EP0467817B1 - Rotative sheet feeder for the accurate positioning of sheet-like elements on flat supports - Google Patents

Abstract

The invention relates to a rotary sheet feeder, characterised in that it comprises at least one stationary magazine (10) for storing stacked sheet-like elements (8), a pressure roller (11) interacting with a device (4) for continuously supplying the flat supports (2) to be each provided with a sheet-like element (8), at least one member (22) for picking up and placing, one by one, the sheet-like elements by means of suction, and means (12 to 17) for supporting and driving the said picking-up member (22) which are arranged so as to confer on the latter a trajectory (30, 30') which is, at least in part, hypocycloidal such that two cusps (31, 32) of the hypocycloid coincide, on the one hand, with the point for picking up a sheet-like element (8) from the said magazine (10) and, on the other hand, with the point for transferring the said element (8) to the said pressure roller (11). <??>Application to the positioning of sheet-like elements using flat supports, especially windows or bags on cardboard blanks. <IMAGE>

Description

The present invention relates to the placement on flat supports, such as cardboard blanks for example, of sheet elements, such as windows or sachets, and aims to solve the problem of automatic and precise removal, at high rate, of said sheet elements, one by one, on individual flat supports.

The manufacture of composite boxes in particular, constituted in the well-known manner of a cardboard case inside which a bag or sheath formed by a plastic film is glued, poses the problem of placing the bags one by one. on cardboard cutouts without disturbing the production rates. It is indeed important that each bag is positioned with rigorous precision and that such placement is carried out flawlessly repeatedly, if possible at the same rate as that of ejection of the blanks at the outlet of the press.

Furthermore, from documents FR-A-2,305,298, US-A-4,696,715 and FR-A-2,487,310, various devices are known for transferring sheet elements taken from a stack to deposit them in a place. determined, in particular in superposition with another element.

However, these devices do not allow the two elements to be positioned mutually with precision and at high speed because the kinematics used does not allow it.

The object of the present invention is precisely to solve this problem and that, more generally, of the precise placement at high speed, of any sheet element (plastic film, window, sachet, paper, cardboard, PVC, etc.) on a flat support, in particular a blank of cardboard or other material, cut and grooved to form a folding box, composite or not.

• au moins un magasin fixe, réglable en translation, de stockage des éléments en feuille empilés,
• un rouleau presseur coopérant avec un dispositif d'amenée en continu des supports plats à munir chacun d'un élément en feuille,
• au moins un organe de saisie et dépose un à un par aspiration des éléments en feuille, et
• des moyens de support et d'entraînement dudit organe de saisie agencés pour conférer à ce dernier-une trajectoire dont une partie est hypocycloïdale et comprend deux points de rebroussement dont l'un coïncide avec le point de saisie d'un élément en feuille audit magasin et dont l'autre coïncide avec le point de transfert dudit élément audit rouleau presseur, la trajectoire de l'élément immédiatement en amont du point de transfert étant un arc de cercle tangent à un organe récepteur,

grâce à quoi, chaque élément en feuille est, au premier point susdit, solidarisé dudit organe de saisie avec une vitesse relative nulle entre l'organe de saisie mobile et l'élément en feuille immobile et, au second point susdit, transféré de l'organe de saisie audit organe récepteur entraîné en synchronisme avec l'organe de saisie de manière qu'à ce second point de transfert la vitesse relative entre l'organe de saisie et ledit organe récepteur soit nulle, en vue d'assurer un positionnement précis, continu et à haute cadence des éléments en feuille sur lesdits supports plats.To this end, the subject of the invention is a rotary feeder for the precise placement of sheet elements on flat supports comprising:

