Patent Description:
Agricultural combine harvesters are machines designed for harvesting and processing crops such as wheat or corn. Crops are cut from the field on a wide area by the header mounted at the front of the combine. By an auger or a belt system included in the header, the harvested material is brought to a central area of the header, and from there it is transported by the feeder to a threshing mechanism comprising laterally or longitudinally mounted threshing rotors and further to the cleaning section comprising a number of sieves where grains are separated from any remaining crop residue.

The header is suspended on a cradle frame attached at the front of the feeder. In modern combines, this cradle frame is movable with respect to the feeder housing in order to allow a freedom of movement to the header during the harvesting operation. The cradle frame is usually configured so that a pivoting motion is allowed both around a horizontal axis that is perpendicular to the longitudinal axis of the harvester and about a second axis parallel to said longitudinal axis. The first degree of freedom allows the cradle and thereby the header to be tilted forward or backward relative to the feeder housing, while the second degree of freedom allows a lateral flotation of the header.

A known way of operationally coupling the header to the combine utilises a driveline from the combine's power source to the header which passes along one side of the feeder where it is coupled to a drive axle on the header through a transverse gearbox, configured to transfer the rotation of the driveline oriented in the forward direction of the combine to a rotation of the header drive axle oriented transversally to said forward direction. In presently known systems of this type, the transverse gearbox is bolted to the side of the feeder, which requires a complex rotational connection between the gearbox and the header's drive axle in order to allow the header to undergo the above-described movements relative to the feeder. The angular range of said rotational connection however limits the amplitude of the header's movements, especially when both degrees of freedom, tilting and lateral floatation, are simultaneously available.

As combines increase in size and as the requirements in terms of the header movement increase, the existing mechanisms are therefore no longer sustainable.

<CIT> describes a feeder assembly with a belt drive system making use of a pair of tension pulley assemblies, which are connected by a rod and levers, with tension pulley assembly being biased by a spring assembly.

The present invention is related to a combine harvester in accordance with the appended claims. In a harvester according to the invention, the driveline for driving the moving components of the combine header comprises a belt drive mounted laterally with respect to the feeder housing. The feeder is the crop transport device mounted at the front of the combine, to which the header is removably attached. The invention is related to combines equipped with a feeder housing that comprises a movable cradle frame at the front, configured to receive the header, so that a controlled movement of the cradle frame, for example a forward/backward tilting and sideways tilting movement, may be imparted to the header during a harvesting run. The belt drive is configured to transfer the rotation of a first drive axle that is part of the driveline, to the rotation of a second axle that is mounted on and rotatable with respect to the movable cradle frame and to which the drive axle of the header can be coupled. According to the invention, the belt drive comprises two pulleys which are maintained in a common plane regardless of the movement of the cradle frame and thereby of the header, relative to the feeder housing. To this aim, the pulleys are rotatably mounted in a longitudinally extendable bridge structure, and the pulleys are coupled to the first and second axles through couplings which allow a misalignment between the pulleys and the axles, for example through universal joints.

The invention thereby enables the use of a belt drive for driving a combine header that is movable relative to the feeder housing. The belt drive is operational without undue loads on the belt or misalignment of the pulleys, regardless of the header's position relative to the feeder. Optionally, a belt drive is mounted on both sides of the feeder housing.

Preferred embodiments will now be described with reference to the drawings. The detailed description is not limiting the scope of the invention, which is defined only by the appended claims. The terms 'front' and 'back' or 'rear' are referenced to the front and back side of the combine harvester. The 'forward direction' of the combine harvester refers not to a single geometrical axis but to the general direction from the rear of the vehicle to the front.

