EP0370886B1 - Method and apparatus for storing cylindrical objects on a support surface - Google Patents

Abstract

Method and apparatus for strapping layers of cylindrical objects intended to be placed on a pallet. According to the invention, the strapping machine (16) effects the strapping of layers (12) of such objects with the interposition of a wedge (34) of thickness chosen so as to obtain, after removing the wedge, a loose strapping which enables the layers to be mounted on top of one another, imbricated quincuncially. Application to the storage of box bases packaged in rolls. <IMAGE>

Description

The invention relates to a method of storing cylindrical objects, for example bottoms of circular boxes packed in rolls, on a flat support such as for example a pallet.

The invention also relates to a machine for implementing this method.

In the canning industry, large quantities of cut metal discs are used to form the bottom of cans. The most common of these boxes is the so-called "three-piece" box in which two bottoms are crimped at the ends of a cylindrical box body. We are therefore often faced with problems of storage, handling and transport of such funds. Conventionally, the bottoms are stacked and wrapped so as to form rolls. These rolls must be put on pallets for transport and / or storage. To do this, they can be arranged horizontally next to each other to form overlapping layers nested in one another, staggered due to the cylindrical shape of the rollers, which constitutes a factor of stability of the load of the palette. However, this stability is only acquired if a flexible strip, most often made of paper, is interposed between the layers and the rollers. Palletization is manual and the paper strip is unrolled by the operator, according to an optimal configuration between the rollers and the layers, as and when the load on the pallet is built up. These operations therefore require a certain amount of manpower and take time.

The invention proposes a new process facilitating the loading of the pallet, which can be largely automated and in which stability is no longer ensured by the special arrangement of a flexible strip, between rollers and layers, but thanks to straps applied to each layer of rollers. Of course, beyond the particular problem of the rollers of the box bottoms, the invention applies more generally to the handling and grouping of any cylindrical objects.

With this in mind, the invention therefore relates to a method of storing cylindrical objects on a flat support such as a pallet, characterized in that it consists in placing such objects in parallel and side by side to form, each time , a layer, to achieve at least one strapping of such a layer by creating an excess of the perimeter of said strapping relative to the stretched perimeter of the section of said layer flat and to stack such layers thus strapped on said flat support so that these overlap one another, staggered.

The term "stretched perimeter" refers to the length of the strip which would make the strapping if it was applied tight, that is to say without play around the layer in question. The basic idea of the invention therefore consists in making a loose, but preferably controlled, strapping around each layer of objects so that it can overlap in staggered rows with the lower and upper layers, as was already the case with the flexible band laid manually. Thus, the layers can not slide relative to each other as would be feared if the straps were tight. Stability can therefore always be ensured by the staggered mounting and it is even improved compared to the mounting using the flexible strip.

In practice, loose strapping is ensured by interposing a wedge along the layer, when tightening the strapping strip.

In this spirit, the invention therefore also relates to a machine for grouping cylindrical objects for staggered stacking on a flat support such as a pallet, characterized in that it comprises means for forming a layer of such objects , means of transport for conveying said layer through strapping means arranged transversely to these means of transport, a shim disposed on the side of the path of said layer in the vicinity of the strapping means and in a location such that it is interposed between an edge of said layer and a strapping strip at the time of the formation of a tight strapping and means for releasing said wedge from said strapping.

The wedge preferably has two thicknesses making it possible to reduce the predetermined excess of the perimeter of strapping for the lower layer and the upper layer of the pallet load. A mobile assembly makes it possible to move the wedge, in particular to select the part of the wedge which must be inserted in the strapping.

• la figure 1 est une vue schématique en élévation d'un ensemble d'objets cylindriques, en l'occurrence des rouleaux de fonds de boîtes emballés, montés sur un support plat ou palette, conformément au principe de l'invention;
• la figure 2 est une vue générale schématique en perspective d'une machine permettant de charger la palette;
• la figure 3 est une vue de détail à plus grande échelle illustrant l'agencement de la cale prévue sur la machine de la figure 2;
• les figures 4a et 4b sont des vues de détail illustrant le fonctionnement de la machine au moment du cerclage; et
• les figure 5a et 5b sont des vues de détail illustrant le fonctionnement de la machine au moment du dégagement de la cale.

The invention will be better understood and other advantages thereof will appear more clearly in the light of the following description of a machine implementing its principle, given solely by way of example and made with reference to the drawings annexed in which:

• Figure 1 is a schematic elevational view of a set of cylindrical objects, in this case packaged box bottom rolls, mounted on a flat support or pallet, in accordance with the principle of the invention;
• Figure 2 is a general schematic perspective view of a machine for loading the pallet;
• Figure 3 is a detail view on a larger scale illustrating the arrangement of the shim provided on the machine of Figure 2;
• Figures 4 a and 4 b are detailed views illustrating the operation of the machine at the time of strapping; and
• Figures 5 a and 5 b are detail views illustrating the operation of the machine at the time of release of the wedge.

