EP0009570B1 - Thread supply checking device for the bottom thread of a sewing machine - Google Patents

Thread supply checking device for the bottom thread of a sewing machine Download PDF

Info

Publication number
EP0009570B1
EP0009570B1 EP79102827A EP79102827A EP0009570B1 EP 0009570 B1 EP0009570 B1 EP 0009570B1 EP 79102827 A EP79102827 A EP 79102827A EP 79102827 A EP79102827 A EP 79102827A EP 0009570 B1 EP0009570 B1 EP 0009570B1
Authority
EP
European Patent Office
Prior art keywords
gripper
thread
bobbin
light source
light
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
EP79102827A
Other languages
German (de)
French (fr)
Other versions
EP0009570A1 (en
Inventor
Günter Meier
Patrice Jean Kemmel
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Dorina Nahmaschinen GmbH
Original Assignee
Dorina Nahmaschinen GmbH
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Dorina Nahmaschinen GmbH filed Critical Dorina Nahmaschinen GmbH
Publication of EP0009570A1 publication Critical patent/EP0009570A1/en
Application granted granted Critical
Publication of EP0009570B1 publication Critical patent/EP0009570B1/en
Expired legal-status Critical Current

Links

Images

Classifications

    • D—TEXTILES; PAPER
    • D05—SEWING; EMBROIDERING; TUFTING
    • D05B—SEWING
    • D05B59/00—Applications of bobbin-winding or -changing devices; Indicating or control devices associated therewith
    • D05B59/02—Devices for determining or indicating the length of thread still on the bobbin

Definitions

  • the invention relates to a thread supply monitor according to the preamble of patent claim 1.
  • Such thread supply monitors are already known which have corresponding openings in the bobbin and hook for optical scanning of the lower thread supply.
  • the gripper shaft is pierced to create a light channel.
  • this possibility does not bring the light source very close to the gripper and is only possible with a gripper design in which the coil is arranged extremely strongly eccentrically to the gripper axis.
  • the bobbin must have a shape that differs from the normal bobbin design so that a thread supply display can be carried out at all.
  • both the light source and the light receiver should be able to be moved close to the gripper in order to eliminate as many interference factors as possible.
  • the innovation is therefore based on the task of deflecting the light beam within the gripper so that the transmitter and receiver can be attached directly to the outside of the gripper.
  • the measure of forming a deflection surface on the gripper body itself which is only acted upon by the light beam for a fraction of the gripper rotation, differs fundamentally from the stationary deflection surface which is present outside the gripper in the prior art. It also has the advantage that it is not possible to use special coil shapes, but rather commercially available coils with openings in the coil flanges.
  • the deflecting surface is advantageously polished to avoid light scattering.
  • the part of the bobbin thread indicator (light source or light receiver) arranged close to the front of the hook must be able to be moved out of its position for changing the bobbin.
  • This part is therefore advantageously pivotally mounted and coupled to the housing flap covering the gripper.
  • the part arranged in front of the gripper (light source or light receiver) is attached to the housing flap itself.
  • the sewing machine shown in FIG. 1 has an upper arm 1, which is connected to a base 3 via a stand 2.
  • the base 3 is supported by a base plate 4 and is equipped with a fabric support arm 5, in which the lower stitch-forming tools, in particular a lockstitch gripper 6, are mounted.
  • the lockstitch gripper 6 (Fig. 2) consists of a hook body 7 and a cover bracket 8, which form the circumferential part of the hook 6, as well as a lower capsule 9 and an upper capsule 10, which form the fixed part of the hook and for receiving a thread spool 11 serve.
  • bobbin thread is wound on the bobbin 11, which forms the seam together with the upper thread during stitch formation.
  • the gripper body 7 has a base 12 which is connected to a hub 13 for fastening the gripper 6 on a gripper shaft 14 which is driven in a known manner and is mounted in the fabric support arm 5.
  • annular cutout 15 is provided which, together with the adjoining wall of the cover bracket 8, forms a raceway for a bearing rib 16 provided on the lower capsule 9.
  • a pin 17 extends outwards from the center of the bottom of the lower capsule 9 and receives a central sleeve 18 which forms part of the upper capsule 10. In the vicinity of its outer end, the pin 17 has an annular groove 19, with which a lock 20 provided on the upper capsule 10 interacts.
  • the lock 20 is provided with a folding lever 21 which is connected to a slide 22 via a hinge pin 23.
  • the slide 22 is slidably mounted in a guide 24 in the upper capsule 10. It also has an opening 25, the edge of which engages in the annular groove 19 of the pin 17 when the folding lever 21 is folded in.
  • the folding lever 21 also has an opening 26 into which the end of the pin 17 is inserted.
  • a radial slot 27 is provided in the bottom of the upper capsule 10, which is attached to the slide 22 for free movement Limit screw 28 is used.
  • the gripper body 7 is provided with an opening 29, the wall of which in the region of the hub 13 is designed as a deflection surface 30 for a light beam 31.
  • the deflection surface 30 extends at an angle to the axis of the gripper 6.
  • the light beam 31 is emitted by a light source 33 attached directly in front of the gripper 6 on the inside of a housing flap 32 on the fabric support arm 5.
  • the thread bobbin 11 equipped with flanges 34 has a plurality of axially parallel bores 35 arranged in pairs at the attachment point of the flanges 34.
  • the bottom of the lower capsule 9 is provided with a slot 36 which is aligned with the openings 25 and 26 in the slide 22 and in the folding lever 21 and with the radial slot 27 in the upper capsule 10.
  • the bore 35, the slot 36, the radial slot 27 and the openings 25 and 26 are formed and arranged with respect to one another in such a way that the light beam 31 emitted by the light source 33 can run axially parallel through the gripper 6 in a certain rotational position as soon as the bores 35 in the bobbin 11 1 and thus the slot 36 in the lower capsule 9 are not covered by the lower thread.
  • the light beam 31 is deflected at the deflection surface 30 and fed to a light receiver 37 which is attached to the fabric support arm 5 directly behind the gripper 6 in the area of the free space between the base 12 and the hub 13 of the gripper body 7.
  • a blinking display diode 38 Arranged on the outside of the upper arm 1 in the field of vision of the operator of the sewing machine is a blinking display diode 38, which indicates that the lower thread in the thread bobbin 11 is going out.
  • FIG. 3 shows a simplified circuit diagram of the electrical components required for the function of light source 33, light receiver 37 and display diode 38.
  • the light source 33 which can consist of an infrared light-emitting diode which is operated in pulses via a flasher unit 46.
  • the light receiver 37 designed as a phototransistor is connected to the line 39 via a series resistor 41 and a connection point 42.
  • a capacitor 43 is connected to the connection point 42 and is connected via a threshold amplifier 44 to the set input S of a flip-flop memory 45.
  • the reset input R of the memory 45 is connected to an arrangement, not shown, which supplies it with a reset pulse when the sewing machine motor, not shown, starts up.
  • the output ⁇ of the memory 45 is connected to the display diode 38, which is connected to the positive pole of the voltage source via a series resistor 47.
  • the bobbin of thread on the bobbin 11 has decreased so far that the light beam 31 can at least partially pass through the bores 35 and thus the slot 36 in the bottom of the lower capsule 9, it is guided onto the deflection surface 30 in the hub 13 of the hook body 7 , deflected there and received by the light receiver 37.
  • the latter becomes conductive and discharges the capacitor 43, which was previously charged via the series resistor 41, as soon as the discharge pulse reaches the set threshold. of threshold amplifier 44 exceeds d. H. the. Unterfadenvordat has dropped below a certain value, the amplifier 44 sends a signal to the set input S of the flip-flop memory 45.
  • both the bores 35 rotate when the lower thread is unwound from the thread spool 11 and the slot 29 when the gripper body 7 rotates independently of one another, so that the triggering of a display pulse requires a certain sewing period. Since a display pulse is only triggered when both the opening 29 and the bores 35 are located in the area of the light beam 31, the response time after falling below one certain thread supply vary somewhat. However, due to a sufficient number of bores 35 arranged in pairs in the thread spool and due to the low thread consumption per stitch formation, the size of the response area of the bobbin thread indicator is not significant.
  • the housing flap 32 on the fabric support arm 5 is folded down and at the same time the light source 33 connected to it is brought out of the area of the gripper 6.
  • the coil 11 can also consist of translucent material. In this case, the holes 35 are not absolutely necessary.
  • the triggering of the response range of the bobbin thread display is then determined by the dimension of the slot 36 in the bottom of the lower capsule 9.
  • control means can also be provided which automatically stop the motor drive.

