Shelving system with multi-level storage racks

Abstract

A vertical lift (7) for a shelving system (1) configured with multi-level storage racks (2) defining an aisle (3) between them, in which storage and retrieval machines (4) travel along the racks as operating devices for storing and retrieving loads from the racks. Within the base area of ​​the racks (2), an aisle (3), the vertical lift (7) is arranged such that the storage and retrieval machines (4) can travel past the vertical lift (7) along the rack front sides facing the aisle (3). The vertical lift (7) has two lifting platforms (8) arranged one above the other, which can be moved independently of one another along a vertical lifting mast (9). The platforms (8) are guided on different sides of the vertical lifting mast (9), and each lifting platform (8) has a two-zone, horizontally aligned lift conveyor (11).wherein a zone (11B) of the respective lift conveyor (1) of the lifting platform (8) is designed to be pivotable by means of a pivoting mechanism (12) such that the zone (11B) can be arranged below or above the respective other fixed zone (11A).

Description

The invention relates to a rack storage system having multilevel storage racks, which define a gate between them, in which rack storage and retrieval units travel along the racks as storage units for storing and removing items to be loaded into the racks, wherein at least one vertical lift is arranged within the base area of the racks of a gate such that the rack storage and retrieval units can travel past the vertical lift along the front sides of the racks facing the gate according to claim 1.FIG. 8 of AT 516 231 A1 discloses a buffer conveyor which is likewise reversible and is arranged on one side next to a lift with a reversible lift conveyor.It is known from EP 2 794 431 B1 to arrange lifts vertically within the racks in a rack storage system with storage racks which define a gate between them, in which shuttles travel along the racks as operating devices in the storage levels, in such a way that the shuttles can travel past them on the one hand and can discharge or pick up loaded material, which is conveyed further to the lift or originates from the lift, via buffer conveyors arranged next to the lifts on both sides. In a storage connection plane, i.e. the feed to the storage or discharge from the storage, the lift, on the other hand, is positioned between an infeed conveyor and an outfeed conveyor. It is thus possible that, on the one hand, the shuttles are decoupled from the operation of the lift and, on the other hand, the lift can simultaneously pick up and deliver cargo.EP 3 738 907 A1 discloses a rack storage system having multilevel storage racks which define a gate between them, in which shuttles in the storage levels travel along the racks as operating devices for storing and removing items to be loaded into the racks, wherein at least one vertical lift is arranged within the base area of the racks of a gate such that the shuttles can travel past the vertical lift on rails along the front sides of the racks facing the gate and can discharge or pick up items to be loaded via a buffer conveyor arranged next to the vertical lift, wherein the buffer conveyor conveys items to the lift or takes them over from the lift, wherein the system is configured such that items are loaded and also picked up only on one side of the lift in a storage connection level, characterized in that the storage conveyor and the removal conveyor of the storage attachment plane are both arranged on one side next to the lift as a single double conveyor in the support surface of only one rack, and that the double conveyor has a longitudinal division such that one longitudinal half conveys towards the lift and the other longitudinal half conveys away from the lift in the same plane.These systems have the problem that the vertical lift is often the eye of the needle, since it limits the input and output speed of the system.One possibility for increasing the performance of such vertical lifts is to provide more than one lifting platform per vertical lift.Thus, for example, EP 2 523 877 B1 and EP 2 979 996 B1 and DE 20 2004 008 678 U1 disclose double-deck vertical lifts.US 2022 / 0 073 278 A1 discloses a material handling system having a vertical lift and two vertically oriented carriages independently positionable on a vertical support structure by respective drive systems. A processor subsystem selects one of the two carriages to move an article from at least one feeder conveyor to a selected level of an automatic storage and delivery system. The processor subsystem simultaneously positions the other carriages to avoid a collision.However, the vertical reach of the respective lifting platforms lying one above the other is always limited by the other lifting platform arranged above or below.In contrast, the object of the present invention is to provide such a storage system which simultaneously has an increased capacity of the vertical lift and nevertheless the vertical lift or its lifting platforms can be moved over the entire shelf height.This object is achieved by the vertical lift for a rack storage system as set forth in claim 1. Advantageous embodiments are evident from the dependent claims and the description.According to the invention, it has been recognized that if the platforms are guided on different sides of the vertical lifting mast and each lifting platform has a two-zone horizontally oriented lift conveyor, wherein a zone of the respective lift conveyor of the lifting platform is designed to be pivotable by means of a link mechanism in such a way that the zone can be arranged below or above the respective other fixed zone, it becomes possible for each lifting platform to be movable over the entire height of the lift, since the pivoting means does not prevent the lifting platforms from interfering with one another and allow them to pass one another. In other words, the lifting platform or its lift conveyor can be pivoted out of the way, so that the respective other lifting platform with the lift conveyor likewise pivoted is not obstructed. This is possible because the guides of the platforms take place on different sides of the vertical lifting mast. Thus, the lifting drives of the lifting platforms running on different sides of the lifting mast do not interfere with each other.It is preferred if the