CONTAINER HANDLING

Abstract: Apparatus for moving the bale arms (9) of a container (1) from one operating position to another includes means (57) for locating the container in a predetermined position relative to the apparatus. Two bale arm engaging means (43) each engage a respective one of the bale arms. Means (49, 51) are provided for moving each bale arm engaging means along a path of travel which closely corresponds to that of the respective bale arm while the bale arm engaging means remains in engagement with the bale arm, thereby ensuring complete movement of the bale arm between the operating positions.

Description: Container Handling Field of the invention This invention relates to container handling and in particular to the handling of containers in the form of plastic baskets or trays which are used to transport all types of products from manufacturers, producers and suppliers to retailers of these products. Typically such baskets or trays are used many times, being returned by the retailers to the source once the products have been unloaded. Such reusable plastic baskets or trays are referred to as "Returnable Transport Packaging" (RTP) in the industry. Background of the invention The plastic containers (baskets or trays) of the type with which this invention is concerned are provided with a pair of arms in the form of metal rods or plastic located at both ends of the square or oblong, open-topped basket. Each arm, known as a bale arm, extends along an upper edge of the side of the container, each end of the bale arm being located in a respective recess or slot located in the body of the container. The arrangement is such that the bale arm can be moved between at least two positions. In the first position, the bale arm lies outside the open top of the container. With the two bale arms in this first position, then two or more containers may be stacked in a "nested" configuration with one container lying almost wholly within another lower container. The bale arms are used in this position when the containers are empty and are to be returned to their source. In this way, a stack of containers will take up a minimum amount of space. When the bale arms are in a position other than that for nested stacking, they extend across the container at a position spaced inwardly from their respective end walls. Accordingly, when containers are stacked one upon another they are each seated on the bale arms of the next lower container and are therefore in a "denested" configuration. The bale arms are then said to be "inboard" whereas when they are in their "nesting" position, they are stated to be "outboard". Some containers allow only a single inboard position for the bale arms. Others are designed such as there are two or more inboard positions which differ from each other by the height of the bale arm relative to the container. In a first inboard position, the bale arm may be located at the height of the upper edge of the container. In a second inboard position, the bale arm may be located well below the upper edge of the container. The first inboard position would be used when the container is substantially full of the product to be transported. The second inboard position may be used when the container is substantially less than full. It is important that the bale arms are firmly located in whatever is their appropriate position at the time. This is particularly so in the case where the containers are being used to transport goods to a retailer. The containers are delivered in stacks and particularly the lower containers may have to support considerable weight which bears on the bale arms. If the bale arms are not firmly located in their proper position, then the containers may become damaged and the goods being carried may also be damaged. For this reason, the container is often designed so that the bale arms, at least when in the or one of their inboard positions, are positively engaged in such positions so that they cannot easily be dislodged therefrom. Hitherto, the bale arms of containers of the type of which this invention is concerned are moved manually between their two or more possible positions. Although this method of operation will tend to ensure that the bale arms are properly positioned, particularly when intended to be positioned in inboard positions, the procedure is a highly time-consuming one. It would clearly be advantageous if the bale arms could be moved between their positions by some form of apparatus which could operate automatically, thereby releasing operator time. Containers have been used in, for instance, the bread industry, which include bale arms movable between two positions, typically an outboard position and an inboard position. In the case of these containers, the bale arms are relatively accessible above the edge of the containers and are moved from one position above the edge of the container to another position above the edge. Furthermore, the bale arms in their inboard position are not particularly firmly located in that position. Apparatus for moving the bale arms of such containers has been employed. Such apparatus includes a tapered arm or plough which engages the bale arm at the side of the container near one of its ends. On relative movement of the plough across the top of the