Storage and retrieval unit and method for controlling product storage shelving, especially a commission device

A storage and retrieval unit (1) is provided for operating a product storage shelving (2), which has at least one shelf, on which essentially cubic products (4, 5, 6) are arranged and held. The products can be removed and fed to a driven, essentially horizontal continuous belt (8) of a height-adjustable storage and retrieval unit that is movable along the product storage shelving. The products removed are centered by a centering device with a lateral product centering element (9), which is arranged on a transverse side of the continuous belt (8) in the area of at least one longitudinal end of the continuous belt. The lateral product centering element centers a product removed from the product storage shelving (2) against a lateral longitudinal stop (10) of the continuous belt (8). Differently configured cubic products may be handled by the storage and retrieval unit in an easy, fast and reliable manner.

FIELD OF THE INVENTION

The present invention pertains to a storage and retrieval unit and a method for operating a product storage shelving, which has at least one shelf, on which essentially cubic products are arranged and held, and from which said products can be removed and fed to a driven, essentially horizontal continuous belt of the height-adjustable storage and retrieval unit which can be displaced along the product storage shelving, wherein the products removed are centered by a centering device.

BACKGROUND OF THE INVENTION

A storage and retrieval unit of the above-mentioned type is known from, e.g., EP 0 866 002 A2; this storage and retrieval unit can be used to remove products to be commissioned from the product storage shelving, but also to introduce products into the product storage shelving, doing so by means of two continuous belts, with an operating finger each being provided on the longitudinal end sides. To remove products from an oblique storage shelving, the storage and retrieval unit is placed with its operating finger under the lowermost frontmost product of the storage shelving. The storage and retrieval unit is then lifted, so that the operating finger or the frontmost end of the continuous belt is lifted as well, it extends below the frontmost lowermost product from the product storage shelving, lifts the product via a stopper and thus places same on the continuous belt of the storage and retrieval unit. Products remaining in the storage shelving push the frontmost product out of the shelf during the product removal because of their own weight. The products delivered onto the continuous belt are centered by the centering device in the form of adjustable lateral product guides, which are provided on each side of the continuous belt in the form of two bent guide rails. The two guide rails are adjusted laterally and vertically simultaneously in relation to the transverse direction of the continuous belt. The drawback is that only identically configured products or individual goods can be guided or centered by the two guide rails.

SUMMARY OF THE INVENTION

The object of the present invention is to design a storage and retrieval unit of the type described in the introduction such that differently configured cubic products can also be handled in a simple, reliable and fast manner.

The object of the present invention is, furthermore, to provide a simple and reliable method for removing products from a product storage shelving by means of a storage and retrieval unit of the type described in the introduction.

According to the invention, a storage and retrieval unit is provided for operating a product storage shelving, which has at least one shelf, on which essentially cubic products are arranged and held and from which such products can be removed and fed to a driven, essentially horizontal continuous belt of the height-adjustable storage and retrieval unit that is movable along the product storage shelving. The products removed are centered by a centering device. The centering device comprises a lateral product centering element, preferably a centering plate, which is arranged on a transverse side of the continuous belt in the area of at least one longitudinal end of the continuous belt. The lateral centering plate or the lateral centering plates is/are set to the width of the product or corresponding to the width of the product. The effect of the lateral displacement of the products is generated by the displacement of the continuous belt and of an extension belt section that may be optionally arranged upstream. The continuous belt is connected with the centering plate on the side of the lateral longitudinal stop. As a result, the products are centered after the removal from the product storage unit, preferably by operating fingers, in the lateral product centering element set to the product width, and are as a result always oriented on one side to the continuous belt and stored on same. The product will then be in contact with the lateral longitudinal stop. The lateral product centering element may have conical stop faces in the form of vertical guide plates, which facilitate the passage of the product without the possibility of jamming.

