Cutting unit for an agricultural vehicle

Abstract

The present invention concerns an improved cutting unit configured to be easily integrated in a ventral position into a common agricultural tractor, of any size and power. Compared to known solutions, the invention allows a significant reduction in energy consumption since it enables to carry out at the same time grass cutting as well as other works on an agricultural land e.g. trimming or phytosanitary treatments, inter-row processing or management of leaf walls.

Description

[0001] TITLE: CUTTING UNIT FOR AN AGRICULTURAL VEHICLE

[0002] TECHNICAL FIELD

[0003] The invention concerns agricultural equipment, in particular equipment for cutting and mowing grass.

[0004] BACKGROUND ART

[0005] Mowing or cutting grass is an activity that must be carried out periodically, to keep tidy and clean grassy surfaces such as a public park or an agricultural land.

[0006] In the case of grassy surfaces of a certain size, this activity is commonly carried out by means of a "lawn tractor", i.e. a self-propelled four-wheel machine driven by an operator and equipped with a cutting unit having blades rotating around vertical axes, located ventrally or in a ventral position i.e. on the lower part of the tractor between the wheels.

[0007] Machines of this type are well known and are intended exclusively for cutting grass on surfaces such as public parks, private gardens, golf courses. Indeed, they are not designed for cutting grass in agricultural areas or spaces such as areas between rows of vines or orchards. In fact, the size of the wheels does not allow the lawn tractor to manage the roughness of the terrain. For this reason, grass cutting of an agriculture land is normally carried out using a lawnmower towed by a common agricultural tractor. The movement of the cutting blades is ensured by a kinematic connection to the tractor's power driving shaft or more rarely, by an autonomous engine.

[0008] The use of a lawnmower towed by a tractor is not the optimal solution for cutting grass on agricultural surfaces for several practical reasons.

[0009] First of all, the use of a dedicated lawnmower requires planning the grass cutting operation since this equipment must be previously connected to the tractor. This use makes not possible to cut the grass if the operator set up the tractor to carry out other activities, such as plant trimming or phytosanitary treatments, inter-row work or management of leaf walls. A second limitation is the impossibility of connecting the lawnmower roller to the tractor together with other towed equipment, such as an agricultural sprayer, as these have a size that is not compatible with a towed lawnmower roller. In any case, the problem of sharing the same power drive would be difficult to solve even if the size made it possible to use the lawnmower roller with another towed equipment.

[0010] In theory, the combined use of a lawnmower roller and another agricultural equipment is possible e.g. by connecting them “in cascade” one behind the other or by placing the lawnmower roller at the rear and the other equipment at the front of the tractor. However, this configuration increases the length of the tractor, making maneuvers very problematic especially near the headlands.

[0011] Clearly, the practical need to mow the grass separately from other agricultural activities determines an increase in energy costs and environmental impact that becomes increasingly unsustainable.

[0012] Patent literature reports lawnmower equipment integrated into tractors, even in a ventral position.

[0013] For example, the Italian application 102009901783022, in the name of Adriatica Macchine Agricole Sri, discloses a device for an agricultural vehicle and an agricultural vehicle equipped with such a device. The invention is useful for land cleaning works, e.g. cutting grass (or brushwood, reeds, shrubs, etc.), crushing cutting debris or distribution of cutting debris on the ground. In particular, as expressly explained in the patent specification, the device is aimed at small tractors with limited power, such as the one depicted in Figure 3, of the type used for greenery maintenance on small plots of land, parks, golf courses or sports fields in general.

[0014] Therefore, it is clear that application 102009901783022 does not provide any useful teaching to those skilled in the art wishing to integrate a cutting unit into a tractor of the type commonly used in agricultural works, nor to install such a unit as an “after-market” component on any agricultural tractor available.

[0015] In the state of the art, it is also known from the US4120136, in the name of Massey-Ferguson Inc. a device for supporting a mower under a tractor. It is however evident, for example from Figure 1 and Figure 3 that this device presents a considerable construction complexity and cannot be installed on any agricultural tractor already on the market. Furthermore, it is aimed at a lawn tractor like the one disclosed in the Italian application 102009901783022 and therefore has the same problems.

[0016] The problem of mowing grass using a tractor of the type commonly used in agricultural activities has not yet been satisfactorily addressed. Therefore, it is still possible to improve a cutting unit that can be integrated into a common agricultural tractor to facilitate mowing grass.

