EP0451087B1 - Thread tension controlling device for sewing machine - Google Patents

Thread tension controlling device for sewing machine Download PDF

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Publication number
EP0451087B1
EP0451087B1 EP91810088A EP91810088A EP0451087B1 EP 0451087 B1 EP0451087 B1 EP 0451087B1 EP 91810088 A EP91810088 A EP 91810088A EP 91810088 A EP91810088 A EP 91810088A EP 0451087 B1 EP0451087 B1 EP 0451087B1
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EP
European Patent Office
Prior art keywords
thread
spring
regulating device
lever
needle
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Expired - Lifetime
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EP91810088A
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German (de)
French (fr)
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EP0451087A1 (en
Inventor
Hanspeter Vogel
Niklaus Wacker
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Fritz Gegauf AG
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Fritz Gegauf AG
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Publication of EP0451087A1 publication Critical patent/EP0451087A1/en
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    • D—TEXTILES; PAPER
    • D05—SEWING; EMBROIDERING; TUFTING
    • D05B—SEWING
    • D05B49/00—Take-up devices, e.g. levers, for the needle thread
    • D05B49/02—Take-up devices, e.g. levers, for the needle thread operated by cams or linkages

Definitions

  • the present invention relates to a thread regulating device for sewing machines according to the preamble of patent claim 1.
  • the upper thread leading to the eye of the needle must track the movement of the needle during the stitching process, ie when the needle is lowered onto and into the sewing material, so that there are no short-term tensile stresses on the thread which impair the stitch formation process. It has therefore been known for a long time, for example from German Patent No. 63675, to arrange an oscillating articulated thread lever above the needle, which lever is moved up and down essentially synchronously with the needle, so that the thread fed to the needle eye is neither jerky nor tensed forms a loose loop that can wind around the needle.
  • the well-known joint thread encoder orders from the link, the small drive crank and the actual thread upper joint. All three parts are hinged together.
  • the operation of the thread lever is essentially dependent on the radius of the crank pin and its position relative to the arm shaft crank, the length of the handlebar and the position of its suspension in the head of the machine.
  • the rotation of the arm shaft crank forces the hinged parts of the joint thread lever to follow, and as a result of this controlled movement, the thread-guiding eye of the thread lever describes a path that should essentially correspond to the speed curve of the eye of the needle.
  • the known thread take-up levers cannot track the thread absolutely exactly at the eye of the needle at every point in time of a stitch formation process, which is why thread regulating springs are inserted into the thread run, which compensate and also take on further tasks during the stitch formation process.
  • the thread regulating spring has the following tasks: It must take up the upper thread that is loosened when the thread take-up device moves downwards until the eye of the needle penetrates the material. This prevents the needle from sticking into the loose thread the thread cannot wrap around the needle tip and twisting of the thread before entering the eye of the needle is also prevented. Thread breaks or impairments of the seam are avoided in this way.
  • the thread regulating spring comes into action again shortly before the hook loosens the widened upper thread loop. It causes the upper thread loop to be pulled off gently and smoothly before the thread take-up takes effect and pulls the thread up and into the material at an increased speed.
  • the thread regulating spring can also serve to pull off the upper thread loop slipping through between the bobbin case finger and the retaining means preventing rotation of the capsule at the exact moment when the finger and the retaining means do not lie against one another. This results in a soft and low-noise thread take-off. Due to its function, the thread regulating spring may only exert a relatively weak tensile effect on the thread. At the right moment, however, it must act on the thread quickly and with as little loss as possible. Accordingly, the location, the design and the type of attachment of the spring are of considerable importance. The spring should also be arranged so that the operator does not have to pay particular attention to inserting the thread into the regulating spring when threading the machine.
  • a thread take-up element which keeps the thread under tension under the action of a spring during a certain period of the stitch formation process.
  • the thread take-up element is arranged near a position in which the thread-guiding part of the thread take-up element is located when the upper thread loop passes between the rotary stop for the bobbin case. With this arrangement, a uniform and low-noise thread take-off is achieved by the hook. However, it is not possible to take up the loose upper thread released by the thread feeder at the beginning of the needle downward movement and to prevent the formation of a loose thread section leading to the needle eye.
  • a thread regulating device is also known which contains a thread regulating spring deflecting the thread.
  • the object of the invention is to provide a particularly simple thread regulating device for articulated thread levers which optimally picks up the loose thread between the thread take-up lever and the needle eye or the gripper in different phases of a stitch formation cycle.
