GB2083333A - Mowing machine - Google Patents

Abstract

A crop cutting and conditioning apparatus has two vertical axis rotary drum cutters 13, each having an upper rotor with a crop conveying surface 19 and a lower rotor carrying knives 21. Gears drive the upper and lower rotors at different peripheral velocities. The lower rotor has an annular rim 18 having an upper surface shaped to continue the outline of the conveying surface 19. The knives 21 protrude outwardly from beneath the rim 18 and rotate with the rim. A wiper brush (not shown) mounted on the conveying surface 19 projects outwardly over the rim 18 for lifting and transferring crop to the surface 19. The upper rotor has conditioning brushes 35 for conveying crop and conditioning crop by relative movement between the brushes and the crop. The envelope of brush tips on the rotor may be conical. The population of brush elements may vary with rotor height. The conditioning brushes may be mounted on the conveying surface 19. The upper and lower rotors may be rotated in opposite senses to effect at least partial shear cutting. <IMAGE>

Description

SPECIFICATION Apparatus for conditioning crop The present invention relates to apparatus for the conditioning of crops especially, but not exclusively, grasses, and is concerned in some respects with apparatus for cutting and conditioning crop.

In some aspects the present invention is concerned with improved arrangements of combinations of crop conditioning devices with crop cutting devices. In other aspects, the present invention is concerned with improvements in crop conditioning devices themselves.

Modern crop cutting devices are usually mowers of the rotary type which sever the crop by impact, using free swinging knives attached near the periphery of discs which may be used alone (disc mowers), or which may form lower skirts of vertical drums which assist in conveying the cut crop towards the rear of the machine (drum mowers). In each case the discs which support the knives serve to convey the cut crop to the rear. Knife tip speeds have to be in the broad range of 70 to 90 metres per second, to ensure clean cutting in most crops and conditions, where impact is used. At these speeds it has been found that the power requirement for conveying the crop by the discs is very considerable. In some aspects the invention is concerned with reducing the power requirement for cutting the crop and/or for conveying the cut crop.

In some aspects the present invention is concerned with improved arrangements of combinations of crop conditioning devices with crop cutting devices. Such a device is shown in a previously published US Patent No. 3977165 (Klinner et al) which shows a form of drum cutter in which the main upper drum rotor is driven at a different rate of rotation from a lower rotor which carries the cutting knives of the cutting device. In this arrangement, conditioning devices are provided on the upper surface of the crop conveying skirt of the upper drum rotor which is rotated at a different rate of rotation from the cutting knives. In practice a problem arises with such an arrangment in that it is difficult to maintain the correct close vertical clearance of the two rotary components, especially when the disc diameter is large and foreign objects are present on the surface of the field.

In some aspects the present invention seeks to provide a rotary cutting apparatus of an improved and simplified nature having regard to the drum cutters described in this US patent specification.

In other aspects, the present invention is directed towards means for conditioning crops. Forage crops such as grasses which are surplus to immediate requirements are usually cut and field-dried to provide animal fodder, particularly hay or silage, for the feeding of animals when fresh forage crops are not available. In temperate, especially maritime climates, the crops are at risk between cutting and harvesting (i.e. the field exposure time) because the adverse effects of light and rain and micro-organism activity can produce appreciable nutrient and dry matter losses. Accordingly, it is important to minimize the field exposure time to reduce the risk of such losses. However, the crops cannot be harvested until they have dried to a sufficiently high dry matter content for safe storage as animal fodder. In the case of hay, a dry matter content of about 80% is usually required.

The speed at which surface and sap moisture evaporate from the cut crop during field exposure depends inter alia on the physical condition of the crop. The principal barrier to moisture loss is the cuticle and the layer of epicuticular wax on the crop surface, and it is now common practice in agriculture to mechanically treat the crop in order to damage this barrier. Such mechanical treatment, which may take the form of crushing, lacerating, bruising, splitting, bending or scuffing the stem and leaves of the crop, is known as "conditioning". A variety of conditioning devices have been used or proposed, for example as in UK Patents Nos. 588439 (Chilton), 662303 (Goodall), 1 303970 (Bucher Guyer), US Patent No. 3977165 (Klinner et al) and PCT published application No.

PCT/GB79/00053-publication No. WO 79/00863 (BSRAE). The earlier of the devices described in these publications would often cause undesirable deep tissue damage to the crop resulting in high dry matter and nutrient losses, and were also unsatisfactory when attempts were made to condition a wide swath of crop, as the complexity and weight of machines increased considerably with width. The form of conditioning described in the last of the specifications set out above has allowed considerable progress to be made in producing acceptable conditioning with a light and relatively inexpensive conditioning device, and the present invention is concerned in some aspects, although not exclusively, with improvements in relation to the form of conditioning described and claimed in the said PCT patent application.

Another factor which affects the amount of time the crop lies in the field after cutting is the number of passes required to cut and condition the crop. In some cases the crop requires three or more passes, including cutting, conditioning the crop after it has fallen to the ground, and finally tedding to restructure the swath so that it maintains a fast drying rate. Many proposals have been made in the past for reducing the number of passes by combining cutting and conditioning in a single machine, and such combined machines are described, inter alia, in the PCT application numbered above. In another aspect, the present invention is particularly concerned, although not exclusively, with apparatus for carrying out in a single pass the cutting and conditioning operation.In this connection the present invention is concerned in its main aspects with cutting and/or conditioning crop by rotary movement about a vertical axis.

Such cutting and conditioning by rotary movement about a vertical axis is known in itself, for example in the UK Patent No. 1303970 (Bucher Guyer), US Patent No. 3977165 (Klinner et al) and PCT application No.

PCT/GB79/00053 (BSRAE) mentioned above. In the UK Specification No. 1 303970 (Bucher Guyer) the conditioning rotor is described, inter alia, as a vertical "squirrel cage type of rotor rotating behind a vertical axis drum mower, whereas in the US Patent No. 3977165 (Klinner) the conditioning devices are described as conditioning elements mounted on the upper surface of the crop conveying skirt of a vertical axis drum mower.

The PCT application No. PCT/GB79/00053 (BSRAE) mentions the possibility of two counter-rotated brushes fitted vertically so as to cover the opening between the drums of twodrum mowers to give a simple swath-forming arrangement. The brushes are described as being cylindrical or conical.

In accordance with a first independent aspect of the present invention, there is provided crop cutting and conditioning apparatus comprising one or more crop cutting devices for cutting crop by rotary motion about a vertical axis, the or each crop cutting device comprising a first rotor and a secnd rotor, the first and second rotors being mounted for rotation about a common vertical axis, the first rotor including cutting means for cutting crop by rotation of the first rotor, and the second rotor comprising a crop conditioning device for engaging crop and for conditioning the crop by relative movement between the conditioning device and the crop engaged thereby, and drive means for driving the first and second rotors in rotation at different peripheral velocities such as to effect cutting of crop by the cutting means and conditioning of crop by the conditioning device, in which the conditioning device comprises a multiplicity of stiff resilient elongate conditioning elements for conditioning the crop during the said relative movement by an action consisting predominantly of surface damage to the crop, the elements being yieldable in response to engagement with the crop and being yieldable at least predominantly by bending of the elements along at least part of the crop engaging portions of the lengths thereof, and the elements being sufficiently stiff to return to their undeflected dispositions when free from engagement with the crop at least predominantly by virtue of the stiffness of the elements.

