METHOD AND APPARATUS FOR REMOVING AN ARTICLE FROM A TRAY

Abstract

A method and apparatus for removing items from trays is useful with a plurality of trays. The item is removed in the removal assembly by raising the movable bottom portion of the tray at least to the level of the tray rim using an item lifter from beneath the tray. The item lifter includes a lifting base and a plurality of lifting blocks attached to the lifting base. The lifting blocks are sized and arranged to engage the bottom portion of the tray through the opening in response to the lifting of the lifting base. The lifting blocks are sized and arranged to maintain the orientation of the tray, with at least one block positioned outside the tray near the rim. The item is then moved out of the bottom portion of the raised tray.

Description

METHOD AND APPARATUS FOR REMOVING AN ARTICLE FROM A TRAY DESCRIPTION OF THE INVENTION The present invention relates to a material handling system and, in particular, to a method and apparatus for removing an item from a carrier, also known as a tray. Such a method is also known as extraction. The following description may refer to an item such as a package or product, but intends to use these terms interchangeably. Trays are useful in material handling systems. Because they are of uniform size, or a limited number of sizes, they allow automated equipment, such as automated warehouses and similar systems, to handle standardized loads. Furthermore, the use of trays eliminates the concern that the item's walls may have irregular or unstable bottoms that could interfere with transport via conventional conveyors. One difficulty with using trays is the extraction process. Each tray necessarily has a raised side surrounding it to contain the product. To remove the product from the tray, it is necessary to raise the product high enough to clear the side of the tray by removing the product from the bottom. While this can be achieved by raising the product while holding the tray stationary or by holding the product stationary and lowering the tray, the unloading process is essentially the same in principle. The process must be carried out at a speed sufficient to maintain the throughput of the conventional material handling system and not add substantial cost to the system. Of course, it must be carried out repeatedly without damaging the item or causing a jam. The present invention is useful with trays of at least two different sizes. By having trays of various sizes, the tray size can be better adapted to the size of the item being handled. This reduces wasted space in the system by preventing large trays from handling small items while still having sufficient capacity to handle larger items. The present invention also has the capability of extracting items from the trays with the long side of the tray facing forward or the short side of the tray facing forward in the transport direction. This is useful because automated load calculation algorithms for automatic palletizers are able to optimize load placement by choosing not only the item's location within the load but also its orientation.Therefore, the present invention provides a useful method and apparatus for extraction that provides maximum flexibility by being able to use multiple trays of different sizes and extraction in multiple different orientations. According to one aspect of the present invention, a method and apparatus for removing items from trays is useful with a plurality of trays. Each tray has a base, a rim around the base, an opening in the base, and a bottom portion covering the opening. The bottom portion is liftable from the base. A tray supporting an item on its bottom portion is transported to an extraction assembly. The item is extracted from the extraction assembly by raising the bottom portion at least to the level of the tray rim with an item lifter from beneath the tray. The item lifter includes a lifting base and a plurality of lifting blocks attached to the lifting base. The lifting blocks are sized and arranged to engage the bottom portion of the tray through the opening in response to the lifting of the base.The 20 lifting blocks are sized and arranged to maintain the tray's orientation, with at least one block positioned outside the tray near the edge. The item is moved off the bottom of the raised tray. The tray can be elongated with long sides and short sides perpendicular to the long sides. The opening qr Lznn / rznz / E / YiAi can be elongated having long sides parallel to the long sides of the tray and short sides parallel to the short sides of the tray. The lifting blocks can be sized and arranged to engage the bottom of the tray through the opening and to maintain the orientation of the tray with at least one of the blocks positioned outside the tray next to the edge, regardless of whether the short edge of the tray faces forward or the long edge faces forward with respect to the direction of the conveyor. Some of the trays can be small trays, and some of the trays can be large trays that are larger than the small trays. A small tray or a large tray can be conveyed to the extraction apparatus with the long side forward or the short side forward. The conveyor can be a conveyor belt with a plurality of narrow, evenly spaced belts that operate at the same speed, and the lifting blocks are sized and arranged between the belts