JPH0819682A - Bobbin thread controllable sewing machine - Google Patents

Abstract

PURPOSE:To provide a sewing machine capable of securely controlling the bobbin thread feed to obtain a suitable stitch balancing thread tension and reducing the production cost. CONSTITUTION:Power is transmitted by a cam 16 integrally rotated with the lower shaft of this bobbin thread controllable sewing machine. When the thread take up lever goes down from the highest position and goes up from the lowest position, the bobbin thread controller 18 is moved up and down and the bobbin thread 24 is pinched by the bobbin thread controller 18 and the inner shuttle upper face 26a and released when the lower shaft 10 is rotated to a designated angle.

Description

【発明の詳細な説明】Detailed Description of the Invention

【０００１】[0001]

【産業上の利用分野】本発明は、上糸と下糸とを縫目形
成手段によって絡ませると共に、下糸を所定のタイミン
グで制御する下糸制御可能なミシンに関するものであ
る。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sewing machine capable of controlling a lower thread at a predetermined timing while entwining the upper thread and the lower thread with a stitch forming means.

【０００２】[0002]

【従来の技術】従来、ミシン使用者あるいはミシン自身
が布厚、糸太さ、並びに、縫製速度などの縫製条件を感
知し、上糸張力や上糸供給量を調節あるいは制御するこ
とによりミシンの糸調子を適正な状態に保っていた。し
かし、上糸張力や上糸供給量だけを調節あるいは制御し
て糸調子を適正化することでは、必ずしも充分な糸調子
は得られず、特に薄手の加工布に対してはその傾向が強
かった。従って、特公昭６３−６０３３号公報に記載さ
れているように、下糸条件の調節により糸調子を適正化
するミシンがあり、ミシン使用者が下糸張力の強さをミ
シン機枠外部から調整し、上糸張力と適合させ適正な糸
調子を得ている。このような下糸を狭持するミシンにお
いては、下糸と狭持する部材との摩擦による抵抗は押圧
する程度であり、下糸の引き出し不可能に拘束する程強
くはなかった。2. Description of the Related Art Conventionally, a sewing machine user or the sewing machine itself senses sewing conditions such as cloth thickness, thread thickness, and sewing speed, and adjusts or controls the upper thread tension and the upper thread supply amount. The thread tension was kept in a proper state. However, by adjusting or controlling only the upper thread tension and the upper thread supply amount to optimize the thread tension, it is not always possible to obtain a sufficient thread tension, and this tendency is particularly strong for thin work cloth. . Therefore, as described in JP-B-63-6033, there is a sewing machine that optimizes the thread tension by adjusting the lower thread condition, and the sewing machine user adjusts the strength of the lower thread tension from the outside of the machine frame. The thread tension is matched with the needle thread tension to obtain a proper thread tension. In such a sewing machine that holds the lower thread, the resistance due to the friction between the lower thread and the member that holds the lower thread is only a pressing force, and is not so strong that the lower thread cannot be pulled out.

【０００３】また、下糸を制御するミシンとしては、特
公昭６１−３５１９号公報や特開昭６３−２７００９１
号公報に記載されているように、縫い目形成時ごとに行
われる下糸たぐり量を制御して、適正な糸調子を得よう
とするミシンがある。このような下糸をたぐり量を制御
するミシンでは、上糸によっては下糸の引き出しが不可
能になるようには拘束されていなかった。Further, as a sewing machine for controlling the lower thread, Japanese Patent Publication No. 61-3519 and Japanese Patent Laid-Open No. 63-270091.
There is a sewing machine which attempts to obtain an appropriate thread tension by controlling the amount of bobbin thread dragging performed each time a seam is formed, as described in Japanese Patent Laid-Open Publication No. H11-242242. In such a sewing machine that controls the amount of bobbin threading, some bobbin threads are not constrained so that the bobbin thread cannot be pulled out.

【０００４】更に、特開昭６１−２６５１８９号公報に
記載されているように、上糸の引き出し量情報とミシン
位相角情報を検出しその検出結果をもとに演算により、
下糸が巻かれているボビンの回転をロックしたり、ロッ
クを解除したりすることで上糸張力と適合させ適正な糸
調子を得るミシンがある。Further, as described in Japanese Patent Laid-Open No. 61-265189, information on the amount of pull-out of the upper thread and information on the phase angle of the sewing machine are detected, and calculation is performed based on the detection result.
There is a sewing machine that locks the rotation of a bobbin around which a bobbin thread is wound or unlocks the bobbin to adjust the tension of the bobbin thread to obtain an appropriate thread tension.

【０００５】[0005]

【発明が解決しようとする課題】しかしながら、上述し
たような従来のミシンにおいては、特公昭６３−６０３
３号公報、特公昭６１−３５１９号公報、並びに、特開
昭６３−２７００９１号公報に記載されているミシンに
おいては、下糸を制御しているが、下糸を引き出し可能
である。従って、糸調子は最終的には上糸の張力と下糸
の張力の釣合によって決定されるので、縫い目毎の糸調
子の不安定さやミシン本体や上糸側の不測の事態により
下糸に大きな引き出し力がかかってしまった場合には、
下糸が必要以上に引き出されてしまい糸調子がくずれ易
い。However, in the conventional sewing machine as described above, Japanese Patent Publication No. 63-603.
In the sewing machines described in Japanese Patent Publication No. 3 and Japanese Patent Publication No. 61-3519, and Japanese Patent Laid-Open Publication No. 63-270091, the lower thread is controlled, but the lower thread can be pulled out. Therefore, since the thread tension is finally determined by the balance between the tension of the upper thread and the tension of the lower thread, the lower thread will be sewn to the lower thread due to instability of the thread tension at each seam or an unexpected situation on the sewing machine body or the upper thread side. If a large pull-out force is applied,
The bobbin thread is pulled out more than necessary and the thread tension tends to collapse.

