EP0742170B1 - Device for feeding a web in a station working on it in a stopped condition, the web being fed in a continuous manner - Google Patents

Abstract

The feeder consists of a first drive roller (10) and a satellite roller (20) which can oscillate about it between upper and rear positions on side levers (52, 53, 55) On the drive roller's shaft. The driving pinion (29) of the satellite roller (20) meshes with a toothed gear (14) of the same diameter fixed to the drive roller shaft. The feeder is equipped with a counterweight (80) which is rotated by the toothed gear (14) and is mounted on an arm (70) which pivots about the drive roller shaft (12) and is connected by a mechanism (54, 60, 61, 62, 65) to the side levers (52, 53), enabling it to oscillate in the opposite direction to the satellite roller. The counterweight is driven by a pinion (76) of the same diameter as gear (14), and has moments of inertia relative to its axis of rotation and to the axis of arm (70).

Description

The present invention relates, within a machine comprising several successive workstations, with one device feeding a strip of material into a station working on it stopping, this strip running in the machine continuously. Such a stationary workstation can be a platen printing press or cutting.

As the platen press is a machine station which requires a temporary stop of the tape running during the operation printing or cutting it occurs, due to the power continuous, an accumulation of tape in the form of an upstream mouth. The function of the feeding device is to create cyclically and permanently check this mouth which lengthens during the stop due to work of the platen press, and which shortens as soon as the supply to the press resumes for the subsequent operation, these operations are scrolling cyclically. Such a feeding device is necessary because that a floating mouth causes from a certain speed of scrolling of the strip of positioning faults of this strip in the hurry. To this end, several feeding devices have already been designed.

Document US 4,060,187 describes a supply device comprising two lateral circular plates mounted facing each other side walls of the frame, and this in rotation along a first axis. A cylinder through which the strip of material is mounted between the two plates according to a second axis of rotation eccentric with respect to the first, the rotation plates cyclically lowering the cylinder, therefore the strip, to form a mouth according to a pseudo-sinusoidal function. Counterweights diametrically opposite the cylinder are also mounted on the discs. Since the time to stop at the maximum of the mouth is relatively short, it is expected, at this level, an early and then late correction of the position angular bearings holding the cylinder in the turntables, which extend this deadline. A screw device makes it possible to modify the eccentricity of the cylinder and counterweights, so the length of the loop, depending on the cutting or printing format.

Operating to satisfaction, it turns out, however, that the complexity eccentricity adjustment and position correction devices angular at the low point, implying the presence of many parts heavy, prevents increasing the feed rate of the tape above a certain value. Indeed, a simple reinforcement of each of the parts, thereby increasing their inertness, is no longer sufficient to hold the accelerations in play, and there appear vibrational phenomena harmful to the precision of the location of the strip in the platen press.

In addition, the slight initial variations in tension in the belt, induced by this type of feeding device are also amplified during an acceleration of the cadence, which also alters the precision of the location.

In addition, the speed of movement of the cylinder being variable, in particular by its position correction at the low point, the engine torque necessary to set in motion this feeding device is not regular, and this irregularity increases with cadence. It is then impossible to use high-performance "brushless" electric motors. Finally, this complex device is very expensive to produce.

Another type of feeding device comprises a first drive roller, also called "roll call" or "drive sensitive ", around which a second satellite roll mounted around two lateral levers pivoting on the axis of this drive roller: first towards upstream to temporarily increase the path of the strip, which stops the portion of tape under the downstream stage, then downstream to introduce very quickly the next portion in the deck.

To coordinate the rotational speeds of these two rollers, and thus avoid any sliding of the strip, the pinion for driving the roller satellite is meshed with a gear of equal size secured to the axis of the drive roller. This absence of sliding avoids altering printing in the case of a printed strip which is in contact with the satellite roll by its printed side, and it keeps the relative positioning of the strip in the platen press relative to the other stations upstream.

The document "Ingenious Mechanisms" published in 1969 by Industrial Press Inc. describes in paragraph 14 a device for feeding this type in which the satellite roll located under the band and above the drive roller oscillates substantially in a horizontal plane to form a loop developing backwards. The tension in the tape is maintained by a second pair of drive and satellite rollers located downstream of the platen press, and oscillating in synchronism thanks to a common lower zipper. However, requiring a double pair of rollers and a complex mechanism of simultaneous drive, this device was quickly abandoned as soon as we wanted to increase the pace.