Landscapes

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

Description

Die Erfindung betrifft einen Fadenvorratswächter nach dem Oberbegriff des Patentanspruches 1.The invention relates to a thread supply monitor according to the preamble of patent claim 1.

Es sind bereits derartige Fadenvorratswächter bekannt, die zum optischen Abtasten des Unterfadenvorrates entsprechende Durchbrechungen in Spule und Greifer aufweisen. Gerade bei optischen Fühlanordnungen besteht die Notwendigkeit, die Lichtquelle und den Lichtempfänger nahe genug an die Abtaststelle zu verlegen, um eine genügend starke und wegen der Verschmutzungsgefahr durch Nähflusen genügend exakte optische Erfassung des Fadenvorrates auf der Spule sicherzustellen. Bei einer bekannten Anordnung (US-A-2350397) ist daher die Greiferwelle durchbohrt, um einen Lichtkanal zu schaffen. Diese Möglichkeit bringt aber keine sehr große Annäherung der Lichtquelle an den Greifer und ist nur möglich bei einer Greiferausführung, bei der die Spule extrem stark exzentrisch zur Greiferachse angeordnet ist. Außerdem muß die Spule eine von der normalen Spulenausführung abweichende Form aufweisen, damit eine Fadenvorratsanzeige überhaupt durchführbar ist.Such thread supply monitors are already known which have corresponding openings in the bobbin and hook for optical scanning of the lower thread supply. Especially with optical sensing arrangements, there is a need to move the light source and the light receiver close enough to the scanning point in order to ensure a sufficiently strong optical detection of the thread supply on the bobbin, which is sufficiently precise and due to the risk of contamination by sewing lint. In a known arrangement (US-A-2350397), therefore, the gripper shaft is pierced to create a light channel. However, this possibility does not bring the light source very close to the gripper and is only possible with a gripper design in which the coil is arranged extremely strongly eccentrically to the gripper axis. In addition, the bobbin must have a shape that differs from the normal bobbin design so that a thread supply display can be carried out at all.

