Crop harvesting apparatus and methods

Abstract: Apparatus for harvesting crop comprises a rotor 11 mounted on a mobile frame 12 and carries a succession of transverse combs 14 each formed of an array of outwardly projecting teeth 15 transverse to the direction of movement of the apparatus through the crop. Each tooth 15 is pointed with side edges diverging away from the distal tip of the tooth. The rotor rotates in the overshot mode and the combs intrude into the crop and gather crop stems between adjacent pairs of teeth and detach grain and grain heads, or other required crop parts, by rubbing or breaking the parts free from the stems. The junction of adjacent teeth 15 preferably has an enlarged aperture 21 to assist stripping and to allow withdrawal of stripped stems.

Description: The present invention relates to apparatus for, and methods of, harvesting crop. The invention is concerned with detaching from the stems or other plant parts of standing crop, seeds, seed-bearing parts, leaves, twigs, flowers, or other predetermined required portion of the crop, collecting the required portion, and leaving the remaining stripped parts of the crop standing in the field. The invention has particular but not exclusive application in the harvesting of grain crops, such as wheat, oats, barley, and rice. The invention also has application in the stripping of leaves, young shoots, and sometimes blossom from crops. Examples include lucerne (alfalfa) leaves for protein production, and the leaves and flowers of herbs and other crops used for the extraction of essential oils and other constituents. The present specification contains subject matter in common with patent application No. 85904843.1, publication number 0195810, from which the present specification has been divided. In US-A-1418542 (Dill) a harvester for stripping grain from standing crop has a stripper reel composed of a series of spirally arranged stripper bars having stripper teeth or fingers. The stripper teeth are triangular and the side edges, which diverge from the distal tip, have upstanding flanges which strip and catch the grain and throw it back into troughs formed at the base of each row of stripping teeth. A stationary hood encases the reel and is open at its lower front portion. In US-A-2372821 (Gathercoal) a machine for picking flower blossoms such as pyrethrum, has a cylindrical drum rotated near the middle of a mobile machine having a front and rear hopper for collection of the picked flowers. The drum carries radially extending arms which are parallel sided for most of their length but are tapered at the distal ends. The arms are flat on their forward faces throughout their length. The rotor is said to be rotated at high speed and the flower heads are said to be thrown centrifugally into one of the hoppers. Each arm is said to have a sharp cutting edge and the pyrethrum flowers are harvested by being struck by the arms and snapped from their stems by the action of the rapidly revolving arms and are then thrown centrifugally into one of the hoppers. In patent SU-A-898989 (Danchencko et al), and in a paper entitled "Threshing Standing Rice with a Brush-Type Combing Device" by Danchencko, N.N., Mekhanizatsiya i Elektrifikatsiya Sel'skogo Khozyaistva 1984, 9, 30-31, (date of publication unknown) there is disclosed a device for threshing standing rice plants by a brush rotor of spring-steel wires. The rotor rotates in the overshot mode in a reception chamber which is very widely spaced from the rotor and the grain is collected at the rear by an upwardly directed conveyor. The stripping work is done by the tips of the wire brushes, which are of uniform length. It is an object of the present invention to provide improved apparatus for and methods of stripping required parts from a standing crop, usually the most valuable parts of the crop, namely the seed, leaves and/or flowers. It is an object of the invention to overcome many of the disadvantages of known harvesting methods and devices, and to simplify, hasten and make less expensive the harvesting process. It is a further object to make less weather dependent the disposal or harvesting of the remaining crop which is left standing in the field. According to the present invention there is provided apparatus for harvesting required crop parts from standing crop comprising: a mobile frame for movement over the ground; a rotor mounted for driven movement relative to the frame; a plurality of crop engaging elements mounted on the rotor so as to project outwardly therefrom; guide means co-operating with the crop engaging elements to form a crop flow passage; and drive means for driving the rotor so as to detach from standing crop predetermined required parts of the crop and to move the detached crop parts along the crop flow passage; the rotor being arranged in such a manner as to carry the elements at a front region of the apparatus upwardly and rearwardly relative to the direction of forward travel of the apparatus, the crop engaging elements being arranged to engage standing crop while projecting forwardly relative to the direction of forward travel of the apparatus, and the guide means comprising a cover extending around at least part of the region in which the elements are moved upwardly and rearwardly by the rotor; at least some of the crop engaging elements having discrete distal tips for entering into and dividing crop and being shaped to provide in operation a plurality of crop gathering regions each having converging boundaries, and at least some of the crop engaging elements having surfaces extending across the direction of movement of the elements by the rotor for moving the detached crop parts; characterised in that the crop engaging elements having the said surfaces are made of flexible resilient material, and the drive means is arranged to drive the crop engaging elements at a speed such as to impel the detached crop parts by the said surfaces in a fast moving stream along the crop flow passage between the cover and the peripheral path of the element tips, the shape of the cover being such that, throughout the region where the cover extends around the upwardly and rearwardly moving elements, the cover diverges from the peripheral path of the element tips in the direction of crop flow. The invention encompasses apparatus for detaching from the stems or other plant parts of standing crop, seeds, seed-bearing parts, leaves, twigs, flowers and/or other predetermined required parts of the crop, by rubbing and/or breaking and/or tearing the parts from the stems. By the term standing crop is meant crop in the field before any harvesting operation has been carried out on it, for example before any cutting operation, and the term standing crop includes crop which may be laid, leaning, or twisted, as well as upright crop. In accordance with one preferred feature at least some of the crop engaging elements comprise crop stripping elements each of which has a narrow tip for entering into and dividing crop, and has side edges for detaching the required crop parts, the said side edges diverging from each other in a direction away from the distal tip of the element. Preferably the said side edges diverge from each other over a major proportion of the crop engaging length of the element. Preferably the said side edges diverge from each other away from the distal tip of the element at a total included angle greater than 15°. Conveniently the angle lies in the range 20° to 70°, more preferably in the range 25° to 60°, and most preferably in the range 25° to 45°. Conveniently the angle is about 30°. Preferably the diverging side edges diverge