Wrapping machine

Abstract

A wrapping machine (1) for wrapping a load (100) with a band (50) made of a cellulose and / or vegetable fibers based material, in particular paper, unwound from a reel (51) comprises an upright (3), a moving carriage (4) movable along the support upright (3), unwinding apparatus (5) for supporting a reel (51) of band and provided with roller means (20) for unwinding the band (50), moving means (2; 62; 72) for moving said upright (3; 63; 73) and said load (100) around each other for a plurality of wrapping turns and a supporting arm (10) supporting pressure means (11) and cutting means (12) respectively to press a portion of the band (50) on the load (100) at the end of the wrapping and to cut the band (50); the unwinding apparatus (5) is fixed to the moving carriage (4) rotatably about a tilt axis (S) to tilt along with the band (50) during the wrapping of the load (100) and the supporting arm (10) is rotatably fixed to the moving carriage (4) about a rotation axis (X) so as to rotate between a non-operating position (A), in which the pressure means (11) and the cutting means (12) are spaced apart from the load (100), and an operating position (B), in which they are substantially in contact with the load (100).

Description

[0001] Wrapping machine

[0002] The invention relates to wrapping machines for wrapping a load with a band made of a paper and / or cellulose or vegetable fibers based material.

[0003] In the packaging sector, the use of sheets and bands made of paper material or similar material is well known for packaging products, typically envelopes and bags. In particular, the use of Kraft-type paper, also called wrapping paper, for packaging is widely used, since this paper is characterized by a high resistance, in particular to traction and punctures and tears, and longitudinal and transverse elasticity. Kraft paper can be smooth or have creases or micro-creases that accentuate the elasticity thereof.

[0004] By virtue of its mechanical features and its complete recyclability, Kraft paper can also be validly used for wrapping palletized loads, i.e., loads formed by a single product or by a plurality of products grouped and arranged on a pallet, in place of the films of cold-extensible plastic material generally used. In fact, the need to reduce the use and consumption of plastics is increasingly felt also in the field of wrapping palletized products, which, as is known, if not correctly handled and above all disposed of, significantly contribute to environmental pollution. Paper is instead an eco-friendly and eco-sustainable material obtainable both from recycling pre-existing paper and from sustainable productions.

[0005] The known wrapping machines for wrapping with paper typically comprise an unwinding apparatus which is movable parallel and / or about a wrapping axis and which supports a reel of paper band from which the paper band 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.

[0006] In wrapping machines provided with a rotary table for supporting the load, during the wrapping cycle the latter is rotated about a vertical wrapping axis, while the unwinding apparatus is moved parallel to the wrapping axis with a reciprocating motion along a fixed column of the wrapping machine.

[0007] In wrapping machines with a 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 wrapping 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.

[0008] Even in self-propelled wrapping machines, also called self-propelled wrapping robots, the load remains static during wrapping since these machines are configured to rotate about it in order to wrap it with the band. Self-propelled wrapping machines include a trolley or carriage that supports a vertical upright along which the unwinding apparatus is movable, with a reciprocating linear motion. The carriage is provided with motorized driving wheels and a steering device comprising one or more steering wheels, operated by a steering mechanism. The steering mechanism may be operated via a guide bar by an operator to manually drive the machine in a manoeuvring configuration, or from a feeler element capable of following the profile or external shape of the load in an operational working configuration, in which the self-propelled machine turns autonomously and automatically around the load to wrap it with the film.

[0009] The unwinding apparatus is generally provided with a series of rollers for diverting the unwound paper band from the reel towards the load during the unwinding.

[0010] In order to avoid folds and wrinkles in the paper during the wrapping, the unwinding apparatus is generally mounted on the wrapping machine so that it can be tilted about a horizontal axis by an angle substantially equal to the helical wrapping angle, such a helical angle being a function, as known, of the vertical linear displacement of the unwinding apparatus in one wrapping turn.

[0011] To this end, various solutions are known for tilting the unwinding apparatus, which are generally rather complex and costly.

[0012] At the end of the wrapping the paper band must be fixed to the load and then cut to obtain a first paper flap fixed to the load and a second paper flap connected to the reel and retained by special gripping means.

[0013] In particular, the first paper flap is positioned by suitable pressure means on the load and fixed to the layers of paper already wrapped around the load by means of glue or adhesive. Cutting means are also included for cutting the paper band.

[0014] A problem of the pressure and cutting means of the known wrapping machines lies in the difficulty of executing a precise and correct cut of the paper and in making the first paper flap obtained from the cut adhere optimally to the load.

[0015] It is an object of the invention to improve the known wrapping machines suitable for wrapping a load with a paper band or cellulose and / or vegetable fibers based material in particular with a palletized load formed by a plurality of products grouped and superimposed on a pallet.

[0016] Another object is to provide a wrapping machine which allow any type of load to be wrapped firmly and compactly by means of a paper band or the like, avoiding the formation of folds and wrinkles on said band during the wrapping and reducing and substantially eliminating the risks of its breakage or tearing.

[0017] A further object is to provide a wrapping machine that allows the various bands or strips of paper band wrapped around the load to be optimally fixed in order to achieve a firm, compact and robust wrapping of the load.

[0018] A still further object is to provide a wrapping machine which allow to precisely and accurately cut the paper band at the end of the wrapping and to optimally fix a terminal flap of the band, obtained from the cut, to a side wall of the load.