container, the tapered shape of the plough causes the bale arm to be lifted and moved to its other position. This known approach to moving the bale arm is not appropriate for the sort of containers with which this invention is concerned. The bale arm is normally not accessible for engagement of a plough approaching the bale arm along its length. Furthermore, even if the bale arm were accessible, the movement of the plough relative to the bale arm would not result in the bale arm being firmly located in its inboard position due primarily to the direction of movement of the bale arm, typically downwardly, during the last stage of its path of travel into the inboard position. Statements of invention According to the present invention there is provided apparatus for moving the bale arms of a container from one operating position to another operating position, the apparatus comprising means for locating the container in a predetermined position relative to the apparatus, two bale arm engaging means, each for engaging a respective one of the bale arms, means for moving each said bale arm engaging means along a path of travel which closely corresponds to that of its respective bale arm while said bale arm engaging means remains in engagement with its respective bale arm, thereby ensuring complete movement of the bale arm from one operating position to the other operating position. Accordingly, apparatus in accordance with the present invention provides for positive engagement of each of the bale arms and for moving each bale arm along its path of travel between each operating position by causing the bale arm engaging means to follow a similar path of travel. In this way, completion of the movement of the bale arm engaging means ensures that its respective bale arm also completes its intended travel path. As a result the bale arm which, in many versions of the container of the type of which this invention is concerned, completes its path of travel to an inboard position by undergoing a downward or even reverse direction movement, can be made to complete this movement even against frictional forces which are intended to ensure good positive locking of the bale arm in its inboard position. Preferably, the means for moving the bale arm engaging means includes means for moving said bale arm engaging means in at least two different directions and a controller for effecting said movement in a predetermined manner. In one embodiment of the present invention, said bale arm moving means includes a cam and cam follower arrangement. In another embodiment, the bale arm moving means includes means for moving the bale arm engaging means in two directions, preferably substantially at right angles to each other, by means of guide means arranged along each of said two directions and power sources for effecting said movement along each of said two directions, said power sources being controlled in a predetermined manner to effect the required movement. For instance the power sources may be under the control of a pre-programmed computer. Preferably, apparatus in accordance with the present invention includes means for firmly holding the container in said predetermined position relative to the apparatus. Such holding means are of value to ensure that the container as a whole is not moved by the bale arm moving means rather than just the bale arms relative to the container. This is particularly the case when the bale arms have to be moved against frictional or other forces intended to provide locking engagement of the bale arms in one or other of its operating positions. The present invention also provides a method for moving the bale arms of an open topped container between any two of the operating positions of said bale arms, the method comprising locating the container in a predetermined position relative to apparatus of the invention, causing the bale arm engaging means of said apparatus to engage respective bale arms, and causing the bale arm moving means of said apparatus to effect movement of the bale arms between said operating positions. Brief description of the drawings The accompanying drawings are as follows: Figure 1 is a perspective view of a first container of a type with which the invention is concerned and with the bale arms in one operating position; Figure 2 is a perspective view of the container Figure 1 and with the bale arms in a second operating position; Figure 3 is a perspective view of a second container of the type with which this invention is concerned and with the bale arms in a first operating position; Figure 4 is a perspective view of the container of Figure 3 and with the bale arms in a second operating position; Figure 5 is a perspective view of the container of Figure 3 and with the bale arms in a third operating position; Figure 6 is a top perspective view of part of first apparatus in accordance with the present invention; Figure 7 is an underneath perspective view of the apparatus of Figure 6; Figure 8 is a top plan view of the apparatus of Figure 6; Figure 9 is a perspective view of second apparatus accordance with the present invention. Figure 10 is a side elevation of the apparatus of Figure 9; and Figure 11 shows detail of part of the apparatus of Figure 9. Detailed description of the invention The present invention will