substantially on either side of a normal to the moveable support means. It is preferred that each crop stripping element has a transverse surface between the said diverging side edges, for impelling the detached crop parts along the crop flow passage. By a transverse surface is meant a surface which extends principally transverse to the direction of the movement of the element by the rotor. The surface may conveniently be substantially flat, but in some arrangements may be curved, preferably slightly concave. The elements may be of varying shapes which will be set out hereinafter, but it is preferred particularly that the distal tip region of each crop stripping element is pointed with the side edges diverging from the apex of the element, preferably the distal tip region having a transverse leading surface. In accordance with one preferred feature of the invention, there are provided on side edges of the crop stripping elements, and/or at the junction of adjacent crop stripping elements, relief spaces for detaching crop parts by the effect of edges of the spaces and/or for allowing stripped remaining crop parts to be released from the elements. For example the crop stripping elements may be formed by the teeth of a series of transverse combs mounted on the support means transverse to the direction of movement of the support means, there being provided at the junction of adjacent side edges of adjacent teeth on a comb an aperture allowing stripped stems to be released from the comb, the said aperture having side edges adapted to strip the required parts from the crop stems. As a general feature, in some forms the crop engaging elements may be arranged on the rotor (which constitutes a moveable support means) in rows transverse to the general direction of crop movement of the apparatus, and the spacing between distal tips of adjacent elements along a row may be made substantially greater than the narrowest distance between the two adjacent elements. For example the spacing between distal tips of adjacent elements along a row may be greater than three times the minimum distance between the two adjacent elements. It is preferred that each element is a transverse element having an overall width transverse to the direction of movement of the element by the support means which is greater than its depth along the direction of movement. Preferably each element is a substantially planar element having a principal plane transverse to the direction of movement of the element by the support means. In many preferred forms, each element has a portion at or in the region of its base which is narrower than the widest part of the crop engaging portion of the element. A number of preferred and optional features have been set out, in accordance with the invention. In accordance with one particularly preferred combination of such features, at least some of the crop engaging elements comprise crop stripping elements each of which has a narrow tip for entering into and dividing crop and has side edges which diverge from each other in a direction away from the distal tip of the element over at least a substantial portion of the crop engaging length of the element for detaching crop parts from standing crop, the leading crop engaging surface of each crop stripping element between its diverging edges being a transverse surface for impelling detached crop parts along the crop flow passage; the crop stripping elements being mounted in a position such as to engage crop unsupported by other components of the apparatus, and being driven in movement in such a manner that detached crop parts do not reside to any substantial extent on the moving crop stripping elements; the crop flow passage having at its intake region a horizontal clearance from the distal tips of the crop stripping elements of at least the effective pitch of the crop stripping elements. The features set out in this combination may be present separately in some forms of the invention. A preferred range for the horizontal clearance at the intake region of the crop flow passage is that the clearance is at least equal to the effective pitch of the crop stripping elements and is no greater than half the diameter of the peripheral path of the element tips when the elements are moved by the rotor, the clearance being sufficient to allow detached crop parts to enter the crop flow passage but not so great as to allow loss of detached crop parts. By the effective pitch of the crop stripping elments is meant the pitch of elements which are transversely adjacent to each other as the elements are presented to the crop by movement of the moveable support means, whether the adjacent elements are presented in single rows transverse to the movement, or whether effectively adjacent elements are positioned as offset elements in succeeding rows presented to the crop. Conveniently at least some of the crop engaging elements comprise crop stripping elements having relief spaces on side edges of the elements, and/or at the junction of adjacent elements. In one preferred form of such an arrangement, the relief spaces are arranged for allowing stripped stems or other remaining crop parts to be released from the elements, and/or for providing edges of the elements adapted to strip required parts of the crop. In accordance with a preferred feature it may be provided that at least some of the relief spaces are defined by re-entrant edges of the elements adapted to strip crop parts from regions of the standing crop which face forwardly relative to the intended direction of movement of the apparatus. In accordance with another preferred feature it may be provided that the crop stripping elements are mounted in rows transverse to the direction of movement of the moveable support means, succeeding rows of crop stripping elements being slanted in opposite directions so that co-operation between succeeding rows of oppositely slanted elements forms funnel-shaped intake regions, followed inwardly by relief spaces. In some arrangements it may be provided generally in accordance with the invention that crop stripping elements are mounted in rows transverse to the direction of movement of the moveable support means, elements in succeeding rows being substantially aligned with each other along the direction of movement of the moveable support means, crop being gathered between elements which are adjacent to each other along a row. In other arrangements it may be provided generally in accordance with the invention that the crop stripping elements are mounted in rows transverse to the direction of movement of the moveable support means, elements in succeeding rows being offset from each other transverse to the direction of movement of the moveable support means, the elements in each row being spaced apart in such a manner that crop is gathered between elements which are effectively adjacent to one another in presentation to the crop, but are positioned in succeeding rows. In accordance with another aspect of the present invention, the outwardly projecting crop engaging elements may vary in shape and/or size and/or inclination. In one example, the crop engaging elements comprise crop stripping elements arranged on the mobile support means in rows transverse to the direction of movement of the moveable support means, the profile of each row being shaped to provide portions projecting outwardly to greater and lesser extents. In other examples, some of the outwardly extending crop engaging elements extend outwardly from the moveable support means to a greater extent than others, the longer elements being arranged for disentangling, lifting and/or