FR2707948A1 - Device and method for packaging a product in a tray - Google Patents

Abstract

This is a device (2, 2', 2'', 2''') and a method for packaging a product (3) in a tray (4) made from rigid sheet material. The device includes a first element (11) for turning down a first flap (8a) over the top (9) of the product, means (12) for displacing the first element between a high position (13, 54), separate from the product, and a low position (14, 55), in which the first element rests through gravity on the first said flap (8a) bearing on the top of the product, a second element (27) for turning down a second flap (8b) over the top of the first flap, and means (31) for displacing the second element between a high position (56), separate from the product, and a low position (58), in which the second element rests through gravity on the said second flap, pressing it over the first flap.

Description

DEVICE AND METHOD FOR TARGE PACKAGING OF A PRODUCT
IN A TRAY
The present invention relates to a device and a method for automatically packaging a product in a tray made of rigid sheet material, such as cardboard, corrugated cardboard or the like, comprising a belt and a bottom, said belt being provided with a first and a second upper side flaps, facing each other, arranged to overlap each other in the folded position on the product.

 It finds a particularly important although not exclusive application in the field of packaging in a tray of corrugated cardboard sheet, of products whose height dimensions can vary from one product to another.

 Devices for automatic packaging of a product are already known in a sheet of cardboard using the overwrapping technique known as "wrap around" in Anglo-Saxon language.

 This technique involves wrapping the product with a sheet of paper.

 The product is placed on a bottom provided with flaps which are then pressed for example by jacks or push plates on the product itself.

 Such a technique requires having a product of volume and repetitive shape, perfectly defined, making it possible in particular to provide fixed cylinder strokes.

 It therefore has drawbacks as soon as one wants to package products, for example fragile, whose shape is irregular, and in particular whose height can vary from one product to another, which is for example the case of breads or rusks whose volume varies depending on the baking temperature and / or the amount of yeast used.

 The present invention aims to provide a device and a method for packaging a product which better meets those previously known than the requirements of the practice, in particular in that it allows automatic or semi-automatic packaging of products whose height varies. from one product to another, in a simple and easy to implement manner, without risking damaging the product.

 To this end, the present invention proposes in particular a device for packaging a product in a tray made of sheet material comprising a belt and a bottom, said belt being provided with first and second upper side flaps, in screw screw, arranged to cover each other in the folded position on the product, characterized in that it comprises a first element for folding the first flap over the top of the product, means for moving said first element between a position high, away from the product and a low position where the first element rests by gravity on said first flap resting on top of the product, a second element for folding the second flap on top of the first flap, and means for moving said second element between a high position, away from the product and a low position where the second element rests by gravity on said second flap by applying it to the first flap .

 Such an arrangement allows the pressurization of the areas above the first flap and below the second flap, areas which, one or the other, have been at least partially glued beforehand.

 In advantageous embodiments, use is made of one and / or the other of the following arrangements - the means for moving the first or second folding element comprise means for transversely moving said element between a first position , released from any contact with the flap concerned and a second position of contact with the flap concerned above the product, and means for releasing said element so that it falls by gravity from said second position onto said flap concerned - the first folding element comprises a transverse bar parallel to the direction of the first flap, capable of coming to bear on said first flap - the second folding element comprises a folding plate, a portion of the end of which is adapted to come to bear on the second flap - the means for moving at least one of the folding elements comprise a negative action cam - the means for release of the folding element comprise a single-acting cylinder, with negative action - the tray consisting of a bottom connected on each of its sides to a flap to form said belt, it comprises means for erecting a last side flap to close said belt on itself around the base of the product before folding the flaps.

 The invention also provides a method of packaging a product in a tray made of rigid sheet material, comprising a belt and a bottom, said belt being provided with first and second upper side flaps facing each other. screws, arranged to overlap each other in the folded position on the product, characterized in that after introduction of the product into the tray and gluing of an area above the first flap or below an area of the second flap, one folds down gravitatively on the first flap a first folding element which comes to bear its own weight on said first flap itself then coming into contact with the top of the product, and one folds gravitatively on the second flap a second element of folding the second flap over the top of the first flap where it is fixed by pressurizing said areas, at least one of which has been previously glued.

 Advantageously, to fold one of the folding elements, the element is first moved transversely between a first position, free from any contact with the flap concerned and a second position of contact with the flap concerned above the product, then releases said element so that it falls by gravity from said second position onto said flap concerned.

 In an advantageous embodiment, the tray consisting of a polygonal bottom connected on each of its sides to a flap to form said belt, a last side flap is erected to close said belt on itself around the product before folding the flaps .

 The invention will be better understood from the following description of an embodiment of the device according to the invention given by way of non-limiting example.

 The description refers in particular to the accompanying drawings in which - Figure 1 is a mechanical diagram of an embodiment of the device according to the invention.

