This invention relates to a co l packaging plant. In-aii those concerns in which coils are produced or processed there is currently a serious problem related to their packaging for production or processing purposes. The coils, consisting generally of rolls of sheet steel, aluminium alloy or steel alloy, are generally of large dimensions (diameter up to 2 m, width up to 2 m) and considerable weight (from 15 to 27 tons). Coils require to be packaged both for their handling within the factory and for their subsequent transport and storage. The sheet metal coils generally originate from coating, electro- galvanizing or other surface treatment lines which increase the value of the coils but leave them subject to deterioration because of surface impact or oxidation, this being particularly evident during sea transportation or storage under moist and variable temperature conditions.

Current packaging systems (paper, metal box) do not provide optimum product preservation and in particular are of high cost, with numerous other drawbacks related to the danger of the packaging operations and tα the difficulty of disposing of the materials after use.

Coils are mainly packaged by the following two briefly described procedures .

A first procedure involves packaging with paper. The packaging material is in the form of a sheet of oxled plastic-coated paper bonded to a nylon mesh. The packaging operations comprise positioning the coils on the previously cut sheet by means of an overhead crane, followed by manual wrapping and folding, then closure by metal straps. A second procedure uses a metal box. In addition to the paper, a steel sheet of about 0.6 mm thickness is used, cut and bent manually about the outside of the coil, and fixed to two sheet steel covers cut and bent manually. This second procedure is that which is mostly used, particularly when greater product protection is required. The limitations of both these used methods are:

Considerable labour requirement as the operations involved are totally manual (from 7 to "4 persons per two working shifts),

Low productivity 13 coils packaged pei hour in the case of paper and only 7 to 9 if using a metal box; - High risk of working accidents. Cutting, positioning and fixing the steel sheet, which is thin, sharp and of large dimensions, are often a source of accidents Uπpackaging is also very dangerous as the outer steel sheet has to be held until it has been completely unrolled; - Low packaging quality. The currently used systems are unable to protect the product against the risk of oxidation, which can result in serious loss of coil value. In the case of packaging

with paper, there is also a serious risk of deformation due to surface impact during movement;

High environmental impact. Once used, the packaging cannot be reused, and is also difficult to dispose of because it comprises different materials (paper, plastic, steel).

Various attempts have been made to solve some of these problems, such as the use of heat-shπnkable materials, or machines for automating the manual operations, but no effectively alternative solution has been tried up to the present time within a European or world context.

An object of the present invention is to provide a coil packaging plant which overcomes all the aforeiisted drawbacks. A particular further object is to automate the packaging process, increase plant productivity, reduce accident risk, ensure absolute protection against knocks and atmospheric agents, and enable the materials to be totally recycled after use.

These objects are attained according to the present invention by a coil packaging plant as indicated in claim 1 and in the sub- claims. The characteristics and advantages of a coil packaging plant according to the present invention will be more apparent from the description thereof given hereinafter by way of non-limiting example, with reference to the accompanying schematic drawings, in which: Figure 1 is a plan view of a plant according to the present invention seen from above; Figure 2 is an elevation of a detail of Figure 1 in the direction

of the arrow A ;

Figure 3 i≤ an elevation of the plant of Figure 1 in the direction of the arrow B;

Figure 4 is an elevation of the plant of Figure 1 in the direction of the arrow C,

Figure 5 is a plan view of a second embodiment of a plant according to the present invention seen from above;

Figure 6 is an elevation of the plant of Figure 5 in the direction of-the arrow D; Figure 7 is an elevation of the plant of Figure 5 in the direction of the arrow E;

Figure 8 is an elevation of the plant of Figure 5 in the direction of the arrow F;

Figure 9 is an elevation of the plant of Figure 5 in the direction of the arrow G;

Figure 10 is a view of a coil packaged in accordance with the invention and provided with hoops on its lateral surface.

Figure 1 is a plan view from above of a coil packaging plant constructed in accordance with the present invention, its individual constituent devices or units being shown schematically.

The plant comprises a feed conveyor 11 on which individual coils

12 are positioned to be fed to a portal-type transfer device 13.

The portal-type transfer device 13 feeds a single coil from a position associated with the feed conveyor to a position associated with a manipulator. Specifically, the manipulator consists of a rotatable and raisable cradle. The cradle 14 can be moved from the position in which it receives the coil 12 from the

conveyor to a position lying between a support unit comprising two rotation heads 15 provided wxth coil support mandrels 16. The plant of the invention is completed by a unit for treating the coil, during its packaging, with a film of polyethylene, polyethylene plus nylon, or plastic material in general. The treatment unit comprises a chamber 17 for vacuum-treating, weighing and labelling the complete package and a packaging material feed device 18. The keyboard of a central processing unit 19 controls the operation of the various plant devices and units.

As is easily understood from Figure 1 , the coils 12 are fed along the feed conveyor 11, which acts as a buffer for the plant. The portal-type transfer device 13 is operated by a suitable command fed in via the keyboard of the central processor unit 19. A self- aligning rocker arm of the transfer device withdraws a coil 12 from the conveyor 11 then travels along suitable rails 21 to reach a position in proximity with and axial to the cradle 14. The cradle 14 is then raised by an actuator'22 positioned below it and receives the coil 12, to leave the rocker arm 20 of the transfer device 13 to return to its retracted initial position.