  • the thread regulating spring can be connected in a simple manner to the thread-guiding part of the thread take-up device by plugging it onto a pin arranged on the thread take-up device and securing it itself by appropriate shaping.
  • the thread passed through the thread take-up lever is fed through the spring clip with reduced thread tension at any time safely tensioned and / or held captive in the thread guide opening.
  • the lower sewing machine arm 3 and the upper arm 5 of the sewing machine 7 are placed on a base plate 1. Behind the upper machine arm 5, a spool of thread 11, which is attached to a spool of thread spool 13, is partially visible.
  • the machine has a schematically illustrated handwheel 15, a needle holder 17 and a needle 19 fastened in the needle holder 17.
  • two vertically running grooves 23 and 25 are visible, which are connected to one another below by a semicircular groove 27.
  • the groove 25 extends over the entire height of the upper sewing machine arm 5. Die Groove 23 continues on the top 20 of the sewing machine arm 5 to the rear.
  • a conventionally designed thread tensioning device 29 is arranged and shown schematically.
  • the thread-leading part 30 of a thread transmitter 31 oscillating in a vertical plane which is explained in more detail in the section according to FIG. 2, is visible.
  • the thread transmitter 31 which is designed, for example, as an articulated thread transmitter, is of a known design and consists of a link 33 which on the one hand can be pivoted on a fixed axis 35 and whose second end is connected to the thread transmitter lever 36 by a joint 37.
  • the thread take-up lever 36 is also connected via a joint 39 to a crank or crank disk 41 in terms of drive.
  • the needle bar 45 is also articulated on the crank or crank disk 41 by means of a connecting rod 43.
  • the drive conditions for the joint thread transmitter 31 were selected such that the movement of the hook-shaped, thread-guiding part 30 runs completely within the sewing machine housing. Accordingly, a relatively sensitive thread regulating spring 47 is also arranged completely protected within the sewing machine housing.
  • the thread regulating spring 47 is attached directly to the three-leg thread take-up lever 36 in the example, the front end of which comprises the thread-guiding part 30.
  • the thread regulating spring 47 preferably has a spring clip 49 which is U-shaped in plan and which surrounds the fader-guiding part 30 of the thread take-up lever 36 on both sides.
  • the thread regulating spring 47 which is made of thin spring wire, has at the attachment point on the thread take-up lever 36 a cylinder jacket-shaped winding package 51, which is pushed onto a pin 53 attached to the thread take-up lever 36.
  • One end 55 of the spring 47 in the region of the winding package 51 is guided tangentially out of the cylindrical jacket-shaped part, bent twice and engages around the thread take-up lever 36.
  • the bent end 55 lies with its outermost section on the thread take-up lever 36 and secures the spring 47 against rotation on the pin 53.
  • the spring clip 49 of the thread regulating spring 47 which is guided around the thread-guiding part 30, also has a bent end 57, which engages in a cylindrical bore 48 in the axis of the pin 53.
  • the thread regulating spring 47 is also bent downward in a V-shape and, together with the hook-shaped part 30, forms a guide opening 59 for one of the spool 11 through the groove 23, via the thread tensioning device 29 and the groove 25 leading to needle 19 upper thread 61.
  • a stop nose 63 and 65 is formed at the top and bottom, which limits the pivoting range of the spring clip 49 upwards and downwards.
  • the upper thread 61 is guided from the thread reel 11 sitting on the thread reel pin 13 of the machine on the upper side 20 via thread deflections (not shown) and through the thread tensioning device 29 to the thread feeder 31.
  • the thread 61 When the thread 61 is inserted into the thread take-up lever 36, the thread first lies on the spring clip 49 of the thread regulating spring 47 and, as soon as the spring is tensioned, slides under the hook-shaped thread-guiding part 30 of the thread take-up lever 36, so that it is in the opening 59 in the loose state Thread regulating spring 47 and fader-guiding part 30 remains trapped and can no longer be unthreaded.
  • the thread-guiding needle 19 moves against a material 4 lying on the arm 3.
  • the thread take-up lever 36 simultaneously performs a faster downward movement than the needle bar 45 with the needle 19, so that loose thread is created between the thread take-up lever 36 and the eye of the needle , which is now taken up by the spring clip 49 of the thread regulating spring 47 so that the thread remains slightly tensioned in the area of the needle 19.
  • the spring clip 49 can only take up thread until it lies against the stop lug 63 of the thread take-up lever 36 and the thread comes into contact with the thread-guiding part 30 at point A. In the meantime, however, the eye of the needle has penetrated the material 4, so that the loose thread can no longer get caught on the needle tip or twist before entering the eye of the needle.
  • the looper in the lower arm 5 now grips the upper thread loop formed in a known manner, expands it and guides it around the lower thread supply in the bobbin case.
  • the loose upper thread between the thread take-up lever 36 and the sewing material 4 is practically completely pulled off.
  • the thread feeder 36 also begins its upward movement, the spring clip 49 initially still storing the maximum possible thread quantity.

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  • Engineering & Computer Science (AREA)
  • Textile Engineering (AREA)
  • Sewing Machines And Sewing (AREA)

Description

Gegenstand der vorliegenden Erfindung ist eine Fadenreguliervorrichtung für Nähmaschinen gemäss Oberbegriff des Patentanspruches 1.The present invention relates to a thread regulating device for sewing machines according to the preamble of patent claim 1.

