Cutting unit with leaf spring pack as cutting element carrier

Description

[0001] The present invention relates to a cutting unit for attachment to a harvesting machine, comprising a frame extending at least substantially over the working width of the cutting unit, which frame comprises an attachment frame with attachment means for connection to a feed channel of a harvesting machine, wherein the frame comprises rockers pointing in the working direction, to the front ends of which cutting elements for cutting the crop are fastened.

[0002] Headers are usually equipped with rigid frames, at the front ends of which are permanently installed cutter bars with a number of oscillating knife blades arranged next to one another. These blades use oscillating knife movements to cut the crop lying on the cutter bar from the stubble remaining in the field. This allows the crop to fall onto the header and from there be conveyed via the intake channel to the harvester for further processing. However, with such rigid frames and rigidly installed cutter bars, it is difficult to pick up the crop, especially on uneven ground conditions when the crop is close to the ground, as is the case with laid grain or soybeans, for example. It may also be desirable to cut the crop as close to the ground as possible, either for reasons of field hygiene or to achieve the highest possible straw yield.While ground-tracking controls are known for guiding the headers close to the ground, they often react too slowly to capture and convey as much of the crop as possible, even in difficult conditions. Ground contour following is also not possible in partial widths of rigid headers, which has a detrimental effect on increasingly wider headers. Often, due to adjustments made by harvester operators, the headers are still guided too high to avoid damage from contact with soil or stones.

[0003] From WO 2007 / 095 430 A2, it is known to attach the rockers, to whose front ends the cutter bar with the knife blades is attached, to a pivot joint on the rear cutting unit frame. This allows the cutter bar, with its up-and-down movable rockers, to better adapt to changing ground contours, even in certain areas of the working width. However, it remains unclear how the rockers should be kept as close to the ground as possible. The weight of the cutter bar alone is not sufficient to ensure close-to-ground knife guidance.

[0004] From US Pat. No. 5,464,371 A, it is known to support a rigid, pivoting rocker, at the front end of which a cutter bar with knife blades is mounted, with a leaf spring assembly, allowing the cutting unit to adapt more flexibly to the soil conditions. This results in a pivoting movement of a rocker, rigid along its length, around a rotational axis, which is only supported by springs. However, due to the oscillation behavior of the leaf springs, the cutter bar is not held consistently close to the ground.

[0005] US 4,599,852 A shows a single leaf spring as the rocker, which has a curved shape to allow free swinging. Due to the free swinging of a single spring, the cutter bar cannot be guided firmly enough on the ground. The same applies to the cutting mechanism disclosed in US 2008 / 022646 A.

[0006] The document FR 2 324 219 A1 shows a cutting unit with a knife bar which is held by several individual leaf springs arranged at a distance from one another.

[0007] It is the object of the present invention to provide a cutting unit with a holder for the cutting elements that easily adapts to the ground contour without being prone to uncontrolled swinging.

[0008] The problem is solved for a generic cutting device in that several or all of the rockers are each designed as a leaf spring assembly composed of several spring leaves, several spring leaves lying flat on top of one another as a leaf spring assembly are held together on the frame between clamping elements at their frame-side end, only one or more of the spring leaves arranged in the upper area of ​​the leaf spring assembly are connected to the cutting elements and one or more of the spring leaves held between the clamping elements on the frame and arranged in the lower area of ​​the leaf spring assembly end in front of the connection zone of the spring leaves arranged in the upper area of ​​the leaf spring assembly with the cutting elements, as seen in the working direction.

[0009] The use of a leaf spring assembly designed according to the invention results in a spring behavior that is more precisely tailored to the intended application. The multi-layered spring leaves, held at their frame-side ends, support each other during spring movements. Friction, which occurs on the facing surfaces of the spring leaves during spring movements, further dampens spring movements, especially those in which the spring leaves swing downward.

[0010] Because not all of the spring leaves attached to the frame are connected to the cutting elements, the spring leaves connected to the cutting elements exhibit particularly soft and responsive compression behavior - i.e., an upward spring movement. Particularly at the beginning of the compression movement from a rest position, which is primarily achieved by the deformation of the spring leaves directly connected to the cutting elements, no strong restoring forces build up in these spring leaves. Therefore, small compression movements can be carried out particularly sensitively. If the ground pressure that triggered the evasive movement that has already begun continues, for example because the ground surface beneath the cutting elements continues to rise, the restoring forces built up in these spring leaves also increase.In addition, as the spring deflection progresses, the spring blades connected to the cutting elements increasingly rest on the additional spring blades, which in turn build up restoring forces through deformation. In this way, a spring deflection is slowed down by progressively increasing restoring forces. During larger spring deflections, these restoring forces ensure that the deflected spring blade(s) quickly return the cutting elements to their original position when the ground pressure acting on the cutting elements decreases again.

