Cutting unit for a combine harvester
A length-adjustable support beam in the cutting unit of a combine harvester compensates for bending-induced length changes, addressing material fatigue and maintaining axle lever stability for extended durability and ease of maintenance.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- SCHRATTENECKER FRANZ
- Filing Date
- 2024-11-05
- Publication Date
- 2026-05-15
AI Technical Summary
Existing cutting units for combine harvesters experience material fatigue and exert high lateral and torsional forces on axle levers due to strong bending when following uneven surfaces, leading to reduced durability and potential damage.
A length-adjustable support beam is integrated beneath the flexible cutter bar, allowing it to compensate for length changes during bending, maintaining consistent distances between axle levers and preventing transverse and torsional forces.
The solution ensures prolonged and damage-free operation on uneven surfaces by minimizing forces on axle levers, enhancing the cutting unit's robustness and facilitating easy maintenance.
Smart Images
Figure AT2024060431_15052026_PF_FP_ABST
Abstract
Description
[0001] Cutting unit for a combine harvester
[0002] Technical field
[0003] The invention relates to a cutting unit for a combine harvester with a cutter bar comprising a flexible support bar, which is height-adjustable relative to the support frame by means of several axle levers arranged distributed over the width of the cutting unit, which engage at one end on the cutter bar and at the other end on a support frame.
[0004] State of the art
[0005] A cutting unit for a combine harvester is known from WO2020257838A1. The cutting unit comprises a flexible cutterbar, in particular with a flexible support bar, on which several fingers and a cutter bar that can be moved longitudinally along the support bar may be arranged. The relative movement between the cutter bar and the fixed fingers allows grain or other material arranged between the cutter teeth and fingers to be cut in a manner known from the prior art. The flexible cutterbar is height-adjustable relative to the support frame by means of several axle levers distributed across the width of the cutting unit, which engage the cutterbar at one end and a support frame at the other. Because the support bar, and thus the entire cutterbar, is designed to be flexible and height-adjustable transversely to the direction of travel, the cutterbar can adapt to the contour of the surface to be cut transversely to the direction of travel of the combine harvester.This can be done depending on actuators and sensors, as can be seen in WO2020257838A1. However, a disadvantage is that with particularly strong bending of the cutter bar, resulting from following especially uneven surfaces to be mowed, the cutter bar exerts high lateral and torsional forces on the axle levers, which lead to material fatigue of these axle levers.
[0006] From EP4136954A1 a cutting unit with a support beam comprising several support beam sections is known, wherein the support beam sections are movable relative to each other.
[0007] US4446683 shows a cutting unit with a cutter bar comprising several separate cutter bar sections.
[0008] Description of the invention
[0009] The invention is therefore based on the objective of proposing a robust cutting unit for a combine harvester that enables the longest possible and damage-free use, even on particularly uneven surfaces to be mowed.
[0010] The invention solves the stated problem by designing the support beam to be length-adjustable in the longitudinal direction. According to the invention, the support beam, via which the cutter bar is connected to the axle levers, can compensate for length changes in the longitudinal direction. This prevents the axle levers from being pulled towards each other, as is the case in the prior art, even with particularly strong curvature of the flexible cutter bar transversely to the cutting or travel direction, since the length-adjustable support beam compensates for any bending-related shortening of the cutter bar. In this way, the normal distances between the axle levers remain essentially constant – within the limits of the possible length compensation – so that no transverse or torsional forces are exerted on them. Within the scope of the invention, a support beam is provided beneath a flexible support beam or a flexible cutter bar, conforming to the contour of the surface to be mowed transversely to the cutting or travel direction.The beam is understood to be a beam that adapts, at least in essence, to the direction of travel of the combine harvester. For this purpose, the support beam or the cutter bar can be held to the frame of the header unit by means of spring plates or longitudinal links. The flexible and length-adjustable support beam can have fingers or double fingers. The flexible and length-adjustable support beam can be the connecting link between the remaining components of the cutter bar and the axle levers. The flexible and length-adjustable support beam can form a guide for a cutter bar, resulting in a particularly compact cutter bar. The cutter bar can also be designed to be flexible.
[0011] A structurally simple length adjustment of the support beam, and thus of the cutter bar, which also facilitates easy maintenance, is achieved when the support beam comprises several separate support beam sections that can be moved relative to each other in the longitudinal direction. For example, if only one support beam section is damaged, it can be replaced independently of the other, intact support beam sections.
[0012] To enable the beam sections to be joined together to form a single beam in a simple and safe manner, it is proposed that one end section of the beam section be attached to an axle lever associated with that beam section, and the other end section of the same beam section be attached to a different axle lever associated with that beam section. Depending on the length of the beam sections, they can therefore run between just two adjacent axle levers, or, in the case of longer beam sections, connect several axle levers together, so that one end section of the beam section is attached to a first axle lever and the other end section of the same beam section is attached to a second axle lever not adjacent to the first, with at least one further axle lever connected to the beam section between the first and second axle levers.The degree of length compensation of the support beam, and thus of the cutter bar, can be adjusted by changing the number of beam sections used. To achieve sufficient flexibility of the support beam, it can incorporate or be made of spring steel.
[0013] In principle, length adjustability can be achieved by connecting the support beam sections to the axle levers at both ends via floating bearings. To maintain an overall stable cutter bar despite the length adjustability, the support beam sections can be connected at one end via a floating bearing to a first axle lever assigned to the respective support beam section, and at the other end via a fixed bearing to a second axle lever assigned to the respective support beam section. In the simplest case, the floating bearing can be a screw connection inserted into a slot located in one end section of the support beam section, allowing the support beam section to slide along its slot.In the simplest case, the fixed bearing can be a screw connection inserted into a hole located in the other end section of the beam section, so that the beam section is immovable along this hole.
