DOUBLE-KNAB CUTTING SYSTEM

Description

[0001] The invention relates to a double-blade cutting system comprising a bar back on which a knife back for an upper knife and a knife back for a lower knife are arranged, and a plurality of double-blade cutting elements are fastened to the knife back, wherein the upper and lower knives are driven in an oscillating back and forth manner, and knife guides for the upper knife and knife guides for the lower knife are fastened to the bar back, which knife guides comprise guide arms, wherein a projection is formed on the bar back on its side facing away from the knife guides at least in the area between adjacent knife guides with guide arms for the lower knife and the knife guides with guide arms for the upper knife.

[0002] The double-blade cutting systems discussed here are used to cut all types of stalk crops, such as green fodder, specialty crops, grain, vegetables, and the like. They are also used for trimming hedges, roadside vegetation, and in water management (both along watersides and underwater).

[0003] Such a double-blade cutting system is known, for example, from DE 31 02 861 A1 and DE 15 82 418 A1. Double-blade cutting systems achieve optimal mowing results with large working widths, especially with low drive power. A particularly distinctive feature of double-blade cutting systems is a clean, smooth, low-vibration cut of the crop. This is highly desirable, for example, when producing clean forage and also demonstrably guarantees optimal regrowth of the crop.

[0004] A gap is formed between the back of the beam and the back of the knives. This gap is necessary to prevent the guide arms of the lower knives from colliding with the back of the beam during the back and forth (pendulum) movement of the guide arms. This danger arises from the structural design of the guide arms of the lower knives. These extend from the knife guides initially above the back of the beam and, at the ends of the back of the beam facing away from the knife guides, dip downwards in front of the knife back towards the ground and accommodate the lower knife in the area of ​​the guide blades. The material thickness of the guide arms themselves and their pendulum movement require a sufficient gap between the back of the beam and the back of the knives to enable unhindered movement of the guide arms of the lower knives.

[0005] The familiar double-blade cutting systems fulfill their intended tasks. However, the gap between the back of the bar and the back of the blades poses the risk that loose crop cut by the cutting elements can become lodged in the gap and clog it. This significantly impedes the crop flow through the double-blade cutting system. In extreme cases, this can lead to an interrupted crop flow. Such an interrupted crop flow results in the crop, which must be discharged rearward over the back of the bar during the further course of mowing, being held back by the clogging crop, and the last cut crop gradually being pushed forward into the still-standing crop.This crop is then turned over and consequently cut at a significantly greater height above the ground, which over time leads to an increase in stubble height and, in extreme cases, the cutting ability of the cutting unit is completely lost.

[0006] Against this background, the invention is based on the object of creating a double-blade cutting system in which the risk of clogging of the gap between the back of the beam and the back of the blades is reduced while simultaneously allowing unhindered movement of the guide arms of the lower blades. According to the invention, this object is achieved with the features of patent claim 1.

[0007] The invention provides a double-blade cutting element for oscillating double-blade cutting systems, which, on the one hand, ensures unhindered movement of the guide arms of the lower blades and, on the other hand, reduces the risk of clogging of the gap between the bar back and the blade backs. By providing the projection, the gap is reduced in certain areas, thereby reducing the possibility of grass clippings becoming lodged. This results in improved crop flow. In particular, the risk of crop flow interruption is minimized.

[0008] For the understanding of the present invention, individual terms are defined below: Cutting unit: Describes the entire assembly comprising the bar back, blade guide elements, and mowing blades, including the interface to the support frame and the oscillating drive. Bar back: Describes the profile that holds the blade guide elements, including the rocker blade guides. Blade guide elements: Describes the rocker blade guides that guide the upper and lower blades and are attached to the bar back. Mowing blade: Describes the arrangement of the blade back and a multitude of individual blades attached to it. Guide blade: Describes a blade blade equipped with a guide pin for holding the blade on the rocker blade guide.

[0009] In a further development of the invention, the projection is formed between two adjacent knife guides with guide arms for the lower knife. Consequently, the projection extends over the entire distance between two guide arms for the lower knife. This also reduces the gap in the area of ​​the guide arms for the upper knives, which also significantly improves the crop flow in this area and further reduces the risk of clogging the gap between the back of the beam and the knife backs.

[0010] Further developments and refinements of the invention are specified in the remaining subclaims. Embodiments of the invention are illustrated in the drawings and described in detail below. They show: Figure 1: a sectional plan view of a double-blade cutting system according to the prior art; Figure 2 a) a sectional plan view of a beam back according to the prior art; Figure 2 b) a section along the line AA in Figure 2 a) ; Figure 3 shows a section through a double-blade cutting system according to the prior art; Figure 4 shows a sectional plan view of a double-blade cutting system according to the present invention; Figure 5 a) shows a sectional plan view of a beam back according to the present invention; Figure 5 b) shows a section along the line AA in Figure 5 a) ; Figure 5 c) the section along the line BB in Figure 5 a) Figure 6 shows a section through a double-blade cutting system according to the present invention.

