GB2200526A - Harvesting apparatus - Google Patents

Abstract

Harvesting apparatus comprising a mobile frame, and means for detaching from standing crop predetermined required parts of the crop such as grain, leaving stripped stems in the field. The detaching means may strip grain from the stems whereby the harvested crop mixture contains a high proportion of free grain which has been thrashed by the stripping means, and this is separated from the crop mixture before the crop mixture is passed to the threshing drum. In one form of the invention an apertured screen 40 is provided beneath a transverse conveying auger 27 so that free grain passes through the screen while the crop mixture is being conveyed towards the threshing means. Separated free grain is collected and transported to the normal cleaning and separating mechanism of the combine harvester after the thrashing drum. The combine may have a conventional cutter-bar header, the screen being below the transverse auger. The conveying means may be an overhead chain and slat conveyor, or series of paddles instead of an auger. <IMAGE>

Description

HARVESTING APPARATUS The present invention relates to apparatus for harvesting crop.

The apparatus is concerned with harvesting apparatus for detaching grain, or other required portions of a crop, from a standing crop, to leave the remaining stripped parts of the crop standing in the field. The invention has -particular application in the harvesting of grain crops, such as wheat, oats, barley and rice. There have been proposed previously a large number of different forms of apparatus for stripping crop in this way, and the present invention is particularly applicable in connection with the apparatus and method set out in our previous patent application, WO 86/01972 (NRDC). In such apparatus one of the main advantages is that the crop mixture leaving the stripping means has a much lower portion of unwanted material than is the case with a conventional cutting table of a combine harvester.However, the mixture leaving the stripper still contains unwanted material such as straw, and the mixture is therefore fed to a threshing means for separating the required crop parts such as the grain.

It has been found -that, in the case of a grain crop, the mixture leaving the stripping means includes a substantial proportion of free grain, which has in effect been threshed by the action of the stripping means. It is one object of the present invention, at least in preferred embodiments, to provide apparatus for separating such free grain from the crop mixture before the crop mixture is passed to a threshing means.

However, in a broader aspect, it is an object of the invention to provide means for separating other free required crop parts from a harvested mixture of free required crop parts and other material.

According to the present invention in a first aspect there is provided apparatus for harvesting crop comprising a mobile frame for movement over the ground) crop stripping means for stripping from a standing crop required parts of the crop, a conveying auger arranged transverse to the direction of forward travel of the apparatus for receiving detached crop material from the crop stripping means and conveying the crop material transversely to the direction of forward travel of the apparatus, and an apertured screen beneath the auger for separating required crop parts from the crop material by the crop parts passing through the apertured screen as the stripped crop material is moved over the screen by the auger.

The apertured screen may comprise a perforated sheet of material, for example having circular holes, or may be formed by any member suitable to form the base of the pathway under the auger and having apertures which may be circular, rectangular, or of any other appropriate shape. For example the apertured screen may comprise a grill or grating.

The auger may be a conventional single flight auger-, or multiple flight auger, or may have separated paddle flights, or other means for transferring the mixture in an axial direction generally in the manner of an auger.

Preferably, the auger is arranged to receive crop material from the crop stripping means across substantially the full width of the auger, and to gather the material transversely to an exit from the auger which is narrower than the width of the auger.

For example the auger may be a centre feed auger having a centrally placed exit from the auger.

In a preferred form, the stripping means comprises a plurality of outwardly projecting crop stripping elements mounted on a moveable support means in a transverse array across the direction of forward movement of the frame, and drive means for driving the moveable support means to move the crop stripping elements upwardly through the crop as the apparatus moves forwardly, so as to detach from standing crop predetermined required parts of the crop. Preferably the moveable support means is a rotor mounted for rotation about an axis transverse to the direction of movement of the apparatus.

In one preferred arrangement, there is provided a brush or other flexible material attached to the outer edge of the auger flight, for facilitating passage of free crop parts through the apertured screen by sweeping the crop mixture across the screen. In addition, or as an alternative, there may be included a series of flexible paddles mounted on a central core of the auger, for sweeping over the apertured screen and for urging free crop parts through the screen.

