FR2605592A1 - Method for boxing products in flexible sachets presented in bulk and continuously, and device implementing the said method - Google Patents

Abstract

The present invention relates to a method for boxing products in flexible sachets presented in bulk and continuously, as well as to a device implementing the said method. This device is characterised in that it places in line the conveyor-vibrator 2 supplying a belt conveyor 3 whose speed of advance is maintained at a predetermined value V, supplying, in its turn, a belt (carpet) 4a whose useful transport length can vary within wide proportions by means of retraction and stretching of the head 5 of the belt (carpet) 4a, alternately, in a horizontal plane, and whose speed of advance is maintained at a predetermined value greater than the predetermined value V by a positive and adjustable quantity x, thus making up rows of sachets 1 on an accummmulation area 7.

Description

 The present invention relates to a method of casing products in flexible bags which are presented in bulk and continuously, as well as a device implementing said method.

 We are well aware of all the difficulties of casing products having little rigidity or having very deformable external shapes, such as, for example, sachets containing candies; such sachets cannot be directly collected at the end of production except piling them in bulk with the consequences always observed of numerous deteriorations of the sachets and their contents as well as the lack of homogeneity of this type of casing, causing losses of Considerable volume in the transport and storage of such oversized crates, obviously increasing the packaging costs as well as the handling costs.

 some boxing techniques have been carried out so far, in an attempt to provide a solution to this type of problem, considering that it is advisable, before the boxing proper, to carry out a certain number of preparations: the sachets are presenting in bulk at the entrance to the packing station, must first be arranged flat and their contents also distributed inside, the sachets are then taken up individually or in groups and deposited in a box which is evacuated as soon as '' it is full, thus triggering the arrival of a new cash register at the cashing station and so on ...

 It is easy to understand that in such a scheme, the casing presents a very discontinuous operation and it is often only at the cost of a tortuous play of accumulation zones coupled or not with learned turnstiles that we arrive at hide certain operations such as transporting or moving the boxes, juxtaposing the bags in the same boxes or packing operations, filling control, in order to obtain an acceptable fluidity in the packing process, related to the product flow at the entrance to the station. If it is already difficult to obtain good coordination in a unitary packing process, it nevertheless appears that it is preferable to deposit products in the box, in full rows previously formed, making it possible to obtain even more uniform storage.

 In this sense, the present invention provides a solution to this problem of continuously casing products in flexible bags, adding to the advantages of depositing in complete rows all the advantage of precise and variable positioning as desired, from bags to inside the solon boxes the defined configuration, either in juxtsposition, or in partial position. To this end, the present invention relates to a process of casing of product in flexible bags being presented in bulk and continuously allowing, d on the one hand, the precise positioning of said sachets in their crate according to a configuration which can, on request, vary instantly without interrupting the packing and providing, on the other hand, a final control of the filling of the crates, characterized in that a) the sachets are supplied in bulk on a vibrating conveyor which ensures good distribution of the product in the sachets; b) the sachets are then taken up by a conveyor belt, driving said sachets at constant speed, to a second conveyor arranged in the axis of the first and whose running speed is greater than the speed of the first conveyor d 'an adjustable positive quantity, intended to impose a spacing between the successive sachets; c) the head of the second conveyor, mounted on a movable plate, can advance or retract horizontally along the axis of said conveyor, providing a mat of useful length depending on the advancement or retreat of the head of said conveyor 4; d) a sachet, being detected at the end of said mat, triggers the rapid recoil of the head of the mat, thus releasing the sachet, while continuing to move back to allow the next sachet, in a combined movement of advancing the mat and retreating of the head, to be released in a predetermined position relative to the previous bag and so on until constituting the deposition of a full row on a horizontal accumulation zone, which can then release said row which comes thus increase the filling of a box positioned for this purpose by a pallet conveyor; e) either directly by gravity, f) or indirectly by means of a new bucket conveyor feeding a gripping device, to positively integrate the rows of bags in said box, g) at the same time and to allow the accumulation zone emptied of its contents to return to the advanced position, with a speed of advance at least equal to the speed of movement of the belt which has the effect of virtually interrupting the removal, while bringing the head to the entry to the accumulation zone where it marks a stop time just sufficient for a sachet to be detected again and the cycle repeated identically according to the steps from "d", until complete filling from the box, h) said box is then evacuated by the pallet conveyor and positioned under a filling control plate which descends into the box to successively pack the contents and check the filling level; i) the pallet conveyor simultaneously taking a new box to the packing station, the complete cycle is renewed for its filling.

