Patent Description:
The known wrapping machines comprise an unwinding apparatus which is movable along and/or about a winding axis and which supports a reel of film from which the film is unwound to be wrapped around the load so as to form a series of strips or bands generally having a helical trend, by virtue of the combination of the relative linear and rotational movements between the unwinding apparatus and the load.

In wrapping machines provided with a rotating table to support the load, during the wrapping cycle the latter is rotated about a vertical winding axis, while the unwinding apparatus is moved parallel to the winding axis with alternating motion along a fixed upright of the wrapping machine.

In wrapping machines with horizontal rotating ring or rotating arm, the load remains static during the wrapping, while the unwinding apparatus is moved with respect to the latter both in rotation about a vertical winding axis and in translation parallel to the latter. To this end, the unwinding apparatus is fixed to a ring structure or to an arm rotatably supported by a machine frame and so as to rotate around the load.

The unwinding apparatus substantially comprises a support frame, fixed to the rotating ring or arm or slidably connected to the fixed upright, which rotatably supports a reel holder shaft on which the film reel is mounted, a pair of pre-stretch rollers for stretching and unwinding the film and one or more guide rollers for diverting the film towards the load during the unwinding.

The film of plastic material is unwound by the reel and wrapped around the aforesaid rollers according to a path which allows a correct unwinding and a desired pre-stretch or elongation.

If the film is depleted, the reel must be replaced with a new reel. More precisely, the elongated core or central element, of cardboard or plastic, around which the plastic film was wrapped, must be removed.

Such a replacement procedure is generally performed manually by one or more operators who, after stopping the machine and positioning the unwinding unit at an appropriate height from the ground, proceed to remove the core of the depleted reel from the relative reel holder shaft and then insert and lock the new film reel.

In some high-performance wrapping machines, in particular horizontal rotating ring wrapping machines, the replacement procedure is performed automatically without the intervention of operators. For this purpose, the wrapping machine is provided with a system capable of removing and receiving the core of the depleted film reel from the reel holder shaft of the unwinding apparatus and mounting on the reel holder shaft a new film reel taken from a carriage or support positioned on the machine.

Some known reel core removal or extraction systems see for instance <CIT>, envisage reel holder shafts of the wrapping machine comprising a cylindrical body having an external diameter slightly smaller than the internal diameter of the reel core, an upper end which is fixed to the supporting frame of the unwinding apparatus and a lower end which is provided with a pair of opposite and movable brackets or supporting arms in rotation. In particular, the two arms are rotatable together at the same time between a closed or folded configuration and an open or unfolded configuration.

In the open configuration, the two arms are arranged protruding from opposite sides outwards with respect to the cylindrical body and in a substantially horizontal position so as to form a support for the film reel inserted on the reel holder shaft. More precisely, in the open configuration the two arms abut and support the film reel core.

In the closed configuration, the two arms are instead folded towards the inside of the reel holder shaft in an almost vertical position so as not to protrude externally from the cylindrical body and have in particular a radial transverse dimension, i.e., in a direction perpendicular to a longitudinal rotation axis of the reel holder shaft, i.e., almost horizontal, smaller than the external diameter of the cylindrical body and the internal diameter of the reel core so as to allow the removal or insertion thereof.

The removal system then comprises a removing apparatus adapted to interact with this type of reel holder shaft and is provided with a supporting element having a hollow cylindrical cup-like shape. More precisely, the supporting element is open at the top so as to receive therein, during the removal procedure, the lower end of the reel holder shaft with the arms arranged in the open configuration and disengaged and spaced from a lower edge of the aforesaid core so as to support the latter.

The supporting element has in particular an upper peripheral edge, substantially circular, arranged around the opening and having dimensions such as to abut and support the reel core during the removal procedure.

