HARVESTING MACHINE WITH IMPROVED CLEANING UNITS

Abstract: The harvesting machine comprises a conveyor (2) to be moved along the soil provided with means for engaging the plants to be dug up for pulling plants from the soil and transporting them. Arranged along the conveyor are cleaning units (10) for cleaning the parts of the plants that have been removed from the soil. The cleaning units comprise arms (12) to be moved back and forth on opposite sides of a central vertical plane (11) of the conveyor. According to the invention, each of the arms has an extreme position closest to the vertical plane, wherein it extends from its fixed end substantially in the direction of transport (5) and towards the vertical plane, and the arms on opposite sides of the conveyor have been arranged in mutually staggered relationship in the direction of transport. Advantages: simple construction, minor damage to the roots and effective removal of adherent earth.

Description: Title: Harvesting machine with improved cleaning units This invention relates to a harvesting machine for pulling plants from a soil, such as small trees, shrubs, leek, comprising a conveyor to be moved along the soil, the conveyor comprising means for engaging the plants to be dug up for exerting thereon at least a force directed away from the soil and for transporting plants from its forward end to its rear end, the forward end being located lower than the rear end and cleaning units being arranged along the conveyor for cleaning the part of the plant that has been removed from the soil, these cleaning units comprising arms to be moved back and forth on opposite sides of a central vertical plane of the conveyor and, at least partly, substantially transversely to this plane. Such a machine is known from U.S. Patent No. 3,262,503. In operation, this known harvesting machine is moved over the soil in a direction parallel to the vertical plane of the conveyor, while the conveyor engages a plant and conveys it from the forward end to the rear end at a speed substantially equal to the speed of travel of the harvesting machine. Owing to the inclined orientation of the conveyor, i.e., the forward end is located lower than the rear end, each plant engaged by the conveyor is accordingly pulled from the soil in substantially upright orientation. In the area of the rear end of the conveyor, there may be provided means for discharging, collecting and, optionally, bundling the plants pulled from the soil. In this harvesting machine, the arms are each mounted on one of two shafts, each arranged on one side of said vertical plane and parallel to the conveyor, the arms each extending from the shafts towards an area under the conveyor. During the transport of the plants along the conveyor, the shafts are rotated back and forth through a given angle, so that the arms of the cleaning units knock against the parts of the plants that have been pulled from the soil. The adherent earth is removed from these parts in that the adherent earth is shaken off the corresponding parts of the plants. A drawback of this known apparatus is that in digging up young shrubs and two to three-year-old trees, and in particular in digging up trees having a large root system and a great many root-hairs, such as three-year-old beech trees, the root system and in particular the root hairs may be damaged to an undesirably large extent. A further drawback of this apparatus is that the arms on opposite sides of the conveyor must be driven in mutual synchronization. Since it is important that between the arms a large space is available, particularly in vertical direction, for allowing the harvested plants to pass through, it is laborious to mutually connect these drive means. Netherlands patent application 7808024 discloses an apparatus for harvesting leaved tuberous crops which comprises a conveyor with means for engaging the plants to be dug up for exerting thereon at least a force directed away from the soil and for conveying the plants from its forward end to its rear end, the forward end being located lower than the rear end and two arms being arranged on opposite sides of the conveyor, which arms alternately beat the roots of the plants supplied counter to the direction of transport. In this apparatus, too, the roots of plants having a relatively inflexible stem are considerably deformed when they are pulled along the arms in the direction of transport and the arms must be driven in synchronization. Moreover, a relatively large amount of earth remains hanging between the roots. The object of the present invention is to provide a harvesting machine which, in cleaning such parts of lifted plants as have have been pulled from the soil, causes little or at least less damage to such parts, while the problem of synchronization of the movement of the arms on opposite sides of the conveyor has been solved and thorough removal of earth from the roots can be accomplished. This object is accomplished in accordance with the invention in that in an apparatus as described in the preamble, each of the arms, at least in its position closest to the vertical plane, extends from its fixed end substantially in the direction of transport and towards the vertical plane, and the arms on opposite sides of the conveyor have been arranged in