LANE DESCRIPTION

The present invention relates to a device for the automatic stacking of a unit load in a storage lane such as, for example, a lane in an automated warehouse. The present invention relates to a device for the automatic stacking of a unit load in a storage lane equipped with special guide systems of improved effectiveness and utility.

In recent years, the use of automated warehouses structured to allow the automatic stacking of unit loads has increased considerably. Among the various types of automatic warehouses, those commonly referred to as "drive-in" warehouses are particularly in demand. These warehouses are designed to store products with cyclical handling, and use supporting structures combined with special handling and guide systems for the unit loads. Drive-in racks are known to enable a better use of space than other types of racks since, for example, they eliminate the need for retrieval aisles. Warehouses of this type also prove to be extremely productive when many unit loads with the same item code are handled in sequence, for example when using the known LIFO (Last in- First out) operating method.

From the construction point of view, then, drive-in racks comprise a structure of struts and uprights that defines a plurality of storage lanes of variable dimensions depending on the loads to be stacked. In the most modern versions, unit loads are stacked/retrieved on/from these lanes using automatic devices. In practice, these devices stack automatically and in series a plurality of unit loads upon support guides positioned along opposite sides of the storage lane. In detail, stacking begins from one end of a lane, or in any case from the first free position encountered in the lane. The unit load is placed on the device by an operator or by an automatic means. The device maintains the load raised above the support guides until the storage position is reached. At this point, the device lowers the load so that it rests on said guides.

Obviously, these devices also permit the retrieval of unit loads present in the storage lane in a corresponding manner.

One of the main problems encountered with systems of this type is posed by the need to know the position of the device in the lane in order to ensure its correct operation.

European Patent no. EP 0197448 Bl describes an automatic stacker comprising wheels supported by rails; the automatic stacker is equipped with a photoelectric cell directed towards the rail in order to detect the absence of the rail; it is also equipped with a photoelectric cell capable of detecting the presence of a load. In this way the position of the automatic stacker can be accurately determined at the end of the lane and in the presence of a load. This positioning system, in addition to being not very safe is also not very precise, since it does not allow the position of the stacker to be determined at other times. Moreover, the stacker always stops in a sudden, brusque manner, with the consequent risk of uncontrolled movements of the load.

Based on these considerations, there is clearly a need to provide a device for the automatic stacking of unit loads that is more efficient than current devices both in terms of manufacturing and assembly costs and in terms of performance and reliability.

The task of the present invention is therefore to provide a device for the automatic stacking of a unit load that overcomes the problems of known types of devices.

In particular, in the context of this task, an object of the present invention is to provide a device for the automatic stacking of a unit load that makes it possible to determine with precision and continuity the position of the device within the lane.

Another object of the invention is to provide a device that enables the best possible management of movement and stopping operations for the device.

Yet another, but not the last, object of the present invention is to provide a device for the automatic stacking of a unit load that is both highly reliable and easily manufactured at competitive costs.

The present invention therefore relates to a device for the automatic stacking of a unit load, characterised in that it comprises:

a frame provided with a plurality of wheels adapted to allow the translation of said device along a storage lane;

a platform adapted to provide a support surface for said unit load;

means of movement operationally connected to one or more of said wheels to enable said translation of said device;

means of command and control of said means of movement;

means of supplying power associated with said frame and operationally connected to said means of command and control and to said means of movement;

means of position detection adapted to send and receive a positioning signal along a direction parallel to said storage lane, operationally connected to said means of command and control.

In this manner, since the means of position detection act along a direction parallel to said storage lane and can cover the entire length thereof, the device is capable of monitoring with continuity and precision its position within the storage lane. Moreover, thanks to this constant monitoring of position, it is possible to precisely control stopping operations in per-determined positions, adjusting both the speed and the stopping point as required.

Preferably, said means of detection comprise means of sending and receiving a laser adapted to determine the position of said device in said lane. Moreover, advantageously, said means of detection are positioned in a front portion of said device.

According to a particular embodiment of the device object of the present invention, said means of position detection are housed in a casing fitted with a cover, the front part of said cover being provided with an opening.

Preferably, said means of position detection are adapted to send to said means of command and control a first positioning signal corresponding to a first pre-determined position of said device in said lane. In this case, said means of command and control are adapted to send to said means of movement a first slowing signal following reception of said first positioning signal.

