GB2160753A - Whole crop harvesting or separating apparatus - Google Patents

Abstract

A whole crop harvester 4 comprises a threshing first rotor 12 operative also to separate out the grain content of the crop and to commence stalk breaking. Unseparated material from the first rotor 12 is fed to a contra-rotating stalk-breaking second rotor 16. Rotor 16 is also operative to continue the grain separation process begun at rotor 12 and to feed material into a stalk-chopping third rotor 24. The same features may also be used in a stationary threshing machine. <IMAGE>

Description

SPECIFICATION Whole crop harvesting or separating apparatus The present invention relates to whole crop harvesting orseparating apparatus i.e. to harvesting or separating apparatus, for use with cereals, pulses, grasses and other crops which harvestthestalkparts ofthe crop as well as the grain-bearing or seed- bearing upper parts of the crop. For convenience, the term "grain" will be used to refer to seeds as well as to grain proper. In particuiar, but not exclusively, the invention relates to a whole crop harvesting or separating apparatus for use with wheat.

According to the present invention, a whole crop harvesting or separating apparatus comprises a threshing first rotor feeding the stalks into a second rotor operative to continue the stalk-breaking process begun by the first rotor. Preferably the two rotors rotate in opposite senses and stalks leave the first rotoralong a path which is substantiallytangential to the two rotors.

Conveniently, the first rotor is operative both to separate outthe grain content ofthe crop and to commence stalk-breaking and the stalk-breaking second rotorwhich is also operative to continue the grain separation process begun at the first rotor and to feed material into a stalk-chopping third rotor.

Conveniently, material is fed from the second rotor to the third rotor along a path lying substantially radiallyofthethird rotor.

Conveniently, the apparatus also includes a grain conveyor adapted tofeed separated grain to a grain-bagging location orto a separator operative to separate the grain from any material other than grain (M.O.G.) reaching the grain conveyor.

Conveniently, one or more of the rotors is operative to provide a stream of airto assist in the separation of the grain from the M.O.G.

Conveniently, the apparatus includes drive means for the first and second rotors operative to drive the second rotor significantly faster e.g. at about one and half times, the peripheral speed of the first rotor.

Typically, for example, the second rotor might rotate at a peripheral speed of between 20 and 30 metres per second compared with between 15 and 20 metres per secondforthefirst rotor Conveniently, the first rotor co-operates with a concave on which crop-engaging bars are spaced apart in the direction of rotation ofthe rotor by 30 mm or less, a preferred spacing being 20 mm or less.

Conveniently, the first and second rotors andlor concaves are of similar or substantially identical construction.

It will be appreciated that the apparatus of the present invention may equally well take the form of a mobile harvesting machine or a stationary threshing machine.

An embodiment of the invention will now be described, by way of example only, with reference to the accompanying drawing which shows a partially diagrammatic representation of a whole crop harvester as viewed from the rear of the harvester looking forwards.

Thus, referring now to the drawings, a tractormounted whole crop harvester4foruse in the whole crop harvesting of wheat, comprises a crop-threshing first rotor 12 rotating clockwise to receive crop from a chain and slatfeed elevator 14 and feed ittangentially into a contra-rotating straw-breaking second rotor 16.

The feed elevator 14 is fed axially from one end ofan auger 17 itself preceded by a conventional or largely conventional combine harvestertable assembly offset to cut the standing crop and designedfora minimum cutting height of down to 50 mm above ground level.

Although shown in its operative position, the table assembly can, if desired, be moved to a transport position by pivoting it about a vertical axis 18 until it lies lengthwise ofthe harvester.

Although the primary purposes of having the table assembly movable into a transport position is to reduce the effective width of the harvester to a value acceptablefor road transport, it also enablesthe harvester to be used as a stationery thresher. This is done by detaching the drive to the table assembly and placing a collection hopperatthe position occupied by the table assembly during harvesting.

Alternatively, ifthetable assembly is driven when in its transport position,the towing tractor can instead be reversed to lay open the field and spread out a window forcollection during a subsequent crop- harvesting run ofthe machine.

The so-called "threshing rotor" 12 is conveniently a 500 mm long 500 mm diameter open-framework drum fitted with six detachable beater bars of conventional construction, three having right-handed serrations and three having left-handed serrations. The drum is designed to rotate with a peripheral speed of from 15 to 25 metres per second and in addition to threshing it will also operate to separate outthe grain content of the crop and to commence stalk-breaking.

The concave 20 with which the drum 12 co-operates is preferably an open-framework concave adapted to provide the drum with a 190 wrap in two 95 sections.

The first of these sections is radiussed to provide a drum-to-concave gap tapering in the direction of drum rotation from an initial clearance of 8 mm at the leading end of the gap to a 3 mm clearance at the rear end. Preferably,the drum-to-concave gap is adjustable. The second section of the concave is radiussed to provide a 3 mm drum-to-concave adjustable clearance and both sections ofthe concave are lined by 3 mm wide 20 mm deep bars spaced on 16 mm centres.

