EP0509958A1 - Method and device for transfering bobbins during unwinding - Google Patents

Abstract

The method and the device for transferring bobbins during unwinding, according to the invention, are based on a bobbin hub (5), an inner shaft (70) of which can slide axially under the action of a gripping shaft (82) forming part of the transfer device (3). <??>By bringing the transfer device so as to face the hub of a rotating bobbin and by withdrawing the inner shaft of the hub, the said hub is disconnected from the machine (1), the bobbin (21, 20) continuing to rotate with its hub fixed to the transfer device. It is then possible to move the transfer device along directions located in the plane of rotation of the bobbin and to bring it so as to face another axis of the machine in order to fix once again the hub thereon according to a procedure which is the reverse of the preceding one. <??>Thus it is possible to move a rotating bobbin, especially a bobbin delivering a cigarette-paper strip, without the said paper strip experiencing a torsional force. <??>Other operations relating to the automatic running of the machine are possible with the aid of the transfer device according to the invention. <IMAGE>

Description

The present invention relates to a method for transferring a spool or a wafer during unwinding, from a first unwinding position to a second unwinding position, the device used for this purpose and a reel or wafer hub necessary for the execution of the process.

In many production machines, one of the components involved in the product produced by said machine is in the form of a finite length element wound on a reel; Given the productivity demanded of this machine, it is generally not possible to stop it when a reel is empty in order to replace it. Many devices have been developed which make it possible to join a lower end of the component placed on a nearly empty reel, to the upper end of the component placed on a full reel, so that said component can be delivered continuously without it is necessary to stop the machine. An operation of this kind generally requires moving the coils. When the component to be cut is a ribbon, easily tearable and / or deformable, the operation of moving the reels is complicated since it is not possible to bias the ribbon and the latter must always be unwound in the same plane .

This problem is particularly acute in paper feeding machines as found in the cigarette industry. Indeed, the paper tape used in these machines, whether the paper tape directly surrounding the tobacco of the cigarette or that surrounding the filter of the cigarette, is extremely thin and fragile and is unwound at very great speed. This ribbon of paper is generally wound in a single turn on a flat reel, or on a wafer. Since it is not possible to stop the machine to change the paper wafer when it is empty, devices have been developed which make it possible to connect, during operation, one end of a ribbon of paper. a patty at another end of a paper ribbon from another patty. Such devices are described in particular in patent applications CH 4413 / 87-0, 711 / 88-6 and 2750 / 90-5.

A first object of the invention is therefore to provide a method and means making it possible to transfer a wafer of paper during unwinding from an axis of rotation of the machine to another axis of rotation of the machine, without risking tearing or twist the paper tape, another object of the invention being to be able to carry out the previous operation without having to stop the machine, while a third object of the invention is to be able to carry out this operation fully automatically. Another object of the operation is to be able to add the device according to the invention to a known machine for unwinding cigarette paper and to have said device, automatically, carry out all the operations of transferring pancakes and / or centers wafers, as well as storage, necessary for the operation of said machine, while a last object of the invention is to provide a wafer hub for carrying out the method according to the invention.

To achieve these goals, the cigarette paper dispensing machine is provided with a wafer transfer device according to the invention, as described in claims 5 to 13, for the application of the method according to the invention, described in claims 1 to 4, as well as wafer hubs according to claims 14 to 17.

• la figure 1 est une vue en perspective d'une partie d'une machine d'alimentation en papier de cigarette ainsi que d'une partie du dispositif de transfert selon l'invention,
• la figure 2A est un vue en élévation d'un moyeu de galette selon l'invention,
• la figure 2B est une vue en coupe du même moyeu de galette,
• la figure 3 est une vue schématique en perspective d'une autre partie du dispositif de transfert selon l'invention,
• la figure 4A est une vue de côté en coupe partielle d'une partie du dispositif de transfert selon l'invention,
• la figure 4B est une vue par-dessus en coupe partielle du dispositif de la figure 4A,
• la figure 4C est une vue par l'arrière en coupe partielle du dispositif des figures 4A et 4B,
• les figures 5A, 5B et 5C représentent diverses étapes de fonctionnement du dispositif de transfert et du moyeu de bobine, selon l'invention, et
• les figures 6A, 6B et 6C représentent d'autres étapes de fonctionnement du dispositif de transfert selon l'invention.