[0019] Another further object is to provide a wrapping machine having simple and economical construction and precise and reliable operation.

[0020] These and other objects are achieved by a wrapping machine according to claim 1.

[0021] The invention can be better understood and implemented with reference to the attached drawings which illustrate some exemplifying and non-limiting embodiments thereof, in which:

[0022] Figure 1 is a perspective view of a wrapping machine of the invention, of the rotary table type, associated with a palletized load to be wrapped, shown in dashed lines;

[0023] Figure 2 is a partial and enlarged top plan view of the wrapping machine of Figure 1 illustrating, in particular, an unwinding apparatus and a supporting arm provided with fixing means and cutting means and arranged in a non-operating position;

[0024] Figure 3 is a partial, enlarged top view of the wrapping machine shown in Figure 1, illustrating the unwinding apparatus and the supporting arm provided with fixing and cutting means and arranged in an operating position.

[0025] Figure 4 is a side, partial and enlarged view of the wrapping machine of Figure 1, illustrating in particular the unwinding apparatus and the supporting arm with the fixing means and the cutting means and arranged in the non-operating position;

[0026] Figure 5 is a front perspective view of the unwinding apparatus and of the supporting arm with the fixing means and the cutting means, in which some parts have been removed to better highlight others;

[0027] Figure 6 is an enlarged section along plane VI- VI of Figure 4.

[0028] Figure 7 is a rear perspective view of the unwinding apparatus and the supporting arm with the fixing means and the cutting means, in which some parts have been removed to better highlight others;

[0029] Figures 8 and 9 are enlarged details of Figure 7 illustrating a connecting pin for connecting the unwinding apparatus to a moving carriage;

[0030] Figure 10 is an enlarged front view of the unwinding apparatus and the supporting arm with the fixing means and the cutting means, in which some parts have been removed to better highlight others;

[0031] Figure 11 is a partial and enlarged perspective view of the supporting arm and the pressure means and the cutting means, illustrating in particular a pressure roller, cutting means in an extended position and a gripping device in a closed position;

[0032] Figure 12 is an enlarged perspective view of the pressure means and the cutting means, illustrating in particular the cutting means in the retracted position and the gripping device in the open position;

[0033] Figure 13 is a top plan view of a wrapping machine of the invention of the rotating arm type and associated with a load;

[0034] Figure 14 is a top plan view of a wrapping machine of the invention of the self-propelled type and associated with a load.

[0035] With reference to Figures 1 to 12, the wrapping machine 1 of the invention is shown, arranged to wrap a load 100 with a band 50 unwound from a reel 51. The band 50 is made of a paper and / or cellulose and / or vegetable fibers based material; for example, it is a Kraft paper band of a known type, commercially available. The load 100 is, for example, a palletized load formed by a single product or by a plurality of products grouped and arranged on a pallet 101.

[0036] The wrapping machine 1 comprises an upright 3, a moving carriage 4 slidably coupled to, and movable along, the upright 3, a unwinding apparatus 5, comprising a first mounting frame 6 to rotatably support a reel 51 of band 50 and roller means 20 for unwinding from the reel 51 and guiding the band of material 50, in particular towards the load 100, and moving means 2 for moving the upright 3 and the load 100 around each other for a plurality of wrapping turns.

[0037] In particular, in the embodiment illustrated in figures 1 to 12, the wrapping machine 1 of the invention is of the rotary table or rotating platform type, i.e. the moving means comprise a rotary table 2 which is adjacent to the upright 3, also called column or pole, and adapted to receive and support the load 100. The table 2 is rotatable about a wrapping axis W, in particular a substantially vertical one.

[0038] The first mounting frame 6 of the unwinding apparatus 5 supports a reel-holder shaft 30 rotatably about a first longitudinal axis XI of rotation and arranged to receive a reel 51 of band and an upper contrasting elastic element 39 coaxial to said reel-holder shaft 30 and cooperating with the latter to support the reel 51. The unwinding apparatus 5 may further comprise brake means fixed to the first mounting frame 6 and associated with, and acting on, the reel-holder shaft 30 to adjust a rotation speed thereof about the first longitudinal axis XI of rotation.

[0039] The moving carriage 4 is moved along the upright 3, parallel to the wrapping axis W by driving means of a known type and not illustrated in detail, in particular with reciprocating motion, both upward and downward.

[0040] The wrapping machine 1 also comprises a supporting arm 10 that supports pressure means 11 and cutting means 12 configured respectively to press a portion of the band 50 on the load 100 at the end of a wrapping cycle and to cut the band 50 so as to make a first band flap fixed to the load 100 and a second band flap connected to the reel 51, as better explained in the following description.

[0041] The unwinding apparatus 5 is rotatably fixed to the moving carriage 4 about a tilt axis S, which is in particular substantially orthogonal to the upright 3 so as to tilt with the band 5 during wrapping of the load 100, while the supporting arm 10 is rotatably fixed to the moving carriage 4 about a rotation axis X, which is in particular substantially parallel to the upright 3 so as to rotate between a non-operating position A, in which the pressure means 11 and the cutting means 12 are spaced apart from the load 100 (fig. 2), and an operating position B, in which the pressure means 11 and the cutting means 12 are substantially abutting against the load 100 (fig. 3).