[0017] DISCLOSURE OF INVENTION

[0018] Object of the invention

[0019] The present invention intends to overcome the limitations and drawbacks of the solutions known in the art, by providing a cutting unit for agricultural tractors characterized by a new arrangement, configuration and combination of the constituent parts which, as will be seen below, are suitable for providing ease of use in cutting grass on agricultural surfaces, in particular between rows of plants.

[0020] Particularly, the main object is to provide a cutting unit which is not of the towed-type but which can be integrated into an agricultural tractor, as an OEM (“Original Equipment Manufacturer”) component, in a ventral position similarly to common lawnmower tractors. This purpose also includes integrate said cutting unit in a ventral position into an agricultural tractor of any type available in the market, even as a retrofit component i.e. as an after-market component.

[0021] A second purpose of the present invention is to provide a cutting unit for an agricultural tractor that allows the operator to mow grass while carrying out other agricultural works assisted by the tractor such as trimming plants, phytosanitary treatments, inter-row works or management of leaf walls. This purpose also includes reducing energy consumption and the environmental impact of agricultural works in line with the growing attention of entrepreneurs and public opinion on these issues.

[0022] A third purpose of the present invention is to provide a cutting unit for an agricultural tractor that can be used on agricultural land of any extension as long as it is accessible by a common agricultural tractor of any size and power.

[0023] A further purpose of the present invention is to provide a cutting unit for mowing grass that is robust, simple to make and assemble, and capable of achieving the highest safety standard for the operator.

[0024] Finally, a final purpose of the present invention is to provide a cutting unit for mowing grass at low costs to facilitate its widespread diffusion.

[0025] Technical solution

[0026] These and still other purposes, which shall appear more clearly hereinafter, are achieved by a cutting unit for an agricultural tractor, whose general characteristics are defined by the enclosed claim 1 , while the features of advantageous embodiments are set forth in the corresponding dependent claims.

[0027] The object of the present invention is also achieved by a an agricultural tractor equipped with a built-in unit for cutting grass whose general and detailed characteristics are set forth, respectively, in the enclosed claim 13.

[0028] The aforementioned claims, to which reference is made for the sake of brevity of exposition, are specifically and concretely defined below and are intended to be an integral part of this description.

[0029] In summary, the inventive concept underlying the invention is making possible to apply to a common agricultural tractor, of any size and power, a cutting unit similar to those used in common lawn tractors i.e. in agricultural machines exclusively dedicated to cutting grass on grassy surfaces and not on agricultural land. Reducing in practice such an inventive concept has led to a configuration allowing the application of the cutting unit in a ventral position (i.e. between the tractor axles) even as a retrofit, i.e. as an after-market component.

[0030] Brief description of drawings

[0031] The features and advantages of the present invention will be more fully understood by reference to the following drawings:

[0032] Figure 1 illustrates the cutting unit according to the invention integrated into a common agricultural tractor in a ventral position;

[0033] Figure 2 shows a common agricultural tractor that integrates the cutting unit according to the invention in a ventral position, (a), is a lateral view, (b) is a rear view and (c) is a top view;

[0034] Figure 3 shows the support of the cutting unit with the height adjustment device, in (a), to be installed on the right side of the tractor, while in (b), on the left side of the tractor, Figure 4 shows the body of the cutting unit according to the invention, in (a) a perspective view from above, while in (b) a perspective view from the rear;

[0035] Figure 5 shows the cutting device according to the first preferred embodiment with evidence of the arrangement of the blades and the driving system, in (a) a top view, in (b) a bottom view;

[0036] Figure 6 shows the cutting device according to the second preferred embodiment with evidence of the arrangement of the blades and the driving system, in (a) a top view, in (b) a bottom view;

[0037] Figure 6 shows the cutting device according to the third preferred embodiment with evidence of the arrangement of the blades and the driving system, in (a) a top view, in (b) a bottom view.

[0038] These drawings illustrate and demonstrate various features and embodiments of the present invention but are not to be construed as limiting the invention.

[0039] DETAILED DESCRIPTION OF THE INVENTION

[0040] With reference to the enclosed drawings, the cutting unit according to the present invention is defined by the reference number (1). Said cutting unit (1) is intended for a self-propelled agricultural vehicle and comprise: a cutting device (10) for mowing grass, branches and the like, which can be activated from an off state to an on state, and vice versa; a body (20) shaped to include, at least in part, the cutting device (10) and provide protection to the operators in the on state; means for transmitting motion (31) to said cutting device (10) mechanically connected to at least one power generator (30); a control unit (50) configured to enable the switching on or off and other functions of said cutting device (10),

[0041] With respect to known solutions, said cutting unit (1) is characterized in that: it includes one or more columnar supports (40) which allow said body (20) to be fixed to a standard agricultural tractor (T), of any size and power, to one or more several positions in height with respect to the ground; and it is configured to be mechanically integrated in a ventral position into said agricultural tractor (T) both as an OEM component or as an after-market component.

