A straw conveyor device in a combine harvester.
The present invention relates to a straw conveyor device in a combine harvester, comprising an endless conveyor belt for transport of straw from a cutter apparatus in a direction towards a threshing cylinder, wherein an auxiliary conveyor is provided above said conveyor belt.
It is known to use endless conveyor belts in order to bring the straw from the cutter apparatus of a combine harvester in a direction towards, possibly all the way up to, a thresh¬ ing drum. Usually it is used a conveyor belt having trans¬ verse ribs, and the straw is moved by the ribs on the lower, straight part of the belt, in that a board is provided in a certain distance b'elow said part of the belt, in order to support the straw while being moved by the belt. The belt is mounted stationary, which brings about that straw may pile up in front of the entrance end of the belt, behind the cutter apparatus, in particular when the straw is of a small length, so that the cut straw does not reach the belt. The location of the belt relatively to the cutter apparatus is optimal only for one particular straw length. Because such belts with transverse ribs are used together with transverse screw conveyors which bring the straw from the outer end of the cutter apparatus towards the middle of the combine har¬ vester it is not possible to place the entrance end of the belt close to the cutter apparatus.
It is also known to use conveyor belts which convey the straw lying on the upper side of the belts. Whether the belt comprises transverse ribs or not, the straw will tend to slide laterally when the combine harvester is working in a sloping terrain, so that the straw is conveyed only to one side of a thresher drum. This causes a straw pile up and possibly a stoppage.
For the known combination of conveyor belts and transverse screw conveyors it is known to use cutter blades which are adapted to the straw length, so that the straw is cut in a
suitable distance from the belt relatively to the straw length. This involves replacement of cutter blades when the straw length varies, which is a time consuming work and often leads to omission of the work, so that the combine harvester works with cutter blades which are not optimally adapted to the straw length. Another disadvantage is of course that the purchase of several sets of cutter blades means increased investment costs.
When using conveyor belts which extend substantially along the entire width of the cutter apparatus the entrance end of the belt may be situated as close to the cutter apparatus that the straw will fall down on the belt irrespective of the strawlength. A problem is, as mentioned, that the straw may slide laterally in sloping terrain. Moreover, the transportation of straw may be inefficient, in particular when the belt is sloping upwardly towards a threshing cylinder. Thus is of course still worse when the combine harvester works downhill.
A device as mentioned introductorily is known from Norwegian Acceptance Print No. 148941. Here the auxiliary conveyor is a rotor situated at the exit end of the conveyor belt, and it only acts to bring the straw to a threshing cylinder.
The object of the present invention is to provide a device which permits an efficient transportation of the straw, irrespectively of the straw length and irrespectively of whether the combine harvester works with lateral slope or downhill.
According to the invention this is achieved with a device as specified in the succeeding claim 1.
The conveyor belt, which is driven continuously during the threshing, will by means of said device convey the straw very efficiently, irrespectively of the straw length, because the auxiliary conveyor may be placed in a distance .from the cutter apparatus which is adapted to the straw length and approxi-
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mately corresponds to said length. Thereby the cut straw, which falls rearwardly towards the belt, will immediately enter between the belt and the auxiliary conveyor, and the straw will efficiently be carried rearwardly, and possibly be thrown, so that it falls down on the rear end of the belt or behind the belt. The straw will almost instantane¬ ously assume the velocity of the belt. When the straw length varies the auxiliary conveyor or its entrance end may be moved along the upper side of the belt, so that the distance from the cutter apparatus is always optimal.
It is not presupposed that the shifting of or changing the length of the auxiliary conveyor must be performed by means of mechanically and/or hydraulic means, because there is in practice not necessary to perform frequent adjustments. Compared with for instance the work of replacing cutter blades the shifting or changing the length of the auxiliary conveyor, also manually, is simple. It may for instance have a shaft or shaft pins which are mounted in shiftable bearing housings, which may for instance be clamped anywhere along rails . Alternatively the auxiliary conveyor may be rotatable on a shaft or two shaft pins, and these may for instance be shiftable in grooves along the conveyor belt. Of course means may be provided for a more or less automatic- shifting or changing of the length, as for instance hydraulic cylinders- which are connected to bearing housings or to a shaft of the auxiliary conveyor. The latter may also be mounted on a manually, mechanically or hydraulically shiftable slide or frame.