Der zum Öhr der Nadel führende Oberfaden muss beim Einstichvorgang, d.h. beim Absenken der Nadel auf und in das Nähgut der Bewegung der Nadel nachgeführt werden, damit keine kurzfristigen Zugspannungen auf den Faden wirken, welche den Stichbildevorgang beeinträchtigen. Es ist daher seit langem bekannt, z.B. aus dem Deutschen Reichspatent Nr. 63675, oberhalb der Nadel einen oszillierenden Gelenkfadenhebel anzuordnen, welcher im wesentlichen synchron mit der Nadel auf- und abbewegt wird, damit der den, Nadelöhr zugeführte Faden weder ruckartig angespannt wird, noch eine lose Schlaufe bildet, die sich um die Nadel winden kann. Der bekannte Gelenkfadengeber bestellt aus dem Lenkerglied, der kleinen Antriebskurbel und dem eigentlichen Fadenbergelenk. Alle drei Teile sind gelenkig miteinander verbunden. Die Wirkungsweise des Fadenhebels ist im wesentlichen abhängig von dem Radius des Kurbelzapfens und seiner Stellung zur Armwellenkurbel, der Länge des Lenkers und der Lage seiner Aufhängung im Kopf der Maschine. Durch die Drehung der Armwellenkurbel werden die gelenkig miteinander verbundenen Teile des Gelenkfadenhebels gezwungen zu folgen, und als Endergebnis dieser gesteuerten bewegung beschreibt das fadenführende Auge des Fadenhebels einen Weg, der im wesentlichen dein Geschwindigkeitsverlauf des Nadelöhrs entsprechen sollte.
Die bekannten Fadengeberhebel können den Faden nicht in jedem Zeitpunkt eines Stichbildevorganges absolut exakt dem Nadelöhr nachführen, weshalb Fadenregulierfedern in den Fadenlauf eingefügt werden, die einen Ausgleich bewirken und zudem weitere Aufgaben beim Stichbildevorgang übernehmen. Je nach Art des Greifersystemes hat die Fadenregulierfeder folgende Aufgaben: Sie muss den bei der Abwärtsbewegung des Fadengebers lose werdenden Oberfaden so lange aufnehmen, bis das Nadelöhr in das Nähgut eindringt. Dadurch kann die Nadel nicht in den losen Faden stechen, der Faden kann sich nicht um die Nadelspitze schlingen und die Verdrillung des Fadens vor dem Eintritt in das Nadelöhr wird ebenfalls verhindert. Fadenbrüche oder Beeinträchtigungen der Naht werden so vermieden. Kurz bevor der Greifer die aufgeweitete Oberfadenschlinge abwirft, tritt die Fadenregulierfeder erneut in Aktion. Sie bewirkt ein weiches und ruckfreies Abziehen der Oberfadenschlinge, bevor der Fadengeber wirksam wird und den Faden mit erhöhter Geschwindigkeit nach oben und in das Nähgut einzieht.
Die Fadenregulierfeder kann aber auch dazu dienen, die zwischen dem Spulenkapselfinger und dem die Drehung der Kapsel verhindernden Rückhaltemittel durchschlüpfende Oberfadenschlinge genau in dem Moment abzuziehen, in welchem der Finger und das Rückhaltemittel nicht gegeneinander anliegen. Dadurch wird ein weicher und geräuscharmer Fadenabzug erzielt. Funktionsbedingt darf die Fadenregulierfeder nur eine verhältnismässig schwache Zugwirkung auf den Faden ausüben. Sie muss aber im geeigneten Moment schnell und möglichst verlustfrei auf den Faden einwirken. Dementsprechend sind die örtliche Anordnung, die Ausbildung und die Befestigungsart der Feder von erheblicher Bedeutung. Die Feder sollte ausserdem so angeordnet sein, dass die Bedienungsperson beim Einfädeln der Maschine nicht speziell auf das Einlegen des Fadens in die Regulierfeder achten muss.
Aus der US-PS 4,856,443 ist ein Fadenaufnahmeelement bekannt, welches den Faden während einer bestimmten Periode des Stichbildevorganges unter der Wirkung einer Feder gespannt hält. Das Fadenaufnahmeelement ist nahe einer Position angeordnet, in welcher sich der fadenführende Teil des Fadenaufnahmeelementes befindet, wenn die Oberfadenschlinge zwischen dem Drehanschlag für die Spulenkapsel hindurchgeht. Mit dieser Anordnung wird ein gleichmässiger und geräuscharmer Fadenabzug vom Greifer bewirkt. Es ist aber nicht möglich, den zu Beginn der Nadel-Abwärtsbewegung vom Fadengeber freigegebenen losen Oberfaden aufzunehmen und die Bildung eines losen zum Nadelöhr führenden Fadenabschnittes zu verhindern.
Aus der Schweizer Patentschrift 421,673 ist weiter eine Fadenreguliervorrichtung bekannt, welche eine den Faden auslenkende Fadenregulierfeder enthält. Diese Anordnung erfordert einen komplizierten Aufbau der Fadenspannungsvorrichtung und hat, bedingt durch den sich ändernden Umschlingungswinkel des Fadens am Federarm, eine ungleichmässige Federwirkung.
Aus der im Europäischen Recherchenbericht genannten UA-A-4,736,698 ist eine weitere Fadenreguliervorrichtung bekannt, die mit einem Kurvenfadenheber zusammenarbeitet. Das fadenführende Auge dieses Fadenhebels bewegt sich auf der gleichen Kreisbahn wie die Fadenregulierfeder. Bei diesem Fadengeber entsteht - im Gegensatz zum Gelenkfadengeber - während der Abwärtsbewegung kein loser Faden, welcher sich verdrillen oder um die Nadelspitze legen kann.
Die weiter genannte US-A-4,422,395 betrifft einen Fadengeber, dessen fadenführende Teil durch einen Federbügel gebildet wird. Dieser wirkt nicht im Sinne einer Fadenabzugsfeder.The upper thread leading to the eye of the needle must track the movement of the needle during the stitching process, ie when the needle is lowered onto and into the sewing material, so that there are no short-term tensile stresses on the thread which impair the stitch formation process. It has therefore been known for a long time, for example from German Patent No. 63675, to arrange an oscillating articulated thread lever above the needle, which lever is moved up and down essentially synchronously with the needle, so that the thread fed to the needle eye is neither jerky nor tensed forms a loose loop that can wind around the needle. The well-known joint thread encoder orders from the link, the small drive crank and the actual thread upper joint. All three parts are hinged together. The operation of the thread lever is essentially dependent on the radius of the crank pin and its position relative to the arm shaft crank, the length of the handlebar and the position of its suspension in the head of the machine. The rotation of the arm shaft crank forces the hinged parts of the joint thread lever to follow, and as a result of this controlled movement, the thread-guiding eye of the thread lever describes a path that should essentially correspond to the speed curve of the eye of the needle.
The known thread take-up levers cannot track the thread absolutely exactly at the eye of the needle at every point in time of a stitch formation process, which is why thread regulating springs are inserted into the thread run, which compensate and also take on further tasks during the stitch formation process. Depending on the type of hook system, the thread regulating spring has the following tasks: It must take up the upper thread that is loosened when the thread take-up device moves downwards until the eye of the needle penetrates the material. This prevents the needle from sticking into the loose thread the thread cannot wrap around the needle tip and twisting of the thread before entering the eye of the needle is also prevented. Thread breaks or impairments of the seam are avoided in this way. The thread regulating spring comes into action again shortly before the hook loosens the widened upper thread loop. It causes the upper thread loop to be pulled off gently and smoothly before the thread take-up takes effect and pulls the thread up and into the material at an increased speed.
However, the thread regulating spring can also serve to pull off the upper thread loop slipping through between the bobbin case finger and the retaining means preventing rotation of the capsule at the exact moment when the finger and the retaining means do not lie against one another. This results in a soft and low-noise thread take-off. Due to its function, the thread regulating spring may only exert a relatively weak tensile effect on the thread. At the right moment, however, it must act on the thread quickly and with as little loss as possible. Accordingly, the location, the design and the type of attachment of the spring are of considerable importance. The spring should also be arranged so that the operator does not have to pay particular attention to inserting the thread into the regulating spring when threading the machine.
From US-PS 4,856,443 a thread take-up element is known which keeps the thread under tension under the action of a spring during a certain period of the stitch formation process. The thread take-up element is arranged near a position in which the thread-guiding part of the thread take-up element is located when the upper thread loop passes between the rotary stop for the bobbin case. With this arrangement, a uniform and low-noise thread take-off is achieved by the hook. However, it is not possible to take up the loose upper thread released by the thread feeder at the beginning of the needle downward movement and to prevent the formation of a loose thread section leading to the needle eye.
From Swiss Patent 421,673 a thread regulating device is also known which contains a thread regulating spring deflecting the thread. This arrangement requires one complicated structure of the thread tensioning device and, due to the changing wrap angle of the thread on the spring arm, has an uneven spring effect.
Another thread regulating device is known from UA-A-4,736,698 mentioned in the European search report, which cooperates with a curved thread lifter. The thread-guiding eye of this thread lever moves in the same circular path as the thread regulating spring. In contrast to the articulated thread dispenser, this thread dispenser does not produce any loose thread during the downward movement, which can twist or wrap around the needle tip.
The further mentioned US-A-4,422,395 relates to a thread feeder, the thread-guiding part of which is formed by a spring clip. This does not work in the sense of a thread take-off spring.