<FIG> is a schematic image of a combine harvester <NUM> as known today, comprising a header <NUM> mounted at the front of the combine. The header comprises knives <NUM> maintained at a given height above ground level while the combine moves through a field of crops that are to be harvested. A rotating reel <NUM> guides the crops towards the knives. Cut crops are transported from both lateral sides of the header towards a central area by an auger <NUM>. The main body <NUM> of the combine is supported by front and rear wheels <NUM> and <NUM> and comprises the threshing rotors and cleaning section generally known by the skilled reader and not depicted as such in <FIG>. From the central area of the header <NUM>, crops are transported into the main body <NUM> of the combine by a feeder <NUM>. The feeder <NUM> is inclined upwards from the header <NUM> towards the main body <NUM> and comprises moving belts <NUM> inside a housing <NUM>. The belts transport the crops upwards, from an inlet section <NUM> of the feeder to an outlet section <NUM>. At the front of the feeder, a cradle frame <NUM> is mounted, onto which the header <NUM> is mounted and secured. As described in the introductory portion, the cradle frame <NUM> is movable relative to the feeder <NUM>. The cradle frame may at least be pivotable about a tilting axis for tilting the header forward or backward, and preferably also about a longitudinal axis for allowing the header to undergo a lateral flotation. These movements are controlled by actuators (not shown) mounted between the feeder housing <NUM> and the cradle frame <NUM>. The rotation of the reel <NUM> and the auger <NUM> is driven by a header drive axle which is itself rotatably coupled to the driveline of the combine as described in the introductory portion.

<FIG> shows a detail of one side of the feeder <NUM>, in a combine harvester according to an embodiment of the invention. The feeder housing <NUM> and the cradle frame <NUM> are indicated in the drawing. The cradle frame <NUM> is mounted on a tiltable front portion <NUM> of the feeder. The tiltable portion <NUM> is capable of tilting forward and backward with respect to the feeder housing <NUM>. The cradle frame <NUM> itself is mounted on the tiltable portion <NUM> and is configured to perform a sideways swinging motion with respect to said tiltable portion <NUM>, about an axis oriented in the driving direction of the harvester. Actuators (not shown) are provided for driving the forward/backward and sideways movements of the tiltable portion <NUM> and of the cradle frame <NUM>.

The harvester's driveline for driving the movement of the components of the header, such as the knives <NUM> and the auger <NUM>, comprises a belt drive <NUM> arranged on the side of the feeder housing. The belt drive <NUM> transfers the rotation of a first axle <NUM>, visible in <FIG>, about central rotation axis <NUM>' shown in <FIG>, to a second axle <NUM> that rotates about central rotation axis <NUM>'. Onto the second axle <NUM>, a drive axle of the header will be coupled when the header is attached to the cradle frame <NUM>. The header's drive axle will preferably be coupled colinearly with the second axle <NUM>.

The rotation of the first axle <NUM> is driven by the remainder of the driveline that is not shown in detail in <FIG>, and which may comprise multiple drive shafts and gearboxes configured according to any arrangement known in the art, and driven by a power source within the harvester. This may be the engine of the harvester or a separate hydraulic or electric motor.

The belt drive <NUM> comprises a first pulley <NUM> mounted on the first axle <NUM>, a belt <NUM> and a second pulley <NUM> mounted on the second axle <NUM>. The arrow indicates the direction of the standard operational angular rotation of the belt drive <NUM>, i.e. the rotation applied for the normal operation of the header during a harvesting run. At least one tension roller <NUM> is present for tensioning the belt <NUM> through the action of a compression spring <NUM>. It is well known that instead of a compression spring, also a tension spring or torsion spring can be used to apply tension to a belt via a tension roller. In the embodiment shown in the drawings, a second tension roller <NUM> is present on the opposite side of the belt. The tension roller assembly shown in <FIG> will be described in more detail later in this description.

The central rotation axis <NUM>' is fixed with respect to the feeder housing <NUM>. This means that the first axle <NUM> is rotatable relative to the feeder housing through a set of bearings which are fixedly mounted with respect to said feeder housing. These bearings <NUM> are not visible in <FIG> but they are visualized in <FIG>. Likewise, the central rotation axis <NUM>' of this second axle <NUM> is fixed with respect to the cradle frame <NUM>, i.e. the axle <NUM> is rotatable relative to the cradle frame <NUM> through a set of bearings which are fixedly mounted with respect to the cradle frame <NUM>. These bearings <NUM> are visualized also in <FIG> and <FIG>. This means that as the cradle frame <NUM> moves relative to the feeder housing <NUM> under the influence of the forward/backward and sideways tilting actuators, the rotation axes <NUM>' and <NUM>' are in a constantly changing spatial relation one with respect to the other. The belt drive <NUM> is configured to be able to drive the rotation of the second axle <NUM>, regardless of the spatial relation between these rotation axes <NUM>' and <NUM>', i.e. regardless of the position of the cradle frame <NUM> relative to the feeder housing <NUM>.

