Apparatus for winding and unwinding a power cable of a self-propelled operating machine

Abstract

An apparatus (1; 200) for winding and unwinding a power cable of a self-propelled operating machine, comprising a cable winder (10; 210) configured to wind and unwind an electrical cable (100; 1000) having a first piece (100a; 1001) wound on said cable winder (10; 210) and a second piece (102; 1002) unwound from said cable winder (10; 210); a cable-guide assembly (15; 215) configured to engage said second piece (102; 1002) for guiding a winding and / or unwinding of said electrical cable (100; 1000) from said cable winder (10; 210); a tensioner (25; 225) mounted on said cable- guide assembly (15; 215) and configured to engage said second piece (102; 1002) to pull in an unwinding direction (S) directed away from said cable winder (10; 210) a tensioning stretch (106; 1006) of said second piece (102; 1002) extended from said cable winder (10; 210) to said tensioner (25; 225).

Description

[0001] Apparatus for winding and unwinding a power cable of a self-propelled operating machine

[0002] DESCRIPTION

[0003] The present invention relates to the field of self-propelled cable- powered operating machines. In particular, the present invention relates to an apparatus for winding and unwinding a power cable of a self-propelled operating machine.

[0004] In the context of the present description, self-propelled operating machines are defined as vehicles capable of moving and operating on often uneven ground or with poor grip. Examples of self- propelled operating machines are earth-moving machines, mining machines, demolition machines, combine harvesters and the like.

[0005] Electric self-propelled cable-powered operating machines capable of operating in a confined space have been developed. In these operating machines, electrical supply provides the necessary power for locomotion and / or movement of the respective working appendages (such as earth-moving shovels). The electrical supply can be direct, via electric motors, or indirect, e.g. via a hydraulic system pressurised by one or more electric pumps.

[0006] These operating machines typically require substantial electrical power, which makes the incorporation of on-board power batteries un-convenient. The provision of an electrical cable to power this type of operating machine makes it possible to provide the high power required without adding weight.

[0007] The electrical power for operating machines of this type is provided by a typically fixed, high-voltage electrical power source arranged near the operating machine work area. The electrical power cable typically comprises a plurality of electrical conductors with cross-sections sized according to the electrical power to be transmitted, and one or more sheaths separating the conductors from each other and protecting them from environmental conditions. The electrical conductors within the power cable are sized to transmit electric currents, typically in alternating current, with voltages between 400V and 36kV, intensities between 200A and 800A, and powers between 80kW and 30MW. The sheaths are configured and sized to protect the electrical conductors in the environmental conditions in which the operating machines operate.

[0008] The size of conductors and sheaths typically make power cables relatively heavy and with a limited mechanical flexibility.

[0009] Operationally, the electrical power cable is unwound on the ground between the operating machine and the power source and is exposed to typically harsh environmental conditions and the risk of damage caused by the operations of the operating machine, which could, for example, crush it with its tracks or wheels.

[0010] In order to prevent the length of cable on the ground from obstructing the works of the operating machine, a cable winder mounted on the operating machine and configured to wind the exceeding portion of cable and unwind the portion of cable covering the distance between the operating machine and the power source is used.

[0011] The cable winder exerts a winding force on the electrical cable, typically constant, to wind the exceeding portion of the cable onto the ground. Thus, when the operating machine moves away from the power source, it puts the electrical cable under traction, overcoming the winding force exerted by the cable winder and causing it to unwind, thus laying the electric cable on the ground behind the operating machine. On the other hand, when the operating machine approaches the power source, the winding force exerted by the cable winder makes it possible to wind the exceeding electrical cable.

[0012] The Applicant has observed that by keeping the electrical cable constantly tensioned between the power source and the cable winder, it tends to wear out and be easily damaged. The Applicant has noticed, for example, that when the operating machine moves transversely in relation to the cable laid on the ground, the latter tends to creep transversely on the ground following the operating machine. Under these conditions, the sheath is stressed and the electrical cable may hit obstacles on the ground, risking damage or jamming.

[0013] The Applicant has further noted that by keeping the electrical cable constantly tensioned between the power source and the cable winder, the angle between the electrical cable and the operating machine could become non-optimal in certain situations, for example when the operating machine moves, when manoeuvring, in directions angled relative to the direction from the cable winder to the power source along which the cable is laid. This can lead, for example, to the power cable being crushed by the operating machine.

[0014] The Applicant has perceived that, in order to reduce wear of the electrical cable, the tension on the electrical cable laid on the ground between the cable winder and the power source could be reduced or eliminated. This would reduce wear of the electrical cable and the risk of damage.

[0015] The Applicant has perceived that, in order to reduce or eliminate the tension of the electrical cable on the ground, its unwinding and winding could be controlled by driving the cable winder in such a way as to adjust the length of the unwound cable according to parameters of the operating machine representative of its movements and / or its position in the work area. Thus, the unwinding of the cable would not occur by pulling the cable on the ground between the power source and the cable winder, and the dragging effect of the cable on the ground would be avoided or reduced.

[0016] The present invention therefore relates, in a first aspect thereof, to an apparatus for winding and unwinding a power cable of a self- propelled operating machine.

[0017] Preferably, a cable winder is provided. The cable winder is configured to wind and unwind an electrical cable having a first piece wound on said cable winder and a second piece unwound from said cable winder.

[0018] Preferably, a cable-guide assembly. The cable-guide assembly is configured to engage said second piece to guide a winding and / or unwinding of said electrical cable from said cable winder.

[0019] Preferably, a tensioner is provided. The tensioner is mounted on said cable-guide assembly and configured to engage said second piece to pull in an unwinding direction, directed away from said cable winder, a tensioning stretch of said second piece extended from said cable winder to said tensioner. In a second aspect thereof, the present invention relates to a self- propelled operating machine assembly.

