Grasping Device

Abstract

A gripping device (100) suspended from a load handling device for lifting and moving stacked containers within a grid storage structure comprising a plurality of tracks arranged in a grid pattern above the stack of containers. The gripping device comprises a frame (101) and at least one gripping assembly (151) mounted to the frame. The gripping assembly includes at least two grippers (152), each configured to engage a container positioned below the frame. Each gripper is movable between a gripping position for gripping the container and a release position for releasing the container. The gripping device further comprises a single linear actuator (161) coupled to the at least two grippers by a linkage assembly (162) such that actuation of the single linear actuator drives the at least two grippers substantially simultaneously between the gripping position and the release position.

Description

[Technical field]

[0001] The present invention relates to the field of gripping devices, more specifically to a gripping device for a load handling device for lifting and moving stacked storage containers in a grid storage structure. [Background technology]

[0002] Some commercial and industrial activities require systems that allow for the storage and retrieval of a large number of different products. WO2015 / 185628A describes a storage and fulfillment system in which a stack of storage containers is placed into a lattice storage structure. The containers are accessed by load handling devices operable on rails or tracks positioned on the top of the lattice framework structure.

[0003] The load handling device typically includes a gripping device for releasably gripping the storage container at the top of the stack, and a lifting mechanism for raising and lowering the container.

[0004] Situations may arise that prevent the gripping device from properly aligning and engaging the top of a container in a stack, which may lead to the gripping device failing to grip the container, or may lead to the gripping device precariously gripping only a portion of the top of the container.

[0005] The present invention aims to provide improvements to gripping devices used by load handling devices. Summary of the Invention

[0006] In a first aspect, the present invention provides a gripping device suspended from a load handling device for lifting and moving containers stacked in a grid storage structure comprising a plurality of tracks arranged in a grid pattern above the stack of containers, the gripping device comprising: a frame having a top and a bottom side, the frame comprising a substantially downwardly extending peripheral wall defining at least one opening through the top and bottom sides of the frame; and a gripping mechanism attached to the peripheral wall and configured to releasably grip a container from beneath the frame.

[0007] The gripping device may further comprise at least one electrical and / or electronic component occupying a portion of the opening.

[0008] The frame may be substantially rectangular. The at least one opening may be substantially rectangular.

[0009] The peripheral wall may further define at least one recess on a bottom side of the frame, and the at least one opening may extend into the recess. The recess may be substantially rectangular. The peripheral wall may extend substantially horizontally on an upper side of the frame to define the recess.

[0010] The frame may further include a bridge member extending across the frame between the two opposing sides of the peripheral wall. The bridge member may extend centrally across the frame. The bridge member may have a bottom surface that is recessed relative to a bottom of the peripheral wall.

[0011] At least one electrical and / or electronic component may be mounted on or within the bridge member. The at least one electrical and / or electronic component may include a printed circuit board, a processor, and / or an electrical cable or wire.

[0012] The gripping mechanism may include at least one gripper extending below the peripheral wall to releasably grip a container from below the frame. The gripping mechanism may include a gripping assembly having at least two grippers and a single linear actuator, the single linear actuator coupled to the at least two grippers by a linkage assembly such that actuation of the single linear actuator actuates the at least two grippers substantially simultaneously. The gripping assembly may be mounted to one end of the frame. In particular, the at least two grippers and optionally the linear actuator may be mounted to the peripheral wall at one end of the frame. The gripping mechanism may include two gripping assemblies mounted to opposite ends of the frame.

[0013] The gripping device may include at least one sensor for detecting a distance between the frame and an object located below the frame. The at least one sensor may be attached to the perimeter wall. The gripping device may include a sensor for each gripping assembly.

[0014] The gripping device may further comprise at least one guide member attached to the frame and extending below the frame to be received by a corresponding portion of the container to align the frame with the container. The guide member may extend further below the frame than the gripping mechanism, and in particular the grippers of the gripping mechanism. The gripping device may comprise a plurality of guide members, each guide member attached to a respective corner of the frame.

[0015] The gripping device may have a substantially planar shape.

[0016] The present invention also provides a load handling device for lifting and moving containers stacked in a stack within a lattice framework structure comprising a plurality of tracks arranged in a lattice pattern above the stack of containers, the load handling device comprising: The main body, a drive mechanism operatively arranged to move the bodies on the tracks of the grid storage structure; a gripping device according to the first aspect of the invention for releasably gripping a container in a stack in a lattice structure; and a lifting mechanism configured to raise and lower the gripping device relative to the body.

[0017] The body may house at least a portion of the drive mechanism.

[0018] In a second aspect, the present invention provides a gripping device suspended from a load handling device for lifting and moving containers stacked in a grid storage structure comprising a plurality of tracks arranged in a grid pattern above the stack of containers, the gripping device comprising: a frame having a top side and a bottom side; and at least one gripping assembly attached to the frame, the at least one gripping assembly comprising: at least two grippers, each gripper of the at least two grippers configured to engage a container located beneath the frame, each gripper movable between a gripping position for gripping the container and a release position for releasing the container; and a single linear actuator coupled to the at least two grippers by a linkage assembly such that actuation of the single linear actuator drives the at least two grippers substantially simultaneously from a gripping position to a release position and / or from the release position to the gripping position.

[0019] In some embodiments of the second aspect, each gripper of the at least two grippers may comprise a pair of legs pivotally mounted to the frame such that the grippers are movable away from each other to define an open configuration corresponding to either the gripping position or the release position and toward each other to define a closed configuration corresponding to the other of the gripping position and the release position, each leg of the pair of legs comprising a foot configured to engage a container when the gripper is in the gripping position. The open position may correspond to the gripping position and the closed configuration may correspond to the release position.

[0020] The legs in each pair of legs may be engaged with one another such that pivotal rotation of one of the legs in each pair of legs causes pivotal rotation of the other leg in each pair of legs in the opposite direction. The legs in each pair of legs may be matingly engaged with one another, for example the legs in each pair of legs may include teeth that matingly engage with one another, including one leg of each pair that includes one tooth that matingly engages with a corresponding recess on the other leg of the pair.

[0021] The linkage assembly may include a linkage arm engaged with one leg from each pair of legs, wherein linear movement of the linkage arm by the linear actuator may move the at least two grippers substantially simultaneously between the open and closed configurations.

[0022] The feet of the legs in each pair of legs may extend in opposite directions away from each other.

[0023] The at least one gripping assembly may be mounted along one end of the frame. The gripping device can include a first gripping assembly mounted along one end of the frame and a second gripping assembly mounted along an opposing end of the frame.

[0024] In an alternative embodiment of the second aspect, each gripper of the at least two grippers may include a single leg, each leg being horizontally linearly movable relative to the frame between a gripping position and a release position, and each leg may include a foot configured to engage a container when the gripper is in the gripping position.

[0025] The at least two grippers may be resiliently biased in one direction, i.e., toward either the gripping position or the release position. The linear actuator may be configured to drive the at least two grippers in the opposite direction against the resiliently biased, i.e., toward the other of the gripping position and the release position. The at least two grippers may be resiliently biased by a spring. Alternatively, the linear actuator may be configured to drive the at least two grippers in both directions, i.e., between the gripping position and the release position.

[0026] The linkage assembly may include a linkage arm engaged between the legs of the at least two grippers. The linkage arm may be integrally formed with the at least two grippers.

[0027] The at least one gripping assembly may be mounted along one end of the frame. The gripping device may include a first gripping assembly mounted along one end of the frame and a second gripping assembly mounted along an opposite end of the frame. The feet of the first gripping assembly may face in an opposite direction to the feet of the second gripping assembly. The at least two grippers of the first gripping assembly may move in an opposite direction to the at least two grippers of the second gripping assembly when moving between the gripping position and the release position.

[0028] In an embodiment of the second aspect, each leg may extend below the frame, with each foot positioned below the frame.

[0029] Each foot may include an upwardly facing engagement surface for engaging with a downwardly facing engagement surface of the container.

[0030] The at least two grippers may be in substantially the same vertical plane. The linear actuator may be mounted to the frame adjacent to the at least two grippers. The frame may include a peripheral wall to which the at least one gripping assembly and the linear actuator are mounted. The linear actuator may have a longitudinal body aligned parallel to the vertical plane in which the grippers are located (i.e., the body has a longitudinal axis aligned parallel to an actuation direction of the linear actuator, and the longitudinal axis of the body is aligned parallel to the vertical plane in which the grippers are located).