To enable this characteristic feature of the invention, the pulleys <NUM> and <NUM> are configured to rotate relative to an extendable bridge structure <NUM> coupled between the pulleys. In addition to this, the rotation of the first and second axle <NUM>,<NUM> is coupled to the respective pulleys <NUM>, <NUM> through joints which allow at least a minimal degree of angular misalignment between the rotation axes <NUM>' and <NUM>' of the first and second axle on the one hand, and the respective rotation axes of the first and second pulley <NUM> and <NUM> on the other. Preferably, two universal joints are applied, as is the case in the embodiment shown. The section view of <FIG> illustrates the position of the first and second universal joint <NUM> and <NUM>. It is to be noted that <FIG> shows the belt drive <NUM> as seen from the side of the feeder housing, i.e. the position of the first and second pulleys is reversed compared to the view shown in <FIG>.

<FIG> also illustrates the manner in which the bridge structure <NUM> is constructed according to the exemplary embodiment shown in the drawings. The bridge structure comprises a first and second portion 30a and 30b, which can move one relative to the other in the longitudinal direction of the belt drive <NUM>. To this aim, the portions 30a and 30b of the bridge structure <NUM> each comprise a set of an upper and lower hollow tube <NUM> fixed to each other by transversal supports <NUM>, wherein one set of tubes can slide inside the other set of tubes. The radial tolerance of the sliding tubes is minimal so that lateral motion of the bridge portions 30a and 30b one relative to the other is virtually excluded.

The bridge structure <NUM> may be brought into practice in various other ways than the one illustrated in the drawings. Instead of the structure with the sliding tubes <NUM>, any structural form can be applied to the bridge portions 30a and 30b that allows a one-dimensional retraction or extension of the bridge structure as a whole. For example, one bridge portion could be in the form of a beam having a rectangular cross-section, while the other comprises a frame configured to move relative to the beam and in the longitudinal direction thereof, through a set of gliding or rolling elements (i.e. only a translation of the bridge portions relative to each other in the longitudinal direction is allowed, not a rotation).

The section view of <FIG> shows that the second pulley <NUM> rotates relative to the bridge structure's second portion 30b, through a set of bearings <NUM> mounted between flanges <NUM> which are fixed to the bridge portion 30b, and an outer surface of the pulley <NUM>. This means that the pulley <NUM> is not capable of undergoing any substantial movement relative to the bridge structure <NUM>, other than the rotation about its central axis <NUM>'. The first pulley <NUM> is mounted in the same way relative to the bridge structure's first portion 30a. As illustrated in <FIG>, the central rotation axes <NUM>' and <NUM>' of the pulleys <NUM> and <NUM> are thereby kept parallel one relative to the other, by the bridge structure <NUM>. At the same time, because of the presence of the universal joints <NUM> and <NUM>, the central rotation axes <NUM>' and <NUM>' of the pulleys <NUM> and <NUM> are allowed to become misaligned with respect to the respective rotation axes <NUM>' and <NUM>' of the first and second axles <NUM> and <NUM>. <FIG> respectively show the belt drive <NUM> in a position where said rotation axes are aligned and non-aligned.

The extendable bridge structure <NUM> together with the universal joints <NUM> and <NUM> has the effect of maintaining the two pulleys <NUM> and <NUM> aligned in the same plane, regardless of the position of the cradle frame <NUM>. In this way, the belt transmission <NUM> remains operational under optimal conditions in terms of the loads exhibited on the belt <NUM>, when the cradle frame <NUM> is tilted back and forth and/or sideways with respect to the feeder housing <NUM>. The bridge structure <NUM> as a whole may become tilted and may extend and retract as a function of the cradle frame movement, but the pulleys <NUM> and <NUM> remain in the same plane relative to each other and relative to the bridge structure <NUM>.

