GB2033200A - Root-crop Harvester - Google Patents

Abstract

A pull-type sugar beet harvester has a beet topper 58, beet lifting wheels 26, 27 feeding a rearwardly travelling primary conveyor, and a forwardly travelling delivery conveyor 34 laterally offset from the primary conveyor to receive beet therefrom and to deliver the beet to a tank 36. The lateral offset of the secondary conveyor enables a corresponding offset of the tank and the drawbar 18 to be provided whereby the front end of the drawbar is laterally offset two row widths from the topper and the tractor cropside wheels 20 run between topped and untopped crop rows, whereby steering the harvester and entering the crop at the headlands is made much easier. <IMAGE>

Description

SPECIFICATION Sugar Beet Harvesters This invention relates to sugar beet harvesters, an expression which in this specification and the claims following is intended to cover not just harvesters which are suitable for harvesting sugar beet only and no other crop, but also havesters which are capable of harvesting similar root crops such as chicory.

In the case of pull-type (i.e. tractor-drawn) sugar beet harvesters, the constraints put upon the design engineer by the nature of the crop and the articulated form of the tractor/implement combination have resulted in the production of harvesters which are extremely difficult for a tractor driver to steer correctly both when entering the crop from a headland and when proceeding down the row. These constraints do not appiy or not to the same extent in selfpropelled beet harvesters, as will be apparent from what follows.

Looking first at the design constraints imposed by the crop, there is the fact that the crop is heavy and is often harvested in mid winter in heavy soil conditions, and in the case of tankertype harvesters, when the tank is full it may contain in the region of 2250 kilogrammes of beet. Draught requirements of such a harvester are therefore considerable.

Then there are the factors arising from the articulated form of the tractor implement combination. Firstly, the combination must have a reasonably small turning circle, to avoid large headlands. Secondly, the hitching of the harvester to the tractor must be such that the line of action of the draught forces in relation to the centre of gravity of the harvester allows the harvester to follow the tractor freely without crabbing. The turning circle requirement imposes limitations on the overall permissible length of the harvester, which means that in-line beet topping (i.e. with the beet topper in-line with the beet lifter) is ruled out.The result of the hitching requirement mentioned above is that for tanker type harvesters the drawbar usually has to be in-line with the tank, and for most currently-available tanker type harvesters this means that the drawbar is also in line with the beet lifting wheels.

As a result, during harvesting the off side wheels of the tractor and the beet harvester have to pass between rows of untopped beet and this makes steering very difficult firstly because with 500 millimetre spacing between crop rows there is little more-than 300 millimetres of space for the wheels anyway. Additionally, the untopped crop is just a mass of green foliage providing no guidance as to where the row centres are.

Thus it is an object of the present invention to provide a trailed tanker-type beet harvester wherein the problems identified above are mitigated or overcome.

According to the present invention there is provided a sugar beet harvester comprising: a frame; ground wheels to support the frame, a hopper for harvested beet, the hopper being mounted on the frame; root lifting means to lift from the ground roots to be harvested; root topping means to remove leafy matter from beet to be harvested; a primary conveyor having an inlet end positioned to receive roots from the root lifting means, the conveyor extending upwards and rearwards in the direction of operative forward motion of the harvester from its inlet end and having a discharge end positioned rearwardly of the hopper;; a secondary conveyor having an inlet end positioned to receive roots from the primary conveyor, the conveyor extending upwards and forwards in the direction of operative forward motion of the harvester from its inlet end and having a discharge end positioned to discharge roots into the hopper; and a drawbar for connection to a tractor, wherein the secondary conveyor is laterally offset in one direction from the primary conveyor and wherein the front end of the drawbar is laterally offset, also in said one direction, from the root topping means by two row widths.

An embodiment of the invention will now be described by way of example with reference to the accompanying drawings in which: Figure 1 shows a side and front perspective view of a sugar beet harvester and tractor in operation harvesting beet; Figure 2 shows a plan view of the harvester of Figure 1; Figures 3 and 4 show side elevation and rear elevation views respectively of the harvester of the preceding Figures, the directions of viewing being indicated by arrows Ill and IV in Figure 2.In Figure 4 a guard over a rotary transfer device is shown partly cut away to show the transfer device itself and its relationship to other parts of the harvester; Figure 5 shows a side and rear perspective view of the tractor and harvester seen in Figure 1, the direction of viewing being indicated by arrow V in Figure 2; Figure 6 shows a perspective view of the rotary transfer device seen in Figures 4 and 5, the direction of viewing being indicated by arrow VI in Figure 2; Figure 7 shows an exploded perspective view of the parts which make up the rotary transfer device of the preceding Figures; Figure 8 shows, diagrammatically, a section on the line VIll-Vill in Figure 2 through transfer restriction means between primary and secondary conveyors of the harvester; and Figure 9 shows a front elevation view of the harvester (see arrow IX in Figure 2), omitting the draught bar which connects it to the tractor.