[0031] The gripping device may further comprise at least one guide member mounted to the frame for receipt by a corresponding portion of the container to align the frame with the container. The at least one guide member may extend further down the frame than the grippers of the at least one gripping assembly. The gripping device may comprise a plurality of guide members, each guide member mounted to a respective corner of the frame.

[0032] The frame may have a rectangular shape.

[0033] The present invention also provides a load handling device for lifting and moving containers stacked in a grid storage structure comprising a plurality of tracks arranged in a grid pattern above the stack of containers, the load handling device comprising: The main body, a drive mechanism operatively arranged to move the body on the lattice framework; a gripping device according to the second aspect for releasably gripping a container in a stack in a grid storage structure; and a lifting mechanism configured to raise and lower the gripping device relative to the body.

[0034] The body may house at least a portion of the drive mechanism.

[0035] In a third aspect, the present invention provides a gripping device suspended from a load handling device for lifting and moving containers stacked in a grid storage structure comprising a plurality of tracks arranged in a grid pattern above the stack of containers, the gripping device comprising: A frame, a gripping mechanism attached to the frame configured to releasably grip a container from beneath the frame; a fastening device attached to the frame and configured to fasten a free end of the reeled cable; and a cable tensioner configured to place the cable under tension in use, the cable tensioner comprising: A truck mounted on the frame; a carriage slidably mounted on the track and configured to engage the cable in use; and a biasing device configured to bias the carriage away from the securing device and towards one end of the track so as to place the cable under tension when the carriage is engaged with the cable in use.

[0036] The biasing device may comprise a spring, e.g., a coil spring, e.g., an extension or compression spring. One end of the spring may be coupled to the carriage and the other end of the spring may be fixed relative to the frame or track. The cable tensioner may further comprise a roller mounted on the carriage configured to engage the cable in use. The roller may be an idler roller.

[0037] The carriage may be movable along the track under the bias of the biasing device to a stop position. The cable tensioner may further comprise a detector configured to detect when the carriage is in the stop position. The gripping device may further comprise a processor configured to control operation of the gripping device, and the detector may be configured to send a signal to the processor when the detector detects that the carriage is in the stop position. The processor may be configured to stop or cease operation of the gripping device in response to a signal from the detector. The detector may comprise a mechanical switch, e.g. a microswitch.

[0038] The fixation device may be a clamp.

[0039] The cable tensioner may be at least partially housed by a portion of the frame, the frame may define an aperture for receiving the cable within said portion of the frame. The cable tensioner may further comprise a cover rigidly attached to the carriage and configured to cover the aperture in the frame throughout the entire range of movement of the carriage on the track. The cover may define a smaller aperture (i.e., smaller than the aperture in the frame) in communication with the aperture in the frame for receiving the cable.

[0040] The present invention also provides a load handling device for lifting and moving containers stacked in a stack within a lattice framework structure comprising a plurality of tracks arranged in a lattice pattern above the stack of containers, the load handling device comprising: The main body, a drive mechanism operatively arranged to move the bodies on the tracks of the grid storage structure; a gripping device according to the third aspect for releasably gripping a container in a stack in a grid storage structure; and a lifting mechanism configured to raise and lower the gripping device relative to the body.

[0041] The body may house at least a portion of the drive mechanism.

[0042] The load handling device may further include a cable having a first end disposed on a reel located on or within the body of the load handling device and a second end secured to the frame of the gripping device by a fastening device, the cable engaged with a cable tensioner between the first and second ends.

[0043] The cable may change direction at the cable tensioner. The cable may change direction substantially 90 degrees. The cable may extend substantially vertically between the reel and the cable tensioner, or may extend substantially horizontally between the cable tensioner and the fixation device.

[0044] The cable may be configured to transmit power from the body of the load handling device to the gripping device and / or to transmit data between the body of the load handling device and the gripping device. The cable may be a flexible flat cable.

[0045] A gripping device according to the invention may combine any or all of the first to third aspects defined above, for example a gripping device according to the invention may have an opening as defined in the first aspect, and / or a gripping mechanism as defined in the second aspect, and / or a cable tensioner as defined in the third aspect. [Brief description of the drawings]

[0046] Aspects and exemplary embodiments of the present invention are described with reference to the accompanying drawings. [Figure 1] FIG. 1 is a schematic perspective view of a lattice storage structure and a container. [Diagram 2] FIG. 2 is a schematic plan view of the top track of the storage structure of FIG. [Diagram 3] FIG. 3 shows a load handling device on top of the lattice structure of FIG. [Figure 4] FIG. 4 is a schematic perspective view of a single load handling device with the lifting mechanism in a lowered configuration. [Diagram 5] FIG. 5 is a schematic cut-away view of the load handling device of FIG. 4 with the lifting mechanism in a raised and lowered configuration. [Figure 6] FIG. 6 is a schematic perspective view of a storage container. [Figure 7] FIG. 7 is a perspective view of the gripping device. [Figure 8] FIG. 8 is a perspective view of the gripping device of FIG. 7 attached to a tether. [Figure 9] FIG. 9 is a perspective view of the gripping device in FIG. [Figure 10] 10 is a perspective view of the gripping device of FIG. 7 with the bridge member cover removed. [Figure 11] FIG. 11 is a perspective view of a cable tensioner from the gripping device of FIG. [Figure 12] FIG. 12 shows perspective views of the gripping assembly from the gripping device of FIG. 7 when the grippers are in (a) an open configuration and (b) a closed configuration. [Figure 13] FIG. 13 shows the gripper assembly of FIG. 12 from the opposite side. [Figure 14] FIG. 14 shows a gripping device having an alternative gripping mechanism. [Figure 15] 15 is a perspective view of the storage container of FIG. 6 being gripped by the gripping device of FIG. [Figure 16] FIG. 16 is an end view of FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0047] 1 illustrates a storage structure 1 comprising upright members 3 and horizontal members 5, 7 supported by upright members 3. The horizontal members 5 extend parallel to each other and to an illustrative x-axis. The horizontal members 7 extend parallel to each other and to an illustrative y-axis and laterally to the horizontal members 5. The upright members 3 extend parallel to each other and to an illustrative z-axis and laterally to the horizontal members 5, 7. The horizontal members 5, 7 form a grid pattern defining a plurality of grid cells. In the illustrated example, the storage containers 9 are arranged in stacks 11 beneath the grid cells defined by the grid pattern, with one stack 11 of containers 9 per grid cell.

[0048] FIG. 2 shows a large scale plan view of a section of a track structure 13 forming part of the storage structure 1 illustrated in FIG. 1 and positioned on top of the horizontal members 5, 7 of the storage structure 1 illustrated in FIG. The track structure 13 may be provided by the horizontal members 5, 7 themselves (e.g. formed in or on a surface of the horizontal members 5, 7) or by one or more additional components mounted on top of the horizontal members 5, 7. The track structure 13 shown comprises x-direction tracks 17 and y-direction tracks 19, i.e. a first set 17 of tracks extending in the x-direction and a second set 19 of tracks extending in the y-direction, transversely to the tracks 17 in the first set 17 of tracks. The tracks 17, 19 define apertures 15 at the centres of the grid cells. The apertures 15 are sized to allow a container 9 positioned directly below the grid cell to be lifted and lowered through the apertures 15. The x-direction tracks 17 are provided in pairs separated by channels 21 and the y-direction tracks 19 are provided in pairs separated by channels 23. Other arrangements of the track structures may also be possible.

[0049] Figure 3 shows multiple load handling devices 31 moving on top of the storage structure 1 illustrated in Figure 1. The load handling devices 31, which may also be referred to as robots or bots, are provided with a set of wheels for engaging with a corresponding x-direction track 17 or y-direction track 19 to enable the bots 31 to move across the track structure 13 and reach a particular grid cell. The illustrated pair of tracks 17, 19 separated by channels 21, 23 allows the bots 31 to occupy adjacent grid cells (or pass each other) without colliding with each other.

[0050] 4, the bot 31 comprises a body 33 with one or more components mounted therein or thereon that enable the bot 31 to perform its intended functions. These functions may include moving across the storage structure 1 on the track structure 13 and raising or lowering containers 9 (e.g., from or into stacks 11) so that the bot 31 can retrieve or place containers 9 at specific locations defined by the grid pattern.

