SOIL CULTIVATING MACHINE

Abstract: The invention relates to a soil cultivating machine which comprises at least one roller (10) provided with scrapers (26), whereby a scraper (26) comprises a support (27) that is situated at least partly at the front side of the roller (10) and comprises a scraping portion (28) located at the rear side of the roller (10). The support (27) for the scraping portion (28) of the scraper (26) is formed by an arm that extends at least over half the circumference of a cylindrical carrier (12) of the roller (10). The cultivating machine has a plurality of soil cultivating members (3) to the rear of which the roller (10) is arranged so as to be adjustable and fixable in height in several positions.

Description: SOIL CULTIVATING MACHINE The invention relates to a soil cultivating machine comprising at least one roller provided with scrapers. In known machines of this kind the scrapers are arranged mostly at the rear side of the roller, which scrapers do not have a free end at the rear side, so that under unfavourable conditions the scraping effect can partly, or even completely, be lost. The construction according to the invention ensures a scraping effect, according to which the scraped-off soil can be removed via a free end of the scraper. According to the invention this is achieved in that a scraper comprises a support which is situated at least partly at the front side of the roller and comprises a scraping portion located at the rear side thereof. By means of this provision it is possible to obtain a pulling wiping-off of the soil, which soil is gradually loosened to be finally removed via the free end of the scraper. According to an other aspect of the invention it is possible to obtain a free end of a scraping portion of a scraper if the scraping portion of the scraper has two ends, one end of which is arranged near the roller while the other end is situated in a free position. A further aspect of the invention concerns a construction wherein, between the scrapers, the roller is provided with cams which extend rearwardly relative to the direction of rotation of the roller and also comprise a portion extending at least substantially transversely to the direction of travel of the machine. By means of this provision it is possible to have the roller rotate more forcefully, while in addition an intensive mixing of the soil with plant remnants, like straw and weeds, can be obtained. A still further aspect of the invention concerns a construction wherein the scraping portion of the scraper has a front end and a rear end of a smaller width than near the middle. This shape of the scraper may prevent clogging in case of the presence of many crop remnants. According to the invention, a scraper may extend substantially alongside a cam of the roller, as a result of which the adhering soil can be caught immediately in the vicinity of the cam. Furthermore, a scraper according to the invention may be constructed as a rod, as a result of which a breaking effect is obtained and the scraper can be produced in an inexpensive manner using a minimum of material. For a better understanding of the invention and to show how the same may be carried into effect, reference will now be made, by way of example, to the accompanying drawings, in which: Figure 1 is a plan view of a soil cultivating machine comprising a roller according to the invention, Figure 2 is, to an enlarged scale, a section taken on the line II - II in Figure 1, Figure 3 is an elevation according to the arrow III in Figure 2, Figure 4 is a section according to Figure 2 of a second embodiment of a construction in accordance with the invention, Figure 5 is an elevation according to the arrow V in Figure 4, Figure 6 is a section according to Figure 2 of a third embodiment of a construction in accordance with the invention, Figures 7 and 8 each are an elevation according to the arrow VII, respectively VIII, in Figure 6, Figure 9 is a section according to Figure 2 of a fourth embodiment of a construction in accordance with the invention, Figure 10 is an elevation according to the arrow X in Figure 9, Figure 11 is a section according to Figure 2 of a fifth embodiment of a construction in accordance with the invention, and Figure 12 is an elevation according to the arrow XII in Figure 11. The apparatus shown in the drawings concerns a soil cultivating machine, in particular a machine for che preparation of a seed bed. The machine comprises a hollow- frame portion 1 extending transversely to the direction of travel A and carrying, equally interspaced at preferably 25 centimeters, the upwardly, preferably vertically, directed shafts 2 of soil working members 3. Each of the soil working members 3 comprises an at least substantially horizontal carrier 4, which is arranged on the end of a shaft 2 projecting at the bottom from the frame portion 1. At its ends, the carrier 4 is provided with downwardly extending soil working elements 5 in the form of tines. The ends of the hollow frame portion 1 are provided with plates 6, which extend at least substantially parallel to the direction of travel A of the machine and which reach to above the frame portion 1. Near the front side, the plates 6 are provided with a pivot 7, which extends transversely to the direction of travel A and around which are arranged swivably arms 8 extending rearwardly along the inner side of the plates. At the rear side, each of the arms 8 comprises a support 9 which extends obliquely downwardly and rearwardly. Between the lower ends of the supports 9 there is arranged, freely rotatably, a roller 10 which in this embodiment is constructed as a