Strapping head, strapping apparatus, strapping method and wrapping apparatus

Abstract

A strapping head (1) is disclosed that is configured to wind and tighten a strip-shaped element around a load, the strapping head (1) comprising a containing casing (2) defining at least one chamber that is suitable for containing operating components of the strapping head (1) configured to perform at least: - one winding and tensioning step for winding and tensioning said strip-shaped element around the load, - one cutting step for cutting the strip-shaped element and - one immobilizing step for immobilizing opposite ends of the strip-shaped element so as to form at least one closed loop around the load. At least one through opening (3) arranged for connecting fluidly said at least one chamber to the outside environment is obtained in said containing casing (2). The strapping head (1) further comprises: - blowing means (6) arranged for drawing a fluid to be pressurized from outside the containing casing (2) and sending the fluid to be pressurized to the at least one chamber in the form of a flow of pressurized fluid having a pressure greater than that outside said containment casing (2), the blowing means (6) comprising an inlet (7) for the fluid to be pressurized and an outlet for the flow of pressurized fluid; and - supplying means (9) arranged for placing said blowing means (6) in fluid connection with the containing casing (2) to convey the flow of pressurized fluid from the blowing means (6) to inside the at least one chamber so that by traversing the at least one chamber and exiting the through opening (3) the fluid removes powder material present in the at least one chamber, expels the powder material outside the casing (2) and / or prevents powder material entering the at least one chamber from outside. A strapping apparatus, a wrapping apparatus and a strapping method are further disclosed.

Description

Background of the invention

[0001] The invention relates to a strapping head configured to wind and tighten a strip-shaped element around a load, a so-called strap.

[0002] The invention further relates to a strapping apparatus provided with this strapping head.

[0003] Moreover, the invention further relates to a wrapping apparatus provided with this strapping apparatus.

[0004] Lastly, the invention also relates to a strapping method for strapping a load.Prior art

[0005] Strapping apparatuses are known each comprising a strapping head configured to wind a load, in particular a palletized load, with a flexible strip-shaped element, a so-called strap, for example made of plastics or metal, and firmly tighten, or tension, the strip-shaped element around the load to give the load greater resistance, in particular during the conveying steps. In particular, the strapping head is arranged for creating one or more closed loops of strip-shaped element around the load.

[0006] During the winding step, the strip-shaped element is unwound from a reel and a first free end of the strip-shaped element is dragged around the load.

[0007] In order to remain taut around the load, the strip-shaped element is first tensioned and then cut from the strapping head so as to obtain a second end and the two ends of the strip-shaped element wound around the load are fixed together, for example by welding, so as to form at least one closed loop.

[0008] In order to perform the strapping operations, prior art strapping heads comprise operating components installed inside a containing casing.

[0009] Such operating components comprise, in particular, winding means configured to position the strip-shaped element around the load, tensioning means configured to tighten firmly the strip-shaped element around the load, cutting means configured to cut the strip-shaped element to obtain the second free end and joining means configured to immobilize the two ends of the strip-shaped element so as to form at least one closed loop.

[0010] One drawback of known strapping heads is that dirt accumulates inside the containing casing, for example in the form of powder material, in particular fine lead powder, which can damage one or more of the operating components of the strapping head. This powder material can originate, for example, from the strip-shaped element, which during winding around the load can release material because of the friction against the surfaces of the operating components on which it slides, from normal wear to the operating components of the strapping head located inside the containing casing and / or from dust or other material present inside a processing line along which the strapping apparatus of the strapping head is arranged.

[0011] In order to avoid an accumulation of this dirt inside the containing casing, it is necessary to perform maintenance and cleaning tasks on the strapping head that involve having to dismantle the strapping heads from the support frame to which they are fitted and open the containing casing to be able to reach the zones affected by the accumulation of powder material and remove the powder material.

[0012] The maintenance and cleaning tasks require lengthy or anyway not insignificant downtime to proceed with the removal of the powder material from the operating components of the strapping head. This extends the time necessary for completing a complete cycle of winding the load with the strip-shaped element.

[0013] Strapping head maintenance time thus significantly affects the productivity of known strapping apparatuses.

[0014] From the patent documents CN213862808 U, CN214029298 U and EP0022615 Al belonging to the state of the art, suction systems for the removal of powdery material and fumes are known. However, the removal of powdery material and fumes by suction is often not very effective and does not prevent the entry of powdery material and fumes into the strapping chamber.

[0015] There is thus ample room for improvement of the prior art.Summary of the invention

[0016] One object of the invention is to improve known strapping heads for winding and tightening a strip-shaped element around a load.

[0017] Another object is to make a strapping head that enables an accumulation of powder material inside the containing casing to be avoided.

[0018] Another object is to make a strapping head that enables productivity to be increased considerably compared with known strapping heads.

[0019] A further object is to obtain a strapping head that is simple and easily installable in already known strapping apparatuses.

[0020] These objects of the invention, and still others, are achieved with a strapping head, a strapping apparatus, a wrapping apparatus and a strapping method according to what is defined in the appended claims.