【０００６】また、特開昭６１−２６５１８９号公報に
記載されているミシンにおいては、上糸の引き出し量情
報を加味するため計算処理能力を持ったミシンでしか実
現できず上糸検出、演算処理や駆動装置のためミシンが
高価になってしまったり、上糸検出場所と実際の縫い目
との場所の違いによる下糸制御のタイミングズレや、演
算時間、駆動装置動作開始までの時間的な遅れが１針の
間においても発生してしまう。また、ミシンの高速回転
時には、ボビンの拘束による下糸制御を行っているため
糸が勢いよく繰り出され、ボビンが勢いで空転してしま
い効果的な糸制御方法ではないという問題点がある。Further, in the sewing machine disclosed in Japanese Patent Laid-Open No. 61-265189, since the information on the amount of pulling out the upper thread is taken into consideration, it can be realized only by the sewing machine having the calculation processing capability, and the upper thread detection and arithmetic processing are performed. The sewing machine becomes expensive due to the machine and the drive device, the timing difference of the bobbin thread control due to the difference between the upper thread detection position and the actual stitch position, the calculation time, and the time delay until the operation of the drive device start It occurs even during one stitch. Further, when the sewing machine rotates at a high speed, the bobbin is restrained by the bobbin thread, so that the bobbin is unreeled and the bobbin spins unintentionally, which is not an effective thread control method.

【０００７】本発明は、上述した問題点を解決するため
になされたものであり、下糸を確実に制御でき常に安定
した適正な糸調子が得られると共に、上糸側の不測の事
態により下糸に大きな引き出し力がかかってしまった場
合でも下糸が必要以上に繰り出されてしまい糸調子がく
ずれることがなく、安定して下糸を制御して、ソフトな
縫い目や薄手の加工布でもきれいな糸調子が得られ、縫
い目形成と下糸制御とが時間的な遅れなく、小型で安価
なミシンを提供することを目的とする。The present invention has been made in order to solve the above-mentioned problems, and the bobbin thread can be reliably controlled so that a stable and proper thread tension can always be obtained, and the bobbin thread is lowered due to an unexpected situation. Even if a large amount of pulling force is applied to the thread, the bobbin thread will not be unnecessarily paid out and the thread tension will not be disturbed, and the bobbin thread can be controlled stably, making it possible to clean even soft seams and thin work cloths. An object of the present invention is to provide a small-sized and inexpensive sewing machine in which a thread tension is obtained, and stitch formation and bobbin thread control are not delayed in time.

【０００８】[0008]

【課題を解決するための手段】この目的を達成するため
に本発明の請求項１記載の下糸制御可能なミシンは、下
糸を蓄えている下糸供給源から針板の針穴に至る下糸供
給路の間で下糸を挟持拘束する接近位置と、下糸の挟持
拘束を解放する隔離位置とにわたって相対移動可能な一
対の下糸係合体と、下糸係合体が接近位置と隔離位置と
にわたって移動するように、縫目形成手段に連結された
係合体駆動手段とを備えている。In order to achieve this object, a lower thread controllable sewing machine according to claim 1 of the present invention extends from a lower thread supply source accumulating a lower thread to a needle hole of a needle plate. A pair of bobbin thread engaging bodies that are relatively movable between an approach position where the bobbin thread is clamped and constrained between the bobbin thread supply paths and an isolation position where the bobbin thread clamping constraint is released, and the bobbin thread engaging body is isolated from the approach position. And an engagement body driving means connected to the stitch forming means so as to move over the position.

【０００９】また、請求項２記載の下糸制御可能なミシ
ンは、加工布の送り完了に呼応するように下糸係合体が
隔離位置から接近位置に移動した後に、上糸のループが
下糸供給源を通過するように、下糸係合体を接近位置か
ら隔離位置に移動する係合体駆動手段を備えている。Further, in the sewing machine capable of controlling the bobbin thread according to a second aspect of the invention, after the bobbin thread engaging body moves from the separating position to the approaching position so as to respond to completion of feeding of the work cloth, the loop of the bobbin thread is a bobbin thread. Engagement body drive means for moving the lower thread engagement body from the approach position to the isolated position so as to pass through the supply source is provided.

【００１０】更に、請求項３記載の下糸制御可能なミシ
ンは、上糸の引き上げ開始に呼応するように下糸係合体
が隔離位置から接近位置に移動した後に、上糸の引き上
げ完了または加工布の送りの開始に呼応するように、下
糸係合体を接近位置から隔離位置に移動する係合体駆動
手段を備えている。Further, in the sewing machine capable of controlling the bobbin thread according to a third aspect of the present invention, after the bobbin thread engaging body moves from the isolated position to the approaching position so as to correspond to the start of the lifting of the upper thread, the completion or processing of the upper thread is completed. Engagement body drive means for moving the lower thread engagement body from the approaching position to the separating position is provided so as to respond to the start of feeding of the cloth.