[0051] The illustrated bot 31 includes a first set 35 and a second set 37 of wheels mounted on the body 33 of the bot 31 and enabling the bot 31 to move in the x and y directions, respectively, along the tracks 17 and 19, respectively. In particular, two wheels 35 are provided on the shorter side of the bot 31 as seen in FIG. 4, and two more wheels 35 are provided on the opposite shorter side of the bot 31 (not visible in FIG. 4). The wheels 35 engage with the track 17 and are rotatably mounted on the body 33 of the bot 31 to enable the bot 31 to move along the track 17. Similarly, two wheels 37 are provided on the longer side of the bot 31 as seen in FIG. 4, and two more wheels 37 are provided on the opposite longer side of the bot 31 (not visible in FIG. 4). The wheels 37 engage with the track 19 and are rotatably mounted on the body 33 of the bot 31 to enable the bot 31 to move along the track 19.

[0052] The bot 31 also comprises a container lifting mechanism 39 configured to raise and lower the container 9. The illustrated lifting mechanism 39 comprises four tethers 41, which are connected at their lower ends to a container gripping device 43. The tethers 41 may be in the form of cables, ropes, tapes, or any other form of tether having the necessary physical properties to lift the container 9. The gripping device 43 comprises a gripping mechanism 150 configured to engage with a feature of the container 9. For example, the containers 9 may be provided with one or more apertures on their upper side that the gripping mechanism can engage. Alternatively or additionally, the gripping means may be configured to hook under a rim or lip of the container 9 and / or clamp or grab the container 9. The tethers 41 may be wound up or unwound to raise or lower the gripping device 43 as required. One or more motors or other means may be provided to effect or control the winding up or down of the tethers 41.

[0053] As can be seen in FIG. 5, the body 33 of the illustrated bot 31 has an upper portion 45 and a lower portion 47. The upper portion 45 is configured to accommodate one or more operating components (not shown). The lower portion 47 is disposed below the upper portion 45. The lower portion 47 comprises a container receiving space or cavity for accommodating at least a portion of the container 9 lifted by the lifting mechanism 39. The container receiving space is sized such that enough of the container 9 can fit inside the cavity to allow the bot 31 to move across the top track structure 13 of the storage structure 1 without the underside of the container 9 getting caught on the track structure 13 or another portion of the storage structure 1. Once the bot 31 reaches its intended destination, the lifting mechanism 39 controls the tether 41 to lower the gripping device 43 and the corresponding container 9 out of the cavity and into the intended position. The intended location may be a stack 11 of containers 9 or an exit point of the storage structure 1 (or an entrance point of the storage structure 1 if the bot 31 moves to collect containers 9 for storage within the storage structure 1). In the illustrated example, the upper portion 45 and the lower portion 47 are separated by a physical partition, although in other embodiments the upper portion 45 and the lower portion 47 may not be physically divided by a particular component or portion of the body 33 of the bot 31.

[0054] The container receiving space of the bot 31 may not be within the body 33 of the bot 31. For example, the container receiving space may instead be adjacent to the body 33 of the bot 31, e.g., in a cantilever arrangement with the weight of the body 33 of the bot 31 balancing the weight of the container to be lifted. In such an embodiment, the frame or arm of the lifting mechanism 39 may project horizontally from the body 33 of the bot 31, and the tether 41 may be disposed at respective positions on the projecting frame / arm and configured to be raised and lowered from those positions to raise and lower a container into the container receiving space adjacent the body 33. The height at which the frame / arm is attached to and projects from the body 33 of the bot 31 may be chosen to provide a desired effect. For example, it may be preferable for the frame / arm to project at a high level above the body 33 of the bot 31 to allow a larger container (or multiple containers) to be lifted into the container receiving space below the frame / arm. Alternatively, the frame / arms may be positioned to protrude below the body 33 (but high enough to accommodate at least one container between the frame / arms and the track structure 13) to keep the center of mass of the bot 31 lower when the bot 31 is loaded with a container.

[0055] To enable the bot 31 to move in first and second directions on different wheels 35, 37, the bot 31 includes a wheel positioning mechanism for selectively engaging a first set of wheels 35 with a first set of tracks 17 or a second set of wheels 37 with a second set of tracks 19. The wheel positioning mechanism is configured to raise and lower the first set of wheels 35 and / or the second set of wheels 37 relative to the body 33, thereby enabling the load handling device 31 to selectively move in either a first direction or a second direction across the tracks 17, 19 of the storage structure 1.

[0056] The wheel positioning mechanism may include one or more linear actuators, rotary components, or other means for raising and lowering at least one set of wheels 35, 37 relative to the body 33 of the bot 31 to move the at least one set of wheels 35, 37 off of or into contact with the tracks 17, 19. In some examples, only one set of wheels is configured to raise and lower, such that the act of lowering one set of wheels can effectively lift the other set of wheels off of the corresponding tracks, while the act of raising one set of wheels can effectively lower the other set of wheels into contact with the corresponding tracks. In other examples, both sets of wheels may be raised and lowered, advantageously meaning that the body 33 of the bot 31 remains at substantially the same height, thus not requiring the weight of the body 33 and components mounted thereon to be raised and lowered by the wheel positioning mechanism.

[0057] FIG. 6 shows a perspective view of an exemplary storage container 50 that can be gripped by the gripping device 43. The storage container 50 includes a base 51 and four side walls 52 that extend from the base 51 to form an open rectangular container that can be used to store items such as groceries. A rim 53 at the top of the container 50 forms the top surface of the container. The container 50 includes an engagement portion 54 for engaging a corresponding feature of a gripping device for gripping the container. In particular, the container 50 includes an aperture or opening 54 defined in the rim 53 for receiving a corresponding feature of the gripping device. At each corner of the container 50 is a notch or aperture 55 extending from the rim 53 toward the base 51 for engaging a further corresponding feature of the gripping device to align the gripping device with the container 50.

[0058] In use, the storage container 50 may contain articles that protrude (accidentally or otherwise) above the top of the container. Such items could potentially obstruct the path of the gripping device 43 as it is lowered towards the top of the storage container. This could result in the gripping device 43 not being able to get close enough to the top of the container 50 for the gripping mechanism to successfully engage the storage container, and / or could result in the gripping device being misaligned with the storage container such that the gripping mechanism does not engage the storage container or only partially or unstably engages the storage container.

[0059] A gripping device which can be used in conjunction with the load handling device 31 to alleviate this problem is now described with reference to Figures 7 to 16.

[0060] 7, the gripping device 100 comprises a frame 101 having a generally planar shape with a top side 102 and a bottom side 103. In use, the frame 101 is oriented such that a stack of storage containers is located beneath the frame 101.

[0061] As illustrated in FIG. 8, the frame 101 is connected to the lifting mechanism 39 by four spooled tethers 180 secured near or at each of the corners of the frame 101 via brackets 104 attached to the frame 101. Each tether 180 is in the form of a reel or spooled tape 180 with a first end engaging a reel or spool 181 positioned within the body of the bot 31 and a second free end 182 extending downward toward the frame 101 and secured to a respective bracket 104. The tape 180 is wound and unwound as the gripping device is raised and lowered, respectively. For simplicity, the components for winding and unwounding the tape 180 are not shown in FIG. 8, but in general any suitable motorized mechanism can be used to rotate the reels together or individually.

[0062] The free end 182 of each tape 180 is releasably attached to a respective bracket 104 via a bolt or pin 105 that is inserted through an aperture extending through the free end 182 of the tape 180 and a corresponding aperture in the bracket 104. The bolts 105 may be quick release bolts. For example, the bolts 105 may include a radially extending protrusion that can retract under a spring-loaded mechanism for quick insertion and extraction. Alternatively, the apertures in the brackets 104 and at the free ends 182 of the tapes 180 may be keyed and the bolts 105 may be shaped to allow insertion of the bolts 105 through the apertures in one or more angular positions but prevent withdrawal of the bolts 105 in other angular positions (i.e., the bolts 105 may be inserted and then rotated to lock the bolts 105 in place). By using quick release bolts or other quick release fastening means, the gripping device 100 may be quickly removed from the tape 180 of the lifting mechanism 39, which allows for quicker and more efficient maintenance of the gripping device 100 or lifting mechanism 39. Each bolt 105 may be tethered to the frame 101 via a lanyard 106, which prevents the bolts 105 from being misplaced and allows the user to easily position the bolts 105 when reattaching the tape 180 to the gripping device 100. Other releasable fastening means (quick release or otherwise), such as clamp arrangements, hook arrangements, screw arrangements, nut and bolt arrangements, etc., may be used to attach the free end 182 of each tape 180 to the frame 101.

