Baler and method for forming bale

Abstract

To provide a baler equipped with a device for joining (reducing the width of) the film used to wrap the bale, and a device which is more efficient and stable, more robust and reduced in complexity and cost.SOLUTION: A baler (1) for forming bales of crops, includes: a compression chamber (2); a pick-up unit (3); a binding device for providing a binding film for wrapping the bale; and a width reducing device (4). The width reducing device (4) includes a pair of rollers (401), supported by a first arm (402A) and a second arm (402B) and movable between an approached position, where the rollers (401) are in contact with edges of the binding film so that a width of the film is narrowed, and a spaced apart position, where the rollers are distanced from the edges of the binding film. The width reducing device (4) includes a hydraulic actuator (403) for moving the first and second arms so as to move the pair of rollers between said approached and spaced apart positions.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a baler and a method of forming a bale. [Background technology]

[0002] A baler or baling press is a machine that picks up previously cut agricultural crops such as rice straw, grass, wheat, corn, etc. (hereinafter referred to as "hay") from the ground, compresses them, forms bales from the hay, and releases them into a field. The press may be coupled to the rear of a machine such as a tractor driven by an operator and towed by the tractor (or other towing vehicle). Typically, a baling press includes a pick-up unit that picks up the hay from the ground and includes a pick-up roller at its front, a compression chamber for forming a bale, and a rotating device for feeding the hay picked up from the ground into the compression chamber of the baling press.

[0003] The compression chamber may be a fixed diameter or a variable diameter compression chamber. In particular, a baler having a fixed diameter compression chamber includes a number of rollers that define the compression chamber. The rollers rotate about an axis of rotation, thereby imparting a rotational motion to the hay fed into the compression chamber.

[0004] Once formed inside the compression chamber, the bale is tied with a tying material. The bale can be tied with different types of material, for example nets or films. Furthermore, the bale tied with a tying material can also be wrapped with a film. In this case, the film is applied after the bale has been tied. The wrapping of the bale can take place in the baling press (inside the compression chamber) or after the bale has been released by the baling press. There are also solutions in which the bale is wrapped with a film directly after it has been formed in the compression chamber, without first being tied with a tying material. Usually, the film is a plastic film. In such cases, the plastic film is therefore applied directly to the formed bale inside the compression chamber. In particular, in these cases, the baler comprises a tying (wrapping) device and the bale is wrapped after it has been formed, while it is still inside the compression chamber. In particular, in these solutions, the tying material (i.e. the film) is delivered by a tying device mounted inside the baler and wrapped around the formed bale. In particular, the strapping material is fed into the compression chamber and between the rotating rollers and the bale and is moved around the periphery of the bale by the rotational movement of the bale and the rotational movement of the plurality of rotating rollers.

[0005] One of the difficulties that may be encountered in this field is that if a bale is tied (wrapped) with a film, problems may arise in moving the film when it needs to be applied to the bale and / or when the film is cut after it has been wrapped around the bale.

[0006] In this regard, it is known that joining (pushing together) both sides of the film at the beginning of the wrapping process so that the width of the film is reduced makes it easier to apply than if the film were stretched around its entire width. Furthermore, gathering the two sides of the film together after it has been wrapped around the veil makes it easier to cut than a film that is stretched around its entire width.

[0007] Thus, in this field there are several devices and methods in which two gathering elements (for reducing the width of the film) contact the edges of the film. These elements are moved reciprocally towards and away from each other to gather both sides of the film together. In this context, patent document US20200323143A1 provides a gathering device for selectively joining both sides of a film wound around a veil, comprising a pair of gathering elements acting in conjunction with the respective edges of the film and driven by a motor. In that document, the drive system includes a motor and a reduction gear. The gathering elements are moved laterally between a non-operating position and an operating position to gather the film as required.

[0008] Other prior art examples of joining devices for joining two sides of a film are described in the patent documents EP1170984B1, US20040055268A1, EP3278658B1, EP3729950A1, EP1872648B1, EP2022318B1, WO2021219534A1, DE102019210962A1 and EP2506701B1.

[0009] However, the prior art devices and methods have several drawbacks and can be improved. Indeed, there is a need in the art to provide a baler with an apparatus for splicing (reducing the width of) the film used to wrap the bale, and an apparatus that is more efficient, stable, more robust, and of reduced complexity and cost. Summary of the Invention

[0010] SUMMARY OF THE DISCLOSURE It is an object of the present disclosure to provide a baler and bale forming method that overcomes the above-mentioned shortcomings of the prior art.

