Apparatus and methods for handling and wrapping cylindrical objects

Abstract

The invention provides an apparatus for wrapping a film around a cylindrical object. The apparatus comprises a wrapping table configured to support the cylindrical object on a plurality of support rollers enabling rotation of the cylindrical object. At least one wrapping arm is configured to stretch film across the outer surface of the cylindrical object by rotating the at least one wrapping arm or the wrapping table to wrap the film around the cylindrical object in partially overlapping layers. A loading assembly is movable between a lowered position and a raised position to bring the cylindrical object to the wrapping table in a loading direction substantially perpendicular to longitudinal axes of the support rollers. The longitudinal axes of the support rollers of the wrapping table are inclined to the horizontal and the loading assembly is operable to move between the lowered position and the raised position by rotation about a loading assembly axis that is also inclined to the horizontal.

Description

[0001] APPARATUS AND METHODS FOR HANDLING AND WRAPPING CYLINDRICAL OBJECTS

[0002] The present invention relates to apparatus and methods for handling and wrapping cylindrical objects such as bales of consolidated material. Aspects and embodiments of the invention relate particularly to apparatus and methods for use in wrapping cylindrical objects with a film.

[0003] Background to the invention

[0004] In the agricultural industry, it is common to compact materials into consolidated bales for handling, transport, storage and reuse. Example materials include grass, maize, sugar beet pulp and other plant matter. Bales of wood chips, wood shavings, wood wool, organic waste and other biomass are also formed and used in other industries. It is common to wrap the bales of material with a plastic film or foil, either using combination machines designed to form and fully wrap a bale, or using machines designed for wrapping pre-formed bales. Pre-formed cylindrical bales might be partially wrapped in the baling machine by providing a net or a plastic film that covers the entire curved side surface of the bale. In such cases it is still necessary to fully wrap the bale in order to seal the end planes of the bale and increase the coverage over the curved surface for protection and containment.

[0005] When wrapping pre-formed bales, a wrapping machine is required to pick up the bale from the ground, transfer it to a wrapping location on the machine, and return the wrapped bale to the ground. This must be achieved with minimal loosening or loss of material, and minimal damage to the bale and the wrapping film. Bales formed from some materials are more prone to damage than others. For example, bales formed from grass or other matter that can be compacted into a cohesive mass are relatively stable, whereas bales formed from dry and small material particles (e.g. wood chips) or heavy and slippery material particles (e,g. sugar beet pulp) are of relatively low stability, and required careful handling, particularly before they are fully wrapped.

[0006] Conventional wrapping devices have a supportive surface underneath the bale, often referred to as a wrapping table, and means of achieving relative rotation between the bale and at least one film roll. The relative rotation could either be due to a stationary bale and a moving film roll, or the bale may be rotated with respect to a static film roll.

[0007] Typically, a cylindrical bale is also slowly turned around its own axis on the wrapping table at a speed adapted to the rotational velocity of the film roll, to ensure a certain overlap of the foil from one turn to the next. In conventional wrapping methods, every layer of film will wrap the centre of the bales side surfaces, but only a small portion of the edges of said side surfaces. A consequence is that much more plastic film foil will be applied in the centre of the sides than on the edges. The number of layers is essential for the preservation of the bales’ material, where more layers give a better preservation. For example, for bales with diameter 1150mm and width 1200mm and standard width of the plastic film of 750mm, in order to obtain a foil wrapped bale with at least six layers of foil at every point of the bale, the centre of the sides of the bale is provided with approximately 27 layers of foil. This means that an excessive amount of plastic foil, and number of rotations of the film roll is necessary to achieve the required coverage. If the bale is covered as the example above, with 27 layers in the central cluster, and 6 at the edges, the edges will be the point of leakage and thus the limiting factor for the quality of the bales’ preservation.

[0008] WO 2023 / 106929 describes a bale wrapping apparatus that improves the efficiency of bale wrapping by applying the film with an inclination angle between the wrapper arm and the wrapping table, where the wrapping table is shorter than a typical bale length so that an end of the bale is unsupported.

[0009] WO 2015 / 185732 describes a bale wrapping machine that has an inclined bale supporting arrangement to help prevent a bale from drifting off from the end of the rollers and to compensate for offset wrapping that occurs when the bale is rotated at increased speeds.

[0010] Summary of the invention

[0011] There is generally a need to develop bale wrapping and / or handling machines to enable effective implementation of efficient wrapping methods, in particular those using inclined wrapping tables. It is amongst the aims and objects of aspects the invention to provide a bale wrapping machine and / or method of use which enables efficient bale wrapping in terms of film consumed and / or wrapping time. It is a further aim and object of aspects of the invention to provide a bale wrapping machine that reduces damage to bales and / or loss or loosening of materials.

[0012] It is a further aim and objective of aspects of the invention to enable implementation of efficient wrapping methods in a machine package that is compact to facilitate transport (e.g. on public roadways).

[0013] [B]

[0014] According to a first aspect of the invention, there is provided an apparatus for wrapping a film around a cylindrical object, the apparatus comprising: a wrapping table supported by a base frame, the wrapping table configured to support the cylindrical object and comprising a plurality of support rollers configured to rotate the cylindrical object on the wrapping table about a longitudinal axis of the cylindrical object; at least one wrapping arm configured to stretch film across the outer surface of the cylindrical object by rotating the at least one wrapping arm or the wrapping table, thereby wrapping the film around the cylindrical object in partially overlapping layers; a loading assembly for loading a cylindrical object to be wrapped into the wrapping table; wherein the loading assembly is movable between a lowered position in which the loading assembly is operable to engage the cylindrical object on the ground, and a raised position; wherein movement from the lowered position to the raised position brings the cylindrical object to the wrapping table in a loading direction substantially perpendicular to longitudinal axes of the support rollers; wherein the longitudinal axes of the support rollers of the wrapping table are inclined to the horizontal; wherein the loading assembly is operable to move between the lowered position and the raised position by rotation about a loading assembly axis; and wherein the loading assembly axis is inclined to the horizontal.