Die Neuerung bezweckt die Beseitigung dieses Nachteiles. Vor allem sollen sowohl Lichtquelle als auch Lichtempfänger dicht an den Greifer herangerückt werden können, um möglichst viele Störfaktoren auszuschalten.The innovation aims to eliminate this disadvantage. Above all, both the light source and the light receiver should be able to be moved close to the gripper in order to eliminate as many interference factors as possible.

Der Neuerung liegt daher die Aufgabe zugrunde, den Lichtstrahl innerhalb des Greifers so umzulenken, daß Sender und Empfänger unmittelbar an der Außenseite des Greifers angebracht werden können.The innovation is therefore based on the task of deflecting the light beam within the gripper so that the transmitter and receiver can be attached directly to the outside of the gripper.

Diese Aufgabe wird bei einem Fadenvorratswächter nach dem Oberbegriff des Patentanspruches 1 dadurch gelöst, daß eine im Winkel zur Achse des Greifers verlaufende Wandfläche einer Aussparung im Boden des Greiferkörpers die Umlenkfläche für den Lichtstrahl bildet.This object is achieved with a thread supply monitor according to the preamble of claim 1 in that a wall surface running at an angle to the axis of the gripper forms a recess in the bottom of the gripper body the deflecting surface for the light beam.

Die Maßnahme, am Greiferkörper selbst eine Umlenkfläche auszubilden, die nur während eines Bruchteiles der Greiferumdrehung vom Lichtstrahl beaufschlagt wird, unterscheidet sich grundlegend von der beim Stand der Technik vorhandenen außerhalb des Greifers angeordneten ruhenden Umlenkfläche. Sie bringt außerdem den Vorteil, daß keine besonderen Spulenformen, sondern handelsübliche Spulen mit Durchbrechungen in den Spulenflanschen verwendet werden können.The measure of forming a deflection surface on the gripper body itself, which is only acted upon by the light beam for a fraction of the gripper rotation, differs fundamentally from the stationary deflection surface which is present outside the gripper in the prior art. It also has the advantage that it is not possible to use special coil shapes, but rather commercially available coils with openings in the coil flanges.

Vorteilhafterweise ist die Umlenkfläche zur Vermeidung von Lichtstreuung poliert.The deflecting surface is advantageously polished to avoid light scattering.

Das dicht vor der Frontseite des Greifers angeordnete Teil der Unterfadenvorratsanzeige (Lichtquelle oder Lichtempfänger) muß zum Spulenwechsel aus seiner Lage wegbewegbar sein. Vorteilhafterweise ist dieses Teil daher schwenkbar gelagert und mit der den Greifer abdeckenden Gehäuseklappe gekoppelt.The part of the bobbin thread indicator (light source or light receiver) arranged close to the front of the hook must be able to be moved out of its position for changing the bobbin. This part is therefore advantageously pivotally mounted and coupled to the housing flap covering the gripper.

In besonders einfacher Ausbildung ist das vor dem Greifer angeordnete Teil (Lichtquelle oder Lichtempfänger) an der Gehäuseklappe selbst befestigt.In a particularly simple embodiment, the part arranged in front of the gripper (light source or light receiver) is attached to the housing flap itself.

In der Zeichnung ist ein Ausführungsbeispiel eines Unterfadenvorratswächters dargestellt. Es zeigen:

  • Fig. 1 eine schaubildliche Ansicht einer Nähmaschine mit geöffneter Greiferabschlußklappe,
  • Fig. 2 einen Schnitt durch den Greifer nach Linie 11-11 der Fig. 1 und
  • Fig. 3 einen vereinfachten Schaltplan zur Steuerung des Fadenvorratswächters.
In the drawing, an embodiment of a bobbin thread guard is shown. Show it:
  • 1 is a perspective view of a sewing machine with an open gripper end flap,
  • Fig. 2 shows a section through the gripper along line 11-11 of Fig. 1 and
  • Fig. 3 shows a simplified circuit diagram for controlling the thread supply monitor.

Die in Fig. 1 dargestellte Nähmaschine weist einen Oberarm 1 auf, der über einen Ständer 2 mit einem Sockel 3 verbunden ist. Der Sockel 3 wird von einer Bodenplatte 4 getragen und ist mit einem Stofftragarm 5 ausgestattet, in dem die unteren Stichbildewerkzeuge, insbesondere ein Doppelsteppstichgreifer 6, gelagert sind.The sewing machine shown in FIG. 1 has an upper arm 1, which is connected to a base 3 via a stand 2. The base 3 is supported by a base plate 4 and is equipped with a fabric support arm 5, in which the lower stitch-forming tools, in particular a lockstitch gripper 6, are mounted.