[0011] This object is fully achieved by the baler and method of the present disclosure as characterized in the appended claims.

[0012] The present disclosure, according to one aspect thereof, provides a baler. The baler is configured to form a bale of agricultural produce. The bale is preferably round. The bale may have other shapes. The baler includes a compression chamber. The compression chamber may be a fixed diameter or a variable diameter compression chamber. The compression chamber is configured to impart a rotational motion to the agricultural produce to form the bale.

[0013] The baler includes a pick-up unit configured to pick up the agricultural produce from the ground and deliver it to the compaction chamber. The baler includes a strapping device. The strapping device includes a film reel. The film reel provides a strapping film for wrapping the bale.

[0014] The strapping device includes a film input unit configured to pull the strapping film from the film reel and input the strapping film into the compression chamber, such that the rotational movement of the bale results in the bale being wrapped by the strapping film.

[0015] The baler includes a width reducing device disposed downstream of the film input unit and includes a pair of rollers.

[0016] The pair of rollers are movable between a close position where the rollers contact the edges of the bundling film to narrow the width of the film, and a separate position where the rollers are spaced apart from the edges of the bundling film.

[0017] The width reduction device includes a first arm and a second arm. The first and second arms each support a corresponding roller of the pair of rollers. The width reduction device includes a hydraulic actuator. The hydraulic actuator includes a first hydraulic cylinder connected to the first arm. The hydraulic actuator includes a second hydraulic cylinder connected to the second arm. The hydraulic actuator is configured to move the first arm and the second arm to move the pair of rollers between the close position and the spaced apart position.

[0018] This solution makes it possible to obtain a width reduction device (for joining both sides of a film) that is particularly robust and efficient, the hydraulic actuator being able to move and hold the arms (that support the rollers) so that the rollers contact the edges of the film and bring them together, and also to hold the rollers in a close position so that they do not separate due to the forces of the film. Moreover, the solution is simple and reliable.

[0019] In one example, the baler comprises a tailgate. The tailgate is movable between a closed position, in which the compression chamber is closed to form the bale, and an open position, in which the tailgate is opened to release the bale formed inside the compression chamber. The baler comprises a hydraulic tailgate actuator for moving the tailgate between said open and closed positions. The baler comprises a hydraulic circuit. The hydraulic circuit is hydraulically connected to the hydraulic tailgate actuator and to the first and second hydraulic cylinders and supplies them with hydraulic fluid. Thus, in this solution, the hydraulic circuit already provided in the baler for operating the tailgate is also used to operate the hydraulic actuators of the first and second arms, thus moving the rollers between the approach and the away positions. This solution is particularly efficient and simple.

[0020] It should be noted that the applicant has also developed alternative embodiments not falling within the subject matter claimed herein, which may also include a hydraulic circuit dedicated to a pair of rollers and not connected to the baler's hydraulic circuit connected to the hydraulic tailgate actuator.

[0021] In one example, the hydraulic circuit includes a closed configuration, in which the circuit is configured to perform a closing operation to move the tailgate from an open position to a closed position and a separating operation to move the pair of rollers from an approaching position to a separating position.

[0022] In one example, the hydraulic circuit is configured to perform closing and disengaging operations during at least some overlapping time intervals.

[0023] What follows is a description of the basic solution.

[0024] In one example, the hydraulic circuit includes a discharge line for connecting the first and second hydraulic cylinders to a discharge reservoir. The discharge reservoir is provided on a tractor that tows the baler. The hydraulic circuit includes an electrovalve. The electrovalve is inserted into the discharge line. The electrovalve is movable between an active position that allows hydraulic fluid to flow through the discharge line toward the discharge reservoir and an inactive position to prevent hydraulic fluid from reaching the discharge reservoir.

[0025] The hydraulic circuit may also include a control unit connected to the electrovalve for switching the electrovalve to an active position to allow the roller to move to the approach position.

[0026] In one example, the hydraulic circuit also includes a fluid accumulator hydraulically connected to the first and second hydraulic cylinders, the accumulator being filled with gas.

[0027] The gas in the accumulator is separated from the hydraulic oil of the hydraulic circuit via a separation element.

[0028] In one example, the hydraulic circuit includes a first portion connected to the first and second hydraulic cylinders. The hydraulic circuit includes a second portion connected to the hydraulic tailgate actuator. The hydraulic circuit includes a hydraulic duct. The first and second portions of the hydraulic circuit are connected via the hydraulic duct. The hydraulic circuit includes a one-way valve inserted in the hydraulic duct.