In particular, the upper peripheral edge of the supporting element has an internal diameter greater than the radial transverse dimension of the two arms arranged in the open configuration, to allow the insertion of the reel holder shaft, and an external diameter such that the width of the upper peripheral edge forms a flat supporting surface (circular crown) capable of stably supporting the reel core. In fact, the external diameter of the core is generally comprised between the internal diameter and the external diameter of the upper peripheral edge of the supporting element.

During the automated reel core removal procedure, the machine unwinding apparatus is lowered so that the lower end of the reel holder shaft can be inserted inside the supporting element by a length which allows the arms to be disengaged from the core so that they can be rotated in the closed configuration. The reel core is supported and maintained raised by the outer edge of the supporting element.

With the arms in the closed configuration, the unwinding apparatus can be lifted vertically so as to disengage the reel holder shaft from the reel core which remains resting on the supporting element. The latter can be mounted on a special mobile frame approaching or moving away from an operative area of the wrapping machine in order not to obstruct the wrapping procedure.

A disadvantage of the known systems described above for removing the cores of depleted reels lies in the fact that they do not allow the removal or extraction of cores of reels having a reduced thickness and therefore with an external diameter less than or almost equal to the internal diameter of the supporting element. In this case, in fact, during the lowering of the reel holder shaft, the core would also be inserted inside the supporting element or in any case it would fit on the upper peripheral edge of the latter without being able to be removed. Even in the case of cores with an external diameter slightly greater than the internal diameter of the supporting element, the upper peripheral edge of the latter would not be able to support the core in a stable and reliable manner, in particular in the case in which the latter, typically made of cardboard, has a deformed or undamaged lower end. However, the use of a supporting element having a reduced internal diameter to support smaller cores would require the use of supporting arms of the reel holder shaft of necessarily reduced length to allow it to be inserted into the supporting element in the open configuration. However, arms of reduced extension or length would not ensure a stable and reliable support of the film reel, especially in the case of reels with thicker core and/or with damaged, deformed lower end. In fact, in these cases the reel may move along the reel holder shaft and even exit.

It is therefore necessary to mount supporting elements and supporting arms on the removing apparatus and on the wrapping machine, respectively, commensurate with the dimensions (thicknesses) of the cores of the film reels used.

These changes, in addition to requiring the wrapping machine to stop, are expensive and require time and skilled labour.

Another disadvantage of the known systems is that the insertion of the reel holder shaft inside the supporting element requires a great deal of precision and accuracy in order to avoid collisions between the lower end of the reel holder shaft and the upper edge of the supporting element, collisions which could damage one or both components.

An object of the invention is to improve the known wrapping machines provided with systems configured to remove a core or central element of a depleted film reel from a reel holder shaft of the machine.

Another object is to provide a wrapping machine having a system which allows to remove reel cores having different thicknesses, even small, without modifying the reel holder shaft. A further object is to provide a wrapping machine having a system for removing reel cores which is inexpensive, safe and reliable.

These and further objects are achieved by a wrapping machine according to one or more of the claims set out below.

The invention can be better understood and implemented with reference to the attached drawings which illustrate exemplifying and non-limiting embodiments thereof, in which:.

With reference to <FIG>, a system <NUM> of the wrapping machine <NUM> of the invention is illustrated, configured to remove a core <NUM> of film reel from a reel holder shaft <NUM> of an unwinding apparatus <NUM> of said wrapping machine <NUM>. The wrapping machine <NUM>, illustrated in <FIG> by way of example and not of limitation, is for example a horizontal rotating ring machine of a known type, and the unwinding apparatus <NUM> is also of a known type and comprises film unwinding and pre-stretching rollers and a reel holder shaft <NUM>.

The reel holder shaft <NUM> is rotatably fixed to the unwinding apparatus <NUM> and is configured to support a film reel.

The system <NUM> comprises a removing apparatus <NUM> adapted to receive from the reel holder shaft <NUM> and remove therefrom a core <NUM> of a depleted film reel.