mutually staggered relationship in the direction of transport. Owing to the configuration of the arms according to the invention, the parts pulled from the soil, during transportation along the conveyor, are gradually passed along those arms without these parts each time abutting against parts of the arms. A further advantage of the design of the arms according to the invention is that they are always directed substantially transverse to the main direction of the roots of most types of plants to be processed, so that the arms cannot penetrate the root systems of harvested plants or penetrate them only to a limited extent. Thus, damage to the root systems is further prevented. The arms arranged in mutually staggered relationship on opposite sides of the conveyor exert a shaking action on the roots over a relatively long part of the conveyor, so that a thorough removal of earth can be achieved while keeping the force of impact of each ot the arms low. Further, the arms can be driven independently of each other without risk of roots becoming wedged between two oppositely arranged arms. The roots pass from the free end of an arm, which moves with a relatively large amplitude, towards the fixed portion of a next arm, which moves with a relatively slight amplitude. Thus, it can be ensured that when passing from one arm to the next, the roots will not become wedged between successive arms swivelling simultaneously towards the vertical median plane of the conveyor, while yet the arms can be arranged at small intervals in the direction of transport. Oppositely arranged arms may even overlap each other in the direction of transport without risk of roots or root systems becoming wedged between these successive arms. Further, damage to the roots is further prevented in that the roots can freely deflect towards the side of the conveyor that is remote from the arms. This is advantageous in particular during the processing of plants whose root systems have cross-sections that are mutuall very different. Because the root systems are enabled to deflect towards the side of the conveyor that is remote from the arm, the apparatus according to the invention is in general relatively unsusceptible to the setting of the distance from the arms to the axis of the conveyor. Adjusting the apparatus is thereby facilitated and will often not be necessary at all. An additional advantage of the invention is that it permits the use of relatively flexible arms becaus they are always directed substantially in the direction of transport. As a consequence, a harvesting machine according to the invention can also be used for many types of crops having relatively vulnerable parts to be harvested for consumption, such as carrots, leek, onions, potatoes, sugar beets and cassava. In the case of potatoes, for instance, it is a problem that the parts of the plants that project above the ground and have been cut off constitute a risk in the spread of diseases and therefore are sprayed. This in turn constitutes an undesirable imposition on the environment. The use of the harvesting apparatus according to the invention enables the potatoes and the like, plant and all, to be pulled from the soil- for the potatoes to be subsequently separated from the plant portions, so that no plants that must be sprayed are left behind in the field. Hereinafter, one embodiment of the invention will be further illustrated and explained, by way of example, with reference to the accompanying drawings, in which: Fig. 1 is a perspective view of an embodiment of a harvesting machine according to the invention; Fig. 2 is a schematic perspective view of a conveyor with cleaning units of a harvesting machine according to the embodiment shown in Fig. 1; Fig. 3 is a top plan view of two cleaning units according to the invention; Fig. 4 is a side elevation of the left-hand cleaning unit as shown in Fig. 3; Fig. 5 is a top plan view of a different setting of the cleaning units; and Fig. 6 is a top plan view of yet another setting of the cleaning units as shown in Fig. 3. Fig. 1 is an overall view of a harvesting machine according to the invention. The harvesting machine is designed as a trailer to be coupled a tractor. It is equally possible, however, to design the harvesting machine as a construction to be supported by the tractor and capable of picking up the plants laterally of the tractor. The harvesting machine according to the embodiment shown comprises a pivotally suspended depth adjustment roller 1 having connected thereto a plough-share (not shown) . Arranged in laterally offset relationship to the depth adjustment roller and upstream thereof in the direction of travel is a conveyor 2 comprising two clamping belts 3 arranged in side by side parallel relationship. The conveyor inclines upwards counter to the direction of travel and is adapted to clamp a plant 4 (see Fig. 2) between the clamping belts 3 and discharging the plant 4 in the direction of transport indicated with an arrow 5, counter to the direction of travel. The height of the conveyor 2 relative to the soil can be set by means of a hand wheel 6, while the pressure force of the clamping belts 3 can be set by means of a hand wheel 9. Arranged behind the conveyor 2 (in the direction of travel) are packers 7 and a bundling apparatus 8 for