[0020] Preferably, an electrically powered self-propelled operating machine is provided. The self-propelled operating machine comprises at least one electrically powered locomotion actuator configured to actuate a locomotion of said operating machine and / or at least one electrically powered working actuator configured to drive at least one working appendage of said operating machine.

[0021] Preferably, an apparatus according to the first aspect mounted on said operating machine is provided.

[0022] Preferably, an electrical cable is provided. The electrical cable is at least partially wound on the cable winder of said apparatus and electrically connected to an electrical power source and to said operating machine to power said at least one locomotion actuator and / or at least one working actuator.

[0023] The Applicant found that keeping the tensioning stretch tensioned makes it possible to wind and unwind the electrical cable correctly and neatly from the cable winder according to operational requirements. Providing tension for the tensioning stretch by means of a tensioner mounted on the apparatus allows to keep the length of the electrical cable extended from the tensioner to the electrical power source non-tensioned, reducing wear and the risk of damage thereof.

[0024] The cable winder is rotatable about the pivot axis to wind and unwind the electrical cable. In this description and in the accompanying claims, terms such as "axial", "axially" and the like refer to directions parallel to the pivot axis.

[0025] The apparatus is configured to be used in an operational configuration with a substantially predetermined position in relation to the ground. In this predetermined position, the pivot axis of the cable winder is oriented horizontally. In this description and in the accompanying claims, terms such as "horizontal", "horizontally", "vertical", "vertically", "above", "below" and the like refer to this predetermined position.

[0026] Terms such as "transverse" and "transversely" refer to directions perpendicular to the pivot axis and oriented horizontally with respect to the predetermined position of the apparatus in the operational configuration.

[0027] The electrical cable has a main longitudinal extension direction, the expression "winding direction" refers to a direction aligned with the longitudinal direction of the electrical cable and directed towards the cable winder. The expression "unwinding direction" refers to a direction aligned with the longitudinal direction of the electrical cable and opposite to the winding direction.

[0028] The term "electrically powered" refers to actuators having a direct or indirect electrical power, e.g. an electric motor or a hydraulic motor driven by a pressurised hydraulic fluid and moved by one or more electric pumps.

[0029] The present invention, in at least one of the aforesaid aspects, may be implemented according to one or more of the following preferred embodiments, possibly combined to each other.

[0030] Preferably, said tensioner is configured to pull said tensioning stretch in the unwinding direction during a winding of said electrical cable on said cable winder.

[0031] Preferably, said tensioner is configured to pull said tensioning stretch in the unwinding direction during an unwinding of said electrical cable from said cable winder.

[0032] Preferably, said cable winder is configured to pull said tensioning stretch in the unwinding direction when said electrical cable is not wound and is not unwound.

[0033] Preferably, said cable winder is configured to control a length of electrical cable that is unwound according to an operating need of a self-propelled operating machine powered by said electrical cable.

[0034] Preferably, said tensioner is configured to keep a tension on said tensioning stretch in the unwinding direction.

[0035] Preferably, said tensioner is configured to keep a predetermined tension, preferably substantially constant, on said tensioning stretch in the unwinding direction.

[0036] Preferably, a control unit is provided.

[0037] Preferably, said control unit is configured to drive said cable winder in order to adjust a length of electrical cable unwound from said cable winder.

[0038] Preferably, said cable winder is feedback-controlled in order to control the length of the electrical cable unwound from said cable winder.

[0039] Preferably, said cable winder is feedback-controlled in order to control the length of the electrical cable unwound according to an operating need of a self-propelled operating machine. Preferably, at least one sensor is provided. The at least one sensor is configured to measure operating parameters related to said self- propelled operating machine, such as position and / or direction of movement and / or speed.

[0040] Preferably, said control unit is configured to drive said cable winder to adjust the unwound length of the electrical cable according to signals received from said at least one sensor.

[0041] Preferably, said control unit is configured to unwind from said cable winder a length of electrical cable longer than a distance between said operating machine and said electrical power source.

[0042] Preferably, said control unit is configured to unwind from said cable winder a length of electrical cable sufficient to keep a distal portion of said electrical cable extended between said apparatus and said electrical power source non-tensioned.

[0043] Preferably, said tensioner comprises two dragging surfaces facing each other.

[0044] Preferably said dragging surfaces are flat.

[0045] Preferably, said dragging surfaces are configured to receive between them a portion of the second piece.

[0046] Preferably, said dragging surfaces are configured to fictionally retain said portion of the second piece interposed between them.

[0047] Preferably, said dragging surfaces are configured to press against said portion of the second piece interposed between them.

[0048] Preferably, said tensioner is configured to exert a predetermined force in the unwinding direction on said dragging surfaces. Preferably, said dragging surfaces are movable in the unwinding direction during an unwinding of said electrical cable from said cable winder.

[0049] Preferably, said dragging surfaces are movable in a winding direction opposite to the unwinding direction during a winding of said electrical cable on said cable winder.

[0050] Preferably, said dragging surfaces are configured to adhere to the portion of electrical cable interposed between them without slipping.

[0051] Preferably, said dragging surfaces are movable dragged by said electrical cable.

[0052] Preferably, said tensioner comprises two tensioning tapes wound on closed paths on which so-called dragging surfaces are defined.

[0053] Preferably, said cable winder is configured to drive a winding of said electrical cable by overcoming a tension exerted by said tensioner on said tensioning stretch in the unwinding direction.

[0054] Preferably, a winding of said electrical cable on said cable winder is carried out by driving said cable winder in such a way that a traction exerted by said cable winder on said tensioning stretch in the winding direction overcomes the traction exerted by said tensioner in the unwinding direction.

