The present invention concerns an apparatus for handling layers of palletised goods and of the kind indicated in the preamble of claim 1. Background of the Invention

In order to provide effective and cheap distribution of goods, many goods are distributed on pallets, by way of example on so-called EU pallets (800 x 1200 mm). Yet a continuing increasing need has appeared for also dispatching orders comprising smaller consignments of goods in a correspondingly efficient way. Statistically it has appeared that many orders for small shops actually consist of consignments of goods often consisting of very few layers or maybe just a single layer of palletised goods.

WO 2000/64790 Al and WO 2008/019691 Al disclose apparatuses for handling layers of palletised goods, the apparatuses comprising a vertically displaceable lift head with a horizontal suction face which in size is adapted to a pallet and consisting of a large number of downwards open suction chambers. The suction face is arranged to be moved downwards against the top side of an upper layer of individually or groupwise packed goods on a pallet, where the suction chambers via individual valves are connected with a source of vacuum incorporated in the lift head, and where the apparatuses are intended for interacting with depalletising systems known per se.

The valves between the suction chambers and the source of vacuum are designed as ball valves with very light thin-walled valve bodies that are enclosed in the suction chamber by means of lateral projections or by means of a retainer net, and which interact with upper round valve openings with spherical valve seats at the bottom if the actual suction chamber is not closed at the bottom by contacting the top side of the goods in an upper pallet layer. Along the outer sides of the suction face, the lift head comprises squeezing means adapted to exert an inwardly pressure at the outer sides of the goods in at least an uppermost pallet layer. In connection with each valve there are arresting means adapted to prevent the valve balls from shutting off the valves, such that it is ensured hereby that the shut-off valves of the suction face can be forcibly opened where there is a contact to the goods in the pallet layer, and can be forcibly opened where there are gaps or openings in the pallet layer. The descriptions of these previous inventions are hereby incorporated in the present application by reference.

In connection with the hitherto common handling of layers of palletised goods, one has primarily worked with rectilinear lifting and moving of pallet layers, i.e. moving pallet layers mutually between positions on mutually perpendicular pallet ways.

Experiments have been made using robot technology for moving palletised layers of goods by means of current suction heads. However, using robots means an entirely different movement pattern which also includes swinging movements of suction heads, putting significantly greater demands on the suction ability in order to hold the relatively heavy and possibly open pallet layer in a secure way during swinging movements where centrifugal force actions occur.

Object of the Invention The invention has the object of indicating a new and improved apparatus of the kind specified in the introduction, that is an apparatus for handling layers of palletised goods which enables achieving greater certainty, by way of example by mechanised layerwise destacking of individual articles from a pallet, that is even if the individual pallet layers include gaps between the articles or include articles that are film-covered in such a way that openings in the pallet layer are formed upwards, and even if there is used a lifting head operated by a robot with occurrence of relatively rapid swinging movements.

Description of the Invention

The apparatus according to the invention is characterised in that the skirt at at least one side of the suction plane is connected with a flexible curtain which is adapted to be moved along the underside of a pallet layer of goods carried by the suction plane and/or the squeezing pads, and be lifted off the next pallet layer or the pallet, such that the curtain is stretched or suspended at the underside of the lifted pallet layer and capable of supporting the latter.

By means of simple measures is hereby achieved a new and significantly improved apparatus for handling pallet layers of mixed goods, making it possible to handle many different types of palletised goods in layers with great certainty, in spite of using robot technology that includes relatively rapid swinging movements of the suction head.

With the object of achieving an efficient and rapidly operating apparatus, in a preferred embodiment according to the invention it is designed such that the skirt interacts with a two-part flexible curtain which at opposing ends of the suction face each are connected with the skirt and adapted to from each their side of the suction face to be moved inwardly along the underside of the lifted pallet layer to a position predominantly at the middle under the suction face.

