An agricultural device

Abstract

The invention relates to and agricultural device comprising: - a frame with a transverse beam, - a plurality of hoe supports, each hoe support comprising: a first attachment member extending in horizontal direction and being attachable to different locations on the transverse beam of the frame, two arms hingedly connected with an upper end to the first attachment member, a second attachment member extending in horizontal direction and being hingedly connected to the two arms to form a moveable parallelogram, - a plurality of hoes connectable to a corresponding second attachment member, and - a centrally adjustable spring system connected between the frame and the plurality of hoe supports to apply a bias spring force to the respective parallelograms.

Description

[0001] TITLE OF THE INVENTION

[0002] An agricultural device

[0003] BACKGROUND OF THE INVENTION

[0004] The invention relates to the cultivation of crops which requires a lot of different operations, including but not limited to tillage, which is the agricultural preparation of soil by mechanical agitation, e.g. using digging, stirring and overturning.

[0005] Tillage that is deeper and more thorough resulting in soil with a rough texture is classified as primary, while tillage that is shallower to produce finer soil and is sometimes more selective, e.g. of location, is classified as secondary. Weed control throughout the growing season during the maturation of the crop plants falls under secondary tillage. Such shallow, selective secondary tillage of row crop fields that kills weeds while sparing the crop plants may alternatively be referred to as cultivating or cultivation.

[0006] Although tillage can be done by hand, tilling is typically carried out with draft-animal- powered or mechanized work in which an agricultural device including harrows, hoes, or other tools to work the ground is drawn over a field to carry out primary and / or secondary tillage.

[0007] Hence, tillage can be done non-selective, usually prior to seeding or planting requiring agricultural devices which evenly work the soil of a field, alternatively referred to as fullfield agricultural preparation, and can be done selective, usually after seeding or planting during maturation of the crop plants in which care should be taken to spare the crop plants. It is for instance known to sow seeds or plant crops in rows and during the maturation of the crop plants only use hoes for weed control in between the rows.

[0008] Hoes are typically arranged in an array on a rack where the height of the rack above ground determines the depth at which the hoes work the ground. The hoes may be arranged on arms having spring-like behavior allowing the hoe to move out of the way when for instance a rock is hit and subsequently return to the desired position. However, a disadvantage is that the used spring stiffness is relatively high and thus the moving range is limited. Combined with the characteristic that the ground to be worked is never perfectly flat, this results in unsatisfactory hoeing which is either too shallow or too deep.

[0009] Changing to pivotable spring-biased arms as proposed in WO2022 / 211634A1 in the name of the same applicant allowed to reduce the spring stiffness used and increase the moving range but unfortunately resulted in unsatisfactory weeding as well.

[0010] SUMMARY OF THE INVENTION

[0011] In view of the above it is an object of the invention to provide an improved agricultural device for weed control.

[0012] According to the invention, there is provided an agricultural device comprising: a frame with a transverse beam, a plurality of hoe supports, each hoe support comprising: o a first attachment member extending in horizontal direction and being attachable to different locations on the transverse beam of the frame, o two arms hingedly connected with an upper end to the first attachment member, o a second attachment member extending in horizontal direction and being hingedly connected to the two arms to form a moveable parallelogram, a plurality of hoes connectable to a corresponding second attachment member, and a centrally adjustable spring system connected between the frame and the plurality of hoe supports to apply a bias spring force to the respective parallelograms.

[0013] The invention is based amongst others on the insight by the inventors that the unsatisfactory weeding in WO2022 / 211634A1 is caused by the orientation of the hoe, which is only correct for a single angular orientation of the respective arm, and the location of the hoe on the arm, which determines the moment arm of the force applied by the hoe on the soil and thus the equilibrium position of the arm and hoe.

[0014] A benefit of using a moveable parallelogram and attaching the hoe to the second attachment member is that the hoe will always have the same orientation independent of the angular orientation of the parallelogram. A further benefit is that the moment of the force applied by each hoe on the soil is independent of the location of the hoe on the second attachment member. Hence, irrespective of the location of the hoe, the same equilibrium position / orientation applies.

[0015] A further advantage of the horizontal orientation of the first and second attachment members is that movement of the parallelogram in case of increased resistance encountered by the hoe results in an initially substantially backwards horizontal motion that transitions to a substantially upwards vertical motion. This results in a smoother operation of the hoe, especially in case of obstacles or relatively high resistance, where this motion profile allows to circumvent the obstacle or relatively high resistance.