The process for transferring wafers as well as a preferred embodiment of the device allowing this transfer are more particularly understandable from the drawing in the appendix with the figures where:

• FIG. 1 is a perspective view of part of a machine for supplying cigarette paper as well as part of the transfer device according to the invention,
• FIG. 2A is an elevation view of a wafer hub according to the invention,
• FIG. 2B is a sectional view of the same wafer hub,
• FIG. 3 is a schematic perspective view of another part of the transfer device according to the invention,
• FIG. 4A is a side view in partial section of a part of the transfer device according to the invention,
• FIG. 4B is a view from above in partial section of the device of FIG. 4A,
• FIG. 4C is a rear view in partial section of the device of FIGS. 4A and 4B,
• FIGS. 5A, 5B and 5C represent various stages of operation of the transfer device and of the coil hub, according to the invention, and
• Figures 6A, 6B and 6C show other stages of operation of the transfer device according to the invention.

FIG. 1 represents the front part of a machine for supplying cigarette paper 1 comprising a part for unwinding 10 of paper cakes arranged at the lower part of the machine 1, as well as an upper part 11 intended for the storage of full patties and disposal of empty patties centers. From the set of wafers 2 visible on the machine 1, there is a paper wafer 20 being unwound around an axis 12 of the machine 1, the paper ribbon being driven further, in the direction of the arrow, on an unrepresented part of the machine. When the first wafer 20 rotating around the axis 12 is almost empty, the upper end of a paper tape of a second wafer 21 disposed on an axis 13 of the machine will be connected to a lower end of the paper tape of the first wafer 20, by a device, known in the art, described in patent application CH 2750 / 90-5, and not shown in the figure so as not to clutter it. When the paper ribbons are connected and it will be the wafer 21 which will feed the machine, it will be necessary to remove the balance from the wafer 20 and eliminate it, then transfer the wafer 21 unwinding around the axis 13 , so as to unwind it around the axis 12 and finally to bring on the axis 13 a new wafer 22 coming from the storage axis 14 disposed in the upper part 11 of the machine 1. There are also in the figure, the part 15 responsible for eliminating the wafer centers 23, and a buffer position pin 16 whose usefulness will be explained later.

A transfer device 3 according to the invention, of which only a part is visible in the figure, has been added to the machine 1.

The different transfers of paper wafers 2, from one axis position to another, as well as the loading of wafers from the stock and the elimination of wafer centers, are done for example using the transfer device 3 according to the invention, a worm screw 30 of which can be seen in the figure, the length of which corresponds approximately to the height of the machine 1 or at least the height necessary for the different transfers, and pivoting between two bearings 31A and 31B, actuated by an electric motor 32 and a transmission of known execution movement, so to raise or lower a horizontal beam 33 by means of a nut 34. The device 3 is fixed to a frame integral with the machine 1. The rest of the device fixed to the horizontal beam 33 is visible in particular in the figure 3.

A wafer braking device 4 is part of the transfer device according to the invention; it may for example consist of a rotating toothed wheel 40, braked by any electro-mechanical means, mounted on a lever 41 which can pivot around an axis 42 parallel to the axis of rotation of the toothed wheel 40, as well as a second toothed wheel 43, also braked by any electro-mechanical means. The operation of this device will be explained later.

FIG. 2A represents, seen from the front, a wafer hub 5 according to the invention. The paper wafer 2, of which only the lower part is shown in the figure, consists of a paper ribbon wound on a single turn around a center 23, consisting of a hollow cylindrical element, the height of which corresponds to the width of the paper tape, made of strong cardboard or plastic. The hub 5 is intended to allow the rotation of the wafer about its central axis; for this, it consists of a first part 50, preferably having the shape of a triangle with highly rounded tips, coming to be inserted inside the center 23, and maintaining said center using three points 51 , mounted on springs 52, arranged in bores formed on each of the rounded parts of the triangular part 50 and which are slightly encrusted in the inner cylindrical surface of the center 23. Thus, the three points 51 can retract when the hub 5 is introduced into the center 23 and then firmly maintain said center on the hub 5. We can still see on the upper part of the figure a portion of a toothed wheel 53, used for braking the wafer, as will be explained below.

In Figure 2B, there is a section along line II-II of the previous figure. The machine 1 has bores, centered on the axes 12, 13 and 16, in which are mounted hub supports 6, intended to support a paper wafer 2 on its hub 5. The different hub supports being identical for each of the axes 12, 13 and 16, a single hub support 6 is described here. The hub support 6 preferably comprises first of all a hollow cylindrical casing 60, fixed in a conventional manner on the bore of the frame of the machine 1. A collar sleeve 61 is screwed onto the inner front part of the cylindrical casing, the collar of the sleeve 61 projecting from the outside face of the machine 1. The hub support 6 also comprises an internal bell-shaped part 62, moved in two axial positions by a jack 63 placed on the rear of said hub support, or by any other suitable means, as well as a plurality of balls 64, held in a ball cage, not shown, and arranged along a circumference between the rear face of the sleeve 61 and a shaped surface truncated cone 66 disposed on the inner part of the bell 62. The usefulness and operation of this device will be explained below.

