EP0414599B1 - Binding device with twisting head and binding machine equipped with such devices, especially for binding coils of metal wire - Google Patents

Abstract

The present invention relates to a binding device which comprises, on a frame (7), means for inserting a flexible tie (F) around an article to be bound comprising guidance units (10, 11) to cause the two ends of the tie to cross over each other, and a head (32) for twisting the latter disposed at the rear of the said guidance units and formed from a clamp (32a) fitted at the end of a rotary body (33). <??>According to the invention, this binding device comprises means of guidance and driving in translation (41, 42, 43, 44) of the twisting head (32) preferably constituted by a nut (42) integral with the frame (7), in which is screwed a threaded section of the body (33) of the twisting head (32), mounted in a sliding manner in a unit for coupling (44) to a means ensuring its driving in rotation, the said guidance units of the flexible tie furthermore being retractable in synchronism with the translation of the twisting head. <??>Application to compacting and binding devices for coils of iron wire, provided with several of these binding devices distributed in a circle. <IMAGE>

Description

The present invention relates to a binding device which comprises, on a frame (7) associated with a support structure for an article to be bound, means for the establishment of a flexible link (F) around the latter comprising guide members and an actuation mechanism for these guide members, to cause the two end strands of the flexible link to intersect, and a twisting head thereof arranged at the rear of said guide members and formed of a clamp mounted on the end of a rotary body, this binding device comprising means for guiding and driving in translation the twisting head during its rotation.

Such tying devices are described for example in document FR-A-2 186 000 (which closes the base of the preamble of claim 1) and they are found in particular on the compactors-binders of iron wire crowns, in which they are distributed in a circle on a common support, behind the compacting unit.

As is known, a drawback of current compactors is that, in each binding device, the twisting head can, for construction reasons, act only at a great distance, of the order of 60 min, of the wire crown. If this has no consequence on the quality of the binding of the crowns of wires having a high elasticity which compensates for this twisting game after compaction, it is quite different when the wire is produced by rolling with an increased diameter thereby reducing the elasticity of the formed crown. It follows in fact that the insufficiently tight links around the wire ring, often slide along the latter, for example during handling or transport, and that the ring can thus come undone.

We also know, from another document FR-A-2 381 664, a twisting head which is driven in a translational movement towards the crown to bind as it rotates. This double movement is however obtained by means of a pneumatic or hydraulic control system which is very complex and costly to produce. In addition, no means is provided in this document for guiding the binding wire in front of the twisting head.

The present invention has set itself the objective of remedying this drawback and, to do this, it proposes a binding device of the type specified in the introduction, which is characterized in that said means for guiding and driving in translation comprise a nut integral with the frame, into which a threaded part of the body of the twisting head is screwed, as well as a toothed pinion retained around the body of the twisting head by an axial groove connection and meshing with a driving toothed wheel, and in that the actuating mechanism of the guide members is capable of operating in synchronism with the translational movement of the twisting head in order, beforehand in advance of the latter, to move said guide members from their active position by Intercrossing of the end strands of the flexible link, adjacent to the twisting head clamp, at a rest position placing them outside the trajectory of the twisting head and, after receiving the latter, bring them back from their rest position to their active position.

The twisting head can thus, during its rotation, advance in the direction of the ring of wire to be tied, until it approaches it at a distance which is certainly still limited in practice, but sufficiently reduced, by approximately half, to ensure good quality firm binding in combination with the elasticity of the wire crown, even when the wire is obtained by rolling.

Furthermore and according to another characteristic of the invention, the clamp consists of two jaws articulated on the body of the twisting head, each extending beyond their axis of articulation by a rear heel, and is further associated with a jack formed in the body with its rod directed towards the heels of the jaws and ending with a head of generally conical shape intended to engage between the latter, the heels of the jaws of the collet being further recalled to each other at rest. There are thus simple means for actuating the clamp which also do not increase the overall size of the binding device.

For their part, said flexible link guide members are preferably constituted by pivoting wire guide spouts, intersecting in the active position in the translation path of the twisting head.