orientating crop and shorter elements for effecting crop stripping. In a yet further example, the elements may comprise stripping elements mounted in rows transverse to the direction of movement of the moveable support means, the elements consisting of elongate fingers slanted to one side, succeeding rows of elements being slanted optionally in opposite directions so that co-operation between succeeding rows of oppositely slanted elements effects crop stripping, preferably the co-operation between succeeding rows forming funnel-shaped intake regions, followed inwardly by relief spaces. In accordance with another feature of this aspect of the present invention, it may be provided that the elements comprise crop stripping elements mounted in rows transverse to the direction of movement of the moveable support means, the elements being moveable relative to each other transversely and being secureable in selected positions so as to vary the profile of the elements presented to crop for stripping different forms of crop. Those features and aspects of the present invention which have been set out above are concerned mainly with the shape and operation of crop stripping elements, and there will now be set out a number of advantages and features in this connection. Although it is preferred that the crop engaging elements for stripping the crop are generally planar elements having a principal plane transverse to the direction of movement of the elements, such planar elements may be variously shaped along the crop engaging edges for example by being scalloped, notched or otherwise recessed, to increase the rubbing effect. Crop stripping elements may consist of arrays of generally triangular teeth, each tooth being bent longitudinally or rolled transversely or having its edges rolled or bent forwards on the crop engaging surface, in order to scoop detached seed or crop particles, to minimise losses. It is particularly preferred that the crop stripping elements are formed by teeth of a comb comprising a planar transverse rib of solid material shaped to provide the teeth. Conveniently the crop stripping elements are formed of synthetic plastics material, but they may be made of metal or other materials of adequate strength and wear resistance. The elements may comprise arrays of pointed, generally triangular teeth at the root of which are formed elongate straight or slanted recesses, to increase the duration and extent of the work done by the elements on the crop. There may also be provided circular, square, trapezoidal or other shapes of relief apertures wider than the narrowest part of each recess between pairs of teeth, to enable seed heads, stems, tillers or branches to received all-round treatment, and after being stripped, to withdraw from the stripping space without interfering with incoming crop. In general it is preferred that transverse arrays of crop stripping elements are arranged along the crop conveying means so that tips of successive rows follow the same path, but this is not essential and elements may be variously staggered from row to row in some arrangements, for example being displaced laterally by half the tooth pitch. Considering the invention in general, it is to be appreciated that the actual process of stripping will involve contact of different parts of the stripping elements with the crop at different times as the apparatus moves forwardly into the crop during the upward movement of the elements. Preferably the elements are shaped so that a progressive stripping action takes place as the machine moves forwardly and elements intrude to a greater extent into the crop. The provision of a relief space or aperture at the junction of each pair of adjacent stripping elements may be made for detaching the required parts of the crop by engagement of the crop with the edges of an aperture at the junction of each pair of adjacent elements, and for the different, or additional, purpose of assisting release of crop from the elements after stripping. It is one particular preferred feature of the invention that such a relief space or aperture can be defined by a re-entrant edge and can assist in stripping required parts of the crop from the forward facing part of the stems which may not normally be engaged by the side edges of the elements. Where the crop engaging elements are arranged in transverse arrays, each transverse array of elements will normally be arranged at right angles to the direction of forward travel of the apparatus, for example the arrays of outwardly projecting elements may lie in radial planes of a rotor passing through the axis of rotation of the rotor. However in other arrangements the transverse arrays of crop engaging elements may lie across the direction of forward travel of the apparatus, but at an angle thereto, and the arrays may of course be rectilinear or curved. For example transverse arrays of elements may be formed as helical formations formed around and along the axis of a rotor. Such helical arrays may provide a more aggressive crop stripping action. Conveniently crop stripping elements may be arranged in groups joined integrally together, and may be provided with means for easily detaching the groups for example by snapping the elements onto fasteners left in situ on the moveable crop support means. As has been mentioned, arrays of crop stripping elements may be provided in which there are at intervals longer, protruding elements, to disentangle, loosen, lift and/or orientate crop which would otherwise be unfavourably presented. In some arrangements, such longer elements may be mounted between adjacent rows of stripping elements at intervals along the moveable crop support means, so that they protrude and engage unfavourably presented crop in advance of closely spaced arrays of stripping elements, the longer elements optionally being held in their normal operating position by resilient biassing means, to protect them against ground contact or atypical loads. Optionally, the longer elements between adjacent rows of stripping elements may be mounted on a common transverse member so secured that the elements may be pivotted and locked in alternative angular positions, or may be fully reclined. When the stripping elements in successive arrays are aligned along the direction of movement of the support means, this is particularly suitable for detaching, for example, seeds from the ends of stems, and for defoliating plants. Relief recesses (where provided) between laterally adjacent elements should, in such cases, preferably be symmetrical. If alternate arrays of elements are laterally offset by half the element pitch, then a lateral shaking action is imparted to the crop, and this will result in more plant material becoming detached. If relief recesses are slanted to one side at the bases thereof, this results in an even more severe action, and may be used to break off the ends of plants or branches of shrubs and the like. In accordance with a further aspect of the present invention at least some of the crop engaging elements comprise planar crop stripping elements having principal planes transverse to the direction of movement of the elements, the elements being resiliently mounted, as well as being made of flexible resilient material, to prevent or inhibit damage by impact with the ground or foreign objects. In some arrangements it may be provided that the said elements are formed by the teeth of a succession of transverse combs mounted on the support means and each having an array of outwardly projecting teeth mounted in a row transverse to the direction of movement of the frame through the crop, each comb being