[0055] Preferably, the winding direction is directed towards the cable winder.

[0056] Preferably, the winding direction is opposite to the unwinding direction. Preferably, keeping a constant unwound length of said electrical cable from said cable winder is carried out by driving said cable winder in such a way that a traction exerted by said cable winder on said tensioning stretch in the winding direction is substantially equal to the traction exerted by said tensioner in the unwinding direction.

[0057] Preferably, said cable-guide assembly is configured to guide a guided portion of the second piece along a guide axis.

[0058] Preferably, said cable-guide assembly is configured to guide a guided portion of the second piece in the unwinding and winding direction.

[0059] Preferably, said tensioner is configured to engage said guided portion of the second piece.

[0060] Preferably, said dragging surfaces are parallel to the winding direction and unwinding direction.

[0061] Preferably, a cleaning member is provided. The cleaning member is mounted on said cable-guide assembly and configured to engage said second piece to clean said second piece, wherein said tensioner is mounted between said cleaning member and said cable winder.

[0062] Preferably, said cleaning member is configured to engage said guided portion of the second piece.

[0063] Preferably, said cleaning member comprises a plurality of brushes, preferably two.

[0064] Preferably, each brush of the cleaning member comprises a cleaning surface. Preferably, a plurality of bristles are placed on said cleaning surface.

[0065] Preferably, said cleaning member is configured to receive a portion of said second piece between two cleaning surfaces facing each other.

[0066] Preferably, said cleaning member is configured to clean said second piece by moving said cleaning surfaces in the unwinding direction.

[0067] Preferably, moving said cleaning surfaces in the unwinding direction allows the cleaning member to rub against the electrical cable to remove dirt and impurities, and to direct the removed material away from the cable winder and / or tensioner.

[0068] Preferably, said cleaning surfaces are flat.

[0069] Preferably, said cleaning surfaces are movable along the guide axis.

[0070] Preferably, said cleaning surfaces are defined on respective brush tapes wound along a closed path.

[0071] Preferably, said cable winder is mounted rotatable about a pivot axis.

[0072] Preferably, said cable winder is mounted on a frame.

[0073] Preferably, said cable-guide assembly comprises a carriage slidingly mounted on said frame in a sliding direction parallel to said pivot axis.

[0074] Preferably, said carriage is driven alternately along the sliding direction to follow a winding of said electrical cable on said cable winder and / or an unwinding of said electrical cable from said cable winder. Preferably, said cable-guide assembly comprises a plurality of guide members.

[0075] Preferably, said guide members are configured to guide a guided portion of said second piece. Preferably, said guide members are configured to direct the guided portion of said second piece along the guide axis.

[0076] Preferably, said guide members comprise a plurality of rollers.

[0077] Preferably, said guide members comprise proximal guide members and distal guide members.

[0078] Preferably, said guided portion is extended between said proximal guide members and distal guide members.

[0079] Preferably, said distal guide members are mounted further away from said cable winder than said proximal guide members.

[0080] Preferably, said proximal guide members are movable in the sliding direction together with said carriage.

[0081] Preferably, said distal guide members are mounted at the distal end of said arm.

[0082] Preferably, said guide axis extends from said proximal guide members to said distal guide members.

[0083] Preferably, said tensioner is mounted between said proximal guide members and said distal guide members.

[0084] Preferably, said cleaning member is mounted between said proximal guide members and said distal guide members to engage said guided portion. Preferably, said proximal guide members are configured to engage said tensioning stretch of the second piece.

[0085] Preferably, said cable-guide assembly comprises an arm.

[0086] Preferably, said arm is extended away from said cable winder from a proximal end to a distal end.

[0087] Preferably, said arm is extended from the proximal end to a distal end parallel to the guide axis.

[0088] Preferably, said tensioner is mounted on said arm.

[0089] Preferably, said cleaning member is mounted on said arm.

[0090] Preferably, a distance between said tensioner and said distal guide members is less than 1 metre, preferably less than 0.7 metres, even more preferably less than 0.5 metres.

[0091] In a first embodiment, said arm is mounted on said carriage.

[0092] Preferably, said arm is integral with said carriage.

[0093] Preferably, said arm is movable in the sliding direction together with said carriage.

[0094] Preferably, said guide members are mounted on said arm. Preferably, all said guide members are mounted on said arm.

[0095] Preferably, said proximal guide members are mounted at the proximal end of said arm.

[0096] Preferably, said tensioner is movable in the sliding direction together with said carriage.

[0097] Preferably, said cleaning member is movable in the sliding direction together with said carriage.

[0098] Preferably, said distal guide members are movable in the sliding direction together with said carriage.

[0099] Preferably, said arm has a length of between 1 and 3 metres, preferably between 1.5 and 2 metres, even more preferably between 1.6 and 1.8 metres.

[0100] Preferably, a distance between said distal guide members and a point of separation of said electrical cable from said cable winder is equal to or less than 2 metres.

[0101] In a second embodiment, said arm is connected to said frame independently of said carriage.

[0102] Preferably, said arm protrudes from said frame.

[0103] Preferably, said arm is movable with respect to said frame independently of said carriage.

[0104] Preferably, said proximal guide members are not mounted on said arm.

[0105] Preferably, said arm is not movable in the sliding direction together with said carriage.

[0106] Preferably, said arm is hinged to said frame at its proximal end.

[0107] Preferably, said arm is rotatable with respect to said carriage about a hinge axis perpendicular to a plane in which said pivot axis lies.

[0108] Preferably, said arm is movable to change an orientation of said guide axis with respect to said cable winder.

[0109] Preferably, said arm is configured in such a way that, in an operational configuration, the distal end of said arm is placed close to the ground.

