Gripping device

Abstract

To provide a gripping device for a load handling device.SOLUTION: A gripping device can be suspended from a load handling device which lifts containers stacked in a grid storage structure and moves them. The gripping device includes a frame, and at least one gripping assembly (151) mounted on the frame. The gripping assembly includes at least two grippers, and each gripper is constituted so as to be engaged with the container positioned below the frame. Each gripper can move between a gripping position for gripping the container and a release position for releasing the container. The gripping device includes a single linear actuator (161) connected to at least two grippers by a linkage assembly (162) in such a manner that at least two grippers are substantially simultaneously driven between the gripping position and the release position by the actuation of the single linear actuator.SELECTED DRAWING: Figure 13

Description

Technical Field

[0001] The present invention relates to the field of gripping devices. More specifically, the present invention relates to a gripping device for a load handling device that lifts and moves storage containers stacked in a stack in a grid storage structure.

Background Art

[0002] Some commercial and industrial activities require systems that allow for the storage and retrieval of a number of different products. WO2015 / 185628A describes storage and fulfillment where stacks of storage containers are arranged within a grid storage structure. The containers are accessed by a load handling device operable on rails or tracks positioned at the top of the grid framework structure.

[0003] The load handling device typically comprises 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 can arise where the gripping device is prevented from properly aligning and engaging with the top of the container within the stack. This can lead to the gripping device failing to grip the container or gripping only a portion of the top of the container insecurely.

[0005] The present invention aims to provide an improvement to the gripping device used by a load handling device.

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 stack 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 an upper side and a bottom side, the frame comprising a substantially downwardly extending peripheral wall that defines at least one opening passing through the upper and bottom sides of the frame. And a gripping mechanism attached to the peripheral wall and configured to releasably grip a container from below the frame.

[0007] The gripping device may further comprise at least one electrical and / or electronic component that occupies a part 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 the 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 at the upper side of the frame so as to define the recess.

[0010] The frame can further comprise a bridge member extending across the frame between two opposite sides of the peripheral wall. The bridge member may extend centrally across the frame. The bridge member may have a bottom surface recessed with respect to the bottom of the peripheral wall.

[0011] The at least one electrical and / or electronic component may be attached 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 comprise at least one gripper extending below the peripheral wall for releasably gripping the container from below the frame. The gripping mechanism may comprise a gripping assembly having at least two grippers and a single linear actuator, and the single linear actuator is coupled to the at least two grippers by a linkage assembly such that actuation of the single linear actuator causes the at least two grippers to actuate substantially simultaneously. The gripping assembly may be attached to one end of the frame. In particular, the at least two grippers and optionally the linear actuator may be attached to the peripheral wall at one end of the frame. The gripping mechanism may comprise two gripping assemblies attached to opposite ends of the frame.

[0013] The gripping device may comprise at least one sensor for detecting the distance between the frame and an object located below the frame. The at least one sensor may be attached to the peripheral wall. The gripping device may comprise 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 so as to be received by a corresponding portion of the container for aligning the frame with the container. The guide member may extend further below the frame than the grippers of the gripping mechanism, particularly. The gripping device may comprise a plurality of guide members, each guide member being 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 a container stacked in a stack within a grid framework structure comprising a plurality of tracks arranged in a grid pattern above the stack of containers, the load handling device comprising a body, and A drive mechanism operably arranged to move the body on a track of a grid storage structure, A gripping device according to a first aspect of the present invention for releasably gripping a container in a stack within a grid 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 a container stacked in a stack 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 an upper 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 of the at least two grippers being configured to engage a container located below the frame, each gripper being 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 from the gripping position to the release position and / or from the release position to the gripping position substantially simultaneously.

[0019] In some embodiments of the second aspect, each gripper of at least two grippers is pivotally attached to the frame so as to be movable away from each other to define an open configuration corresponding to either a gripping position or a 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 may comprise a foot configured to engage the 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 each other such that a pivotal rotation of one leg in each pair of legs causes a pivotal rotation of the other leg in the pair of legs in the opposite direction. The legs in each pair of legs may be engaged with each other in a meshing engagement. For example, the legs in each pair of legs may comprise teeth that engage with each other in a meshing engagement. This includes one leg of each pair having one tooth that engages with a corresponding recess on the other leg of the pair.

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

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

[0023] At least one gripping assembly may be attached along one end of the frame. The gripping device can comprise a first gripping assembly attached along one end of the frame and a second gripping assembly attached along the opposite end of the frame.

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

[0025] The at least two grippers may be elastically biased in one direction, i.e., towards 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, i.e., towards the other of the gripping position and the release position, against the elastic biasing. The at least two grippers may be elastically 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 comprise 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] At least one gripping assembly may be attached along one end of the frame. The gripping device may comprise a first gripping assembly attached along one end of the frame and a second gripping assembly attached along the opposite end of the frame. The feet of the first gripping assembly may be oriented in the opposite direction to the feet of the second gripping assembly. The at least two grippers of the first gripping assembly may move in the 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 and each foot is positioned below the frame.

[0029] Each foot may comprise an upwardly engaging surface for engaging the downwardly engaging surface of the container.