formed of stiff material, and being resiliently mounted to allow yielding of the comb by tipping or rocking movement rearwardly, there being provided resilient biassing means urging the comb towards its normal operating position. Alternatively, each comb may be formed of material which is sufficiently stiff to perform effectively the stripping function but has adequate resilience to bend and restore in response to resilient atypical loads. Such resilience is preferable where the planar comb is forwardly inclined relative to the movement of the elements, since deflection by a resilient comb need not increase the outward extension of the elements, e.g. need not increase the diameter of a rotor. Forwardly inclined crop stripping elements are in general often a preferred feature since these give a scooping action to detached crop parts. It is a particularly preferred general feature that the crop engaging elements may be mounted in a position such as to engage crop unsupported by other components of the apparatus. In preferred embodiments, it may be arranged that the only components of the apparatus to enter into the crop and to divide and gather the crop in the region at which the said crop parts are stripped from the crop, are driven moving elements which are mounted on the said moveable support means. It is a preferred general feature that the distal ends of the crop engaging elements are pointed at the tips so as to minimise disturbance of the crop. It is arranged as a general feature that the crop engaging elements are driven in movement in such a manner that detached crop parts do not reside to any substantial extent on the moving crop stripping elements. In general, those aspects of the invention which have been described with reference to apparatus according to the invention, may also be provided with reference to methods of harvesting in accordance with the invention, and vice-versa. In particular there may be provided in accordance with the present invention a method of harvesting crop comprising: moving through a standing crop a harvesting apparatus; moving at a front region of the apparatus a plurality of crop engaging elements which project outwardly from a rotor on which they are mounted, the movement of the elements being a movement upwardly and rearwardly relative to the direction of forward travel of the apparatus; engaging the standing crop by the moving elements while projecting forwardly relative to the direction of movement of the apparatus, at least some of the crop engaging elements having discrete distal tips for entering into and dividing crop and being shaped to provide in operation a plurality of crop gathering regions each having converging boundaries, and at least some of the crop engaging element having surfaces extending across the direction of movement of the elements by the rotor for moving the detached crop parts; detaching from standing crop predetermined required parts of the crop; conveying the detached crop parts along a crop flow passage beneath a cover which extends around at least part of the region in which the elements are moved upwardly and rearwardly by the rotor; and collecting the detached crop parts; characterised in that the said conveying step comprises impelling detached crop parts along the crop flow passage by elements made of flexible resilient material, and rotating the rotor at a speed such as to impel the detached crop parts by the said surfaces in a fast moving stream along the crop flow passage between the cover and the peripheral path of the element tips, the shape of the cover being such that, throughout the region where the cover extends around the upwardly and rearwardly moving elements, the cover diverges from the peripheral path of the element tips in the direction of crop flow. It is a feature of the present invention that the crop engaging elements are moved at a relatively high speed. A number of criteria can be used to establish the required high speed, for example the speed of movement of the crop engaging elements relative to the frame may be set to be substantially greater than the forward speed of movement of the frame. Preferably the tip speed of the crop engaging elements is greater than 5 m/s, most preferably greater than 10 m/s. The forward speed of the frame may be in a range up to 10 km/hour, preferably in the range 3 to 9 km/hour. In examples of preferred methods embodying the invention, a method of harvesting cereals may include moving the crop engaging elements relative to the frame at a speed such that the tip speed of the elements is in the range 10 to 25 m/s. In accordance with another preferred example, a method of harvesting lucerne (alfalfa) includes moving the crop engaging elements relative to the frame at a speed such that the tip speed of the elements is in the range 15 to 30 m/s. As has been mentioned, it is a general preferred feature of the present invention that the crop engaging elements may enter the crop with minimum disturbance, and move upwardly through the crop to strip the required parts of the crop without the need for the crop to be supported in an upright position by any stationary guide members projecting forwardly of the said moving crop engaging elements. It is to be appreciated that there may be provided in some arrangements additional stationary lifting elements for raising the crop to the moving crop engaging elements in suitable manner where the crop is laid, but there is, at least in preferred embodiments of the invention, no requirement for stationary guide elements to hold the crop in the upright position during stripping in the vertical crop region swept by the crop stripping elements. As has been mentioned, the guide means consists of a hood or cover over the upwardly and rearwardly moving elements. It is preferred that the said hood may be moveable either closer to or further from the crop engaging elements, and/or around a curved path around the front of the path of movement of the elements. There may be provided a concave plate under the rotor, and this may also be adjustable, for example about a circular path centred on the axis of the rotor. Particular advantage is obtained if there are provided means for adjusting the overhead hood, and an adjustable concave beneath a stripping rotor, since together these adjustments limit the intrusion of crop into the rotor space, and give control of the degree of stripping and the manner of stripping the crop. In accordance with another feature of the invention, there may be provided means for adjusting the height of support means for the crop engaging elements, either together with the height of the overhead hood, or independently of the height of the overhead hood, to allow adjustment of the height at which the crop engaging elements enter the crop and move upwardly through the crop. The present invention has a number of applications, particularly in the harvesting of grain. The stripped material can be collected into trailers or bulk containers for transportation to a central plant for processing. In the case of cereals and other seeds this may include completion of the threshing process and separation of the seed from material other than grain. Alternatively, particularly with cereals and other seeds, the stripped material may be fed directly into a processing machine, such as a combine harvester, for immediate threshing and cleaning. At a central plant or in the field the material other than grain may be collected loose or pressed for utilisation. Generally, the invention finds application in the harvesting of mature seeds and grains, in the vining of peas and in the defoliation