The reel holder shaft <NUM> comprises a lower end <NUM> provided with one or more abutment arms or brackets <NUM> angularly spaced about a first longitudinal axis X1 of the reel holder shaft <NUM> and movable between an open configuration A for abutting and supporting the core <NUM> mounted on the reel holder shaft <NUM> and a closed configuration B for allowing to remove, or insert, the core <NUM> from/into said reel holder shaft <NUM>.

In the embodiment illustrated in <FIG> by way of example and not of limitation, the reel holder shaft <NUM> of the wrapping machine comprises two abutment arms <NUM> positioned diametrically opposite at the lower end <NUM> and mounted rotatably about respective axes parallel to each other and orthogonal to the first longitudinal axis X1. The first longitudinal axis X1 is the rotation axis of the reel holder shaft <NUM> and is substantially vertical. However the lower end <NUM> of the reel holder shaft <NUM> can be provided with a single abutment arm <NUM> rotatable about a respective axis orthogonal to the first longitudinal axis X1 or can be provided with three or more abutment arms <NUM> arranged angularly and regularly spaced about the first longitudinal axis X1 and rotatably mounted about respective axes parallel to each other and orthogonal to the first longitudinal axis X1.

The removing apparatus <NUM> comprises a supporting element <NUM> provided with a side wall <NUM> which forms an internal cavity <NUM>, in particular substantially cylindrical, having an upper opening <NUM> and an upper peripheral edge <NUM> which bounds the aforesaid upper opening <NUM> and forms a flat supporting surface adapted to abut and maintain raised the core <NUM> when the lower end <NUM> of the reel holder shaft <NUM> is inserted into the internal cavity <NUM> in a removing configuration E with the abutment arms <NUM> disengaged and/or spaced from the core <NUM>.

The side wall <NUM> of the supporting element <NUM> comprises a plurality of elastic elements <NUM> arranged angularly spaced about and parallel to a second longitudinal axis X2 of the supporting element <NUM> so as to form with their respective central portions <NUM> the internal cavity <NUM> having a first internal diameter D1 greater than a first transverse dimension L1 of the lower end <NUM> with the abutment arms <NUM> arranged in the open configuration A.

The second longitudinal axis X2 is a longitudinal symmetry axis of the supporting element <NUM> and is substantially vertical.

The elastic elements <NUM> also comprise respective upper portions <NUM> shaped so as to form the upper peripheral edge <NUM> and the upper opening <NUM>, the latter having a second internal diameter D2 that is almost equal to an internal diameter Di of the core <NUM>.

The second diameter D2 of the upper opening <NUM> is preferably wider than a second transverse dimension L2 of the lower end <NUM> with the abutment arms <NUM> arranged in the closed configuration B. The second transverse dimension L2 is smaller than an internal diameter Di of the core <NUM>.

The elastic elements <NUM> are configured to elastically bend, in particular towards the outside, i.e. away from the second longitudinal axis X2, and to open wide when abutted by the abutment arms <NUM> in the open configuration A so as to allow inserting the lower end <NUM> into the internal cavity <NUM>. The elastic elements <NUM> when disengaged from the abutment arms <NUM> return to the initial non-bent configuration.

Each elastic element <NUM> has an elongated shape, in particular in a direction parallel to the second longitudinal axis X2, and a constant thin thickness. Each elastic element <NUM> is for example an elongated lamina or thin sheet of rectangular section.

The flexible elements <NUM> are made of an elastic metal alloy, for example spring steel.

Each elastic element <NUM> comprises a lower end portion 15a, connected to the central portion <NUM> and opposite the upper portion <NUM>, fixed to a base <NUM> of the supporting element <NUM> to allow said elastic element <NUM> to elastically bend on a respective bending plane passing through the second longitudinal axis X2.

The upper portion <NUM> of each elastic element <NUM> is folded internally towards the second longitudinal axis X2 so forming a respective contacting wall 16a arranged to be abutted by the abutment arms <NUM>, in particular in the open configuration A, during the insertion of the lower end <NUM> of the reel holder shaft <NUM> into the internal cavity <NUM>, and a flat supporting wall 16b arranged to abut and support the core <NUM>, in particular a lower end <NUM> of the latter. The contacting walls 16a and the supporting walls 16b of the plurality of elastic elements <NUM> form respectively the upper opening <NUM> and the upper peripheral edge <NUM> of the supporting element <NUM>.

