Patent Description:
More particularly, the present invention relates to a working tool, e.g. for an agricultural machine, provided with a drive assembly for a working member and a tensioning assembly for a flexible connection member of said drive assembly.

Working tools such as, but not limited to, tools for agricultural machines, which comprise a working member adapted to be rotated with respect to a predetermined rotation axis in order to perform the work for which the tool is designed, are known.

The working member may, for example, be a cutting blade or a cutting wire for cutting grass, a drill bit, a milling cutter, an auger, etc..

To set the working member in rotation, a drive assembly is used which allows a torque to be transferred from a drive motor, for example mounted on the agricultural machine, to the working member.

A known embodiment of the drive assembly comprises a first shaft rotatably associated with a rigid frame solely with respect to a first rotation axis (adapted to be connected to the drive motor of the tool) and on which a first pulley is keyed, a second shaft rotatably associated with said rigid frame solely with respect to a second rotation axis, with which the working member is rotationally associated and on which a second pulley is keyed.

The transmission of torque between the first and second shafts takes place by means of a flexible transmission member at least partially wound around the first pulley and the second pulley.

This flexible transmission member, generally a belt, in particular made of polymeric material with a trapezoidal cross-section, with use tends to wear and stretch, ending up not adhering well to the pulleys and therefore causing a decrease in the transmissible torque which manifests itself as slippage of the flexible transmission device.

To overcome this problem, tensioning assemblies are known which are provided with an idle wheel or a skid, hinged to a sliding frame or hinged to the rigid frame, which is constantly pushed against the flexible transmission member by a spring in order to stretch it, thus recovering the play due to wear as it arises.

However, this solution is not without its problems, in particular, the contact between the idle wheel and the flexible transmission member contributes to the wear of this member. <CIT> discloses a power transmission device comprising a driving side supporting member; a first transmission wheel supported by said driving side supporting member;
a driven side supporting member supported by said driving side supporting member in a manner enabling said driven side supporting member to be moved in a direction orthogonal to the rotational axis of said first transmission wheel; a second transmission wheel supported by said driven side supporting member; a power transmission member having an endless loop configuration which is wound around said first transmission wheel and said second transmission wheel to enable power transmission between said first and second transmission wheels.

Aim of the present invention is to solve said disadvantage of the prior art. Another aim is that of achieving such objective within the context of a rational, efficacious and relatively cost effective solution.

Such aims are achieved by the characteristics of the invention reported in the independent claims. The dependent claims outline preferred and/or particularly advantageous aspects of the invention.

The invention, particularly, makes available a tool as defined in claim <NUM>.

Thanks to this solution, a tool provided with a tensioning assembly is made available, which effectively allows the flexible transmission member to be kept under tension without the need to introduce additional contact surfaces with the flexible member which wear it out, thus allowing to extend the useful life of the flexible transmission component.

Compared to prior art devices, in fact, the solution makes it possible to exploit the contact surfaces of the pulleys to tension the flexible transmission member, without the need to introduce the idle wheel or the skid of the prior art devices.

Another aspect of the invention provides that the tensioning assembly comprises an elastic body interposed between the first section and the second section, configured to push the second section in a direction away from the first section along the sliding axis.

Thanks to this solution, the tensioning assembly is configured to automatically generate an elastic force that allows the second section to be pushed away from the first section, and therefore the second drive shaft to be pushed away from the first drive shaft, without the need for manual operation by a tool user.

The tensioning assembly is therefore particularly effective.

Still another aspect of the invention provides that the elastic body can be a helical compression spring.

Thanks to this solution, the tensioning assembly a particularly functional construction architecture that is intuitive and quick to assemble.

A further aspect of the invention provides that the tool comprises an end-of-stroke assembly configured to limit the minimum distance between the first drive shaft and the second drive shaft along the sliding axis. Thanks to this solution, the tool is particularly safe and reliable.

In particular, thanks to the end-of-stroke assembly, it is possible to avoid the possibility that, in the event that the tool encounters a resistant force acting in the opposite direction to that of the elastic element along the sliding axis, the second drive shaft may move towards the first, with the result that in this case the flexible transmission member would no longer be under tension and could slip on the pulleys.

This is particularly common where the tool is a brush cutter tool or any other tool that makes a cut in at least one direction perpendicular to the rotation axis of the second shaft. In this case, during the advancement, for example through the grass to be cut, a resistant force is generated that tends, in absence of the end-of-stroke assembly, to bring the second shaft closer to the first shaft, overcoming the force of the elastic element, i.e. the spring.

Overall, the the end-of-stroke assembly is therefore configured to prevent a resisting force acting in the opposite direction to that of the elastic element along the sliding axis from overcoming the force of the elastic element (i.e. from causing deformation, particularly of the elastic element) causing the second drive shaft to approach the first drive shaft.

This situation also arises in the event of accidental impacts while using the tool. It should be pointed out that it is not possible to use elastic elements that generate a force greater than these resistant forces, as they would tend to generate a too high force on the flexible transmission member.

Furthermore, a further aspect of the invention provides that the end-of-stroke assembly is configured to allow for a variation in the value of the minimum distance between the first drive shaft and the second drive shaft. Thanks to this solution, the end-of-stroke assembly is configured to adapt to the conditions of use/wear of the flexible drive member.

In particular, as the flexible transmission member wears out and/or stretches, the elastic element by pushing the second drive shaft away from the first drive shaft, allows the second drive shaft to be placed at a gradually greater distance from the first drive shaft, so as to compensate for the wear/stretch of the flexible transmission member and to maintain the correct tension of the flexible transmission member throughout its useful life.

The end-of-stroke assembly, in turn, by allowing a variation of the minimum distance, ensures that there is always a correct end-of-stroke even when the flexible transmission member is elongated and/or worn, so as to avoid slippage.

Another aspect of the invention provides that the end-of-stroke assembly may be configured to automatically vary the value of the minimum distance between the first shaft and the second shaft abased on the value of the distance between the first shaft and the second shaft.

Thanks to this solution, the end-of-stroke assembly does not need to be controlled by an operator using the tool.

As a result, it is possible to constantly maintain the correct functioning of the tool, and to avoid the possibility of any malfunction due to possible forgetfulness by the operator.

A further aspect of the invention provides that the end-of-stroke assembly may comprise:.

Thanks to this solution, the end-of-stroke assembly has a particularly simple construction structure that can be easily and quickly assembled.

Furthermore, a further aspect of the invention provides that the rotation axis of the cam may be horizontal and perpendicular to the sliding axis, and that the cam may be provided with a cam profile subtended at an angle having a centre on the rotation axis of the cam and less than <NUM>°, and that from its upper end which is at a predetermined distance from the rotation axis, it gradually presents a smaller distance from the rotation axis with a monotonous decreasing course until a lower end of the cam profile.

Thanks to this solution, when the abutment surface advances with the rest of the second section along the sliding axis, i.e. it moves along the sliding axis in a direction away from the second drive shaft from the first drive shaft, the cam rotates due to its own weight by rotating it constantly maintains contact with the abutment surface.

In particular, the special cam profile allows to gradually compensate the stroke made by the abutment surface along the sliding axis, so that the contact between the cam and the abutment surface is obtained in every position of the abutment surface along the sliding axis.

In particular, each displacement of the abutment surface along the sliding axis in a direction away from the first drive shaft causes a rotation of the cam due to the weight force acting on it, which allows the gradually greater protruding portion to be placed (i.e. further away from the rotation axis of the cam) in contact with the abutment surface.

Thanks to this there is therefore provided an automated system for varying, or adjusting, the minimum distance between the first shaft and the second shaft without the need for any electrically actuated sensors or actuators.

The proposed solution is therefore particularly robust, simple and compact.

In particular, the rotation of the cam so that the most protruding portion rotates downwards can be assisted by an elastic element configured to pull downwards a portion of the cam interposed between said cam profile and the rotation axis.

This elastic element improves the operating speed, prevents cam jamming due to possible prolonged non-use of the tool and prevents vibrations from causing the cam to rotate in a direction opposite to that imparted by the weight force of the cam.

The invention further makes available a landscaping apparatus comprising:.