- Figure la is an example of a package obtained with a tray used for packaging products with a parallelepiped base, of the sliced bread type.

- Figures 2 and 3 are schematic views respectively from the front and side, on a larger scale, of the folding elements of the flaps according to the embodiment of the invention more particularly described here.

FIG. 4 is a schematic view showing an embodiment of the means for moving the bar of FIGS. 2 and 3.

- Figure 5 is a simplified diagram of a packaging machine for automatic and simultaneous packaging of four trays with four devices according to the invention.

 Figure 1 shows a system 1 comprising several packaging devices, for example two devices 2 and 2 'arranged side by side.

 The device 2 allows the packaging of the products 3 substantially parallelepipedic, for example formed for sliced breads pre-wrapped in cellophane paper, in trays 4 of double-sided corrugated cardboard, of small thickness (for example 2 mm).

 The trays 4 (see also FIG. 1 a) comprise a rectangular bottom 5 and a belt 6 constituted by rectangular lateral flaps 7 perpendicular to the bottom 5 and respectively connected to each of the sides of the bottom by fold lines 7 '.

 Two of the flaps 7, facing each other, each comprise an identical upper lateral flap 8a and 8b, for example in the form of a handle handle, connected to the corresponding flap by a fold line 8 'parallel to the fold lines 7 'lower of the corresponding flap.

 The maximum transverse dimension of the flaps, perpendicular to the fold line 8 ', is such that the two flaps overlap each other in the folded position on the top 9 of the product 3, the base 10 of which is inserted by friction or with a slight play in the parallelepipedic belt of the tray.

 The device 2 comprises an arm 11 for folding down a first flap 8a on the top 9 of the product, and means 12 for moving the arm between a high position 13, separated from the product and said first vertical flap 8a, and a low position 14, where the arm rests by gravity on the first flap pressed by the weight of the arm on top of the product.

 The arm is for example constituted by a V-shaped metal part 15 provided with two branches of unequal lengths, able to pivot around a fixed axis 16 located at the junction between said branches of the V.

 The longest branch has at its end a crossbar 17 for plating.

 The shortest branch is in turn connected at its end by a ball joint 18 connecting with the displacement means 12.

 These include for example a vertical rod 19 fixed at its upper end pivotally to the ball joint and cooperating at its lower end in the form of a fork via a friction surface, with the end of an arm lever 20.

 Means 21 for guiding the rod between a high position for spacing the arm and a low position for the gravitational release of the rod 19, and therefore of the arm, over a sufficient stroke, are also provided.

 The other end of the lever arm 20 is rigidly connected to an actuating bar 22 by a push cylinder 23.

 The displacement means 12 further comprise a cam 24, said to have negative action, taking into account the action of the jack which therefore acts continuously in the opposite direction to the cam. The cam rotates around an axis 25 and is arranged to cooperate with a roller 26 secured to the lever arm 20.

 The device 2 also comprises a folding plate 27 of the second flap 8b on the first flap.

 The plate 27, for example metallic, is pivotally mounted around an axis 28, and comprises a first rectangular part 29 extending longitudinally in the direction of the container to be formed, on the side of said container relative to the axis 28, and a tab 30 located on the other side of the axis.

 The axis 28 is integral with the means 31 for transversely moving the plate between a first position clear of any contact with the second flap 8b and a second position of contact with the second flap 8b above the product.

 The means 31 comprise a movable assembly 32 actuated by a cam 33 with negative action and a pusher cylinder 34 acting against the direction of the cam.

 The crew 32 comprises a part 35 provided with a first arm 36 secured to the axis 28, and with a second arm 37, for example forming an angle of 1500 with the first.

 The part 35 is pivotally mounted around an axis 38 located between the two arms.

 In FIG. 1, the part 35 is shown diagrammatically with a third arm 39 connected by a linkage system 40 shown in phantom, for controlling the part 35 ′ of the other device mounted in series, which makes it possible not to use only one moving crew actuation system for the two devices.

 The end of the arm 37 is connected by an axis 41 to a vertical rod 42, itself connected in the lower part to the end of a square piece 43.

 The part 43 is pivotable about an axis 44, fixed, perpendicular to the plane of the bracket, provided with two branches of substantially equal length, and located at the junction between the branches 45 and 46 thereof.

 The end of the branch 45 is pivotally connected to the rod 42 and that of the branch 46 is connected to the push cylinder 34.

 The branch 45 is moreover provided with a roller 47 arranged to cooperate with the cam 33.

 Means for supplying and controlling the device (not shown) are also provided.

 In particular, in a manner known per se, they include rotary actuating motors for the cams, control means, for example mechanical, for the movements of two cams with one another in order to respect the sequences, etc.

 The cylinders 23 and 34 are cylinders known in themselves, at constant pressure.