[0011] If the spring leaves arranged in the upper section of the leaf spring assembly, which are connected to the cutting elements, are deflected upwards by ground pressure acting on the cutting elements, the spring leaves arranged below them have less damping effect, so that an evasive movement upwards is only slightly dampened. The friction between the spring leaves on each other is also less pronounced with an upward spring movement. Because the spring leaves arranged in the lower section of the leaf spring assembly end before the connection zone of the spring leaves arranged in the upper section of the leaf spring assembly with the cutting elements, viewed in the working direction, increased ground pressure forces resulting from a rising ground level in the area of ​​the swing arm and acting on the cutting elements are not transferred directly to these spring leaves.The ground pressure forces therefore act in particular on the spring leaves located in the upper section of the leaf spring assembly, which are connected to the cutting elements, and bend them upwards, as long as they act on these spring leaves and are strong enough to bend them upwards. However, during a downward spring movement, the spring leaves located in the upper section of the leaf spring assembly rest on the spring leaves below, thereby supporting and braking them in their downward movement. This is especially true if the spring leaves located in the upper section would rebound downwards beyond the zero position if they were not caught and braked during this movement by the spring leaves located in the lower section.

[0012] The selection of the number, material, material thickness, length, and positioning of the spring leaves bundled into a package results in a spring behavior that, on the one hand, allows the spring leaves holding the cutting elements to deflect quickly and easily when they encounter raised ground. On the other hand, however, the restoring forces built up during the deflection movement push the cutting elements back down as soon as the ground pressure acting on the cutting elements decreases, without causing undesirable, ongoing oscillations. Damping downward oscillations largely prevent sinusoidal rebound.The individual spring leaves are made of a material elasticity that allows for a wide range of compression and rebound movements within the scope of the bending forces occurring during normal operation of the cutting unit, without the spring leaves becoming brittle and breaking due to material fatigue. Due to their elasticity, the spring leaves return to their original shape and position when the force acting on them from the ground pressure is removed.

[0013] The responsiveness of the leaf spring assemblies composed of multiple spring leaves is also improved compared to the prior art due to their lower mass inertia, as rigid rockers are completely eliminated. The spring deflection movements are more flexible because the individual or multiple spring leaves to which the cutting elements are attached are movable almost over their entire length, particularly upwards. Rigid rockers can only pivot around their pivot point to offset increased ground pressure. The springs acting at a point along their length must necessarily be shorter, resulting in less flexible spring behavior and significantly poorer spring response.

[0014] By connecting the spring assembly to the frame using clamping elements, the leaf spring assembly is easy to install. The clamping elements rest on opposing surfaces, at least on the top and bottom of the leaf spring assembly, compressing the leaf spring assembly from the outside so that it can no longer move longitudinally. The clamping elements connected to the frame effectively transfer the load-bearing forces to the cutting unit frame. However, the clamping elements allow the leaf springs to exhibit elastic spring movements across their entire length, which would lead to brittle fractures in the connection zone over time if the leaf springs were rigidly connected to the frame.

[0015] According to one embodiment of the invention, at least one or more of the spring leaves, which are held together at their frame-side ends between clamping elements on the frame, are connected to the cutting elements and have recesses for the passage of connecting elements that connect fastening plates placed on the top and bottom of the spring leaf or leaves for connecting the cutting elements to the rocker. A few spring leaves are still sufficiently flexible to allow the cutting elements held on the rockers to adapt easily to the ground. By using at least two spring leaves held one on top of the other, the frictional forces during oscillating movements of the spring leaves can be used to dampen the oscillating movements.To ensure that the second spring leaf can move relative to the first spring leaf in the direction of shear during spring movements, the recess in the second spring leaf must be designed as an elongated hole, into which a sleeve is preferably inserted to pass the connecting element. This applies accordingly to other spring leaves, if present. Attaching the cutting elements to one or more spring leaves via interconnected mounting plates enables flexible movement of the spring leaves without causing brittle fractures in the connection zone between the cutting elements and the spring leaves, which could occur with a fixed connection.

[0016] According to one embodiment of the invention, a tension strut is attached to the underside of each leaf spring assemblies. The front end of the tension strut is connected to the front section of the leaf spring assemblies and extends from there rearward towards the frame, where it is movably held in an elongated hole, with the front and rear ends of the elongated hole forming a stop for movements of the leaf spring assemblies. The oscillating movements that the spring leaves of the leaf spring assemblies can perform are limited by the stops via the tension strut. As long as the rear end of the tension strut moves within the length of the elongated hole, the leaf spring assemblies and spring leaves can freely move in or out of the spring assemblies and are not restricted by the stops. However, if the tension strut hits a stop, further compression or rebound movement is immediately stopped.The spring movements of the rockers can thus be kept within a range in which flexible adjustment of the cutting elements to changes in the surface contour of the cultivated field is sensible, such as a compression movement of the cutting elements from a neutral position up to 15 cm in height. Larger changes in the height of the cutting elements must then be accommodated by other adjusting devices, such as a corresponding height adjustment of the harvester's intake channel, support elements on the harvester's intake channel, ground supports such as a height-adjustable wheel chassis or the like. The tension strut can be equipped with overload protection such as a shear bolt or a targeted material weakening on the connecting components, which separates the connection between the tension strut and the elongated hole if a load acting on the overload protection exceeds the permissible limit.Such overload protection allows the leaf spring assembly to compress beyond the range limited by the slotted hole, helping to prevent major damage to the cutting unit. The tension rod itself can be longitudinally elastic to prevent hard impacts. Dampers can also be arranged in the slotted hole near the end stops.

