JP3576022B2

JP3576022B2 - Multi needle double chain stitch machine

Info

Publication number: JP3576022B2
Application number: JP02249699A
Authority: JP
Inventors: 雅彦西川; 治堂安
Original assignee: ペガサスミシン製造株式会社
Priority date: 1999-01-29
Filing date: 1999-01-29
Publication date: 2004-10-13
Anticipated expiration: 2019-01-29
Also published as: TW441651U; CN1263960A; JP2000218071A; CN1123660C

Description

【０００１】
【産業上の利用分野】
本発明は、多本針二重環縫いミシンに関するもので、特に、薄く腰のない生地に良好な二重環縫い目を形成できる２本針または３本針二重環縫いミシンに関するものである。
【０００２】
【従来の技術】
図１０に示すような２本の針１，２を有する従来の多本針二重環縫いミシンは、左右に並列して配置され右針２の針下端が左針１の針下端より高く針棒下端に固定された２本の針１，２と、右側から各針に向かって進退するルーパ３とを備える。図９に示すように二重環縫目Ｓは、ルーパ３に掛けられてループ状となる左針糸４Ｌ及び針糸５Ｌと生地（図示を省略）からルーパ目孔３ｅを経てルーパ３に沿うルーパ糸６とによる糸三角形に左針１と右針２がそれぞれ降下し、下死点を経て上昇するとともにルーパ３が後退し右死点を経て前進して各針に形成された新たな針糸ループをすくうようにして構成されている。
【０００３】
上記構成の二重環縫いミシンで生地に二重環縫い目Ｓを形成させるために、従来より各針１，２と糸調子器群７ａ，７ｂ、７ｃとの針糸経路間に針糸制御機構８が配置されている（図１０）。この針糸制御機構８は、針棒１ａの上端に固定された針棒糸道９と、ミシンアームＡに固定された針糸道ホルダー１０と、揺動軸１１に一方端を固定し他方の自由端に通し孔１２ａ，１２ｂを備え揺動軸１１を中心に揺動する針糸捌キ１２とからなる。針棒糸道９は針棒１ａの上端を起点として前記ミシンの生地送り方向Ｆと反対方向に延びており、その先端部に複数個の糸道孔９ａ，９ｂを備える。針棒糸道９は針棒１ａの昇降運動に連動して昇降動する。針糸道ホルダー１０は左右の針糸４，５を個別に案内するための複数個の針糸道１０ａ，１０ｂを備え、各針糸道はそれぞれ上下に位置調節可能に針糸道ホルダー１０に固定され、右針糸道１０ｂは左針糸道１０ａより高く設定されている。また、針糸道ホルダー１０は、長孔１０ｈおよびネジ１３を介して上下位置を調節可能に固定でき、これにより各針糸道１０ａ，１０ｂの上下位置を一括して調節できる。揺動軸１１は針棒１ａの昇降運動に連動して揺動する。針糸捌キ１２は左右の針糸４，５を個別に案内するよう複数個の通し孔１２ａ，１２ｂにそれぞれ通している。糸調子器群７は、左右の針糸４，５用に配置された糸調子器７ａ，７ｂと、ルーパ糸６用の配置された糸調子器７ｃとからなり、対応する糸に張力を付与するものである。
【０００４】
図１１は図１０におけるミシンの針１，２と針糸道１０ａ，１０ｂとの針糸経路間で制御された各針糸４，５の糸捌き量を示している。図中、縦軸Ｅは各針糸４，５の糸捌き量（ｍｍ）を表し、横軸Ａはミシン主軸Ｍの１回転分、すなわち、一縫い目形成過程分に相当する角度の３６０度を表している。ミシン主軸Ｍは、角度が０゜のとき、左右の針が各自の上死点となるように構成されている。尚、ミシン主軸Ｍの角度が９０゜付近において左側の針１が前記糸三角形に降下し、ミシン主軸Ｍの角度が１２０゜付近において右側の針２が前記糸三角形に降下する。また、ミシン主軸Ｍの角度が２１０゜付近においてルーパ３が右針２に形成された新たな針糸ループをすくい、ミシン主軸Ｍの角度が２４０゜付近においてルーパ３が左針１に形成された新たな針糸ループをすくう。左針糸４の糸捌き量は１０゜付近から増加し初め１８０゜付近で最大になり、３３０゜付近でゼロになっている。右針糸５の糸捌き量は２０゜付近から増加し初め１７０゜付近から２１０゜付近の間最大を維持し３４０゜付近でゼロになっている。ミシン主軸Ｍの角度５０゜付近から３４０゜付近の間において、右針糸の糸捌き量は左針糸の糸捌き量を上回っている。
【０００５】
【発明が解決しようとする課題】