[0042] The moving carriage 4 further comprises a second mounting frame 8.

[0043] The unwinding apparatus 5 is rotatably fixed to the moving carriage 4 about the tilt axis S so as to tilt with the band 50 during the wrapping of the load 100. More precisely, the first mounting frame 6 of the unwinding apparatus 5 is rotatably connected to the second mounting frame 8 of the moving carriage by means of a connecting pin 7. More in detail, the connecting pin 7 is rotatably fixed to the first mounting frame 6, for example to a connecting element 16 of the latter, and is coupled to the second mounting frame 8. Specifically, the connecting pin 7 is inserted into, and coupled to, a seat 18 of the second mounting frame 8 of the moving carriage 4. In particular, the connecting pin 7 is mounted on the connecting element 16 by means of a bearing or a rotation bushing 19.

[0044] The moving carriage 4 is slidably coupled to the upright 3 by means of two pairs of rollers 34 inserted and sliding inside longitudinal guides 35 made inside the upright 3. Each pair of rollers 34 is mounted free to rotate on the end of a respective supporting shaft 36 fixed to the second mounting frame 8.

[0045] The latter comprises, for example, a "U" shaped plate provided with a first portion 8a, on which the supporting shafts 36 of the rollers 34 are fixed, a second portion 8b parallel and opposite to the first portion 8a, to which the supporting arm 10 is fixed and a third portion 8c, which connects the first portion and the second portion and is orthogonal thereto, in which the seat 18 is formed to receive the connecting pin 7, for example secured therein by interference fit.

[0046] The moving carriage 4 also comprises a third mounting frame 9 connected to the second mounting frame 8 and configured to rotatably support the supporting arm 10 about the rotation axis X. In other words, the supporting arm 10 is rotatably fixed to the third mounting frame 9 about the rotation axis X so as to rotate between the non-operating position A and the operating position B. In particular, the third mounting frame 9 has a box-like shape and is fixed to the second portion 8b of the second mounting frame 8.

[0047] Thus, the unwinding apparatus 5 and the supporting arm 10 are articulated to the moving carriage 4 independently of each other thanks to the independent connection to the second mounting frame 8, respectively of the first mounting frame 6 of the unwinding apparatus 5 and of the third mounting frame 9 that supports the supporting arm 10.

[0048] With particular reference to Figures 8 to 10, the wrapping machine 1 comprises first elastic means 31 interposed between the first mounting frame 6 of the unwinding apparatus 5 and the second mounting frame 8 of the moving carriage 4 and configured to control and limit an oscillating movement of the winding apparatus 1 about the tilt axis S. In particular, the first elastic means are adapted to maintain the unwinding apparatus 5 in a neutral position N in the absence of external forces, in particular of a traction force exerted by the band 50 during the wrapping of the load 100. In the neutral position N the first longitudinal axis XI of the reel-holder shaft 30 is substantially vertical, i.e. the unwinding apparatus 5 is substantially horizontal.

[0049] The elastic means 31 also limit the tilting of the unwinding apparatus 5 about the tilt axis S in the two rotation directions to a first maximum tilt angle and a second maximum tilt angle for example ranging between 2° and 10°. The first maximum tilt angle corresponds, for example, to the maximum tilt angle of the unwinding apparatus 5 during its movement along the upright 3 from bottom to top, in one phase of the wrapping cycle of the load 100, while the second maximum tilt angle corresponds to the maximum tilt angle of the unwinding apparatus 5 during its movement from top to bottom in another phase of the wrapping cycle of the load 100.

[0050] As better explained in the following description, during the wrapping of the load 100 the unwinding apparatus 5 is tilted by the same band 50 by an angle with respect to the wrapping axis W substantially equal to a wrapping angle of the band around the load 100, so as to avoid the formation of folds and wrinkles on the band 50.

[0051] As is known, the wrapping angle is the angle formed by a longitudinal edge 50a of the paper band 50 with a reference plane orthogonal to the wrapping axis W, i.e., substantially horizontal. This wrapping angle is a function of the vertical linear displacement of the unwinding apparatus 1 along the upright 3 during one wrapping cycle.

[0052] The first maximum tilt angle and the second maximum tilt angle may be equal or different; for example, the second maximum tilt angle may be smaller than the first maximum tilt angle.

[0053] The first elastic means comprise, for example, a pair of first springs 31 interposed between the first mounting frame 6 and the second mounting frame 8 on opposite sides of the tilt axis S i.e. of the connecting pin 7, in particular they are fixed to the supporting frames 6, 8 in a mirror position with reference to a reference plane L passing through the tilt axis S and orthogonal to the first longitudinal axis XI of the reel -holder shaft 30.

[0054] Each first spring 31, in particular a coil spring of the compression type, is connected to a respective first supporting element 32 of the first mounting frame 6 and to a respective second supporting element 33 of the second mounting frame 8.

[0055] More precisely, each first spring 31 comprises a first end 31a fixed to a respective first bracket- shaped supporting element 32 and fixed to the connecting element 16 of the first mounting frame 6 and a second end 31b inserted in a connecting pin 43 connected to the second ledge-shaped supporting element 33 and fixed to the third portion 8c of the second mounting frame 8 (figure 8).