EP-A 0 305 230, which corresponds to the preamble of claim 1, describes another device of this type in which the satellite roller located downstream and above the band oscillates in an oblique plane oriented downwards under the drive cylinder to form a loop developing downward. The tension in the tape is held at the entrance to the platen press by means of a "sliding" cylinder, that is to say a cylinder rotating at high speed and against which the strip is maintained by suction due to radial conduits bringing communication the external surface and an internal box placed under vacuum more or less strong, and whose extent corresponds to the contact surface.

However, this rotary vacuum cylinder is not very reliable at high speed and its maintenance is delicate. In addition, in this device the strip is delivered to itself over a long distance between the oscillating roller and the sliding cylinder, distance over which can appear significant fluctuations as we increase the cadence.

Above all, there is a significant variation in the engine torque necessary for the general training of this type of feeding device when the pinion of the satellite roller rolls in one direction then in the other the along the toothed wheel secured to the axis of the drive roller. This variation also excludes, a priori, the use of electric motors efficient but at constant torque.

In addition, the cyclic launch of the satellite roll upstream, whether from below or from above to stop the strip downstream, induces forward constraint in the frame, followed immediately after by a backward constraint when the satellite roller returns to its position initial. These alternative constraints in the horizontal plane, increasing very quickly with cadence, generate vibrations directly detrimental to the correct location of the strip in the plate, and cause premature fatigue of parts, especially bearings.

The object of the present invention is a supply device of a band in a station working it at a standstill, this band arriving from upstream stations continuously, which is able to support a high rate, for example greater than 350 cycles per minute, while ensuring high precision of the belt stop position in the platinum, of the order of 1 / 10th of a millimeter. In particular, the structure and the arrangement of the constituent parts of this device must be relatively simple to reduce production costs accordingly and allow the vibrations in the vertical plane and the band flutter.

These goals are achieved by a device as described in claim 1 and including especially a first drive roller around which oscillates upstream then downstream a second satellite roller mounted on two lateral levers pivoting on the axis of this drive roller, the drive pinion of the satellite roller being meshed with a gear of equal diameter secured to the axis of the roller drive (wheel along which the pinion rolls during oscillations satellite roller), because it further comprises a counterweight driven in rotation from the gear of the axis, this counterweight being mounted on a arm pivoting around the axis and connected by a mechanism to the levers for oscillate in the opposite direction of the satellite roller.

Preferably, the counterweight pinion has a diameter identical to that of the gear wheel of the axle with which it is also meshed; the counterweight presenting moments of inertia with respect to its axis of central rotation and relative to the axis of the arm identical to those of satellite roll.

Advantageously, one of the levers holding the satellite roller has a toothed segment in the form of a circular sector centered on the axis of the drive roller, and meshed with a first integral toothed wheel an axis of return parallel to this axis of the drive roller, a second toothed wheel secured to the return axle being meshed with a wheel inverter itself geared to a circular toothed sector of the arm swivel carrying the counterweight. This relatively simple mechanism allows to give the arm and the counterweight an oscillation exactly in the right direction reverse levers and satellite roller.

Preferably, the satellite roll is located above the roll and oscillates in a substantially horizontal plane to optimize the potential length of the stopped tape. The band then goes below of the drive roller and exits above the satellite roller.

So, as seen "driver side" (Figure 1), that is to say from on the left lateral side with respect to the direction of travel of the strip, the drive roller rotates clockwise and the satellite roller rotates in the opposite direction. When the satellite roll is pulled upstream, its pinion rolls clockwise along the spur gear, momentarily decreasing the torque consumed. Conversely, the counterweight pinion, also rotating in counterclockwise also rolls clockwise counterclockwise along the gear wheel, which increases momentarily its consumed drive torque compensating for the loss from the satellite roll. The drive torque consumed at the entrance to the device is then practically constant.

According to a preferred embodiment, the counterweight oscillates in the same horizontal plane as the satellite roll, which moreover achieves a compensation of the upstream / downstream constraints of the device on the frame.

In other words, the unusual addition of a rotating counterweight to the end of a swinging arm, this assembly simulating a second roller satellite moving in opposite direction, allows to reuse the combination a drive roller and a satellite roller to form a loop, but at much higher rates. An advantage retained by this device according to the invention is that the law of advancement of the strip includes an acceleration phase in which the value and the variation acceleration are controlled, in particular so that at start of the tape, which is a critical phase since it is necessary to ensure the detachment of the belt from the platen press tool, this acceleration and its variation have a low value, and that the acceleration then increases gradually.