Further features and advantages of the invention will be more apparent after reading the following description provided by way of non-limiting example, with the aid of the illustrated figures in the accompanying drawings.

With particular reference to such figures, an apparatus has been globally indicated by <NUM>, for example a landscaping apparatus <NUM>, in particular a brush cutter apparatus <NUM> configured to perform landscaping operations, for example, turf mowing operations.

The apparatus <NUM> comprises an agricultural machine <NUM>, in particular configured to allow at least one tool <NUM> to be removably connected to the agricultural machine <NUM>, for example for working the soil or for landscaping.

The tool <NUM> is driven by mechanical energy, in particular a torque, generated by the agricultural machine <NUM>.

The agricultural machine <NUM> comprises a support frame, a motor (not illustrated) installed on the support frame, and at least one pair of drive wheels <NUM> including a left wheel and a right wheel, i.e., a left wheel located on a left sidewall of the agricultural machine <NUM> and a right wheel located on a right sidewall of the agricultural machine <NUM>, which are rotatably associated with the support frame, for example (only) with respect to substantially coaxial rotation axes, and which receive a drive torque from the motor.

In this discussion, the terms "lower" and "upper" refer respectively to the proximal portion and the distal portion of the considered element, to the resting ground of the agricultural machine <NUM>. The term "vertical" indicates a component arranged substantially perpendicular to the resting ground.

The term "horizontal" indicates a component arranged substantially parallel to the resting ground. Furthermore, the terms "front" and "rear" are to be interpreted according to the normal forward direction (not reverse) of the agricultural machine <NUM>.

Furthermore, the terms "left" and "right" are to be interpreted on the basis of a plan view such as that in <FIG> and <FIG> and on the basis of the normal forward direction of the agricultural machine <NUM>.

The agricultural machine <NUM> has a longitudinal (essentially horizontal) axis, which is for example parallel to a normal forward direction (not in steering conditions) of the agricultural machine <NUM>.

The axes of rotation of the wheels <NUM> are substantially perpendicular to the longitudinal axis of the agricultural machine <NUM> (and are also horizontal).

The agricultural machine <NUM> comprises an output shaft (not visible in the figures as it is covered by a protective case) adapted to be mechanically connected to the tool in order to transmit to it the torque necessary to actuate the tool.

This output shaft may be in the form of a power take-off or, as in the illustrated embodiment, of a shaft with which a drive pulley (or a toothed wheel) is rigidly integral in rotation. In the preferred embodiment illustrated in the figures, the agricultural machine <NUM><NUM> is a walking tractor.

In particular, it is provided only with the pair of wheels <NUM>, which can be both drive wheels and, for example, independent in rotation of each other.

The walking tractor comprises a handlebar <NUM> (for example provided with a pair of diverging handlebars <NUM>), preferably hinged to the support frame (with respect to a substantially vertical rotation axis), to govern the directionality of the walking tractor and on which a plurality of commands (buttons and levers) are placed that allow to control the actuation of the motor, the advancement and the actuation of the tool <NUM>.

These commands will not be further described as they are known to those skilled in the art.

For the typical dimensions of a walking tractor, the maximum transverse overall dimensions of the handlebar <NUM> in a direction perpendicular to the longitudinal axis of the agricultural machine <NUM> (i.e. along a direction parallel to the axes of rotation of the wheels <NUM>) are equal to or greater than the maximum transverse overall dimensions defined along the same transverse direction by the pair of wheels <NUM>.

In particular, the handlebars <NUM> can protrude laterally both to the right and to the left with respect to the pair of wheels <NUM>.

In the case of hinged handlebars <NUM>, these overall dimensions are to be taken into account when the walking tractor advances along the normal forward direction and is therefore in a steering angle position equal to zero.

When the handlebars <NUM> is rotated to perform a steering manoeuvre it could protrude with respect to the overall dimensions of the wheels <NUM> only on the left or only on the right.

The support frame of the agricultural machine <NUM>, i.e. the walking tractor, and, for example, the protective cases associated therewith, have smaller transverse overall dimensions than the handlebar <NUM>.

In other words, the handlebar <NUM> is, in the illustrated embodiment, the element of the walking tractor with the largest transverse overall dimensions of all the elements of the walking tractor.

However, it cannot be ruled out that in an alternative embodiment not illustrated, it may be the pair of wheels <NUM> that altogether has the largest transverse overall dimensions of all the elements of the walking tractor.

The working apparatus <NUM> further comprises, as anticipated above, a tool <NUM> actuated by the output shaft of the agricultural machine <NUM>, i.e. the walking tractor.

In the illustrated embodiment, the tool <NUM> is a landscaping tool <NUM>, in particular a brush cutter tool <NUM> adapted to be connected to the agricultural machine <NUM> and configured to operate for mowing the turf.

Notwithstanding the embodiment illustrated, it will become clear in the following that the special characteristics described below can also be applied to other types of tools, such as milling cutters, grinding wheels, drills, augers or in any case any tool <NUM> provided with a working member suitable for being set in rotation with respect to a rotation axis in order to perform the work for which it was designed (such as drill bits, grinding wheel discs, milling cylinders, drill bits, etc.).

The tool <NUM> therefore comprises a working member (not illustrated), in particular in the illustrated case of the brush cutter tool <NUM> the working member is a cutting member U, which allows said mowing to be carried out and which, as anticipated above, is driven in rotation by means of the torque transmitted by the agricultural machine <NUM> in the manner that will appear more clearly below.

The cutting member U can for example be a blade or a wire wound on a spool, as known to the skilled in the art.

For example, the cutting tool <NUM> (or tool <NUM> for cutting) may comprise a central body carrying a plurality of flexible cutting filaments (not illustrated as known per se), which protrude radially from the central body outwards.

The brush cutter tool <NUM> comprises, first of all, a support arm <NUM> adapted to be connected to the agricultural machine <NUM>.

In particular, the support arm <NUM> has a first longitudinal end by means of which it is connected to the agricultural machine <NUM> and an opposite second longitudinal end at which the cutting member U is arranged.

In detail, the support arm <NUM> comprises a first segment <NUM>, which makes available said first longitudinal end of the support arm <NUM>, and a second segment <NUM> which makes available said second longitudinal end of the support arm <NUM>.

The first segment <NUM> may have a rigid base frame T1, i.e. not deformable under normal working loads to which it is subjected, for example made of metal.

The first segment <NUM> may take the form of a first tubular body, for example with a quadrangular section, defining a through channel.

In fact, in the embodiment illustrated, the base frame T1 is substantially U shaped, i.e. it has a base section (rectilinear and substantially flat) which substantially defines the base of the first tubular body and two opposite lateral sections which are derived (vertically and upwards) from the base section, substantially squared therewith, and define opposite lateral faces of the first tubular body.

Again, the first segment <NUM> may comprise a cover adapted to occlude the base frame T1 in a position opposite to the base section, so as to occlude superiorly the through channel defined by the first tubular body, i.e. by its base frame T1.

The first segment <NUM> is removably connected to the agricultural machine <NUM>, i.e. to its support frame, by means of fixing means (at least in part placed at the first longitudinal end of the arm).

Such fixing means preferably allow the arm to be fixed to the agricultural machine <NUM> without residual degrees of freedom between the first longitudinal end and a portion of the frame of the agricultural machine <NUM> directly in contact with the arm.

By way of example only, such fixing means may comprise snap-fitting means <NUM> and elastic retaining means.

For example, said snap-fitting means <NUM> may comprise a pair of opposite forks made on the first segment <NUM> of the support arm <NUM>, for example which are derived from the lateral faces of the first tubular body, and receiving seats made in the support frame of the agricultural machine <NUM> each of which is adapted to accommodate snap-fittingly a respective one of said forks.

Said elastic retaining means may comprise a pair of elastic traction springs, each having an end associated (coupled) with the support frame of the agricultural machine <NUM> and an opposite end associated with the first segment <NUM> of the support arm <NUM>, for example coupled in a respective ear made on the first segment <NUM> and which, for example, is laterally derived from a respective lateral face of the first tubular body.