[0056] With particular reference to figures 4, 5 and 7, the roller means 20 comprise a dancer roller 23 arranged to be engaged by the band 50 exiting the winding apparatus 1 and directed towards the load 100. The dancer roller 23, free to rotate about a second longitudinal axis X2 of rotation, has opposite connecting ends 23a which are slidably coupled to the first mounting frame 6 in such a way as to be movable and / or tiltable on an adjusting plane K passing through the second longitudinal axis X2 of rotation of the dancer roller 23 and parallel to the tilt axis S.

[0057] More precisely, the connecting ends 23 a of the dancer roller 23 are slidably engaged in respective rectilinear, facing and opposite through slots 24 of the first mounting frame 2 and are configured so that the dancer roller 23 can be moved linearly along an adjusting direction R, in particular substantially parallel to the tilt axis S, and is tiltable about one of a plurality of further tilt axes V substantially orthogonal to the second longitudinal axis X2 of rotation of the dancer roller 23 and to the tilt axis S. The through slots 24 are made on opposite upper and lower plates of the first mounting frame 6.

[0058] In operation, the dancer roller 23 engaged by the band 50 tilts with the latter exiting the unwinding apparatus 5, that is, it tilts by an angle and in a direction that are a function of the angle and the tilting direction of the band 50 that is wrapped around the load 100. In addition, the entire dancer roller 23 can be linearly moved along the direction of R by the band 50, with the connecting ends 23a sliding within the respective straight through slots 24.

[0059] Second elastic means 25 are provided, which are fixed to the first mounting frame 6 and acting on the connecting ends 23 a of the dancer roller 23 to keep it or return it to a resting position in the absence of external forces, in particular of a traction force exerted by the band 50 during the wrapping of the load 100. In the rest position, the second longitudinal axis X2 of rotation of the dancer roller 23 is substantially orthogonal to the tilt axis S and the connecting ends 23 a of the dancer roller 23, for example, abut end portions of the through slots 24.

[0060] As better explained in the following description, the second elastic means 25 oppose the traction force or tension exerted by the band 50 during the wrapping around the load 100.

[0061] The second elastic means comprise, for example, a pair of second springs 25, in particular coil springs of the traction type, each of which having a first end 25a fixed to the first mounting frame 6 and a second end 25b connected by means of a respective cable 26 and respective return pulleys 27 to a connecting end 23a of the dancer roller 23.

[0062] In particular, the first end 25a of each second spring 25 is adjustably fixed to a fixing element 17 of the first mounting frame 6. More precisely, the fixing element 17 comprises a plurality of mutually spaced apart fixing holes to which the aforementioned first ends 25a of the second springs 25 can be fixed by means of pins or screws to adjust a tension or traction force to be exerted by the cables 26 on the dancer roller 23.

[0063] The roller means 20 of the unwinding apparatus 5, in addition to the dancer roller 23, comprise a plurality of guide rollers 21 and an unwinding roller 22 adjacent to the reel 51 and, for example, controllable in terms of rotational speed. In particular, the unwinding roller 22 may be associated with a brake or a motor, so as to control a traction or “pulling” force of the band 50 during the wrapping cycle, specifically in such a way as to keep the value of said traction force within a predefined range, in order to avoid, on the one hand, the band breaking and, on the other hand, the load being wrapped too loosely.

[0064] The unwinding roller 22 can operate in cooperation or alternatively with any brake means acting on the reel-holder shaft 30.

[0065] The guide rollers 21 and the dancer roller 23 can be made of carbon fiber which is, among other things, an antistatic material that prevents the deposition and accumulation of dust of material, e.g. paper, generated by the sliding and wrapping of the band 50 around the rollers. In addition, as evidenced by numerous tests conducted by the Applicant, the carbon fibre rollers absorb the tangential stresses that are generated during wrapping, thus allowing the mechanical components that support the rollers to be safeguarded.

[0066] The pressure means 11 comprise at least one pressure roller 41 mounted on a fourth mounting frame 40 that is fixed to an external end 10a of the supporting arm 10, in particular opposite to an internal end 10b of the supporting arm 10 which is rotatably connected to the moving carriage 4 and, more precisely, to the third mounting frame 9 of the latter.

[0067] The pressure roller 41 is mounted, free to rotate about a respective longitudinal axis, to two opposite first connecting brackets 47 of the fourth mounting frame 40. The pressure roller 41 comprises at least one outer layer of elastomeric material, or the like.

[0068] The cutting means 12 comprise a blade 42, in particular a serrated blade, slidably supported by the fourth mounting frame 40 and having a length equal to, or longer than, a width of the band 50. The blade 42 is movable on a cutting plane T orthogonal to the band 50 and transverse, in particular orthogonal, to opposite longitudinal edges 50a of the band 50 to abut and cut the latter. The blade 42 is housed within a casing 44, of elongated shape, fixed to the fourth mounting frame 40 and provided with an elongated opening 45. The blade 42 is movable on the cutting plane T between a retracted position D, in which it is completely contained inside the casing 44 so as not to interact with the band 50 and not to be accessible to an operator, and an extended position E, in which the blade 42 partially protrudes from the casing 44 through the elongated opening 45 so as to abut and cut the band 50.

[0069] The blade 42 is actuated between the retracted position D and the extended position E by first actuating means of known type, not described and illustrated.