しかし、上記のような従来の装置では、図１１に示すように、ミシン主軸の角度が２４０゜以降、すなわち、針が下死点を経て上昇するとともにルーパが前進して右針糸ループをすくった時点から上死点までの糸緩みが十分でなく、針からルーパの腹部を経て生地に伸びるループ状の右針糸量が少なくなる。従って、生地からルーパの目孔に連なるルーパ糸をループ状右針糸によってルーパの腹部に沿わせることになる。その結果、ループ状右針糸とルーパ糸とで形成される糸三角形中に右針が降下しない、いわゆる、「帰りの目飛び」が起きてしまうという懸念があった。
【０００６】
従って、本発明の目的は、上記のような問題を簡単な構成で解決し確実に二重環縫い目を形成できる多本針二重環縫いミシンを提供することにある。
【０００７】
【課題を解決するための手段】
本発明の請求項１に係る装置は、上記目的を達成するために、針棒下端に左右に並列して配置され、右の針下端が左の針下端より高く針棒下端に固定された少なくとも２本の針と、右側から各針に向かって進退するルーパとを備え、該針とルーパが協働してルーパに掛けられてループ状となる針糸と生地からルーパ目孔を経てルーパに沿うルーパ糸とによる糸三角形を形成した後、生地に二重環縫い目を形成する多本針二重環縫いミシンにおいて、針棒上端に固定され複数個の糸道孔を対向して設けた一対の糸案内と、ミシン機枠に固定され、前記糸道孔の間を横切るよう生地送り方向に対して前上がりとなる方向に沿って延びる第１カムと針棒の昇降方向に沿って延びる第２カムを形成した糸捌きとを備え、前記針棒の降下に伴って前記針が前記糸三角形に降下したときに一対の糸案内間の針糸が第１カムに係合し、下死点を経て針が上昇するとともにルーパが前進して針糸ループをすくうまで第２カムとの係合を維持しその後に両カムへの係合を順次解除するようにしたことを特徴とするものである。
【０００８】
請求項２に係る装置は、第１カムによる針糸の係合解除が最も右側の針に挿通された針糸から行われていることを特徴とするものである。
【０００９】
請求項３に係る装置は、第２カムへの係合時における前記糸案内間の各針糸の経路長は右側の針に挿通された針糸ほど長くなされていることを特徴とするものである。
【００１０】
【作用】
本発明の請求項１によれば、前記針棒の降下に伴って前記針が前記糸三角形に降下したときに一対の糸案内間の各針糸が第１カムに順次係合する。そして、下死点を経て上昇する針とともにルーパが前進して針糸ループをすくうまで第２カムとの係合を維持した後に両カムへの係合を順次解除する。解除後の各針糸は急激に弛められ、ルーパに掛けられてループ状となる各針糸は生地からルーパ目孔へ連なるルーパ糸をルーパに沿わせない。
【００１１】
本発明の請求項２によれば、前記糸三角形における各針糸への係合解除が最も右側のループ状の針糸から行われることとなる。
【００１２】
本発明の請求項３によれば、縫目中における右針糸の比率が多くなる。
【００１３】
【発明の実施の形態】
以下、本発明の実施の形態を図面に基づいて説明するが、従来ミシンと共通する部分についてはその説明を省略する。図１は本発明に係る２本針二重環縫いミシンの全体斜視図である。針棒１ａの上端には一対の針棒糸道１４，１４（一対の糸案内）が固定されている。一対の針棒糸道１４，１４は前記ミシンの生地送り方向Ｆと反対方向に延び且つその先端部が上方に曲げられている。上方に曲げられた針棒糸道１４，１４の先端部には左針糸用の糸道孔１４ａ，１４ａおよび右針糸用の糸道孔１４ｂ，１４ｂが対向する部分に配置されている。図２に示すように、両糸道孔１４ａ，１４ｂは前記生地送り方向Ｆに対して前上がりとなる方向に沿っており、針棒１ａの昇降方向と交差する方向に沿っている。左針糸用の糸道孔１４ａ，１４ａは右針糸用の糸道孔１４ｂ，１４ｂよりも低く且つ生地送り方向Ｆの後方側に設定されている。
【００１４】
ミシン機枠の一部を構成するミシンアームＡには針棒１ａの昇降時に前記針棒糸道１４，１４間の各針糸に係合する糸捌き１５が配置されている。この糸捌き１５は、前記生地送り方向Ｆに対して前上がりとなる方向に沿って延びる第１カム１５ａと、針棒１ａの昇降方向に沿って延びる第２カム１５ｂとを形成している。第１カム１５ａは前記針棒糸道１４，１４の両糸道孔の間を横切るように第１長孔１６とネジ１７によりブラケット１８に固定される。ブラケット１８は第２長孔１９とネジ２０とを介してミシンアームＡに固定される。ブラケット１８の第２長孔１９とネジ２０とにより、糸捌き１５は針棒１ａの昇降方向に沿って上下に固定位置を変更でき、針棒糸道１４，１４間の各針糸４，５との係合タイミングを調節できる。ブラケット１８の第１長孔１６とネジ１７とにより、糸捌き１５は前記生地送り方向Ｆに沿って前後に固定位置を変更でき、糸道孔間の各針糸４，５の経路長を調節できる。左右の針糸道１０ａ，１０ｂはほぼ同じ高さに設定されている。
