Device for loading and unloading egg containers

Abstract: A device for loading an egg container (1) with stacks of filled egg trays comprises a collection table (5), means (6-9) for moving the collection table (5) in a vertical direction to the level of the various container shelves (3), means (12) for moving stacks of egg trays, placed on the collection table (5), into the container (1), means (13) for moving a first pair of stacks of egg trays with respect to the container (1) so that said pair is positioned near one short side of the container (1) and for moving a second pair of stacks of egg trays with respect to the container (1) so that said pair is positioned near the other short side of the container (1) in order to create space for accomodating a third pair of stacks of egg trays. An unloading device comprises a collection table (5), means (41) for pushing the middle two of six stacks, standing in pairs in a container shelf (3), on to the collection table (5), means (43) for pushing two stacks, standing at some distance from each other on a container shelf (3), towards each other, means (44) for pushing two pairs of stacks, placed in a square, on to the collection table (5), and means (40) for moving stacks, standing on the collection table (5), in a transverse direction.

Description: The invention relates in the first instance to a device for loading an egg container with stacks of filled egg trays, which container consists of a number of shelves supported above each other in a frame, each shelf being intended to accommodate six stacks of egg trays. In modern poultry farms, many tens of thousands of eggs are produced daily. These are usually supplied on a conveyor belt and placed automatically on egg trays. The egg trays are stacked, in a different automatic device, with at least six trays to a stack. Finally, the trays have to be placed in a container. Hitherto, this loading of an egg tray container has been carried out manually. In view of the fact that the conveyance of the eggs, the loading of the trays and the stacking of the trays are completely automated and that the loading of an egg tray container is monotonous and fairly laborious work, said manual loading presents a considerable drawback. The object of the invention is to overcome this disadvantage and to provide a device by means of which stacks of trays filled with eggs can be stacked and destacked completely automatically in to and from an egg tray container. One problem arising in this connection, which is solved by the invention, is that the frame of the container has L-shaped vertical corner profile sections, which prevent six stacks of egg trays from being able to be slid simultaneously on to a shelf of a container. The stacking device is defined by the features of claim 1, whereas claim 8 is related to the definition of the disclosed destacking device. Preferred embodiments of said devices are defined in the sub claims. The invention will now be described in more detail with the aid of the figures, which illustrate an exemplary embodiment of a loading device and an exemplary embodiment of an unloading device. Figure 1 shows a view in perspective of a device for loading an egg container. Figure 2 shows a view in perspective of the rear side of a spreading device to be used in the device shown in Figure 1. Figure 3 shows a view in perspective of the drive device of the spreading device. Figure 4 shows a view in perspective of the actual spreading element of the spreading device. Figure 5 shows a plan view in a first position. Figure 6 shows a plan view in a second position. Figure 7 shows a diagrammatic view, in perspective, of a device for unloading an egg container. Figure 8 shows a plan view, in a first position, of the device shown in Figure 7. Figure 9 shows a plan view of a second position. The device illustrated in Figures 1 to 6 is employed for loading a movable egg container 1 with stacks of filled egg trays. Each stack comprises, for example, six trays and is fed via a conveyor 2. The egg container 1 consists of a number of shelves 3 supported above each other in a frame. At the corners, the frame possesses vertical posts 4 in the shape of an L-profile section. Each shelf can support six stacks of filled egg trays. These are arranged in pairs. The device comprises a collection table 5 which is suspended from a gantry 6 by means of chains 7. These run over chain wheels 8 which can be driven by a motor 9 in order to move the collection table 5 upwardly or downwardly. The feed conveyor 2 terminates directly adjacent of the collection table 5 and when two stacks of filled egg trays have arrived at the end of the conveyor 2 and the collection table has been brought to the level of the conveying surface of the conveyor 2, the two stacks can be pushed on to the table 5 by means of a pushing device (pneumatic, hydraulic, mechanical). One problem is that it is not possible to slide six stacks of filled egg trays simultaneously from the table 5 onto a shelf 3 of the container, since the vertical L-profile sections 4 of the frame of the container form an obstruction. According to the invention, this problem could be solved by moving a first pair of stacks into the container, moving the container to a position in which said pair is located near a short side of the container, moving a second pair of stacks into the container and moving the container to a position in which said second pair is located near the opposite short side and finally moving a third pair of stacks in the space between the first and second stacks. In the present embodiment, however, the following sequence for loading a container shelf is employed: firstly, two pairs of filled stacks of trays, with some distance between them, are pushed, by means of the pushing device 11 onto the table 5 and from this table 5, by means of a pushing device 12 onto the corresponding shelf 3 (see Figure 5); the two pairs of stacks of trays are then pushed away from each