[0021] In one embodiment, a strapping head, configured to wind and tighten a strip-shaped element around a load, comprises a containing casing defining at least one chamber that is suitable for containing operating components of the strapping head configured to perform at least: one winding and tensioning step for winding and tensioning said strip-shaped element around the load, one cutting step for cutting the strip-shaped element and one immobilizing step for immobilizing opposite ends of the strip-shaped element so as to form at least one closed loop around the load; at least one through opening arranged for connecting fluidly the at least one chamber to the external environment being obtained on the containing casing; the strapping head further comprises: blowing means arranged for drawing a fluid to be pressurized from outside the containing casing and sending the fluid to be pressurized to the at least one chamber in the form of a flow of pressurized fluid having a pressure greater than that outside said containment casing, the blowing means comprising an inlet for the fluid to be pressurized and an outlet for the flow of pressurized fluid; and supplying means arranged for fluidly connecting the blowing means with the containing casing to convey the flow of pressurized fluid from the blowing means to inside the at least one chamber so that by traversing the at least one chamber and exiting the through opening, the fluid removes powder material present in the at least one chamber, expels the powder material outside the casing and / or prevents powder material entering the at least one chamber from outside.

[0022] Owing to the strapping head according to the invention, which comprises blowing means that generates a flow of pressurized fluid having a pressure greater than that outside said containment casing and sends the flow of pressurized fluid, by means of supplying means, to one or more chambers located inside a containing casing of the strapping head that houses operating components of the latter, powder material that is possibly present in one or more chambers can be removed and taken outside the containing casing by the flow of pressurized fluid and by the provision of discharge openings obtained in the containing casing. In other words, the flow of pressurized fluid acts as a cleaning operating fluid for cleaning the inside of the containing casing. Further, the pressure inside the one or more chambers located inside the containing casing is greater, owing to the flow of pressurized fluid generated by the blowing means, than the pressure outside the containing casing. This contributes to preventing powder material entering from outside the containing casing.

[0023] In this manner, the productivity of the strapping head according to the invention is increased because frequent machine downtime due to maintenance and cleaning tasks is substantially avoided. Further, owing to the flow of pressurized fluid, the useful life of the operating components of the strapping head housed inside the containing casing is significantly increased compared with prior art strapping heads.

[0024] Lastly, the strapping head according to the invention has the advantage of being constructionally simple and easily installable in already known strapping apparatuses because it is sufficient to install the blowing means on the support frame of the strapping apparatus for example in the same way in which the containing casing is fitted to the support frame, and connect the blowing means to the one or more chambers located in the containing casing by the supplying means.

[0025] The same above advantages are accordingly detectable in a strapping apparatus and in a wrapping apparatus provided with a strapping head according to the invention, and in a strapping method that involves generating the flow of pressurized fluid and making the flow of pressurized fluid traverse the containing casing.Short description of the drawings

[0026] The invention can be better understood and implemented with reference to the appended drawings, which illustrate an embodiment thereof by way of non-limiting example, in which: Figure 1 is a perspective view of a first side of a strapping apparatus according to the invention; Figure 2 is a perspective view like that of Figure 1 taken from another angle; Figure 3 is a perspective view of a second side of a strapping apparatus according to the invention; Figure 4 is a perspective view like that of Figure 3 taken from another angle; Figure 5 is a view of the second side of the strapping apparatus according to the invention; Figure 6 is a side view of Figure 5; Figure 7 is a top view of Figure 5; Figure 8 is a view of the first side of the strapping apparatus according to the invention; Figure 9 is a side view of Figure 8; Figure 10 is a perspective view of blowing means provided in a strapping head according to the invention; Figure 11 is a perspective view of a containing casing of the strapping head according to the invention; Figure 12 is a perspective view of a containing casing of the strapping head according to the invention provided with a through opening. Detailed description

[0027] With reference to the aforesaid Figures, 1 indicates overall a strapping head according to the invention configured to wind and tighten a strip-shaped element around a load, a so-called strap, during a strapping operation.

[0028] The load to be wound with the strip-shaped element can be arranged resting on a support like, for example, a pallet, i.e. can be a palletized load that has been wound with the strip-shaped element.

[0029] The load can be made up of a product or of a plurality of products, for example, grouped on the support.

[0030] The strip-shaped element is made of a material that is such as to make the material flexible so that it can be wound around the load and can be easily brought up to the profile of the load.

[0031] The strapping head 1 is in fact intended to wind and firmly tighten, i.e. tension, the strip-shaped element around the load to stabilize the load, thus bestowing on the load greater resistance and protection, in particular during the load conveying steps.

[0032] In particular, the strapping head 1 is configured to create one or more closed loops of the strip-shaped element around the load. Such closed loops are applied to the load so as to follow an external profile thereof.

[0033] At the end of the strapping operation performed by the strapping head 1, the load is secured, for example to its support, by the one or more closed loops of strip-shaped element.

[0034] The strip-shaped element is made, in particular, of plastics and / or metal depending on the type of load to be wound.

[0035] In particular, the strip-shaped element can be made of one of the following materials: polypropylene (PP), polyester (PET) and / or metal. The strip-shaped element can also be made of a material that comprises a combination of the aforementioned materials.

[0036] For example, the strip-shaped element can be made of metal like, for example, aluminium. A strip-shaped element made of aluminium possesses some advantages, including the fact of having great mechanical resistance (and thus enables great robustness to be obtained in the one or more closed loops around the load), of being extremely ductile (and is thus easily windable around the load) and light (and does not therefore increase the mass of the load). Lastly, aluminium is easy to recycle and can be recycled at a reduced cost.

[0037] Also, for example, the strip-shaped element can be made of polypropylene.

[0038] Also, for example, the strip-shaped element can be made of polyester, which is the toughest of the plastics of which the strip-shaped element can be made. The strip-shaped element made of polyester is used, in particular, to stabilize a heavy and medium heavy load that requires great tenacity during the operations of moving, transport and storage.