The first segment <NUM> has along its own longitudinal axis L1, for example substantially horizontal, an end connected to the support frame as described above and an opposite free end substantially aligned with each other along said longitudinal axis of the first segment <NUM>.

The longitudinal axis of the first segment is preferably parallel to the longitudinal axis of the agricultural machine. In detail, the longitudinal axis of the first segment lies on a vertical centreline plane of the agricultural machine on which the longitudinal axis of the agricultural machine also lies. This vertical centreline plane is substantially placed at equal distance from the left wheel and the right wheel.

The second segment <NUM> has along its own longitudinal axis L2, for example substantially horizontal, a first axial end connected to the free end of the first segment <NUM> and an opposite second axial end aligned with the first axial end along the longitudinal axis L2 and at which the working member, i.e. the cutting member U, is arranged.

The second segment <NUM> is movably connected to the first segment <NUM>, in detail it is rotatably associated therewith.

In particular, the second segment <NUM>, for example by means of said first longitudinal axial end, is hinged to the first segment <NUM> (i.e. to said free end thereof), with respect to at least one hinge axis C, for example substantially vertical and preferably also transverse (for example orthogonal) to the longitudinal axes L1,L2 of the first segment <NUM> and of the second segment <NUM>.

Further, the second segment <NUM> is connected to the first segment <NUM> with a possibility of rotating between a first position in which the longitudinal axes L1,L2 of the first segment <NUM> and of the second segment <NUM> lie on parallel vertical lying planes or between which a first angle (of non-zero value) is defined, and at least a second position in which the longitudinal axes L1,L2 of the first segment <NUM> and of the second segment <NUM> lie on vertical lying planes between which a second non-zero angle and/or greater than the first angle is defined.

The rotation about the hinge axis C is preferably the only degree of freedom present between the first segment <NUM> and the first axial end of the second segment <NUM>.

A possible constructional embodiment which makes available the hinging of the second segment <NUM> to the first segment <NUM> will be illustrated in detail below.

In detail, the second segment <NUM> comprises a first section <NUM>, which makes available said first axial longitudinal end of the second segment <NUM>, and a second section <NUM> which makes available said second axial longitudinal end of the second segment <NUM> at which the cutting member U is arranged.

The first section <NUM> and the second section <NUM> of the second segment <NUM> are integral in rotation about said hinge axis C with respect to the first segment <NUM>.

Furthermore, the rotation about the hinge axis C is preferably the only degree of freedom present between the first section <NUM> of the second segment <NUM> and the first segment <NUM>. The first section <NUM> may have a respective rigid base frame T2, that is, not deformable under the normal work loads to which it is subjected, for example made of metallic material.

The base frame T2 of the first section of the second segment <NUM> is therefore hinged with respect to the hinge axis C to the base frame T1 of the first segment <NUM>.

The first section may take the form of a second tubular body, for example with a quadrangular section, defining a second through channel.

In particular, the base frame T2 of the first section <NUM> may be substantially U-shaped, i.e. having a base section (rectilinear and substantially planar) which substantially defines the base of the second tubular body and two opposite lateral sections deriving (vertically and upwards) from the base section, substantially squared therewith, and defining opposite lateral faces of the second tubular body.

Again, the first section <NUM> can comprise a cover selectively adapted to occlude the base frame in a position opposite to the base section, so as to occlude superiorly the through channel defined by the first section <NUM> of the second segment <NUM>.

The second section <NUM> may comprise and may have a respective rigid base frame T3, that is, not deformable under the normal work loads to which it is subjected, for example made of metallic material.

The base frame T3 of the second section <NUM> is made independent of the base frame T2 of the first section <NUM> and is connected thereto in the manner illustrated below.

In the same way as the first section <NUM>, the second section <NUM> may be in the form of a tubular body, in particular a third tubular body, for example with a quadrangular section and, defining a third through channel.

In particular, the base frame T3 of the second section <NUM> is substantially U-shaped, i.e. it has a base section (straight and substantially planar) which substantially defines the base of the third tubular body and two opposite lateral sections deriving (vertically and upwards) from the base section, substantially squared therewith, and define opposite lateral faces of the third tubular body.

Furthermore, the second section <NUM> can comprise a respective cover selectively adapted to occlude the base frame in a position opposite to the base section so as to occlude superiorly the third through channel defined by the second section <NUM> of the second segment <NUM>.

As mentioned above, the second segment <NUM>, by hinging the first section <NUM> to the first segment <NUM>, can therefore rotate about said hinge axis C.

More specifically, the tool <NUM> may comprise a sleeve coaxial to the hinge axis C and rigidly fixed (i.e. fixed without residual degrees of freedom) to the first segment <NUM>, for example to the base frame T1 of the first segment <NUM>.

In particular, the first sleeve <NUM> has a longitudinal central axis coaxial to the hinge axis C and is fixed to the first segment <NUM> arranged with said longitudinal central axis transverse, for example orthogonal, to the longitudinal axis L1 of the first segment <NUM>, i.e. arranged with said longitudinal central axis which is substantially vertical.

For example, the first sleeve <NUM> is cylindrical and axially hollow.

The first section <NUM> of the second segment <NUM> of the support arm <NUM>, has a flanging, i.e. a cylindrical jacket <NUM>, which circumferentially embraces the first cylindrical sleeve <NUM> so as to thus form the hinge between the first segment <NUM> and the second segment <NUM>.

In the illustrated embodiment, the (flanging, i.e., said) cylindrical jacket <NUM> is derived from the base frame T2 of the first section <NUM> and is preferably made in a monolithic body therewith.

A pair of bushings, which are interposed between an inner cylindrical surface of the cylindrical jacket <NUM> and an outer cylindrical surface of the first sleeve <NUM> may be associated with the cylindrical jacket <NUM>, so as to allow the second segment <NUM> to rotate about the first sleeve <NUM> with reduced (substantially absent) friction.

The brush cutter tool <NUM> then comprises a rotation blocking assembly of the second segment <NUM> with respect to the first segment <NUM> configured to selectively block the relative rotation with respect to the hinge axis C between the first segment <NUM> and the second segment <NUM>, at least in the first position and in the second position, and to selectively allow a free rotation between the first segment <NUM> and the second segment <NUM>.

The blocking assembly comprises, first of all, a toothed crown <NUM> associated with one between the first segment <NUM> and the second segment <NUM>, in particular an angular section of toothed crown <NUM> associated with one between the first segment <NUM> and the second segment <NUM>.

For example, as can be seen in <FIG>, the toothed crown <NUM> is rigidly fixed (i.e. fixed without residual degrees of freedom) to the first segment <NUM>.

The toothed crown <NUM> has a plurality of notches, angularly spaced apart along the circumferential development of the toothed crown <NUM>, and a plurality of grooves <NUM> each defined between a respective pair of consecutive notches along the circumferential development of the toothed crown <NUM>.

The fixing assembly further comprises an insertion pin <NUM> associated with the other one between the first segment <NUM> and the second segment <NUM>, for example associated with the second segment <NUM>, particularly with the first section <NUM> of the second segment <NUM>.

In particular, the insertion pin <NUM> is operable between an engagement position in which it is constrained by shape coupling to the toothed crown <NUM> and prevents rotation of the second segment <NUM> with respect to the first segment <NUM>, and a disengagement position in which it is released from the toothed crown <NUM> and allows rotation of the second segment <NUM> with respect to the first segment <NUM>.

In other words, in the engagement position the insertion pin <NUM> is selectively inserted into one of the grooves <NUM> defined between the notches of the toothed crown <NUM> defining a shape coupling with the toothed crown <NUM> which prevents any rotation of the second segment <NUM> with respect to the first segment <NUM>.

In particular, each groove <NUM> is arranged in a respective angular position along the circumference of the toothed crown <NUM> that is different from the other grooves <NUM>.

The coupling of the insertion pin <NUM> with each of the grooves <NUM> therefore defines a different second position of the second segment <NUM> with respect to the first segment <NUM>. That is, depending on the groove <NUM> in which the insertion pin <NUM> is inserted, there is a different second angle defined between the longitudinal axes L1 ,L2 of the first segment <NUM> and of the second segment <NUM>.