The apparatus according to the invention is suitably designed such that a transverse end of respective curtain parts are connected with the skirt, that an opposite end of respective curtain parts are connected to a rotating shaft for each their magazine with associated drive motor, that respective curtain parts between the skirt and the magazines run around each their transverse shaft which is adapted to be moved inwardly along the underside of the lifted pallet layer, as the transverse shafts are designed or provided at opposing ends with a toothed rim which is in driving engagement with a stationary toothed rack running along opposite sides of the suction face perpendicularly to the transverse shafts, and that the transverse shafts are drivingly connected with each their drive motor.

With the object of ensuring a secure and stable engagement between toothed rim and toothed rack, the apparatus according to the invention is designed such that the transverse shafts and the associated drive motors are suspended in support holders at opposite sides of a support frame by means of support rollers. The rollers are supported on a preferably complementary support profile of the support frame.

The apparatus according to the invention is suitably further designed such that that the drive motors are constituted by rapid reversible servomotors, possibly with suitable gearing. Description of the Drawing

The invention is explained in more detail in the following with reference to the drawing, on which:

Fig. 1 shows a perspective view of an embodiment of an apparatus with a lift head according to the invention handled by a robot;

Fig. 2 shows a plan view of the apparatus shown in Fig. 1 , as seen from the top;

Fig. 3 shows a plan view of the lift head, as seen from above;

Fig. 4 shows a view, partly in section, of a preferred embodiment of a lift head for an apparatus according to the invention, as seen from the side and shown with an embodiment for a curtain which is inserted under the suction face of the lift head;

Fig. 5 shows a view, partly in section, from the side of the lift head shown in Fig. 4, where a pallet layer of box-shaped goods are carried by the suction face, and where the curtain is inserted under the pallet layer;

Fig. 6 shows a view, partly in section, from the side of the matter shown in Fig. 4, where it is further shown that the pallet layer is clamped and partially supported by a surrounding skirt with internal inflatable squeezing pads;

Fig. 7 shows a plan view corresponding to Fig. 3, as seen from above, where curtain parts are inserted under the pallet layer;

Fig. 8 shows a partly sectional view, as seen from the side, where curtain parts are inserted under the pallet layer;

Fig. 9 shows a detail view, showing a front end of the curtain during insertion under the pallet layer; and

Fig. 10 shows a detail, showing an embodiment of an insertion mechanism for the curtain for an apparatus according to the invention. Detailed Description of Embodiments of the Invention

In a preferred embodiment, the apparatus according to the invention includes a lift head 2 adapted for destacking by layers of articles from a filled pallet that by way of example is taken from a rollerway.

The lift head 2, which is suspended from a common industrial robot 3, interacts with an external vacuum source in the form of a powerful centrifugal blower which via an air distribution chamber and individual ball valves 8 communicate with a large number of downwardly open suction chambers 6 that together constitute a common rectangular suction face 4, which is adapted in size for a standard pallet, by way of example an EU pallet or a UK pallet.

The lift head 2 includes, as with WO 2000/64790 Al and WO 2008/019691 Al mentioned in the introduction, a special vertically adjustable, outer squeezing arrangement which at the outer sides of the suction face comprises a number of inflatable squeezing pads 12 as well as a skirt 10. The squeezing pads 12 are operated by a high pressure blower, by way of example a side duct blower.

The lift head 2 is mounted in a common industrial robot 3, meaning that the movement pattern of the lift head 2 is considerably extended compared with the normal movement pattern where the lift head 2 is suspended from either a stationary or a movable lift hanger. As a novelty, the industrial robot 3 provides relatively rapid swinging movements, meaning that pallet layers suspended under the suction face 4 of the lift head 2 may also be subjected to centrifugal forces, which is a new occurrence.

In order to ensure optimal sucking function of the suction face 4 and also during swinging movements to avoid throwing around with goods from a pallet layer suspended under the suction face 4 in an uncontrolled way, the suction head 2 on the apparatus according to the invention includes a lower curtain 14 which, cf. the preferred embodiment shown in the drawing, consists of two curtain parts 18, 18' that may be moved inwardly from each their side of the suction face 4 in the way described below along the underside of the suction face 4 or preferably along the underside of a pallet layer 15, to a position about the middle under the suction face 4 and the pallet layer 15, respectively.

