Screen assembly

Abstract

A screen assembly is provided that includes one or more planar members including one or more screens supported by rocker arms configured to swing the members back and forth. At least one rocker arm is connected to one of the components by a tapered connection device comprising first and second connectors having mating tapered surfaces. The conical connecting device can be fixed and released from one side of the rocker arm. To this end, a first connecting piece is rotatably mounted in an opening of the rocker arm, through which a fixing bolt passes and through the first connecting piece and is screwed into a second connecting piece, the latter being fixed to or integral with the planar part. The first connector is also provided with a threaded portion on one side of the rocker arm, so that after the fixing bolt is removed, a pin can be inserted into the first connector, and an auxiliary bolt can be screwed into the threaded portion, thereby separating the tapered surface.

Description

Technical Field

[0001] The present invention relates to agricultural machinery and in particular to improvements in the cleaning section of combine harvesters, primarily but not exclusively. Background Art

[0002] A combine harvester includes a screen assembly located in the cleaning section of the harvester, which is the area where grain kernels are separated from crop residues. The screen assembly typically includes a grain pan and one or more screens mounted in a rectangular frame, sometimes referred to as cleaning boots. The grain pan and screen are subject to a back-and-forth rocking motion, which may also be superimposed on a lateral rocking motion. The back-and-forth motion is driven by a drive mechanism that drives the rocking motion of support arms that are laterally coupled to the grain pan and screen. Several sets of these rocking arms are included to achieve a phase difference in the back-and-forth motion between different components, in particular a phase difference between the motion of the grain pan and the motion of one or more screens.

[0003] Due to the rocking motion caused by the drive mechanism, the connections between these sieves and grain pans and the respective rocker arms are subject to high forces. Therefore, these connections are usually realized as conical connections between matching and coaxial conical surfaces, which results in high strength and little or no play between the connected parts.

[0004] However, a problem with the conical connections currently used in this context is that they are usually designed to be secured or released from inside the cleaning section, for example by bolts which are inserted into the connection from the screen or grain pan area towards the swing arm. Accessing the connection in this way is often difficult, which makes replacement and maintenance of these connections a time-consuming task.

[0005] This problem may be exacerbated by the fact that these connections may be difficult to disengage due to the high friction between the tapered surfaces. Summary of the invention

[0006] The present invention relates to a screen assembly and a related method as described in the accompanying claims. Therefore, the present invention relates to a screen assembly comprising one or more planar components, which include one or more screens, supported by a rocker arm configured to actuate a back and forth rocking movement of the components. At least one rocker arm is connected to one of the components by a conical connection comprising a first and a second connection member, said connection member having matching conical surfaces. The conical connection device can be fixed and released from one side of the rocker arm. To this end, the first connection member is rotatably mounted in an opening in the rocker arm, and a fixing bolt passes through the opening and through the first connection member and is screwed into the second connection member, which is fixed to the planar component or is integral with the planar component. The first connection member is also provided with a threaded portion on one side of the rocker arm, allowing a pin to be inserted into the first connection member after removing the fixing bolt and an auxiliary bolt to be screwed into the threaded portion, thereby forcing the conical surfaces apart. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 is a conceptual side view of a combine harvester known in the prior art.

[0008] Figure 2 A grain pan of a screen assembly according to an embodiment of the invention is shown including four rocker arms connected to the grain pan.

[0009] Figure 3 A tapered connection device according to one embodiment of the present invention is shown.

[0010] Figure 4 yes Figure 3 Magnified view of the middle cone connection in the fixed position.

[0011] Figure 5 Shows the release Figure 3 Method of connecting the device in a tapered shape.

[0012] Figure 6 A tapered connection device according to another embodiment of the present invention is shown. DETAILED DESCRIPTION

[0013] Preferred embodiments will now be described with reference to the accompanying drawings.The detailed description does not limit the scope of the invention, which is defined solely by the appended claims.