[0042] In summary, thanks to the columnar supports (40), the cutting unit (1) can be integrated into a tractor (T) in a ventral position (and not used as a towed unit) in a way that is illustrated in the enclosed Figures 1 and 2. The supports (40), schematically depicted in Figure 3, are preferably fixed to the sides of the tractor (T), one on the right and the other on the left.

[0043] As will be explained in the following, advantageously the columnar supports (40) have a “universal configuration” that can be fixed to the load-bearing structure of a tractor (T) of the type commonly used in agricultural works. It is thus possible to integrate the cutting unit (1) in a simple way, without complex works on the tractor (T), even after the sale of the tractor.

[0044] With reference to the enclosed Figure 5 or 6, the cutting device (10) includes one or more cutting elements (11) and means for transmitting the motion (31) which are designed to transfer the rotary motion of the power generator (30) to the cutting elements (11) so as to obtain an effective cutting and shredding of grass, branches, reeds, shrubs and the like.

[0045] In a first preferred embodiment, the cutting elements (11) are one or more blades which rotate around axes (12) oriented so that the cutting plane is preferably orthogonal to the grassy surface to be cut. Preferably, the rotating blades (11) are three and are all identical to each other.

[0046] However, for the purposes of implementing the present invention, different choices can be made regarding the type of blade (e.g. single or double-edged), the number of rotating blades, their diameter, arrangement (e.g. aligned or staggered) and orientation.

[0047] Even other types of rotating cutting elements (11) such as wires or chains can be used. Combinations of different types of cutting elements are also possible.

[0048] In any case, the cutting elements (11) are set in rotary motion around their respective axes (12) by means of motion transmission means (31) in the form of belts, pulleys, toothed belts, chains, or other equivalent connecting means.

[0049] These can be maintained at the correct tension by means of pulleys or belt tensioner springs. In the first embodiment, the belts (31) are all connected to the shaft of the power generator (30), substantially perpendicular to the ground, so that the cutting elements (11) rotate in the same direction.

[0050] However, it is possible to arrange the belts with a cross-belt connection to reverse the rotational motion of one or more of the rotating blades (11). In this way it is possible to accumulate the clipped grass on the sides of the cutting unit (1) or in a central position. In any case, the means for transmitting motion (31) are placed above the body (20).

[0051] In a further preferred embodiment, the cutting elements (11) are one or more cutter bars (e.g. of the type used in common “hedge trimmers” tools) which consist of a fixed or mobile toothed blade, slidingly fixed to a mobile blade.

[0052] In this case, the blades (11) are set in a reciprocating rectilinear motion, so that the grass, shrubs or reeds are cut by the “guillotine” action of two adjacent teeth of the blades.

[0053] In any case, the means for transmitting the motion (31) are located above the body (20).

[0054] The blades move on a cutting plane that is preferably parallel to the grassy surface to be mowed.

[0055] In this embodiment, the rotary motion of the power generator (30) is transformed into a rectilinear reciprocating motion by means for the transmission of motion (31) such as an eccentric, although cam transmissions, or oscillating yoke or glyph transmissions, or means based on similar kinematics can be equivalently used.

[0056] The cutting unit (1) according to the present invention includes a body (20), which supports and accommodates the cutting device (10) and which protects the operator from the cutting elements (11) or from fragments of shrubs or reeds or even stones projected by the rotating blades. The body has a shape like that shown in the attached Figure 4.

[0057] In a first embodiment, the body (20) is made up of a single piece, or of two or more segments (23) fixed to each other, so as to obtain a body having a fixed geometry.

[0058] In alternative embodiments, the body (20) is made up of two or more segments (23) slidingly constrained to each other, as shown in the enclosed Figure 6, so that the overall geometry of the body can be varied.

[0059] A sliding mechanism useful for this purpose can be easily obtained, e.g. by fixing on a first segment pins that engage corresponding slots appropriately directed and obtained on a second segment adjacent to the first. The movement of a segment with respect to another adjacent one can be achieved by means of an actuator (26), for example a double-acting hydraulic (or pneumatic) cylinder.