[0110] Preferably, a distance between said distal guide members and a point of separation of said electrical cable from said cable winder is greater than 2 metres and preferably equal to or greater than 2.5 metres.

[0111] Preferably, said proximal guide members are movable along the sliding direction together with said carriage independently of said distal guide members.

[0112] The features and advantages of the present disclosure will result from the following detailed description of some embodiments thereof, provided solely by way of non-limiting example, in which reference will be made to the accompanying drawings, wherein:

[0113] - Figure 1A shows a schematic view of an apparatus for winding and unwinding a power cable of a self-propelled operating machine in accordance with the present invention, in an operating configuration in which it is mounted on an operating machine;

[0114] - Figure IB shows a detailed schematic view of an operating configuration of an apparatus for winding and unwinding a power cable of a self-propelled operating machine in accordance with the present invention.

[0115] - Figure 2 shows a perspective view of the apparatus of Figure IB;

[0116] - Figure 3 shows a view from above of the apparatus of Figure IB;

[0117] - Figure 4 shows a side view of the apparatus of Figure IB;

[0118] - Figure 5 shows a section view of the apparatus in Figure IB; - Figure 6 shows a schematic side view of an apparatus for winding and unwinding a power cable of a self-propelled operating machine according to a different embodiment in accordance with the present invention;

[0119] - Figure 7 shows a view from above of the apparatus of Figure 6.

[0120] A first embodiment of an apparatus for winding and unwinding a power cable of a self-propelled operating machine, which is the object of the present invention, is globally indicated by the numerical reference 1 in Figures 1A to 5 and will be referred to hereinafter by the abbreviated notation "apparatus 1".

[0121] The apparatus 1 can be mounted on an operating machine 110, preferably an electrically powered earth-moving machine, and is configured to wind and unwind an electrical cable 100 having a distal end 101 connected to an electrical power source 101a, as schematically shown in Figure 1A.

[0122] The operating machine 110 is of the self-propelled type and comprises at least one locomotion actuator configured to drive locomotion wheels or tracks 110a of the operating machine 110 and at least one working actuator configured to drive a working appendage 110b of the operating machine 110, such as for example a mechanical earth-moving shovel.

[0123] The apparatus 1 comprises a frame 5, configured to support the components described below. The frame 5 comprises two axial elements 6 shaped like beams, parallel to each other. The frame 5 further comprises two transverse elements 7 shaped like beams, parallel to each other and perpendicular to the axial elements 6.

[0124] The axial and transverse elements 6, 7 of the frame 5 define a rectangular profile. The frame 5 can be installed on the operating machine 110 in a position raised from the ground. In order to attach the frame 5 to the operating machine 110, two coupling portions 8 are provided at one of the axial elements 6.

[0125] The frame 5 comprises an axially oriented sliding guide 9. The sliding guide 9 is defined by one of the axial elements 6 and is opposite to the coupling portions 8.

[0126] A cable winder 10 is mounted on the frame 5. The cable winder 10 is rotatable about a pivot axis R. The frame 5 is configured to support the cable winder 10 in a position raised from the ground. The cable winder 10 is rotatably hinged to the transverse elements 7. The cable winder 10 is arranged within the rectangular profile of the frame 5, between the axial elements 6 and between the transverse elements 7. In particular, the cable winder 10 is placed between the coupling portions 8 and the sliding guide 9.

[0127] The cable winder 10 comprises a flanged drum 11, rotatable about the pivot axis R. The cable winder 10 is configured to wind and unwind an electrical power cable 100.

[0128] The electrical cable 100 is configured to power the operating machine 110 with a power electrical current. The power electrical current is sufficient to power the actuators of the operating machine 110. Preferably, the operating machine 110 comprises one or more electric pumps (not shown) powered by the electrical cable 100 and configured to pressurise a hydraulic system (not shown) that drives one or more hydraulic motors of the operating machine. For example, in a preferred embodiment, the locomotion actuator comprises an electric motor powered directly by the electrical cable 100, while the working actuator comprises a hydraulic motor driven by the hydraulic system.

[0129] The electrical cable 100 is configured to transmit a high-voltage alternating current to the operating machine 110.

[0130] The electrical cable 100 comprises a plurality of conductors sized according to the electrical current to be transmitted and one or more protective sheaths covering the conductors.

[0131] A rotation actuator 12, preferably the hydraulic type, is configured to exert a torque on the cable winder 10 and to implement a rotation of the cable winder 10 about the rotation axis R to wind or unwind the electrical cable 100. The rotation actuator 12 is preferably driven by the hydraulic system of the operating machine 110.

[0132] A rotating manifold (not shown) is arranged in the drum 11 to electrically connect a proximal end (not shown) of the electrical cable 100 to the operating machine 110, and in particular to a power unit of its electric actuators and / or electric pumps.

[0133] The rotating manifold is configured to keep the electrical contact between the electrical power source 101a and the operating machine 110 via the electrical cable 100, irrespective of the angular position of the drum 11 about the pivot axis R.

[0134] Operationally, a first piece 100a of the electrical cable 100 is wound onto the cable winder 10, comprising its proximal end. A second piece 102 of the electrical cable 100, contiguous to the first piece 100a and comprising the distal end 101, is unwound from the cable winder 10 and directed to the operating machine 110.

[0135] The apparatus 1 comprises a cable-guide assembly 15 configured to guide the second piece 102 during the unwinding of the cable winder 10 so as to allow an orderly winding of the electrical cable 100 onto the cable winder 10 and an orderly unwinding of the electrical cable 100 from the cable winder 10.

[0136] The cable-guide assembly 15 comprises a carriage 16 slidingly mounted on the frame 5 in an axial sliding direction D. The carriage 16 is mounted on the sliding guide 9 and slides along it in an axial sliding direction D. The sliding guide 9 is shaped as a guide for the carriage 16.