Die Aufgabe der Erfindung besteht nun darin, eine besonderes einfache Fadenreguliervorrichtung für Gelenkfadenhebel zu schaffen, die den losen Faden zwischen dem Fadengeberhebel und dem Nadelöhr bzw. dem Greifer in verschiedenen Phasen eines Stichbildezyklus optimal aufnimmt.The object of the invention is to provide a particularly simple thread regulating device for articulated thread levers which optimally picks up the loose thread between the thread take-up lever and the needle eye or the gripper in different phases of a stitch formation cycle.

Gelöst wird diese Aufgabe durch eine Fadenreguliervorrichtung gemäss den Merkmalen des Anspruches 1.This object is achieved by a thread regulating device according to the features of claim 1.

Durch die direkte Anordnung eines Federbügels auf dem oszillierenden Fadengeberhebel und die sich daraus ergebende zeitweilige Verwendung des Federbügels als Führung des Fadens auf dem Fadengeberhebel ergibt sich ein konstanter gleichbleibender Umschlingungswinkel und daher gleichbleibende Reibverhältnisse, unabhängig von der momentanen Lage des Fadengeberhebels bzw. der Nadel.The direct arrangement of a spring clip on the oscillating thread take-up lever and the resulting temporary use of the spring clip to guide the thread on the thread take-up lever results in a constant, constant wrap angle and therefore constant friction conditions, regardless of the current position of the thread take-up lever or the needle.