The curtain 14 and the curtain parts 18, 18', respectively, consist of a thin, flexible curtain of wear-resistant airtight material, for example a thin canvas-covered rubber curtain. A synthetic neoprene-rubber curtain is preferably used, by way of example with an anti- friction coating on the side in contact with the underside of the pallet layer 15 and the suction face 14, respectively.

In other words, the curtain parts 18, 18' have double function, namely to ensure optimal sucking function when operating with pallet layers 15 with goods having a relatively open structure - by way of example film-covered bottle groups - and to counteract dropping of heavy articles - by way of example during relatively rapid swinging movements of the suction head 2.

In connection with Figs. 7-10 it is explained in more detail how the two-part curtain consisting of the curtain parts 18, 18' in practice are moved inwardly from both sides of the suction face 4 along the underside of a pallet layer 15 to a position about the middle under the pallet layer 15. By arrows 17, 17' it is indicated that Figs. 7-10 show a situation where respective curtain parts 18, 18' are on their way inwardly towards the end position about the middle under the pallet layer 15, at which there will be a narrow transverse open slot of about 20 mm which will not be covered by the curtain parts 18, 18'.

When the suction face 4 of the suction head 2 is moved downwardly for abutting upon a pallet layer 15 of by way of example box-shaped articles as shown, the curtain parts 18, 18' will be moved right up to respective sides of the suction face 4 and be entirely rolled up on each their transverse shaft 22, 22' in each their magazine 24, 24' by means of the servomotors 26, 26'.

Subsequently, the curtain parts 18, 18' are moved by activating the servomotors 34,

34' for rotating movable transverse shafts 28, 28' which at opposing ends are designed or provided with toothed rims 30, 30' engaging stationary toothed racks 32, 32'. The foremost double ends 20, 20' of the curtain parts 18, 18' running around the transverse shafts 28, 28' are hereby moved inwards along the underside of the pallet layer 15 until they reach the previously mentioned position about the middle under the pallet layer 15.

Prior to releasing the pallet layer 15 from the suction face 4 at the desired position, the curtain parts 18, 18' are again to be moved outwards in order to release the pallet layer 15. This is effected by means of the servomotors 26, 26' which draw the curtain parts 18, 18' outwardly to both sides until the curtain parts 18, 18' are again disposed at their initial positions rolled up on transverse shafts 22, 22' of the magazines 24, 24'.

It is to be noted that the application of the curtain 14 is not always required or necessary, even though the suction head 2 is handled by means of industrial robot 3, for example when handling very light or just semi-heavy pallet layers 15, and where the case is pallet layers 15 with relatively light, closed box packings with sealed surface.

Moving the curtain parts 18, 18' in and out along each their part of the underside of the pallet layer 15 or the suction face 4 occurs very fast - by way of example in the course of about 1-2 seconds.

Finally, it is to be mentioned that an alternative method of rapid moving in and out of the curtain parts 18, 18' under the pallet layer 15 will be to use common servomotors 26, 26' for the magazines 24, 24 and the transverse shafts 28, 28', as the latter by way of example could be connected to the servomotors 26, 26' by means of an endless toothed belt running between toothed rims 30, 30' at opposite ends of the shafts 28, 28' and the servomotors 26, 26' and over vertically adjustable tensioning gear wheels at each side of the suction head 2. Another alternative would be to use flexible drive shafts between common servomotors for the magazines 24, 24' and the transverse shafts 28, 28'.

Reference numbers of the drawing

2 lift head

3 industrial robot

4 suction face 6 suction chamber

8 valve

10 skirt

12 squeezing pads 14 curtain

15 pallet layer

16, 16' transverse ends of curtain parts (at skirt)

18, 18' curtain parts

20, 20' opposite ends of curtain parts (at the middle under suction face) 22, 22' shafts, stationary (magazines)

24, 24' magazine

26, 26' electric drive motor (servomotor)

28, 28' transverse movable shafts

30, 30' toothed rim at opposite ends of movable shafts 32, 32' toothed rack, stationary

34, 34' electric drive motor (servomotor)

36, 36' support holder

38, 38' support frame with

39, 39' support profile 40, 40' support rollers