[0016] In other words, the first and second attachment members extend in a horizontal direction substantially parallel to the ground, and the arms extend vertically when the parallelogram is in the orientation forming a rectangular. An advantage thereof is that the response of the parallelogram is more in line with expected variations in ground resistance and the forward motion of the frame when working the ground. The best response for the hoe, when for instance hitting a rock when moving forwards, is to move backwards and subsequently upwards. A horizontal parallelogram allows to provide such a response while a standing parallelogram will mainly move up and down and thus will work as well, but less smooth. A standing parallelogram is for instance shown in EP3578024A1 for a weeding machine using harrow tines, where a harrow tine is held by a parallelogram construction with the first and second attachment members extending in a substantially vertical direction. Due to this construction, movement of the parallelogram will result in a mainly vertical motion of the harrow tine and minimal horizontal movement. When hitting an obstacle or relatively high resistance, the harrow tine will not have sufficient time to circumvent the obstacle or relatively high resistance causing a non-smooth operation of the harrow tine.

[0017] In an embodiment, the second attachment member is configured to connect only one hoe to the hoe support. When two or more separate hoe parts are used that could easily have been connected to each other to form a single hoe element that is able to substantially perform the same function is also considered to be one hoe.

[0018] The use of the first attachment member allows to provide a parallelogram for each hoe while having sufficient flexibility in where each parallelogram is located on the frame allowing to easily adapt the agricultural device to the field, because depending on the type of crop grown, the distance between rows of crops is not necessarily always the same, so that preferably the agricultural device is able to handle different distances.

[0019] The use of individual parallelograms for each hoe allows each hoe to adapt itself to the soil and thus allows each hoe to individually move out of the way without influencing the other hoes. The centrally adjustable spring system has the benefit that the bias spring force applied to the parallelograms can be centrally and thus simultaneously controlled for all hoes.

[0020] In an embodiment, the hoe is a ridging hoe or ridging former for use in ridging machines.

[0021] In an embodiment, the first attachment member is configured to be clamped to the transverse beam. Preferably, the first attachment member is to be clamped around the transverse beam without interacting with specific elements on the transverse beam. Main advantages thereof may be that the transverse beam in principle does not require any adaptations to be suitable to attach the first attachment member thereto and can thus be of simple design, that in principle an infinitely number of positions are available to attach the first attachment member to the first attachment member, and / or that attaching, removing and / or repositioning can be done relatively easy and quick. In an embodiment, the second attachment member is configured to clamp a hoe thereto. Main advantages may be that the hoe can be of relatively simple design, that attaching, removing and / or repositioning can be done relatively easy and quick, and / or that it allows for simple adjustments in attachment height relative to the parallelogram when needed.

[0022] In an embodiment, the first and second attachment member are identical. Although the design of the first and second attachment member itself may therefore be more complex as a single attachment member is configured to attach to the transverse beam and to attach a hoe thereto, the main advantages are that it requires only a single design and only one fabrication process / line, and that during assembly of the hoe support it is not possible to make a mistake by using the wrong attachment member.

[0023] In an embodiment, the centrally adjustable spring system comprises a spring per hoe support connected with one end to one of the two arms or the second attachment member of the respective hoe support, and connected with another end to a cable, and wherein the centrally adjustable spring system further comprises a cable manipulator to simultaneously manipulate all cables allowing to set a pretension of the springs by setting a cable length between the springs and the cable manipulator.

[0024] In an embodiment, the cable manipulator is a rotatable cylindrically shaped member on which all cables are wound, and wherein a cable length between the springs and said member can be set by rotation of said member.

[0025] In an embodiment, the centrally adjustable spring system is configured such that a moment applied by the bias spring force to the respective parallelograms is substantially constant for a predefined angular range of the parallelograms.

[0026] In an embodiment, the centrally adjustable spring system includes a pneumatic or hydraulic cylinder.

[0027] A hydraulic cylinder may be used as cable manipulator, wherein a cable length between the springs and the cable manipulator is dependent on the position of the piston within the hydraulic cylinder. The hydraulic cylinder may alternatively or additionally be combined with an accumulator filled with gas for each hoe, wherein the accumulator provides the bias spring force and the hydraulic cylinder is used to centrally adjust the spring constant of the accumulators.