Die Fadenregulierfeder kann auf einfache Weise mit dem fadenführenden Teil des Fadengebers verbunden werden, indem sie auf einen am Fadengeber angeordneten Zapfen aufgesteckt wird und durch entsprechende Formgebung sich selbst sichert.The thread regulating spring can be connected in a simple manner to the thread-guiding part of the thread take-up device by plugging it onto a pin arranged on the thread take-up device and securing it itself by appropriate shaping.

Der durch den Fadengeberhebel geführte Faden wird durch den Federbügel bei verminderter Fadenspannung jederzeit sicher gespannt und/oder in der Fadenführungsöffnung gefangen gehalten.The thread passed through the thread take-up lever is fed through the spring clip with reduced thread tension at any time safely tensioned and / or held captive in the thread guide opening.

Anhand eines illustrierten Ausführungsbeispieles wird die Erfindung näher erläutert. Es zeigen:

  • Figur 1 eine Seitenansicht einer Nähmaschine,
  • Figur 2 einen Querschnitt längs Linie II-II in Figur 1 und
  • Figur 3 einen Grundriss der Regulierfeder.
The invention is explained in more detail with the aid of an illustrated embodiment. Show it:
  • FIG. 1 shows a side view of a sewing machine,
  • Figure 2 shows a cross section along line II-II in Figure 1 and
  • Figure 3 is a plan view of the regulating spring.

Auf eine Grundplatte 1 ist der untere Nähmaschinenarm 3 und der obere Arm 5 der Nähmaschine 7 aufgesetzt. Hinter dem oberen Maschinenarm 5 ist eine Garnrolle 11, welche auf einem Garnrollenstift 13 aufgesteckt ist, teilweise sichtbar. Die Maschine weist ein schematisch dargestelltes Handrad 15, einen Nadelhalter 17 und eine im Nadelhalter 17 befestigte Nadel 19 auf. Im vorderen Teil 21 des oberen Nähmaschinenarmes 5 sind zwei vertikal verlaufende Nuten 23 und 25 sichtbar, welche unten durch eine halbkreisförmige Nut 27 miteinander verbunden sind. Die Nut 25 erstreckt sich über die gesamte Höhe des oberen Nähmaschinenarmes 5. Die Nut 23 findet ihre Fortsetzung auf der Oberseite 20 des Nähmaschinenarmes 5 bis zur Rückseite. Im Zentrum des bogenförmigen Abschnittes 27 zwischen den Nuten 23 und 25 ist eine herkömmlich ausgebildete Fadenspannungsvorrichtung 29 angeordnet und schematisch dargestellt. Innerhalb der Nut 25 ist der fadenfürende Teil 30 eines in einer vertikal liegenden Ebene oszillierenden Fadengebers 31, welcher im Schnitt gemäss Figur 2 näher erläutert wird, sichtbar.The lower sewing machine arm 3 and the upper arm 5 of the sewing machine 7 are placed on a base plate 1. Behind the upper machine arm 5, a spool of thread 11, which is attached to a spool of thread spool 13, is partially visible. The machine has a schematically illustrated handwheel 15, a needle holder 17 and a needle 19 fastened in the needle holder 17. In the front part 21 of the upper sewing machine arm 5, two vertically running grooves 23 and 25 are visible, which are connected to one another below by a semicircular groove 27. The groove 25 extends over the entire height of the upper sewing machine arm 5. Die Groove 23 continues on the top 20 of the sewing machine arm 5 to the rear. In the center of the arcuate section 27 between the grooves 23 and 25 a conventionally designed thread tensioning device 29 is arranged and shown schematically. Within the groove 25, the thread-leading part 30 of a thread transmitter 31 oscillating in a vertical plane, which is explained in more detail in the section according to FIG. 2, is visible.

Der beispielsweise als Gelenkfadengeber ausgebildete Fadengeber 31 ist von an sieh bekannter Bauweise und besteht aus einem Lenker 33, der einerseits auf einer festen Achse 35 schwenkbar ist, und dessen zweites Ende andererseits mit dem Fadengeberhebel 36 durch ein Gelenk 37 verbunden ist. Der Fadengeberhebel 36 ist zudem über ein Gelenk 39 mit einer Kurbel oder Kurbelscheibe 41 antriebsmässig verbunden. An der Kurbel oder Kurbelscheibe 41 ist mittels eines Pleuels 43 auch die Nadelstange 45 angelenkt.The thread transmitter 31, which is designed, for example, as an articulated thread transmitter, is of a known design and consists of a link 33 which on the one hand can be pivoted on a fixed axis 35 and whose second end is connected to the thread transmitter lever 36 by a joint 37. The thread take-up lever 36 is also connected via a joint 39 to a crank or crank disk 41 in terms of drive. The needle bar 45 is also articulated on the crank or crank disk 41 by means of a connecting rod 43.