Hereinafter, where reference is made to a "crop cutting and conditioning apparatus as hereinbefore defined" there is meant a crop cutting and conditioning apparatus comprising one or more crop cutting device for cutting crop by rotary motion about a vertical axis, the or each crop cutting device comprising a first rotor and a second rotor, the first and second rotors being mounted for rotation about a common vertical axis, the first rotor including cutting means for cutting crop by rotation of the first rotor, and the second rotor comprising a crop conveying and conditioning device for engaging crop for the purpose of conveying it and for conditioning the crop by relative movement between the conditioning device and the crop engaged thereby, and drive means for driving the first and second rotors in rotation at different peripheral velocities such as to effect cutting of crop by the cutting means and conditioning of crop by the conditioning means.

Hereinafter, where reference is made to a "conditioning device as hereinbefore defined" there is meant a conditioning device comprising a multiplicity of stiff, resilient, elongate conditioning elements for conditioning the crop by relative movement between the crop and the conditioning device by an action consisting predominantly of surface damage to the crop, the elements being yieldable in response to engagement with the crop, and being yieldable at least predominantly by bending of the elements along at least part of the crop engaging portions of the lengths thereof, and the elements being sufficiently stiff to return to their undeflected dispositions when free from engagement with the crop at least predominantly by virtue of the stiffness of the elements.

Where reference is made to the elements being sufficiently stiff to return to their undeflected dispositions of at least predominantly by virtue of the stiffness of the elements, it is to be appreciated that the base of an element may be secured to a support member of the conditioning device by a mounting which has itself a degree of resilience, for example by being clamped to a support member by clamping means including resilient material. Such a resilient mounting may contribute to the return of an element to its undeflected disposition, but it is a feature of the conditioning device set out above that the elements are sufficiently stiff to return to their undeflected dispositions predominantly by virtue of the stiffness of the elements.

Where, as will be described hereinafter, the elements are mounted in tufts with a plurality of elements set closely together, it will be appreciated that adjacent elements will assist each other in the return to an undeflected disposition when free from engagement with crop, but again it will be appreciated that this return is effected predominantly by virtue of the stiffness of the elements. Similarly where, as will be described hereinafter, the conditioning device comprises a rotary device, the return of the elements to their undeflected dispositions may be assisted by the effects of centrifugal force, but again the elements are returned predominantly by virtue of the stiffness of the elements.

In any of the arrangements above, there may be provided the feature that the second rotor of each cutting device provides a crop conveying surface (conveniently an outwardly extending and downwardly inclined crop conveying surface) for conveying cut crop to the rear of the apparatus, and there is provided on the crop conveying surface at least one conditioning device comprising a straight or curved linear array of conditioning elements upstanding from the crop conveying surface, the array being aligned at least approximately along a direction which, when viewed from above, is inclined at an angle of inclination to a radius of the said vertical axis of the crop conditioning device and is inclined to the horizontal.

Preferably the said array extends at least substantially over the whole of the width of the crop conveying surface from the outer to the inner edge thereof.

Also preferably the said angle is chosen to be such as to inhibit excessive scattering of cut crop and to assist inward movement of cut crop through a gap formed between two adjacent cutting devices, so as to form a suitable swath for drying.

Preferably the said angle is such that the outer end of the array trails the said radius, and the angle formed with the radius is greater than 30 , preferably in the range of 50 to 70 , most preferably about 60 .

Preferably the angle the upstanding array makes with the horizontal plane is such that its upper edges or tips are trailing the base in the direction of rotor rotation. Preferably the angle to the horizontal is between 30 and 70 , most preferably 45 to 60 .

In any of the arrangements above, there may be provided the feature that each second rotor includes or consists of a conditioning device comprising a plurality of conditioning elements directed outwardly from the said vertical axis of the second rotor, the envelope of the outer tips of the conditioning elements having a shape such that over at least a part of the height of the second rotor the radius of the envelope decreases with increase of height of the second rotor.

Preferably the shape of the envelope is such as to achieve height-related differential conditioning of crop in which crop is more severely conditioned by the lower portions of the second rotor than by the upper portions.

In any of the arrangements above, there may be provided the feature that the second rotor includes or consists of a conditioning device comprising a plurality of conditioning elements directed outwardly from the said vertical axis of the second rotor, the said conditioning elements comprising elongate elements secured in groups distributed around the second rotor, the elements of each group being aligned along a direction which when viewed from above is inclined at an angle of inclination to a radius of the said vertical axis of the second rotor.

Preferably the second rotor is arranged so that the said angle is adjustable.

Also preferably the said angle is such that the outer ends of the elongate elements trail the said radius, and the angle formed is preferably in the range of 20 to 60 .

In any of the arrangements above, there may be provided the feature that the second rotor of each cutting device includes or consists of a conditioning device comprising a plurality of conditioning elements directed outwardly from the said vertical axis of the said second rotor, the population of conditioning elements being arranged to decrease with increasing height of the second rotor.

Preferably the non-uniformity of the conditioning elements is arranged to be such as to produce height-related differential conditioning of crop in which crop is conditioned with greater severity by lower parts of the said second rotor than by upper parts.

In accordance with a second independent aspect of the invention, there is provided crop cutting and conditioning apparatus as hereinbefore defined in which the second rotor of the or each cutting device provides a crop conveying surface for conveying cut crop to the rear of the apparatus, and there is provided on the crop conveying surface at least one conditioning device comprising a straight or curved linear array of conditioning elements upstanding from the crop conveying surface, the array being aligned at least approximately along a direction which, when viewed from above, is inclined at an angle of inclination to a radius of the said vertical axis of the crop conditioning device.

In accordance with a third independent aspect of the present invention, there is provided crop cutting and conditioning apparatus as hereinbefore defined in which the second rotor includes or consists of a conditioning device comprising a plurality of conditioning elements directed outwardly from the said vertical axis of the second rotor, the envelope of the outer tips of the conditioning elements having a shape such that over at least a part of the height of the second rotor the radius of the envelope decreases with increase of height of the second rotor.

In accordance with a fourth independent aspect of the invention, there is provided a crop cutting and conditioning apparatus as hereinbefore defined in which the second ro tor includes or consists of a conditioning device comprising a plurality of conditioning elements directed outwardly from the said vertical axis of the second rotor, the said conditioning elements comprising elongate elements secured in groups distributed around the second rotor, the elements of each group being aligned along a direction which when viewed from above is inclined at an angle of inclination to a radius of the said vertical axis of the second rotor.

In accordance with a fifth independent aspect of the invention, there is provided a crop cutting and conditioning device as hereinbefore defined in which the second rotor of the or each cutting device includes or consists of a conditioning device comprising a plurality of conditioning elements directed outwardly from the said vertical axis of the second rotor, the population of conditioning elements being arranged to vary with height of the second rotor, e.g. to decrease with increasing height of the second rotor.

