Abstract:
A header support for supporting a header during road transport of an agricultural harvester. The header support has a header mounted to it in order to reduce a front axle load of the agricultural harvester. During harvesting, a support wheel of the header support is folded upwardly so it does not touch the ground during harvesting. The rotation axis of the support wheel extends in a substantially vertical plane during harvesting. This allows for a simple construction of the header support and reduces the vibration loads on the bearing of the support wheel during harvesting.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims priority to Belgium Application No. 2016/5462 filed Jun. 23, 2016, the contents of which are incorporated herein by reference. 
       FIELD OF THE INVENTION 
       [0002]    The invention pertains to a harvester header support for supporting a header of an agricultural harvester during road transport, and to a combination of an agricultural harvester with such a harvester header support. 
       BACKGROUND OF THE INVENTION 
       [0003]    Modern agricultural harvesters, such as combine harvesters and forage harvesters, are heavy pieces of machinery, which in many cases have to travel over public roads from one field to another. In many countries regulations exist that prescribe a maximum axle load for vehicles travelling on public roads. The current developments in agricultural harvesters lead to an increase of the axle loads of these harvesters. In particular when a header is attached to the agricultural harvester during road transport, the front axle load can reach levels which are close to or even above the maximum allowable axle load for public roads. 
         [0004]    It is known from the prior art to provide one or more support wheels on the front parts of the agricultural harvester. These support wheels are generally connected to the header or to the feeder of the agricultural harvester. 
         [0005]    It is known to use support wheels that are in contact with the ground during road transport as well as during the harvesting operation on the field, and alternatively, to use support wheels that are in contact with the ground during road transport or during the harvesting operation on the field. 
         [0006]    Generally, it is disadvantageous if the support wheels contact the ground during harvesting, so when the agricultural harvester is driven over the field. Support wheels that contact the ground during harvesting have to be rather large in order to avoid undesired compacting of the ground and the undesired formation of ruts in the field, which is impractical and expensive. 
         [0007]    If the support wheels are designed to be in contact with the ground during either road transport or during harvesting (when the harvester is driven over the field), provisions have to be made to avoid ground contact of the support wheels when such ground contact is not desired. 
         [0008]    EP1046329 discloses to remove the support wheels entirely when the harvester is made ready for harvesting, and to mount the support wheels again when the harvester is made ready for driving on the road. 
         [0009]    WO2010/130745 discloses a harvester which requires the use of support wheels during harvesting, but not during road transport. In this harvester, the support wheels are mounted on a frame which is pivoted inwards, i.e. towards the center line of the harvester parallel to the driving direction of the harvester, when the harvester is made ready for road transport. In this road transport mode, the axis of the support wheels extends substantially parallel to the main driving direction of the harvester, in a substantially horizontal plane. The main driving direction of the harvester is straight ahead. 
         [0010]    Removing the support wheels after use and mounting them when they are needed again is highly impractical and labor-intensive. There is limited space available for a frame in the vicinity of the header and/or feeder, and a complex movement may be required to transfer the support wheels from their position during road transport to their position during field operation and/or vice versa. In addition, the bearings of the support wheels may be susceptible of damage caused by vibrations when the support wheels are not in contact with the ground. 
       SUMMARY OF THE INVENTION 
       [0011]    It is the object of the invention to provide an improved harvester header support. 
         [0012]    According to the invention, this object is achieved with a harvester header support for supporting a header of an agricultural harvester during road transport, which harvester header support comprises: 
         [0013]    a frame, which frame comprises: 
         [0014]    a harvester interface, which is connectable to an agricultural harvester, 
         [0015]    a first arm, which arm is pivotably connected to the harvester interface, 
         [0016]    a first support wheel which comprises a first rotation axis and a tread, which first support wheel is rotatable around the first rotation axis, 
         [0017]    a first wheel connector, which is adapted to connect the first support wheel to the first arm of the frame, while allowing the first support wheel to rotate about the first rotation axis, 
         [0018]    an arm drive, which is adapted to pivot the first arm relative to the harvester interface, in which the harvester header support has a road transport mode and a field operation mode and the arm drive is adapted to transfer the harvester header support from the road transport mode into the field operation mode and/or vice versa, 
         [0019]    in which road transport mode the first support wheel is in a road transport position which allows the first support wheel to bear at least a part of the weight of the header, and in which road transport position the first rotation axis of the first support wheel extends in a substantially horizontal plane, and 
         [0020]    wherein in the field operation mode, the first support wheel is in a field operation position in which the first support wheel is free from the weight of the header and in which field operation position the first rotation axis of the first support wheel extends in a substantially vertical plane. 
