WO2012097813A1

WO2012097813A1 - A method and an apparatus for transferring eggs from egg-trays to an egg processing apparatus

Info

Publication number: WO2012097813A1
Application number: PCT/DK2011/050014
Authority: WO
Inventors: Martin SØRENSEN; Jens Kristian Sønderby KRISTENSEN
Original assignee: Sanovo Technology A/S
Priority date: 2011-01-19
Filing date: 2011-01-19
Publication date: 2012-07-26

Abstract

The invention relates to an apparatus and a method for transferring eggs from egg -trays to an egg processing apparatus, comprising the step of delivering trays of eggs to a pick-up zone, lifting the eggs from the trays ( 3 ) using a first lifting device (7), and transferring the eggs to a receiving conveyor (4) for further transportation to the egg processing apparatus (1). The transfer step includes setting the eggs down on a positioning device (8), collecting them to form a larger array, lifting them from the positioning device using a second lifting device ( 9 ), and setting them down on the receiving conveyor. Eggs are preferably set down on the positioning device in small arrays, each corresponding substantially to the array represented by an egg tray. The positioning device preferably comprises holding devices (82), each for holding an egg and which are displaceable in relation to each other.

Description

A method and an apparatus for transferring eggs from egg-trays to an egg processing apparatus

The present invention relates to a method for transferring eggs from egg-trays to an egg processing apparatus, comprising the steps of delivering trays of eggs to a pick-up zone, lifting the eggs from the trays, and transferring the eggs to a receiving conveyor for further transportation to the egg processing apparatus. The invention further relates to an apparatus for transferring eggs from egg-trays to an egg processing apparatus.

Such a method and apparatus is known from DK163118B, where sets of loading heads, each comprising an array of suction cups corresponding in number and configuration to the eggs in the egg trays, are mounted on a carrousel. The carrousel moves the loading heads be- tween a pick-up zone, where they each pick up an entire egg tray with eggs, a tray release zone, where the trays are released while still holding on to the eggs, and finally an egg release zone. This method and apparatus have proven very reliable in practice, but the ever increasing demand for higher capacity, demands that eggs are delivered to modern egg processing apparatuses in larger arrays.

These problems have been dealt with in WO96/21610 and WO2008/063064, which teach methods for unloading four or more trays at a time. Both of these publications, however, involve systems where a conveyor carrying the full egg trays crosses the receiving conveyor. This has two major disadvantages. For one, the apparatus takes up a lot of space, which is generally undesirable and particularly so, when the machine is to be used with an egg washer or grader installed on a farm. Secondly, the empty trays are usually returned via substantially the same route as they enter the egg processing plant in order to allow all tray handling to be performed by one operator or team of operators and therefore have to be taken back past the receiving conveyor. Regardless whether this is done by a conveyor or manually, it involves a need for space and the risk of malfunction.

It is therefore the object of the invention to provide a method and an apparatus capable of unloading eggs into large arrays without necessitating a complex tray return system.

This is achieved with a method where the step of transferring the eggs to the receiving conveyor comprises the steps of:

setting the eggs down on a positioning device,

collecting the eggs to form a larger array by changing the distance between at least some of the eggs,

lifting the eggs from the positioning device, and

setting the eggs down on the receiving conveyor.

The repositioning of the eggs from the small arrays represented by the egg trays to a larger array by means of the positioning device constitutes an intermediate step not known from the prior art. This not only allows a more precise positioning of the eggs in the larger array, than what is known from the direct transfer from tray to conveyor known from the WO-publications. It also allows the use of a relatively simple and hence reliable unloading device operating substantially in one horizontal level, such as the one known from DK163118B, and trays can be kept on one side of the positioning device.

An apparatus according to the invention for achieving the same advantages comprises a positioning device for collecting the eggs by changing the distance between at least some of the eggs, where a first lifting device for lifting eggs from the trays is arranged for setting the eggs down on an in-feed section of the positioning device, and a second lifting device for lifting eggs from the positioning device and transferring them to the receiving conveyor.

It is preferred that eggs are lifted from at least two trays at a time and set down on the positioning device in small arrays, each corresponding substantially to the array represented by an egg tray. These small arrays are then shifted towards each other for the formation of a larger array.

The expression "an array corresponding substantially to the array represented by an egg tray" is to be understood as a set of eggs having substantially the same mutual distance in all directions as they did on the tray. As an example, a common type of egg tray used for hen's eggs on poultry farms includes six rows and five columns, where rows and columns are perpendicular to each other and forming a rectangular array. The set of eggs constituting the small arrays would in that case include the same number of rows and columns and have the same length and width as it did on the tray.