• at least one fixed magazine, adjustable in translation, for storing stacked sheet elements,
• a pressure roller cooperating with a device for continuously feeding flat supports to each be provided with a sheet element,
• at least one gripping member and deposits one by one by suction of the sheet elements, and
• means for supporting and driving said gripping member arranged to give the latter a trajectory, part of which is hypocycloidal and comprises two cusps, one of which coincides with the gripping point of a sheet element at said store and the other of which coincides with the transfer point of said element to said pressure roller, the trajectory of the element immediately upstream from the transfer point being an arc of a circle tangent to a receiving member,

whereby, each sheet element is, at the aforementioned first point, secured to said gripping member with a zero relative speed between the movable gripping member and the stationary sheet element and, at the aforesaid second point, transferred from the gripping member to said receiving member driven in synchronism with the gripping member so that at this second transfer point the relative speed between the gripping member and said receiving member is zero, in order to ensure precise positioning, continuous and at high rate of sheet elements on said flat supports.

According to one embodiment, said gripping and depositing member is constituted by at least one suction cup and the means suitable for conferring on this member said trajectory are constituted by a suction cup holder rotatably mounted around an axis parallel to the axis of the pressure roller and itself driven in rotation about an axis which is parallel to it, in synchronism with the speed of rotation of the pressure roller, means being provided, indexed on the rotation of the axis of the suction cup holder, to give at the suction cup, said hypocycloidal curve with the two cusps at the two gripping points and deposits elements in sheet respectively.

In a more particular application of the invention to the placement of sachets on cardboard blanks of composite boxes, said sachets are detachably secured by tearing off heels, the whole heel-sachets being bundled and stored in said store and , in order to facilitate tearing of the sachets, means are provided for communicating to said gripping member and depositing, when gripping a sachet, a slight and clear backward movement, without interrupting the continuous movement of said gripping member and depositing a trajectory hypocycloid.

• Figure 1 est une vue schématique en élévation latérale d'une machine linéaire de fabrication de boîtes composites à sachet interne équipée d'un margueur conforme à l'invention ;
• Figure 2 est une vue en perspective des moyens propres à conférer aux organes de saisie et dépose du margeur de la figure 1 la trajectoire hypocycloïdale désirée ;
• Figure 3 illustre la trajectoire hypocycloïdale de la ventouse de saisie et dépose entre les postes de dépose et de saisie ;
• Figures 4a à 4i illustrent différentes phases successives de la saisie d'un sachet ;
• Figures 5a à 5c illustrent trois phases successives de la dépose d'un sachet ;
• Figure 6 représente un sachet à talon ;
• Figure 7 est une vue en pespective schématique d'un magasin à sachets conformes à la figure 6, et
• Figure 8 est une vue en élévation latérale du magasin de la figure 7.

Other characteristics and advantages will emerge from the description which follows of an embodiment of the device of the invention, description given by way of example only and with reference to the appended drawings in which:

• Figure 1 is a schematic side elevational view of a linear machine for manufacturing composite boxes with an internal bag equipped with a feeder according to the invention;
• Figure 2 is a perspective view of the means suitable for imparting to the gripping and depositing members of the feeder of Figure 1 the desired hypocycloidal trajectory;
• Figure 3 illustrates the hypocycloidal trajectory of the gripping and depositing suction cup between the depositing and gripping stations;
• Figures 4a to 4i illustrate different successive phases of the seizure of a sachet;
• Figures 5a to 5c illustrate three successive phases of the removal of a bag;
• Figure 6 shows a heel bag;
• FIG. 7 is a diagrammatic perspective view of a bag store in accordance with FIG. 6, and
• Figure 8 is a side elevational view of the store of Figure 7.

In Figure 1 there is shown in 1 a suction conveyor responsible for conveying one by one of the blanks of cardboard 2 cut and grooved intended to constitute cases of composite boxes with internal sachet, said blanks being placed on the conveyor 1 to the using an appropriate positioning device 3.

The blanks 2 are transferred to a conveyor 4 arranged in the extension of the conveyor 1, where they are first glued, in the known manner, by a gluing device 5 responsible for depositing on the upper face of each blank 2 the lines gluing the sachet which must be placed on the blank and whose positioning must be particularly precise. Two such bonding lines have been symbolized by way of illustration at 6 in FIG. 1.

