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(11) | EP 2 388 197 A1 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | Machine for continuous cartooning of products |
| (57) Machine for continuous cartoning of products (P) inside cardboard boxes (100), comprising
a product conveyor (2), a box conveyor (3) and a loading station (4) with a product-inserter
group (5), operating with continuous motion; an additional group (10) for keeping
a box in shape during the product-insertion operation, by temporarily inserting a
shaping pin (11) into a box, from the opposite side to the product-insertion side,
during the passage of the box through said loading station (4).
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Field of application
Prior Art
[0002] A cartoning machine of the type herein considered comprises a loading station, essentially with at least one first conveyor that transports the products and one second conveyor that transports the empty cardboard boxes. Appropriate inserting devices transfer the products from the first conveyor into the boxes on the second conveyor, without a solution of continuity of the movement of said conveyors. Typically, the two conveyors are positioned side by side, with products and boxes transported at the same speed and pitch, so that a product on the first conveyor, during transit through the loading station, is facing a respective box; the inserting devices are represented by pushers with an alternating piston motion, which push each product into the respective box, as the product and box proceed side by side along the loading station. This type of cartoning machine (or line) is well known.
[0003] Cardboard boxes are normally parallelepiped shaped with a square or rectangular cross-section.
[0004] In some applications, however, there is a need to use boxes with a more elaborated cross-section. For example, the use of substantially tubular cardboard boxes, with flat upper and lower faces and two slightly curved sides, for example rounded so that the box has a "barrel" cross-section, is becoming widespread. Other examples may contemplate a hexagonal section, etc. The requirement for a box with a special shape and section may arise from purely aesthetic or marketing considerations, or from the need for an appropriate product holding, due to the shape of the actual product, for example. The product, purely as an example, may be a flowpack containing a backed foodstuff, a snack, etc. and may have an elongated or flattened section.
[0005] The boxes are generally loaded in the form of blanks into an appropriate magazine, and picked up by a carton feeder, in a rapid movement, which opens them and feeds them to the respective conveyor.
[0006] Handling complex-shaped boxes poses some problems that are not easy to solve. In particular, boxes with a complex shape, with rounded sides for example, have been found to be more exposed to occasional deviations from the design specification. A box positioned on the relative conveyor may fail to comply with the specification due, for example, to the effect of the flexibility of the cardboard and/or the rapid movement of the carton feeder. For example, the curvature of the walls may be less accentuated than expected or, in extreme cases, may be opposite to the design curvature (inverted walls). Consequently, it may be impossible to insert the product, causing a reject or in the worst case a blockage of the machine. Similar drawbacks may derive from incorrect positioning of the front closing flaps of the box, which may also hinder loading of the product and/or prevent correct closure.
[0007] For a better understanding of the technical problem underlying the invention, reference is made to the accompanying Fig. 6 which represents the cross-section of a cardboard box 100, given by way of example. This box has flat upper face 101 and lower face 102 and sides 103 curving outwards, obtaining a rounded cross-section. The curve of the sides 103 is obtained when the blank is opened, by the separator, and positioned on the conveyor. Due to the effect of the intrinsic flexibility of the cardboard and/or defect in the quality of the blanks, the rounded sides 103 may not open sufficiently, giving a narrower cross-section, or may invert and assume the configuration indicated by the dotted line 104, which prevents the insertion of the product. Similar problems are encountered with boxes of another shape, more complex than the common square or rectangular cross section.
[0008] The problem is accentuated as the speed of the machine in pieces per minute [pcs/min] increases and therefore as the working speed of both the box separator and the conveyors and product inserters increases. In fact, the market requires machines that are increasingly faster and more accurate. In a machine designed to operate at high speeds, the tolerance levels are usually lower compared to a slower machine, and any deviations from the specifications become more insidious.
Summary of the invention
[0009] The aim of the invention is to enable an effective and certain insertion of products into boxes with complex cross-sections, such as for example boxes with variously polygonal or rounded sections or more generally with curved walls, in a cartoning machine with continuous operation.