[0029] In one example, the pair of rollers has a helical shape. In one example, one roller of the pair of rollers has a helical shape twisted in a first direction and the other roller of the pair has a helical shape twisted in a second direction. The second direction is opposite to the first direction so as to impart an upward motion to the film.

[0030] This solution makes it possible to act on the film in a particularly efficient manner and to prevent unwanted movements of the film.

[0031] In one example, the pair of rollers has a grooved profile.

[0032] According to one aspect, the present disclosure provides a method for forming a bale of agricultural crops, the method including the steps of picking up the agricultural crops from the ground via a pick-up unit of a baler and conveying the agricultural crops into a compression chamber of the baler.

[0033] The method includes imparting a rotational motion to the crop within a compression chamber to form a bale. The method includes unwinding a tie film from a film reel. The method includes feeding a tie film into the compression chamber such that the rotational motion of the bale results in the bale being wrapped by the tie film. The method includes moving a pair of rollers between a close position where the rollers contact an edge of the tie film to narrow the width of the film, and a spaced position where the rollers are spaced from the edge of the tie film. The rollers are supported by a first arm and a second arm.

[0034] The method includes moving a first arm and a second arm via a first hydraulic cylinder and a second hydraulic cylinder, respectively, to move a pair of rollers between the close position and the spaced position.

[0035] In one example, the method includes moving a tailgate of a baler via a hydraulic tailgate actuator between a closed position in which the compression chamber is closed to form a bale and an open position in which the tailgate is opened to release the bale formed within the compression chamber.

[0036] The method includes supplying hydraulic fluid to both the hydraulic tailgate actuator and the first and second hydraulic cylinders via a hydraulic circuit.

[0037] In one example, the pair of rollers are moved to the spaced apart position in response to closing of the tailgate.

[0038] In one example, the method includes moving an electrovalve inserted in a discharge line connecting the first and second hydraulic cylinders to a discharge reservoir provided on a tractor towing the baler between an active position for allowing hydraulic fluid to flow through the discharge line toward the discharge reservoir and an inactive position for preventing hydraulic fluid from reaching the discharge reservoir.

[0039] The method includes moving an electrovalve to an active position to move the roller to an approximated position.

[0040] In one example, the fluid accumulator is hydraulically connected to the first and second hydraulic cylinders, and the accumulator is filled with gas that is separated from the hydraulic fluid of the hydraulic circuit via a separation element.

[0041] In one example, the hydraulic circuit includes a first portion connected to the first and second hydraulic cylinders. The hydraulic circuit also includes a second portion connected to a hydraulic tailgate actuator.

[0042] The hydraulic circuit includes a hydraulic duct. The first portion and the second portion are connected via the hydraulic duct. The hydraulic circuit includes a one-way valve inserted in the hydraulic duct.

[0043] In one example, when the roller contacts the film tie in the approach position, the roller imparts an upward motion to the film. [Brief description of the drawings]

[0044] These and other features will become more apparent from the following description of preferred embodiments, illustrated purely as non-limiting examples in the accompanying drawings, in which: [Figure 1] 1 illustrates a baler and a tractor pulling the baler according to one or more embodiments of the present disclosure. [Diagram 2] FIG. 2 is a diagram of the compression chamber and pick-up unit of the baler. [Diagram 3] 1 shows a film width reduction device. [Figure 4] 1 shows a pair of rollers in an approaching position. [Diagram 5] 1 shows a first embodiment of a hydraulic circuit. [Figure 6] 2 shows a second embodiment of a hydraulic circuit. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0045] With reference to the attached drawings, the numeral 1 denotes a baler (or baling press) for forming bales from agricultural crops. The baler 1 comprises a compression chamber 2. The baler 1 comprises a frame. The frame has an interior space. The baler 1 also comprises a pick-up unit 3. The baler 1 comprises the compression chamber 2. The pick-up unit 3 is configured to pick up hay (agricultural crop) from the ground and feed it into the compression chamber 2. The pick-up unit has an inlet. The pick-up unit comprises an outlet. The inlet faces the ground. The outlet of the pick-up unit is located inside the baler 1. The outlet faces the interior space. The compression chamber is configured to compress the hay to form a bale. The hay is fed into the compression chamber 2 via the outlet of the pick-up unit 3 in the feed direction. The baling press 1 comprises a number of guide rollers. The number of guide rollers is installed in the interior space of the baler (Figure 2). In this example, the diameter of the compression chamber 2 is fixed. In this example, the rollers rotate and impart a rotational movement to the hay inside the compression chamber. Thus, in this example, the guide rollers define the compression chamber. In another exemplary embodiment (not shown), the diameter of the compression chamber may be variable. Thus, in this example, the size of the bale forming zone of the compression chamber increases as the bale gradually forms inside the chamber. In this example (variable chamber), the baling press also comprises a number of belts. The belts are juxtaposed to one another in the interior space.