[0015] In this regard horizontal means a horizontal plane in the frame of reference of the apparatus. It will be appreciated that if the apparatus itself is inclined to the horizontal, the horizontal plane of reference of the apparatus will also be inclined. The loading assembly axis may be inclined in a direction transverse to the loading direction. A direction transverse to the loading direction means in a plane that is intersected by an imaginary line in the direction of travel of an object being loaded.

[0016] The loading assembly axis may be in a vertical plane that is parallel to the longitudinal axes of the support rollers.

[0017] The longitudinal axes of the support rollers of the wrapping table may be inclined to the horizontal at a table angle, which may be between around 5 degrees and 15 degrees. The loading assembly axis may be inclined to the horizontal in a direction transverse to the loading direction at a loading assembly angle, which may be between around 5 degrees and 15 degrees. The loading assembly angle may be equal to, or substantially equal to, the table angle. The loading assembly angle and / or the table angle may be approximately 9 degrees.

[0018] By inclining the loading assembly axis to the horizontal, the loading assembly can bring the cylindrical object to the inclined wrapping table with the cylindrical object in an inclined orientation in a single movement, enabling a smooth and gentle loading of a cylindrical object onto the wrapping table. In contrast, a horizontally pivoting loading assembly may bring the cylindrical object to the wrapping table in a misaligned orientation, with risk of damage to the cylindrical object prior to wrapping. The improved loading of the cylindrical object is achieved by a simple mechanism with few moving parts. With the invention, the cylindrical object may be aligned with the wrapping table when the loading assembly is in its raised position, reducing risk of damage to the cylindrical object, such as loosening or loss of the bale material.

[0019] The apparatus according to any preceding claim, wherein the loading assembly is configured to bring a cylindrical object from a ground orientation and into alignment with the wrapping table orientation in a single movement of the loading assembly

[0020] The loading assembly may comprise a pair of lifting arms, each lifting arm being pivotally mounted to the base frame at an opposing side of the base frame. The lifting arms may be mounted to the base frame at respective mounting points, the mounting points being vertically offset from one another. The loading assembly may comprise a bale retainer configured to retain a bale on the loading assembly. The bale retainer may comprise a grapple arm operable to move between a closed position and an open position. The bale retainer may be oriented parallel to the ground level when the loading assembly is in its lowered position. The grapple arm may be oriented parallel to and adjacent to the ground level when the loading assembly is in its lowered position. In the lowered position, the bale retainer and the bale grapple may be horizontally oriented in parallel with the orientation of the base frame. In the raised position, the bale retainer may be inclined with respect to the base frame.

[0021] The wrapping table may be configured to be pivoted about a horizontal transverse axis between at least two positions. The at least two positions may comprise two of a bale receiving position in which the wrapping table is tipped towards the loading assembly; a bale wrapping position in which the wrapping table is substantially symmetrical about a vertical axis; and a bale ejecting position in which the wrapping table is tipped away from the loading assembly.

[0022] In a method of using the apparatus of any preceding claim to load a cylindrical bale onto the wrapping table of the apparatus, the method comprising operating the loading assembly to bring the bale from a ground orientation and into alignment with the inclined wrapping table orientation in a single movement of the loading assembly.

[0023] [A]

[0024] According to a second aspect of the invention, there is provided an apparatus for wrapping a film around a cylindrical object, the apparatus comprising: a base frame and a pair of wheels mounted to the base frame and having respective wheel axles; a wrapping table supported by the base frame, the wrapping table configured to support the cylindrical object and comprising a plurality of support rollers configured to rotate the cylindrical object on the wrapping table about a longitudinal axis of the cylindrical object; at least one wrapping arm configured to stretch film across the outer surface of the cylindrical object by rotating the at least one wrapping arm or the wrapping table, thereby wrapping the film around the cylindrical object in partially overlapping layers; wherein the pair of wheels is mounted to the base frame on a support assembly; and wherein the apparatus comprises an actuator operable to act on the support assembly to change the vertical position of the wheel axes of each of the pair of wheels with respect to the base frame; wherein the change to the vertical position of one wheel axle is in an opposing direction to the change to the vertical position of the other wheel axle, thereby changing or controlling the inclination of the base frame with respect to the ground.

[0025] The respective axles of the pair of wheels may be offset from one another.

[0026] At least one of the pair of wheels may be mounted to the base frame via a support member, the support member being pivotally connected to the base frame at a pivot point displaced from the wheel axle (radially from the wheel axle). The actuator may be operable to act on the support member to rotate the support member with respect to the base frame. The actuator may comprise a hydraulic actuator, and may comprise a linear actuator. The actuator may comprise a hydraulic cylinder. The actuator may be mounted between the base frame and a mounting point on the support member. The mounting point may be radially displaced from the pivot point of the support member so that movement of the actuator effects rotation of the support member.

[0027] The apparatus may comprise a support member for each wheel of the pair of wheels, each support member being pivotally connected to the base frame at a pivot point displaced from a respective wheel axle (radially from the wheel axle). The wheel axles may be radially displaced from the pivot point in different radial directions. The radial directions may be oriented at approximately or equal to 180 degrees from one another.

[0028] The support members may be fixed to one another. Rotation of one support member may cause rotation of the other support member. Each support member may be attached to a support rod. Rotation of one support member may cause rotation of the other support member via rotation of the support rod.

[0029] The longitudinal axes of the rollers of the wrapping table may be inclined with respect to the base frame. Alternatively, the longitudinal axes of the rollers of the wrapping table may be parallel to the base frame. Features of the second aspect of the invention may combined with the first aspect of the invention, and embodiments of the second aspect of the invention may comprise preferred or optional features of the first aspect of the invention.