The installation of FIG. 1 comprises a suction cylinder 7 of the type used on "cellophaneuses" or machines for placing windows in window boxes, which cylinder 7 is responsible for transferring onto the blank 2 passing under it a bag 8 constituted by example of a pocket of transparent thin plastic film, closed at one end and open at the other, and brought by a rotary feeder according to the invention and generally designated by the reference numeral 9.

The feeder 9 is responsible for removing, one by one, the bags 8 stored at 10 in the feeder, stacked with their plane arranged vertically, parallel to the axis of the suction cylinder 7.

An embodiment of the store 10 for storing and presenting the bags 8 will be described below.

A mechanism for gripping and depositing the bags 8 one by one is provided for taking the bags 8 from the magazine 10 and depositing them on the cylinder 7 and more precisely making them pinch between the latter and a pressure roller 11, applied elastically against the cylinder 7 and trained at the same speed as him.

This gripping and depositing mechanism, more precisely represented in FIG. 2, comprises three suction cup holders 12, carried by bars 13 parallel to the axis of the suction cylinder 7 and rotatably mounted in two circular flanges 14a and 14b wedged on a shaft central 15 also parallel to the axis of the cylinder 7. The bars 13 are equidistant from the shaft 15 and offset between them by 120 °.

The shaft 15 and the flanges 14a, 14b are rotated in synchronism with the cylinder 7 by an appropriate transmission 16, the direction of rotation 17 of the assembly 15-14a, 14b being opposite to that of the cylinder 7.

The assembly 15-14a, 14b is mounted journalling in two lateral, vertical frame plates 19.

Each suction cup holder 12 is mounted in a fixed but adjustable manner along the bars 13 and comprises a set of two suction cups connected by a flexible pipe 20 and an O-ring connection 21 to a vacuum source not shown. One (22) of two suction cups has a substantially larger surface area than that of the other suction cup 23.

The bars 13 pass through one (14a) of the flanges and are integral at their end with a kind of pinion 24 provided with teeth 25 capable of meshing with a fraction of crown 26 integral with the frame 19 and internally carrying a toothing formed by 'pins or projections 27 located on the path of the teeth 25.

The crown 26 extends over an arc of 180 ° and is coaxial with the axis of the shaft 15. In the illustrated embodiment, the half-crown 26 extends from the lowest point of the bars , during the rotation of the assembly 15-14a, 14b, which corresponds to the point of depositing a bag 8 (FIG. 3) on the cylinder 7, up to the highest point.

When turning the flange 14a has a pinion 24 at the lower end of the half-crown 26, the teeth 25 of the pinion 24 mesh with the pins 27 and the bar 13 concerned rotates about its axis while continues to rotate l 'shaft 15, so that the suction cups 22, 23 of the suction cup holder 12 of said bar 13 begin to describe hypocycloids as illustrated in Figure 3. Arrived at the top of the half-crown 26, the teeth 25 escape the pins 27 and the rotation of the bar 13 relative to the flange 14a is blocked by a semi-annular slide 28, taking over from the half-crown over 180 ° and constraining a projection 29 integral with each pinion 24 to make the bars 13 immobile relative to the flanges 14a, 14b until said bars return to the low point of their travel.

In FIG. 3, the hypocycloidal trajectory 30 of the central contact point of the suction cup 22 has been illustrated with a bag 8, with in particular the turning point 31 of the suction cup 22 at the level of the magazine 10 and the turning point (theoretical) 32 of the suction cup 22 at the level of the cylinder 7.

In the embodiment shown the pinions 24 are dimensioned so that between the two successive cusps (32 then 31 following the direction of rotation 17 of the shaft 15) the shaft 15 has described an arc of 90 °, the magazine 10 of the feeder being placed accordingly.

Such a hypocycloidal trajectory 30 allows the suction cup 22 to contact a bag 8 of the magazine battery 10 with an approach perpendicular to the bag and a zero speed at the time of contact, which will also be that of the vacuum applied to the suction cup 22, which results in an entry with a particularly clean, precise and repetitive positioning of the suction cup at any speed of rotation of the shaft 15, that is to say at any rate of conveying of the blanks 2 by the conveyor 4.