[0046] The belts are wrapped around guide rollers (whose configuration differs from that illustrated in FIG. 2 because it differs from that of the guide rollers of the embodiment in which the diameter of the compression chamber is fixed) to define an endless loop. The loop is deformable to define the compression chamber. Furthermore, the rollers are rotatable to guide the belts around the loop. In particular, each portion of the belts is tensioned between two successive rollers.

[0047] The belts thus surround the periphery of the bale formed inside the compression chamber, and in particular, as the bale gradually forms inside the compression chamber, the belts deform, thus adapting to the shape of the bale formed inside the compression chamber.

[0048] Thus, a variable diameter compression chamber can be an alternative to a fixed diameter chamber (Figure 2).

[0049] The pick-up unit 3 comprises a pick-up roller. The pick-up roller picks up the hay from the ground. In one example, the pick-up roller is configured to rotate in a direction opposite to the direction of movement of the baling press so as to sweep the hay upwards. The pick-up roller comprises a number of tines protruding from the pick-up roller for sweeping the hay.

[0050] The pick-up unit may also include a pair of windshield arms and a rotating windshield cylinder (deflector roller) fixed between the windshield arms.

[0051] The pick-up unit also comprises a rotor. The rotor 2012 is arranged downstream of the pick-up roller. The rotor feeds the hay picked up from the ground to the compression chamber of the baling press 1. The rotor comprises a feed blade. The baling press 1 comprises a feed channel. The feed channel extends between an inlet and an outlet. The inlet faces the pick-up roller. The outlet defines an opening of the compression chamber.

[0052] The baling press 1 may be equipped with a number of knives for cutting the picked up crop as it travels through the feed channel. The baler 1 may be towed by a tractor T. The tractor has a power take-off (PTO) for transmitting power (driving force) to the baling press.

[0053] The baler includes a strapping device that includes a film reel that supplies a strapping film that wraps the bale. The strapping film may be a plastic film.

[0054] The strapping device includes a film feed unit, which pulls the strapping film from the film reel and feeds it into the compression chamber, where the rotational movement of the bale results in the bale being wrapped by the strapping film. In this way, the strapping device feeds the strapping film into the compression chamber. The strapping device may be installed at the top of the baler. In another example, the strapping device is installed in the middle part of the baler. In one example, the strapping device is installed outside the compression chamber and adjacent to the rotating rollers. In particular, as the film passes between the rollers and enters the compression chamber, it is placed between the crop and the rollers and is wound around the bale by the rotational movement of the rollers and the rotational movement of the crop itself. Between the strapping device and the rollers, there may be two rollers that rotate in opposite directions to pull the film between them from the film reel and transfer the film to the rollers.

[0055] The strapping device may comprise two rotating cylinders downstream of the reel, between which the film is wound and transported to the compression chamber.

[0056] The baler 1 includes a width reduction device 4 disposed downstream of the film input unit. The width reduction device 4 includes a pair of rollers 401 that are movable between a close position where the rollers contact the edges of the bundled film so as to narrow the width of the film, and a separate position where the rollers are separated from the edges of the bundled film. The width reduction device includes a first arm 402A and a second arm 402B, each of which supports a corresponding roller of the pair of rollers 401.

[0057] The width reduction device also includes a hydraulic actuator including a first hydraulic cylinder 4030A connected to the first arm 402A and a second hydraulic cylinder 4030B connected to the second arm 402B, and the hydraulic actuator is configured to move the first arm and the second arm so as to move a pair of rollers between the approaching position and the separated position.

[0058] Therefore, the rollers 401 are arranged at the left and right edges of the film.

[0059] The first and second arms are actuated by the first and second hydraulic actuators and move towards and away from each other along a direction perpendicular to the longitudinal direction of the film. When the first and second arms move towards each other, the rollers are arranged at the approaching position and press the edges of the film so as to reduce the width of the film.