【００１１】[0011]

【作用】上記の構成を有する本発明の請求項１記載の下
糸制御可能なミシンにおいては、一対の下糸係合体は、
下糸を蓄えている下糸供給源から針板の針穴に至る下糸
供給路の間で下糸を挟持拘束する接近位置と、下糸の挟
持拘束を解放する隔離位置とにわたって相対移動する。
係合体駆動手段は、下糸係合体を接近位置と隔離位置と
にわたって移動させる。In the bobbin thread controllable sewing machine according to claim 1 of the present invention having the above structure, the pair of bobbin thread engaging members are
Relative movement between an approaching position where the lower thread is clamped and restrained between the lower thread supply path that stores the lower thread and the needle hole of the needle plate, and an isolated position where the lower thread clamp constraint is released. .
The engagement body drive means moves the lower thread engagement body between the approach position and the isolation position.

【００１２】また、請求項２記載の下糸制御可能なミシ
ンにおいては、加工布の送り完了に呼応するように下糸
係合体が隔離位置から接近位置に移動した後に、上糸の
ループが下糸供給源を通過するように、下糸係合体が接
近位置から隔離位置に移動して、加工布の送り完了後に
下糸の引き出しが不可能になる。Further, in the sewing machine capable of controlling the lower thread, the loop of the upper thread is lowered after the lower thread engaging body is moved from the isolated position to the approaching position so as to respond to the completion of feeding the work cloth. The bobbin thread engaging body moves from the approach position to the isolated position so as to pass through the thread supply source, and the bobbin thread cannot be pulled out after the feeding of the work cloth is completed.

【００１３】更に、請求項３記載の下糸制御可能なミシ
ンにおいては、上糸の引き上げ開始に呼応するように下
糸係合体が隔離位置から接近位置に移動した後に、上糸
の引き上げ完了または加工布の送りの開始に呼応するよ
うに、下糸係合体が接近位置から隔離位置に移動して、
上糸の引き上げ完了後または布送り中に、下糸の引き出
しが可能になる。Further, in the sewing machine capable of controlling the bobbin thread according to a third aspect of the present invention, after the bobbin thread engaging body moves from the isolated position to the approaching position so as to respond to the start of the lifting of the upper thread, the completion of the upper thread pull-up or The lower thread engaging body moves from the approaching position to the separating position so as to respond to the start of feeding the work cloth,
After the completion of pulling up the upper thread or during feeding of the cloth, the lower thread can be pulled out.

【００１４】[0014]

【実施例】以下、本発明を具体化した一実施例を図面を
参照して説明する。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

【００１５】まず、図１に示すように、本実施例におけ
る下糸制御可能なミシンは、ミシン機枠２に固定された
駆動源である電動モータ４よりミシン機枠２に固定され
た上軸６が回転駆動され、さらに駆動伝達ベルト８によ
りやはりミシン機枠２に固定された下軸１０が上軸６と
同じ回転速度で回転駆動される。下軸１０はギア１２が
下軸１０と一体となって回転するよう固定されており、
回転運動をミシン機枠２に固定された外釜１４に伝達す
る。この時外釜１４は下軸１０に対し倍速で回転させら
れ、これによってスムーズに上糸を捕捉し下糸２４と交
錯させ縫い目を形成する。First, as shown in FIG. 1, a bobbin thread controllable sewing machine according to this embodiment has an upper shaft fixed to the sewing machine frame 2 by an electric motor 4 which is a drive source fixed to the sewing machine frame 2. 6 is rotationally driven, and further, the lower shaft 10 also fixed to the sewing machine frame 2 by the drive transmission belt 8 is rotationally driven at the same rotational speed as the upper shaft 6. The lower shaft 10 is fixed so that the gear 12 rotates integrally with the lower shaft 10,
The rotary motion is transmitted to the outer hook 14 fixed to the sewing machine frame 2. At this time, the outer hook 14 is rotated at a double speed with respect to the lower shaft 10, whereby the upper thread is smoothly captured and intersects with the lower thread 24 to form a stitch.

【００１６】その下軸１０には、さらにこの外釜１４を
駆動するためのギア１２のさきに下糸係合体を制御する
ためのカム１６が下軸１０と一体となって回転するよう
固定されている。一方このカム１６の外周部には一方の
下糸係合体である下糸拘束体１８の一部分であるカムフ
ォロアー部１８ｂが接している。この下糸拘束体１８は
ベース部材２０に揺動可能に支持されており、ベース部
材２０はミシン機枠２に固定されている。Further, a cam 16 for controlling the lower thread engaging body is fixed to the lower shaft 10 so as to rotate integrally with the lower shaft 10 before the gear 12 for driving the outer hook 14. ing. On the other hand, a cam follower portion 18b which is a part of the lower thread restraining body 18 which is one lower thread engaging body is in contact with the outer peripheral portion of the cam 16. The lower thread restraint body 18 is swingably supported by a base member 20, and the base member 20 is fixed to the sewing machine frame 2.