According to a first embodiment of a supply device for the strip from the satellite roller to the workstation, a pressure roller, or a plurality of pressure rollers, is installed from the axis of the roller satellite through elastic means to press the strip of material against the satellite roller with a predetermined pressure, and this close to the start line of the strip out of this satellite roll. These measures ensures an effective pushing of the belt during the feeding of the press to plate on the occasion of the narrowing of the loop by movement downstream from the satellite roll.

Usefully, the device also includes a telescopic shelf guiding the strip between the exit of the oscillating satellite roll and the entry of the station working the stationary band, this tablet comprising a pair of quasi-stationary horizontal downstream combs located one above the other and fixed, in rotation, to the entrance to the workstation, and a pair of combs upstream and downward oscillating horizontal located at the exit of the roller satellite (ie at the level of the upper generator) and fixed in rotation around the axis of this satellite roll; the upper oscillating combs and lower being respectively held in sliding, for example by rails or slides, in line with stationary downstream combs with their teeth offset laterally.

According to a first variant of the tablet, the downstream combs are held respectively by an upper cross member and a lower cross member integral with a pair of side rails whose downstream ends are mounted rotating near the entrance to the workstation, and whose ends upstream are engaged in external rollers mounted on two plates side pivoting on the axis of the satellite roller. The upstream combs are then held by a vertical pair of solid or tubular sleepers secured to the side plates.

Advantageously then, the pressure roller is mounted on two horizontal side levers articulated respectively on each plate lateral oscillating, one or a pair of vertical lateral cylinders mounted also against the plates exerting a pressure force on the levers predetermined.

According to another variant of the tablet, the combs are confined in two half-caissons: one quasi-stationary attached to the entrance to the work station and the other oscillating connected in rotation to the axis of the satellite roller that it encompasses, the teeth of the lower combs being supported individually by vertical plates emerging orthogonally from caisson bottoms, the teeth of the upper combs being supported by vertical plates or tubes descending from the ceilings, the interpenetration of these plates or tubes forming longitudinal flow chambers of the air emerging, at the bottom of each respective box, in rooms transverse with side windows.

In this variant, the air flows generated by the displacements intermittent band and combs are channeled in a plane horizontal to prevent the strip from being pressed against friction upper or lower combs.

According to a second embodiment of a supply device for the strip from the satellite roll to the workstation, this second mode coming as an alternative or in addition to the first embodiment, a vertical pair of towing rollers is mounted near the entrance to the next stationary work station, such as a platen press, (or at the outlet of the telescopic shelf) to supply the belt with the correct tension in this station.

A device for driving one of the towing rollers particularly well associated with the supply device described previously includes a belt passing through a pulley secured to the tractor rollers as well as by two discs located respectively on each of the two branches of a vertical lever mounted free to rotate on the axis of the drive roller; the upper disc being integral with the axis of transmission from the satellite roller, which transmission axis crosses the upper arm of the lever and prints the roller oscillation on it satellite; the lower disc, of diameter identical to that of the upper disc, being held by the lower arm of the lever so as to have a position symmetrical to the upper disc with respect to a line connecting the axis of the tractor roller and the axis of rotation of the lever when it is in middle position of oscillation.

As can be easily understood, if the diameter of the disc upper is also identical to that of the satellite roller, then, this device to lift and oscillating discs gives the belt a movement of advance intermittent whose speed is strictly identical to that of the belt of paper. If the diameters of the pulley and the tractor roller are extra identical, then this roller pulls the tape at exactly the same speed, therefore with an always constant tension pre-established. Alternatively, the diameter of the disc may be different from that of the satellite roller provided that the diameters of the pulleys and tractor roller have proportionally the same difference.

If the gap between the axis of the drive roller and the axis of the roller satellite is important then the belt winding arc around the pulley of the tractor roller may be too weak to transmit a intermittent movement at high speed and under heavy load. The device drive is then completed, at this pulley of the roller tractor, by a rear return pulley and a return pulley, the symmetry between the discs and between the roller pulley and the deflection pulley being made in relation to the line connecting the axis of the rear pulley and the axis of lever rotation.