[0014] refer to Figure 1 , a currently known combine harvester 1 comprises an engine 2 and a header 3 for cutting crops from the field and for collecting the crops into the inlet of a feeder 4. The feeder delivers the crops to one or two threshing rotors 5, which separate the larger crop material from the grain and smaller residues. A longitudinally mounted threshing rotor may be applied, as shown, but a transversely mounted rotor may equally be used.

[0015] The cleaning section 6 of the harvester includes a screen assembly including a grain pan 7 and a plurality of screens 8 for separating grain from smaller residues. Insufficiently separated crop material, also known as tailings, may be returned for cleaning after re-threshing by a tailings screw conveyor 9. Completely separated grain is collected in a grain box 10 by the combined action of a cleaning grain screw conveyor 11 and a grain elevator 12. From the grain box 10, the grain may be discharged from the harvester through another screw conveyor 13 and a rotatable nozzle 14 at the bottom of the grain box. Small crop residues, also known as chaff, are blown toward the rear of the harvester by a blower 15. Larger crop residues such as crop stems and leaves are moved to a chopping and spreading assembly 16, where they may be chopped into smaller particles and spread across a wider swath behind the advancing combine harvester.

[0016] As previously mentioned, the grain pan 7 and the screen 8 are connected to a drive mechanism. Figure 1 Not shown in the figure but known, the drive mechanism is configured to actuate the components of the screen assembly to rock back and forth. Typically, the grain pan 7 is configured to rock in anti-phase relative to one or more screens 8.

[0017] The present invention is not limited to Figure 1 The specific configuration shown in is only used to describe the context in which the present invention is applicable. In fact, the present invention is applicable to any screen assembly including a back-and-forth moving cleaning component.

[0018] Figure 2 A grain pan 20 of a screen assembly according to an embodiment of the present invention is shown. The pan is supported by four rocker arms 21 which are pivotally connected at one end to a support structure (not shown) so as to pivot about respective pivots 22. At their other ends, the rocker arms 21 are connected to the grain pan 20 by transverse connections 23 between the arms 21 and support brackets 24 which support a frame 25 of the grain pan 20. A drive mechanism (not shown, but generally known in the art) actuates the arms 21 in a rocking motion about their pivots 22, thereby rocking the pan back and forth so as to propel grain and other crop material toward a screen (not shown) mounted downstream of the grain pan 20.

[0019] Figure 3 A side view of a rocker arm 21 and part of a grain pan 20 is shown. The support structure 19 is partially shown, as well as the pivot 22 at one end of the rocker arm 21, at which end the arm is pivotably mounted on the support structure 19. It can be seen that the support bracket 24 is formed by different plate elements 24', which are connected to the frame 25 by bolt connections 26. This is only one example of a possible support bracket and the invention is not limited to this example. Figure 3 A cross-sectional view of the transverse connecting device 23 is shown in FIG. Figure 4 The lateral connection device 23 is a conical connection device according to an embodiment of the present invention. The connection device is suitable for use between the rocker arm 21 and the grain plate 20 and between the rocker arm and the screen.

[0020] The connection device 23 comprises a first connection member 30 and a second connection member 31 aligned along a common longitudinal axis 32 and having matching tapered surfaces 33 and 34 arranged coaxially about the axis 32. In the illustrated embodiment, the first connection member 30 comprises an outer (male) tapered surface 33 and the second connection member 31 comprises an inner (female) tapered surface, but the reverse may also be possible.

[0021] The first link 30 is rotatably mounted in an opening 35 in the rocker arm 21, which is located at the opposite end of the arm relative to the pivot axis 22. A swivel bearing 36 is mounted between the first link 30 and the opening 35 in the rocker arm 21, allowing the first link 30 to rotate relative to the arm 21 about the central axis 32. The bearing 36 is preferably a flexible bearing, allowing the first link 30 to have a certain degree of additional movement relative to the arm 21 in addition to rotation about the axis 32, such as a limited deviation of the link 30 from the vertical orientation shown relative to the arm 21. This may be necessary, for example, where a side-to-side rocking motion of the grain pan or screen is superimposed on a fore-and-aft rocking motion.