As for the mechanism for actuating the wire guide spouts, it comprises two articulated links each on one side on a respective wire guide spout and on the other on a common lever mounted pivoting in its center on the frame and s 'articulating, by a projection on the rod of a jack.

The present invention also relates to a binder of articles of annular shape, in particular to a compactor-binder of wire wreaths, of the type comprising several binding subassemblies arranged in a circle on a common support, and constituted by devices binding as defined above.

In a preferred embodiment considerably simplifying the control of the twisting heads of the various tying devices, the latter are oriented in the same direction with their axes substantially parallel to the central axis of the article to be bound and their coupling pinions mesh with a common driving gear.

• la figure 1 représente schématiquement, en vue de côté, une compacteuse-lieuse conforme à l'invention ;
• la figure 2 est une vue en coupe agrandie schématique selon la ligne II-II de la figure 1 ;
• la figure 3 est une vue de côté, en coupe partielle, d'un dispositif de liage selon l'invention incorporé dans la compacteuse-lieuse des figures 1 et 2 ;
• la figure 4 est une vue en coupe longitudinale, selon la ligne IV-IV de la figure 3, de la tête de torsadage de ce dispositif de liage ;
• la figure 5 représente schématiquement en vue arrière, le système de commande des différentes têtes de torsadage des dispositifs de liage de la compacteuse-lieuse ;
• les figures 6 et 7 sont des schémas illustrant deux phases du fonctionnement du dispositif de liage ; et
• la figure 8 est une vue de face agrandie de la tête de torsadage, faite selon la flèche A de la figure 4.

The present invention will now be described in more detail, but without any limiting character, with reference to the accompanying drawings in which:

• Figure 1 shows schematically, in side view, a compactor-binder according to the invention;
• Figure 2 is an enlarged schematic sectional view along line II-II of Figure 1;
• Figure 3 is a side view, in partial section, of a binding device according to the invention incorporated in the compactor-binder of Figures 1 and 2;
• Figure 4 is a longitudinal sectional view, along the line IV-IV of Figure 3, of the twisting head of this binding device;
• Figure 5 shows schematically in rear view, the control system of the different twisting heads of the binding devices of the compactor-binder;
• Figures 6 and 7 are diagrams illustrating two phases of the operation of the binding device; and
• FIG. 8 is an enlarged front view of the twisting head, made according to arrow A in FIG. 4.

The compactor-binder exemplified in FIG. 1 is formed by a compacting unit proper 1 followed by a binding unit 2. In a manner known per se, the compacting unit 1 comprises a carriage 3 which, after having received a cylindrical crown of wire to be tied, formed in an upstream winding station, moves it and compresses it against an anvil 4 by passing it around an axial mandrel 5 projecting in front of the latter.

Behind the anvil 4, the binding unit 2 has four identical binding devices 6 which, as shown in FIG. 2, are bolted at 6a, by their respective frame 7, on one side, facing the anvil 4, of a common support 2a on which they are distributed in a circle being mutually offset by 90 °. The binding devices 6 are associated with respective binding wire reels designated as a whole by 8. They also have a main working axis X parallel to the axis Y of the mandrel 5 and positioned in the extension of the space for receiving the crown to be bound, defined between the latter and a respective lateral arm 9 also formed projecting at the front of the anvil 4.

We will now describe with reference to Figures 3 and 4 the structure of one of the binding devices 6, identical in all respects to the other three.

The first of these figures shows first of all on the front face of the binding device, two thread guide noses 10, 11 slightly offset in a direction perpendicular to the plane of the drawing. These thread guide beaks are provided with respective channels 10a, 11a converging towards one another in the direction of the anvil 4 until they intersect. Furthermore, each thread guide beak 10 or 11 is extended at the rear by a respective support leg 12 or 13 articulated at 14 or 15 on the frame 7, around axes parallel to each other and perpendicular to the main axis. X of the device. On each of these legs 12,13, is further articulated, respectively at 16 and 17, a link 18,19, long for the wire guide 10 and short for the wire guide 11. The two links 18,19, directed towards the central axis Y of the binding unit 2, are articulated at 20 and 21 on a rocking lever 22, itself carried in its center by an axis 23 journalling in the frame 7. At the rear of this axis 23, the lever 22 is provided with a protrusion 24 hinged at its end on a stud 25 blocked between two circular flanges 26, 27 formed at the end of the rod 28, of a jack 29 carried by the support 2a. This jack 29, centered on the axis Y of the binding unit 2, is common to the four binding devices 6 and therefore, when it is in extension, it places and maintains the thread guide beaks 10.11 of each of them in their active position in FIG. 3, by means of the respective mechanisms constituted by the rocking lever 22 and the links 18,19.