【００１７】図２に示すように、縫製物はミシン機枠２
に固定された針板２２の上を送り歯２３によって布送り
される。針板２２には下糸２４が針板２２上部に抜け出
ることができるように針穴２２ａが形成されている。外
釜１４内には下糸拘束体１８と対となる下糸係合体であ
る内釜２６がある。下糸拘束体１８の一部分である下糸
把持部１８ａとこの内釜２６の上面部２６ａとで下糸２
４を引き出し不可能なように把持する。下糸拘束体１８
はベース部材２０の一部であるベース部材軸部２０ａに
揺動可能に支持され、カムフォロアー部１８ｂはカム１
６の外周と接触し、このカム面に沿って揺動可能となっ
ている。バネ２８はカムフォロアー部１８ｂを常時カム
１６外周部に押し付けており、同時に下糸把持部１８ａ
を下方に押し付ける働きをする。As shown in FIG. 2, the sewing product is a sewing machine frame 2
It is fed by the feed dog 23 on the needle plate 22 fixed to the. A needle hole 22a is formed in the needle plate 22 so that the lower thread 24 can escape to the upper portion of the needle plate 22. Inside the outer hook 14, there is an inner hook 26 which is a lower thread engaging member which is paired with the lower thread restraining member 18. The lower thread gripping portion 18a, which is a part of the lower thread restraining body 18, and the upper surface portion 26a of the inner hook 26,
Grasp 4 so that it cannot be pulled out. Lower thread restraint 18
Is swingably supported by a base member shaft portion 20a which is a part of the base member 20, and the cam follower portion 18b is the cam 1
It is in contact with the outer circumference of 6 and can swing along this cam surface. The spring 28 constantly presses the cam follower portion 18b against the outer peripheral portion of the cam 16, and at the same time, the lower thread gripping portion 18a.
It works by pushing down.

【００１８】図３に示すように、内釜２６には糸供給源
としてのボビン３０が収納されて下糸２４を縫い目形成
のため供給する。ボビン３０から出た下糸２４は内釜２
６の下糸１６に張力を付与するための内釜板バネ部２６
ｂにより下糸２４を挟み通過抵抗を与えている。ただし
この通過抵抗は糸のよりをとる程度であり微弱もしくは
ほとんど抵抗はない程度である。さらに下糸２４は針板
２２の針穴２２ａに導かれ縫製物に至り上糸と共に縫い
目を形成する。この下糸供給路の途中に下糸拘束体１８
の一部分である下糸把持部１８ａと内釜２６の上面部２
６ａとで下糸２４を引き出し不可能なように把持する機
構となっている。As shown in FIG. 3, a bobbin 30 as a thread supply source is housed in the inner hook 26 and supplies the lower thread 24 for forming a stitch. The lower thread 24 from the bobbin 30 is the inner hook 2
Inner hook plate spring portion 26 for applying tension to the lower thread 16 of
The lower thread 24 is sandwiched by b to provide passage resistance. However, this passage resistance is such that the yarn is twisted and is weak or has almost no resistance. Further, the lower thread 24 is guided to the needle hole 22a of the needle plate 22 and reaches the sewn product to form a stitch together with the upper thread. A lower thread restraining member 18 is provided in the middle of the lower thread supply path.
Upper thread portion 18a of the inner hook 26 and the lower thread gripping portion 18a that is a part of
It is a mechanism for holding the lower thread 24 with 6a so that it cannot be pulled out.

【００１９】次に、上述した各要素の動作詳細について
説明する。Next, the details of the operation of each element described above will be described.

【００２０】図２及び図４に示すように、ミシン駆動時
下軸１０が回転するとそれにともない下軸１０に固定さ
れたカム１６が一体となって回転する。この時下軸１０
は１つの縫い目形成に対し常に１回転している。よって
カム１６も１回転するので本機構も１つの縫い目に対し
１サイクルの動作が完了する。さて下糸拘束体１８はこ
のカム１６の外周面にカムフォロアー部１８ｂが接して
いるためカム１６外周の凹凸に応じて揺動する。すると
下糸把持部１８ａは上下に動作し、内釜２６の上面部２
６ａとの間に相対的な位置関係の変化を発生する。図２
に於いてはカムフォロアー部１８ｂはカム１６外周面の
凹部に接しているので下糸把持部１８ａは内釜上面部２
６ａと接し、下糸２４をボビン３０から引き出し不可能
に挟持拘束する接近位置となる。As shown in FIGS. 2 and 4, when the lower shaft 10 rotates when the sewing machine is driven, the cam 16 fixed to the lower shaft 10 rotates together with it. Lower shaft 10 at this time
Always makes one revolution per stitch formation. Therefore, since the cam 16 also makes one rotation, this mechanism completes one cycle of operation for one stitch. Since the cam follower portion 18b is in contact with the outer peripheral surface of the cam 16, the lower thread restraining body 18 swings in accordance with the unevenness of the outer periphery of the cam 16. Then, the bobbin thread gripping portion 18a moves up and down, and the upper surface portion 2 of the inner hook 26
A change in the relative positional relationship occurs with 6a. Figure 2
In this case, since the cam follower portion 18b is in contact with the concave portion of the outer peripheral surface of the cam 16, the lower thread gripping portion 18a is the upper hook portion 2 of the inner hook.
The bobbin thread 24 comes into contact with 6a and comes close to the bobbin 30 so that it cannot be pulled out from the bobbin 30.

