TECHNICAL FIELD

[0001] The present invention relates to the palletising of packaged goods EG cartons , shrink or tray wrapped packaging & is especially relevant to shelf ready product packaging, more particularly although not exclusively, to automation equipment for the handling of any of the above products.

BACKGROUND

[0002] The handling of goods from manufacture to warehousing and subsequently to distribution almost invariably involves the loading and unloading of pallets. "Shelf ready" cartons of product have become more and more important particularly in supermarkets. A problem of handling some packaging / cartons of product stems from the fact that many cartons cannot be gripped from the top or sides, but only from underneath due to the nature of the nature of tear away shelf ready cartons or tray type carton packaging with a completely open top & sometimes sides.

[0003] So called Tyne Style grippers are known which are provided with a load bearing block activated by an air cylinder or servo motor projecting from rear of the gripper. This arrangement however more than doubles the depth of the gripper demanding an increase in footprint of system size and an increase in the pitch between pallets. Moreover, these type of grippers require tynes which are required to fit in between the rollers of an incoming pick off station, and are easily damaged & not suitable for many products that would run better on a belt type surface.

[0004] It is an object of the present invention to address or at least ameliorate some of the above disadvantages.

Notes

[0005] The term "comprising" (and grammatical variations thereof) is used in this specification in the inclusive sense of "having" or "including", and not in the exclusive sense of "consisting only of.

[0006] The above discussion of the prior art in the Background of the invention, is not an admission that any information discussed therein is citable prior art or part of the common general knowledge of persons skilled in the art in any country. SUMMARY OF INVENTION

[0007] Accordingly, in a broad form of the invention, there is provided a layer picking gripper for handling one or more cartons of products; the gripper including at least one gripper assembly; each assembly comprising a vertical fixed clamping plate and a vertical articulated clamping plate; the articulated clamping plate operable between a fully open position and a clamping position; the assembly further including a retractor plate; the retractor plate operable between a first retracted position and a second extended position.

[0008] Preferably, the retractor plate in the first retracted position is in a vertical position and in the second position is in a horizontal position.

[0009] Preferably, the gripper assembly includes a housing; a vertical surface of the housing facing the clamping plate forming the fixed plate.

[00010] Preferably, the housing contains a retracting and extending mechanism for retracting and extending the retractor plate between the first vertical position within the housing and the second horizontal position projecting from the housing.

[00011] Preferably, the retractor plate comprises an assembly of hinge elements along opposing opposite sides of the retractor plate; the hinge elements including overlapping structures arranged to limit relative rotation between adjacent hinge elements between a vertical position and a horizontal position.

[00012] Preferably, each hinge element incorporates a link of a chain; the links engaging sequentially with driven sprockets located within the housing.

[00013] Preferably, corresponding opposing hinge elements are interconnected by connecting elements to form a platform when the retractor plate is in the horizontal position.

[00014] Preferably, activation of the driven sprockets in a retraction process draws the links of each chain and the overlapping elements into vertical grooves provided within the housing.

[00015] Preferably, the articulated clamping plate is movably mounted to a slide assembly extending from an upper portion of the housing; an actuator mounted to the slide assembly moving the articulated clamping plate between the fully open position and the clamping position.

[00016] Preferably, the gripper assembly is an end effector of a robot.

[00017] Preferably, in use, in the extended position, the retractor plate is positioned proximate the one or more cartons of product to be lifted such that an upper surface of the extender plate is coincident with an underside of the one or more cartons of product.

[00018] Preferably, the layer picking gripper comprises two gripper assemblies; each gripper assembly supported side by side from a supporting structure; the supporting structure including a robot mount for connecting the gripper to an arm of a robot. [00019] Preferably, each gripper assembly is rotatably mounted to the supporting structure; actuators at each gripper assembly operable to rotate each gripper assembly about a vertical axis.

[00020] In another broad form of the invention, there is provided a method of layer picking one or more cartons of product of a layer of cartons; the method including operation of a layer picking gripper; the layer picking gripper comprising at least one gripper assembly; the assembly including a vertical fixed plate, an articulated clamping plate and a retractor plate; the method including the steps of:

- manoeuvring the gripper assembly over the one or more cartons with the articulated

clamping plate in a first fully open position,

- lowering the gripper so as to position the one or more cartons between clamping surfaces of the vertical fixed plate and articulated clamping plate,

- activating the retractor plate from a first retracted vertical position to a projecting horizontal position; an upper surface of the retractor plate at a level at which the retractor plate is below an underside of the one or more cartons,

- activating the articulate clamping plate to draw the one or more cartons onto the retractor plate and clamping the one or more cartons between the fixed vertical plate and the articulated clamping plate.

[00021] Preferably, the retractor plate when retracted in the first vertical position is located within a housing of the gripper assembly.