fixed zone is arranged on the guide on the vertical mast and the pivotable zone is arranged on the opposite vertical mast side.The pivoting mechanism can connect the pivotable zone to the fixed zone via a controllable and driven gear or joint (e.g. lever, with or without slotted links, gear mechanisms, articulated rods, etc.). Thus, both zones remain aligned horizontally, so that goods located thereon do not fall down. One possibility would be, for example, the use of motor-driven articulated arms which connect the pivotable zone to the fixed zone. A pair of articulated arms could thereby drive the pivoting movement, while a second pair of articulated arms holds the pivotable zone in a horizontal orientation during pivoting. The second articulated arm pair can be designed in two or more parts for this purpose. Both pairs of swivel arms are attached to the swivellable zone at different ends.The pivoting mechanism can likewise be configured in such a way that the two zones are aligned with one another in the vertical direction after pivoting.If the lift conveyor is designed with a reversible drive, the lift conveyor can be used for both depositing and removing.Preferably, the lift conveyor has zones of equal size.If the two zones of the lift conveyor are separated along the central longitudinal axis of the lifting mast, sufficient distance is easily created in the pivoted state for moving past one another.By means of a sensor system and control, the pivoting of the two zones relative to one another is initiated and monitored. A central control of the rack storage system, which also assumes the control of the vertical lift, knows, on the basis of the travel commands or the destinations of the items to be loaded, when the lifting platforms must "pass" and then specifically controls the pivoting or pivoting back. The controller can initiate the pivoting after receiving the item to be loaded, if appropriate before the start of the vertical movement. Alternatively, the pivoting can be carried out dynamically during the journey.The controller may determine and evaluate the absolute position of the lifting platforms. For this purpose, the lifting mast can be provided with barcode markings, which are read out or scanned by a barcode reader on the respective lifting platform. The controller can then determine the absolute vertical position of the lifting platform on the lifting mast via the barcode read out. Thus, at any time, i.e. also during travel or at standstill, the position of the respective lifting platform can be determined by the controller.The pivoting of the respective pivotable platform can be monitored via sensors, such as inductive proximity switches, which provide a binary signal, "object detected / not detected", for example, to the controller. Thus, one can grasp the end position of the swingable conveyors.For this purpose, inductive proximity switches can be arranged in the region of the pivot arms in order to recognize, on the one hand, their almost horizontal orientation (non-pivoted position) and, on the other hand, their almost vertical orientation (pivoted position). It would also be conceivable to use absolute value encoders on the drive (e.g. angle gear motor) or simple limit switches on the pivot arms, etc.If the pivotable zone is situated below the fixed zone in the pivoted position such that the distance approximately corresponds to the distance from storage planes with buffer conveyors, two storage planes or buffer conveyors situated one above the other can be simultaneously operated, although in the classic sense it is not a double-lifting basket. This can be achieved if the pivot arms are dimensioned accordingly.The storage rack system is preferably a so-called shuttle system in which shuttles (as storage and retrieval devices) travel in the storage levels along the racks as retrieval devices for storing and removing cargos into the racks. The shuttles travel on rails along the front sides of the shelves facing the gate past the vertical lift and can discharge or pick up loaded goods via a buffer conveyor arranged next to the vertical lift, wherein the buffer conveyor conveys loaded goods on to the lift conveyor or takes over them from the lift conveyor in the non-pivoted arrangement.Further details of the invention will become apparent from the following description of exemplary embodiments with reference to the drawing, in which FIG. 1 shows a schematic perspective view of a vertical lift between indicated buffer conveyors in an upper and a lower plane of a storage rack; FIG. 2 shows the view from FIG. 1 in another position of the vertical lift; FIG. 3 shows the view from FIG. 1 in yet another position of the vertical lift during pivoting of the zones of the lift conveyors of the lifting platforms; FIG. 4 shows the view from FIG. 1 in yet another position of the vertical lift when the lifting platforms pass one another, and FIGS. 5A-D are enlarged fragmentary views of zones of a lift conveyor in various positions; and FIGS. 6 to 8 are schematic perspective views of an embodiment of a lifting platform during the pivoting of the zones of the lift conveyor; and FIG. 9 shows a schematic perspective view of an embodiment of a lifting platform with illustration of a variant of the absolute position measurement via barcode markings on the lifting mastshow.In the figures, a rack storage system, denoted as a whole by 1, is shown, having multilevel storage racks 2, which define between them a gate 3 in which shuttles 4 travel in the storage levels along the storage racks as operating devices for storing and removing items of cargo L into the storage racks.At least one vertical lift 7 is arranged within the base area of the storage shelves 2 of a lane 3 in such a way that the shuttles 4 can travel past the vertical lift 7 on rails 5 along the front sides of the shelves facing the lane 3 and can each discharge loaded material via a buffer conveyor 6A arranged next to the vertical lift 7 or can pick up loaded material arranged on the other side, as is indicated in FIG. 1.In other words, in the storage plane, the vertical lift 7 is arranged between two buffer conveyors 6A, B within the storage rack 2. It is understood that the vertical lift 7 can also be arranged on the end face on the storage rack 2 or also without buffer conveyors or a one-sided arrangement of the buffer conveyors. Thus, the buffer conveyors 