In the disengagement position, the insertion pin <NUM> is moved away from the toothed crown <NUM>, that is, it does not in any way make contact with it, and the second segment <NUM> is free to rotate with respect to the second segment <NUM>.

The blocking assembly also comprises an actuating lever <NUM> integral with the insertion pin <NUM> and configured to move the same between the engagement position and the disengagement position.

In particular, the actuating lever <NUM> is hinged to one between the first segment <NUM> and the second segment <NUM>.

For example, in the illustrated embodiment where the crown is fixed to the first segment <NUM>, the actuating lever <NUM> is hinged to the second segment <NUM>, with respect to a substantially horizontal hinging axis and orthogonal to the longitudinal axis L2 of the second segment <NUM>.

In detail, the actuating lever <NUM> can be hinged to the first section <NUM> of the second segment <NUM>, internally to the second through channel defined by it, by means of a support bracket <NUM> which is derived cantilevered and substantially squared from the first section <NUM> of the base frame T2 of the second tubular body of the first segment <NUM>, and which has a slot for receiving a fixing pin connecting the actuating lever <NUM> which defines said hinging axis for the actuating lever <NUM>.

In particular, the actuating lever <NUM> has an upper end, arranged externally to the second tubular body defined by the first section <NUM> of the second segment <NUM>, at which a gripping handle may be arranged.

The actuating lever <NUM> then has an opposite lower end to which the insertion pin <NUM> is rigidly fixed (i.e., fixed without residual degrees of freedom).

The actuating lever <NUM> is movable, about said hinging axis, between a distancing position, corresponding to the disengagement position of the insertion pin <NUM>, wherein the lower end of the actuating lever <NUM> is distal from the toothed crown <NUM>, and a nearing position, corresponding to the engagement position of the insertion pin <NUM>, wherein the lower end of the actuating lever <NUM> is proximal to the toothed crown <NUM>.

The blocking assembly further comprising elastic action means associated with the actuating lever <NUM> and adapted to automatically push the same towards the nearing position. Such elastic action means comprise, for example, an elastic traction spring provided with an end coupled near the toothed crown <NUM>, for example connected to the support bracket <NUM> in a position proximal to the toothed crown <NUM>, and with an opposite end, distal from the toothed crown <NUM>, associated (coupled) with the actuating lever <NUM> at the lower end thereof.

The actuating lever <NUM> is therefore movable towards (and in) the distancing position in contrast to the elastic force of the traction spring, which otherwise tends to push the actuating lever <NUM> towards (and in) the nearing position.

The cutting member U, as anticipated, is associated with the second segment <NUM> and arranged at the second axial longitudinal end thereof made available by the second section <NUM>.

The brush cutter tool <NUM> comprises a rotational drive assembly of the cutting member U, which allows the motion imposed by the power take-off of the agricultural machine <NUM> to be transmitted to the cutting member U.

The drive assembly makes it possible, in particular, to actuate the cutting device U both when the second segment <NUM> is in the first position and when the second segment <NUM> is in the second position, i.e. in any of the second positions.

In particular, the drive assembly is configured to transmit said motion imposed on the cutting member U so as to actuate the same with respect to a rotation axis orthogonal to the longitudinal axis L2 of the second segment <NUM>.

The drive assembly comprising, first of all a first drive shaft <NUM> rotatably associated with the first segment <NUM> with respect to a first rotation axis R1, for example substantially vertical and transverse (e.g. orthogonal) to the longitudinal axis L1 of the first segment <NUM>.

The first rotation axis R1 is parallel to the hinge axis C, preferably coincident (coaxial) with it, around which the second segment <NUM> rotates with respect to the first segment <NUM>. In particular, the first drive shaft <NUM> can be rotatably inserted inside the first sleeve <NUM> fixed to the first segment <NUM>, maintaining a single rotational degree of freedom around the first rotation axis R1 with respect to said first sleeve <NUM>.

In detail, the first drive shaft <NUM> is inserted inside the first sleeve <NUM> with interposition of rolling elements, for example ball bearings, which allow the first drive shaft <NUM> to rotate inside the first sleeve <NUM>.

More precisely, the first drive shaft <NUM> can be coaxially inserted inside the first sleeve <NUM>, with the first rotation axis R1 therefore coinciding with the longitudinal central axis of the first sleeve <NUM>, that is coinciding with the hinge axis C between the second segment <NUM> and the first segment <NUM>.

A return pulley <NUM> or toothed return wheel and a first pulley <NUM> or first toothed wheel are keyed onto the first drive shaft <NUM>, i.e. connected and integral in rotation.

The return pulley <NUM> is adapted to be connected to the power take-off of the agricultural machine <NUM>.

For example, the return pulley <NUM> is connected to the drive pulley connected to the output shaft of the agricultural machine <NUM> by means of a flexible transmission member <NUM>, for example a belt or chain, which transmits the rotary motion of the output shaft to the return pulley <NUM> (and thus also to the first drive shaft <NUM> and to the first pulley <NUM>).

The drive assembly then comprises a second drive shaft <NUM> to which the cutting member U is associated (integral) in rotation, for example it is associated (integral) with a lower end of the second drive shaft <NUM>.

The second drive shaft <NUM> is rotatably associated with the second segment <NUM> with respect to a second rotation axis R2, which is distinct and spaced out by a non-zero amount from the first rotation axis R1 (and aligned with the first shaft along the longitudinal axis L2 of the second segment <NUM>).

In the embodiment illustrated, the second rotation axis R2 is parallel to the first rotation axis R1.

In particular, the second drive shaft <NUM> is associated with the second section <NUM> of the second segment <NUM>.

More in detail, the second segment <NUM> can comprise a second sleeve <NUM>, which is axially hollow and for example cylindrical, rigidly fixed (i.e. fixed without residual degrees of freedom) to the second section <NUM>, for example to the base frame T3 of the second section <NUM>.

In particular, the second sleeve <NUM> has a longitudinal central axis and is fixed to the second section, inside the third through channel defined by it, arranged with said longitudinal central axis transverse, for example orthogonal, to the longitudinal axis L2 of the second segment <NUM>.

The second drive shaft <NUM> may be inserted within the second sleeve <NUM> fixed to the second section <NUM> of the second segment <NUM>, maintaining a single rotational degree of freedom with respect to said second rotation axis R2.

In detail, the second drive shaft <NUM> is inserted inside the second sleeve <NUM> with interposition of rolling elements, for example ball bearings, which allow the second drive shaft <NUM> to rotate inside the second sleeve <NUM>.

The first drive shaft <NUM> and the second drive shaft <NUM> are mechanically connected in rotation.

In particular, a second pulley <NUM> or toothed wheel connected in rotation to the first pulley <NUM> by means of a flexible connection member closed in a ring is keyed to the second drive shaft <NUM> (that is fixed and integral in rotation).

In particular, the second drive shaft <NUM> has an upper end which is arranged within the third through channel defined by the third tubular body of the second section <NUM> of the second segment <NUM>, to which said second pulley <NUM> is keyed, and an opposite lower end which protrudes inferiorly beyond the first section <NUM> of the base frame T3 of the third tubular body, and is arranged externally to the third tubular body, to which the cutting member U is connected (and integral in rotation).

Returning to the conformation of the second segment <NUM>, the second section <NUM> is connected to the first section <NUM> with the possibility of oscillating about an oscillation axis P parallel to the longitudinal axis L2 of the second segment <NUM>, that is transverse, for example orthogonal, to the second rotation axis R2.

In particular, the cutting element U is integral with the second section <NUM> in the oscillation with respect to said oscillation axis P.

In other words, the second section <NUM> rotating about said oscillation axis P, by means of the second sleeve <NUM> rotates with itself the second drive shaft <NUM> and therefore the cutting member U connected thereto.

More precisely, the second section <NUM> rotates with respect to the first section <NUM> about said oscillation axis P by means of a (single) oscillation pin <NUM> defining said oscillation axis P.

In detail, as better visible in <FIG>, the first section <NUM> of the second segment <NUM> can comprise a third sleeve <NUM>, which is axially hollow and for example cylindrical, rigidly fixed (i.e. fixed without residual degrees of freedom) to the first section <NUM>, for example to the base frame T2 of the first section <NUM>.