【００１５】
左針用の針糸４は図示しない糸供給源から糸調子器群の糸調子器７ａ、針糸ホルダーの針糸道１０ａ、針糸捌キの通し孔１２ａ、針棒糸道の糸道孔１４ａ，１４ａを経て左針１の目孔に通され、右針用の針糸５は図示しない糸供給源から糸調子器の糸調子器７ｂ、針糸ホルダーの針糸道１０ｂ、針糸捌キの通し孔１２ｂ、針棒糸道の糸道孔１４ｂ，１４ｂを経て右針２の目孔に通される。
【００１６】
次に、上記のように構成された本発明の２本針二重環縫いミシンについて、図２ないし図８に基づいてその作用を説明する。
図８に示すように、ミシン主軸Ｍの角度が０゜、すなわち、針棒１ａが上死点のとき、一対の針棒糸道１４，１４の各糸道孔に挿通された各針糸４，５は糸捌き１５の第１カム１５ａに係合しておらず上方に位置している（図２）。針棒１ａの降下に伴って、各針糸４，５の糸捌き量とも２０゜付近からほぼ同じように上昇し始める。ミシン主軸Ｍの角度が９０゜付近に到達すると、まず、ルーパ３に掛けられてループ状となる針糸４Ｌと生地からルーパ目孔３ｅを経てルーパ３に沿うルーパ糸６とで形成された糸三角形に左針１先端が到達する。この時、図３に示すように、左針用の糸道孔１４ａ，１４ａ間に挿通された左針糸４が糸捌き１５の第１カム１５ａに係合する。
【００１７】
引き続き、針棒１ａが更に降下し、ミシン主軸Ｍの角度が１２０゜付近に到達すると、ルーパ３に掛けられてループ状となる針糸５Ｌと生地からルーパ目孔３ｅを経てルーパ３に沿うルーパ糸６とで形成された糸三角形の針糸４Ｌと針糸５Ｌとの間に右針２が到達する。この時、図４に示すように、右針用の糸道孔１４ｂ，１４ｂ間に挿通された右針糸５が糸捌き１５の第１カム１５ａに係合する。針棒１ａの更なる降下によって、ミシン主軸Ｍの角度が１３０゜付近に到達すると左針糸の糸捌き量は最大になり、ミシン主軸Ｍの角度が１７０゜付近に到達すると右針糸の糸捌き量は最大になる。第１カム１５ａに係合された各糸道孔間の針糸４，５はこの時期に第２カム１５ｂへスライドされ、その係合状態が維持される（図５）。この係合状態において、糸道孔１４ｂ，１４ｂ間の針糸５の経路長は糸道孔１４ａ，１４ａ間の針糸４の経路長よりも長くなっている。
【００１８】
針棒１ａ下端に固定された針１，２が下死点を経て上昇し、ミシン主軸Ｍの角度が２１０゜付近に到達すると、まず、右針２の上昇とともにルーパ３が前進して右針２に形成された新たな針糸ループをすくう。引き続き、針棒１ａが上昇し、ミシン主軸Ｍの角度が２４０゜付近に到達すると、左針１の上昇とともにルーパ３が前進して左針１に形成された新たな針糸ループをすくう。これらの間において第２カム１５ｂに係合された針棒糸道１４，１４間の各針糸４，５が第１カム１５ａへスライドする（図６）。右針糸の糸捌き量は、ミシン主軸Ｍの角度が２００゜付近に到達まで最大を維持し、その後、急激減少してゆき、左針糸の糸捌き量は、ミシン主軸Ｍの角度が２３０゜付近に到達まで最大を維持し、その後、減少していく。針１，２が下死点を経て上昇し、ルーパ３が針１，２に形成された新たな針糸ループをすくうまで、糸捌き１５のカムに各針糸４，５を係合させているので、その針糸ループが捩れない。これはルーパ３に針糸ループを確実にすくわせるのに有効である。
【００１９】
ルーパ３が両針１，２に形成された針糸ループをすくった後、第１カム１５ａに係合された糸道孔１４ｂ，１４ｂ間の針糸５が係合解除され（図７）、その後、第１カム１５ａに係合された糸道孔１４ａ，１４ａ間の針糸４が係合解除される。これらの係合解除により、生地からルーパ目孔３ｅに連なるルーパ糸６がルーパ３の腹部に沿わなくなり、その結果、前記糸三角形が安定的に形成できる。また、各針糸４，５が糸捌き１５の第２カム１５ｂに係合している状態において右糸道孔間の針糸の経路長が左針用のものよりも長くなるので、その係合状態が解除された後に右側のループ状の針糸の弛み度合が左側のものよりも多くなる。その結果、縫目中における右針糸の比率が多くなって全体的に伸びのある二重環縫い目を形成することができる。糸捌き１５におけるカム１５ａ，１５ｂの作用により、ミシン主軸Ｍの角度１４０゜付近から２２０゜付近の間において、右針糸の糸捌き量は左針糸の糸捌き量を上回り、それ以外の間は、双方ともほぼ同量の糸捌き量となる。
【００２０】
図１０の従来のミシンと図１の本発明を実施したミシンで縫った場合における各糸量の比較を以下の表１に示す。
【００２１】
【表１】