of annual and perennial crops as well as shrubs, incuding the non-destructive harvesting of leaves and shoots in one or repeated passes over the crop. The present invention provides a number of advantages as a result of only the seed-bearing parts of cereal, pulse, herbage and other crops being collected for passage through a harvester, such as a combine harvester. Because less unwanted material is taken in, the work rate and output of the harvester can be greatly increased, sometimes by a factor of two or more. The straw left standing will dry quickly after rain and can be burnt easily and completely (if it is to be disposed of in this way), with the ash becoming uniformly distributed. If the straw is to be chopped for incorporation into the soil, comminution mechanisms can be more effective with standing straw than in windrowed straw because the stems are still attached to the ground. Even distribution of the chopped material is more easily achieved. If the straw is to be harvested, it can be readily cut by a windrower, for example attached to a tractor which pulls and powers the harvesting machine. If desired the straw may be cut immediately by a mowing mechanism of known design mounted behind the stripping header. Embodiments of the invention will now be described by way of example with reference to the accompanying drawings in which:- Figure 1(a) is a diagrammatic side view in section of one general form of apparatus for harvesting crop, embodying the present invention; Figure 1(b) is a perspective view of part of a rotor suitable for use in the apparatus shown in Figure 1(b); Figures 2(a) to (j) show examples of different forms of crop stripping teeth embodying the present invention; Figures 3 and 4 show examples of shapes of individual teeth which may be used in embodiments of the invention; Figures 3(a) and 3(b) show two alternative cross-sections of the tooth shown in Figure 3, taken along the lines A-A; Figures 4(a) and 4(b) show two alternative cross-sections of the tooth shown in Figure 4, taken along the lines A-A; Figure 5 shows a further modified form of a comb which may be used in embodiments of the invention, and Figure 5(a) shows a diagrammatic side view in cross-section of the comb, taken along the lines A-A in Figure 5; Figure 6 shows a further modified form of a comb which may be used in embodiments of the invention, and Figure 6(a) shows a diagrammatic side view in cross-section of the comb taken along the lines A-A in Figure 6; Figure 7 is a diagrammatic side view in section of a modification of the apparatus of Figure 1(a), embodying the invention, in which an additional grain threshing rotor is positioned to the rear of the main grain stripping rotor; Figures 8(a) and 8(b) show respectively a diagrammatic side view partly in section and a diagrammatic plan view, of a modification of the apparatus shown in Figure 1(a), embodying the invention, in which there is provided to the rear of the main stripping rotor various crop directing and arresting and transverse and longitudinal crop conveying means; Throughout this specification, corresponding components of the various arrangements shown are indicated by like reference numerals. For simplicity, the functions and inter-relationships between the various components are not described in connection with each figure when these have been described previously. It is particularly to be appreciated that where corresponding components have like reference numerals, the appropriate description applies equally each time those elements are referred to. Referring first to Figure 1(a) there is shown in diagrammatic side view the generalised layout of an embodiment of the present invention for harvesting crop. The apparatus comprises a mobile frame for movement over the ground, indicated generally at 12. Mounted on the frame 12 is a moveable support means 5 which is a rotor 11. Mounted on the rotor 11 are a plurality of outwardly projecting crop engaging elements 15, which may take a number of forms in accordance with the invention, as has been described hereinbefore or will be described hereinafter. The rotor 11 is driven by drive means which may conveniently comprise a gear box and power train driven by a tractor, or other power source such as the engine of a combine harvester. 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. There are provided guide means co-operating with the crop engaging elements 15 to form a crop flow passage 33. The guide means are constituted by a hood or cover 18 which extends around at least part of the front half of the rotor and defines with the rotor elements 15 the crop flow passage 33 along which crop is conveyed by the rotor. The hood or cover 18 prevents forward projection of parts of the crop detached by the rotor 11. 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 crop. 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 parts to be detached are detached by rubbing and/or breaking and/or tearing the parts from the stems. After the detachment, the required crop parts are conveyed upwardly and rearwardly over the rotor 11, and pass to crop conveying means indicated generally at 9. Usually the crop transfer means 9 will include means for transferring crop laterally, and means for conveying the crop rearwardly. Conveniently the transverse crop transfer means may be an auger, but may alternatively be a transverse conveyor belt. Conveniently the rearward crop transfer means may be a conveyor, although other means may be provided. In the examples shown in Figure 1(a) the stripping rotor 11 is arranged to deliver the stripped material against a loosely suspended check curtain 131. From this it falls on to a belt conveyor 154, which extends the full width of the rotor 11, is transported rearwards and is delivered into a cross conveyor auger 155 rotating in a transverse well 156. It is particularly to be appreciated that the arrangement of Figure 1(a) indicates a general layout of apparatus embodying the invention, and that the various components shown may be provided in practice by any of the appropriate components which have been described hereinbefore, or are to be described hereinafter. Referring now to Figure 1(a), and Figure 1(b), there is shown one form of a crop stripping apparatus embodying the invention, which conveniently may be used as a header for a combine harvester, or may be used in conjunction with other threshing and grain separating apparatus. (The particular example shown in Figure 1(b), should also be taken to illustrate, when appropriate, any of the forms of the invention shown diagrammatically in other figures, when those forms utilise crop engaging elements of the configuration shown in Figure 1(b)). The apparatus comprises a rotor 11 mounted in a main frame 12 for movement through the crop to be harvested. The rotor 11 comprises an inner core 13 generally in the form of a circular section or multi-sided cylinder, and a succession of transverse combs 14 spaced circumferentially around the rotor 11. As shown in Figure 1(b), each comb 14 maybe formed from a transverse rib of solid material shaped to provide an array of teeth 15 mounted in a row transverse to the direction of movement of the harvesting apparatus through the crop. Each tooth 15 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, which in the example shown, is part circular. Each aperture 21 is formed by relieved portions of adjacent teeth at the base regions thereof. Thus each tooth has a portion at or in the region of its base which is narrower than the widest part of the portion which has diverging side edges. In the examples shown, each comb is formed from