APPARATUS FOR HANDLING LAYERS OF PALLETISED GOODS

Abstract: An apparatus for handling layers of palletised goods is described, comprising a vertically displaceable lift head (6) with a mainly horizontal suction face (40) which is substantially adjusted in size for a pallet, e.g. an EU pallet, and which consists of a large number of downward open suction chambers (36) arranged for being moved downward against the upper side of an upper layer of individually or groupwise packed goods on a pallet, and which via individual valves is connected with a vacuum source (26) preferably integrated in the lift head (6), where said individual valves between said suction chambers (36) and the vacuum source (26) are designed as ball valves with spherical valve bodies (38) interacting with round valve openings with preferably spherical valve seats and arranged for being automatically actuated to shut off the ball valves if the relevant suction chamber is not blocked downwards by contacting the upper side of the goods at the uppermost pallet layer, and that the lift head (6) along the outer sides of the suction face (40) preferably comprises squeezing means arranged for exerting an inwardly directed pressure on at least the lower part of the outer sides of the goods of the upper pallet layer. By simple measures it is hereby possible to mechanise layered destacking of individual goods from a pallet and subsequent reformation of new pallets with layers of individual goods.

Description: Apparatus for Handling Layers of Palletised Goods The present invention concerns an apparatus for handling layers of palletised goods and of the kind indicated in the preamble of claim 1. In order to make effective and cheap and to simplify distribution of goods, most goods are sold on pallets, preferably the so-called EU pallets (800 x 1200 mm). Anyway, a widespread need has appeared for also dispatching orders comprising lesser amounts of goods in a correspondingly effective way. Statistically it appears that many orders for small shops actually consist of consignments of goods most often consisting of very few layers or maybe just a single layer of palletised goods. Until now several attempts have been made to mechanise such a layer-wise subparti- tioning of palletised goods of every kind without success, including goods packed in cardboard packings, goods in single bags or sacks, goods in bundled bag packings or even foil encased bottle goods on a carrying bottom of cardboard, as it has been attempted to develop a mechanical system for destacking in layers of palletised goods and subsequent restacking the individually destacked layers upon a new, composite pallet which may be handled in a correspondingly effective way in final distribution as the usual whole pallets. US-A-3 406 938 and US-A-3 229 953 describe a lifting device and an item holder using relatively complicated lifting or holding faces which consist of a large number of lesser chambers that are open toward the lifting face and the holding face, respec- tively. For lifting or holding of e.g. plate shaped items with different outer shape or size in the printing industry it is known to use lifting or holding faces with a differentiated vacuum chamber system, i.e. with a number of uniform, but individually connected chambers, which by means of a valve system may be connected with one or more vacuum sources in such a way that sheets or plates with individual shape or size may be lifted or held fast with one and the same lifting or holding face. The invention has the object of indicating a new and improved apparatus of the kind indicated in the introduction, and which by means of simple measures makes possible mechanising destacking in layers of individual goods from a pallet and subsequent reformation of new pallets with layers of individual goods. The apparatus according to the invention is characterised in that said individual valves between said suction chambers and the vacuum source are designed as ball valves with spherical valve bodies interacting with round valve openings with preferably spherical valve seats and arranged for being automatically actuated to shut off the ball valves if the relevant suction chamber is not blocked downwards by contacting the upper side of the goods at the uppermost pallet layer, and that the lift head along the outer sides of the suction face preferably comprises squeezing means arranged for exerting an inwardly directed pressure on at least the lower part of the outer sides of the goods of the upper pallet layer. By means of simple measures there is hereby achieved a new and improved apparatus which makes possible to handle multiple different types of palletised goods in layers with great certainty. Notably, by means of the apparatus according to the invention - where suction lift