EP0533628B1 - Needle selection device for a knitting machine - Google Patents

Needle selection device for a knitting machine Download PDF

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Publication number
EP0533628B1
EP0533628B1 EP92810712A EP92810712A EP0533628B1 EP 0533628 B1 EP0533628 B1 EP 0533628B1 EP 92810712 A EP92810712 A EP 92810712A EP 92810712 A EP92810712 A EP 92810712A EP 0533628 B1 EP0533628 B1 EP 0533628B1
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EP
European Patent Office
Prior art keywords
needles
magnetic
keys
selection
selection device
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Expired - Lifetime
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EP92810712A
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German (de)
French (fr)
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EP0533628A3 (en
EP0533628A2 (en
Inventor
Michel Moulin
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Atelier de Construction Steiger SA
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Atelier de Construction Steiger SA
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Publication of EP0533628A2 publication Critical patent/EP0533628A2/en
Publication of EP0533628A3 publication Critical patent/EP0533628A3/en
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Publication of EP0533628B1 publication Critical patent/EP0533628B1/en
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    • D—TEXTILES; PAPER
    • D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
    • D04B—KNITTING
    • D04B15/00—Details of, or auxiliary devices incorporated in, weft knitting machines, restricted to machines of this kind
    • D04B15/66—Devices for determining or controlling patterns ; Programme-control arrangements
    • D04B15/68—Devices for determining or controlling patterns ; Programme-control arrangements characterised by the knitting instruments used
    • D04B15/78—Electrical devices
    • D—TEXTILES; PAPER
    • D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
    • D04B—KNITTING
    • D04B15/00—Details of, or auxiliary devices incorporated in, weft knitting machines, restricted to machines of this kind
    • D04B15/66—Devices for determining or controlling patterns ; Programme-control arrangements
    • D04B15/82—Devices for determining or controlling patterns ; Programme-control arrangements characterised by the needle cams used