[0039] The strapping head 1 can be associated with, or be comprised in, a strapping apparatus 100 arranged for strapping a load automatically. The strapping apparatus 100 is thus arranged for carrying out the strapping operation that enables the strip-shaped element to be positioned around the load to form one or more closed loops.

[0040] The strapping apparatus 100 can comprise a supplying device for supplying the strip-shaped element, which is of known type and which will not be disclosed in detail below. For example, the supplying device can comprise a support unit for supporting a reel of strip-shaped element and a movement unit arranged for moving the strip-shaped element to the strapping head.

[0041] In use, the strip-shaped element is unwound from the reel.

[0042] The strapping apparatus 100 can be associated with, or be comprised in, a wrapping apparatus 1000, for example of the rotating load type, arranged for winding a winding film around the rotating load by applying a certain number of winding turns or winding strips around the load. The film is normally wound around the load before the strapping operation. This film is made of an elastic material and / or plastics, for example can be an extendible film having elasticity that is such as to be able to be applied around the load following the conformation thereof and, at the same time such as to keep the load together stably. Further, the film can be, in particular, a macroperforated film and / or a biodegradable film and / or a heat-sensitive film.

[0043] The strapping head 1 comprises a containing casing 2 defining at least one chamber suitable for containing operating components. These operating components are configured to perform the strapping operation. For this purpose, these operating components are configured to perform at least one winding and tensioning step for winding and tensioning said strip-shaped element around the load, one cutting step for cutting the strip-shaped element and one immobilizing step for immobilizing opposite ends of the strip-shaped element so as to form at least one closed loop around the load .

[0044] In order to perform the winding and tensioning step of the strip-shaped element around the load, the operating components of the strapping head 1 can comprise winding means configured to position the strip-shaped element around the load and tensioning means arranged for tensioning the strip-shaped element around the load. For example, the winding means can be arranged for guiding a first free end or a first strip, of the strip-shaped element around the load two wind the load, whilst the strip-shaped element is unwound from the reel. Also, the winding means can comprise a unit for launching and recovering the strip-shaped element.

[0045] The winding means and the tensioning means are of known type and will not be disclosed in detail further on in the description. For example, the winding means and / or the tensioning means can comprise a plurality of rollers and / or motor-driven wheels that are suitable for sliding the strip-shaped element exiting the strapping head 1, during the load winding step, and to enable the strip-shaped element to return into the strapping head 1, during the tensioning step. The winding means and / or the tensioning means can further comprise a motor and transmission means arranged for transmitting the motion generated by the motor to the plurality of motor-driven rollers and / or wheels.

[0046] In order to perform the cutting step of cutting the strip-shaped element after the load has been wound and tightened by at least one ring of strip-shaped element, the operating components of the strapping head 1 can further comprise, cutting means arranged for separating the strip-shaped element from the supplying device from which it is unwound and obtaining a second free end, or a second strip, of the strip-shaped element wound around the load.

[0047] The second free end is arranged, in particular, opposite the first free end, which is part of a portion of strip-shaped element already wound and tightened around the load.

[0048] Lastly, in order to perform the step of immobilizing the opposite ends of the strip-shaped element, i.e. the first and the second end, so as to form at least one closed loop around the load, the operating components of the strapping head 1 can further comprise, immobilizing means. The immobilizing means can comprise, for example, a welding device or a clamping device arranged for immobilizing the two free ends. In this manner, at the end of the strapping operation, the strapping head 1 will have formed one or more closed rings of strip-shaped element tightened around the load.

[0049] The containing casing 2 can have a box shape, as in the embodiment illustrated in the Figures.

[0050] The containing casing 2 can be made of a metal, like, for example, steel.

[0051] At least one through opening 3 arranged for connecting fluidly the at least one chamber to the environment outside the containing casing 2 is obtained on said containing casing 2.

[0052] A fluid can traverse the containing casing 2 through the through opening 3, for example from the inside to the outside of the containing casing 2.

[0053] The through opening 3 can be shaped as a longitudinal slit. In particular, the through opening 3 can be obtained in an outer wall 5 of the containing casing 2. In the embodiment illustrated in the Figures, the through opening 3 is obtained in a lower outer wall of the containing casing 2, where lower in this case means the wall nearest a floor on which the strapping apparatus 100 can be located in use.

[0054] The through opening 3 can be made near a transit opening 25 configured to enable the strip-shaped element to pass through and is also obtained in the containing casing 2.

[0055] In one embodiment, the through opening 3 and the transit opening 25 can coincide. In other words, the transit opening 25 can also act as a through opening 3.

[0056] On the containing casing 2, a vent opening 30 can be obtained that can comprise as in the embodiment illustrated in the Figures, a plurality of holes 31, for example arranged radially, obtained in a portion of a further outer wall 32 of the containing casing 2. The vent opening 30 enables the inside of the containing casing 2 to be placed in flowing communication with the external environment and can thus act to expel hot air generated by the winding means and / or by the tensioning means, in particular by the motor thereof.

[0057] The strapping head 1 further comprises blowing means 6 arranged for drawing a fluid to be pressurized from outside the containing casing 2 and sending the fluid to be pressurized to the at least one chamber in the form of a flow of pressurized fluid.

[0058] The fluid to be pressurized can be, for example, air, in particular at ambient temperature.

[0059] The blowing means 6 comprising an inlet 7 for the fluid to be pressurized and an outlet for the flow of pressurized fluid.