[0030] According to a third aspect of the invention, there is provided an apparatus for wrapping a film around a cylindrical object, the apparatus comprising: a base frame and a pair of wheels mounted to the base frame and having respective wheel axles; a wrapping table supported by the base frame, the wrapping table configured to support the cylindrical object and comprising a plurality of support rollers configured to rotate the cylindrical object on the wrapping table about a longitudinal axis of the cylindrical object; at least one wrapping arm configured to stretch film across the outer surface of the cylindrical object by rotating the at least one wrapping arm or the wrapping table, thereby wrapping the film around the cylindrical object in partially overlapping layers; wherein at least one of the pair of wheels is mounted to the base frame via a support member, the support member being pivotally connected to the base frame at a pivot point displaced from the wheel axle; and wherein the apparatus comprises an actuator operable to act on the support member to rotate the support member with respect to the base frame and change the vertical position of the wheel axle with respect to the base frame, thereby changing or controlling the inclination of the base frame with respect to the ground.

[0031] The support member may be a part of a support assembly, and the change to the vertical position of one wheel axle is in an opposing direction to the change to the vertical position of the other wheel axle, thereby changing or controlling the inclination of the base frame with respect to the ground.

[0032] Features of the third aspect of the invention may combined with the first or second aspects of the invention, and embodiments of the third aspect of the invention may comprise preferred or optional features of the first or second aspects of the invention.

[0033] [D]

[0034] According to a fourth aspect of the invention, there is provided an apparatus for wrapping a film around a cylindrical object, the apparatus comprising: a wrapping table configured to support the cylindrical object and comprising a plurality of support rollers configured to rotate the cylindrical object on the wrapping table about a longitudinal axis of the cylindrical object; at least one wrapping arm configured to stretch film across the outer surface of the cylindrical object by rotating the at least one wrapping arm with respect to the wrapping table about a rotation axis, thereby wrapping the film around the cylindrical object in partially overlapping layers; wherein the at least one wrapping arm is supported above the wrapping table by a support structure; and wherein the support structure is adjustable to enable the rotation axis of the at least one wrapping arm to be changed.

[0035] The support structure may comprise an upper structure and a lower structure, wherein the orientation of the upper structure is adjustable with respect to the lower structure to enable the rotation axis of the at least one wrapping arm to be changed. The orientation of the upper structure may be adjustable by inclining the upper structure with respect to the lower structure, which may be by pivoting the upper structure with respect to the lower structure.

[0036] The lower structure may comprise a column, which may extend substantially vertically from the base frame. The upper structure may comprise a horizontally extending beam joined to the lower structure. An upper column may join the beam to the column, or the beam may be coupled directly to the column. The horizontal beam may be oriented in a plane that is approximately perpendicular to the column, although this is not essential as long as the beam extends in a horizontal dimension away from the column.

[0037] The lower structure and the upper structure may be joined together by a pinned coupling, and the pinned coupling may enable the upper structure to pivot with respect to the lower structure. The apparatus may comprise an actuator which acts on the upper and lower structures to adjust the position of the upper structure with respect to the lower structure. The actuator may act across the pinned coupling, and may be attached to the upper structure and the lower structure. The actuator may be a hydraulic actuator. The actuator may be a linear actuator. The actuator may be a hydraulic cylinder which may extend across the pinned joint, and which may be tied to each of the upper and lower structure at respective ends. Where the lower structure comprises an upper column, the upper column may be operable to be inclined with respect to the lower structure under control of a control system for the actuator.

[0038] The longitudinal axes of the rollers of the wrapping table may be inclined with respect to the base frame. Alternatively, the longitudinal axes of the rollers of the wrapping table may be parallel to the base frame.

[0039] The wrapping arm may be configured such that a longitudinal axis of a film to wrapped is oriented at an angle in the range of around 20 to 35 degrees to a longitudinal axis of the bale rollers.

[0040] The wrapping arm may be configured such that a centre line of a film to wrapped passes a bale centre point with a maximum offset or deviation from the centre point of 10% of the bale diameter, and preferably 5% of the bale diameter.

[0041] The wrapping arm may be configured such that a film is wrapped over at least one of the edges of the bale between the cylindrical surface and the circular ends.

[0042] Features of the fourth aspect of the invention may combined with the first to third aspects of the invention, and embodiments of the fourth aspect of the invention may comprise preferred or optional features of the first to third aspects of the invention.

[0043] According to a fifth aspect of the invention, there is provided a method of configuring the apparatus of the fourth aspect of the invention, the method comprising: adjusting the support structure to change the rotation axis of the at least one wrapping arm to achieve a desired wrapping geometry for a selected bale size.

[0044] Features of the fifth aspect of the invention may combined with the first to fourth aspects of the invention, and embodiments of the fifth aspect of the invention may comprise preferred or optional features of the first to fourth aspects of the invention. Brief of the drawings

[0045] There will now be described, by way of example only, various embodiments of the invention with reference to the drawings, of which:

[0046] Figure 1 is a front view of a bale wrapping machine according to an embodiment of the invention, loaded with a bale;

[0047] Figure 2A is a simplified schematic isometric view of the bale wrapping machine of Figure 1 , having certain parts removed to improve clarity;

[0048] Figure 2B is a simplified schematic front view of the bale wrapping machine of Figure 2A, loaded with a bale;

[0049] Figures 3A and 3B are schematic isometric representations of a base frame of the machine of Figures 2A and 2B;

[0050] Figures 4A and 4B are respectively schematic isometric and front representations of the base frame of Figures 3A and 3B with axles offset in a first position;

[0051] Figures 5A and 5B are respectively schematic isometric and front representations of the base frame of Figures 3A and 3B with axles offset in a second position;

[0052] Figure 6 is a block diagram schematically showing the functional components of a control system for a bale wrapping machine according to an embodiment of the invention;

[0053] Figures 7A, 7B and 7C are respectively isometric, front and side views of a bale wrapping machine according to an embodiment of the invention with a loading assembly in a lowered position;

[0054] Figures 8A and 8B are respectively front and side views of the bale wrapping machine of Figures 7A to 7C with the loading assembly in a raised position;

[0055] Figure 9 is a side view of the bale wrapping machine of Figures 7 and 8 in a bale wrapping position; Figure 10 is a side view of the bale wrapping machine of Figures 7 and 8 in a bale ejection position;

[0056] Figure 11 is a schematic representation of a bale wrapping arm and bale geometry according to wrapping methods used in embodiments of the invention;

[0057] Figure 12 is an enlarged view of an adjustment mechanism of the bale wrapping machine of Figure 1 ;

[0058] Figure 13 is a front view of the bale wrapping machine of Figure 1, loaded with a bale of different dimensions; and

[0059] Figure 14 is a block diagram schematically showing the functional components of a control system in an embodiment of the invention.