Just behind the two thread guide nozzles 10,11 is a twisting head 32 which will be described with reference to FIGS. 3, 4 and 8.

The rear part of this twisting head 32 consists of a body of revolution 33, retained by bearings 34,35 with seals 34a, 35a inside a bore 36 of the frame 7, formed between the legs d hinge 10,11. Beyond the front bearing 34, an extension 33a of the body 33 carries a clamp 32a consisting of two jaws 37.38 articulated around parallel axes 39.40 perpendicular to the axes of articulation 14.15 of the 12,13 legs of the thread guide beaks. In their rest position shown in Figure 4, these jaws 37,38 are held slightly apart by return springs, not shown, acting between heels 37a, 38a extending them beyond their axes of articulation 39.40 .

In FIG. 3, it can still be seen that the jaws 37, 38 have a rectangular shape for accommodating themselves, with minimum clearance, in a cutout 52 of complementary shape, formed in the rear face of the thread guide beaks 10, 11 . Figures 3, 4 and 8 also show that on their front face and along their free edge 37b, 38b, the jaws 37,38 are each provided with an open channel 37c or 38c, these two channels tilting while converging on the X axis of the twisting head so, thanks to their mutual offset, visible in FIG. 8, to find themselves respectively in the alignment of the channels 10a, 11a of the thread guide beaks 10.11, when the two jaws 37 , 38 are in their open position shown in FIG. 4.

This same figure also shows that, in its middle part, the body 33 of the twisting head 32 has an externally threaded section 41 which is screwed into a fixed nut 42 secured, by a screw 42a, to the wall of the bore 36. At its rear end, the body 33 carries, by means of one or more axial grooves 43, a pinion 44 (FIG. 3). As shown in FIG. 2 as well as the schematic view of FIG. 5, the four pinions 44 of the twisting heads 32 of the four binding devices 6 mesh, by means of intermediate pinions 45, with a common central toothed wheel 46 placed in rotation by a hydraulic motor 47.

In the rotary body 33 of the twisting head, the cavity 48 of a hydraulic cylinder is also provided, the rod 49 of which is centered on the axis X ends in a frustoconical head 50 directed towards the interval defined between the heels 37a , 38a of the two jaws 37.38.

We will now explain the operation of the binding unit 2 provided with the binding devices 6 described above.

Each of the binding devices 6 being in the state illustrated in FIG. 4, a thin flexible and continuous binding wire F coming from one of the reels 8 and driven by a motorized pulley 30 mounted on the frame 7 with its counter tension roller 30a, engages in channel 38c of jaw 38 of the twisting head, then in channel 11a in alignment with the thread guide spout 11 for, at the outlet of the latter, come to gird a section of the crown by following guide grooves, not shown, formed in an opening of the anvil 4, along the corresponding arm 9 and along the mandrel 5. The bonding wire then returns to the height of the second wire guide 10, the channel 10a of which it crosses, then the aligned channel 37c of the second jaw 37, thus crossing on itself. Beyond, the free end of the wire is grasped by a clamp 31 actuated by a jack not shown, clamp which by cooperating with the reel 8 and its pulley 30, tends the binding wire F around the crown. In the following instant, the actuator 48 is activated and the frustoconical head 50 of its rod 49 engages between the heels 37a, 38a of the jaws 37, 38 to bring the front clamping spouts closer to the latter, so that they firmly secure wire F near its crossover point on itself. Consequently, a shear, not shown, intervenes to cut the wire F on the side of the pulley 30, and thus form a flexible link whose two interlaced strands F₁, F₂ (FIG. 6) are immobilized in the twisting head 32.