To be able to reach a high capacity, it is preferred that the first lifting device comprises at least two loading heads configured with arrays of catching devices, such as suction cups, corresponding substantially to the array represented by an egg tray. It is, however, also possi- ble to use a lifting device having one larger loading head capable of unloading multiple trays at a time, to use multiple lifting devices or to use a lifting device unloading only one tray at a time but operating at high speed . The latter embodiment is, however, less preferred as it will tend to result in damages to the eggs.

The small arrays are advantageously set down in a row and collected to an elongate larger array, which may then be moved so as to give room for a new row of small arrays. This new row is then collected into a second larger array and the two larger arrays are then collected by moving the second larger array towards the first larger array. By moving and collecting larger arrays in this manner, a continuous or indexed flow of eggs may be formed . In this the term "continuous flow" is intended to indicate that the flow is substantially homogenous with only small variations in the distances between eggs, while an "indexed flow" is used to indicate that spaces are present between sub-arrays. Said sub-arrays will usually correspond to the larger arrays formed by the collection of the small arrays, but need not do so. Regardless of the nature of the flow itself, the movement of the eggs may be either continuous or indexing, meaning that the eggs are moved constantly or intermittently, respectively.

In practice, the collection of small arrays and the movement and collection of the larger arrays may be achieved by providing the positioning device with a plurality of holding devices, each for receiving a single egg and at least some of which are displaceable in relation to each other. In a first position, corresponding to the set-down position of the small arrays, the holding devices are in a configuration, where they form small arrays corresponding substantially to the array represented by an egg tray. In a second position, corresponding to the collected position of the small arrays, they form a larger array. At least some of them are subsequently moved to a third position, where the larger arrays are collected to form either a continuous column or an array corresponding to several trays in both directions, as will be explained in detail below. The movement between the first and second position need only be in one direction, but the movement to the third and possible fur- ther positions require movement is a second direction transverse thereto, away from the in-feed section .

The pattern of movement can be achieved with holding devices, such as plastic cups, arranged on bars, along which they can be moved, and where the ends of the bars are attached to chains, at least one of which is driven so as to provide the movement away from the in-feed section .

The movement of the holding devices along the bars can be achieved by providing each of them with an engagement member, preferably projecting downwards, and passing the bars across a system of guide tracks. Engagement between the guide track(s) and the engagement member will then force the holding device to move along the bar in a manner well known to the skilled person . This of course entails that the movement of the holding device from the first to the second position involves movement in two directions.

Having thus been collected the eggs may be transferred from the positioning device to the receiving conveyor in large, coherent groups, which improves the efficiency of many egg processing apparatuses.

The collection of eggs can be performed with the eggs held in an orientation, where their longest axis is substantially vertical, and thus substantially without changing the mutual distance between eggs taken from the same tray. The receiving conveyor will very often be a roller conveyor and once the eggs are transferred thereto they will be oriented with their longest axis being substantially horizontal and aligned with the rollers. As the longest axis of the eggs are usually longer than the distance between eggs on the tray, this re-orientation leads to collisions between eggs, often resulting in damaged egg shells. If the egg processing apparatus is an egg breaker, this need not be a problem, but if the eggs are intended for being sold as shell eggs, such damages are unacceptable. It is therefore preferred to increase the mutual distance between eggs to a distance corresponding substantially to the average largest dimension of the eggs, so that the eggs come to lay end-to-end on the conveyor.

Some roller conveyors, however, are made with profiled rollers having narrowings, which form pocket-like hollows on the conveyor surface, as is well known to the skilled person . Eggs will tend to end up one in each of these hollows and the mutual distance between the eggs should thus be adapted to the distance between the hollows rather than the size of the eggs.

When using a roller conveyor it is usually sufficient to increase the distance in one direction aligned with the length axis of the rollers, when the eggs are set down thereon . If using other types of conveyors or if the distance between rollers is relatively large, it may, however, be expedient to increase the distance in both directions.

Presently it is considered expedient to increase the distance when the eggs are lifted from the positioning device, which may be achieved by using a second lifting device comprises a loading head, where the mutual distance between catching devices is adjustable at least in one direction . It is, however, also possible to increase the distance already in the first lifting device or on the positioning device.