         [0021]    In accordance with the invention, the harvester header support comprises a frame which comprises a harvester interface and a first arm. The harvester interface is connectable to an agricultural harvester. The first arm is pivotably connected to the harvester interface. Optionally, the harvester is adapted to be connected to a feeder and/or to a header of an agricultural harvester. 
         [0022]    The harvester header support further comprises a first support wheel. The first support wheel is rotatable about a first rotation axis. The first support wheel comprises a tread, which is adapted to engage the ground when the first support wheel is used during road transport. The frame is adapted to connect the first support wheel to the agricultural harvester. 
         [0023]    The harvester header support further comprises a first wheel connector, which is adapted to connect the first support wheel to the first arm of the frame. The first wheel connector allows the first support wheel to rotate about the first rotation axis. For example, the first wheel connector comprises a first shaft with a bearing, which bearing has an inner ring which is fixed to the shaft and an outer ring which is fixed in a central opening of the first support wheel. Alternatively, the first support wheel comprises a shaft which is fixed at the center of the support wheel, and the first wheel support comprises at least one bearing but preferably two bearings. Each bearing has an inner ring and an outer ring. The inner ring of is fixed to the shaft of the first support wheel. 
         [0024]    The harvester header support further comprises an arm drive, which is adapted to pivot the first arm relative to the harvester interface. 
         [0025]    The harvester header support has a road transport mode and a field operation mode. The arm drive is adapted to transfer the harvester header support from the road transport mode into the field operation mode and/or vice versa. Optionally, this involves moving, e.g. pivoting, the first arm of the frame relative to the harvester interface. In a possible embodiment, the arm drive is adapted to transfer the harvester header support from the road transport mode into the field operation mode as well as from the field operation mode into the road transport mode. Alternatively, one of these transfers is effected partly or entirely by gravity. 
         [0026]    In the road transport mode, the first support wheel is in a road transport position. The road transport position allows the first support wheel to bear at least a part of the weight of the header. The reduces the front axle load of the agricultural harvester. In the road transport position, the tread of the first support wheel will usually engage the ground. In the road transport mode, the first rotation axis of the first support wheel extends in a substantially horizontal plane. 
         [0027]    In the field operation mode, the first support wheel is in a field operation position in which the first support wheel is free from the weight of the header and in which field operation position the first rotation axis of the first support wheel extends in a substantially vertical plane. 
         [0028]    So, when the harvester header support is transferred from the road transport mode to the field operation mode or vice versa, the first support wheel is tilted about a tilt axis which extends in horizontal direction, substantially parallel to the main driving direction of the agricultural harvester—the main driving direction of the agricultural harvester being straight ahead. An advantage of this arrangement is that the frame can be kept very simple and robust. A single pivot in the frame per support wheel suffices to allow the harvester header support to be transferred from the road transport mode to the field operation mode or vice versa. This also makes it possible to keep the arm drive simple and cheap. 
         [0029]    Furthermore, in accordance with the invention, the first support wheel is arranged such that the first rotation axis is arranged in a substantially vertical plane when the harvester header support is in the field operation mode. In the field operation mode, the first support wheel is free from the weight of the header, and usually, it will not be in contact with the ground. As a consequence, the first support wheel has to bear hardly any weight, so the bearing or bearings of the first support wheel and/or the first wheel connector that make possible the rotation of the first support wheel about the first rotation axis are not under tension and any roller bodies in them can move within the bearing clearance. 
         [0030]    During harvesting, the agricultural harvester is driven over a field, e.g. a corn field or a wheat field, and the uneven terrain of the field causes vibrations in vertical direction. With the harvester header support mounted onto an agricultural harvester, these vibrations are transferred to the first support wheel as well. With the first rotation axis extending in a substantially vertical plane, this vertical vibration load is shared by all the roller bodies in the bearing, and not just borne by a few of them as would be the case if the wheel&#39;s rotation axis would be in a horizontal plane. Therewith, the arrangement with the first rotation axis extending in a substantially vertical plane when the harvester header support is in the field operation mode reduces the risk of runway pitting and runway indentation in the bearing or bearing of the first support wheel and/or the first wheel connector. In addition, this reduces the need for using pretensioned bearings for the first support wheel and/or first wheel connector, which reduces the costs of the harvester header support. 
         [0031]    The agricultural harvester can for example be a combine harvester or a forage harvester. 