Definitions

  • the present invention relates to an electromagnetic device for selecting the needles of a rectilinear knitting machine as defined in the preamble of claim 1.
  • the magnetic ramps are made up of two L-shaped parts between which a permanent magnet is placed.
  • the selection channel is formed between the short branches of the L.
  • This device has the advantage over previous devices of being very compact and of working without any moving part, by acting directly on the keys or the needles. In the event of a current failure in the electromagnet, the needles should remain out of work, thus avoiding destruction.
  • this device did not give the expected results because in the central areas of small air gap, the keys are subjected to two balanced opposing forces and there is therefore no bonding force allowing the keys to follow a ramp. There is also no magnetic holding force of the keys in these areas, which results in selection errors.
  • the bonding force on the ramps is negligible and the magnetic retaining force opposite to the attraction force depends on the magnetomotive force of the magnets.
  • a mechanically armed spring is associated with each key.
  • the key brought into position working by a cam, is retained or not in the working position when it passes in front of an electromagnet against the action of its spring.
  • This device requires a large magnetic force and, in addition, the springs tire, wear and break.
  • the object of the invention is to provide a truly efficient electromagnetic selection device, allowing high working frequencies and low electrical consumption.
  • the selection device according to the invention is defined in claim 1.
  • the magnetic flux enters and leaves the key or the needle on the same face of the key, respectively the needle, so that a safe selection is obtained.
  • Figure 1 is a schematic sectional view of a selection device showing a key out of work.
  • Figure 2 shows the same key in the working position.
  • Figure 3 is a schematic view of a selector whose electromagnet works in attraction.
  • FIG. 4 represents the magnetic attraction profile of the upper ramp of the selector of FIG. 3.
  • FIG. 5 represents the magnetic attraction profile of the lower ramp of the selector of FIG. 3.
  • Figure 6 is a schematic view of a selector working in bonding.
  • FIG. 7 represents the magnetic attraction profile of the upper ramp of the selector shown in FIG. 6.
  • FIG. 8 represents the magnetic attraction profile of the lower ramp of the same selector.
  • FIG. 9 is an elevation view of one of the magnetic ramps of the selectors according to FIG. 3 or 6.
  • Figure 10 is a top view of the same magnetic ramp.
  • Figure 11 shows the magnetic flux produced in a magnet through a key.
  • Figure 12 shows the magnetic flux produced by another magnet.
  • Figure 13 is an elevational view of one of the magnetic ramps of a selector according to an alternative embodiment.
  • FIG. 14 is a top view of the ramp shown in FIG. 13.
  • Figure 15 is an elevational view of a magnetic ramp of a selector according to another alternative embodiment.
  • Figure 16 is a sectional view along XVI-XVI of Figure 15.
  • Figure 17 is a front view of an exemplary embodiment of the selection device, shown in a more elaborate form.
  • Figure 18 is a side view of the same device, seen in direction A.
  • Figure 19 is a side view of the same device seen in direction B.
  • FIGs 1 and 2 there is shown schematically, in section, one of the needle beds 1 of a rectilinear knitting machine, needle bed having grooves 2 in which are arranged keys 3 provided with a heel 4 and pushing, known manner, needles not shown here. Part 3 could also be a needle.
  • a carriage with its cams 6 To this carriage is fixed a selection device 7 comprising a channel 8 intended to be crossed by the keys 3 during the movement of the carriage 5 along the needle bed.
  • the keys or needles 3 pass through the channel 8 without being moved and their heel 4 is not driven by the cam 6 of the carriage.
  • the keys or needles 3 are raised so that their heel 4 can be driven by the cams 6.
  • This operating principle is based on two opposite and continuous magnetic ramps 9 and 10, with a very high bonding force, and having at least one zone 11, called neutral, in which the magnetic bonding force is canceled.
  • the selection is made in this neutral zone by an electromagnet 12.
  • the forces necessary to move these needles or these keys are very variable.
  • One needle can be lifted with a few tens of grams while the next one requires, for example, more than one hundred grams.
  • the needles or keys adjacent to the selected key or needle must remain in their position.
  • the magnetic ramps of the device hold them with high bonding forces, while the bonding force is zero for the needle or the key being in the neutral zone 11.
  • the neutral zone 11 can be used in two different ways.
  • Figures 3 to 5 illustrate a first way.
  • the needles or keys 3 entering the selection channel 8 are aligned then systematically attracted against the lower magnetic rail 9.
  • FB represents the bonding force when the key is in contact with the lower magnetic rail 9
  • FH the bonding force when the key is in contact with the upper ramp 10
  • FE the force of attraction of the electromagnet 12 when the key or needle is still against the lower ramp 9.
  • Figures 4 and 5 show the profile of these forces along the selection channel 8. These figures show that by means of a neutral zone 11 of appropriate width, the electromagnet 12 acts only on a key or needle at a time.
  • FIGS 6 to 8 show another way of using the neutral zone 11.
  • the electromagnet 12 selects the needles 3 by working in bonding.
  • the needles or keys 3, at the input of the selector are first attracted against the lower ramp 9 so as to impose their position when the direction of movement of the machine changes, then on the upper ramp 10. They follow this ramp 10 to the output of the selector if the electromagnet 12 is activated when passing through the neutral zone 11.
  • the electromagnet 12 is not activated when a needle arrives in the neutral zone 11, this needle will be attracted by the lower magnetic ramp 9 by a force FB '( Figure 7) and will stick to the lower ramp 9.
  • FIG. 8 shows that the profile of the force of attraction of the lower ramp 8 has a point at the level of the neutral zone so as to ensure the attraction of the key or the needle.
  • the channel and each of the needles or keys passing through the channel constitute a bistable system controlled by the electromagnet.
  • FIGS. 4, 5, 7 and 8 can easily be produced in the magnetic ramps represented in FIGS. 9 to 12.
  • These figures represent for example the lower ramp 9.
  • This ramp consists of two pole pieces 12 and 13 in the form of a strip of magnetic hard metal, between which are placed a number of permanent magnets 14, preferably made of rare earth.
  • the pole pieces 12 and 13 are not interrupted in the area neutral 11.
  • the keys or needles 3 are directly in contact with the pole pieces 12 and 13, unlike known magnetic ramp systems in which the selection members slide on non-magnetic hard metal pieces and the ramps are interrupted at the selection electromagnet.
  • the thickness of the strips 12 and 13 and the dimensions of the magnets 14 are calculated so that the part of the pole pieces in contact with the keys or needles 3 is magnetically saturated. This ensures a bonding force of the keys or needles 3 independent of the distribution of these keys or needles on the two ramps 9 and 10.
  • the neutral zone 11 is created by placing the magnets 14 so that the direction of the magnetic fluxes ⁇ I and ⁇ II are reversed on either side of the neutral zone 11, as illustrated in FIGS. 11 and 12.
  • a part ⁇ III of the magnetic flux is short-circuited by the pole pieces at the level of the neutral zone 11 where the pole pieces have a thinning 15.
  • the importance of this flux ⁇ III depends on the section of the pole pieces 12 and 13 at the level of the neutral zone 11. This provides a way to choose the width of this neutral zone. The larger the section, the more the magnetic short-circuit will interest a larger portion of the magnets and the more the neutral zone 11 will be extended.
  • FIGS. 13 and 14 illustrate an example in which the neutral zone is created by means of a metal part 16 magnetically shorting the permanent magnets 14 in the neutral zone.
  • the force profiles shown in FIGS. 4, 5, 7 and 8 can be modified by giving the two pole pieces 12 and 13 a different shape. For example, if one of the two pole pieces is lower than the other, a air gap is created, which has the effect of reducing the bonding force. Such an embodiment is shown in Figures 17 to 19 which will be described later.
  • Figures 15 and 16 show yet another embodiment of the magnetic ramps.
  • the ramp 9 may consist of a U-shaped pole piece 13 ′ between the wings of which a strip 12 ′ is placed constituting the other pole piece of the magnets 14.
  • the attractive force of the magnetic ramps can also be reinforced by additional magnets placed next to the ramps, for example in the case of FIG. 6.
  • FIG. 17 to 19 illustrate a practical example of embodiment of the selection device.
  • the selection device is mounted on a bracket 17 which is fixed on the carriage 5 of the machine. On this bracket 17 are fixed, by means of screws, two supports 18 and 19.
  • the support 18 supports the upper ramp 10 and the electromagnet 12.
  • On the support 19 is fixed the lower magnetic ramp 9.
  • the magnetic ramps are made as shown in Figures 9 to 12, with the difference that at the entrance to the selection station, the pole piece 12 a of the upper ramp 10 extends lower than the pole piece 13a of this same ramp, and this practically up to 'to the neutral zone.
  • the keys or needles coming into contact with the upper ramp 10 are thus only in contact with a single pole piece and are therefore only retained by a reduced magnetic force.
  • the pole piece 12a can thus play the role of a cam bringing the keys or needles near the lower magnetic ramp 9 which attracts them.
  • the coil of the electromagnet 12 has a low inductance so as to allow the attraction of keys or needles at very high frequencies.