 According to an additional characteristic of the method according to the invention, the filling of the boxes is checked by advantageously using the pressure plate.

which comes, in a first phase, to pack the contents of the boxes at the end of the filling cycle, and, in a second phase, the same descending plate at constant pressure on the contents of the box will detect a filling fault if the stroke is too long or vice versa, if the plate is positioned according to a correct stroke, which will detect an excess of filling if the pressure is too strong.

 In accordance with a first variant of the method according to the invention, the products in flexible bags are introduced by gravity from an area where the bags are previously accumulated in complete rows which fall, at the opening of flaps provided for this purpose, in the box where they will generally be stacked row on row in two juxtaposed sets, for obvious economic reasons; the casing station being fixed in space and comprising only one casing line, it is therefore advisable to move the box under the station to constitute the juxtaposition of successive rows. In this case, the box arriving at the station d 'cashing by a pallet conveyor is supported by the action of two lateral flanges enclosing the box, thus separated from the pallet conveyor; the two flanges being integral with a mobile carriage, they can move in a horizontal direction, transversely with respect to the packing axis, and alternately drive the body on either side of the accumulation zone, in thus creating two juxtaposed stacks of complete rows of sachets; at the end of the cycle, the box is evacuated to the control zone, while the next is positioned under the packing station.

 In accordance with a second variant of the method according to the invention, the products in flexible bags, previously accumulated in complete rows over an area from which they are released by the opening of flaps provided for this purpose, are taken up by a forwarding conveyor not step by step to position a bucket under the flaps of the accumulation zone at each stop.

 On one of its sides, each bucket is provided with a transverse pusher capable of tightening the row of bags in said bucket for placing the case on the side; the pushers are actuated by a linkage coming into positive support on a fixed guide rail whose predetermined shape induces progressive displacement. The bucket conveyor then feeds a gripping system which comes by vacuum, removing the contents of the two buckets to deposit them directly in the crate, so as to constitute at once the two juxtaposed piles of complete rows of sachets.

 The various movements of the gripping system are obtained by conventional means of a "two-axis" robot; on the other hand, the particular gripping element consists of a deformable support provided on either side with horizontal coplanar plates comprising the vacuum system such as suction cups for example. The two plates then "cap" the last two buckets of the transporter to effect the transfer in the box; during the transfer, the deformable support of the trays will bring the said trays together for removal in juxtaposed stacks and, in a reverse movement, the support will reposition on two new buckets to carry out a new removal, until the case is completely filled which will then be evacuated to the control area, while the next one is positioned under the casing station.

 Whatever the variant of execution of the process, a casing of products in flexible sachets is carried out under the best filling conditions since it is possible at any time to estimate the overlap and / or the relative position of the sachets in each layer of the stacking: it is therefore possible to obtain not only great precision but also constant homogeneity in the packing of such products.

An embodiment of the present invention will be described below, by way of non-limiting example, with reference to the appended drawing in which
Figure 1 is a schematic plan view of the casing device in its variant with recovery and positive transfer, showing the relative location of the main elements of the device.

 FIG. 2 represents an elevation view of the device according to FIG. 1.

 Figures 3A, 3B, 3C, 3D, 3E are schematic elevational views respectively illustrating the five main states of the retractable head conveyor to form complete rows of bags on an accumulation area.

 FIG. 4 is a diagrammatic view of the casing device according to the variant of the invention shown in FIG. 1.