         [0032]    In a possible embodiment, the first wheel connector is adapted to allow pivoting of the first support wheel about a pivot axis, which pivot axis in the road transport mode extends in a substantially vertical plane. This allows the first support wheel to follow steering movements on the road of the agricultural harvester to which the harvester header support is connected in use. This reduces the wear of the tread of the first support wheel, and if the tread is part of a tire, it reduces the wear of that tire. 
         [0033]    Optionally, the first wheel connector is adapted to allow pivoting of the first support wheel about the pivot axis over a pivot angle which is 10° or less, preferably 5° or less, optionally 3° or less. 
         [0034]    Optionally, the main driving direction extends along the bisector of the pivot angle. So, if the pivot angle is for example 10°, the first support wheel can pivot over 5° to the left and over 5° to the right relative to the main driving direction. 
         [0035]    If the road transport position of the first support wheel of the harvester header support when used on an agricultural harvester is close to the front wheel or front track of the agricultural harvester, this is sufficient to follow the steering movements of the agricultural harvester. This embodiment allows a simple and robust construction. 
         [0036]    In a possible embodiment, the arm drive comprises a hydraulic assembly, which hydraulic assembly comprises a hydraulic cylinder and a fluid line system for feeding hydraulic fluid to the hydraulic cylinder and receiving hydraulic fluid from the hydraulic cylinder. The fluid line system  32  optionally comprises a plurality of fluid lines. The fluid line system comprises a hydraulic connector, which hydraulic connector is adapted to connect the fluid line system to a hydraulic system of the agricultural harvester. 
         [0037]    An agricultural harvester typically has an hydraulic system on board. In this embodiment, the hydraulic system of the agricultural harvester can be used to operate the arm drive of the harvester header support. This way, the need for physical handling of the harvester header support, in particular of the first support wheel thereof, by the driver or operator of the agricultural harvester is reduced or even eliminated. 
         [0038]    In a possible embodiment, the frame further comprises a second arm, which is pivotably connected to the harvester interface. In this embodiment, the harvester header support further comprises: 
         [0039]    a second support wheel, which comprises a second rotation axis and a tread, which second support wheel is rotatable around the second rotation axis, 
         [0040]    a second wheel connector, which is adapted to connect the second support wheel to the second arm of the frame, while allowing the second support wheel to rotate about the second rotation axis, and 
         [0041]    in which road transport mode the second support wheel is in a road transport position which allows the second support wheel to bear at least a part of the weight of the header, and in which road transport position the second rotation axis of the second support wheel extends in a substantially horizontal plane, and 
         [0042]    wherein in field operation mode, the second support wheel is in a field operation position in which the second support wheel is free from the weight of the header and the second rotation axis of the second support wheel extends in a substantially vertical plane. 
         [0043]    In this embodiment, the harvester header support comprises two support wheels, which in use for example can be arranged on opposite sides of a header or feeder of an agricultural harvester. 
         [0044]    Optionally, the second wheel connector is adapted to allow pivoting of the second support wheel about a pivot axis, which pivot axis in the road transport mode extends in a substantially vertical plane. This allows the second support wheel to follow steering movements on the road of the agricultural harvester to which the harvester header support is connected in use. Optionally, the second wheel connector is adapted to allow pivoting of the second support wheel about the pivot axis over a pivot angle which is 10° or less, preferably 5° or less, optionally 3° or less. 
         [0045]    Optionally, in the road transport position the distance between the first support wheel and the second support wheel is 3.5 meters maximum. 
         [0046]    Optionally, in the field operation position, the distance between the first support wheel and the second support wheel is larger than the distance between the first support wheel and the second support wheel in the road transport mode. 
         [0047]    Optionally, in the road transport position the distance between the first support wheel and the second support wheel is 3.5 meters maximum and in the field operation position, the distance between the first support wheel and the second support wheel is larger than the distance between the first support wheel and the second support wheel in the road transport mode. 
         [0048]    The invention further pertains to a combination of an agricultural harvester and a harvester header support according to the invention. The agricultural harvester has a front wheel or front track, and the harvester header support is connected to the agricultural harvester. In the road transport mode, the first support wheel is arranged in front of the front wheel or front track of the agricultural harvester. The indication “front” is regarded in the main driving direction of the agricultural harvester, which main driving direction is straight ahead. 
         [0049]    Optionally, the agricultural harvester has a feeder, and the harvester header support is connected to the feeder. 
         [0050]    Optionally, the agricultural harvester has a header, and the harvester header support is connected to the header. 
         [0051]    The agricultural harvester can for example be a combine harvester or a forage harvester. 