collecting and binding the harvested plants into bundles. It is also possible, however, to collect the harvested plants for instance in a bin or simply throw them back onto the soil. In operation, the plough-share is drawn through the soil downstream of the conveyor 2, so that the soil under the plant to be harvested is cut and loosened and the plant is question can easily be lifted by the conveyor 2. The rearward speed of the conveyor is preferably set at a speed equal to the speed of displacement of the harvesting machine along the soil, so that the plants are pulled from the soil in substantially upright orientation. Arranged along the conveyor 2 are two cleaning units 10 for shaking the parts of the plants that have been pulled from the soil. The cleaning units 10 are arranged on opposite sides of a central vertical plane 11 (see Figs 5 and 6) of the conveyor 2 and comprise arms 12 extending substantially transverse to the plane 11, adapted to be moved back and forth. As shown in Fig. 2, during transport of plants from the forward end 13 to the rearward end 14 of the conveyor (see Fig. 2) , the cleaning units tap against the parts of the plants that have been removed from the soil as they pass by. The earth adhering to the roots of the plants is thereby largely shaken off the roots. Each of the arms 12, at least in its position closest to the vertical plane, extends from its fixed end substantially in the direction of transport 5 and towards the vertical plane 11 (see also Figs 3, 5 and 6) . Owing to this configuration of the arms 12, during transport along the conveyor 2, the roots of the lifted plants 4 are gradually passed along these arms 12 without the roots each time abutting against parts of the arms. The arms 12 are directed substantially transverse to the main direction of the roots of most types of plants to be harvested, so that during tapping relative movements of parts of a root system are limited. This enables susbstantial prevention of any damage to the roots of lifted plants during cleaning. Owing to the arms 12 being oriented substantially in the direction of transport, the use of relatively flexible arms is possible. As a consequence, a harvesting machine according to the invention can also be used for many types of crops having relatively vulnerable parts to be harvested for consumption, such as carrots, leek, onions, potatoes, sugar beets and cassava. Specially adapted arms can be used for processing different types of plants. For processing crops having vulnerable subsoil parts, the arms may for instance be made of supple resilient plastics material. For tuberous crops, the arms may advantageously be composed of a plurality of resilient stems. For limiting the surface pressure of the arms against the crop parts to be cleaned, the arms may each be formed as a resilient flat strip so as to prevent bruising. Relative mutual movements of the parts of a root system of a lifted plant during cleaning can be limited by providing the arms 12 each with a free end 13 bent away from the vertical plane 11 (see Figs 2, 3, 5, and 6) . According to the embodiment shown, the arms 12 are each in operation non-rotatably mounted on an shaft 14 in turn mounted for back and forth rotation, extending approximately transverse to the direction of transport 5 and parallel to the vertical plane 11. This offers the advantage that the deflection of the parts of an arm 12 that tap the parts of a lifted plant 4 that have been removed from the soil, increases in the direction of transport 5, i.e., according as the adherent earth has been loosened more and the roots have been allowed to settle. In other words, the plant is only tapped relatively hard by the time the earth has been somewhat loosened and the roots have been allowed to settle, which prevents damage to the distal parts of the plant facing the arm 12. It is observed that the shafts 14, instead of being directed parallel to the vertical plane 11, may also be inclined downwards away from the plane 11. This makes it possible to arrange longer arms 12 spaced from the clamping belts, instead of close to the belts 3, these arms 12 yielding a relatively large deflection upon rotation of the shaft 14 through a given angle. Such portions of the roots as are located relatively far from the clamping belts 3 and can be bent over a relatively large distance, are accordingly bent from their neutral position by a greater distance during cleaning. If the root portions that are located close to the clamping belts 3 are bent over too large a distance, this may have a whiplash effect on the distal root portions and hence cause damage to the roots. To prevent damage to the plants, it is of further advantage if the arms 12 on opposite sides of the conveyor 2 are arranged in staggered relationship relative to each other (see Figs 3, 5 and 6) . This prevents the subsoil portions of a plant from becoming wedged between arms 12. The shafts 14 are each connected with three or four arms 12. It is thus ensured that also in the case of plants having relatively long or short subsoil portions, such portions are adequately cleaned. Further, the provision of several arms 12 on each shaft 14 ensures a distribution of the pressure exerted by the arms 12, so that bruising or breaking of roots of lifted plants is