[0030] At least two grippers may be in substantially the same vertical plane. The linear actuator may be attached to the frame adjacent to at least two grippers. The frame may comprise a peripheral wall to which at least one gripping assembly and the linear actuator are attached. 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 the operating 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 attached to the frame so as to be received by a corresponding part of the container for aligning the frame with the container. At least one guide member may extend further below the frame than the grippers of at least one gripping assembly. The gripping device may comprise a plurality of guide members, each guide member being attached to a respective corner of the frame.

[0032] The frame may have a rectangular shape.

[0033] The present invention also provides a cargo handling device for lifting and moving a container stacked in a stack within a grid storage structure comprising a plurality of tracks arranged in a grid pattern above a stack of containers, the cargo handling device comprising a body, a drive mechanism operably arranged to move the body on the grid framework, and a gripping device according to a second aspect for releasably gripping a container within a stack in the 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 part 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 a container stacked in a stack in a lattice storage structure comprising a plurality of tracks arranged in a lattice pattern above the stack of containers. The gripping device comprises: a frame; a gripping mechanism attached to the frame and configured to releasably grip the container from below the frame; a fixing device attached to the frame and configured to fix the free end of the wound cable; a cable tensioner configured to place the cable under tension during use, the cable tensioner comprising: a track mounted on the frame; a carriage slidably mounted on the track and configured to engage the cable during use; a biasing device configured to bias the carriage in a direction away from the fixing device towards one end of the track so as to place the cable under tension when the carriage is engaged with the cable during use.

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

[0037] The carriage may be movable along the track under the biasing of a biasing device to a stop position. The cable tensioner may further comprise a detector configured to detect when the carriage is at the stop position. The gripping device may further comprise a processor configured to control the 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 at the stop position. The processor may be configured to stop or halt the operation of the gripping device in response to a signal from the detector. The detector may comprise a mechanical switch, such as a microswitch.

[0038] The fixing device may be a clamp.

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

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

[0041] The body may accommodate at least a part of the drive mechanism.

[0042] The load handling device may further comprise 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 fixed to the frame of the gripping device by a fixing device, and the cable is engaged with a cable tensioner between the first end and the second end.

[0043] The cable may change direction at the cable tensioner. The cable can change direction substantially by 90 degrees. The cable may extend substantially vertically between the reel and the cable tensioner and may extend substantially horizontally between the cable tensioner and the fixing 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] The gripping device according to the present invention can combine any or all of the first to third aspects defined above. For example, the gripping device according to the present invention may have the opening defined in the first aspect, and / or the gripping mechanism defined in the second aspect, and / or the cable tensioner 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

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

Figure 15

Figure 16

[0047] FIG. 1 illustrates a storage structure 1 including an upright member 3 and horizontal members 5, 7 supported by the upright member 3. The horizontal members 5 extend parallel to each other and to an exemplary x-axis. The horizontal members 7 extend parallel to each other and to an exemplary y-axis and laterally with respect to the horizontal members 5. The upright members 3 extend parallel to each other and to an exemplary z-axis and laterally with respect 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, a storage container 9 is disposed within a stack 11 directly below a grid cell 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 1 forming part of the storage structure 1 illustrated in FIG. 1 and positioned at the uppermost part of the horizontal members 5, 7 of the storage structure 1 illustrated in FIG. 1. The track structure 1 may be provided by the horizontal members 5, 7 themselves (e.g., formed within or on the surface of the horizontal members 5, 7) or by one or more additional components mounted on the uppermost part of the horizontal members 5, 7. The illustrated track structure 1 includes an x-direction track 17 and a y-direction track 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 and laterally with respect to the tracks 17 in the first set 17 of tracks. The tracks 17, 19 define an aperture 15 at the center of the grid cell. The aperture 15 is sized to enable a container 9 positioned directly below the grid cell to be lifted and lowered through the aperture 15. The x-direction tracks 17 are provided in pairs separated by a channel 21, and the y-direction tracks 19 are provided in pairs separated by a channel 23. Other arrangements of the track structure may also be possible.

[0049] FIG. 3 shows a plurality of load handling devices 31 that move to the top of the storage structure 1 illustrated in FIG. 1. The load handling device 31, which may also be referred to as a robot or bot, is provided with a set of wheels for engaging with a corresponding track 17 in the x - direction or track 19 in the y - direction in order to enable the bot 31 to move across the track structure 13 and reach a specific grid cell. The illustrated pair of tracks 17, 19 separated by channels 21, 23 enables the bots 31 to occupy (or pass by each other) adjacent grid cells without colliding with each other.

[0050] As illustrated in FIG. 4, the bot 31 includes a body 33 on or in which one or more components are installed to 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 (e.g., from or to the stack 11) the container 9 so that the bot 31 can pick up or place the container 9 at a specific position defined by the grid pattern.