         [0052]    In a possible embodiment of the a combination of an agricultural harvester and a harvester header support according to the invention, the agricultural harvester comprises a hydraulic system, and the arm drive of the harvester header support comprises a hydraulic assembly. The hydraulic assembly of the arm drive comprises a hydraulic cylinder and a fluid line system for feeding hydraulic fluid to the cylinder and receiving hydraulic fluid from the hydraulic cylinder. The fluid line system comprises a hydraulic connector, which hydraulic connector is connected to the hydraulic system of the agricultural harvester. 
         [0053]    An agricultural harvester typically has an hydraulic system on board. In this embodiment, the hydraulic system of the agricultural harvester can be used to operate the arm drive of the harvester header support. This way, the need for physical handling of the harvester header support, in particular of the first support wheel thereof, by the driver or operator of the agricultural harvester is reduced or even eliminated. 
         [0054]    Optionally, the agricultural harvester comprises a foldable header. The foldable header has an unfolded mode in which the foldable header is adapted to be operated for harvesting crop and a folded mode in which the foldable header is adapted for road transport. The foldable header comprises a folding device for bringing the foldable header from the folded mode into the unfolded mode and/or vice versa. The hydraulic system of the agricultural harvester comprises a header folding control valve which is adapted to actuate the folding device. In this variant, the hydraulic connector is connected to the hydraulic system of the agricultural harvester at a location between the header folding control valve and the folding device. 
         [0055]    This arrangement allows to use the header folding control valve to operate not only the folding and/or unfolding of the foldable header, but also to transfer the harvester header support from road transportation mode to field operation mode and/or vice versa. This way, no additional valve has to be provided to transfer the harvester header support from road transportation mode to field operation mode and/or vice versa. This arrangement furthermore allows to simultaneously bring the foldable header in the folded mode and to transfer the harvester header support from field operation mode to road transportation mode when the agricultural harvester is prepared for driving on the road. Likewise, this arrangement allows to simultaneously bring the foldable header in the unfolded mode and to transfer the harvester header support from road transportation mode to field operation mode when the agricultural harvester is prepared for harvesting. 
         [0056]    In a possible embodiment of the a combination of an agricultural harvester and a harvester header support according to the invention, the combination further comprises a second header harvester support according the invention. So, this case, two separate harvester header supports are provided, each having their own frame including their own harvester interface. 
         [0057]    Optionally, the first support wheel of the first header harvester support is located on the right side of the agricultural harvester and the first support wheel of the second header harvester support is located on the left side of the agricultural harvester. 
         [0058]    Optionally, both the first support wheel and the second support wheel arranged in front of the front wheel or front track of the agricultural harvester. 
         [0059]    In a possible embodiment of the a combination of an agricultural harvester and a harvester header support according to the invention, the frame of the harvester header support further comprises a second arm, which is pivotably connected to the harvester interface. In this embodiment, the harvester header support further comprises 
         [0060]    a second support wheel, which comprises a second rotation axis and a tread, which second support wheel is rotatable around the second rotation axis, 
         [0061]    a second wheel connector, which is adapted to connect the second support wheel to the second arm of the frame, while allowing the second support wheel to rotate about the second rotation axis, and 
         [0062]    in which road transport mode the second support wheel is in a road transport position which allows the second support wheel to bear at least a part of the weight of the header, and in which road transport position the second rotation axis of the second support wheel extends in a substantially horizontal plane, and 
         [0063]    wherein in field operation mode, the second support wheel is in a field operation position in which the second support wheel is free from the weight of the header and the second rotation axis of the second support wheel extends in a substantially vertical plane. 
         [0064]    So, this case, a single separate harvester header support is provided, with a single harvester interface, but with two arms. On each arm, a separate support wheel is mounted by a separate wheel connector. 
         [0065]    Optionally, the first support wheel is located on the right side of the agricultural harvester and the second support wheel is located on the left side of the agricultural harvester. 
         [0066]    Optionally, both the first support wheel and the second support wheel arranged in front of the front wheel or front track of the agricultural harvester. 
         [0067]    The invention further pertains to a combination of a foldable harvester header and a harvester header support according to the invention. 