avoided. According to the embodiment shown, the arms 12 are each made from resilient bar stock which has been bent at the fixed ending of the arms to form at least one coil 22. Thus, while using a relatively stiff and insensitive material, yet a supple, yielding arm 12 can be provided, likewise to limit damage to the former subsoil parts of the lifted plants. Fig. 5 shows the cleaning units as shown in Fig. 3 though adjusted in such a way that of a pair of arms 12 arranged one behind another in the direction of transport, an arm 12 has a position closest to the vertical plane 11 which is closer to the vertical plane 11 than the corresponding position of an arm 12 arranged upstream of the first-mentioned arm 12. In Fig. 5 the arms 12 are all shown in their position closest to the vertical plane. This configuration of the arms 12 offers the advantage that former subsoil portions are bent further and shaken more intensively according as more earth has been shaken off these portions. This is advantageous, in line with the principle that, on the one hand, for the residual earth t be removed, more vigorous shaking of the root system is required according as more earth has been removed from the root system, and, on the other, more vigorous shaking of the root system without damage is possible according as more eart has been removed from the root system and this system has become looser and more flexible. As shown in Fig. 6, the above principle can be further applied by arranging that of two adjacent arms 12 located one behind the other in the direction of transport, the downstrea arm 12 in operation can be pivoted through a wider angle than the upstream arm 12. The arms 12 in their pivotal positions closest to the vertical plane 11 are indicated by solid lines, while their positions remotest from the vertical plane 11 are shown in broken lines. The drive mechanism of the cleaning units 10 according to the invention will now be described with reference to Figs 3 and 4. The arms 12 arranged in succession in the direction of transport 5 are connected in groups to the shafts 14 discusse above. Each of the shafts 14 is coupled with a crank 15. Each of the cranks 15 on one side of the conveyor 2 is pivotally connected with one of two drive rods 16 extending substantially parallel to the conveyor 2. The drive rods 16 are each connected via a ball joint 17 to a coupling rod 18 which in turn is connected to a pivot pin 19 which can be driven by a motor 20 for rotation according to a path 21 having a radius smaller than the effective length of each of the cranks 15. The pivot pin 19 rotating according to path 20 imparts in operation a back and forth motion to the coupling rod 18, which motion is transmitted by the coupling rod via the joint 17 to the drive rod 16. The back and forth motion of the drive rod 16 is transmitted to the cranks 15, which in their turn impart the motion to the shafts 14 which are thereby given a back and forth rotary motion. This back and forth rotary motion of the shafts 14 causes the arms 12 to pivot back and forth towards and from the central vertical plane 11, so that they tap against a passing portion of a lifted plant. The transmission according to the embodiment shown is of simple construction and can be combined with clamping belts 3 of which a portion is shown in Figs 3 and 4. Instead of being provided with shafts 14 transverse to the direction of transport, as according to the embodiment shown, a harvesting machine according to the invention may also comprise, as is known as such, two shafts extending on opposite sides of the vertical plane, parallel to the conveyor, and adapted for back and forth rotation for driving the motions of the arms. In that case, the arms may each be connected with an intermediate arm which in operation is non- rotatably connected with one of the shafts adapted for back and forth rotation, which intermediate arm can be pivoted transverse to the direction of transport in correspondence with the back and forth rotation of the above mentioned shafts. Such a construction offers the advantage that existing harvesting machines fitted with such shafts can simply be converted into harvesting machines according to the invention. It is then of importance that the intermediate arms are so shaped that they always remain outside the path of transport of the subsoil portions of the lifted plants. Harvesting machines according to this embodiment of the invention are preferably fitted with more than one arm and preferably four arms for each intermediate arm. Thus, in a manner comparable to that in which several arms are mounted on each shaft 14, it is ensured that plants having relatively long or short subsoil portions also have their subsoil portions adequately shaken. Further, by using several arms for each intermediate arm, a distribution of the pressure exerted by the arms is accomplished, so that bruising or breaking of roots of lifted plants is prevented. The intermediate arms may be made from resilient bar stock, which in the area of the fixed end of that intermediate arm is bent to form at lest one coil. Thus the intermediate arms may on the one hand be made from insensitive material and on the other provide a supple suspension of the arms so as to prevent damage to the roots of lifted plants.