with the lifting base raised. The small trays can have a long rim the same length as the short rim of the large trays and a short rim that is half the length of the long rim of the large trays. The small trays can have an opening as long as the opening of the large tray is wide. A method and apparatus for removing items from trays, according to one aspect of the invention, has a plurality of trays, each tray having a base and a bottom portion that can be lifted from the base. Each tray further has a rim around the base and an opening in the base that is covered by the bottom portion. Some of the trays are large trays, and some are small trays that are smaller than the large trays. The opening of the large trays is larger than the opening of the small trays. A tray supporting an item on its bottom is transported to an extraction assembly. The item is extracted in the extraction assembly by lifting the bottom portion at least to the level of the rim of the tray with an item lifter from beneath the tray.The article lifter includes a lifting base and a plurality of blocks fixed to the lifting base. Some of the blocks are lifting blocks that are dimensioned and arranged to engage the bottom of the tray through the opening in response to the lifting base, and at least one of the blocks is a guide block that is dimensioned and arranged to maintain the orientation of the tray with the guide block positioned outside the tray next to the edge. The blocks are dimensioned and arranged on the lifting base in which at least two of the blocks are lifting blocks and at least one of the blocks is a guide block, whether the article is removed from a large tray or a small tray, and whether the article is removed from a tray that is oriented with its long edge forward or its short edge forward.The item moves off the bottom of the raised tray. The blocks can be arranged in rows, with at least one of the base row blocks being the base row block, at least two of the inner row blocks being outside the inner row block relative to the base row block, and at least two of the outer base row blocks being outside the inner row block relative to the base row block. A large tray can be extracted using the base row block, with the inner row blocks being the lifting blocks and at least one of the outer row blocks being a guide block. A small tray can be extracted using the base row block, with at least one of the inner row blocks being a lifting block and at least one of the inner row blocks being a guide block. At least one of the outer row blocks can be a guide block for extracting a small tray. These and other objects, advantages, purposes, and features of this invention will become evident upon reviewing the following specification together with the drawings. qr Lznn / pznz / E / YiAi BRIEF DESCRIPTION OF THE DRAWINGS qr Lznn / rznz / E / YiAi FIGURE 1 is a perspective view of a method and apparatus for removing an item from a tray according to an embodiment of the invention; FIGURE 2 is the same view as FIGURE 1 with the tray removed to illustrate the details of the extraction apparatus; FIGURE 3 is a bottom plan view taken in the I1I-III direction in Figure II illustrating a large tray 10 oriented with its long edge forward; FIGURE 4 is the same view as FIGURE 3 illustrating the large tray oriented with its short edge forward; FIGURE 5 is the same view as FIGURE 3 illustrating a small tray oriented with its long edge forward; and FIGURE 6 is the same view as FIGURE 3 illustrating the small tray oriented with its short edge forward. Reference to numbered elements in the present invention will now be described with the accompanying figures, in which the elements in the following written description correspond to elements numbered in the same way in the figures. A method and apparatus 10 for extraction is adapted for removing, or extracting, an item A from a tray 12 in the direction indicated by the arrow marked Divert. Although it is preferable to carry only one item A in each tray, it is also possible to place two or more items in each tray. Each of the trays 12 is elongated and has a long side 13 and a short side 14, with a base 15 and a rim 16 around the base. A bottom 20 floats within the rim 16 and can be lifted from beneath the base in a manner discussed in more detail below. The bottom 20 is a generally flat sheet with veins. 21 reinforcements formed below, as best seen in the Figures 3-6. Tray 12 further includes an elongated opening 18 in the base 15, with the lower portion 20 covering the opening. Tray 12 is either large, as shown in Figures 3 and 4, or small, as shown in Figures 5 and 6, which is smaller than the large tray. The small trays are approximately half the size of a large tray, so that two small trays placed with their long sides 13 in contact have approximately the same surface area as one large tray. One or more cavities 44 are formed on each of the sides 13, 14 of the tray 12. The cavities 44 are adapted to engage with linearly actuated fingers (not shown) for use in storing and retrieving the tray on a rack as described in detail in the commonly assigned European patent application Lznn / rznz / E / YiAi, filed on August 24, 2020, entitled, SYSTEM FOR STORAGE OF PRODUCT CONVEYORS, Serial Number EP20192434.7 (Attorney File 120157EP), the description of which is incorporated herein by reference in its entirety. Each