【００２１】この時、下糸把持部１８ａと内釜上面部２
６ａとの間には下糸２４が挟まれており、下糸把持部１
８ａはバネ２８によって下方つまり内釜上面部２６ａに
押し付けられ、この力によって下糸２４が加工布に供給
されないように拘束されている。図４に於いてはカムフ
ォロアー部１８ｂはカム１６外周面の凸部に接している
ので下糸把持部１８ａと内釜上面部２６ａとの間隔が発
生し、下糸２４を解放する隔離位置となる。この時は、
下糸２４を拘束する力が解放されるので、下糸２４は自
由にボビン３０より引き出し可能になる。At this time, the lower thread gripping portion 18a and the inner hook upper surface portion 2
The lower thread 24 is sandwiched between the lower thread 6a and the lower thread 6a.
8a is pressed downward by the spring 28, that is, against the upper surface 26a of the inner hook, and this force restrains the lower thread 24 from being supplied to the work cloth. In FIG. 4, since the cam follower portion 18b is in contact with the convex portion of the outer peripheral surface of the cam 16, a gap is generated between the lower thread gripping portion 18a and the inner hook upper surface portion 26a, and the lower position is separated from the lower thread. Become. At this time,
Since the force for restraining the lower thread 24 is released, the lower thread 24 can be freely pulled out from the bobbin 30.

【００２２】図５のタイミングチャートの横軸はミシン
１回転中の上軸６の回転角度を表し、回転角度０゜は針
棒最上点、回転角度１８０゜は針棒最下点であり、回転
角度３６０゜は再び針棒最上点に戻って１つの縫い目が
形成されることになる。縦軸は、それぞれの上軸回転角
度における天秤の上下動作、送り歯の水平動作、送り歯
の上下動作、針棒の上下動作そして下糸拘束体１８の下
糸把持部１８ａ上下動作作動量を表す。The horizontal axis of the timing chart of FIG. 5 represents the rotation angle of the upper shaft 6 during one rotation of the sewing machine. The rotation angle 0 ° is the needle bar uppermost point, and the rotation angle 180 ° is the needle bar lowermost point. The angle of 360 ° returns to the uppermost point of the needle bar again to form one stitch. The vertical axis represents the vertical movement of the balance, the horizontal movement of the feed dog, the vertical movement of the feed tooth, the vertical movement of the needle bar, and the vertical movement amount of the lower thread gripping portion 18a of the lower thread restraining body 18 at each upper axis rotation angle. Represent

【００２３】上軸回転角度０゜において針棒が最上点か
らだんだん下降してくる。同時に天秤は上昇中で、上糸
の糸締めを行っており、送り歯２３は加工布を送り始め
る。この時下糸把持部１８ａは下降位置つまり下糸２４
を挟持拘束する接近位置にあり下糸２４はボビン３０か
ら引き出されない。この結果、下糸糸締めが上糸糸締め
と同時になされ、縫い目が形成されると共に、下糸２４
及び上糸のたるみが解消される。At the upper shaft rotation angle of 0 °, the needle bar gradually descends from the uppermost point. At the same time, the balance is ascending, tightening the upper thread, and the feed dog 23 starts to feed the work cloth. At this time, the lower thread grip portion 18a is in the lowered position, that is, the lower thread 24a.
The bobbin thread 24 is not pulled out from the bobbin 30 because the bobbin thread 24 is in an approaching position where it is clamped and restrained. As a result, the bobbin thread tightening is performed at the same time as the upper thread tightening, a seam is formed, and the bobbin thread 24
Also, the slack of the upper thread is eliminated.

【００２４】その糸締めが完了すると、下軸１０の回転
と共に下糸拘束体１８のカムフォロアー部１８ｂがカム
１６の外周面の凹部に接して、下糸把持部１８ａは上昇
し（Ｖ点）、下糸２４を解放する隔離位置となる。そし
て、下糸２４は解放され布送りにより必要な分だけボビ
ン３０から引き出される。さらに、上軸６が回転し、布
送りが終了すると、下軸１０の回転と共に、下糸拘束体
１８のカムフォロアー部１８ｂがカム１６外周面の凸部
に接して、下糸把持部１８ａは再び下降し（Ｗ点）、下
糸２４を挟持拘束する接近位置となる。下糸２４は把持
され縫製に不必要な糸はボビン３０から引き出されな
い。このことによって余分な下糸２４が供給されて縫い
目を乱すことが防止される。このとき、針は加工布中に
到達している。When the thread tightening is completed, the cam follower portion 18b of the lower thread restraining member 18 comes into contact with the concave portion of the outer peripheral surface of the cam 16 as the lower shaft 10 rotates, and the lower thread gripping portion 18a moves up (point V). , It becomes the isolation position where the lower thread 24 is released. Then, the lower thread 24 is released and is pulled out from the bobbin 30 by a required amount by cloth feeding. Further, when the upper shaft 6 rotates and the cloth feeding ends, the lower shaft 10 rotates and the cam follower portion 18b of the lower thread restraining body 18 comes into contact with the convex portion of the outer peripheral surface of the cam 16 so that the lower thread gripping portion 18a It descends again (point W), and comes to the approach position where the lower thread 24 is clamped and restrained. The bobbin thread 24 is gripped, and threads unnecessary for sewing are not pulled out from the bobbin 30. This prevents excessive bobbin thread 24 from being supplied and disturbing the seam. At this time, the needle has reached the work cloth.