The method and apparatus according to the invention was originally developed for use in the processing of hen's eggs and are described for such use herein, but it is to be understood that they may also be used for eggs from other species of birds, such as ducks, quails, ostriches or turkeys. Likewise, fruit, vegetables, confectionery and other items of relatively uniform size and shape may be handled according to the invention .

In the following the invention will be described in further detail with reference to the drawing, where :

Fig. 1 is a schematic representation of a system for use in the method according to the invention,

Fig. 2 shows an apparatus according to the invention seen from above and with the second lifting device in a first position,

Fig. 3 corresponds to Fig . 2 but with the second lifting device in a second position,

Fig. 4 corresponds to Figs. 2 and 3 but with the second lifting device in a third position, and

Fig. 5 shows an embodiment of a positioning device seen from above in a slightly perspective view.

A system for handling eggs according to the invention comprising an egg processing apparatus 1 and an apparatus 2 for transferring eggs from egg-trays 3 to a receiving conveyor 4 is illustrated in a dia- grammatic form in Fig. 1. Relative sizes of the different parts of the system shown is not to be regarded as limiting in any way and additional component may be add or interposed without departing from the invention.

The eggs processing apparatus 1 may be a washer, a grader, an egg breaking apparatus, a packer or the like and has here been depicted in a partially cutaway form. Likewise, a tray feeding device 5 and a series of tray removal devices 6, which may be conveyors or any other suitable means, have been depicted as open-ended to illustrate that the exact configuration thereof is not important to the invention.

In this embodiment the transfer apparatus consists of a first lifting device 7, a positioning device 8 and a second lifting device 9, but further components may be included.

The first lifting 7 picks up eggs from trays 3, only one of which is shown, at a pick-up zone (delimited by dotted lines) of the tray feed- ing device 5, turns as indicated by the arrows and sets the eggs down on an in-feed section 81 (delimited by dotted lines) of the positioning device 8.

Here, the first lifting device 7 and the tray feeding device 5 and the tray removal device 6 are shown in a configuration corresponding to the first lifting device being of the carrousel type described in DK163118B and having a loading head adapted for unloading three trays at a time. Other types of lifting devices may of course be used, but it is preferred that the first lifting device is capable of lifting eggs from two or more trays at a time, possibly having two or more separate loading heads to enable easy maintenance and repair. The tray feeding device 5 is here depicted as a single line conveyor supplying stacks of egg trays and the tray removal device 6 is depicted a series of three parallel conveyors, but it is to be understood that this is only one of a number of possible embodiments. For example, the tray feeding device may supply the trays one by one in stead of in stacks or it may be arranged perpendicularly to the direction depicted in Fig . 1, either as a series of conveyors, as for the trays removal device shown, or as a single wider conveyor.

The second lifting device 9 is depicted as a portal lifting device overlapping substantially equal sections of the positioning device 8 and receiving conveyor 4 and having a loading head (not shown), which is adapted to run back and forth as indicated by the arrow A. In other embodiments the second lifting device 9 may, however, be of a different type, such as the swinging arm device 9' shown in Figs. 2-4, and as for the first lifting device the configuration and capacity may be adapted to demands, including the use of two or more loading heads.

In Figs. 2-4 only the receiving conveyor 4, the positioning device 8 and the second lifting device 9' are shown, the primary difference between these figures being the position of the loading head 91 of the second lifting device.

The receiving conveyor 4 is depicted as a roller conveyor and in Figs. 3 and 4 some of the rollers 41 have been removed in order so make details of the loading head 91 appear more clearly.

The positioning device 8, which may be embodied as shown in more detail in Fig . 5, comprises a plurality of holding devices 82 only some of which are shown in Figs. 2 and 3, while they are left out entirely in Fig. 4. In the in-feed section 81 these holding devices are arranged in rectangular arrays 83,84,85 having six rows and five columns thus corresponding to the array represented by an egg tray. In Fig. 2, 3 and 5 three arrays are depicted, meaning that a row across the positioning device consists of fifteen holding devices in total, but different numbers of arrays may be used just as the individual arrays may be adapted for different tray types. An examples of another tray type is one having seven rows and six column and where the rows are off-set in relation to each other so that the centre of an outermost egg of a row is located approximately midway between the centres of the first and second egg of the neighbouring row. Holding and lifting devices will then have to be adapted for the off-set configuration.

The holding devices 82, are preferably cup-shaped and made of plastic or metal as shown in Fig . 5. As may be seen, these cups have an open bottom, the eggs being held by four fingers arranged at mutual angles of approximately 90 degrees. This prevents the formation of a vacuum in the cup underneath the egg and decreases the risk of eggs sticking to the cup if cracked or soiled .