[0060] Varying the geometry of the body (20) is a remarkable useful feature that allows the segments to which the cutting elements (11) are fixed to be displaced towards specific directions. In this way, segments can be displaced towards e.g. the base of the trunk of the plants, or the size of the cutting unit (1) can be reduced when the tractor (T) travels along a road, thus respecting the road circulation regulations provided for agricultural vehicles without the need to obtain additional approvals for the vehicle.

[0061] The body (20) and the segments (23) are preferably made of stamped sheet metal, although other materials such as technopolymers or fibreglass can be used.

[0062] If the cutting device (10) includes rotating blades (11), each of the respective axes is rotatably supported by a bushing or by a bearing located on the top of the body (20) or of specific segments (23). If the cutting device (10) includes cutting bars (11), each of these is fixed by means of a blade holder support to the upper wall (or to the side walls) of the body (20) or of specific segments (23).

[0063] Finally, to facilitate the driver to get in and out the driving position, the body (20) includes a platform (24) and one or more clearance lights having also a safety function.

[0064] As previously mentioned, means for transmitting the motion (31) of the cutting unit (1) allow the cutting elements (11) to be moved by transferring mechanical power from a suitable generator (30) or from a plurality of power generators.

[0065] In a first embodiment, the power generator (30) is a hydraulic motor connected via a suitable hydraulic circuit to a pump. Depending on the equipment of the tractor (T), the hydraulic pump is connected to the power drive, directly or via an electric generator, but it can also be powered by the accumulator of the electric circuit of the tractor (T).

[0066] To reduce the environmental impact, inevitably related to the management of the hydraulic fluid, alternative embodiments provide for the use of a pneumatic motor or an electric motor as a power generator (30).

[0067] In these further embodiments, the electric motor (30), or alternatively the pneumatic motor, is electrically connected to an electric generator or to an electric accumulator.

[0068] Preferably, the generator or the electric accumulator are part of the OEM electrical circuit of the tractor (T). Otherwise, the generator uses the power driving shaft of the tractor (T).

[0069] Alternatively, the generator or the electric accumulator are components of the cutting unit (1) according to the invention and are not part of the first equipment of the tractor (T).

[0070] For example, the power generator (30) is an electric rechargeable accumulator suitably positioned in the tractor to facilitate recharging through an external socket connected to the local electrical network.

[0071] In further embodiments, the power generator (30) is a combustion engine connected via a suitable supply circuit to a fuel tank. Preferably, the supply circuit is connected to the tractor tank by means of bleed valve. However, it can also be a dedicated tank fixed to the tractor (T) or to the body (20) of the cutting unit (10) in a position selected to facilitate filling.

[0072] In any case, the power generator (30) is mechanically connected by means for transmitting motion (31) to the cutting device (10).

[0073] From the description provided so far, it shall be evident to those skilled in the art that the power generator (30) can be made up of two separate engines, for example two hydraulic engines (30) directly transmitting the rotary motion to a first and a third rotating blade (111 ,111') and via a transmission belt to a second and a fourth rotating blade (112,112').

[0074] The cutting unit (1) according to the invention is characterized by the fact that it includes columnar supports (40) to attach said body (20) to a common agricultural tractor (T), of any size and power, at a fixed or variable height with respect to the ground.

[0075] The supports (40) holds the cutting unit (1) and by means of a movement mechanism allows the cutting unit (1) to be displaced from a rest configuration in which the body (20) is in a raised position and the cutting device (10) is not activated, to a cutting configuration in which the body (20) is in a lowered position and the cutting device (11) is activated.

[0076] For this purpose the supports (40) can be shaped in different ways.

[0077] In one embodiment, the support (40) consists of a base element (41), fixed to the body (20) by means of first flanges (43), and one or more linear actuators (45) fixed both to the base element (41) and to the tractor (T) by means of second flanges (44). For example, two or four hydraulic cylinders can be used, each having a flanged body fixed to the base element (41) and having the stem fixed to the structure of the tractor (T).

[0078] The hydraulic cylinders (45) are activated by the operator via the control unit (50).

[0079] To displace the cutting unit (1) between the rest and cutting configurations, other types of linear actuators (45) can be used, for example hydraulic cylinders, jacks, linear electric motors.

[0080] In other alternative embodiments, illustrated in the enclosed Figure 3, the columnar support (40) consists of a base element (41) having a first tubular body (42) protruding therefrom and a second tubular body (42') slidably constrained to the first (42). Preferably the first tubular body (42) is inserted into the second tubular body (42'). The base element (41) is fixed to the body (20) by means of first flanges (43), while the second tubular body (42') is fixed to the tractor (T) by means of second flanges (44). Finally, the two tubular bodies (42,42’) are constrained one to the other by a linear actuator (45).