[0070] A gripping device 13 is also fixed to the external end 10a of the supporting arm 10, adjacent to the pressure means 11 and the cutting means 12 and arranged to grip and retain the band 50 and in particular a second band flap connected to the reel 50 and generated by the cutting of the band 50 by the blade 42 at the end of the wrapping cycle.

[0071] In particular, the gripping device 13 is fixed to the fourth mounting frame 40 next to the cutting means 12 and on the opposite side with respect to the pressure means 11. In particular, the gripping device 13 is fixed to a second connecting bracket 48 of the fourth mounting frame 40.

[0072] The gripping device 13 comprises, for example, a gripper formed by a fixed jaw 13a, connected to the second connecting bracket 48, and a movable jaw 13b rotatably coupled to the fixed jaw 13a and actuated by second actuator means of a known type, not described and illustrated, between a closing configuration Cl in which it abuts against the fixed jaw 13a to grip and retain the band 50, and an opening configuration C2, in which said movable jaw 13b is spaced apart from the fixed jaw 13a so as not to interact with the band 50 during the wrapping of the load 100.

[0073] The supporting arm 10 is rotated about the rotation axis X between the non-operating position A and the operating position B by drive means 46 fixed to the moving carriage 4. The drive means 46 comprise, for example, a linear actuator, of the electric or pneumatic type, having a first end rotatably connected to the third mounting frame 9 of the moving carriage 4 and a second end rotatably connected to the internal end 10b of the supporting arm 10.

[0074] The wrapping machine 1 of the invention further comprises at least one dispensing unit for dispensing an adhesive substance, arranged to spray or by spraying or similar process an adhesive substance on portions of the band 50, in particular portions intended to be wrapped on edges of the load 100. The dispensing unit is, for example, fixed to the first mounting frame 6 of the unwinding apparatus 5, positioned so as to dispense adhesive substance to the band 50 exiting the roller means 20.

[0075] The adhesive substance is, for example, a cold glue, supplied to the dispensing unit, for instance, by an external feeding unit, separate and independent from the wrapping machine 1.

[0076] Alternatively, the dispensing unit may dispense the glue in dots or discontinuous sections. However, the method of dispensing the spray or spray glue allows greater and better adhesion between the layers of paper applied and wrapped on the load and ensures a greater glued surface and greater overall resistance of the wrapping made. In addition, for this dispensing, the use of a dedicated controller (PLC) is not necessary, on the contrary, in the case of dispensing of glue in dots or discontinuous sections.

[0077] The operation of the wrapping machine 1 of the invention includes during a wrapping cycle of the load 100 that the unwinding apparatus 5 delivers the paper band 50 unwound from the reel 51 by virtue of the rotation about the wrapping axis W of the rotary table 2, on which the load 100 is positioned.

[0078] An initial flap of the band 50 made of paper is preliminarily fixed to the load 100 by gripping means 130 of the wrapping machine 1, provided on the rotary table 2 and arranged in a raised position to hold an initial flap of the band 50 (for example obtained by cutting the band in a previous wrapping cycle) so that it is covered and pressed by one or more strips of band wrapped around the load, according to a well known method and used in rotary table wrapping machines.

[0079] During the wrapping process, the unwinding apparatus 5 is moved by the moving carriage 4 with a reciprocating motion along the upright 3 so that the load 100 is wrapped by a plurality of partially overlapping strips of band with a helical pattern, thanks to the combination of relative linear and rotational movements between the unwinding apparatus 5 and the load 100. In particular, the band 50 is wrapped with a predefined wrapping angle which depends on the vertical linear displacement of the unwinding apparatus 5 during one wrapping turn. Since the unwinding apparatus 5 is mounted on the moving carriage 4 so that it can rotate about the tilt axis S, during wrapping it can be tilted by the unwinding band 50 in such a way that the band (more precisely its longitudinal edges 50c) is tilted relative to the wrapping axis W by a tilt angle substantially equal to the wrapping angle, so as to avoid the formation of folds and wrinkles on the paper band 50.

[0080] In particular, thanks to the connecting pin 7, rotatably fixed to the connecting element 16 of the first mounting frame 6 of the unwinding apparatus and inserted in, and coupled to, the seat 18 of the second mounting frame 8 of the moving carriage 4, and to the first elastic means 31, interposed between the first and second mounting frame 6, 8, the unwinding apparatus 5 can be easily and stably tilted during wrapping. In particular, the first springs 31 of the first elastic means, which are fixed to the supporting frames 6, 8 in a mirror position with reference to the reference plane L, allow to control and limit an oscillating movement of the unwinding apparatus 1 about the tilt axis S. More precisely, the first springs 31 maintain the winding apparatus 5 in the neutral position N (in which the first longitudinal axis XI is substantially vertical) in the absence of external forces, in particular in the absence of a traction force exerted by the band 50 during the wrapping of the load 100. Furthermore, the first elastic means 31 limit the tilting angles of the unwinding apparatus 5 about the tilt axis S in the two rotation directions respectively to a first maximum tilt angle and to a second maximum tilt angle in particular ranging between 2° and 10°.