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  • Engineering & Computer Science (AREA)
  • Textile Engineering (AREA)
  • Knitting Machines (AREA)

Description

La présente invention concerne un dispositif de sélection électromagnétique des aiguilles d'une machine à tricoter rectiligne tel que défini au préambule de la revendication 1.The present invention relates to an electromagnetic device for selecting the needles of a rectilinear knitting machine as defined in the preamble of claim 1.

Un tel dispositif a été proposé dans le document DE-A-1 585 001. Les rampes magnétiques sont constituées de deux pièces en L entre lesquelles est disposé un aimant permanent. Le canal de sélection est formé entre les courtes branches des L. Ce dispositif présente, sur les dispositifs antérieurs, l'avantage d'être très compact et de travailler sans aucune partie mobile, en agissant directement sur les clavettes ou les aiguilles. En cas de défaillance du courant dans l'électroaimant, les aiguilles devraient rester hors travail en évitant ainsi toute destruction. Ce dispositif n'a toutefois pas donné les résultats escomptés car dans les zones centrales de faible entrefer, les clavettes sont soumises à deux forces antagonistes équilibrées et il n'existe donc pas de force de collage permettant aux clavettes de suivre une rampe. Il n'existe pas non plus de force de retenue magnétique des clavettes dans ces zones, ce qui produit des erreurs de sélection. La force de collage sur les rampes est négligeable et la force de retenue magnétique opposée à la force d'attraction dépend de la force magnétomotrice des aimants.Such a device has been proposed in document DE-A-1 585 001. The magnetic ramps are made up of two L-shaped parts between which a permanent magnet is placed. The selection channel is formed between the short branches of the L. This device has the advantage over previous devices of being very compact and of working without any moving part, by acting directly on the keys or the needles. In the event of a current failure in the electromagnet, the needles should remain out of work, thus avoiding destruction. However, this device did not give the expected results because in the central areas of small air gap, the keys are subjected to two balanced opposing forces and there is therefore no bonding force allowing the keys to follow a ramp. There is also no magnetic holding force of the keys in these areas, which results in selection errors. The bonding force on the ramps is negligible and the magnetic retaining force opposite to the attraction force depends on the magnetomotive force of the magnets.

Dans une autre catégorie de dispositifs de sélection, dont un exemple est décrit dans le document FR-A-2 030 533, un ressort armé mécaniquement est associé à chaque clavette. La clavette, amenée en position de travail par une came, est retenue ou non en position de travail lors de son passage devant un électroaimant contre l'action de son ressort. Ce dispositif nécessite une force magnétique importante et, en outre, les ressorts se fatiguent, s'usent et cassent.In another category of selection devices, an example of which is described in document FR-A-2 030 533, a mechanically armed spring is associated with each key. The key, brought into position working by a cam, is retained or not in the working position when it passes in front of an electromagnet against the action of its spring. This device requires a large magnetic force and, in addition, the springs tire, wear and break.

L'invention a pour but de réaliser un dispositif de sélection électromagnétique véritablement performant, autorisant des fréquences de travail élevées et une faible consommation électrique.The object of the invention is to provide a truly efficient electromagnetic selection device, allowing high working frequencies and low electrical consumption.

Le dispositif de sélection selon l'invention est défini à la revendication 1.The selection device according to the invention is defined in claim 1.

Dans cette configuration, le flux magnétique entre et sort de la clavette ou de l'aiguille sur la même face de la clavette, respectivement de l'aiguille, de telle sorte qu'une sélection sûre est obtenue.In this configuration, the magnetic flux enters and leaves the key or the needle on the same face of the key, respectively the needle, so that a safe selection is obtained.

Les dessins annexés représentent, à titre d'exemple, quelques formes d'exécution de l'invention.The accompanying drawings show, by way of example, some embodiments of the invention.