[0017] According to one embodiment of the invention, the cutting unit has sensors that detect the movements of the tension struts in the respective elongated holes. The sensors transmit a position signal corresponding to the respective pivot position to an evaluation electronics system connected to the sensors. The sensors provide the evaluation electronics with information about whether the leaf spring assemblies are performing any evasive movements at all and how strongly the cutting elements are compressed at a given point in time or over a specific time interval. The movement data transmitted by the sensors allow conclusions to be drawn about whether the cutting unit is lowered far enough to actually utilize the flexibility of the leaf spring assemblies and to cut the crop as close to the ground as possible; they indicate if the cutting unit is guided too low, and they allow conclusions to be drawn about the unevenness of the area to be worked.The speed of the movements can also be used to determine whether there are smooth changes in the ground surface, such as hills or hollows, or whether there are stones in the field that require a quick evasive movement. The evaluation electronics can use sensors to monitor the movements of the tension struts and to display the movements and / or the remaining spring travel. Warning signals can be issued when the stops are reached and / or adjustment recommendations can be given to the harvester driver and / or control signals can be sent to control systems on the header and / or harvester side for height control of the header. These lead to an automatic adjustment of the header height and / or a rotation of the header around the axis of rotation pointing in the direction of travel.

[0018] According to one embodiment of the invention, one or more support elements are mounted on one or more leaf spring assemblies, which support conveying surfaces located above the leaf spring assemblies. The support elements comprise individual leaf springs or a leaf spring assemblies to connect a conveying surface to the respective leaf spring assemblies. The conveying surface can be actively driven, as in the case of a revolving belt conveyor, or it can be a passive conveying surface, such as a floor plate, on the upper side of which the cut crop is moved in the direction of the intake channel. Due to the movements of a leaf spring assemblies, the conveying surfaces are also movable with the leaf spring assemblies and require special support. A support element does not impair the spring movements of the respective leaf spring assemblies.However, it does allow a conveyor surface located above the leaf spring assembly to be supported on the leaf spring assembly in such a way that it follows the spring movements of the leaf spring assembly. Since the cutting elements attached to the leaf spring assembly also follow the spring movements of the leaf spring assembly, there are hardly any changes in the relative spatial position of the cutting elements and the conveyor surfaces to one another, even when the leaf spring assemblies compress or rebound. Despite the constant possible compression and rebound movements of the leaf spring assemblies, the conveying of the cut crop is not impaired. This eliminates the need for complex supports for the conveyor surfaces on the header frame and additional technical precautions to prevent deterioration in crop flow and crop losses.If several support elements are arranged on a spring leaf or a leaf spring assembly, it is possible to support a conveying surface at several points, for example in the front area close to the cutting elements and in the rear area, the area further away from the cutting elements. Since the spring movements of a spring leaf or a spring assembly are weaker in the area further away from the cutting elements than in the area immediately adjacent to the cutting elements, the combination of a support adjacent to the cutting elements and an additional support further away results in a calming of the spring behavior of the multiply supported conveying surface across its working width. A spring movement of a spring leaf or a leaf spring assembly then results in changes in the angle of attack of the conveying surface to the cutting elements.

[0019] According to one embodiment of the invention, at least one of the support elements is connected to the rocker arm so that it can move longitudinally. The compression and rebound movements of a rocker not only result in changes in the spatial position of the conveying surfaces in the vertical direction, but also in the horizontal direction. This is particularly true if the conveying surface adjoins the cutting elements at the transition point to the conveying surface in a sealing manner. In this case, the conveying surface must follow every movement made by the cutting elements in the horizontal direction in order to avoid crop losses. If a fixed spatial relationship between the support element and the conveying surface is to be maintained, it is advantageous if at least one of the support elements is connected to the rocker arm so that it can move longitudinally, because the support element can then follow the movements of the conveying surface in the horizontal direction thanks to its corresponding mobility.Longitudinal mobility should be ensured, particularly in the working direction and counter to the working direction. During pivoting movements of the rocker arm, the support element moves along the longitudinal axis of the rocker arm. The support element can engage around the rocker arm to move along the rocker arm guided by the positive locking mechanism, and / or the support element can be guided by grooves in the rocker arm that extend into the springs formed on the support element.

