Field of the invention

The present invention relates to cell trays for transportation of containers. In particular, the invention relates to transportation of beverage bottles loaded in a diagonal pattern onto a cell tray. More specifically the present invention relates to the preamble portions of claims 1, 8 and 10.

Background art

Beverage containers, such as bottles and cans, are typically transported in crates, on cell trays, on a pallet wrapped with plastic film or packed in cardboard boxes. Since card- board boxes produce a significant amount of waste, reusable alternatives are preferred. Consequently, crates and cell trays have become a popular way of transporting beverage containers, bottles in particular. When transporting in crates, the frame of the crate extends above bottles and the crates are stacked on top of each other such that, it is the frames that bear the weight of above stacked crates. Crates are therefore an advantageous way of transporting containers in that they are very sturdy and protect the contents well. They are suitable even when only partially loaded.

On the other hand empty crates take up a similar amount of space than full crates, which is inconvenient in returning the empty crates. Wine bottles, for example, are not returned to the manufacturer after use because the glass material is recycled through other chan- nels. As a result wine crates return to the manufacturer empty, wherein they take up an excessive amount of unutilized space. Furthermore, such heavy duty crates require a great amount of raw material and large tools to manufacture. Crates are therefore not the most economical way of transporting bottles, which is why cell trays have been introduced as an alternative requiring a minimal amount of space. Cell trays differ significantly from crates in that both the tray and the bottles participate in supporting the stack. Typical cell trays feature supporting organs on the receiving surface, i.e. top surface, with aid of which separate bottles and cans are supported into place. The trays are conventionally designed so that they are suitable for transporting both sepa- rate bottles or cans and multipackages. While aiming to minimize the outer dimensions of a tray, the edges of the tray are usually low and cannot therefore provide similar support for the contents as the frame of a crate. Thus, the vertical load is directed to the containers. For accommodating this, the bottom face of the tray is usually equipped with fur- ther supporting organs, which fit to the top portions of the containers and which secure the container horizontally in place. The cell trays are used for securing the containers to each other horizontally, while the self-supporting containers are used to carry vertical loads.

Cell trays can be loaded in a matrix-like or a diagonal pattern. In matrix-like patterns the container positions are arranged in rows that follow the orthogonal directions the frame. In diagonal patterns the position rows are angled in respect to the typically rectangular frame. Matrix-like patterns are mostly suitable for crates, in which the frame provides both horizontal and vertical support. Cell trays, on the other hand, can be loaded in diagonal patterns. The diagonal pattern enables the containers to overlap vertically so that the necks of bottles in the lower tray extend between the bottle bottoms of the tray above. Trays suitable for diagonal container patterns are described in greater detail in EP 0853053 Al and EP 0784577 Al .

Disadvantages of the prior art

However, known diagonal cell tray constructions feature considerable disadvantages. Known trays are orientation sensitive, wherein upon loading, every other tray must be turned 180 degrees in relation to the tray below to form a stack. Because of the orientation sensitivity of known trays, the automation of forming stacks of bottles and trays has been challenging. Each tray must be stored in a correct position as being readily available for a gripper of a robot. Alternatively, the gripper or robot must be equipped with com- puter vision for determining the orientation or the information concerning the orientation of the tray must be available in some other form. There are problems in manual handling as well. Because trays intended for diagonal loading patterns are orientation sensitive, effort must also be made to rotate the tray into correct position when stacking empty trays. The problem in manual handling occurs typically in retail shops, where empty trays are stacked for return to the manufacturer. Stacking of trays has been aided by pro- viding trays with aligning protrusions, holes and such that prevent stacking in a wrong orientation. These aids have not, however, eliminated unnecessary work related to the orientation of trays. In conclusion, the described sensitivity in both automated and manual handling is a known issue, which has not been solved in a cost-effective way. Aim of the invention

It is therefore an object of the present invention to solve at least some of the problems of the prior art and to provide an improved cell tray being suitable for automated loading in a diagonal pattern.

Summary of the invention The object of the invention is accomplished with a novel cell tray according to the invention, wherein the tray comprises a number of bottle positions arranged to accommodate a different number of containers on the tray. According to the invention, the number of bottle positions is at least twice as large as the number of containers in the loading pattern. The bottle positions are also arranged in a matrix-like pattern, whereby a diagonal pattern can be loaded onto the tray without a specific orientation thereof.

According to one embodiment, containers are particularly bottles and the tray comprises a rectangular frame and an essentially flat loading surface defined by the frame for supporting bottle bottoms in the number of bottle positions. Furthermore, the tray comprises apertures provided through the loading surface in each bottle position for receiving the bottleneck of a container in a lower tray. The lower terminal end of the aperture is advantageously provided with a chamfer for providing supportive engagement with a bottle shoulder.