In accordance with the invention, cylindrical objects 11 made up here of rolls of bottoms of packaged boxes are arranged in horizontal layers 12 on a flat support 13 or palette. Each layer is stabilized by several straps 14 (three in the example shown) of flexible strip, for example of plastic. Each strapping is loose so that the layers can be staggered, as shown, under the effect of their own weight, the strip taking a wavy position visible in Figure 1. The excess length of the strapping is, depending on the configurations, of the order of 2 to 4% relative to the stretched perimeter. This excess is checked at strapping. It is reduced for the lower layer 12 a and for the layer 12 b so that the strip can take a rectilinear shape at the level of the pallet and on the surface of the load.

The machine 15 making it possible to obtain a loose and controlled strapping of the rollers, incorporates a conventional strapping machine 16 designed to perform tight strapping. The strapping machine is therefore associated with means making it possible to create and control the desired excess perimeter of said strapping, without modifying the operating conditions of the strapping machine itself. The machine 15 making it possible to group together the cylindrical objects 11 (the bottoms of boxes packed in rolls) comprises means for forming a layer 12, constituted by a distributor 21 with an inclined plane supplying a belt conveyor 22 with intermittent movement controlled by a timer 23 forming a feeler. The latter is placed on the side of the conveyor 22 above the inclined plane, to count the rollers coming to accumulate side by side on said conveyor 22 in order to constitute a layer 12. During the preparation of such a layer, the first roller is positioned against a lateral guide 24, located on the other side of the conveyor 22 relative to the timer 23 then the other rollers are successively placed side by side in lateral support. When the number of rollers required is on the conveyor 22, the latter is actuated to transfer the layer 12 onto transport means 25 arranged to convey said layer to a support 13, the strapping machine 16 is installed transversely with respect to these means of transport. carriage for each layer 12 preformed passes through the winding part 16 has the strapping machine 16. the objects are moved together in the direction of their own axes parallel 25. the transport means comprise two belt conveyors 26, 28 located in line with each other. The framework winding 16a extends perpendicularly to the transport plane, between the two belt conveyors which move at the same speed. Above the conveyor 28 is a flap 30 pivotally mounted about a horizontal axis perpendicular to the path of the rollers. This component constitutes a retractable stop against which the rollers are applied before the first strapping of a layer. This referencing allows a better conformation of the layer by aligning all the rollers in the transverse direction.

According to an important characteristic of the invention, a wedge 34 carried by a movable assembly 35 is arranged on the side of the path of the layer 12, that is to say more precisely in the vicinity of the strapping frame 16 a . The moving element 35 is of a conventional type with pinion and rack, capable of moving the shim between the winding frame 16 a and a front position (relative to the direction of movement of the layer) beyond a release fork 38 located opposite the conveyor 28. The movable assembly (and consequently the wedge) is arranged to move parallel and at the same speed as the means of transport 26, 28. The wedge comprises two sections of thicknesses different predetermined. The thinner section 34 a is positioned in the frame 16 a , at the time of strapping when the layer 12 during strapping, must constitute either the first layer 12 a or the last layer 12 b on the pallet. On the contrary, the portion 34 b, the thicker, which is positioned in the frame 16 has in the case of one layer 12. The necessary offset is effected by the control of the mobile cleaning 35, that is to say by varying its rear position. The two sections 34 a , 34 b of the wedge have a flat common face 36 on the side of the rollers. The travel of the moving assembly is much greater than what is necessary to vary the position of the wedge in the vicinity of the strapping machine. This race allows "to accompany" the layer to the location of the release fork. While the release of the wedge was near the frame 16a, the strapping loop, when released and relaxed might get caught in the space between the two carriers. The release fork 38 is mounted movable substantially perpendicular to the direction of movement of the layer. It makes it possible to retain the strip of the strapping during a withdrawal movement of said wedge. To do this, said fork 38 is, for example, mounted at the end of the rod of a pneumatic cylinder 39 or the like, oriented perpendicular to the direction of movement of the layer. Operation will be described in more detail below.

Finally, it should be noted that the wedge is not only mounted on a mobile assembly 35 with alternating linear movement along the transport means 25, but that it is also pivotally mounted around an axis 42 perpendicular to the layer 12 (c (i.e. here a vertical axis) to be able to be applied without play against the roller closest to this layer, by the force developed by the strapping means themselves. The arrangement is that of Figure 3 where the wedge is shown in the rest position, that is to say not stressed by the strapping strip. It is pivotally mounted around the axis 42, itself mounted on the movable assembly 35. It comprises a lever arm 43 at the end of which is articulated a rod 45 crossing without contact a stop 46 integral with the crew mobile. A spring 47 is mounted in compression between the stop 46 and another stop carried by the other end of the rod 45. This mounting is such that, in the absence of stress, the surface 36 of the wedge intended to come into contact with the nearest roller is practically parallel to it, but a few millimeters apart. When strapping, the strip wraps around the entire layer and the selected portion 34 a or 34 b of the wedge and the strapping machine performs a tight strapping in the usual way, applying the shim against the nearest roller and also eliminating any play that might remain between the different rollers. This perfectly controls the excess perimeter that one wishes to attribute to the strapping of the layer and which only depends on the thickness of the shim.