[0010] The solution involves equipping the loading station with a system to keep the boxes in shape by temporarily insertion into the box of an appropriate shaping pin, operated in a synchronised way with the box conveyor and the product-inserter group.
[0011] The problem is therefore solved with a machine for continuous cartoning of products, said machine comprising at least a first product conveyor, a second box conveyor, a loading station with a group for inserting products inside the boxes, from a product-insertion side, said first conveyor and second conveyor and said inserter unit being operated with a continuous and synchronised motion, by which said inserter unit transfers products from said first conveyor into boxes with ends open and positioned on said second conveyor, characterised in that: the machine comprises at least a further group for keeping said boxes in shape, said further group being synchronised with said product conveyor, box conveyor and inserter unit, said further group comprising at least one shaping pin operated with a movement of insertion into a box and subsequent extraction from said box, from a side opposite to said product-insertion side, during the passage of the box through said loading station.
[0012] Preferably, said at least one shaping pin is operated to enter the box, entering by a fixed linear extent, substantially at the same time the product is inserted from the opposite side of the box. For example, the insertion of the shaping pin into the box takes place slightly before, or substantially at the same time as, the insertion of the product.
[0013] An object of the invention is also respective method for the continuous cartoning of products, wherein: a plurality of products and a plurality of boxes are transported by a first conveyor and by a second conveyor respectively; the products are transferred with a continuous insertion movement from said first conveyor into boxes on said second conveyor, the first and second conveyors having a synchronised advance motion and an arrangement of products and boxes with the same pitch; the insertion of products being effected from a product insertion side of the boxes arranged on said second conveyor, said method being characterised in that at least one shaping pin is inserted into each of said boxes, from a side opposite to said product insertion side, substantially concurrently with the initial phase of insertion of the product into the box.
[0014] In a preferred application, the boxes have a substantially tubular shape. An application consists in handling boxes that have curved side walls, for example boxes with rounded cross-sections.
[0015] Some preferred structural aspects are now described. Reference is made to at least one shaping pin; in practice a plurality of shaping pins are preferably provided, the number of said pins corresponding to the number of product inserters of the insertion group, so that every step of inserting a product is assisted by a respective shaping pin.
[0016] In a preferred embodiment, said at least one shaping pin comprises a shaft portion and a head portion. Advantageously, the shaft portion is made of metal while the head portion is made of a plastics material. Furthermore, the head portion is advantageously replaceable in order to configure the machine to operate with boxes of different shapes. More preferably, the pin or pins comprise a shaped head, advantageously with a tapered insertion end, for example in the shape of a wedge, arrow, etc., these embodiments being equivalent. A tapered shape of the head end of the shaping pin facilitates entry into the box even when, for example, the inlet section of a box on the conveyor is smaller than expected under design conditions, due to a deformation of the box or incorrect opening of the blank.
[0017] Preferably, said at least one shaping pin is operated with an alternating rectilinear motion relative to a conveying unit, which is synchronised with said product conveyor and box conveyor. The conveying unit is for example a conveyor belt. In particular, the alternating rectilinear motion involves: an insertion phase of the shaping pin into a box, to a fixed distance of penetration; a subsequent phase of extraction of the pin from the box, to leave the internal volume of the box free and enable the complete insertion of the product. More preferably, the insertion and extraction of the shaping pin occur along a substantially straight portion of the travel of the product and box conveyors respectively, alongside each other along the part of the machine that corresponds to the loading station.
[0018] Said alternating motion is advantageously operated by a mechanical guide, or a cam system, or equivalent mechanical device. In one embodiment, said at least one shaping pin is controlled by a bearing connected to said pin and engaged in a guide that is fixed relative to said conveying unit. More preferably, said at least one shaping pin comprises a shank portion and a head portion; the shank portion slides linearly on a respective fixing support on said conveying unit; at least one rotating bearing is connected to the shank portion, and said bearing can engage a guide that is fixed in relation to the conveying unit. The engagement between said bearing and said guide imparts the above-mentioned alternating motion on the shaping pin. Each shaping pin can optionally be connected to a resilient device, such as a spring.