• la figure 1 est une vue schématique du côté conducteur d'un dispositif d'alimentation selon l'invention,
• la figure 2 est une vue schématique en coupe transversale du dispositif d'alimentation,
• la figure 3 est une vue schématique en perspective du dispositif d'alimentation, tel que vu du côté opposé du conducteur,
• la figure 4 est une vue schématique en perspective de deux demi-caissons enveloppant une table télescopique de guidage,
• la figure 5 est une vue schématique en coupe selon le plan V - V de la figure 4 pour une table télescopique assemblée, et
• la figure 6 est une vue schématique du côté conducteur d'un dispositif d'entraínement de rouleau tracteur associé au dispositif d'alimentation selon l'invention,

   figures dans lesquelles une pièce donnée du dispositif est toujours désignée par la même référence.The invention will be better understood from the study of an embodiment taken without any limitation being implied and illustrated in the appended figures in which:

• FIG. 1 is a schematic view of the driver side of a supply device according to the invention,
• FIG. 2 is a schematic cross-sectional view of the supply device,
• FIG. 3 is a schematic perspective view of the supply device, as seen from the opposite side of the conductor,
• FIG. 4 is a schematic perspective view of two half-boxes enclosing a telescopic guide table,
• FIG. 5 is a schematic sectional view along the plane V - V of FIG. 4 for an assembled telescopic table, and
• FIG. 6 is a diagrammatic view from the driver's side of a tractor roller driving device associated with the feeding device according to the invention,

figures in which a given part of the device is always designated by the same reference.

As illustrated in Figure 1, the feeder sequential of a band 3 in a station 1 working it at standstill, such than a platen press, this strip arriving upstream continuously, mainly comprises a drive roller 10, arranged transversely to the direction of travel of the strip, and above which a satellite roller 20 oscillates, parallel to the roller drive 10, this satellite roller oscillating from upstream to downstream between the positions 20 and 20 'substantially in a horizontal plane. In this case, the moving strip 3, guided by feed rollers 5 and 5 'pass in below the drive roller 10, performs there between a half and three-quarters of a turn up before going over the roller satellite 20 whose output is located at the tools of the platen press 1. In this way, the upstream movement of the satellite roll of the position 20 'to 20 (to the right of Figure 1) momentarily extends the last loop of the strip, which then stops the portion located in the platen press 1.

Referring to Figures 2 and 3, the central axis 12 of the roller drive 10 is held by bearings in the right side walls 7, central 8 and left 9 of the frame, the walls 7 and 8 close together forming a bathtub. This drive roller 10 is driven by a motor-reducer 18 illustrated schematically on the wall 7 directly in the extension of the axis 12. A main toothed wheel 14 is integral with this drive axis 12.

The central axis of rotation 27 of the satellite roller 20 is, for its part, held by bearings 28 in the upper end of two levers 55, 52/53 both mounted in rotation through bearings on the roller axis 12 training. The lower branches 53 of these levers are united rigidly by a low inertia cylinder-cross 56. The end of the axis 27 satellite roller 20 is integral with a pinion 29 meshed with the wheel main gear 14. More particularly, this pinion 29 and gear 14 have an identical diameter, so that the average speeds of rotation of the drive rollers 10 and satellite roller 20 are strictly identical.

A beautiful 50 hung by means of a bearing on the axis 27 of the satellite roller 20 makes it possible to pull the latter cyclically from upstream to downstream, the parallelism of the roller 20 relative to the roller 10 being maintained by to the cylinder crosses 56.

As is, this sequential feeder consumes a engine drive torque jerky and generates many vibrations making it unusable at high speed. For this, the device according to the invention further comprises a counterweight 80 in the form of a cylindrical mass mounted in rotation around an axis 74 mounted through a bearing at the upper end of a swing arm 70 rotating itself, through a bearing 71, around the axis 12 of the drive roller 10. The axis 74 is also integral with a counterweight pinion 76 meshed with the wheel main gear 14. The diameter of the pinion 76 is equal to that of this wheel main gear 14 so that the average speed of rotation of the counterweight 80 is identical to that of the satellite roller 20.

Furthermore, and as always illustrated in Figures 2 and 3, the axis of rotation of the lever 52/53 consists of a cylinder 51 on the one hand held in the central wall 8 by an external bearing and on the other hand holding, also at means of bearings, the through axis 12 for driving the roller 10. This cylinder 51 is completed at its outer end, that is to say between the walls 7 and 8 of the frame constituting a bathtub, by a toothed segment 54 in shape of circular sector centered on the axis of rotation 12 of the roller 10. This toothed segment 54 is meshed with a first return wheel 61 secured to a return axle 60 held at each end by bearings in the walls of the bath 7, 8. A second wheel of return 62 secured to the return axis 60 meshes with an inverting wheel 65 whose axis of rotation, not illustrated, is also held at each end by bearings in the walls 7 and 8 of the bath. This reversing wheel 65 is also meshed with a toothed sector 67 of the arm 70, this sector 67 being centered on the bearing 71 of the arm. This mechanical transmission prints on the arm 70 an oscillation in rotation in the opposite direction levers 55, 52/53.