is combined with squeezing action - it is achieved with great certainty to lift pallet layers consisting of foil packed bottles where otherwise a great possibility exists of false air gaps at lateral directions because bottle packings usually have upwardly decreasing cross-sections. It has even proved possible to lift pallet layer where apertures appear in the layer, either because some packings have been removed from the layer, or because the cross-sectional shape or the size of the packing simply is not a multiple of the cross-dimensions of the pallet layer. The apparatus according to the invention is suitably thus designed that said squeezing means are constituted by a number of inflatable bags arranged at respective outer sides of the lift head within a pressure absorbing outer casing thereof. With the purpose of ensuring a very simple and suitable construction, the apparatus according to the invention may advantageously be thus designed that between the vac- uum source and said suction chambers there is an air distribution chamber which at a lower, preferably horizontal, wall plate is designed with a common shut-off valve consisting of a circle of mutually separated valve openings arranged in the wall plate and of a valve plate rotatably suspended therein and designed with a corresponding circle of valve openings, the valve plate being arranged for activation by means of a pneumatic cylinder inserted between the wall plate and a radial arm of the valve plate. The apparatus according to the invention may furthermore be suitably designed so that said squeezing means furthermore are arranged in a vertically adjustable way relative to the lift head, so that the active squeezing area may be adjusted according to the height of the actual goods in respective pallet layers. For use in lifting pallet layers consisting of relatively light, fragile goods, for example groupwise foil packed plastic cups not standing up to the use of the indicated squeez- ing means, and which furthermore may be lifted by means of an evenly distributed, less powerful suction, the apparatus according to the invention may advantageously be designed so that each of said suction chambers comprises arresting means arranged to prevent the valve balls abutting on the valve seats for shutting off the ball valves. In a simple way, the said arresting means may be constituted by a common wire net ex- tending through the respective suction chambers above the valve balls, and which may be moved downward for preventing abutment of the valve balls against the valve seats. As mentioned, the vertically displaceable lift head preferably comprises said vacuum source which preferably is constituted by a powerful centrifugal fan, the axial inlet port of which is connected with said air distribution chamber. The apparatus according to the invention is furthermore designed so that it comprises or is arranged for being connected to a pressurised air source which inter alia is used for activating said ro- tatable valve plate and for inflating said bags which are emptied of air again by cou- pling to the suction side of the vacuum source. With the intention of also mechanising the subsequent subpartitioning of a pallet layer, the apparatus according to the invention may thus advantageously be so designed that said depalletising system comprises a support plate arranged for carrying a layer of palletised goods and for being displaced between a receiving position under the lift head and a delivery position beside the lift head, and a pushing device arranged for pushing a layer palletised goods from the support plate and further onto a division conveyor. Suitably, the apparatus according to the invention may be further designed so that the surface of the support plate is wholly or partially provided with a friction facing designed to retain possible intermediate cardboard when the pallet layer is pushed from the support plate to the division conveyor, and that the division device comprises means arranged for retaining possible intermediate cardboard for removal by retracting the support plate to the receiving position. The invention is explained in the following in connection with the drawing, on which: Fig. 1 shows a side view partly in section, cf. see the line A-A in Fig. 2, of a palletising system comprising an embodiment of an apparatus according to the in- vention, Fig. 2 shows a view from above of the palletising system shown in Fig. 1, Fig. 3 shows a side view partly in section, cf. the sectional line B-B in Fig. 2, of a palletising system comprising an embodiment of an apparatus according to the invention, Fig. 4 shows a side view partly in section of an embodiment of a lift head for an apparatus for lifting in layers of palletised goods according to the invention as shown lowered over a