packer roller. Near the rear side of the frame portion 1 there is provided an adjusting mechanism, which comprises a screw spindle 11 by means of which the arms 8 are adjustable in height about the pivots 7 situated near the front side of the frame portion 1, in such a way that by means of the roller 10 the working depth of the soil working members 3 can be regulated. The roller 10 comprises a cylindrical carrier 12 on which there are arranged, equally interspaced, groups of plate-shaped tines or cams 13. Two tines or cams 13 are shaped from one piece of plate. The tines or cams 13 each comprise an at least substantially radially extending straight side which at its free end merges in an S-shaped side situated at least substantially tangentially relative to the axis of rotation a of the roller 10 (see Figure 2), and which side, relative to the direction of rotation B of the roller, is situated at the leading side. Near the rear side, there is arranged between the arms 8 a hollow beam 14 which extends transversely to the direction of travel A and which, as is apparent from Figure 2, seen in plan view, is situated exactly in front of the axis of rotation a of the roller 10. The beam 14 comprises a U-shaped portion 15 formed from plate, the legs of which portion extend somewhat upwardly and forwardly. The legs are each provided with a squarely bent portion which by means of bolts 16 is clamped against a straight plate 17. At the ends of the beam 14, the U-shaped portion 15 is provided with supports 18 which under the beam are freely swivable about a pivot 19 arranged at the inner side of each of the arms 8. The upper side of the supports 18, which extend to above the upper side of the arms 8, is provided with a swivable support portion 21 comprising a screw-threaded bore, with which a screw spindle 22 can co-operate. The screw spindle 22 extends into the direction of travel A of the machine and, near the front end, is supported by means of a support 23 which, like the support portion 21, is pivotable about a shaft which extends transversely to the direction of travel A and which is supported by lips 24A arranged at both sides of the arms 8. Onto the plate 17 at the front side of the beam 14 there are mounted plate-shaped supports 24 by means of the bolts 16 with which the plate is clamped against the bent ends of the legs of the U-shaped portion 15. The supports 24 extend substantially parallel to the direction of travel A of the machine. To the plate-shaped supports 24 there are attached by means of bolts 25 scrapers 26 which, as is apparent from Figures 1 and 3, each are located between two adjacent crowns of tines or cams 13. The scrapers 26 each comprise a support in the form of a strip-shaped support arm 27, the broadest side of which extends at least substantially parallel to a plane perpendicular to the axis of rotation a of the roller 10. Each support arm 27 comprises, counted from the attachment to the plateshaped support 24, a straight portion which is situated at least substantially tangentially relative to the axis of rotation a of the roller 10 and which in the region of the axis of rotation merges into a portion that is concentrical relative to the axis of rotation a, the said latter portion being situated at a slight distance from the outer side of the cylindrical carrier 12. As is apparent from Figure 2, the width of the latter portion of the support arm 27 gradually decreases to a point substantially perpendicular below the axis of rotation a of the roller 10, from where the width remains practically constant to the end. The inner side of the end is located at a point where a radial with a vertical plane through the axis of rotation a includes an angle of + 450. The end extends somewhat upwardly and is provided with a plate-shaped portion 28. The plate-shaped portion 28 comprises a rectangular portion which extends to beyond the end of the strip-shaped support arm 27 over a length which approximately corresponds to the width of the end, all this such that the free end of the plate shaped portion 28 is situated in the region of the ends of the tines or cams 13. The angular portion of the plate-shaped portion 28 extends to near the crowns of tines or cams 13 (Figure 3) and preferably has a width of + 10 centimeters. From the inner side of the end, the angular portion of the plate-shaped portion 28 merges via a folding line into a V-shaped portion, of which the point, directed forwardly relative to the direction of rotation B of the roller, is situated at a circumferential angle of + 300 with the vertical plane through the axis of rotation a of the roller 10. The V-shaped portion lies against the outer circumference of the cylindrical carrier 12 and also determines the free space between the carrier 12 and the inner side of the portion of the strip-shaped arm 27 which is concentrical relative to the axis of rotation a. The rectangular portion of the plate-shaped portion 28 includes with the tangential plane in the region of the inner side of the free end of the strip-shaped arm 27 an angle of + 300 (Figure 2). The strip-shaped arms 27 are arranged such that they are situated in the middle between two adjacent crowns of tines or cams 13 (Figure 3). By means of the screw spindles 22 which are disposed above the arms 8, extend in the direction of travel A and are arranged at least substantially horizontally, it is possible to swivel the beam 14 around the pivots 19, in which connection the distance between the inner side of the strip-shaped arm 27, the plate-shaped portion 28 and the outer circumference of the cylindrical carrier 12 changes. Preferably, however, the whole