In any of the arrangements above, there may be provided the feature that the second rotor provides a crop conveying surface for conveying cut crop to the rear of the apparatus by rotation of the second rotor, and in which the first rotor has an upper surface or surfaces positioned adjacent to the crop conveying surface of the second rotor, the or each said upper surface having at least a part thereof shaped to continue the general outline of the crop conveying surface of the second rotor at least at the transition region between the said upper surface and of the said crop conveying surface, the cutting means being arranged to protrude outwardly from beneath the said upper surface or surfaces of the second rotor.

In any of the arrangements above, there may be provided the feature that the second rotor provides a crop conveying surface for conveying cut crop to the rear of the apparatus by rotation of the second rotor, and in which the first rotor extends outwardly beyond the perimeter of the crop conveying surface of the second rotor, and the second rotor includes one or more resilient wiper devices projecting outwardly beyond the perimeter of the crop conveying surface over at least part of the outer region of the first rotor, for lifting and transferring crop from the first rotor to the crop conveying surface of the second rotor.

In any of the arrangements above, there may be provided the feature that the drive means is arranged to drive the first and second rotors in rotation in opposite senses in such a manner that the cutting by the cutting means is at least in part shear cutting effected by the action of the two rotors in opposite directions on the crop.

In accordance with a sixth independent aspect of the invention, a crop conditioning apparatus comprises a pair of crop conditioning rotors each mounted for rotation about a vertical axis with the vertical axes spaced apart transversely relative to an intended direction of forward travel of the apparatus, and drive means for driving the rotors in counter rotation in such a manner that crop is passed between the rotors from the front to the rear of the apparatus and is conditioned by relative movement between the conditioning rotors and the crop engaged thereby, in which each conditioning rotor comprises a conditioning device comprising a plurality of conditioning elements directed outwardly from the said vertical axis of the conditioning rotor, the envelope of the outer tips of the conditioning elements having a shape such that over at least a part of the height of the conditioning rotor the radius of the envelope decreases with increase of height of the conditioning rotor.

In accordance with a seventh independent aspect of the invention a crop conditioning apparatus comprises a pair of crop conditioning rotors each mounted for rotation about a vertical axis with the vertical axes spaced apart transversely relative to an intended direction of forward travel of the apparatus, and drive means for driving the rotors in counter rotation in such a manner that crop is passed between the rotors from the front to rear of the apparatus and the crop is conditioned by relative movement between the conditioning rotors and the crop engaged thereby, in which each crop conditioning rotor comprises a conditioning device comprising a plurality of conditioning elements directed outwardly from the said vertical axis of the conditioning rotor, the said conditioning elements comprising elongate elements secured in groups distributed around the conditioning rotor, the elements of each group being aligned along a direction which when viewed from above is inclined at an angle of inclination to a radius of the said vertical axis of the conditioning rotor.

In accordance with an eighth independent aspect of the invention a crop conditioning apparatus comprises a pair of crop conditioning rotors each mounted for rotation about a vertical axis with the vertical axes spaced apart transversely relative to an intended direction of forward travel of the apparatus, and drive means for driving the rotors in counter rotation in such a manner that crop is passed between the rotors from the front to rear of the apparatus and the crop is conditioned by relative movement between the conditioning rotors and the crop engaged thereby, in which each conditioning rotor comprises a conditioning device comprising a plurality of conditioning elements directed outwardly from the said vertical axis of the conditioning rotor, the population of conditioning elements being arranged to vary with height of the rotor, e.g. to decrease with increase in height of the condi tioning rotor.

In any of the cutting arrangements above, there may be provided a first cutting feature that the first rotor includes cutting means for cutting crop by rotation of the first rotor, and the second rotor provides a crop conveying surface for conveying cut crop to the rear of the apparatus by rotation of the second rotor, and there being drive means for driving the first and second rotors in rotation to different peripheral velocities such as to effect cutting of crop by the cutting means and conveying of crop by the conveying surface, in which the first rotor has an upper surface or surfaces positioned adjacent to the crop conveying surface of the second rotor, the or each said upper surface having at least a part thereof shaped to continue the general outline of the crop conveying surface of the second rotor at least at the transition region between the said upper surface and the said crop conveying surface, the cutting means being arranged to protrude outwardly from, or outwardly from beneath, the said upper surface of surfaces of the second rotor.

Preferably the upper surface of the first rotor comprises an annular rim coaxial with and surrounding an outer edge of the crop conveying surface of the second rotor. Conveniently the crop conveying surface of the second rotor is an outwardly extending and downwardly inclined frusto-conical or inverteddish shaped surface and the annular rim continues the outwardly extending and downwardly inclined conveying surface of the second rotor.

Alternatively, the first rotor may have a plurality of said upper surfaces, and each said upper surface is provided by a discrete projecting portion projecting outwardly beyond the outer edge of the second rotor, each projecting portion having a cutting knife mounted to protrude outwardly from, or outwardly from beneath, the projecting portion.

Preferably each said projecting portion has an upper surface which over at least a portion thereof is inclined to the horizontal in the direction of peripheral movement of the first rotor in such a manner as to form a slight ramp acting to lift cut crop towards the conveying surface of the second rotor.

Also in any of the cutting arrangements above, there may be provided a second cutting feature that the first rotor includes cutting means for cutting crop by rotation of the first rotor, and the second rotor provides a crop conveying surface for conveying cut crop to the rear of the apparatus by rotation of the second rotor, and there is provided drive means for driving the first and second rotors in rotation at different peripheral velocities such as to effect cutting of crop by the cutting means and conveying of crop by the conveying surface, in which the first rotor extends outwardly beyond the perimeter of the crop conveying surface of the second rotor and the second rotor includes one or more resilient wiper devices projecting outwardly beyond the perimeter of the crop conveying surface over at least part of the outer region of the first rotor, for lifting and transferring crop from the first rotor to the crop conveying surface of the second rotor.

Preferably the resilient wiper device or devices extend outwardly over the cutting path of the cutting means.

Further in any of the cutting arrangements above, there may be provided a third cutting feature that the first rotor includes cutting means for cutting crop by rotation of the first rotor, and the second rotor comprises crop conveying means for conveying cut crop to the rear of the apparatus by rotation of the second rotor, and there is provided drive means for driving the first and second rotors in rotation in opposite senses in such a manner that the cutting by the cutting means is at least in part shear cutting effected by the action of the two rotors in opposite directions on the crop.

There will now be described a number of preferred features which may be provided in accordance with the conditioning device which has been referred to in various arrangements.

Preferably the said conditioning device comprises a crop conditioning device as hereinbefore defined.

In connection with all those aspects of the invention set out above in which a crop cutting and conditioning apparatus has crop cutting devices with first and second rotors, there is provided in accordance with another general aspect of the invention a modification in which the first and second rotors of each cutting debive are replaced by a single rotor which provides both the conditioning device and the cutting means, so that in such an aspect the crop conditioning device and the cutting means are driven in rotation at the same speed.

In particular forms of the invention, the conditioning device comprises a brush in which the tips of the conditioning elements are distributed over a region extending in two directions. Conveniently the elements may be arranged in a brush of conventional form, that is to say in which groups of elements are mounted together in tufts, and the positions of the tips of the elements are to at least some extent random. However other forms of brush will be readily apparent, and in particular the brush may comprise elements which are disposed in a regular, non-random, pattern.