[0060] The strapping head 1 further comprises supplying means 9 arranged for fluidly connecting, in particular hermetically, the blowing means 6 to the containing casing 2 to convey the fluid from the blowing means 6 to inside the at least one chamber so that by traversing the at least one chamber and exiting the through opening 3 the flow of pressurized fluid removes powder material present in the at least one chamber, expels the powder material outside the casing 2 and / or prevents powder material entering the at least one chamber from outside.

[0061] Via the inlet 7, in use, the fluid is sucked in from the outside and introduced into the blowing means 6, whereas the flow of pressurized fluid is expelled via the outlet outside the blowing means 6 and is conveyed inside the containing casing 2 owing to the supplying means 9.

[0062] The through opening 3 is designed, in particular, for the transit of the flow of pressurized fluid. In other words, the through opening 3 acts as a discharge opening.

[0063] The powder material that could accumulate inside the containing casing 2 is, for example, fine lead powder, which may harm one or more of the operating components of the strapping head 1. The powder material may originate, for example, from the strip-shaped element, which during winding around the load may release material because of the friction against the surfaces on which it slides, from normal wear to the operating components of the strapping head 1 provided inside the containing casing 2 and / or from dust or other material present inside a processing line along which the strapping head 1 is arranged.

[0064] The flow of pressurized fluid thus acts, in use, as a cleaning operating fluid for cleaning the inside of the containing casing 2. Further, owing to the blowing means 6 that pressurizes the fluid and to the supplying means 9 that hermetically connects the outlet of the blowing means 6 to the inside of the containing casing 2, the pressure to inside the at least one chamber is greater than external pressure and this prevents powder material entering from outside to inside the at least one chamber.

[0065] For example, the pressure of the pressurized fluid is greater than the pressure outside the containment casing 2 of the strapping head 1 by a value that falls within the range of 150 mbar - 250 mbar. The external pressure is, for example, an atmospheric pressure of approximately 1013 mbar, in particular referred to a fluid such as air at a temperature of 20°C present outside the containment casing 2 of the strapping head 1. In other words, the pressure difference between the inside of the chamber and the outside has a value that falls within the range of 150 mbar - 250 mbar.

[0066] Owing to the blowing means 6 and to the supplying means 9, therefore, powder material does not accumulate in the strapping head 1.

[0067] The blowing means 6 can comprise at least one blower 10 fitted outside the containing casing 2. The blower 10 can comprise the inlet 7 for the fluid to be pressurized and the outlet for the flow of pressurized fluid.

[0068] The outlet means 9 can comprise a supply conduit element 11 a first end 12 of which is mounted to the blower 10 at the outlet and at least one second end 13 of which is connected to the containing casing 2 so as to lead into the at least one chamber so that, in use, the flow of pressurized fluid can circulate from the at least one blower 10 to the at least one chamber. The flow of pressurized fluid is then expelled in use from the at least one chamber to outside the containing casing 2 through the at least one through opening 3.

[0069] Each end 12, 13 of the supply conduit element 11 is mounted, in particular hermetically, to the at least one blower 10 or to the containing casing 2 by a respective connecting element 14.

[0070] Each connecting element 14 can comprise, for example, a quick coupling.

[0071] In Figure 10 the outlet of the blowing means 6 is not visible because it is covered by a connecting element 14 and by the supply conduit element 11.

[0072] In order to obtain the fluid connection between the blowing means 6 and the containing casing 2 and thus enable the flow of fluid to reach inside the containing casing 2, suitable delivery holes are obtained in the containing casing 2.

[0073] The supply conduit element 11 can comprise a main portion 15 and a plurality of branch portions 16 that extend from an end of the main portion 15, which end is opposite the first end 12.

[0074] In the containing casing 2, several chambers (two or more than two chambers) can be defined that are separated from one another by respective dividing wall means. Each of the chambers can be connected to a respective branch portion 16 extending from the main portion 15 of the supply conduit element 11.

[0075] In this case, i.e. when the inside of the containing casing 2 is separated into several chambers, at least one respective through opening 3 arranged for fluid connection with the external environment for evacuating the flow of pressurized fluid can be obtained in each chamber. Each branch portion 16 leads into a respective chamber.

[0076] Always in the case in which the inside of the containing casing 2 is separated into several chambers, a respective connecting opening that is arranged for connecting fluidly each chamber to one or more respective chambers can be obtained in one or more of the respective dividing wall means that separate the chambers.

[0077] In other words, when the interior of the containing casing 2 comprises a plurality of chambers, the latter can be connected fluidly to the exterior by the respective through openings and / or can be connected fluidly together by the respective connecting openings.

[0078] In one embodiment, a common through opening 3 to more than one chamber or to all the chambers can be provided. For example, in the embodiment illustrated in the Figures, the through opening 3 is unique and common to all the chambers present.

[0079] In one embodiment that is not illustrated in the Figures, the outlet means 9 can comprise more than one supply conduit element 11, each supply conduit element 11 comprising a respective first end mounted by a respective first connection to the at least one blower 10 at the outlet and a respective second end connected, in particular mounted by a respective second connection, to the containing casing 2 so as to lead into a respective chamber so that, in use, at least one part of the flow of pressurized fluid can circulate from the at least one blower 10 to each chamber.

[0080] In other words, the strapping head 1 can be provided with a plurality of distinct supply conduit elements 11 each of which leads into a respective chamber provided in the containing casing 2.

[0081] In one embodiment, each supply conduit element 11 comprises a single conduit. In particular, each supply conduit element 11 consists of one and only one conduit.