According to the preferred embodiment shown in <FIG>, the bridge structure <NUM> furthermore comprises springs <NUM> mounted between the two portions 30a and 30b. The springs <NUM> are mounted so as to act as compression springs, pushing the bridge portions 30a and 30b away from each other regardless of the relative position of these bridge portions 30a and 30b. At the same time, the spring force exerted by the springs <NUM> is insufficient to obstruct - within a given range - the relative movement of the bridge portions 30a and 30b actuated by the movement of the cradle frame <NUM>. The fact that the springs <NUM> push the bridge portions away from each other counteracts forces acting on the universal joints <NUM> and <NUM> and oriented transversally with respect to the axles <NUM> and <NUM>, as a consequence of the belt tension, and thereby increases the mechanical stability of the belt drive <NUM>. The bridge structure <NUM> can however also be implemented without the springs <NUM>.

The length of the belt <NUM> is configured in conjunction with an appropriate belt tensioning system, so that sufficient belt tension is applied for realizing the transmission of the rotation of the first axle <NUM> to the second axle <NUM>, regardless of whether the bridge portions 30a and 30b are closer together or further apart, within a given operational range of the relative position of these bridge portions. In the embodiment represented in the drawings, a double tension roller assembly is provided comprising an upper and a lower tension roller <NUM> and <NUM>. The assembly further comprises a bracket <NUM> that is pivotable relative to the bridge structure <NUM>, about a pivot <NUM> oriented essentially perpendicularly to the bridge structure <NUM>, and located on the first bridge portion 30a. The tension rollers <NUM> and <NUM> are rotatably mounted at the outer ends of the bracket <NUM>. The bracket <NUM> is furthermore provided with a transversally oriented lever arm <NUM> that is coupled at its end to the second portion 30b of the bridge structure <NUM> through the compression spring <NUM>. This latter compression spring <NUM> thus pushes the tension rollers <NUM> and <NUM> against the belt in respective upper and lower contact areas <NUM>' and <NUM>' (see <FIG>).

The tensioning system may be equipped with a single tensioning roller instead of two tensioning rollers. In the embodiment shown in the drawings, at least the tensioning roller <NUM> at the top is required as the bracket <NUM> is oriented optimally for exerting tension to the belt when the belt drive is working in the forward operational direction indicated by the arrow in <FIG>, which is the normal operational direction of the belt drive during a harvesting run. A particular feature of the invention is the fact that the distance between the pulleys <NUM> and <NUM> is variable, due to the extraction and extension of the bridge structure <NUM>. When this distance becomes smaller, the length of the belt increases relatively to said distance and the tensioning system must be able to maintain a minimum required belt tension. The second tensioning roller <NUM> increases the overall belt displacement at the lower side of the belt drive, allowing it to compensate more of the excess belt length caused by the pulleys moving toward each other. The second roller <NUM> is thereby advantageous in maintaining a sufficient belt tension regardless of the relative position of the pulleys one with respect to the other. In addition, in the embodiment shown in the drawings, the orientation of the bracket <NUM> is such that the second roller <NUM> provides an optimal tensioning force when the belt drive operates in the reverse direction (see further).

It is particularly advantageous that the pivot <NUM> is located on one bridge portion 30a while the end point of the compression spring <NUM> is located on the other bridge portion 30b. In this way, the orientation of the spring <NUM> and the bracket <NUM>, as well as the spring force exerted by the spring <NUM>, are changing as a function of the relative position of the bridge portions 30a and 30b. Combined with an appropriately selected length and material of the belt <NUM> and appropriately designed dimensions of the bracket <NUM> and its lever arm <NUM>, this allows to adjust the belt tension to an optimal value as the length of the bridge structure <NUM> extends or retracts. The tensioning system thereby acquires a self-regulating capacity. The invention is however not limited to the belt tensioning system shown in the drawings. For example, the pivot <NUM> and the point at which the compression spring <NUM> is attached to the bridge structure may be located on the same portion 30a or 30b of the bridge structure. In this case, the tensioning force applied by the rollers <NUM> and <NUM> on the belt is not or to a lesser degree dependent on the relative position of the bridge portions 30a and 30b. Other alternative tensioning systems may be equipped with a hydraulic or pneumatic piston instead of the compression spring <NUM>.