now be described, by way of examples only, with reference to the accompanying drawings. Figure 1 shows a typical plastic basket 1 of the type with which this invention is concerned. Basket 1 is open topped and oblong and has sides which taper slightly downwardly from the upper edges of the container to its base 3. The short sides 5 and the long sides 7 of the container are provided with parallel, continuous ridges giving the sides a stepped appearance. Container 1 is provided with two bale arms 9, each running along the upper edge of a respective short side 5 of the container 1. Each end of a bale arm 9 extends into an adjacent long side wall 7 of the container, terminating in an outwardly extending pivot portion located in a hole 11 extending through the wall 7 of the container. As shown in Figure 1 , the bale arms are in their outboard position allowing stacking of a plurality of containers in a nested configuration. Figure 2 of the accompanying drawings shows the same basket 1 but with the bale arms 9 in another, inboard position. To reach this position, the bale arms are moved along an arcuate path inwardly towards the centre of container 1 about the pivot position provided by holes 11. It will be appreciated that, with the bale arms in the position shown in Figure 2, the containers can be stacked one on top of the other with one container resting on the bale arms of the next lower container. The containers have bale arm locating recesses on their undersides. The containers would be stacked in this way when they are loaded with products for delivery to a retailer. Figure 3 of the accompanying drawings shows a second container of the type with which the invention is concerned. In this case, the plastic container 13 is broadly similar to that shown in Figure 1 and includes two bale arms 15. As shown in Figure 3, the bale arms are in their outboard positions. In this case there are two inboard positions which are provided by the ends 17 of the bale arms being located in elongate curved slots 19. The inner wall of container 13 is provided with guides 21 which allow the bale arms to achieve their second inboard position. Figure 4 of the accompanying drawings shows the container 13 with the bale arms 15 located in a first inboard position. In this position the bale arms are at the level of the upper edge of the container 13, which position is appropriate for the stacking of containers fully loaded with goods. It will be appreciated that, in moving from their outboard positions to this inboard position, the bale arms have followed a path similar to the Figure 1 container with the ends 17 of the bale arms remaining in their original position within slots 19. The inner portion 23 near each end 17 of each bale arm 15 engages, at the end of its movement to the inboard position shown in Figure 4, between the outer skin of long wall 25 of container 13 and the inner skin of this wall. The inner skin is broken to provide guide slots 27 and the position of engagement is indicated at 29 at the upper edge of guide slots 27 remote from short wall 31 of container 13. The distance between the inner and outer skins of walls 25 is slightly less than the diameter of the bale arm so that the bale arm is a force fit into this gap over the last portion of its movement from the outboard to the inboard position. In this way, there is a positive locking engagement of the bale arm in the inboard position. Equally, significant force has to be applied to the bale arm to cause it to complete its path of travel to the inboard position. Referring to Figure 5 of the accompanying drawings, the container 13 of Figure 3 is shown with its bale arms 15 in their second inboard positions. In this case, the bale arms 15 have been moved not only inwardly from their Figure 3 positions but also downwardly within the container 13. This second inboard position is suitable for the situation where the containers are partially loaded, up to a level below that of the bale arms in Figure 5. Accordingly the containers can then be stacked one on top of the other with the bale arms in this second inboard position thereby saving space as compared with the stacking of containers having the bale arms in their Figure 4 positions. It can be seen that, with the bale arms in their second inboard positions, the ends 17 of the bale arms are located at a lower position within slots 19 and that the curved portions 23 of the bale arms, near the ends 17, extend into the guide slots 27. Again the skins of the side walls 13, and/or the width of the guide slots 27 can be such that there is frictional resistance to the bale arms reaching their second inboard positions, thereby ensuring that the bale arms remain positively engaged in these positions. Referring to Figure 6 to 8 of the accompanying drawings, there is illustrated part of apparatus forming a first embodiment of the present invention. The apparatus includes a conveyor 30 having conveyor tracks 32 and side guides 34, the conveyor being for delivering a plastic container to the location where the bale arms are to be moved from an outboard position to an inboard position or vice versa. Associated with the conveyor is a stop member movable between raised and lowered positions and operated to stop the movement of the basket along the conveyor