[0011] The double-blade cutting system chosen as an exemplary embodiment consists of a bar back 1 on which a blade back 2 for an upper blade 4 and a blade back 3 for a lower blade 5 are arranged. A plurality of double-blade cutting elements 6 are attached to the blade back 2 for the upper blade 4; a plurality of double-blade cutting elements 7 are attached to the blade back 3 for the lower blade 5. The double-blade cutting elements 6 and 7 are attached to the blade backs 2, 3 by means of fastening means 8.

[0012] Attached to the back of the beam 1 are knife guides 10 for the upper knife 4 and knife guides 110 for the lower knife 5. The knife guides 10, 110 comprise guide arms 11, 111. The guide arms 11 have spring properties, whereby the upper knife 4 with its cutting elements 6 is pressed against the lower knife 5 with its cutting elements 7.

[0013] Bushings are formed at the free ends of the guide arms 11, 111, of which only the bushing 112 of the guide arm 111 of the lower blade 5 is shown in the figures. The bushings serve to accommodate guide pins on double-blade cutting elements 6, 7, of which only the guide pin 71 of a cutting element 7 of the lower blade 5 is shown in the figures. The knife blades provided with a guide pin each form a guide blade, which Figure 3 and 6 which is labelled "7 F" as an example for the lower knife guide shown.

[0014] A projection 20 is formed in sections on the side of the beam back 1 facing away from the knife guides 10, 110. In the area of ​​the projections 20, a gap y is formed between the beam back 1 and the knife backs 2, 3. As can be seen, the projection 20 extends in the area between adjacent knife guides 110 with guide arms 111 for the lower knife 5. Thus, in the exemplary embodiment, the projection 20 also extends through the area of ​​the knife guides 10 with guide arms 11 for the upper knife 4.

[0015] Between the projections 20, recesses 21 are formed, which increase the distance between the bar back 1 and the blade backs 2, 3. This distance essentially corresponds to the width of the gap x between the bar back 1 and the blade backs 2, 3 according to the prior art, as described in Figure 1As a result, it is ensured that the guide arms 111 for the lower blade 5 have the freedom of movement known from the prior art and required for unhindered movement.

[0016] As can be seen, the projections 20 each have a radius that forms the transition to the recesses 21. On the back of the beam 1, on its side facing away from the knife guides 10, 110, in the area of ​​the guide arms 11 for the upper knife 4, a flattened portion 23 is formed. In the exemplary embodiment, this flattened portion is formed by a milling cut at an angle to the horizontal.

[0017] In a modification of the embodiment, it is also possible, if necessary, to interrupt the projections 20 in the area of ​​the guide arms 111 for the lower blade 4 and to provide recesses 21 there.

[0018] Due to the projections 20, the gap y formed between the bar back 1 and the knife backs 2, 3 is reduced compared to the gap x known from the prior art. Only in the area of ​​the guide arms, and particularly in the area of ​​the guide arms for the lower knife, is the projection interrupted by recesses, thus ensuring smooth mobility of the guide arms during operation. At the same time, the projections significantly improve crop flow due to the reduced gap.

Claims

1. Dual knife cutting system consisting of a beam back (1), on which a knife back (2) for an upper knife (4) and a knife back (3) for a lower knife (5) are arranged and a plurality of dual knife cutting elements (6, 7) are attached to the knife backs (2, 3), wherein the upper knife (4) and lower knife (5) are driven to move back and forth in an oscillating manner, and knife guides (10) for the upper knife (4) and knife guides (110) for the lower knife (5) are attached to the beam back (1), which comprise guide arms (11, 111), wherein on the beam back (1) on its side facing away from the knife guides (10, 110), at least in the area between adjacent knife guides (110) with guide arms (111) for the lower knife (5) and the knife guides (10) with guide arms (11) for the upper knife (4), a projection (20) is respectively formed, characterised in that in the area of the guide arms (111) for the lower knife (5) recesses (21) are formed in the projection (20).

2. Dual knife cutting system according to claim 1, characterised in that the projection (20) is formed in each case between two adjacent knife guides (110) with guide arms (111) for the lower knife (5).

3. Dual knife cutting system according to claim 1 or 2, characterised in that the projections (20) each have a radius.

4. Dual knife cutting system according to claim 2 or 3, characterised in that a flattened portion (23) is respectively formed on the beam back (1) on its side facing away from the knife guides (10, 110) in the area of the guide arms (11) for the upper knife (4).