Immediately afterwards, the cradle is lowered and rotated, and then shifted along an appropriate runway 23 to reach a position between the two rotation heads 15. When in this position the cradle is again raised to locate the coil 12 axially to the heads 15 or rather the mandrels 16. These latter are then moved so that, after a support element of a material identical to or compatible with the packaging has been

inserted into the coil central hole, the two mandrels 16 are inserted into the opposing ends of the central hole in the coil 12, and into its internal support element. When the coil is in this location, the cradle is lowered to leave the coil free to rotate rigidly with the mandrels, the packaging material feed device 18 then feeding the packaging film so that it arrives below the coil. The rotation cycle then commences to wrap the coil in its package, complete with sharp-edge protection rings 24 of a material compatible with or identical to the package, and unwound from reels 25. The reels 25 are located in the feed device 18 together with a reel of packaging material 26. When wrapping is complete the film is cut and thermowelded in three places, namely at the holes into which the mandrels were inserted and along a generating line on the lateral surface in line with the cut.

When the coil has been packaged it is transferred into the chamber 17 in which it is put under vacuum, weighed and then provided with its label completely automatically. The coil treated and packaged in this manner is withdrawn from the cradle and again transferred to the feed conveyor 11, which this time acts as an exit buffer zone.

Hence according to the present invention a coil vacuum-packed in polyethylene film or plastic film in general is obtained, which is able to maintain its integrity for a long period and under the various stress conditions.

With a plant of the invention and with the aforegoing procedure a series of important advantages are obtained.

In addition to the considerable protection of the coil against atmospheric agents and in general against the external environment, high productivity is achieved with only a very small number of personnel employed. This is because the plant is totally automatic and requires only operator employed on the control keyboard.

Furthermore, good quality packaging is obtained having a certain strength but from low-cost material. This material (monorπaterial or plastic material in general such as polyethylene film), used both as the support element within the coil and as the outer covering, is inter alia easily available and is ecological as it can be very easily recycled.

Advantageously the type of material is such as to prevent accidents both to the plant and to the personnel who have subsequently to handle the packaged coil once received.

Figures 5-9 show a second embodiment of a plant according to the present invention, in which equal elements and parts carry the same reference numerals. From Figure 5 it can be seen that the plant comprises a feed conveyor 11 on which individual coils 12 are positioned to be fed to a portal-type transfer device 13. During its travel along the conveyor 11 the individual coils 12 pass through a device 30 for measuring the dimensions of the fed coil 12 to be packaged, and for controlling and arranging further operations and devices located downstream within the plant.

A first of these operations is implemented by a device 31 for preparing a tubular element and for inserting this tubular element

into an empty central hole in the coil 12.

This device takes a certain quantity of plastic material from a packaging material feed device 32, winds it into a tube and then inserts it into the central hole in the coil, if necessary fixing it by a weld or the like.

The co l then reaches the portal-type transfer device 13, provided with a pair of expandable mandrels 33 which grip the coil 12 to move forwards through the plant. The individual coil 12 is then moved from a position associated with the feed conveyor 1 to a position associated with a manipulator This manipulator consists of a rotatable and raisable cradle 14.

The cradle 14 can be moved from this position for receiving the coil 12 from the conveyor to a subsequent position in correspondence with a further device in which wrapping with the plastic material takes place.

In this respect, there is provided a coil wrapping unit for its packaging with a film of polypropylene or generally similar plastic material This wrapping unit comprises a device 18 for feeding packaging material for the lateral surface, and which is applied about the lateral surface, and a further device 34 for feeding packaging material to form circular end covers to be placed on the side ends of the coil 12. For this purpose a manipulator 36 is provided to carry the circular covers 35 one after another into correspondence with the side ends of the coil 12 while arranged on the cradle 14, which is able to rotate through at least 180° in order to be able to present both its ends. The manipulator 36 can also be provided with a welding

device which welds the circular covers 35 to the tubular element positioned within the central hole in the coxi 12. A chamber can also be provided for vacuum-treating, weighing and labelling the complete package, as in the preceding case. Finally the wrapped coil 12 can be gripped by the pair of expandable mandrels 33 of the portal-type transfer device 13 and replaced on the conveyor 11 for its storage. The keyboard of a central processing unit 19 controls the operation of the various plant devices and units. The device 18 for feeding packaging material for tiie lateral surface could also provide plastic hoops 37 to be applied to the outside of the packaged coil 12, as shown in Figure 10. With this plant a coil packaged in polypropylene can be obtained having a perfectly wrapped lateral surface to which two circular covers positioned on the two side ends have been applied, and possibly welded. To achieve this, the transverse dimension of the film wrapping this lateral surface and of the central tube inserted into the coil hole can be left excessive to form a seat into which these two lateral covers can be inserted and the abundant edges be folded over onto the two ends, the edge of the central tube being folded in the same manner.