[0081] In this way, by acting on the linear actuator (45) it is possible to vary the height of the body (20) with respect to the ground in a range of positions selectable by the operator according to the height of the grass to be cut. Advantageously, it is possible to provide the tubular bodies (42,42’) with pins to limit the excursion of the support (40) and prevent the cutting unit (1) from being lowered in a position that could cause damage e.g. because it is too close to the ground. Preferably, the actuators (45) are activated by the operator via the control unit (50) and are of the hydraulic type, such as an oil-dynamic cylinder, or electric, such as a linear motor, or a screw, toothed rod or hydraulic jack. Alternatively, the actuator (45) is a manual drive, for example a lever.

[0082] Regardless of how the mechanism that displace the cutting unit (1) between the rest / cutting configurations is made, the second flanges (44) are shaped so that it is possible to integrate the cutting unit (1) in ventral position into any type of agricultural tractor (T).

[0083] In particular, each of the second flanges (44) includes an anchor flange (441) to be fixed to a structural part of the tractor (T) and a counterflange (442). Advantageously, the anchor flange (441) is a variable component designed according to the construction features of the tractor (T) to which the cutting unit (1) is integrated, while the counterflange (442) is a fixed component identical for all types of tractor. In this way, a “universal conformation” for the supports (40) of the cutting unit (1) has been disclosed.

[0084] From the description herein provided, it shall be apparent to those skilled in the art that the cutting unit (1) is configured so as to be integrated in a ventral position in the tractor (T), both as an OEM component (“Original Equipment Manufacturer”) and as a “after-market” component.

[0085] The cutting unit (1) according to the invention includes a control unit (50) which, as mentioned before, controls the switching on / off of the cutting device (10) and its displacement from the rest configuration to the cutting configuration, and vice versa.

[0086] In one embodiment, the control unit (50) is configured to manage other functions such as the power supplied by the cutting device (10); the number of revolutions or cycles of the cutting elements (11); the switching off of the cutting device (10) for safety reasons; the height of the cutting elements (11) with respect to the ground; error or malfunction conditions of the cutting unit (1) such as the blocking of one of the cutting elements (11).

[0087] For this purpose, the control unit (50) includes one or more sensors such as: speed regulators or rev counters; safety sensors to detect the opening of the cabin doors; load cells to detect the presence of the operator in the driving position; photodiodes to activate the emergency lights.

[0088] Other types of sensors may be identified by the skilled in the art on the basis of this description. The disclosure of the cutting unit according to the invention is continued through the exposition of three preferred but not exclusive embodiments, the detailed explanation of which is reported below.

[0089] First preferred embodiment

[0090] In the first preferred embodiment, herein described by way of example and not limitation, the cutting unit (1) is placed in a ventral position between the two axles of a common agricultural tractor (T).

[0091] In this embodiment, the cutting unit (1) includes a body (20) made of sheet metal which has a platform (24) to facilitate the operator to get in the driving seat of the tractor (T).

[0092] The body (20) is attached to the structure of the tractor (T) by means of two supports (40,40') fixed to the right and left sides of said tractor (T) as illustrated in the enclosed Figure 1. The supports (40) have variable-height and are based on the slidingly constrained tubular bodies (42,42') described previously.

[0093] In the first preferred embodiment, the base element (41) of one of the two tubular bodies (42,42') has a recess (411) whose function will be explained below.

[0094] The body (20) can be positioned in different cutting positions depending on the needs. In particular, the body is displaced by gravity from the rest configuration to the cutting configuration, while the return to the rest position is enabled by a single-acting hydraulic cylinder (45), constrained to the tubular bodies (42,42’) and activated by the operator via the control unit (50).

[0095] In the first preferred embodiment of the invention, herein described by way of example and not limitation, the cutting unit (1) includes a cutting device (10) consisting of three identical rotating blades (11) with a diameter of 700 mm, arranged in a triangle as shown in Figure 5.

[0096] In this embodiment, means for transmitting motion (31) are positioned above the body (20) and consist of two belts (31 ,31’), kept in tension by two spring-loaded belt tensioners. The belts (31 , 3T) connect the shaft (121) to two grooves of the main cutting blade (111), which is directly connected to the engine driving shaft (30) and to the other two shafts (122,122’) of the two towed cutting blades (112,112’).

[0097] The belts are connected so that the lawn clippings are released centrally and not laterally.