【００２２】
【発明の効果】
以上のように、本発明によれば、下死点からの針の上昇時に、針からルーパの腹部を経て生地に伸びるループ状の針糸によって、生地からルーパの目孔に連なるルーパ糸がルーパに沿うことがなくなるので、確実に前記糸三角形を形成して二重環縫い目を形成できるという効果を奏する。また、下死点からの針の上昇時に、針に形成される針糸ループに捩れが生じないので、針糸ループをルーパで確実にすくうことができる。
【００２３】
請求項２によれば、前記糸三角形における各針糸への係合解除が右側のループ状針糸から行われるので、前記糸三角形の形成をより確実に行うことができる。
【００２４】
請求項３によれば、縫目中における右針糸の比率が多くなるので、全体的に伸びのある二重環縫い目を形成できる。
【図面の簡単な説明】
【図１】本発明に適用される多本針二重環縫いミシンの外観斜視図である。
【図２】同上ミシンの要部説明図である。
【図３】同上ミシンの要部説明図である。
【図４】同上ミシンの要部説明図である。
【図５】同上ミシンの要部説明図である。
【図６】同上ミシンの要部説明図である。
【図７】同上ミシンの要部説明図である。
【図８】同上ミシンの各針糸の糸捌き量を説明する図である。
【図９】従来の２本針二重環縫いミシンによって形成されるシームの構成図である。
【図１０】従来の多本針二重環縫いミシンの外観斜視図である。
【図１１】従来の多本針二重環縫いミシンの各針糸の糸捌き量を説明する図である。
【符号の説明】
１，２左右の針（複数本の針）
１ａ針棒
３ルーパ
３ｅルーパ目孔
４左針用の針糸
４Ｌループ状針糸
５右針用の針糸
５Ｌループ状針糸
６ルーパ糸
７糸調子器（複数の糸調子器）
１４，１４一対の針棒糸道（一対の糸案内）
１４ａ，１４ｂ糸道孔（糸通し孔）
１５糸捌き
１５ａ第１カム
Ｍ主軸（ミシン主軸）
Ｓ二重環縫い目[0001]
[Industrial applications]
The present invention relates to a multi-needle double chain stitch sewing machine, and more particularly to a two-needle or three-needle double chain stitch sewing machine capable of forming a good double chain stitch on a thin, stiff fabric.
[0002]
[Prior art]
A conventional multi-needle double chain stitch sewing machine having two