As shown in the drawings, a root crop harvester in the form of a sugar beet harvester 10 comprises a frame 12 mounted on rear ground wheels 14, 16, a drawbar 18 whereby the harvester is drawn by a tractor 20, and a drive input shaft 22 for connection to the power takeoff drive of the tractor.

Harvester 10 further comprises a pre-topper (not shown) for removing the tall growth from beet which has gone to seed (seedy beet), root topping means in the form of a main beet topper 24 to remove the leafy matter from beet to be harvested, and an associated top cleaning and soil clearing disc 25, and a root crop lifting assembly comprising a pair of beet lifting wheels 26, 27 to lift from the ground roots to be harvested, the wheels being preceded by associated skids 28, 29. In addition there is a primary elevator conveyor 30 or digger web, a rotatable transfer device or scrubber 32, a secondary elevator conveyor 34, a hopper or tank 36 for harvested beet mounted on frame 12, and a discharge elevator conveyor 38 provided in hopper 36 to discharge beet from the hopper.

The above mentioned principal parts of harvester 10 will now be described in more detail.

Drive input shaft 22 drives all mechanisms of harvester 10, except the main topper 24, through a drive train comprising input shafts 40 and associated universal joints 42, a principal bevel gearbox and an associated countershaft togetherwith certain belt drives and chain and sprocket drives and shaft and gearbox drives. These latter parts of the drive train are identified collectively in the drawings by reference numeral 44.

Main topper 24 is driven from ground wheel 16 through gearboxes 46, 48 a shaft 50 and a chain and sprocket drive 52.

The principal components of main beet topper 24 are a topper support frame 54, a blade support arm 56 carrying a horizontal topper blade, and a feeler wheel 58 positioned above the blade and connected to chain and sprocket drive 52 for rotation at a rate slightly greater than that at which it would rotate if allowed to run freely along the ground.

Topper support frame 54 is mounted on main frame 12 for pivotal movement about horizontal axis 60 at its front end and is counterbalanced at its rear end by a double acting coil compression spring assembly 62. Blade support arm 56 is mounted on a topper support frame 54 for pivotal movement about a horizontal axis 64 at its rear end and is supported at its front end by a tension spring 66 to allow the blade limited downward movement away from feeler wheel 58 to allow clearance of rocks and stones. Top cleaning disc 25 is journalled on an arm 67 carried by frame 12.

A top clearing device 68 comprising pivoted rubber flails 70 rapidly rotated by the tractor's p.t.o. about a horizontal fore/aft axis 72 is positioned behind topper 24 to clear severed tops laterally away from the topped but as yet unlifted roots.

Beet lifting wheels 26, 27 are mounted in spaced-apart face-toface relationship, for free rotation about respective axes which are inclined so that the wheels converge both downwardly and rearwardly.

A set of pivoted rubber flails is mounted for rapid rotation about a horizontal axis in a path which takes them between the lifter wheels thereby promoting the smooth flow of crop onto primary elevator conveyor 30. The flails are enclosed by a housing 74.

The primary elevator conveyor 30 comprises a pair of spaced endless flexible tension members 76, 78 one at each edge of the conveyor and joined by a series of spaced parallel bars 80 providing a grid or web on which the lifted crop is conveyed while earth is shaken out and passes between the bars and falls to the ground. The conveyor is trained round front rollers 82 rear driven sprockets 84 and guide rollers 86, 88, 90 in an upper conveying run 92 and a return run 94 and is driven in the directions indicated, by the tractor's p.t.o. An undriven and optionally weighted length of conveyor 95 similar to conveyor 30 and called a top trace, is mounted adjustably over run 92 so as to hang down into the path of the crop and thereby slow down the crop and promote thorough crop clearing.

The inlet end 96 of primary conveyor 30 is positioned immediately behind lifting wheels 26, 27 and the conveyor extends upwards and rearwards with respect to the direction F of operative forward motion of harvester 10 at a relatively shallow inclination of 1 6 degrees with respect to the horizontal. This angle may be up to 25 degrees but is preferably not more than 20 degrees.