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

[0052] The robot 31 also includes a container lifting mechanism 39 configured to raise and lower the container 9. The illustrated lifting mechanism 39 includes four tethers 41 that 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 physical characteristics necessary to lift the container 9. The gripping device 43 includes a gripping mechanism 150 configured to engage the features of the container 9. For example, the container 9 may be provided with one or more apertures on their upper side with which the gripping mechanism can engage. Alternatively or additionally, the gripping means may be configured to hook under the rim or lip of the container 9 and / or to clamp or grip the container 9. The tethers 41 may be wound up or down as necessary to raise or lower the gripping device 43. 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 from FIG. 5, the illustrated body 33 of the bot 31 has an upper portion 45 and a lower portion 47. The upper portion 45 is configured to house one or more operating components (not shown). The lower portion 47 is disposed below the upper portion 45. The lower portion 47 includes a container receiving space or cavity for receiving at least a portion of the container 9 lifted by the lifting mechanism 39. The container receiving space is sized such that sufficient of the container 9 can fit inside the cavity to enable the bot 31 to move across the topmost track structure 13 of the storage structure 1 without the lower side of the container 9 catching on the track structure 13 or another portion of the storage structure 1. When the bot 31 reaches its intended destination, the lifting mechanism 39 controls the tether 41 to remove the gripping device 43 and the corresponding container 9 from the cavity and lower them to the intended position. The intended position may be the stack 11 of containers 9 or the exit point of the storage structure 1 (or, if the bot 31 has moved to collect a container 9 for storage within the storage structure 1, the entry point of the storage structure 1). In the illustrated example, the upper portion 45 and the lower portion 47 are separated by a physical partition, but 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 main body 33 of the bot 31. For example, the container receiving space may instead be adjacent to the main body 33 of the bot 31, and may be, for example, a cantilever arrangement having the weight of the main body 33 of the bot 31 that balances 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 main body 33 of the bot 31, the tethers 41 may be disposed at respective positions on the projecting frame / arm, and may be configured to be raised and lowered from those positions to raise and lower the container within the container receiving space adjacent to the main body 33. The height at which the frame / arm is attached to and projects from the main body 33 of the bot 31 may be selected to provide the desired effect. For example, it may be preferable for the frame / arm to project at a high level above the main body 33 of the bot 31 to enable a larger container (or containers) to be lifted into the container receiving space below the frame / arm. Alternatively, the frame / arm may project below the main body 33 (provided it is high enough to accommodate at least one container between the frame / arm and the track structure 13) and may be arranged 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 main body 33, thereby enabling the load handling device 31 to selectively move in either the first direction or the second direction across the tracks 17, 19 of the storage structure 1.

[0056] The wheel positioning mechanism can 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 at least one set of wheels 35, 37 away from or into contact with the tracks 17, 19. In some examples, only one set of wheels is configured to move up and down, and the act of lowering one set of wheels can effectively lift the other set of wheels from the corresponding track, while the act of raising one set of wheels can effectively lower the other set of wheels into contact with the corresponding track. In other examples, both sets of wheels may be moved up and down, and advantageously, the body 33 of the bot 31 remains substantially at the same height, meaning that the weight of the body 33 and the components attached thereto need not 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 extending from the base 51 to form an open rectangular container that can be used to store items such as food products. The top rim 53 of the container 50 forms the upper surface of the container. The container 50 includes an engagement portion 54 for engaging corresponding features 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 the corresponding features of the gripping device. At each corner of the container 50, there is a notch or aperture 55 extending from the rim 53 towards the base 51 for engaging further corresponding features of the gripping device to align the gripping device with the container 50.

[0058] In use, the storage container 50 may include articles that project (accidentally or otherwise) above the top of the container. Such items may potentially interfere with the path of the gripping device 43 when the gripping device is lowered towards the top of the storage container. This may 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 engage well with the storage container, and / or may result in the gripping device being misaligned with the storage container such that the gripping mechanism does not engage with the storage container, or engages only partially or unstably with the storage container.

[0059] A gripping device that can be used with the load handling device 31 to mitigate this problem will be described with reference to FIGS. 7 to 16.

[0060] As shown in FIG. 7, the gripping device 100 includes a frame 101 having a generally planar shape with an upper side 102 and a bottom side 103. In use, the frame 101 is oriented such that a stack of storage containers is located below the frame 101.

[0061] As shown in FIG. 8, the frame 101 is connected to the lifting mechanism 39 by four winding tethers 180 that are fixed 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 having a first end engaged with a reel or spool 181 located within the body of the bot 31 and a second free end 182 extending downwardly towards the frame 101 and fixed to the respective bracket 104. The tape 180 is wound and unwound as the gripping device rises and falls respectively. For simplicity, the components for winding and unwinding the tape 180 are not shown in FIG. 8, but generally any suitable motor mechanism can be used to rotate the reels together or individually.

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

[0063] FIG. 8 also shows an electrical cable in the form of a flat flexible cable (FFC) 190 that includes a conductor 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 around 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 a non-connected state in FIG. 8). The FFC 190 is wound and unwound as the gripping device 100 moves up and down. 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 will be described in more detail later.

[0064] The gripping device 100 further includes a gripping mechanism 150 attached to the frame 101 and configured to releasably grip a container from below the frame 101. Further details of the gripping mechanism 150 will also be described later.