 Figure 5 is a schematic side view of the casing device according to the variant of the invention providing a direct filling by gravity.

 Figure 6 is an elevational view of the variant of the invention according to the previous figure.

 In accordance with FIG. 1, the flexible sachets 1 are presented on a vibrating conveyor 2 whose oscillations are superimposed on the main advance movement, thereby creating a uniform distribution of the products, such as candy, in the sachets 1 which gives them a relatively constant average thickness, as well as a relative flattening. As is, the sachets 1 are then taken up individually on a conveyor 3 driven by a DC motor at an advance speed fixed for the example at V m / s.

In resumption of this transporter 3 succeeds a new transporter 4 which offers several characteristics illustrated by the set of diagrams of FIG. 3.

 A first characteristic linked to the conveyor 4 results from the running speed of its winding band adjusted, by virtue of a direct current motor, to a value greater than the speed V of the conveyor 3; the adjustable speed differential between the output of the conveyor 3 and the input of the conveyor 4 creates a spatial offset between the successive sachets 1, proportional to the same speed differential, in order to provide dead times usable later in the packing process. Another characteristic of the conveyor 4, according to the invention, emerges from the retractable head 5 of said conveyor 4 which can oscillate longitudinally between two predetermined extreme positions in accordance with FIGS. 3A and 3B in the plane of the mat 4a receiving the sachets 1, which allows the useful conveyor length to be varied.

It will be noted that the movements of the retractable head 5 are obtained by known means of a mobile carriage or any other system with a lever arm driven advantageously by a direct current advance motor.

 Furthermore, the total length of the conveyor belt 4 being constant by construction and the movements of the head 5 introduce a modification of the useful length of the belt 4a, it is advisable to act on the return length 4b of said belt, correspondingly variable , to keep a constant belt tension; in this regard, a guide drum 6 is interposed in the part of the strip which is back under the belt 4a, to compensate, with each movement of the head 5, the variations in length which result therefrom. Indeed the drum 6 can move longitudinally under the carpet 4a, in a horizontal plane, the axis of rotation of said drum 6 being mounted on a mobile carriage whose movement, combined with that of the head 5, is controlled by a motor variable speed advantageously direct current.

 Thus perfected, the conveyor 4 can execute complete rows of sachets 1 on an accumulation zone 7 while continuously receiving the sachets 1 predisposed on the conveyor 3.

 FIG. 3A illustrates the first phase of approaching the sachets 1 whose relative spacing is obtained thanks to the speed differential of the two conveyors 3 and 4. A first sachet arriving at the end of the conveyor 4, the head 5 of said conveyor 4 then being in the maximum advanced position, is detected by a conventional position detector which triggers the recoil of the head 5 according to arrow A; in parallel, the drum 6 moves in the same direction to fold the excess tape back 4b induced by the recoil of the head 5, in order to keep constant the tension of the belt 4a and of the head 5, in order to keep constant the belt tension 4a and release the advanced part of the conveyor 4.

 As soon as the recoil of the head 5 is initiated, the bag 1 falls on a fixed plate 7 and constitutes the start of the row; the recoil of the head 5 continues until the arrival of the next bag, offset by the speed differential by a value such that its removal comes to take place next to the first bag on the plate 7, with or without overlapping partial according to the type of packing which one wishes to carry out, in accordance with FIG. 3B, and so on until constituting a complete row as shown in FIG. 3C. When the head 5 reaches the end of the plate 7 defining the accumulation zone, the movement of the head 5 and correspondingly of the tensioning drum 6 is then reversed, to bring the head 5 back to the advanced position, without changing the running speed of the belt 4a which normally continues to supply bags 1, as shown in Figure 3D, where the bag 1 arrives on the conveyor 4 at normal speed.