It is preferred that the conditioning elements are sufficiently stiff to penetrate and move through a stream of crop, and it is also preferred that the elements condition the crop by an action which consists predominantly of suface abrasion of the crop. It is further preferred that the elements are yieldable by bending substantially along the whole of the free lengths thereof.

In one form, the tips of the elements may be distributed substantially uniformly and the population of the elements at the tips may lie in the range 1 to 20 elements per sq. cm, preferably in the range 3 to 1 6 elements per sq. cm. In another form the elements may be arranged in spaced apart tufts of elements and the population of the elements in each tuft at the tips may lie in the range 1 to 20 elements per sq. cm, preferably in the range 3 to 1 6 elements per sq. cm.

Conveniently each tuft may be formed of one or more lengths of element material doubled over and secured within a protective, resilient retaining sleeve or tube to a supporting base in the region of the fold of the doubled over element length or lengths. In such a case a convenient method of producing a linear array of elements is to secure a series of such doubled over lengths of element material at spaced-apart positions along a split length of tubing, the elements being secured in the tubing by a bolt or like fastening means passing through the sides of the tubing on either side of the split. Conveniently such doubled over lengths of element material are arranged to project from the tube at an angle to each other so as to form a generally V-shaped pair of conditioning tufts.In accordance with a seventh particular aspect of the present invention, such a form of V-shaped tufts may also be provided in other forms of conditioning device other than hereinbefore defined.

Alternatively the conditioning elements may be constructed by moulding or otherwise performing plastics or other resilient material.

Also conveniently each element or group of elements in a tuft may be supported and protected at the base thereof by a sleeve of resilient material.

In general terms, the conditioning elements may be of the form described in the published P.C.T. patent application No.

PCTZGB79/00053.

With reference to the crop cutting and conditioning devices referred to above as described in U.S. Patent No. 3977165 (Klinner et al), the present invention represents in a number of aspects improvements over the devices previously described. Work at the National Institute of Agricultural Engineering at Wrest Park, Silsoe, Bedford, England in the late 1 960s had shown that the knife carrying discs of rotary mowers, both of the drum and disc type, could be fitted with conditioning attachments in such a way that their mowing performance was not impaired and the action of the attachments imparted to the crop a conditioning treatment simultaneous with the cutting. The effectiveness of the various atattachments, all made of steel, was good, but there were two serious disadvantages.Firstly, a significant percentage of crop was too severely treated so that dry matter losses would become rather high. Secondly, any stones or other heavy objects which were picked up by the mower were projected at times in a hazardous manner. The arrangement shown in Fig. 24 of U.S. Specification No. 3977165 was intended to attempt to overcome these difficulties by providing a slower rate of rotation of the upper drum rotor than the lower knife carrying disc.However, from the engineering point of view, it is difficult to construct a rotary mower (particularly of large diameter disc type as used in modern drum mowers) in such a way that in the hostile environment of typical grass fields, the small clearance between the upper and lower discs and the pivoted knives is maintained, and the step which cut crop has to climb onto the conveying surface does not constitute so great an obstacle that the power requirement of the machine is drastically increased.In preferred arrangements of the present invention, it is possible to provide rotary mowers on which the cutting knives are driven at the optimum speed for impact cutting, i.e. between approximately 70 and 95 m/s, but the crop conveying discs are driven at a very much lower spped, so that resilient conditioning devices attached to them will neither fragment the crop excessively nor propel foreign objects dangerously. Furthermore, and most importantly, the risk of collision between metal components can be arranged to be minimal.

Embodiments of the invention will now be described by way of example with reference to the accompanying drawings in which: Figure 1 is a cross-section showing from the side the outer half of a twin unit, two-speed crop cutting apparatus embodying the invention, but generally of the drum mower kind; Figure 2 is a side view partly in crosssection of a modified form of the crop cutting apparatus of Fig. 1; Figure 3 is a cross-section showing from the side a further modification of the crop cutting apparatus shown in Fig. 1; Figure 1(a) is a diagrammatic perspective view of the general layout of a crop cutting apparatus embodying the present invention as shown in the preceding Figures, but with crop conveying and/or conditioning devices attached; ; Figures 4 and 4(a) are side and plan diagrammatic representations respectively of a modification of a crop cutting apparatus of the form shown in the proceeding Figures; Figures 5 and 5(aj are diagrammatic side and plan views respectively of a further modification of crop cutting apparatus embodying the invention of the general form in the preceding Figures; Figures 6, 6(a), 7 and 7fa) are diagrammatic side and plan views respectively of a further modification of the crop cutting apparatus shown in the preceding Figures, in which a lower rotor includes discrete projecting portions;; Figures 8 and 8(a) show a side crosssection and plane view respectively of a crop conditioning apparatus embodying the present invention and suitable for use in connection with the crop cutting apparatus shown in the preceding Figures; Figure 9 is a diagrammatic side view of crop cutting and conditioning apparatus embodying the invention in which an array of conditioning elements is provided on an upper rotor of a crop cutting device; Figure 10 is a diagrammatic side view of a modification of the crop conditioning apparatus of Fig. 9; Figure ills a diagrammatic side view of a deflecting and conditioning means provided between a pair of adjacent crop cutting and conditioning devices embodying the invention;; Figures 12, 12(a) and 12(b) are diagrammatic side, perspective and plan views respectively of a crop conditioning device embodying the invention for use in a crop cutting and conditioning apparatus; Figures 13, 14 and 14(a), 15 and 15(a) (b) (c) (d) and (e), 16 and 16(a) show various diagrammatic side, plane, and perspective views of modifications of the crop conditioning device shown in Figs. 1 2 and 12(a); Figures 17, 17(a), 18, 18(a) and 18(b) show diagrammatic side views and plan views respectively of a crop cutting and conditioning apparatus in which there are mounted on an upper rotor of the conditioning device, groups of conditioning elements arranged in various configurations and forms; and Figures 19, 19(a) and 20 show diagrammatic plan and side views variously of preferred forms of conditioning elements suitable for use in the embodiments of the preceding Figures.

Fig. 1 is a cross-section showing from the side the outer half of a twin unit, two-speed crop cutting apparatus embodying the invention and generally of the drum mower kind.

From a transverse drive shaft 11 a center spindle 1 2 of the drum cutter indicated generally at 1 3 is driven by means of two bevel gears 14. At its base the spindle 12 runs in a thrust bearing 1 5 and has attached to it a skid disc 1 6 which is freely rotatable in known manner. Above the skid disc 1 6 there is fixedly attached to the spindle 1 2 a support disc 1 7 which constitutes a first, lower rotor of the cutting device and which carries a narrow frusto-conical rim 1 8 which may for example be 50mm wide.The shape of the rim 1 8 is such that its sloping upper surface is a continuation of the shape of a crop conveying skirt 1 9 attached to the base of the central drum 20 of the cutting device 1 3. Pivoted knives 21 are attached to the underside of the narrow rim 1 8 in such a way that upon meeting an obstruction each knife can swing through 360 . The knife carrying rim 1 8 is entirely smooth on its crop facing surface and may for example be coated with polytetrafluoroethylene or other durable low friction material.