【００２５】さらに上軸６が回転すると針棒は最下点を
越え上糸は糸ループを形成し、外釜１４によって捕捉さ
れ、内釜２６を上糸の糸ループがくぐる。ただし、この
時に下糸把持部１８ａが下降位置のままであると上糸の
糸ループが内釜２６をくぐることができない。この為、
上糸の糸ループが内釜２６をくぐるときにのみ一時的に
下糸拘束体１８のカムフォロアー部１８ｂがカム１６外
周面の凸部に接するようにして、下糸把持部１８ａを上
昇させ（Ｘ点）、上糸と下糸２４とを交差させる。上糸
が内釜２６をくぐり終わると、再度下糸拘束体１８のカ
ムフォロアー部１８ｂがカム１６外周面の凹部に接する
ようにし、下糸把持部１８ａを下降位置に戻し（Ｙ
点）、下糸２４は再び拘束状態となる。さらに上軸６が
回転してミシン１回転による縫い目形成の１サイクルが
終了する。When the upper shaft 6 further rotates, the needle bar exceeds the lowest point and the upper thread forms a thread loop, which is caught by the outer hook 14 and passes through the inner hook 26 by the thread loop of the upper thread. However, if the lower thread gripping portion 18a remains in the lowered position at this time, the upper thread thread loop cannot pass through the inner hook 26. Therefore,
Only when the thread loop of the upper thread passes through the inner hook 26, the cam follower portion 18b of the lower thread restraining body 18 is temporarily brought into contact with the convex portion of the outer peripheral surface of the cam 16 to raise the lower thread gripping portion 18a ( (X point), the upper thread and the lower thread 24 are crossed. When the upper thread has passed through the inner hook 26, the cam follower portion 18b of the lower thread restraining body 18 is again brought into contact with the concave portion of the outer peripheral surface of the cam 16, and the lower thread gripping portion 18a is returned to the lowered position (Y
Point), the lower thread 24 is again in the restrained state. Further, the upper shaft 6 rotates to complete one cycle of stitch formation by one rotation of the sewing machine.

【００２６】尚、上述したように、下糸拘束体１８の送
り開始に伴う拘束から解放への切り替えは、送り開始に
まったく一致する必要はなく、各ミシンの性能に応じて
実験などにより適宜設定すれば良い。同様に、下糸拘束
体１８の送り完了に伴う解放から拘束への切り替えは、
送り完了にまったく一致する必要はなく、各ミシンの性
能に応じて実験などにより適宜設定すれば良い。As described above, the switching from the restraint to the release accompanied by the start of feeding the lower thread restraining body 18 does not need to coincide with the start of feeding at all, and is appropriately set by an experiment or the like according to the performance of each sewing machine. Just do it. Similarly, switching from release to restraint upon completion of feeding of the lower thread restraint body 18
It is not necessary to match the completion of feeding at all, and it may be appropriately set by experiments or the like according to the performance of each sewing machine.

【００２７】上述した下糸制御可能なミシンでは、下糸
２４を不安定でばらつきの大きい摩擦抵抗などによって
与えられる張力によって糸調子をとるのではなく、確実
下糸２４を挟持するより確実な糸量制御によるので、安
定した糸調子が得られる。また、糸量を制御するのに中
間介在物（検出信号等により作動するアクチュエータ）
を介さず直接下糸２４を拘束及び解放するので、迅速に
下糸供給量を制御することができる。In the above-described bobbin thread controllable sewing machine, the bobbin thread 24 is not held in tension by tension given by unstable and widely varying frictional resistance, but a more reliable thread that holds the bobbin thread 24 securely. Since the quantity is controlled, a stable thread tension can be obtained. In addition, an intermediate inclusion (actuator that operates according to detection signals, etc.) is used to control the yarn amount.
Since the bobbin thread 24 is directly restrained and released without going through, it is possible to quickly control the bobbin thread supply amount.

【００２８】また、布送り時や縫目形成時など下糸２４
の引き出しが必要なときには、非常に小さな力で円滑に
糸が供給されるので加工布に無理な力がかかること無く
布縮みが起こらず、薄い加工布においてもきれいな縫い
目を得ることができる。一方上糸側の不測の事態や、他
の要因で下糸２４が不必要なときに大きな張力がかかっ
てしまった場合においても、不必要に下糸２４がボビン
３０から引き出されず、縫い目のトラブル（下糸の絡み
や引っかかりなど）が起こらない。縫い目の形成で最も
大切な糸締め時においても、あらかじめ必要糸量が布送
り中に確保された後に、下糸２４の引き出しを禁止して
から上糸の糸締めを行うので、締まった縫い目が確実に
形成される。The bobbin thread 24 is also used for feeding the fabric and forming stitches.
When it is necessary to pull out the thread, the thread is smoothly supplied with a very small force, so that the work cloth is not contracted without applying an excessive force, and a clean seam can be obtained even with a thin work cloth. On the other hand, even when an unexpected situation occurs on the upper thread side or when a large tension is applied when the lower thread 24 is unnecessary due to other factors, the lower thread 24 is not unnecessarily pulled out from the bobbin 30 and a seam trouble occurs. (Bottom thread is not entangled or caught). Even at the time of thread tightening, which is the most important step in forming seams, after the required thread amount is secured during cloth feeding in advance, the bobbin thread 24 is prohibited from being pulled out and then the upper thread is tightened. It is surely formed.