[0028] A pneumatic cylinder may be used as cable manipulator as well but may additionally or alternatively be used as spring as well. In an embodiment, each hoe support has a pneumatic cylinder, wherein a pressure inside the pneumatic cylinders is centrally adjustable thereby setting the spring constant of the pneumatic cylinder.

[0029] In an embodiment, the predefined angular range may be defined using an angle a, with a being the angle between one of the arms 23 and the vertical, and with angle a being positive when the arm is inclined backwards opposite the bias spring force. The angle a may then be between -10 and +45 degrees, preferably between -5 and +40 degrees, more preferably between 0 and +35 degrees, most preferably between 0 and 30 degrees, for instance between 5 and 30 degrees.

[0030] In an embodiment, the agricultural device comprises a wheel mountable to the frame at different heights to set a distance between the frame and the ground.

[0031] In an embodiment, the wheel is mountable to the first attachment member.

[0032] In an embodiment, the wheel is mountable to the second attachment member to set a distance between the second attachment member and the ground.

[0033] In an embodiment, the hoe comprises a coupling member to connect the hoe to the second attachment member, wherein the wheel is mountable to the coupling member to set a distance between the second attachment member and the ground. In an embodiment, the agricultural device has a forward moving direction, and the bias spring force to be applied by the centrally adjustable spring system to the parallelogram is directed substantially in the forward moving direction.

[0034] The invention also relates to a hoe support comprising: a first attachment member attachable to different locations on a transverse beam of a frame of an agricultural device to extend in horizontal direction during use, two arms hingedly connected with an upper end to the first attachment member, a second attachment member hingedly connected to the two arms to extend in horizontal direction during use to form a moveable parallelogram and configured to connect a hoe thereto.

[0035] In an embodiment, the hoe support also includes a hoe connectable or connected to the second attachment member.

[0036] It will be clear for the skilled person that features and embodiments described in relation to a hoe support of the agricultural device may apply mutatis mutandis to the hoe support described above, and vice versa.

[0037] BRIEF DESCRIPTION OF THE DRAWINGS

[0038] The invention will now be described in a non-limiting way by reference to the accompanying drawings in which like parts are indicated by like reference symbols, and in which:

[0039] Fig. 1 schematically depicts a top view of a piece of land being worked with an agricultural device according to an embodiment of the invention,

[0040] Fig. 2 schematically depicts a side view of a portion of the agricultural device depicted in Fig. 1, and

[0041] Fig. 3 schematically depicts a force diagram indicating the forces applied by the centrally adjustable spring system to the parallelograms in different orientations. DETAILED DESCRIPTION OF THE INVENTION

[0042] Fig. 1 schematically depicts a piece of land 1 used for the cultivation of crops. The piece of land 1 is shown after row-wise seeding or planting resulting in rows of crops 2 interspersed with empty strips of land 3.

[0043] Usually, the piece of land is worked before the seeding / planting and / or during seeding / planting and / or after seeding / planting. Fig. 1 depicts a situation in which the piece of land 1 is worked using an agricultural device 10 after seeding / planting, e.g. for weed control.

[0044] In the situation depicted in Fig. 1, the agricultural device 10 is moved over the piece of land using a vehicle 5, e.g. a tractor, robot or dedicated vehicle. Alternatively, any other driving force originating from animal or human may be used as well. Both the agricultural device 10 and the vehicle 5 are depicted highly schematically and are transparent to clearly show the row of crops 2 and the strips of land 3 below the agricultural device 10 and the vehicle 5. The agricultural device 10 may include one or more wheels (not shown in Fig. 1) to provide at least partial self-support allowing the vehicle 5 to pull or push the agricultural device 10 over the piece of land 1 or the agricultural device 10 may entirely be supported by the vehicle 5, e.g. by being mounted to or being integral with the vehicle 5, to be moved over the piece of land 1 along with the vehicle 5.

[0045] Fig. 2 schematically depicts a side view of a portion of the agricultural device 10 of Fig. 1. The agricultural device 10 comprises a frame with a transverse beam 11. The transverse beam 11 extends substantially parallel to the ground perpendicular to an intended moving direction MD of the agricultural device 10 over a piece of land by the vehicle 5.

[0046] The agricultural device 10 further includes a plurality of hoe supports 20. For simplicity and clarity reasons, only one hoe support 20 is depicted in Fig. 2.