[0020] According to one embodiment of the invention, the longitudinally movable support element is movably driven in its movement by one or more coupling rods that are supported in the front section of the rocker arm or the cutting element. The coupling rods are rigid and define a distance between two points determined by their length. With several coupling rods arranged one behind the other and connected by a movable axis, slight changes in the length of the coupling rods due to buckling movements may occur, but these are negligible. The coupling rods are connected to their connection points in a rotationally movable manner.If, during upward or downward movement of the swing arm, the distance between the front section of the swing arm or the cutting element and the point at which the support element connected to the coupling rods is currently located shortens, the coupling rods push the support element backwards along the swing arm so that the distance between the front section of the swing arm or the cutting element and the support element remains at least approximately the same. If the swing arm swings back to its original position and the distance between the front section of the swing arm or the cutting element and the point at which the support element connected to the coupling rods is currently located increases, the coupling rods pull the support element forward again along the swing arm. In this way, the coupling rods transfer movement of the cutting element to the support element during compression and rebound movements in the longitudinal direction.The support in the front section of the swing arm refers to an area in front of the support element moved by the coupling rod. The closer the front support of the coupling rod is to the cutting element, the smaller the length differences resulting from oscillating movements of the cutting element in relation to the longitudinally movable support element. However, even if the front end of the coupling rod is supported in the middle section of the swing arm, useful displacement movements of the support element can be achieved. This is especially true if part of the distance between the longitudinally movable support element and the cutting element is bridged by a rigid component other than a coupling rod.

[0021] According to one embodiment of the invention, a holding element is connected to the longitudinally movable support element, which delimits the movable conveying surface and guides it via drivers. Due to its longitudinal mobility, the support element is well suited to ensuring that the conveying surface is guided even when the conveying surface moves in a horizontal direction. This is particularly true when it is a movably driven conveying surface, as is the case with the circulating conveyor belts of a draper cutting unit. For example, a guide groove can be formed in the holding element, through which a shaped body formed on the circulating conveyor belt and shaped complementarily to the guide groove passes. In the conveying direction of the circulating conveyor belt, this creates a guide that holds the conveyor belt in the desired position.The retaining element can also serve to secure the edge of the conveying surface against crop losses by closing gaps to adjacent components, for example by means of appropriate strips, webs and sealing bodies, which can also be made of an elastic material.

[0022] According to one embodiment of the invention, a holding element is connected to the longitudinally movable support element, which supports and guides a movable rear wall of the conveyor path of the crop over the cutting unit. When the conveyor surface moves in a horizontal direction, gaps of varying sizes would arise between the edge of the conveyor surface adjacent to the rear wall and the rear wall, through which gaps crop material could be lost and undesirable material could build up, restricting the mobility of the components and leading to damage to the components. The movable rear wall allows the latter to follow the movements of the conveyor surface in a horizontal and / or vertical direction. Because the holding element is designed to support and guide the movable rear wall, the holding element transfers the movements of the rocker to the rear wall. The rear wall therefore moves synchronously with the conveyor surface.This prevents the formation of gaps of different sizes between the rear wall and the conveying surface.

[0023] According to one embodiment of the invention, the retaining element seals the transition between the conveying surface and the rear wall. This additional sealing prevents crop losses and the buildup of material accumulation.

[0024] According to one embodiment of the invention, support elements of adjacent leaf spring assemblies are connected by one or more webs pivotally connected to the support elements. Although the pivotable webs allow for the deflection of individual leaf springs or leaf spring assemblies due to their pivotal connection, they can dampen excessive deflection of individual leaf spring assemblies in the vertical direction. The webs are also suitable for supporting individual spring leaves or entire leaf spring assemblies against possible movements in a direction transverse to the direction of travel. The webs are also suitable for transferring restoring forces from one spring leaf or leaf spring assemblies to an adjacent spring leaf or leaf spring assemblies.Viewed across the working width of a cutting unit, the webs help to dampen spring movements of individual spring leaves and / or leaf spring assemblies and smooth them out across the working width of the cutting unit.

[0025] According to one embodiment of the invention, the front section of the rocker arm is supported on the middle section of the rocker arm via a torque support. If the cutting element encounters an obstacle as the harvester moves forward, which obstacle is shaped in such a way that the rocker arm cannot avoid it by an evasive movement, there is a risk that the cutting element could be pushed downwards and completely bent over. This risk arises in particular from the fact that the spring leaf(s) to which the cutting element is attached have a certain degree of flexibility. To reduce the risk of the cutting element accidentally bending, the front section of the rocker arm is supported on the middle section of the rocker arm via a torque support. The torque support is preferably rigid.It is connected at its front end to the blade angle to which the cutting element is attached, and at its rear end to a support element that is attached to the swing arm.