BRIEF DESCRIPTION OF DRAWINGS

[00022] Embodiments of the present invention will now be described with reference to the accompanying drawings wherein:

[00023] Figure 1 is a perspective view of a gripper assembly according to the invention;

[00024] Figure 2 is a further perspective view of the gripper assembly of Figure 1 with a articulated clamping plate in a retracted position;

[00025] Figure 3 is another perspective view of the gripper assembly of Figures 1 and 2 with a retractor plate in a retracted position,

[00026] Figure 4 is a perspective view from below of the gripper assembly of Figures 1 to 3; [00027] Figures 5 and 5A are perspective views of a sub-assembly of the gripper assembly of Figures 1 to 4;

[00028] Figure 6 is a side view of the gripper assembly of Figures 1 to 4 attached to the arm of a robot for use,

DESCRIPTION OF EMBODIMENTS

[00029] With reference to Figures 1 to 6, a layer picking gripper according to the invention, for handling one or more cartons of products, includes at least one gripper assembly 10. Each assembly comprising a vertical fixed clamping plate 12 and a vertical articulated clamping plate 14. The articulated clamping plate 14 is operable between a fully open position, as shown in Figure 1, and a clamping position as shown in Figure 2.

[00030] As best seen in Figure 4, the vertical articulated clamping plate 14 is mounted to a slide system 18 at the underside of a main support plate 20. A rotary actuator 22 mounted to the top of the main support plate 20 drives the slide system 18 and the articulated clamping plate 14 between the fully open position of Figure 1 and the clamping position of Figure 2.

[00031] The assembly further including a retractor plate 16 which is operable between a first retracted position as shown in Figure 3 and a second extended position as shown in each of the other figures. The retractor plate 22 in the first retracted position of Figure 3, is retained within a housing 24, supported from the main support plate 20. In the second position, the retractor plate 16 is in the projecting horizontal position of Figure 1, 2 and Figures 4 to 7. With particular reference to Figures 5 and 5A, the sub assembly of the housing 24, comprising side plates 26 and 28 and cover plate 29, includes a sprocket drive system 30, comprising of a pair of sprockets 32 (only one of which is visible in Figure 5) interconnected by drive shaft 34, and driven into rotation by rotary actuator 36 via a drive belt and pulley system 38.

[00032] As best seen in the inset view of Figure 4, the retractor plate 16 is made up of a number of plate elements 40 interlinked by hinge elements 42 along opposing opposite sides of the retractor plate. The hinge elements 42 incoiporate overlapping structures 44 arranged to limit rotation of adjacent hinge elements between a vertical position and a horizontal position. Each hinge element 42 further incorporate a link 46 of chains extending along each opposite side of the retractor plate 24. The links 46 engage sequentially with the driven sprockets 32 located within the housing 24 as seen in Figures 5 and 5A.

[00033] Referring again to Figures 5 and 5A, each inward facing surface of the side plates 26,28 of the housing 24 is provided with a groove 48, comprising a curved section (hidden by the sprockets 32) concentric with the sprockets 32, and a vertical section, adapted to accept the chain links 46 and the overlapping structures 44 as a sliding fit. As the actuator 36 is activated in a retraction process, the driven sprockets 32 draw the links 46 of each chain together with the overlapping structures 44 into the grooves 48 to retract the retractor plate 16 into the housing 24.

[00034] The gripper assembly 10 is provided with a connector element 50 mounted to the main support plate 20. In a single gripper assembly mode of operation, the gripper assembly is attached to an arm of an industrial robot 52, becoming an end effector of the robot.

[00035] Alternatively, a pair of gripper assemblies 10 may be supported from a bridging structure with the connector elements 50 of each assembly rotatably connected to the bridging structure and the bridging structure in turn connected to the robot's arm. In this second dual configuration, one or each of the gripper assemblies may be rotated through 90degrees to suit various carton orientation layers. Also in this dual arrangement, one of the gripper assemblies in modified in that the clamping plate is removed or at least has no vertical component. The bridging structure has provision for moving one of the dual mountings relative the other, thus allowing that gripper assembly at 90degrees to the other, to act as a clamp, drawing some cartons of a layer of cartons against those retained in the other gripper assembly.

[00036] Thus in use, the single gripper assembly or the dual gripper assembly, manipulate by the robot, can be used to pick a layer of shelf ready cartons of product from a pick off station, either a carton loading conveyor, or from a pallet of stacked cartons. In a picking sequence, the or each gripper assembly is initially in a state in which the articulated clamping plate 14 is in the fully extended position and the retractor plate 16 retracted. The robot may lower the gripper assembly over the layer of cartons, or the layer may have been transported by conveyor to a position between the clamping plate 14 and the fixed plate 12. The retractor plate 16 is then extended and place up against the pick off station. When the product ready signal is received by the robot, the clamping plate 14 draws the cartons onto the retractor plate and the robot then moves to place the collected cartons to a deposit location. To deposit, the retractor plate is retracted, and the clamping plate eased to release the cartons, with the robot retreating for a following cycle.

[00037] A major advantage over known layer picking grippers lies in the unique retractor plate. By retracting the retractor plate into the vertical housing, the space required for operating the gripper assembly, both in single gripper and dual gripper assembly mode reduced, thus allowing a closer spacing of pallets in a layer picking operation.