Referring to Figure 3 illustrating the device on the opposite side conductor, the drive roller 10 of the strip 3 and the wheel main gear 14 rotate counterclockwise while the satellite roller 20 driven by its toothed pinion 29 rotates in clockwise. Likewise, the cylindrical counterweight 80 driven by its pinion 76 also rotates clockwise watch.

If the connecting rod 50 is pulled upstream, that is to the left of the Figure 3, the pinion 29 momentarily rolls in the opposite direction clockwise along the main gear 14, which causes, during this movement, a fall in the drive torque consumed by this satellite roller 20. However, simultaneously, the arm rotary 70, driven by mechanism 54, 60-65, rotates in the direction of clockwise, which causes rolling in the same direction pinion 76 along the main gear 14, which increases momentarily the drive torque consumed by this counterweight 80. As soon as this counterweight 80 is dimensioned so that its moment of inertia with respect to its center of rotation and with respect to axis 12 of the drive roller 10 is identical to the moment of inertia corresponding to the satellite roller 20, compensation is obtained for momentary variations in torque causing the load on the gear motor 18 on axis 12, admittedly important, is rigorously constant, which allows the use of particularly efficient electric motors of the type "brushless".

Likewise, since it is possible to size the mass and the inert of the counterweight 80 independently, the counterweight is going to be dimensioned in mass so as to counterbalance the effect of the mass of the satellite system, and this in a horizontal plane and for the part close to the frame 8.

In addition, the traction of the connecting rod 50 on the axis 27 of the satellite roller 20 is reflected at the level of the rotation cylinder 51 in the central wall of frame 8, and similarly, at the side wall 9. However, the evolution of this tensile force is compensated by the tilting simultaneous forward of counterweight 80 in the same horizontal plane as that of the movement of the satellite roller 20. A similar attenuation occurs develops when the satellite roll returns downstream.

In order to ensure a rigorously exact positioning of the strip in the workstation, it is important that the position of it is also permanently maintained correctly throughout the feeding device, and more particularly on the path between the satellite roll 20 and the entrance to station 1 when the delay loop shrinks with the introduction of a new portion of band in this station.

To this end, and according to a first embodiment of a device the satellite roll tape to the work station better visible in Figure 1, there is provided a pressure roller 30 acting at the outlet of the satellite roller 20 in order to effectively push the band forward during a feeding sequence, and, in combination, a double shelf telescopic guide consisting of upper and lower combs downstream quasi-stationary 44 between which a pair of combs oscillates upper and lower moving parts 45.

As best seen in Figures 1 and 2, two side plates 21 are mounted in rotation about the axis 27 of the satellite roller 20. These plates are engaged by rollers 23 in guide rails 24 mobile in rotation 25 at their downstream end, i.e. close to the press with plate 1. On the internal face of each plate is mounted a lever horizontal 32 whose upstream end is held by an axis of rotation then that the downstream end is held by a remote-controlled cylinder, the pressure roller being rotatably mounted on these two levers. So we can adjust by means cylinders 34 the pressure force of the roller 30 against the satellite roller 20.

Above all, the side plates 21 guided by the rails 24 keep the combs by means of two cross tubes 22 upper and lower oscillating downstream 45 in the extension of the combs stationary 44 held in turn by cross tubes 42 fixed to these same rails 24. Thus, when the satellite roller 20 rolls around the drive roller 10, the side plates 21 always remain correctly aligned along the rails 24, and the same is true for the combs constituting a double guide shelf for the paper strip running at very high speed when introduced into the platen press 1. Thus guided, the strip 3 remains flat and keeps its register.

Figures 4 and 5 illustrate an alternative of the first embodiment in which the combs constituting the double telescopic shelf are confined in two half-boxes:
a quasi-stationary 78 downstream connected by a fastener 97 in rotation at a fixed point close to the entrance to the station, or directly to the lower plate if its stroke is short; and an oscillating 79 with the satellite roller 20 which it encompasses and to the axis of which it is connected in rotation, these two half-boxes being connected to each other by longitudinal sliding rails not shown.

The downstream half-box 78 has a significant primary ceiling 84 connected at its downstream end to two small side walls 93 of length between a quarter and a fifth of the length of the ceiling, walls themselves connected to a secondary bottom 83 of length between a third and a quarter of the length of the ceiling.

