Shelf storage system with robots with hooks or fingers for gripping and lifting shelves and corresponding method for gripping shelves

Description

1. Field of the invention

[0001] The field of the invention is that of warehouse logistics, and in particular the storage and automatic return of products.

[0002] More specifically, the invention relates to a product storage and return system.

[0003] The invention finds particular application in the storage of products in warehouses. 2. State of the art

[0004] For example, from document NO317366 B1, automated structures for storing bins containing products in a three-dimensional grid are known, in which the bins are stored one above the other in columns on which rails have been fixed to allow the movement of robots to pick up or place a bin in a column and transport it on the grid-shaped rail network to another storage column or a collection point, where, for example, the bin is transferred onto a conveyor or into an elevator.

[0005] To pick up a bin from a column, document NO317366 B1 proposes using a platform suspended by cables that can move vertically, equipped with gripping clips to grab the bin placed at the top of the stack of bins stored in the column by its upper part.

[0006] A disadvantage of this known technique is that it only allows one bin to be sampled at a time from a storage column. This limitation is particularly detrimental when one wishes to sample a bin located below several bins in a stack. It is then necessary to remove each of the bins placed above the bin one by one to be able to access the bin to be sampled and to temporarily store them outside the column, which significantly increases the overall time required to sample the target bin and can cause difficulties in the movement of the robots on the grid due to the presence of the bins that have been removed to access the target bin and that are waiting to be redeposited in the column. In addition, this known technique does not allow the sampling of several target bins stacked on top of each other in a single operation.

[0007] In order to overcome this drawback, it was considered to implement a frame or arms that could slide along a stack of bins, equipped with claws to be able to grasp a bin from the stack located under one or more bins and lift this bin and the bins placed above it in the same movement.

[0008] Document EP 0 767 113 A2 describes a system according to the preamble of claim 1, a method according to the preamble of claim 12 and a robot equipped with such a lifting frame whose frame has the shape of a rectangular tube. A disadvantage of this tube-shaped frame is that its height corresponds to the height of the maximum stack of bins that can be stored in a column, in order to be able to pick this maximum stack in a single operation, which restricts its use in a warehouse where the height may not be sufficient.

[0009] Document WO 2013 / 167907 A1 also describes a robot equipped with arms fitted with grippers for picking up a stack of several bins from a column.

[0010] A disadvantage of these known techniques of frame or arm equipped with grippers is that there is a risk of failure of the hydraulic, pneumatic or electrical control systems for operating the grippers, which requires intervention to repair the robot and disrupts, or even requires shutdown, of the storage facility.

[0011] Another disadvantage of these known techniques is that they are complex to implement and require significant maintenance. 3. Objectives of the invention

[0012] The invention therefore aims in particular to overcome the drawbacks of the state of the art cited above.

[0013] More specifically, the invention aims to provide a technique for storing and returning products which allows rapid and reliable removal of products.

[0014] Another objective of the invention is to provide such a technique which is simple to implement and has a reduced cost.

[0015] Another objective of the invention is to provide such a technique which allows storage of products in bins of different heights. 4. Statement of the invention

[0016] These objectives, as well as others that will appear later, are achieved using an automatic product storage and return system comprising: a plurality of bins intended to receive said products; an installation for storing said bins comprising a plurality of storage columns arranged in a grid and configured to receive a vertical stack of bins from said plurality of bins, and at least one robot operating above said grid, capable of transporting said bins and picking up and depositing said bins in said columns, said robot comprising means for gripping and lifting at least one bin comprising a mobile support, such as a frame or an arm, configured so as to be able to slide vertically around said bins.

[0017] According to the invention, said means for gripping and lifting at least one container comprise at least one element extending substantially vertically, mounted to move relative to said support between: a stable equilibrium position in which the lower end of said element is not subjected to the action of any horizontal thrust or the resultant of the horizontal thrust forces exerted on the lower end of said element is zero; and at least one non-equilibrium position, in which the resultant of the horizontal thrust forces exerted on the lower end of said element is non-zero, and the lower end of said element is moved to one side or the other of its position in said equilibrium position. and said trays have at least one tab having a housing for locking said movable element in said stable equilibrium position, substantially turned downwards and an inclined portion substantially turned upwards making it possible to push the lower end of said movable element towards the outside of said tray, in one of said non-equilibrium positions, when said support moves downwards.

[0018] The invention thus proposes, in a novel and clever way, to implement a support on which is mounted at least one element that is mobile relative to it and that can be moved away from a stable equilibrium position to pick up a stack of bins from a storage column and lift it. This technical solution is particularly advantageous because, in addition to its simplicity of implementation and its efficiency, it proves to be very reliable and does not require maintenance.