As we saw above, the hub 5 is composed of a triangular part 50, supporting the center 23 of the wafer 2 by means of three points 51 mounted on the springs 52 and arranged in radial bores made in the rounded parts of the points of the triangular part 50. The part triangular 50 is mounted on two ball bearings 54 arranged outside a central bush 55. A transversely movable axis part 7, consisting of a rod 70, can slide axially inside two bore bearings 56A , 56B disposed at the ends of the central bush 55, between two extreme positions, defined by the clearance that a circlip 71 can take, disposed on an outer circumference of the rod 70, in a cylindrical cavity 57 arranged on the inner cylindrical face of the central socket 55 between the bearings 56A and 56B. The extreme stop positions of the circlip 71 inside the cavity 57 are such that for a position, as shown in the figure, the front face 72 of the rod 70 is flush with the front face 58 of the central bush 55 and the other end 73 of the rod 70 is completely engaged in a bore 65 arranged axially in the collar sleeve 61. A circular groove 74 is arranged on a periphery close to the rear part 73 of the rod 70, its axial position being determined by the axial position of the balls 64 arranged under the bell-shaped part 62.

When the rod 70 is fully engaged in the bore 65, in order to maintain the hub 5 around an axis of the machine 1, the jack 63 pushes the bell 62 against the collar sleeve 61 in order to press the balls 64, via the truncated cone surface 66 disposed under the bell, inside the circular groove 74 of the rod 70. A relaxation of the jack 63 on the contrary allows the balls to escape from said groove to release the rod 70.

For the other extreme position of the rod 70 inside the central sleeve 55, the front face 72 of said rod protrudes relative to the front face 58 of the hub, by a distance corresponding to the possible axial displacement of the rod 70, or the possible movement of the circlip 71 inside the cylindrical cavity 57 between the bearings 56A and 56B.

A blind bore 75 is arranged on the front face 72 of the rod 70, coaxial with said rod, and also comprising a groove 76 for a ball retaining device.

FIG. 2B therefore represents a wafer 2, fixed on a hub 5, the central bush 55 of which is fixed to the machine 1 along an axis 12, 13 or 16, by means of a rod 70 fixed in the hub support 6, the rotation of the wafer 2 being authorized by the bearings 54 arranged between the central bush 55 and the triangular part 50.

A part of the transfer device 3 according to the invention is shown diagrammatically in perspective in FIG. 3. As shown here, the represented face of the device faces that of the machine 1. The device 3 firstly comprises, according to a preferred embodiment, the worm 30, rotated between the two bearings 31A and 31B via the motor 32, as shown in Figure 1. The horizontal beam 33 comprises at one of its ends a device d 'nut 34, engaged in the screw 30. The other end of the horizontal beam 33 slides in a rail or a vertical slide 17, of known technique, integral with the frame of the machine 1, in order to prevent the rotation of said beam horizontal around the screw 30, and guide it so that it remains horizontal. Instead of the guide 17, it is also possible to have a second endless screw, driven in the same movement as the screw 30 and engaged in a second nut device disposed at the other end of the horizontal beam as the nut device 34. The rotation of the screw 30, in one direction or the other, therefore causes a displacement of the horizontal beam 33, up or down, by means of the nut device 34. The horizontal beam 33, supporting the rest of the transfer device as will be seen below, therefore allows said transfer device to move along the Z axis, in a positive or negative direction, and to take any position along this axis. Directly under the horizontal beam 33, an intermediate piece 35 is connected to the horizontal beam 33 by means of a motorized slide 36 of known technique (visible in FIG. 4C), allowing relative movement of the intermediate piece 35 relative to to the horizontal beam 33, along the axis X, in one direction or the other, said intermediate piece being able to assume any position along this axis. A mobile support 37 is placed directly under the intermediate piece 35, connected to said intermediate piece by a motorized slide 38 described below (visible in FIGS. 4A and 4C), allowing relative movement of the mobile support 37 relative to the intermediate piece 35, along the Y axis, in one direction or the other, said movable support being able to take any position along this axis. Thus, any point of the mobile support 37 can take any position in space, within the limit of the possible movement of the screw 30 and of the slides 36 and 38.

The gripping device 8, disposed on the movable support 37 firstly comprises three fingers entry 80 preferably arranged in a triangle, fixed relative to said mobile support, and the operation of which will be explained later. It also includes a retractable sleeve 81, which can move relative to said mobile support along the Y axis, under the action for example of a pneumatic or hydraulic double-acting cylinder 94 (see FIG. 4B) and which can take two extreme positions on this axis, a retracted position and an advanced position.