La figure 1 est une vue schématique, en coupe, d'un dispositif de sélection montrant une clavette hors travail.Figure 1 is a schematic sectional view of a selection device showing a key out of work.

La figure 2 représente la même clavette en position de travail.Figure 2 shows the same key in the working position.

La figure 3 est une vue schématique d'un sélecteur dont l'électroaimant travaille en attraction.Figure 3 is a schematic view of a selector whose electromagnet works in attraction.

La figure 4 représente le profil d'attraction magnétique de la rampe supérieure du sélecteur de la figure 3.FIG. 4 represents the magnetic attraction profile of the upper ramp of the selector of FIG. 3.

La figure 5 représente le profil d'attraction magnétique de la rampe inférieure du sélecteur de la figure 3.FIG. 5 represents the magnetic attraction profile of the lower ramp of the selector of FIG. 3.

La figure 6 est une vue schématique d'un sélecteur travaillant en collage.Figure 6 is a schematic view of a selector working in bonding.

La figure 7 représente le profil d'attraction magnétique de la rampe supérieure du sélecteur représenté à la figure 6.FIG. 7 represents the magnetic attraction profile of the upper ramp of the selector shown in FIG. 6.

la figure 8 représente le profil d'attraction magnétique de la rampe inférieure du même sélecteur.FIG. 8 represents the magnetic attraction profile of the lower ramp of the same selector.

La figure 9 est une vue en élévation de l'une des rampes magnétiques des sélecteurs selon la figure 3 ou 6.FIG. 9 is an elevation view of one of the magnetic ramps of the selectors according to FIG. 3 or 6.

La figure 10 est une vue de dessus de cette même rampe magnétique.Figure 10 is a top view of the same magnetic ramp.

La figure 11 représente le flux magnétique produit dans un aimant à travers une clavette.Figure 11 shows the magnetic flux produced in a magnet through a key.

La figure 12 représente le flux magnétique produit par un autre aimant.Figure 12 shows the magnetic flux produced by another magnet.

La figure 13 est une vue en élévation de l'une des rampes magnétiques d'un sélecteur selon une variante d'exécution.Figure 13 is an elevational view of one of the magnetic ramps of a selector according to an alternative embodiment.

La figure 14 est une vue de dessus de la rampe représentée à la figure 13.FIG. 14 is a top view of the ramp shown in FIG. 13.

La figure 15 est une vue en élévation d'une rampe magnétique d'un sélecteur selon une autre variante d'exécution.Figure 15 is an elevational view of a magnetic ramp of a selector according to another alternative embodiment.

La figure 16 est une vue en coupe selon XVI-XVI de la figure 15.Figure 16 is a sectional view along XVI-XVI of Figure 15.

La figure 17 est une vue de face d'un exemple d'exécution du dispositif de sélection, représenté sous une forme plus élaborée.Figure 17 is a front view of an exemplary embodiment of the selection device, shown in a more elaborate form.

La figure 18 est une vue de profil du même dispositif, vu dans la direction A.Figure 18 is a side view of the same device, seen in direction A.

La figure 19 est une vue de profil du même dispositif vu dans la direction B.Figure 19 is a side view of the same device seen in direction B.

Aux figures 1 et 2, on a représenté schématiquement, en coupe, l'une des fontures 1 d'une machine à tricoter rectiligne, fonture comportant des rainures 2 dans lesquelles sont disposées des clavettes 3 munies d'un talon 4 et poussant, de manière connue, des aiguilles non représentées ici. La pièce 3 pourrait aussi être une aiguille. En 5 est représenté schématiquement un chariot avec ses cames 6. A ce chariot est fixé un dispositif de sélection 7 comportant un canal 8 destiné à être traversé par les clavettes 3 lors du déplacement du chariot 5 le long de la fonture.In Figures 1 and 2, there is shown schematically, in section, one of the needle beds 1 of a rectilinear knitting machine, needle bed having grooves 2 in which are arranged keys 3 provided with a heel 4 and pushing, known manner, needles not shown here. Part 3 could also be a needle. At 5 is shown schematically a carriage with its cams 6. To this carriage is fixed a selection device 7 comprising a channel 8 intended to be crossed by the keys 3 during the movement of the carriage 5 along the needle bed.

Lorsque le dispositif de sélection 7 n'est pas activé, les clavettes ou aiguilles 3 traversent le canal 8 sans être déplacées et leur talon 4 n'est pas entraîné par la came 6 du chariot. Par contre, lorsque le poste de sélection 7 est activé, les clavettes ou aiguilles 3 sont soulevées de telle sorte que leur talon 4 peut être entraîné par les cames 6.When the selection device 7 is not activated, the keys or needles 3 pass through the channel 8 without being moved and their heel 4 is not driven by the cam 6 of the carriage. On the other hand, when the selection station 7 is activated, the keys or needles 3 are raised so that their heel 4 can be driven by the cams 6.