[0060] Detailed of preferred embodiments

[0061] Embodiments of the invention are described in the context of the handling and wrapping of bales of consolidated material. .Example materials include, but are not limited to, grass, maize, sugar beet pulp and other plant matter, wood chips, wood shavings, wood wool, organic waste and other biomass. The principles of the invention may also be applied to the handling and wrapping of cylindrical objects in general, which may be objects other than bales. Nevertheless, the following example embodiments illustrate the application of the invention to the handling and wrapping bales, in which the invention has particular benefits and advantages.

[0062] Referring firstly to Figure 1 , 2A and 2B, there is shown a bale wrapping machine 100 loaded with a bale 1. Figure 1 is a front view of the bale wrapping machine 100 and bale 1 , and Figures 2A and 2B are respectively isometric and front simplified schematic views of the machine, having certain parts removed to improve clarity.

[0063] The machine 100 is designed to be towed by a vehicle such as a tractor (not shown), and has a base frame or chassis 12, a wrapping table 14 comprising multiple rollers 16, and a bale loading assembly 18. Two wheels 20a, 20b (together 20) are mounted on the base frame 12, and an extending member 22 of the base frame has a coupling 24 at a forward end. Together, the base frame, wheels and coupling enable towing of the machine 100 by a vehicle in a position that enables the bale loading assembly 18 to be brought into proximity with a preformed cylindrical bale on the ground.

[0064] Also provided on the machine is a bale wrapping assembly 120 (omitted from Figures 2A and 2B) comprising a wrapping arm 122 that supports film rolls 124, and a support structure 126 that suspends the wrapping arm 122 above the bale 1.

[0065] The machine 100 is shown in Figure 1 with the loading assembly 18 returned to a lowered position, having previously loaded the bale 1 onto the wrapping table 14 such that the curved cylindrical surface of the bale rests on the wrapping table. Figures 2A and 2B show the loading assembly in a raised position. The wrapping table 14 comprises four support rollers 16, which have roller axes substantially parallel to the longitudinal axis of the cylindrical bale (and perpendicular to the circular end surfaces of the bale). The four support rollers each define a line of contact for the bale surface, and are positioned to form a concave arrangement that corresponds (at least approximately) to the curvature of the bale surface. The support rollers comprise two inner rollers 16a, close to the lowest part of the cylindrical bale, that is close to a vertical line passing through the centre of an end plane of the bale 1. Two outer rollers 16b are displaced circumferentially from the inner rollers, and contact the bale surface at positions vertically higher on the bale. The rollers enable rotation of the bale about its longitudinal axis during wrapping. One or more of the rollers is driven to rotate about its axis by drive motor 19, which is a hydraulic motor, to cause rotation of the bale during wrapping. A greater or lesser number of rollers 16 may be provided in alternative embodiments.

[0066] As shown most clearly in Figures 1 and 2B, the wrapping table 14 is inclined with respect to the base frame 12 . The axes of the rollers 16 are inclined with respect to the horizontal plane of the base frame by an angle of inclination 0i in a transverse direction of the machine. In this regard transverse means in a direction between the two wheels, and generally at right angle to the normal forward direction of the machine in use. Angle 0i may be measured in a vertical plane that is oriented transverse to the machine and parallel to axes of rotation of the wheels. Inclining the wrapping table facilitates retention of a bale on the table. Gravity acts on the bale to retain it towards the “low” side of the table, which is provided with an end roller 17 (omitted from Figures 2A and 2B) that prevents further movement. A typical angle 0i is 9 degrees, although other angles may be used in alternative embodiments. Inclining the angle of the rollers of the wrapping table also facilitates wrapping a film at an inclined angle with respect to a supported bale, as will be described further below. The wrapping table may be inclined, or the axis of a wrapping arm may be inclined, or a combination of both, in order to achieve the desired film orientation.

[0067] As is most clearly shown in Figure 2A, the wheels 20a and 20b are mounted to the base frame 12 on respective wheel axes which are offset from one another in a fore-aft direction of the machine. Wheel 20a is mounted with its axis in a rearward position with respect to the axis of the wheel 20b (and axis of wheel 20b is therefore in a forward position with respect to the axis of wheel 20a).

[0068] Figures 3A and 3B are further simplified schematic isometric representations of the base frame 12 of the machine 100, with various components, including the wrapping table 14 and loading assembly 18 removed for clarity. The base frame 12 is shown as being substantially rectangular in form for simplicity of the description.

[0069] Wheels 20a and 20b are mounted on axes that are offset from one another in a fore-aft direction of the machine. The wheels are mounted to the base frame 12 via a wheel support assembly generally shown at 26. The support assembly 26 comprises a respective support member 28a and 28b for each wheel. The support members 28 are each joined to a support rod 29, which is pivotally mounted to the base frame on a support axis 30. Wheel axles 31a and 31b are located on respective wheel axes that are displaced from the support axis in different directions, so that the wheels are not coaxial with the support axis. In the position shown in Figures 3A and 3B, the support member 28a offsets the axis of wheel 20a in a rearward direction, and the support member 28b offsets the axis of wheel 20b in a forward direction.