[0047] The hoe support 20 comprises a first attachment member 21, a second attachment member 22 and two arms 23 hingedly connected to the first and second attachment member 21, 22 to form a moveable parallelogram. The hoe support 20 can be attached to the transverse beam 11 using the first attachment member 21. To this end, and in this exemplary embodiment, the first attachment member 21 comprises a recess 24 for receiving the transverse beam 11 and a clamping member 25 to clamp the first attachment member 21 to the transverse beam 11. In this way, clamping can be done at any desired location along the transverse beam 11.

[0048] The second attachment member 22 is used to attach a hoe 30 to the frame via the parallelogram. To this end, and in this exemplary embodiment, the second attachment member 22 comprises a hole 26 to receive a coupling member like a tube or beam 30a to which the hoe 30 is connected. The tube or beam 30a can for instance be clamped in the hole 26.

[0049] It is preferred that each hoe support 20 supports only one hoe 30 so that each hoe 30 is free to move due to interaction with the ground without influencing other hoes.

[0050] The agricultural device 10 further comprises a centrally adjustable spring system 40 connected between the frame and the plurality of hoe supports 20 to apply a bias spring force to the parallelogram, in this example to one of the arms 23.

[0051] The centrally adjustable spring system 40 comprises a spring 41 per hoe support 20 connected to one of the two arms 23 of the respective hoe support. The spring 41 may alternatively be connected to the second attachment member 22. The spring is pretensioned by connecting the opposite end of spring 41 to a cable 42 that is wound on a rotatable cylindrically shaped member 43. By connecting all hoe supports via a spring 41 and cable 42 to the rotatable cylindrically shaped member 43, the angular orientation of the member 43 allows to set the length of the cable 42 between the member 43 and the springs 41 and this allows to set the pretension for all springs and thus hoe supports 20 simultaneously.

[0052] Fig. 3 schematically depicts a force diagram indicating the forces applied by the centrally adjustable spring system to the parallelograms in two different orientations. The diagram only shows one arm 23 of the parallelogram formed by the hoe support 20. The arm 23 is indicated in two different angular orientations having a different angle a with respect to the vertical. To distinguish between the two different orientations, the arm in the orientation having the smallest angle a is indicated using reference numeral 23 and the arm in the orientation having the largest angle a is indicated using reference numeral 23'.

[0053] For arm 23, the bias spring force applied by the centrally adjustable spring system is indicated using reference symbol Fv. For arm 23', this bias spring force is indicated using reference symbol Fv'. Due to the arm having rotated backwards, i.e. away from the spring, the spring 41 has elongated and thus the bias spring force Fv' is larger than bias spring force Fv.

[0054] However, the rotation also affected the moment arm of the forces. For arm 23, the moment arm is al and for arm 23', the moment arm is a2 with a2 being smaller than al.

[0055] The centrally adjustable spring force is preferably configured such that for a predetermined range of angle a, the moment of the bias spring force applied to the respective parallelogram is substantially constant. Hence, when the shown orientations in Fig. 3 are within said predetermined range of angle a, Fv * al is substantially equal to Fv' * a2, so that independent of the angular orientation of the parallelogram, the spring system applies the same moment.

[0056] The predetermined range of angle a, with a being the angle between arm 23 and the vertical, and with angle a being positive when the arm is inclined backwards opposite the bias spring force, may be between -10 and +45 degrees, preferably between -5 and +40 degrees, more preferably between 0 and +35 degrees, most preferably between 0 and 30 degrees, for instance between 5 and 30 degrees.

[0057] Referring to Fig. 2 again, the first attachment member 21 and the second attachment member 22 may be identical. Hence, each attachment member 21, 22 may include both the recess 24 for attaching the attachment member to a transverse beam 11 and the hole

[0058] 26 for attaching a hoe 30 via the tube or beam 30a to the attachment member.

[0059] Although not explicitly mentioned above, but clearly shown in the drawings, the first attachment member 21, the second attachment member 22 and the arms 23 form a parallelogram in which the first and second attachment members 21, 22 extend horizontally substantially parallel to the ground, and in which the arms extend substantially vertical.

[0060] This means that when the arms move from for instance a position in which angle a is -5 or 0 to a position in which angle a is 30 or 40, the initial motion is mainly horizontal and subsequently upwards thus allowing to easily circumvent obstacles or regions of increased resistance.