[0063] Also shown in FIG. 8 is an electrical cable in the form of a flat flexible cable (FFC) 190 that includes electrical conductors and may be used to transfer data and / or power between the bot 31 and the gripping device 100. Similar to the tether 180, the FFC 190 is wound on a reel or spool 191 positioned within the body of the bot 31, with a first end engaged to the reel 191 and a second free end 192 connected to the frame 101 (the FFC 190 is shown in an unconnected state in FIG. 8). The FFC 190 is wound and unwound, respectively, as the gripping device 100 is raised and lowered. The frame 101 is configured to receive the free end 192 of the FFC 190 for connection to other electrical and electronic components attached to the frame 101, as described in more detail below.

[0064] The gripping device 100 further comprises a gripping mechanism 150 attached to the frame 101 and configured to releasably grip a container from beneath the frame 101. Further details of the gripping mechanism 150 are also provided below.

[0065] 7, the frame 101 comprises four elongated frame members 107 joined together to form a substantially rectangular frame having a substantially downwardly extending perimeter wall 108 that defines a central substantially rectangular opening or notch 111. The opening 111 extends completely through the top and bottom sides 103 of the frame 101.

[0066] The openings 111 through the frame 101 provide headroom for any objects that protrude above the top of the container as the gripping device 100 is being lowered towards the top of the container. In particular, as the gripping device 100 is being lowered towards the top of the container, any items that protrude above the top of the container are more likely to protrude through the openings 111 without impeding the descent of the gripping device 100, rather than hitting a part of the frame 101 and impeding its descent.

[0067] In addition to extending substantially downward, the perimeter wall 108 may also extend substantially horizontally on the top side 102 of the frame 101. For example, as shown in FIG. 7 and FIG. 9 (showing the underside of the frame 101), each frame member 107 may be formed as a bent metal plate having a side 109 that extends substantially downward and a top 110 that extends substantially horizontally. Each frame member 107 may alternatively be described as having a substantially L-shaped profile with an L-shaped base oriented toward the top side 102 of the frame 101. By extending substantially downward and substantially horizontally on the top side 102 of the frame 101, the perimeter wall 108 may define a recess 112 in the bottom side 103 of the frame 101, with the opening 111 extending into the recess 112. The recess 112 provides the frame 101 with more headroom, for example, as compared to a frame 101 that does not have a recessed bottom side 103. The substantially horizontal portions 110 of the frame members 107 also provide a convenient surface for joining the frame members 107 to one another and / or for attaching other components. However, it is not necessary that the peripheral wall 108 extend substantially horizontally on the upper side 102 of the frame 101. Instead, the peripheral wall 108 may extend substantially only downwardly, or only one or more portions of the peripheral wall 108 may extend substantially horizontally (e.g., some frame members 107 may have an L-shaped profile and some frame members 107 may have a flat profile).

[0068] The rectangular shape of the frame 101 is convenient for gripping a rectangular storage container. However, the frame 101 is not limited to a rectangle, and may have other shapes, for example, a circle, a triangle, another rectangle, or another polygon, depending on the shape of the object to be gripped. Note that "rectangle" as used herein also includes a square. The shape of the frame 101 can be changed, for example, by changing the number and / or shape of the frame members 107. The shape of the opening 111 is also not limited to a rectangle, and may have other shapes, for example, a circle, a triangle, another rectangle, or another polygon. The shape of the opening 111 may be the same shape as the frame 101.

[0069] Frame 101 is also not limited to being formed from separate frame members joined together, but instead may be formed as a single piece, for example by metal stamping or die casting.

[0070] The frame 101 further comprises a bridge member extending across the frame 101 between the two ends of the frame 101 (i.e., extending across the opening 111 between two opposing sides of the peripheral wall 108), thereby dividing the opening 111 into two smaller openings 111a, 111b on either side of the bridge member 120. However, the frame 101 may still be considered to have a single opening 111 that is partially occupied by the bridge member 120. The bridge member 120 preferably extends centrally across the frame 101 so that the frame 101 has an even weight distribution, which may allow the frame 101 to be more easily maintained in a horizontal orientation as it is raised or lowered, and may simplify the control and / or configuration of the lifting mechanism 39. However, the bridge member 120 is not limited to extending centrally across the frame 101, but may instead be located closer to one side of the frame 101 than the other.

[0071] The bridge member 120 can be conveniently used to route or mount electrical and / or electronic components for operating the gripping device 100. The electrical and / or electronic components may be mounted on an exterior surface of the bridge member 120, or the electrical and / or electronic components may be mounted inside the bridge member 120 (i.e., the bridge member 120 may be hollow). FIG. 10 shows the gripping device 100 of FIG. 7 with the top cover 121 of the bridge member 120 removed. The bridge member 120 comprises a printed circuit board (PCB) 122 mounted inside the bridge member 120. The PCB 122 may comprise a processor, a processor or control module and circuitry that may be configured to provide power to the gripping mechanism 150, control the gripping mechanism 150, receive and process data from various sensors on the gripping device 100, and receive and send data and / or instructions to a processor or control module in the body of the bot 31. The electrical and / or electronic components may also include electrical cables or wires for transmitting power and / or data.

[0072] The bridge member 120 in FIG. 10 extends between two ends of the frame 101 to which the components of the gripping mechanism 150 are attached. This provides convenient cable routing management for electrical cables entering and exiting the gripping mechanism 150. However, this is not required and the bridge member 120 may extend across the frame 101 between any two ends. The frame 101 may also include more than one bridge member, for example in a cross arrangement where two bridge members cross, or in a parallel arrangement where the bridge members extend parallel to one another. Such a bridge member arrangement results in the frame opening 111 being divided into more than two smaller openings.

[0073] The bottom of the bridge member 120 may also be recessed relative to the bottom of the peripheral wall 108. This provides additional headroom and helps to mitigate the loss of headroom due to the presence of the bridge member 120 in the opening 111.

[0074] In alternative embodiments of the gripping device 100, the bridge member 120 may not be present. In these embodiments, components (e.g., electrical and / or electronic and / or mechanical components) may be attached to one side of the frame 101 (e.g., to the perimeter wall 108 itself, or to a housing attached to the perimeter wall 108) rather than to the bridge member 120. Alternatively or additionally, to eliminate the use of the bridge member 120 and make more space available for the opening 111, some of the electrical and / or electronic components previously attached to the bridge member 120 may be relocated to the body of the bot 31 rather than being located on the gripping device 100 itself.

[0075] In other alternative embodiments, the peripheral wall 108 may only define a recess 112 at the bottom of the frame 101, with no opening through the frame 101. A frame having only a recess still provides the advantage of providing some headroom for items that protrude above the top of the container.

[0076] The frame 101 further comprises an upwardly extending bracket 113 attached to the bridge member 120. The purpose of the bracket 113 is to trigger a sensor, e.g., an optical sensor, positioned in or on the bot 31 so that the bot 31 knows when the gripping device 100 is fully raised and can move to its next destination on the lattice structure. For example, the bot 31 may comprise a photointerrupter sensor that detects when an upwardly extending portion of the bracket 113 interrupts the path between the optical transmitter and the optical receiver to detect when the gripping device 100 is in the fully raised position. The bracket 113 is not limited to being mounted on the bridge member 120, but may be mounted elsewhere on the frame 101. The bracket 113 may also take any shape or form suitable for triggering a sensor, e.g., a photointerrupter sensor. Other arrangements for detecting when the gripping device 100 is in the fully raised position are also possible, such as a mechanical contact sensor in the bot 31 that detects when a portion of the gripping device 100 comes into contact with it.