 The device 2 also includes means 48 for releasing the plate 27 so that it falls by gravity from the second position onto the second flap, under the effect of its own weight.

 These means 48 comprise a single-acting cylinder, with negative action which acts on the tab 30.

 FIG. 1a is an example of a package 50 obtained with a tray 4, the flaps 8a and 8b of which, previously glued to at least part of the lower surface of the flap 8b and / or the upper of the flap 8a, have been folded down gravitatively on the product 3, for example crackers, with the device described above.

 In the following drawings, the same reference numbers as those in FIG. 1 are used to designate the same elements.

 Figures 2 and 3 show more precisely the tray 4 at the leveling station itself.

 The tray is conveyed by conveyor means 51, for example a conveyor belt.

 In this embodiment, the folding arm comprises a bar 17, integral with, and perpendicular to, an arm 52 which is arranged to pivot around an axis 53 in a plane parallel to the direction of movement F of the conveyor.

 The bar 17 has for example a weight of a few tens of grams and extends over a length suitable for allowing the flap 8a to be folded down, the bar 52 being sufficiently offset laterally (see FIG. 3) to allow the installation of the conveyor means 51 carrying the tray.

 The arm 17 can pivot around the axis 53 by an angle a between a high position 54 where the bar 17 is entirely disengaged from the vertical flap 8a and the low position 55, variable because it depends on the height of the product, where the arm rests by gravity on the first flap 8a (position 8'a in phantom in Figure 2).

 The device also comprises the plate 27 comprising a flat part 29, extending lengthwise over a sufficient distance, and the tab 30, integral with the part 29.

 As we have seen, the plate 29 is, in turn, arranged to move between a first position 56, free from any contact with the second flap, an intermediate position 57 of contact with the second flap which then comes into position 8'b folded around the fold line provided at the junction with the corresponding flap, and a third position 58 where the plate rests by gravity on the second flap in position 8 "b, which is then applied on the one hand product and on the other hand on the overlapping end of the first flap, previously glued at 60.

 FIG. 2 also shows the single-acting cylinder 48, which, when it disappears, releases the tab 30 and allows the gravity drop of the plate 29.

 FIG. 3 also shows means for closing the last flap 59 of the tray, located at the station for folding down the flaps. These means are for example constituted by a jack 60 actuating a pressure plate 61.

 A stop 62 also provides back pressure on the other side of the package.

 FIG. 4 schematically shows the means for moving the bar 17, according to the embodiment of the invention more particularly described here.

 A structure 63 for supporting the device is provided (in phantom in the figure), the axis 25 of the cam 24 being parallel to the direction of travel 54 of the trays.

 FIG. 5 schematically shows a machine 64 comprising four devices 2, 2 ', 2 "and 2"' according to the invention, mounted on a support structure 65 (in phantom).

 A single cam for moving the arms 20, 20 ', 20 ", 20' '' acting on the first folding elements, in this case the bars and parts 17, 17 ', 17" and 17 "' and 11, 11 ', 11 ", 11' '' on the one hand, and a single set 31 of the means for moving the plates 27, 27 ', 27" and 27 "' on the other hand, are provided.

 These displacement means are actuated in a manner known in itself by electric motors or the like.

 The use of cams allows perfect repeatability of mechanical movements.

 We will now describe the operation of a device, with particular reference to Figures 1 and 2.

 The trays 4 are first of all formed in a manner known per se, for example around a mandrel as described in document EP 468,869.

 The product 3 is then automatically inserted into the tray whose flaps 8a and 8b have remained vertical, which allows for example the introduction of said product from above, in a manner known per se.

 Is then applied to an area below the second flap 8b and / or above the first flap 8a one or more lines of glue.

 The trays are then conveyed by the conveyor 51, for example in groups of four to the folding stations where they are immobilized for the operations which will now be described with reference to FIG. 2.

 In the initial position, the bar 17 is in the high position 54 and the plate 29 is in the high position 56.

 The movements are then executed sequentially in the following manner.

 The cam 24 rotates so as to push down the arm 20, which lets the rod 19 gravitatively descend guided by the means 21.

The rod 19 being integral with the part 11, the bar 17 gradually descends towards the product.

 It hooks on the flap 8a which it comes to support by its weight on the product 3.

 At the end of movement of the bar, it rests on the flap 8a in position 8'a, flap which has therefore pivoted around the fold line 8 'between flap and flap.

 The cam continuing to push the arm 20 downwards, it is the product 3 and its shape which stops the descent of the rod 19 and the bar 17 which therefore rests by its simple weight on the flap 8a which presses on the top of product 3.

 The cam then continues its course while keeping the arm 20 apart downwards, so as to leave room now for the movement of folding of the second flap 8b by the plate 27.

 This is controlled by the cam 33 which acts on the bracket 43.

 Once the bar 17 is supported, the movement of the plate is as follows.