needles

1 and 2 as shown in FIG. 10 is arranged side by side, and the lower end of the right needle 2 is higher than the lower end of the left needle 1. There are provided two

needles

1 and 2 fixed to the lower end of the rod, and a looper 3 which advances and retreats from the right side toward each needle. As shown in FIG. 9, the double chain stitch S extends from the left needle thread 4 </ b> L and the needle thread 5 </ b> L and the cloth (not shown), which are looped by the looper 3, along the looper 3 through the looper eye hole 3 e. The left needle 1 and the right needle 2 respectively descend in the thread triangle formed by the looper thread 6, rise through the bottom dead center, and the looper 3 retreats and advances through the right dead center to form new needles formed on each needle. It is configured to scoop the yarn loop.
[0003]
In order to form the double chain stitch S on the fabric with the double chain stitch machine having the above-described configuration, a needle thread control mechanism has conventionally been provided between the needle thread paths between the

needles

1, 2 and the thread tensioner groups 7a, 7b, 7c. 8 are arranged (FIG. 10). The needle thread control mechanism 8 includes a needle thread path 9 fixed to the upper end of the needle bar 1a, a needle thread path holder 10 fixed to the sewing machine arm A, and one end fixed to the swing shaft 11 and the other end. A needle thread handling key 12 having through holes 12a and 12b at its free end and swinging about a swing shaft 11 is provided. The needle bar thread path 9 extends from the upper end of the needle bar 1a in a direction opposite to the cloth feeding direction F of the sewing machine, and has a plurality of thread path holes 9a and 9b at its tip. The needle bar thread path 9 moves up and down in conjunction with the up and down movement of the needle bar 1a. The needle thread path holder 10 has a plurality of needle thread paths 10a and 10b for individually guiding the left and

right needle threads

4 and 5, respectively. The right needle thread path 10b is fixed higher than the left needle thread path 10a. The vertical position of the needle thread path holder 10 can be adjusted via the elongated hole 10h and the screw 13, so that the vertical position of each of the needle thread paths 10a and 10b can be adjusted collectively. The swing shaft 11 swings in conjunction with the vertical movement of the needle bar 1a. The needle thread handle 12 passes through a plurality of through holes 12a and 12b so as to guide the left and

right needle threads

4 and 5 individually. The thread tensioner group 7 is composed of thread tensioners 7a and 7b arranged for the left and

right needle threads

4 and 5, and a thread tensioner 7c arranged for the looper thread 6, and applies tension to the corresponding thread. Is what you do.
[0004]
FIG. 11 shows the thread handling amounts of the

respective needle threads

4 and 5 controlled between the needle thread paths of the

sewing machine needles

1 and 2 and the needle thread paths 10a and 10b in FIG. In the figure, the vertical axis E represents the thread handling amount (mm) of each of the

needle threads

4 and 5, and the horizontal axis A represents 360 degrees of an angle corresponding to one rotation of the main shaft M of the sewing machine, that is, one stitch forming process. Represents. The sewing machine spindle M is configured such that when the angle is 0 °, the left and right needles are respectively at the top dead center. When the angle of the sewing machine main axis M is around 90 °, the left needle 1 descends to the thread triangle, and when the angle of the sewing machine main axis M is around 120 °, the right needle 2 descends to the thread triangle. When the angle of the sewing machine spindle M is around 210 °, the looper 3 scoops a new needle thread loop formed on the right needle 2, and when the angle of the sewing machine spindle M is around 240 °, the looper 3 is formed on the left needle 1. Scoop a new needle thread loop. The thread handling amount of the left needle thread 4 increases from about 10 °, reaches a maximum at about 180 ° at the beginning, and becomes zero at about 330 °. The thread handling amount of the right needle thread 5 increases from around 20 °, starts at around 170 ° to around 210 °, and reaches a maximum, and becomes zero at around 340 °. Between the vicinity of the angle 50 ° and the vicinity of 340 ° of the main shaft M of the sewing machine, the thread handling amount of the right needle thread exceeds the thread handling amount of the left needle thread.
[0005]
[Problems to be solved by the invention]
However, in the conventional apparatus as described above, as shown in FIG. 11, the angle of the main shaft of the sewing machine is 240 ° or more, that is, the needle rises through the bottom dead center and the looper advances to scoop the right needle thread loop. There is not enough slack from the point of time to the top dead center, and the amount of loop-shaped right needle thread extending from the needle to the fabric through the abdomen of the looper is reduced. Therefore, the looper thread connected to the eye of the looper from the fabric is made to follow the abdomen of the looper by the loop-shaped right needle thread. As a result, there is a concern that the so-called “return skip” may occur, in which the right needle does not descend into the thread triangle formed by the loop-shaped right needle thread and the looper thread.
[0006]
SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a multi-needle double chain stitch sewing machine that can solve the above-described problems with a simple configuration and can form double chain stitches reliably.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, the apparatus according to claim 1 of the present invention is arranged in such a manner that the lower end of the right needle is higher than the lower end of the left needle and is fixed to the lower end of the needle bar. It has two needles and a looper that advances and retreats toward each needle from the right side, and the needle and the looper cooperate with each other to form a loop-shaped needle thread and cloth through the looper through the looper eye to the looper. In a multi-needle double chain stitch sewing machine that forms a double chain stitch on the fabric after forming a thread triangle with a looper thread along the pair, a pair of thread path holes fixed to the upper end of the needle bar and provided facing each other And a first cam fixed to the sewing machine frame and extending along the direction of rising forward with respect to the fabric feeding direction so as to cross between the yarn path holes and a first cam extending along the vertical direction of the needle bar. and a handling member which forms a second cam, wherein with the descent of the needle bar needle Engage needle thread to the first cam between the pair of thread guide when lowering the yarn triangle, and a second cam to scoop looper moves forward needle thread loop with the needle rises through the bottom dead center Is maintained, and then the engagement with both cams is sequentially released.
[0008]
According to a second aspect of the present invention, the disengagement of the needle thread by the first cam is performed from the needle thread inserted through the rightmost needle.
[0009]
The device according to claim 3, wherein the path length of each needle thread between the thread guides at the time of engagement with the second cam is longer as the needle thread inserted through the right needle. is there.
[0010]
[Action]
According to the first aspect of the present invention, each needle thread between the pair of thread guides is sequentially engaged with the first cam when the needle descends to the thread triangle with the descending of the needle bar. Then, the engagement with the two cams is sequentially released after maintaining the engagement with the second cam until the looper advances with the needle rising through the bottom dead center and scoops the needle thread loop. After the release, each needle thread is rapidly loosened, and the loop-shaped needle thread is hung on the looper so that the looper thread extending from the cloth to the looper eye does not follow the looper.
[0011]
According to the second aspect of the present invention, the disengagement of the triangular thread from each needle thread is performed from the rightmost loop-shaped needle thread.
[0012]
According to the third aspect of the present invention, the ratio of the right needle thread in the stitch increases.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings, but description of parts common to conventional sewing machines will be omitted. FIG. 1 is an overall perspective view of a two-needle double chain stitch sewing machine according to the present invention. A pair of needle bar thread paths 14, 14 (a pair of thread guides) is fixed to the upper end of the needle bar 1a. The pair of needle