Then, after moving away from the tensioning clamp 31 and spacing of the thread guide beaks 10, 11 under the effect of the retraction of the rod 28 of the jack 29, each of the twisting heads 32 is rotated by the motor. hydraulic 47, through the gear formed by the central gear 46 and the pinions 45 and 44. During this rotation, each twist head is screwed in its nut 42 and, by sliding in the associated pinion 44, is simultaneously driven in a forward translation movement. This double movement of which the twisting head 32 is subjected allows it to produce a twist T as close as possible to the crown C to be linked (see FIG. 7), in practice at a distance of approximately 3 cm from the latter. The flexible link F is thus well adjusted around the crown C without risk of subsequent slipping.

Once the twist T has been carried out, the pressure is released in the jack 48, the rod 49 with a frustoconical head is retracted by a return spring 51 inside this jack so that the jaws 37.38 open, the rotation of the head twist 32 is reversed and it is therefore translated backwards. The thread guide beaks 10, 11 are then brought back towards each other in the working position by the jack 29 and a new tying cycle can then begin.

Claims (6)

1. Binding device comprising, on a frame (7) associated with a supporting structure (4) for an article to be bound (C), means for placing a flexible bond (F) around said article to be bound (C) comprising guide members (10, 11) and an actuating mechanism (18, 19, 22, 29) of said guide members for bringing the two end lengths (F1, F2) of flexible bound (F) to cross over one another, and a twisting head (32) thereof, arranged at the rear of said guide members and formed by a gripper (32a) mounted on the end of a rotary body (33), said binding device comprising means (41, 42, 43, 44) for guiding and driving the twisting head (32) in translation as it rotates, characterized in that said means for guiding and driving in translation comprise a nut (42) integral with the frame (7) with a threaded portion (41) of the body (33) of the twisting head (32) being threadedly engaged with the nut (42), and a toothed pinion (44) retained around the body (33) if the twisting head (32) by a connection with an axial spline (43) and engaging with a toothed driving wheel (46), and in that the actuating mechanism (18, 19, 22, 29) of the guide members (10, 11) is operable in synchronism with the translation mouvement of the twisting head (32) for, prior to the advancement of said twisting head, moving said guide members from their active position of crossing over the end lengths of the flexible bound, adjacent to the gripper (32a) of the twisting head, to a rest position in which they are positioned out of the path of the twisting head and, further to receiving the latter, returning said guide members from their rest position to their active position.
2. Binding device according to claim 1, characterized in that the gripper (32a) is composed of two jaws (37, 38) articulated on the body (33) of the twisting head (32), each extended, beyond their axis of articulation (39, 40), by a rear heel (37a, 38a) and is further associated with a jack (48) formed in the body (33) with its rod (49) pointing towards the heels of the jaws and ending in a head (50) of a generally conical shape designed to engage between the latter, the heels of the gripper jaws being further biased towards one another in rest condition.
3. Binding device according to claim 1 or 2, characterized in that said members for guiding the flexible bond are constituted by thread guide beaks (10, 11), which pivot, crossing over each other in active position in the translation path of the twisting head.
4. Binding device according to claim 3, characterized in that the actuating mechanism of the thread guide beaks (10, 11) comprises two small links each articulated, on one side, on a respective thread guide beak and, on the other side, on a common lever (22) which is pivotally mounted at its centre (23) on frame (7) and articulates by a protuberance (24) on the rod (28) of a jack (29).
5. Binding apparatus for binding articles of an annular shape, in particular wire coil compacting and binding apparatus of the type comprising several binding subassemblies arranged in a circle on a common support (2a), and constituted by binding devices (6) according to any of claims 1 to 4.
6. Binding apparatus according to claim 5, characterized in that the twisting heads (32) of the binding devices (6) are oriented in the same direction with their axes (X) substantially parallel to the central axis (Y) of the article to be bound (C) and their coupling pinions (44) engage with a common driving gear wheel (46).

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