6B could be arranged in a further storage rack 2 or could also form an interface to a feed or discharge system that connects the remaining warehouse to the storage rack.The respective buffer conveyor 6A, B conveys loaded goods L to the vertical lift 7 or takes on loaded goods from the vertical lift 7. This decouples the movement of the vertical lift 7 from that of the shuttles 4.The vertical lift 7 has two lifting platforms 8A, B arranged one above the other, which can be moved independently of one another along a vertical lifting mast 9 via driven guides 10A, B.The lifting platforms 8A, B are guided on different sides of the vertical lifting mast 9 or are each connected to the guide 10 and each lifting platform 8A, B has a two-zone horizontally oriented lift conveyor 11, wherein a pivotable zone 11B of the respective lift conveyor of the lifting platform is configured pivotably by means of a pivot mechanism 12 in such a way that the zone can be arranged below or above the respective other fixed zone 11A, which is in turn fixed to the guide 10A, B.The respective lift conveyor 11 thus extends between the buffer conveyors 6A, B, so that these can be supplied and removed with cargo L.The pivotable zone 11B is accordingly arranged on the opposite vertical mast side. The zones 11A, B are of the same size and are separated from one another along the central longitudinal axis of the lifting mast 9. They also have a reversible drive.The pivot mechanism 12 connects the pivotable zone 11B to the fixed zone 11A via a controllable and driven gear or joint.This allows the lifting platforms 8A, B to pass one another by pivoting the pivotable zone 11B below the fixed zone 11A, since the lift conveyors 11 of the different lifting platforms 8A, B are then not in the way (cf. FIG. 4 ).For this purpose, as indicated in FIG. 3, the pivotable zone 11B of the lifting platforms 8A, B is pivoted below the fixed zone 11A via the pivot mechanism 12, in each case loaded with cargo L or unloaded, so that a distance is produced between the respective lifting platforms 8A, B at the longitudinal central axis 13.When the corresponding lifting platform arrives at the target plane, the pivotable zone 11B can be pivoted back, so that the buffer conveyors 6A, B or other conveyors can then be reached in order to discharge or pick up the item to be loaded L.In FIGS. 5A-D, the pivoting of the pivotable zone 11B relative to the fixed zone 11A is generally illustrated.Starting from the arrangement next to one another (A) in which the two zones 11A, B of the lift conveyor 11 are aligned horizontally with one another in order to enable the transfer or discharge of cargo L, the pivotable zone 11B is pivoted gradually (cf. intermediate positions (B) and (C) from the position (A) aligned horizontally with the fixed zone 11A) into the position (D) lying vertically one above the other, while maintaining the horizontal alignment via the pivot mechanism 12.In FIGS. 6 to 8, this pivoting is illustrated on the basis of an example in which the lift conveyors 11 are not designed as roller conveyors but as belt conveyors and the pivoting mechanism 12 comprises articulated arms.The pivot mechanism 12 uses articulated arms 15, 16 driven by a motor by a controlled angle gear motor 14, which connect the pivotable zone 11B to the fixed zone 11A. A pair of articulated arms 15 is driven and performs the pivoting movement, while a second pair of articulated arms 16 holds the pivotable zone 11B in a horizontal orientation during pivoting. The second articulated arm pair is designed in two parts for this purpose, or the articulated arms 16 are designed in two parts. Both pairs of swivel arms 15, 16 are attached to the swivellable zone 11B at different ends 17A, B. The two articulated arms 15A, B of the articulated arm pair 15 are connected via a drive shaft 18.A central controller 20 of the rack storage system, which also assumes the control of the vertical lift 7, knows, on the basis of the travel commands or the destinations of the items L, when the lifting platforms 8A, B must "pass" and then specifically controls the pivoting or return pivoting. The controller can initiate the pivoting after receiving the item of cargo L, if appropriate before the start of the vertical movement. Alternatively, the pivoting can be carried out dynamically during the journey.The lifting mast 9 is provided with barcode markings 21, which are read or scanned by a barcode reader 22 on the respective lifting platform 8A, 8B (see FIG. 9 ). The controller 20 can then determine the absolute vertical position of the lifting platform 8A, 8B on the lifting mast 9 via the barcode read out. Thus, at any time, i.e. also during travel or at standstill, the position of the respective lifting platform 8A, 8B can be determined by the controller 20.The pivoting of the pivotable zone 11B of the respective lifting platform 8 is monitored via inductive proximity switches 19 which provide a binary signal, "object detected / not detected", to the controller 20. Thus, one can grasp the end position of the swingable conveyors.For this purpose, the inductive proximity switches 19 are arranged in the region of the pivot arms 15 in order to recognize, on the one hand, their almost horizontal orientation (non-pivoted position, cf. FIG. 6 ) and, on the other hand, their almost vertical orientation (pivoted position, cf. FIG. 8 ). It would also be conceivable to use absolute value encoders on the angle gear motor 14 or simple limit switches on the pivot arms, etc.If the pivotable zone 11B is located below the fixed zone 11A in the pivoted position such that the distance approximately corresponds to the distance from storage planes with buffer conveyors 6A, B, two storage planes or buffer conveyors 6A, B lying one above the other can be simultaneously operated, although in the classic sense it is not a double-lifting basket. This can be achieved if the pivot arms 15, 16 are dimensioned accordingly.List of reference characters1 Rack storage system 2 Storage rack 3 Gate 4 Shuttle 5 Rail 6A, 6B Buffer conveyor 7 Vertical lift 8 Lifting platform 9 Lifting mast 10 Guide 11 Lift conveyor 11A Fixed zone 11B Pivotable zone 12 Pivot mechanism 13 Longitudinal central axis 14 Angle gear motor 15 Articulated arm 16 Articulated arm 17 End 18 Drive shaft 19 Inductive proximity switch 20 Controller 21 Barcode marking 22 Barcode reader