In particular, the third sleeve <NUM> has a longitudinal central axis and is fixed to the first section <NUM>, within the second through channel defined by it, arranged with said longitudinal central axis parallel to the longitudinal axis L2 of the second segment <NUM>.

The second section <NUM> then has a receiving seat facing the third sleeve <NUM> and coaxial thereto.

Said receiving seat is defined for example, by a through hole made in a connection plate <NUM> rigidly fixed to the base frame T3 of the second section <NUM>. For example, such a connection plate <NUM> is arranged within the third through channel defined by the second section <NUM> of the second segment <NUM> and rises upwards, squarely, from the first section <NUM> of the base frame T3 of the second section <NUM>.

The brush cutter tool <NUM>, i.e. the oscillation assembly comprises said oscillation pin <NUM>, the third sleeve <NUM> and the receiving seat made in the third section. The oscillation pin <NUM> is inserted coaxially and, substantially to size, inside the third sleeve <NUM> made in the first section <NUM> and also inserted, and substantially to size, inside the receiving seat made in the second section <NUM>.

Furthermore, the oscillation assembly is configured to oscillate the second section <NUM> with respect to the first section <NUM> selectively between a reference position, in which the rotation axis of the cutting member U lies on a vertical plane, and an inclined position, in which the rotation axis of the cutting member U is transverse to said vertical plane.

The oscillation assembly comprises first of all a straight and rigid support bar <NUM>, i.e. not deformable under the usual loads for which it is intended, which is arranged with its own central longitudinal axis Y lying on a plane perpendicular to the first rotation axis R1 and transverse, e.g. orthogonal, to the longitudinal axis L2 of the second segment <NUM> and transverse.

Further, this longitudinal axis is substantially horizontal.

The support bar <NUM> is hinged to the first section <NUM> of the second segment <NUM>, i.e. by the base frame T2 of the first section <NUM> of the second segment <NUM>, with respect to a rotation axis parallel (and coincident) to its own longitudinal central axis Y.

In particular, the support bar <NUM> can have opposite axial ends, each of which is inserted in a suitable receiving slot, made in a respective second section <NUM> of the base frame T2 of the first section <NUM> of the second segment <NUM>.

Each end of the support bar <NUM> may therefore protrude beyond the slot, resulting external to the second through channel of the first section <NUM>, and have a thread that allows the screwing of a blocking nut that prevents the axial extraction of the support bar <NUM> from the slot.

The support bar <NUM> is therefore inserted inside said slots with the possibility of rotating on itself around its own longitudinal central axis Y.

The oscillation assembly then comprises a first annular support <NUM>, for example a first cam <NUM>, and a second annular support <NUM>, for example a second cam <NUM>, which are fitted on the support bar <NUM> and rigidly fixed thereto, or fixed with no residual degrees of freedom to the support bar <NUM>.

The first annular support <NUM> and the second annular support <NUM> are therefore rotationally integral (without angular shifts between them) to the support bar <NUM> around the longitudinal central axis Y of the support bar <NUM>.

More in detail, the first annular support <NUM> and the second annular support <NUM> are arranged along the support bar <NUM> at a non-zero distance from each other along a direction parallel to the longitudinal central axis Y of the support bar <NUM> and are placed on opposite sides of the support bar <NUM> with respect to a vertical plane containing the oscillation axis P.

Each annular support has (in a respective perimeter contact profile or even cam profile) a first flat perimeter face, and a second preferably flat perimeter face angularly spaced from the first perimeter face with respect to the longitudinal axis of the support bar <NUM>.

The first perimeter faces of the first annular support <NUM> and of the second annular support <NUM> are mutually coplanar, i.e. they are placed at the same radial distance from the longitudinal central axis Y of the support bar <NUM>, while the second faces are placed at a different radial distance from the longitudinal central axis of the support bar <NUM>.

For example, the second perimeter faces lie on parallel planes spaced out by a non-zero distance. However, it is not excluded that the second faces may lie on a single plane inclined with respect to the longitudinal axis of the support bar <NUM>.

Said first and second annular support <NUM> are adapted to make a resting surface <NUM> available for a (flat) abutment surface <NUM> of the oscillation assembly made in the second section <NUM> and integral in oscillation around the oscillation axis P.

The abutment surface <NUM> is held in contact with the first annular support <NUM> and with the second annular support <NUM>, i.e. with the first faces or with the second faces according to the rotation of the support bar <NUM>, by means of a potential force.

Such potential force may be the weight force of a body making the abutment surface <NUM> available and/or an elastic element configured to push the abutment surface <NUM> against the first and second annular support <NUM>. This body is, as will become clear below, the base frame T3 of the second section <NUM> of the second segment <NUM>.

In particular, this abutment surface <NUM> of the oscillation assembly is rigidly integral with the base frame T3 of the second section <NUM> in the oscillation about the oscillation axis P. For example, the second section <NUM> may have a flange <NUM> fixed without residual degrees of freedom to the base frame T3 of the third tubular body, which is adapted to make available said abutment surface <NUM> of the second section <NUM> of the second segment <NUM> adapted for rest in abutment on said abutment surface <NUM> made available by the first annular support <NUM> and by the second annular support <NUM>.

For example, said flange <NUM> can be made as a monolithic body with the base frame T3 of the second section <NUM> of the second segment <NUM>.

In particular, said flange <NUM> may comprise two opposite and parallel lateral segments that are derived from the first base section <NUM> along a direction parallel to the longitudinal axis L2 of the second segment <NUM> (i.e., parallel to the oscillation axis P of the second section <NUM>), and an accessory segment <NUM> that acts as a bridge between the lateral segments, that is it connects the lateral segments and is orthogonal thereto.

Each lateral segment of the flange <NUM> has a flat base surface which is turned and faces the first section <NUM> of the base frame T3 of the second tubular body defined by the first section <NUM> of the second segment <NUM>, and said base surfaces are mutually coplanar and adapted to make available said abutment surface <NUM> of the second section <NUM>.

Regardless of the exact architecture that makes the abutment surface <NUM> available, it is flat, as already mentioned, and lies on a plane perpendicular to the second rotation axis R2, in addition to being integral with said second rotation axis R2 in rotation with respect to the oscillation axis P.

The support bar <NUM> is, therefore, actuatable in rotation about its longitudinal central axis Y between a primary position, corresponding to the reference position of the second section <NUM> (i.e. of the cutting member U) and a secondary position, corresponding to the inclined position of the second section <NUM> (i.e. of the cutting member U).

In particular, in the primary position of the support bar <NUM> the first faces of the first annular support <NUM> and the second annular support <NUM> lie on a plane parallel to the oscillation axis P of the second section <NUM> (and perpendicular to the first rotation axis R1, for example horizontal) and the resting surface <NUM> for the abutment surface <NUM> of the second section <NUM> is made available by said first faces of the first annular support <NUM> and of the second annular support <NUM>.

In the secondary position of the support bar <NUM>, the second faces of the first annular support <NUM> and the second annular support <NUM> lie in respective planes parallel to the oscillation axis of the second section <NUM> (and perpendicular to the first rotation axis R1, for example horizontal) and the resting surface <NUM> for the abutment surface <NUM> of the second section <NUM> is made available by said second faces.

As mentioned above, however, it is not excluded that said faces may be coplanar, in which case in the secondary position of the support bar <NUM> the second faces of the first annular support <NUM> and of the second annular support <NUM> lie on a plane parallel to the oscillation axis of the second section <NUM> (and inclined with respect to the first rotation axis R1) and the resting surface <NUM> for the abutment surface <NUM> of the second section <NUM> is made available by said second faces.

Therefore, as a consequence of the rotation of the annular supports, in the primary position the abutment surface <NUM> lies on a first lying plane parallel to the oscillation axis P and perpendicular to the first rotation axis R1, while in the secondary position the abutment surface <NUM> lies on a second lying plane parallel to the oscillation axis P and inclined with respect to the first rotation axis R1.

The first lying plane and the second lying plane define an acute angle of less than <NUM>°, e.g. less than <NUM>°, at their intersection.