 As the useful length of the carpet 4a increases in front of said bag 1 along arrow B, its arrival at the end of the conveyor 4 is delayed just enough so that, on the one hand, the head 5 has time to return to the maximum advanced position at the entry of the accumulation zone 7 and that, on the other hand, the latter has released the preceding content in accordance with FIG. 3E, so that said bag detected at this instant triggers the recoil movement of the head 5 and is thus released in zone 7 to constitute the start of a new full rank, each cycle continuing thus. It will be noted that the zone 7 is in reality a plate made up of two half-flaps 8a and 8b as shown in FIGS. 2 and 6.

 These flaps 8 are in a horizontal position during the removal of a row by the conveyor 4 and they can pivot down around axes 9a and 9b located outside each half-flap in a vertical position, thus facilitating the steps of 'next casing, as will be seen later.

 In a first variant of the casing device according to I1 invention, the bags 1, formed in full row as just said, are collected in buckets 10 positioned step by step under the accumulation zone 7 by a conveyor 11 arranged perpendicular to the packing line of the conveyor 4 in accordance with Figures 1 and 2.

 As soon as a bucket 10 has received a row of sachets, helped in this by guiding the products thanks to the flaps 8, it moves one step towards a packing station 16. At one of the ends 12 of each bucket 11 a pusher 13, moves longitudinally in the bucket 10 by means of a rod 14 coming into positive support on a guide rail 15, fixedly mounted outside the conveyor 1. The rail 15, thanks to a studied profile in this sense, gradually tightens the bags forming the content of each cup 10 to bring them to the packing station 16 at the longitudinal dimension of the boxes 17. At this time, one or two gripping devices 18, depending on whether one works with one or two packing station, enter the contents of two buckets 10, each by conventional vacuum devices 19, to deposit them positively in the boxes 17 using a conventional "two-axis" manipulator in accordance with FIG. 4.

 The gripping devices 18 comprise a set of levers constituting a deformable parallelogram controlled by a simple jack 20 arranged diagonally. On either side of said parallelogram are arranged the vacuum devices 19. Thus an action of the jack 20 has the effect of tightening or spreading the two devices 19 in order to adapt, during the positive transfer of the rows in the boxes 17, l 'entE'axe of the same rows of products from an initial value equal to that of the buckets 10 to a value corresponding to the width of the boxes 17.

 These boxes 17 are also brought under the packing stations 16 by a pallet conveyor 21 and positioned by retractable stops 22; the rows are introduced by successive layer of two rows juxtaposed until the boxes 17 are filled which are then evacuated on the conveyor 21, in masked time during the return of the transfer tools, to the control station 23 where they arrive against a stop 24, other cases being similarly positioned under the casing station 16 for a new cycle.

 In a simplified variant of the boxing device according to the invention in accordance with FIGS. 5 and 6, each complete row deposited on the accumulation zone 7 by the conveyor 4 is directly introduced into a box 17 brought by the pallet conveyor 21 and positioned, for this purpose, by a stop 25 in line with the accumulation zone 7, the flaps 8 of which, opening, contribute to the safety of filling, by preventing the flaps of the box from closing, and guiding the descent of the sachets 1.

 In the case where cashing is carried out in two juxtaposed stacks of rows of sachets 1 in the box 17 conditioned for this purpose, a simple device for lateral displacement of the box 17 during loading is proposed in the invention. rmément in Figures 5 and 6. Two flanges 26a and 26b enclose the box 17 on either side of the conveyor 21; these flanges are integral with two mobile carriages 27a and 27b which can move horizontally in a transverse direction relative to the packing line, according to the arrows C in FIG. 6.

 The body 17, supported by the flanges 26, can therefore be alternately positioned to the left and to the right of the zone 7 in order to create, at each opening of the flaps 8a, 8b of the said zone 7, a juxtaposition of rows of bags, the movement continuing until the box 17 is completely filled, which is then evacuated by the conveyor 21 to the control station 23 common to all the variants of the process.

 According to one characteristic of the invention, the central station 23 is made up of a plate 28 which covers the contents of the body 17 positioned by means of a stop 24.