It is not even presupposed that the auxiliary conveyor is directly driven in rotation, because it is in the principle sufficient that it is driven by being in contact with the belt, possibly via straw therebetween. It is, however, possible to provide direct drive for the auxiliary conveyor. Due to the fact that it shall be shiftable or be adjustable with respect to its length along the upper side of the belt it is, however, an advantage to avoid usual mechanical drive
means for the auxiliary conveyor if this involves that parts of the drive mechanism has to be shifted when the auxiliary conveyor is to be shifted or adjusted with respect to its length.
A solution which involves that it is not necessary to shift the drive mechanism is that the auxiliary conveyor comprises an endless belt which runs past at least three rollers, of which one roller may be shifted along the conveyor belt, and that the position of one of the remaining rollers may be changed in order to tighten the endless belt, while the third of the rollers is connected to a drive mechanism and is stationary mounted in the combine harvester.
Another solution is that the auxiliary conveyor comprises a rotor which is coupled to at least one endless drive belt or drive chain which has a straight portion along the upper side of the conveyor belt and runs past stationary mounted rollers, and the rotor is operatively connected to at least one such straight portion, and is mounted in such a manner that it may be shifted parallelly to the conveyor belt.
The auxiliary conveyor may, whether it comprises a rotor or an endless belt, be provided with transverse ribs or brushes. This contributes, when the rotor or the endless belt passes the conveyor belt in a certain distance, to carry the straw efficiently along the conveyor belt. Ribs or brushes on the auxiliary conveyor may also be combined with ribs on the conveyor belt. This is particularly advantageous when the auxiliary conveyor comprises brushes, which will bend when they hit the ribs on the conveyor belt, so that wear and damage are avoided.
The essential of the invention is, however, that the auxiliary conveyor may be adjusted according to the straw length. The auxiliary conveyor, when being a rotor, or the entrance end of the auxiliary conveyor, when comprising an endl-ess belt, may be shifted along the upper side of the conveyor belt, so
that the rotor or said entrance end, respectively, is situated in such a distance from the cutter apparatus that the straw falls rearwardly and is immediately brought into the intermediate space between the conveyor belt and the auxiliary conveyor, and thereby to be carried efficiently rearwardly towards a thresher drum.
The invention will in the following be explained more detailed, by means of embodiments shown on the annexed drawings.
In the drawings are mainly shown only those components of a combine harvester which have connection with the invention.
Thus, Fig. 1 shows the forward end of a combine harvester,- being equipped with a first embodiment of a device in accordance with the invention.
Similarly, Fig. 2 shows the forward end of a combine har¬ vester, being equipped with a second embodiment of a device in accordance with the invention.
Fig. 1 shows a combine- harvester comprising an endless conveyor belt 1, adapted to carry straw cut by a cutter apparatus 2 rearwardly to a threshing cylinder 4. Above the conveyor belt is provided an auxiliary conveyor 3, in the form of an endless belt 6 having substantially the same width as the conveyor belt 1. The endless belt 6 runs past three rollers 7, 8 and 9, and may be equipped with transverse brushes 11 which during operation sweep along the conveyor belt 1. In order to permit adjustment of the auxiliary conveyor 3 according to the length of the straw falling rearwardly from the cutter apparatus 2 one roller 7 may be shifted along the conveyor belt 1, as indicated by the arrow A-A . This may be accomplished by for instance that the roller 7 is mounted in (not shown) bearing housings,' or that a roller shaft extends into (not shown) slits extending along the conveyor belt 1. In order to maintain suitable tightness
in the endless belt 6 a second roller 8 is adapted to be shifted parallelly, as indicated by the arrow B-B. The third roller 9 is mounted stationary in the combine harvester, and may appropriately be the driving roller of the auxiliary conveyor, by being connected to a (not shown) drive mechanism. This brings about the advantage that the drive mechanism is not influenced by the shifting of the rollers 7 and 8. It will be appreciated that also the roller 8 may be mounted in shiftable bearing housings or have a shaft which may be shifted in slits. The direction shown for the shifting of the roller 8 is perpendicular to the conveyor belt 1, but this is not a presupposition.