Between the primary position and the secondary position, the support bar <NUM> performs a rotation around its own longitudinal central axis equal to a certain angle smaller than the rounded angle, in particular equal to the acute angle defined by the intersection between the first lying plane and the second lying plane.

The brush cutter tool <NUM> further comprises an assembly for adjusting the position of the support bar <NUM> configured to selectively rotate the support bar <NUM> between the primary position and the secondary position.

The adjustment assembly is further configured to selectively block the support bar <NUM> in at least these two positions (i.e. in the primary position and in the secondary position).

The assembly for adjusting the position of the support bar <NUM> comprises, first of all, a second actuating lever <NUM> integral (i.e. fixed without residual degrees of freedom) to the support bar <NUM> for actuating it in rotation with respect to its longitudinal central axis.

The second actuating lever <NUM> is preferably arranged externally to the second segment <NUM> and has an upper end at which a gripping handle may be arranged, and an opposite lower end by means of which it is rigidly fixed (i.e. fixed without residual degrees of freedom) to the support bar <NUM>, for example at an end of the support bar <NUM> protruding from the first section <NUM> of the second segment <NUM>.

The adjustment assembly further comprises a blocking pin <NUM> integral with the lever and which is derived therefrom when nearing the first section <NUM> of the second segment <NUM>, for example when nearing a lateral face of the second tubular body of the first segment <NUM> in proximity to which the second actuating lever <NUM> is arranged.

The blocking pin <NUM> can be selectively inserted into a first seat, which is made in said lateral face of the first section <NUM> and is positioned and shaped in such a way as to accommodate the blocking pin <NUM> to size in order to make a shape connection when the second actuating lever <NUM> is in the primary position.

In the same way, the blocking pin <NUM> can be selectively inserted into a second seat, which is made in said lateral face and is positioned and shaped in such a way as to accommodate the pin to size and make a shape connection with it when the lever is in the secondary position.

The first seat and the second seat are arranged along an arc of circumference having a vertex on the longitudinal central axis of the support bar <NUM> (i.e. on the rotation axis of the support bar <NUM>).

Furthermore, the first seat and the second seat are angularly spaced apart along said arc of circumference by an angle equal to the angle of rotation performed by the support bar <NUM> between the primary position and the secondary position.

The adjustment assembly may also comprise an abutment pin <NUM> integral with the first section <NUM> and inserted in a slot integral with the second section <NUM>.

The slot, in particular, has a (longitudinal) development such that in the reference position of the second section <NUM> the abutment pin <NUM> is placed in contact with a first end edge B1 of the slot, while in the inclined position of the second section <NUM>, the abutment pin <NUM> is placed in contact on a second end edge B2 of the slot opposite the first edge B1. In other words, the abutment pin <NUM> acts as an end-of-stroke element which prevents further oscillation of the second section <NUM> with respect to the first section <NUM> around the oscillation axis P.

For example, said slot is obtained through the flange <NUM> fixed to the base frame T3 of the second section <NUM> of the second segment <NUM>, and, in particular in the accessory segment <NUM> of the flange <NUM>.

The tool <NUM> may comprise a protective case <NUM> associated with the second segment <NUM>, in particular with the second section <NUM> of the second segment <NUM>, and adapted to circumferentially delimit a working area within which the cutting member U rotates.

In particular, the protective case <NUM> delimits a zone of the working area towards the first segment <NUM>, so as to protect the agricultural machine <NUM> and the user from the working member, i.e. the cutting member U, throwing bodies.

For example, the protective case <NUM> comprises an upper wall, conformed as a disc sector (subtended at a lower angle of <NUM>°), from a radially outer perimeter edge of which a circumferentially curved lateral wall develops downwards, arranged with respect to the second rotation axis R2 and provided with an inner surface having a concavity turned towards the second rotation axis R2.

This lateral wall also comprises an outer surface turned towards the first segment <NUM>. The protective case <NUM> is preferably rotatably connected to the second section <NUM> of the second segment <NUM>, so that its orientation with respect to the second section <NUM> can change when the second segment <NUM> rotates with respect to the first section <NUM>.

In the illustrated embodiment, the protective case <NUM> is rotatably associated with the second sleeve <NUM>, however, it is not excluded that it may be rotatably associated with the base frame of the second section <NUM>, according to a rotation axis parallel (coaxial) to the second rotation axis R2.

Even more preferably, the tool <NUM> comprises a blocking assembly (or orientation mechanism) configured to prevent rotation of the support case about said rotation axis parallel to the second rotation axis R2 during rotation of the second segment <NUM> between the first position and the second position.

In other words, said blocking assembly is configured in such a way that an imaginary line traceable on the protective case <NUM> and parallel to the longitudinal axis of the first section <NUM> when the second segment <NUM> is in the first position of rotation with respect to the first segment <NUM>, remains parallel to said longitudinal axis also when the second segment <NUM> is in the second position of rotation with respect to the first segment <NUM> (and in all intermediate positions).

In the embodiment illustrated, such a blocking assembly comprises an articulated quadrilateral, of which the first segment <NUM> (for example a flange <NUM> which derives externally from its base frame) is the frame of the articulated quadrilateral and the protective case is the rod opposite the frame. Preferably the articulated quadrilateral is an articulated parallelogram.

In particular, the blocking assembly comprises a rod <NUM> (straight and rigid, i.e. not deformable when subjected to the usual loads for which it is intended) provided with an end hinged to the first segment <NUM> (in an eccentric position with respect to the rotation axis of the first segment <NUM> with respect to the second segment <NUM>) with respect to at least a first hinge axis Q1 (parallel to the rotation axis of the first segment <NUM> with respect to the second segment <NUM>) and an opposite end hinged to the protective case <NUM> (in an eccentric position with respect to the second rotation axis R2) with respect to a second hinge axis Q2 parallel and distinct from the first hinge axis Q1.

In the embodiment illustrated, the ends of said rod <NUM> are connected to the protective case <NUM> and to the first segment <NUM> by means of respective spherical joints.

Further, the distance between the rotation axis of the second segment <NUM> with respect to the first segment <NUM> and the first hinge axis Q1 is substantially equal to the distance between the second rotation axis R2 and the second hinge axis Q2, and the distance between the second rotation axis R2 and the rotation axis of the second segment <NUM> with respect to the first segment <NUM> is substantially equal to the distance between the first hinge axis Q1 and the second hinge axis Q2.

In this way, the articulated parallelogram is realised.

As better visible in <FIG>, the tool <NUM> can further comprise a tensioning assembly of the flexible transmission member <NUM> which is at least partially wound on the first pulley <NUM> and on the second pulley <NUM>.

The particular tensioning assembly described below, although referring to the brush cutter tool, can be applied to any tool provided with: a first drive shaft, a second drive shaft to which a working member is rotationally associated, a first pulley integral in rotation with the first drive shaft, a second pulley integral in rotation with the second drive shaft and a flexible transmission member at least partially wound around the first pulley and the second pulley for the transmission of a rotary motion between the two pulleys.

In particular, as will become clear later, the tensioning assembly is configured to keep the flexible transmission member <NUM> suitably tensioned even following its elongation/wear. The tensioning assembly is, in particular, configured to push the second section <NUM> of the second segment <NUM> in a direction away from the first section <NUM> of the second segment <NUM> along a sliding axis S.

The sliding axis S is transverse, i.e. perpendicular to the first rotation axis R1 and the second rotation axis R2. In addition, the sliding axis S is parallel to the longitudinal axis L2 of the second segment <NUM>.

Further, said sliding axis S is, for example, parallel to the oscillation axis P.

By pushing the second section <NUM> away from the first section <NUM>, the tensioning assembly is configured to push the second drive shaft <NUM>, which is for example associated with the second section <NUM> by means of the second sleeve <NUM> and therefore integral with the second section <NUM> slidingly along the sliding axis S, away from the first drive shaft <NUM>, which first drive shaft <NUM> is rotatably associated (indirectly) with the first section <NUM>.

In particular, the first drive shaft <NUM> is (directly) rotatably inserted within the first sleeve <NUM> to which the first section <NUM> is hinged according to a rotation axis coaxial to the first rotation axis R1.