According to another aspect of the invention, a method is provided for removing products from a product storage shelving by means of the storage and retrieval unit. The product storage shelving has at least one oblique shelf, on which essentially cubic products are arranged one after another and are held against a shelf stop at the deepest point of the said oblique shelf. An operating finger of the height-adjustable storage and retrieval unit, which said storage and retrieval unit is movable along the said product storage shelving, can extend under the lowermost product of the products arranged one after another at the said shelf stop, lift same over the shelf stop and transfer same. The transfer is in a centered manner after centering by a centering device to a horizontal, driven continuous belt of the storage and retrieval unit. The continuous belt is guided via end-side defecting rollers. A product removed from the product storage shelving by means of the operating finger is laterally centered against the lateral longitudinal stop by moving the driven continuous belt including an extension belt section optionally arranged upstream after setting a lateral product centering element, preferably a centering plate, to the product width in the transverse direction of the said continuous belt in the direction of the longitudinal stop.

The longitudinal stop is longer than the longitudinal extension of the continuous belt and preferably has above-mentioned extension belt sections on both longitudinal sides of the storage and retrieval unit. By placing or laterally displacing the products removed from the product storage shelving up to the longitudinal stop, the cubic products are positioned along the longitudinal stop at an angle to the continuous belt regardless of their dimensioning and are consequently laterally centered.

The term “cubic products” also comprises nearly cubic products, e.g., even bottles of a nearly cubic shape with a correspondingly short bottle neck, e.g., cubic plastic bottles for pharmaceutical preparations.

Consequently, contrary to the above-mentioned state of the art, cubic products of different size (large and small cubes, large and small and especially also slim parallelepipeds) of a product storage shelving, especially of a commissioning device, can also be handled simultaneously by means of the storage and retrieval unit.

The lateral product centering element, of which one lateral product centering element each is preferably provided at each longitudinal end of the continuous belt, i.e., two lateral product centering elements, which are rigidly connected to one another, is driven by a centering drive, which is actuated by a central control unit, which also actuates the drive of the continuous belt. The path of displacement or setting path of the lateral product centering element corresponds to the width of a product to be handled and is set correspondingly by the central control unit. It is obvious that the product is not pressed by applying a force to the longitudinal stop, but is placed only “loosely” in the angle between the longitudinal stop and the upper strand of the continuous belt. If products of different dimensions are present on a continuous belt placed in such a way, especially at closely spaced locations one after another, these products are arranged in a sufficiently stable manner in such a way that a transverse displacement or transverse shifting of the storage and retrieval unit is also possible along a product storage shelving at least in one direction with great acceleration/deceleration from one location of the storage unit to the other, namely, in the direction in which the products being laterally accelerated/decelerated are pressed to the longitudinal stop.

The products can be stored and conveyed not only at closely spaced locations from one another, but, as an alternative, also with spaces of any desired configuration between the products.

Another aspect of the present invention is that in an advantageous variant of the present invention, the continuous belt including the longitudinal stop can be tilted in the transverse direction of the continuous belt into a pivoted position in which the root of the angle between the longitudinal stop and the continuous belt is located at the deepest point. As a result, products of different dimensions present on the continuous belt are stabilized in such a way that a transverse acceleration/transverse deceleration of the continuous belt is possible in both directions, and the products are held in their centering angle in a sufficiently stable manner.

A storage and retrieval unit designed in such a manner can be handled especially rapidly with a high commissioning output even at large, long product storage shelvings. The tilted position of the continuous belt including the longitudinal stop is set only during a transverse movement of the storage and retrieval unit. If the storage and retrieval unit is in a removal position aligned with a product storage shelving or in a discharge position in relation to a downstream joining conveyor belt, the tilted position of the continuous belt including the longitudinal stop is not set: The continuous belt is located—when viewed in the transverse direction of the continuous belt—in a horizontal position, which is also shared by the shelves of the product storage shelving or the joining conveyor belt.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to the drawings in particular, the storage and retrieval unit1is part of a commissioning device for cubic products to be commissioned or buffered. The storage and retrieval unit1can be positioned via a central control unit at the product storage shelving2at the desired location of a product to be removed, and the removal of the product can also be controlled via the central control unit. The central control unit also controls the individual drives of the storage and retrieval unit1, which will be described below.