When the straw is cut, it will fall down against the conveyor beit 1, and if the end of the straw falls down immediately in front of the roller 7, i.e. to the left of the roller in the drawing, the straw will be caught by the brushes 11 of the auxiliary conveyor 3 and be carried efficiently rearwardly between the auxiliary conveyor and the conveyor belt 1. Thereupon the straw passes a stone collector 14, and is carried to the threshing cylinder 4, whereby in a con¬ ventional manner a beater 6 may be mounted rearwardly of the threshing cylinder. Below the threshing cylinder is a concave element 16. Moreover, knives 15 may be mounted mutually spaced in the transverse direction of the combine harvester.
In addition a grate 17 may be provided, rising from the concave element 16. Possibly a second threshing cylinder (not shown) may be situated, rearwardly of the beater 6.
If the straw is too short to fall down immediately in front of the roller 7 with its upper end, there is a risk that the straw will pile up before the straw is caught by the brushes 11. In order to avoid this the invention permits that the roller 7 may be shifted rearwardly, into a suitable distance from the cutter apparatus relatively to the straw length.
If the straw is of such a length that it does hot fall down
in front of the roller 7, the straw will hit the downwardly running, sloping part of the endless belt 6, and may pile up in front of the auxiliary conveyor 3. A large quantity of straw may then be carried simultane¬ ously between the conveyor belt 1 and the auxiliary conveyor 3, and this may cause operational interruptions. This is avoided by shifting the roller to the right in Fig. 1, so that the long straw falls with its upper end immediately in front of the roller 7.
The auxiliary conveyor 3 causes an efficient transport¬ ation of straw in the direction towards the threshing cylinder 4, and prevents that the straw slides laterally on the conveyor belt 1 in sloping terrain. In addition is achieved an efficient transportation of straw even when the combine harvester is working downhill, in such a manner that the transportation path is steep.
Fig. 2 shows ah embodiment in which an auxiliary con¬ veyor 3 in the form of a rotor equipped with brushes 11 is provided above a conveyor belt 1. The rotor 5 is with its shaft 18 mounted in a slit 19 which is parallel to the conveyor belt 1. The other end of the shaft is mounted in a corresponding slit. The rotor 5 is driven by an endless drive belt or drive chain 10, which runs past two stationary rollers 12 and 20, and one of these rollers is connected to a (not shown) drive mechanism. In the example also the roller 12 is equipped with brushes 11. The drive belt or drive chain is situated either at the ends of the rollers 12 and 20 and the rotor 5 or it has a small width, so that it does not prevent the straw in falling down to the conveyor belt after having been cut by the cutter apparatus 2. In the example the conveyor belt 1 is equipped with transverse ribs 21.
Moreover is shown a threshing drum 4, a grate 17, a concave element 16, in addition to a drum 22 and a second grate 23, which are conventional elements without any particular connection to the invention. Moreover, a rotor 13 equipped with brushes 24 is mounted above the roller 12. The purpose of the rotor 13 is to bring the straw up to the threshing cylinder 4 in cooperation with the roller 12.
It will be appreciated that the roller 5 may be shifted along the conveyor belt 1, depending on the straw length, in an analogous manner as the roller 7 shown in Fig. 1 and with the same effect, i.e. that the position of the roller may be adjusted to be optimal in relation to the straw length with respect to efficient transportation towards the threshing cylinder 4. Provided that a drive chain 10 is used which co¬ operates with a (not shown) toothed wheel on the rotor 5, on both sides thereof, shifting of the rotor 5 can only take place after the connection with the chain is released at least on one side of the rotor 5, for instance by slackening of the chain, for instance by a slight movement of the roller 20 or the roller 12. Provided that the rotor 5 is only in engagement with the chain 10 on one side, shifting of the rotor 5 may also take place during operation. Thus, the shaft 18 of the rotor 5 may be connected to for instance hydraulic cylinders for parallel displacement, possibly controlled from the operator's seat in the combine harvester. It is, however, not imperative that shifting of the rotor 5 must be possible without manual work, since frequent adjustments during operation are normally not necessary. Therefore, the shaft 18 may be mounted in such a manner that it has to be loosened and shifted manually, whereupon it is fastened manually in the desired position.
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