[0019] The product conveyor and box conveyor are of a known type, for example chain conveyors, and their embodiment is not essential for the purposes of the invention. The synchronised command and control of the product conveyor, box conveyor and the unit that carries the shaping pins is achieved using known techniques.
[0020] The invention allows the correction of an error in the shape of a box during the critical phase of product insertion; the insertion of the above-described shaping pin allows to restore the cross section of the box, by correcting an error in shape caused by the flexibility of the cardboard and/or by the handling made by the carton feeder. The invention avoids that a box reaches the loading station outside design specifications, which could compromise insertion of the product. The advantages of the invention therefore comprise a more certain and reliable handling of high production capacities and the possibility to work with complex-shaped boxes, maintaining a fast and stable process. These advantages will become more evident with the aid of the following description of a preferred embodiment.
Brief description of the Figures
[0021]
Fig. 1 is a top view of the machine for loading products into cartons, according to an embodiment of the invention.
Fig. 2 is a detail showing some of the units of the machine in Fig. 1, particularly the shaping-pin inserter unit.
Fig. 3 shows schematically the shaping-pin inserter unit of Fig. 2, alongside the box conveyor, in the loading station of the machine in Fig. 1.
Fig. 4 is a detail of Fig. 2, relating to one of the shaping pins.
Fig. 5 shows schematically the mechanical control of the pins of the unit in Fig. 2.
Fig. 6 is a schematic section of one of the types of boxes that can be used advantageously with the machine in Fig. 1.
Detailed description of the invention
[0022] A machine for continuous cartoning of products is shown as a whole in Fig. 1. The products P are fed by a launch belt 1 and loaded onto a continuous-motion product conveyor 2, with the appropriate pitch p. For this purpose, the conveyor 2 is preferably configured with a series of product-carrying pockets or equivalent devices to contain and convey the products, appropriately spaced apart.
[0023] The machine inserts said products P into boxes 100, which are transported by a box conveyor 3, with the same pitch p. The boxes 100 have, for example, a tubular-prismatic shape with rounded side walls, as illustrated in Fig. 6.
[0024] The product conveyor 2 and the box conveyor 3 are synchronised and have the same speed of advance. In a portion of the machine which is identified as loading station 4, the conveyors 2 and 3 run side by side, so that a product P on the product conveyor 2 is aligned and along the same axis of a respective open box 100 which is positioned on the juxtaposed box conveyor 3. An inserter group 5 operates within the loading station 4 and in the example comprises a plurality of inserter devices 6 which act with a substantially piston movement. The inserters 6 are connected to a chain conveyor belt; an appropriate mechanical control causes an advance of the inserters 6 coordinated with the motion of the conveyors 2 and 3, so that for each passage (work cycle) an inserter 6 pushes a product P from a product-carrying pocket on the conveyor 2 into a box 100 on the conveyor 3.
[0025] The entire process occurs with a continuous movement, i.e. without stopping either conveyor 2 or conveyor 3, until all of the products P are inserted into the boxes. A section 7 that closes and possibly glues the flaps is provided downstream of the loading station 4. The products P enter the boxes from an insertion side of the loading station 4, which coincides with the position of the inserter group 5 in relation to the box conveyor 3. For example, in Fig. 2, looking at the machine from the feed side where the belt 1 is located, the product insertion side is on the left.
[0026] In greater detail, the boxes 100 are formed from flat blanks contained in a magazine 8 and are deposited on the conveyor 3 by a carton feeder 9. A flat blank, picked up by the carton feeder 9, is opened following fold lines in the blank, assuming for example the configuration of Fig. 6.