Each supporting wall 16b has dimensions such that the upper peripheral edge <NUM> thus obtained, which forms a kind of flange, has a width equal to or greater than a wall thickness of the core <NUM>.

The contacting wall 16a and the supporting wall 16b of the upper portion <NUM> of each elastic element <NUM> are respectively almost parallel and almost perpendicular to the second longitudinal axis X2.

The upper portion <NUM> of each elastic element <NUM> further comprises an inclined section 16c interposed between the contacting wall 16a and the supporting wall 16b and converging towards the base wall <NUM>. The inclined sections 16c of the upper portions <NUM> of the plurality of elastic elements <NUM> form a draft wall or portion which facilitates insertion of the lower end <NUM> of the reel holder shaft <NUM> into the internal cavity <NUM> of the supporting element <NUM>.

In the removing configuration E, the upper portions <NUM> are adequately spaced apart from the abutment arms <NUM> to allow the latter to be freely rotated inwards without collisions, towards the first longitudinal axis X1 in the closed configuration B.

The two abutment arms <NUM> are rotated between the open configuration A and the closed configuration B by a driving shaft <NUM> passing inside the reel holder shaft <NUM> and moved along the first axis X1 by actuating means of a known type and not illustrated, acting on an upper end portion <NUM> of said driving shaft <NUM>.

A lower portion <NUM> of driving shaft <NUM> comprises an annular groove <NUM> in which rollers <NUM> are engaged that are fixed to the abutment arms <NUM>. Thereby, by linearly moving the driving shaft <NUM> from a raised position R to a lowered position L and vice versa, the abutment arms <NUM> are rotated respectively from the open configuration A to the closed configuration B (<FIG>). The driving shaft <NUM> is maintained in the lowered position by a spring <NUM> acting on the upper end portion <NUM>.

The removing apparatus <NUM> further comprises first supporting means <NUM> arranged to support the supporting element <NUM>, in particular slidably and elastically along the second longitudinal axis X2, and second supporting means <NUM> adapted to support the first supporting means <NUM>, in particular to move the supporting element <NUM> in an operating position where it is able to receive the reel holder shaft <NUM>.

The first supporting means <NUM> comprise a base element <NUM> to which the supporting element <NUM> is fixed and which is slidably connected to a first support <NUM> of the second supporting means <NUM>. The first supporting means <NUM> also include elastic means <NUM>, for example a coil spring, that are interposed between the first support <NUM> and the base element <NUM> and are adapted to maintain the latter in a raised position and allow its lowering in order to absorb a possible downward thrust generated by the insertion of the reel holder shaft <NUM> in the supporting element <NUM>.

In the embodiment of the removing apparatus <NUM> illustrated in <FIG> and <FIG>, second supporting means <NUM> comprise the first support <NUM> in the form of an elongated arm or beam, a second support <NUM> elongated, almost vertical, which rotatably supports the first support <NUM> and is fixed to a platform or base <NUM> provided with supporting feet.

A linear actuator <NUM> is fixed to the base <NUM> and connected to the first support <NUM> to rotate the latter between an operative position and an inoperative position about an almost horizontal rotation axis.

In the operative position the first support <NUM> is substantially horizontal and positions the first supporting means <NUM> with the supporting element <NUM> inside an operative area of the wrapping machine to allow the reel holder shaft <NUM> with the core <NUM> to be inserted into the supporting element <NUM>.

In the inoperative position, the first support <NUM> is raised in a vertical or inclined position so as to position the first supporting means <NUM> with the supporting element <NUM> outside the operating area of the wrapping machine.

