Load of goods comprising a plurality of layers, and a method and a machine for producing said load

[57] ABSTRACT

A load of goods comprising several superposed layers of goods, and a method and a machine for producing said load, said load being enclosed in plastics fdm and arranged to be lifted by means of a fork truck without being supported on a pallet. For this purpose the bottom layer is narrower than the layers positioned thereabove, whereby spaces are formed at either side of the bottom layer to accommodate the lifting legs of a fork lift truck. The bottom layer is enclosed separately in shrinking film and welded to the film surrounding the remaining goods layers in such a manner that a very strong joint is formed ensuring that the bottom layer of the load does not separate from the superposed layers upon lifting of the entire load by means of a fork truck.

Claims, 12 Drawing Figures

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PATENTED DEC 101974

853,218

SHEET 1 OF 6

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PATENTED DEC 101974

SHEET 2 OF 6

853.218

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PATENTEE OEC101974

853,218

SHEET 3 OF 6

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PATENTED EEC 101974

853,218

SHEET U OF 6

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PATENTED ΕΧ!0ΒΤ4

853,218

SHEET S OF 6

Fig.8

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PATENTED 101974

3,853,218

SHEET 6 OF 6

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3,853,218

LOAD OF GOODS COMPRISING A PLURALITY OF LAYERS, AND A METHOD AND A MACHINE FOR PRODUCING SAID LOAD

BACKGROUND OF THE INVENTION ⁵

It is known to use pallet loaders to stack goods in superposed layers. It is likewise known to enclose the entire pallet load, including the pallet proper on which the load rests, in shrinking foil. In order to make it pos- 10 sible to transport a pallet load of this kind by means of a fork truck, the openings in the pallet through which the truck forks are to be inserted, must remain open and as a result the shrinking foil cannot seal the pallet load hermetically. 15

SUMMARY OF THE INVENTION

The present invention has for its purpose to provide a load enclosed in a shrinking foil in such a manner that the pallet is no longer necessary for transporting the 20 load. More precisely, the invention concerns loads of the kind wherein the bottom goods layer terminates at a considerable distance from the side edges of the layer of goods positioned immediately above the bottom one such that two longitudinal spaces are formed there to ²⁵accommodate the legs of a lifting fork, and the film is arranged to extend into these spaces so as to cover those sides thereof which face outwards and downwards. It is characteristic of the invention that the bottom layer of goods is enclosed separately in the plastics ³⁰film and that the film enclosing the upper layer or layers is welded to the film of the bottom layer along two parallel longitudinal sides.

This method of assembling and enclosing the load has proved to be very valuable, particularly when the arti- ³⁵cles making up the load are heavy, consisting for instance of cement bags. Under these circumstances it is important to see to it that the bottom goods layer does not separate from the remaining layers when the load is lifted by the truck fork legs, as these legs engage in ⁴⁰the empty spaces or channels formed in the load and thus do not support the bottom layer of the load directly during lifting.

As the bottom layer is narrower than the immediately upper layer of goods (as the bottom layer does not ex- ⁴⁵tend all the way up to the edges of the load) and because an identical film web is used to wrap the bottom layer and the rest of the layers, which means that the web of film used for the bottom layer has the same width as the web of film used for the rest of the layers, ⁵⁰two surplus portions of this film web will be formed at two opposite ends of the bottom layer. These surplus film portions (ends) are bent upwards into contact with the film web extending along the lower face of the second layer in succession and are secured to this film web. The joint thus provided between the two lower' layers of goods is sufficiently strong to ensure that the bottom layer will adhere to the rest of the goods layers when the entire load is lifted. ₆θ

A still stronger joint is obtained if the upper plastic ⁰film is allowed to hang down in front of the side edges of the bottom layer and these dependent web lengths of the film attached to the film enclosing the bottom layer. ₆₅

The invention also concerns a method and a machine for assembling and producing loads of the kind referred to.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be described more in detail in the following with reference to the accompanying drawings, wherein

FIG. 1 illustrates in a perspective view six loads wrapped in shrinking plastics film in accordance with the invention and positioned in superposed rows,

FIG. 2 illustrates on a somewhat larger scale one load of this kind during transport by means of a fork truck,

FIG. 3 is a perspective view of the bottom layer of goods enclosed in shrinking film,

FIG. 4 shows in an end view a load being wrapped in film,

FIG. 5 shows the same load at a later stage of the wrapping procedure,

FIG. 6 is a diagrammatic side view of a machine in accordance with the invention for stacking and wrapping goods,

FIG. 7 is a vertical cross section through the machine along line VII-VII of FIG. 6,

FIG. 8 is a side view of a machine in accordance with a second embodiment of the invention for wrapping of loads,

FIG. 9 illustrates on an enlarged scale that portion of the machine where the hermetic sealing of the load is performed,

FIG. 10 is a vertical cross section through this machine along line X—X of FIG. 9,

FIG. 11 illustrates the load after film shrinkage, the load having been turned to correct position for transport by means of a fork truck, and

FIG. 12 illustrates an end view of a load wrapped in accordance with a third modification of the teachings of the invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