Im erfindungsgemässen Beispiel wurden die Antriebsverhältnisse für den Gelenkfadengeber 31 so gewählt, dass die Bewegung des hakenförmigen, fadenführenden Teiles 30 vollständig innerhalb des Nähmaschinengehäuses verläuft. Dementsprechend ist auch eine relativ empfindliche Fadenregulierfeder 47 vollständig innerhalb des Nähmaschinengehäuses geschützt angeordnet. Die Fadenregulierfeder 47 ist direkt auf dem im Beispiel dreischenkligen Fadengeberhebel 36 befestigt, dessen vorderes Ende den fadenführenden Teil 30 umfasst. Vorzugsweise weist die Fadenregulierfeder 47 einen im Grundriss U-förmig ausgebildeten Federbügel 49 auf, welcher den faderführenden Teil 30 des Fadengebershebels 36 beidseitig umgibt.
Die Fadenregulierfeder 47, welche aus dünnem Federdraht hergestellt ist, weist an der Befestigungsstelle am Fadengeberhebel 36 ein zylindermantelförmiges Windungspaket 51 auf, das auf einem am Fadengeberhebel 36 angebrachten Zapfen 53 aufgeschoben ist. Das eine Ende 55 der Feder 47 im Bereich des Windungspaketes 51 ist tangential aus dem zylindermantelförmigen Teil herausgeführt, zweimal abgekröpft und umgreift den Fadengeberhebel 36. Das abgekröpfte Ende 55 liegt mit seinem äussersten Abschnitt am Fadengeberhebel 36 anund sichert die Feder 47 gegen eine Drehung auf den Zapfen 53. Der um den fadenführenden Teil 30 herumgeführte Federbügel 49 der Fadenregulierfeder 47 weist ebenfalls ein abgekröpftes Ende 57 auf, welches in eine zylindrische Bohrung 48 in der Achse des Zapfens 53 eingreift. Im Bereich des hakenförmigen fadenführenden Teils 30 des Fadengeberhebels 36 ist die Fadenregulierfeder 47 zudem V-förmig nach unten gebogen und bildet zusammen mit dem hakerförmigen Teil 30 eine Führungsöffnung 59 für einen von der Garnrolle 11 durch die Nut 23, über die Fadenspannungsvorrichtung 29 und die Nut 25 zur Nadel 19 führenden Oberfaden 61.
An der Vorderkante des fadenführenden Teils 30 ist oben und unten je eine Anschlagnase 63 bzw. 65 ausgebildet, welche den Schwenkbereich des Federbügels 49 nach oben und nach unten begrenzt. Bei vollständig nach unten ausgeschwenkter Regulierfeder 47 ergibt sich zwischen der Nase 67 des fadenführenden Teils 30 und der Feder 47 eine schlitzförmige Einführöffnung, durch die der Oberfaden 61 vor Beginn des Nähens eingelegt werden kann.In the example according to the invention, the drive conditions for the joint thread transmitter 31 were selected such that the movement of the hook-shaped, thread-guiding part 30 runs completely within the sewing machine housing. Accordingly, a relatively sensitive thread regulating spring 47 is also arranged completely protected within the sewing machine housing. The thread regulating spring 47 is attached directly to the three-leg thread take-up lever 36 in the example, the front end of which comprises the thread-guiding part 30. The thread regulating spring 47 preferably has a spring clip 49 which is U-shaped in plan and which surrounds the fader-guiding part 30 of the thread take-up lever 36 on both sides.
The thread regulating spring 47, which is made of thin spring wire, has at the attachment point on the thread take-up lever 36 a cylinder jacket-shaped winding package 51, which is pushed onto a pin 53 attached to the thread take-up lever 36. One end 55 of the spring 47 in the region of the winding package 51 is guided tangentially out of the cylindrical jacket-shaped part, bent twice and engages around the thread take-up lever 36. The bent end 55 lies with its outermost section on the thread take-up lever 36 and secures the spring 47 against rotation on the pin 53. The spring clip 49 of the thread regulating spring 47, which is guided around the thread-guiding part 30, also has a bent end 57, which engages in a cylindrical bore 48 in the axis of the pin 53. In the area of the hook-shaped thread-guiding part 30 of the thread take-up lever 36, the thread regulating spring 47 is also bent downward in a V-shape and, together with the hook-shaped part 30, forms a guide opening 59 for one of the spool 11 through the groove 23, via the thread tensioning device 29 and the groove 25 leading to needle 19 upper thread 61.
On the front edge of the thread-guiding part 30, a stop nose 63 and 65 is formed at the top and bottom, which limits the pivoting range of the spring clip 49 upwards and downwards. When the regulating spring 47 is pivoted completely downward, there is a slot-shaped insertion opening between the nose 67 of the thread-guiding part 30 and the spring 47, through which the upper thread 61 can be inserted before the sewing begins.

Der Oberfaden 61 wird von der auf dem Garnrollenstift 13 der Maschine sitzenden Garnrolle 11 auf der Oberseite 20 über nicht gezeichnete Fadenumlenkungen und durch die Fadenspannungsvorrichtung 29 hindurch zum Fadengeber 31 geführt. Beim Einlegen des Fadens 61 in den Fadengeberhebel 36 liegt der Faden zunächst auf dem Federbügel 49 der Fadenregulierfeder 47 und gleitet, sobald die Feder gespannt wird, unter den hakenförmigen fadenführenden Teil 30 des Fadengeberhebels 36, so dass er im losen Zustand in der Oeffnung 59 zwischen Fadenregulierfeder 47 und faderführendem Teil 30 gefangen bleibt und nicht mehr ausfädeln kann.The upper thread 61 is guided from the thread reel 11 sitting on the thread reel pin 13 of the machine on the upper side 20 via thread deflections (not shown) and through the thread tensioning device 29 to the thread feeder 31. When the thread 61 is inserted into the thread take-up lever 36, the thread first lies on the spring clip 49 of the thread regulating spring 47 and, as soon as the spring is tensioned, slides under the hook-shaped thread-guiding part 30 of the thread take-up lever 36, so that it is in the opening 59 in the loose state Thread regulating spring 47 and fader-guiding part 30 remains trapped and can no longer be unthreaded.