[0022] The second connecting element 31 is fixed to the supporting bracket 24 by means of bolt connections 27 and 28. According to other embodiments, an example of which will be given later, the second connecting element can be fixed to said bracket in other ways, or it can be integral with the supporting bracket or even with the grain pan.

[0023] The first and second connectors 30 and 31 include respective longitudinal internal openings 40 and 41 that are coaxially disposed and aligned with each other about the longitudinal axis 32. The opening 40 in the first connector 30 extends completely through the connector 30 from one side of the rocker arm 21 to the opposite side.

[0024] The threaded fixing bolt 42 passes through the opening 35 of the rocker arm 21 and the inner opening 40 of the first connecting member 30, and is screwed into the second connecting member 31. To this end, the opening 41 of the second connecting member 31 is provided with an inner thread 43 matching the outer thread of the fixing bolt 42. By tightening the head 44 of the bolt 42 on the outer end of the first connecting member 30 on one side of the rocker arm 21, the tapered surfaces 33 and 34 are forced into close contact with each other, thereby fixing the connection device.

[0025] like Figure 4 As shown, the inner opening 40 of the first connecting member 30 includes an internal threaded portion 45 at one end of the first connecting member 30 inserted into the opening 35 of the rocker arm 21. The inner diameter of the threaded portion 45 is larger than the outer diameter of the fixing bolt 42, so the fixing bolt 42 does not interact with the threaded portion 45. The fixing bolt 42 can be freely inserted into the opening 40 and only interlocks with the internal thread 43 of the second connecting member 31.

[0026] The function of the additional threaded portion 45 is related to the separation of the connectors 30 and 31 from each other. According to a preferred embodiment, the method of separating the connectors comprises the following steps. First, the fixing bolt 42 is removed by screwing it out from the opening 41 of the second connector 31. However, at this time, the connectors are still interlocked by the friction between the tapered surfaces 33 and 34.

[0027] like Figure 5As shown, the pin 46 is then inserted into the opening 40 from the right side shown in the figure, i.e., through the opening 35 of the rocker arm 21. The diameter of the pin 46 is larger than the outer diameter of the fixing bolt 42, but smaller than the diameter of the opening 40. Therefore, the pin 46 can be freely inserted into the opening 40 of the first connecting member 30, but cannot be inserted into the opening 41 of the second connecting member 31, i.e., the distal end surface 47 of the pin 46 is blocked by the entrance of the opening 41, as shown in FIG. Figure 5 The length of the pin 46 is such that when the distal end surface 47 contacts the second connecting member 31 , the proximal end surface 49 is located between the entrance of the opening 40 and the depth of the threaded portion 45 .

[0028] Now use the auxiliary threaded bolt 48, whose threads match the internal threaded portion 45. The auxiliary bolt 48 is screwed into the threaded portion 45 until it contacts the proximal end face 49 of the pin 46. By continuing to turn the head of the auxiliary bolt 48, the connecting pieces 30 and 31 are forced apart.

[0029] The advantage over existing tapered connections for supporting screen assembly components is that the connection is easily accessible from the side of the assembly. Therefore, securing and releasing the connection is easier than with existing arrangements.

[0030] exist Figures 3 to 5 In the embodiment shown, the internal opening 41 in the second connecting member 31 passes from one side, where the bolt 42 of the second connecting member 31 is screwed into the opening 41, to the other side. The bolt 27 fixing the second connecting member 31 to the support bracket 24 is screwed into the opening 41 from the other side. This configuration makes it possible to access the opening 41 from the other side by unscrewing the bolt 27. Due to this possibility, the connecting members 30 and 31 can be separated by screwing the auxiliary bolt 48 into the opening 40 from one side of the arm 21, inserting a pin from the other side and knocking the pin from the other side. However, this is a less preferred release method because it requires access to the connection device from the inside of the screen assembly, which is generally more difficult to do. Therefore, the release method described above is preferred and applies regardless of whether the opening 41 can be accessed from the inside of the screen assembly.