pallet layer and with unactivated squeezing means, Fig. 5 shows a view of the lift head, cf. Fig. 4, seen from below, Fig. 6 shows a side view partly in section of the lift head shown in Fig. 4 for an ap- paratus according to the invention, shown lowered over a pallet layer of boxes and with activated squeezing means, Fig. 7 shows a view of the lift head cf. Fig. 6 as seen from below, Fig. 8 shows a plan view of a preferred embodiment of a vacuum valve at the lift head shown in Figs. 4 and 6 for an apparatus according to the invention, Fig. 9 shows a plan side view of depalletising system comprising an apparatus according to the invention, Fig. 10 shows a plan view from above of the depalletising system shown in Fig., Fig. 1 1 shows a detailed view of the depalletising system shown in Figs. 9 and 10, where a filled pallet is placed in starting position under the lift head, Fig. 12 shows a detailed view of the depalletising system shown in Figs. 9 and 10, where a pallet layer is lifted up and a support plate is moved in under the pallet layer, Fig. 13 shows a detailed view of the depalletising system shown in Figs. 9 and 10, where the pallet layer is lowered onto the support plate and moved out to pusher, Fig. 14 shows a detailed view of the depalletising system shown in Figs. 9 and 10, where the pallet layer is pushed from the support plate out to a division conveyor, Fig. 15 shows a detailed view of the depalletising system shown in Figs. 9 and 10, where the single packings are moved away from each other on the division conveyor, and Fig. 16 shows a detailed view of the depalletising system shown in Figs. 9 and 10, where the single packings are transferred to transverse conveyor. The palletising system 2 shown in Figs. 1 - 3 extends two storeys high and comprises a pallet lifter 4 with an upper, vertically displaceable apparatus according to the in- vention with a lift head 6 arranged for destacking in layers of goods from a filled pallet which by means of the pallet lifter 4 is taken from a roller conveyor 8 at the lowermost level, as the shown palletising system is arranged for destacking in layers of goods which are transferred to special support plates 10 which in the shown version have lower, vertical foot rests 12. The support plates 10, which are somehow larger than the pallets, are arranged for absorbing vertical loads between the single pallet layers, so that these may consist of relatively fragile goods. For destacking and inter- mediate handling of layers of more robust units of goods a simple plane support plate may be used. When, as shown in Fig. 1 , the issue is about handling more regular, box-shaped items 14, which by themselves form self-supporting pallet layers, these may easily be handled without use of special support plates with footrests in that such regular pallet layers may be restacked without any problems directly to a new pallet consisting of mutually different goods. However, in that case a somewhat different palletising system is required where the lift head 6 is suspended from a beam making possible displacing the lift head in the lateral direction, for example between two pallet lifters arranged side-by-side. At the lower left of Fig. 1 appears furthermore a pallet magazine for stacks of empty pallets. At the top of Fig. 2 is shown a chain conveyor 16 for supplying filled support plates to combined destacker and stacker 18 and a chain conveyor 20 for transporting filled support plates to intermediate storage, while at the bottom of Fig. 2 there is shown a combined destacker and stacker 22 for empty support plates and a reversible chain conveyor 24 for supplying and removing stacks, each with six support plates, to and from intermediate storage. Fig. 3 shows a side view of details appearing at the top of Fig. 2. The lift head 6, which is shown in more detail in Figs. 4 - 7, comprises a vacuum source in the form of a powerful centrifugal fan 26, the central inlet port 28 of which is connected via a short tube piece 30 to a rectangular air distribution chamber 32 that via a special rotatable valve 34 (Fig. 8) is connected with a large number (23 x 19 = 437) suction chambers 36 with quadratic cross-section. The suction chambers 36 are open downwards, while upwards they are connected with the front of the rotatable valve 34 via round valve openings with spherical edges downward or valve seats which to the outer spherical surface of very light, thin-walled, spherical valve bodies 38. In each suction chamber 36 there is confined a spherical valve body 38 by means of not shown side projections or by a suitable lower holding net. The suction chamber 36 together form a rectangular, lower suction face 40 fitting in cross-section to a stan- dard pallet, e.g. an EU pallet with dimensions of 800 x 1200 mm across or a UK pallet