Zu Beginn des Stichbildevorganges bewegt sich die fadenführende Nadel 19 gegen ein auf dem Arm 3 liegendes Nähgut 4. Der Fadengeberhebel 36 führt gleichzeitig eine schnellere Abwärtsbewegung als die Nadelstange 45 mit der Nadel 19 aus, so dass zwischen dem Fadengeberhebel 36 und dem Nadelöhr loser Faden entsteht, welcher nun durch den Federbügel 49 der Fadenregulierfeder 47 aufgenommen wird, damit der Faden im Bereich der Nadel 19 leicht gespannt bleibt. Der Federbügel 49 kann nur Faden aufnehmen, bis er an der Anschlagnase 63 des Fadengeberhebels 36 anliegt und der Faden an der Stelle A in Kontakt mit dem fadenführenden Teil 30 gelangt. Inzwischen ist aber das Nadelöhr in das Nähgut 4 eingedrungen, so dass sich der lose Faden nicht mehr an der Nadelspitze verfangen oder sich vor dem Eintritt in das Nadelöhr verdrillen kann. Der Greifer im unteren Arm 5 (nicht sichtbar) erfasst nun die in bekannter Weise gebildete Oberfadenschlinge, weitet sie aus und führt sie um den Unterfadenvorrat in der Spulenkapsel herum. Dabei wird der lose Oberfaden zwischen dem Fadengeberhebel 36 und dem Nähgut 4 praktisch vollständig abgezogen.
Sobald der Greifer die aufgeweitete Oberfadenschlinge abgeworfen hat und die Fadenregulierfeder 47 den wieder lose werdenden Oberfaden durch eine Schwenkung im Gegenuhrzeigersinn nach oben aufnimmt, beginnt auch der Fadengeber 36 seine Aufwärtsbewegung, wobei der Federbügel 49 zunächst noch die maximal mögliche Fadenmenge speichert. Erst im oberen Bereich seiner Bewegungsbahn ist kein loser Faden zwischen dem Nähgut 4 und dem Fadengeberhebel 36 mehr vorhanden so dass der Fadengeberhebel 36 den gebildeten Stich im Nähgut 4 festziehen kann und gleichzeitig auch ein neues Fadenstück von der Garnrolle 11 abzieht, um dieses für den nächsten Stichbildevorgang bereit zu halten. Beim Festziehen des Oberfadens liegt dieser an der Stelle A unten am fadenführenden Teil 30 des Fadengeberhebels 36 an (vgl. die in strichpunktierten Linien in Figur 2 angedeutete obere Stellung des Fadengeberhebels 36).At the beginning of the stitch formation process, the thread-guiding needle 19 moves against a material 4 lying on the arm 3. The thread take-up lever 36 simultaneously performs a faster downward movement than the needle bar 45 with the needle 19, so that loose thread is created between the thread take-up lever 36 and the eye of the needle , which is now taken up by the spring clip 49 of the thread regulating spring 47 so that the thread remains slightly tensioned in the area of the needle 19. The spring clip 49 can only take up thread until it lies against the stop lug 63 of the thread take-up lever 36 and the thread comes into contact with the thread-guiding part 30 at point A. In the meantime, however, the eye of the needle has penetrated the material 4, so that the loose thread can no longer get caught on the needle tip or twist before entering the eye of the needle. The looper in the lower arm 5 (not visible) now grips the upper thread loop formed in a known manner, expands it and guides it around the lower thread supply in the bobbin case. The loose upper thread between the thread take-up lever 36 and the sewing material 4 is practically completely pulled off.
As soon as the looper has dropped the widened upper thread loop and the thread regulating spring 47 picks up the loosening upper thread by swiveling it counterclockwise upwards, the thread feeder 36 also begins its upward movement, the spring clip 49 initially still storing the maximum possible thread quantity. Only in the upper area of its movement path is there no longer a loose thread between the sewing material 4 and the thread take-up lever 36, so that the thread take-up lever 36 can tighten the stitch formed in the sewing material 4 and at the same time also pulls a new piece of thread from the thread spool 11 in order for the next one Keep stitch stitching ready. When the upper thread is tightened, it rests at point A at the bottom on the thread-guiding part 30 of the thread take-up lever 36 (cf. the upper position of the thread take-up lever 36 indicated in dash-dotted lines in FIG. 2).