Inside the retractable sleeve 81, there is a gripping rod 82 which can move coaxially with respect to said retractable sleeve, along the Y axis, under the action for example of a double-acting pneumatic or hydraulic cylinder. 96 (see Figure 4A) and can take two extreme positions on this axis, a retracted position and an advanced position.

A preferred embodiment of the actuating device 9 of the movable support 37, of the retractable sleeve 81 as well as of the gripping rod 82 is shown in FIG. 4A, which is a partial sectional side view of the device, the Figure 4B which is a partial sectional view over the device and Figure 4C which is a rear view in partial section of the device.

The actuation in the direction Y of the movable support 37 relative to the intermediate part 35 is clearly visible in FIGS. 4B and 4C. It is done, for example, by means of an electric motor 90, preferably a stepping motor, the carcass of which is fixed to the intermediate piece 35 by means of a fixing piece 39. A shaft 91, threaded on its rear part, rotating along an axis parallel to the axis of rotation of the motor, respectively parallel to the axis Y, is driven in rotation by the motor 90, via a pulley and belt transmission 92. The shaft 91 is also fixed in a bore of the fixing plate 39. The threaded rear end of the shaft 91 is engaged in a nut 93 which is fixed in a conventional manner known from the mobile support technique 37. As indicated above, the mobile support 37 is supported under the intermediate piece 35 by the slides 38. Thus, the rotation of the rotor of the motor 90 causes the rotation of the shaft 91, which is screwed or is unscrewed in the nut 93, thereby causing the displacement, in one direction or the other, along the axis Y, of the movable support 37 relative to the intermediate piece 35.

The device allowing movement along the Y axis of the retractable sleeve 81 relative to the movable support 37 is clearly visible in FIG. 4B. For example, a double-acting hydraulic or pneumatic cylinder 94 has its body fixed to the movable support 37, while its piston is secured to a rod fixed to a rear plate 95 fixed to the rear part of the retractable bush 81. The slides 86 allow the relative movement along the Y axis of the retractable sleeve 81 relative to the movable support 37, under the action of the jack 94.

In FIG. 4A, there is a device allowing movement along the Y axis of the gripping rod 82, relative to the retractable bush 81. For example, a double-acting hydraulic or pneumatic cylinder 96 has its body fixed to the bush retractable 81, while its piston is integral with a rod fixed to another rear plate 97 fixed to the rear part of the gripping rod 82.

The double-acting hydraulic or pneumatic cylinder 98 has its outer body fixed to the rear plate 97, while its piston actuates a rod ending in a point 87, which slides in a longitudinal bore arranged in the gripping rod 82. Balls 88, held in radial bores arranged near the end of said gripping rod, can be pushed outwards or brought back inwards, under the action of the pointed rod 87, respectively of the cylinder 98, in order to cooperate, as described below, with the groove 76 provided in the bore 75 of the rod 70 of the transversely movable axis part 7 mentioned above.

We can still see in FIG. 4A another double-acting hydraulic or pneumatic cylinder 99, the body of which is fixed to the movable support 37 and located behind the gripping finger 80. The piston of the cylinder 99 actuates another rod ending in a point 84 the tip of which is inserted into a slot arranged in a pin 85, which can move in a radial bore arranged near the end of the gripping finger 80. The shape of said slot is such that, under the action of the tip of the rod 84, respectively of the jack 99, the pin can project radially out of the bore of the gripping finger or, on the contrary, retract inside, in order to grasp a center of wafer 23 as explained below. In Figure 4A, the pin is shown in the retracted position. Each of the three gripping fingers 80 is provided with the same device.

Now that the various components and the operation of the elements constituting the transfer device have been described, reference can be made to FIGS. 5A, 5B and 5C where we see some steps of the process of gripping a wafer of paper during reeling for its transfer from axis 13 to axis 12 for example.

In FIG. 5A, there is, as in FIG. 2B, the end 73 of the rod 70 engaged in the bore 65 of the collar sleeve 61 fixed to the frame of the machine 1 in the manner described above. The balls 64 are engaged in the groove 74 of the rod 70 in order to firmly hold the said rod inside the bore 65. The wafer 21 therefore unwinds, being fixed to the axis 13 of the machine.

The transfer device was brought in front of the wafer hub 5, in particular the gripping rod 82 was brought in front of the bore 75 arranged in the rod 70 by the displacements Z-X described above. The retractable sleeve 81 has been advanced relative to the mobile support 37, so that its front face is flush with the free face of the central sleeve 55. As can be seen in the figure, from the rear position of the mobile support 37, the gripping fingers 80 (only one of which is shown in the figure) remained recessed with respect to the retractable sleeve 81.