tray 12 further includes a pair of parallel grooves 46 formed on a surface of the underside of each tray 12. As shown in Figure 4, the recessed grooves 46 formed in the base 15 extend parallel to the long side 13 of the large trays. As shown in Figure 5, the grooves 46 extend parallel to the short side 14 of the small trays. The grooves 46 are configured to interact with the guide strips (not shown) on the storage shelves to prevent the tray from changing position and / or orientation over time on the shelf, as described in detail in the commonly assigned European patent application, filed on August 24, 2020, entitled, SYSTEM FOR STORAGE OF PRODUCT CARRIERS, serial number EP20192437.0 (Attorney File No. 120158EP), the description of which is incorporated herein for reference in its entirety. The 46 slots are widened at each end to guide the slot over the corresponding guide strip. The extraction apparatus 10 is supported by a frame 20 composed of a pair of separate side channels qr Lznn / rznz / E / YiAi that also support a transport apparatus, such as a conveyor 24. The conveyor 24 transports the trays 12 in the direction indicated by the flow arrow with the elevator facing either the long side forward, as shown in Figures 3 and 5, or the short side forward, as shown in Figures 4 and 6. The extraction apparatus 10 includes an article elevator 26 comprising a lifting base 32 and a plurality of blocks 36 fixed to the lifting base. The lifting base 32 is selectively raised by an actuator (not shown) that can be pneumatically, hydraulically, or electrically operated. The blocks 36 are sized and arranged to raise the bottom of the tray 20 and to stabilize the tray during extraction, regardless of the tray size and orientation.In particular, regardless of the size and orientation of the tray, at least two blocks 36, called lifting blocks, are lifted into the opening 18 by engaging the bottom 20 of the tray in response to the lifting of the base 32 and at least one of the blocks 36, called the guide block, is positioned outside the tray next to the edge to maintain the orientation of the tray. In the illustrated embodiment, the conveyor 24 is a conveyor belt with a plurality of closely spaced narrow belts 25 that are driven at the same speed. The blocks 36 25 are sized and arranged to be between the belts 25 qr Lznn / rznz / E / YiAi when the lifting base 32 is raised. Another conveyor configuration, such as rollers or wheels, could be used. A diverter 20, such as a pusher, extends to divert item A from the tray in the diverter direction with the movable bottom in a raised state. The item will therefore pass over the rim 16. A tray rotator 30 upstream of the extraction apparatus 10 selectively rotates the tray 90 degrees if the tray is not in the orientation to discharge item A in the orientation required by the carcass loading algorithm.Such a tray rotator may be a selectively raised pin that engages an opening in a yield edge of the tray to rotate the tray in response to forward movement of the tray or the like. The 26 blocks have a size and orientation so that at least two of the blocks are lift blocks to raise the lower movable part 20 stably, regardless of the size and orientation of the tray. The blocks 36 are sized and oriented such that at least one of the blocks is a guide block adjacent to an outer edge of the tray to resist tray movement during extraction, regardless of the tray's size and orientation. In the illustrated embodiment, this is achieved by arranging the blocks 36 in rows, with at least one of the blocks 38 forming a base row, at least two of the blocks 40 forming an inner row with respect to the base row block, and at least two of the blocks 42 forming an outer row that are outside the inner row blocks with respect to the base row block. The blocks in one row are of a different size and shape than the blocks in a different row. The blocks in each row are generally symmetrical about an X-axis that forms a 45-degree angle with respect to the direction of transport, as shown in Figure 2. The blocks 10 differ somewhat from being completely symmetrical, for example, since a block 36c in the outer row is split in order to accommodate a conveyor belt 25. A large tray 12 is extracted with the base row block 38, the inner row blocks 40, and at least one of the outer row blocks 42 being lifting blocks, and the other of the outer row blocks 42 being a guide block, as seen in Figures 3 and 4. A small tray 12 is extracted with the base row block 38, and at least one of the inner row blocks 40 being lifting blocks, and at least one of the inner row blocks 40 being a guide block. See FIGURES 5 and 6.With a small tray, at least one of the 42 outer row blocks can also be a guide block as seen in FIGURES 5 and 6. It should be understood that all references to lifting the article or product from the tray may refer either to having a stationary base with the product at the bottom raised above the base or to having a stationary product at the bottom with the tray base lowered from the product. Changes and modifications to the embodiments specifically described may be carried out without departing from the principles of the present invention, which is intended to be limited only by the scope of the appended claims, interpreted in accordance with the principles of patent law, including the doctrine of equivalents.