Claims

Vertical lift (7) for a rack storage system (1) which is configured with multilevel storage racks (2) which define a gate (3) between them, in which rack operating devices (4) travel along the racks as operating devices for storing and removing items to be loaded into the racks, wherein the vertical lift (7) is arranged within the base area of the racks (2), of a gate (3), in such a way that the rack operating devices (4) can travel past the vertical lift (7) along the front sides of the racks facing the gate (3), wherein the vertical lift (7) has two lifting platforms (8) arranged one above the other, which can be moved independently of one another along a vertical lifting mast (9), characterized in that, the platforms (8) being guided on different sides of the vertical lifting mast (9) and each lifting platform (8) having a two-zone horizontally oriented lift conveyor (11), wherein a zone (11B) of the respective lift conveyor (1) of the lifting platform (8) is designed to be pivotable by means of a pivoting mechanism (12) in such a way that the zone (11B) can be arranged below or above the respective other fixed zone (11A).Vertical lift according to claim 1, characterised in that the fixed zone (11A) is arranged on the guide (10) on the vertical mast (9) and the pivotable zone (11B) is arranged on the opposite vertical mast side.Vertical lift according to claim 1 or 2, characterised in that the swivel mechanism (12) connects the swivellable zone (11B) to the fixed zone (11A) via a controllable and driven gear (14) or joint (15, 16).Vertical lift according to one of the preceding claims, characterized in that the lift conveyor (11) is configured with a reversible drive.Vertical lift according to one of the preceding claims, characterized in that the lift conveyor (11) has zones (11A, B) of equal size.Vertical lift according to one of the preceding claims, characterized in that the two zones (11A, B) of the lift conveyor (11) are separated along the central longitudinal axis (13) of the lifting mast (9).

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