[0098] In the first preferred embodiment of the invention, herein described by way of example and not limitation, the blades (11) are rotated, directly or indirectly, by means of a power generator (30).

[0099] In this embodiment, the power generator (30) is a single hydraulic motor connected via a suitable hydraulic circuit to a pump (not shown) which is in turn powered by an electric generator connected to the power driving shaft of the tractor. The hydraulic motor (30) is fixed to the base element (41) of the tubular body (40,40') and it is provided with a recess (411) to facilitate maintenance operations without need to disassemble or remove the motor.

[0100] From the description provided it is evident how the cutting unit (1), being suspended between the two wheel axles, compensate for terrain undulations without the need for shock absorbers or other devices.

[0101] Other details for implementing the first preferred embodiment can be obtained from the general description provided previously.

[0102] Second preferred embodiment

[0103] The second preferred embodiment of the invention, herein described by way of example and not limitation, refers to a cutting unit (1) characterized in that the body (20) has a variable geometry. As illustrated in Figure 6, the body (20), made of sheet metal, consists of a central segment (231), placed in a ventral position between the tractor axles (T) and two identical lateral segments (232,232') arranged laterally and symmetrically with respect to said central segment (231).

[0104] By means of suitable means, the central segment (231) is slidably constrained to the two lateral segments (232,232'). In this embodiment, the constraint means are pins fixed to the central segment (231) and inserted into corresponding slots obtained on the two lateral segments (232,232'). By appropriately shaping the slots, it is possible to vary the geometry of the body (20) so that the two lateral segments (232,232’) open.

[0105] Movement of two lateral segments (232,232’) from the close to the open configuration is ensured by two hydraulic cylinders (26,26’), one for each lateral segment (232,232’).

[0106] In the second preferred embodiment of the invention, herein described by way of example and not limitation, the cutting unit (1) includes a cutting device (10) consisting of four rotating blades (11) having a diameter of 400 mm and arranged as in Figure 6.

[0107] Similarly to the previous embodiment, means for transmitting motion (31) are positioned above the body (20) and consist of two belts (31 , 3T), kept in tension by two spring belt tensioners.

[0108] In this embodiment, the power generator consists of a pair of hydraulic motors (30,30') connected via a suitable hydraulic circuit to a pair of pumps (not shown) which in turn are powered by an electric generator connected to the power drive shaft of the tractor.

[0109] The two motors (30,30’) directly rotate two rotating blades (111 ,111’) which are rotatably fixed to the central segment (231) in a front position by means of suitable bushings. Preferably, the two rotating blades (111 ,11 T) are symmetrically positioned with respect to the axis of the body (20). The other two rotating blades (112,112’) are rotatably fixed by means of bushings to the two lateral segments (232,232’), one blade for each segment.

[0110] The two rotating blades (112,112’) are rotated by means of belts (31 , 3T) each kinematically connecting the shaft (121 ,121’) to a groove of the main cutting blade (111 ,111’) and to the corresponding shaft (122,122’) of the towed rotating blade (112,112’). Preferably, the rotating blades (12) have rotation directions such that the clipped grass, shrubs, reeds or similar are projected under the central segment (231).

[0111] Furthermore, when the geometry of the body (20) is changed, each shaft (121 ,121’) maintains substantially the same distance from the corresponding shaft (122,122’) so that the two belts (31 , 3T) are kept at the correct tension. In any case, as mentioned before, two spring belt tensioners are placed, one for the two units (121 ,31 ,122) and (121’, 3T, 122’).

[0112] Finally, depending on the diameter of the rotating blades (112,112’) and their positioning in the lateral segments (232,232’), the towed rotating blades (112,112’) can be offset to prevent them from touching each other in the close configuration. For this purpose, it is sufficient for the corresponding shafts (122,122’) to have a different length.

[0113] It shall be evident to those skilled in the art that varying the geometry of the body (20) from an open configuration to a close configuration represents a distinguishing feature which provides a number of advantages: first, the possibility of enlarging the cutting surface and covering the entire area between adjacent plant rows (typically they are at a distance of about 3.0 meters); second, an increase in the maneuverability of the tractor (T) especially on curves and in narrow spaces; finally, the possibility of driving on the road without special approvals or permits.

[0114] Other details for implementing the second preferred embodiment can be obtained from the previous embodiment.