[0065] As shown in FIG. 7, the frame 101 includes four elongated frame members 107 joined to each other to form a substantially rectangular frame, and the substantially rectangular frame has a substantially downwardly extending peripheral wall 108 that defines a substantially rectangular opening or notch 111 in the center. The opening 111 extends completely through the upper and bottom sides 103 of the frame 101.

[0066] The opening 111 through the frame 101 provides headroom for any object protruding above the upper part of the container when the gripping device 100 is lowered towards the upper part of the container. In particular, when the gripping device 100 is descending towards the upper part of the container, any item protruding above the upper part of the container is likely to pass through the opening 111 without preventing the descent of the gripping device 100, rather than hitting a part of the frame 101 and preventing its descent.

[0067] In addition to extending substantially downward, the peripheral wall 108 may also extend substantially horizontally on the upper side 102 of the frame 101. For example, as shown in FIGS. 7 and 9 (showing the lower side of the frame 101), each frame member 107 may be formed as a bent metal plate having a side portion 109 that extends substantially downward and an upper portion 110 that extends substantially horizontally. Each frame member 107 may alternatively be described as having a substantially L-shaped contour with an L-shaped base oriented toward the upper side 102 of the frame 101. By extending substantially downward and substantially horizontally on the upper side 102 of the frame 101, the peripheral wall 108 can define a recess 112 within the bottom side 103 of the frame 101, and the opening 111 extends into the recess 112. The recess 112 provides, for example, more headroom in the frame 101 as compared to a frame 101 where the bottom side 103 is not recessed. The substantially horizontal portion 110 of the frame member 107 also provides a convenient surface for joining the frame members 107 to each other and / or for attaching other components. However, it is not essential for the peripheral wall 108 to extend substantially horizontally on the upper side 102 of the frame 101. Instead, the peripheral wall 108 may extend substantially only downward, 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, such as circular, triangular, other quadrilateral, or other polygonal shapes, depending on the shape of the object to be gripped. Note that the "rectangle" as used herein 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 not limited to a rectangle and may have other shapes, such as circular, triangular, other quadrilateral, or other polygonal shapes. The shape of the opening 111 may be the same as the shape of the frame 101.

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

[0070] Frame 101 further includes a bridge member that extends across frame 101 between two ends of frame 101 (i.e., extends across opening 111 between two opposing sides of peripheral wall 108), thereby dividing opening 111 into two smaller openings 111a and 111b on both sides of bridge member 120. However, frame 101 may still be considered to have a single opening 111 that is partially occupied by bridge member 120. Bridge member 120 preferably extends centrally across frame 101 such that frame 101 has a uniform weight distribution, thereby making it possible to more easily maintain a horizontal orientation when frame 101 is raised or lowered, and can simplify the control and / or configuration of lifting mechanism 39. However, bridge member 120 is not limited to extending centrally across frame 101 and may instead be disposed closer to one side of frame 101 than the other.

[0071] The bridge member 120 can be conveniently used for routing or mounting electrical and / or electronic components for operating the gripping device 100. The electrical and / or electronic components may be attached on the outer surface of the bridge member 120, or the electrical and / or electronic components may be attached 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 upper cover 121 of the bridge member 120 removed. The bridge member 120 includes a printed circuit board (PCB) 122 attached inside the bridge member 120. The PCB 122 may include a processor or a control module and circuits configured to supply power to, control, receive and process data from various sensors on the gripping device 100, and receive and send data and / or instructions to a processor or a 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 of FIG. 10 extends between two ends of the frame 101 to which components of the gripping mechanism 150 are attached. This provides convenient cable routing management for the electrical cables entering and exiting the gripping mechanism 150. However, this is not essential, and the bridge member 120 may extend across the frame 101 between any two ends. The frame 101 may also include two or more bridge members, for example, in an intersecting arrangement where two bridge members intersect, or in a parallel arrangement where the bridge members extend parallel to each other. Such bridge member arrangements result 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 with respect to the bottom of the peripheral wall 108. This helps to provide additional headroom and reduce the loss of headroom due to the presence of the bridge member 120 within the opening 111.

[0074] In an alternative embodiment 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., the peripheral wall 108 itself, or a housing attached to the peripheral wall 108) instead of 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 that were previously attached to the bridge member 120 may be repositioned on the body of the bot 31 rather than being positioned on the gripping device 100 itself.

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

[0076] Frame 101 further includes an upwardly extending bracket 113 attached to the bridge member 120. The purpose of the bracket 113 is to trigger a sensor, such as an optical sensor, located within or on the bot 31 so that the bot 31 knows when the gripping device 100 has been fully lifted and can move to the next destination on the grid structure. For example, the bot 31 may include a photointerrupter sensor that detects when the upwardly extending portion of the bracket 113 blocks the path between an optical transmitter and an optical receiver in order to detect when the gripping device 100 is in a fully raised position. The bracket 113 is not limited to being attached on the bridge member 120 and may be attached at other locations on the frame 101. The bracket 113 may also take any shape or form suitable for triggering a sensor, such as a photointerrupter sensor. Other arrangements for detecting when the gripping device 100 is in a fully raised position are also possible, for example, a mechanical contact sensor within the bot 31 that detects when a part of the gripping device 100 contacts it.