[0019] Within the scope of the invention, the support may take, for example, the form of a chassis, one or more plates, a frame that can surround a tray on at least three sides or an arm. This support may be a single piece or formed of several separate parts.

[0020] It should also be noted that the locking housing can take any hollow shape, for example a concave shape or a hollow triangle shape, etc., without departing from the scope of the invention.

[0021] In an advantageous embodiment of the invention, said movable element is a hook intended to hang from said support, pivotally mounted around an axis relative to said support.

[0022] In another advantageous embodiment of the invention, said movable element is a finger guided in translation in a horizontal slide and cooperating with one or more return springs in said stable equilibrium position.

[0023] In particular embodiments of the invention, it may be envisaged that said means for gripping and lifting at least one container comprise two or three movable elements, and that said legs have two or three legs, said legs being placed relative to each other so that when said support moves around a container or a stack of containers, each of said movable elements is substantially opposite one of said legs of the container or containers of the stack.

[0024] In a particular embodiment of the invention, said means for gripping and lifting at least one container comprise four movable elements and said legs have four tabs, said legs being placed relative to each other so that when said support moves around a container or a stack of containers, each of said movable elements is substantially opposite one of said tabs of the container or containers in the stack.

[0025] According to a particular aspect of the invention, said movable element is mounted substantially at one end or at one corner of said support.

[0026] In advantageous embodiments of the invention in which said means for gripping and lifting at least one container comprise several movable elements, said elements are each mounted substantially at a different end or corner of said support.

[0027] In an advantageous embodiment of the invention, said locking tab is formed in one piece with said trays.

[0028] In a particular embodiment of the invention, said hook is formed from a rod having a lug projecting on one side substantially at the free end of said rod.

[0029] According to a particular aspect of the invention, said inclined portion comprises an inclined plane.

[0030] According to a particular embodiment of the invention, said locking housing has a curvature in the form of a branch of a hyperbola, a parabola or a truncated ellipse.

[0031] Advantageously, said trays have guide stops opposite said locking housing intended to push said movable element against said locking housing.

[0032] In particular embodiments of the invention where said means for gripping and lifting at least one tray comprise a single movable element, provision may be made to implement slides, for example fixed or formed on the uprights, to guide the corners of the trays. Provision may also be made to secure or form the tab on the lower part of the trays.

[0033] In a particular embodiment of the invention, said gripping and lifting means comprise at least one rack or a plurality of cables secured to said support and means for actuating said rack or said cables to raise or lower said support.

[0034] Advantageously, the chassis of said robot has an opening allowing the passage of said support through said chassis in order to be able to lift a bin or a stack of bins from above said chassis or vice versa to place a bin or a stack in a column under said robot through said opening.

[0035] The invention also relates to a method for gripping by a robot a stack of bins in a storage column of a storage installation comprising a plurality of storage columns arranged in a grid, said robot operating above said grid and comprising means for gripping and lifting at least one bin comprising a mobile support configured so as to be able to slide vertically around said bins and at least one element movable relative to said support, and preferably four elements movable relative to said support, between: a stable equilibrium position in which the lower end of said movable element is not subjected to the action of any horizontal thrust or the resultant of the horizontal thrust forces exerted on the lower end of said element is zero; and at least one non-equilibrium position, in which the resultant of the horizontal thrust forces acting on the lower end of said movable element is non-zero, and the lower end of said element is moved to one side or the other of its position in said equilibrium position, said trays of said stack having at least one leg, and preferably four legs, having a housing for locking said mobile element substantially turned downwards and an inclined portion substantially turned upwards making it possible to push the free end of said movable element towards the outside of said container when said support moves downwards.

[0036] It will be noted that within the framework of the invention, the stack of bins can be made up of all the bins in the stack of bins stored in the column or only of an upper part of the stack of bins stored in the column.

[0037] According to the invention, such a method comprises the following steps: moving said support around downwards around said stack to a height at the level of the tray located at the bottom of the stack where said movable element is engaged in said locking housing of said tab of the tray located at the bottom of the stack; from said height, moving said support upwards to the upper level of said column, causing said stack to be lifted and removed from said column. 5. List of figures