[0070] The machine comprises an actuator 32 coupled between mounting point 34 on the support member 28a and a mounting point 35 on the base frame 12. The actuator 32 is a hydraulic cylinder operable to be moved continuously between an extended condition and a retracted condition. The mounting point 34 is radially displaced from the support rod axis 30, so that a linear force from the actuator causes pivoting of the support member 28a about the support axis, changing the position of the wheel axle 31a. Support members 28a and 28b are rotationally fixed to the support rod 29, therefore the rod rotates and the support member 28b also pivoted about the support axis to change the position of the wheel axle 31b. Since the wheel axes are offset by the respective support members in opposing directions (at 180 degrees around the support axis), the wheel axes are moved in opposing directions in the vertical direction.

[0071] As shown by the arrows in Figure 3A, retraction of the actuator 32 causes anti-clockwise rotation of the support assembly 26, moving the wheel 20a downwards, and wheel 20b upwards with respect to the base frame. As shown by the arrows in Figure 3B, extension of the actuator 32 causes clockwise rotation of the support assembly 26, moving the wheel 20a upwards, and wheel 20b downwards with respect to the base frame 12.

[0072] Referring now to Figures 4A to 5B, the effect of the movement of the wheel position is schematically shown in the context of uneven ground 40, 41. Figures 4A and 4B show that rotation of the support assembly 26 as shown in Figure 3A can be used to achieve a horizontal orientation of the base frame 12 on terrain that is graded transversely, sloping upwards from left to right. The base frame 12 is maintained horizontally or controlled or adjusted to a horizontal position, and therefore the desired transverse inclination of the wrapping table 14 is achieved. In the present example, this would be orientation of the wrapping table at around 9 degrees to assist in retaining the bale on the machine.

[0073] Similarly, Figures 5A and 5B show that rotation of the support assembly as shown in Figure 3B can be used to achieve a horizontal orientation of the base frame 12 on terrain that is graded transversely, sloping downwards from left to right. As with Figures 4A and 4B, the base frame 12 is maintained horizontally or controlled or adjusted to a horizontal position and the desired transverse inclination of the wrapping table 14 is achieved.

[0074] Figure 6 is a block diagram schematically showing the functional components of a control system for the machine of Figures 2A and 2B. The control system, generally shown at 50, comprises a control unit 51 , an axle position sensor 52, an inclination sensor 53, and the axle position actuator 54. The control unit may be a part of a dedicated hardware unit for the machine, located on the machine itself or remotely from the machine. The system comprises a human machine interface (HMI) 55 which may also be a part of a dedicated hardware unit, or may be in separate hardware communicating with the control unit. The control system 50 may alternatively or in addition be partially implemented in other computer hardware, such as in a module of a general equipment control unit, or as software running on a general computer or mobile computer processing device.

[0075] The control unit 51 is in communication with the axle position sensor 52 and inclination sensor 53, and sends a control signal to the axle position actuator 53 depending on data from the sensors 52 and 53 and operational requirements. The axle position actuator 54 can be adjusted until the inclination sensor signals that the desired inclination has been achieved. Control of the axle position can be automated according to preset requirements, for example an acceptable range of deviation from the preferred angle of inclination. Alternatively, or in addition, an operator can manually set the axle position using the interface 55.

[0076] The described system enables control of the inclination of a bale handling and / or bale wrapping machine with a simple mechanical arrangement and few moving parts. This is particularly useful for bale wrapping machines which use inclined wrapping tables to achieve efficient film wrapping. If the actual inclination angle of the wrapping table with respect to the true horizontal is too high due to transversely sloping ground, the forces on acting on the end plane of the bale from the end roller 17 may be sufficiently high to cause loosening or loss of material and / or damage to the bale. This risk is exacerbated for relatively low stability bales. Additionally, if the actual inclination angle of the wrapping table becomes too low, there is a risk that the bale will fall from the open end of the wrapping table. The axle offset arrangement described mitigates these potential drawbacks of inclined wrapping tables by enabling adjustment and control of the position of the wrapping table surface to within an acceptable deviation (e.g. + / - 5 degrees) from the desired angle.

[0077] Although the foregoing example has an inclined wrapping table, it should also be appreciated that in a further alternative embodiment, the wrapping table is not inclined with respect to the base frame. A wrapping table that is designed to be horizontal may be maintained in or adjusted to a horizontal position by the solution of this aspect of the present invention. It should also be appreciated that this aspect of the invention may be used to incline the base frame and the wrapping table (including a horizontal wrapping table) to any desired angle within the range of adjustment of the wheel axles. In some embodiments, the axle offset arrangement may be used to incline the base frame and / or bale wrapping table with respect to the horizontal, for example to facilitate retention of the bale on the machine.

[0078] Reference is now made to Figures 7A to 8B, which are additional simplified, schematic views of the bale wrapping machine 100. The structure and features of the machine 100 are described above with reference to Figures 1 , 2A and 2B. Figures 7A, 7B and 7C additionally show isometric, front and side views of the bale wrapping machine 100 with the loading assembly in a lowered position. Figures 8A and 8B are respectively front and side views of the bale wrapping machine 100 with the loading assembly 18 in a raised position. Wheel 20b is omitted from Figures 7C and 8B for clarity. As shown in Figures 7A to 7C, the loading assembly 18 comprises a bale retainer, generally shown at 60, attached to a pair of lifting arms 62a, 62b. The lifting arms 62a, 62b are pivotally mounted to the base frame 12 at respective mounting points 63a, 63b. As will be described in more detail below, the mounting points 63a, 63b are vertically offset to define a loading assembly rotation axis L which is inclined to the base frame of the machine.