with dimensions of 1000 x 1200 mm across. In Fig. 4, the lift head 6 is lowered around a pallet layer 42 consisting of regular, box- shaped items in such a way that the suction face 40 just contacts the upper side of the pallet layer 42. This is surrounded by a special vertically adjustable, outer squeezing arrangement 44 which at each of the outer sides of the suction face comprises a number of inflatable bags 46 together with an inner skirt 48 and outer skirt 50. The squeezing arrangement 44 is surrounded by an outer skirt or a casing 52 arranged for absorbing the reaction pressure of the squeezing bags 46 when these are inflated and exert an inward directed squeeze pressure on the outer sides of the pallet layer 42. Vertical adjustment and thereby adjusting the squeezing arrangement 44 depending on the height of the actual goods in the pallet layer occurs by means of a preferably motor driven winch 54 and lift slings 56 at each side of the lift head 6. The squeezing bags 46 and possibly the cavity between the skirts 48 and 50 are inflated via control valves by means of pressurised air from a pressurised air source at a pressure of about 0.2 bar, so that the pallet layer 42 is squeezed between the squeezing bags 46 simultaneously with the suction face 40 being activated by operating the rotatable valve 34. When the squeezing pressure is subsequently to be relieved, this takes place quickly by resetting the control valves and connecting the bags to the suction side of the vacuum source, the centrifugal fan 26 that delivers a vacuum of about 0.1 bar. If the actual pallet layer to be lifted by means of the lift head 6 consists of relatively light and fragile packing items that do not stand up to lateral pressure, and which do not require very great suction pressure either, the overall suction pressure may be lowered by forcibly controlling the spherical valve bodies in such a way that they are pre- vented in shutting off the valve openings. This may be achieved, for example, in a simple way by means of a common vertically adjustable wire net extending through the suction chambers and placed over the valve bodies so that these are hindered in blocking the valve openings to the vacuum source. The said rotatable valve shown in Fig. 8 consists of a circle of mutually separated valve openings 58 arranged at the lower wall of the air distribution chamber 32 and of a valve plate 60, which is rotatable in relation thereto, with a corresponding circle of valve openings 62, the valve plate 60 being arranged for rotation for opening and closing the rotatable valve 34 by means of pressurised air cylinders 64 interacting with radial arms of the valve plates 60. The depalletising system shown in Figs. 9 and 10 comprises a stationary pallet lifter 62 co-operating with not shown roller conveyors for supplying and removing pallets and co-operating with a likewise stationary lifting arrangement 64 with a complete lift head 6. The depalletising system comprises a support plate 66 (so-called stripper plate) arranged for being displaced between a receiving position 68 under the lift head 6 and a delivering position 70 at the side of the lift head 6, in that the support plate 66 is intended for receiving a pallet layer from the lift head 6 and displacing the pallet layer to the delivery position 70. In the delivery position 70 there is furthermore mounted a push device 72 which between two endless chain conveyors 74 has two transverse beams 76, of which one is arranged for pushing a pallet layer from the support plate 66 to a division conveyor 78, and of which the other is provided with fingers arranged for retaining possible intermediate layer cardboard from the support plate 66 when this is displaced to the deliv- ery position 68 again so that the intermediate layer cardboard may be removed. In order to be able to retain possible intermediate layer cardboard when the pallet layer is pushed from the support plate 66 to the division conveyor 78, the support plate 66 is designed or provided with friction coating. Under the push device 72 there is a transversely running belt conveyor 80 intended for receiving and removing possible inter- mediate layer cardboard which is situated primarily between each of the pallet layers when there are "holes" in the pallet layer, e.g. due to irregularly shaped units of goods. As it most clearly appears from Figs. 10, 15 and 16, the division conveyor 78 is arranged in such a way that the single units of goods are mutually separated both in lateral direction and in direction of transport as the division conveyor 78 furthermore is divided into sections with increasing transport speed so that the units of goods get sufficient mutual distance in the direction of transport for facilitating the transfer to a subsequent transverse conveyor 82.