[0077] As mentioned above, the bot 31 may include a spooled flat flexible cable (FFC) 190 (shown in FIG. 8) for transferring data / power between the bot 31 and the gripping device 100. Referring to FIG. 10, the free end of the FFC 190 is received within the bridge member 120 via an aperture 124 (visible in FIG. 11) in the bridge member 120 and via a cable tensioner 130 configured to maintain the FFC 190 in tension (i.e., remove slack) when the gripping device 100 is raised or lowered by the lifting mechanism 39. The free end of the FFC 190 is then received in a clamp 123 on the inside of the bridge member 120 and interfaces with the PCB 122 via another FFC 125. The clamp 123 is in the form of two plates that can be moved closer together or further apart by adjusting one or more screws. However, other clamping arrangements may be used to reversibly secure the free end of the FFC 190 to the frame 101, or other fastening devices commonly known in the art (e.g., screws, bolts, hooks, etc.) may be used.

[0078] The cable tensioner 130 is positioned on top of the bridge member 120 and includes a cover 131 defining an aperture 132 that communicates with the aperture 124 in the bridge member 120 for receiving the FFC 190 therein. FIG. 11 illustrates a cross-sectional view of the bridge member 120 showing the components of the tensioner 130 with the cover 131 removed and the bridge member cover 124 made transparent. As shown in FIG. 11, the tensioner 130 further includes a carriage 134 slidably mounted on the linear track 133 and an idler roller 135 rotatably mounted on the carriage 134. The roller 135 engages the FFC 190 between the clamp 123 and the FFC reel 191 when the FFC 190 is connected to the gripping device 100. In particular, the FFC 190 is received substantially vertically into the bridge member 120 through an aperture 132 in the tensioner cover 131, and then turns substantially 90 degrees through contact with the idler roller 135 to extend substantially horizontally between the tensioner 130 and the clamp 123.

[0079] The tensioner 130 further comprises a biasing device in the form of two tension springs 137 coupled to the carriage 134 to bias the carriage 134 towards one end of the track 133 and away from the clamp 123 ( FIG. 11 shows the springs 137 and carriage 134 in an uncoupled state). In the example shown in FIG. 11 , the carriage 134 comprises a hook 136 that engages with a hook or ring on one end of the spring 137, although any suitable engagement between the spring 137 and the carriage 134 may be used. In use, the spring 137 biases the carriage 134 along the track 133 such that the roller 135 is pulled against the FFC 190, which helps to maintain tension on the FFC 190 as it is wound and unwound during the raising and lowering of the gripping device 100. The strength (ie, spring constant) of the spring 137 can be selected to provide adequate tension to the FFC 190 throughout the range of motion of the gripping device 100.

[0080] The cable tensioner 130 further comprises a microswitch 138 (also known as a microswitch or snap action switch) mounted at the end of the track 133 against which the carriage is biased. The microswitch 138 is for detecting when there is complete slack in the FFC 190, e.g., when a portion of the gripping device 100 and / or lifting mechanism 39 has failed in some manner. In particular, during normal operation, the FFC 190 is normally spaced away from the microswitch 138 by the FFC 190 being pulled against the biasing force of the spring 137. However, in one or more failure modes, the FFC 190 may become completely slack, causing the spring 137 to pull the carriage 134 fully back to a parked position, causing the carriage 134 to trip the microswitch 138, which sends a signal to a processor that may be used to stop or halt operation of the gripping device 100. Instead of the microswitch 138, other methods of detecting when the carriage 134 reaches a stop position may be used, such as other types of mechanical contact sensors, non-contact sensors such as optical sensors, etc.

[0081] The aperture 124 in the bridge member 120 for receiving the FFC 190 is sized to accommodate the sliding movement of the carriage 134 (especially when some components, such as the idler roller 135, protrude above the height of the bridge member 120 as shown in FIG. 11 ). The cover 131 of the tensioner 130 is rigidly attached to the carriage 134 so as to move with the carriage 134 relative to the bridge member 120 as the carriage 134 slides back and forth along the track 133. The cover 131 is sized such that the cover 131 always covers the aperture 124 of the bridge member 120, regardless of the position of the carriage 134. The aperture 132 of the cover is smaller than the aperture 124 of the bridge member 120. The cover 131 serves to stop any undesirable objects entering the bridge member 120 that may interfere with the operation of the tensioner 130.

[0082] 11 includes two tension springs 137, alternative arrangements may be used to bias the idler roller 135 against the FFC 190. For example, a different number of springs (e.g., one spring or more than two springs) may be used, or a different type of spring may be used, such as a compression spring configured to push (instead of pull) the idler roller 135 against the FFC 190.

[0083] 11 is configured to tension an FFC 190 that transmits power and / or data, the cable tensioner 130 can be used with other types of cables, for example, non-flat cables or non-electrical cables. The cable tensioner 130 also need not be located in or on the bridge member 120, but instead may be located anywhere on the frame 101.

[0084] The cable tensioner 130 is particularly useful in arrangements where the FFC reel 191 or other cable reels are not rotated by individual motors (where the tension in the cables can be controlled by adjusting the speed of rotation). For example, the FFC reel 191 may be mounted with other reels (e.g., the tether reel 181) on the same shaft driven by a single motor, and each cable may wind and unwind at a different speed. Thus, the cable tensioner enables an arrangement where multiple cable reels do not require their own individual motors, while still allowing each cable to be held under tension as the gripping device is raised and lowered.

[0085] The gripping mechanism 150 of the gripping device 100 will now be described with reference to FIGS.

[0086] The gripping mechanism 150 comprises a gripping assembly 151 mounted to a downwardly extending portion of the peripheral wall 108 at one end of the frame 101. An identical gripping assembly 151 is mounted to the peripheral wall 108 at an opposite end of the frame 101. Each gripping assembly 151 comprises two grippers 152 spaced apart along a portion of the peripheral wall 108. When the frame 101 is in an assembled state, each gripper 152 is located adjacent or near a respective corner of the frame 101. Each gripper 152 comprises a pair of legs 153 pivotally mounted to the peripheral wall 108 such that the legs are movable away from each other to define an open configuration and towards each other to define a closed configuration. FIG. 12(a) shows a perspective view of the gripping assembly 151 in an open configuration, and FIG. 12(b) shows a perspective view of the gripping assembly 151 in a closed configuration.

[0087] The legs 153 of each gripper 152 extend below the frame 101 (i.e., below the peripheral wall 108). Each leg 153 includes a foot 154 that is located below the frame 101. The feet 154 of each pair of legs 153 extend or point outward in opposite directions. When the legs 153 are in the closed configuration, the feet 154 are adjacent to each other and are receivable within corresponding apertures 54 in the rim 53 of the container 50. However, when the legs 153 are in the open configuration, the feet 154 are spaced apart a distance that is greater than the size of the apertures 54. Thus, once the feet 154 (in the closed configuration) are received within the apertures 54 in the rim 53 of the container 50, moving the legs 153 from the closed configuration to the open configuration causes the feet 154 to engage the rim 53 of the container 50, allowing the storage container to be lifted by the gripping device 100. In particular, each foot 154 has an upwardly facing surface 155 configured to engage a downwardly facing surface on the rim 53 of the storage container 50. To release the container 50, the feet 153 are moved from the open configuration to the closed configuration, which disengages the feet 154 from the container's rim 53 and allows the feet 154 to be removed from the aperture 54 in the rim 53 of the container 50.

[0088] The legs in each pair of legs 153 are engaged with one another such that pivotal rotation of one leg 153 in one direction causes pivotal rotation of the other leg 153 in the opposite direction. Thus, the pairs of legs 153 can be driven between open and closed positions by driving only one of the legs 153 of each pair. The engagement between the legs 153 may be a meshing engagement. For example, as shown in FIG. 12, the legs 153 are provided with teeth 156 that mesh with one another to form a toothed gear arrangement. This includes an arrangement in which one leg 153 of the pair has only one tooth and the other leg 153 of the pair has a corresponding recess for receiving the tooth. Other engagements for transmitting rotational motion between the legs 153 of each pair are also possible, for example, cam arrangements or friction gear arrangements.

[0089] Figure 13 shows the underside of the gripper assembly of Figure 12. As shown in Figure 13, each gripper assembly 151 further includes an actuation mechanism 160 for driving the gripper 152 between the open and closed configurations. Figure 13(a) shows the positions of the components of the actuation mechanism 160 when the gripper 152 is in the open configuration, and Figure 13(b) shows the positions of the components of the actuation mechanism 160 when the gripper 152 is in the closed configuration.