[0115] Third preferred embodiment

[0116] The third embodiment, herein described by way of example and not limitation of the invention, refers to a cutting unit (1) which has substantially the same configuration of the first embodiment apart from the cutting device (10) which in this case does not include rotating cutting elements rather fixed or mobile blades, even in combination with each other to form cutting bars. In practice, as in a common hedge trimmer the cutting of grass, shrubs, reeds and the like on the agricultural surface is due to the simultaneous action of two toothed blades, slidingly constrained to each other.

[0117] For this purpose, it is necessary that at least one of the toothed blades is placed in linear reciprocating motion by suitable kinematic mechanisms for transforming the rotary motion of the engine shaft (30) into rectilinear reciprocating motion of the cutting elements.

[0118] In this embodiment, a suitable kinematic mechanism is an eccentric of the type used in common hedge trimmers. However, other equivalent means can be employed, for example a cam converter or an yoke or glyph, or other equivalent kinematic mechanisms well known to those skilled in the art.

[0119] In the third embodiment, herein described as an example and not a limitation of the invention, the cutting unit (1) includes three identical cutting bars, each being formed by a fixed blade and a movable blade.

[0120] In this embodiment, the fixed and movable blades are hold in a blade-holder frame which is in turn fixed internally to the body (20). Furthermore, the cutting bars are positioned close to and between the axles of the tractor (T).

[0121] The cutting device (10) according to the third embodiment of the present invention is very useful in the presence of shrubs and reeds as it avoids the projection of fragments as well as stones.

[0122] Other details for implementing the third preferred embodiment can be obtained from the previous embodiments.

[0123] CONCLUSIONS

[0124] To conclude, it has been shown that the invention described hereinabove fully achieves the intended aim and objects. In particular, the cutting unit according to the present invention is novel and inventive and it is based on an original arrangement, configuration and combination of the components, which makes more efficient the operations of mowing grass of agricultural surfaces, and more generally cleaning agricultural surfaces from brushwood, shrubs and the like.

[0125] In particular, the invention allows to combine mowing of grass, shrubs, reeds, and the like on agricultural land with other agricultural works such as topping, phytosanitary treatments, interrow works, or management of leaf walls. In this way, energy costs associated with agricultural works can be lowered.

[0126] Although the description and examples provided contain many details, these should not be construed as limiting the scope of the invention but simply as illustrations of some embodiments of the present invention. Therefore, the present disclosure is not limited to the exemplary embodiments shown and described herein.

[0127] For example, it shall be apparent to the person skilled in the art that by combining the two embodiments described a cutting unit including both rotating cutting elements and cutting bars can be obtained.

[0128] Hence, any modification of the present invention which falls within the scope of the following claims is considered to be part of the present invention.

[0129] Where the characteristics and techniques mentioned in any claim are followed by reference signs, these reference marks have been applied solely for the purpose of increasing the intelligibility of the claims and consequently these reference marks have no limiting effect on the interpretation of each element identified by way of example from these reference signs.