From the underside of the ceiling 84 descend a plurality of longitudinal vertical metal plates 87, each supporting a tooth downstream upper comb 47 in the form of a sheet longitudinal horizontal. Teeth 47 start from the bottom edge of a vertical transverse upper end half-wall, the edge of which upper is connected to the ceiling 84, and terminate substantially in the middle of the ceiling. On the other hand, the vertical plates 87 only start from a certain distance from the transverse half-wall, for example equivalent to a tenth of the length of the ceiling, to create a transverse chamber upper 96 'opening on both sides on side windows upper 94 formed in the side walls. These plates end at the level of the teeth, possibly by an oblique vertical edge.

From the upper face of the bottom also emerge a plurality of longitudinal vertical metal plates 89, each carrying a tooth downstream comb comb 49 in the form of a horizontal sheet longitudinal, the lower teeth 49 being of the same spacing as the upper teeth, but laterally offset by half a spacing. Of similar to the top, these teeth start from the top edge of a transverse vertical half-wall of lower end, the edge of which lower is connected to the corresponding edge of the secondary bottom 83; and this end little behind the upper teeth. The vertical plates do not also start only from a certain distance from the half-wall transverse to create a lower transverse chamber 96 opening on both sides on lower side windows 95 with side walls 93.

In addition, the upstream half-box 78 has a substantial bottom primary 82, if desired partially glazed, connected, at the level of the satellite roller 20, with two side walls 90 oblique upstream except for an advanced triangular downstream, walls themselves connected to a secondary ceiling 85 having a series of longitudinal grooves corresponding to the vertical upper plates 87 of the downstream half-box 78. The faces upper of the primary bottom 82 and secondary ceiling 85 of the half-box upstream 79 are at height with the lower faces respectively of the bottom secondary 83 and primary ceiling 84 of the downstream half-box 78, faces of contact where sliding support rails can be installed.

From the underside of the ceiling 85 descend a plurality of tubular structures 86 whose lower horizontal faces constitute the teeth 46 of the upper upstream comb. The upstream ends of the faces lower / teeth are connected together by an intermediate plate 77 horizontal transverse whose upstream edge joins a vertical half-wall transverse upper end, half-wall whose upper edge is connected to secondary ceiling 85. The upstream ends of the structures however stop before this transverse end half-wall in order to create a transverse chamber 92 opening on either side on side windows 92.

The primary bottom 82 ends upstream, at the roller satellite 20, in an oblique plate held by the side walls 90, plate oblique from which triangular ribs 88 support the teeth lower upstream comb 48. These teeth are here in the form of sheets longitudinal horizontal laterally between two structures upper tubulars 86.

Furthermore, in each of the tubular structures 86 and at level of this intermediate horizontal plate 77 is installed one of a series of pressure rollers 31, corresponding to pressure roller 30 of the figure 1, permanently keeping the strip pressed against the roller satellite 20.

In Figure 5 illustrating, in section, the nesting of the two half-caissons, the parts of the upstream half-caisson are hatched in lines fine while the parts of the downstream half-box are hatched in bold lines. As can easily be seen, the lower teeth 48 and 49 are finding side by side first constitute a lower shelf surmounted an upper shelf consisting of upper teeth 46 and 47 also side by side, these shelves being separated by a small height h defining the imposed passage of the strip. This spacing h is found also between the upper end transverse half-walls and bottom of the downstream half-box 78.

Above all, the lower plates 88 and 89 create chambers 99 horizontal longitudinal lower telescopic, while the plates 87 associated with tubular structures 86 create chambers horizontal longitudinal upper 98 also telescopic. These chambers impose on the ambient air stirred by the oscillating movement of the semi-box 79 of the horizontal flows reaching the transverse chambers upstream 91 and downstream 96 where these flows enter and exit laterally always at the horizontal. Vertical air flows likely to flatten so harmful band against upper or lower shelf are so practically annihilated in this alternative of the first embodiment.

According to a second embodiment of a supply device for the strip from the satellite roll to the workstation illustrated in the figure 6, maintaining the correct position of the strip is only ensured by a pair of tractor rollers 40, 41 intermittently driven by so that their peripheral speed is practically identical to the intermittent belt speed, allowing continuous application a constant slight pull on this strip 3 leaving the satellite roll.