Beyond the cusp point 31, the suction cup 22 continues its hypocycloidal movement (30 ′) ascending to a point diametrically opposite to point 32 relative to the shaft 15 and corresponding to the moment when the pinion 24 leaves the half crown 26 at its upper end. During this second part (30 ′) of hypocycloidal trajectory, the suction cup 22 carries with it a bag 8. From the high point of the trajectory of the suction cup 22, the latter then describes a simple circle up to the point of cusp 32 as shown on the right side of Figure 3, the suction cup 22 with its bag 8 being turned outwards. At point p, the bag 8 is released by the suction cup and is supported on the cylinder 7 by the suction orifices 7a of the cylinder (FIG. 2). At point 32 the suction cup touches the cylinder 7 with zero relative speed, the cylinder 7 and the rotary assembly 13-15-22 being driven at the same speed of rotation.

The positioning of the bag on the cylinder 7 is therefore particularly precise and repetitive at any rate.

The advantage of the hypocycloidal trajectory of the suction cup 22 from said point 32 intervenes for the release of the suction cup 22 with respect to the pressure roller 11 which would be on the trajectory of said suction cup if there were not to leave from point 32 the start of the hypocycloidal path 30.

For ease, the trajectory of the bag 8 from its gripping to its removal has been described and shown in Figures 1 and 3 with the only suction cup 22. In reality, the two suction cups 22 and 23 grip the bag but according to slightly different illustrated by FIGS. 4a to 4i, on the one hand, and 5a to 5c, on the other hand, and linked to the existence special means to facilitate the tearing of a bag 8 from the store 10. Previously, reference is made to FIG. 6 which illustrates a method of packaging the bags 8 which is particularly suitable for the device of the invention.

In this Figure 6, there is shown a bag 8 in the flat state connected at the top to a heel 8a separated from the bag by a line of incisions 8b. The heel 8a is constituted for example by the extension of one of the walls of the bag 8. In addition, the heel 8a is pierced with two secant holes 8c relative to the line of incisions 8b.

The bags 8 and their heel are stacked and the assembly is threaded on two fingers 33 of the magazine 10 which will be described later with reference to Figures 7 and 8 an embodiment.

Returning now to FIGS. 4a to 4i, it will be observed that each bag 8 is gripped by the large suction cup 22 in the vicinity of the separation line 8b and by the small suction cup 23 in the vicinity of the other end.

The precise process of entering and tearing off a bag 8 from the magazine 10 is illustrated in FIGS. 4a to 4f.

FIGS. 4a to 4c illustrate the end of the hypocycloidal stroke 30 of the suction cup 22 up to the cusp point 31 (FIG. 4c).

It is first of all the small suction cup 23 (FIG. 4a), due to its position relative to the suction cup 22 on the suction cup holder 12 and the setting of the latter on the bar 13, which contacts the bag 8 at item 10, in its lower part. The suction cup 23 is put under vacuum at this time, the control of the suction cups 23 and 22 being indexed on the rotation of the flanges 14a, 14b and therefore of the cylinder 7.

The suction cup 23 begins to peel off the lower part of the bag 8 (Figure 4b) when the suction cup 22 begins to contact the upper part of said bag.

When the suction cup 22 is at the cusp point 31 (FIG. 4c) it is put under vacuum to grip the upper part of the bag.

In order to facilitate the separation of the bag 8 from its heel 8a at the height of the line 8b, a mechanism is then actuated to temporarily bring back the suction cups 22, 23 temporarily. This mechanism illustrated in FIG. 2 comprises a cam 34, adjustable in angular position, moved rotation in synchronism with the shaft 15 and provided with a recess 35. The cam 34 acts on a pusher 36 sliding in a guide 37 secured to the frame 19 and articulated at its end on a pin 38 secured to the half-crown 26 in sort of communicating to the latter a slight rotational movement around the axis of the shaft 15, the half-crown being mounted on ball bearings for this purpose on the frame 19.