In other words, the tensioning assembly, by pushing on the second section <NUM>, pushes the second pulley <NUM>, which is integral with the second drive shaft <NUM>, away from the first pulley <NUM>, which is integral with the first drive shaft <NUM>, thus putting the flexible transmission member <NUM> wound thereon under tension.

In particular, the tensioning assembly can be configured to push the second section <NUM> in a direction away from the first section <NUM> along the sliding axis S constantly (i.e., at any instant of time), and automatically, i.e., without the need for adjustments by an operator using the tool <NUM>.

The tensioning assembly comprises, first of all, an elastic body <NUM> interposed between the first section <NUM> and the second section <NUM> and arranged so that the elastic force generated by it is developed (mainly) along a direction parallel to the sliding axis S.

In particular, the elastic body <NUM> is configured to push the second section <NUM> in a direction away from the first section <NUM> along the sliding axis S, as anticipated above.

The second section is always kept pushed in the direction of away from the first section by the elastic body during the use of the tool.

In the absence of forces acting on the second section in the direction of the sliding axis, a distance of the second drive shaft from the first drive shaft is defined solely by the thrust exerted by the spring.

In the embodiment represented in the pictures, the elastic body <NUM> comprises a helical compression spring (i.e. exerting an elastic force that resists a compressive force exerted on the spring).

The helical spring is interposed between the first section <NUM> and the second section <NUM> and is also arranged with its own longitudinal axis, along which it mainly exerts the resistant elastic force, parallel to the sliding axis S.

In particular, the helical spring is interposed between the first portion <NUM> and the second portion <NUM> and mounted pre-compressed, i.e. in a state of deformation such that its length along the longitudinal axis is less than the length along the longitudinal axis of the spring in an undeformed state, i.e. in the absence of external forces acting on the helical spring. As can be better seen in said <FIG>, the helical spring is provided with a first longitudinal end which is placed in abutment on the first section <NUM> and with an opposite longitudinal end which is placed in abutment on the second section <NUM>.

For example, the first longitudinal end is placed in abutment on the third sleeve <NUM> (which accommodates the oscillation pin <NUM> and is fixed without residual degrees of freedom to the first section <NUM> of the second segment <NUM>) that is on an edge of the proximal third sleeve <NUM> and facing the second segment <NUM>, while the second longitudinal end is placed in abutment on the connection plate <NUM> (which is fixed without residual degrees of freedom to the second section <NUM> of the second segment <NUM> and on which the receiving seat for the oscillation pin is defined <NUM>).

However, it is not excluded that in an embodiment not illustrated and less preferred due to its complexity and therefore greater possibility of malfunctions, instead of the elastic element there may be a linear actuator configured to push the second section <NUM> in the direction away from the first section <NUM>.

The tool <NUM> can also comprise an end-stroke assembly configured to limit (only) the minimum distance between the first drive shaft <NUM> and the second drive shaft <NUM> along the sliding axis S, that is to limit the minimum distance between the first rotation axis R1 (of the first drive shaft <NUM>) and the second rotation axis R2 (of the second drive shaft <NUM>) along the sliding axis S.

The end-of-stroke assembly is, in other words, configured to obviate the possibility (that is to say, prevent) that, for example because of resistant forces due to normal use (which develop, for example, while mowing the turf) or due to expected impacts, the second drive shaft <NUM> may move closer to the first drive shaft <NUM>. In that case, if the second driving shaft could be able to move towards the first driving shat, it would place the flexible transmission member <NUM> in a condition of failed of or insufficient tensioning, which could lead to a slippage thereof on the first pulley <NUM> and on the second pulley <NUM> and, therefore, to a failed operation of the working member (i.e. the cutting member U).

Overall, the end-of-stroke assembly is therefore configured to prevent a resisting force acting in the opposite direction to that of the elastic element along the sliding axis from overcoming the force of the elastic element (i.e. from causing deformation, particularly of the elastic element) causing the second drive shaft to approach the first drive shaft. The limit end-of-stroke assembly only prevents the second drive shaft from approaching the first drive shaft, leaving free the movement of the second drive shaft away from the first drive shaft under the force exerted by the element, rubber band.

The end-of-stroke assembly, in particular, can be configured to allow a variation of the value of the minimum distance between the first drive shaft <NUM> and the second drive shaft <NUM>, i.e. between the first rotation axis R1 and the second rotation axis R2, with respect to the sliding axis S.

For example, in one embodiment not illustrated and less preferred, the end-of-stroke assembly can comprise a blocking body which can be selectively positioned, in a controllable manner (for example by screwing into a suitable thread), in a plurality of different positions along a direction parallel to the sliding axis S and adapted to block/prevent (for example by interference) the displacement of the second drive shaft <NUM> nearing the first drive shaft <NUM> along the sliding axis S beyond the position in which it is arranged (which therefore substantially defines said minimum distance).

In the preferred embodiment, visible in <FIG>, the end-of-stroke assembly comprises a so-called tappet cam mechanism, provided with a cam rotatable with respect to the first section <NUM> of the second segment <NUM>, i.e. to the base frame of the first section <NUM>, according to a rotation axis perpendicular to the sliding axis S in which the tappet is made available by an abutment surface <NUM> of the second section <NUM> of the second segment <NUM>, i.e. integral with the base frame of the second section <NUM> of the second segment <NUM>, for example turned towards the first segment <NUM>.

In particular, the tappet is made available by the oscillation pin <NUM> (which substantially defines the follower of the mechanism) which slides along the sliding axis S (however remaining axially contained within the third sleeve <NUM> integral with the first section <NUM> of the second segment <NUM>).

The rotation of the cam <NUM> in a predetermined direction of rotation causes a thrust on the abutment surface <NUM> along the sliding axis S in the direction away from the first portion <NUM> of the second segment <NUM>.

Just by way of simplification, with reference to <FIG>, the direction of rotation of the cam <NUM> is anti-clockwise.

Preferably, the end-of-stroke assembly is configured to automatically vary the value of the minimum distance between the first shaft and the second shaft on the basis of the value of the distance between the first shaft and the second shaft.

In such a case, the cam <NUM> of the mechanism is driven into rotation by its own weight force or at most by its own weight force and by a spring in the manner which will become more evident below.

In the illustrated embodiment, the end-of-stroke assembly comprises, first of all, an abutment surface <NUM> integral with the second section <NUM> slidingly along the sliding axis S in the direction nearing the first section <NUM>.

Said abutment surface <NUM> is, for example, turned towards and facing one end of the first section <NUM> distal from the second section <NUM>.

Said abutment surface <NUM> is, in the illustrated embodiment, made available by an axial end (lying on a flat surface) of the oscillation pin <NUM>.

In particular, as better visible in <FIG>, the oscillation pin <NUM> has a first axial end (which protrudes axially beyond the third sleeve <NUM> at the second section <NUM> and) which is placed in abutment on the second sleeve <NUM> inside which the second drive shaft <NUM> is slidingly associated, and an opposite second axial end (which protrudes axially beyond the third sleeve <NUM> at the first portion <NUM> and) which makes available said abutment surface <NUM>.

In practice, the oscillation pin <NUM> is slidable with respect to both the first section <NUM> and the second section <NUM> along its oscillation axis P (which is then parallel to the sliding axis S) and is made integral with the second section <NUM> in the movement along the sliding axis S only when nearing the first section <NUM> by means of the thrust generated by the second sleeve <NUM> on the first end of the oscillation pin <NUM>.

In fact, the second section <NUM> moving closer to the first section <NUM> pushes with the second sleeve <NUM> on the oscillation pin <NUM> causing it to slide inside the third sleeve <NUM> along the sliding axis S in the direction nearing the first section <NUM>.

Therefore, the abutment surface <NUM> can slide with the second section <NUM> along the sliding axis S only in the nearing direction from the first section <NUM>.

Were it not for the cam <NUM>, the oscillation pin <NUM>, therefore the abutment surface <NUM> would be free to move independently of the second section <NUM> in the direction away from the first section <NUM> along the sliding axis S.

The cam <NUM> (which substantially defines the moving part of the cam tappet mechanism <NUM>) is rotatably associated with the first section <NUM> with respect to a substantially horizontal rotation axis W and transverse, preferably orthogonal, to the sliding axis S (and moreover lying on a plane perpendicular to the first rotation axis R1).