[0137] The carriage 16 comprises a plurality of sliding rollers 17 configured to engage the sliding guide 9. Some of the sliding rollers 17 are arranged vertically above the sliding guide 9 and other sliding rollers 17 are arranged vertically below the sliding guide 9. The sliding rollers 17 are configured to constrain the carriage 16 to run axially along the sliding guide 9, preventing rotation.

[0138] A sliding actuator (not shown) is arranged on the frame 5 for sliding the carriage 16 on the sliding guide 9.

[0139] The carriage 16 comprises an arm 18. The arm 18 has a main extension direction lying in a plane perpendicular to the pivot axis R. The main extension direction of the arm 18 is substantially tangent to the drum 11. The main extension direction of the arm 18 is also inclined with respect to the transverse direction. The arm 18 has a length of between 1 and 3 metres, preferably between 1.5 and 2 metres, even more preferably between 1.6 and 1.8 metres.

[0140] The arm 18 extends along its main extension direction from a proximal end 18a to a distal end 18b. The proximal end 18a is closer to the cable winder 10 than to the distal end 18b. The arm 18 is inclined so that the proximal end 18a is arranged higher than the distal end 18b above the ground in the operational configuration of the apparatus 1.

[0141] The cable-guide assembly 15 comprises a plurality of guide members 20 mounted on the arm 18 and configured to engage a guided portion 103 of the second piece 102. The guide members

[0142] 20 are configured to orient the guided portion 103 along a guide axis X. The guide axis X is parallel to the main extension direction of the arm 18. During the winding of the electrical cable 100 onto the cable winder 10, the guide members 20 are configured to direct the guided portion 103 in a winding direction A parallel to the guide axis X and directed towards the cable winder 10. During the unwinding of the electrical cable 100 from the cable winder 10, the guide members 20 are configured to direct the guided portion 103 in an unwinding direction S parallel to the guide axis X and directed away from the cable winder 10.

[0143] The guide members 20 comprise a plurality of proximal guide members 21 arranged at the proximal end 18a. During the unwinding of the electrical cable 100, the proximal guide members

[0144] 21 are configured to receive a proximal portion 104 of the electrical cable 100 just unwound from the cable winder 10 and divert it along the unwinding direction S. During the winding of the electrical cable 100, the proximal guide members 21 are configured to direct the guided portion 103 towards the cable winder 10.

[0145] The proximal guide members 21 comprise a plurality of rollers, preferably four. The proximal guide members 21 define an opening

[0146] 22 configured to be run by the second piece 102 of the electrical cable 100. The opening 22 has a section perpendicular to the guide axis X. The proximal guide members 21 are arranged along the sides of a quadrangular, preferably square, perimeter of the opening 22.

[0147] The guide members 20 comprise a plurality of distal guide members 23 arranged at the distal end 18b. During the winding of the electrical cable 100, the distal guide members 23 are configured to receive a distal portion 105 of the second piece 102 lying on the ground and divert it in the winding direction A. During the unwinding of the electrical cable 100, the distal guide members

[0148] 23 are configured to release the guided portion 103, allowing it to divert with respect to the unwinding direction S, for example towards the operating machine 110.

[0149] The distal guide members 23 comprise a plurality of rollers arranged to define a passage 24 configured to be run by the electrical cable 100. The passage 24 has a quadrangular section, preferably square, perpendicular to the guide axis X. The passage

[0150] 24 has a section increasing as it moves away from the cable winder 10.

[0151] The distal guide members 23 are mounted at a distance equal to or less than 2 metres from a point 102a between the first piece 100a and the second piece 102 where the electrical cable 100 separates from the winder 10.

[0152] A tensioner 25 is mounted on the cable-guide assembly 15. The tensioner 25 is configured to engage the second piece 102 to pull it in the unwinding direction S. Thus, the tensioner 25 puts tension on a tensioning stretch 106 of the second piece 102 extending between the cable winder 10 and the tensioner 25. The tensioner

[0153] 25 is mounted on the arm 18 along the guide axis X. The tensioner 25 is arranged between the proximal guide members 21 and the distal guide members 23.

[0154] Figure 5 shows a section of a preferred embodiment of the tensioner 25. The tensioner 25 comprises two tensioner tapes 26, opposite to each other with respect to the guide axis X and facing each other. Each tensioner tape 26 is wound along a closed path on respective tensioner rollers 27. At least one of the tensioner rollers 27 is motorised to drive the tensioner tape 26 along the closed path.

[0155] Each tensioner tape 26 comprises a flat dragging surface 28 extended between the two respective tensioner rollers 27. The dragging surface 28 is parallel to the guide axis X and preferably perpendicular to the rotation axis R. The dragging surfaces 28 of the two tensioner tapes 26 face each other. Each dragging surface 28 can be moved parallel to the guide axis X when the respective tensioner tape 26 is moved along the respective closed path.

[0156] The dragging surfaces 28 of the two tensioner tapes 26 face each other and define a passage 29 between them for the guided portion 103 of the second strip 102 oriented along the guide axis X. The dragging surfaces 28 are configured to receive the guided portion 103 between them in the passage 29 and press on the guided portion 103 to exert a friction on the latter.