[0038] Other characteristics and advantages of the invention will appear more clearly on reading the following description of two embodiments of the invention, given as simple illustrative and non-limiting examples, and the appended drawings among which: there figure 1 is a perspective view of an exemplary embodiment of a product storage and return system according to the invention; figure 2 is a view of a robot of the system presented with reference to the figure 1 positioned above a column to pick up a stack of bins; the figure 3 is a detailed perspective view of a frame equipped with hooks of a robot of the system presented with reference to the figure 1 , represented alone; the figure 4 is a perspective view of a tray of the system presented with reference to the figure 1 , represented alone; the Figure 5illustrates a step in the picking of a stack of bins by a robot of the system presented with reference to the figure 1 , during the descent of the frame activated by the robot; the figure 6 illustrates another step in the picking of a stack of bins by a robot of the system presented with reference to the figure 1 , during the descent of the frame activated by the robot; the figure 7 illustrates yet another step in the picking of a stack of bins by a robot of the system presented with reference to the figure 1 , when raising the frame and after the lug of the hooks has passed the lower end of the inclined plane of the legs; figure 8 illustrates another step in the picking of a stack of bins by a robot of the system presented with reference to the figure 1 , in which the robot frame lifts the stack of bins; the figure 9illustrates a step in the removal of a stack of bins in a column, in which the hooks become detached from the stack of bins; the figure 10 illustrates another step in the placement of a stack of bins in a column, in which the robot frame moves up along the stack of bins; figure 11 is a representation of another embodiment of a frame equipping a robot with a system according to the invention. 5. Detailed description of the invention

[0039] There figure 1 illustrates, in a perspective view, an example of an automated product storage and return system according to the invention implemented within a warehouse.

[0040] This system 10 comprises a storage installation 11 formed of uprights 12 arranged according to the plan of a grid, delimiting storage columns 13, or cells, juxtaposed allowing the storage of bins 14 stacked on top of each other.

[0041] In this particular embodiment of the invention, covers 15 close the upper opening of the columns 13. When they are tilted flat, they rest on beams and horizontal crosspieces connecting the upper ends of the uprights 12 in the longitudinal direction and in the transverse direction and form a rolling platform for self-guided robots 16 ensuring the transport of the bins and making it possible to place or remove one or more bins from a column.

[0042] These covers 15 are also pivotally mounted to allow access to the bins stored beneath them in a column. It is the robots 16 which allow these covers 15 to be tilted vertically by pushing or pulling on the free end of the covers.

[0043] There figure 2illustrates a robot 16 positioned above a column 13 to pick up a stack of bins 14 from a column 13, after having tilted the cover 15 closing the column 13 vertically.

[0044] To pick up this stack of bins, this robot 16 activated the descent of a frame 21 into the column 13. This frame 21 has an internal opening having a width greater than the external width of the bins 14, which allows it to slide around the bins 14.

[0045] The frame 21 is in this particular embodiment of the invention fixed to racks actuated by motorized pinions (not shown in the figure 2 ). Rotation of the pinions in one direction or the other drives the racks downwards or upwards, which allows the frame 21 to slide vertically in the column 13 around the trays 14.

[0046] In this particular embodiment of the invention, the frame 21 is formed of two vertical “U”-shaped plates 22 facing each other, as can be seen in the figure 3 where frame 21 is shown alone.

[0047] Four hooks 31 are pivotally mounted at the four corners of the frame 21 around a transverse axis 32, below which they hang. These hooks 31 are intended to cooperate with legs 41 formed in one piece with the trays 14, an illustration of which can be seen in the figure 4 , which is a perspective view of an isolated container with a substantially parallelepiped external shape. These hooks 31 have a rod-shaped body 33 at the free end of which a lug 34 projects at a right angle and extends parallel to the axis of rotation 32 of the hook 31.

[0048] As can be seen on the figure 4, the legs 41 are formed projecting from the upper edge of the longer side faces of the tray 14, near the upper corners thereof. Of identical shapes, the legs 41 formed on the same face are oriented in opposite directions and are symmetrical with respect to a transverse plane of the tray 14.

[0049] These legs 41 have in the upper part, in their thickness, two inclined planes 42 and 43 meeting at a point 46 which are connected in the lower part by a curved locking housing 44, turned downwards, the section of which is in the form of a hyperboloid branch. It should also be noted that the upper inclined plane 42 is turned upwards.

[0050] A tab 45 of substantially the same thickness as the lug 41 is also formed projecting from the upper contour of the tray 14, under the locking housing 44. This tab 45 forms a guide stop which makes it possible to push the free end of the hooks 31 of the frame 21 against the locking housing 44 when the latter is substantially at the height of the locking housing 44 of the lugs of a tray 14.

[0051] It has been illustrated on the figures 5 to 8 different stages of picking up a stack of bins from a storage column 13 by a robot 16 positioned above the column 13. For the sake of readability, only one leg 41 of a bin 14 and one hook 31 are shown on the figures 6 to 8 .