[0082] According to another embodiment that is not illustrated in the Figures, it is possible to provide a single supply conduit element 11 that comprises, in particular consists of, a single conduit and fluid is placed in communication for the transit of the flow of fluid from the outside inside the containing casing 2 and from here outside, by suitable opening means that can comprise one or more connecting openings and at least one through opening 3.

[0083] In other words, depending on the embodiments, the fluid connection between the at least one blower 10 and the inside of the containing casing 2 can be achieved by a single conduit or by a plurality of single conduits, each leading into a respective chamber.

[0084] In each supply conduit element 11 the main portion 15 and the plurality of branch portions 16 can be connected together to a respective end by connecting means 17. In particular, the end of the main portion 15 and of each branch portion 16 are hermetically connected to the connecting means 17 by a respective further connecting element 24.

[0085] The main portion 15 is connected fluidly to the blowing means 6, in particular to the outlet, in particular at an end of the main portion 15 that is the first end 12 of the supply conduit element 11.

[0086] Each branch portion 16 is connected fluidly to a respective chamber (in particular at an end of each branch portion 16, each end representing a second end 13 of the supply conduit element 11) so that at least one part of the flow of pressurized fluid reaches the inside of each respective chamber.

[0087] With reference to the embodiment shown in the Figures, the connecting means 17 of the strapping head 1 comprises a three-way connection, in particular a Y or T connection, and the containing casing 2 comprises two chambers (not shown in the Figures), a first chamber and a second chamber that are separated from one another by dividing wall means. The dividing wall means comprises, in particular, a separating wall. This separating wall is, in particular, continuous, i.e. devoid of openings that fluidly connect the two chambers. In other words, the two chambers are not in flowing communication. For example, a chamber (for example the first chamber) can house the immobilizing means, whereas the other chamber (for example the second chamber) can house the winding means and the tensioning means. In this case, the blowing means 6 comprises a blower 10 and the supply conduit element 11 comprises a main portion 15 arranged for connecting the outlet of the blower 10 to the connecting means 17 and two branch portions 16 that branch off from the connecting means 17. A branch portion 16 is configured to connect the connecting means 17 to a chamber, for example the first chamber, whereas the other branch portion 16 is configured to connect the connecting means 17 to the other chamber, for example the second chamber. In other words, in the embodiment shown in the Figures, there is only one supply conduit element 11 with two branch portions 16, one for each chamber, and a main portion 15.

[0088] The blowing means 6 can comprise at least one further blower, each further blower being mounted outside the containing casing 2 and comprising a respective inlet for a respective fluid to be pressurized and a respective outlet for a respective outlet flow of pressurized fluid to be conveyed inside the containing casing 2. In other words, the strapping head 1 can comprise a plurality of blowers.

[0089] The strapping head 1 can further comprise further outlet means arranged for fluidly connecting, in particular hermetically, each further blower to the inside of the containing casing 2. Each of such further outlet means can be shaped like the outlet means 9 disclosed previously.

[0090] In particular, each further conduit means can be configured to connect a respective further blower to a respective chamber obtained inside the containing casing 2.

[0091] In one embodiment, the strapping head 1 can comprise a plurality of blowers flowingly connected to a single chamber. For example, the strapping head 1 can comprise a total of four blowers 10, in which a blower 10 is placed flowingly connected to a first chamber and the other three blowers are all connected to a second chamber. Also in this case, each blower is connected to one or more chambers by respective outlet means each of which can be shaped like the outlet means 9 disclosed previously.

[0092] Each blower 10 present can comprise one or more impellers arranged for rotating around a respective axis of rotation R to generate a respective flow of fluid. Each impeller can be provided with a plurality of blade elements configured to convey the fluid from the inlet 7 to the outlet of a respective blower 10. Each blower 10 present comprises at least one motor 19 (for example an electric motor) arranged for rotating the one or more impellers.

[0093] Each impeller can have a rotation direction D, in particular clockwise as indicated with an arrow indicated in Figure 10.

[0094] Each impeller can be provided with a rotatable support in particular in the form of a disc or ring to an outer edge of which the blade elements are mounted so as to protrude radially from the outer edge to the outside of the support. The rotatable support is mounted, in particular, concentrically to the axis of rotation R so that in use, the rotatable support rotates around the axis of rotation R. In other words, the axis of rotation R is the axis of rotation of the support.

[0095] Each motor 19 can be provided with a drive shaft mounted along an axis of rotation R of an impeller. Alternatively, the drive shaft of each motor 19 can be mounted staggered with respect to the axis of rotation R of the impeller.

[0096] Each blower 10 present can comprise a shell 18 inside which a housing is obtained for a respective impeller. In other words, each impeller is housed in the housing obtained inside a respective shell.

[0097] The blowing means 6 can further comprise a suction channel 22 arranged for connecting the inlet 7 of the blowing means 6 to the housing obtained in the shell 18 and a discharge channel 23 arranged for connecting the housing obtained in the shell 18 to the outlet of the blowing means 6.

[0098] In other words, the housing is connected fluidly to the inlet 7 of the blowing means 6 by the suction channel 22 and to the outlet of the blowing means 6 by the discharge channel 23 of the blowing means 6.

[0099] Each flow of pressurized fluid, in use, once generated, proceeds on a flow path that is directed from inside the housing to the outlet of the blowing means 6.

