FR2962425A1 - Method for forming stack of predetermined number of parallelepiped flat and elongated objects e.g. sardine cases, involves tilting objects one by one in housing, and sequentially introducing objects into housing by gravity to form stack - Google Patents

Abstract

The method involves arranging (41) parallelepiped flat and elongated objects in a string, along an orientation by positioning (411) the objects on edge. A predetermined number of the objects are separated (42) from an end of the string. The separated objects are sequentially introduced (43) into housing by gravity so as to form a stack of objects, where the separated objects are tilted one by one in the housing during sequential introduction of the objects. The stack is automatically extracted (44) from the housing. An independent claim is also included for a device for forming a stack of a predetermined number of parallelepiped flat and elongated objects, comprising a separation unit.

Description

FIELD OF THE INVENTION The field of the invention is that of packaging.

More specifically, the invention relates to a method and a corresponding device for forming piles of substantially parallelepipedal and elongated flat objects, such as for example boxes of sardines. The invention finds particular application in the development of promotional batches of manufactured products. 2. State of the art In the canning factories, it is common for a conveyor carrying stacks of boxes stacked to a promotional packaging machine to be stopped because of a fall of a stack. We note in particular more frequent stops if the carpet conveys stacks of elongated boxes, whose balance is much more unstable if the boxes are not properly superimposed. To remedy this problem, it is conventional to permanently post one or more operators around the carpet to manually reshape the unstable batteries and / or remove the collapsed batteries. In some cases, the stacks are hand-crafted by operators before being placed on the carpet. These tasks are tedious and represent an expense. There is therefore a demand for automation techniques to form stacks of cans properly aligned without human intervention.

Machines are known to stack very fine objects, such as sheets of paper or towels, using transfer wheels with unitary receptacles for collecting the objects one by one and to deposit them in battery. These techniques are however not adapted to be implemented with thicker objects, which are indeed likely to impede the rotation of the wheel, and may cause a blockage thereof. It has also been proposed to use an arm of a robot for stacking cans. This technique has the disadvantage of being complex and expensive. Moreover, this technique does not allow to reach high rates. It is indeed necessary to limit the speed of movement of the robot arm to avoid falling objects. It has also been thought to converge to the same position two ramps offset in height by one step corresponds to the thickness of a can so as to superimpose flat cylindrical canisters collected at these ramps. This technique, however, has many disadvantages. A disadvantage of this technique is that it is not flexible. It must indeed provide as many ramps as boxes in the stack. In addition, multiplying the number of ramps is expensive.

Another disadvantage of this technique is that it is bulky. Another disadvantage of this technique is that the timing and feeding of the ramps is complex. OBJECTIVES OF THE INVENTION The invention therefore has the particular objective of overcoming the disadvantages of the state of the art cited above. More specifically, the invention aims to provide a technique of automatic formation of a stack of objects suitable for elongated objects. An object of the invention is also to provide such a technique which is reliable. Another object of the invention is to provide a technique which makes it possible to form stacks of objects at a regular rate. In particular, an objective of the invention is, in at least one particular embodiment of the invention, to provide a technique that makes it possible to form at least thirty stacks per minute from the same file of objects.

Another object of the invention is to provide such a technique that is simple to implement, and a reduced cost. Yet another object of the invention is to provide such a technique which is easily adaptable depending on the number of objects per stack and the shape of the objects. 4. Objective of the invention These objectives, as well as others which will appear later are achieved by means of a method of forming at least one stack consisting of a predetermined number of substantially parallelepiped flat objects. and of elongated shape, especially of cans. The invention particularly relates to objects of a thickness greater than five millimeters, and preferably of a thickness substantially equal to or greater than one centimeter. According to the invention, such a method comprises: a step of arranging said objects in a row, in a substantially similar orientation; a step of separating a predetermined number of said objects from an end of said queue; a step of sequentially introducing said separated objects into a housing by gravity, so as to form said stack. Thus, in an unprecedented manner, the invention proposes to automatically constitute a suitably formed stack of a predetermined number of thick and elongated objects, by taking these objects in a single file. The approach of the invention is also particularly simple. The principle of the invention is indeed based on the observation that it is sufficient to drop a predetermined number of objects oriented identically in a housing sequentially to form a regular stack of these objects. It should be noted that in the context of the invention, by the term "sequential" when referring to the term "introduction" it is meant that the 4 objects of each stack engage following and following a predefined order in housing. Preferably, said arranging step comprises a step of positioning said objects on edge.