bar thread paths

14 and 14 extend in a direction opposite to the fabric feeding direction F of the sewing machine, and the tips thereof are bent upward. At the distal ends of the needle

bar thread paths

14, 14 bent upward, thread path holes 14a, 14a for left needle thread and thread path holes 14b, 14b for right needle thread are arranged at opposing portions. As shown in FIG. 2, both yarn path holes 14a, 14b is along the direction to be raised before with respect to the cloth feed direction F, it is along the direction intersecting the lifting direction of the needle bar 1a. The thread path holes 14a, 14a for the left needle thread are set lower than the thread path holes 14b, 14b for the right needle thread and on the rear side in the fabric feeding direction F.
[0014]
On the sewing machine arm A which constitutes a part of the sewing machine frame, there is arranged a thread handling 15 which engages with each needle thread between the needle bar thread paths 14 when the needle bar 1a is raised and lowered. The thread separating device 15 forms a first cam 15a extending along a direction that rises forward with respect to the cloth feeding direction F, and a second cam 15b extending along a direction in which the needle bar 1a moves up and down. The first cam 15a is fixed to a bracket 18 by a first slot 16 and a screw 17 so as to cross between the two thread passage holes of the needle

bar thread passages

14,14. The bracket 18 is fixed to the sewing machine arm A via the second slot 19 and the screw 20. The second slot 19 of the bracket 18 and the screw 20 allow the thread handler 15 to change its fixed position up and down along the vertical direction of the needle bar 1a. Can be adjusted at the timing of engagement. The first slot 16 of the bracket 18 and the screw 17 allow the thread handling unit 15 to change the fixed position back and forth along the fabric feeding direction F, and adjust the path length of each

needle thread

4 and 5 between the thread path holes. it can. The left and right needle thread paths 10a and 10b are set at substantially the same height.
[0015]
The needle thread 4 for the left needle is supplied from a thread supply source, not shown, from a thread tensioner 7a of a thread tensioner group, a needle thread path 10a of a needle thread holder, a through hole 12a of a needle thread handling key, and a thread path hole of a needle bar thread path. The needle thread 5 for the right needle is passed through an eye hole of the left needle 1 through 14a, 14a, and a thread tension source 7b of a thread tensioner, a needle thread path 10b of a needle thread holder, and a needle thread handling device are provided from a thread supply source (not shown). The right needle 2 is passed through the through hole 12b of the key and the thread path holes 14b, 14b of the needle bar thread path.
[0016]
Next, the operation of the two-needle double chain stitch sewing machine of the present invention configured as described above will be described with reference to FIGS.
As shown in FIG. 8, when the angle of the main shaft M of the sewing machine is 0 °, that is, when the needle bar 1a is at the top dead center, each needle thread 4 inserted into each thread hole of the pair of needle

bar thread paths

14 , 5 are not engaged with the first cam 15a of the thread handling 15, and are located above (FIG. 2). With the lowering of the needle bar 1a, the thread handling amount of each of the