[0100] In use, when a motor 19 is driven, the respective drive shaft rotates around the respective axis of rotation R the one or more impellers to which it is connected. In particular, the drive shaft rotates the rotatable support / s of the respective impeller / s. The rotation of each impeller causes that the fluid (for example air) enters the blowing means 6 through the inlet 7 and from here the fluid is guided by the suction channel 22 to the impeller. In the impeller, the fluid particles are subjected to a centrifugal force generated by the rotation of the impeller, in particular by the blade elements of the impeller, which centrifugal force takes the fluid to the outer edge of the impeller whilst the pressure inside the shell 18 increases. In fact, at each rotation, the kinetic energy of the sucked fluid increases and this translates into a pressure increase. Accordingly, the fluid sucked from outside the blowing means 6 becomes a flow of pressurized fluid, i.e. with a pressure greater than that that the fluid had before entering the blowing means 6.

[0101] Owing to the centrifugal force generated by the rotation, the flow of pressurized fluid is pushed in the rotation direction D. The flow of pressurized fluid circulating in the impeller is then conveyed by the blade elements to the discharge channel 23 from which it leaves, through the outlet of the blowing means 6, to the outlet means 9. Owing to the supplying means 9 the flow of pressurized fluid then reaches the chamber / s provided inside the containing casing 2 where it prevents, owing to the pressure that is greater than the pressure outside the containing casing 2, dirt like powder material being able to enter from the outside into the containing casing 2. At the same time, the flow of pressurized fluid removes any powder material present inside the containing casing 2, dragging the power material with it outside the containing casing 2 through the respective through opening 3.

[0102] The strapping head 1 can further comprise a filtering device 20 arranged for filtering the fluid to be pressurized entering the blowing means 6.

[0103] The filtering device 20 is fluidly connected to the inlet 7 of the blowing means 6 by a connecting conduit 21 of the strapping head 1 arranged for connecting, in particular hermetically, the inlet 7 of the blowing means 6 to the filtering device 20.

[0104] The filtering device 20 can comprise, or consist of, a cartridge suction filter.

[0105] When the filtering device 20 is present, in use, the fluid is sucked in from the outside of the strapping head 1 to the inside through the filtering device 20 that provided with a suitable suction mouth. In this case, the fluid then traverses the filtering device 20 and from here reaches the blowing means 6 passing through the connecting conduit 21 connected in turn to the inlet 7. From here, the fluid is then conveyed to the suction channel 22 and the path thereof then continues as disclosed previously.

[0106] The strapping head 1 can further comprise, or be associated with, a control unit configured to control operating parameters of each blower 10 and / or of each motor 19. The control unit can comprise a programmable logic controller (PLC).

[0107] The control unit is configured to vary the fluid flow rate. The fluid flow rate can be varied, for example, varying the number of revolutions of each motor 19 present. Also, the fluid flow rate can be varied, for example, when the revolutions of each motor 19 are constant, by acting on a variable geometry of the blades of each impeller or on partitions arranged for varying a transit section for the fluid so as to appropriately restrict the delivery of the fluid. The partitions can be made, for example, in each blower 10 near each respective outlet. In particular, the control unit can act on each motor 19 to vary the number of revolutions thereof, or on each variable geometry impeller, or can move the partitions appropriately.

[0108] The strapping apparatus 100, which can be provided with the or with which the strapping head 1 can be associated, comprises a support frame 101. In the embodiment of a strapping apparatus 100 illustrated schematically in Figures 1 to 9, the support frame 101 has a portal shape. In particular, the support frame 101 can comprise a pair of upright elements 102 and a crossbeam element 103, the latter being joined to a respective upright element 102 near respective ends.

[0109] The strapping head 1 can be mounted to the support frame 101 so as to be supported in a suspended position above the load to be strapped, i.e. to be wound and tightened with the strip-shaped element.

[0110] For example, the support frame 101 can comprise a beam 104 to which the strapping head 1 can be mounted, for example by connecting elements of known type comprising, for example, one or more plates, one or more flanges, one or more bars, screws and nuts.

[0111] The beam 104 can be connected to the pair of upright elements 102 so that the direction of the prevalent extent thereof is substantially parallel to that of the crossbeam element 103 and in particular, substantially parallel to a floor on which the support frame 101 is positioned. In particular, the beam 104 can be slidably mounted to the pair of upright elements 102 by connecting means of known type so as to be able to be moved along a vertical direction in function of the height of the load to be strapped, where the term "vertical direction" means a direction parallel to the direction of the force of gravity.

[0112] In another embodiment of strapping apparatus 100, which is not shown in the Figures, the strapping head 1, in use, operates along the vertical direction on a side of the load and can be fixed or movable along a horizontal direction that is substantially perpendicular to the vertical direction (vertical strapping with strapping head 1 mounted to the support frame 101 in a position that is lateral to the load).

[0113] In a further embodiment of strapping apparatus 100, which is shown in the Figures, the strapping head 1, in use, operates along the horizontal direction on a side of the load and can be movable along the vertical direction and / or along the direction perpendicular to the side of the load (horizontal strapping with strapping head 1 mounted to the support frame 101 in a position that is lateral to the load).

[0114] In yet another embodiment of the strapping apparatus 100, which is shown in the Figures, the strapping head 1, in use, operates along the horizontal direction on a lower part of the load and can be movable along the vertical direction (vertical strapping with strapping head 1 mounted to the support frame 101 in a lower position, i.e. below, with respect to the load).

[0115] The wrapping apparatus 1000, which can be provided with the strapping apparatus 100, or with which the strapping apparatus 100 can be associated, can comprise an advancement line arranged for moving the load along an advancement direction. The support frame 101 is positioned, in particular, at a portion of the advancement line of the load.