The product storage shelving2has oblique shelves, which are arranged at closely spaced locations next to each other, forming storage planes, and at closely spaced locations one on top of another, forming a plurality of storage planes. The product storage shelving2is schematically shown in the left-hand part ofFIG. 4A.

Another product storage shelving2is located on the other side of the storage and retrieval unit1according to the right-hand part ofFIG. 8A.

The two product storage shelvings2form an automatic aisle, in which the storage and retrieval unit1can be displaced longitudinally or can travel longitudinally, so that it can be positioned at individual selected shelves of the product storage shelving2.

The storage and retrieval unit1has an essentially symmetrical design in relation to its longitudinal extension in order to make it possible to operate both product storage shelvings2according toFIGS. 4A and 8A, which are located at spaced locations from each other, by means of end-side operating fingers7.

The operating fingers7are driven circulating belts which are short in their longitudinal extension with a central, narrow circulating belt, which is longer than the rest of the driven circulating belts and forms the farthest projecting extension of the storage and retrieval unit on the longitudinal end side.

The storage and retrieval unit1according toFIG. 1is composed of a product handling unit19and a base unit18according toFIG. 2.

The base unit18comprises, among other things, a back frame24, a continuous belt drive17as well as bases26, which are located at spaced locations from one another and on which the product handling unit19according to the top part ofFIG. 2can be fastened in a positioned manner.

The product handling unit19comprises, in turn, as this is shown inFIG. 3, a continuous belt unit20, a tilting unit21, a carrier unit22, as well as a connection unit23.

The continuous belt unit20has essentially a continuous belt8, which is led over end-side deflecting rollers and can be driven by the continuous belt drive17in both directions, and a longitudinal stop10, which not only extends over the entire length of the continuous belt8on the transverse side of the continuous belt shown inFIG. 3, but also projects on both longitudinal ends of the continuous belt8, and the frontmost vertical ends are bent.

The longitudinal stop10may be a vertical flat guide plate12or an angle plate.

The continuous belt unit20is fastened on a carriage plate27of the tilting unit21.

The tilting unit21contains, furthermore, a pivoting drive28and a pivot axis29, as is shown especially inFIG. 3. The tilting unit21is in turn connected via the carriage plate27with the carrier unit22by means of a guide, at the longitudinal ends of which the two operating fingers7of the storage and retrieval unit, which said operating fingers are connected to one another via the connection unit23, are fastened.

A centering device3with a lateral product centering element9each in the form of a centering plate and with a centering drive30is located in the area of the mounted operating fingers7at each longitudinal end, wherein the centering plates are rigidly connected to one another. The centering plate usually has, at least on the inlet side, a conical expansion in the form of an obliquely extending, vertical guide plate, which makes possible the satisfactory entry of a product.

Furthermore, the storage and retrieval unit1has a counting device16in the form of a counting photocell in the area of each centering device3as well as at least one reference photocell15in the area of each longitudinal end of the continuous belt8.

The reference photocells15and the counting devices16are connected with the central control unit, which synchronously controls all the above-mentioned drives as well as the operating fingers7.

The mode of operation of the storage and retrieval unit1will be described below on the basis ofFIGS. 4A through 12B.

According toFIGS. 4A and 4B, the storage and retrieval unit1according toFIGS. 1 through 3is positioned in a removal position of an oblique shelf oaf left-hand product storage shelving2. The left-hand operating finger7extends under the shelf stop of the selected shelf The shelf stop is located at the left-hand operating finger7. The selected product4to be commissioned is lifted over the shelf stop and is fed over a driven extension section to the continuous belt8of the storage and retrieval unit1, which said continuous belt is in the horizontal starting position A. The selected product4is then counted by means of the counting device16and at the same time centered by the centering device3. The centering plate of the centering device is first set to the selected product4corresponding to the width of the product. The center plate of the centering device is actuated by centering drive30. The product is moved onto the driven continuous belt and then arranged at the lateral longitudinal stop or laterally centered by the guide plate or centering plate. The product is moved by the forward movement of the driven extension section and by the continuous belt being driven synchronously.

