FIG. 14 is a view corresponding to FIG. 13 for explaining the lifting and lowering operation of the presser bar and the presser bar hug.
FIG. 15 is a longitudinal front view of FIG. 5O-O line.
FIG. 16 is a view corresponding to FIG. 15 for explaining the operation of the presser lifting rotation member.
FIG. 17 is a block diagram of a control system of an electronically controlled sewing machine.
FIG. 18 is a flowchart of drive prohibition control.
FIG. 19 is a flowchart of drive stop control.
FIG. 20 is a schematic perspective view of a presser foot lifting mechanism according to a conventional technique.
[Explanation of symbols]
M Electronically controlled sewing machine
16 Sewing machine motor
18 Sewing needle
21 Work clamp
25 Material presser vertical movement mechanism
28 Manual operation lever
28a Engagement part
30 Thread tension mechanism
31 Tension release mechanism
32 Thread loosening member
40 Material presser vertical movement mechanism
41 Presser lifter rotation member
42 Roll
48 Knee control lever
62 Height detector
66 Operation detection switch

Claims

A sewing needle that is moved up and down by the sewing machine motor, a presser foot attached to the lower end of the presser bar, a presser foot up-and-down movement mechanism that switches the presser foot between the press position and the raised position, and Thread tension mechanism that applies tension to the upper thread that reaches the eye hole, tension release mechanism that switches this thread tension mechanism to the tension release state, manual operation lever that operates the presser foot vertical movement mechanism by manual operation, and other than manual operation A sewing machine presser lifting device provided with a second operation member for operating the presser foot vertical movement mechanism by the operation of
Switch means for detecting that the second operation member is operated to the presser foot raising side and outputting an operation detection signal;
A drive prohibition control means for prohibiting the drive of the sewing motor when receiving a detection signal from the switch means in the stop state of the sewing motor;
A sewing presser lifting device for a sewing machine comprising:

A height detection means for detecting the height position of the presser bar in real time; a detection signal from the height detection means and the switch means during sewing; the switch means is outputting an operation detection signal; and 2. A drive stop control means for stopping the drive of the sewing machine motor on condition that the height position of the presser bar is higher than the height at the start of output of the operation detection signal. Sewing presser lifting device for sewing machine.

A presser-lifting rotary member that raises the presser bar by operating the second operating member, an operation control member for a thread loosening member that operates a tension release mechanism in conjunction with the rotation of the presser-lifting rotary member, and a switch 3. The sewing machine according to claim 2, further comprising an operation control member of the means, wherein the thread loosening member is configured to operate a tension release mechanism at a later stage of the rotation operation of the presser lifting rotation member. Work clamp lifting device.

The horizontal lever length from the rotation center of the presser lifting rotation member to the central operating portion of the rotary roller that raises the presser bar when the presser lifting rotation member rotates is decreased as the rotation angle increases. The sewing machine presser lifting / lowering device according to claim 3, wherein the sewing presser lifting / lowering device is provided.

The drive prohibition control means prohibits the drive of the sewing motor even when the height position detected by the height detection means is equal to or greater than a predetermined value corresponding to the vicinity of the uppermost position of the presser foot when the sewing machine motor is stopped. The presser foot lifting device for a sewing machine according to any one of claims 2 to 4.

The presser foot is configured to be locked at its raised position via an engagement portion formed on the manual operation lever, and the lock state at the raised position of the presser foot can be released by operating the second operating member. The sewing machine presser lifting device according to any one of claims 1 to 5 .