[0157] Through the friction exerted by the dragging surfaces 28, the tensioner 25 is configured to grip a portion of the electrical cable 100 interposed between the dragging surfaces 28. The tensioner 25 can be driven to pull the portion of the electrical cable 100 interposed between the dragging surfaces 28 in the unwinding direction S. Thus, the tensioner 25 can keep the tensioning stretch 106 of the second piece 102 under tension. The dragging surfaces 28 are movable in the winding direction A during the winding of the electrical cable 100 and in the unwinding direction S during the unwinding of the electrical cable 100. The dragging surfaces 28 are configured to drag a portion of the electrical cable 100 interposed between them in the unwinding direction S during the unwinding of the electrical cable 100 to keep the tensioning stretch 106 of the second length 102 tensioned. The dragging surfaces 28 are also configured to be dragged by the portion of the electrical cable 100 interposed between them in the winding direction A during the winding of the electrical cable 100 while keeping the tensioning stretch 106 of the second piece 102 tensioned.

[0158] The guide members 20 comprise first tensioning rollers 30 mounted on the arm 18 between the tensioner 25 and the proximal guide members 21. The guide members 20 further comprise second tensioner rollers 31 mounted on the arm 18 between the tensioner 25 and the distal guide members 23. The first tensioner rollers 30 and the second tensioner rollers 31 are configured to accompany the guided portion 103 of the electrical cable 100 within the tensioner 25, and in particular between the dragging surfaces 28.

[0159] The first tensioner rollers 30 comprise a pair of rollers configured to receive the guided portion 103 therebetween. Similarly, the second tensioner rollers 31 comprise a pair of rollers configured to receive the guided portion 103 therebetween.

[0160] The guide members 20 are configured to direct the guided portion 103 so that it passes through the tensioner 25 oriented parallel to the guide axis X regardless of the orientation of the proximal portion 104 and the distal portion 105 of the second piece 102. A cleaning member 32 is mounted on the cable-guide assembly 15. The cleaning member 32 is configured to engage the guided portion 103 of the second piece 102 to remove dirt and impurities, e.g. collected by the unwound portion of the electrical cable 100 lying on the ground (such as soil, mud, dust or sand). In particular, the cleaning member 32 is configured to remove dirt and impurities from the electrical cable 100 during the winding before it reaches the tensioner 25, so that it does not penetrate between the dragging surfaces 28.

[0161] The cleaning member 32 is mounted on the arm 18 along the guide axis X between the tensioner 25 and the distal guide members 23.

[0162] Figure 5 shows a sectional embodiment of a preferred embodiment of the cleaning member 32. The cleaning member 32 comprises two brushes 33, opposite to each other with respect to the guide axis X and facing each other. Each brush 33 comprises a brush tape 34 wound along a closed path on brush rollers 35, at least one of which is motorised to move the brush tape 34 along the closed path. Each brush 33 is provided with a plurality of bristles protruding from the respective brush tape 34 and movable along the closed path by moving the brush tape 34.

[0163] The brush tape 34 of each brush 33 comprises a flat cleaning surface 36 extended between two brush rollers 35. The cleaning surface 36 is parallel to the guide axis X and preferably perpendicular to the pivot axis R. The cleaning surface 36 is movable along the guide axis X by moving the brush tape 34 along the closed path.

[0164] The cleaning surfaces 36 of the two brush tapes 34 face each other and define a passage 37 for the guided portion 103 of the second piece 102. The bristles of the brushes 33 are configured to contact a portion of electrical cable 100 interposed between the cleaning surfaces 36 in the passage 37.

[0165] The cleaning member 32 is configured to move the cleaning surfaces 36 in the unwinding direction S during the winding of the electrical cable 100 so as to move the bristles in the opposite direction to the portion of the electrical cable 100 interposed between the cleaning surfaces 36 in the passage 37. Thus, the bristles rub against the portion of electrical cable 100 interposed between the cleaning surfaces 36 and directed towards the tensioner 25, removing the dirt.

[0166] The guide members 20 comprise first cleaning member rollers 38 mounted on the arm 18 between the cleaning member 32 and the tensioner 25, in particular between the cleaning member 32 and the second tensioner rollers 31. The guide members 20 further comprise second cleaning member rollers 39 mounted on the arm 18 between the cleaning member 32 and the distal guide members 23. The first cleaning member rollers 38 and the second cleaning member rollers 39 are configured to accompany the guided portion 103 of the electrical cable 100 within the cleaning member 32, and in particular between the cleaning surfaces 36.

[0167] The first cleaning member rollers 38 comprise a pair of rollers configured to receive the guided portion 103 between them. Similarly, the second cleaning member rollers 39 comprise a pair of rollers configured to receive the guided portion 103 therebetween.

[0168] The guide members 20 are configured to direct the guided portion 103 so that it runs through the cleaning member 32 oriented parallel to the guide axis X regardless of the orientation of the proximal portion 104 and the distal portion 105 of the second piece 102.

[0169] The carriage 16 can be moved axially in an alternating way to follow the winding and unwinding of the electrical cable 100 on the cable winder 10 and to guide it by means of the proximal guide members 21. The guide members 20, the tensioner 25 and the cleaning member 32 are axially moved integrally with the carriage 16.

[0170] Operationally, the electrical cable 100 is unwound from the cable winder 10 depending on the position and needs of the operating machine 110. For example, a sensor 111 (e.g. a GNSS-type position sensor) mounted on the operating machine 110 detects the position thereof and a control unit 112 mounted on the apparatus 1 or on the operating machine 110 controls the unwinding of the electrical cable 100 from the cable winder 10 based on signals received from the sensor 111.

[0171] The cable winder 10 is driven to adjust the length of the electrical cable 100 unwound according to the operating requirements of the operating machine 110. The cable winder 10 is feedback driven to adjust the length of the unwound electrical cable 100. The tensioner 25 is driven to keep a substantially constant tension on the tensioning stretch 106 by exerting a force on the tensioning stretch 106 in the unwinding direction S, opposite to the cable winder 10. The cable winder 10 is thus able to unwind a length of the electrical cable 100 such that the distal portion 105 is not tensioned. The tension on the tensioning stretch 106 exerted by the tensioner 25 enables the orderly winding and unwinding of the electrical cable 100 by the cable winder 10. A second embodiment of an apparatus for winding and unwinding a power cable of a self-propelled operating machine, which is the subject matter of the present invention, is globally indicated by the numerical reference 200 in Figures 6 and 7 and will be referred to hereinafter by the abbreviated notation "apparatus 200".