[0027] The machine comprises a group indicated as a whole by 10, located substantially at said loading station 4, for maintaining the shape of the boxes 100 during the insertion phase of products P. In the example shown in the Figures, said group 10 substantially maintains or restores the roundness of the walls 103 of a box, during the product insertion phase, by temporarily inserting an appropriate shaping pin 11 into the box, from the side opposite the product-insertion side, as illustrated above. The inserter group 5 and said group 10 with shaping pins 11 are located on opposite sides of the loading station, as shown in Fig. 1.
[0028] The group 10 comprises a plurality of shaping pins 11, the same in number as the inserter units 6. When a product P enters a box 100 pushed by the respective inserter 6, a shaping pin 11 is inserted at least partially into said box 100, with the purpose of maintaining the curved walls 103 spaced apart in accordance with the design rounded form, and in accordance with the specification of the box itself.
[0030] A shaping pin 11 comprises a shank portion 12 and a head portion 13. The head 13 is connected to the shank 12; preferably said head 13 is interchangeable. The shank 12 slides in relation to a block 14 for fixing to a conveyor belt 15, driven by two pulleys 16 and 17. A rotating bearing 18 is provided on the shank portion 12. Due to the dragging effect imparted by the belt 15, said bearing 18 can engage in a guide groove 19 which is made in a fixed part 20 of the group 10. In particular, the bearing 18 engages in the guide groove 19 due to the effect of the relative motion between the belt 15 and the fixed part 20.
[0031] This groove 19 is shaped so as to impart to the shaping pin 11 a forward and backward movement respectively approaching and moving away from said conveyor 3 and achieving the temporary insertion of the pin into a box 100 located on the conveyor 3, during the passage through the loading station 4.
[0032] The head portion 13 (Fig. 4) has the shape of an irregular hexagon, with a wedge-shaped or arrow-shaped tapered head, due to two inclined lateral faces 13a that converge and merge into a front face 13b. More generally, a tapered front head part is preferred in order to facilitate the entry of the shaping pin 11 into the box.
[0033] Fig. 5 is a diagram of the mechanical control of the shaping pins 11. The guide groove 19 is shaped with at least a first oblique forward travel section 19a and a second oblique return travel section 19b. When the bearing 18 runs along the forward travel section 19a, the shaping pin 11 extends beyond the group 10 and relative conveyor belt 15, entering to a certain extent a corresponding box 100, while from the opposite side the product P, pushed by one of the inserters 6 of the group 5, enters the same box 100. The effect of the pin 11, particularly thanks to the wedge shape of the head 13, is to space apart the rounded walls of the box and facilitate the entry of the product. Next, when the bearing 18 runs along the return travel section 19b, the pin 11 withdraws from the box while the product P gradually enters. The forward and backward movement, combined with the dragging movement of the conveyor belt 15, causes the shaping pins 11 to follow the trajectory 21 shown in Fig. 5.
[0034] It may be noted that, during operation, the conveyor belt 15 advances at the same linear speed as the conveyors 2 and 3 and so enables synchronism with these conveyors; an appropriate spatial arrangement of the guide 19 brings about the desired synchronism between the shaping pins 11 and product inserters 6, from opposite sides of the loading station 4. In other words, the movement of one of the product inserters 6 is synchronised with the action of a respective shaping pin 11.
[0035] The interaction between unit 10 and the insertion of products is further explained by Fig. 3. In the foreground, the unit 10 is shown together with its motor 22, which drives the conveyor belt 15 and the shaping pins 11 associated with it. Fig. 3 also shows that the conveyor 3 of the boxes 100 is formed essentially of two chains 30 and 31, and pairs of transport elements 32, 33 fixed to said chains 30 and 31, the distance between paired elements 32, 33 being equal to the above-mentioned pitch p. The continuous load in fact requires that the pitch of the products is equal to the pitch of the boxes, on conveyors 2 and 3 respectively.
[0036] The products P in the example are shown as flowpacks having a slightly flattened oval section, to be contained in a box of the type shown in Fig. 6.