[0052] As can be seen on the Figure 5, in a detail view where only one plate 22 of the frame 21 is shown, when the frame 21 begins to descend into the storage column, the hooks 31 then hang vertically above the legs 41 of the bin 14 placed at the top of the stack of bins to be taken.

[0053] When the frame continues its descent and the lug 34 at the free end of the hooks 31 reaches the legs 41, it gradually slides on the inclined plane 42 (see figure 6 ), which pushes the free end of the hook 31 towards the outside of the tank and causes the hook 31 to tilt upwards.

[0054] When the frame 21 continues its descent and the lug 34 passes under the lower end 61 of the inclined plane 42, the hook 31 tends to tilt back into a vertical position and first comes to rest on the tongue 45 (see figure 7), then when the lug passes under the lower end 71 of the tab 45, it returns to a vertical position. If the frame 21 continues its descent again, the lug 34 will come into contact with a tab 41 of the next bin in the stack and will be gradually moved outwards by the tab 41 of this bin and so on.

[0055] If, on the contrary, the frame 21 is commanded to rise, immediately after the lug 34 has passed the lower end 61 of the inclined plane 42, the lug 34 will be pushed back by the tab 45 against the profile 81 of the outermost locking housing 44 and will gradually slide along it. It should also be noted that in this particular embodiment of the invention, the tab 45 also makes it possible to keep the hook 31 inclined and tilted upwards. When the frame 21 continues to rise and the lug 34 is positioned at the highest point 82 of the locking housing 44 (see figure 8 ), the hook 31 then lifts the bin 14 with which it is engaged and the bins placed above it, which allows this stack of bins to be raised to the level of the robot circulation area, above the storage column. It will be noted that an opening 23 is provided in the robot chassis to allow passage for the stack of bins, when the latter is raised using the frame 21.

[0056] The robot 16 can then move back 15 to replace the cover above the column and move towards a new column 13 where it has received instructions to deposit the stack of bins or towards a depositing column 17, in which the stack of bins 14 is lowered by actuating the movement of the frame 21 and deposited on an elevator (not shown in the figure). figure 1 ) located at the base of the deposit column 17 to be transported to a delivery station.

[0057] THE figures 9 And 10illustrate the steps of placing a stack of bins, which has been picked up by a robot from one column, into another storage column.

[0058] After having tilted vertically the cover 15 covering the storage column in which the stack of bins is to be placed, the robot, which is positioned above this storage column, activates the descent of the frame 21 supporting the stack of bins 14. During this first step, the hooks 31 are locked in the legs 41 of the lower bin of the stack, in the position illustrated in the figure 8 .

[0059] When the lower tray of the stack of trays touches the bottom of the column 13 or comes into contact with a stack of trays already stored in the column, the frame 21 is again moved downwards to be able to disengage the hooks 31 from the tabs 41 of the lower tray of the stack. The lug 34 which was positioned at the high point 82 of the locking housing then slides progressively downwards along the inner profile 83 of the locking housing 44.

[0060] In this particular embodiment of the invention, it should be noted that a return spring, or a leaf spring, (not shown in the figures) can be mounted on the axis of rotation of the hooks to facilitate the return of the hooks 31 to a vertical position and to maintain them there.

[0061] When the frame 21 is sufficiently lowered and the lug 34 comes out of the locking housing 44, the hook 31 returns to a vertical position (see figure 9). The robot 16 can then operate the raising of the frame 21. The lug 34 then rises along the leg 41 by sliding against the lower inclined plane 43 of the leg 41 (see figure 10 ), which pushes the hook 31 towards the inside of the tray 41 while tilting it upwards, until it reaches the upper tip 46 of the tab 41. In this particular embodiment of the invention, it should be noted that when the lug 34 passes under the inner end 91 of the inner profile 83 of the locking housing 44, the rod 33 of the hook 31 is in a vertical position.

[0062] The frame 21 then continues to rise and the lug 34 detaches from the leg 41, which allows the hook 31 to return to a vertical position, until it meets the leg 41 of the tray above the previous tray and is pushed inwards again, and so on until the frame 21 leaves the column 13 and the robot 16 can move again on the grid.

[0063] It has been represented on the figure 11 , a variant of implementation of a frame 1101 allowing the collection of bins.

[0064] This frame 1101 is formed of two vertical plates 1102 in a “U” shape facing each other, each equipped with two fingers 1103 movable substantially at their corners, the head 1103 1 of which projects outside the plates 1102 and is guided in translation in a slide 1104 oriented in the plates 1102 and oriented in the horizontal direction (represented by the double arrow 1107 on the figure 11 ).