FIG. 5B shows that the gripping rod 82 has been engaged in the bore 75 of the rod 70, then that the point 87 has been pushed in order to force the balls 88 into the groove 76 in order to secure the rod 70 to the rod 82. Then the jack 63 has been actuated to remove the bell-shaped part 62 in order to release the balls 64 from the groove 74 to thereby release the rear part 73 of the rod 70.

It is then possible to pull the gripping rod 82 backwards, by the action of the jack 96 as explained above, and to bring the rod 70 inside the bore arranged in the retractable sleeve 81, as shown in FIG. 5C, from a distance such that the rear portion 73 of the rod 70, which was engaged in the bore 65 of the collar sleeve 61, comes completely out of said bore, so that the hub 5 is completely disengaged from the hub support 6, respectively of machine 1. As explained above, the distance of axial displacement of the rod 70 corresponds to the distance that the circlip 71 can travel, inside the cylindrical cavity 57, before coming to abut against the bore bore 56A. As shown in the figure, the wafer, which continued to unwind during the operations described above, is now held integral with the transfer device, while being able to continue to unwind.

By acting on the endless screw 30, in order to move the horizontal beam 33 in the Z direction, as well as on the intermediate piece 35 in order to move it in the X direction, without actuating any of the movements Y, it is possible to transfer the wafer in rotation in the XZ plane, which does not risk tearing or twisting the paper tape during dispensing.

After reaching the new position where the wafer must be unwound, for example the axis 12, we find ourselves in an arrangement similar to that of FIG. 5C, the gripping rod 82 then being advanced to make the rear end 73 penetrate. of the rod 70 inside the bore 65 of the hub support 6, as in FIG. 5B. The jack 63 is actuated so that the balls 64 are pressed by the frusto-conical surface 66 of the bell 62 in the groove 74, to hold the rod 70 in the bore 65, while the point-shaped rod 87 is withdrawn by the jack 98, in order to release the balls 88 from the groove 76 arranged in the bore 75 of the rod 70. It then suffices to act on the jack 94 to remove the retractable bush 81, in order to completely separate the hub 5 of the transfer device, as shown in FIG. 5A.

During this entire transfer operation, the pancake 20 could continue to unwind, its axis of rotation passing from the axis 13 of the machine to the axis 12, without torsional stresses being applied to the paper tape.

Another function that the transfer device according to the invention can accomplish is to load a full wafer onto a hub 5 and unload a remnant of wafer from said hub. For this, with reference to FIG. 2A, it can be seen that the triangle-shaped part 50 of the hub 5 has on one of its branches a bore into which a part 59 has been introduced, filling said bore and whose specific mass is slightly higher than that of the material constituting the triangle-shaped part. Thus, a slight imbalance is created, sufficiently small not to hinder the rotation of the hub 5, but sufficiently large so that, when stationary, the tip of the triangle comprising the unbalance 59 is automatically placed downwards after a time, of the order of a few seconds, relatively short after stopping the rotation of the hub. Thus the empty spaces located between the flat faces of the triangle-shaped part 50 and the inside diameter of the center 23 of the wafer 2 are always located opposite the three gripping fingers 80 secured to the movable support 37.

The different phases of extracting a wafer center or fitting a full wafer are visible in FIGS. 6A, 6B and 6C.

In FIG. 6A, there is a balance of wafer 20, on its center 23 disposed on a hub 5 secured to an axis of the machine, for example the buffer axis 16. The wafer 20 is not in rotation and the hub 5 has taken its position of equilibrium as described above. As before, the transfer device is brought in front of the hub 5, the fingers grip 80 being set back from the front face of the wafer. Pins 85 are in retracted position.

Then the movable hub support 37 is advanced, under the action of the motor 90 and of the threaded shaft 91, as described above, so as to bring it to the position visible in FIG. 6B, where the gripping fingers 80 engage in the empty spaces located between the flat faces of the triangle-shaped part 50 and the inside diameter of the center 23 of the wafer 20. By actuating the rods in the shape of a tip 84, by the jacks 99, these push the pins 85 outwards which become embedded in the center 23 of the wafer 20. Since the holding force of the center 23 on the pins is higher than that exerted by the springs 52 acting on the tips 51, it is possible, by removing the gripping fingers 80, respectively the movable support 37, as shown in FIG. 6C, to extract the center 23 from the hub 5 and to move the entire device to go and release said center towards the part disposal centers 15. From in a completely similar way, but in the opposite direction, it is possible to go and get a full wafer 22 on the storage axis 14 and bring it to an empty hub 5.

It is now possible to explain the complete operation of the transfer device, with regard to the operation of a machine for connecting two ends of a paper tape, in particular a machine as described in the patent application CH 2750 / 90-5.