[0079] The bale retainer 60 has a side portion 64, which extends from lifting arm 62a on the side of the forward extending member 22 of the base frame. When the loading assembly is in the lowered position shown in Figures 6A to 6C, the side portion 64 extends in a forward direction of the machine from a proximal part of the lifting arm 62a, and loops back to join the lifting arm at a distal end of the lifting arm (when the loading assembly is in the raised position as shown in Figures 8A and 8B, the extension of the side portion is in an upward direction). A first cross member 65 extends between the lifting arms 62a, 62b at their distal ends. A bale grapple 66 is pivotally mounted on the distal end of the lifting arm 62b, and has an extending section 66a connected to a cross section 66b at a right angle via an elbow bend 66c. An actuator in the form of a hydraulic cylinder 67 is attached between the lifting arm 62b and the extending section, and is operable to retract and extend to move the bale grapple between a closed position shown in Figures 7 and 8, and an open position in which the grapple 66 is rotated about a vertical axis, as shown by the dotted lines in Figure 7A.

[0080] The lifting arms 62a, 62b are each mounted to the base frame of the machine on pivoting mounts so that the loading assembly can rotate between the lowered position and the raised position. A second cross member 68 joins the lifting arms, and a third cross member 69 extends across the lifting arms and supports a bale sensor 70. A lifting mechanism (not shown) is coupled to the loading assembly 18 and is operated to move the loading assembly between the lowered and raised positions to bring a bale to the wrapping table.

[0081] As most clearly shown in Figures 7B and 7C, in the lowered position, the bale retainer 60, and in particular the bale grapple 66, is horizontally oriented in parallel with the orientation of the base frame 12, and the bale grapple is aligned with the bottom of the wheels 20 and therefore the ground. However, in the raised position, shown in Figures 8A and 8B, the bale retainer 60 is inclined with respect to the base frame and the horizontal, due to the rotating movement of the loading assembly about the inclined axis L. The axis L is inclined with respect to the base frame in a direction transverse of the base frame, and transverse of the loading direction of the bale. The inclination angle 02 matches inclination angle 01 of the wrapping table.

[0082] In use, the machine is brought into proximity with a bale with the bale grapple 66 opened, so that an end plane of the bale is adjacent the side portion 64 of the bale retainer 60, and cylindrical surface of the bale is transverse to the machine. When the presence of the bale is detected by the bale sensor 70, the bale grapple 66 is closed around the front of the bale. The lifting mechanism is then operated to lift the lifting arms and raise the loading assembly.

[0083] A bale loaded onto the loading assembly will be lifted from the ground and moved towards the wrapping table in the loading direction D. Due to the alignment of the rotation axis L, the bale is moved from a horizontal orientation to an inclined orientation in a single movement of the loading assembly. When the loading assembly is fully raised, as shown in Figures 8A and 8B, the bale is inclined at the same inclination as the inclined bale wrapping table. The bale is therefore brought to the bale wrapping table at the correct orientation, enabling smooth and gentle loading of the unwrapped bale to the wrapping table with reduced forces on the bale. This gentle loading reduces potential for damage to the unwrapped bale which could cause loosening and / or loss of material, or partial disintegration of the bale.

[0084] Figures 7A to 8B show the wrapping table 14 having a generally concave shape that is tipped forwards towards the loading assembly 60 about an axis transverse to the machine. Tipping the wrapping table 14 forwards in this manner facilitates loading of a bale from the loading assembly 60; the lip to the table created by the forwardmost roller is lowered to facilitate transfer of the bale onto the table. In addition, the lip to the table created by the rearmost roller is raised, which helps prevent unintended rolling of the bale off the back of the table.

[0085] Figure 9 shows the wrapping table 14 in a bale wrapping position. Compared with the table position in Figures 7 and 8, the table 14 is no longer tipped forwards, and is in a neutral or symmetrical position. The loading assembly 60 is moved to the lowered position to provide clearance for the operation of a wrapping arm (not shown in Figure 9).

[0086] Figure 10 shows the bale wrapping table 14 in a bale ejection position. The bale table is tipped backwards sufficiently for a bale (e.g. after wrapping) to be easily ejected from the rear of the table 14 and the machine.

[0087] The fore and aft tipping of the wrapping table around a horizontal transverse axis is achieved by a hydraulic mechanism (not shown) within the machine. These features provide loading and / or ejection improvements when handling and / or wrapping bales.

[0088] Figure 11 is a simplified, transparent side view showing an advantageous bale wrapping geometry that achieves efficient use of wrapping film and efficient wrapping time. In the arrangement shown, a bale 101 is supported on a wrapping table 114 consisting of two pairs of support rollers, R1, R2 (only one roller of each pair is visible in the drawing). The wrapping table and bale 101 are inclined in relation to the base frame 112, and the wrapping arms 122 are inclined in the opposing direction, resulting in an angle 03 between the centre line Bciof the bale and the centre line Fciof the film 123 being wrapped.

[0089] Figure 11 shows a desirable configuration of the machine in which the film is wrapped over at least one of the edges of the bale between the cylindrical surface and the circular ends (in this case edge 103), and the centre line Fciof the film passes at a distance d above the bale centre point Bcp. A deviation from crossing of the foil centre line Fcithrough the bale centre point Bciis acceptable within the scope of the invention but the offset or deviation d preferably does not exceed 10% of the bale diameter and more preferably not more than 5% of the bale diameter. In an optimised configuration of the device, the foil centre line Fciof passes through the bale centre point Bcp, i.e. through the exact centre of the bale, and the film may overlap both edges 103 and 105 between the cylindrical surface and the circular ends. A typical angle 03 for the described wrapping method is in the range of 20 to 35 degrees.

[0090] To facilitate wrapping of the film over a lower edge 105 between the cylindrical surface and the circular ends, the support rollers R1 and R2 have a length less than the bale length. The rollers R1 , which are close to the lowermost part of the bale, have an extension only slightly less than the bale length, leaving about 10% of the bale length unsupported. The second support roller pair R2 is significantly shorter, leaving about 45% of the bale length unsupported. This arrangement of gradually shorter support rollers when moving from the lowermost part of the bale up to higher parts enables the desired manner of bale wrapping. The reduced extension of the support rollers is required to avoid conflict thereof with the foil to be wrapped. It will be appreciated that more than two roller pairs may be provided, and typically there will be 2 or 3 pairs of rollers.

