GB2165733A - Root-crop lifting apparatus - Google Patents

Abstract

A lifting apparatus for root crops has a fixed lifting wheel (10) and a displaceable lifting wheel (17) which, in relation to the direction of movement, point in towards each other rearwards and downwards. The displaceable lifting wheel (17) is mounted on a pivot arm (12) which, by means of a hinge (6), is mounted in a pivotable manner on a support arm (5) which supports the fixed lifting wheel (10). Between the displaceable lifting wheel (17) and the support arm (5), a hydraulic cylinder device (13) is inserted. This device is pivotably mounted at both ends, so that a stone between the lifting wheels will press these away from each other. After the passage of a stone, the pressure in the hydraulic cylinder will urge the wheels together again. A stop mechanism consisting of a threaded part (8), a screw (9) and a stop plage (16) is provided to determine the minimum distance between the wheels. <IMAGE>

Description

SPECIFICATION Root-crop lifting apparatus The invention relates to a root-crop lifting apparatus. Such apparatus is typically mounted on a root-crop harvester and has a plurality of lifting units each comprising two root-crop lifting wheels which are indeed towards each other rearwardly and downwardly in relation to the direction of movement.

As a rule, a plurality of such apparatus is used side by side in the harvesting, for example, of beets. When the two lifting wheels pass on opposite sides of a beet, the beet is lifted up out of the earth and thrown to the rear, for example onto a conveyor beltforfurther handling.

In such an apparatus, known from the Danish Patent Publication 147 331,the lifting wheels (also called take-up wheels) are mounted on respective branches of a substantially U-shaped and resilient yoke. The lifting apparatus can be adjusted for root-crops of different sizes by means of a stayboltwhich can bring the branches of the yoke more or less together.

If a sufficiently large stone comes in between the lifting wheels, these will simply stand still. It is thus necessaryto drive backwards in orderto remove the stone. Consequently, harvesting time is lost and, moreover, some beets will invariably be lost also.

An attemptto solve this problem has been made with flexible stone ejectors, but these have that disadvantage that earth and stones can get jammed after separation of the wheels, the result being thatthe wheels will not go completely backto the worki I position again, and thus the distance between them becomes too great.

Constructions are also known in which intermediate disks are used to determine the minimum distance between the lifting wheels. The adjustment of the lifting apparatus to suit the size of the relevant root crop isthen atime-consuming matter.

It would therefore be desirable to provide a rootcrop lifterwithoutthe above-mentioned disadvan tages, in that it would be able to function regardless of whether there are stones between the lifting wheels, and also easy to adjust.

According to the invention, there is provided a root crop lifting apparatus for use on a root-crop harvester, the lifting apparatus comprising two lifting wheels which are inclined towards each other rearwardly and downwardly, relative to the direction of movement, and which are arranged to rotate to clamp the root cropsand liftthem outoftheearth,a supportarm on which one lifting wheel is rotatably mounted, a pivot arm on which the other lifting wheel is rotatably mounted, the opposed end of the pivot arm being pivotably mounted on the support arm in such a way thatthe distance in the horizontal plane between the lifting wheels can be varied, and an axially movable displacement element mounted between the support arm and that end of the pivot arm adjacentthe other lifting wheel If a stone comes in between the lifting wheels, the displaceablewheel on the pivot arm will move out to the side The stone will eitherfail out from between the wheels, or be drawn through them and thrown to the rear in the same way as a beet. It is thus not necessary for the lifting ofthe root crops to be interrupted. For the same reason, less power is required to operate the lifting wheels, which rotate exclusively as a result of friction against the earth.

It is advantageous for the lifting apparatus to be so constructed that the end ofthe pivot arm remote from the wheel is pivotably mounted on the side ofthe support arm which faces towards the other wheel, the axis of rotation runs substantially at right angles to the support arm, and the end ofthe displacement element remotefrom the wheel is pivotably mounted on the support arm's opposite lengthwise side, i.e. that side which faces towards the wheel. This construction has proved to function excellently in practice, whilst being atthe same time relativelysimpleto produce.

The displacement element is preferably an hyd raulic piston-cylinder device connected to a pressure accumulator, the result achieved being thatthe wheels are urgedtowards each other bythe device.

When the displaceable wheel has moved to the side for a stone, the lifting wheels will consequently and without problems find their way backtothe starting position.

It is advantageous ifthe lifting apparatus includes a stop such thatawell-defined minimum distance between the lifting wheels can be thereby determined in a simple manner.

if the stop consists of a screw or like device mounted in relation to the one lifting wheel, the other lifting wheel having a stop plate to abut againstthe screw in the stop position, the distance between the wheels can be adjusted in a very simple manner. The displace mentelementwill alwaysseekto press the lifting wheels together, towards the stop, so thatthe desired distance can be selected merely by adusting the screw.

Preferably,the support arm, the pivot arm and the displacement element extend at least approximately radially in relation to the lifting wheels.

Finally, a compact and solid construction is achieved if the support arm has a U-shaped cross section, and the displacement element is disposed within the support arm, the opening of the support arm facing towardsthe displaceable wheel.

The invention will now be further described, byway of example, with reference to the accompanying drawings, in which; Fig. lisa longitudinal sectional viewthrough a lifting apparatus according to the invention; Fig. 2 shows the lifting apparatus as seen from above in the direction of the arrows on the line I-I of Fig.1;and Fig. 3 shows the lifting wheel from the same direction as in Fig. 2, the movement of the displace able wheel being indicated in broken lines.