The operation of the system of the wrapping machine <NUM> of the invention configured to remove a core <NUM> of a depleted film reel from the unwinding apparatus <NUM> of the wrapping machine <NUM> provides a first insertion step in which the reel holder shaft <NUM> is lowered so that the lower end <NUM> thereof is inserted inside the supporting element <NUM> of the removing apparatus <NUM> (<FIG>). To this end, the first support <NUM> of the second supporting means <NUM> is arranged in the operative position, such that the reel holder shaft <NUM> and the supporting element <NUM> of the removing apparatus <NUM> are aligned, and in particular the first longitudinal axis X1 of the reel holder shaft <NUM> and the second longitudinal axis X2 of the supporting element <NUM> are almost coincident.

The reel holder shaft <NUM> carries a core <NUM> of depleted reel which is supported and maintained engaged to said reel holder shaft <NUM> by the two abutment arms <NUM> arranged in the open configuration A in which they abut and support a lower end <NUM> of said core <NUM>.

In the removing configuration E, the lower end <NUM> of reel holder shaft <NUM> is inserted into the internal cavity <NUM> of the supporting element <NUM> by a length or quantity such as to allow raising the core <NUM>, i.e. disengaging and detaching the core from the abutment arms <NUM>. In fact, the core <NUM> abuts and is supported by the upper peripheral edge <NUM> of the supporting element <NUM>, while the lower end of the reel holder shaft <NUM> with the abutment arms <NUM> penetrates the internal cavity <NUM>. The upper peripheral edge <NUM> has dimensions such as to be able to support also cores <NUM> having small thickness i.e., with a small external diameter. To this end, the upper opening <NUM> of the internal cavity <NUM>, bounded by the external peripheral edge <NUM>, has a second diameter D2 almost equal to the internal diameter Di of the core <NUM>. The second diameter D2 is therefore smaller than the first transverse dimension L1 of the lower end <NUM> with the abutment arms <NUM> arranged in the open configuration A.

The internal cavity <NUM>, which is formed by the side wall <NUM> which consists of the plurality of elastic elements <NUM> arranged angularly and regularly spaced about the second longitudinal axis X2, has an internal diameter D1 greater than the first transverse dimension L1 of the lower end <NUM> with the abutment arms <NUM> arranged in the open configuration A so as to allow rotating the abutment arms in the closed configuration B and therefore raising the reel holder shaft <NUM> and disengaging the core <NUM>. To this end, in the removing configuration E, upper portions <NUM> are adequately spaced from the abutment arms <NUM> to allow the latter ones to be freely rotated in the closed configuration B without collisions inside, towards the first longitudinal axis X <NUM>.

It should be noted that it is possible to insert the lower end <NUM> of reel holder shaft <NUM> with abutment arms <NUM> in the open configuration A into the internal cavity <NUM> (having an upper opening <NUM> having a second diameter D2 smaller than the first transverse dimension L1 of the lower end <NUM>) because the side wall <NUM> of supporting element <NUM> is made by the plurality of elastic elements <NUM> that are capable of elastically bending and opening wide when abutted by the abutment arms <NUM>. More precisely, when inserted the abutment arms <NUM> contact and bend a limited number of elastic elements <NUM>, wherein the remaining, and most of the, elastic elements <NUM> remain vertical so as to adequately support the core <NUM>. When the lower end <NUM> is fully inserted into the internal cavity <NUM>, the elastic elements <NUM> that are bent are disengaged from the abutment arms <NUM> and return to the non-bent vertical initial position. In a second removing step of in which the reel holder shaft <NUM> and the core <NUM> are removed, the abutment arms <NUM> are rotated in the closed configuration B by means of the driving shaft <NUM> which is moved from the raised position R (in which the abutment arms <NUM> are in the open configuration A) to the lowered position L.

At this point it is possible to lift and remove the reel holder shaft <NUM> from the supporting element <NUM> since the second transverse dimension L2 of the lower end <NUM> with the abutment arms <NUM> in the closed configuration B is smaller than the internal diameter Di of the core <NUM> and the latter is fully supported by the supporting element <NUM>.