The discharge end 98 of primary conveyor 30 is positioned considerably rearwards of hopper 36 at a position at the rear end of the harvester 10 from which clods, earth, stones, crop tops and other unwanted matter 100 can be conveniently discharged onto the ground. The difference in height between the inlet and discharge ends 96 and 98 of conveyor 30 when harvester 10 is standing on horizontal ground is not more than 800 millimetres.

The position of primary conveyor 30 with respect to hopper 36 is such that the conveyor passes below the non discharge side 102 of the hopper (on the unharvested crop side of the machine).

Secondary elevator conveyor 34 is very much more steeply inclined with respect to the horizontal than primary conveyor 30, as shown in Figure 3, and has a lower end or inlet end 104 laterally offset (on the harvested crop-side of the machine) from the discharge end 98 of conveyor 30, to receive roots from conveyor 30. Conveyor 34 extends in direction F, parallel to conveyor 30 upwards and forwards from its inlet end and has a discharge end 106 positioned to discharge roots into hopper 36. The structure of conveyor 34 is substantially the same as that of conveyor 30 except that conveyor 34 is provided on every eighth bar 80 with a row of upstanding root carrying fingers 108 each 10 centimetres in length and having a slightly bent profile to retain roots more securely.

Rotatable crop transfer device 32 is positioned above the discharge end 98 of primary conveyor 30 and is rotatable by the tractor's p.t.o., about a horizontal axis 1 10 transverse to direction F and in the direction indicated, to transfer roots from the discharge end 98 of conveyor 30 to the inlet end 104 of secondary conveyor 34. The transfer device comprises a drum 112 carrying a projecting transfer formation arranged in the form of a helix on the external surface of the drum. The transfer formation comprises five helically disposed and equally circumferentially spaced rows 114 of rubber strips 11 6, each strip being secured by a bolt 118 and associated nut 120 to its own mounting flange 122 welded to drum 112, there being ten strips and flanges in each row.

Drum 112 is of diameter 450 millimetres and extends across the full width of primary elevator 30. Rubber strips 11 6 are of hardness 90 degrees on the shore A scale, thickness (T) 20 millimetres, width (W) 40 millimetres, length (L) 100 millimetres and exposed length (above flanges 122) 65 millimetres. The angle of the helix of each row 114 of rubber strips is such that opposite ends of successive rows 114 are axially aligned.

As shown in Figure 7, drum 112 is mounted on a shaft 124 journalled in bearings 126 bolted to a pair of upright posts 128 which are themselves slidingly received in a pair of supports 130 welded to harvester frame 12. The posts 128 also carry a pair of brackets 1 32 for a sheet metal guard 134 for transfer device 32.

A sprocket 136 is keyed to shaft 124 and forms part of drive train 44, whereby drum 112 is rotated in the direction indicated i.e. opposing the travel of roots below the drum, at a rate of 45 revolutions per minute (at a ground speed of 6.4 kilometres per hour).

Height adjustment for transfer device 32 relative to the rear end 98 of primary conveyor 30 is provided by means of two cams 138 received on a hexagon shaft 140 which is itself rotatably received in apertures 142 in a pair of flanges 144 welded to frame 12. The lower ends of posts 128 rest on cams 138. Rotation of shaft 140 by means of a spanner causes the cams to adjust the clearance between transfer device 32 and primary conveyor 30 from a nominal minimum up to 50 millimetres. A locking screw 146 is provided to lock the assembly at any desired working height.

Adjustment of the height of transfer device 32 enables it to be adapted to any particular set of harvesting conditions so as to retain all the root crop while allowing a maximum amount of unwanted material to pass below the device and be discharged onto the ground. Many other simple height adjustment mechanisms could equally well be used.

A small transfer hopper 148 is provided to collect beet transferred by device 32 and to retain each beet until it is picked up by the next row of fingers 108 on secondary conveyor 34. Hopper 148 comprises side walls 150, 152 and a grid of bars 154 forming the rear of the hopper. The front of the hopper is constituted by the lower end of secondary conveyor 34 itself. The lower portion 1 56 of each bar 1 54 is mounted on a transverse pin (not shown) for upward pivotal movement about a transverse axis 1 58 from its rest position shown in the drawings in order to allow the passage of fingers 108 through hopper 34 even when stones are jammed between the fingers 108. The portions 1 56 of bars 1 54 return to their rest position under their own weight.