[0060] In particular, the arms 402A and 402B move along a bar extending along a direction perpendicular to the longitudinal direction of the film. Therefore, the arms move linearly along the bar towards and away from each other along a direct linear path without deviating from the curved trajectory. Alternatively, the arms may have a movement with curvature in their trajectory. In one example, the movement of the rollers towards and away from each other can be controlled so as to obtain a desired distance between the rollers. This distance determines the width of the film.

[0061] The beater includes a tailgate. The tailgate is moved by a hydraulic tailgate actuator 7 between a closed position where the compression chamber is closed to form a bale and an open position where the tailgate is opened to release the bale formed inside the compression chamber.

[0062] The tailgate is manufactured according to one or more aspects described in Italian Patent Application No. 102017000093544 in the name of the applicant of the present application and is hereby incorporated herein by reference in its entirety.

[0063] The baler 1 includes a hydraulic circuit 6. In a preferred embodiment, the hydraulic circuit is hydraulically connected to and supplies hydraulic fluid to the hydraulic tailgate actuator and the first and second hydraulic cylinders 4030A, 4030B.

[0064] Thus, in this example, the hydraulic circuit supplies hydraulic fluid to both the hydraulic tailgate actuator 7 and the hydraulic actuator 403 of the width reduction device.

[0065] In this example, the hydraulic circuit 6 includes a first portion 6' connected to the first and second hydraulic cylinders 4030A, 4030B and a second portion 6'' connected to the hydraulic tailgate actuator 7.

[0066] The hydraulic circuit 6 also includes a hydraulic duct connecting the first and second parts. A one-way valve 64 is inserted in said hydraulic duct. Thus, the first and second parts of the hydraulic circuit receive oil only from one reservoir.

[0067] In one example, in a closed configuration of the hydraulic circuit, the hydraulic circuit supplies oil to a tailgate actuator to move the tailgate from an open position to a closed position, and supplies oil to a hydraulic actuator 403 of the width reduction device to move a pair of rollers from a close position to a spaced apart position. Thus, when the tailgate is closed, the rollers are moved to the spaced apart position. These movements of the tailgate and rollers may be simultaneous or partially simultaneous.

[0068] The hydraulic circuit 6 also includes a discharge line 63 for connecting the first and second hydraulic cylinders to a discharge reservoir provided on the tractor T. An electrovalve 65 may be inserted in the discharge line and is movable between an active position that allows hydraulic fluid to flow through the discharge line towards the discharge reservoir and an inactive position to prevent hydraulic fluid from reaching the discharge reservoir.

[0069] The baler includes a control unit connected to the electrovalve for switching the electrovalve to an active position to allow the roller to move to the approach position.

[0070] The hydraulic circuit also includes a fluid accumulator 66 hydraulically connected to the first and second hydraulic cylinders. The accumulator is filled with gas, which is separated from the hydraulic fluid of the hydraulic circuit via a separation element, which may be a rigid partition or a diaphragm.

[0071] The gas has a first pressure when the pair of rollers are in the spaced apart position and a second pressure when they are in the approaching position. The first pressure is greater than the second pressure. Thus, when the rollers move to the spaced apart position, the gas expands.

[0072] Movement of the pair of rollers from the spaced apart position to the approximated position is due to the second pressure in the fluid accumulator.

[0073] The hydraulic circuit 6 is described in more detail below.

[0074] The present disclosure, according to one aspect thereof, provides a hydraulic circuit 6. The hydraulic circuit 6 is configured to supply oil to a hydraulic actuator 403 and / or a hydraulic tailgate actuator 7.

[0075] In particular, the hydraulic circuit 6 is configured to include a first hydraulic cylinder 4030A and a second hydraulic cylinder 4030B and to supply oil thereto. The first hydraulic cylinder 4030A and the second hydraulic cylinder 4030B are preferably two double-acting cylinders. The first hydraulic cylinder 4030A and the second hydraulic cylinder 4030B each include a first hydraulic chamber that receives a pressurized fluid for moving the pair of rollers from a close position to a spaced position, and a second hydraulic chamber that receives a pressurized fluid for moving the pair of rollers from a spaced position to a close position.

[0076] The hydraulic tailgate actuator 7 comprises a first hydraulic chamber which receives pressurized fluid for moving the tailgate to a closed position and a second hydraulic chamber which receives pressurized fluid for moving the tailgate to an open position.