[0077] As described above, the bot 31 may include a wound 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 passes through an aperture 124 within the bridge member 120 (visible in FIG. 11) and through a cable tensioner 130 configured to maintain the FFC 190 in a tensioned state (i.e., remove slack) as the gripping device 100 is raised or lowered by the lifting mechanism 39, and is received within the bridge member 120. Next, the free end of the FFC 190 is received by a clamp 123 inside the bridge member 120 and interfaces with the PCB 122 via another FFC 125. The clamp 123 is in the form of two plates and can be moved closer together or further apart by adjusting one or more screws. However, other clamp arrangements may be used to reversibly secure the free end of the FFC 190 to the frame 101, or other securing devices generally known in the art (e.g., screws, bolts, hooks, etc.) may be used.

[0078] The cable tensioner 130 is positioned at the uppermost part of the bridge member 120 and includes a cover 131 that defines an aperture 132 communicating with the aperture 124 within the bridge member 120 for receiving the FFC 190 into the bridge member 120. 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 a linear track 133 and an idler roller 135 rotatably mounted on the carriage 134. When the FFC 190 is connected to the gripping device 100, the roller 135 engages the FFC 190 between the clamp 123 and the FFC reel 191. In particular, the FFC 190 is received substantially vertically into the bridge member 120 through the aperture 132 within the tensioner cover 131 and then is turned substantially 90 degrees through contact with the idler roller 135 and extends substantially horizontally between the tensioner 130 and the clamp 123.

[0079] The tensioner 130 further includes a biasing device in the form of two tension springs 137 coupled to the carriage 134 that bias the carriage 134 in a direction away from the clamp 123 toward one end of the track 133 (FIG. 11 shows the springs 137 and the carriage 134 in a disengaged state). In the example shown in FIG. 11, the carriage 134 includes a hook 136 that engages a hook or ring at 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 maintain the tension of the FFC 190 as the FFC 190 is wound and unwound during raising and lowering of the gripping device 100. The strength (i.e., spring constant) of the spring 137 can be selected such that an appropriate tension is applied to the FFC 190 over the entire range of movement of the gripping device 100.

[0080] The cable tensioner 130 further includes a microswitch 138 (also known as a microswitch or snap-action switch) attached to the end of the track 133 to which the carriage is biased. The microswitch 138 is for detecting when there is a complete slack in the FFC 190, for example, when part of the gripping device 100 and / or the lifting mechanism 39 fails in some way. In particular, during normal operation, the FFC 190 is usually separated from the microswitch 138 as the FFC 190 is pulled against the biasing force of the spring 137. However, in one or more failure modes, the FFC 190 may completely slacken, as a result of which the spring 137 pulls the carriage 134 fully back to the stop position, trips the microswitch 138 on the carriage 134, and this sends a signal to the processor that may be used to stop or halt the operation of the gripping device 100. Instead of the microswitch 138, other methods of detecting when the carriage 134 reaches the stop position, such as other types of mechanical contact sensors, non-contact sensors such as optical sensors, etc., may be used.

[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, project 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 such that when the carriage 134 slides back and forth along the track 133, it moves with the carriage 134 relative to the bridge member 120. The cover 131 is sized such that it 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 helps to stop any unwanted object that may enter the bridge member 120 and potentially interfere with the operation of the tensioner 130.

[0082] The biasing device of the cable tensioner 130 shown in FIG. 11 includes two tension springs 137, but 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 three or more springs) may be used, or a different type of spring, such as a compression spring configured to push (instead of pull) the idler roller 135 against the FFC 190, may be used.

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

[0084] The cable tensioner 130 is particularly useful in an arrangement where the FFC reel 191 or other cable reels are not rotated by individual motors (which can control the cable tension by adjusting the rotational speed). For example, the FFC reel 191 may be mounted on the same shaft driven by a single motor together with other reels (e.g., the tether reel 181), and each cable may be wound and unwound at different speeds. Thus, the cable tensioner allows 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 be described with reference to FIGS. 12 and 13.

[0086] The gripping mechanism 150 includes a gripping assembly 151 attached to a portion that extends downward below the peripheral wall 108 at one end of the frame 101. The same gripping assembly 151 is attached to the peripheral wall 108 at the opposite end of the frame 101. Each gripping assembly 151 includes two grippers 152 spaced along a part of the peripheral wall 108. When the frame 101 is in the assembled state, each gripper 152 is located adjacent to or near each corner of the frame 101. Each gripper 152 includes a pair of legs 153 pivotally attached to the peripheral wall 108 such that they are movable away from each other to define an open configuration and movable towards each other to define a closed configuration. FIG. 12(a) shows a perspective view of the gripping assembly 151 in the open configuration, and FIG. 12(b) shows a perspective view of the gripping assembly 151 in the 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 located below the frame 101. The feet 154 of each pair of legs 153 extend or face outward in opposite directions. When the legs 153 are in the closed configuration, the feet 154 are adjacent to each other and can be received within corresponding apertures 54 within the rim 53 of the container 50. However, when the legs 153 are in the open configuration, the feet 154 are separated by a distance greater than the size of the aperture 54. Thus, once the feet 154 (in the closed configuration) are received within the aperture 54 within the rim 53 of the container 50, moving the legs 153 from the closed configuration to the open configuration engages the feet 154 with the rim 53 of the container 50 and enables the storage container to be lifted by the gripping device 100. In particular, each foot 154 has an upward-facing surface 155 configured to engage a downward-facing surface on the rim 53 of the storage container 50. To release the container 50, the legs 153 are moved from the open configuration to the closed configuration, which disengages the feet 154 from the rim 53 of the container and enables the feet 154 to be removed from the aperture 54 within the rim 53 of the container 50.