The operation of the machine which has just been described is very simple and follows clearly from the description above. The rollers are deposited on the inclined plane and accumulate on the conveyor 22 immobilized under the control of the timer which performs the countdown. When the number of rollers to constitute a layer is reached, the belt conveyor 22 is actuated, which transfers all of the rollers to the conveyor 26, through the frame 16 a and as far as the conveyor 28, where they come from. 'apply against the lowered flap 30. Depending on the nature of the layer, the moving element places the wedge in the correct position inside the frame, that is to say by choosing the section of suitable thickness. The belt conveyors are stopped for a short time and the strapping machine 16 comes into action (FIGS. 4 a , 4 b ) and performs a tight strapping including the wedge. Then, the flap 30 being raised, the belt conveyors 26 and 28 are restarted as well as the mobile assembly 35 carrying the wedge. The roller layer thus moves until the strapping slightly exceeds the position of the fork 38. From this moment, the pneumatic cylinder, controlling the position of the fork, is actuated and the latter is positioned around hold without touching it (Figures 5 a , 5 b ). The mobile assembly of the hold then performs its return movement, which causes the release of the hold, the strip being held perpendicular to the layer by the fingers of the fork. As soon as the wedge has returned to its rear position inside the frame 16 a , the carriers stop, a second strapping is carried out, the fork returns to its initial position and the belt carriers 26, 28 are again actuated, thus that the moving crew, for transport the new strapping close to the fork. The operations follow one another until a desired number of straps have been made. Layer 12 is then placed on the pallet.

It should be noted that the pivoting mounting of the wedge has a double function. In addition to the backlash, it allows the shim to fade in the event that strapping occurs in the absence of rollers or if the number of rollers is less than it should be. In this case, the strapping machine 16 operates normally, possibly using its own safety devices, but the erasure of the wedge prevents any deterioration of the equipment, in particular of the moving equipment.

Claims (9)

1. A method for storing cylindrical objects (11) on a flat support (13) such as a palette, characterized in that it consists in placing such objects side by side in parallel to form, each time, a layer (12), in forming at least one strapping hoop (14) around the said layer whilst creating (34) a surplus in the perimeter of the said strapping hoop relative to the minimal perimeter of the cross-section of the said flat layer, and in stacking such layers thus encircled on the said flat support so that they become imbricated in one another alternately.
2. A method according to claim 1, characterized in that it consists in creating a predetermined surplus (34) in the said perimeter of the strapping hoop, in particular in dependence on the diameter of the said objects and their number per layer.
3. A method according to claim 2, characterized in that the said predetermined surplus in the said perimeter of the strapping hoop is decreased if the layer in question is the first or the last layer in order of number on the said support.
4. A method according to any one of the preceding claims, characterized in that the said surplus in the perimeter of the said strapping hoop is obtained by placing a spacer (34) in contact with the said layer, preferably alongside one of the objects situated at one end of the said layer, including this spacer in the said strapping hoop, then disengaging the said spacer from the said strapping hoop.
5. A machine for regrouping cylindrical objects (11) in order to stack them overlapping alternately on a flat support (13) such as a palette, characterized in that it comprises means (21, 22) for forming a layer of such objects, transportation means (25) for moving the said layer through hoop-forming means (16) formed transversely to the transportation means, a spacer (34) disposed at the side of the path of movement of the said layer, near the hoop-forming means and in a location such that it is situated between an edge of the said layer and a strap for forming a hoop at the time a hoop is cramped together, and means (34, 38) for disengaging the said spacer from the said hoop.
6. A machine according to claim 5, characterized in that the said spacer (34) is fixed on a movable element (35) and comprises two sections (34a, 34b) having predetermined different thicknesses.
7. A machine according to claim 5 or claim 6, characterized in that the said movable element (35) and the said transportation means (25) are arranged to move at the same speed.
8. A machine according to any one of claims 5 to 7, characterized in that a disengagement fork (38) is mounted to be movable substantially perpendicularly to the direction of movement of the said layer, in order to hold the strap of the said hoop during a retraction movement of the said spacer (34).
9. A machine according to any one of claims 5 to 8, characterized in that the said spacer (34) is mounted to pivot about an axis (42) perpendicular to the said layer, in order to be able to be applied substantially without play against the closest cylindrical object in the said layer by means of the force developed by the said hoop-forming means.

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