Le principe du dispositif de sélection 7 est représenté aux figures 3 à 8.The principle of the selection device 7 is shown in Figures 3 to 8.

Ce principe de fonctionnement repose sur deux rampes magnétiques opposées et continues 9 et 10, à force de collage très élevée, et présentant au moins une zone 11, dite neutre, dans laquelle la force de collage magnétique est annulée. La sélection s'effectue dans cette zone neutre par un électroaimant 12. Dans le cas de la sélection directe sur les aiguilles ou les clavettes, les forces nécessaires pour déplacer ces aiguilles ou ces clavettes sont très variables. Une aiguille peut être soulevée avec quelques dizaines de grammes alors que la suivante requière, par exemple, plus de cent grammes. Dans tous les cas, il faudra fournir un champ magnétique suffisamment important pour provoquer l'attraction de l'aiguille ou de la clavette présentant le plus de frottements. Mais dans ces conditions, les aiguilles ou clavettes voisines de la clavette ou aiguille sélectionnées doivent rester dans leur position. Comme on ne peut éviter que les forces d'attraction s'exercent sur les clavettes voisines, les rampes magnétiques du dispositif les retiennent avec des forces de collage élevées, alors que la force de collage est nulle pour l'aiguille ou la clavette se trouvant dans la zone neutre 11.This operating principle is based on two opposite and continuous magnetic ramps 9 and 10, with a very high bonding force, and having at least one zone 11, called neutral, in which the magnetic bonding force is canceled. The selection is made in this neutral zone by an electromagnet 12. In the case of direct selection on the needles or keys, the forces necessary to move these needles or these keys are very variable. One needle can be lifted with a few tens of grams while the next one requires, for example, more than one hundred grams. In all cases, it will be necessary to provide a magnetic field large enough to cause the attraction of the needle or key having the most friction. However, under these conditions, the needles or keys adjacent to the selected key or needle must remain in their position. As it cannot be avoided that the forces of attraction are exerted on the neighboring keys, the magnetic ramps of the device hold them with high bonding forces, while the bonding force is zero for the needle or the key being in the neutral zone 11.

La zone neutre 11 peut être exploitée de deux manières différentes.The neutral zone 11 can be used in two different ways.

Les figures 3 à 5 illustrent une première manière. Les aiguilles ou clavettes 3 pénètrant dans le canal de sélection 8 sont alignées puis attirées systématiquement contre la rampe magnétique inférieure 9. FB représente la force de collage lorsque la clavette est en contact avec la rampe magnétique inférieure 9, FH la force de collage lorsque la clavette est en contact avec la rampe supérieure 10 et FE la force d'attraction de l'électroaimant 12 lorsque la clavette ou aiguille est encore contre la rampe inférieure 9.Figures 3 to 5 illustrate a first way. The needles or keys 3 entering the selection channel 8 are aligned then systematically attracted against the lower magnetic rail 9. FB represents the bonding force when the key is in contact with the lower magnetic rail 9, FH the bonding force when the key is in contact with the upper ramp 10 and FE the force of attraction of the electromagnet 12 when the key or needle is still against the lower ramp 9.

Les figures 4 et 5 représentent le profil de ces forces le long du canal de sélection 8. Ces figures montrent que moyennant une zone neutre 11 de largeur appropriée, l'électroaimant 12 n'agit que sur une clavette ou aiguille à la fois.Figures 4 and 5 show the profile of these forces along the selection channel 8. These figures show that by means of a neutral zone 11 of appropriate width, the electromagnet 12 acts only on a key or needle at a time.

Les figures 6 à 8 montrent une autre manière d'exploiter la zone neutre 11. Dans ce cas l'électroaimant 12 sélectionne les aiguilles 3 en travaillant en collage. Les aiguilles ou clavettes 3, à l'entrée du sélecteur, sont d'abord attirées contre la rampe inférieure 9 de manière à imposer leur position lors du changement de sens de marche de la machine, puis sur la rampe supérieure 10. Elles suivent cette rampe 10 jusqu'à la sortie du sélecteur si l'électroaimant 12 est activé lors du passage de la zone neutre 11. Par contre, si l'électroaimant 12 n'est pas activé lorsqu'une aiguille arrive dans la zone neutre 11, cette aiguille sera attirée par la rampe magnétique inférieure 9 par une force FB' (figure 7) et viendra se coller sur la rampe inférieure 9.Figures 6 to 8 show another way of using the neutral zone 11. In this case the electromagnet 12 selects the needles 3 by working in bonding. The needles or keys 3, at the input of the selector, are first attracted against the lower ramp 9 so as to impose their position when the direction of movement of the machine changes, then on the upper ramp 10. They follow this ramp 10 to the output of the selector if the electromagnet 12 is activated when passing through the neutral zone 11. On the other hand, if the electromagnet 12 is not activated when a needle arrives in the neutral zone 11, this needle will be attracted by the lower magnetic ramp 9 by a force FB '(Figure 7) and will stick to the lower ramp 9.