         [0068]    Optionally, in this combination the foldable header has an unfolded mode in which the foldable header is adapted to be operated for harvesting crop and a folded mode in which the foldable header is adapted for road transport. The foldable header comprises a folding device for bringing the foldable header from the folded mode into the unfolded mode and vice versa, and a hydraulic actuator system for operating the folding device. The hydraulic actuator system comprises a header folding control valve which is adapted to actuate the folding device. In this variant, the arm drive of the harvester header support comprises a hydraulic assembly. This hydraulic assembly comprises a hydraulic cylinder and a fluid line system for feeding hydraulic fluid to the cylinder and receiving hydraulic fluid from the hydraulic cylinder. The fluid line system comprises a hydraulic connector. The hydraulic connector of the harvester header support is connected to the hydraulic actuating system at a location between the header folding control valve and the folding device. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0069]    The invention will be described in more detail below under reference to the drawing, in which in a non-limiting manner exemplary embodiments of the invention will be shown. 
           [0070]    The drawing in: 
           [0071]      FIG. 1 : illustrates an example of an agricultural harvester which can be used with a harvester header support according to the invention, in side view, 
           [0072]      FIG. 2 : illustrates an example of a combination of an agricultural harvester with a harvester header support according to the invention, in side view, in road transport mode, 
           [0073]      FIG. 3 : illustrates the combination of an agricultural harvester with a harvester header support of  FIG. 2 , in side view, in field operation mode, 
           [0074]      FIG. 4 : illustrates a first embodiment of a harvester header support according to the invention, in road transportation mode, in front view, 
           [0075]      FIG. 5 : illustrates a second embodiment of a harvester header support according to the invention, in road transportation mode, in front view, 
           [0076]      FIG. 6 : illustrates the embodiment of  FIG. 5 , in field operation mode, in front view, 
           [0077]      FIG. 7 : illustrates an embodiment of a combination of a harvester header support with an agricultural harvester which comprises a foldable header, in top view. 
           [0078]      FIG. 1  illustrates an example of an agricultural harvester  1  which can be used with a harvester header support according to the invention, in side view. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0079]    In this example, the agricultural harvester  1  is a combine harvester. The agricultural harvester  1  comprises a header  3 , which is adapted to cut crop from the field. The agricultural harvester  1  further comprises a feeder  2 , which is adapted to receive crop from the header  3  and to transport the crop further into the agricultural harvester  1 . In the agricultural harvester  1 , the crop is optionally processed, e.g. cut into smaller pieces and/or threshed. 
         [0080]    The agricultural harvester  1  further comprises two front wheels  4 , one of which is shown in  FIG. 1 . In an alternative embodiment, the agricultural harvester may comprise a two front tracks instead of the front wheels  4 . 
         [0081]    The agricultural harvester  1  is adapted to be driven over the ground  100 . The ground  100  may for example be a road or a field. The agricultural harvester  1  has a main direction of driving D, which is straight ahead. 
         [0082]      FIG. 1  shows the combine harvester in field operation mode, so with the header  3  just above the ground  100 . In this position, the header  3  can be used to cut crop from the field. 
         [0083]      FIG. 2  illustrates an example of a combination of an agricultural harvester  1  with a harvester header support  20  according to the invention, in side view, in road transport mode. 
         [0084]    In the embodiment of  FIG. 2 , in road transport mode the header  3  is lifted above the ground  100  by tilting the feeder  2  upwardly relative to the position of the feeder  2  shown in  FIG. 1 . 
         [0085]    In the embodiment of  FIG. 2 , the harvester header support  20  is connected to the feeder  2 . The harvester header support  20  comprises a frame  21  which comprises a harvester interface  22  and a first arm  23 . The first arm  23  is pivotably connected to the harvester interface  22 . 
         [0086]    The harvester header support  20  further comprises a first support wheel  25 . The first support wheel  25  is rotatable about a first rotation axis. The first rotation axis is in this embodiment parallel to the plane of the ground, directed perpendicular to the plane of the drawing. The first support wheel  25  comprises a tread  26 , which is adapted to engage the ground  100  when the first support wheel  25  is used during road transport. The frame  21  is adapted to connect the first support wheel  25  to the agricultural harvester  1 . 
         [0087]    The harvester header support  20  further comprises a first wheel connector  24 , which is adapted to connect the first support wheel  25  to the first arm  23  of the frame  21 . The first wheel connector  24  allows the first support wheel  25  to rotate about the first rotation axis. 
         [0088]    The harvester header support further comprises an arm drive  30 , which is adapted to pivot the first arm  23  relative to the harvester interface  22 . The arm drive  30  is adapted to transfer the harvester header support  20  from the road transport mode into the field operation mode and/or vice versa. Optionally, this involves moving, e.g. pivoting, the first arm  23  of the frame  21  relative to the harvester interface  22 . In a possible embodiment, the arm drive  30  is adapted to transfer the harvester header support from the road transport mode into the field operation mode as well as from the field operation mode into the road transport mode. Alternatively, one of these transfers is effected partly or entirely by gravity. 