needle threads

4 and 5 starts to rise almost in the same manner from around 20 °. When the angle of the main shaft M of the sewing machine reaches about 90 °, first, the thread formed by the needle thread 4L that is hung on the looper 3 to form a loop and the looper thread 6 from the cloth through the looper eye 3e and along the looper 3. The tip of the left needle 1 reaches the triangle. At this time, as shown in FIG. 3, the left needle thread 4 inserted between the left needle thread path holes 14a, 14a engages with the first cam 15a of the thread handling 15.
[0017]
Subsequently, when the needle bar 1a further descends and the angle of the main shaft M of the sewing machine reaches about 120 °, the needle thread 5L which is hung on the looper 3 and forms a loop from the cloth and the looper along the looper 3 through the looper eye 3e. The right needle 2 reaches between the needle thread 4L and the needle thread 5L, which are formed by the thread 6 and a triangular thread. At this time, the right needle thread 5 inserted between the thread paths 14b for the right needle engages with the first cam 15a of the thread handling 15, as shown in FIG. When the angle of the sewing machine main shaft M reaches about 130 ° due to the further lowering of the needle bar 1a, the thread handling amount of the left needle thread becomes maximum, and when the angle of the sewing machine main shaft M reaches about 170 °, the thread of the right needle thread becomes large. The amount of handling is maximized. The

needle threads

4 and 5 between the thread passage holes engaged with the first cam 15a are slid to the second cam 15b at this time, and the engaged state is maintained (FIG. 5). In this engaged state, the path length of the needle thread 5 between the thread path holes 14b, 14b is longer than the path length of the needle thread 4 between the thread path holes 14a, 14a.
[0018]
When the

needles

1 and 2 fixed to the lower end of the needle bar 1a rise through the bottom dead center and the angle of the main shaft M of the sewing machine reaches about 210 °, the looper 3 moves forward with the rise of the right needle 2 and the right needle first. The new needle thread loop formed in No. 2 is scooped. Subsequently, when the needle bar 1a moves up and the angle of the main shaft M of the sewing machine reaches about 240 °, the looper 3 moves forward with the rise of the left needle 1 and scoops a new needle thread loop formed on the left needle 1. Between these, the

needle threads

4 and 5 between the needle

bar thread paths

14 and 14 engaged with the second cam 15b slide to the first cam 15a (FIG. 6). The threading amount of the right needle thread maintains the maximum until the angle of the sewing machine spindle M reaches about 200 °, and then decreases sharply. Maintain the maximum until reaching ゜, then decrease. The

needle thread

4 and 5 are engaged with the cam of the thread handling 15 until the

needles

1 and 2 rise through the bottom dead center and the looper 3 scoops a new needle thread loop formed on the

needles

1 and 2. So that the needle thread loop does not twist. This is effective to ensure that the looper 3 is scooped with the needle thread loop.
[0019]
After the looper 3 scoops the needle thread loop formed on both

needles

1 and 2, the needle thread 5 between the thread passage holes 14b and 14b engaged with the first cam 15a is disengaged (FIG. 7). Thereafter, the needle thread 4 between the thread path holes 14a, 14a engaged with the first cam 15a is released. By releasing these engagements, the looper thread 6 continuing from the fabric to the looper eye hole 3e does not follow the abdomen of the looper 3, and as a result, the thread triangle can be formed stably. Further, in a state where each of the

needle threads

4 and 5 is engaged with the second cam 15b of the thread handling 15, the path length of the needle thread between the right thread path holes is longer than that for the left needle. After the disengagement state is released, the slack degree of the loop-shaped needle thread on the right side becomes larger than that on the left side. As a result, the ratio of the right needle thread in the seam is increased, and a double-ringed seam that is entirely elongated can be formed. Due to the action of the cams 15a and 15b in the thread handling 15, the thread handling amount of the right needle thread exceeds the thread handling amount of the left needle thread between about 140 ° and 220 ° of the main shaft M of the sewing machine. Are both approximately the same amount of thread handling.
[0020]
Table 1 below shows a comparison of thread amounts when sewing is performed with the conventional sewing machine shown in FIG. 10 and the sewing machine according to the present invention shown in FIG.
[0021]
[Table 1]