[0088] The legs in each pair of legs 153 are engaged with each other such that the pivotal rotation of one leg 153 in one direction causes the pivotal rotation of the other leg 153 in the opposite direction. Thus, the pair of legs 153 can be driven between the open position and the closed position by driving only one of each pair of legs 153. 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 each other 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 each pair of legs 153, such as a cam arrangement or a friction gear arrangement, are also possible.

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

[0090] The actuating mechanism 160 includes a single linear actuator 161 for driving each gripper 152 between the open configuration and the closed configuration. The linear actuator 161 generates linear motion and may be any suitable type of linear actuator 161, such as an electromechanical actuator or a linear solenoid actuator (e.g., a bistable linear solenoid actuator).

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

[0092] The linkage assembly 162 shown in FIG. 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 includes a flag member 165 that is rigidly attached to the linkage arm 163. Thus, the flag member moves linearly with the linkage arm 163 between an open flag position corresponding to the open configuration of the gripper 152 and a closed flag position corresponding to the closed configuration of the gripper 152. The linkage assembly further includes a sensor for detecting the position of the flag member 165, enabling the controller on the gripping device and / or the bot 31 to determine whether the gripper 152 is in the 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 blocked by the flag member 165 as the flag member 165 moves from the open flag position to the closed flag position or vice versa. In an alternative embodiment, the flag member 165 may be located at other locations on the linkage assembly 162 or at other locations on the gripping assembly 151. For example, the flag member 163 may be rigidly fixed to one of the legs 153 of one or more of the grippers 152 such that the flag member 163 rotates with the leg 153 between the open flag position and the closed flag position.

[0094] The linear actuator 161 is arranged to operate in a direction parallel to the vertical plane in which the gripper 152 is located (i.e., a direction parallel to the portion of the peripheral wall 108 to which the gripper 152 is attached). The linear actuator 161 includes a main body having a longitudinal axis, and the main body is arranged together with the longitudinal axis aligned parallel to the operating direction of the linear actuator. In this way, the longitudinal main 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 attached to the peripheral wall 108 in a compact arrangement. Alternatively, the linear actuator 161 may be attached to another portion of the frame 101 adjacent to the gripper 152. Further, only a single linear actuator 161 is required to drive a plurality of grippers 152, which further reduces the size of the gripping assembly 151.

[0095] Figures 12 and 13 show a gripping assembly 151 having two grippers 152, but 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, the linkage assembly can couple the linear actuator 161 to all of the grippers 152 such that the operation of a single linear actuator 161 drives all of the grippers 152 between the open position and the closed position substantially simultaneously. Alternatively, the individual gripping assemblies 151 may include two or more linear actuators 161, and each linear actuator is configured to drive a corresponding group of two or more grippers 152 between their open and closed positions substantially simultaneously via respective linkage assemblies.

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

[0097] The linear actuation mechanism 160 of the gripping assembly 151 also has a synergistic effect with the opening 111 within the frame 101. In particular, as described above, the linear actuation mechanism 160 enables the gripping assembly 151 to be compactly mounted to or proximate the peripheral wall 108, which makes more space available towards the center of the frame 101 for the opening 111. However, the gripping mechanism 150 can also be used with other forms of gripping devices, such as 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 a linear or rotary actuator and may be driven by its own individual actuator.

[0098] The gripping device 100 of FIG. 7 has two gripping assemblies 151 attached to opposite ends of the frame 101, but the frame 101 may comprise only one gripping assembly 151 or three or more gripping assemblies 151, depending on the shape of the frame 101 and the object to be gripped. The gripping assemblies 151 also do not need to be provided at opposite ends of the frame 101 and may be provided at any position on the frame 101 that enables the gripping device 100 to stably grip and lift the object being gripped.

[0099] Furthermore, the gripper 152 does not necessarily need to 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 pinch grip (e.g., by reversing the orientation of the legs 154 such that the tips face inward), and may engage the storage container 50 by gripping around a corresponding portion of the storage container 50. Generally, 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] FIG. 14 shows a schematic view of a gripping device 200 having an alternative gripping mechanism 250. Similar to the gripping mechanism 150 described above, the alternative gripping mechanism 250 includes two gripping assemblies 251 attached to opposite ends of the frame 201.

[0101] Each gripping assembly 251 includes two grippers 252 spaced along a portion of the peripheral 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 positioned below the frame. Each leg 253 is linearly movable relative to the frame 201 in a horizontal direction (i.e., a direction orthogonal to the top / upward and bottom / downward directions) between a gripping position and a release position. Each leg 253 may be slidably attached to the frame.