The invention has particular use in apparatus in which the said auger is a feed auger for collecting crop mixture from the full width of an array of stripping elements, and for gathering the crop mixture for onward conveying to a threshing means.

In a preferred form the apparatus includes threshing means arranged to receive from the auger crop material conveyed over the screen. Preferably the apparatus includes further conveying means for collecting crop parts which have passed through the perforated screen and conveying the crop parts to join further crop parts to join further crop parts which have been separated by the threshing means.

The invention has particular use where the apparatus is adapted to strip free grain and grain heads from a standing grain crop. the said apertured screen being dimensioned to allow free grain to pass through the apertures while preventing passage of grain heads.

The apparatus has particular application in a harvesting apparatus of the kind set out in our published patent application No; WO 86/01972. The present invention has particular use where a mobile harvesting apparatus includes crop stripping elements mounted on a rotor, each of the elements having a discrete narrow tip for entering into and dividing crop, and having edges for detaching required crop parts, the sides of the elements diverging from each other in a direction away from the distal tip of the element, and each crop stripping element having a transverse surface between the said diverging sides for impelling the detached crop parts along a crop flow passage, the drive means being arranged to drive the crop stripping elements at a speed such that detached crop parts do not reside to any substantial extent on the moving crop stripping elements, and the arrangement being such as to deliver from the rotor a high-speed stream of detached crop parts in a wide crop stream extending transverse to the direction of forward movement of the apparatus. Such a wide crop stream is then conveniently collected centrally by a transverse auger, which in accordance with the invention can be made to serve an additional function of separating crop parts from the mixture by the use of the apertured screen beneath the auger.

The use of the present invention in such apparatus may be used to increase the grain through-put when the harvested grain crop is passed to a conventional combine harvester, and also to reduce the amount of damage to seed caused by the severe action of the threshing drum. It is known that the composition of the material harvested by a stripping rotor of the kind set out above contains between 20% and 72% of free grain (an average value may be 47%) that has been threshed by the action of the stripping rotor. If this amount of grain can be separated from the main flow of material into the combine threshing and separating mechanism, it will (a) not pass through the threshing drum and risk damage, and (b) reduce the amount of grain to be separated by the drum and following separating system, whether this system consists of straw walkers, an axial flow separating system, or a multi-drum type, or other type of grain/straw separating mechanism. Reducing the loading on these components allows an increase in the grain harvesting capacity of the combine harvester.

Embodiments of the invention will now be described by- way of example with reference to the accompanying drawings in which: Figure 1 is a diagrammatic side view of apparatus for separating free grain from a mixture of grain and other material in a mobile harvesting apparatus; Figure 2 is a perspective view of part of a conveying auger shown in Figure 1, and embodying the invention; Figure 3 is a perspective view of a modification of the conveying auger of Figure 2; Figure 4 is a diagrammatic perspective view of an elevator shown in Figure 1; and Figure 5 is a front view of a crop stripping rotor suitable for use in the apparatus of Figure 1.

Referring to Figures 1 and 5, the apparatus shown by way of example is a harvesting apparatus for stripping grain from a cereal crop. The apparatus comprises a mobile frame 12 on which is mounted a rotor 11, carrying outwardly projecting crop engaging elements 15. The rotor 11 is driven in the so-called overshot mode so that the crop engaging elements 15 are moved in an upward direction at the front of the apparatus. A hood or cover 18 extends around at least part of the front half of the rotor and defines with the rotor elements 15 a crop flow passage 33 along which crop is conveyed by the rotor.

In operation, rotation of the rotor 11 moves the crop engaging elements 15 so that the distal tips of the elements enter the crop with minimum disturbance of the stems of the crop1 the elements 15 then move upwardly through the crop, gathering one or more crop stems. As the elements 15 reach the upper parts of the crop the required crop parts, for example grain, are detached from the stems. After detachment, the required crop parts are conveyed upwardly and rearwardly over the rotor 11 and pass to a transverse crop feed auger 27 positioned within a collecting trough 28, for transferring crop laterally towards the centre of the apparatus. The crop is then transferred rearwardly by a slatted chain elevator 31 up an inclined pathway.