This allows, at least in some cases, to form a more compact queue. According to a particular embodiment of the invention, said step of sequential introduction comprises a step of switching in block said separate objects in said housing.

A stack is thus obtained in a single switching step, which saves time. In another particular embodiment of the invention, said step of sequential introduction comprises a step of tilting said separate objects one by one in said housing.

This removes a risk of blocking several objects concomitantly in the housing. According to a particular aspect of the invention, said separation step comprises a step of holding an object of said queue adjacent to said predetermined number of objects intended to be separated from said queue.

The objects in a stack are easily removed from all subsequent objects in the queue. Advantageously, said arranging step comprises a step of transferring at least one of said objects positioned on edge inside a pipe inclined with respect to the vertical and configured so as to dispose said object flat, in the direction of the length. The objects are thus automatically arranged in the same orientation, thanks to the conduit, which is clever and inexpensive. According to a particular aspect of the invention, such a method comprises a step of automatically extracting said stack from said housing.

This frees the housing for a next stack, without manual intervention.

According to a particular aspect of the invention, said extraction step comprises: a step of shifting said housing; a step of driving and / or pushing said stack out of said housing. The invention also relates to a device for forming at least one stack consisting of a predetermined number of substantially parallelepipedic and elongated objects, in particular cans, from a substantially oriented line of objects. similar, comprising: - means for separating a predetermined number of said objects from an end of said queue; means for sequentially introducing said predetermined number of objects into a housing by gravity, so as to form said stack. Preferably, said separating means comprise: - means for retaining an object adjacent to said predetermined number of objects intended to be separated from said file, comprising at least a first stop movable between a stop position in which said stopper retains said adjacent object and a retracted position in which said adjacent object is released, - a second movable stop temporarily retaining said end of said file; means for synchronizing said first and second stops. We can thus take a precise number of objects in the queue. Advantageously, said housing is secured to a turntable adapted to transport said housing in a position offset from said insertion means. Thus, a new battery can very quickly be formed in line with the introduction means. In a particularly advantageous embodiment of the invention, said plate has a plurality of identical housings arranged in an angular pitch corresponding to that of a stepper motor driving said plate. One after the other, each slot of the tray can thus periodically receive an object stack.

Preferably, a device as described above comprises means for extracting said stack of objects from said housing comprising at least one element belonging to the group comprising at least: conveyor belt; - pushing device. Advantageously, said housing comprises means for securing at least one wedge member inside said housing, so as to adjust the shape of said housing to that of said stack of objects. It is thus possible to form with the same device stacks of objects of different shapes and / or in different numbers. In at least one advantageous embodiment of the invention, such a device comprises means for automatically orienting said objects of said queue in a predefined position comprising: means for taking said objects on edge; - An inclined duct relative to the vertical, configured to dispose said objects flat during their transfer through said duct. Such a device thus makes it possible to form piles of elongated objects completely automatically. It is in particular conceivable that objects taken by this device can be initially loose. 5. List of Figures Other features and advantages of the invention will appear more clearly on reading the following description of two embodiments of the invention, given by way of simple illustrative and non-limiting examples, and the accompanying drawings. among which: 7 - Figure 1 is a schematic perspective view of a first part of a device for automatic formation of piles of boxes of sardines according to the invention; - Figure 2 illustrates the second part of the device shown in Figure 1; FIG. 3 is a detailed view of the zone for extracting the piles of sardine boxes from the device represented in FIG. 1; FIG. 4 details the steps of a method according to the invention executed by the device of FIG. 1, in the form of a block diagram; FIG. 5 is a diagrammatic perspective view of a second example of a device according to the invention making it possible to form stacks of boxes of sardines, at the moment when the row of boxes of sardines is stopped; FIG. 6 is a view of the end zone of the conveyor of the device shown in FIG. 5, after the door holding the boxes of sardines at the front of the line has been raised; - Figure 7 is a top view of the turntable of the device shown in Figure 5, to illustrate the extraction of a box of sardines out of a housing, under the pressure of a tongue. 6. Detailed Description of the Invention 6.1 Recall of the Principle of the Invention The principle of the invention is therefore based on the implementation of a housing in which objects of the same line falling in this dwelling will pile up. following a defined sequence. 6.2 EXAMPLE OF EMBODIMENT OF THE INVENTION FIG. 1 illustrates an embodiment of a device for forming piles of boxes of sardines according to the invention. This device 10 comprises a belt conveyor 11 on which are poured, in bulk, boxes of sardines 12 in size 1/13.