         [0089]    In the road transport mode, the first support wheel  25  is in a road transport position. The road transport position allows the first support wheel  25  to bear at least a part of the weight of the header  3 . In the road transport position, the tread  26  of the first support wheel  25  will usually engage the ground  100 . In the road transport mode, the first rotation axis of the first support  25  wheel extends in a substantially horizontal plane.  FIG. 2  shows the first support wheel  25  in the road transport position. 
         [0090]      FIG. 3  illustrates the combination of an agricultural harvester  1  with a harvester header support  20  of  FIG. 2 , in side view, in field operation mode. 
         [0091]    In field operation mode, the first support wheel  25  is in a field operation position in which the first support wheel is free from the weight of the header  3 . In the field operation position, the first rotation axis  27  of the first support wheel  25  extends in a substantially vertical plane. 
         [0092]      FIG. 4  illustrates a first embodiment of a harvester header support according to the invention, in road transportation mode, in front view. 
         [0093]    In the embodiment of  FIG. 4  the harvester header support  20  is shown in a situation in which it is connected to a side wall of the feeder  2 . The harvester header support  20  comprises a frame  21  which comprises a harvester interface  22  and a first arm  23 . The first arm  23  is pivotably connected to the harvester interface  22  via pivot  28 . 
         [0094]    The harvester header support  20  further comprises a first support wheel  25 . The first support wheel  25  is rotatable about a first rotation axis  27 . The first support wheel  25  comprises a tread  26 , which is adapted to engage the ground  100  when the first support wheel  25  is used during road transport. The frame  21  is adapted to connect the first support wheel  25  to the agricultural harvester  1 . 
         [0095]    The harvester header support  20  further comprises a first wheel connector  24 , which is adapted to connect the first support wheel  25  to the first arm  23  of the frame  21 . The first wheel connector  24  allows the first support wheel  25  to rotate about the first rotation axis  27 . 
         [0096]    The harvester header support further comprises an arm drive  30 , which is adapted to pivot the first arm  23  relative to the harvester interface  22 . The arm drive  30  is adapted to transfer the harvester header support  20  from the road transport mode into the field operation mode and/or vice versa. Optionally, this involves moving, e.g. pivoting, the first arm  23  of the frame  21  relative to the harvester interface  22  via pivot  28 . In a possible embodiment, the arm drive  30  is adapted to transfer the harvester header support from the road transport mode into the field operation mode as well as from the field operation mode into the road transport mode. Alternatively, one of these transfers is effected partly or entirely by gravity. 
         [0097]    In the road transport mode, the first support wheel  25  is in a road transport position. The road transport position allows the first support wheel  25  to bear at least a part of the weight of the header  3 . In the road transport position, the tread  26  of the first support wheel  25  will usually engage the ground  100 . In the road transport mode, the first rotation axis of the first support  25  wheel extends in a substantially horizontal plane.  FIG. 4  shows the first support wheel  25  in the road transport position. 
         [0098]    In the embodiment of  FIG. 4 , the first wheel connector  24  is adapted to allow pivoting of the first support wheel  25  about a pivot axis  29 . In the road transport mode, which is shown in  FIG. 4 , the pivot axis extends in a substantially vertical plane. This allows the first support wheel  25  to follow steering movements on the road of the agricultural harvester to which the harvester header support is connected in use. 
         [0099]    Optionally, the first wheel connector  24  is adapted to allow pivoting of the first support wheel  25  about the pivot axis  29  over a pivot angle which is 10° or less, preferably 5° or less, optionally 3° or less. 
         [0100]    In the embodiment of  FIG. 4 , the arm drive  30  comprises a hydraulic assembly  35 . The hydraulic assembly  35  comprises a hydraulic cylinder  31  and a fluid line system  32  for feeding hydraulic fluid to the hydraulic cylinder  31  and receiving hydraulic fluid from the hydraulic cylinder  31 . The fluid line system  32  optionally comprises a plurality of fluid lines. The fluid line system  32  comprises a hydraulic connector  33  The hydraulic connector  33  is adapted to connect the fluid line system  32  to a hydraulic system  5  of the agricultural harvester, which is only schematically shown in  FIG. 4 . 
         [0101]    An agricultural harvester typically has an hydraulic system  5  on board. In this embodiment, the hydraulic system  5  of the agricultural harvester can be used to operate the arm drive  30  of the harvester header support  20 . 