a flat sheet-like rib of solid material, having cut therein, or otherwise formed, a series of keyhole shaped apertures, forming the said teeth. The rotor 11 is driven to rotate in the so-called overshot mode, so that the combs 14 are moved in an upward direction at the front of the apparatus. There is provided over the front of the rotor 11 the hood or cover 18 to prevent forward projection of parts of the crop detached by the rotor 11. In operation, rotation of the rotor 11 moves the combs 14 so that the narrow or pointed distal tips of the teeth 15 enter the crop with minimum disturbance of the stems 19 of the crop. The teeth 15 then move upwardly through the crop, gathering between adjacent side edges of adjacent teeth one or more crop stems. As the teeth 15 reach the seed-bearing heads of the crop, the seeds, or seed heads, are detached by rubbing the seeds free, or snapping off the seed heads. The seeds and seed heads are removed by engagement of the crop with the side edges 16 and 17 of the teeth, and by engagement with the edges 20 of the apertures 21 at the base of the junctions of adjacent side edges 16 and 17. The operation of the apparatus is as follows. The cover 18 forms with the rotor 11 a crop flow passage 33. An upturned leading portion 32 of the cover usually engages crop first during forward movement of the apparatus. The upturned leading portion 32 of the rotor cover 18 engages the crop and preferably seals off the crop passage 33 immediately in front of the overshot rotor 11. Material including grain and grain heads is dislodged and then impelled upwardly and rearwardly along the passage 33, by the effect of the combs 14. The overhead hood 18 is important in avoiding forward projection of grain and grain heads. The stripped crop stems 19 pass under the machine and remain standing in the field. To avoid straw being pressed into the ground by tractor or machine wheels, dividers may be fitted in front of the wheels to force the crop residue apart temporarily. It will normally be necessary to provide means for adjusting the height above ground of the stripping rotor 11 so as to be at the correct height in relationship to the height of the seed-bearing heads or other required parts of the crop. The height above the ground of the stripping rotor unit alone may be varied, or the height of the whole header arrangement may be varied according to conditions. For example, the rotor will need to be lowered in order to gather the desired material efficiently where crops are exceptionally short or laid. Proximity sensors may be attached at the front of the stripping rotor cover 18, and the output signal may be used to keep the rotor height adjusted automatically in relation to the crop horizon and/or to adjust the height of the rotor cover. It should be noted that by adjustment of the speed of the combing ribs 14, together with appropriate arrangements of the geometry of the components, selective harvesting of only the ripest seed, particularly of herbage seed, may be effected during successive passes of the crop. Figures 2(a) to 2(g) show a number of alternative forms of the combs 14 which may be used on the stripping rotor 11. In Figure 2(a) a comb 14 consists of plain, deep serrations forming the teeth 15. The junction 42 between adjacent side edges 16 and 17 of adjacent teeth 15 is slightly radiused as a recess to avoid crop becoming wedged therein. Normally the combs 14 are arranged so that successive teeth 15 follow the same peripheral path, but in some arrangements it may be advantageous laterally to offset alternate combs 14 by half the tooth pitch. In the comb 14 shown in Figure 2(b) the gap or recess 44 between each pair of adjacent teeth 15 is extended at the narrowest point between adjacent side edges 16 and 17 to terminate in an elongate slot 21. The end of each slot 21 may be relieved as shown in dotted lines to aid withdrawal of stripped stems and avoid interference with incoming crop. In Figure 2(c) the slots 21 of the recesses 44 are directed to one side, which aids stripping of seeds off the forward pointing side of stems or seed heads. In an arrangement such as shown in Figure 2(c) alternate combs 14 around the circumference of the rotor may be mounted so that the slots 21 point in opposite directions. The slots 21 may be relieved at their innermost end, as shown in Figure 2(b). Figure 2(d) shows the most preferred form of comb for stripping cereals and small seeds and for defoliating legumes. The teeth 15 have generally the shape of an arrow head, the recess 44 between adjacent pairs of teeth having generally the shape of a keyhole. The distance between the closest points of the adjacent side edges 16 and 17, indicated in the region 45, frequently determines the amount of extraneous matter being collected with the seeds and other required material. The relief apperture 21 at the inner end of the recess 44, again promotes stripping of seeds on the leading face of seed heads and facilitates the withdrawal of stems after stripping. The side edges 16 and 17 may be rounded at the narrowest part of the recess 44 as shown in dotted lines. In Figure 2(e) the rubbing edges 16 and 17 of the teeth 15 have been recessed at 46 to help treat the forward face of crop heads and to achieve effective stripping in particularly tough crops. In Figure 7(f) an alternative arrangement is shown in which some edges of teeth are serrated. Where only one side edge is serrated as in Figure 2(f), it is preferred to reverse the directions of alternate combs 14 around the circumference of the rotor 11. Figure 2(g) illustrates yet another alternative design in which both side edges of each tooth 15 are serrated. Figure 2(h) shows alternatively shaped relief spaces at the base of the recesses between stripping teeth. In Figure 2(j) there are shown teeth 15 having apertures 21 which are inclined in one direction, followed by teeth shown partly in dotted lines, 15', in the next following row of teeth, inclined in the opposite direction. The succeeding combs of teeth 15 and 15' shown in Figure 2(j) are offset so that the outwardly projecting tips overlap. If alternate stripping rib elements are optionally moved laterally, for example by sliding them inside a retaining channel as will be described hereinafter, then the dimensions of the intake funnels and of the stripping recesses formed by each pair of ribs can be adjusted to suit different crops, conditions and requirements for stripping. It should be noted that the combs 14 are formed in preferred arrangements by transverse planar ribs, conveniently made of flat, sheet-like, synthetic plastics material. However, optionally the leading face of each tooth may be concave. Not every rib 14 need be profiled to form teeth. Good effects can be obtained when alternate ribs 14 are plain edged to scoop up material dislodged by the preceding rib. It is not necessary that such alternate plane ribs should have the same depth radially as the profiled ribs; a reduced depth is often preferable. Variation of the depth of plain ribs following stripping combs gives yet another means of controlling the depth of intrusion of the crop into the rotor space. It is also advantageous at times for the operative plane of the ribs and/or combs to be slightly forwardly or rearwardly inclined to the transverse radial plane. Figure 1(b) shows a perspective view of a detail of a stripping comb, in respect of a crop harvesting apparatus embodying the invention. As has been mentioned, Figure 1(b) should be taken to illustrate various forms of the invention. In Figure 1(b) there is shown a transverse array of crop stripping elements 