The drum 20, skirt 1 9 and internal supporting webs 22 constitute a second, upper rotor which is mounted by bearings 23 and 24 on the central spindle 12, and is driven from the transverse shaft 11 at the top by a second pair of bevel gears 25 and through a gear wheel 26 and internal gear ring 27. The speed at which the upper rotor 1 9-20, is driven may for example be 20 m/s at the circumference of the crop conveying skirt 19, but may in other cases be in the range 10 m/s to 40 m/s. As shown in Fig. 1 by the two arrows, both the knife carrying rim 1 8 and the crop conveying skirt 1 9 rotate in the same direction, namely towards the rear on the inner side of the cutting device 1 3 which faces towards the other cutting device (not shown).Thus in conventional manner the crop is gathered inwardly between the two cutting devices and transferred rearwardly to form a swath. Thus on the second cutting device (not shown) the rotating components revolve in the opposite direction so that cut crop is conveyed to the rear through the cen-tral space betweenn the adjacent cutting devices.

Fig. 2 is a side view partly in cross-section of a modified form of the crop cutting apparatus of Fig. 1, and in this and other embodiments corresponding elements are indicated by like reference numerals. In this modification the bevel gears 14 and 25 are so arranged that the knife carrying rim 1 8 rotates in the opposite direction to the direction of rotation of the crop conveying skirt 1 9.

Fig. 3 is a cross-section showing from the side a further modification of the crop cutting apparatus shown in Fig. 1, and again corresponding elements are indicated by like reference numerals. In the modification of Fig. 3, the crop conveying skirt 1 9 is driven in rotation by an external gear ring 27' meshing with a gear 26'.

Fig. 1 (a) is a diagrammatic perspective view of the general layout of a crop cutting apparatus embodying the invention in the form shown in Fig. 1 or Fig. 2, but with crop conveying and/or conditioning attachments 28 attached to the upper surfaces of the crop conveying skirts 1 9. The attachments shown are support bars for conditioning elements as shown hereinafter. The two crop cutting devices are indicated generally at 1 3 and 13' and are shown as supported from an overhead frame 29 suitable for attachment to the three point linkage of a tractor.

Figs. 4 and 4(a) are side and plan diagrammatic representations respectively of a modifi cation of the crop cutting apparatus of the form shown in the preceding figures, and again corresponding elements are indicated by like reference numerals. Fig. 4 shows the skid disc 1 6 at the base of the cutting device, a spoked disc 1 7 which carries the outer rim 1 8 and knives 21, and a wheel 31 fitted between adjacent spokes in such a way that only when the disc 1 7 is deflected downwardly at its edge, for example by a foreign body, will the wheel 31 prevent further deflection by coming into contact with the skid disc 1 6. The plan view in Fig. 4(a) shows how the pivoted knives 21 can rotate through 360 between the spokes 30, and it also shows a simple mounting arrangement of the safety wheel 31 between support bars 32.

Figs. 5 and 5(a) are diagrammatic side and plan views respectively of a further modification of the crop cutting apparatus shown in the preceding figures. Fig. 5 discloses an alternative construction of the knife carrying rim 1 8 in which the rim 1 8 is attached to the support disc 1 7 by means of spaced apart angled brackets 33. This method of construction ensures that any crop which may enter through the gap between the knife carrying rim 1 8 and the crop conveying skirt 1 9 can leave again through the gaps between brackets 33 under the influence of centrifugal forces.

Figs. 6 and 6(a) are diagrammatic side and plan views respectively of a further modification of the crop cutting apparatus shown in the preceding figures, in which the lower support disc 1 7 consists of a dished pressing from which smaller discs have been cut as indicated at 17' to save weight. To provide locating and mounting means for the knives 21, part-moon shaped plates 18' are welded to an upstanding rim 17" which is also recessed at the top to allow each knife to swing through a full 360 on impact with a heavy object. In this modification, the projections 18' fulfill a similar function to the rim 1 8 in the preceding figures, and as shown in Fig. 6, the shape of each projection 18' is such as to continue the shape of the upper surface of the crop conveying skirt 19.In a modified version shown in Figs. 7 and 7(a), each plate 18' is in the form of a ramp acting to lift out crop towards the conveying surface 1 9 of the upper rotor.

Figs. 8 and 8(a) show a side cross-section and plan view respectively of an apparatus embodying the present invention and suitable for use in connection with the crop cutting apparatus shown in the preceding figures. Fig.

8 shows a wiper device 34 in the form of a tuft of resilient crop conditioning elements (also referred to as filaments) 35 formed of synthetic plastics material. The tuft 34 is bolted onto the crop conveying skirt 1 9 in such a way that is supported on two sides by a shallow bracket 36 to prevent the tuft from turning under the influence of centrifugal force or load applied to its tip. In the plan view of Fig. 8,the tuft 34 is shown to be orientated in such a way that, relative to a radius of the crop conveying skirt 1 9, the tips of the elements 35 are trailing. It is also shown that the elements 35 overhang the knife carrying rim 1 8 and may extend over the cutting path of the cutting knives 21.The number of wiping tufts 34 fitted near the perimeter of the crop conveying skirt 1 9 may be varied from two per disc to several times the number of cutting knives.

Fig. 9 is a diagrammatic side view of a crop cutting and conditioning apparatus embodying the invention and is particularly concerned with a linear array 37 of crop conditioning elements 35 which are provided on the crop conveying skirt 1 9 of a crop cutting and conditioning device 1 3. Fig. 9 shows a knife carrying rim 1 8 of the form described with reference to the previous figures, and also shows a tuft 34 protruding out over the rim 1 8. The rim wiping tuft is shown to be followed by an attachment to the crop conveying skirt 1 9 which consists of a rearwardly leaning angle bar 38 to which are attached on the upwardly inclined trailing face thereof a series of tufts 39 of synthetic plastics conditioning elements 35 similar to the elements described with reference to Fig. 8(a). The conditioning elements of the embodiments described with reference to Figs. 8 onwards of the present description may conveniently be of any of the forms described in published pending PCT Application No.

PCT/TB79/00053-Publication No.

W079/00863. It is an object of the attachment shown in Fig. 9 as a whole to drive itself under the cut crop, forcing the crop upwards so that it is scratched and abraded by the tufts of plastics material during acceleration. To maintain the drum unit of the cutting device 1 3 in balance in operation, two attachments 38 are normally required, although a counter-weight may be fitted on the opposite side of the crop conveying skirt 1 9 and this may be appropriate on a relatively small diameter cutting device. As in the case of the rim wiping tuft 34, the multi tuft attachment 37 is fitted at an angle to a radius of the vertical axis of the cutting device 1 3 so that the outer end of the attachment 37 trails the radius. The angle which the attachment 38 makes with a radius of the vertical axis of the cutting device 1 3 (when viewed from above) determines whether the crop is scattered at the rear of the mower or whether it is formed into a distinct swath. The greater the enclosed angle between the radius and the attachment, the neater the swath will be, up to an optimum position. By way of example the scattering effect often persists at angles of up to about 30 but at around 60 a distinct swath is formed in most crops. In Fig. 10 there is shown a diagrammatic side view of a modification of the apparatus of Fig. 9, and the inclination of the crop conveying skirt 1 9 has been accentuated by the base of the attachment 38 being tapered down towards the rim.This configuration makes it difficult for the crop to move towards the centre of the crop conveying skirt 19, and conditioning is largely confined to the lower crop regions. To prevent crop moving too easily into an upward direction and out of the working zone of the attachments, a spring loaded deflector (as shown at 39 in Fig. 11) may be provided.