[0172] The apparatus 200 is conceptually similar to the apparatus 1 except for the variations described below.

[0173] The apparatus 200 comprises a frame 205, conceptually similar to the frame 5. The frame 205 comprises an axially oriented sliding guide 209, conceptually similar to the sliding guide 9.

[0174] A cable winder 210 is mounted on the frame 205, conceptually similar to the cable winder 10. The cable winder 210 is rotatable about a pivot axis R. The frame 205 is configured to support the cable winder 210 in a position raised from the ground. The cable winder 210 is configured to wind and unwind an electrical cable 1000 conceptually similar to the electrical cable 100.

[0175] Operationally, a first piece 1001 of electrical cable 1000 is wound on the cable winder 210. A second piece 1002 of electrical cable 1000, contiguous to the first piece 1001, is unwound from the cable winder 210 and directed to the operating machine.

[0176] The apparatus 200 comprises a cable-guide assembly 215 configured to guide a guided portion 1003 of the second piece 1002 during the rotation of the cable winder 210 so as to allow an orderly winding of the electrical cable 1000 on the cable winder 210 and the orderly unwinding of the electrical cable 1000 from the cable winder 210.

[0177] The cable-guide assembly 215 comprises a carriage 216, conceptually similar to the carriage 16, which is slidingly mounted on the frame 210 in the axial direction. The carriage 216 is mounted on the sliding guide 209 and slides axially along it.

[0178] The cable-guide assembly 215 comprises an arm 218. The arm 218 has a main extension direction lying in a plane perpendicular to the pivot axis R. The arm 218 extends along its main extension direction from a proximal end 218a to a distal end 218b. The arm 218 has a length of between, for example, 2 metres to 3 metres.

[0179] The proximal end 218a is closer to the cable winder 210 than the distal end 218b. The arm 218 is inclined so that the proximal end 218a is arranged higher than the distal end 218b above the ground in the operational configuration of the apparatus 200. The distal end 218b is configured to be positioned at the ground, at a distance of less than 30 cm from the ground, preferably less than 20 cm, even more preferably less than 10 cm,

[0180] The arm 218 is hinged to the frame 205 at the proximal end 218a. The arm 218 is movable about a hinge axis C in order to move the distal end 218b with respect to the proximal end 218a. The hinge axis C is perpendicular to a plane comprising the pivot axis R.

[0181] Unlike the arm 18 of the apparatus 1, the arm 218 is not mounted on the carriage 216 and is not axially movable together with it.

[0182] The cable-guide assembly 215 comprises a plurality of guide members 220 configured to engage a guided portion 1003 of the second piece 1002.

[0183] The guide members 220 comprise a plurality of proximal guide members 221 mounted on the carriage 216. The carriage 216 can be moved axially in an alternating way to follow the winding and unwinding of the electrical cable 1000 on the cable winder 210. The proximal guide members 221 are moved integrally with the carriage 216 to guide the winding and unwinding of the electrical cable 1000 on the cable winder 210.

[0184] The guide members 220 comprise a plurality of distal guide members 223 mounted at the distal end 218b of the arm 218.

[0185] The distal guide members 223 are mounted at a distance equal to or higher than 2.5 metres from a point 1002a between the first piece 1001 and the second piece 1002 wherein the electrical cable 1000 separates from the winder 210.

[0186] A tensioner 225, conceptually similar to the tensioner 25 of the apparatus 1, is mounted on the arm 218, between the proximal guide members 221 and the distal guide members 223.

[0187] The guide members 220 comprise first tensioner rollers 230 and second tensioner rollers 231 mounted on the arm 218 and similar respectively to the first tensioner rollers 30 and second tensioner rollers 31 of the apparatus 1.

[0188] A cleaning member 232, conceptually similar to the cleaning member 32 of the apparatus 1, is mounted on the arm 218. The cleaning member 32 is mounted on the arm 18 along the guide axis X between the tensioner 25 and the distal guide members 23.

[0189] The guide members 220 comprise first cleaning member rollers 238 and second cleaning member rollers 239 mounted on the arm 218 and similar respectively to the first cleaning member rollers 38 and second cleaning member rollers 39 of the apparatus 1.

[0190] Unlike apparatus 1, in the apparatus 200 the tensioner 225, the cleaning member 232 and the distal guide members 223 are not axially movable in a manner integral to the carriage 216.

Claims

CLAIMS1. Apparatus (1; 200) for winding and unwinding a power cable of a self-propelled operating machine, comprising: a cable winder (10; 210) configured to wind and unwind an electrical cable (100; 1000) having a first piece (100a; 1001) wound on said cable winder (10; 210) and a second piece (102; 1002) unwound from said cable winder (10; 210); a cable-guide assembly (15; 215) configured to engage said second piece (102; 1002) to guide a winding and / or an unwinding of said electrical cable (100; 1000) from said cable winder (10; 210); a tensioner (25; 225) mounted on said cable-guide assembly (15; 215) and configured to engage said second piece (102; 1002) to pull in an unwinding direction (S) directed away from said cable winder (10; 210) a tensioning stretch (106; 1006) of said second piece (102; 1002) extended from said cable winder (10; 210) to said tensioner (25; 225).