The machine illustrated in FIG. 6 for stacking goods in layers numbered 1, 2, 3, one on top of the other, comprises at its top portion a conveyor 4 for feeding goods 5 into the machine and a conveyor 6 for discharging the load 7, when completed, from the machine. The machine also comprises an elevator carriage 8 arranged to move stepwise from an upper position downwards, each step performed by said carriage corresponding to the height of the respective layer of goods 1, 2 and 3. Below the conveyor 4 is arranged a feeder plate 10 which is displaceable in the direction illustrated by double arrow 9 up to the position 10' illustrated in dash-and-dot lines in FIG. 6 above the conveyor 6, past a vertically displaceable stripper means 11. Two supply rolls 13 and 14 holding webs 15 and 16, respectively, of shrinking plastics film are mounted in the machine stand 12. At the left turning point of the feeder plate 10 is positioned the fixed welding head 17 of a welding unit, this welding head cooperating with a counter head 18 positioned at the forward end of the feeder plate 10. The counter head 18 serves as a film conveyor means or is provided with a film conveyor for the shrinking film 15 at its free end. The width of film webs 15, 16 is, as appears from FIG. 7, considerably larger than the width of goods layers 1,2, and 3, in case the shrinking film is to enclose the entire load 7. For this purpose the machine is provided at the short sides

3,853 3 of its stand 12 with a welding unit 20 comprising a stationary head 21 and a welding head 22 arranged to be swung in over the stationary one, which serves as a counter head.

Arrangement of the load 7 and the wrapping thereof 5 in shrinking film is effected in the following manner with the aid of the machine illustrated in FIGS. 6 and 7. A number of articles 5 are advanced by the conveyor 4 to the left in accordance with FIG. 6 down onto the feeder plate 10 which moves to the left at the same 10 speed. At the same time, the film 15 is fed by the head 18 into contact with the free end of the film 16 in front of the fixed head 17 of the welding unit. The film webs 15 and 16 are thus welded together and assume a position immediately above the conveyor 6 on the elevator 15 carriage 8, the initial position of which corresponds to its uppermost position closely beneath the feeder plate 10 in the position thereof designated 10'. The stripper means 11 descends to operative level and prevents the articles 5 from returning together with the feeder plate 20 10 when the latter moves back to its original position. The bottom goods layer thus will be positioned centrally on the conveyor 6 and rest on the shrinking film webs 15 and 16. The elevator carriage 8 will descend one step, whereafter the course of events related above 25 will be repeated; this time, however, the machine will handle a larger number of articles 5 and the stripper means designated 11' will be the one in function. When the bottom layer of goods 1 was being completely enclosed by the shrinking film, the layer of goods posi- ³⁰tioned immediately on top thereof was simultaneously brought to rest on fresh lengths of film webs 15, 16. The layers 2 of goods comprising a larger number of articles 5 and consequently being broader than the bottom layer 1, rest in a central position on this bottom ³⁵layer such that longitudinal, empty or free spaces 23 will be formed, extending on either side of the bottom layer 1 below the edge portions of the layer 2 positioned immediately above the bottom one. Successive layers 3 of goods are advanced into the machine and ⁴⁰stacked on layer 2 but the feeder plate 10 is not moved sufficiently far to the extreme left to permit the welding head 18 to reach up to welding head 17 (see FIG. 6) and consequently no welding together of film webs 15 and 16 occurs. The layers 2 and 3 thus are not individu- ⁴⁵ally wrapped in film. After deposit of the top layer 3' of goods on the stack the elevator carriage 8 descends a further step, and thereafter the feeder plate 10 together with the welding head 18 are moved into contact with the welding head 17 to weld film webs 15 and 16 ⁵⁰together, forming a banderole 24 (FIG. 4) of such a width that two film lengths 25 will hang down, one at either side of the side edges 26 of the bottom layer and the film banderole 27 covering these edges.

The complete load 7 is thereafter transported on the conveyor 6, away from the point of stacking up to the subsequent station of treatment. The latter comprises a frame 28 which may be lowered over the load 7 and which is provided with air nozzles 29, having a source ₆θ of hot air (not illustrated) connected thereto. Above the conveyor 6 on either side thereof two heating plates 30, heated e.g. by hot air, are arranged, these heating plates 30 being pressed laterally against the bottom layer 1 when actuated by piston-and-cylinder units 31, ₆₅32 operated by pressurized air.

During their movement towards one another the heating plates 30 force the two dependent parts or ,218 lengths 25 of the banderole 24 against and into contact with the banderole 27, whereby these two film portions are laminated together. The frame 28 is thereafter lowered while at the same time hot air is sprayed onto the banderole 24 which shrinks and thus is made to enclose goods layers 2, 3, and 3' tightly.

When completely wrapped, the load 7 may be moved by a fork truck 33 (FIG. 2), resting on the truck fork legs 34, which engage in the longitudinal spaces 23, and the load may thereafter be stacked, for instance as illustrated in FIG. 1. Owing to the strong adherence between the two film banderoles 24 and 27 as a result of the lamination of the dependent lengths 25 of the banderole 24 to the banderole 27, is ensured that the packages forming the bottom layer of goods and positioned in the gap between the fork legs 34, do not separate from the superposed layers when the entire load is lifted by the truck fork.