When the hollow 35 is under the pusher 36, which happens at the moment when the suction cup 22 reaches the cusp point 31 (FIG. 4c), the pusher 36, permanently urged downwards by a suitable spring not shown, descends slightly and causes the half-crown 26 to pivot downwards. This causes the suction cups 22 and 23 to pivot slightly, by the pinion 24, as illustrated in FIGS. 4d to 4f. The backward movement of the suction cup 22 provides (FIG. 4d) a dry tearing of the bag 8 from its heel 8a.

When the pusher 36 leaves the recess 35 and returns to its anterior position the suction cups gradually resume (normal figures 4g to 4i) their normal position, the suction cup 22 returning to the normal hypocycloidal trajectory 30 ′ from the cusp point 31.

FIGS. 5a to 5c respectively illustrate the reaching by the suction cup 22 of point 32 (removal of the bag on the cylinder 7), the bag 8 being still held by the two suction cups 22 and 23, then (FIG. 5b) the start of the hypocycloidal trajectory 30 of the suction cup 22 also causing that of the suction cup 23 which withdraws, the suction cup 23 being vented to release the bag 8 as well as the suction cup 22 and, finally (FIG. 5c), the retraction towards the inside the suction cups 22, 23 so as to escape from the pressure roller 11.

FIGS. 7 and 8 illustrate an embodiment of a loader or magazine 10 storing the bag 8-heel 8a assemblies side by side vertically. These assemblies are suspended from two horizontal fingers 33 engaged in the holes 8c.

The gripping plane of the bags 8 is delimited by a vertical frame 39 provided with fingers 40 for peripheral retention of the bags.

The fingers 33, beyond the frame 39 (suction cup side 22, FIG. 8), are bent upwards at 33a so as to collect, with a view to their evacuation, the heels 8a which remain threaded on the fingers 33 after tearing of the bags 8.

An endless belt 41 provided with projections 42 driven by appropriate means is responsible for constantly pushing the heels 8a, with, then without, their bag, towards the curved part 33a of the fingers, in the direction of the upper part of the case 43 of the charger. or store 10 from which the heels 8a will be removed, being easily extracted from the fingers 33 by the notch formed in the holes 8c by the line 8b.

The removal of the sachets 8, instead of taking place on the suction cylinder 7, could just as easily be carried out directly on the conveyor belt 4 with the help of a pressure roller similar to the roller 11 applied elastically against said carpet and trained in synchronism with the latter.

The loader or magazine 10 is adjustable in translation and is designed according to the type of sheet elements to be put in place, the presentation of the elements being always the same, that is to say with the elements stacked flat and the stack placed perpendicular to the hypocycloidal approach path of the gripping suction cup (s) in the vicinity of the cusp point of the bag gripping station.

Finally, the invention is not limited to the embodiments shown and described above but on the contrary covers all the variants in particular as regards the nature, shapes, dimensions of the sheet elements to be assembled or fixed on a support. dish of any type, nature, shape or size whatsoever. Likewise, the gripping and transport system mounted on the member 12 can be arranged differently with a single suction cup or more than two suction cups arranged in any configuration. A number of bars 13 and therefore of suction cup holders 12, different, less than or more than three, may be provided and several stores 10 may also be provided if space permits, provided that several sets of members are also provided, such as 24 to 29 and 34 to 38 to control the various hypocycloidal trajectories and the detachment of the bags to the various stores.