         [0102]      FIG. 5  illustrates a second embodiment of a harvester header support  20  according to the invention, in road transportation mode, in front view. 
         [0103]    In the embodiment of  FIG. 5  the harvester header support  20  is shown in a situation in which it is connected to a top wall of the feeder  2 . The harvester header support  20  comprises a frame  21  which comprises a harvester interface  22  and a first arm  23 . The first arm  23  is pivotably connected to the harvester interface  22  via pivot  28 . 
         [0104]    The harvester header support  20  further comprises a first support wheel  25 . The first support wheel  25  is rotatable about a first rotation axis  27 . The first support wheel  25  comprises a tread  26 , which is adapted to engage the ground  100  when the first support wheel  25  is used during road transport. The frame  21  is adapted to connect the first support wheel  25  to the agricultural harvester  1 . 
         [0105]    The harvester header support  20  further comprises a first wheel connector  24 , which is adapted to connect the first support wheel  25  to the first arm  23  of the frame  21 . The first wheel connector  24  allows the first support wheel  25  to rotate about the first rotation axis  27 . 
         [0106]    The harvester header support further comprises an arm drive  30 , which is adapted to pivot the first arm  23  relative to the harvester interface  22 . The arm drive  30  is adapted to transfer the harvester header support  20  from the road transport mode into the field operation mode and/or vice versa. Optionally, this involves moving, e.g. pivoting, the first arm  23  of the frame  21  relative to the harvester interface  22  via pivot  28 . In a possible embodiment, the arm drive  30  is adapted to transfer the harvester header support from the road transport mode into the field operation mode as well as from the field operation mode into the road transport mode. Alternatively, one of these transfers is effected partly or entirely by gravity. 
         [0107]    In the road transport mode, the first support wheel  25  is in a road transport position. The road transport position allows the first support wheel  25  to bear a part of the weight of the header  3 . In the road transport position, the tread  26  of the first support wheel  25  will usually engage the ground  100 . In the road transport mode, the first rotation axis of the first support  25  wheel extends in a substantially horizontal plane.  FIG. 5  shows the first support wheel  25  in the road transport position. 
         [0108]    In the embodiment of  FIG. 5 , the frame  21  further comprises a second arm  43 , which is pivotably connected to the harvester interface  22 . 
         [0109]    In the embodiment of  FIG. 5 , the harvester header support  20  further comprises a second support wheel  45 . The second support wheel  45  comprises a second rotation axis  47  and a tread  46 . The second support wheel  45  is rotatable around the second rotation axis  47 . 
         [0110]    In the embodiment of  FIG. 5 , the harvester header support  20  further comprises a second wheel connector  44 . The second wheel connector  44  is adapted to connect the second support wheel  45  to the second arm  43  of the frame  21 , while allowing the second support wheel  45  to rotate about the second rotation axis  47 . 
         [0111]    In the road transport mode, the second support wheel  45  is in a road transport position which allows the second support wheel  45  to bear a part of the weight of the header. In the road transport position the second rotation axis  47  of the second support wheel  45  extends in a substantially horizontal plane.  FIG. 5  shows the second support wheel in the road transport position. In the road transport position, the tread  46  of the second support wheel  45  will usually engage the ground  100 . 
         [0112]    In the embodiment of  FIG. 5 , the first wheel connector  24  is adapted to allow pivoting of the first support wheel  25  about a pivot axis  29 . In the road transport mode, which is shown in  FIG. 5 , the pivot axis  29  extends in a substantially vertical plane. This allows the first support wheel  25  to follow steering movements on the road of the agricultural harvester to which the harvester header support  20  is connected in use. 
         [0113]    Optionally, the first wheel connector  24  is adapted to allow pivoting of the first support wheel  25  about the pivot axis  29  over a pivot angle which is 10° or less, preferably 5° or less, optionally 3° or less. 
         [0114]    Likewise, the second wheel connector  44  is adapted to allow pivoting of the second support wheel  45  about a pivot axis  49 . In the road transport mode, which is shown in  FIG. 5 , the pivot axis  49  extends in a substantially vertical plane. This allows the second support wheel  45  to follow steering movements on the road of the agricultural harvester to which the harvester header support  20  is connected in use. 
         [0115]    Optionally, the second wheel connector  44  is adapted to allow pivoting of the second support wheel  45  about the pivot axis  49  over a pivot angle which is 10° or less, preferably 5° or less, optionally 3° or less. 