A first embodiment of the device subject of the present invention, has it that said means of command and control are adapted to send to said means of movement a second stop signal following the reception of said first positioning signal, after a pre-determined period of time. Alternatively, said means of position detection are adapted to send to said means of command and control a second positioning signal corresponding to a second pre-determined position of said device in said lane. In this case, said means of command and control are adapted to send to said means of movement a second stop signal following the reception of said second positioning signal.

Advantageously, the device subject of the present invention comprises means of supplying power associated with said frame and operationally connected to said means of command and control, to said means of position detection and to said means of movement.

These and other features of the present invention will become more apparent from the following detailed description of an embodiment thereof, which is illustrated by no way of limitation in the accompanying drawings, in which:

Figure 1 shows a perspective view of a possible embodiment of a stacking device according to the invention, illustrated in a first operating position;

Figure 2 shows a perspective view of a possible embodiment of a stacking device according to the invention, illustrated in a second operating position;

Figure 3 shows a perspective view of a possible embodiment of a stacking device according to the invention, illustrated in a third operating position; Figure 4 shows a perspective view of a detail of a stacking device according to the invention;

Figure 5 shows a perspective view of another detail of a stacking device according to the invention.

With reference to the figures, the device 1 according to the invention comprises a frame 2 provided with a plurality of wheels 3 arranged to allow the translation of the device 1 along a storage lane 10, such as a lane in an automated warehouse of the "drive-in" type, having a pair of guides 11 and 12. Advantageously, in order to avoid risks due to the possible failure of the device 1 to stop, the lane 10 is normally also provided with stopping surfaces 13 and 14, constituted for example of plates at right angles to the guides 11 and 12 and integral with them.

It is in any case understood that the device can also be used in other applications, that is in all those cases, for example, where there is a need for automatic stacking in a well-defined lane of a plurality of unit loads.

The device 1 comprises a platform 4 configured to provide a support surface for a unit load, for example a pallet 20. The dimensions of the platform 4, like the dimensions of the entire device 1, can advantageously vary according to the dimensions and type of load that needs to be stacked.

The translation of the device 1 along the guides 1 1 and 12 of the storage lane 10 is achieved by means of first means of movement (not illustrated because they are inside the device 1) that are associated with the frame 2 and at the same time are operationally connected to one of more of said wheels 3. In practice, the first means of movement are assigned to provide the energy needed for movement of the wheels 3, and consequently also of the device 1, along the storage lane 10. These means of movement can expediently be constituted of an electric motor.

In the embodiment of the device 1 according to the invention, illustrated in the figures, the frame 2 has a substantially prismatic configuration with a rectangular layout. In particular, this configuration comprises a front side 6, a rear side 7 and a pair of sides 8 and 9 extending parallel to each other between the front side 6 and the rear side 7.

The device 1 according to the invention also comprises means of command and control of said means of movement. In practice, in the case that the movement is provided by an electric motor, these means of command and control can be expediently constituted of a unit for driving said electric motor adapted to determine its start, speed and stopping.

Moreover, a peculiar feature of the invention is that the device 1 comprises means of position detection 5 adapted to send and receive a positioning signal in a direction parallel to said storage lane 10, operationally connected to said means of command and control.

Thanks to these means of position detection 5, the device 1 is able to know with extreme precision its own position in the lane and can therefore perform the requested operations precisely and reliably. Moreover, as we shall see better below, thanks to the means of command and control, it is possible to regulate with extreme precision the speed and stopping point of the device 1. For example, it is possible to slow the device 1 near the end of the lane 10, thereby avoiding collisions against the stopping surfaces 13 and 14, and possible damage to the device 1 or unwanted and hazardous movements of the unit load 20.

Advantageously, the device 1 according to the invention also comprises means of supplying power associated with said frame 2 and operationally connected to said means of command and control and said means of movement. In practice, said means of supplying power can be constituted, for example, of a battery that powers the electric motor for movement, the means of position detection and the command and control boards.

According to a particularly preferred embodiment of the invention, said means of supplying power comprise a plurality of lithium cells connected in series.