15 constituting combs 14, mounted on moveable crop support means 5. The moveable crop support means 5 is mounted on a main frame 12. Between the teeth 15 of the combs 14 are provided relief apertures 21, defined by edges 20. Each tooth 15 has diverging side edges 16 and 17. Figures 3 and 4 show that individual stripping teeth 15, particularly when made from metal or when moulded in plastic, may be convexly or concavely cupped on the crop engaging face, or may be provided with radiused or folded edges. Used concavely they give a scooping action, and conversely they tend to squeeze crop passing between them. In Figures 5 and 6 there are shown alternatives to full-width, continuous combs 14 which have been shown previously. In Figures 5 and 6, comb portions are shown in which each have two teeth 15, or each have one tooth 15 and which are individually mounted on the moveable support means 5. Single, twin or multiple-tooth portions of the comb 14 may be designed so that they can be clipped or sprung into position over for example a rivet 71 passing between two locating ribs 72 and 73 at the base. To replace them or to remove broken remnants, a tool, for example a screwdriver, may be inserted through a hole 74 provided to spring the lower resilient lugs apart so that the slot 75 opens sufficiently to pass over the rivets 71. Figure 5(a) is a view in the direction of the arrows A-A in Figure 5. An alternative mounting arrangement in Figure 16 shows a grooved pin 76 and locking clip 77 being utilised. Figure 6(a) is a view in the direction of the arrows A-A in Figure 6 and shows a resilient washer 78 inserted under the spring clip 77. If only one base flange (not shown) for mounting the elements is used, then provision of a resilient washer or cone at either end of the securing pin will provide overload protection for the tooth sections by allowing them to pivot from the mounting flange momentarily. Figure 7 illustrates a simple form of re-threshing arrangement, and shows a modification of the apparatus of Figure 1(a). Grain detached by the stripping rotor has a tendency to move along the underside of the rotor cover 18 and can pass through two banks of separator fins 101 cantilevered out from the cover 18 and angled in the downstream direction. Larger particles makng contact with the fins are directed downwardly, and particles floating above the rotor 11 are directed upwardly by a guide plate 99, to be forced into rubbing contact with a suitably transversely ribbed rotor 100 by solid banks of overhead tufts 98. This system requires a cleaning operation to follow. In Figures 8(a) and 8(b) are shown yet a further modification of the apparatus of Figure 1(a). A stripping rotor 11 with a curved front cover 18, is followed in the direction of crop flow by a louvre arrangement 130 which permits air but not crop particles to escape upwardly. Material stripped off the crop is thrown against a loose crop curtain 131 hanging from a light supporting structure and flows downwards into a collecting trough 28 formed by a downward sloping wall 132 behind the lower rear quarter of the stripping rotor 11 and a rearwardly upward sloping wall 133. A conveyor 137 is arranged to sweep the bottom of the trough 28 by paddles 134 suspended from a chain or belt 135. Wear strips 136, conveniently made of wood, and attached to the rearwardly and upwardly sloping wall 133, prevent frictional contact with the wall 133. The upper return part of the paddle conveyor 137 is shielded by a cover plate 138. As shown in Figure 8(b), which generally is an unobstructed view in the direction of the arrow B in Figure 8(a), paddle-type conveyors 137 in both halves of the header unit convey stripped material towards the centre for onward transportation by, for example, a slatted, conveyor 31 perpendicular to the transverse axis of the header 125. To prevent an accumulation of material in the unswept area opposite the entrance to the secondary conveyor, a "butterfly" deflector 140 is formed by two inversely curved deflector panels 141 and 142 sloping downwardly from a central ridge 143. (The deflector 140 in Figure 8(b) is a view taken in the direction C in Figure 8(a) and is not a view in the direction B , which is the direction of the remainder of Figure 8(b).) Returning to Figure 8(a), behind the rotor 11 is shown an optional resilient panel 144 stretched transversely across the header between end plates (not shown). The purpose of the panel 144 is to arrest particles leaving the rotor 11 late, causing them to fall into the bottom of the conveyor pan, and also to prevent any particles which may be ricochetting forwardly from re-entering the rotor space. Above the panel is shown an optional roller 145, which may be driven or left self-rotating in bearings, to prevent accumulation of material on the upper edge of the transverse panel in some crops and conditions. There will now be discussed a number of general features which may be applicable to various embodiments set out above. In addition to means for adjusting the height of the stripper mechanism and/or the hood or other guide means, by judgement of the operator, there may be provided sensors on or in front of the stripping header, or each section of such a header, to identify the crop horizon, the signals derived from the sensors being used to control the height of the stripping header or a section thereof, automatically. Normally the lower extent of stripper height setting will be provided by skids under or to the rear of bottom-dead-centre. A further additional feature which may be provided in any of the embodiments described, comprises a reciprocating cutter bar or rotary cutter which may be fitted for severing the stripped material at a preselected height above ground, after stripping. Considering now generally the dimensions which may be used in embodiments of the invention, preferably the stripping rotor 11 for cereal and most forage crop has an overall diameter of 500-600 mm. However, smaller diameters are suitable for short or low crops, and larger diameters for particularly tall crops. By way of example, appropriate tip speeds of stripping rotors embodying the invention for the harvesting of cereals range from less than 10 m/s to approximately 25 m/s, and for harvesting lucerne (alfalfa) leaf, speeds should be in the range of 15 to 30 m/s. Although the stripping rotor 11 in Figure 1(a) is shown as having eight rows of elements fewer or more may be used. The combs or ribs, or other forms of rows of elements, need not be arranged in straight rows perpendicular to the direction of travel but they may be curved or helically mounted, to even out the drive torque and achieve delivery of the stripped material to one side or into the centre of any collecting device. By way of example of particular dimensions which may be used, the rotor shown in Figure 1(a) may have a diameter of 550 mm overall; the diameter of an inner core may be 300 mm, and the depth of each element from the tip to the base of a recess between adjacent elements may be 80 mm. In typical use in standing cereal crops, the bottom of the rotor may be set to 25 to 30 cm above the ground. Conveniently the bottom of the rotor may be set to a height equivalent to about one quarter of the height of the crop. Where the overall diameter of the rotor is in the range 400 mm to 700 mm, the rate of rotation of the rotor may be preferably in the range 250 to 950 rev/min. Rotor outer diameters may vary from approximately 0.2 to 1.0 m diameter, the preferred range being 0.4 to 0.6 m diameter. Tip speeds of the crop engaging elements may vary within the approximate range 5 to 40 m/s.