[0077] In a first embodiment of the hydraulic circuit 6, the hydraulic circuit comprises a first supply line 61. The first supply line 61 is hydraulically connected to a first hydraulic chamber of the first hydraulic cylinder 4030A, a first hydraulic chamber of the second hydraulic cylinder 4030B and a first hydraulic chamber of the hydraulic tailgate actuator 7. The first supply line 61 comprises a first branch 61A connected to the first hydraulic chamber of the hydraulic tailgate actuator and a second branch 61B hydraulically connected to the first hydraulic chamber of the first hydraulic cylinder 4030A and the first hydraulic chamber of the second hydraulic cylinder 4030B, respectively. In that way, the first supply line 61 transmits high pressure to said hydraulic chambers to move the pair of rollers and / or to move the tailgate.

[0078] The hydraulic circuit 6 comprises, in one embodiment, a second supply line 62. The second supply line 62 is hydraulically connected to a second hydraulic chamber of the hydraulic tailgate actuator 7. Thus, when oil is pumped via the first supply line 61 to the first hydraulic chamber of the hydraulic tailgate actuator, oil is discharged from the second supply line 62, so that the second supply line 62 functions as a discharge line. Conversely, when the movement has to be reversed, oil is pumped via the second supply line 62 to the second hydraulic chamber of the hydraulic tailgate actuator and oil is discharged from the first supply line 61, so that the first supply line 61 functions as a discharge line.

[0079] The first supply line 61 is also hydraulically connected to a first hydraulic chamber of the first hydraulic cylinder 4030A and a first hydraulic chamber of the second hydraulic cylinder 4030B. That is, when the first supply line 61 is placed under high pressure, the high pressure moves the pair of rollers from a close position to a far position, and moves the tailgate from an open position to a closed position.

[0080] The hydraulic circuit 6 comprises a discharge line 63 configured to allow discharging oil contained in the first hydraulic chamber of the first hydraulic cylinder 4030A and in the first hydraulic chamber of the second hydraulic cylinder 4030B. The discharge line 63 branches off from the second branch 61B of the first supply line 61.

[0081] The hydraulic circuit 6 includes a first check valve 64. The first check valve 64 blocks the second branch 61B of the first supply line 61. In particular, the first check valve 64 is configured to prevent oil from flowing in a direction from the first and / or second hydraulic cylinders 4030A, 4030B to the first branch 61A.

[0082] The hydraulic circuit 6 includes an electrovalve (i.e., a valve having multiple positions) 65. The electrovalve 65 is movable between an active position, in which oil can flow through the discharge line 63 to the discharge system of the tractor, and an inactive position PDS, in which a second check valve 651 is positioned to block the discharge line to prevent oil from reaching the discharge system of the tractor.

[0083] Finally, the hydraulic circuit 6 comprises a pressure accumulator 66. The pressure accumulator 66 is filled with oil and gas (possibly separated from the oil by a separating film) and is hydraulically connected to the second hydraulic chamber of the first hydraulic cylinder 4030A and to the second hydraulic chamber of the second hydraulic cylinder 4030B.

[0084] Having described the structural components of the hydraulic circuit, the operation of the system will now be described with reference to these components in order to actuate the pair of rollers 401. In particular, oil is pumped through the first supply line 61, in particular through the second branch 61B. The electrovalve is in the inactive position PDS, so that oil cannot flow towards the discharge system of the tractor, and as a result reaches the first hydraulic chamber of the first hydraulic cylinder 4030A and the first hydraulic chamber of the second hydraulic cylinder 4030B. The second hydraulic chamber of the first hydraulic cylinder 4030A and the second hydraulic chamber of the second hydraulic cylinder 4030B discharge into the accumulator 66, which increases in pressure due to the reduction in the available space for gas. These hydraulic movements move the pair of rollers 401 from the approach position to the distance position. Meanwhile, the oil pumped into the first branch 61A of the first supply line 61 closes the tailgate 5.

[0085] Then, when the bale is wrapped and ready to be discharged from the baler, the control unit switches the electrovalve 65 to the active position PAT. Thus, the first hydraulic chamber of the first hydraulic cylinder 4030A and the first hydraulic chamber of the second hydraulic cylinder 4030B are in hydraulic communication with the discharge system, so that the pressure of the accumulator 66 transfers fluid from the accumulator 66 to the second hydraulic chamber of the first hydraulic cylinder 4030A and the second hydraulic chamber of the second hydraulic cylinder 4030B, thus moving the pair of rollers 401 from the separated position to the approaching position. The first check valve 64 ensures that the oil does not return towards the first supply line 61 (first branch 61A).