【００２９】構成的にも各種演算など必要がないためコ
ンピュータ等の演算装置、ミシン駆動以外の余分なアク
チエータやセンサ等の搭載の必要もなく、非常に小型に
安価に達成できる。タイミング的にも演算処理時間、各
種アクチエータ、センサの動作開始指令から動作開始ま
での時間的ロス、縫い目から離れた位置での検出による
縫い目までのタイミングズレが発生しないので、縫い始
め１針目から縫い終わりまで均一できれいな縫い目が保
証される。Since various operations are not required in terms of configuration, it is not necessary to install an arithmetic unit such as a computer, an extra actuator or a sensor other than the sewing machine drive, and it is possible to achieve a very small size at low cost. In terms of timing, the processing time, various actuators, the time loss from the operation start command of the sensor to the operation start, and the timing deviation to the stitch due to the detection at the position away from the seam do not occur, so sewing from the first stitch at the sewing start A uniform and clean seam is guaranteed to the end.

【００３０】尚、本発明は上述した実施例に限定される
ものではなく、その主旨を逸脱しない範囲において種々
の変更を加えることが可能である。例えば本実施例では
下糸係合体を下糸拘束体１８ｂと内釜２６とで構成した
がこれらの代わりに下糸２４を把持できる構成であれば
良く、例えば外釜１４、ボビン３０、針板２２、釜止
め、送り歯２３、糸切り用部材やミシン機枠２の一部で
構成しても良い。また本実施例では下糸係合体を制御す
るために下軸１０にカム１６を取り付けて構成したが、
この代わりに下糸係合体の動作を制御できる方法であれ
ば良く、専用のアクチエータ例えばソレノイド、モータ
を釜の回転に同期したリンクにより連結して設置しても
良い。また下軸１０からミシン回転情報を得るのではな
く上軸６、縦軸、釜軸、電動モータ４０、駆動ベルト８
からでも可能である。It should be noted that the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the invention. For example, in the present embodiment, the bobbin thread engaging body is composed of the bobbin thread restraining body 18b and the inner hook 26, but instead of these, any structure that can hold the lower thread 24 may be used. For example, the outer hook 14, the bobbin 30, the needle plate. 22, the hook stopper, the feed dog 23, the thread cutting member, and a part of the machine frame 2 of the sewing machine. In this embodiment, the cam 16 is attached to the lower shaft 10 to control the lower thread engaging body.
Instead of this, any method may be used as long as it can control the operation of the lower thread engaging body, and a dedicated actuator such as a solenoid or a motor may be connected and installed by a link synchronized with the rotation of the shuttle. Further, the sewing machine rotation information is not obtained from the lower shaft 10, but the upper shaft 6, the vertical axis, the shuttle shaft, the electric motor 40, the drive belt 8
It is possible from

【００３１】[0031]

【発明の効果】以上説明したことから明かなように、本
発明の請求項１記載の下糸制御可能なミシンにおいて
は、上糸側の不測の事態や、他の要因で下糸がこれ以上
不必要なときに大きな張力がかかってしまった場合にお
いても、下糸が狭持拘束されているので、不必要に下糸
が引き出されず縫い目のトラブルが防止れている。さら
に、係合体駆動手段を介して縫目形成手段によって下糸
係合体が駆動されるように構成されているので、布厚や
縫模様等に対応したの情報に基づく演算装置やアクチュ
アータ等を設ける必要が無いので、ミシンのコストを低
くできる。そして、下糸を不安定でばらつきの大きい摩
擦抵抗などによって生じる張力によって糸調子をとるの
ではなく、下糸を狭持拘束することによって確実な下糸
制御ができるので、安定した糸調子が得られる。As is apparent from the above description, in the bobbin thread controllable sewing machine according to claim 1 of the present invention, the bobbin thread is no longer moved due to an unexpected situation on the upper thread side or other factors. Even if a large tension is applied when it is not necessary, the lower thread is held and restrained, so that the lower thread is not unnecessarily pulled out and a seam trouble is prevented. Further, since the lower thread engaging body is driven by the stitch forming means via the engaging body driving means, it is possible to operate an arithmetic unit or an actuator based on information corresponding to the cloth thickness, the sewing pattern, or the like. Since it is not necessary to provide the sewing machine, the cost of the sewing machine can be reduced. Then, the bobbin thread is not controlled by tension caused by unstable and widely varying frictional resistance, but rather, the bobbin thread is clamped and restrained so that the bobbin thread can be reliably controlled, so that a stable thread tension can be obtained. To be

【００３２】また請求項２記載の下糸制御可能なミシン
においては、上糸のループが釜をくぐれるように、その
下糸の狭持拘束が解除されるので、下糸の狭持拘束が縫
目形成に支障にならずに、上糸と下糸とを絡める時以外
の縫い目のトラブルを防止できる。Further, in the sewing machine capable of controlling the bobbin thread according to a second aspect of the present invention, since the pinching constraint of the bobbin thread is released so that the loop of the upper thread passes through the shuttle, the pinching constraint of the bobbin thread is sewn. It is possible to prevent troubles in the seam other than when the upper thread and the lower thread are entangled, without hindering the eye formation.