In the wrapping described above the width of the film webs 15 and 16 is imagined to only slightly exceed the length of the load 7. When the film shrinks, it will keep the various packages together but the load will not be hermetically sealed. If the shrinking film is to enclose the load 7 entirely it is necessary to use considerably wider film webs 15, 16 (see FIG. 7) and only in such cases may the welding units 20 be put to use. In FIG. 7 is shown the manner in which the lower portion or length 35 of the ends of the banderole 24 rests on the fixed heads 21. The heads 22 are used to press the ends of the upper portions or lengths 36 of the banderole against the lower film portions 35 to permit the two film portions to be welded together. Consequently, layers 2, 3 will be completly enclosed in shrinking film. In the same manner, the ends of the film banderole 27 for the bottom goods layer 1 have previously been welded together. In the subsequent shrinking process the film will fit tightly around the load in the usual manner such that the welding joints will be only faintly apparent.

Loads may also be wrapped in a different manner and with the aid of a machine which differs from the one described above. A wrapping machine constructed as appears from FIGS. 8, 9, and 10 may be used to wrap in shrinking film a load 7 from a pallet loader of conventional type, the bottom layer 1 (see FIG. 11) of said load 7 terminating at a considerable distance from the side edges of the layers 2, 3 of goods positioned thereabove. A wrapping machine of this kind comprises three conveyors 37,38, and 39 arranged in aligned succession. A portal 40 extends above the conveyor 37, the loads 7 being advanced through said portal in the direction illustrated by arrow 41 (FIG. 8). Above the portal transversely to the direction of advancement is mounted a supply roll 42 holding shrinking film 43, which is dispensed in such a manner that at the feedingout end of the portal it will hang down on either side of the load 7. Between the conveyors 37 and 38 is arranged a combined cutter-and-welder device 44 by means of which the dependent side portions or side lengths 45 of the film web 43 are moved into contact with one another in front of the load and when the latter is advanced one step these lengths meet also behind the load 7, such that the latter will be completely enclosed in shrinking film which thus surrounds the load like a hood. Below the conveyor 38 at the starting end thereof is rotatably mounted a supply roll 46 holding shrinking film 47 which is fed onto the conveyor 38 in such a manner that the bottom layer 1 of the load 7 will

3,853,218 rest on this film web. At the starting end of the conveyor 38 as also at its terminal end and at its sides, welding units are provided each one of which comprises one fixed head 48, 49 (FIG. 9) and 50, 51 (FIG. 10), respectively, as well as one movable head 52, 53 (FIG. 9) and 54,55, respectively, these movable heads being arranged to move in across its associated fixed head. These welding units function to weld the marginal portion 56 of the dependent side lengths 45 of the film hood 57 to the longitudinal portions 58 of the film 47 as well as to its transverse marginal portions formed after cutting of the film web in the transverse direction. As a result, the enclosure of the load 7 will be air-tight. The load thus enclosed will be advanced through a shrinking tunnel 59 (FIG. 8) by the conveyor 39, whereby the film will be shrunk tightly around the load.

In this case the load 7 is imagined transported through the portal 40 and through the shrinking tunnel 59 in a position wherein its narrowest layer 1 of goods is at the top (see FIG. 10) to eliminate any risk that the stack of goods will slide or collapse during transport. When the load 7 has passed through the shrinking tunnel 59 it is turned upside-down by any convenient turning mechanism known per se to the position illustrated in FIG. 11 in which it may be engaged by the lifting legs 34 of a fork truck 33.

In FIG. 12 is illustrated a load 7 the bottom layer 1 of goods of which is wrapped separately in shrinking film 27 as illustrated in FIGS. 3 and 7. On top of this bottom layer, the layers 2, 3, and 3' have been stacked by means of a pallet loader known per se, without, however, being enclosed in shrinking film. This load 7 is advanced through the portal 40 in accordance with FIG. 8 and enclosed in shrinking film 43 in such a way that a film hood 57 as illustrated in FIG. 9 is formed. The dependent marginal portions 56 of the film hood 57 are thereafter pressed by the heating plates 30 into contact with the shrinking film 27 surrounding the bottom layer 1 and laminated thereto. Also this method provides a good joint and strong adherence between the film hood 57 and the film 27, in addition to which the load will be air-tightly enclosed and the amount of shrinking film used minimal.

The machines in accordance with the invention may also comprise means to join together by means of welding any such portions of the film surrounding the upper layers 2, 3, and 3' as may hang down at the short ends of the load, and the film surrounding the bottom goods layer 1, thus providing a secure joint between these two films also at the short ends of the load.

The embodiments as illustrated and described are to be regarded as examples only and the goods stacking machines as well as the wrapping mechanisms may be constructively altered in a variety of ways within the scope of the appended claims. The shrinking frame 28 (FIG. 4) may, instead of hot air nozzles 29, have electric heat radiators. The shrinking frame 28 may also be provided with brushes which upon lowering of the frame over the load 7 sweep over the film banderole 24 and smoothens it in a downwards direction.