Method and device for unloading of a container with an aperture

Background to the invention

The present invention relates to a method for unloading of a container with an aperture, which method comprises presenting and locking of the container to a retaining means with the aperture in the container against a means which closes the aperture and with the lower edge of the aperture level or substantially level with a substrate for the retaining means, moving of the retaining means with the container locked to it and the means which closes the aperture in the container from a presenting and locking position to a preparatory position for unloading of the container with the container's aperture directed substantially downwards and goods in the container resting upon the means which closes the aperture, and moving of the means which closes the container's aperture, relative to the retaining means with the container locked to it, for progressive exposure of the container's aperture and the goods in the container resting upon the means which closes the aperture, so that the exposed goods fall down onto a device for carrying the goods away.

The present invention relates also to a device for unloading of a container with an aperture, which device comprises a retaining means to which the container is marshalled and locked with the aperture in the container against a means which closes the aperture and with the lower edge of the aperture level or substantially level with a substrate for the retaining means, at least one pivot means which pivots the retaining means with the container locked to it and the means which closes the aperture in the container, from the presenting and locking position to a preparatory position for unloading of the container with the container's aperture directed substantially downwards and goods in the container resting upon the means which closes the aperture, and at least one means for moving the means which closes the container's aperture, relative to the retaining means with the container locked to it, for progressive exposure of the container's aperture and the goods in the container so that the exposed goods fall down onto a device for carrying the goods away. Such unloading devices are known in various versions. Thus, for example, US 3651967 refers to and describes a device for unloading of a container. The device comprises a tiltable cradle on which the container is placed. When the container is in position on the cradle, the latter cooperates with a gate which closes the open side of the container. The container, cradle and gate are moved upwards from an upright position to an oblique position. In one version, the gate is thereafter moved downwards relative to the cradle and the container by a rack and pinion mechanism. The open side of the container is thus progressively exposed so that goods can slide down to a conveyor via a passage in the gate.

The known device is thus based on the height resulting from its being placed in the oblique position. Space is thus provided for the gate to move downwards.

Brief description of the invention The object of the present invention is to improve and simplify the construction and functioning of unloading devices of the kind indicated above so that, for example, no wear and tear is suffered by the goods handled and the goods are at all times handled in a controlled manner, and so that the overall height of the unloading device is as small as possible. This object is achieved according to the invention by the fact that during the movement of the retaining means with container locked to it and the means which closes the aperture in the container, from the presenting and locking position to the preparatory position for unloading of the container, the retaining means with the container and the means which closes the container are tilted in such a way that the lower edge of the aperture in the container remains level or substantially level with the substrate for the retaining means, and by the fact that during the movement of the means which closes the container's aperture, relative to the retaining means with container locked to it, the aperture of the container and the goods in the container are progressively exposed, while at the same time the retaining means with container locked to it is caused to remain in the preparatory position for unloading of the container with the lower edge of the container aperture level or substantially level with the substrate for the retaining means.

The object of the present invention is also achieved by the fact that the pivot means is so configured that during the movement of the retaining means with container locked to it and the means which closes the container's aperture from the presenting and locking position to the preparatory position for unloading of the container, it tilts the retaining means with the container and the means which closes the container in such a way that the lower edge of the aperture in the container remains level or substantially level with the substrate for the retaining means, and by the fact that the means which closes the container's aperture is so configured that during its movement relative to the retaining means with container locked to it, it allows progressive exposure of the container's aperture and the goods in the container while at the same time the retaining means with container locked to it remains in the preparatory position for unloading of the container with the lower edge of the container aperture level or substantially level with the substrate for the retaining means.

Other objects and advantages of the invention will be apparent to one skilled in the art who examines the attached drawings and the detailed description of preferred embodiments set out below.

Brief description of the drawings

Figs. 1 and 2 respectively are a view in perspective and a view from the side of an unloading device according to the present invention in an initial position when a carriage with a container has been run up to the device. Fig. 3 is a view in perspective showing the device when the transfer of the container to presenting and locking position on a retaining means has begun and a door to the container has begun to open.

Fig. 4 is a view in perspective showing the transfer of the container proceeding and the door to it fully open. Fig. 5 is a side view illustrating the device with the container in presenting and locking position on a retaining means.

Fig. 6 is a side view corresponding to Fig. 5 of the device with the container in preparatory position for unloading.

Fig. 7 is a side view corresponding to Figs. 5 and 6 of the device with the container in a first unloading position.

Fig. 8 is a side view corresponding to Figs. 5-7 of the device with the container in a second unloading position.

Fig. 9 is a side view corresponding to Figs. 5-8 of the device with the container in a third unloading position. Figs. 10 and 11 respectively are a side view corresponding to Figs. 5-9 and a view in perspective of the device with the container in a fourth unloading position.

Fig. 12 depicts in a perspective view the device with the container when the retaining means has returned to the initial position and the movement of the container back to the carriage has begun. Fig. 13 depicts in a perspective view corresponding to Fig. 12 the device when the container is almost back on the carriage and the closing of the door to the container has begun.

Lastly, Fig. 14 is a view in perspective corresponding to Figs. 12 and 13 which illustrates the device with the container back on the carriage and the door to it fully closed.

Detailed description of preferred embodiments of the invention

The drawings illustrate a device according to the present invention for unloading of a container 1. The container 1 is with advantage of the kind used on board aircraft for carrying flight passengers' baggage. The container 1 has in this case a side aperture. The side aperture is normally kept closed by, for example, a door, but the door is opened when the container 1 is to be emptied by means of the device according to the present invention.

Figs. 1 and 2 depict the device according to the invention before the container 1 is presented in it. The container 1 in Figs. 1 and 2 is still on a carriage 2 on which it is conveyed to the unloading device. The unloading device comprises a retaining means 3. The retaining means 3 is adjustable in the height direction to adapt it to a load surface 4 for the container 1 on the carriage 2. When the container 1 has been opened (Figs. 3 and 4), it is presented on the retaining means 3 by being moved across from the carriage 2 and locked in a suitable manner to the retaining means with the side aperture in the container against a means 5 which closes the aperture and with the lower edge of the aperture level or substantially level with a substrate 6 for the retaining means (position A in Fig. 5). To this end, the retaining means 3 has at least one locking means or locking portion which cooperates with at least one locking means or locking portion on the container 1. These locking means or locking portions may each have a shape appropriate to the purpose. The means 5 which closes the aperture in the container 1 is for example connected to the retaining means 3. The retaining means 3 and the means 5 which closes the aperture are for example also disposed substantially perpendicular to one another irrespective of whether they are connected to one another or merely placed near one to another. This is illustrated in the drawings, in which the retaining means 3 in Figs. 1-5 is thus disposed substantially horizontally and the means 5 which closes the aperture in the container 1 is disposed substantially vertically. The retaining means 3 comprises in the version depicted an unloading table 7 on which the container 1 is placed and locked. The unloading table 7 may with advantage have on its surface 8 which receives the container 1 balls 9 or other types of sliding means on which the container can be moved to the presenting and locking position A.

In addition to the retaining means 3 and the means 5 which closes the aperture in the container 1 , the device according to the present invention also comprises at least one pivot means which moves the retaining means with container locked to it and the means which closes the aperture in the container, from the presenting and locking position A to a preparatory position (position B in Fig. 6) for unloading of the container. The aperture of the container 1 in this preparatory position B is directed substantially downwards and goods in the container rest upon the means 5 which closes the aperture. The pivot means may be of any form and construction appropriate for the purpose and is therefore not described in more detail here. The pivot means is nevertheless so configured that during the movement of the retaining means 3 with container 1 locked to it and the means 5 which closes the aperture, from the presenting and locking position A to the preparatory position B for unloading of the container, it tilts the retaining means with the container and the means which closes the container in such a way that the lower edge of the aperture in the container remains level or substantially level with the substrate 6 for the retaining means, i.e. tilting takes place, for example, about a pivot axis c which runs coaxially or parallel with the lower edge of the

aperture in the container. In the version depicted in the drawings, this entails the pivot means being so configured that tilting from the presenting and locking position A to the preparatory position B for unloading of the container takes place, for example, about a pivot axis c which runs coaxially or parallel with a connection line or notional intersection line between the retaining means 3 and the means 5 which closes the aperture. The position B according to Fig. 6 is thus reached. In the version of the device according to the present invention which is depicted in the drawings, the pivot means effects an approximately 45" tilt of the retaining means 3 with container 1 locked to it and the means 5 which closes the aperture, but pivoting within the range of about 30 ^° to 90 ^° , e.g. at least about 40 ^° to 45 ^° and particularly about 75 ^° , makes for satisfactory unloading of the container. The pivot means comprises with advantage a motor (not depicted) which via a suitable transmission (not depicted) effects tilting of the retaining means 3 with container 1 locked to it and the means 5 which closes the aperture.

Tilting is thus effected in all situations in such a way that neither the retaining means 3 with container 1 locked to it nor the means 5 which closes the container's aperture move in the height direction beyond the change in position involved in the tilting.

Finally, the device according to the present invention also comprises at least one means which is intended, when the container is in the preparatory position B for its unloading, to move the means 5 which closes the aperture of the container 1 , relative to the retaining means 3 with container locked to it, for progressive exposure of the container's aperture and the goods in the container so that the exposed goods fall down onto a device 10 for carrying the goods away. This progressive unloading of the container 1 is illustrated in Figs. 7-11 , which show the means 5 which closes the aperture at the beginning of, during and at the end of an unloading process and the movement to which said means is thereby subjected.

Figs. 7-11 also show the means 5 which closes the container aperture so configured that during its said movement relative to the retaining means 3 with container 1 locked to it, it allows progressive exposure of the container's aperture and the goods in the container without the retaining means with container locked to it moving in the height direction from the preparatory position B for unloading of the container, i.e. the means which closes the aperture is so configured that the overall height of the device according to the invention is not affected by the movement of the means which closes the aperture. The retaining means 3 with container 1 locked to it thus remains in the preparatory position B for unloading of the container without movement in the height direction, i.e. with the lower edge of the container aperture level or substantially level with the substrate 6 for the retaining means, while at the same time the means 5 which closes the container aperture moves. The means 5 which closes the aperture may be actually configured in various different ways, e.g. it may move

sideways relative to the retaining means 3 with container 1 locked to it but at the same time achieve gentle unloading of the container without the goods therein being damaged when they fall down onto the device 10 for carrying the goods away, or the means which closes the container's aperture according to the invention may alternatively be configured to move downwards relative to the retaining means with container locked to it, for progressive exposure of the container's aperture, beginning from the top at the portion of the aperture situated furthest from the retaining means.

The means 5 which closes the aperture of the container 1 may according to an advantageous version comprise an endless conveyor belt (not depicted) which may for example be powered to feed the goods in the container which rest upon it towards the exposed portion of the container aperture.

In the preferred version depicted in the drawings, the means 5 which closes the aperture of the container 1 comprises instead a quadrilateral frame 11 delineating the extent of said means, and a closing element 12 supported for movement in the frame. The closing element 12 preferably takes the form of a fabric 13 folded double in the frame (see particularly Fig. 2). One end 13a of the fabric 13 is attached immovably on the upper side (the surface 8) of the retaining means 3 at the lower edge 11a of the frame 11. The other end 13b of the fabric 13 is attached movably on the underside 3b of the retaining means 3 (see Figs. 7-10). The closing element 12 comprises in addition a cylinder 14 which is supported for movement in the frame 11 (the side portions 11c and 11d of the frame) and about which the fabric 13 is folded. The fabric 13 thus forms an inner strand 13c extending upwards from its immovably attached end 13a, runs round the cylinder 14 and forms an outer strand 13d running downwards which continues down and in under the underside 3b of the retaining means 3. During exposure of the aperture of the container 1 , the fabric 13 is gathered on the underside 3b of the retaining means 3 and is, for example, wound up about a spindle or is drawn along the retaining means, whereupon the cylinder 14 supported in the frame 11 is drawn downwards in the frame by the fabric. When the means 5 which closes the container aperture returns, the cylinder 14 supported in the frame is activated and caused to move upwards, whereupon the fabric on the underside 3b of the retaining means 3 (of the unloading table 7) is drawn out, e.g. it is unwound from the spindle or drawn back along the retaining means, until the cylinder reaches the upper edge 11 b of the frame 11. The winding up or drawing of the fabric 13 on/along the underside 3b of the retaining means 3 and the movement of the cylinder 14 are effected by, for example, motors (not depicted) which are connected via suitable transmissions (not depicted) to the fabric and the cylinder respectively. An example of a conceivable alternative to the above arrangement is for the endless conveyor belt or the fabric 13 to be caused to move in one direction or the other along the substrate 6 for the retaining means 3 instead of in under the retaining means.

To facilitate the feeding of the goods out from the container 1 , the device according to the invention comprises in addition at least one feedout means which can be presented at at least one of the sides of the exposed portion of the container's aperture and is configured to help to feed towards the exposed portion of the container aperture the goods in the container 1 which rest upon the means 5 which closes the container aperture and/or are wedged firmly inside the container, particularly internally at the sides of the container. In the version depicted, this feedout means comprises driving rollers 15 and 16 which at least partly delineate the sides of the exposed portion of the container aperture. The driving rollers 15, 16 thus help by rotation to feed towards the exposed portion of the container aperture the goods in the container 1 which rest upon the means 5 which closes the container aperture and/or are wedged firmly inside the container. The driving rollers 15, 16 are movable from an inactive position at the side or in front of the container aperture (at the side of or behind the fabric 13) according to Figs. 1 , 3 and 4 to the position depicted in the drawings which at least partly delineates the sides of the exposed portion of the container aperture (see for example Fig. 11 ), in order to feed towards the exposed portion of the container aperture the goods in the container 1 which rest upon the means 5 which closes the container aperture and/or are wedged firmly inside the container. Movement from inactive to active position takes place, for example, when the exposed portion of the container aperture amounts to about 350 mm. The driving rollers 15, 16 are further configured for movement, together with the means 5 which closes the aperture in the container 1 , relative to the retaining means 3 with container locked to it. Movement is possible both downwards and upwards. To this end, the driving rollers 15, 16 in the version depicted in the drawings are supported for movement on the frame 11 of the means 5 which closes the aperture of the container 1. Support is provided by arms 17 which are movable by sliding on the frame 11 and accompany the upward and downward movements of the cylinder 14. The arms 17 may be arcuate or articulated to facilitate access to the goods inside the container 1 which are close to the container aperture. The driving rollers 15, 16 are powered for rotation in a suitable manner not illustrated in more detail. The driving rollers 15, 16 are powered in such a way that they rotate in opposite directions, seen in the drawings as the right driving roller 15 rotating anticlockwise and the left driving roller 16 rotating clockwise. An alternative to said driving rollers 15, 16 would be to use only one driving roller movable to the respective side of the exposed portion of the container aperture. The driving roller or rollers 15, 16 may also be arranged for rotation through at least 90 ^° on the arms 17 to make it easier in particular to feed out goods in the container 1 which have become trapped at the bottom of the container aperture. To this end, the respective driving rollers 15, 16 should be made of a relatively soft material, e.g. rubber, and have protrusions which can grip the goods.

As an alternative or supplement to the driving rollers 15, 16, it is conceivable that the retaining means 3 takes the form not of an unloading table with, for example, balls or other types of sliding means, but one or more conveyor belts or the like for moving the container 1 to the presenting and locking position A. For example, the retaining means 3 according to the invention may in addition comprise at least two conveyor belts which may, before and/or during the movement of the means 5 which closes the aperture of the container 1 , relative to the retaining means with container locked to it, be tilted obliquely from the preparatory position B for unloading, so that the container thereon can be tilted to one side or the other in order to release goods which have become trapped inside the container, especially internally at the sides of the container. The retaining means 3 or the thus obliquely tiltable conveyor belts may possibly also have shaking means for shaking the container 1 so that goods trapped inside the container can be freed more quickly and more easily. When the goods have been freed and fed out, the obliquely tiltable conveyor belts are moved back to the preparatory position B for unloading. As another alternative or supplement to said driving rollers 15, 16 and/or to the possibility of tilting the container 1 by means of obliquely tiltable conveyor belts to make it easier to feed out the goods in the container, the device according to the invention may comprise at least one feedout means which may be presented at the lower edge of the exposed portion of the container aperture. This feedout means may for example comprise at least one driving roller which is adapted to at least partly delineating the lower edge of the exposed portion of the container aperture and which by rotation thus helps to feed towards the exposed portion of the container aperture the goods in the container 1 which rest upon the means 5 which closes the container aperture and/or are wedged firmly inside the container. In the version depicted in the drawings, the driving rollers may be disposed up to adjacent to the closing element 12 which is supported for movement in the frame 11 of the means 5 which closes the aperture of the container 1. The driving roller may for example be trilateral in order more easily to be able to extricate goods which have become trapped or wedged firmly at the lower edge of the exposed portion of the container aperture, and be powered for rotation in a suitable manner. Upon exposure of the container aperture, the driving roller initially places itself in such a way that one side of it is in the same plane as the inner strand 13c of the fabric 13. When the driving roller comes into the exposed portion of the container aperture, it begins to rotate.

To achieve as smooth a transfer as possible of the goods from the container and the means 5 which closes the aperture of the container 1 to the device 10 for carrying the goods away, the means which closes the container's aperture and/or the device for carrying the goods away from the container according to the invention are/is adapted and/or configured in such a way that they maintain a given constant distance from one another during the

movement of the means which closes the container's aperture, relative to the retaining means with container locked to it, for progressive exposure of the container's aperture. To this end, as may be seen in the drawings, the device 10 for carrying the goods away from the container 1 is associated, in the version depicted, with the means 5 which closes the container's aperture (at d in Figs. 7-10), and accompanies it when it moves relative to the retaining means 3 with container locked to it. To carry the goods away from the container 1 , the device 10 may also be connected to the means 5 which closes the container's aperture. Accordingly, this association with or connection to the means 5 which closes the container's aperture is at the portion 5a thereof (of the fabric 13) which is situated (momentarily) closest to the exposed portion of the container's aperture, so that goods which fall out through the container aperture do so directly onto said device 10 for carrying the goods away without being damaged. In the version depicted in the drawings, the device 10 for carrying the goods away from the container 1 is adapted and/or configured to perform a substantially arcuate pivoting movement when it accompanies the means 5 which closes the container's aperture during the movement of said means 5 relative to the retaining means 3 with container locked to it, and the means which closes the container aperture is supported, via the retaining means, for both sliding and pivoting on the substrate for the retaining means in order to maintain said given constant distance from said device for carrying the goods away from the container. The last-named is effected in a suitable manner by means of the rails 18 depicted in the drawings, which are mounted on or form part of the substrate 6 for the retaining means 3 and on which the retaining means and the means 5 which closes the container aperture are movable by sliding via brackets 19 in which said retaining means and said means which closes the container aperture are supported for pivoting. In the version depicted, at least the brackets 19 also form part of said pivot means. The device 10 for carrying the goods away from the container 1 comprises, for example, at least one endless conveyor belt 20. For the conveyor belt 20 to be able to accompany the means 5 which closes the aperture of the container 1 during the movement of said means 5 relative to the retaining means 3 with container locked to it, and to perform said arcuate pivoting movement in such a way that the given constant distance from the means which closes the container aperture is maintained when said means 5 is slid and pivoted, in the version depicted said conveyor belt is supported for sliding, at the end situated nearest to the retaining means with container locked to it and the means which closes the container aperture, in posts 21 each disposed on their respective side of the conveyor belt and supported for pivoting in brackets 22 in the substrate 6. The end of the conveyor belt 20 situated furthest from the retaining means 3 with container 1 locked to it and the means 5 which closes the container aperture is supported for pivoting in brackets 23 in the substrate 6. According to the invention, the conveyor belt 20 may have stop means 24 which prevent

goods from sliding downwards along the conveyor belt 20 in cases where the conveyor belt runs substantially obliquely downwards from the means 5 which closes the aperture in the container 1 to at least one second conveyor belt 25, 26 which runs substantially horizontally for further conveying of the goods from the container. These stop means 24 run substantially transversely to the direction of the conveyor belt 20. Similarly, the conveyor belt 20 may have drag means 27 which, in cases where the conveyor belt runs slightly downwards or, as in the drawings, substantially horizontally from the means 5 which closes the aperture in the container 1 to at least one second conveyor belt 25, 26 which runs substantially horizontally for further conveying of the goods from the container, draw the goods with them from the container to said second conveyor belt which runs horizontally. Like the stop means 24, the drag means 27 run substantially transversely to the direction of the conveyor belt 20. Both the stop means 24 and the drag means 27 may in an advantageous version comprise flaps (not depicted) facing respectively in a longitudinal direction on the conveyor belt 20. In the version depicted in the drawings, both the stop means 24 and the drag means 27 take the form of ribs 28 running transversely to the direction of the conveyor belt 20.

According to an alternative version, the conveyor belt 20 may be bipartite and comprise an upper first half closer to the retaining means 3 and a lower second half closer to the horizontally running conveyor belts 25, 26. During operation, the upper half slides on top of the lower half of the conveyor belt 20, which may itself alternatively be fastened to the conveyor belt 25 with the object of maintaining a constant distance from, or overlap relative to, the latter. The upper half of the conveyor belt 20 may itself be at least partly capable of being introduced into the container 1. The upper half of the conveyor belt 20 may thus comprise, for example, three conveyor belts running in parallel, with the possibility of at least the middle conveyor belt being introduced into the container 1 to make it easier to feed goods out from the container and particularly to prevent goods from being trapped at the bottom of the container aperture.

The conveyor belt 20, which is run at a velocity of preferably about 5 m/min, ends about 200 mm above the downstream conveyor belt 25, which moves substantially perpendicular to the conveyor belt 20. A final portion of the conveyor belt 25 runs obliquely upwards at an angle of inclination of about 40° relative to the substrate 6 and ends about 200 mm above a further conveyor belt 26. The belt velocity is about 20 m/min on the conveyor belt 25 and about 25-30 m/min on the conveyor belt 26. The conveyor belt 26 also has ball rollers 29 which guide the goods in so that they are centred towards the middle.

The conveying of the goods, the jumps between the conveyor belts 20, 25 and 26 and the increased velocity of the conveyor belts separate the goods and move them in towards the centre of the respective belts.

After completion of unloading of the container 1 , the retaining means 3 with container locked to it returns to the presenting and locking position A, after which the container moves back to the carriage 2 while at the same time the door to it closes. This is illustrated in Figs. 12-14. In addition, the driving rollers 15, 16 return to inactive position and the means 5 which closes the container aperture also assumes an initial position, although this latter is not depicted in the drawings. The device according to the present invention will then be ready to receive another container for unloading.

It will be obvious to one skilled in the art that in addition to what is indicated by the above description the method and the device according to the present invention can be modified and altered within the scope of the claims set out below without departing from the idea and object of the invention. Thus the various parts of the device according to the invention may of course vary in construction and positioning. For example, the retaining means 3 need not comprise an unloading table 7 of the configuration depicted for presenting and locking a container 1. Pivoting, lifting and driving means may likewise take many different forms, as also may the actual means 5 which closes the container's aperture, any associated driving rollers 15, 16, moving and driving devices for them etc. It should also be noted that the device according to the present invention is usable for unloading of many different kinds of containers, even for example soft containers in cassettes placed on carriages.