when the basket reaches the station where the bale arms are to be moved. Located above this station is the assembly illustrated in Figures 6 to 8. The assembly includes side support rails 31 between which extend central cylinder support plates 33. Mounted on the underneath of each support plate 33 is a cylinder block 35, the arrangement being such that block 35 is pivotally connected to the underside of a respective plate 33 by means of a pair of ball link connectors 37 having spacer bosses 39. Extending from each cylinder block 35 are piston and guide rods 41. These in turn are connected to a pusher plate 43 which extends transversely to guide rails 31. Each pusher plate 43 is of generally elongate rectangular shape and has downwardly depending end portions 45. Each end portion 45 includes a stepped lower part, providing a thin flanged lower pusher finger 47. Pusher plate 43 is provided at each outer edge with a cam follower 49. Each cam follower 49 is located within the cam slot 51 of a cam profile plate 53. Each cam profile plate 53 is in turn connected to a respective guide rail 31 via a spacer boss 55. As a result of the above described arrangement, there are provided two pusher plates 43 which are mounted for movement, effected by extension and retraction of the pistons from cylinder block 35, along a path dictated by the shape of cam slot 51. A container, such as container 1 of Figure 1 , is positioned below the above described assembly which is then lowered to a position where pusher fingers 47 lie just outside bale arms 9 in their outboard positions. The assembly is also provided with a pair of compression cylinders 57 depending downwardly from the lower surfaces of support plates 33 and adjacent the inner surfaces of guide rails 31. These cylinders may be operated to cause plungers to extend downwardly therefrom to engage the upper edges of long wall 7 of container 1. In this way, the container may be held securely in position on the conveyor. To further ensure that the container is in the correct position, the conveyor may be provided with lateral guide members which provide a tapered mouth portion ensuring that the container is centred on the conveyer as it moves under the above described assembly. The provision of the conveyor stop member, the conveyor guides and the compression cylinders 57 with their associated plungers ensures that the container is delivered to exactly the right position below the assembly and is maintained firmly in that position during the subsequent operation. Once in position, the cylinders 35 are operated so that pusher plates 43 are moved inwardly towards support plates 33 following the path of travel dictated by cam slots 51. The pusher fingers 47 engage with the bale arms and cause them to follow a corresponding path about their pivot points 11. Accordingly the bale arms follow an arcuate path terminating in a relatively steep downward portion during which the bale arms become frictionally engaged between the skins of walls 7. Since there is continual engagement of the pusher fingers with the bale arms during the whole of the path of travel of the bale arms, it is ensured that the bale arms reach the end of their path of travel as dictated by cam slots 51. Accordingly, the bale arms achieve their desired inboard position without any danger that this movement is incomplete resulting in subsequent damage to the containers or their contained goods. Referring to Figures 9 to 11 of the accompanying drawings, there is illustrated a second embodiment of apparatus in accordance with the present invention. As with the first described embodiment the apparatus would typically include a conveyor 60 having conveyor tracks 62 and side guides 64, a stop member 66 for stopping the movement of a container 61 at the appropriate position and guide rails for ensuring that the container is properly positioned laterally when it is brought to a stop. The apparatus further includes the assembly shown in Figures 9 to 11. A fixed support mast 63 supports slides 65 on which is mounted for vertical movement a carrier 67. Mounted on carrier 67 is a pair of arms 69, each of which extends downwardly from carrier 67 in a direction towards the upper edges of short side walls 71 of container 61. A servo motor 73 is mounted on carrier 67 and may be operated to effect movement of a continuous belt (not shown) running within carrier 67. One of the arms 69 engages the upper run of the drive belt and the other of arms 69 engages the lower run of this belt. In this way, movement of the belt causes the arms 69 to move in opposite directions, either towards each other or away from each other. As best seen in Figures 10 and 11 , each arm 69 has fixed to its lower edge one part 75 of a bale arm gripping jaw 77. Part 75 of gripping jaw 77 is firmly fixed to arm 69. The other part 79 of the gripping jaw 77 is pivotally attached to part 75 by means of support bracket 81, attached to arm 69, and pivot 83. Attached to part 79 of jaw 77, on that side remote from part 75 of jaw 77, is a pivot arm 85 extending to pivot 87. Also attached to pivot 87 is the piston 89 of a piston and cylinder arrangement. The cylinder 91 of this arrangement is pivotally attached at its end remote from piston 89 to the carriage 93 to which arm 69 is also