As a starting point, and with reference to FIG. 1 to identify the position of the axes, it is possible to have a wafer 21 which unwinds from the axis 13 of the machine 1, the axis 12 being free and a second empty hub 5 being placed in standby on the buffer axis 16. At least one full wafer 22 is stored on the axis 14. In order to brake the rotation of the wafer 21 and to give the paper tape a constant tension, the braking toothed wheel 40 is meshed with the toothed wheel 53 secured to the hub 5 supporting the wafer 21. In this position, not shown, the lever 41 is in the high position. When a certain amount of the wafer 21 has been unwound, it is necessary, in order to proceed with the connection of the ends of the ribbons as explained in the aforementioned patent application, to bring the wafer 21 from the axis 13 to the axis 12. For this, we proceed as indicated with reference to Figures 5A, 5B and 5C, or we bring the transfer device 3 in front of the hub 5 disposed on the axis 13, we introduce the gripping rod 82 in the bore 75 of the rod 70, these two elements are blocked by the balls 88, the rear end 76 of the said rod is released from its engagement by the balls 64 and the gripping rod 82 is removed, which pulls the rod 70 and the detaches from the hub support 6, respectively from the axis 13. By moving the slides in the XZ plane as described above, the transfer device 3 is brought in front of the axis 12 on which the hub 5 is fixed. the way described. During this transfer movement, the lever 41 of the braking device accompanied this movement, by pivoting about its axis 42, so that the braking wheel 40 remains meshed with the toothed wheel 53 secured to the hub 5, so that the tension exerted on the paper tape remains constant. When the hub 5 is in place on the axis 12, the second braking wheel 43 meshes with the toothed wheel 53, in order to effect the braking effect, while the lever 41 goes back to the starting position. Thus, the rotating wafer 21 has been transferred from the axis 13 to the axis 12, the ribbon not undergoing any lateral torsional stress, since the plane of rotation of the wafer has not not varied and the tape remaining braked so as to undergo a constant tensile force.

The next step is to get a full wafer 22 of the stock portion arranged along the axis 14 and bring it to the empty hub 5 arranged waiting on the buffer axis 16. For this, the transfer device is moved towards the axis 14, the three gripping fingers 80 are inserted inside the center 23 of the first wafer, the pins 85 are actuated to grip said center, then by withdrawing the movable support 37 backwards, this wafer is retrieved from storage. The transfer device then moves towards the buffer axis 16 where an empty hub 5 is installed. Since the hub is stopped, the faces of the triangle-shaped part 50 are arranged so as to be able to receive the fingers gripping 80 which support the center 23 of the wafer 22. The gripping fingers 80 are therefore advanced, by advancing the movable support 37, so that the rear of the wafer abuts against the toothed wheel 53. The pins 85 now the center 23 on the gripping fingers 80 are then retracted, which means that said center is now retained by the points 51 pressed by the springs 52 and is therefore secured to the hub 5.

It is now a matter of transferring the wafer mounted on a hub from the buffer position 16 to the axis 13 which has been previously released. For this, although it is stopped, the hub 5 is gripped by the gripping rod 82, detached from the axis 16 then transferred and fixed to the axis 13 as previously.

Following this, a series of operations begins, consisting in opening the wafer 21 arranged on the axis 13, eliminating the upper turns, putting the wafer in rotation, bringing the end of the paper ribbon in front of the paper ribbon drop down from of the wafer 20 located on the axis 12, to cut the said paper strip and to connect the two free ends so that it is now the upper wafer, arranged on the axis 13, which feeds the machine. These different operations which are not part of the present patent application will not be described more fully here, a full description of them can be found in the patent application cited above.

The wafer 20, which is almost empty, on its center 23 is now stopped on the axis 12. The transfer device comes in front of said axis 12, the gripping rod 82 comes to grip the rod 70, separates it from the hub support 6 disposed on the axis 12 and the entire transfer device is withdrawn back so as to be able to pass over the wafer 21 being unwound on the axis 13, then comes to be positioned opposite the buffer axis 16 in order to fix the hub therein in the manner described, then the balance of the wafer as well as the center 23 are extracted from the hub 5 by the gripping fingers 80 and brought towards the axis 15, which comprises a device for transporting empty centers 23 with an endless belt and which is responsible for eliminating the empty centers from the machine.

This operation being carried out, we find ourselves at the beginning of the cycle and it is possible to repeat the various operations described.

Another possible operation of the transfer device consists in using it to load the stock of full pancakes 22 on the axis 14; in fact, given the size of the various elements of the machine, this axis cannot generally be directly accessible. This operation can only be done when the machine is stopped. For this, a hub 5 being arranged on any of the accessible axes, preferably the buffer axis 16, a wafer is placed manually on this hub, then the transfer device is controlled in order to come to grip only the wafer and its center, by the grip fingers 80, and to bring it in front of the storage axis 14 to deposit it there.