Claims

CLAIMSWhat is claimed:1) Cutting unit (1) for a self-propelled agricultural vehicle, said unit comprising: a cutting device (10) for mowing grass, branches and the like, which can be activated from an off state to an on state, and vice versa; a body (20) shaped to include, at least in part, the cutting device (10) and provide protection to the operators in the on state; means for transmitting motion (31) to said cutting device (10) mechanically connected to at least one power generator (30); a control unit (50) configured to enable the switching on or off and other functions of said cutting device (10), wherein said cutting unit (1) is characterized in that it includes one or more columnar supports (40) which allow said body (20) to be fixed to a standard agricultural tractor (T), of any size and power, to one or more several positions in height with respect to the ground, said cutting unit (1) which is further characterized in that it is configured to be mechanically integrated in a ventral position in said agricultural tractor (T) both as an OEM component or as an after-market component.2) Cutting unit (1) according to claim 1 wherein the cutting device (10) includes: one or more cutting elements (11) having a rotary motion around respective axes (12), and wherein said one or more cutting elements (11) are blades, wires, chains, or a combination thereof; means for transmitting motion (31) consisting of one or more belts, pulleys, toothed belts, chains, or other equivalent connection means, suitable for transferring to said one or more cutting elements (11) the rotary motion from said at least one power generator (30) in concordant or discordant rotary motion;optionally, belt tensioners, chain tensioners, grooves or other equivalent elements to maintain said means for transmitting motion tensioned and in the correct position (31).3) Cutting unit (1) according to claim 1 wherein the cutting device (10) includes: one or more cutting elements (11) configured to have a linear alternative motion and wherein said one or more cutting elements (11) are of the type having a fixed blade or a movable blade, or a combination thereof; means for transmitting motion (31) with eccentric, cam, oscillating yoke, or based on other equivalent kinematics suitable for transforming the rotary motion of said at least one power generator (30) into alternative rectilinear motion of said one or more cutting elements (11).4) Cutting unit (1) according to claim 1 or 2 or 3 wherein said at least one power generator (30) is selected from: an engine attached to one of said supports (40), an engine attached to said tractor (T), a power drive of said tractor (T), or a combination thereof, where said engine is chosen from one of the following: a hydraulic or pneumatic motor, connected to a pump via a suitable hydraulic / pneumatic circuit; or an electric motor, electrically connected via a suitable power supply circuit to an electric generator, or to a rechargeable electric accumulator, wherein said generator or accumulator are optionally parts of the original equipment of the tractor (T); or an internal combustion engine, connected via a suitable power circuit to a fuel tank, wherein said tank is optionally a part of the original equipment of the tractor (T).5) Cutting unit (1) according to claim 4 wherein said pump or said electric generator are powered by the electric accumulator of the tractor or by the engine of said tractor (T).6) Cutting unit (1) according to one or more of the previous claims wherein said body (20) further includes: a platform configured to facilitate the operator to access the driver's seat of said tractor (T); or one or more clearance lights with safety functions.7) Cutting unit (1) according to one or more of the previous claims characterized in that said body (20) has a variable geometry and includes at least two segments (23) slidably connected to each other and at least one actuator (26) for displacing said segments (23).8) Cutting unit (1) according to claim 7 wherein said body (20) includes: a central segment (231) and two lateral segments (232,232') arranged laterally with respect to said central segment (231); and means for slidingly connecting the central segment (231) to said two lateral segments (232,232'); at least one actuator (26) to move one, or both, the lateral segments (232,232') with respect to the central segment (231).9) Cutting unit (1) according to one or more of the previous claims wherein said one or more supports (40) further comprise one or more actuators (42) which allow said cutting unit (1) to assume: a rest configuration, wherein the body (20) is in a raised position and said cutting device (10) is not activated; a cutting configuration, wherein the body (20) is in a lowered position and said cutting device (11) is activated, wherein switching from said rest configuration to said cutting configuration, and vice versa, is obtained via a mechanical, hydraulic, electric actuator activated by a manualdrive or by the control unit (50), and wherein said one or more actuators (42) are selected from the group consisting of: a hydraulic actuator, a pneumatic actuator, an electric actuator, or a combination thereof.10) Cutting unit (1) according to one or more of the claims wherein said support (40) includes: a base element (41), fixed to the body (20) by means of first flanges (43), and one or more linear actuators (45) fixed both to the base element (41) and to the tractor (T) by means of second flanges (44); or a base element (41) having a first tubular body (42) protruding thereof and a second tubular body (42') slidably fastened to said first tubular body (42), wherein said base element (41) is fixed to the body (20) by means of first flanges (43) and said second tubular body (42') is fixed to the tractor (T) by means of second flanges (44), said tubular bodies (42,42') being mutually constrained to each other by a linear actuator (45).11) Cutting unit (1) according to claim 9 or 10 wherein said second flanges (44) have a universal design, i.e. applicable to any type of tractor (T), said conformation comprising: anchoring flanges (441) to be fixed to a structural part of the tractor (T), configured according to the construction features of the tractor (T) to which the cutting unit (1) is integrated; and corresponding counterflanges (442) to be fixed to the base element (41), or to the second tubular body (42'), whose shape is independent of the construction characteristics of the tractor (T) to which the cutting unit (1) it is integrated.12) Cutting unit (1) according to one or more of the previous claims wherein the control unit (50) includes one or more sensors to manage one or more of the following functions: cutting device (10) switching on / off; the number of turns or cycles of said one or morecutting elements (11); cutting device (10) switching off triggered by safety sensors detecting the opening status of the tractor doors (T) or the presence of the driver in the driving position; the height of the cutting elements (11) with respect to the ground; error or malfunction conditions of the cutting unit (1).13) Agricultural machine characterized in that it mechanically integrates the cutting unit (1) according to one or more of claims 1 to 12 in a ventral position between the axles, wherein said cutting unit (1) is fixed by means of supports (40), preferably two supports (40) fixed to the right side and the left side of said tractor (T).14) Agricultural machine according to claim 13, characterized by the fact that it is configured for mowing of grass, shrubs, reeds and the like in agricultural land at the same time as carrying out other agricultural activities such as trimming, phytosanitary treatments, inter-row processing or management of leaf walls.

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