[0026] According to one embodiment of the invention, a gear unit with an output shaft connected thereto for driving the cutting elements and / or conveyor elements for transporting the crop is mounted in a slotted hole in the frame, allowing it to move longitudinally. The longitudinally movable gear unit facilitates spring movements of the spring leaves and / or leaf spring assemblies.

[0027] According to one embodiment of the invention, the spring characteristic of the spring leaves of a leaf spring assembly of a rocker arm is designed such that, upon a 10 cm deflection of a cutting element attached to it, the spring characteristic generates a contact pressure from the generated restoring forces that ranges between 15 kg and 80 kg. This design of the spring characteristic results in a good compromise between guiding the cutting elements close to the ground and sufficiently flexible response to changes in the height of the field contours crossed by the cutting unit.

[0028] According to one embodiment of the invention, leaf spring assemblies with different spring characteristics are installed in a cutting unit. These different spring characteristics allow the contact pressure generated by the various rockers to be adjusted to the different weight loads of the individual rockers, resulting in the most uniform contact pressure possible across the working width of the cutting unit.

[0029] It is expressly pointed out that the above-described embodiments of the invention can be combined with the subject matter of the main claim, either individually or in any combination, provided that there are no technically compelling obstacles to this.

[0030] Further modifications and embodiments of the invention can be found in the following description and the drawings.

[0031] The invention will now be explained in more detail using exemplary embodiments. They show: Fig. 1: a view from the front of a harvesting machine with a cutting unit, Fig. 2: a view of a cutting unit from the rear, Fig. 3: a view of a cutting unit from a view from the front and above, Fig. 4: a view of the Fig. 3 shown cutting mechanism, but without the conveying elements, Fig. 5: a detail view of the fastening zone of a leaf spring assembly on the frame, Fig. 6: a detail view obliquely from above onto a rocker, Fig. 7: a detail view obliquely from below onto a rocker, Fig. 8: a detail view of the area of ​​a rocker, Fig. 8a: an enlarged detail view of a connection zone between spring leaves and the cutting elements, Fig. 9: a view of a leaf spring assembly with a gear arranged next to it, Fig. 10: spring characteristics of rockers, and Fig. 11: a sectional view through the cutting mechanism.

[0032] In Fig. 1 Shown is a frontal view of a harvesting machine 2 with a cutting unit 4. The cutting unit 4 has a frame 6, which is connected to the intake channel 10 of the harvesting machine 2 via an attachment frame 8.

[0033] From the Fig. 2 In the view from behind of the cutting unit 4 shown, it can be seen that attachment means 12 such as catch hooks are arranged on the attachment frame 8.

[0034] In Fig. 3 1 shows a view of a cutting unit 4 from an oblique front and top view. This view shows that the cutting unit has a number of conveyor elements 14. In the illustrated embodiment, these are continuously rotating belt conveyors, two outer belt conveyors of which convey the cut crop toward the center and discharge the crop onto another belt conveyor, which conveys the crop rearward toward the intake channel 10 of the harvesting machine 2. Instead of belt conveyors, screw conveyors, for example, can also be used in cutting units 4 to convey the crop. Other conveyor elements are also conceivable.Above the ground-side conveyor elements 14 there is a further conveyor element 14, a reel which, during a rotating movement with the reel fingers and the rods to which the reel fingers are attached, dips into the standing crop, supports it while the stalks are cut close to the ground, and after cutting, deposits the stalks on the ground-side conveyor elements.

[0035] At the front of the cutting unit 4 is a cutting element 18 in the form of a cutter bar. The cutter bar is driven in an oscillating manner to cut the crop at its stems or stalks. Depending on the crop and its condition, it is desirable to guide the cutting element 18 as close to the ground as possible to avoid crop losses. For example, with soybeans, it is necessary to cut the stalks very close to the ground to avoid soybean losses. Likewise, with laid grain, it is advantageous to cut as close to the ground as possible to avoid crop losses there as well.

[0036] The cut crop is conveyed along the rear wall 17 of the cutting unit 4 by the conveyor elements 14. The rear wall 17 is designed to be closed to prevent crop losses there as well.

[0037] In Fig. 4 is a view of the Fig. 3 The cutting unit 4 shown is shown, although the conveyor elements in the area of ​​the side frames have been omitted. This makes the rockers 16, on which the cutting element 18 is held, particularly visible. The central conveyor belt is shown as an example of a conveyor element 14.

[0038] Several or all of the rockers 16 consist of leaf spring assemblies 20, which are composed of several spring leaves 22. Several or all of the flat spring leaves 22 are held together as a leaf spring assembly 20 at their frame-side end between clamping elements 24 on the frame 6. The clamping elements 24 are clamping plates, which are connected to the frame 6 by a screw connection. This is shown in the detail view of the Fig. 5 clearly visible.