Intermittent lower roller drive could be carried out by means of an electric motor modulated in speed. However, at the envisaged rates, the piloting of such an engine would be delicate, would pass necessarily by a slightly higher speed setpoint involving a variable slip likely to damage the surface of the bandaged. Intermittent mechanical drive based on cams could also be considered. However, such a mechanism would also prove to be difficult, bulky and expensive. In addition, it would induce strong modulation in the general drive torque of the machine, which is precisely the reverse of the aims sought. Preferably within the framework of the invention, uses the drive of the satellite roller to carry out a drive secondary differential of the tractor roller 40 as illustrated in FIG. 6, and partially on the left side of Figure 2.

This drive first comprises a bent vertical lever 33 located on the external face of the wall 9 on the driver side and mounted free in rotation on an extension of the axis 12 of the roller drive 10. The end of the upper branch substantially vertical of the lever is crossed by an extension of the axis 27 drive of the satellite roller giving this lever its movement oscillation. A first upper disc 35 is mounted at the end of this axis 27, either at the end of this upper branch of the lever 33, and is therefore rotated at the same angular speed as the roller satellite. The end of the lower branch oblique downstream of the lever 33 carries a second lower disc 36 whose diameter is identical to the disc superior.

This training then includes a training hen 37 integral with the end of the axis of the tractor roller 40 and located on the face external of the wall 9 in the same vertical plane containing the disks 35 and 36 thus allowing the installation of an endless belt 59 passing around these discs and pulley. In order to be able to ensure a sufficient winding arc belt 59 around pulley 37, a pulley is also provided rear 38 and a return pulley 39 from the belt to the lower disc 36.

As can be seen in Figure 6, the angle of the lever 33 and the layout of the chicken 39 are such that the path of the belt 59 has symmetry with respect to the line (x) connecting the axis of rotation 12 of the lever and axis of rotation of the rear pulley 38 when the upper branch of the lever 33 is vertical, ie in the middle position of oscillation. So, when the satellite roller and the upper disc 35 are pulled back towards position a1, the increase in the upper horizontal path of the belt 59 is compensated by a decrease of equal value of the path path between the return pulley 39 and the lower disc 36 having advanced in its position a1. A reverse effect appears when advancing the disc 35 towards position a2 causing the lower disc 36 to recede. Thanks to this layout, the length of the path remains practically constant, the minimal variations being absorbed without further by the elasticity of the belt.

Assuming at first that the diameter of the disc 35 is equal to that of the satellite roller 20 to which it is directly connected, and that the diameter of the hen 37 is equal to that of the tractor roller 40 at which it is also directly linked, we can see that the speed and intermittent acceleration of movement of the belt 59 between the disc 35 and the pulley 37 is strictly identical to that of the band 3, and it the same is true for the peripheral speed of the tractor roller 40. This roller 40 therefore effectively pulls the tape at the right time, and this under a constant voltage preset. In practice, the diameter of the disc 35 can be different from that of roller 20 as long as it is the same between the pulley 37 and roller 40.

It should be noted that the counterweight 80 will then be resized to also balance the additional inertias of the rollers 40, 41, etc. (see figure 6).

If this second embodiment of feeding the strip in workstation 1 appears lighter therefore less inert than the first using pressure rollers and telescopic table, we can obviously combine to perfect control of this band.

It should be noted that the tube 10 can be replaced by the extension of axis 60 to frame 9 and addition of an arrangement pinion / toothed segment analogous to the figures 61/54 on the lever 55, the tube 10 and the extended axis 60 each having specific advantages in the convenient.

Claims (12)