Claims (10)

  1. Thread regulating device for sewing machines, having a pivotal thread dispensing system and a regulating spring, which is disposed in the thread path between the thread tensioning device and the eye of the needle and keeps the thread temporarily tensioned, characterised in that the spring (47) is directly disposed on the thread guiding member (30) of the thread dispensing lever (36) and is entrained by the latter on its path of movement during the formation of a stitch.
  2. Thread regulating device according to claim 1, characterised in that the mounting location for the spring (47), together with the thread guiding member (30) of the thread dispensing lever (36), executes a translatory movement.
  3. Thread regulating device according to one of claims 1 or 2, characterised in that a cylindrical pin (53) is disposed on the member (30) of the thread dispensing lever (36) as a retaining means for the spring (47), the spring (47) being non-rotatably mounted on said pin.
  4. Thread regulating device according to claim 3, characterised in that the spring (47) has a cylindrical set of coils (51), which sits firmly on the pin (53) as a result of having been slipped thereover.
  5. Thread regulating device according to claim 4, characterised in that a first, doubly bent wire portion (55) extends from the set of coils (51) and engages around the thread dispensing lever (36).
  6. Thread regulating device according to one of claims 4 or 5, characterised in that a spring clip (49) extends from the set of coils (51), said clip lying laterally on the thread guiding member (30) and forming therewith a closed thread guiding aperture (59).
  7. Thread regulating device according to claim 6, characterised in that the spring clip (49) surrounds the thread guiding member (30) in a U-shaped manner.
  8. Thread regulating device according to claim 7, characterised in that the end (57) of the spring clip (49) is bent down and retained in a bore (48) in the centre of the pin (53).
  9. Thread regulating device according to one of claims 1 to 8, characterised in that a guide aperture (59) for guiding the thread (61) is formed in the thread guiding member (30) of the thread dispensing lever (36) by a hook-shaped projection member (67) and the spring clip (49).
  10. Thread regulating device according to claim 9, characterised in that the thread (61) is secured by the spring clip (49) in the thread guiding aperture (59).
EP91810088A 1990-04-05 1991-02-07 Thread tension controlling device for sewing machine Expired - Lifetime EP0451087B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CH1153/90A CH681094A5 (en) 1990-04-05 1990-04-05
CH1153/90 1990-04-05

Publications (2)

Publication Number Publication Date
EP0451087A1 EP0451087A1 (en) 1991-10-09
EP0451087B1 true EP0451087B1 (en) 1995-04-05

Family

ID=4203723

Family Applications (1)

Application Number Title Priority Date Filing Date
EP91810088A Expired - Lifetime EP0451087B1 (en) 1990-04-05 1991-02-07 Thread tension controlling device for sewing machine

Country Status (5)

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US (1) US5131338A (en)
EP (1) EP0451087B1 (en)
JP (1) JPH0489273U (en)
CH (1) CH681094A5 (en)
DE (2) DE59105071D1 (en)

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1037018C (en) * 1994-02-08 1998-01-14 周鹤鸣 Five-lever thread pickup mechanism with adjustable thread feed for sewing machine
DE19617945C1 (en) * 1996-05-04 1997-09-11 Union Special Gmbh Thread control for a chain stitch sewing machine
US6047653A (en) * 1997-06-13 2000-04-11 Cash; David R. Sewing machine with a take-up lever moving up and down through one cycle per revolution of a rotary cylindrical hook base
JP4995447B2 (en) * 2005-08-16 2012-08-08 株式会社鈴木製作所 Flat stitch sewing machine
CN105734847B (en) * 2016-03-07 2018-08-21 徐州力达缝纫设备制造有限公司 Sewing machine with thread-off prevention line wire picking device

Family Cites Families (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE45813C (en) * 1900-01-01 gebr. nothmann in Berlin N., Neue Hochstr. 20 Thread dispenser for sewing machines
US197107A (en) * 1877-11-13 Improvement in take-up mechanisms for sewing-machines
US875610A (en) * 1903-03-26 1907-12-31 William N Parkes Thread-controlling mechanism for sewing-machines.
US994509A (en) * 1910-07-09 1911-06-06 Singer Mfg Co Thread-controller for sewing-machines.
US1245338A (en) * 1914-10-03 1917-11-06 Arbetter Felling Machine Company Slack-thread-take-up mechanism for blindstitch sewing-machines.
US1370228A (en) * 1919-10-27 1921-03-01 Thomas E Scully Double take-up spring for needle-bars on sewing-machines
CH421673A (en) * 1965-06-11 1966-09-30 Gegauf Fritz Ag Needle thread tensioning device on sewing machines
US4411395A (en) * 1981-08-14 1983-10-25 Riviera Marine & Tackle Co. Downrigger swivel base
US4422395A (en) * 1982-03-12 1983-12-27 The Singer Company Thread handling arrangement with fiber carrying strip and cam
CH668092A5 (en) * 1985-12-06 1988-11-30 Gegauf Fritz Ag THREAD CONTROL FOR SEWING MACHINES.
JPS62170289A (en) * 1986-01-21 1987-07-27 ブラザー工業株式会社 Thread take-up machine of sewing machine
CA1301555C (en) * 1986-06-23 1992-05-26 Yoshio Mikuni Thread take-up lever device for sewing machines
JPH0728975B2 (en) * 1987-03-19 1995-04-05 蛇の目ミシン工業株式会社 Automatic needle thread hooking device for sewing machine
US4856443A (en) * 1987-05-15 1989-08-15 Okamura & Co. Needle thread tensioning device for a swing machine

Also Published As

Publication number Publication date
JPH0489273U (en) 1992-08-04
DE59105071D1 (en) 1995-05-11
US5131338A (en) 1992-07-21
CH681094A5 (en) 1993-01-15
EP0451087A1 (en) 1991-10-09
DE9101845U1 (en) 1991-05-08

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