[0081] During wrapping, thanks to the dancer roller 23 of the roller means 20, which is moveable and / or elastically tiltable on the adjusting plane K passing through the second longitudinal axis X2 and parallel to the tilt axis S, the band 4 can be tilted (together with the dancer roller 23) about one of a plurality of further tilt axes V that are substantially orthogonal to the tilt axis S. In this way the unwinding apparatus 5 during wrapping allows the band 50 a compensating movement at two degrees of freedom, i.e. about two tilt axes (tilt axis S and further tilt axis V) allowing to more effectively and efficiently avoid the formation of folds and wrinkles on such band and reducing and substantially eliminating the risks of breakage or tearing thereof. In addition, the dancer roller 23, since it is constrained to the first mounting frame 6, by means of the second elastic means 25 fixed to the first mounting frame 6 and acting on the connecting ends 23 a of the dancer roller 23 through cables 26 and return pulleys 27, exerts a defined traction force on the band 50 exiting the unwinding apparatus 5, also useful to prevent the formation of folds and wrinkles on this band 50.

[0082] The second elastic means 25 also make it possible in order to maintain or return the dancer roller 23 to a resting position in the absence of external forces, in particular in the absence of a traction force exerted by the band 50.

[0083] During wrapping, the dispensing unit dispenses an adhesive substance onto the band 50 exiting the unwinding apparatus 1, for example by spraying or nebulizing the adhesive onto portions of the band 50 intended to be wound on the edges (i.e. the vertical lines defined by the junction of two respective side walls) of the load 100.

[0084] Numerous tests carried out by the Applicant have shown that when the overlapping strips of band 50 adhere to and are joined together mainly at the edges of the load 100, the resulting wrapping is more stable, robust, and secure.

[0085] Once the wrapping of the load 100 with a defined number of strips of band 50 is completed, the rotary table 2 is stopped and the unwinding apparatus 5 is positioned at a predefined location along the upright 3, for example fully lowered or raised.

[0086] The supporting arm 10 is then rotated about the rotation axis X from the non-operating position A to the operating position B to allow the pressure means 11 and the cutting means 12 to be substantially in contact with the load 100. More precisely, the pressure roller 41 presses the band 50 against the wall of the load 100 to make it adhere firmly, while the blade 42 is moved on the cutting plane T from the retracted position D to the extended position E so as to partially escape from the casing 44 through the elongated opening 45 and thus cut the band 50.

[0087] Before cutting, that is, before activating the blade 42, the gripping device 13 previously arranged in the opening configuration C2 (in which the movable jaw 13b is spaced apart from the fixed jaw 13a so as not to interact with the band 50) is actuated in the closing configuration Cl (in which the movable jaw 13b abuts against the fixed jaw 13a) to grip and retain the band 50. In this way, after cutting by the blade 42, a first band flap is glued to the load 100 (at its side wall) and a second band flap, which is connected to the reel 50, is retained by the gripping device 13.

[0088] At a later stage, the moving carriage 4 can be moved along the upright 3 in a lowered position to allow the gripping means 130 of the wrapping machine 1, activated in the raised gripping position, to grip and retain the second band flap retained by the gripping device 13 which at this point can be disengaged and arranged in the opening configuration C2 to allow the supporting arm 10 to be returned to the non-operating position A.

[0089] Figure 13 illustrates another embodiment of the wrapping machine 1 of the invention of the rotating arm type, i.e. with the moving means comprising a rotating arm 62 that supports the upright 63 and is rotatable about a wrapping axis W, in particular vertical, so as to rotate the upright 3, the moving carriage 4, the unwinding apparatus 5 and the supporting arm 10 around the load 100 with the pressure means 11, the cutting means 12 and the gripping device 13. The rotating arm 62, of known type, is arranged substantially horizontally and is rotatably supported about the wrapping axis W by a mounting frame 65 of the wrapping machine 1. Figure 14 illustrates a further embodiment of the wrapping machine 1 of the invention of the self-propelled type, also called wrapping robot, in which the moving means comprise a self- propelled trolley or carriage 72 to which the upright 73 is fixed and which is provided with at least one driving wheel 74 and guiding means 75 to direct the carriage 72 so that it rotates around the load 100 during a wrapping cycle for a plurality of wrapping turns. The moving carriage 4 that supports the unwinding apparatus 2 and the supporting arm 10 with the pressure means 11, the cutting means 12 and the gripping device 13 is moved along the upright 73.

[0090] Thanks to the wrapping machine 1 of the invention, it is therefore possible to wrap any type of load in a firm and compact way by means of a band made of a cellulose and / or vegetable fibers based material, in particular paper, avoiding the formation of folds, creases, wrinkles on the band during wrapping and reducing and substantially eliminating the risks of breakage or tearing thereof.

[0091] The unwinding apparatus 5 during operation can in fact be tilted about the tilt axis S by the band 50 itself in such a way that the latter is tilted with respect to the wrapping axis W by a tilt angle substantially equal to the wrapping angle of the band 50 around the load 100.

[0092] The tilting of the unwinding apparatus 5 about the tilt axis S is further controlled and limited by first elastic means 31 that are interposed between the first mounting frame 6 of the unwinding apparatus 5 and the second mounting frame 8 of the moving carriage 4. More precisely, the first elastic means 31 limit a rotation of the unwinding apparatus 5 about the tilt axis S in the two rotation directions respectively to a first maximum tilt angle and to a second maximum tilt angle, in particular ranging between 2° and 10°. In addition, the first elastic means 31, which are arranged to maintain the wrapping apparatus 5 in a neutral position N in the absence of external forces, in particular in the absence of a traction force exerted by the band 50 during the wrapping of the load 100 elastically opposing the tilting of the unwinding apparatus 5, contribute to keeping the band 50 tight.