The wafer transfer device during unwinding described above represents a preferred preferred embodiment; it is obvious that various variants can be envisaged concerning in particular the mechanical devices described. For example, one or more of the actuators of movement by jack can be replaced by commands of movement by electromagnet or by any other suitable device. Likewise, the movements along the X, Y and Z axes can be carried out by elements different from those described here. It is the same for the transfer method which can be different from that described, depending on the constitution of the transfer device.

Various devices not shown in the figures complement the transfer device according to the invention; in particular, an electronic control allows the automation of the various stages of operation of the device; detectors are responsible for monitoring the filling state of the wafers during dispensing, 20, respectively 21, other limit switches enslave all of the movements described so that the electronic control always knows the exact position of the various components of the transfer device, and a wafer advance device is provided on the stock so that the wafer to be grasped is always in the same plane.

Claims (22)

Method for transferring a reel or a wafer during unwinding (21), between a first unwinding axis (13) and a second unwinding axis (12) of a machine (1), while said wafer remains in a constant plane of rotation during said transfer, characterized in that said transfer takes place by means of a transfer device (3) moving in space and capable of coming to grip a hub (5) of said wafer in rotation, to separate said hub from said first unwinding axis, to transfer said hub and the wafer in rotation to said second unwinding axis and to fix the hub to said second unwinding axis. Transfer method according to claim 1, characterized in that a part (7) of said wafer hub is gripped by a part (82, 88) of said transfer device and is then withdrawn from a support portion (6) of the machine in a direction perpendicular to said plane of rotation of the wafer. Transfer method according to claim 2, characterized in that during the transfer of the wafer from said first reel axis to said second reel axis, said wafer is braked. Method according to one of the preceding claims, characterized in that it applies to a machine for unwinding a strip of cigarette paper. Transfer device for carrying out the method according to claim 2 or 4, characterized in that it comprises on the one hand: - A first means of movement in a first direction, which may consist of a horizontal beam (33) driven in a translational movement by means of at least one endless screw (30) and a nut device (34 ), a second means of displacement in a second direction perpendicular to said first direction, which may consist of an intermediate support (35), fixed to said horizontal beam by means of a motorized slide (36), a third means of displacement in a third direction perpendicular to said first and second directions, which may consist of a mobile support (37), fixed to said intermediate support by means of a motorized slide (38), a retractable socket (81) which can take two positions in a direction parallel to said third direction, relative to said movable support, - a gripping rod (82) which can take two positions in a direction parallel to said third direction, with respect to said retractable socket; on the other hand: - a plurality of hub support devices (6), arranged on a plurality of axes of the machine (12,13,16),
as well as: - a wafer hub device (5), capable of supporting a rotating wafer and comprising a part (7) which can slide axially in said third direction. Device according to claim 5, for carrying out the method according to one of claims 3 or 4, characterized in that it further comprises a braking device (4) accompanying the wafer transfer course. Device according to claim 5, characterized in that it further comprises a plurality of gripping fingers (80), fixed relative to said movable support, each of said fingers comprising a retractable pin (85) capable of projecting radially, in order to grip a wafer center (23). Device according to claim 5, characterized in that it further comprises an automatic process control device. Device according to claim 5, characterized in that said retractable bush comprises displacement means in said third direction, said displacement means being able to consist of a hydraulic or pneumatic jack (94) whose body is integral with said movable support while the piston is integral with said retractable socket, or in an electromagnet. Device according to claim 5, characterized in that said gripping rod comprises displacement means in said third direction, said displacement means being able to consist of a hydraulic or pneumatic jack (96) whose body is integral with said retractable bushing while the piston is integral with said gripping rod, or in an electromagnet. Device according to claim 10, characterized in that said gripping rod comprises a plurality of balls (88), arranged on a circumference close to the front end of said rod gripping, in radially arranged bores, said balls being able to project out of said gripping rod under the action of a rod finished in a point shape (87), moved by actuating means which can consist of a hydraulic cylinder or tire (98), the body of which is fixed to the rear part of said gripping rod and the piston of which actuates said rod, which ends in a point shape. Device according to claim 5, characterized in that the machine comprises in particular a first reel axis (13), a second reel axis (12), a buffer axis (16), a storage axis (15) and an axis elimination of wafer centers (14). Device according to claims 5 and 12, characterized in that said first axis and second reel axis as well as the buffer axis of the machine are each provided with a hub support consisting of a flanged sleeve (61) projecting and fixed to the face of the machine, a hollow cylindrical casing (60) fixed to the rear part of said collar sleeve, of a bell-shaped part (62), coaxial and inside said casing