The rotation axis W of the cam <NUM> is also parallel to a lying plane of the abutment surface <NUM>.

For example, the cam <NUM> can be hinged to the support bracket <NUM> (fixed without residual degrees of freedom to the, for example welded, to the base frame of the first section <NUM>) and arranged inside the through channel of the second tubular body defined by the first section <NUM>.

The cam <NUM> is adapted to be arranged (preferably directly) in contact with the abutment surface <NUM>.

In particular, the cam <NUM> has a cam profile <NUM> by means of which it is placed (directly) in abutment on the abutment surface <NUM> made available for example by the oscillation pin <NUM>.

Said cam profile <NUM> is, in particular, defined by an arc of a circle subtended at an angle having its centre on the rotation axis of the cam <NUM> and less than <NUM>°.

In particular, the cam profile <NUM> has an upper end (i.e., placed at a height along the upper vertical in use) which is located at a distance from the rotation axis W, and a lower end, i.e. placed at a height along the lower vertical axis in use) which is located at a distance from the rotation axis W less than the distance between the upper end and the rotation axis of the cam <NUM>.

In addition, the cam profile <NUM> has a gradually smaller distance from the rotation axis W with a monotonous decreasing course from the upper end to the lower end.

The cam profile <NUM> is therefore placed in abutment on the abutment surface <NUM>, with the cam <NUM> free to rotate around its own rotation axis under the effect of its own weight force, so that a rotation of the cam <NUM> with respect to its rotation axis in a predetermined direction of rotation, that is in the direction that causes a lowering of the upper end along the vertical, causes a thrust on the abutment surface <NUM> in the distancing direction of the second section <NUM> from the first section <NUM> along the sliding axis S.

As mentioned above, the preferred end-of-stroke assembly is configured to automatically vary the value of the minimum distance between the first drive shaft <NUM> and the second drive shaft <NUM> based on the value of the distance between the first drive shaft <NUM> and the second drive shaft <NUM>.

In other words, the distance between the first drive shaft <NUM> and the second drive shaft <NUM> along the sliding axis S, i.e., the distance between the first rotation axis R1 and the second rotation axis R2, varies according to the wear/elongation conditions of the flexible transmission member <NUM> by means of the tensioning assembly which pushes the second section <NUM> away from the first section <NUM> so as to keep (at all times) the flexible transmission member <NUM> in tension.

The end-of-stroke assembly can therefore be configured to adapt the minimum distance between the first drive shaft <NUM> and the second drive shaft <NUM> to the distance defined between them by means of the tensioning assembly.

More in detail, the end-of-stroke assembly is configured so that the minimum distance is equal to the distance defined by means of the tensioning assembly.

In other words, the end-of-stroke assembly makes it possible to prevent any retraction along the sliding axis S of the second section <NUM>, or any approach of the second drive shaft <NUM> to the first drive shaft <NUM>.

In particular, following a "correction", i.e. a variation, of the distance between the first drive shaft <NUM> and the second drive shaft <NUM> by the tensioning assembly, the oscillation pin <NUM> may be in a condition such that its first axial end is not in abutment on the second sleeve <NUM> inside which the second drive shaft <NUM> is slidably received.

In this condition, the minimum possible distance between the first drive shaft <NUM> and the second drive shaft <NUM> would be less than the distance defined between said shafts by means of the tensioning assembly.

In fact, in this condition, for example following an impact, the second drive shaft <NUM> may retract along the sliding axis S until the second sleeve <NUM> comes into abutment again on the first end of the oscillation pin <NUM>.

The proposed end-of-stroke assembly, on the other hand, makes it possible to "correct", i.e. to vary automatically (without the need for adjustment by an operator), the minimum distance each time, and substantially simultaneously, the tensioning assembly varies the distance between the first drive shaft <NUM> and the second drive shaft <NUM>.

In fact, as the tensioning assembly pushes the first second drive shaft <NUM> away from the first drive shaft <NUM>, the cam <NUM>, by effect of its own weight force, rotates and, thanks to its particular profile, pushes on the abutment surface <NUM> of the oscillation pin <NUM> causing it to slide along the sliding axis S in the direction away from the first section <NUM> keeping it, substantially continuously abutting on the second sleeve <NUM> integral with the second section <NUM>.

As mentioned above, the rotation of the cam <NUM> about its rotation axis W may be assisted by an elastic element <NUM>.

In particular, said elastic element <NUM> can be configured to pull, i.e. to exert a traction force such as to push, downwards, the cam <NUM>, i.e. to push the cam <NUM> in rotation in the predetermined direction (direction such as to lower (with respect to the vertical) the upper end of the cam profile <NUM>).

Such an elastic element <NUM> comprises, for example, a helical traction spring provided with a longitudinal axis along which it mainly exerts said elastic traction force.

The elastic spring is arranged with said longitudinal axis orthogonal to the rotation axis of the cam <NUM>.

In particular, said elastic spring has a first axial end which is connected (coupled) to the first section <NUM> and an opposite second end which is connected (coupled) to the cam <NUM>, for example in a position interposed between the cam profile <NUM> (between the upper and lower ends of the cam profile <NUM>) and the rotation axis of the cam <NUM>.

For example, the first end of the elastic spring may be coupled on the base frame T2 of the first section <NUM>, while the second end of the elastic spring is coupled on a lug made on the cam <NUM>, for example made available by a pin fitted in a through slot made on the cam <NUM> and arranged with a longitudinal axis parallel to the rotation axis.

In the embodiment illustrated, in the first position the longitudinal axis of the first segment and the longitudinal axis of the second segment are parallel to each other (and for example lie on the vertical centreline plane of the agricultural machine).

In the second position, the longitudinal axis of the second segment is inclined with respect to the vertical centreline of the agricultural machine.

Furthermore, the length of the second segment in the direction of the respective longitudinal axis and the angle between the first segment and the second segment in the second position are such that the second rotation axis protrudes laterally with respect to the maximum overall lateral dimensions of the agricultural machinery when the second segment is in the second position.

Furthermore, the protective case is shaped in such a way as to protrude laterally with respect to the maximum overall dimensions of the agricultural machine. Furthermore, when the second segment is in the second position in rotation with respect to the first segment, the protective case protrudes laterally on one side only with respect to the maximum overall dimensions of the agricultural machine (more than half protrudes with respect to the maximum overall dimensions).

Claim 1:
Tool (<NUM>) comprising:
- a first section (<NUM>) and a second section (<NUM>) slidingly associated with the first section (<NUM>) with respect to a sliding axis (S),
- a working member (U),
- a rotational drive assembly of the working member provided with:
∘ a first drive shaft (<NUM>) rotatably associated with the first section (<NUM>) with respect to a first rotation axis (R1),
∘ a second drive shaft (<NUM>) rotatably associated with the second section (<NUM>) with respect to a second rotation axis (R2) and to which the working member is rotationally associated,
∘ a first pulley (<NUM>) integral in rotation with the first drive shaft (<NUM>) and a second pulley (<NUM>) integral in rotation with the second drive shaft (<NUM>),
∘ a flexible transmission member (<NUM>) at least partially wound around the first pulley (<NUM>) and the second pulley (<NUM>) for the transmission of a rotary motion between the two pulleys,
- a tensioning assembly of the flexible transmission member (<NUM>), said tensioning assembly being configured to push the second section (<NUM>) away from the first section (<NUM>) along the sliding axis (S), wherein the tensioning assembly comprises an elastic body (<NUM>) interposed between the first section (<NUM>) and the second section (<NUM>) and configured to push the second section (<NUM>) in a direction away from the first section (<NUM>) along the sliding axis (S), the tool (<NUM>) comprising an end-of-stroke assembly configured to limit the minimum distance between the first drive shaft (<NUM>) and the second drive shaft (<NUM>) along the sliding axis (S), preventing the second drive shaft (<NUM>) from moving towards the first drive shaft (<NUM>), wherein the end-of-stroke assembly is configured to allow a variation in the value of the minimum distance between the first drive shaft (<NUM>) and the second drive shaft (<NUM>).