[0116] The wrapping apparatus 1000 can further comprise programmable electronic control means configured to correlate the operating parameters of the strapping head 1 with the operating parameters of other parts of the advancement line or of the processing line. In particular, the programmable electronic control means is configured to synchronize the operating steps of the strapping head 1, i.e. the drive of the operating components thereof, with the steps of the other parts of the advancement line or of the processing line.

[0117] For example, the programmable electronic control means is configured to coordinate the drive of the strapping head 1 in accordance with a movement of the load along the advancement direction, in particular on the basis of a speed of a conveyor provided in the advancement line and on which the load to be strapped is located.

[0118] In use, the strapping head 1 is used in a method for strapping a load, like, in particular, a palletized load.

[0119] The method for strapping a load comprises the step of setting up a strapping head 1, which step comprises, in particular, the step of fitting the strapping head 1 to the support frame 101 in a position above a work zone to which the load is taken to be subjected to the strapping operation. For example, the strapping head 1 is fitted to the beam 104 so as to protrude downwards, i.e., in use, to the load.

[0120] A strapping head 1 is set up to perform the strapping operation that comprises the steps of: positioning a strip-shaped element around the load; tightening the strip-shaped element around the load; cutting the strip-shaped element; and immobilizing the two ends of the strip-shaped element so as to form at least one closed loop.

[0121] The step of positioning the strip-shaped element around the load comprises a winding step that is performed by the winding means so as to wind the load with at least one revolution of the strip-shaped element.

[0122] The step of tightening the strip-shaped element around the load comprises a tensioning step that is performed by the tensioning means so as to tighten the strip-shaped element around the load.

[0123] The step of tightening the strip-shaped element around the load occurs after the step of positioning the strip-shaped element around the load.

[0124] Between the step of positioning the strip-shaped element around the load and the tensioning step, the strapping method can comprise a retaining step of retaining the first ends of the strip-shaped element.

[0125] The step of cutting the strip-shaped element comprises the step of separating, owing to the use of the cutting means, the strip-shaped element from the supplying device from which the strip-shaped element is, in use, unwound. In this manner, a portion of strip-shaped element is obtained wound and tensioned around the load with a second end of the free strip-shaped element. The step of separating the strip-shaped element from the supplying device enables a new first free end of the strip-shaped element connected to supplying means and intended to wind another load to be defined.

[0126] The step of cutting the strip-shaped element is performed, in particular, after the step of cutting the strip-shaped element.

[0127] The strapping method further comprises the step of drawing a fluid to be pressurized and generating from the fluid to be pressurized a flow of pressurized fluid by means of the blowing means 6. In particular, in use, each motor 19, for example following a signal sent by the control unit, which, in turn, can receive a command from the control means, rotates the one or more impellers of the one or more blowers 10 which entails generating respective flows of pressurized fluid (for example one for each impeller) which are sent to the outlet means 9.

[0128] The strapping method further comprises the step of conveying the flow of pressurized fluid by the outlet means 9 to inside at least one chamber obtained inside the containing casing 2 of the strapping head 1 so that by traversing the at least one chamber and exiting the through opening 3, the fluid removes any powder material present in the at least one chamber, expels the powder material outside the casing 2 and prevents powder material entering inside the at least one chamber from outside.

[0129] The step of conveying the flow of pressurized fluid can occur at the same time as the step of positioning the strip-shaped element around the load and / or the step of tightening the strip-shaped element around the load. The step of conveying the flow of pressurized fluid can occur continuously, i.e. driving the blowing means 6 can be independent of the strapping operation.

[0130] Owing to the blowing means 6 of the strapping head 1, a flow of pressurized fluid is then generated that is conveyed, by means of the outlet means 9, to one or more chambers provided inside the containing casing 2. In this manner, any powder material possibly present inside the one or more chambers can be removed and taken outside the containing casing 2 by the flow of pressurized fluid and by providing at least one through opening 3 obtained in the containing casing 2. In other words, the flow of pressurized fluid acts as a cleaning operating fluid for cleaning the inside of the containing casing 2. Further, owing to the flow of pressurized fluid generated by the blowing means 6, the pressure inside the one or more chambers located inside the containing casing 2 is greater than that outside the containing casing 2, which contributes to preventing the powder material entering the inside of the containing casing 2 from the outside.

[0131] In this manner, the productivity of the strapping head 1 is high and greater than known strapping heads because frequent machine downtime because of maintenance and cleaning tasks is avoided. Further, owing to the flow of pressurized fluid, the working life of the operating components of the strapping head 1 housed inside the containing casing 2 is significantly increased with respect to prior art strapping heads.

[0132] Lastly, the strapping head 1 is constructionally simple and easily installable in already known strapping apparatuses because it is sufficient to install the blowing means 6 on the support frame 101 of the strapping apparatus 100 and connect the blowing means 6 to the one or more chambers located in the containing casing 2 by the supplying means 9.