As stated above, the presence of the two tension rollers <NUM> and <NUM> is useful for realizing optimal belt tension in both the forward and reverse rotational direction of the belt drive. Reversing the direction of rotation can be realized by constructing the driveline so that the rotation of the first axle <NUM> is reversible. Another way in which the reversibility may be realized is illustrated in the drawings and best visible in <FIG> and <FIG>. A hydraulic motor <NUM> is mounted on the second bridge portion 30b. The hydraulic motor drives a small gear <NUM> that drives the rotation of a larger internal gear <NUM> fixed to the pulley <NUM>, in the direction opposite the normal rotational direction of the pulley when it is driven by the first axle <NUM>. The motor <NUM> may be configured so that the small gear extends axially when the hydraulic motor is turned on and retracts when the motor is turned off. Alternatively, a clutch mechanism may be used for decoupling the hydraulic motor <NUM> from the small gear <NUM> when the belt drive is operating in the normal rotational direction.

According to an alternative embodiment, the hydraulic motor <NUM> is mounted on the cradle frame <NUM> and said motor is then configured to drive the inverse rotation of the second axle <NUM>, by a suitable gear coupling between the small gear <NUM> driven by the hydraulic motor <NUM> and a larger gear fixed to the axle <NUM>.

When the motor <NUM> reverses the direction of rotation of the belt drive <NUM>, the complete driveline upstream of the belt drive <NUM> is reversed also, which may be allowable. However, any embodiment that includes the hydraulic motor <NUM> mounted in connection with the second axle <NUM> and the second pulley <NUM> may include a means for decoupling the first axle from the driveline of the harvester, when the belt drive is driven in the reverse direction.

Instead of the universal joints <NUM> and <NUM>, the belt drive <NUM> could be equipped with homokinetic couplings, or if the misalignment between the axles <NUM> and <NUM> and the pulleys <NUM> and <NUM> is not too high, crowned spline couplings could be used. Various types of homokinetic couplings are well known, and include double cardan joints.

As seen in <FIG>, and in more detail in <FIG>, an additional connection <NUM> may be present between the bridge structure <NUM> and the feeder housing <NUM>, and placed in close proximity to the first pulley <NUM>. This connection is aimed at limiting the free rotation of the belt drive <NUM> as a whole about its own longitudinal axis. This degree of freedom is a consequence of the presence of the two universal joints <NUM> and <NUM>. The connection <NUM> comprises an L-shaped rod <NUM>, that is coupled to a support block <NUM> fixed to the bridge structure <NUM>, for example welded to and mounted in between the tubes <NUM>. The horizontal portion of the L-shaped rod <NUM> is rotatable relative to the support block <NUM>. The support block <NUM> and the horizontal portion of the L-shaped rod <NUM> are movable relative to each other in the axial direction of said horizontal portion, wherein this axial movement is limited between the bend of the L-shaped rod and a blocking bolt <NUM> at the outer end of the L-shaped rod. The vertical portion of the L-shaped rod is capable of moving up and down and of rotating in any direction (preferably by a ball joint) relative to a bracket <NUM> fixed to the side of the feeder housing <NUM>. In this way, the bridge structure <NUM> is capable of undergoing any displacement relative to the feeder housing <NUM> actuated by the tilting movements of the header, while the rotation of the bridge structure <NUM> about its own longitudinal axis is limited to a predefined range. The connection <NUM> is preferably placed as close as possible to the first pulley <NUM>, as the movements of the bridge structure <NUM> actuated by the header movements are smaller in this area. However, the connection <NUM> could placed on the side of the second pulley <NUM>.