[0102] Each gripping assembly 251 further includes a single linear actuator (not shown) configured to drive two grippers 252 between a gripping position and a release position. The gripping assembly 251 further includes a linkage assembly 262 that couples the linear actuator to each gripper 252 such that actuation of the linear actuator drives the grippers 252 substantially simultaneously between the gripping position and the release position. The linear actuator may be any suitable type of linear actuator, such as an electromechanical actuator or a linear solenoid actuator (e.g., a bistable linear solenoid actuator).

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

[0104] In use, the feet 254 of each leg 253 may be received within respective apertures 54 within the rim 53 of the container 50 when the legs 253 are in the release position. Once the feet 254 are received within the apertures, by moving the legs 253 from the release position to the gripping position, the feet 254 move beneath the rim 53 such that the upward-facing surfaces 255 of each foot 254 engage the downward-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 includes two gripping assemblies 251 at opposite ends of the frame 201. As shown in FIG. 14, one leg 254 of the gripping assembly 251 faces in the opposite direction to the leg 254 of the other gripping assembly 251. Further, when the gripper 252 of one gripping assembly 251 moves between the gripping position and the release position, it is moved in the opposite direction to the gripper 252 of the other gripping assembly 251. In this way, the container 50 can be gripped more securely compared to an arrangement where the legs 254 of both gripping assemblies 251 face in the same direction and move in the same direction. However, this is not essential, and the legs of both gripping assemblies 251 may face in the same direction and move in the same direction.

[0106] Instead of a linear actuator that drives the gripper 252 of the gripping assembly 251 from the gripping position to the release position and from the release position to the gripping position, the gripper 252 may optionally be elastically biased towards the gripping position using, for example, a spring (not shown). In such an arrangement, the linear actuator only needs to drive the gripper 252 in one direction against the elastic biasing 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 perform any work and only needs to allow the gripper 252 to move to the gripping position under elastic biasing (the actuator may be reversely drivable). Alternatively, the gripper 252 may be elastically biased towards the release position, and the actuator may be configured to drive the gripper 252 against the elastic biasing to move the gripper 252 to the gripping position. By elastically biasing the gripper 252 towards either the gripping position or the 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 to reduce the operating cost and extend the battery life of the battery-powered bot 31.

[0107] Similar to the gripping mechanism 150, the gripping mechanism 250 also allows for a compact configuration where the body of the linear actuator can be aligned with and adjacently mounted to the gripper 252. The gripping mechanism 250 is not limited to having two gripping assemblies 251, each having two grippers 252. Similar to the gripping mechanism 150, the gripping mechanism 250 can have a different number of gripping assemblies disposed at any location on the frame, and the gripping assemblies can have a different number of grippers 252 depending on the size and shape of the frame and the object to be gripped.

[0108] The frame 201 illustrated in FIG. 14 includes a material, such as a sheet of metal, having upwardly extending sides that form a substantially upwardly extending peripheral wall 208. The peripheral wall 208 further extends substantially horizontally at the upper side to form a channel 215 for receiving the integrally formed gripper 252 and linkage arm 263 of the gripping assembly. The frame 201 defines an aperture or slot 216 within 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 allow for 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 that form a substantially downwardly extending peripheral wall 208. Such a frame defines a recess on 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 and may be mounted on the frame 201 by other suitable means that allow for linear movement, such as a cam on the linkage arm 263 and a linear cam track defined within the peripheral wall 208.

[0111] The frame 201 illustrated in FIG. 14 does not have an opening, but the frame 201 may define an opening that extends through the upper and bottom sides, similar to the opening 111 of the frame 101. The frame 201 may include any other features of the frame 101, such as the guide member 140, the sensor 114, the cable tensioner 130, etc. The gripping mechanism 250 may also be used with the frame 101 shown in FIG. 7, for example, by attaching the gripping assembly to the frame member 107.

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

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

[0114] Referring back to FIG. 7, the gripping device 100 further includes guide members 140 attached to each corner of the frame 101. Each guide member 140 extends downwardly of the peripheral wall 108 and has an elongated shape that extends further downwardly of the peripheral wall 108 than the gripper 152 of the gripping mechanism 150, particularly the gripping mechanism 150. The guide member 140 is configured to mate or engage with a notch or opening 55 at the corner of the storage container 50 in order to assist in aligning the frame 101 over the top of the storage container 50 when the gripping device 100 is lowered so that the gripper 152 is received in the opening 54 of the rim 53 of the container 50 in the correct position.

[0115] The gripping device 100 of FIG. 7 has four guide members 140 (one at each corner of the rectangular frame 101), but 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 member 140 is not limited to being attached to the corners of the frame 101 and may be attached at any position on the frame 101, such as an edge.