Horizontal bars 86 (only one of which is shown in Figs. 2 and 3) spanning from one side of the positioning device to another carries the holding devices 82. At the ends, the bars are attached to driven chains 80, so that they can be moved as indicated by the arrow B, but it is also possible to use only a single chain or other drive means. As may be made out in Fig .5, the chains go around so that once the eggs have been lifted from the holding devices at the left-hand side of Fig . 5, closest to the receiving conveyor 4, the holding devices go over the edge and are returned head-down along the underside of the positioning device to come back up at the in-feed section 81 at the right-hand side of Fig. 5. Apart from being a structurally simple and thus reliable solution, this also has the advantage that if an egg was for some reason not lifted by the second lifting device, it will discharged so that is does not cause problem during the next process cycle. Moreover, a washer may be installed on the underside of the positioning device for cleaning dirty holding devices.

In this, the holding devices 82 are described as been adapted for receiving one egg at a time, but it is to be understood that it is also possible to employ larger holding devices. As an example, each row of the smaller arrays may be one integral holding device, but it is still preferred, though not necessary, that it has some kinds of hollows or partitions that define a position for each egg .

The holding devices in Fig . 5 are mounted so that the cup is located to the side of the bar. This means that dirt or egg contents falling or dripping from the eggs do not end up on the bar, where it might hinder movement of the holding device in relation to the bar as will be described later.

At least some of the holding devices 82 have downwards projecting engagement members (not shown); in this embodiment the outermost holding devices 82', 82" on each bar. When the bars 83 are moved forward, the engagement members come into contact with guide rails or tracks 87, resulting in the holding devices of the two outermost arrays 83,85 being gradually forced towards the centre of the bar and eventually coming into contact with the middle array 84. This may best be seen in Fig . 5. In this way a larger array 89 of fifteen columns and six rows is formed and the space needed for a new set of holding devices for receiving a new set of eggs is created.

As may be seen in Fig. 4 the positioning device in this embodiment is provided with an additional set of guide rails 88, which are intended to come into engagement with engagement members on the outermost holding devices of the middle array 84 and/or the innermost holding devices of the outer arrays 83,85. These guide rails 88 help to a precise positioning of the holding devices in relation to the second lifting device and are therefore considered advantageous though not necessary for the invention.

As described above the holding devices pass along the underside of the positioning devices to be returned to their first position. For this purpose a separate system of tracks or rails (not shown), corresponding to the one described above, is preferably provided on the underside, but it is also possible to use one and the same system of rails, which is engaged by the engagement members of the holding device both from above and from below. It is of course possible to provide other configurations of engagement members and guides 87,88 and the bars 83 may even be left out by in stead mounting the holding devices 82 as a mesh or on several parallel chains. These and other alternatives will be readily imagin- able to the skilled person.

The movement of the holding devices 82 away from the in-feed section 81 may be continuous meaning that the chains 80 run at a substantially constant speed . At present it is, however, preferred to operate the positioning device in an indexing manner, where the holding devices are stopped when receiving eggs for the first lifting devices and then moved forward.

The holding devices 82 are advanced further towards the receiving conveyor 4, while maintaining a small distance D between each of the larger arrays formed, thus forming an indexed flow of eggs. Once three larger arrays 89 have been collected in this way, the eggs are lifted from the holding devices by means of the second lifting device 9', the loading head 91 of which is swung in over the holding devices by means of the arm 92. The eggs are preferably lifted using suction cups 93, but other means including mechanical grabbers may be employed.

The arm 92 is now swung over the receiving conveyor as shown in Fig. 3 and illustrated by arrows to the position shown in Fig . 4, where the eggs are set down. As may be seen, the distance between rows of suction cups 93 on the loading head 91, when seen in the length direction of the rollers 41 of the receiving conveyor 4, is gradually increased during the swinging motion, so that the distances between the suction cups are substantially uniform when reaching the position in Fig . 4. In this embodiment this is achieved by eliminating the spaces represented by the distance D in Fig. 2 and 5, but it is also possible to increase the overall dimensions of the array represented by the loading head 91. Likewise, it is also possible to increase the distance in the first lifting device or on the positioning device by movement of the holding devices, thus forming a continuous flow of eggs without the distances D.