[0093] The dancer roller 23 of the roller means 20, which is elastically movable and / or tiltable on an adjusting plane K passing through its second longitudinal axis X2 and parallel to the tilt axis S, also allows to tilt the band 50, together with the same dancer roller 23, about one of a plurality of further tilt axes V which are substantially orthogonal to the tilt axis S.

[0094] The unwinding apparatus 5 of the machine of the invention therefore allows, during the wrapping of the paper band 50, a compensating movement at two degrees of freedom, namely about two tilt axes S and V, which are orthogonal to each other.

[0095] The wrapping machine 1 of the invention also allows the various bands or band strips wrapped around the load 100 to be optimally fixed so as to achieve a firm, compact and robust wrapping of the load.

[0096] In particular, with the supporting arm 10 in the operating position B, the pressure roller 41 presses the band 50 against the wall of the load 100 to make it adhere firmly, while the blade 42 is moved on the cutting plane T from the retracted position D to the extended position E so as to partially escape from the casing 44 through the elongated opening 45 and thus cut the band 50.

[0097] Before cutting, the gripping device 13 is operated in the closing configuration Cl to grip the band 50 and in particular to retain a second band flap connected to the reel and obtained after cutting by the blade 42.

[0098] It is to be noted that since the supporting arm 10 is rotatably supported by the moving carriage 4, which also supports the unwinding apparatus 5 and is movable along the upright 3, the band 50 at the end of the wrapping can be fixed at any desired height along a side wall of the load 100, i.e. in an upper or lower or central portion of the load 100. It is therefore not necessary to position the unwinding apparatus 5 at the same height as the gripping means placed on the rotary table as occurs in known machines in which the arm that supports the pressure means and the cutting means is fixed to a fixed structure of the machine, typically a base. The fixing and cutting operation of the band can take place at any height of the load 100 also thanks to the gripping device 13 supported by the supporting arm 10 and adjacent to the cutting means 12 that is able to grip and retain the second band flap 50 connected to the reel 51 and generated by the cutting. This second band flap can subsequently be transferred to the gripping means 130 of the wrapping machine 1 to disengage the gripping device 13 and return the supporting arm 10 to the non-operating position A and make the wrapping machine 1 ready for a new wrapping cycle.

[0099] The independent connection to the moving carriage 4 of the unwinding apparatus 5 and the supporting arm 10 allows to decouple the weight and the mechanical stresses associated on the one hand with the tilting of the unwinding apparatus 5 about the tilt axis S, and on the other hand with the rotation of the supporting arm 10 about the rotation axis X. Therefore, the connecting pin 7 can be optimized for the rotatable support of the unwinding apparatus 5 only, and the supporting arm 10 can be optimized for the support of the pressure means 11 and the cutting means 12 only, therefore the complexity of the components used and their wear are reduced. The possibility of moving the pressure means 11 and the cutting means 12 closer to / away from the load 100 independently of the unwinding apparatus 5 allows to optimize the occupation of the space during the wrapping of the load 100.

[0100] In addition, any maintenance or replacement of parts of the unwinding apparatus 5 can take place separately and independently of the supporting arm 10 and the pressure means 11 and cutting means 12, and vice versa.

Claims

CLAIMS1. Wrapping machine (1) for wrapping a load (100) with a band (50) made of a cellulose and / or vegetable fibers based material, in particular paper, unwound from a reel (51) comprising: an upright (3; 63; 73); a moving carriage (4) slidably coupled to, and movable along, said upright (3; 63; 73); an unwinding apparatus (5) comprising a first mounting frame (6) arranged to rotatably support a reel (51) of band (50) and roller means (20) for unwinding from said reel (51) and guiding said band (50); moving means (2; 62; 72) for moving said upright (3; 63; 73) and said load (100) around each other for a plurality of wrapping turns; a supporting arm (10) that supports pressure means (11) and cutting means (12) configured respectively for pressing a portion of said band (50) against the load (100) at the end of a wrapping cycle and for cutting said band (50) so as to create a first band flap fixed to said load (100) and a second band flap connected to the reel (50); characterised in that said moving carriage (4) comprises a second mounting frame (8) and a third mounting frame (9) connected to the latter; said unwinding apparatus (5) is rotatably fixed to said moving carriage (4) about a tilt axis (S), in particular substantially orthogonal to the upright (3; 63; 73), by means of a connecting pin (7) rotatably fixed to said first mounting frame (6) and coupled to said second mounting frame (8) so as to tilt with the band (50) during the wrapping of the load (100); said supporting arm (10) is rotatably fixed to said third mounting frame (9) about a rotation axis (X), in particular substantially parallel to the upright (3; 63; 73), so as to rotate between a non-operating position (A), in which said pressure means (11) and said cutting means (12) are spaced apart from said load (100), and an operating position (B) in which said pressure means (11) and said cutting means (12) are substantially in contact with said load (100).

2. Wrapping machine (1) according to claim 2, wherein said connecting pin (7) is rotatably fixed to a connecting element (16) of said first mounting frame (6) and is inserted in, and coupled to, a seat (18) of a second mounting frame (8) of said moving carriage (4).