 In a first phase, the plate 28 is lowered into the body 17 by conventional jacks 29 in order to carry out a compaction; in a second phase, the same plate 28 is positioned in the box, at a height corresponding to a normal theoretical filling of the same box, then the pressure is controlled which, at this altitude, requests the plate 28, and this pressure is compared to the theoretical pressure range resulting from normal filling. If the pressure observed is higher, this means that the filling is excessive; conversely, the platform being limited to a constant descent pressure, the race observed until it stops on the contents of the box must correspond to a theoretical altitude above which the box will be insufficiently filled.

 It will be observed that the execution times of these tamping and filling control functions are carried out in masked time as, moreover, all the other operations of conveying the body or transfer whether it is the accumulation 7 or of the gripping device 18. All of the operations, whether they follow one another or are carried out in masked time, are fully coordinated by a programmable automaton. It is obvious that any other combination in the succession of the steps of the method according to the invention or any other arrangement for implementing it would be fully within the scope of the present invention.

Claims (12)

 1.- Method of casing products in single bags in bulk and continuously allowing, on the one hand, the precise positioning of said bags in their case according to a configuration which can, on request, vary instantly without interrupting the packing and providing, on the other hand, a final control of the filling of the boxes, characterized in that: a) the sachets (1) are supplied in bulk on a vibrating conveyor (2) which ensures a good distribution of the product in the sachets; b) the sachets (1) are then taken up by a conveyor belt (3), driving said sachets (1) at constant speed (V), to a second conveyor (4) arranged in the axis of the first and whose the running speed is greater than the speed (V) of the first belt conveyor by an adjustable positive quantity (x), intended to impose a spacing between the successive sachets (1); c) the head (5) of the second conveyor (4), mounted on a movable plate, can move forward or backward horizontally along the axis of said conveyor (4), - by providing a mat (4a) of a useful length depending on the advancement or retreat of the head (5) of said conveyor (4); d) a sachet (1), being detected at the end of said mat (4a), triggers the rapid retraction of the head (5) of the mat (4a) thereby releasing the sachet (1), while continuing to retreat to allow the next sachet, in a combined movement of advancing the carpet (4a) and receding the head (5), to be released in a predetermined position relative to the previous sachet and so on until constituting the -deposition of '' a full row on a horizontal accumulation zone (7), which can then release said row which thus increases the filling of a box (17) positioned for this purpose by a pallet conveyor (21) e) either directly by gravity, f) either indirectly by means of a new transporter (11) with buckets (10) feeding a gripping device (18), to positively integrate the rows of bags (1) in said box (17) , g) at the same time and to allow the accumulation area ~ lation (7) emptied of its contents to return to the original position for r a new loading, the head (5) of the belt (4e) returns to the advanced position, with an advance speed at least equal to the speed of movement of the belt (4a) which has the effect of virtually interrupting the removal , while returning the head (5) to the entry of the accumulation zone (7) where it marks a stopping time just sufficient for a bag (1) to be detected again and the cycle renewed at l '' identical according to the steps from d, until complete filling of the box (17), h) said box (17) is then evacuated by the pallet conveyor (21) and positioned under a plate (28) of con filling plate which descends into the box (17) to successively pack the contents and check the filling level; i) the pallet conveyor (21) simultaneously taking a new box (17) to the packing station (16 or 16 '), the complete cycle is renewed for its filling.  2.- Method according to claim 1 characterized in that in step d, a pneumatic presser (28,29), descending into the box (17) to successively compact the bags 1 and a filling control, detects - incomplete filling by checking the presser stroke (28,29) - excessive filling by checking the pressure.  3.- Method according to any one of the preceding claims, characterized in that for the continuous casing of products in flexible bags stacked row by row in two sets juxtaposed in a box whose filling is carried out by gravity, characterized in that that said box (17) is supported by a mobile carriage (27) which can move in a horizontal direction, transversely with respect to the packing axis, in order to laterally move the box (17), for example to the left after the removal of a first complete row, by a distance substantially equal to the width of said row by triggering the deposit in the box of a new full row juxtaposed with the previous one, the box (17) then being, by a reverse movement , brought to the right of the first row to receive a new row, then moved again to the left to receive the next row and so on until the box is completely filled (17).  