Claims

1. Strapping head (1) configured to wind and tighten a strip-shaped element around a load, said strapping head (1) comprising a containing casing (2) defining at least one chamber suitable for containing operating components of said strapping head (1) configured to perform at least: - one winding and tensioning step for winding and tensioning said strip-shaped element around said load, - one cutting step for cutting said strip-shaped element and - one immobilizing step for immobilizing opposite ends of said strip-shaped element so as to form at least one closed loop around said load; at least one through opening (3) arranged for connecting fluidly said at least one chamber to the outside environment being obtained on said containing casing (2); said strapping head (1) being characterized in that it further comprises: - blowing means (6) arranged for drawing a fluid to be pressurized from outside said containing casing (2) and sending the fluid to be pressurized to said at least one chamber in the form of a flow of pressurized fluid having a pressure greater than that outside said containment casing (2), said blowing means (6) comprising an inlet (7) for said fluid to be pressurized and an outlet for said flow of pressurized fluid; and - supplying means (9) arranged for placing said blowing means (6) in fluid connection with said containing casing (2) to convey said flow of pressurized fluid from said blowing means (6) to inside said at least one chamber so that by traversing said at least one chamber and exiting said through opening (3) said fluid removes powder material present in said at least one chamber, expels the powder material outside said containing casing (2) and / or prevents powder material entering said at least one chamber from outside.

2. Strapping head (1) according to claim 1, wherein said blowing means (6) comprises at least one blower (10) fitted outside said containing casing (2) and comprising said inlet (7) for said fluid to be pressurized and said outlet for said flow of pressurized fluid, said supplying means (9) comprising a supply conduit element (11) a first end (12) of which is fitted to said at least one blower (10) at said outlet and a second end (13) of which is connected to said containing casing (2) so as to lead into said at least one chamber so that, in use, said flow of pressurized fluid can circulate from said at least one blower (10) to said at least one chamber.

3. Strapping head (1) according to claim 1 or 2, wherein in said containing casing (2) several chambers are defined that are separated from one another by respective dividing wall means, and wherein said supply conduit element (11) comprises a main portion (15) connected fluidly to said blowing means (6) and a plurality of branch portions (16), each branch portion (16) extending from said main portion (15), each of said chambers being connected to a respective branch portion (16), and wherein in each chamber at least one respective through opening (3) is arranged for fluid connection with the outside environment to evacuate said flow of pressurized fluid.

4. Strapping head (1) according to claim 3, wherein said main portion (15) and said plurality of branch portions (16) are connected to a respective end by connecting means (17).

5. Strapping head (1) according to claim 4, wherein said connecting means (17) comprises a three-way connection, said containing casing (2) comprises a first chamber and a second chamber, and said supply conduit element (11) comprises said main portion (15) arranged for connecting said outlet to said connecting means (17) and two branch portions (16), one of which is arranged for connecting said connecting means (17) to said first chamber and the other is arranged for connecting said connecting means (17) to said second chamber.

6. Strapping head (1) according to any one of the preceding claims, as claim 3 is appended to claim 2, wherein said blowing means (6) comprises a further blower, or further blowers, each further blower being fitted outside said containing casing (2) and comprising a respective inlet for a respective fluid to be pressurized and a respective outlet for a respective flow of pressurized fluid.

7. Strapping head (1) according to claim 6, and further comprising further supplying means, each of which is arranged for placing a respective further blower in fluid communication with said containing casing (2), said further supplying means being each shaped like said supplying means (9).

8. Strapping head (1) according to claim 6 or 7, wherein said at least one blower (10) and / or said further blower each comprises one or more impellers arranged for rotating around a respective axis of rotation (R) and provided with respective pluralities of blade elements configured to pressurize said fluid and convey said fluid from said inlet (7) to said outlet, and a motor (19) arranged for rotating one or more impellers.

9. Strapping head (1) according to any one of the preceding claims, and further comprising: - a filtering device (20) arranged for filtering said fluid to be pressurized entering said blowing means (6); and - a connecting conduit (21) arranged for connecting fluidly said inlet (7) of said blowing means (6) to said filtering device (20).

10. Strapping head (1) according to claims 8 or 9 as claim 9 is appended to claim 8, and further comprising a control unit configured for controlling operating parameters of said blower / s (10) and / or of said motor / s (19).

11. Strapping apparatus (100) for strapping a load comprising: - a support frame (101) in the shape of a portal; and - a strapping head (1) according to any one of claims 1 to 10 configured to apply and tighten a strip-shaped element around a load, said strapping head (1) being fitted to said support frame (101) so as to be supported by the latter in a position suspended above said load.

12. Method for strapping a load comprising setting up a strapping head (1) comprising a containment casing (2) defining at least one chamber suitable for containing operating components of said strapping head (1) to perform the steps of: - positioning a strip-shaped element around said load; - tightening said strip-shaped element around said load; - cutting said strip-shaped element; - immobilizing the two ends of said strip-shaped element so as to form at least one closed loop; said method being characterized in that it further comprises the steps of: - drawing a fluid to be pressurized and generating from said fluid to be pressurized a flow of pressurized fluid by blowing means (6), said pressurized fluid having a pressure greater than that outside said containment vessel (2); and - conveying said flow of pressurized fluid by supplying means (9) inside said at least one chamber of said containing casing (2) of said strapping head (1) so that by traversing said at least one chamber and exiting a through opening (3) obtained in said containing casing (2) said flow of pressurized fluid removes powder material present in said at least one chamber, expels the powder material outside said containing casing (2) and / or prevents powder material entering said at least one chamber from outside.

13. Wrapping apparatus (1000) arranged for wrapping the film around a load by applying a certain number of coils around said load, said wrapping apparatus comprising an advancement line arranged for moving said load along an advancement direction and a strapping apparatus (100) according to claim 11, wherein a support frame (101) for supporting said strapping apparatus (100) is positioned at a portion of said advancement line of said load.

14. Wrapping apparatus (1000) according to claim 13, and further comprising programmable electronic control means configured to coordinate driving a strapping head (1) according to any one of claims 1 to 10 in accordance with a movement of said load along said advancement line.

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