[0039] In Fig. 6 a detailed view of a swing arm 16 is shown. In the detail view in Fig. 6 It can be seen that only two spring leaves 22 reach into the front area of ​​the cutting unit 4, because several spring leaves 22 end before that. The spring leaves 22 that end before that are those spring leaves 22 that are located in the lower area of ​​the leaf spring assembly 20. These end, viewed in the working direction, before the connection zone 26 of the spring leaves 22 arranged in the upper area of ​​the leaf spring assembly 20 with the cutting elements 18. This is clearly visible in the view from below, which is shown in the Fig. 7 is shown.

[0040] In Fig. 8 a section of a cutting unit 4 is shown in the area of ​​a rocker 16. This view shows a leaf spring assembly 20 which is composed of at least four spring leaves 22. In the exemplary embodiment shown, only the uppermost spring leaf 22 extends forward into the area of ​​the cutting elements 18 to which it is connected. For connection to the cutting element 18, a fastening plate 32 is placed on the uppermost spring leaf 22. On the underside of the uppermost spring leaf 22 there is also a fastening plate 32, which is not visible in the view shown, however. The upper and lower fastening plates 32 are connected to one another by connecting elements 30. The connecting elements 30 can be, for example, rivets or screws or other fastening means.In order for the connecting elements 30 to be able to connect the fastening plates 32 to one another, there is a corresponding recess 28 in the spring leaf 22 through which the connecting elements 30 can be passed.

[0041] From the Fig. 8 It is also evident that a tension strut 34 is attached to the underside of the leaf spring assembly 20. The tension strut 34 is connected at its front end to the front section 36 of the leaf spring assembly 20. The tension strut extends from there rearward toward the frame 6, where it is movably held in an elongated hole 38, which is in Fig. 7 is shown. The front and rear ends of the elongated hole 38 form a stop for movements of the leaf spring assembly 20 when the tension strut strikes there during spring movements of the leaf spring assembly 20.

[0042] Also from Fig. 7 It can be seen that the elongated hole 38 has a sensor 40 which, via a lever linkage, detects the movements of the tension struts 34 in the elongated hole 38. The sensors 40 transmit a position signal corresponding to the respective pivot position to an evaluation electronics unit 42 connected to the sensors 40.

[0043] From the Fig. 8 It can be seen that two support elements 44 are placed on the leaf spring assembly 20 in the exemplary embodiment, which support the conveying surfaces located above the leaf spring assembly. Fig. 8 The conveying surfaces are not shown in order not to obscure the view of the support elements 44. The conveying surfaces can be loosely placed on the support elements 44, so that the conveying surfaces are only supported flatly by the support elements 44, but the conveying surfaces can also be firmly connected to the support elements 44.

[0044] In Fig. 8 It is shown that the support elements 44 of adjacent leaf spring assemblies 20 can be connected by one or more webs 46 pivotally connected to the support elements 44. The webs 46 extend transversely to the working direction of the cutting unit 4. Webs 46 can, for example, prevent conveyor belts from sagging between the leaf spring assemblies 20 and thereby conveying the crop in a wave-like motion. Supported by the webs 46, a belt conveyor remains in a consistent horizontal plane. The webs 46 also limit the mobility of the leaf spring assemblies 20 transversely to the direction of travel.

[0045] In Fig. 8a 2 shows an enlarged sectional view of a connecting zone 26 between spring leaves 22 and the cutting elements 18. In this exemplary embodiment, two spring leaves 22 extend into the connecting zone 26. A fastening plate 32 is placed from above on the upper spring leaf 22, and a fastening plate 32 is placed from below on the lower of the two spring leaves 22. In order that the lower spring leaf 22 can compensate for length differences between the upper and lower leaf spring packages during oscillating movements of the leaf spring package 20 in one of the directions of movement indicated by the double arrow, the recesses 28b in the lower spring leaf 22, in contrast to the recesses 28a in the upper spring leaf 22, are designed as elongated holes which allow a relative movement of the lower spring leaf 22 in relation to the upper spring leaf 22 as length compensation.

[0046] In Fig. 9 It can be seen that in the cutting unit 4, a gear 48 is held in a slot 52, laterally offset from the rear end of a leaf spring assembly 20. Longitudinal movements of the output shaft 50, which could result from oscillating movements of adjacent leaf spring assemblies 20, as they are caused by the Fig. 9 are indicated by the double arrow, can now be compensated via the holder in the elongated hole 52 in the direction of the double arrow shown there.