attached. Operation of cylinder 91 causes piston 89 to move from its retracted position shown in Figure 11, in which jaw 77 is open, to its extended position shown in Figure 10 in which jaw 77 is closed. The above described apparatus may also include clamping arms (not shown) to hold down the container 61 in its correct position by engaging on the upper edges of the container. In use the container 61 is brought by means of the conveyor to the position shown in Figures 9 to 11. Vertical movement of carriage 67 is then effected by means of servo motor 95 and horizontal movement of arms 69 is effected by means of servo motor 97 via the drive belt located within carriage 67. Initially the arms 69 are moved, with jaws 77 open, so that the jaws embrace their respective bale arms. The jaws are then closed by operation of cylinders 91 and the vertical and horizontal movements of carriage 67 and arms 69 are then effected so that the jaws follow a predetermined path of movement which closely corresponds to the path of movement of the bale arms in moving to an inboard position. During the whole of this path of movement, the jaws firmly grip the bale arms and ensure that the bale arms are fully carried to the inboard position into which they are locked by frictional engagement with the body of the container 61. It will be appreciated that the apparatus described with reference to Figures 9 to 11 may have associated with it means a plurality of paths of movement to be followed by arms 69. In this way the apparatus may be used to move the bale arms of containers having more than one inboard position along a desired path of travel. Furthermore such apparatus may be controlled so as to accommodate the different paths of movement, as well as shapes and sizes, of different types of containers. The above described apparatus may include one or more sensors for monitoring that the operation is being performed satisfactorily. For instance sensors may be located within the jaw 77 of arms 69 to ensure that the bale arms are correctly positioned within the jaws and that the movement of the bale arms has been completed. It will be appreciated that apparatus such as that described above may be powered by, for instance, electricity or pneumatic power or a combination thereof. Such power sources may include vacuum power.

Claims: CLAIMS 1. Apparatus for moving the bale arms of a container from one operating position to another operating position, the apparatus comprising means for locating the container in a predetermined position relative to the apparatus, two bale arm engaging means, each for engaging a respective one of the bale arms, means for moving each said bale arm engaging means along a path of travel which closely corresponds to that of its respective bale arm while said bale arm engaging means remains in engagement with its respective bale arm, thereby ensuring complete movement of the bale arm from one operating position to the other operating position. 2. Apparatus according to Claim 1 wherein the means for moving the bale arm engaging means includes means for moving said bale arm engaging means in at least two different directions and a controller for effecting said movement in a predetermined manner. 3. Apparatus according to Claim 1 or Claim 2 wherein the bale arm moving means includes a cam and cam follower arrangement. 4. Apparatus according to Claiml or Claim 2 wherein the bale arm moving means includes means for moving the bale arm engaging means in two directions by means of guide means arranged along each of said two directions and power sources for effecting said movement along each of said two directions, said power sources being controlled in a predetermined manner to effect the required movement. 5. Apparatus according to claim 4 wherein said two directions are substantially at right angles to each other. 6. Apparatus according to Claim 4 or Claim 5 wherein the power sources are under the control of a pre-programmed computer. 7. Apparatus according to any of the preceding claims and including means for firmly holding the container in said predetermined position relative to the apparatus. 8. Apparatus according to any of the preceding claims and including a conveyor for delivering the containers to said predetermined position and stop means for stopping the movement of the container when said predetermined position is reached. 9. Apparatus according to any of the preceding claims, said apparatus being adjustably operable to move the bale arms to the container between two selected operating positions in the case where the bale arms to the container are movable between at least three operating positions. 10. A method for moving the bale arms of an open top container between any two of the operating positions of said bale arms, the method comprising locating the container in a predetermined position relative to apparatus as claimed in any of the preceding claims, causing the bale arm engaging means of said apparatus to engage respective bale arms, and causing the bale arm moving means of said apparatus to effect movement of the bale arms between said operating positions.

Inventors: OAKES FRANK, OAKES, FRANK
Applicants: OAKES FRANK, ROTAPAK LTD, OAKES, FRANK, ROTAPAK LIMITED
Application year: 1999
Main classification: B25J11
IPC codes: B65D21