The connection <NUM> may be omitted, in which case a limited free rotation of the bridge structure <NUM> about its longitudinal axis is allowed, which will however necessarily be limited by a number of constructional constraints determined for example by the dimensions of the belt drive <NUM> and its spatial relation to the cradle frame <NUM> and the feeder housing <NUM>, or by the characteristics of the joints <NUM> and <NUM>. According to a number of embodiments, these constraints are sufficient to limit the free rotation of the bridge structure, and in those cases the connection <NUM> is not required.

<FIG> and <FIG> illustrate two alternative structures of the belt drive <NUM>, having however the same functionality as the embodiment described above. <FIG> shows a first alternative. <FIG> show section views of the first axle <NUM> and the first pulley <NUM> at the feeder side. <FIG> shows a section view of the second axle <NUM> and the second pulley <NUM> at the side of the cradle frame. The belt <NUM> is visible in all the views. Referring first to <FIG>, the first pulley <NUM> is mounted at the end of the axle <NUM> via a spherical bearing <NUM> that allows a misalignment of the pulley <NUM> relative to the axle <NUM>. A disc <NUM> is fixed to the axle <NUM>, for example through a spline connection, so that the disc <NUM> rotates together with the axle <NUM>. The disc <NUM> is provided with <NUM> guiding members in the form of rods <NUM> extending outward from the surface of the disc in the direction of the pulley <NUM>. The rods <NUM> are fixed to, for example welded to the disc <NUM>, and oriented parallel to the axle <NUM>. The rods <NUM> are preferably placed along two orthogonal lines X and Y as shown in the drawing. However, the number of guiding members, their exact shape and their position may be different from the embodiment shown. What is important is that the guiding members <NUM> are able to interact with elongated radial openings <NUM> provided in the pulley <NUM>, into which openings the guiding members <NUM> are inserted so as to transfer the rotation of the axle to the rotation of the pulley <NUM>, while a misalignement between the axle <NUM> and the pulley <NUM> is allowed via the spherical bearing <NUM>. In the embodiment shown, the openings have the form of <NUM> radially oriented slots <NUM>, placed at angular positions which correspond to the positions of the rods <NUM>, so that the rods <NUM> are inserted into the slots <NUM>. The rods <NUM> are thereby movable relative to the slots <NUM> in the longitudinal direction thereof. The diameter of the rods <NUM> is dimensioned relative to the width of the slots <NUM> so that the rods <NUM> may move easily up and down in the slots <NUM>. A limited lateral play between the rods <NUM> and the slots <NUM> is allowable. However in the embodiment shown, virtually no lateral movement of the rods <NUM> relative to the slots <NUM> is possible. In this case, suitable materials may be chosen, which allow sliding of the rods relative to the slots, possibly aided by a suitable lubricant or coating. Through the interaction between the rods and the slots, the disc <NUM> transfers the rotation of the axle <NUM> to a rotation of the pulley <NUM>, whilst allowing a misalignment between the axle <NUM> and the pulley <NUM>. In this way, this construction is equivalent to the function of the universal joint <NUM> in the first embodiment.

As seen in <FIG>, the second pulley <NUM> is coupled to the second axle <NUM> in the same manner as described above for the first axle and the first pulley, i.e. by a spherical bearing <NUM>, a disc <NUM> fixed to the second axle <NUM> and provided with rods <NUM> which are slideably inserted into radial slots <NUM> in the second pulley <NUM>.

The bridge structure <NUM> in this embodiment is located to one side of the pulleys <NUM> and <NUM>. <FIG> respectively show the first and second portions 30a and 30b of the bridge structure, each comprising a ring <NUM>. The pulleys <NUM> and <NUM> are rotatable relative to this ring <NUM> via ball bearings <NUM>. The bodies of the bridge portions 30a and 30b are depicted as beam elements which are translatable in a suitable manner relative to each other in the longitudinal direction of the bridge structure. The second bridge portion 30b could for example be a frame that is translatable relative to the beam element 30a through rollers, as suggested earlier in this description.