[0090] The actuation mechanism 160 includes a single linear actuator 161 for driving each gripper 152 between the open and closed configurations. The linear actuator 161 generates linear motion and may be any suitable type of linear actuator 161, for example, an electromechanical actuator or a linear solenoid actuator (e.g., a bi-stable linear solenoid actuator).

[0091] A linkage assembly 162 couples the linear actuator 161 to each gripper 152 such that actuation of the linear actuator 161 drives each gripper 152 between the open and closed configurations substantially simultaneously. In particular, the linkage assembly 162 includes a linkage arm 163 that engages one leg of each pair of legs 153, such that linear movement of the linkage arm 163 by the linear actuator 161 causes pivotal rotation of the leg 153 that engages the linkage arm 163. However, because the legs 153 of each pair are engaged to one another (as described above), actuation of only one of the legs 153 of each pair by the linkage arm 163 pivots both legs 153 of each pair, thereby moving the grippers 152 between the open and closed configurations substantially simultaneously.

[0092] 13 further includes an intermediate linkage member 164 that rigidly couples the linear actuator 161 to the linkage arm 163. However, the linkage assembly 162 may alternatively be formed as a single linkage member that directly couples the linear actuator 161 to each gripper 152.

[0093] The linkage assembly 162 further comprises a flag member 165 rigidly attached to the linkage arm 163. The flag member thus moves linearly with the linkage arm 163 between an open flag position corresponding to an open configuration of the gripper 152 and a closed flag position corresponding to a closed configuration of the gripper 152. The linkage assembly further comprises a sensor for detecting which position the flag member 165 is in, allowing a controller on the gripping device and / or the bot 31 to determine whether the gripper 152 is in an open or closed configuration. The sensor may be any suitable known type of sensor, for example a photointerrupter sensor in which a laser or optical beam is interrupted by the flag member 165 when the flag member 165 moves from the open flag position to the closed flag position or vice versa. In alternative embodiments, the flag member 165 may be located elsewhere on the linkage assembly 162 or elsewhere on the gripper assembly 151. For example, the flag member 163 may be rigidly secured to one of the legs 153 of one or more grippers 152 such that the flag member 163 rotates with the legs 153 between the open and closed flag positions.

[0094] The linear actuator 161 is arranged to actuate in a direction parallel to the vertical plane in which the gripper 152 is located (i.e., parallel to the portion of the peripheral wall 108 to which the gripper 152 is attached). The linear actuator 161 comprises a body having a longitudinal axis, the body being arranged with the longitudinal axis aligned parallel to the direction of actuation of the linear actuator. In this manner, the longitudinal body of the linear actuator 161, the linkage assembly 162, and the gripper 152 can all be aligned in the same direction, and thus the linear actuator 161, the linkage assembly 162, and the gripper 152 can be mounted to the peripheral wall 108 in a compact arrangement. Alternatively, the linear actuator 161 may be mounted to another portion of the frame 101 adjacent to the gripper 152. Furthermore, only a single linear actuator 161 is needed to drive multiple grippers 152, which further reduces the size of the gripper assembly 151.

[0095] 12 and 13 show the gripping assembly 151 having two grippers 152, the gripping assembly 151 is not limited to two grippers 152 and may have three or more grippers 152 depending on the size of the frame 101 and the object to be gripped. For a gripping assembly having three or more grippers 152, a linkage assembly can couple the linear actuator 161 to all of the grippers 152 such that actuation of a single linear actuator 161 drives all of the grippers 152 substantially simultaneously between their open and closed positions. Alternatively, an individual gripping assembly 151 may include two or more linear actuators 161, each configured to drive a corresponding group of two or more grippers 152 substantially simultaneously between their open and closed positions via a respective linkage assembly.

[0096] The linear actuator 161 may be controlled by a controller mounted on the frame 101 (e.g., in the bridge member 120) or in the body of the bot 31. Power to the linear actuator 161 may come from a power source (e.g., a battery) of the bot 31 or may be supplied via an FFC 190 or other electrical cable.

[0097] The linear actuation mechanism 160 of the gripping assembly 151 also has a synergistic effect with the openings 111 in the frame 101. In particular, as described above, the linear actuation mechanism 160 allows the gripping assembly 151 to be compactly mounted to or close to the perimeter wall 108, which makes more space available toward the center of the frame 101 for the openings 111. However, the gripping mechanism 150 can also be used with other forms of gripping devices, for example, gripping devices that do not have openings through the top and bottom sides. Conversely, the gripping device 100 (which has openings through the top and bottom sides) does not require all aspects of the gripping mechanism 150 described above. For example, each gripper 152 may be driven by its own individual actuator, which may be a linear or rotary actuator.

[0098] 7 has two gripping assemblies 151 attached to opposite ends of the frame 101, the frame 101 may include only one gripping assembly 151 or more than two gripping assemblies 151, depending on the shape of the frame 101 and the object to be gripped. The gripping assemblies 151 also do not have to be provided at opposite ends of the frame 101, but may be provided at any location on the frame 101 that allows the gripping device 100 to stably grip and lift the object to be gripped.

[0099] Additionally, the gripper 152 need not necessarily be engageable with the storage container 50 in the open configuration. Instead, the gripper 152 and / or the storage container 50 may be configured such that the gripper engages the storage container 50 when in the closed configuration. For example, the gripper 152 may be configured to provide a claw or pincer grip (e.g., by reversing the orientation of the feet 154 so that the tips face inward) and may engage the storage container 50 by gripping around a corresponding portion of the storage container 50. In general, the gripper 152 is movable between a gripping position for gripping the container 50 and a release position for releasing the container 50. The open configuration of the gripper 152 may correspond to either the gripping position or the release position, and the closed configuration may correspond to the other of the gripping position and the release position.

[0100] 14 shows a schematic diagram of a gripping device 200 having an alternative gripping mechanism 250. Similar to the gripping mechanism 150 described above, the alternative gripping mechanism 250 comprises two gripping assemblies 251 attached to opposite ends of the frame 201.

[0101] Each gripping assembly 251 includes two grippers 252 spaced apart along a portion of the perimeter wall 208. In contrast to the grippers 152 of the gripping assembly 151, each gripper 252 has only a single leg 253 that extends below the frame and includes a foot 254 located below the frame. Each leg 253 is linearly movable relative to the frame 201 in a horizontal direction (i.e., a direction perpendicular to the top / upward and bottom / downward directions) between a gripping position and a release position. Each leg 253 may be slidably mounted to the frame.

[0102] Each gripping assembly 251 further comprises a single linear actuator (not shown) configured to drive the two grippers 252 between the gripping and release positions. The gripping assembly 251 further comprises a linkage assembly 262 coupling the linear actuator to each gripper 252 such that actuation of the linear actuator substantially simultaneously drives the grippers 252 between the gripping and release positions. The linear actuators may be any suitable type of linear actuator, for example, an electromechanical actuator or a linear solenoid actuator (e.g., a bi-stable linear solenoid actuator).

[0103] Linkage assembly 262 includes linkage arms 263 that engage legs 253 of each gripper 252. In the gripping mechanism 250 shown in FIG. 14 , linkage arms 263 are integrally formed with each gripper 252, which reduces and simplifies the components of gripping mechanism 250, allows for the use of less expensive manufacturing techniques such as plastic injection molding or 3D printing, and simplifies assembly of the gripping mechanism. However, linkage assembly 250 may also be formed as a separate component from grippers 252.

[0104] In use, the feet 254 of each leg 253 may be received within a respective aperture 54 in the rim 53 of the container 50 when the legs 253 are in the release position. Once the feet 254 are received in the apertures, moving the legs 253 from the release position to the gripping position causes the feet 254 to move below the rim 53 such that an upwardly facing surface 255 of each foot 254 engages a downwardly facing surface of the rim 53 of the container 50, thereby enabling the container 50 to be lifted.

[0105] As described above, the gripping device 200 comprises two gripping assemblies 251 at opposite ends of the frame 201. As shown in FIG. 14, the feet 254 of one of the gripping assemblies 251 face in an opposite direction to the feet 254 of the other gripping assembly 251. Furthermore, the gripper 252 of one gripping assembly 251 is moved in an opposite direction to the gripper 252 of the other gripping assembly 251 when moving between the gripping position and the release position. In this way, the container 50 can be gripped more reliably compared to an arrangement in which the feet 254 of both gripping assemblies 251 face in the same direction and move in the same direction. However, this is not required and the feet of both gripping assemblies 251 may face in the same direction and move in the same direction.