The boxes of sardines 12 falling at the end of this conveyor 11 are collected on sleepers 13 regularly spaced, passing under this end of the conveyor 11, and driven by these sleepers in the direction of travel represented by the arrow A. A harrow 14 is mounted at the entrance of a retaining cover 15 matching the path of the crosspieces 13. It makes it possible to drop the sardine boxes not resting substantially vertically on edge on the crosspieces 13. The boxes 12 transit under the hood 15 , before being deposited on edge on the strip 16 of a horizontal belt conveyor oriented parallel to the crosspieces 13.

It should be noted that several boxes of sardines can be transported by the same crosspiece 13, and be deposited simultaneously in line, one behind the other, on the belt strip 16. As can be seen in FIG. the belt 16 opens on a conduit 21 of an inner diameter slightly greater than the width of a sardine box, inclined downwards by an angle of about 25 °. During the passage in this duct 21, the equilibrium of each box 12 is broken, because of the curved surface of the duct 21. The boxes of sardines 12, which have an asymmetry, fall flat on their lower face 22, heavier . At their exit from the duct 21, the boxes 12, oriented lengthwise, are transported in a row by a horizontal roller conveyor 24 in the direction of the plate 23. A rocking lever 25 of vertical axis 26 is fixed in the vicinity of the end 27 of the conveyor 24. The lever 25 separates three boxes 212 from the end of the row of boxes of sardines in this embodiment of the invention. This lever 25 comprises a first stop 28 at the end of its arm 251. When the second arm 210 of the lever 25 is pulled by the actuator 29 in the direction of the arrow B, the stop 28 extends above the belt of the conveyor 24. In this stop position, the stop 28 retains the boxes of sardines 212 which accumulate progressively against it at the front of the line.

When the measuring heads of the three proximity sensors 211 arranged facing the lever 25, of inductive or capacitive type, for example, each detect the presence of a sardine box 212 vis-à-vis, the actuator 29 regrows the arm 210 in the opposite direction of the arrow B. The second stop 213 formed at the end of the second arm 210 is then placed at the height of the belt 24, and retains the box 214 according to the three boxes 212 in the queue, and more generally blocks the passage upstream of the lever 25. The fact of pushing the arm 210 of the lever 25 also frees the three boxes 212 which are driven by the conveyor 24.

Note that the length of the lever 25, and more precisely the distance between the two stops 28 and 213, is substantially equal to the sum of the lengths of the three boxes of sardines 212, intended to form a stack of three boxes of sardines. In variants of this embodiment of the invention, it may also be envisaged to adapt the length of the lever to form stacks of only two boxes of sardines or conversely of four boxes or more, and / or to adapt the length of the lever according to the length of the boxes of the batch of boxes to put in piles. At the end 27 of the conveyor 24, the boxes 212 thus released tilt one by one flat in a housing 214, fixed on the plate 23 in line with this end 27, where they are superimposed. In particular, care was taken to limit the speed of advance of the conveyor belt 24, to allow the boxes to stack in a suitable sequence. When the third box of sardines 212 is introduced by gravity into the housing 214, a proximity sensor 215 mounted above the housing 214 emits a signal controlling the actuation of a stepper motor which rotates the plate 23 It is noted that in this embodiment of the invention, the plate 23 performs five complete turns per minute.

In FIG. 3, it can be seen that, in this embodiment of the invention, the plate 23 carries eight identical housings 214 regularly arranged in a star shape on the edge of the plate 23. These housings 214 have a substantially shaped lateral wall 31. U, whose internal contours substantially follow the outer shape of the sardine boxes 212.

The housings 214 having no bottom, the piles 32 formed of three boxes slide on the surface of a fixed plate 33 placed under the turntable 23. When rotating the batteries 32 on a half turn, the batteries 32 are maintained in their housing 214 by a vertical belt 34 in an arc which closes the distal end of the housing 214.