The selected product4is registered by the reference photocells15according toFIG. 4Aand, as was mentioned above, the continuous belt8is put into operation by the continuous belt drive17, so that the product4is delivered into the position on the continuous belt8shown inFIGS. 5A and 5B, and the continuous belt18is then stopped.

The continuous belt8including the longitudinal stop10are subsequently tilted by means of the tilting unit21by actuating the pivoting drive28from the horizontal starting position A shown inFIG. 4Binto a tilted oblique position B according toFIG. 5Bin such a way that the root11of the angle between the longitudinal stop10and the continuous belt8is located at the lowest point, which is a point adjacent to the continuous belt and the longitudinal stop when the continuous belt and the longitudinal stop are in the pivoted position. Thus, not only is the selected product4centered on the continuous belt8, but also held in the root of the angle in a stable manner.

In the pivoted position B of the continuous belt8as shown inFIG. 5B, the storage and retrieval unit1is subsequently brought in the automatic aisle between the two product storage shelvings1in the transverse direction Q of the continuous belt8into another removal position of a differently configured cubic product5of the product storage shelving2, left, and is again tilted back there into the horizontal starting position A according toFIG. 6B. The differently configured cubic product5is then laterally centered in the same manner as the product4and moved onto the continuous belt8and is positioned especially at a closely spaced location from product4. Both products4and5are then again brought into the pivoted position B according to theFIG. 7Bin order to position the storage and retrieval unit1at a comparatively high lateral acceleration at another product storage shelving2according to theFIG. 8B.

Before the introduction of the additional product6according toFIGS. 8A and 8B, the horizontal starting position A according toFIG. 8Bis again set, and the latter product6is subsequently arranged on the continuous belt8according toFIG. 9B, laterally centered and at a closely spaced location from the first product4. It is obvious that the products4and5were transferred before to the right on the continuous belt8from the position shown inFIGS. 7A and 7Binto the position shown inFIGS. 8A and 8B.

All three products4,5and6are then again centered in the pivoted position according toFIG. 9Band optionally sent to additional removal sites of the product storage shelvings2.

The process is repeated until the continuous belt8is completely filled or the commissioning order has been completed.

The products4,5and6are finally delivered from the pivoted position B onto the joining conveyor belt13in the horizontal starting position A according toFIGS. 11A and 11Band12A and12B by the continuous belt8in an exactly positioned manner, preferably at closely spaced locations from one another, and each product4,5and6is identified by a product recognition means14in the form of a scanner, which is located above the inlet area of the joining conveyor belt13, and detected by an image processing means40according toFIGS. 12A and 12B, with which visual detection of the actual state of the product and optionally tracing in relation to the product is made possible. The visual detection may also be used for documentation and traceability with respect to the shipped or packaged products.

The products are subsequently sent to a packaging station41, in which the commissioned products are packaged and are hauled off from there.

While the image processing means40is located according toFIGS. 12A and 12Bin the area of the joining conveyor belt13after the product recognition means14above the joining conveyor belt13at such a spaced location that comparatively tall cubic products can also be removed without touching, the image processing means40is located in a correspondingly high area in the packaging station41according toFIGS. 11A and 11B.

As can be seen, differently configured products are handled by the present invention rapidly and reliably with the storage and retrieval unit1without the possibility of tilting over laterally. If the products4,5and6have, e.g., identification features in the form of bar codes on their top side, these are satisfactorily detected by the scanner according toFIGS. 11A and 11B, because the products cannot tilt over.

It is apparent that the products may also be removed differently from the continuous belt8, e.g., in a collecting container.