Der Doppelsteppstichgreifer 6 (Fig. 2) besteht aus einem Greiferkörper 7 und einem Abdeckbügel 8, die den umlaufenden Teil des Greifers 6, bilden sowie aus einer Unterkapsel 9 und einer -Oberkapsel 10, die den feststehenden Teil des Greifers bilden und zur Aufnahme einer Fadenspule 11 dienen. Auf der Fadenspule 11 wird in bekannter Weise Unterfaden aufgespult, der bei der Stichbildung zusammen mit dem Oberfaden die Naht bildet.The lockstitch gripper 6 (Fig. 2) consists of a hook body 7 and a cover bracket 8, which form the circumferential part of the hook 6, as well as a lower capsule 9 and an upper capsule 10, which form the fixed part of the hook and for receiving a thread spool 11 serve. In a known manner, bobbin thread is wound on the bobbin 11, which forms the seam together with the upper thread during stitch formation.

Der Greiferkörper 7 weist einen Boden 12 auf, der mit einer Nabe 13 zur Befestigung des Greifers 6 auf einer im Stofftragarm 5 gelagerten in bekannter Weise angetriebenen Greiferwelle 14 verbunden ist.The gripper body 7 has a base 12 which is connected to a hub 13 for fastening the gripper 6 on a gripper shaft 14 which is driven in a known manner and is mounted in the fabric support arm 5.

Im Greiferkörper 7 ist eine ringförmige Ausfräsung 15 vorgesehen, die zusammen mit der daran anschließenden Wand des Abdeckbügels 8 eine Laufbahn für eine an der Unterkapsel 9 vorgesehene Lagerrippe 16 bildet.In the gripper body 7 an annular cutout 15 is provided which, together with the adjoining wall of the cover bracket 8, forms a raceway for a bearing rib 16 provided on the lower capsule 9.

Von der Mitte des Bodens der Unterkapsel 9 verläuft ein Stift 17 nach außen, der eine zentrische Hülse 18 aufnimmt, die einen Teil der Oberkapsel 10 bildet. In der Nähe seines äußeren Endes weist der Stift 17 eine Ringnut 19 auf, mit welcher eine an der Oberkapsel 10 vorgesehene Verriegelung 20 zusammenwirkt.A pin 17 extends outwards from the center of the bottom of the lower capsule 9 and receives a central sleeve 18 which forms part of the upper capsule 10. In the vicinity of its outer end, the pin 17 has an annular groove 19, with which a lock 20 provided on the upper capsule 10 interacts.

Die Verriegelung 20 ist mit einem Klapphebel 21 versehen, der mit einem Schieber 22 über einen Scharnierstift 23 verbunden ist. Der Schieber 22 ist in einer Führung 24 in der Oberkapsel 10 verschiebbar gelagert. Außerdem weist er eine Öffnung 25 auf, deren Rand bei eingeklappten Klapphebel 21 in die Ringnut 19 des Stiftes 17 eingreift. Auch der Klapphebel 21 weist eine Öffnung 26 auf, in die sich das Ende des Stiftes 17 einlegt. Außerdem ist ein Radialschlitz 27 in dem Boden der Oberkapsel 10 vorgesehen, die zur freien Bewegung einer in dem Schieber 22 befestigten Begrenzungsschraube 28 dient.The lock 20 is provided with a folding lever 21 which is connected to a slide 22 via a hinge pin 23. The slide 22 is slidably mounted in a guide 24 in the upper capsule 10. It also has an opening 25, the edge of which engages in the annular groove 19 of the pin 17 when the folding lever 21 is folded in. The folding lever 21 also has an opening 26 into which the end of the pin 17 is inserted. In addition, a radial slot 27 is provided in the bottom of the upper capsule 10, which is attached to the slide 22 for free movement Limit screw 28 is used.

Der Greiferkörper 7 ist mit einem Durchbruch 29 versehen, dessen Wandung im Bereich der Nabe 13 als Umlenkfläche 30 für einen Lichtstrahl 31 ausgebildet ist. Dazu verläuft die Umlenkfläche 30 im Winkel zur Achse des Greifers 6. Der Lichtstrahl 31 wird von einer unmittelbar vor dem Greifer 6 an der Innenseite einer Gehäuseklappe 32 am Stofftragarm 5 angebrachten Lichtquelle 33 ausgestrahlt.The gripper body 7 is provided with an opening 29, the wall of which in the region of the hub 13 is designed as a deflection surface 30 for a light beam 31. For this purpose, the deflection surface 30 extends at an angle to the axis of the gripper 6. The light beam 31 is emitted by a light source 33 attached directly in front of the gripper 6 on the inside of a housing flap 32 on the fabric support arm 5.