After making a half turn, the piles 32 are extracted from their housing 214 by a drive belt 35, circulating under the plate 23, on which they are pushed by the plate 23 through a notch 331 made in the Fixed tray 33. A lug 37 fixed to the belt 36 guides the batteries out of the housing.

The carpet 35 then conveys the batteries to a packaging unit (not shown in FIG. 3), for example a cartoner, so as to affix an advertising cardstock around each of the stacks. FIG. 4 summarizes, in the form of a block diagram, the steps of the method according to the invention for forming cells produced within the device 10. In a first step 41, the sardine boxes 12 have been arranged automatically in in a similar orientation, consisting of this embodiment of the invention in a flat orientation in the length direction.

This step comprises a positioning step 411 of the boxes 12 on edge, followed by a transfer step 412 of each of the boxes 12 inside the inclined conduit 21 to arrange the boxes flat, in the lengthwise direction, at their output on the carpet 24. A predetermined number of these boxes of sardines, in this case three boxes, were separated from the front end of the queue, in a step 42, holding the box of sardines. adjacent to these in the queue during a step 421. These three boxes were then introduced sequentially into the housing 214 by gravity, during a step 43, by rocking one by one in the housing 214 (step 431), within which they are deposited forming a stack 32. In a step 44, the stack 32 has been extracted from the housing 214 by driving it on the belt 35 (step 442), after having made rotate the housing 214 a half turn around the axis of the tray 23, so as to shift the housing 214 relative to the end 27 of the conveyor 24 (step 441). 6.3 Another Exemplary Embodiment of the Invention Another example of a device 50 according to the invention is shown in FIG. In Figure 5, the sardine boxes 52 poured loose on the flat surface 51 are manually poured on edge by an operator 53, shown in dashed lines in this figure. The operator feeds a line 54 of sardine boxes placed on edge and oriented in a similar manner, the back turned towards the turntable 55. It has for this purpose a roller table 56 facilitating the transport of the boxes to the right before pushing them onto the belt 57 of a conveyor at the start 541 of the line 54. The table 56 advantageously has on its underside oblong slots (not shown), so as to ensure the evacuation of residual waste cardboard , clinging to the boxes.

A system 58 for separating a set of boxes from the end end 542 of the queue 54, and for example two boxes 59 in the embodiment described here, is mounted at the front of the conveyor 57. This system 58 comprises a pivoting door 510, of axis 511, and two retractable claws 512, mounted symmetrically on either side of the conveyor 56. Each claw 512 has a finger 513 fixed on a pivoting plate 514, of axis 515, actuated by a cylinder 516. 12 The movement of the claws 512 is synchronized with that of the revolving door 510. In FIG. 5, the row of sardine boxes 54 is stopped, in abutment against the door 510.

The fingers 513 fit between the two boxes 59 and the box 517, adjacent in line to these two boxes, and are held in this position by the thrust of the cylinder 516 on the plate 514. The boxes 59 are introduced into the housing 518 located at the end of the conveyor 57 by actuating the actuator electric actuator 519. The cylinder 519 pulls on the door 510, which pivots upwardly about the horizontal axis 511. The two contiguous boxes 59 are immediately driven by the strip 57, and tumble together in the housing 518, as can be seen in Figure 6, which is a representation of the area surrounding the end of the conveyor 57, immediately after the door 510 has been raised. At the same time, the box 517, and consequently the following boxes in the queue 54, are held by the fingers 513, on which they abut. A sensor 520 detects when the boxes 58 have left the band 57. This sensor 520 then emits a signal to the cylinder 519, which retracts and folds the door 510, then a signal to each of the cylinders 516, after a period of time delay. about 0.4s. The cylinders 516 are actuated and pull on the plates 514 to bring them back into a retracted position, which separates the fingers 513 and releases the progression of the line 54 along the conveyor 57. Figure 7 is a top view of the turntable 55, to which are fixed five other housings 710 identical to the housing 518, after a rotation of a quarter turn in the counterclockwise direction. The battery 71 formed boxes 59 was extracted from the housing 518 under the thrust of the movable tongue 72, and deposited on the belt 73 of a conveyor, for routing to a steamer.

The tongue 72 is formed on an arm of a swinging lever 74, swinging in the direction of the arrow 77 to the passage of the housing 214.

The lever 74 is mounted on the shaft 741 integral with the fixed plate 75. A return spring 76 whose end is fixed to the arm of the lever opposite the tongue, tends to bring the tongue 72 towards the center of the turntable 55 .