[0037] As the boxes 100 advance on the conveyor 3 (from left to right in Fig. 3), a product P is loaded into each box, due to the effect of the inserters 6; at the same time, a shaping pin 11 operates in each box 100, synchronised with the opposite inserter 6.
[0038] A lid 105 and flaps 106 of the box are shown from the side of the group 10, which are closed in section 7 (shown in Fig. 1) further downstream. Said lid and/or said flaps can be appropriately opened out by fixed and/or rotating devices provided for this purpose. It must also be noted that the shaping pin 11 may contribute to correctly opening out the flaps 106 to the advantage for example of the operation of closing and/or glue application units.
1. Machine for continuous cartoning of products (P) inside cardboard boxes (100), said
machine comprising at least a first product conveyor (2), a second box conveyor (3),
a loading station (4) with a product insertion group (5) for inserting products inside
the boxes, from a product-insertion side, said first conveyor and second conveyor
and said product insertion group being operated with a continuous and synchronised
motion, by means of which said insertion group (5) transfers products from said first
conveyor into boxes with open ends positioned on said second conveyor, characterised in that:
the machine comprises at least a further group (10) for keeping said boxes in shape, said further group (10) being synchronised with said product conveyor (2), box conveyor (3) and insertion group (5), said further group (10) comprising at least one shaping pin (11) operated with a movement of insertion into a box and subsequent withdrawal from said box, from a side opposite to said product-insertion side, during the passage of the box in said loading station (4).
2. Machine according to claim 1, said at least one shaping pin (11) being operated to
enter a box, penetrating to a fixed linear distance, substantially at the same time
that the product (P) is inserted from the opposite side of the box.
3. Machine according to claim 1 or 2, said at least one shaping pin (11) comprising a
head (13) which is shaped with a tapered end for insertion into the boxes.
4. Machine according to claim 3, said at least one shaping pin (11) comprising a shank
portion (12) and a head portion (13), the head portion being replaceable on the shank
portion.
5. Machine according to any of the preceding claims, said at least one shaping pin (11)
being operated with an alternating rectilinear motion in relation to a conveying unit
(15), said conveying unit (15) being synchronised with said product conveyor (2) and
box conveyor (3).
6. Machine according to claim 5, said at least one shaping pin (11) being operated by
a bearing (18) associated to said shaping pin and engaging a guide (19) that is fixed
relative to said conveying unit (15).
7. Machine according to claim 6, in which said at least one shaping pin (11) comprises
a shank portion (12) and a head portion (13); the shank portion being linearly sliding
on a respective fixing support on said conveying unit (15); in which a rotating bearing
(18) is associated to the shank portion (12), and said bearing can engage with a guide
(19), the engagement between said bearing and said guide being such as to impart said
alternating motion to the shaping pin.
8. Machine according to any of the preceding claims, said unit (10) comprising a plurality
of shaping pins (11), the number of said pins corresponding to a number of product
inserters (6) of said product insertion group (5).
9. A method for continuous cartoning of products (P) inside cardboard boxes (100), where:
a plurality of products and a plurality of boxes are transported by a first conveyor
(2) and by a second conveyor (3) respectively; the products are transferred with a
continuous insertion movement from said first conveyor into boxes on said second conveyor,
the first and second conveyors having a synchronised advance motion and an arrangement
of products and boxes with the same pitch; the insertion of products being effected
from an insertion side of the boxes arranged on said second conveyor, said method
being characterised in that a shaping pin (11) is temporarily inserted into a box (100), from a side opposite
said product insertion side, substantially concurrently with the initial phase of
insertion of the product into the box.
10. Method according to claim 9, said boxes (100) having a substantially tubular or prismatic
shape.
11. Method according to claim 10, said boxes (100) having rounded side walls (103).
12. The use of a machine according to any of claims 1 to 9, for cartoning products (P)
in boxes (100), said boxes preferably having a tubular shape with rounded side walls
(103).