other by means of a spreading element 13 until the stacks stand at the transverse edges said shelf (Figure 6), and finally two stacks of trays, supplied in the meantime on the table 5, are slid into the space between the two stacks which have been pushed away from each other (Figure 6). The spreading element 13 comprises two insertion plates 14 which can be swivelled about a vertical swivelling spindle 15. By means of two pneumatic or hydraulic small cylinders 16, which are each mounted between a fixed plate 17 and an insertion plate 14, the insertion plates can be swivelled from the position shown in Figure 5, in which they converge towards each other, to the position shown in Figure 6, in which they run parallel to each other. In the position shown in Figure 5, the insertion plates 14 can be easily introduced into the space between two pairs of stacks of trays on a container shelf 3. The insertion element 13 is also suspended, by means of chains 18, from a gantry 19. These chains run over chain wheels 21, which can be driven by a motor 22 in order to move the insertion element 13 upwardly or downwardly. The gantry 19 can be moved to and fro in a horizontal direction by a pneumatic or hydraulic cylinder 23. To enable the plates 14 of the spreading element 13 to be moved away from each other and towards each other, each of the plates 14 is attached to a nut 24 mounted on a threaded spindle 25 which can be driven by a motor 26. The direction of the screw thread is different for the one nut and for the other nut. Furthermore, a plate 27 is attached to each of the plates 14, said plate 27 being in turn attached to sliding pieces 28 which are mounted on guide rods 29. These guide rods 29 are fitted in brackets 31 projecting from a plate 32 which, on the rear side, is provided with tubes 33 through which run guide rods 34. The gantry 6 of the collection table 5 can be moved horizontally over a relatively small distance by means of a pneumatic or hydraulic cylinder 35. With the aid of this cylinder 35, after the correct vertical position with respect to a container shelf 3 has been determined, the table 5 can be moved towards said shelf, whereby a longitudinal edge of the table 5 comes to rest on a longitudinal edge of the corresponding shelf. Stacks of filled trays can thus be slid from the table 5 on to the shelf 3 without difficulty. In order to determine the correct position of the table 5 with respect to a shelf 3, a sensor 39 is fitted under the table 5. A sensor 37 is attached to the spreading element 13, for determining the correct position of the spreading element with respect to a container shelf 3. After the spreading element has been introduced into the space between two pairs of stacks of egg trays, by employing the cylinder 23, both the two cylinders 16 and the motor 26 are actuated, whereby the plates 17 of the spreading element attain the position shown in Figure 6, where the pairs of stacks of trays engage approximately the L-shaped profile sections 4 of the frame. A subsequent pair of stacks of trays is then pushed, by the pushing device 12, into the space between those stacks of trays which have been pushed away from each other. In order to receive new stacks, the collection table 5 always returns to the level of the upper surface of the conveyor 2. The container 1 is secured, at the beginning of loading, by a sensor 36 which is fixed with the aid of two pneumatic or hydraulic clamps 38. The vertical and horizontal movement of the table 5, the vertical and horizontal movement of the spreading element 13, and the movement of the pushing device 11 are controlled with the aid of an electronic control device (not shown), the sensors 39 and 37 always ensuring the desired vertical position of the table 5, and of the spreading element 14, with respect to the successive shelves of a container. After the shelves of a container have been loaded, the clamps 38 are unlocked manually or automatically and the loaded container is replaced by an empty container. The device shown in Figures 7 to 10 is suitable for unloading a container 1 loaded with stacks of filled egg trays. In fact, this device works in reverse sequence with respect to the loading device: firstly, the middle pair of three pairs of stacks of trays placed on a container shelf 3 is pushed onto a table 5 (Figure 8) by means of a pneumatic or hydraulic pushing device 41; these stacks are moved in the direction of a discharge conveyor 2 by means of a pushing device 40. The remaining two pairs of stacks of trays are then moved towards each other by pushing devices 43 and the resulting square of stacks is pushed by the pushing device 44 on to the table 5. After the table 5 has been brought to the level of the upper surface of the conveyor 2, the three pairs of stacks are finally pushed successively onto the conveyor 2 by means of the pushing device 40. The pushing device 41 is connected to a plate 45 which, led through bars 46 by means of chains (not shown), can be moved upwardly and downwardly along legs 42 of a gantry. The pushing devices 43 are connected to a U-frame 48 which, led in tubes 49, can be moved in a horizontal direction by means of pushing device 44. The legs 42 form part of a gantry which can be moved to and fro by the pushing device 47. The correct vertical position with respect to a selected container shelf will be determined by sensors (not shown). The pushing device 40 is connected to the table 5 which can be moved upwardly and downwardly by driven chains in the same way as in the case of the loading device shown in Figures 1 to 6 inclusive. The collection table will again be provided with pushing means comparable with the pushing means 35, in order to push the table towards the container in such a way that an edge thereof engages below an edge of a container shelf. In this case too, a sensor comparable with the sensor 36 is used to determine the correct vertical position of the table 5 with respect to a container shelf.