In the position shown in FIG. 7, a pin 78 fixed under the surface of the plate 55, at the height of the housing 518, bears on the internal lateral surface 721 of the tongue 72, in the shape of a cam, and pushes the tongue towards the 55. A pawn is also fixed under each of the housing 710.

This tongue 72 will be brought towards the center of the plate 55 by the return spring 76 as soon as the pin will exceed the top of the boss 722 of the lever 74, until the passage of the next housing. 6.4 Other optional features and advantages of the invention In variants of the embodiment of the invention detailed above, it may also be provided to secure a shim, for example by clipping, by screwing, or by any other means of appropriate known connection to the housing in which the stacks of object are formed, when changing the size, number or shape of the objects forming each of the stacks.

In another variant, it may be envisaged, without departing from the scope of the invention, to separate the objects intended to form the stack by pushing them to the side, so as to move them away from the alignment of the line of objects .

Claims (13)

REVENDICATIONS1. Method for forming at least one stack (32,71) consisting of a predetermined number of substantially parallelepipedal and elongated flat objects, in particular cans (212,52), characterized in that it comprises: a step (41) of arranging said objects in a row, in a substantially similar orientation; a step (42) of separating a predetermined number of said objects from an end of said queue; a step (43) of sequentially introducing said separated objects into a housing (214, 518) by gravity, so as to form said stack. 2. Method according to claim 1, characterized in that said arranging step comprises a step (411) of positioning said objects on edge. 3. Method according to claim 2, characterized in that said step of sequential introduction (43) comprises a step of switching in block said separate objects in said housing. 4. Method according to any one of claims 1 to 3, characterized in that said step of sequential introduction (43) comprises a step (431) of tilting said separate objects one by one in said housing. 5. Method according to any one of claims 1 to 4, characterized in that said separating step (42) comprises a step (421) of retaining an object of said queue adjacent to said predetermined number of objects intended to be separated from said file. 6. Method according to any one of claims 1 to 5, characterized in that said arranging step (41) comprises a step (412) of transferring at least one of said objects positioned on edge inside of a pipe inclined with respect to the vertical and configured so as to dispose said object flat, in the direction of the length. 7. Method according to any one of claims 1 to 6, characterized in that it comprises a step (44) of automatic extraction of said stack out of said housing. 8. Method according to claim 7, characterized in that said extracting step (44) comprises: a step (441) of shifting said housing; a step of driving (442) and / or pushing said stack out of said housing. 9. Device (10) for forming at least one stack (32,71) consisting of a predetermined number of substantially parallelepipedal flat objects of elongate shape, in particular of cans (212,52), from an object line (54) of substantially similar orientation, characterized in that it comprises: means for separating a predetermined number of said objects from an end of said queue (54); means for sequentially introducing said predetermined number of objects into a housing (214, 518) by gravity, so as to form said stack (32, 71). 10. Device according to claim 9, characterized in that said separating means comprise: - means for retaining an object adjacent to said predetermined number of objects to be separated from said file, comprising at least a first stop (28). ) movable between a stop position in which said stop retains said adjacent object and a retracted position in which said adjacent object is released, - a second movable stop (213) temporarily retaining said end of said file; means for synchronizing said first and second stops. 11. Device according to any one of claims 9 and 10, characterized in that said housing (214,518) is integral with a turntable (23,55) adapted to transport said housing (214,518) in a position offset from said means introduction. 12. Device according to claim 11, characterized in that said plate (23,55) has a plurality of identical housings (214,710) arranged in an angular pitch corresponding to that of a stepper motor driving said plate (23). , 55). 13. Device according to any one of claims 11 and 12, characterized in that it comprises means for extracting said stack of objects (54) out of said housing (518) comprising at least one member belonging to the group comprising at least: - training mat (73); - pushing device (72). 16. Device according to any one of claims 9 to 13, characterized in that said housing comprises means for securing at least one wedge member inside said housing (214,518,710), so as to adjust the shape of said housing ( 214,518,710) to that of said stack of objects. 17. Device according to any one of claims 9 to 14, characterized in that it comprises means for automatically orienting said objects of said queue in a predefined position comprising: - means for sampling said objects on edge; - An inclined duct relative to the vertical (21), configured to dispose said objects flat during their transfer through said duct (21).