These bars run at right angles to the direction of crop flow.

The so-called "straw-breaking" second rotor 16 which is of the same or similar construction and dimensions as rotor 12 is positioned vertically overthe first rotor and as already discussed, it rotates in an anti-clockwise sense to allow a tangential feed of drop from the first rotor to the second. In addition to straw-breaking, the rotor 16 is also effective to continue the grain separation process begun at the first rotor.

The distance between the two rotor centres is typically 550 mm and the peripheral speed of rotor 16 is adjustable from between 20 metres per second and 30 metres per second.

Like concave 20, the concave 22 for rotor 16 is also of an open-framework construction and orovides 170C wrap in two 85 sections with the first section tapering to provide a 3 mm rotor-to-concave clearance as before. Similarly, the concave 22 is lined with 3 mm wide20 mm deep bars spaced on 16 mm centresand the rotor-to-concave clearance is adjustable to allow adjustmentforwear.

As will be seen from the drawings, material leaving the second rotor 16 is discharged along a path lying radially of a so-called "straw-chopping" third rotor 24 positioned 250 mm above rotor 16 and offset to its left as viewed in the drawing. The rotor 24 is fitted with twelve shear plates each 50 mm deep, 6 mm thick and extending the flu 0.5 metres ofthe drum width. The centre-to-centre spacing between rotors 16 and 24 is 550 mm.

In operation, the rotor 24 is rotated in the same anti-clockwise sense as rotor 16 but at a greater peripheral spped of between 40 and 50 metres per second.

The concave 26 for rotor 24 is a single section closed construction providing the rotor with a 90 wrap.

Again, the concave is lined with 10 mm square section bars spaced on 20 mm centres and with an adjustable rotor-to-concave clearance to compensate for wear.

Atthe discharge end of concave 26, the rotor 24 will wither operate to spread the chopped straw overthe field orto discharge it horizontally to a straw-bagging platform (not shown) atthe left-hand side ofthe machine.

Atypical straw bag size would be one cubic metre capacity into which the straw would be packed at a density of between 30 and 40 kg per cubic metre, say.

For easy changeover, it is convenientto provide the straw-bagging platform with attachment means for two bags with a crop flow detector so that while one bag is being filled at one location, that already filled at the other location can be replaced by an empty bag.

In operation ofthe apparatus, the rotors 12,16 and 24 are driven from the tractor p.t.o. at speeds within the ranges referred to above and the threshing rotor 12 will remove about 90% of the total grain content present in the crop input and some 15% to 20% of the total M.O.G. content.

Afurther8% ofthetotal grain content will be removed by rotor 16 together with 15% to 20% of the M.O.G. content, the straw component being finely broken by the action of rotor 16.

The remaining 1 % to 2% ofthetotal grain content and the remaining 60% to 70% of the total straw content will be removed by the rotor24to the straw-bagging platform referred to earlier.

Material separated out at the first and second rotors on the other hand and passing through concaves 20, 22, is transferred forwards by augers 28,30 respectivelyto a chain and flap elevator 32, either directly in the caseofauger28orvia a chute 33 in the case ofauger 30.

At its upper end, the elevator 32 can discharge the material into a horizontal auger34which conveys the material rearwardsto a grain-bagging platform at35 with similar changeoverfacility to that already de scribed fo rthe jtraw-bagging platform. Conveniently, the capacity of each grain bag is half a cubic metre and the density of the grain and straw mix in each bag is between 90 and 120 keg per cubic metre. The mix can then be taken to a conventional farm-located cleaner to separate out the grain content in the usual way.

The drawings show an alternative construction however in which the bagging platform at35 has been replaced by a bolt-on grain-cleaner unit 36 and at least in this case the tube for auger 34 is progressively cut away to give a roughly evenly spread discharge over the whole length ofthe auger.

In essence, unit 36 comprises an inlet duct38 extending across the full 0.5 metre width of the machine and traversed by a traverse duct 40 through which a cross-flow air (42) is induced bythewindage from rotating drum 24. The slot width of duct 38 is typicallyabout75 mm to induce the necessary momentum in the auger discharge entering the cross-fl ow 42.

In this version ofthe apparatus, grain discharged from duct 38 will be substantially unaffected by the winnowing action of cross-flow 42 and will pass directly to a horizontally reciprocating screen cleaner 44 where the grain will pass through the inclined upper sieve section 46 onto an inclined plate section 48 which will direct itto the cross auger 50. The latter will take the grain to a bragging unit atthe rear oft he machine.

Any unthreshed heads or heavy straw also present in the grain contentwill in due course be discharged from the lower edge of the reciprocating sieve section into a chute portion 52 from whence itwill return via duct54throughthe open faces ofthe chain and slat elevator l4to join the incoming crop on its way to threshing rotor 12.