Referring to Figure 5, the rotor 11 comprises an inner core 13 and a succession of transverse combs 14 spaced circumferentially around the rotor. Each tooth 15 of the comb has side edges 16 and 17 which diverge from each other in a direction away from the distal tip of the tooth 15. There is provided at the junction of each adjacent pair of side edges 16 and 17 of adjacent teeth 15, an enlarged aperture 21 formed by relieved portions of adjacent teeth at the base regions thereof.

In operation material including free grain, grain heads, and some straw, is dislodged by the side edges and apertures 21 of the teeth 15, and is impelled upwardly and rearwardly along the passage 33 to the auger 27.

The general operation of the crop stripping rotor 11 may be as set out in our prior published patent application WO 86/01972.

With reference to Figures 1 and 2, the base of the auger trough 28 is constructed from perforated material forming an apertured screen 40, the perforated material having an aperture size best suited to the type of grain being harvested. For cereal crops the best size may be 12 mm round holes, but this can range from about 8 to 14 mm. Alternatively the holes could be square, rectangular or any other suitable shape. The perforated material may form the total area of the auger trough, or simply form part of it along the axis of the auger, with non-perforated sheet forming the remainder.

By necessity, the auger usually has a clearance of about 10 mm between itself and the auger trough.

Embodiments of the invention may include such an arrangement, but preferably, for separation to be more effective, the perforated material may be swept by a brush or flexible material attached to the auger.

Referring to Figure 3 there is shown a modification of the apparatus in which rubber or other flexible paddles 41 are mounted on the core of the auger, following the auger screw over the full length of the auger. Also shown in Figure 4, brush or other flexible material 42 is attached to the outer edge of the auger flight over the full length of the auger. Both elements are intended to sweep the perforated screen area intermittently, and the two forms of sweeping element may be provided as alternatives, or in combination.

Beneath the perforated auger trough 28 is provided a further auger 43, shown in Figure 1, for collecting free grain and transporting the grain. Where the apparatus comprises a grain stripping header fitted to a conventional combine harvester, the grain separated at the perforated screen 40 is conveniently conveyed by the auger 43 and by a further upwardly inclined elevator 44 to the grain pan of the conventional combine harvester, for cleaning by the combine sieves.

Referring now to Figures 1 and 4, an additional separating of free grain from the mixture may be achieved by an apertured screen 50 forming the base of the pathway along which crop is elevated by the chain and slat elevator 31. The apertured screen 50 may be formed of perforated material such as has been described previously.

Material pa-ssing through the perforated screen 50 is collected in a trough 51 and conveyed transversely by a further auger 52. The free grain is then transferred by a further inclined elevator 53 to the cleaning system of the combine. The material leaving the elevator 31 passes to a threshing drum 54. Grain threshed from the drum 54 then passes to the grain pan or straw walkers 55 for separation and cleaning in the usual way. Any un-threshed heads that may be collected by the pre-separator system formed by the two perforated screens 40 and 50, will be returned to the combine threshing drum 54 by way of the normal returns system.

In addition to the features of the invention set out in the introduction of the specification, there is also provided in accordance with a broad aspect of the present invention apparatus for harvesting crop comprising a mobile frame for movement over the ground, crop gathering means for removing from a standing crop required parts of the crop, conveying means arranged transverse to the direction of forward travel of the apparatus for receiving detached crop material from the crop gathering means and conveying the crop material transversely to the direction of forward travel of the apparatus, and an apertured screen beneath the conveying means for separating required crop parts from the crop material by the crop parts passing through the apertured screen as the crop material is moved over the screen by the conveying means.

It is to be appreciated that in this broad aspect of the invention, the pre-separator- system according to the invention may have application in conventional combine harvesters using cutter bar headers, particularly when dealing with crops that shatter easily, for example oil seed rape. In such circumstances the output of the cutter bar header frequently contains a high proportion of free seeds.

Separation of these will ease the load on the threshing drum and cleaning system of the conventional combine harvester in the same way as has been described for a harvester which strips crop and leaves standing stems.