Advantageously, in order to increase battery life and the efficiency and reliability of the entire system, said means of supplying power comprise a control circuit comprising means of equalising the recharge and use of said cells.

One of the problems normally encountered with power supply units constituted of a plurality of lithium cells connected in series is in fact due to possible non-uniformity in the charge status (tension) of each individual cell. In substance, it may occur that, both when recharging and when in use, the tension of one or more cells is lower than the others. The effective duration (i.e. the ability to deliver current) is therefore governed by the weakest element. Instead, in the device according to the invention, the presence of a control circuit comprising means of equalisation makes it possible to always have the same tension in each cell, both during recharging and when in use. In practice, in the presence of different tensions, each cell can be disconnected by means of an appropriate automatic switch and reconnected when its tension level reaches a value corresponding to that of the other cells.

For example, the control circuit may advantageously comprise, for each cell, a digital switch, a voltmeter and a load resistance. In this manner, the effective duration of the battery, as well as the reliability and efficiency of the device 1 are considerably increased.

A much preferred embodiment of the device 1 according to the invention has it that said means of position detection 5 comprise means of sending 51 and receiving 52 a laser adapted to determine the position of the device 1 in said lane 10. In practice, the means of sending a laser 51 send a signal in a direction parallel to the lane 10, which is reflected by an appropriate reference surface, for example the stopping surfaces 13 and 14, and, once it is picked up by the means of receiving 52, said signal makes it possible to determine the distance of the device 1 from said reference surface and, consequently, the position of the device 1 in the lane 10.

Preferably, the means of position detection 5 are positioned in a front portion 6 of said device 1.

According to a preferred embodiment, said means of position detection 5 are housed in a casing 50 fitted with a cover 55. To allow the passage of the laser signal, the front part of said cover 55 is provided with an opening 56 that allows the transmission and reception of the signal by said means of sending 51 and receiving 52 a laser.

Preferably, the means of position detection 5 are adapted to send to said means of command and control a first positioning signal corresponding to a first pre-determined position of said device 1 in said lane 10.

In turn, the means of command and control are adapted to send to said means of movement a primo first slowing signal following reception of said first positioning signal.

In practice, by way of example and with reference to figures 1 to 3, once the device 1 has left the unit load 20 in the desired position in the lane 10, it begins to return to the initial position at the start of the lane 10. While moving, the device 1 is able to monitor its position in the lane 10 with precision and continuity, through the means of position detection.

At a pre-determined distance, for example near the end of the lane 10 (Figure 2), the means of position detection 5 send to the means of command and control a first positioning signal

(proximity signal), as a result of which the speed imparted to the device 1 by the means of movement is gently slowed.

The device 1 (Figure 3) may be stopped automatically a pre-determined period of time after reception of the first positioning signal, this period of time being calculated by the means of command and control based on the speed of the device 1 and the distance it still has to travel before it reaches the pre-determined stopping point. In practice, a pre-determined period of time after reception of said first positioning signal, the means of command and control are adapted to send to said means of movement a second stop signal, causing the device 1 to stop in the desired position.

Alternatively, the means of position detection may send to the means of command and control a second positioning signal corresponding to a second pre-determined position of the device 1 in the lane 10, corresponding in the example in question to the final stop position shown in Figure 3. In turn, the means of command and control send to the means of movement a second stop signal, causing the device 1 to stop in a position at the end of the lane 10 illustrated in Figure 3.

The same approaching, slowing and stopping procedure can obviously be performed at specific points for the retrieval or stacking of the unit load 20, given that the device 1 always knows its position in the lane 10 thanks to the means of position detection 5.

In practice, when the point of retrieval or stacking of the unit load 20 in the lane 10 is known, the device 1 as it approaches this point can be slowed in a first pre-determined position and stopped at the specific point of retrieval or stacking, using the same procedure described above for the position at the end of the lane 10.

The technical solutions adopted for the device according to the invention enable it to fully achieve the pre-set tasks and objects. The device thus conceived is extremely reliable given the continuous position control it possesses. The device also has a configuration that is simple, extremely compact and easily manufactured, which advantageously makes it possible to contain both manufacturing costs and assembly costs.

In practice, the materials used and the dimensions and contingent forms can be any according to requirements and to the state of the art.