[0047] In Fig. 10 Two possible spring characteristics 54a, 54b of rockers are shown. From the two spring characteristics 54a, 54b shown, it can be seen that the leaf spring assembly 20 of a rocker 16 is designed such that, when a cutting element 18 attached to it is deflected by, for example, 10 cm, it generates a contact pressure from the built-up restoring forces that is approximately 35 kg - as shown by spring characteristic curve 54a - and 60 kg - as shown by spring characteristic curve 54b. According to one embodiment of the invention, the spring characteristics of the leaf spring assembly 20 of a rocker 16 lie in a range between 15 kg and 80 kg. Leaf spring assemblies 20 with different spring characteristics 54 can be installed in a cutting unit 4.Thus, the leaf spring assemblies 20 closest to the center belt of a Draper cutting unit can generate a lower contact pressure, for example, according to spring characteristic curve 54a, because they are already subjected to a greater weight load from drive components and frame parts than other leaf spring assemblies 20, which then have a spring characteristic curve 54b with higher contact pressures to compensate for the lower weight load of these leaf spring assemblies 20. The result should be the most uniform contact pressure possible across the working width of the cutting unit 4, with which the cutting unit 4 glides over the ground surface.

[0048] In Fig. 11 is a sectional view through the cutting unit 4. The conveying element 14 in the Fig. 11 The exemplary embodiment shown shows a circulating belt conveyor which forms the conveying surface 56 on its upper side. During upward and downward movements of the cutting element 18 and the rocker 16, which are indicated by corresponding arrows, changes in the spatial position of the conveying surface 56 occur. The conveying surface 56 must also be supported in a changed spatial position and guided in its conveying movement. For this purpose, the support elements 44a, 44b are attached to the rocker 16 in a longitudinally movable manner, which is indicated by the double arrows. The movements of the longitudinally movable support element 44b are transmitted via the coupling rod 58, which in the exemplary embodiment acts with its rear end on the support element 44b and with its front end on the support element 44a. The support element 44a is supported on the front end of the cutting unit 4 via a rigid torque support 66.In this way, the torque support acts like another coupling rod 58. The coupling rod 58 and the torque support 66 transmit movements of the cutting element 18 in the longitudinal direction to the support elements 44a, 44b.

[0049] Due to their longitudinal mobility, the support elements 44a, 44b can follow the movements of the conveying surface 56 in a direction along the rocker arm 16. In this way, the support of the conveying surface 56 can be maintained even during upward and downward movements of the cutting element 18. In order to hold and guide the conveying surface 56 during upward and downward movements of the rocker arm 16 and the cutting element 18, a holding element 60 is mounted on the rear support element 44. In the exemplary embodiment, this holding element has a V-shaped groove as a driver 62. The belt conveyor is provided on the inside of its conveyor belt with a vulcanized profile that is shaped complementarily to the shape of the driver and engages in the cross section of the V-shaped groove as a driver 62.When the support element 44b moves along the rocker arm 16, the driver 62, with its V-shaped groove, entrains the belt conveyor and displaces it forward or backward in accordance with the longitudinal movement of the support element 44b. As a result, the front edge of the belt conveyor always remains in a sealed position relative to the cutting element 18 in the longitudinal direction of the rocker arm 16, so that no gaps arise at the front edge of the belt conveyor during movements of the rocker arm 16 and / or the cutting element 18, which could cause material loss and buildup. If the conveying surface 56 is not formed by a revolving belt conveyor but rather a rigid sheet, the driver can also be designed as a simple belt, hinge, or the like.

[0050] The holding element 60 is provided with a web 68, which prevents crop losses over the rear edge of the belt conveyor. The web 68, as a component of the holding element 60, is also connected to the movable rear wall 64, which supports and guides the conveying path of the crop rearward over the cutting unit 4. The movable rear wall is held by the holding element 60 via the web 68. The mobility of the movable rear wall 64 is also indicated by a double arrow. When the longitudinally movable support element 44b moves, the holding element 60 takes the movable rear wall 64 with it in the respective direction of movement. Since the holding element 60 has a closed surface in the transition area between the conveying surface 56 and the rear wall 64, it seals the transition between the conveying surface 56 and the rear wall 64.

[0051] In Fig. 11 It can be seen that the front section 36 of the rocker arm 16 is supported on the middle section 70 of the rocker arm 16 via a torque support 66. The front end of the torque support 66 is connected to the blade bracket 72, to which the cutting element 18 is attached. The rear end of the torque support 66 is connected to the support element 44a, which in turn is attached to the rocker arm 16. Bezugsziffernliste

[0052] 2 Harvester 4 Cutting unit 6 Frame (cutting unit) 8 Attachment frame 10 Feed channel 12 Attachment 14 Conveyor element 16 Rocker arm 17 Rear wall 18 Cutting element (knife bar) 20 Leaf spring package 22 Spring leaf 24 Clamping element 26 Connecting zone 28 Recess 30 Connecting element 32 Mounting plate 34 Tension strut 36 Front section 38 Slotted hole (tension strut) 40 Sensor 42 Evaluation electronics 44 Support element 46 Web 48 Gearbox 50 Output shaft 52 Slotted hole (gearbox) 54 Spring characteristic curve 56 Conveying surface 58 Coupling rod 60 Holding element 62 Carrier 64 Rear wall 66 Torque support 68 Web 70 Middle section 72 Blade angle