Die mit Flanschen 34 ausgestattete Fadenspule 11 weist eine Mehrzahl von paarweise angeordneten achsparallelen Bohrungen 35 an der Ansatzstelle der Flansche 34 auf. Außerdem ist der Boden der Unterkapsel 9 mit einem Schlitz 36 versehen, der mit den Öffnungen 25 und 26 im Schieber 22 und im Klapphebel 21 sowie mit dem Radialschlitz 27 in der Oberkapsel 10 fluchtet. Die Bohrung 35, der Schlitz 36, der Radialschlitz 27 sowie die Öffnungen 25 und 26 sind so ausgebildet und zueinander angeordnet, daß der von der Lichtquelle 33 ausgestrahlte Lichtstrahl 31 in einer bestimmten Drehlage des Greifers 6 achsparallel durch ihn hindurch verlaufen kann, sobald die Bohrungen 35 in der Fadenspule 11 1 und damit auch der Schlitz 36 in der Unterkapsel 9 nicht durch Unterfaden abgedeckt sind. Dabei wird der Lichtstrahl 31 an der Umlenkfläche 30 umgelenkt und einem Lichtempfänger 37 zugeleitet, der unmittelbar hinter dem Greifer 6 im Bereich des freien Raumes zwischen dem Boden 12 und der Nabe 13 des Greiferkörpers 7 am Stofftragarm 5 befestigt ist.The thread bobbin 11 equipped with flanges 34 has a plurality of axially parallel bores 35 arranged in pairs at the attachment point of the flanges 34. In addition, the bottom of the lower capsule 9 is provided with a slot 36 which is aligned with the openings 25 and 26 in the slide 22 and in the folding lever 21 and with the radial slot 27 in the upper capsule 10. The bore 35, the slot 36, the radial slot 27 and the openings 25 and 26 are formed and arranged with respect to one another in such a way that the light beam 31 emitted by the light source 33 can run axially parallel through the gripper 6 in a certain rotational position as soon as the bores 35 in the bobbin 11 1 and thus the slot 36 in the lower capsule 9 are not covered by the lower thread. The light beam 31 is deflected at the deflection surface 30 and fed to a light receiver 37 which is attached to the fabric support arm 5 directly behind the gripper 6 in the area of the free space between the base 12 and the hub 13 of the gripper body 7.

An der Außenseite des Oberarmes 1 ist im Blickbereich der Bedienungsperson der Nähmaschine eine im Blinkbetrieb arbeitende Anzeigediode 38 angeordnet, die das Ausgehen des Unterfadens in der Fadenspule 11 anzeigt.Arranged on the outside of the upper arm 1 in the field of vision of the operator of the sewing machine is a blinking display diode 38, which indicates that the lower thread in the thread bobbin 11 is going out.

Die Fig. 3 zeigt einen vereinfachten Schaltplan, der für die Funktion von Lichtquelle 33, Lichtemfänger 37 und Anzeigediode 38 erforderlichen elektrischen Bauteile.3 shows a simplified circuit diagram of the electrical components required for the function of light source 33, light receiver 37 and display diode 38.

Von dem Pluspol einer Spannungsquelle fließt Strom über eine Leitung 39 und einen Widerstand 40 zu der Lichtquelle 33, die aus einer Infrarotlicht emittierenden Diode bestehen kann, welche über einen Blinkergeber 46 pulsweise betrieben wird. An der Leitung 39 ist über einen Vorwiderstand 41 und eine Verbindungsstelle 42 der als Fototransistor ausgebildete Lichtempfänger 37 angeschlossen. An die Verbindungsstelle 42 ist ein Kondensator 43 angeklemmt, der über einen Schwellwertverstärker 44 mit dem Setzeingang S eines Flipflop-Speichers 45 verbunden ist. Der Rücksetzeingang R des Speichers 45 ist mit einer nicht dargestellten Anordnung verbunden, die Ihm beim Anlauf des nicht dargestellten Motors der Nähmaschine einen Rücksetzimpuls zuleitet.Current flows from the positive pole of a voltage source via a line 39 and a resistor 40 to the light source 33, which can consist of an infrared light-emitting diode which is operated in pulses via a flasher unit 46. The light receiver 37 designed as a phototransistor is connected to the line 39 via a series resistor 41 and a connection point 42. A capacitor 43 is connected to the connection point 42 and is connected via a threshold amplifier 44 to the set input S of a flip-flop memory 45. The reset input R of the memory 45 is connected to an arrangement, not shown, which supplies it with a reset pulse when the sewing machine motor, not shown, starts up.

Der Ausgang Ö des Speichers 45 ist mit der Anzeigediode 38 verbunden, die über einen Vorwiderstand 47 an dem Pluspol der Spannungsquelle liegt.The output Ö of the memory 45 is connected to the display diode 38, which is connected to the positive pole of the voltage source via a series resistor 47.

Die Vorrichtung arbeitet wie folgt:

  • Beim Nähen dreht sich der umlaufende Teil des Greifers 6 in bekannter Weise mit der Greiferwelle 14, während sein stillstehender Teil durch ein nicht dargestelltes Anhaltestück festgehalten wird. Die über die Leitung 39, den Widerstand 40 und den Blinkergeber 46 mit Strom versorgte Lichtquelle 33 sendet einen scharf gebündelten, pulsierenden Lichtstrahl 31 durch die beiden Öffnungen 26 und 25 in der Verriegelung 20 und den Radialschlitz 27 im Boden der Oberkapsel 10. Wenn genügend Unterfaden in der Fadenspule 11 vorhanden ist, sind deren Bohrungen 35 und der Schlitz 36 im Boden der Unterkapsel 9 verdeckt und der weitere Durchtritt des Lichtstrahles 31 durch den Greifer 6 wird verhindert.
The device works as follows:
  • When sewing, the rotating part of the hook 6 rotates in a known manner with the hook shaft 14, while its stationary part is held by a stop piece, not shown. The light source 33, which is supplied with current via the line 39, the resistor 40 and the flasher unit 46, sends a sharply focused, pulsating light beam 31 through the two openings 26 and 25 in the lock 20 and the radial slot 27 in the bottom of the upper capsule 10. If there is enough bobbin thread is present in the thread bobbin 11, the bores 35 and the slot 36 in the bottom of the lower capsule 9 are covered and the further passage of the light beam 31 through the gripper 6 is prevented.