The distance between the eggs should be increase at least so that it corresponds to the maximum length of the eggs being handled, typically at least 75 mm for hen's eggs. Roller conveyors used in egg processing systems, however, are usually provided with profiled rollers as also shown in Figs. 2-4, where the profiling creates hollows approximately the size of a hen's egg. This helps keeping the eggs in order on the conveyor. The distance between each hollow is typically 76-85 mm and, accordingly, the distance between the suction cups should also be increased to approximately 76-85 mm. Other dimensions will of course apply when handling eggs from other species of birds or items of other origins.

In the embodiments shown in Figs. 2-5, the eggs are collected into a final array corresponding to nine trays arranged in three rows and three columns, but it is of course also possible to transfer the arrays described as larger arrays above, which are formed when three trays of eggs are collected . Likewise it is to be understood that the invention is not limited to rows of three trays, but that two, four or more trays may be included in each row.

The invention is not to be regarded as limited by the description of preferred embodiments given above and it is to be understood that the components described may be combined in other ways and/or used in a different order without necessarily departing from the scope of the invention. Likewise, alternatives to the components described may be used, an example being the use of different types of lifting devices.

Claims

P A T E N T C L A I M S

1. A method for transferring eggs from egg-trays to an egg processing apparatus, comprising the step of:

a) delivering trays of eggs to a pick-up zone,

b) lifting the eggs from the trays, and

c) transferring the eggs to a receiving conveyor for further transportation to the egg processing apparatus,

cha racte rized in that the step c) comprises the steps of:

setting the eggs down on a positioning device,

lifting the eggs from the positioning device, and

setting the eggs down on the receiving conveyor.

2. A method according to claim 1, ch a racterized in that eggs are set down on the positioning device in at least two small arrays, each corresponding substantially to the array represented by an egg tray with regards to number of rows and columns and to mutual distance between eggs, and that these small arrays are then shifted to- wards each other for the formation of a larger array.

3. A method according to claim 2, ch a racterized in that the larger array formed by the collection of the at least two small arrays are moved so as to give room for a new set of small arrays, which are then collected into a second larger array, and that the two larger arrays are then collected by moving the second larger array towards the first larger array.

4. A method according to claim 3, ch a racterized in that the collection of larger arrays is performed continuously so as to form a continuous or indexing flow of eggs.

5. A method according to any of the preceding claims, ch a racterized in that the mutual distance between eggs is increased, at least in one direction, to a distance corresponding at least to the average largest dimension of the eggs.

6. An apparatus for transferring eggs from egg-trays to an egg processing apparatus, comprising a pick-up zone, a first lifting device for lifting eggs from the trays and a receiving conveyor for further transportation to the egg processing apparatus, ch a racterized in that it further comprises a positioning device for collecting the eggs into larger arrays by changing the distance between at least some of them, said first lifting device being arranged for setting the eggs down on an in-feed section of the positioning device, and a second lifting device for lifting eggs from the positioning device and transferring them to the receiving conveyor.

7. An apparatus according to claim 6, ch a racterized in that the first lifting device comprises at least two loading heads with arrays of catching devices configured to correspond substantially to the array represented by an egg tray.

8. An apparatus according to claim 6 or 7, cha racte rized in that the positioning device comprises a plurality of holding devices at least some of which are displaceable in relation to each other between a first position and a second position, where, in the first position, the holding devices form small arrays corresponding substantially to the array represented by an egg tray, and, in the second position, they form a larger array.

9. An apparatus according to claim any of claims 6-8, ch a racterized in that the positioning device comprises a plurality of holding devices, which are moveable in a direction away from the in- feed section.

10. An apparatus according to claim 9, ch a racterized in that the holding devices are arranged on a continuous conveyor so as to allow them to form one or more continuous or indexed columns.

11. An apparatus according to any of claims 6-10, where the holding devices are arranged on bars, along which they can be moved, and where the ends of the bars are attached to chains, at least one of which is driven.

12. An apparatus according to any of claims 6-11, where the movements of the holding devices are performed substantially without changing the mutual distance between the holding devices forming each of the small arrays.

13. An apparatus according to any of claims 6-12, where the second lifting device comprises a loading head configured with an array of catching devices corresponding at least to the array represented by four egg trays arranged two-by-two.

14. An apparatus according to any of claims 6-13, cha racte rized in that the second lifting device comprises a loading head configured with an array of catching devices and that the mutual dis- tance between catching devices is adjustable at least in one direction.

15. An apparatus according to claim 14, ch a racterized in that the catching devices are moveable between a first position, where they are arranged with mutual distances corresponding to the mutual distances between eggs in the egg tray, and a second position, where the mutual distances at least in one direction corresponds substantially to the average largest dimension of the eggs.