is so adjusted that the V-shaped portion of the plate-shaped portion 28 practically bears against the outer circumference of the cylindrical carrier 12. Near the ends of the hollow frame portion 1 there are arranged plates 29, which plates are pivotable about a shaft which extends in the direction of travel A and which is formed by a part of a carrier arm 30, and during operation assume a position as is indicated in Figure 1. Inside the hollow frame portion 1, the shafts of the soil working members 3 are each provided with a straight-toothed gear wheel 30A, in such a way that the gear wheels on the shafts 2 of adjacent soil working members 3 are in driving connection with each other. Near the middle, a shaft is extended upwardly and reaches with its extension into a gear box 31 which is arranged at the top side of the hollow frame portion 1. Inside the gear box 31, the extension is via a conical gear transmission and a change-speed gear 32 located at the rear side of the gear box in driving connection with a shaft 33, which extends into the direction of travel A and which at the leading side projects outside the gear box and via an intermediate shaft 34 can be coupled with the take-off shaft of a tractor to move the apparatus. In order to be able to attach the machine to a tractor, the front side of the hollow frame portion 1 is provided with a trestle 35 comprising a three-point hitch for coupling to the three-point lifting device of a tractor. The working of the apparatus described in the foregoing is as follows: During operation, the machine is coupled with the trestle 35 to the three-point lifting device of the tractor and, during forward movement in the direction of travel according to arrow A, the respective soil working members 3 are caused to rotate from the take-off shaft of the tractor via the intermediate shaft 34 and the transmission described in the foregoing in a direction as indicated by arrows in Figure 1, whereby the downwardly extending tine-like soil working members 5 work at least adjoining strips of soil. As has already been stated, the depth of penetration of the respective soil working members 3 can be adjusted by means of the roller 10. Prior to the work being started, the desired position of the scrapers 26 can be adjusted by means of the screw spindles 22. As has already been stated, preferably a position is adjusted in which the plate-shaped portion 28 bears with its V-shaped portion against the outer circumference of the cylindrical carrier 12. However, if the soil contains crop remnants, it may be advantageous to enlarge the distance between the outer circumference of the carrier 12 and the scrapers 26 somewhat. By means of the scraper 26 according to the embodiment shown it is achieved that soil possibly adhering to the roller and reaching between the crowns of tines or cams 13 already at the front side is caught by means of the strip-shaped support arm 27 near the middle between two crowns of tines or cams, and is subsequntly wiped off at the rear side of the roller exactly above the ground via the V-shaped portion bearing against the cylindrical carrier 12 and the by means of a bend bentoff rectangular portion of the plate-shaped portion 28, the wiped-off soil via the rectangular portion of the plate-shaped portion 28 being dropped in small quantities directly onto the surface compressed by the roller 10 and undesirable clod formation being prevented. Owing to the specific position of the scraping plate-shaped portion 28, whereby the portion is attached near the roller and extends freely rearwardly, crop remnants like straw and weeds can be removed easily. Owing to the position of the scrapers 26 according to the invention there is obtained a so-called pulling action, according to which the adhering soil carried along by the roller 10 is wiped off gradually via the strip-shaped arm 27 and finally via the plate-shaped portion 28, which greatly enhances an effective scraping activity. By enlarging the distance between the scrapers 26 and the cylindrical carrier 12 it is possible to effect the removal of the wiped-off soil tven at a lower position, which may be useful on very heavy soils. In the embodiment shown in Figures 4 and 5, scrapers 36 are arranged in front of the roller 10A in the same manner as in the first embodiment; however, here the beam 14 is fixed relative to the arms 8 to portions of the arms which extend to behind the supports 9. In this embodiment, the scrapers 36 are practically identical with the scrapers 26 in the first embodiment. However, the free end of a strip-shaped arm 37 is situated at a higher level, so that the free end of a plate-shaped portion 38 is located in the region of the axis of rotation a of the roller 1 OA (Figure 4). Each plateshaped portion 38 has a V-shaped portion directed forwardly relative to the direction of rotation of the roller, the point of which portion is situated at a circumferential angle of + 450 with the vertical plane through the axis of rotation a of the roller. In the region of the inner side of the free end of the stripshaped arm 37, the V-shaped portion of the plate-shaped portion 38 merges via a folding line into a portion which is substantially V-shaped having a rearwardly directed, truncated point with a side which is situated at least substantially parallel to the axis of rotation a of the roller 10A (Figure 5). The roller lOA comprises tines or cams 39, which each have an at least substantially radially extending side, which via an angle of + 300 merges into an at least substantially tangentially extending side (Figure 4), which merges in a radial side of the next adjoining tine or