[0106] Instead of a linear actuator driving the gripper 252 of the gripping assembly 251 from the gripping position to the release position and back, the gripper 252 may optionally be resiliently biased towards the gripping position, for example using a spring (not shown). In such an arrangement, the linear actuator only needs to drive the gripper 252 in one direction against the resilient bias to move the gripper 252 to the release position. When the gripper 252 needs to return to the gripping position, the actuator does not need to do any work and only needs to allow the gripper 252 to move to the gripping position under the resilient bias (the actuator may be back-drivable). Alternatively, the gripper 252 may be resiliently biased towards the release position and the actuator may be configured to drive the gripper 252 against the resilient bias to move the gripper 252 to the gripping position. By elastically biasing the gripper 252 toward either the gripping or release position and requiring the linear actuator to drive the gripper 252 in only one direction, less energy is required by the linear actuator during operation, which helps reduce operating costs and extend battery life for the battery-powered bot 31.

[0107] Like gripping mechanism 150, gripping mechanism 250 also allows for a compact configuration in which the body of the linear actuator can be aligned and mounted adjacent to the grippers 252. Grip mechanism 250 is also not limited to having two gripping assemblies 251 each having two grippers 252. Like gripping mechanism 150, gripping mechanism 250 can have a different number of gripping assemblies located anywhere on the frame, and the gripping assemblies may have a different number of grippers 252 depending on the size and shape of the frame and the object being gripped.

[0108] The frame 201 illustrated in FIG. 14 includes a sheet of material, for example metal, having an upwardly facing side forming a substantially upwardly extending peripheral wall 208. The peripheral wall 208 further extends substantially horizontally on the upper side to form a channel 215 for receiving an integrally formed gripper 252 and linkage arm 263 of a gripping assembly. The frame 201 defines an aperture or slot 216 in the channel 215 in which the gripper 252 is received such that the gripper 252 extends below the frame 201. The slot 216 is sized to permit linear movement of the gripper 252 between a gripping position and a release position. The frame 201 may be advantageous in that it can be inexpensively formed from a single sheet of material.

[0109] Alternatively, the frame 201 may be formed as a sheet of material having downwardly bent sides forming a substantially downwardly extending peripheral wall 208. Such a frame defines a recess in the bottom side of the gripping device. The peripheral wall 208 may further extend substantially horizontally at the bottom side to form a channel 215 for receiving the gripping assembly 251. The aperture or slot 216 for receiving the gripper 252 may be repositioned such that the gripper 252 extends below the frame 201.

[0110] The gripping assembly 251 does not necessarily have to be received within the channel 215, but may be mounted on the frame 201 in other suitable manner to enable linear motion, such as a cam on the linkage arm 263 and a linear cam track defined in the peripheral wall 208.

[0111] 14 does not have an opening, the frame 201 may define an opening extending through the top and bottom sides, similar to the opening 111 of the frame 101. The frame 201 may include any of the other features of the frame 101, such as the guide members 140, the sensors 114, the cable tensioners 130, etc. The gripping mechanism 250 may also be used with the frame 101 shown in FIG. 7, for example, by mounting the gripping assembly on the frame member 107.

[0112] Gripping mechanism 250 may be advantageous over gripping mechanism 150 in that it requires fewer components, the components may be less expensive to manufacture, movement of gripper 252 is simpler, there is less wear on the components, and assembly of the gripping mechanism is simpler.

[0113] Although the gripping mechanism 250 is described above using a linear actuator, a rotary actuator (e.g., an electric motor) may alternatively be used in conjunction with the gripping mechanism 250, and the linkage assembly 262 may be configured to convert rotational motion from the rotary actuator into linear motion to drive the linear motion of the gripper 252.

[0114] 7, the gripping device 100 further comprises guide members 140 attached to each corner of the frame 101. Each guide member 140 has an elongated shape that extends below the peripheral wall 108 and extends further below the peripheral wall 108 than the gripping mechanisms 150, and in particular the grippers 152 of the gripping mechanisms 150. The guide members 140 are configured to mate or engage with corner notches or openings 55 of the storage container 50 to help align the frame 101 over the top of the container 50 when the gripping device 100 is lowered such that the grippers 152 are in the correct position to be received by the openings 54 in the rim 53 of the container 50.

[0115] 7 has four guide members 140 (one at each corner of the rectangular frame 101), the gripping device 100 may include a different number of guide members 140 (i.e., at least one guide member) depending on the shape of the frame and the object to be gripped. Also, the guide members 140 are not limited to being attached to the corners of the frame 101, but may be attached to any position on the frame 101, for example, to an edge.

[0116] The gripping device 100 further comprises one or more sensors 114 mounted on the peripheral wall 108 to determine when the gripping device 100 reaches a predetermined height above the rim 53 of the storage container 50 as it is lowered. The predetermined height corresponds to a position where the gripper 152 of the gripping device 100 is received in the aperture 54 of the rim 53 of the container 50 and driving the gripper 152 to the open configuration engages the gripper 152 with the underside of the rim 53. In the gripping device 100 of FIG. 7, the sensor 114 is mounted on the end of the frame to which the gripping assembly 151 is mounted, thereby enabling the gripping device 100 or bot 31 to determine whether each individual gripping assembly 151 is in the correct engagement position with respect to the container 50. The sensor 114 may be, for example, a distance sensor that uses light or ultrasound to determine the distance between the frame 101 and the rim 53 of the container 50. Alternatively, the sensor 114 may be a mechanical contact sensor, for example positioned below the frame 101 and configured to contact and trigger the rim of the container once the frame 101 reaches a predetermined height above the rim 53.

[0117] Figures 15 and 16 show perspective and end views of the gripping device 100 engaged with a storage container. As seen in Figures 14 and 15, the grippers 152 are received within apertures 54 in the rim 53 of the container 50 and are in their open configuration such that the feet 154 of the grippers 152 engage the underside of the rim 53 of the container 50 and can lift the container 50.

[0118] 15, the openings 111 in the frame 101 provide headroom above the storage container 50 for any items that protrude above the top of the container 50 when the frame 101 is being lowered toward or engaged with the container. In particular, when the frame 101 is being lowered toward the storage container 50, any items that would normally protrude above the top of the container that would impede the lowering of the gripping device 100 will likely instead protrude into or through the recesses 112 or openings 111.

[0119] The openings in the frame 101 also provide the added benefit of reducing the weight of the frame 101 compared to a solid frame without openings, which means that less energy is required to raise and lower the gripping device 100, thereby increasing the uptime and reducing operating costs of the battery-powered bot. The invention as originally claimed in the present application is set forth below. [1] A gripping device suspended from a load handling device for lifting and moving stacked containers in a grid storage structure having a plurality of tracks arranged in a grid pattern above the stack of containers, comprising: a frame having a top side and a bottom side; and at least one gripping assembly attached to the frame, the at least one gripping assembly comprising: at least two grippers, each gripper of the at least two grippers configured to engage a container located beneath the frame, each gripper movable between a gripping position for gripping the container and a release position for releasing the container; a single linear actuator coupled to the at least two grippers by a linkage assembly such that actuation of the single linear actuator drives the at least two grippers substantially simultaneously from the gripping position to the release position and / or from the release position to the gripping position. [2] The gripping device described in [1], wherein each gripper of the at least two grippers comprises a pair of legs pivotally mounted to the frame so as to be movable away from each other to define an open configuration corresponding to either the gripping position or the release position, and towards each other to define a closed configuration corresponding to the other of the gripping position and the release position, and each leg of the pair of legs comprises a foot configured to engage the container when the gripper is in the gripping position. [3] The gripping device described in [2], wherein the open position corresponds to the gripping position and the closed configuration corresponds to the release position. [4] The gripping device described in [2] or [3], wherein the legs in each pair of legs are engaged with each other such that pivotal rotation of one of the legs in each pair of legs causes pivotal rotation of the other leg in each pair of legs in the opposite direction. [5] A gripping device as described in [4], wherein the legs in each pair of legs are interlockingly engaged with each other. [6] The gripping device described in [4] or [5], wherein the linkage assembly includes a linkage arm engaged with one leg from each pair of legs. [7] A gripping device as described in any one of [1] to [6], wherein the feet of the legs in each pair of legs extend in opposite directions away from each other. [8] The gripping device described in [1], wherein each of the at least two grippers has a single leg, each leg being movable horizontally and linearly relative to the frame between the gripping position and the release position, and each leg having a foot configured to engage the container when the gripper is in the gripping position. [9] The gripping device described in [8], wherein the at least two grippers are elastically biased toward either the gripping position or the release position.