To be precise, a cell tray according to the invention is characterized by what is stated in the characterizing portion of claim 1. The object of the invention is on the other hand accomplished with a novel method according to the invention, wherein a number of containers is loaded in a diagonal pattern to a tray having a matrix-like arrangement of bottle positions, the number of which is at least double the number of containers in the pattern, whereby containers can be loaded without a specific orientation of the tray.

To be precise, a method according to the invention is characterized by what is stated in the characterizing portion of claim 8. Benefits gained with the aid of the invention

Considerable benefits are gained with aid of the present invention. Due to the novel cell tray arrangement, automated loading of the containers in a diagonal pattern is insensitive to the orientation of the cell tray. On the contrary, the novel construction of the tray can be loaded automatically regardless of its orientation. Obviously the tray shall upon load- ing be in a predetermined position, but this can arranged with conveyors and simple stoppers, for example, requiring a minimal degree of automation. This significantly reduces requirements for the loading system in terms of providing sensors and alike to the system. As a result, the automated loading of cell trays can be arranged in a straightforward and inexpensive way. With a streamlined automation system, the loading process is more robust. The need for ensuring the correct orientation in manual handling is also significantly reduced.

Because the cell tray according to the invention has a number of bottle positions and - ultimately - receiving apertures, the tray can be applied for a plurality of different kinds of containers. Most likely applications include beverage bottles, such as soda and beer bottles, but also wine bottles and other containers having a neck-like top portion fitting the aperture. Moreover, the same tray can be used for containers of different size, wherein the number of occupied bottle positions vary depending on the container size. This reduces the need for a large variety of different trays, which is logistically and economically especially advantageous. While the present invention solves problems relating to diagonal loading patterns, the multi-purpose tray can also be used for matrix-like loading patterns, when transporting containers, which are small enough to fit in a matrix-like pattern. This feature further increases the flexibility of the present tray. According to one embodiment of the invention, the loading surface of the tray is essentially flat, which is especially advantageous for the accommodating a large variety of bottles.

Brief description of drawings In the following, an embodiment of the present invention is described with reference to the accompanying drawings, in which:

Fig. 1 presents an isometric view of a diagonally patterned cell tray according to background art,

Fig. 2 presents an isometric view of a cell tray according to one embodiment of the present invention,

Fig. 3 presents an elevated top view of the cell tray of Fig. 2,

Fig. 4 presents an isometric bottom view of the cell tray of Fig. 2,

Fig. 5 presents a cross-section view of the cell tray of Fig. 2,

Fig. 6 presents an isometric view of a stack of two cell trays of Fig. 2 both loaded with 27 beverage bottles,

Fig. 7 presents an isometric cross-section view of the stack of cell trays of Fig. 6,

Fig. 8 presents an orthogonal view of the stack of cell trays of Fig. 7, and

Figs. 9 and 10 present a stack of Figs. 6 to 9, respectively, loaded with wine bottles.

Description of preferred embodiments As is apparent from Fig. 1, known cell trays suitable for diagonal loading patterns typically feature a certain amount of container positions arranged in a predetermined pattern conforming to the eventual loading pattern. Between the container positions are usually support organs supporting on the one hand containers loaded onto the tray and on the other hand the top portions of the containers of the tray below. Referring to the tray of Fig. 1, the tray features 27 bottle positions arranged in a diagonal pattern and having a upwardly protruding housings for receiving the necks of bottles loaded on a tray lower in the stack of trays. Said necks extend above the supporting surface of the tray above, whereby the stack can be made as low as possible due to vertically overlapping layers. De- scribed housings have become somewhat an industrial standard due to their recognized ability to provide outstanding horizontal support, which is important in ensuring the stability of the stack.

In this context, the term matrix-like pattern refers to a pattern, in which elements are arranged in mutually orthogonally intersecting rows, which are parallel to either side of a quadrilateral frame of reference, the tray frame to be precise. In this context the term diagonal pattern refers to a pattern, the rows of elements of which are - unlike the elements of a matrix-like pattern - not arranged parallel to a side of the tray, but rather arranged to an angled orientation in relation to the direction of a quadrilateral frame of reference. The term diagonal pattern is an established term in the field. While the concept according to the invention can be applied to different sorts of containers, the most likely application is the transportation of bottles, beverage bottles in particular. Generally speaking the tray according to the invention is suitable for containers having a neck-like top portion fitting the receiving aperture in the bottom surface of the tray. Embodiment providing a cell tray for beverage bottles is therefore described in the following. Referring to Fig. 2, the cell tray according to the invention features a completely novel concept for transporting bottles in a diagonal pattern. As is apparent from the Figs. 2 to 8, the cell tray 1 according to a preferred embodiment the invention features a quadrilateral frame having four consecutively orthogonal sides 8. The corners between two encountering sides 8 are preferably rounded. The inner surfaces of the sides 8 have a series of out- wardly extending bulges so as to provide outward recesses for receiving the bottom outer jacket surfaces of the bottles loaded onto the tray 1.