Claims: Apparatus for harvesting required crop parts from standing crop comprising: a mobile frame (12) for movement over the ground; a rotor (11) mounted for driven movement relative to the frame; a plurality of crop engaging elements (15) mounted on the rotor so as to project outwardly therefrom; guide means co-operating with the crop engaging elements to form a crop flow passage (33); and drive means for driving the rotor (11) so as to detach from standing crop predetermined required parts of the crop and to move the detached crop parts along the crop flow passage; the rotor (11) being arranged in such a manner as to carry the elements (15) at a front region of the apparatus upwardly and rearwardly relative to the direction of forward travel of the apparatus, the crop engaging elements (15) being arranged to engage standing crop while projecting forwardly relative to the direction of forward travel of the apparatus, and the guide means comprising a cover (18) extending around at least part of the region in which the elements (15) are moved upwardly and rearwardly by the rotor (11); at least some of the crop engaging elements (15) having discrete distal tips for entering into and dividing crop and being shaped to provide in operation a plurality of crop gathering regions (44) each having converging boundaries (16,17), and at least some of the crop engaging elements having surfaces extending across the direction of movement of the elements by the rotor for moving the detached crop parts; characterised in that the crop engaging elements (15) having the said surfaces are made of flexible resilient material, and the drive means is arranged to drive the crop engaging elements (15) at a speed such as to impel the detached crop parts by the said surfaces in a fast moving stream along the crop flow passage (33) between the cover (18) and the peripheral path of the element tips, the shape of the cover (18) being such that, throughout the region where the cover extends around the upwardly and rearwardly moving elements, the cover diverges from the peripheral path of the element tips in the direction of crop flow. Apparatus according to claim 1 in which the elements which provide the said crop gathering regions also provide the said crop impelling surfaces. Apparatus according to claim 1 or 2 in which each of the said crop engaging elements (15) having the said discrete distal tips for entering into and dividing crop, has side edges (16,17) which diverge from each other in a direction away from the distal tip of the element. Apparatus according to claim 3 in which each said element (15) with diverging side edges has a transverse surface extending between the said diverging side edges (16,17), which constitutes the said impelling surface for impelling detached crop parts along the crop flow passage (33). Apparatus according to claim 3 or 4 in which the said side edges (16,17) diverge from each other away from the distal tip of the element (15) over a major proportion of the crop engaging length of the element. Apparatus according to claim 3, 4 or 5 in which the said side edges (16,17) diverge from each other at a total included angle in the range 25° to 45°. Apparatus according to any preceding claim in which each said crop engaging element (15) of flexible resilient material has a portion at or in the region of its base which is narrower than the widest part of the element. Apparatus according to any preceding claim in which at least some of the crop engaging elements (15) have relief spaces (21) at the junction of adjacent elements for allowing stripped remaining crop parts to be released from the elements. Apparatus according to claim 8 in which at least some of the relief spaces (21) are defined by reentrant edges of the elements. Apparatus according to any preceding claim in which crop engaging elements (15) are mounted in rows transverse to the direction of movement of the elements by the rotor (11), elements (15) in succeeding rows being substantially aligned with each other along the direction of movement of the elements by the rotor (11) Apparatus according to any preceding claim in which each said impelling surface of an element (15) is a substantially flat surface. Apparatus according to any preceding claim in which each said impelling surface of an element (15) is forwardly inclined relative the direction of rotation of the rotor. Apparatus according to any preceding claim in which the cover (18) extends around substantially the whole region in which the elements (15) are moved upwardly and rearwardly by the rotor (11). Apparatus according to any preceding claim in which there is provided immediately to the rear of the rotor (11) an endless conveyor (154) positioned with its upper run leading rearwardly away from the rear of the rotor (11). Apparatus according to any preceding claim in which the drive means is arranged to drive the crop stripping elements (15) at a tip speed greater than 10m/s. Apparatus according to claim 15 in which the drive means is arranged to drive the crop stripping elements (15) at a tip speed in the range 10m/s to 25m/s. Apparatus according to claim 15 in which the drive means is arranged to drive the crop stripping elements (15) at a tip speed in the range 15m/s to 30m/s. Apparatus according to any preceding claim including means for collecting detached required crop parts. A method of harvesting crop comprising: moving through a standing crop a harvesting apparatus; moving at a front region of the apparatus a plurality of crop engaging elements (15) which project outwardly from a rotor (11) on which they are mounted, the movement of the elements being a movement upwardly and rearwardly relative to the direction of forward travel of the apparatus; engaging the standing crop by the moving elements (15) while projecting forwardly relative to the direction of movement of the apparatus, at least some of the crop engaging elements (15) having discrete distal tips for entering into and dividing crop and being shaped to provide in operation a plurality of crop gathering regions (44) each having converging boundaries (16,17), and at least some of the crop engaging element having surfaces extending across the direction of movement of the elements by the rotor for moving the detached crop parts; detaching from standing crop predetermined required parts of the crop; conveying the detached crop parts along a crop flow passage (33) beneath a cover (18) which extends around at least part of the region in which the elements (15) are moved upwardly and rearwardly by the rotor (11); and collecting the detached crop parts; characterised in that the said conveying step comprises impelling detached crop parts along the crop flow passage (33) by elements (15) made of flexible resilient material, and rotating the rotor (11) at a speed such as to impel the detached crop parts by the said surfaces in a fast moving stream along the crop flow passage (33) between the cover (18) and the peripheral path of the element tips, the shape of the cover (18) being such that, throughout the region where the cover extends around the upwardly and rearwardly moving elements, the cover diverges from the peripheral path of the element tips in the direction of crop flow. A method according to claim 19 in which the elements which provide the said crop gathering regions also provide the said crop impelling surfaces. A method according to claim 19 or 20 including detaching and conveying crop parts by crop engaging elements (15) having discrete distal tips and side edges (16,17) which diverge from each other in a direction away from the distal tip of the element. A method according to claim 21 including impelling detached crop parts along the crop flow passage (33) by transverse impelling surfaces each of which extends between the said diverging side edges (16,17) of an element (15). A method according to any of claims 19 to 22 including rotating the rotor (11) to drive the crop stripping elements (15) at a tip speed greater than 10m/s. A method according to claim 23 including rotating the rotor (11) to drive the crop stripping elements (15) at a tip speed in the range 10m/s to 25m/s. A method according to claim 23 including rotating the rotor (11) to drive the crop stripping elements (15) at a tip speed in the range 15m/s to 30m/s.

Inventors: KLINNER WILFRED ERWIN, KLINNER, WILFRIED ERWIN
Applicants: BRITISH TECH GROUP, BRITISH TECHNOLOGY GROUP LIMITED
Application year: 1985
Main classification: A01D41
IPC codes: A01D41