[0022]
【The invention's effect】
As described above, according to the present invention, when the needle is lifted from the bottom dead center, the looper thread extending from the fabric to the eye of the looper is formed by the loop-shaped needle thread extending from the needle to the fabric through the abdomen of the looper. Therefore, there is an effect that the thread triangle can be surely formed to form a double ring seam. Further, when the needle is raised from the bottom dead center, the needle thread loop formed on the needle is not twisted, so that the needle thread loop can be reliably scooped by the looper.
[0023]
According to the second aspect, the disengagement of the thread triangle from each needle thread is performed from the right loop needle thread, so that the thread triangle can be formed more reliably.
[0024]
According to the third aspect, since the ratio of the right needle thread in the stitch increases, a double-ring stitch that is entirely elongated can be formed.
[Brief description of the drawings]
FIG. 1 is an external perspective view of a multi-needle double chain stitch sewing machine applied to the present invention.
FIG. 2 is an explanatory view of a main part of the sewing machine.
FIG. 3 is an explanatory view of a main part of the sewing machine.
FIG. 4 is an explanatory view of a main part of the sewing machine.
FIG. 5 is an explanatory view of a main part of the sewing machine.
FIG. 6 is an explanatory view of a main part of the sewing machine.
FIG. 7 is an explanatory diagram of a main part of the sewing machine.
FIG. 8 is a diagram illustrating a thread handling amount of each needle thread of the sewing machine.
FIG. 9 is a configuration diagram of a seam formed by a conventional two-needle double chain stitch sewing machine.
FIG. 10 is an external perspective view of a conventional multi-needle double chain stitch sewing machine.
FIG. 11 is a diagram illustrating a thread release amount of each needle thread of a conventional multi-needle double chain stitch sewing machine.
[Explanation of symbols]
1,2 left and right needles (multiple needles)
1a Needle bar 3 Looper 3e Looper eye hole 4 Needle thread 4L for left needle Loop needle thread 5 Needle thread 5L for right needle Loop needle thread 6 Looper thread 7 Thread tensioner (plural thread tensioners)
14, a pair of needle bar thread paths (a pair of thread guides)
14a, 14b thread path hole (thread passing hole)
15 Thread handling 15a First cam M spindle (sewing machine spindle)
S double chain stitch

Claims

針棒下端に左右に並列して配置され、右の針下端が左の針下端より高く針棒下端に固定された少なくとも２本の針と、右側から各針に向かって進退するルーパとを備え、該針とルーパが協働してルーパに掛けられてループ状となる針糸と生地からルーパ目孔を経てルーパに沿うルーパ糸とによる糸三角形を形成した後、生地に二重環縫い目を形成する多本針二重環縫いミシンにおいて、針棒上端に固定され複数個の糸道孔を対向して設けた一対の糸案内と、ミシン機枠に固定され、前記糸道孔の間を横切るよう生地送り方向に対して前上がりとなる方向に沿って延びる第１カムと針棒の昇降方向に沿って延びる第２カムを形成した糸捌きとを備え、前記針棒の降下に伴って前記針が前記糸三角形に降下したときに一対の糸案内間の針糸が第１カムに係合し、下死点を経て針が上昇するとともにルーパが前進して針糸ループをすくうまで第２カムとの係合を維持しその後に両カムへの係合を順次解除するようにしたことを特徴とする多本針二重環縫いミシン。At least two needles which are arranged side by side at the lower end of the needle bar, the lower end of the right needle is higher than the lower end of the left needle, and are fixed to the lower end of the needle bar, and a looper which advances and retreats from the right side toward each needle. The needle and the looper cooperate with each other to form a triangular thread triangle formed by the looped needle thread and the looped needle thread from the fabric through the looper eye hole, and then forming a double ring seam on the fabric. In the multi-needle double chain stitch sewing machine to be formed, a pair of thread guides fixed to the upper end of the needle bar and provided with a plurality of thread path holes facing each other are fixed to the sewing machine frame, and a gap between the thread path holes is provided. A first cam extending along a direction that rises forward with respect to the fabric feeding direction so as to traverse, and a yarn handling formed with a second cam extending along the elevating direction of the needle bar. needle thread is first between a pair of thread guide when said needle drops into the yarn triangle It engages the arm, so as to release the engagement to subsequently both cam to maintain engagement between the second cam until the looper moves forward scoop needle thread loop with the needle rises through the bottom dead center sequentially Multi-needle double chain stitch machine characterized by the following.

第１カムによる針糸の係合解除が最も右側の針に挿通された針糸から行われていることを特徴とする請求項１に記載の多本針二重環縫いミシン。 2. The multi-needle double chain stitch sewing machine according to claim 1, wherein the disengagement of the needle thread by the first cam is performed from the needle thread inserted through the rightmost needle.

第２カムへの係合時における前記糸案内間の各針糸の経路長は右側の針に挿通された針糸ほど長くなされていることを特徴とする請求項１または２に記載の多本針二重環縫いミシン。 3. The multiple thread according to claim 1, wherein a path length of each needle thread between the thread guides at the time of engagement with the second cam is longer as a needle thread inserted through the right needle. 4. Needle double chain stitch machine.