[0116] The gripping device 100 further comprises one or more sensors 114 attached to the peripheral wall 108 to determine when the gripping device 100 has reached a predetermined height above the rim 53 of the storage container 50 when the gripping device 100 is descending. 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 into an open configuration engages the gripper 152 under the rim 53. In the gripping device 100 of FIG. 7, the sensor 114 is attached to the end of the frame to which the gripping assembly 151 is attached, whereby the gripping device 100 or the bot 31 can determine whether each individual gripping assembly 151 is in the correct engagement position relative to the container 50. The sensor 114 may be, for example, a distance sensor that uses light or ultrasonic waves 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] FIGS. 15 and 16 show perspective and end views of the gripping device 100 engaged with the storage container. As seen in FIGS. 14 and 15, the gripper 152 is received within the aperture 54 of the rim 53 of the container 50 and is in its open configuration such that the feet 154 of the gripper 152 engage under the rim 53 of the container 50 and can lift the container 50.

[0118] As can be seen from FIG. 15, the opening 111 of the frame 101 provides headroom above the storage container 50 for any item that protrudes above the top of the container 50 when the frame 101 is descending towards the container or is engaged with the container. In particular, when the frame 101 is being lowered towards the storage container 50, any item that protrudes above the top of the container, which would normally impede the descent of the gripping device 100, is likely to instead protrude into or through the recess 112 or the opening 111.

[0119] The opening in the frame 101 also provides the added advantage of reducing the weight of the frame 101 as compared to a solid frame without an opening, which means that less energy is required to raise and lower the gripping device 100, thereby increasing the operational time of the battery-powered bot and reducing the operating cost.

Claims

1. A gripping device suspended from a load handling device for lifting and moving a container stacked in a stack in a lattice storage structure having a plurality of tracks arranged in a lattice pattern above the stack of containers, comprising a frame having an upper 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 of the at least two grippers being configured to engage a container located below the frame, each gripper being 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 from the gripping position to the release position and / or from the release position to the gripping position substantially simultaneously.

2. Each of the at least two grippers is pivotally attached to the frame by a pair of legs 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 the container when the gripper is in the gripping position. The gripping device according to claim 1.

3. The gripping device according to claim 2, wherein the open position corresponds to the gripping position and the closed configuration corresponds to the release position.

4. The gripping device according to claim 2 or 3, wherein the legs in each pair of legs are engaged with each other such that pivotal rotation of one leg in each pair of legs causes pivotal rotation of the other leg in each pair of legs in the opposite direction.

5. The gripping device according to claim 4, wherein the legs in each pair of legs are meshingly engaged with each other.

6. The gripping device according to claim 4 or 5, wherein the linkage assembly comprises a linkage arm engaged with one leg from each pair of legs.

7. The feet of the legs in each pair of legs extend in opposite directions away from each other, the gripping device according to any one of claims 1 to 6.

8. Each gripper of the at least two grippers comprises a single leg, each leg being linearly movable horizontally relative to the frame between the gripping position and the release position, each leg comprising a foot configured to engage the container when the gripper is in the gripping position, the gripping device according to claim 1.

9. The at least two grippers are elastically biased towards either the gripping position or the release position, the gripping device according to claim 8.

10. The linear actuator is configured to drive the at least two grippers against the elastic biasing to the other of the gripping position and the release position, the gripping device according to claim 9.

11. The linear actuator is configured to drive the at least two grippers between the gripping position and the release position, the gripping device according to claim 8.

12. The linkage assembly comprises a linkage arm engaged between the legs of the at least two grippers, the gripping device according to any one of claims 8 to 11.

13. The linkage arm is integrally formed with the at least two grippers, the gripping device according to claim 12.

14. Each leg extends below the frame, each foot being located below the frame, the gripping device according to any one of claims 1 to 13.

15. Each foot comprises an upward engaging surface for engaging the downward engaging surface of the container, the gripping device according to any one of claims 1 to 14.

16. The at least two grippers are in substantially the same vertical plane, the gripping device according to any one of claims 1 to 15.

17. The linear actuator is attached to the frame adjacent to the at least two grippers, the linear actuator having a longitudinal body aligned parallel to the vertical plane in which the grippers are located, the gripping device according to claim 16.

18. The at least one gripping assembly is attached along one end of the frame, the gripping device according to any one of claims 1 to 17.

19. The gripping device according to claim 18, comprising a first gripping assembly attached along one end of the frame and a second gripping assembly attached along the opposite end of the frame.

20. The feet of the first gripping assembly face in a direction opposite 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 a direction opposite to the at least two grippers of the second gripping assembly. The gripping device according to claim 19 when directly or indirectly dependent on claim 8.

21. The gripping device according to any one of claims 1 to 20, further comprising at least one guide member attached to the frame so as to be received by a corresponding portion of the container for aligning the frame with the container.

22. The gripping device according to claim 21, wherein the at least one guide member extends further downward of the frame than the grippers of the at least one gripping assembly.

23. The gripping device according to any one of claims 1 to 22, wherein the frame has a rectangular shape.

24. A cargo handling device for lifting and moving a container stacked in a stack within a grid storage structure comprising a plurality of tracks arranged in a grid pattern above a stack of containers, a main body, a drive mechanism operably arranged to move the main body on a grid framework, a gripping device as defined in any one of claims 1 to 23 for releasably gripping a container within a stack in the grid storage structure, and a lifting mechanism configured to raise and lower the gripping device relative to the main body.

Images