[0086] In addition to the embodiments described above, further solutions of the hydraulic circuit 6 are also conceivable, which are explained below purely by way of example.

[0087] In this further embodiment, the hydraulic circuit 6 is entirely dedicated to the pair of rollers 401 and has no common branches with the circuit for operating the tailgate.

[0088] Specifically, the hydraulic circuit 6 includes a high line 71 that is always under high pressure. Further, the hydraulic circuit 6 includes a low line 72, which is connected to the discharge system and is thus always under low pressure. Further, the hydraulic circuit 6 includes a first pair of branch portions 73 that are hydraulically connected to the first hydraulic chambers of the first hydraulic cylinder 4030A and the second hydraulic cylinder 4030B, respectively. The hydraulic circuit 6 includes a second pair of branch portions 74 that are hydraulically connected to the second hydraulic chambers of the first hydraulic cylinder 4030A and the second hydraulic cylinder 4030B, respectively.

[0089] The hydraulic circuit 6 also includes a selector valve 75. The selector valve is a four-way valve and is hydraulically connected to the first pair of branch portions 73 (connected to a single hydraulic line), the second pair of branch portions 74 (connected to a single hydraulic line), the high line 71, and the low line 72.

[0090] The selector valve includes one or more of the following configurations. That is, - An idle position PF where the high line 71 communicates with the low line 72 so that no operating operation is performed, the idle position PF, - An approaching position where the high line 71 communicates with the second pair of branch portions 74 and the low line 72 communicates with the first pair of branch portions 73 to move the pair of rollers 401 from the separated position to the approaching position, the approaching position, - A separated position where the high line 71 communicates with the first pair of branch portions 73 and the low line 72 communicates with the second pair of branch portions 74 to move the pair of rollers 401 from the approaching position to the separated position, including one or more of the separated positions.

[0091] Further, the pair of rollers 401 has a helical shape. One of the pair of rollers has a helical shape twisted in a first direction, and the other of the pair of rollers has a helical shape twisted in a second direction. The second direction is opposite to the first direction so as to give an upward movement to the film.

[0092] Thus, when the rollers contact the film bundle in the approach position, the rollers impart an upward motion to the film. The pair of rollers have a grooved profile. [Prior art documents] [Patent documents]

[0093] [Patent Document 1] US20200323143A1 [Patent Document 2] EP1170984B1 [Patent Document 3] US20040055268A1 [Patent Document 4] EP3278658B1 [Patent Document 5] EP3729950A1 [Patent Document 6] EP1872648B1 [Patent Document 7] EP2022318B1 [Patent Document 8] WO2021219534A1 [Patent Document 9] DE102019210962A1 [Patent Document 10] EP2506701B1 [Patent Document 11] IT102017000093544

Claims

1. A baler (1) for forming bales of agricultural crops, comprising: a compression chamber (2) for imparting a rotational movement to said crops to form said bale; a pick-up unit (3) configured to pick up the crop from the ground and feed it into said compression chamber; - a binding device, a film reel providing a bundling film for wrapping the bale; a film input unit configured to unwind the bundling film from the film reel and input the bundling film into the compression chamber such that the bundling film is wrapped around the bale by a rotational movement of the bale; and a width reduction device (4) arranged downstream of said film input unit, A pair of rollers (401) movable between a close position where the rollers contact the edge of the bundling film so as to narrow the width of the film and a separate position where the rollers are separated from the edge of the bundling film; a width reduction device (4) including a first arm (402A) and a second arm (402B) each supporting a corresponding roller of the pair of rollers; The reduction device includes a hydraulic actuator (403) having a first hydraulic cylinder (4030A) connected to the first arm (402A) and a second hydraulic cylinder (4030B) connected to the second arm (402B), the hydraulic actuator being configured to move the first arm and the second arm so as to move the pair of rollers between the close position and the spaced position.

2. a tailgate, movable between a closed position in which the compression chamber is closed to form the veil, and an open position in which the tailgate is opened to release the veil formed inside the compression chamber (2); - a hydraulic tailgate actuator (7) for moving the tailgate between the open and closed positions; A baler (1) according to claim 1, comprising a hydraulic circuit (6) hydraulically connected to said hydraulic tailgate actuator and to said first and second hydraulic cylinders (4030A, 4030B) and supplying them with hydraulic fluid.