As can be seen from Fig. 3, the frame of the tray 1 encloses a rectangular loading surface, which is surrounded by the inner gouged surfaces of the sides 8. The loading surface is essentially flat, whereby it features no protruding support members engaging with the contents of the tray as is the case with the tray of Fig. 1. The loading surface does how- ever have 54 bottle positions arranged in a matrix-like 6 by 9 array. Each bottle position has an area, in the middle of which there has been provided an aperture 2, which extends vertically through the tray 1. The loading surface of the tray 1 is advantageously provided with a sufficient number of through holes 4, which act as dewatering holes. For improving the handling of the tray 1 , the loading surface can be equipped with a variety of gripping points designed specifically for automated handling equipment. For example, the loading surface is - according to one embodiment - equipped with four gripping surfaces 5, which can be gripped with a vacuum gripper. Also, the loading surface can be equipped with gripping holes 7, into which expanding grippers can be inserted for grip- ping the tray 1.

As viewed from the bottom in Fig. 4, there are corresponding bottle positions in the bottom surface of the tray 1. The apertures 2 have chamfered bottom portions 3, which are described in greater in the following.

Referring to Fig. 5 presenting six adjacent bottle positions, the tray 1 according to the invention has a low and simple construction. Defined by the sides 8 of the frame, there is provided an essentially flat loading surface 9. Because the loading surface 9 does not have protruding elements affecting the loading pattern of bottles, the pattern can be chosen somewhat arbitrarily. As said, each bottle position has been provided with an aperture 2, which extends vertically through the tray 1. The lower end of the aperture 3 has a chamfer 3 for a planar engagement with a bottle. To be precise, the chamfered conical receiving surface is shaped so as to conform to the shape of the bottle shoulder intended to be received. The chamfer 3 therefore forms part of the horizontal support keeping the stack of trays stable. The upper portion of the aperture is preferably provided with small nodules or alike for engaging with the neck ring of the bottle 10 of the tray 1 below. Referring to Figs. 6 to 8, the diagonal loading pattern of the tray 1 according to the invention is known as such. According to a preferred embodiment, there are nine adjacent columns of bottles 10, each column having three bottles 10 in a row orthogonal to the columns. The first bottle 10 of every other column is elevated by one bottle position, whereby the pattern is not matrix-like, but diagonal (Fig. 6). The bottle positions are sig- nificantly smaller than the bottles 10 intended for loading. The tray 1 is preferably di- mensioned for use with conventional bottle sizes. As a rule of thumb, the diagonal distance between the centres of apertures 2 should be at least the diameter of the largest bottle 10 intended to be loaded. When said diameter of the bottle 10 matches the diagonal distance between aperture centres, the bottles 10 can be loaded in a diagonal pattern. If the tray 1 is loaded with smaller bottles 10 having a smaller bottom diameter, the tray 1 can be loaded in a matrix-like pattern. As a result, all bottle positions are not occupied when loading in a diagonal pattern. In fact, preferably half of the bottle positions are left vacant. As is illustrated in Fig. 6, the bottom left position, for example, in the lower tray 1 is occupied, whereas the same position in the upper tray 1 is vacant. This way occupa- tion of the same bottle position in consecutive layers of trays alternate, wherein there is a phase shift of one bottle position between the patterns in sequential trays 1 of a stack. As only half of the available bottle positions are occupied, the pattern can be loaded onto the tray 1 regardless of the orientation thereof. In other words, the two trays 1 of Figs. 6 to 8 can be in a same orientation as opposed to loading known pallets of Fig. 1. The bottle positions, apertures 2 thereof in particular, are dimensioned so that the bottles 10 fit firmly into the apertures 2 so that an upper tray 1 locks the top portions of the bottles 10 of a lower tray 1 securely into position. Furthermore, the bottle positions are preferably dimensioned so that the top portions of the lower bottles 10 fit in between the bottoms of bottles 10 in the layer above. As said above, the present invention is applicable for a vast variety of different containers, bottles in particular. As illustrated in Figs. 9 to 10, the tray described above can also be loaded with wine bottles. The wine bottles are loaded in a diagonal pattern, wherein the necks of bottles in the layer below extend between the bottoms of bottles in the layer above. Due to the profile of the apertures 2, the shoulders of the wine bottles rest against the chamfers 3 provided in the lower end of the apertures 2. Table 1: List of reference numbers.