Such a deflector 39 may carry abrasive brush tufts 40, or metal serrations, at its lower end.

The deflector 39 also contributes to the crop layer passing between the two drum units to the rear of the machine being lightly conitioned on top. The angle the deflector 39 makes with the vertical is determined by the setting of an adjustable stop 41, and the pressure which the deflector 39 exerts on the crop depends on the setting of a compression spring 42. To be particularly suited to the embodiments shown in Figs. 9 and 10, the deflector 39 may be spade-shaped when viewed from the front or rear.

Figs. 1 2, 12(a) and 12(b) are diagrammatic side plan and perspective views respectively of a further embodiment of a crop conditioning device embodying the invention, in this case where conditioning elements are provided on bars 43 positioned to extend between the outer edge of the conveying skirts 19, and the upper part of the cutting device 1 3 at the upper end of the central spindle.

The bars are arranged in the general form of a conical "squirrel cage" arrangement, and represent a further movement of the conditioning elements from the positions shown in Fig. 10, so as to be lying at an even steeper angle to the plane of the conveying skirt. The conditioning bars are so fitted that they connect the upper surface of the crop conveying skirt 1 9 with the underside of an upper sealing ring 44 attached to the top of the cutting device 13. In Fig. 12, brush tufts 45 are shown set substantially horizontally, whilst in Fig. 12(b) the tufts 45 are inclined downwardly in the outward direction.In Fig. 12(b) the lower parts of the bars trail the upper parts, whereas in Fig. 1 3 there is shown a modification in which the upper parts of the bars 43 trail the lower parts, relative to the rotation of the rotors, in order to give a greater lifting effect to the crop.

The crop conditioning unit need not necessarily be of an open cage construction, but can consist of a solid cone to which fins for mounting the conditioning elements can be attached.

Figs. 14 and 14(a), 15, 15(a) (b) (c) (d) and (e) and 1 6 and 16(a) show respective diagrammatic side and plan views of modifications of the crop conditioning device shown in Figs. 1 2 and 12(a). Figs. 14 and 14(a) show a skeleton type cone made up in such a way that relative to the direction of rotation the lower ends of mounting bars 49 are trailing.

Conveniently these mounting bars 49 may have mounted on them tufts of crop conditioning elements as have been described hereinbefore. The purpose of the trailing arrangement is to prevent crop from adhering to the conditioning elements too long and assisting in the formation of a neatly arranged swath.

In another modification the skeleton form cone may be formed of mounting bars which trail at the top. This helps to lift laid crops and results in loosely arranged swaths. If the conditioning elements also trail at their tips, relatively gentle treatment is achieved. In Figs.

14 and 14(a) the conditioning elements themselves are omitted for simplicity, but may conveniently be similar to conditioning devices 45, 46, 47 and 48 in Figs. 12 and 13.

In Fig. 1 5 there is shown a further modification of conditioning apparatus, and in this figure mounting bars 50 for conditioning elements 35 are shown to be vertical and to form a skeleton cylinder or squirrel cage.

Alternatively the mounting bars 50 may be provided as ribs on a solid cylinder (not shown). The purpose of the embodiments shown in Fig. 1 5 is to treat the crop before it has time to fall with head ends forwards, and so ensure that the conditioning effect is spread over a much greater length of crop than is possible with conditioning attachments which slope towards the rotor axis at the top.

In some conditions, for example when the crop is leaning or laid, or when the conditioning elements are set so that they sweep a vertifal plane marginally ahead of the tips of the cutting knives, a particularly severe conditioning effect may be obtained, because then the crop is not yet free to move under the impact of the conditioning devices. The situation when the conditioning elements 35 operate in advance of the cutting knives is indicated in Fig. 15(a). When conditioning elements are mounted radially, then the treated crop is scattered over a wide strip at the rear of the mower. This effect may be minimised by angling the carrying bars 50 and conditioning elements 35 so that the tips of the elements are trailing. This latter situation is shown in plan view in Fig. 15(b).Since the angle of the conditioning elements 35 relative to a radius of the main axis of rotation determines the spreading effect and also the severity of treatment, it is desirable to facilitate adjustment of this angle in conformity with prevailing conditions and desired swath structure. In Fig. 15(c) there is shown an adjusting system indicated generally at 51, which requires the mounting bars 50 to be pivoted at the top and bottom at pivot 52 and to carry at either or both ends of each bar 50 a lug 53 which can be swivelled and fixed in any one of a series of holes 54. The most appropriate of angles has been found to be from 0 to 60 angle to the radial, the angle being in such a sense that the conditioning elements trail relative to the radius of rotation.In other modifications, the conditioning structure may be formed with the mounting bars 50 fitted so that a trail at the top or bottom of the rotor in the direction of rotation gives a helical arrangement which imparts respectively a lifting or holding down effect to the crop, for example as shown in Fig. 15(e).

In Fig. 16 mounting bars 55 are shown to be attached at their base a right angles to a crop conveying skirt or dise 56. Towards the top, the bars 55 converge towards the axis of the mower unit 1 3. This embodiment has the advantage that the lowermost conditioning elements 35 sweep the knife carrying rim 18 and the working zone or cutting path of the knives 21 parallel to the direction of inclination of the skirt 19 and rim 18. In order to ensure rigidity od the intermediate knife supporting disc 17, gusset fins or pressed ribs 57 are provided radially along the spokes 30 of the disc 17. In Fig. 16(a) knives 21 are shown to be attached halfway between adjacent spokes 30 so that the knives can swing freely through 360 on impact with a heavy object.Figs. 1 7 and 1 7(a) show a modification in which ramps 18' are provided to lift cut crop towards the conditioning rotor.

Considering generally some of the advantages which may be obtained from the invention as embodied in the structures described, one principal advantage is that there can be provided resilient conditioning elements or devices which may be attached to components which rotate substantially more slowly about an axis than the knives which cut the crop.

Amongst other advantages is that there may be provided a conditioning rotor on which the angle of the conditioning elements is adjustable relative to a radius of the axis about which conditioning elements are rotated, so that crop may be treated at different leveis of severity and may either be spread or arranged in distinct swaths. In some arrangements there may be advantage derived in respect of better cutting performance by arranging that the cutting knives and resilient wiper elements counter rotate in the same vertical plane giving the effect that crop stems are held more positively by the resilient elements at the moment of impact with the knives.Thus in some arrangements a lower rotor carrying cutting elements may be rotated about a vertical axis in one sense, while an upper rotor carrying conditioning elements may be rotated about the same vertical axis but in the opposite sense.