La figure 8 montre que le profil de la force d'attraction de la rampe inférieure 8 présente une pointe au niveau de la zone neutre de manière à assurer l'attraction de la clavette ou de l'aiguille.FIG. 8 shows that the profile of the force of attraction of the lower ramp 8 has a point at the level of the neutral zone so as to ensure the attraction of the key or the needle.

Dans les deux cas, le canal et chacune des aiguilles ou clavettes traversant le canal constituent un système bistable commandé par l'électroaimant.In both cases, the channel and each of the needles or keys passing through the channel constitute a bistable system controlled by the electromagnet.

Les profils des forces représentés aux figures 4, 5, 7 et 8 peuvent être aisément réalisés dans les rampes magnétiques représentées aux figures 9 à 12. Ces figures représentent par exemple la rampe inférieure 9. Cette rampe est constituée de deux pièces polaires 12 et 13 en forme de bande en métal dur magnétique, entre lesquelles sont disposés un certain nombre d'aimants permanents 14, de préférence en terre rare. Les pièces polaires 12 et 13 ne sont pas interrompues dans la zone neutre 11. Les clavettes ou aiguilles 3 sont directement en contact avec les pièces polaires 12 et 13, contrairement aux systèmes de rampes magnétiques connus dans lesquels les organes de sélection glissent sur des pièces en métal dur non magnétique et les rampes sont interrompues au niveau de l'électroaimant de sélection. L'épaisseur des bandes 12 et 13 et les dimensions des aimants 14 sont calculées de telle sorte que la partie des pièces polaires en contact avec les clavettes ou aiguilles 3 est saturée magnétiquement. Ceci assure une force de collage des clavettes ou aiguilles 3 indépendante de la répartition de ces clavettes ou aiguilles sur les deux rampes 9 et 10.The force profiles represented in FIGS. 4, 5, 7 and 8 can easily be produced in the magnetic ramps represented in FIGS. 9 to 12. These figures represent for example the lower ramp 9. This ramp consists of two pole pieces 12 and 13 in the form of a strip of magnetic hard metal, between which are placed a number of permanent magnets 14, preferably made of rare earth. The pole pieces 12 and 13 are not interrupted in the area neutral 11. The keys or needles 3 are directly in contact with the pole pieces 12 and 13, unlike known magnetic ramp systems in which the selection members slide on non-magnetic hard metal pieces and the ramps are interrupted at the selection electromagnet. The thickness of the strips 12 and 13 and the dimensions of the magnets 14 are calculated so that the part of the pole pieces in contact with the keys or needles 3 is magnetically saturated. This ensures a bonding force of the keys or needles 3 independent of the distribution of these keys or needles on the two ramps 9 and 10.

La zone neutre 11 est créée en plaçant les aimants 14 de telle sorte que le sens des flux magnétiques φI et φII sont inversés de part et d'autre de la zone neutre 11, comme illustré aux figures 11 et 12. Dans ce cas, une partie φIII du flux magnétique se court-circuite par les pièces polaires au niveau de la zone neutre 11 où les pièces polaires présentent un amincissement 15. L'importance de ce flux φIII dépend de la section des pièces polaires 12 et 13 au niveau de la zone neutre 11. Ceci fournit un moyen de choisir la largeur de cette zone neutre. Plus la section est grande, plus le court-circuit magnétique intéressera une portion plus étendue des aimants et plus la zone neutre 11 sera étendue. Un choix judicieux de cette section permet d'obtenir une zone neutre 11 qui est de l'ordre de la largeur d'une clavette ou aiguille, ce qui est pratiquement nécessaire dans le cas de jauges fines où le pas est de l'ordre de deux largeurs de clavette (une jauge 16 correspond à un pas de 1,588mm et une largeur de clavette de 0,82mm). De plus, cette déviation du flux magnétique au travers des pièces polaires 12 et 13 permet de minimiser les forces latérales d'attraction lors du passage de la zone neutre 11.The neutral zone 11 is created by placing the magnets 14 so that the direction of the magnetic fluxes φI and φII are reversed on either side of the neutral zone 11, as illustrated in FIGS. 11 and 12. In this case, a part φIII of the magnetic flux is short-circuited by the pole pieces at the level of the neutral zone 11 where the pole pieces have a thinning 15. The importance of this flux φIII depends on the section of the pole pieces 12 and 13 at the level of the neutral zone 11. This provides a way to choose the width of this neutral zone. The larger the section, the more the magnetic short-circuit will interest a larger portion of the magnets and the more the neutral zone 11 will be extended. A judicious choice of this section makes it possible to obtain a neutral zone 11 which is of the order of the width of a key or needle, which is practically necessary in the case of fine gauges where the pitch is of the order of two key widths (a 16 gauge corresponds to a pitch of 1.588mm and a key width of 0.82mm). In addition, this deviation of the magnetic flux through the pole pieces 12 and 13 minimizes the lateral forces of attraction when passing through the neutral zone 11.