[0031] Figure 6 Another embodiment is shown. The first connector 30 is the same as in the first embodiment. The second connector 31 is now integral with the support bracket 29. The opening 41 is now a blind hole and cannot be accessed from the interior of the screen assembly. However, the above Figure 5 The release method shown is suitable for separating Figure 6 The connectors 30 and 31 in the embodiment.

[0032] According to the sieve assembly of the invention, the lateral connection between a set of rockers and the component supported by these rockers may conform to any of the above-described embodiments, whether the component is a grain pan or a sieve. However, not all connection devices have to conform to the invention. For example, only connection devices that require regular replacement or maintenance may conform to the invention, while other connection devices may conform to any prior art design. Therefore, the sieve assembly according to the invention is characterized by the presence of at least one conical connection device as described above and as described in the accompanying claims.

[0033] The screen assembly according to the invention can be used alone, for example as a fixed screen assembly, or integrated in a combine harvester. The invention also relates to a combine harvester comprising a screen assembly according to the invention.

Claims

1. A screen assembly, comprising: Support structure (19); one or more planar members (20) comprising one or more screens; A plurality of rocker arms (21) for carrying a planar component, the rocker arms being mounted transversely relative to the planar component, and the screen assembly further comprising an actuating mechanism configured to actuate a rocking movement of the rocker arms and thereby actuate a rocking movement of the planar component relative to a supporting structure, wherein at least one of the rocker arms (21) is connected to one of the planar components (20) by a conical connection device (23), the conical connection device comprising a first connection member (30) and a second connection member (31) aligned along a common longitudinal axis (32) oriented transversely relative to the rocker arm (21), the first connection member and the second connection member being provided with matching conical surfaces (33, 34), the first connection member (30) being rotatably mounted in an opening (35) in the rocker arm (21), the second connection member (31) being fixed to the planar component (20) or integral therewith, characterized in that: - the connection device (23) is fixed by a fixing bolt (42) which is inserted through the opening (35) in the rocker arm (21) and through the first connection piece (30) and screwed into the second connection piece (31), thereby forcing the matching conical surfaces (33, 34) into close contact with each other, - the first connection piece (30) comprises an internal threaded portion (45) accessible through an opening (35) in the rocker arm (21), the diameter of the internal threaded portion being greater than the diameter of the fixing bolt (42) so that the fixing bolt does not interact with the internal threaded portion (45), and the internal threaded portion (45) enables the auxiliary bolt (45) to be screwed into the first connection piece (30) when the fixing bolt (42) is removed.

2. The assembly of claim 1, wherein the screen assembly is a screen assembly of a combine harvester, and wherein the planar member comprises a grain pan (20) and one or more screens.

3. An assembly according to claim 1 or 2, wherein the second connecting member (31) comprises an opening (41) which is coaxially arranged around the longitudinal axis (32) and passes through the second connecting member (31), wherein a fixing bolt (42) is screwed into the opening (41) at one side of the second connecting member (31), and the second connecting member is releasably fixed to the support bracket (24) of the load-bearing planar component (20) at least by means of a bolt (27), wherein the bolt (27) is screwed into the opening (41) at the other side thereof.

4. An assembly according to claim 1 or 2, wherein the second connecting member (31) is integral with a support bracket (29) carrying the planar component (20).

5. An assembly according to claim 1, 2 or 4, wherein the second connecting member (31) comprises a blind hole (41) which is open to one side and into which the fixing bolt (42) is screwed.

6. A method for releasing the connection between a rocker arm (21) and a planar member (20) in a screen assembly according to any one of the preceding claims, the method comprising the steps of: - Unscrew and remove the fixing screws (42), - inserting a pin (46) having a proximal end (49) and a distal end (47) into the opening (35) in the rocker arm and through the first connecting member (30), the pin being freely insertable into the first connecting member (30) but not being able to pass through the second connecting member (31), so that the distal end (47) of the pin is blocked by the second connecting member (31), - screwing the auxiliary bolt (48) into the internal threaded portion (45) of the first connecting member (30) until said auxiliary bolt contacts the proximal end (49) of the pin, - Continue screwing the auxiliary bolt (48) into the internal threaded portion (45), thereby forcing the tapered surfaces (33, 34) apart.

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