 The cylinder 48 being in the actuated position, pressing on the tab 30, the cam 33 rotates so as to push the rod 42 upwards.

 This acts on the part 35 which pivots around the axis 38 so that the plate 29, initially in position 56 comes into the intermediate position or second position 57 after having hooked the second flap 8b which then takes the folded position 8'b after folding around the fold line 8 'between flap and corresponding flap.

 At the end of this movement, the pivot axis 28 is in the lower position 28 '.

 The cam 33, which continues its rotational movement, is then arranged to maintain the plate in this position.

 The jack 48 is released and the tab 30 being released, the plate 29 falls by gravity on the flap on which it presses by its end portion, to lead to position 58, where said second flap takes the position 8 "b in support on top of the end of the first flap.

 Due to the pressure of the plate, the second flap is then fixed on the first flap, by pressurizing the areas of the flaps facing each other previously glued.

 The cams 24 and 33 continuing to rotate, are then arranged to give back control to the push cylinders 23 and 34 which push against the direction of the bar 17 and the plate 27, which thereby rise upwards, respectively 54 and 56.

 The packaged bread is then taken up by the conveyor means so as to make room for a next tray with its vertical flaps.

 A device and a method like that of the invention have the particular advantage of allowing a significant packaging rate, for example of twenty trays per minute and per station, or eighty trays per minute if four stations are used.

 As is obvious and as follows from the above, the present invention is not limited to the single embodiment previously described.

 On the contrary, it encompasses all the variants thereof, and in particular that in which the folding of the first flap is carried out in two stages, the folding of the second flap being carried out in one stroke.

Claims (11)

 1. Device (2,2 ', 2 ", 2' '') for packaging (3) a product, in a tray (4) made of rigid sheet material, comprising a belt (6) and a bottom ( 5), said belt being provided with first and second upper lateral flaps (8a, 8b), facing each other, arranged to overlap each other in the folded position on the product, characterized in that that it comprises a first folding element (11) of the first flap (8a) on the top (9) of the product, means (12) for moving said first element between a high position (13,54), spaced from the product and a low position (14, 55) where the first element rests by gravity on said first flap (8a) in abutment on the top of the product, a second folding element (27) of the second flap (8b) on the top of the first flap, and means (31) for moving said second element between a high position (56), separated from the product and a low position (58) where the second element rests by gravity s ur said second flap by applying it to the first flap.  2. Device according to claim 1, characterized in that the means (12,31) for moving the first first or the second folding element comprise, means (32) for transversely moving said element between a first position (56), disengaged from any contact with the flap concerned and a second position of contact (57) with the flap concerned above the product, and means (48) for releasing said element so that it falls by gravity from said second position onto said flap concerns.  3. Device according to any one of the preceding claims, characterized in that the first folding element (11) comprises a bar (17) transverse parallel to the direction of the first flap, capable of coming to bear on said first flap.  4. Device according to any one of the preceding claims, characterized in that the second folding element (27) comprises a folding plate (29), a portion of the end of which is capable of coming to bear on the second flap.  5. Device according to any one of the preceding claims, characterized in that the means (12,31) for moving at least one of the folding elements comprise a cam (24,33) with negative action.  6. Device according to any one of claims 2 to 5, characterized in that said means (48) for releasing the folding element comprise a single-acting cylinder, with negative action.  7. Device according to any one of the preceding claims, characterized in that, the tray (4) consisting of a bottom (5) connected on each of its sides to a flap (7) to form said belt, it comprises means (60) for erecting a last lateral flap (59) for closing said belt on itself around the base (10) of the product before folding down the flaps.  8. Application of the device according to any one of the preceding claims to the packaging of a product in a tray of corrugated sheet material.  9. Method for automatic packaging of a product (3) in a tray (4) made of rigid sheet material, comprising a belt (6) and a bottom (5), said belt being provided with a first and with a second upper lateral flaps (8a, 8b), facing each other, arranged to cover each other in the folded position on the product, characterized in that after introduction of the product (3) into the tray (4) and gluing an area above the first flap or below an area of the second flap, a first folding element (11) is gravitatively folded over the first flap which bears its own weight on said first flap even then coming into contact with the top of the product, and a second folding element (27) of the second flap is gravitatively folded over the second flap on top of the first flap where it is fixed by pressurizing said zones, at least of which one was previously glued.  10. Method according to claim 9, characterized in that, to fold down one of the folding elements, said element is first moved transversely between a first position (56), released from any contact with the flap concerned and a second position (57) of contact with the flap concerned above the product, then releasing said element so that it falls by gravity from said second position onto said flap concerned.  11. Method according to any one of claims 9 and 10, characterized in that, the tray (4) consisting of a polygonal bottom (5) connected on each of its sides to a flap to form said belt, erect a last side flap to close said belt (6) on itself around the product before folding the flaps.