[0091] For a given pair of support rollers positioned at a given angle (p from a vertical line through the centre of the cylindrical object (or a vertical line through the centre of an imaginary circle defined by the rollers), there is an inverse correlation between the angle (p (in degrees) and the relative supported length extension Re(N) of the bale, N being an integer 1 , 2 or 3 indicating which pair of support rollers the Re(N) refers to. The larger the angle cp, the shorter the support roller. This may be expressed mathematically in an equation constituting a mandatory feature of one specific aspect of the present invention, namely:

[0092] Re(N) < Nemp " k CPN where

[0093] Re(N) is the extension of the support roller in question as a per centage of the length of the cylindrical object, k is a constant decided empirically

[0094] <PN is the angular position of the support roller in degrees from a vertical line through the centre of the cylindrical object (or a vertical line through the imaginary circle defined by the support rollers),

[0095] Nempis an empiric number found in the development of the present invention. It has been found that Nempis 105 and that k =1.4.

[0096] It is preferred that the length extensions of the support rolls in practice are chosen within 80 to 100% of the calculated value for Re(N) and more preferred in the region 90 to 95%.

[0097] Figure 12 is an enlarged front view of the machine of Figure 1 , showing a part of the support structure 130 of the wrapping assembly 120. The support structure is designed to facilitate the desired wrapping geometries as described above, including for a typical range of bale sizes likely to be encountered. The support structure 130 has a lower structure and an upper structure. The lower structure comprises a column 130 that extends substantially vertically from the base frame of the machine. The upper structure comprises an upper column 132 and a horizontally extending beam 133. The upper column 132 is attached to an upper end of the column 130, and an upper end of the upper column supports the horizontally extending beam 133 at a first end. The opposing end of the beam 133 supports the wrapping arm 122 and its drive mechanism 136.

[0098] The column 130 and upper column 132 are joined together by a pinned coupling 131, which enables the upper column 132 to pivot with respect to the column 130. An actuator in the form of a hydraulic cylinder 135 is attached to the column 130 and the upper column 132 across the joint, such that operation of the cylinder can control the relative angle between the respective axes of the column 130 and the upper column 132. Pivoting of the upper column with respect to the vertical rotates the beam and the rotary axis of the wrapping arm, which in turn changes the angle at which the film is applied to the bale. By controlling the angular position of the upper column 132 by the actuator, adjustments can be made to the wrapping geometry, for example to achieve the desired overlaps as described above.

[0099] Figure 13 is a front view of the bale wrapping machine of Figure 1 loaded with a bale 201 of smaller diameter compared with the bale 1. In Figure 13, the rotational axis of the wrapping arm 122 has been adjusted to optimise the inclination between the film (not shown) and the bale by adjustment of the angular position of the upper column 132 to a more vertical position in line with the column 130.

[0100] The adjustment of the support structure for the wrapping arm as described herein provides a simple mechanism for adjustment of wrapping geometry, for example to enable desired wrapping for a range of sizes of cylindrical object. In embodiments of the invention, adjustment can be automated by entering the bale size into a control system for the bale wrapping machine. Alternatively, or in addition, adjustment can be made by an operator.

[0101] Figure 14 is a schematic block diagram showing the main functional components of a control system for a bale wrapping machine according to an embodiment of the invention. The control system, generally depicted at 140, comprises a control unit 141, a sensor system 142, and actuation system 143, and a human machine interface (HMI) 144. The control unit 141 may be a part of a dedicated hardware unit for the machine, located on the machine itself or remotely from the machine. The human machine interface 144 may also be a part of a dedicated hardware unit, or may be in separate hardware communicating with the control unit. The control system 140 may alternatively or in addition be partially implemented in other computer hardware, such as in a module of a general equipment control unit, or as software running on a general computer or mobile computer processing device. The sensor system 142 comprises a number of physical sensors associated with components of the machine, such as an axle position sensor, an inclination sensor, loader (or loading assembly) status sensor, loader (or loading assembly) angle sensor, wrap table (or wrapping table) angle sensor, wrap arm angle sensor, wrap arm position sensors, bale proximity sensor, bale ejector position sensor, film roller sensors. Each sensor is in signal communication with the control unit 141. The control unit 141 operates the actuation system 143 in response to sensor signals and operation commands. The actuation system 143 comprises a plurality of actuators associated with components of the machine. Some or all of the actuators may be implemented as hydraulic actuators, and thus the control unit may control a hydraulic system. Alternatively, or in addition, some or all of the actuators may be electro-mechanical actuators, and thus the control unit may control an electronic system. The system of actuators comprises an axle position actuator, a wrap arm position actuator, a wrap table (or bale wrapping table) position actuator, a loader (or loading assembly) position actuator, a loader arm (or bale grapple) position actuator, a wrap arm and table drive, cutter actuators, and a bale ejector actuator.

[0102] In use, the control unit may control the actuation system according to programmed routines and settings, in conjunction with signals received from the sensors. In addition, an operator may select particular settings via the HMI, and / or may manually operate some or all of the actuation system via the HMI. In alternative embodiments, the sensor system may comprise additional or alternative sensors for detecting additional or different conditions or statuses of the machine and its components, or may comprise fewer sensors for a simplified control system. Similarly, alternative embodiments may comprise additional or alternative actuators for operating additional or different components of the machine, or may comprise fewer actuators where all components are not present in the machine.