Sobald aber der Unterfadenvorrat auf der Fadenspule 11 so weit abgenommen hat, daß der Lichtstrahl 31 wenigstens zum Teil die Bohrungen 35 und damit den Schlitz 36 im Boden der Unterkapsel 9 passieren kann, wird er auf die Umlenkfläche 30 in der Nabe 13 des Greiferkörpers 7 geleitet, dort umgelenkt und von dem Lichtempfänger 37 aufgenommen. Sobald ein genügend großer Impuls des Lichtstrahles 31 auf den Lichtempfänger 37 auftrifft, wird dieser leitend und entlädt den jeweils vorher über den Vorwiderstand 41 aufgeladenen Kondensator 43. Sobald der Entladeimpuls die eingestellte Schwelle. des Schwellwertverstärkers 44 übersteigt, d. h. der .Unterfadenvorrat unter einen bestimmten Wert gesunken ist, gibt der Verstärker 44 ein Signal auf den Setzeingang S des Flip-Flop-Speichers 45. Dadurch wird dieser gesetzt, so daß die über dem Widerstand 47 am Pluspol liegende im Blinkbetrieb arbeitende Anzeigediode 38 aufleuchtet. Diese bleibt so lange an Spannung bis nach Auffüllen der Fadenspule 11 mit neuem Unterfadenvorrat der Motor betätigt wurde, um den Unterfaden maschinell nach oben zu holen. Ein vom Motor ausgelöstes Signal auf den Rücksetzeingang R schaltet dabei den Schalter 45 um, so daß die Stromversorgung der Anzeigediode 38 abgeschaltet wird.However, as soon as the bobbin of thread on the bobbin 11 has decreased so far that the light beam 31 can at least partially pass through the bores 35 and thus the slot 36 in the bottom of the lower capsule 9, it is guided onto the deflection surface 30 in the hub 13 of the hook body 7 , deflected there and received by the light receiver 37. As soon as a sufficiently large pulse of the light beam 31 hits the light receiver 37, the latter becomes conductive and discharges the capacitor 43, which was previously charged via the series resistor 41, as soon as the discharge pulse reaches the set threshold. of threshold amplifier 44 exceeds d. H. the. Unterfadenvordat has dropped below a certain value, the amplifier 44 sends a signal to the set input S of the flip-flop memory 45. This is set so that the indicator diode 38, which is connected to the positive pole and is flashing, lights up. This remains in tension until after the thread bobbin 11 has been filled with a new bobbin of thread, the motor has been actuated in order to mechanically pull the bobbin up. A signal triggered by the motor to the reset input R switches the switch 45 so that the power supply to the display diode 38 is switched off.

Während die Öffnungen 25 und 26 der Verriegelung 20 sowie der Radialschlitz 27 der Oberkapsel 10 und der Schlitz 36 der Unterkapsel 9 immer im Bereich des Lichtstrahles 31 verharren, drehen sich sowohl die Bohrungen 35 beim Abwickeln des Unterfadens von der Fadenspule 11 als auch der Schlitz 29 beim Umlauf des Greiferkörpers 7 unabhängig voneinander, so daß die Auslösung eines Anzeigeimpulses eine bestimmte Nähdauer erfordert. Da ein Anzeigeimpuls nur dann ausgelöst wird, wenn sich sowohl der Durchbruch 29 als auch die Bohrungen 35 gerade im Bereich des Lichtstrahles 31 befinden, kann der Ansprechzeitraum nach Unterschreiten eines bestimmten Fadenvorrates etwas variieren. Durch eine genügende Anzahl der paarweise angeordneten Bohrungen 35 in der Fadenspule und durch den geringen Fadenverbrauch pro Stichbildung ist die Größe des Ansprechbereiches der Unterfadenvorratsanzeige jedoch nicht nennenswert.While the openings 25 and 26 of the lock 20 and the radial slot 27 of the upper capsule 10 and the slot 36 of the lower capsule 9 always remain in the region of the light beam 31, both the bores 35 rotate when the lower thread is unwound from the thread spool 11 and the slot 29 when the gripper body 7 rotates independently of one another, so that the triggering of a display pulse requires a certain sewing period. Since a display pulse is only triggered when both the opening 29 and the bores 35 are located in the area of the light beam 31, the response time after falling below one certain thread supply vary somewhat. However, due to a sufficient number of bores 35 arranged in pairs in the thread spool and due to the low thread consumption per stitch formation, the size of the response area of the bobbin thread indicator is not significant.

Zum Spulenwechsel wird die Gehäuseklappe 32 am Stofftragarm 5 abgeklappt und damit gleichzeitig die mit ihr verbundene Lichtquelle 33 aus dem Bereich des Greifers 6 gebracht.To change the bobbin, the housing flap 32 on the fabric support arm 5 is folded down and at the same time the light source 33 connected to it is brought out of the area of the gripper 6.