The second diameter D2 of the upper opening <NUM> of the internal cavity <NUM> is preferably wider than the second transverse dimension L2 of the lower end <NUM> with the abutment arms <NUM> in the closed configuration B.

Thanks to the system of the wrapping machine of the invention, it is therefore possible to remove cores or central elements of depleted film reels having any thickness, i.e. with different external diameters, from a reel holder shaft of the wrapping machine without the need to modify the reel holder shaft and in particular the abutment arms.

Thanks to the elastic elements <NUM> forming the side wall <NUM> of the supporting element <NUM>, it is in fact possible to firmly and safely support cores of film reel having different thicknesses, even thin (e.g. with an external diameter less than <NUM> and an internal diameter of about <NUM>-<NUM>), and at the same time interact with reel holder shafts <NUM> having abutment arms <NUM> of standard length, configured to adequately support cores of standard thickness (typically with an outer diameter between <NUM> and <NUM>). In fact, the bending of the elastic elements <NUM> allows to easily insert the lower end <NUM> of reel holder shaft <NUM> with the abutment arms in the open configuration A (for example with a first dimension L1 of about <NUM>) even if the upper opening <NUM> of the internal cavity <NUM> has smaller dimensions (for example a diameter D2 equal to the internal diameter Di of the core <NUM>) in order to effectively also support cores of small thickness.

It should also be noted that thanks to the elastic elements <NUM>, which are capable to elastically bend, the insertion of the reel holder shaft <NUM> inside the supporting element may require less precision and accuracy than that required in the known systems and wrapping machines, since possible collisions between the lower end <NUM> of the reel holder shaft and the upper peripheral edge <NUM> of the supporting element <NUM> do not involve any damage (but only the elastic bending of some elastic elements <NUM>).

Claim 1:
Wrapping machine (<NUM>) comprising an unwinding apparatus (<NUM>) and a system (<NUM>) for removing from said unwinding apparatus (<NUM>) a core (<NUM>) of film reel, said unwinding apparatus (<NUM>) comprising a reel holder shaft (<NUM>) suitable to support a film reel and having a lower end (<NUM>) provided with at least one abutment arm (<NUM>) movable between an open configuration (A) to support said core (<NUM>) inserted in said reel holder shaft (<NUM>) and a closed configuration (B) to allow removing or inserting said core (<NUM>) from/into said reel holder shaft (<NUM>), said system (<NUM>) comprising a removing apparatus (<NUM>) which includes a supporting element (<NUM>) provided with a side wall (<NUM>) forming an internal cavity (<NUM>) having an upper opening (<NUM>) and an upper peripheral edge (<NUM>) which bounds the upper opening and forms a flat supporting surface adapted for abutting and supporting said core (<NUM>) when said lower end (<NUM>) of said reel holder shaft (<NUM>) is inserted into said internal cavity (<NUM>) in a removing configuration (E) with said abutment arm (<NUM>) that is disengaged and spaced from said core (<NUM>), said wrapping machine (<NUM>) being characterized in that said side wall (<NUM>) of said supporting element (<NUM>) comprises a plurality of elastic elements (<NUM>) arranged angularly spaced about and parallel to a second longitudinal axis (X2) of said supporting element (<NUM>) so as to form by means of respective central portions (<NUM>) said internal cavity (<NUM>) having a first diameter (D1) wider than a first transverse dimension (L1) of said lower end (<NUM>) with said abutment arm (<NUM>) arranged in said open configuration (A), said elastic elements (<NUM>) comprising respective upper portions (<NUM>) shaped so as to form said upper peripheral edge (<NUM>) and said upper opening (<NUM>) that has a second diameter (D2) substantially equal to an internal diameter (Di) of said core (<NUM>), said elastic elements (<NUM>) being configured to elastically bend and open wide when abutted by said abutment arm (<NUM>) in said open configuration (A) in order to enable said lower end (<NUM>) to enter said internal cavity (<NUM>).