2. Apparatus (1; 200) according to claim 1, wherein: said tensioner (25; 225) is configured to pull said tensioning stretch (106; 1006) in the unwinding direction (S) during a winding of said electrical cable (100; 1000) on said cable winder (10; 210), during an unwinding of said electrical cable (100; 1000) from said cable winder (10; 210), and when said electrical cable (100; 1000) is not wound and is not unwound.

3. Apparatus (1; 200) according to claim 1 or 2, wherein said cable winder (10; 210) is configured to control a length of electrical cable (100; 1000) unwound as a function of an operating need of a self-propelled operating machine (110) powered by said electricalcable (100; 1000) and said tensioner (25; 225) is configured to keep a predetermined tension on said tensioning stretch (106; 1006) in the unwinding direction (S).

4. Apparatus (1; 200) according to any one of the preceding claims, wherein said tensioner (25; 225) comprises two dragging surfaces (28) facing each other and configured to receive a portion of the second piece (102; 1002) therebetween, said dragging surfaces (28) being configured to fictionally retain said portion of the second piece (102; 1002); and wherein said tensioner (25; 225) is configured to exert a predetermined force in the unwinding direction (S) on said dragging surfaces (28).

5. Apparatus (1; 200) according to any one of the preceding claims, comprising a cleaning member (32; 232) mounted on said cable-guide assembly (15; 215) and configured to engage said second piece (102; 1002) to clean said second piece (102; 1002).

6. Apparatus (1; 200) according to claim 5, wherein said cleaning member (32; 232) comprises a plurality of brushes (33).

7. Apparatus (1; 200) according to claim 6, wherein each brush (33) of the cleaning member (32; 232) comprises a cleaning surface (36).

8. Apparatus (1; 200) according to claim 6 or 7, wherein said cleaning member (32; 232) is configured to receive a portion of said second piece (102;1002) between two of said cleaning surfaces (36) facing each other.

9. Apparatus (1; 200) according to any one of claims 6 to 8, wherein said cleaning member (32; 232) is configured to clean said second piece (102) by moving said cleaning surfaces (36) in the unwinding direction (S).

10. Apparatus (1; 200) according to claim 9, wherein each brush (33) comprises a brush tape (34) wound along a closed path on brush rollers (35), at least one of said brush rollers (35) being motorized to move the brush tape (34) along the closed path, said brush tape (34) comprising said cleaning surface (36).

11. Apparatus (1; 200) according to claim 10, wherein each brush (33) is provided with a plurality of bristles protruding from the respective brush tape (34) and movable along the closed path by moving the brush tape (34).

12. Apparatus (1; 200) according to any one of claims 6 to 11 wherein said tensioner (25; 225) is mounted between said cleaning member (32; 232) and said cable winder (10; 210).

13. Apparatus (1; 200) according to any one of the preceding claims, wherein: said cable winder (10; 210) is rotatably mounted about a pivot axis (R.) on a frame (5; 205) and said cable-guide assembly (15; 215) comprises a carriage (16; 216) slidingly mounted on said frame (5; 205) in a sliding direction (D) parallel to said pivot axis (R); said cable-guide assembly (15; 215) comprises proximal guide members (21; 221) configured to engage said tensioning stretch(106; 1006) and movable in the sliding direction (D) together with said carriage (16; 216); said cable-guide assembly (15; 215) comprises distal guide members (23; 223) configured to engage said second piece (102;1002) and mounted further from said cable winder (10; 210) with respect to said proximal guide members (21; 221); said proximal guide members (21; 221) and distal guide members (23; 223) are configured to guide a guided portion (103;1003) of said second piece (102; 1002) extended between said proximal guide members (21; 221) and distal guide members (23; 223); said tensioner (25; 225) is mounted between said proximal guide members (21; 221) and said distal guide members (23; 223) to engage said guided portion (103; 1003).

14. Apparatus (1) according to claim 13, wherein said cable-guide assembly (15) comprises an arm (18) mounted on said carriage (16) and wherein said proximal guide members (21), said distal guide members (23) and said tensioner (25) are mounted on said arm (18).

15. Apparatus (200) according to claim 14, wherein said cableguide assembly (215) comprises an arm (218) independently connected to said frame (205) with respect to said carriage (216), and wherein said distal guide members (223) and said tensioner (225) are mounted on said arm (218).

16. Apparatus (200) according to claim 15, wherein said arm (218) extends from a first end (218a) to a second end (218b), said arm (218a) being hinged to said frame (205) at said first end(218a) and said distal guide members (223) being mounted at said second end (218b).

17. Self-propelled operating machine assembly, comprising: an electrical self-propelled operating machine (110) comprising at least one electrically powered locomotion actuator configured to actuate a locomotion of said operating machine (110) and / or at least one electrically powered working actuator configured to drive at least one working appendage (110b) of said operating machine (110); an apparatus (1; 200) according to any one of the preceding claims mounted on said operating machine; an electrical cable (100; 1000) at least partially wound on the cable winder (10; 210) of said apparatus (1; 200) and electrically connected to an electrical power source (110a) and to said operating machine (110) to power said at least one locomotion actuator and / or at least one working actuator.

18. Self-propelled operating machine assembly according to claim17, comprising a control unit (112) configured to drive said cable winder (10; 210) to adjust a length of electrical cable (100; 1000) unwound from said cable winder (10; 210), said control unit (112) being configured to unwind from said cable winder (10; 210) a length of electrical cable (100; 1000) sufficient to keep nontensioned a distal portion (105) of said electrical cable (100; 1000) extended between said apparatus (1; 200) and said electrical power source (110a) .

19. Self-propelled operating machine assembly according to claim18, comprising at least one sensor (111) configured to measureoperating parameters relating to said operating machine (110), wherein said control unit (112) is configured to drive said cable winder (10; 210) to adjust an unwound length of the electrical cable (100; 1000) according to signals received from said at least one sensor (111).

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