4.- Method according to any one of claims 1 or 2 characterized in that the gripping device (18) positively and simultaneously introduces two complete rows juxtaposed in the body (17), the transfer time being used to tighten their center distance from an initial value identical to that of the cups (10) to the value necessary for their introduction into the box (17).  5.- Method according to claim 4 characterized in that the length of the rows of products is adjusted to the dimension of the box (17) during their transfer in the cups (10) of the conveyor (11) before taking over by the gripping device (18).  6.- Device for casing products in flexible bags in bulk and continuously implementing the method according to any one of the preceding claims, characterized in that it puts the transporter-vibrator (2) on line supplying a conveyor belt (3) whose running speed is maintained at a predetermined value (V), feeding in turn a belt (4a) whose useful transport length can vary within wide proportions by retraction and stretching of the head (5) of the belt (4a) alternately in a horizontal plane, and the running speed of which is maintained at a predetermined value greater than the predetermined value (V) by a positive and adjustable quantity (x), thus forming rows of bags (1) on an accumulation zone (7) in predetermined overlapping arrangements taking into account the type of packing.  7.- Device according to claim 6 characterized in that the strip return length (4b) of the conveyor (4), variable depending on the position of the retractable head (5), is folded under the belt (4a) of said conveyor (4) by a guide drum (6) whose axis of rotation can move horizontally in a plane parallel to the plane of the belt (4e), and arranged under the same belt (4a) so as to maintain the tension of the conveyor belt (4) constant in a movement combined with that of the head (5).  8.- Device according to any one of claims 6 or 7 characterized in that the accumulation zone (7) allowing the constitution of a full row of bags (1) consists of two flaps (8) longitudinally juxtaposed in a horizontal plane, and being able on command to pivot simultaneously downward around axes (9) arranged on the outer edges of the flaps (8) and coli nary to the line of the carriers (2,3,4,) in order to releasing the full row of sachets (1) either directly in a box (17), the flaps (8) in the vertical position prohibit the closing of the flaps of this box, or indirectly in recovery, the flaps (8) in the vertical position coming to guide the transfer of the sachets (1) into the buckets (10) of a transporter (11).  9.- Device according to claim 8 characterized in that each bucket of the conveyor (11) ensuring the step-by-step transfer of the sachets (1) to the packing station (16) is provided with a pusher (13) which can move inside said bucket (10), in a direction transverse to the direction of travel, by a distance varying with the appropriate profile of a fixed rail (15) on which it is guided through a classic set of rod and rollers (14) in order to tighten the bags (1) at the side of the body (17).  10.- Device according to claim 9 characterized in that the gripping device (18) consists of two heads (19) with conventional vacuum, mounted collinearly on either side of a support (18) with deformable pa , simultaneously covering the contents of two successive cups (10) brought in line with said heads (19) by the conveyor (11) in order to transfer them positively into a box (17), the center distance of the heads (19) thus varying from an initial position identical to the center distance of the cups (10) to a final position substantially equal to the width of a row of bags (1).  11.- Device according to any one of claims 6 to 10 characterized in that all the drive motors of the carriers (2,3,4) as well as the retractable head (5) and the drum (6) advantageously direct current type, can operate at variable speed in order to adjust at will all the absolute or relative speeds of the real or apparent movement of the sachets (1) on the conveyors (2,3,4).  12.- Device according to claim 8, for the continuous casing of products in flexible bags, carried out directly by gravity in a box (17) positioned for this purpose by the pallet conveyor (21) in line with the area of accumulation, characterized in that the box (17) is separated from the conveyor (21) by the clamping of two flanges (26a, 26b) coming to bear on the sides of the box on either side of the conveyor (21), the two flanges (26a, 26b) being integral with a mobile carriage (27) thus ensuring the lateral movement of the box (17) under the boxing area (16), to allow rows of juxtaposed sachets to be placed.