[10] The gripping device described in [9], wherein the linear actuator is configured to drive the at least two grippers to the other of the gripping position and the release position against an elastic bias.

[11] The gripping device described in [8], wherein the linear actuator is configured to drive the at least two grippers between the gripping position and the release position.

[12] A gripping device described in any one of [8] to

[11] , wherein the linkage assembly includes a linkage arm engaged between the legs of the at least two grippers.

[13] The gripping device described in

[12] , wherein the linkage arm is integrally formed with the at least two grippers.

[14] A gripping device as described in any one of [1] to

[13] , wherein each leg extends below the frame and each foot is located below the frame.

[15] A gripping device as described in any one of [1] to

[14] , wherein each foot has an upwardly facing engagement surface for engaging with a downwardly facing engagement surface of the container.

[16] A gripping device described in any one of [1] to

[15] , wherein the at least two grippers are substantially in the same vertical plane.

[17] The gripping device described in

[16] , wherein the linear actuator is mounted on the frame adjacent to the at least two grippers, the linear actuator having a longitudinal body aligned parallel to a vertical plane in which the grippers are located.

[18] A gripping device described in any one of [1] to

[17] , wherein the at least one gripping assembly is mounted along one end of the frame.

[19] The gripping device described in

[18] , comprising a first gripping assembly mounted along one end of the frame and a second gripping assembly mounted along an opposite end of the frame.

[20] The gripping device described in

[19] when directly or indirectly dependent on [8], wherein the feet of the first gripping assembly face in an opposite direction to the feet of the second gripping assembly, and when moving between the gripping position and the release position, the at least two grippers of the first gripping assembly move in an opposite direction to the at least two grippers of the second gripping assembly.

[21] A gripping device described in any one of [1] to

[20] , further comprising at least one guide member attached to the frame to be received by a corresponding portion of the container to align the frame with the container.

[22] The gripping device described in

[21] , wherein the at least one guide member extends further below the frame than the gripper of the at least one gripping assembly.

[23] A gripping device described in any one of [1] to

[22] , wherein the frame has a rectangular shape.

[24] A load handling device for lifting and moving containers stacked in a grid storage structure comprising a plurality of tracks arranged in a grid pattern above the stack of containers, comprising: The main body, a drive mechanism operatively arranged to move the body on the lattice framework; a gripping device as defined in any one of claims [1] to

[23] for releasably gripping a container in a stack in the grid storage structure; a lifting mechanism configured to raise and lower the gripping device relative to the body.

Claims

1. A load handling device (31) for lifting and moving stacked containers (50) in a grid storage structure comprising a plurality of tracks arranged in a grid pattern above the stack of containers (50), comprising: A) a main body (33); B) a drive mechanism operatively arranged to move said body on a lattice framework; C) a gripping device (100, 200) suspended from said load handling device (31) for lifting and moving containers stacked in a stack within a grid storage structure comprising a plurality of tracks arranged in a grid pattern above said stack of containers, said gripping device (100, 200) comprising: i) a frame (101, 210) having a top side (102) and a bottom side (103); ii) at least one gripping assembly (151, 251) attached to said frame (101, 210), said at least one gripping assembly comprising: iii) at least two grippers (152, 252), each gripper (152, 252) of the at least two grippers configured to engage a container (50) located beneath the frame (101, 210), each gripper (152, 252) being movable between a gripping position for gripping the container and a release position for releasing the container; iv) a single linear actuator (161) coupled to the at least two grippers (152, 252) by a linkage assembly (162, 262) such that actuation of the single linear actuator (161) drives the at least two grippers (152, 252) substantially simultaneously from the gripping position to the release position and / or from the release position to the gripping position; D) a lifting mechanism (39) configured to raise and lower the gripping device (100, 200) relative to the body (33); A load handling device (31), characterized in that the linear actuator (161) is arranged to act in a direction parallel to a vertical plane in which the gripper (15, 252) lies.

2. A cargo handling device (31) as described in claim 1, wherein each gripper (152, 252) of the at least two grippers has a pair of legs (153, 253) pivotally mounted to the frame (101, 201) so as to be movable away from each other to define an open configuration corresponding to either the gripping position or the release position, and towards each other to define a closed configuration corresponding to the other of the gripping position and the release position, and each leg of the pair of legs (153, 253) has a foot (154, 254) configured to engage the container when the gripper (152, 252) is in the gripping position.

3. A cargo handling device (31) as described in claim 2, wherein the open position corresponds to the gripping position and the closed configuration corresponds to the release position.

4. A load handling device (31) as described in claim 2 or 3, wherein the legs (153, 253) in each pair of legs are engaged with each other such that pivotal rotation of one of the legs in each pair of legs causes pivotal rotation of the other leg in each pair of legs in the opposite direction.

5. A load handling device (31) as described in claim 4, wherein the legs (153, 253) in each pair of legs interlock and engage with each other.

6. A load handling device (31) as described in claim 4 or 5, wherein the linkage assembly (162, 262) includes a linkage arm engaged with one leg from each pair of legs.

7. A load handling device (31) as described in any one of claims 2 to 6, wherein the leg feet (154, 254) in each pair of legs extend in opposite directions away from each other.

8. A cargo handling device (31) as described in claim 1, wherein each gripper (152, 252) of the at least two grippers has a single leg (153, 253), each leg being horizontally linearly movable relative to the frame (101, 201) between the gripping position and the release position, and each leg having a foot (154, 254) configured to engage the container when the gripper is in the gripping position.

9. A cargo handling device (31) as described in claim 8, wherein the linear actuator (161) is configured to drive the at least two grippers (152, 252) between the gripping position and the release position.

10. A load handling device (31) as described in claim 9, wherein the at least two grippers (152, 252) are resiliently biased towards either the gripping position or the release position.

11. A cargo handling device (31) as described in claim 8, wherein the linear actuator is configured to drive the at least two grippers to the other of the gripping position and the release position against a resilient bias.

12. The linkage assembly (162, 262) includes a linkage arm (163, 263) engaged between the legs (153, 253) of the at least two grippers. A load handling device (31) according to any one of claims 8 to 11.

13. A load handling device (31) as described in claim 12, wherein the linkage arms (163, 263) are integrally formed with the at least two grippers.

14. A load handling device (31) as described in any one of claims 1 to 13, wherein each leg (153, 253) extends below the frame (101, 201) and each foot (154, 254) is located below the frame (101, 201).

15. A cargo handling device (31) as described in any one of claims 1 to 14, wherein each foot (154, 254) has an upwardly facing engagement surface (155, 255) for engaging with a downwardly facing engagement surface of the container.

16. A cargo handling device (31) as described in any one of claims 1 to 15, wherein the at least two grippers (152, 252) are substantially in the same vertical plane.

17. A load handling device (31) as described in claim 16, wherein the linear actuator (161) is mounted to the frame (101, 201) adjacent to the at least two grippers (152, 252).

18. A cargo handling device (31) as described in any one of claims 1 to 17, wherein the at least one gripping assembly (151) is mounted along one end of the frame (101, 201).

19. A cargo handling device (31) as described in claim 18, wherein the gripping device comprises a first gripping assembly mounted along one end of the frame and a second gripping assembly mounted along an opposing end of the frame.

20. A cargo handling device (31) as described in claim 19 dependent on claim 8, wherein the feet of a first gripping assembly (151) face in an opposite direction to the feet of a second gripping assembly (151), and when moving between the gripping position and the release position, the at least two grippers of the first gripping assembly move in an opposite direction to the at least two grippers of the second gripping assembly.

21. A cargo handling device (31) as described in any one of claims 1 to 20, further comprising at least one guide member (140) attached to the frame to be received by a corresponding portion of the container to align the frame with the container.

22. A load handling device (31) as described in claim 21, wherein the at least one guide member (140) extends further below the frame (101, 201) than the grippers of the at least one gripping assembly.

23. A cargo handling device (31) as described in any one of claims 1 to 22, wherein the frame (101, 201) has a rectangular shape.

Images