Returning now to specific embodiments shown in the drawings, Figs. 18, 18(a) and 18(b) show a diagrammatic side view and plan view respectively of a crop cutting and conditioning apparatus comprising a lower rotor consisting of the knife supporting disc 1 7 as shown in previous figures. and an upper rotor consisting of a framework of supporting discs 58 and 59 interconnected by mounting bars 60. In the embodiment of Figs. 1 7 and 17(a) there is provided no upper crop conveying skirt of the kind shown at 1 9 in previous embodiments. Otherwise the upper and lower rotors are mounted for rotation on the spindle 1 2 generally in accordance with the arrangements shown in preceding figures.The bevel gear drives 14 and 25 for the supporting disc 17 and the conditioning rotor framework 58, 59 and 60 are in this embodiment housed in a main beam housing 61, where lubrication can be easily arranged. The conditioning rotor, which is indicated generally at 62 and which constitutes the aforementioned upper rotor, comprises the framework 58, 59 and 60 as described, and conditioning devices 34 attached to the mounting bars 60, the conditioning devices comprising conditioning elements 35 of the kind generally described hereinbefore. The conditioning rotor, built around the spindle 12, can be of open construction or may consist of a solid cylinder with ribs for attaching the conditioning tufts.

The advantage of a "squirrel cage" arrangement of bars, as show, is that the bars 60 may be angled (optionally) to vary the severity of treatment and the swath formation. The advantage of a solid cylinder with fins (not shown) is that simply by removing the conditioning means the machine can be used for mowing alone. In that event an upstanding circular rib indicated at 63 on the knife carrying disc 1 7 just in front of the fins or mounting bars of the crop conditioning rotor, prevents crop from creeping under the cylinder and wrapping around the central spindle.

It is a particular feature of the embodiment shown in Fig. 17 that the population density of the tufts of conditioning elements 35 is varied vertically along the mounting bars 60, as shown. This is intended to cause more severe conditioning to the lower parts of the crop stems than to the upper parts. The distribution of tufts and the population density of the tufts on a conditioning rotor is one way of controlling the distribution and severity of crop treatment.

Figs. 19, 19(a) and 20 show diagrammatic plan and side views variously of alternative forms of conditioning elements suitable for use in the embodiments of the preceding figures. The figures show a method of creating V-form tufts by cutting short slits into the outer edge of a flattened plastic tube 64 and inserting a folded bundle of filaments 35 of synthetic plastics material into the slit with the folded ends inserted first. Next there is inserted a securing bolt 65 through holes in the plastic tube in the position shown to secure the bundle of filaments 35 to a mounting bar 66. This provides a continuous tuft-studded strip. To prevent the slits from running and extending under load conditions, it is preferred that reinforced plastic tubing is used.

Fig. 20 shows a modification of the arrangement of Figs. 1 9 and 19(a) in which the slits are cut into the inner edge of the plastics tubing and individual holes are made in the outer edge through which the tufts protrude.

This gives tufts in the shape of a V, so that paired bunches of conditioning elements can not be deflected towards each other where they emerge from the plastics tube.

Brief reference will now be made to some of the preceding figures and to various features thereof. With regard to the gearing shown in Figs. 1, 2 and 3, it will be appreciated that alternative ways of achieving the differential drive may be provided, such as planetary gearing.

The two mower embodiments with protrusions emanating from the rim give the advantage that the overlap zone between two adjacent, counter rotating and synchronously driven cutting units can be made greater than is possible with plain disc units. As a result the "mane" of long stubble so often left in difficult crops and conditions by rotary mowers is avoided. Cutting width is marginally reduced.

It should be understood that the shape of the ramp-like protrusions in Figs. 8, 8(a), 1 7 and 17(a) can be varied; the most preferred shape is the leading half of a part-moon, as in Fig. 7(a).

The wiper element of Figs. 8 and 8(a) overhanging the cutting rim is not primarily for conditioning the crop; it serves the purpose of assisting crop on to the conveying skirt and prevents repeated contact with the cutting knives. Optionally it can intrude into the cutting zone. The degree of resilience and its construction can vary.

It is to be appreciated that in the embodiments shown, it is not essential that the cutting rotor rotates more quickly than the conveying and conditioning rotor. If a method of cutting is used which achieves the desired results at lower speeds than the lowest effective conditioning speeds of, say, 1 5 m/s, then the ratio of the speed differential between cutting and conditioning components may be reversed.

Returning to consideration of general aspects of the embodiments described hereinbefore, it is to be appreciated that the conditioning elements may, in generality, be of all metal construction, for example by being resiliently mounted metal spokes, wedges or cones. It should also be appreciated that the aspects of the invention set out above may be utilised with an under-driven disc mower as well as with a top driven drum mower. Alternatively the cutting drums may be driven from one end and the crop conveying skirts or conditioning rotor from the other.

Finally, in accordance with a further general aspect of the present invention, advantage may be obtained in some circumstances by providing, eg by removing the knives, a crop conditioning apparatus having conditioning means embodying a particular aspect of the present invention as set out before, but in which the conditioning means is mounted for rotation about an axis or axes spaced from the axis or axes of the cutting means. Indeed in some forms the invention may provide conditioning apparatus for conditioning previously cut crop, there being provided no cutting means associated with the conditioning means.

Claims (28)

1. Crop cutting and conditioning apparatus comprising one or more crop cutting devices for cutting crop by rotary motion about a vertical axis, the or each crop cutting device comprising a first rotor and a second rotor, the first and second rotors being mounted for rotation about a common vertical axis, the first rotor including cutting means for cutting crop by rotation of the first rotor, and the second rotor comprising a crop conditioning device for engaging crop and for conditioning the crop by relative movement between the conditioning device and the crop engaged thereby, and drive means for driving the first and second rotors in rotation at different peripheral velocities such as to effect cutting of crop by the cutting means and conditioning of crop by the conditioning device, in which the conditioning device comprises a multiplicity of stiff resilient elongate conditioning elements for conditioning the crop during the said relative movement by an action consisting predominantly of surface damage to the crop, the elements being yieldable in response to engagement with the crop and being yieldable at least predominantly by bending of the elements along at least part of the crop engaging portions of the lengths thereof, and the elements being sufficiently stiff to return to their undeflected dispositions when free from engagement with the crop at least predominantly by virtue of the stiffness of the elements.

2. Apparatus according to Claim 1 in which the second rotor of each conditioning device provides a crop conveying surface for conveying cut crop to the rear of the apparatus, and there is provided on the crop conveying surface at least one conditioning device comprising a straight or curved linear array of conditioning elements upstanding from the crop conveying surface, the array being aligned at least approximately along a direction which, when viewed from above, is inclined at an angle of inclination to a radius of the said vertical axis of the crop conditioning device and is inclined to the horizontal.

3. Apparatus according to Claim 2 in which the said array extends at least substantially over the whole of the width of the crop conveying surface from the outer to the inner edge thereof.

4. Apparatus according to Claim 2 or 3 in which angles of inclination are chosen to be such as to inhibit excessive scattering of cut crop and to assist inward movement of cut crop through a gap formed between two adjacent cutting devices, so as to form a suitable swath for drying.

5. Apparatus according to Claim 2, 3 or 4 in which the arrangement is such that the outer end of the array trails the said radius, and upper end of the array trails relative to the lower end.