Light chaff and finely chopped straw, however, will be highly responsive to the cross-flow 42 which will carry them to rotor 24 for discharge with the main straw componentto the straw-bagging platform.

Unthreshed heads and heavy straw leaving the duct 38 will behave aerodynamically somewhere between these two extremes and will be deflected by the cross-flow 42 to an intermediate chute 56. From here they will return via duct 54 to the feed elevator 14 for recycling to the rotor 12 etc. with the freshly cut crop from the table assembly.

It should be pointed outthatthe rotor 24 and the associated housing and concave etc. are all detachable allowing the machine to be converted to or manufactured as a two-rotor version which because of its particularconfigurationand mode of operation will be valuable as a largely slope-insensitive machine capable of efficiently removing grain in an undulating terrain. In this case, the output ofthe remaining two rotors might, for example, be ducted to ground for later baling by a conventional baler.

The radial feed to the rotor 24 means thatthe performance of that rotor is largely independent of its direction of rotation and in alternative embodiments, the rotor 24 rotates in the opposite sense to rotor 16 and the material-receiving portions ofthe machine are repositioned and, if necessary redesigned, accordingly.

Turning now to other variations, a first modification (not shown) of the illustrated harvesterdiffers principally only so far as the cross-flow of air 42 is produced by an appropriate fan or blower, excess air being removed from the discharge end of unit 36 through a dust sock. Conveniently, an aircontrol flap is included in duct 40.

Asecond modification (notshown) of the illustrated harvester differs from in principally only in so far as the sieve section 46 of the illustrated embodiment is replaced by the similarly inclined and perforated lower surface of a rotating cleaning cylinder, the upper end of which accepts material from duct38.

In operation of this second modification, any light chaff and finely chopped straw enering the cleaning cylinderfrom duct 38 will be blown by cross-flow42 up the interior ofthe cylinderfor passage along unit 36 as before. The grain componentfrom duct 38, however, will pass through the cylinder perforations for collection by the auger 50 whilst the unthreshed heads will move down the interior of the rotating cylinderfordischarge at its lower end into chute portion 52.

Ciearly, although the specific description refers to a harvesterfor mounting on a four-wheel tractor, this is not essential and the invention should be taken also to include an apparatus for mounting on a two-wheel tractor, for example, orfortowing, as well as an apparatus in the form of a self-propelled machine or a stationary threshing machine.

Although described above in detail only for use with wheat, harvesters and separators according to the present invention may, as already indicated, also be used forthe whole crop harvesting orseparating of other plants especially the other cereals including rice.

Claims (15)

1. Awhole crop harvesting or separating apparatus comprising a threshing first rotor feeding the stalks into a second rotoroperative to continue the stalk-breaking process begun by the first rotor.

2. An apparatus as claimed in Claim 1 in which the two rotors rotate in opposite senses and stalks leave the first rotor along a path which is substantially tangential to the two rotors.

3. An apparatus as claimed in Claim 1 or Claim 2 in which the first rotor is operative both to separate out the grain content of the crop and to commence stalk-breaking and the stalk-breaking second rotor is also operative to continue the grain separation process begun at the first rotor and to feed material into a stalk-chopping third rotor.

4. An apparatus as claimed in Claim 3 in which material is fed from the second rotorto the third rotor along a path lying substantially radially ofthe third rotor.

5. An apparatus as claimed in any preceding claim including a grain conveyor adapted to feed separated grain to a grain-bagging location orto a separator operative to separate the grain from any material other than grain reaching the grain conveyor.

6. An apparatus as claimed in any preceding claim in which one or more of the rotors is operative to provide a stream of airto assist in the separation ofthe grain from material otherthan grain.

7. An apparatus as claimed in any preceding claim where a threshing first rotor and a contra-rotating stalk-breaking second rotor are provided, the harvester including drive means forthe first and second rotors operative to drive the second rotor significantly fasterthanthefirst rotor.

8. An apparatus as claimed in Claim 7 in which the drive means is operative to drive the second rotor at about one and halftimes the peripheral speed ofthe first rotor.

9. An apparatus as claimed in Claim 8 in which the drive means is operative to drive the second rotor at a peripheral speed of between 20 and 30 metres per second compared with between 15 and 20 metres per second forthe first rotor.

10. An apparatus as claimed in any preceding claim in which the first rotor co-operates with a concave on which crop-engaging bars are spaced apart in the direction of rotation ofthe rotor by 30 mm or less.

11. An apparatus as claimed in Claim 10 in which the bars are spaced apart by 20 mm or less.

12. An apparatusasclaimed in any preceding claim in which the first and second rotors and/or concaves are of similar or substantially identical construction.

13. An apparatus as claimed in any preceding claim in the form of a mobile harvesting machine.

14. An apparatus as claimed in any of Claims 1 to 12 in the form ofastationarythreshing machine.

15. A whole crop of sepa rating appa ratus substan- tially as hereinbefore described with reference to and/oras illustrated in the accompanying drawing.