Claims: ______ 1. A harvesting machine for pulling plants from a soil, such as small trees, shrubs, leek, comprising a conveyor to be moved along the soil, said conveyor comprising means for engaging the plants to be dug up for exerting thereon at least a force directed away from the soil and for transporting plants from its forward end to its rear end, the forward end being located lower than the rear end and cleaning units being arranged along the conveyor for cleaning the parts of the plants that have been removed from the soil, said cleaning units comprising arms to be moved back and forth on opposite sides of a central vertical plane of the conveyor and, at least partly, substantially transversely to this plane, characterized in that each of the arms, at least in its position closest to said vertical plane, extends from its fixed end substantially in the direction of transport and towards said vertical plane, and the arms on opposite sides of the conveyor have been arranged in mutually staggered relationship in the direction of transport. 2. A harvesting machine according to claim 1, characterized in that the arms in operation are each non-rotatably connected to a shaft rotating back and forth and extending approximately transverse to the direction of transport and parallel to said vertical plane. 3. A harvesting machine according to claim 2, characterized in that at least one of the shafts is connected with more than one arm. 4. A harvesting machine according to claim 3, characterized in that a plurality of the shafts are each connected with four arms. 5. A harvesting machine according to claim 1, comprising a plurality of arms arranged behind each other in the direction of transport, characterized in that of two arms arranged behind each other in the direction of transport, the arm located downstream in the direction of transport has a position closest to the vertical plane, which is closer to said plane than the corresponding position of the arm located upstream. 6. A harvesting machine according to claim 1, comprising a plurality of arms arranged behind each other in the direction of transport, characterized in that of two arms located behind each other in the direction of transport, the arm that is located downstream in the direction of transport can be pivoted through a wider angle than the arm located upstream. 7. A harvesting machine according to claim 2, comprising a plurality of arms arranged behind each other in the direction of transport, characterized in that the arms are connected to a plurality of shafts arranged behind each other in the direction of transport, each of the shafts being coupled to a crank, each of the cranks being pivotally connected on one side of the vertical plane to one of two drive rods extending approximately parallel to the conveyor and each being connected via a ball joint to a coupling rod which in turn is connected to a pivot pin which can be driven by a motor for rotation according to a path having a radius smaller than the effective length of each of the cranks. 8. A harvesting machine according to claim 2, characterized in that the arms are each made of resilient bar stock, which has been bent in the area of the fixed end of said arm to form at least one coil. 9. A harvesting machine according to claim 1, comprising two shafts to be rotated back and forth, extending on opposite sides of said vertical plane and parallel to the conveyor, characterized in that the arms are each connected to an intermediate arm, which in operation is non-rotatably connected with one of the shafts to be rotated back and forth, which intermediate arm can be pivoted substantially transversely to the direction of transport in correspondence with the back and forth rotation of said shafts. 10. A harvesting machine according to claim 9, characterized in that at least one of the intermediate arms is connected with more than one arm. 11. A harvesting machine according to claim 10, characterized in that a plurality of the intermediate arms are each connected with four arms. 12. A harvesting machine according to claim 9, characterized in that the intermediate arms are made from resilient bar stock, which in the area of the fixed end of said intermediate arm has been bent to form at least one coil. 13. A harvesting machine according to claim 1, characterized in that the arms are made from supple resilient plastics material. 14. A harvesting machine according to claim 1, characterized in that the arms are each composed of a plurality of resilient stalks. 15. A harvesting machine according to claim 1, characterized in that the arms are each designed as a resilient flat strip. 16. A harvesting machine according to claim 1, characterized in that the arms each have a free end bent away from the vertical plane. 17. A harvesting machine according to claim 1, characterized in that the arms each have a configuration bending substantially gradually away from the vertical plane.

Inventors: HILVERTS JAKOB, TIMMERMANS HUBERTUS RENIER MAR, HILVERTS, JAKOB, TIMMERMANS, HUBERTUS, RENIER, MARIA
Applicants: ZIJLSTRA & BOLHUIS BV, ZIJLSTRA & BOLHUIS B.V.
Application year: 1991
Main classification: A01D45
IPC codes: A01D31, A01D45