Claims: CLAIMS 1. Apparatus for handling layers of palletised goods and comprising a vertically dis- placeable lift head (6) with a mainly horizontal suction face (40) which is substantially adjusted in size for a pallet, e.g. an EU-pallet, and which consists of a large number of downward open suction chambers (36) arranged for being moved downward against the upper side of an upper layer of individually or groupwise packed goods on a pallet, and which via individual valves is connected with a vacuum source (26) preferably integrated in the lift head (6), the apparatus comprising or being arranged for co- operating with a depalletising system, c h a r a c t e r i s e d in that said individual valves between said suction chambers (36) and the vacuum source (26) are designed as ball valves with spherical valve bodies (38) interacting with round valve openings with preferably spherical valve seats and arranged for being automatically actuated to shut off the ball valves if the relevant suction chamber is not blocked downwards by contacting the upper side of the goods at the uppermost pallet layer, and that the lift head (6) along the outer sides of the suction face (40) preferably comprises squeezing means arranged for exerting an inwardly directed pressure on at least the lower part of the outer sides of the goods of the upper pallet layer. 2. Apparatus according to claim 1, c h a r a c t e r i s e d in that said squeezing means are constituted by a number of inflatable bags (46) arranged at respective outer sides of the lift head (6) within a pressure absorbing outer casing (52) thereof. 3. Apparatus according to claim 1, c h a r a c t e r i s e d in that between the vacuum source (26) and said suction chambers (36) there is an air distribution chamber (32) which at a lower, preferably horizontal, wall plate is designed with a common shut-off valve (34) consisting of a circle of mutually separated valve openings (58) arranged in the wall plate and of a valve plate (60) rotatably suspended therein and designed with a corresponding circle of valve openings (62), the valve plate (60) being arranged for activation by means of a pneumatic cylinder (64) inserted between the wall plate and a radial arm of the valve plate (60). 4. Apparatus according to claim 1 - 3, characterised in that said squeezing means furthermore are arranged in a vertically adjustable way relative to the lift head (6), so that the active squeezing area may be adjusted according to the height of the actual goods in respective pallet layers. 5. Apparatus according to claim 1, characterised in that each of said suction chambers (36) comprises arresting means arranged to prevent the valve balls (38) abutting on the valve seats for shutting off the ball valves. 6. Apparatus according to claim 5, characterised in that said arresting means are constituted by a common wire net extending through the respective suction chambers (36) above the valve balls (38), and which may be moved downward for preventing the abutment of the valve balls against the valve seats. 7. Apparatus according to claim 1, characterised in that said vacuum source is constituted by a powerful centrifugal fan (26), the axial inlet port (28) of which is connected with said air distribution chamber (32). 8. Apparatus according to claims 1-7, characterised in that it comprises or is arranged for connecting to a pressurised air source which inter alia is used for activating said rotatable valve plate (60) and for inflating said bags (46) which are emptied of air again by coupling to the suction side of the vacuum source. 9. Apparatus according to claim 1, characterised in that said depalletising system comprises a support plate arranged for carrying a layer of palletised goods and for being displaced between a receiving position under the lift head and a delivery position beside the lift head, and a pushing device arranged for pushing a layer palletised goods from the support plate and further onto a division conveyor. 10. Apparatus according to claim 9, characterised in that the surface of the support plate is wholly or partially provided with a friction facing designed to retain possible intermediate cardboard when the pallet layer is pushed from the support plate to the division conveyor, and that the division device comprises means arranged for retaining possible intermediate cardboard for removal by retracting the support plate to the receiving position.

Inventors: ANDERSEN JOHN SJAELLAND, CHRISTENSEN TORBEN, ANDERSEN, JOHN, SJAELLAND, CHRISTENSEN, TORBEN
Applicants: ANDERSEN JOHN SJAELLAND, CHRISTENSEN TORBEN, UNIVEYOR AS, ANDERSEN, JOHN, SJAELLAND, CHRISTENSEN, TORBEN, UNIVEYOR A/S
Application year: 2000
Main classification: B65G47
IPC codes: B25J15, B65G47, B65G57, B65G59, B65G61, B66C1