As shown in Figures 2 and 8, transfer restriction means is provided in the region of the discharge end 98 of primary conveyor 30 to restrict the transfer of roots to secondary conveyor 34 by transfer device 32, whereby the roots are subjected to extra cleaning on the primary conveyor before transfer. The transfer restriction means comprises a fixed gate 1 60 positioned between and extending lengthwise parallel to tile primary and secondary conveyors 30 and 34 respectively above the right hand side wall 152 of transfer hopper 148. Gate 160 is in the form of a channel section sheet metal pressing which thus gives the top edge 1 62 of the gate a rounded profile.One side 1 64 of the gate is integral with side wall 1 52 of hopper 148, and the other side 166 of the gate has a flange 168 clamped between a nylon runnerstrip 170 (on which primary conveyor 30 runs) and frame 12 of the harvester. The height (H) of gate 1 60 is 95 millimetres and its length (i.e. the length of the transfer opening between conveyors 30 and 34) 465 millimetres.

The transfer restriction means could be made adjustable to vary the degree of restriction offered and therefore to vary the degree of extra cleaning provided. The transfer restriction means could, for example, comprise an adjustable gate located in the path of roots between the primary and secondary conveyors 30 and 34, or could be simply in the form of a flow restriction positioned in the region of the discharge end 98 of primary conveyor 30 and in front of transfer device 32 so as to restrict the flow of roots on the primary conveyor to the transfer device.

Discharge conveyor 38 is of similar construction to secondary conveyor 34 having endless tension members 172 and root carrying fingers 1 74 which pass through main hopper 36 to pick up roots and discharge them from the hopper. The discharge conveyor and two associated side plates 1 76 form one side wall 1 78 of hopper 36 and is pivotally mounted on frame 12 for movement about an axis 180 in the region of its lower end between an extended discharge or working position shown in the drawings and a retracted transport position in which the overall width of the harvester 10 is significantly reduced.

A row of beet retaining fingers 182 is mounted at the left hand side (i.e. the harvested crop side) of hopper 36. The fingers mesh with root carrying fingers 1 74 as shown in Figure 2, and fingers 182 are mounted for upward pivotal movement on a common pin (not shown) parallel to axis 1 80 to permit overload release when, for example, stones are jammed between fingers 1 74 as in the case of bars 1 54.

The other side wall 184 of hopper 36 is in the form of an articulated movable wall pivotally mounted on the frame 12 for movement by means of a double-acting ram 1 86 between a discharge position in which it slopes towards discharge conveyor 38, and a retracted storage position providing greater storage capacity for roots in the hopper during harvesting and transport.

Turning now to a consideration of the overall layout of harvester 10, and more particularly to the relative dispositions of the drawbar 18, topper 24, lifting wheels 26, 27 and associated parts of harvester 10 and of tractor 20 and their consequences, reference is directed to Figures 2 and 9 which best show these features.

The first main feature of the layout is that secondary conveyor 34 (which delivers beet to tank or hopper 36) is laterally offset in direction L from primary conveyor 30 by a distance D1 with the result that the centre of gravity 200 of tank 36 itself, when full, is correspondingly offset in the same direction L. This latter consequence arises from the need (for proper and complete filling of the tank) to feed beet into the tank as close as possible to where the centre of gravity 200 of the tank is when the tank is properly filled otherwise the tank fills incompletely and beet may even be spilled over one side of the tank before it is properly full at the other side.

The second main feature of the layout, which is connected with the first, is that the front end 202 of drawbar 1 8 is laterally offset, also in direction L, from beet topper 24 by a distance D2.

Now in Figure 2, the positions of four successive crop rows 204,206, 208, 210 have been indicated diagrammatically. Row 204 is the first row on the unharvested side of harvester 10 i.e. the first row in the field being harvested which has neither been topped nor lifted. Row 206 is next to row 204, and is being topped by topper 24, and the left hand ground wheel 16 of harvester 10 runs between rows 204 and 206.

Each beet of row 206 has of course been topped by the time wheel 16 passes it. Row 208 is of beet which were topped by the harvester in its previous pass in this part of the field and these beet are lifted onto primary conveyor 30 by lifting wheels 26, 27 and the right hand front and rear tractor wheels 212 and 214 respectively run between the topped but as yet unlifted beet of rows 206 and 208. Tractor lefthand wheels 213, 215 run on fully harvested ground, of course. Row 210 is in line with the front end 202 of drawbar 18 and on the centre line of tractor 20, and its beet were lifted in the previous pass of harvester 10.