[0103] The invention provides an apparatus for wrapping a film around a cylindrical object such as a bale. The apparatus comprises a wrapping table supported by a base frame, where the wrapping table is configured to support the cylindrical object on a plurality of support rollers enabling rotation of the cylindrical object. At least one wrapping arm is configured to stretch film across the outer surface of the cylindrical object by rotating the at least one wrapping arm or the wrapping table to wrap the film around the cylindrical object in partially overlapping layers. A loading assembly is movable between a lowered position and a raised position to bring the cylindrical object to the wrapping table in a loading direction substantially perpendicular to longitudinal axes of the support rollers. The longitudinal axes of the support rollers of the wrapping table are inclined to the horizontal; and the loading assembly is operable to move between the lowered position and the raised position by rotation about a loading assembly axis that is also inclined to the horizontal.

[0104] In another aspect, the invention provides a bale wrapping apparatus comprising a base frame and a pair of wheels mounted to the base frame and having respective wheel axles. The apparatus is characterised in that the pair of wheels is mounted to the base frame on a support assembly; and the apparatus comprises an actuator operable to act on the support assembly to change the vertical position of the wheel axes of each of the pair of wheels with respect to the base frame. The change to the vertical position of one wheel axle is in an opposing direction to the change to the vertical position of the other wheel axle, thereby changing or controlling the inclination of the base frame with respect to the ground. In an alternative, the apparatus is characterised in that at least one of the pair of wheels is mounted to the base frame via a support member, the support member being pivotally connected to the base frame at a pivot point displaced from the wheel axle. The apparatus comprises an actuator operable to act on the support member to rotate the support member with respect to the base frame and change the vertical position of the wheel axle with respect to the base frame, thereby changing or controlling the inclination of the base frame with respect to the ground.

[0105] In another aspect, the invention provides a bale wrapping apparatus characterised in that at least one wrapping arm is supported above the wrapping table by a support structure; and wherein the support structure is adjustable to enable the rotation axis of the at least one wrapping arm to be changed.

[0106] The machine and apparatus described herein comprise features and functions that enable efficient bale wrapping in terms of film consumed and / or wrapping time, while reducing damage to bales and / or loss or loosening of materials in a bale. These objectives are delivered in a machine package that is compact enough to enable transport on public roadways. The invention in its aspects and embodiments are particularly suited to inclined wrapping geometries that have improve efficiency for a wide range of bale materials, including low stability bales of relatively loosely consolidated material, such as dry and small material particles (e.g. wood chips) or heavy and slippery material particles (e,g. sugar beet pulp).

[0107] Various modifications to the above-described embodiments may be made within the scope of the invention, and the invention extends to combinations of features other than those expressly claimed herein.

Claims

24Claims:

1. An apparatus for wrapping a film around a cylindrical object, the apparatus comprising: a wrapping table supported by a base frame, the wrapping table configured to support the cylindrical object and comprising a plurality of support rollers configured to rotate the cylindrical object on the wrapping table about a longitudinal axis of the cylindrical object; at least one wrapping arm configured to stretch film across the outer surface of the cylindrical object by rotating the at least one wrapping arm or the wrapping table, thereby wrapping the film around the cylindrical object in partially overlapping layers; a loading assembly for loading a cylindrical object to be wrapped into the wrapping table; wherein the loading assembly is movable between a lowered position in which the loading assembly is operable to engage the cylindrical object on the ground, and a raised position; wherein movement from the lowered position to the raised position brings the cylindrical object to the wrapping table in a loading direction substantially perpendicular to longitudinal axes of the support rollers; wherein the longitudinal axes of the support rollers of the wrapping table are inclined to the horizontal; wherein the loading assembly is operable to move between the lowered position and the raised position by rotation about a loading assembly axis; and wherein the loading assembly axis is inclined to the horizontal.

2. The apparatus according to claim 1, wherein the loading assembly axis is inclined in a direction transverse to the loading direction.

3. The apparatus according to claim 1 or claim 2, wherein the loading assembly axis is in a vertical plane that is parallel to the longitudinal axes of the support rollers.

4. The apparatus according to any preceding claim, wherein the longitudinal axes of the support rollers of the wrapping table are inclined to the horizontal at a table angle, the table angle being between around 5 degrees and 15 degrees.

5. The apparatus according to any preceding claim, wherein the loading assembly axis is inclined to the horizontal at a loading assembly angle, the loading assembly angle being between around 5 degrees and 15 degrees.

6. The apparatus according to claim 4 and claim 5, wherein the loading assembly angle is equal to, or substantially equal to, the table angle.

7. The apparatus according to claim 6, wherein the loading assembly angle and the table angle are approximately 9 degrees.

8. The apparatus according to any preceding claim, wherein the loading assembly is configured to bring a cylindrical object from a ground orientation and into alignment with the wrapping table orientation in a single movement of the loading assembly9. The apparatus according to any preceding claim, wherein the loading assembly comprises a pair of lifting arms, each lifting arm being pivotally mounted to the base frame at an opposing side of the base frame.

10. The apparatus according to claim 9, wherein the lifting arms are mounted to the base frame at respective mounting points, the mounting points being vertically offset from one another.

11. The apparatus according to any preceding claim, wherein the loading assembly comprises a bale retainer configured to retain a bale on the loading assembly, wherein the bale retainer comprises a grapple arm operable to move between a closed position and an open position.

12. The apparatus according to claim 11 , wherein the grapple arm is oriented parallel to and adjacent to the ground level when the loading assembly is in its lowered position.

13. The apparatus according to claim 11 or claim 12, wherein in the lowered position, the bale retainer and the bale grapple are horizontally oriented in parallel with the orientation of the base frame, and in the raised position, the bale retainer is inclined with respect to the base frame.

14. The apparatus according to any preceding claim, wherein the wrapping table is configured to be pivoted about a horizontal transverse axis between at least two positions.

15. A method of using the apparatus of any preceding claim to load a cylindrical bale onto the wrapping table of the apparatus, the method comprising operating the loading assembly to bring the bale from a ground orientation and into alignment with the inclined wrapping table orientation in a single movement of the loading assembly.

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