The illustrated lifting apparatusembodyingthe invention has two opposed lifting wheels, rotatably about inclined axes, of which onewheel loins fixed The drawings originally filed was (were) informal and the print here reproduced is taken from a later filed formal copy.

within the apparatus, the otherwheel 17 being displaceable.

From Fig. lit can be seen that a supp arm 5 is secured to a boom 1 of a root-crop harvester by means of connection parts 2, 3 and4.Thefixedwheel 10is rotatably mounted on an axle 7 secured to the support arm 5.

The displaceable wheel 17 is rotatably mounted on a pivot arm 12 by an axle 15. The pivot arm 12 consists of two parts which are parallel to and enclose the support arm 5,the pivot arm 12 being pivotably mounted on the support arm by means of a hinge pin or pivot 6. All parts in the lifting apparatus are made essentially of metal, preferably iron.

An hydraulic piston-cylinder device 13 is connected at one end by means of a hinge pin or pivot 11 to the inner end ofthe support arm 5. The armS 5 has a U-shaped cross-section, the open side of which is towardsthe displaceable wheel 17. The opposite end of the device 13 is connected to the axle 15 ofthe displaceablewheel 17 by means of a hinge or pivot 14.

Stop means is provided to determined the minimum distance between the wheels 10 and 17, and the hydraulic cylinder 13 is connected with a pressure accumulator (not shown), the function of which is described below.

Figs. 2 and 3 show howthedisplaceable wheel 17 can move in relation to the fixed wheel 10. Itwili be seen thatthe pivots 6 and 11 are disposed on opposite sides of the support arm 5 so thatthe pivot 6 lies on that side ofthe support arm which faces towards the fixed wheel 10.

The mode of operation is as follows. If a stone gets jammed between the lifting wheels 10 and 17, these will be urged away from each other, with compression ofthe cylinderdevice 13. When the stone therefore eitherfalls out or is thrown to the rear in the same way as a beet or other root crop, the cylinder device 13, togetherwiththe pressure accumulator, will urge the wheels back into the original position, without interruption ofthe harvesting.

The stop means comprises a stop plate 16 cooperating with a screw-threaded bolt9to determine the minimum distance between the lifting wheels 10, 17. The bolt 9 is received in a topped or screwthreaded part 8 connected with the supportforthe fixed wheel 10. By rotating the bolt9 to cause itto move axially in or out ofthe part 8,the stop point in relation to the stop plate 16, which is connected with thedisplaceablewheel 17,ischanged.Becauseofthe pressure from the hydraulic cylinder device 13, this simple mechanism is sufficientforthe adjustment of the lifting apparatus to suit all sizes of root crops.

Itwill be evident that root-crop lifting apparatus according to the invention can be embodied in many otherwaysthan as shown in the drawing. The geometry of the apparatus can thus be essentially different without deviating from the scope of the invention, merely the idea of mounting the one lifting wheel on a pivot arm being retained. Moreover, it may be added that a root-crop harvesterwill normally be provided with several lifting apparatus disposed side-by-side or in a row.

Claims (9)

1. A root crop lifting apparatusforuseona root-crop harvester, the lifting apparatus comprising two lifting wheels which are inclined towards each other rearwardly and downwardly, relative to the direction of movement, and which arearrangedto rotate to clamp the root crops and lift them out of the earth, a support arm on which one lifting arm is rotatably mounted, a pivot arm on which the other lifting wheel is rotatably mounted, the opposed end of the pivot arm being pivotably mounted on the support arm in such a waythatthe distance in the horizontal plane between the lifting wheels can be varied, and an axially movable displacement element mounted between the support arm and that end of the pivot arm adjacent the other lifting wheel.

2. A lifting apparatus as claimed in claim 1 wherein the end of the pivot arm remote from the displaceable wheel is pivotably mounted on thatside ofthe support arm which faces towards the fixed wheel,the axis of pivotation extends substantially at right-angles to the support arm, and the end ofthedisplacementelement remote from the displaceable wheel is pivotably mounted on the opposite side of the support arm, the side which faces towards thedisplaceablewheel.

3. A lifting apparatus as claimed in claim 1 or2 wherein the dispiacement element is an hydraulic device which is connected to a pressure accumulator.

4. A lifting apparatus as claimed in claim 1,2 or3 having a stop means arranged to determined a minimum distance between the lifting wheels.

5. A lifting apparatus as claimed in claim 4wherein the stop means comprises a screw orthe like which is mounted for movement relative to the one lifting wheel, the other lifting wheel having a stop plate which abuts againstthe screw in the stop position.

6. A lifting apparatus as claimed in any preceding claim wherein the support arm, the pivot arm and the displacement element extend generally radially ofthe lifting wheels.

7. A lifting apparatus as claimed in any preceding claim wherein the support arm hasa U-shaped cross-section, and the displacement element is disposed within the support arm, the opening ofthe support arm facing towards the displaceable wheel.

8. A root crop lifting apparatus comprising two rotatable lifting wheels biassed to a predetermined relative position in which the axes of rotation are inclined to each other.

9. A root crop lifting apparatus substantially as herein described with reference to the accompanying drawings.