It can now be seen that the lateral offset D2 of front end 202 of drawbar 18 from topper 24 is two row widths in extent, Now, more than 80 per cent of U.K. sugar beet is grown with 500 millimetre row spacing so D2 will usually be one metre in extent, but in view of the fact that some sugar beet is grown at 450 and 550 millimetres row spacing, drawbar 18 and topper 24 are mounted so as to be adjustable laterally to accommodate these and other row widths.

Therefore D2 should not be understood to be limited to any particular row spacing.

As shown in Figure 2, the clevis which forms the front end 202 of drawbar 18, is pivotally connected to a draught bar 216 which is itself mounted between the lower links 218, 220 of tractor 20's three point hitch.

Now the position of the front end 202 of drawbar 18, as discussed above, means that end 202 is approximately longitudinally aligned in direction F with secondary conveyor 34 and hence with the centre of gravity 200 of tank 36.

As a result, the line of action of draught forces applied to harvester 10 is such as to cause the harvester to follow tractor 20 freely without crabbing i.e. the harvester is nicely balanced for draught purposes.

In addition, this position of drawbar 1 8 means that the tractor right hand (crop side) wheels 212, 214 run between topped crop row 208 and the untopped part of row 206. This makes steering of the tractor much easier than if these tractor wheels had to pass between untopped rows 204 and 206, an area covered by a mass of green foliage. This advantage applies both when entering the crop at the headland and when proceeding down the row.

In use, topped beet are lifted by wheels 26, 27 onto the inlet end 96 of primary conveyor 30 which conveys the roots rearwards while sieving out soil. At the rear end 98 of conveyor 30, the helically arranged rows 114 of rubber strips 11 6 engage the beet while earth, clods, stones and crop tops pass under the device and are discharged onto the ground.

The beet themselves are impelled by rubber strips 11 6 towards transfer hopper 148. Gate 160 restricts the flow of beet into hopper 148 so that each root is tumbled for a while on primary conveyor 30 (and is thereby further cleaned) before it drops into hopper 148. It has been observed during field tests that beet are in many cases propelled towards gate 1 60 three times unsuccessfully before they finally pass over the gate.

The spacing of bars 154 of hopper 148 allows further loss of soil as each beet drops into the hopper, and the roots are relatively clean when they are picked up by fingers 108 and delivered to hopper 36 ready for periodic discharge by conveyor 38 into a trailer or the like.

The principal advantages of the embodiment of the invention described above, lie in the ease of steering the harvester both when entering the crop and when proceeding down the row, as already described.

Among modifications which could be made in the above embodiment which are nevertheless within the scope of the invention are the following: 1. use of the invention in combination with alternative root lifting apparatus such as digger shares, and alternative types of root topping means; and 2. use of alternative forms of drivable transfer device in place of device 32, such as a vertical axis top-driven paddle device or a curved or inclined endless transfer conveyor.

Claims (6)

Claims

1. A sugar beet harvester comprising: a frame; ground wheels to support the frame; a hopper for harvested beet, the hopper being mounted on the frame; root lifting means to lift from the ground roots to be harvested; root topping means to remove leafy matter from beet to be harvested; a primary conveyor having an inlet end positioned to receive roots from the root lifting means, the conveyor extending upwards and rearwards in the direction of operative forward motion of the harvester from its inlet end and having a discharge end positioned rearwardly of the hopper; a secondary conveyor having an inlet end positioned to receive roots from the primary conveyor, the conveyor extending upwards and forwards in the direction of operative forward motion of the harvester from its inlet end and having a discharge end positioned to discharge roots into the hopper; and a drawbar for connection to a tractor, wherein the secondary conveyor is laterally offset in one direction from the primary conveyor and wherein the front end of the drawbar is laterally offset, also in said one direction, from the root topping means by two row widths.

2. A harvester according to claim 1 wherein the root lifting means and the front end of the drawbar are laterally offset in said direction from the root topping means by one row width and two row widths respectively.

3. A harvester according to claim 1 or claim 2 wherein the front end of the drawbar is aligned in the direction of operative forward motion of the harvester with the secondary conveyor.

4. A harvester according to any preceding claim wherein a rotatable transfer device is positioned above the discharge end of the primary conveyor and is drivable to transfer roots from the discharge end of the primary conveyor to the inlet end of the secondary conveyor, the rotatable transfer device being spaced above the primary conveyor so as to permit earth, clods, stones, croptops and other green material to pass below the rotatable transfer device and to be discharged on to the ground, while roots are engaged by the transfer device and transferred to the inlet end of the secondary conveyor.

5. A harvester according to claim 1 substantially as described herein and as illustrated in the accompanying drawings.

6. A harvester substantially as described herein and as illustrated in the accompanying drawings.