It should also be appreciated that in this broad aspect of the invention, the conveying means need not necessarily be an auger, but may be for example an overhead chain and slat conveyor, or a series of paddles arranged to push the crop material over the apertured screen to effect the required conveying of the crop transversely to the direction of forward travel of the apparatus.

Returning now to consideration of the main form of the present invention, in which there is provided a transverse auger for conveying and separating a mixture of free grain and grain heads and other material, there may be provided a modification in which roughened elements are attached to the outer surface of the auger flights, and/or to the auger pan, so as to obtain a degree of threshing of unthreshed or partly threshed material, while the material is moved transversely over the auger pan. The roughened elements may be strips of metal of similar nature to conventional rasp bars in a conventional threshing cylinder.

Thus in accordance with this feature of the invention, there may be provided on the conveying means, and/or along the pathway over which the conveying means conveys crop material, threshing members for effecting threshing of crop material during conveying by conveying means.

Another modification which may be provided of an embodiment of the invention when utilising an auger conveying means, is that the auger pan may comprise a number of easily replaceable sections allowing changes of aperture size for widely differing crops.

Alternatively the auger pan may be formed from adjustable aperture sieve sections for example having an action similar to a venetian blind-.

Claims (12)

1. Apparatus for harvesting crop comprising a mobile frame for movement over the ground crop stripping means for stripping from a standing crop required parts of the crop, a conveying auger arranged transverse to the direction of forward travel of the apparatus for receiving detached crop material from the crop stripping means and conveying the crop material transversely to the direction of forward travel of the apparatus, and an apertured screen beneath the auger for separating required crop parts from the crop material by the crop parts passing through the apertured screen as the stripped crop material is moved over the screen by the auger.

2. Apparatus according to claim 1 in which the auger is arranged to receive crop material from the crop stripping means across substantially the full width of the auger, and to gather the material transversely to an exit from the auger which is narrower than the width of the auger.

3. Apparatus according to claim 2 in which the auger is a centre feed auger having a centrally placed exit from the auger.

4. Apparatus according to any preceding claim in which the crop stripping means comprises a plurality of outwardly projecting crop stripping elements mounted on a moveable support means in a transverse array across the direction of forward movement of the frame, and drive means for driving the moveable support means to move the crop stripping elements upwardly through the crop as the apparatus moves forwardly, so as to detach from standing crop predetermined required parts of the crop.

5. Apparatus according to claim 4 in which the moveable support means is a rotor mounted for rotation about an axis transverse to the direction of movement of the apparatus.

6. Apparatus according to any preceding claim in which there is provided a brush or other flexible material attached to the outer edge of the auger flight, for facilitating passage of free crop parts through the apertured screen by sweeping the crop mixture across the screen.

7. Apparatus according to any preceding claim including a series of flexible paddles mounted on a central core of the auger, for sweeping over the apertured screen and for urging free crop parts through the screen.

8. Apparatus according to any preceding claim including threshing means arranged to receive from the auger crop material conveyed over the screen.

9. Apparatus according to claim 8 including further conveying means for collecting crop parts which have passed through the perfdrated screen and conveying the crop parts to join further crop parts which have been separated by the threshing means.

10. Apparatus according to any preceding claim in which the apparatus is adapted to strip free grain and grain heads from a standing grain crop, the said apertured screen-being dimensioned to allow free grain to pass through the apertures while preventing passage of grain heads.

11. Apparatus for harvesting crop comprising a mobile frame for movement over the ground, crop gathering means for removing from a standing crop required parts of the crop, conveying means arranged transverse to the direction of forward travel of the apparatus for receiving detached crop material from the crop gathering means and conveying the crop material transversely to the direction of forward travel of the apparatus, and an apertured screen beneath the conveying means for separating required crop parts from the crop material by the crop parts passing through the apertured screen as the crop material is moved over the screen by the conveying means.

12. Apparatus for harvesting crop substantially as hereinbefore described with reference to-Figures 1, 2, 4 and 5, or Figures 1 to 5, of the accompanying drawings.