Claims

1. An extraction method for removing items from trays, the method being characterized in that it comprises: having a plurality of trays, each of the 5 trays having a base, a rim around the base and an opening in the base and a bottom portion covering the opening, the bottom portion being raised from the base; transporting a tray bearing an item on its bottom portion to an extraction assembly;10 extracting the item in the extraction assembly by raising the lower portion at least to the level of the tray edge with an item lifter from beneath the tray, the item lifter comprising a lifting base and a plurality of lifting blocks attached to the 15 lifting base, the lifting blocks being sized and arranged to engage the lower portion of the tray through the opening in response to the lifting base being raised and the lifting blocks being sized and arranged to maintain the orientation of the tray with at least 20 one of the blocks positioned outside the tray next to the edge; and laterally displacing the item out of the raised lower portion of the tray.

2. The extraction method according to claim 1, characterized in that the tray is elongated and has long sides and short sides perpendicular to the long sides, and the opening is elongated and has long sides parallel to the tray, the long sides and short sides for the short tray, and wherein the lifting blocks are dimensioned and arranged to engage the underside of the tray through the opening and to maintain the orientation of the tray with at least one of the blocks positioned outside the tray adjacent to the edge, regardless of the orientation of the short edge of the tray forward or backward, the long edge being forward with respect to the conveyor direction.

3. The extraction method according to claim 1, characterized in that some of the trays are small trays and some of the trays are large trays that are larger than the small trays, and wherein transporting a tray comprises transporting a small tray with its long side forward or its short side forward, or transporting a large tray with its long side forward or its short side forward.

4. The extraction method according to claim 1, characterized in that the conveyor comprises a conveyor belt with a plurality of spaced narrow belts that are driven at the same speed and the lifting blocks are sized and arranged to be between the belts with the lifting base raised.

5. The extraction method according to claim 3, characterized in that the small trays have a long edge equal to the short edge of the large trays, the small trays have a short edge that is half the long edge of the large trays, and the small trays have an opening that is as long as the opening in the large tray is wide.

6. An extraction method for removing items from trays, the method characterized in that it comprises: 10 having a plurality of trays, each tray having a base and a bottom portion that can be lifted from the base, each tray further having a rim around the base and an opening in the base, which is covered by the bottom portion, some of the trays 15 being large trays and some of the trays being small trays that are smaller than the large trays, the opening in the large trays being larger than the opening in the small trays; transporting a tray that supports an item on its bottom portion to an extraction assembly;extracting the item in the extraction assembly by raising the bottom portion at least to the level of the tray edge with an item lifter from under the tray, the item lifter comprising a lifting base 25 and a plurality of blocks fixed to the lifting base qr Lznn / rznz / E / YiAi, the lifting blocks being dimensioned and arranged to engage the bottom portion of the tray through the opening in response to the lifting of the lifting base, and some of the blocks being guide blocks dimensioned and arranged to maintain the orientation of the tray with the guide blocks positioned outside qr Lznn / eznz / E / YiAi of the tray adjacent to the edge;wherein the blocks are dimensioned and arranged on the lifting base wherein at least two of the blocks are lifting blocks and at least one of the blocks is a figure block if the item is removed from a large tray or a small tray and if the item is removed from a tray that is being oriented with its long edge forward or its short edge forward; and 15 laterally flatten the item out of the raised bottom of the tray.

7. The extraction method according to claim 6, characterized in that the blocks are arranged in rows, at least one of the blocks being a base row, at least two of the blocks being of an inner row with respect to the base row block, and at least two of the blocks being of an outer row that are outside the inner row block with respect to the base row block.

8. The extraction method according to claim 7, characterized in that a large tray is extracted with the base row block, the inner row blocks and at least one of the outer row blocks being lifting blocks and the other of the outer row blocks being a guide block. 5 9. The extraction method according to claim 6, characterized in that a small tray is extracted with the base row block and at least one of the inner row blocks is a lifting block and at least one of the inner row blocks is a guide block. 10 10. The extraction method according to claim 9, characterized in that at least one of the outer row blocks is a guide block.

11. The extraction method according to any of claims 6 to 10, characterized in that the conveyor comprises a conveyor belt having a plurality of narrow, spaced belts driven at the same speed and the blocks are sized and arranged to be between the belts with the lifting plate raised.