D'autres façons de créer la zone neutre sont possibles.Other ways to create the neutral zone are possible.

Les figures 13 et 14 illustrent un exemple dans lequel la zone neutre est créée au moyen d'une pièce métallique 16 court-circuitant magnétiquement les aimants permanents 14 dans la zone neutre.FIGS. 13 and 14 illustrate an example in which the neutral zone is created by means of a metal part 16 magnetically shorting the permanent magnets 14 in the neutral zone.

Les profils de force représentés aux figures 4, 5, 7 et 8 peuvent être modifiés en donnant une forme différente aux deux pièces polaires 12 et 13. Par exemple, si l'une des deux pièces polaires est moins haute que l'autre, un entrefer se crée, qui a pour effet de diminuer la force de collage. Une telle exécution est représentée aux figures 17 à 19 qui seront décrites plus loin.The force profiles shown in FIGS. 4, 5, 7 and 8 can be modified by giving the two pole pieces 12 and 13 a different shape. For example, if one of the two pole pieces is lower than the other, a air gap is created, which has the effect of reducing the bonding force. Such an embodiment is shown in Figures 17 to 19 which will be described later.

Les figures 15 et 16 représentent encore une autre forme de réalisation des rampes magnétiques. Par exemple la rampe 9 peut être constituée d'une pièce polaire en U 13′ entre les ailes de laquelle est placée une bande 12′ constituant l'autre pièce polaire des aimants 14.Figures 15 and 16 show yet another embodiment of the magnetic ramps. For example, the ramp 9 may consist of a U-shaped pole piece 13 ′ between the wings of which a strip 12 ′ is placed constituting the other pole piece of the magnets 14.

La force d'attraction des rampes magnétiques peut être également renforcée par des aimants supplémentaires disposés à côté des rampes, par exemple dans le cas de la figure 6.The attractive force of the magnetic ramps can also be reinforced by additional magnets placed next to the ramps, for example in the case of FIG. 6.

En plus de la zone neutre où s'opère la sélection, il est possible de créer, selon le même principe, d'autres zones neutres, notamment à l'entrée du sélecteur, de manière à assurer le collage des clavettes ou aiguilles sur la rampe désirée.In addition to the neutral zone where the selection is made, it is possible to create, according to the same principle, other neutral zones, in particular at the input of the selector, so as to ensure the bonding of the keys or needles on the desired ramp.

Les figures 17 à 19 illustrent un exemple pratique de réalisation du dispositif de sélection.Figures 17 to 19 illustrate a practical example of embodiment of the selection device.

Le dispositif de sélection est monté sur une équerre 17 qui vient se fixer sur le chariot 5 de la machine. Sur cette équerre 17 sont fixés, au moyen de vis, deux supports 18 et 19. Le support 18 supporte la rampe supérieure 10 et l'électroaimant 12. Sur le support 19 est fixée la rampe magnétique inférieure 9. Les rampes magnétiques sont réalisées comme représentées aux figures 9 à 12, à la différence qu'à l'entrée du poste de sélection, la pièce polaire 12a de la rampe supérieure 10 s'étend plus bas que la pièce polaire 13a de cette même rampe, et ceci pratiquement jusqu'à la zone neutre. Les clavettes ou aiguilles arrivant en contact avec la rampe supérieure 10 ne sont ainsi en contact qu'avec une seule pièce polaire et ne sont donc retenues que par une force magnétique réduite. La pièce polaire 12a peut ainsi jouer le rôle de came amenant les clavettes ou aiguilles à proximité de la rampe magnétique inférieure 9 qui les attire.The selection device is mounted on a bracket 17 which is fixed on the carriage 5 of the machine. On this bracket 17 are fixed, by means of screws, two supports 18 and 19. The support 18 supports the upper ramp 10 and the electromagnet 12. On the support 19 is fixed the lower magnetic ramp 9. The magnetic ramps are made as shown in Figures 9 to 12, with the difference that at the entrance to the selection station, the pole piece 12 a of the upper ramp 10 extends lower than the pole piece 13a of this same ramp, and this practically up to 'to the neutral zone. The keys or needles coming into contact with the upper ramp 10 are thus only in contact with a single pole piece and are therefore only retained by a reduced magnetic force. The pole piece 12a can thus play the role of a cam bringing the keys or needles near the lower magnetic ramp 9 which attracts them.

La bobine de l'électroaimant 12 présente une faible inductance de manière à permettre l'attraction des clavettes ou aiguilles à des fréquences très élevées.The coil of the electromagnet 12 has a low inductance so as to allow the attraction of keys or needles at very high frequencies.