On both sides of the belt drive <NUM>, i.e. at the side of the first pulley <NUM> and at the side of the second pulley <NUM>, the central plane <NUM> of the belt <NUM> is preferably lying close to or coinciding with the central planes of the spherical bearing <NUM> and of the ball bearings <NUM>, so that a minimum of tilting forces are generated in the coupling. An optional compression spring <NUM> may be mounted between the first pulley <NUM> and the first disc <NUM>. If present, this compression spring limits the rotation of the bridge structure <NUM> about its own longitudinal axis, and thereby has the same effect as the connection <NUM> shown in <FIG>. The compression spring <NUM> may therefore replace this connection <NUM> in the embodiment of <FIG>. The compression spring <NUM> is preferably placed at the feeder side, as shown in the drawings, but according to another embodiment, the spring <NUM> may be placed at the cradle frame side, i.e. between the second pulley and the disc <NUM> at this side. Or compression springs may be placed both at the feeder side and at the cradle frame side.

Compared to the version with universal joints <NUM> and <NUM>, the embodiment of <FIG> provides a higher resistance, of the coupling between the pulleys and the axles, to forces acting perpendiculary on these axles. This is because the torque transfer of the axle <NUM> towards the pulley <NUM> (at the feeder side) or vice versa (at the cradle frame side) is separated from the function of allowing a misalignment between the axles and pulleys on both sides. The torque transfer function is fulfilled by the rods <NUM>, while the misalignment function is fulfilled by the spherical bearings <NUM>.

Claim 1:
A combine harvester (<NUM>) comprising :
- a feeder (<NUM>) at the front of the harvester, the feeder (<NUM>) comprising a housing (<NUM>) and a cradle frame (<NUM>) mounted at the front of the feeder (<NUM>), wherein the cradle frame (<NUM>) is configured to receive a header (<NUM>) comprising a header drive axle oriented transversely to the forward direction of travel of the harvester (<NUM>) when the header (<NUM>) is coupled to the cradle frame (<NUM>), and wherein the cradle frame (<NUM>) is movable relative to the feeder housing (<NUM>),
- a driveline configured to drive the rotation of the header drive axle when the header (<NUM>) is coupled to the feeder (<NUM>),
wherein the driveline comprises a belt drive (<NUM>) arranged laterally with respect to the feeder housing (<NUM>), and configured to transmit the rotation of a first axle (<NUM>) of the driveline that is rotatable about a rotation axis (<NUM>') which is fixed relative to the feeder housing (<NUM>), to the rotation of a second axle (<NUM>) of the driveline, configured to be coupled to the header drive axle, the second axle (<NUM>) being rotatable about a rotation axis (<NUM>') that is fixed relative to the cradle frame (<NUM>),
wherein the belt drive (<NUM>) comprises a first pulley (<NUM>) coupled to the first axle (<NUM>), a second pulley (<NUM>) coupled to the second axle (<NUM>), a belt (<NUM>) mounted on the first and second pulley and a tensioning system for the belt,
characterized in that :
- the first pulley (<NUM>) is coupled to the first axle (<NUM>) through a first coupling (<NUM>,<NUM>) that allows a misalignment between the rotation axis (<NUM>') of the first axle (<NUM>) and the rotation axis (<NUM>') of the first pulley (<NUM>),
- the second pulley (<NUM>) is coupled to the second axle (<NUM>) through a second coupling (<NUM>,<NUM>) that allows a misalignment between the rotation axis (<NUM>') of the second axle and the rotation axis (<NUM>') of the second pulley (<NUM>), and
- said belt drive (<NUM>) further comprises an extendable bridge structure (<NUM>) mounted between the first and second pulley (<NUM>,<NUM>), wherein the pulleys (<NUM>,<NUM>) are configured to rotate relative to the bridge structure (<NUM>) and wherein the bridge structure (<NUM>) is extendable and retractable in the longitudinal direction of the belt drive (<NUM>), so that the pulleys (<NUM>,<NUM>) remain essentially aligned in the same plane, regardless of the position of the cradle frame (<NUM>).