【００３３】更に、請求項３記載の下糸制御可能なミシ
ンにおいては、必要糸量が加工布の送り中によって確保
された後に、縫い目の形成で最も大切な糸締め時に下糸
が拘束されており、下糸の張力と上糸の張力が釣り合う
ので、締まった縫目が確実に形成される。また、加工布
を送る際など下糸の引き出しが必要なときには、非常に
小さな力で円滑に糸が引き出し可能になるので、加工布
に無理な力がかかること無く布縮みが起こらず、特に、
薄い加工布においてもきれいな縫い目を得ることができ
る。Further, in the sewing machine capable of controlling the bobbin thread according to claim 3, after the necessary thread amount is secured by feeding the work cloth, the bobbin thread is restrained at the time of thread tightening, which is the most important in forming a seam. Since the tension of the bobbin thread and the tension of the upper thread are balanced, a tight seam is reliably formed. In addition, when it is necessary to pull out the bobbin thread when sending the work cloth, the thread can be drawn out smoothly with a very small force, so the work cloth does not shrink without being forced, and in particular,
A clean seam can be obtained even with a thin work cloth.

【図面の簡単な説明】[Brief description of drawings]

【図１】本発明の下糸制御可能なミシンを示す断面図で
ある。FIG. 1 is a cross-sectional view showing a lower thread controllable sewing machine of the present invention.

【図２】上記ミシンで下糸を挟持した状態を示す側面図
である。FIG. 2 is a side view showing a state in which a lower thread is clamped by the sewing machine.

【図３】上記ミシンの下糸を挟持する構成を示す上面図
である。FIG. 3 is a top view showing a structure for holding a lower thread of the sewing machine.

【図４】上記ミシンで下糸を解放した状態を示す側面図
である。FIG. 4 is a side view showing a state in which a lower thread is released by the sewing machine.

【図５】上記ミシンの上軸１回転中の各部の動きを示す
タイミングチャートである。FIG. 5 is a timing chart showing the movement of each part during one rotation of the upper shaft of the sewing machine.

【符号の説明】[Explanation of symbols]

１６ カム １８ 下糸拘束体 １８ａ 下糸把持部 １８ｂ カムフォロアー部 ２２ 針板 ２２ａ 針穴 ２４ 下糸 ２６ 内釜 ２６ａ 内釜上面 ２６ｂ 内釜板バネ部 ３０ ボビン 16 cam 18 bobbin thread restraint body 18a bobbin thread gripping part 18b cam follower part 22 needle plate 22a needle hole 24 bobbin thread 26 inner hook 26a inner hook upper surface 26b inner hook plate spring portion 30 bobbin

Claims (3)

【特許請求の範囲】[Claims] 【請求項１】 上糸と下糸とを縫目形成手段によって絡
ませると共に、下糸を所定のタイミングで制御する下糸
制御可能なミシンであって、 前記下糸を蓄えている下糸供給源から針板の針穴に至る
下糸供給路の間で下糸を挟持拘束する接近位置と、前記
下糸の挟持拘束を解放する隔離位置とにわたって相対移
動可能な一対の下糸係合体と、 前記下糸係合体が前記接近位置と隔離位置とにわたって
移動するように、前記縫目形成手段に連結された係合体
駆動手段とを備えていることを特徴とする下糸制御可能
なミシン。1. A bobbin thread control sewing machine capable of entwining a bobbin thread and a bobbin thread with stitch forming means and controlling the bobbin thread at a predetermined timing. A pair of bobbin thread engaging bodies that are relatively movable between an approach position for pinching and constraining the bobbin thread between the bobbin thread supply paths from the source to the needle hole of the needle plate and an isolation position for releasing the pinch constraint of the bobbin thread. A bobbin thread controllable sewing machine comprising: an engaging body driving means connected to the stitch forming means so that the bobbin thread engaging body moves between the approaching position and the separating position. 【請求項２】 前記上糸のループと下糸と絡ませて送ら
れる加工布に対して縫い目を形成する下糸制御可能なミ
シンであって、 前記加工布の送り完了に呼応するように前記下糸係合体
が隔離位置から接近位置に移動した後に、前記上糸のル
ープが前記下糸供給源を通過するように、前記下糸係合
体が接近位置から隔離位置に移動することを特徴とする
請求項１記載の下糸制御可能なミシン。2. A lower thread controllable sewing machine that forms a seam on a work cloth fed by being entangled with the loop of the upper thread and the lower thread, wherein the lower thread is adapted to respond to completion of feeding of the work cloth. After the thread engaging body moves from the isolated position to the approaching position, the bobbin thread engaging body moves from the approaching position to the isolated position so that the loop of the upper thread passes through the bobbin thread supply source. A sewing machine according to claim 1, wherein the lower thread can be controlled. 【請求項３】 前記上糸が前記下糸と共に予め設定され
たタイミングで引き上げられる下糸制御可能なミシンで
あって、 前記上糸の引き上げ開始に呼応するように前記下糸係合
体が隔離位置から接近位置に移動した後に、上糸の引き
上げ完了または前記加工布の送りの開始に呼応するよう
に、前記下糸係合体が接近位置から隔離位置に移動する
ことを特徴とする請求項１記載あるいは請求項２記載の
下糸制御可能なミシン。3. A lower thread controllable sewing machine in which the upper thread is pulled up together with the lower thread at a preset timing, and the lower thread engaging body is in an isolated position so as to respond to the start of pulling up the upper thread. 2. The bobbin thread engaging body moves from the approaching position to the separating position so as to respond to the completion of pulling up the upper thread or the start of the feeding of the work cloth after moving from the approaching position to the isolated position. Alternatively, the lower thread controllable sewing machine according to claim 2.