Claims (10)

1. A rotative feeder for exactly positioning sheet elements on flat supports including :

   - at least a fixed magazine (10) which is translatably adjustable for storing stacked sheet elements (8),

   - a pressing roller (11) which cooperates with a device (4) adapted to continuously supply flat supports (4) in order to provide each of them with a sheet element (8),

   - at least a member (22) for gripping and laying down sheet elements by sucking them, one after the other; and

   - means (12-17) for holding and driving said gripping member (22) arranged so as to impart the latter a path, a portion of which is an hypocycloidal one (30, 30') and includes two points of reflection (31, 32), one of which (31) coincides with the gripping point of a sheet element (8) at said magazine (10) and the other of which (32) coincides with the transfer point of said element (8) to said pressing roller (11), with the path of the element (8) immediately upstream of said transfer point being an arc of a circle tangent to a receiver member (4, 7).

      whereby, each sheet element is, at said above-mentioned first point, made integral with said gripping member with a relative speed equal to zero between said movable gripping member and said stationary sheet member and, at said above-mentioned second point (32), transferred from said gripping member (22) to said receiver member (4, 7) which is synchronously driven with said gripping member in such a way that, at said second transfer point, the relative speed between said gripping member (22) and said receiver member (4, 7) is equal to zero, with a view to ensuring the exact, continuous and high rate positioning of said sheet elements (8) on said flat supports (2).
2. The feeder as recited in claim 1, characterized in that said receiver member is a sucking cylinder (7) for positioning sheet elements (8) on said flat supports (2) which are supplied to said cylinder (7) by a suitable conveyor (4).
3. The feeder as recited in claim 1, characterized in that said receiver member is a conveyor belt (4) which forwards said flat supports (2).
4. The feeder as recited in one of claims 1 to 3, characterized in that said gripping and laying down member includes at least a suction cup (22) and means apt to impart said path (30, 30') to said member comprise a suction cup-holder (12) rotatably mounted about an axis (13) which is parallel to said pressing roller (11) and itself rotatably driven about a parallel therewith axis (15), in a synchronous manner with the rotating speed of said pressing roller (11), with means indexed on said suction cup-holder (12) rotation axis being provided so as to impart to said suction cup (22) said hypocycloidal curve (30, 30') with both points of reflection (31, 32) at said both gripping and laying down points of sheet elements (8) respectively.
5. The feeder as recited in claim 4, characterized in that said means for imparting to said suction cup (22) said hypocycloidal curve include a pinion (24) which is fixed on said suction cup-holder (12) axle (13) and apt to cooperate, in the travel thereof, with a fixed circular toothing (27) which is centered on the rotation axis (15) of said axle (13).
6. The feeder as recited in one of claims 1 to 5, more specially adapted to the positioning of bags (8) on composite box cardboard flanks, characterized in that said bags (8) are detachably made integral by tearing out heels (8a), the heel-bag assembly being tied into bundles and stored in said magazine (10) and, in order to make said tearing out action easier, means (34-38) are provided to transmit a slight and net backward movement to said gripping and laying down member (22) when a bag (8) is gripped.
7. The feeder as recited in claim 5 and 6, characterized in that said means for communicating said backward movement of said gripping member (22) when a bag (8) is gripped include means (34-38) adapted to provide said circular toothing (27) with a slight rotation around the axis thereof and the return thereof to a normal position.
8. The feeder as recited in claim 7, characterized in that said means for providing said toothing (27) with said temporary rotation include a cam (34) having a recess (35) which acts upon a pusher (36) hinged on a crown fraction (26) which bears said toothing (27), said cam (34) being indexed on the rotation of axle (13) support (14a, 14b) of said suction cup-holder (12).
9. The feeder as recited in one of claims 6-8, characterized in that said suction cup-holder includes two suction cups, one of them (22) being adapted to grip a bag (8) in the vicinity of the tearing out line (8b) and the other one (23) to grip said bag in the vicinity of the other end, with said second suction cup (23) being arranged to grip said bag before the first one.
10. The feeder as recited in one of claims 6-9, characterized in that said magazine (10) includes fixed fingers (33) adapted to be engaged into holes (8c) formed in bag (8) heels (8a), means (41, 42) being provided to push said heels (8a) towards the bag gripping plane, with said plane being defined by a presenting frame (39) provided with positioning fingers (40), said means (41, 42) discharging said heels at the completion of the bag tearing out action.

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