3. Wrapping machine (1) according to one of the preceding claims, comprising first elastic means (31) interposed between said first mounting frame (6) and a second mounting frame (8) of said moving carriage (4) and configured to control and limit a swing movement of said unwinding apparatus (1) about said tilt axis (S), in particular to maintain said unwinding apparatus (5) in the absence of external forces, in particular of a traction force exerted by said band (50), in a neutral position (N), in which in particular a first longitudinal axis (XI) of rotation of a reel-holder shaft (30) of the unwinding apparatus (5) is substantially vertical.

4. Wrapping machine (1) according to claim 3, wherein said first elastic means (31) limit a rotation of said unwinding apparatus (5) about said tilt axis (S) in the two directions of rotation respectively to a first maximum tilt angle and to a second maximum tilt angle, in particular ranging between 2° and 10°.

5. Wrapping machine (1) according to claim 3 or 4, wherein said first elastic means comprise a pair of first springs (31) interposed between said first mounting frame (6) and said second mounting frame (8) on opposite sides of said tilt axis (S), in particular fixed to said supporting frames (6, 8) in mirror positions with respect to a reference plane (L) passing through said tilt axis (S) and orthogonal to the first longitudinal axis (XI) of rotation of said reel-holder shaft (30).

6. Wrapping machine (1) according to claim 5, wherein each first spring (31), in particular a compression coil spring, is connected to a respective first supporting element (32) of said first mounting frame (6) and to a respective second supporting element (33) of said second mounting frame (8).

7. Wrapping machine (1) according to one of the preceding claims, wherein said roller means (20) comprise at least one dancer roller (23) arranged to be engaged by said band (50) exiting the unwinding apparatus (5) and directed towards said load (100), said dancer roller (23) being free to rotate about a second longitudinal axis (X2) of rotation and having opposite connecting ends (23a) slidably coupled to said first mounting frame (6) in such a way as to be movable and / or tiltable on an adjusting plane (K) passing through said second longitudinal axis (X2) and parallel to said tilt axis (S).

8. Wrapping machine (1) according to claim 7, wherein said connecting ends (23a) of said dancer roller (23) are slidably engaged in respective rectilinear, facing and opposite through slots (24) of said first mounting frame (6) and configured in such a way that said dancer roller (23) can be moved linearly along an adjusting direction (R), in particular substantially parallel to said tilt axis (S), and is tiltable about one of a pluralityof further tilt axes substantially orthogonal to said second longitudinal axis (X2) and said tilt axis (S).

9. Wrapping machine (1) according to claim 8, comprising second elastic means (25) fixed to said first mounting frame (6) and acting on said connecting ends (23a) of said dancer roller (23) in order to maintain or return said dancer roller (23) to a rest position in which said second longitudinal axis (X2) is substantially orthogonal to said tilt axis (S).

10. Wrapping machine (1) according to claim 9, wherein said second elastic means comprise a pair of second springs (25), in particular traction coil springs, each of which having a first end (25a) fixed to the first mounting frame (6) and a second end (25b) connected by means of a respective cable (26) and at least one pulley (27) to a respective connecting end (23a) of said dancer roller (23).

11. Wrapping machine (1) according to one of the preceding claims, wherein said pressure means (11) comprise at least one pressure roller (41) mounted on a fourth mounting frame (40) that is fixed to an external end (10a) of said supporting arm (10).

12. Wrapping machine (1) according to any preceding claim, wherein said cutting means (12) comprise at least one blade (42), in particular a serrated blade, slidably supported by a fourth mounting frame (40) that is fixed to an external end (10a) of said supporting arm (10), said blade (42) having a length equal to, or longer than, a width of said band (50) and being movable on a cutting plane (T) which is orthogonal to said band (50) and transverse, in particular orthogonal, to opposite longitudinal edges (50a) of said band (50) so as to abut and cut said band (50).

13. Wrapping machine (1) according to claim 12, comprising a casing (44) fixed to said fourth mounting frame (40), provided with an elongated opening (45) and adapted to house said blade (42), the latter being movable on said cutting plane (T) between a retracted position (D), in which it is completely contained inside said casing (44) so as not to interact with the band (50), and an extended position (E), in which said blade (42) partially protrudes from said casing (44) through said elongated opening (45) so as to abut and cut said band (50).

14. Wrapping machine (1) according to one of the preceding claims, comprising at least one gripping device (13) fixed to an external end (10a) of said supporting arm (10) and adjacent to said pressure means (11) and to said cutting means (12) and arranged to grip and retain said band (50).

15. Wrapping machine (1) according to one of the preceding claims, wherein said moving means (2; 62; 72) comprise a rotary table (2) adjacent to said upright (3) and adapted toreceive and support said load (100), in particular said table (2) being rotatable about a wrapping axis (W), in particular vertical.

16. Wrapping machine (1) according to one of claims 1 to 14, wherein said moving means (2; 62; 72) comprise an arm (62) supporting said upright (63) and rotatable about a wrapping axis (W), in particular vertical, so as to rotate said upright (63) and said unwinding apparatus (5) around said load (100).

17. Wrapping machine (1) according to any one of claims 1 to 14, wherein said moving means (2; 62; 72) comprise a self-propelled carriage (72) supporting said upright (73) and provided with at least one driving wheel (74) and guiding means (75) to direct said carriage (72) so that the latter during a wrapping cycle rotates around said load (100) for a plurality of wrapping turns.

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