Durch Abschwenken des Klapphebels 21 wird der Schieber 22 aus der Ringnut 19 des Stiftes 17 herausgeschoben, wodurch die Oberkapsel 10 zusammen mit der Spule 11 aus der Unterkapsel 9 entnommen werden kann.By pivoting the folding lever 21, the slide 22 is pushed out of the annular groove 19 of the pin 17, whereby the upper capsule 10 together with the coil 11 can be removed from the lower capsule 9.

Die Spule 11 kann auch aus lichtdurchlässigem Material bestehen. In diesem Falle sind die Bohrungen 35 nicht unbedingt erforderlich. Die Auslösung des Ansprechbereiches der Unterfadenvorratsanzeige wird dann von der Abmessung des Schlitzes 36 im Boden der Unterkapsel 9 bestimmt. Zur Vermeidung von Lichtverlust durch verkratzte Oberfläche der Flanschen 34 der Fadenspule 11 1 können dann aber zweckmäßigerweise anstelle der Bohrungen 25 zylindrisch ausgebildete Sacklöcher vorgesehen werden, deren Bodenflächen unterhalb der Oberfläche der Flanschen 34 und daher außerhalb des Verschließbereiches liegen.The coil 11 can also consist of translucent material. In this case, the holes 35 are not absolutely necessary. The triggering of the response range of the bobbin thread display is then determined by the dimension of the slot 36 in the bottom of the lower capsule 9. To avoid loss of light due to the scratched surface of the flanges 34 of the bobbin 11 1, it is then expedient to provide cylindrical blind holes instead of the bores 25, the bottom surfaces of which lie below the surface of the flanges 34 and therefore outside the closing area.

Anstelle der als Anzeigemittel arbeitenden Anzeigediode 38 oder in geeigneter Weise mit ihr gekoppelt, können außerdem Steuermittel vorgesehen sein, welche den Motorantrieb' selbsttätig stillsetzen.Instead of the display diode 38 operating as a display means or coupled to it in a suitable manner, control means can also be provided which automatically stop the motor drive.

Selbstverständlich ist es aus möglich, die Anordnung der Lage der Lichtquelle 33 und des Lichtempfängers 37 zu vertauschen.Of course, it is possible to interchange the arrangement of the position of the light source 33 and the light receiver 37.

Claims (4)

1. Device for monitoring the thread supply in a sewing machine with a double lockstitch- rotary-gripper and a light source, which emits a light beam directed substantially parallel to the gripper axis, which beam passes through recesses in the gripper body, in the spool housing as well as in the spool and is supplied through a guide surface at an angle to the axis of the gripper to a light receiver actuating an indicator - and/or - control means, characterised in that a wall surface of a recess (29) in the base (12) of the gripper body (17) runs at an angle to the axis of the gripper (6) and forms the guide surface (30) for the light beam (31).
2. Device according to claim 1, characterised in that the guide surface (30) is polished.
3. Device according to claim 1, characterised in that the light source (33) arranged on the front of the gripper (6) is pivotally mounted and is coupled with. the housing flap (32) covering the gripper (6).
4. Device according to claim 3, characterised in that the light source (33) is fastened to the housing flap (32).
EP79102827A 1978-09-15 1979-08-06 Thread supply checking device for the bottom thread of a sewing machine Expired EP0009570B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE19787827499U DE7827499U1 (en) 1978-09-15 1978-09-15 THREAD RESERVE GUARD FOR THE LOWER THREAD OF A SEWING MACHINE
DE7827499U 1978-09-15

Publications (2)

Publication Number Publication Date
EP0009570A1 EP0009570A1 (en) 1980-04-16
EP0009570B1 true EP0009570B1 (en) 1983-03-09

Family

ID=6695134

Family Applications (1)

Application Number Title Priority Date Filing Date
EP79102827A Expired EP0009570B1 (en) 1978-09-15 1979-08-06 Thread supply checking device for the bottom thread of a sewing machine

Country Status (4)

Country Link
US (1) US4237807A (en)
EP (1) EP0009570B1 (en)
JP (1) JPS5543897U (en)
DE (1) DE7827499U1 (en)