6. Apparatus according to any preceding Claim in which the second rotor includes or consists of a conditioning device comprising a plurality of conditioning elements directed outwardly from the said vertical axis of the second rotor, the envelope of the outer tips of the conditioning elements having a shape such that over at least a part of the height of the second rotor the radius of the envelope decreases with increase of height of the second rotor.

7. Apparatus according to Claim 6 in which the shape of the envelope is such as to achieve height-related differential conditioning of crop in which crop is more severely conditioned by the lower portions of the second rotor than by the upper portions.

8. Apparatus according to any preceding Claim in which the second rotor includes or consists of a conditioning device comprising a plurality of conditioning elements directed outwardly from the said vertical axis of the second rotor, the said conditioning elements comprising elongate elements secured in groups distributed around the second rotor, the elements of each group being aligned along a direction which when viewed from above is inclined at an angle of inclination to a radius of the said vertical axis of the second rotor.

9. Apparatus according to Claim 8 in which the second rotor is arranged so that the said angle is adjustable.

10. Apparatus according to Claim 8 or 9 in which the said angle is such that the outer ends of the elongate elements trail the said radius, and the angle formed is in the range 20 to 60 .

11. Apparatus according to any preceding Claims in which the second rotor of each cutting device includes or consists of a conditioning device comprising a plurality of conditioning elements directed outwardly from the said vertical axis of the said second rotor, the population of conditioning elements being arranged to decrease with increasing height of the second rotor.

12. Apparatus according to Claim 11 in which the non-uniformity of the conditioning elements is arranged to be such as to produce height-related differential conditioning of crop in which crop is conditioned with greater severity by lower parts of the said second rotor than by upper parts.

1 3. Apparatus according to any preceding Claim in which the conditioning device comprises a brush in which the tips of the conditioning elements are distributed over a region extending in two directions.

14. A crop cutting and conditioning apparatus as hereinbefore defined in which the second rotor of the or each cutting device provides a crop conveying surface for conveying cut crop to the rear of the apparatus, and there is provided on the crop conveying surface at least one conditioning device comprising a straight or curved linear array of conditioning elements upstanding from the crop conveying surface, the array being aligned at least approximately along a direction which, when viewed from above, is inclined at an angle of inclination to a radius of the said vertical axis of the crop conditioning device.

1 5. A crop cutting and conditioning apparatus as hereinbefore defined in which the second rotor includes or consists of a conditioning device comprising a plurality of conditioning elements directed outwardly from the said vertical axis of the second rotor, the envelope of the outer tips of the conditioning elements having a shape such that over at least a part of the height of the second rotor the radius of the envelope decreases with increase of height of the second rotor.

1 6. A crop cutting and conditioning apparatus as hereinbefore defined in which the second rotor includes or consists of a conditioning device comprising a plurality of conditioning elements directed outwardly from the said vertical axis of the second rotor, the said conditioning elements comprising elongate elements secured in groups distributed around the second rotor, the elements of each group being aligned along a direction which when viewed from above is inclined at an angle of inclination to a radius of the said vertical axis of the second rotor.

1 7. A crop cutting and conditioning device as hereinbefore defined in which the second rotor of each cutting device includes or consists of a conditioning device comprising a plurality of conditioning elements directed outwardly from the said vertical axis of the second rotor, the population of conditioning elements being arranged to vary with height of the second rotor.

1 8. Apparatus according to any preceding Claim in which the second rotor provides a crop conveying surface for conveying cut crop to the rear of the apparatus by rotation of the second rotor, and in which the first rotor has an upper surface or surfaces positioned adjacent to the crop conveying surface of the second rotor, the or each said upper surface having at least a part thereof shaped to continue the general outline of the crop conveying surface of the second rotor at least at the transition region between the upper surface and of the said crop conveying surface, the cutting means being arranged to protrude outwardly from beneath the said upper surface of surfaces of the second rotor.

1 9. Apparatus according to any preceding Claim in which the second rotor provides a crop conveying surface for conveying cut crop to the rear of the apparatus by rotation of the second rotor, and in which the first rotor extends outwardly beyond the perimeter of the crop conveying surface of the second rotor, and the second rotor includes one or more resilient wiper devices projecting outwardly beyond the perimeter of the crop conveying surface over at least part of the outer region of the first rotor, for lifting and transferring crop from the first rotor to the crop conveying surface of the second rotor.

20. Apparatus according to any preceding Claim in which the drive means is arranged to drive the first and second rotors in rotation in opposite senses in such a manner that the cutting by the cutting means is at least in part shear cutting effected by the action of the two rotors in opposite directions on the crop.

21. Crop Conditioning apparatus comprising a pair of crop conditioning rotors each mounted for rotation about a vertical axis with the vertical axes spaced apart tranversely relative to an intended direction of forward travel of the apparatus, and drive means for driving of the rotors in counter rotation in such a manner that crop is passed between the rotors from the front to the rear of the apparatus is conditioned by relative movement between the conditioning rotors and the crop engaged thereby, in which each conditioning rotor comprises a conditioning device comprising a plurality of conditioning elements directed outwardly from the said vertical axis of the conditioning rotor, the envelope of the outer tips of the conditioning elements having a shape such that over at least a part of the height of the conditioning rotor the radius of the envelope decreases with increase of height of the conditioning rotor.

22. Crop conditioning apparatus comprising a pair of crop conditioning rotors each mounted for rotation about a vertical axis with the vertical axes spaced apart transversely relative to an intended direction of forward travel of the apparatus, and drive means for driving the rotors in counter rotation in such a manner that crop is passed between the rotors from the front to rear of the apparatus and the crop is conditioned by relative movement between the conditioning rotors and the crop engaged thereby, in which each crop conditioning rotor comprises a conditioning device comprising a plurality of conditioning elements directed outwardly from the said vertical axis of the conditioning rotor, the said conditioning elements comprising elongate elements secured in groups distributed around the conditioning rotor, the elements of each group being aligned along a direction which when viewed from above is inclined at an angle of inclination to a radius of the said vertical axis of the conditioning rotor.

23. Crop conditioning apparatus comprising a pair of crop conditioning rotors each mounted for rotation about a vertical axis with the vertical axes spaced apart transversely relative to an intended direction of forward travel of the apparatus, and drive means for driving the rotors in counter rotation in such a manner that crop is passed between the rotors from the front to rear of the apparatus and the crop is conditioned by relative movement between the conditioning rotors and the crop engaged thereby, in which each conditioning rotor comprises a conditioning device comprising a plurality of conditioning elements directed outwardly from the said vertical axis of the conditioning rotor, the population of conditioning elements being arranged to vary with height of the conditioning rotor.

24. Apparatus according to any of Claims 21 to 23 in which the crop conditioning device comprises a crop conditioning device as hereinbefore defined.

25. Crop cutting and conditioning apparatus as hereinbefore described with reference to any one or any combination of the accompanying drawings.

26. Crop conditioning apparatus as hereinbefore described with reference to any one or any combination of the accompanying drawings.

27. Crop conditioning apparatus having any novel crop conditioning feature or any combination of novel crop conditioning features as disclosed herein.

28. Crop cutting and conditioning apparatus having any novel crop cutting and conditioning feature or any combination of novel crop cutting and conditioning features as disclosed herein.