3. 3. The baler (1) of claim 2, wherein the hydraulic circuit (6) includes a closed configuration, and in the closed configuration, the hydraulic circuit (6) is configured to perform a closing operation to move the tailgate from the open position to the closed position, and a separating operation to move the pair of rollers from the close position to the separated position.

4. 4. A baler (1) according to claim 3, wherein the hydraulic circuit is configured to perform the closing and spacing operations in at least partially overlapping time intervals.

5. The hydraulic circuit includes: - discharge lines (63) for connecting the first and second hydraulic cylinders to a discharge reservoir provided on a tractor (T) towing the baler; an electrovalve (65) inserted in the discharge line and movable between an active position allowing the hydraulic fluid to flow through the discharge line towards the discharge reservoir and an inactive position preventing the hydraulic fluid from reaching the discharge reservoir; A baler (1) according to claim 3 or 4, comprising: a control unit connected to said electrovalve for switching said electrovalve to said active position to enable said roller to move to said approach position.

6. 6. A baler (1) according to claim 5, wherein the hydraulic circuit further comprises a fluid accumulator (66) hydraulically connected to the first and second hydraulic cylinders, the accumulator being filled with gas separated from the hydraulic oil of the hydraulic circuit via a separation element.

7. The hydraulic circuit (6) comprises: a first part (6') connected to said first and said second hydraulic cylinders (4030A, 4030B); - a second part (6'') connected to said hydraulic tailgate actuator (7); a hydraulic duct, said first part and said second part being connected via said hydraulic duct; A baler (1) according to claim 1, further comprising a one-way valve (64) inserted in said hydraulic duct.

8. 2. A baler (1) according to claim 1, wherein the pair of rollers has a helical shape, one roller of the pair having the helical shape twisted in a first direction and the other roller of the pair having the helical shape twisted in a second direction, the second direction being opposite to the first direction so as to impart an upward movement to the film.

9. A baler (1) according to any one of claims 1 to 8, wherein the pair of rollers has a grooved profile.

10. 1. A method for forming a bale of agricultural crops, comprising the steps of: - picking up agricultural produce from the ground via a pick-up unit (3) of a baler (1) and feeding it into a compression chamber (2) of said baler; - imparting a rotational movement to the crop inside the compression chamber to form the bale; - unwinding a tie film from a film reel and feeding said tie film into the compression chamber so that the veil is wrapped by said tie film due to the rotational movement of the veil; - moving a pair of rollers (401) between a close position where the rollers contact the edge of the bundling film so as to narrow the width of the film, and a separate position where the rollers are separated from the edge of the bundling film, the rollers being supported by a first arm (402A) and a second arm (402B); The method includes the step of moving the first arm and the second arm via a first hydraulic cylinder (4030A) and a second hydraulic cylinder (4030B), respectively, to move the pair of rollers between the close position and the spaced position.

11. - moving, via a hydraulic tailgate actuator (7), the tailgate of the baler between a closed position, in which the compression chamber is closed to form the bale, and an open position, in which the tailgate is opened to release the bale formed inside the compression chamber; - supplying hydraulic fluid to both the hydraulic tailgate actuator and the first and second hydraulic cylinders (4030A, 4030B) via a hydraulic circuit (6).

12. The method of claim 11 , wherein the pair of rollers are moved to the spaced apart position in response to closing of the tailgate.

13. - moving an electrovalve (65) inserted in a discharge line (63) connecting the first and second hydraulic cylinders to a discharge reservoir provided on a tractor (T) towing the baler, between an active position allowing the hydraulic oil to flow through the discharge line towards the discharge reservoir and an inactive position preventing the hydraulic oil from reaching the discharge reservoir; - moving the electrovalve to the active position in order to move the roller to the approximated position.

14. 14. The method of claim 13, wherein a fluid accumulator (66) is hydraulically connected to the first and second hydraulic cylinders, the accumulator being filled with gas separated from the hydraulic fluid of the hydraulic circuit via a separation element.

15. The hydraulic circuit includes: a first part (6') connected to said first and said second hydraulic cylinders; a second part (6'') connected to said hydraulic tailgate actuator; a hydraulic duct, said first part and said second part being connected via said hydraulic duct; - a one-way valve (64) inserted in said hydraulic duct.

16. 13. The method of claim 10-12, wherein the roller imparts an upward motion to the bundling film when the roller contacts the bundling film in the approximated position.

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