Families Citing this family (17)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4188901A (en) * 1979-01-25 1980-02-19 The Singer Company Low bobbin thread detection system
DE3014753C2 (en) * 1980-04-17 1985-08-08 Pfaff Haushaltmaschinen Gmbh, 7500 Karlsruhe Supply monitor for the bobbin thread of a sewing machine
SE426717B (en) * 1981-06-16 1983-02-07 Husqvarna Ab SIGNAL DEVICE IN SEWING MACHINE FOR SENSING AND INDICATING THE TRADIN CONTENT ON A SPOIL
IT1161584B (en) * 1982-03-31 1987-03-18 Singer Co REEL DETECTOR SYSTEM AND SPOOL WIRE EXHAUSTION INDICATOR
GB2136564B (en) * 1983-02-18 1986-06-11 El Sew Con Ltd Monitoring textile thread
GB2143549B (en) * 1983-06-16 1987-01-21 Spencer Wright Ind Inc Tufting machine
US4619213A (en) * 1983-09-30 1986-10-28 Tokyo Juki Industrial Co., Ltd Drive control mechanism of sewing machine
DE8516211U1 (en) * 1985-06-03 1985-07-18 Pfaff Industriemaschinen Gmbh, 6750 Kaiserslautern Sewing machine with a thread monitor for the bobbin thread
DE3625630C2 (en) * 1986-07-29 1995-04-27 Mardix Bar Cochva Thread monitoring device for a sewing machine
DE3635140A1 (en) * 1986-10-15 1988-04-21 Zinser Textilmaschinen Gmbh Optical scanning device for detecting a feed bobbin running empty in a spinning or twisting machine
US4763589A (en) * 1987-10-13 1988-08-16 Ssmc Inc. Solar powered indicating device for sewing machines
JP2727017B2 (en) * 1989-06-09 1998-03-11 蛇の目ミシン工業株式会社 Sewing machine lower thread supply control device
JP2899628B2 (en) * 1989-07-14 1999-06-02 蛇の目ミシン工業株式会社 Sewing machine lower thread amount detection display
JP2836252B2 (en) * 1990-12-14 1998-12-14 ブラザー工業株式会社 Sewing machine lower thread remaining amount detection device
JPH06273A (en) * 1992-06-22 1994-01-11 Brother Ind Ltd Bobbin thread remainder detecting device for sewing machine
IL106535A (en) * 1993-07-30 1996-10-31 Orisol Original Solutions Ltd Device for use with a bobbin-less coil of thread
JP6626715B2 (en) * 2016-01-14 2019-12-25 Juki株式会社 sewing machine

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3082968A (en) * 1961-07-25 1963-03-26 Western Electric Co End of strand control mechanism
US3599586A (en) * 1970-06-10 1971-08-17 Singer Co Bobbin thread depletion detector for sewing machines
US3845320A (en) * 1973-03-26 1974-10-29 R Winberg Method and means for detecting the approaching end of a thread and a bobbin therefor

Also Published As

Publication number Publication date
JPS5543897U (en) 1980-03-22
DE7827499U1 (en) 1978-12-21
EP0009570A1 (en) 1980-04-16
US4237807A (en) 1980-12-09

Similar Documents

Publication Publication Date Title
EP0009570B1 (en) Thread supply checking device for the bottom thread of a sewing machine
DE3446682C1 (en) Device for monitoring the bobbin thread supply of a sewing machine
EP0387255B1 (en) Sewing machine with catch thread device
DE2356639A1 (en) SEWING MACHINE
EP0038418B1 (en) Bobbin controlling dewvice for sewing machine
EP1700941B1 (en) Sewing or embroidery machine
DE4121913C2 (en) Cord spindle
DE4141207A1 (en) DEVICE FOR DETERMINING A REMAINING QUANTITY OF A SPOOL THREAD WINDED ABOUT A SPOOL CORE
DE8516211U1 (en) Sewing machine with a thread monitor for the bobbin thread
DE1710996A1 (en) Device for detecting defects in knitted fabrics or the like.
CH709887B1 (en) Sewing or embroidery machine.
CH447900A (en) Device for exposing the beginning of the thread of unwinding heads, which is fixed in the upper or lower winding
EP2076620B1 (en) Thread feeder
DE3707321C1 (en) Sewing machine with a thread monitor for the thread of the bobbin
DE4110332A1 (en) SEWING MACHINE
DE2949225A1 (en) SEWING THREAD DETECTOR FOR SEWING MACHINES
EP0505317A1 (en) Weft guiding device at a weaving machine with fixed weft supply bobbin
DE2059418A1 (en) Device for controlling machines for processing lots of material
DE3532002A1 (en) Winding machine with cop-feed apparatus
DE2624168C3 (en) Method and device for catching a thread when changing the bobbin
DE806621C (en) Gripper arrangement
DE1485161A1 (en) Cutting device for sewing machines
DE8437417U1 (en) Device for monitoring the bobbin thread supply of a sewing machine
DE69006443T2 (en) Device for feeding weft threads in weaving machines.
EP0433775A1 (en) Service carriage for servicing a spinning machine

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Designated state(s): CH FR GB IT SE

ITCL It: translation for ep claims filed

Representative=s name: JACOBACCI CASETTA & PERANI S.P.A.

17P Request for examination filed
ITF It: translation for a ep patent filed

Owner name: JACOBACCI & PERANI S.P.A.

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Designated state(s): CH FR GB IT SE

ET Fr: translation filed
PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: GB

Payment date: 19910723

Year of fee payment: 13

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: FR

Payment date: 19910807

Year of fee payment: 13

ITTA It: last paid annual fee
PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GB

Effective date: 19920806

GBPC Gb: european patent ceased through non-payment of renewal fee

Effective date: 19920806

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FR

Effective date: 19930430

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST

EAL Se: european patent in force in sweden

Ref document number: 79102827.7

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: SE

Payment date: 19970822

Year of fee payment: 19

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: CH

Payment date: 19971002

Year of fee payment: 19

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: SE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 19980807

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: CH

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 19980831

REG Reference to a national code

Ref country code: CH

Ref legal event code: PL

EUG Se: european patent has lapsed

Ref document number: 79102827.7

PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT