1 METHOD MUD LOADING DEVICE FOR LOADING AND UNLOADING CARGO SPACE
The invention relates to a method and loading device for loading and unloading cargo space, in which method: - the cargo space, such as a container or a platform, is limited by an oblong underlayer and walls, and there is a loading opening at its end,
- the loading and the unloading are carried out by moving the cargo units that are to be handled piece by piece between the cargo space and its outer loading space in the desired direction by a transport device that has been pushed inside the cargo space through the loading opening and that is supported onto the underlayer by support wheels, and a manipulator that belongs to it, by which the cargo units are parked in the cargo space or lifted from their places in order to be taken away,
- the cargo units are moved between the cargo space and the loading space so that the cargo space is, at the time of loading, filled from the opposite end to the loading opening and so that it is unloaded in the opposite order, whereby the transport device is correspondingly moved as the handling progresses.
There are several different automatic loading devices known for a trailer. US patent publication 3,727,777 (Hanson) presents a loading device, in which a roller conveyor is pushed inside the trailer, along which conveyor the packages of a set shape are moved inside the cargo space. While the handling progresses, the roller conveyor is moved backwards from underneath the packages. The device according to US publication 5,054,987
(Thornton) can also unload the cargo from the freight space by pushing a wedgelike transfer conveyor underneath the packages and by lifting them on the roller conveyor in order to be moved away. However, both of these devices have the disadvantage that they require the packages to be of a standard shape.
US patent publication 5370492 presents an automatic storage. It can handle single items of a set shape, for example pallets or rolls, and place these into three-dimensionally organised storage places. The loading and unloading of the automatic storage is carried out through one or more input/output storage places. These thereby function as the interfaces of the automatic storage to the outside world.
The cargo space can be arranged into either the drawing car itself, the trailer or a separate container. The loading and unloading of the packages or more generally of the cargo units is normally nowadays carried out by a standard forklift, because the devices described above have not become common. However, forklift loading carries with it a considerable risk of damage to the cargo units.
Specially structured transport vehicles are also known, in which the cargo space includes devices connected to the loading process in order to make the loading faster. It is not possible to use common trucks or containers in connection with these, which is, however, the starting point in relation to this invention.
The cargo units that are to be handled piece by piece are for example pallets, barrels or rolls of paper.
The object of this invention is to achieve a new method and loading device especially to be used in connection with an automatic storage. The characteristic features of the method according to the invention are presented in the adjoining patent claim 1. The characteristic features of the corresponding loading device are presented in patent claim β. The invention can generally be described in such a way that the transfer of the cargo units is divided onto a manipulator that moves on rails in such a way that the parking and carrying are carried out by the manipulator, whereas the actual transfer is
carried out by moving the manipulator that is carrying a cargo unit with the help of the rails from the cargo space to the loading space. Here the automatic storage must be understood in a wide sense. Any kind of mechanised storage place, especially the out-take point of a production line, can be in question.
The other advantages and application forms of the invention are presented later in connection with the application example.
In the following, the invention is presented with reference to the adjoining figures, which present a loading device according to the invention.
Fig 1 shows the loading device in connection with the automatic storage from the side and the cargo space of a trailer as cut,
Fig 2 shows the device in figure 1 seen from the top,
Fig 3 shows the manipulator and the end structure of the rails in detail from the side,
Fig 4 shows the end part of the rail structure and a partial cut of the bogie wheel set of the manipulator
Fig 5 shows the other half of the rail transfer device seen from the direction of the track
Fig 6 shows the machinery in figure 5 from the side
Fig 7 shows a cross-section of the support roller set of the rails
In figure 1, the loading device according to the invention can be seen from the side in its entirety set as a continuation of the automatic storage. In figure , the cargo space 10 is formed by trailer 9, which has been driven onto lifting underlayer 40 due to reasons explained later. The cargo space is generally limited by underlayer 12, walls 13 and possibly ceiling 11. The loading of the oblong cargo space is carried out through loading opening 14, which is essentially driven right next to loading space 15. The conveyor of the automatic
storage is schematically marked by reference number 19 and its transfer place with reference number 16. The need for the above mentioned lifting device 40 of the trailer exists because underlayer 12 needs to be set essentially on the same height as underlayer 17 of the loading space 15 in order to make possible the loading and unloading into cargo space 10, and these must also be kept levelled while the load differs.
The lifting device 40 includes ramp 41 and lifting cylinders 42 in order to lift the support level.
The main parts of the loading device according to the invention are the manipulator 20, the rail structure 30, the transfer device 50 for the rails and the support roller set 60.
In figures 1 and 2, the manipulators are transporting cargo unit 18 to the target place, which has been marked with reference number 18'. The following cargo unit 18 is already waiting at the transfer point 16 of storage conveyor 19. An alternative transfer point has been marked with reference number 16'. This would require a special storage conveyor, which is able to set the pallet onto rails 30 in accordance with the figure.
The manipulator that is later presented more in detail includes rail underlayer 26, turning circle 23, upper frame 24 and gripping devices 21 and 21' as its main parts. A fork and roller arms that are set onto ordinary forklift masts are here presented as the gripping device.
When not loaded, the rail structure is supported by support wheels 43, which have been spring suspended onto it. Due to the loading that is caused by the manipulator, the rails are pushed towards the underlayer everywhere except in the end part 32, in which special support wheel sets have been measured to carry the empty manipulator.
In accordance with figures 1 and 2, the rail structure 30 is driven close to the place 18' that has been chosen for the cargo unit 18 that is to be handled. The end 32' of the rails is 20 - 40 cm from the cargo place that is to be handled, whereby the manipulator that has been driven onto the end structure 32 can lower or lift the pallet that has been set in this place. If the rails happen to stay behind the lowered fork, the rail structure 30 is then pulled towards the inside in order to free the forks. In order to park the cargo units, a sideward movement is also usually needed besides the lifting and lowering movement, which sideward movement is achieved in the manipulator by the side movement bars 22 and 22'.
In figure 3, the manipulator and the end structure of the rails is seen in detail.
The end structures 31 of the rails have as their main support 4 bogies for four rail wheels, in which four rail wheels have been tied so as to be supported by the U-bar 37 and the axles 34. The rail structure is supported from the U-bars with the help of cup springs 38, which are measured so that the rails, when unloaded, still stay off the underlayer but that the weight of the cargo unit pushes the rails against the underlayer.
The rail underlayer of the manipulator is supported with the help of four bogie wheel sets, in which there are rail wheels 25, bogie plates 47 that carry the rail underlayer 26 from the bogie axle 46. The gripping devices 21 and 21' of the manipula- tor are of a standard type, in which fork 28 or roller arm 28' is set to be supported by the lifting device in the forklift mast 27 and correspondingly 27'. Both forklift masts 27 and 27' are still fixed onto side movement device 22 and correspondingly 22', effected by a slide rail, which devices are fixed onto upper frame 24. This can turn through turning circle 23
in relation to rail underlayer 26 and move the cargo unit that it is carrying from one side to the other.
The transfer of manipulator 20 and also of the rail structure 30 itself is done through roller chain 55, which is essentially arranged on the whole length of the rail structure and is attached to its both ends. In the manipulator this roller chain 55 moves over pulling wheel 66, guided by the guide wheels 67, which makes possible the moving of the manipulator by turning the pulling wheel 66.
The figure does not show the engines or the operating devices of the manipulator.
Figure 4 shows the detailed structure of the bogie wheel set of the end part 31 of the rails as also of the bogie wheel of the manipulator. The right side of the I-bar is cut from the front of the axle and its left side is cut from behind it. Support wheel 36 is set in pair on both sides of the I-bar 32 of the rail structure 30, connected with axle 34, which is tied onto the other axle of the bogie structure with a U-bar 37. The axles are tied onto these U-bars with the help of U-attachment 39. U-bars 37 support the I-bar and thereby the whole end part 31 of the rails with the help of bolts 35 and plate springs 38 that are welded onto the I-bars. It is possible to see from figure 4 that plate springs 38 are pushed together when the load becomes greater, until I-bar 31 corresponds to underlayer 12 from its lower surface.
The bogie structure of the manipulator includes bogie axle 46 that is set onto the rail underlayer 26, which axle supports the middle bushing 48. At the same time, this middle bushing connects bogie plates 47, 47', onto which both rail wheels 25 are set, supported by axle 49.
Figures 5 and 6 show the structure of the transfer devices of the rails in a simplified manner. Besides the support wheels 43 that belong to the rails, the rails are supported with a lower and an upper support wheel 51 and 56. In the rail structure, both halves have their own roller chain pulls, in which roller chain 55 is set into groove 59, in which it otherwise rests, but at the place of the manipulator and the transfer device it is lead from the groove up to the pulling wheel set 53. This includes middle pulling wheel 57, which is used through axle 52 from engine transmission 54. It uses symmetrical pulling wheel sets on both sides. In figure 6, the pulling wheel set 53 of the transfer device of the rails is similar to that presented in connection with the manipulator. Roller chain 55 goes over pulling wheel 57 on both sides, being led by the bending wheels 58. Referring to figures 1 and 2, the structure of the support wheel set 60 can be seen in detail in the cross-section of figure 7. So that manipulator 20 can be accurately parked in relation to the transfer point 16 of conveyor 19 of the automatic storage, the rail structure 30 is supported from the I-bars 32 with support wheels 62 and side wheels 64 that are positioned accurately. These support wheels are arranged onto support frame 65 that is positioned into channel 63. With the help of this, the position of the manipulator is better know in the vicinity of the storage place irrespective of the load of the manipulator.
In the following, the loading sequence is presented in its entirety. The cargo units are here pallets.
The car (or trailer) is driven in front of the loading gate with the doors of the cargo space open. The lifting table presented above is situated at the car loading place. It must be possible to lift at least the rear wheels of the car. Most profitably, also the front wheels are lifted as described above. After this, the height and the declivity of the cargo
8 space are measured, which measures are regulated with the help of the lifting table within the set limits of tolerance.
Then the measurements and position of the cargo space in relation to the middle line of the rails are measured. The measuring is carried out e.g. by a laser scanner. A slight directional and positional error of the cargo space can be compensated by the sideward movement of the manipulator.
The actual loading sequence starts by driving the rails of the manipulator so deep inside the cargo space that a space equal to a pallet is left between the rails and the rear wall of the cargo space. The upper frame is turned so that the forks are towards the shelf of the storage, i.e. the transfer point 16. The forks are driven underneath the pallet and the pallet is lifted up from the underlayer of the transfer place. The manipulator is retracted and the upper frame is turned the other way, whereby the forks and the pallet that is carried by them are towards the car. The manipulator is driven onto the rails and the pallet is lowered in the side direction onto the floor that functions as the underlayer of the cargo space, onto the desired place. During the transfer, the pallet is moved, if necessary, sideways so that the load does not touch the wall. If the rails and the forks are not at the same point, the manipulator can retract directly after having lowered the cargo. Otherwise the rails are pulled backwards so much that the forks come out altogether and can be lifted up. When using roller arms, the problem never even presents itself. As the loading progresses, the rails are pulled backwards while the manipulator is in the turning area, on the support wheel set. When the cargo space is full, the rails are completely pulled out of the cargo space, whereby the car can take off.
The unloading of the cargo naturally happens in the opposite order. However, it is necessary to measure the cargo space as
the unloading progresses and to reset the position of the car according to the measurements.