cylindrical and comprising an inner surface portion in the form of a truncated cone (66), said bell-shaped part being moved in a forward or backward movement by means of actuation means which may consist of a piston d '' a hydraulic or pneumatic cylinder (63) whose body is fixed to the rear of said hollow cylindrical casing, a plurality of balls (64), arranged in a cage along a periphery of a longitudinal bore (65) coaxial with the collar socket head, and to the bell-shaped part, and which can assume two positions radially under the action of said portion of surface in a truncated cone. Wafer hub (5) according to claim 5, characterized in that it comprises a part (50), comprising empty spaces, mounted on a central sleeve (55) by means of ball bearings (54), said central bush comprising a bore (56A, 56B) in which a rod (70) can move longitudinally, a first end (73) of said rod comprising a groove (74) along a perimeter, intended to receive the balls arranged under the portion of the truncated cone surface of the bell-shaped part when said first rod end is introduced into said longitudinal bore of said hub support, the other end (72) of said rod comprising a blind bore (75), coaxial, comprising a groove (76) along a perimeter, intended to receive the balls arranged near the end of the gripping rod when said gripping rod is introduced into said blind bore. Wafer hub according to claim 14, characterized in that the perimeter portions of the part comprising empty spaces have a radial bore containing a portion of pointed rod (51) pushed radially outward by a spring (52) disposed at the bottom of said bore. Wafer hub according to one of claims 14 or 15, characterized in that it comprises an unbalance (59) intended to stabilize said hub when stationary according to a determined angular position. Wafer hub according to claims 7 and 16, characterized in that said spaces empty can receive said gripping fingers (80) of said movable support. Wafer hub according to claim 17, characterized in that said empty spaces consist of spaces located between the planar faces of a part (50) of generally triangular shape and the inner perimeter of a wafer center. Braking device according to claim 6, characterized in that it consists of a lever (41), one end of which pivots about a first axis (42) parallel to said third direction, a first toothed wheel (40), braked in rotation, pivoting about a second axis disposed on the other end of said lever and parallel to said first axis, said first toothed wheel being continuously meshed with a second toothed wheel (53) disposed on the wafer support hub during the transfer of said hub between said first reel position to said second reel position, and a third toothed wheel (43), braked in rotation, pivoting around a third axis, parallel to the previous axes and meshing on said second gear when the wafer hub has been transferred to said second unwinding position. Automatic control device according to claim 8, characterized in that it is capable of: - controlling the movement of said transfer device along three coordinate axes, from a standby position, so as to bring it in front of a wafer support hub rotating around a first axis of the machine, - order the advance of a grip rod and its attachment to one end of a rod of said hub, - order the separation of the other end of said rod from said hub from its hub support, - order the withdrawal of said gripping rod by driving said rod from said hub, - controlling the movement of said hub disposed on said transfer device in two directions forming part of the plane of rotation of the wafer in order to bring it in front of a second axis of the machine, - controlling the advance of the gripping rod in order to push said other end of the hub rod into a bore arranged in a hub support on said second reel axis, - order the fixing of said other rod end in said hub support, - controlling the separation of said gripping rod from said hub rod, - order the withdrawal of the gripping rod and the movement of the transfer device towards a waiting position. Automatic control device according to claim 20, characterized in that it is also able to: - controlling the movement of said transfer device along three coordinate axes, from a standby position, so as to bring it in front of a wafer support hub disposed on an axis of the machine, - control the advance of gripping fingers in empty spaces arranged between a portion of the hub and the center of the wafer, - order the protrusion of pins arranged on said gripping fingers in order to grasp the center of the cake, - order the removal of said gripping fingers so to remove said wafer center from the hub, - controlling the movement of said transfer device towards an axis of elimination of the centers, or an axis of storage, control the advance of said gripping fingers in order to deposit the wafer center on said elimination axis, respectively on said storage axis, - command the retraction of said pins in order to release the wafer center, - order the removal of said gripping fingers, - Control the movement of said transfer device to a waiting position. Automatic control device according to claim 21, characterized in that it is also capable of: - controlling the movement of said transfer device along three coordinate axes, from a standby position, so as to bring it in front of a wafer arranged on a storage axis of the machine, - order the advance of gripping fingers under the center of the cake, - order the protrusion of pins arranged on said gripping fingers in order to grasp the center of the cake, - order the withdrawal of said gripping fingers in order to remove said wafer from the storage axis, - controlling the movement of said transfer device towards a wafer hub arranged on an axis of the machine, - controlling the advance of said gripping fingers in order to deposit the wafer on said hub, - command the retraction of said pins in order to release the wafer center, - order the removal of said gripping fingers, - Control the movement of said transfer device to a waiting position.

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