12. The extraction method according to claim 3, characterized in that the small trays have a long rim equal to the short rim of the large trays, the small trays have a short rim that is half the length of the long rim of the large trays, and the small trays have an opening that is as long as the opening in the large tray is wide.

13. An extraction apparatus adapted for removing articles from a plurality of trays, each tray being elongated and having a long side and a short side with a base and a lower portion that can be lifted from the base, the tray further including a rim around the base and an elongated opening in the base, covering the lower portion of the opening, the apparatus characterized in that it comprises: an article lift comprising a lifting base and a plurality of blocks fixed to the lifting base, the blocks being of the size and arrangement necessary to lift the lower portion of a tray with at least two blocks in the opening engaging the lower portion of the tray in response to the lifting of the rising base, and the blocks being of sizes and arrangement to maintain the orientation of the tray with at least one of the blocks positioned outside the tray adjacent to the rim.whether the tray is oriented with its long side forward or its short side forward; and a conveyor that is adapted to transport the tray to the item elevator with the long side forward or the short side forward.

14. The extraction apparatus according to claim 13, characterized in that the elongated opening at the base has long sides parallel to the long sides of the tray and short sides parallel to the short side of the tray and wherein at least two blocks in the opening are adjacent to the long sides of the opening and adjacent to the short sides of the opening.

15. The extraction apparatus according to claim 13, characterized in that some of the trays are small trays and some of the trays are large trays that are larger than the small trays.

16. The extraction apparatus in accordance with any of the indications 13 to 15, characterized in that the conveyor comprises a conveyor belt with a plurality of narrow, spaced belts that are driven at the same speed, and the blocks are sized and arranged to be between the belts with the lifting base raised. 15 17. An extraction apparatus adapted for removing articles from trays, each tray having a base and a bottom portion that can be lifted from the base, each tray further having a rim around the base and an opening in the base that is covered by the bottom portion, some of the trays being large and some of the trays being small trays that are smaller than the large trays, the opening in the large trays being larger than the opening in the small trays; the apparatus characterized in that it comprises: a carrier that is adapted for carrying a tray that supports an article on its bottom portion to an extraction assembly;the extraction assembly adapted to raise the bottom portion at least to the level of the edge of tray 5 with an item lifter from under the tray, the item lifter comprising a lifting base and a plurality of blocks fixed to the lifting base, some of the lifting blocks being blocks that are dimensioned and arranged to engage the bottom portion of the tray 10 through the opening in response to lifting of the lifting base and some of the blocks are guide blocks that are dimensioned and arranged to maintain the orientation of the tray with the guide blocks positioned outside the tray adjacent to the edge;15 wherein the blocks are dimensioned and arranged on the lifting base, at least two of the blocks being lifting blocks and at least one of the blocks being a guide block, whether the item is being removed from a large tray or a small tray and if the item is being removed from a tray that is oriented with its long edge forward or its short edge forward; and a diverter that laterally displaces the item away from the raised bottom of the tray.

18. The extraction apparatus according to claim 17, characterized in that the blocks are arranged in rows, at least one of the blocks being a base row, at least two of the blocks being an inner row with respect to the block of the base row, and at least two of the blocks being an outer row that are outside the block of the inner row with respect to the block of the base row.

19. The extraction apparatus according to claim 18, characterized in that it is adapted to extract a large tray with the base row block, the inner row blocks and at least one of the 10 outer row blocks being lifting blocks and the other of the outer row blocks being a guide block.

20. The extraction apparatus according to claim 18, characterized in that it is adapted to extract a small tray with the base row block and at least one of the inner row blocks being a lifting block and at least one of the inner row blocks being a guide block.

21. The extraction apparatus according to claim 20, characterized in that within at least one of the outer row blocks is a guide block.

22. The extraction apparatus according to claim 17, characterized in that the transport comprises a conveyor belt with a plurality of spaced narrow belts that are driven at the same speed and the blocks qr Lznn / rznz / E / YiAi are of the size and arrangement necessary to be between the belts with the raised lifting plate.

23. The extraction apparatus according to any of claims 17 to 22, characterized in that the small trays have a long edge equal to the short edge of the large trays, the small trays have a short edge that is half the long edge of the large trays, and the small trays have an opening that is as long as the opening in the large tray is wide.

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