[0014] For a compact arrangement of two adjacent beam sections on an axle lever, the end sections of two adjacent beam sections can overlap in the longitudinal direction of the beam and be offset from each other transversely to the longitudinal direction of the beam. The end section of a first beam section with the fixed bearing can form a stop for the end section of a second adjacent beam section with the floating bearing.
[0015] Brief description of the invention
[0016] The invention is illustrated by way of example in the drawing. Fig. 1 shows a schematic perspective view of the cutting device according to the invention.
[0017] Fig. 2 is a detail view of Fig. 1, where, for clarity, the cutter bar is shown in a foreshortened form and
[0018] Fig. 3 shows a top view of a schematically represented cutter bar according to the invention.
[0019] Ways to implement the invention
[0020] A cutting unit 1 according to the invention for a combine harvester (not shown) has, as can be seen in Fig. 1, a support frame 2 with several axle levers 3 articulated to the support frame 2 via joints 4. A cutter bar 5 is arranged at the end sections of the axle levers 3 opposite the joints 4, and is thus height-adjustable relative to the support frame 2 via the axle levers 3. As indicated in Fig. 1, the cutter bar 5 has a flexible support beam 6. Thus, the cutter bar 5 can also be flexible. The cutter bar 5 and the support beam 6 can be flexible and therefore bendable transversely to the direction of travel 7. According to the invention, the support beam 6 is designed to be length-adjustable in the longitudinal direction of the support beam, so that changes in length due to bending in the longitudinal direction of the support beam 6 can be compensated and no transverse and torsional forces are exerted on the axle levers 3 and their joints 4.In addition to the support beam 6, the cutter bar 5 can include a cutter bar 8, which is only indicated in Fig. 1. The cutter bar 8 can be displaced in the longitudinal direction of the support beam relative to fingers 9, which are shown only sporadically for clarity, via a drive mechanism (not shown) in a manner known from the prior art. This creates a cutting area between the fingers 9 and the blades of the cutter bar 8.
[0021] Figure 3 shows a schematic representation of the cutter bar 5, where it can be seen that a plurality of fingers 9 or pairs of fingers are arranged on the support bar 6 along its longitudinal direction. The continuous cutter bar 8 can also be seen in Figure 3.
[0022] As can be seen from all the figures, the support beam 6 can comprise several separate support beam sections 10 that can be moved relative to each other in the longitudinal direction of the support beam, resulting in a simple construction for length adjustability.
[0023] As shown in Fig. 1, one end section of the beam section 10 can be attached to one pivot lever 3 and the other end section of the same beam section 10 to another pivot lever 3. While the pivot levers 3 shown in Fig. 1 are adjacent, meaning that one beam section 10 connects only two pivot levers 3, one beam section 10 can also connect several pivot levers 3. In this case, pivot levers 3 are attached not only to the end sections of the beam sections but also between them.
[0024] The beam sections 10 can be connected at one end via a floating bearing 11 and at the other end via a fixed bearing 12 to their respective associated pivot levers 3. Figure 2 shows in particular that the floating bearing 11 can include an elongated hole 13 through which the beam section 10 is slidably mounted on a receptacle 15 of the pivot lever 3 by means of a screw 14. The screw 14 thus secures the beam section 10 in the axial direction of the screw 14, but allows movement in the longitudinal direction of the elongated hole, so that the head of the screw 14 does not exert a clamping force on the beam section 10. The fixed bearing 12 can be a connection by means of two screws 14 that fasten the beam section 10 to the receptacle 15.
[0025] Figure 3 indicates that the support beam 6 can form a guide for the cutter bar 8. The cutter bar 8 can also be designed to be flexible. In particular, the support beam 6 and / or the cutter bar 8 can be made of spring steel. Figure 2 reveals that adjacent end sections of two neighboring support beam sections 10 are arranged overlapping in the longitudinal direction of the support beam and offset from each other transversely to the longitudinal direction of the support beam, i.e., in the direction of travel 7. In this way, the end sections of two neighboring support beam sections 10 can be attached to a common mounting 15 in a space-saving manner.
Claims
Patent claims 1. Cutting unit (1) for a combine harvester with a cutter bar (5) comprising a flexible support bar (6), which is height-adjustable relative to the support frame (2) via several axle levers (3) arranged distributed over the width of the cutting unit, which engage at one end on the cutter bar (5) and at the other end on a support frame (2), characterized in that the support bar (6) is designed to be length-adjustable in the longitudinal direction of the support bar, wherein the support bar (6) comprises several separate support bar sections (10) that are displaceable relative to each other in the longitudinal direction of the support bar, and wherein one end section of the support bar section (10) is arranged on one axle lever (3) and the other end section of the same support bar section (10) is arranged on another axle lever (3).
2. Cutting unit (1 ) according to claim 1 , characterized in that the support beam sections (10) are connected at one end via a loose bearing (11 ) to a first axle lever (3) assigned to the respective support beam section (10) and at the other end via a fixed bearing (12) to a second axle lever (3) assigned to the respective support beam section (10).
3. Cutting unit (1 ) according to claim 1 or 2, characterized in that the support beam (6) forms a guide for a cutter bar (8) of the cutter bar (5).
4. Cutting unit (1 ) according to one of claims 1 to 3, characterized in that the support beam (6) is made of spring steel.
5. Cutting unit (1) according to one of claims 1 to 4, characterized in that adjacent end sections of two adjacent beam sections (10) are arranged overlapping in the longitudinal direction of the beam and offset from each other transversely to the longitudinal direction of the beam.