[0061] Although reference is made throughout the specification to a spring, any element having spring-like behavior, i.e. an element that can return into shape after being compressed or extended, including for instance pneumatic springs or cylinders, can be used to provide the same function. The spring behavior does not have to be linear although a linear spring is a commonly used and thus cheap solution. A non-linear spring behavior may have the advantage that the angular range for which the moment applied is substantially constant may be larger compared to a linear spring behavior.

[0062] Although not shown in the drawings, one or more wheels may be mounted to the frame, first attachment member 21, second attachment member 22, and / or coupling member 30a to set a distance between the ground and the respective element.

[0063] The invention may alternatively be described by the following clauses:

[0064] 1. An agricultural device comprising: a frame with a transverse beam, a plurality of hoe supports, each hoe support comprising: o a first attachment member attachable to different locations on the transverse beam of the frame, o two arms hingedly connected with an upper end to the first attachment member, o a second attachment member hingedly connected to the two arms to form a moveable parallelogram, a plurality of hoes connectable to a corresponding second attachment member, and a centrally adjustable spring system connected between the frame and the plurality of hoe supports to apply a bias spring force to the respective parallelograms.

[0065] 2. An agricultural device according to clause 1, wherein the first attachment member is configured to be clamped to the transverse beam.

[0066] 3. An agricultural device according to clause 1, wherein the second attachment member is configured to clamp a hoe thereto.

[0067] 4. An agricultural device according to clause 1, wherein the first and second attachment member are identical.

[0068] 5. An agricultural device according to clause 1, wherein the centrally adjustable spring system comprises a spring per hoe support connected with one end to one of the two arms or the second attachment member of the respective hoe support, and connected with another end to a cable, and wherein the centrally adjustable spring system further comprises a cable manipulator to simultaneously manipulate all cables allowing to set a pretension of the springs by setting a cable length between the springs and the cable manipulator.

[0069] 6. An agricultural device according to clause 1, wherein the centrally adjustable spring system is configured such that a moment applied by the bias spring force to the respective parallelograms is substantially constant for a predefined angular range of the parallelograms.

[0070] 7. A hoe support comprising: a first attachment member attachable to different locations on a transverse beam of a frame of an agricultural device, two arms hingedly connected with an upper end to the first attachment member, and a second attachment member hingedly connected to the two arms to form a moveable parallelogram and configured to connect a hoe thereto. A hoe support according to clause 7, further comprising a hoe connected or connectable to the second attachment member.

Claims

C L A I M S1. An agricultural device comprising: a frame with a transverse beam, a plurality of hoe supports, each hoe support comprising: o a first attachment member extending in horizontal direction and being attachable to different locations on the transverse beam of the frame, o two arms hingedly connected with an upper end to the first attachment member, o a second attachment member extending in horizontal direction and being hingedly connected to the two arms to form a moveable parallelogram, a plurality of hoes connectable to a corresponding second attachment member, and a centrally adjustable spring system connected between the frame and the plurality of hoe supports to apply a bias spring force to the respective parallelograms.

2. An agricultural device according to claim 1, wherein the first attachment member is configured to be clamped to the transverse beam.

3. An agricultural device according to claim 1, wherein the second attachment member is configured to clamp a hoe thereto.

4. An agricultural device according to claim 1, wherein the first and second attachment member are identical.

5. An agricultural device according to claim 1, wherein the centrally adjustable spring system comprises a spring per hoe support connected with one end to one of the two arms or the second attachment member of the respective hoe support, and connected with another end to a cable, and wherein the centrally adjustable spring system further comprises a cable manipulator to simultaneously manipulate all cables allowing to set a pretension of the springs by setting a cable length between the springs and the cable manipulator.

6. An agricultural device according to claim 1, wherein the centrally adjustable spring system is configured such that a moment applied by the bias spring force to therespective parallelograms is substantially constant for a predefined angular range of the parallelograms.

7. A hoe support comprising: a first attachment member attachable to different locations on a transverse beam of a frame of an agricultural device to extend in horizontal direction during use, two arms hingedly connected with an upper end to the first attachment member, and a second attachment member hingedly connected to the two arms to extend in horizontal direction to form a moveable parallelogram and configured to connect a hoe thereto.

8. A hoe support according to claim 7, further comprising a hoe connected or connectable to the second attachment member.

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