Claims: Device for loading an egg container (1) with stacks of filled egg trays, the container consisting of a number of shelves (3) supported above each other in a frame, each shelf supporting stacks of egg trays arranged in a layer of three parallel rows, the device comprising: a collection table (5), means (7-9) for moving the collection table in a vertical direction to the different levels of the container shelves, means (12) for transferring the stacks of egg trays from the collection table to the container, means (14) for spacing two rows of stacks of egg trays transferred into the container so that each of said rows is positioned near one short side of the container, thus providing a space between said opposite rows and enabling the subsequent insertion of the third row of stacks by said transfer means (12), said spacing means (14) being displaceable in the vertical direction with respect to the container. Device according to claim 1, characterized in that said spacing means comprises spreading plates (14) for sliding two rows of stacks of egg trays, deposited on a container shelf, away from each other towards said short sides of the container. Device according to claim 2, characterized by clamping devices (38) to securely hold the egg container. Device according to claims 2 or 3, characterized by means for moving the collection table in a horizontal direction with respect to the container until one edge of said table rests on a side edge of a selected container shelf, and by a sensor determining a vertical position of the collection table with respect to a selected container shelf. Device according to one of the claims 2-4, characterized in that the spreading plates (14) comprise two vertically disposed plates arranged adjacent to each other, each of which is connected to a nut (24) mounted on a driven threaded spindle (25). Device according to claim 5, characterized in that each of the two plates is swivellably mounted on a vertical axis (15) between a first position in which said plates converge towards each other, and a second position in which said plates extend parallel to each other, means being provided for swivelling the insertion plates between the said first and second positions. Device according to any of the claims 2-6, characterized in that a sensor (37) is provided at said plates to determine a vertical position of said spreader plates, with respect to a sensed horizontal height position of a container shelf, such that the spreading plates are displaceable in a horizontal direction between two opposite rows of stacks of egg trays. Device for unloading a container loaded with stacks of filled egg trays, said container consisting of a number of shelves supported above each other in a frame, each shell supporting six stacks of egg trays arranged in a layer of three parallel rows, the device comprising; a collection table (5) for supporting said stacks of egg trays, means (7-9) for moving the collection table in a vertical direction to the different levels of the container shelves, means (41) for pushing the middle row of said three parallel rows of stacks from a container shelf onto said collection table, means (43) for bringing the remaining opposite outer rows into abutting position on said container shelf, means (41) for pushing said abutting two rows of stacks from said shelf onto said collection table, and means (40) for transferring said rows from the collection table onto an exit conveyor in a direction transverse to the direction in which the means operate which push stacks from a container shelf on to the collection table, said pushing means (41) being vertically displaceable with respect to the container. Device according to claim 8, characterized by clamping devices (38) to securely hold the egg container. Device according to claims 8 or 9, characterized by means for moving the collection table in a horizontal direction with respect to the container until an edge of said table engages below the edge of a container shelf, and by a sensor (39) determining a vertical position of the collection table with respect to a container shelf, such that the said edge of the table comes into position just below the said edge of a container shelf.

Inventors: KERKHOF MARTINUS WILHELMUS JOH, KERKHOF, MARTINUS WILHELMUS JOHANNES
Applicants: KERKHOF MARTINUS W J, KERKHOF, MARTINUS WILHELMUS JOHANNES
Application year: 1992
Main classification: B65G65
IPC codes: B65G65