Claims (6)

  1. A device for the electromagnetic selection of the needles of a flat-bed knitting machine, comprising at least one section, in which are arranged needles and, if appropriate, keys pushing these needles, and a carriage carrying the needle-selection device (7), this device comprising a selection channel (8) through which the needles (3) or the keys pass and comprising essentially two opposed magnetic ramps (9, 10), at least (10) of which comprises at least one delimited zone (11) where the adhesive force on the magnetic ramps is very low and in which an electromagnet (12) is arranged, which is intended for selecting the needles which are to work, said zone forming a magnetically neutral selection zone, the channel and each of the needles or keys constituting a bistable system controlled by the electromagnet in such a way that the effect of the energization of the electromagnet is to cause the butt (4) of the needle or key to project from the section, so that it is driven by the cams of the carriage, characterized by the fact that each one of the magnetic ramps consists of a plurality of permanent magnets (14) and of pole pieces (12, 13) forming said ramps.
  2. The selection device as claimed in claim 1, characterized by the fact that two permanent magnets (14) of opposite polarity are arranged on each side of the magnetically neutral zone (11), part of the magnetic flux of these two magnets being closed on itself by way of the pole pieces (12, 13).
  3. The selection device as claimed in claim 1, characterized by the fact that the magnetic ramps possess, in the magnetically neutral zcne (11), a piece (16) magnetically short-circuiting the flux of the permanent magnets arranged on either side of the neutral zone.
  4. The selection device as claimed in one of claims 2 or 3, characterized by the fact that the cross-section of the pole pieces (12, 13) and the spacing of the permanent magnets (14) define a magnetically neutral zone (11) of a width corresponding at most to the space separating two needles or keys.
  5. The selection device as claimed in claim 4, characterized by the fact that the pole pieces (12a, 13a) of the same magnetic ramp (10) have different profiles, in such a way that this ramp serves both as a cam for positioning the needles or keys and as a magnetic ramp.
  6. The selection device as claimed in one of claims 1 to 5, characterized by the fact that the pole pieces are magnetically saturated.
EP92810712A 1991-09-20 1992-09-16 Needle selection device for a knitting machine Expired - Lifetime EP0533628B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CH2796/91 1991-09-20
CH279691A CH686141A5 (en) 1991-09-20 1991-09-20 A selection of the needles of a knitting machine.

Publications (3)

Publication Number Publication Date
EP0533628A2 EP0533628A2 (en) 1993-03-24
EP0533628A3 EP0533628A3 (en) 1993-04-07
EP0533628B1 true EP0533628B1 (en) 1996-04-24

Family

ID=4241781

Family Applications (1)

Application Number Title Priority Date Filing Date
EP92810712A Expired - Lifetime EP0533628B1 (en) 1991-09-20 1992-09-16 Needle selection device for a knitting machine

Country Status (8)

Country Link
EP (1) EP0533628B1 (en)
JP (1) JP2673922B2 (en)
KR (1) KR100233755B1 (en)
CH (1) CH686141A5 (en)
DE (1) DE69210152T2 (en)
ES (1) ES2087498T3 (en)
GR (1) GR3020430T3 (en)
MX (1) MX9205337A (en)

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE19508755C1 (en) * 1995-03-10 1996-06-27 Schieber Universal Maschf Magnetic needle selection on flat bed knitting machine
IT1295742B1 (en) * 1997-02-04 1999-05-27 Franco Sciacca METHOD AND EQUIPMENT FOR JACQUARD SELECTION IN A TEXTILE MACHINE
JP6085206B2 (en) 2013-03-26 2017-02-22 住友化学株式会社 Method for producing methacrylate ester

Family Cites Families (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2030533A1 (en) * 1969-07-10 1970-11-13 Lebocey & Cie Georges Circular knitting machine needle selection mechanism
CH622566A5 (en) * 1978-06-05 1981-04-15 Dubied & Cie Sa E
DE2938835C3 (en) * 1979-09-26 1982-04-01 Schaffhauser Strickmaschinenfabrik, Schaffhausen Needle control and selection device for knitting machines, in particular flat knitting machines
GB2107746B (en) * 1981-09-24 1985-03-06 Schieber Universal Maschf Needle selection device for a knitting machine
JPS62299554A (en) * 1986-06-11 1987-12-26 株式会社　平工製作所 Electromagnetic selector in traverse knitting machine
JPH01207448A (en) * 1988-02-12 1989-08-21 Fukuhara Seiki Seisakusho:Kk Electromagnetic needle selector in circular knitting machine
JP2816700B2 (en) * 1989-04-25 1998-10-27 株式会社福原精機製作所 Electromagnetic needle selection device for circular knitting machine

Also Published As

Publication number Publication date
DE69210152T2 (en) 1996-12-12
JP2673922B2 (en) 1997-11-05
EP0533628A3 (en) 1993-04-07
MX9205337A (en) 1993-07-01
KR930006221A (en) 1993-04-21
ES2087498T3 (en) 1996-07-16
DE69210152D1 (en) 1996-05-30
CH686141A5 (en) 1996-01-15
GR3020430T3 (en) 1996-10-31
JPH05214643A (en) 1993-08-24
KR100233755B1 (en) 1999-12-01
EP0533628A2 (en) 1993-03-24

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