         [0116]    In the embodiment of  FIG. 5 , the arm drive  30  comprises a hydraulic assembly  35 . The hydraulic assembly  35  comprises a first hydraulic cylinder  31 , a second hydraulic cylinder, a first fluid line system  32  for feeding hydraulic fluid to the first hydraulic cylinder  31  and receiving hydraulic fluid from the hydraulic cylinder  31 , and a second fluid line system  52  for feeding hydraulic fluid to the second hydraulic cylinder  51  and receiving hydraulic fluid from the second hydraulic cylinder  51 . The fluid line systems  32 ,  52  each optionally comprise a plurality of fluid lines. The first fluid line system  32  comprises a hydraulic connector  33 , and the second fluid line system  52  comprises a hydraulic connector  53 . The hydraulic connectors  33 ,  53  are adapted to connect the fluid line systems  32 ,  52  to a hydraulic system  5  of the agricultural harvester, which is only schematically shown in  FIG. 5 . 
         [0117]    An agricultural harvester typically has an hydraulic system  5  on board. In this embodiment, the hydraulic system  5  of the agricultural harvester can be used to operate the arm drive  30  of the harvester header support  20 . 
         [0118]    Optionally, in the embodiment of  FIG. 5 , in the road transport position the distance between the first support wheel and the second support wheel is 3.5 meters or less. 
         [0119]      FIG. 6  illustrates the embodiment of  FIG. 5 , in field operation mode, in front view. 
         [0120]    In field operation mode, the first support wheel  25  is in a field operation position in which the first support wheel is free from the weight of the header. In the field operation position, the first rotation axis  27  of the first support wheel  25  extends in a substantially vertical plane. In this embodiment, the first support wheel  25  is not be in contact with the ground  100 . In the field operation position, the first support wheel  25  is arranged at a distance above the ground  100 . 
         [0121]    Likewise, the second support wheel  45  is in a field operation position in which the second support wheel  45  is free from the weight of the header. In the field operation position, the second rotation axis  47  of the second support wheel  45  extends in a substantially vertical plane. In this embodiment, the second support wheel  45  is not be in contact with the ground  100 . In the field operation position, the second support wheel  45  is arranged at a distance above the ground  100 . 
         [0122]      FIG. 7  illustrates an embodiment of a combination of a harvester header support  20  with an agricultural harvester  1  which comprises a foldable header  60 , in top view. The harvester header support  20  is shown in field operation mode, and the foldable header in unfolded mode. 
         [0123]    In the embodiment of  FIG. 7 , the agricultural harvester  1  comprises a foldable header  60 . The foldable header  60  comprises a central portion  61  and two lateral portions  62 , one arranged on the right side and the other one arranged on the left side of the central portion  61 . The lateral portions  62  are pivotably connected to the central portion  61 . 
         [0124]    The foldable header  60  has an unfolded mode and a folded mode. In the unfolded mode, the foldable header  60  is adapted to be operated for harvesting crop. The lateral portions  62  extend in line with the central portion  61  and the header  60  is rather wide. In the folded mode, foldable header is adapted for road transport, and the lateral portions  62  do not extend in line with the central portion  61 . For example, the lateral portions  62  are pivoted upwardly. In the folded mode, the header is less wide than in the unfolded mode. This facilitates road transport. 
         [0125]    The foldable header  60  comprises a folding device  65  for bringing the foldable header from the folded mode into the unfolded mode and/or vice versa, and a hydraulic actuator  66  system for operating the folding device  65 . In the embodiment of  FIG. 7 , two hydraulic cylinders are provided in the hydraulic actuator system. 
         [0126]    Either the hydraulic system of the agricultural harvester  1  or hydraulic actuator system  66  of the foldable header  60  comprises a header folding control valve  70  which is adapted to actuate the folding device. 
         [0127]    In the embodiment shown in  FIG. 7 , an embodiment of the harvester header support  20  as shown in  FIG. 5  and  FIG. 6  is applied. 
         [0128]    As is shown in  FIG. 5  and  FIG. 6 , the arm drive  30  of the harvester header support comprises a hydraulic assembly  35 , which hydraulic assembly comprises a hydraulic cylinder  31 ,  51  and a fluid line system  32 ,  52  for feeding hydraulic fluid to the hydraulic cylinder  31 ,  51  and receiving hydraulic fluid from the hydraulic cylinder  31 ,  51 . The fluid line system  32 ,  52  comprises a hydraulic connector  33 ,  53 . 
         [0129]    In the embodiment of  FIG. 7 , the hydraulic connectors  53 , 53  of the harvester header support  20  are connected to the hydraulic actuating system at a location between the header folding control valve  70  and the folding device  65 .