1. Device for supplying a web (3) to a station where it is stopped and processed, this device comprising a first drive roller (10) around which a second swivel roller (20) oscillates upstream and then downstream, the second roller (20) being mounted on two side levers (52 - 53, 55) pivoting on the shaft (12) of this drive roller, the driving pinion (29) of the swivel roller (20) engaging a toothed wheel (14) of equal diameter secured to the shaft (12) of the drive roller, characterized by the fact that the device also comprises a counterweight (80) driven in rotation by the toothed wheel (14) on the shaft (12), said counterweight being mounted on an arm (70) pivoting around the shaft (12) and connected by a mechanism (54, 60, 61, 62, 65) to the levers (52 - 53) so as to oscillate in the opposite direction from the swivel roller (20).
2. Device according to claim 1, characterized by the fact that the counterweight (80) is driven by a pinion (76) having the same diameter as the toothed wheel (14) on the shaft (12) of the drive roller (10), this pinion (76) also engaging the wheel (14), the counterweight (80) having moments of inertia, relative to its central axis of rotation and relative to the axis of the arm (70), identical with the moments of inertia of the swivel roller (20), and having a weight chosen so as substantially to balance the horizontal forces.
3. Device according to claims 1 or 2, characterized by the fact that one of the levers (52 - 53) holding the swivel roller has a toothed segment (54) in the form of a circular sector centred on the shaft (12) of the drive roller (10), and engaging a first toothed wheel (61) secured to a counter-shaft (60) parallel to this shaft (12) of the drive roller (10), a second toothed wheel (62) secured to the counter-shaft (60) engaging a reversing wheel (65) which in turn engages a toothed circular sector (67) of the pivoting arm (70) bearing the counterweight (80).
4. Device according to any of claims 1 to 3, wherein the swivel roller (20) is situated above the drive roller (10) and oscillates in a substantially horizontal plane, characterized by the fact that the counterweight (80) oscillates in the same horizontal plane as the swivel roller (20).
5. Device according to claim 4, characterized by the fact that a pressure roller (30) or a number of pressure rollers (31) are installed, starting from the shaft (27) of the swivel roller, on elastic means (32, 34) for pressing the web of material (3) against the swivel roller (20) at a predetermined pressure, near the starting line of the web outside said swivel roller.
6. Device according to claim 4, characterized by the fact that it also comprises a telescopic table guiding the web (3) between the outlet of the oscillating swivel roller (20) and the inlet of the station (1) for stopping and processing the web, said table comprising a pair of substantially stationary horizontal downstream combs (44) situated one above the other and secured in rotation (25) to the inlet of the work station (1), and a pair of upper and lower oscillating horizontal upstream combs (45) situated at the outlet of the swivel roller (20) and secured in rotation around the shaft (27) of said swivel roller; the upper and lower downstream combs being respectively kept in sliding motion (23, 24) in the prolongation of the corresponding oscillating upstream combs (45), with their teeth offset laterally.
7. Device according to claim 6, characterized by the fact that the downstream combs (44) are respectively held by an upper crossbar and a lower crossbar (42) secured to a pair of side rails (24), the downstream ends of which are mounted in rotation (25) near the inlet of the work station whereas the upstream ends fit into external casters (23) mounted on two side plates (21) pivoting on the shaft (27) of the swivel roller (20), when the upstream combs (45) are held by a vertical pair of crossbars (22) secured to the side plates (21).
8. Device according to claim 7, characterized by the fact that a pressure roller (30) is mounted on two horizontal side levers (32), one lever being joined to each oscillating side plate (21), one or one pair of side vertical jacks (34) being also mounted against the plates and exerting a predetermined pressure on the levers (32).
9. Device according to claim 6, characterized by the fact that the combs are enclosed in two half-boxes, a substantially stationary half-box (78) attached to the inlet of the work station (1) and an oscillating half-box (79) connected in rotation to the shaft (27) of the swivel roller (20) which it encloses, the teeth (48, 49) of the lower combs being individually supported by vertical plates (88, 89) extending at right angles from the bottoms (82, 83) of the boxes, the teeth (46, 47) of the upper combs being held by vertical plates (87) or tubes (86) descending from the tops (84, 85), and the plates or tubes interpenetrating so as to form longitudinal chambers (98, 99) for a flow of air which, at the bottom of each respective box, open into transverse chambers (91, 96) comprising side windows (92, 94, 95).
10. Device according to claim 4, characterized by the fact that a vertical pair of traction rollers (40, 41) is mounted near the inlet of the next station.
11. Device according to claim 10, characterized by the fact that the device for driving one of the traction rollers (40) comprises a belt (59) running over a pulley (37) secured to the traction roller (40) and also comprises two discs (35, 36), one situated on each of the two arms of a vertical lever (33) mounted freely in rotation on the shaft (12) of the drive roller (10), the upper disc (35) being secured to the transmission shaft (27) of the swivel roller (20), which shaft extends through the upper arm of the lever (33) and transmits the oscillation of the swivel roller (20) thereto, the lower disc having the same diameter as the upper disc and being held by the lower arm of the lever so as to have a symmetrical position with the upper disc relative to a line joining the axis of the traction roller to the axis of rotation of the lever when this lever is in the central oscillating position.
12. Device according to claim 10, characterized by the fact that the device for driving one of the traction rollers (40), at the level of the pulley (37) of the traction roller (40), is supplemented by a rear return pulley (38) and an idling pulley (39), the symmetry between the discs (35, 36) and between the pulley (37) of the traction roller (40) and the idling pulley (39) being obtained relative to a line joining the axis of the rear pulley (38) to the axis of rotation of the lever (33).

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