Claims

1. Cutterbar (4) for attachment to a harvesting machine (2), having a frame (6) extending at least substantially over the working width of the cutterbar (4), which has a mounting frame (8) with mounting means (12) for connection to a feeder housing (10) of the harvesting machine (2), wherein the frame (6) has swing arms (16) pointing in the working direction, at the front ends of which cutting elements (18) for cutting the crop are attached, characterized in that several or all of the swing arms (16) are each designed as a leaf spring package (20) composed of several leaf springs (22), several or all leaf springs (22) lying flat on top of one another are held together as a leaf spring package (20) at their frame-side end between tensioning elements (24) on the frame (6), only one or more of the leaf springs (22) arranged in the upper region of the leaf spring package (20) are connected with the cutting elements (18) and one or more of the leaf springs (22) held between the tensioning elements (24) on the frame (6) and arranged in the lower region of the leaf spring package (20) end in front of the connection zone (26) of the leaf springs (22) arranged in the upper region of the leaf spring package (20) with the cutting elements (18), as viewed in the working direction.

2. Cutterbar (4) according to claim 1, characterized in that at least one or more of the leaf springs (22) held jointly between tensioning elements (24) on the frame (6) at their frame-side end is / are connected with the cutting elements (18) and have recesses (28) for the passage of connecting elements (30) which connect fastening plates (32) placed on the upper and lower sides of the leaf spring (22) or the leaf springs (22) to one another for connecting the cutting elements (18) to the swing arm (16).

3. Cutterbar (4) according to claim 1 or 2, characterized in that a tension strut (34) is attached to the underside of each of the leaf spring packages (20), which is connected with the front section (36) of a leaf spring package (20) at its front end and extends from there rearwards in the direction of the frame (6), where it is held movably in an elongated hole (38) and the front and rear ends of the elongated hole (38) form a stop for movements of the leaf spring assembly (20).

4. Cutterbar (4) according to claim 3, characterized in that the cutterbar (4) has sensors (40) which detect the movements of the tension struts (34) in the respective elongated holes (38) and the sensors (40) transmit a position signal corresponding to the respective swivel position to an evaluation electronics (42) connected with the sensors (40).

5. Cutterbar (4) according to one of the preceding claims, characterized in that one or more support elements (44) are placed on one or more leaf spring packages (20), which support conveying surfaces (56) located above the leaf spring package (20).

6. Cutterbar (4) according to claim 5, characterized in that at least one of the support elements (44a, 44b) is connected with the swing arm (16) so as to be longitudinally movable.

7. Cutterbar according to claim 6, characterized in that the longitudinally movable support element (44a, 44b) is movably driven in its movement by one or more coupling rods (58) which are supported in the front section (36) of the swing arm (16) or of the cutting element (18).

8. Cutterbar according to claim 6 or 7, characterized in that a holding element (60) is connected with the longitudinally movable support element (44b), which element delimits the movable conveying surface (56) and guides it via drivers (62).

9. Cutterbar (4) according to one of the preceding claims 6 to 8, characterized in that a retaining element (60) is connected with the longitudinally movable support element (44), which supports and guides a movable rear wall (64) of the conveying path of the crop via the cutterbar (4).

10. Cutterbar (4) according to one of the preceding claims 8 or 9, characterized in that the retaining element (60) seals the transition between the conveying surface (56) and the rear wall (64).

11. Cutterbar (4) according to one of the preceding claims 5 to 10, characterized in that support elements (44) of adjacent leaf spring packages (20) are connected by one or more webs (46) pivotably connected with the support elements (44).

12. Cutterbar (4) according to one of the preceding claims, characterized in that the front section (36) of a swing arm (16) is supported on the middle section of the swing arm (16) via a torque bracket (66).

13. Cutterbar (4) according to one of the preceding claims, characterized in that a gear (48) with an output shaft (50) connected thereto for driving the cutting elements (18) and / or conveyor members (14) for conveying the crop is held in the frame (6) so as to be movable in the longitudinal direction in an elongated hole (52).

14. Cutterbar (4) according to one of the preceding claims, characterized in that the spring characteristic (54) of the leaf springs (22) of a leaf spring package (20) of a swing arm (16) is designed in such a way that, when a cutting element (18) attached thereto is deflected by 10 cm, it generates a contact pressure from the built-up restoring forces which is in a range between 15 kg and 80 kg.

15. Cutterbar according to claim 14, characterized in that leaf spring packages (20) which have different spring characteristics are installed in a cutterbar (4).