[0065] The inner body 1103 2 of the fingers 1103 is mounted between two substantially identical return springs 1105 and 1106 arranged on each side thereof. These springs tend to return the fingers 1103 to a stable equilibrium position substantially coinciding with the center of the slide 1104, when the fingers are moved away from their equilibrium position by being pushed to one side or the other of the center of the slide 1104.

[0066] These fingers are intended to cooperate with tabs formed on the bins 14, to allow one or more bins to be picked up with the frame 1101.

Claims

1. An automatic product (10) storage and retrieval system comprising: - a plurality of bins (10) for receiving said products; - a storage facility for said bins (11) comprising a plurality of storage columns (13) arranged in a grid and configured to receive a vertical stack of said plurality of bins, and - at least one robot (16) operating above said grid, capable of transporting said bins and picking up and depositing said bins in said columns, said robot comprising means for gripping and lifting at least one bin comprising a mobile support, such as a frame (21 ; 1101) or an arm, configured so as to be able to slide vertically around said bins, said means for gripping and lifting at least one bin comprise at least one substantially vertically extending element (341 ; 1103), mounted so as to be movable relative to said support between: - a stable equilibrium position in which the lower end of said member is not subject to the action of any horizontal thrust or the resultant of the horizontal thrust forces acting on the lower end of said member is zero; and - at least one out-of-equilibrium position, in which the resultant of the horizontal thrust forces on the lower end of said member is non-zero, and the lower end of said member is displaced to either side of its position in said equilibrium position, characterised in that said bins have at least one lug (41) having a housing for locking (44) said mobile element in said stable equilibrium position, substantially facing down-wards and a tilted portion substantially facing upwards allowing the lower end of said mobile element to be pushed back towards the outside of said bin, in one of said out-of-equilibrium positions, when said support moves downwards.

2. The system according to claim 1, characterised in that said movable member is a hook (31) for hanging from said support, pivotally mounted about an axis (32) relative to said support.

3. The system according to claim 1, characterised in that said movable element is a finger (1103) guided in translation in a horizontal slide and cooperating with one or more return springs in said stable equilibrium position.

4. The system according to claim 2, characterised in that said means for gripping and lifting at least one bin comprises four members movable relative to said support and said lugs (41) have four lugs, said lugs being positioned relative to each other so that when said support moves around a bin or stack of bins each of said movable members is substantially opposite one of said lugs of the bin or bins in the stack.

5. The system according to any one of claims 1 to 4, characterised in that said locking lug (41) is formed integrally with said bins.

6. The system according to claim 2, characterised in that said hook (31) is formed by a rod (33) having a lug (34) projecting from one side substantially at the free end of said rod.

7. The system according to any one of claims 1 to 6, characterised in that said tilted portion comprises a tilted plane (42).

8. The system according to any one of claims 1 to 7, characterised in that said locking housing (44) has a curvature in the form of a hyperbolic branch, a parabola or a truncated ellipse.

9. The system according to any one of claims 1 to 8, characterised in that said bins have guide stops (45) opposite said lock housings (44) for pushing said movable member against said lock housing.

10. The system according to any one of claims 1 to 9, characterised in that said gripping and lifting means comprise at least one rack or a plurality of cables attached to said support and means for actuating said rack or said cables to raise or lower said support.

11. The system according to any one of claims 1 to 10, characterised in that the chassis of said robot has an opening allowing passage of said support through said chassis to be able to lift a bin or stack of bins from above said chassis or vice versa to deposit a bin or stack in a column below said robot through said opening.

12. A method of gripping by a robot (16) a stack of bins in a storage column (13) of a storage installation comprising a plurality of storage columns '13) arranged in a grid, said robot operating above said grid and comprising means for gripping and lifting at least one bin comprising a mobile support, such as a frame (21; 1101) or an arm, configured so as to be able to slide vertically around said bins and at least one element movable (31; 1103) with respect to said support, and preferably four elements movable with respect to said support between: - a stable equilibrium position in which the lower end of said movable member is not subject to the action of any horizontal thrust or the resultant of the horizontal thrust forces acting on the lower end of said member is zero; and at least one out-of-equilibrium position, in which the resultant of the horizontal thrust forces on the lower end of said movable member is non-zero, and the lower end of said member is moved to either side of its position in said equilibrium position, characterised in that said bins in said stack having at least one, and preferably four, lugs, having a substantially downwardly facing locking housing for said movable member and a substantially upwardly facing tilted portion for pushing the free end of said movable member outwardly of said bin as said support moves downwardly, said method compring the following steps: - moving said support around downwardly around said stack to a height at the bottom of the stack where said movable member is engaged in said locking housing of said bottom of the stack bin lug; - from said height, moving said support up to the upper level of said column, causing said stack to be lifted out of said column.