cam. The at least substantially tangentially extending side of each tine or cam comprises a blade 40, the sides of which extend V-shaped at the side facing the next adjoining tine or cam (Figure 5) and at least substantially near the middle merge into a side extending at least substantially parallel to a plane perpendicular to the axis of rotation a of the roller, which sides via converging sides merge into a side extending at least substantially parallel to the axis of rotation a of the roller 10A. The largest width of a blade 40 is to be found between the sides extending at least substantially parallel to a plane perpendicular to the axis of rotation a of the roller 10A, and amounts to + half the distance between two tines or cams 39 of next adjoining crowns. Owing to the presence of the blades 40, during operation, the roller 1 OA is driven more forcefully, so that the effect of the specific scrapers 36 may be shown to better advantage. Owing to the blades 40 there is also obtained an intensive mixing of soil and crop remnants. The V-shaped free end of a plate-shaped portion 38 provides a proper removal of the scraped-off material, while practically no crop remnants remain adhering to this portion. In the embodiment shown in Figures 6 - 8, too, the beam 14 is fixed between the rear side of the arms 8, the legs of the U--shaped port on extending at least substantially horizontally. In this embodiment, there are provided scrapers 41 which are located between crowns of tines or cams 13 and are bent hairpin-shaped from one piece of material. As is apparent from the drawings, the material has an angular, preferably square, cross-section. The scrapers 41 are arranged such that the free ends of the hairpin are attached to the beam 14, while the bent end of the hairpin is located in the region of the axis of rotation a of the roller 10 to the, relative to the direction of travel A, rear side of the roller 10. Each scraper 4#1 comprises two portions which, from its attachment, by means of clamping pieces 42 and the bolts 16, extend at least substantially tangentially. The said portions in the region of the axis of rotation a of the roller each merge into a portion that extends concentrically with respect to the axis of rotation, over a circumferential angle of + 1200. Subsequently, the latter portion merges into a straight portion which reaches to the bent portion of the scraper and is situated at least substantially parallel to a tangential plane. The bent portion of the hairpin is located at a circumferential angle of some degrees under a horizontal plane through the axis of rotation a (Figure 6). As is apparent from the Figures 7 and 8, the legs of the hairpin are situated in the immediate vicinity of the respective crowns of tines or cams 13. In this embodiment, the beginning of the "pulling" scraping-off takes place along the tines or cams 13, and the scraped-off soil is removed by the tangential portion of the legs of the hairpin. In this embodiment, it is preferred to use a resilient material, e.g. spring steel. This enhances the scraping effect, as does the angularity of the material. Between the scrapers and the outer circumference of the cylindrical carrier 12 of the roller there is a slight space (Figure 6), so that a resilient movement becomes possible. In the embodiment shown in Figures 9 and 10, the roller 43 is provided with, arranged onto the cylindrical carrier 12, crowns of tines or cams 44, which each have blades 45 that are constructed in the same manner as the blades 40 in the second embodiment; however, here the blades 45 are arranged on a side which extends according to a regular curve and merges into the radial side of a tine or cam (see Figure 9). In this embodiment, too, a hollow beam 14 is arranged between the ends of the arms 8, to which are fitted downwardly extending scrapers 46 by means of plate-shaped supports 24. The scrapers 46 comprise a strip-shaped arm 47 located in the middle between the crowns of tines or cams 44. The strip-shaped arms 47 are located at least substantially vertically and are provided at the bottom side with a plate-shaped portion 48 which comprises, directly attached to the arm, an obliquely downwardly and forwardly extending portion which, from the rear side, which extends at least substantially transversely to the direction of travel A, has diverging sides (Figure 10), which at the level of the arm 47 merge into a side extending in the direction of travel A. The latter sides merge into converging sides, in such a way that the front side of the plate-shaped portion 48 has a V-shaped portion which via a folding line merges into the portion that is attached at the bottom side of the arm 47. As is apparent from Figure 9, the V-shaped portion is located over approximately the frontmost half against the outer circumference of the cylindrical carrier 12. The end of the V-shaped portion, which is located at least substantially tangentially, lies in the region of a point where a radial through this point includes an angle of + 450 with the horizontal, respectively vertical, plane through the axis of rotation a of the roller 43. In this embodiment, too, the presence of the blades 45 improves the rotation of the roller and, consequently, the scraping effect of thc substantially V-shaped plate-shaped portions 48. The angle between the two portions of the respective plate-shaped portions 48 is + 300. The last embodiment shown in Figures 11 and 12 comprises a construction in which the arms 8 are prolonged to beyond the obliquely downwardly and rearwardly extending supports 9 and, seen in plan view, reach beyond the roller 10. The extensions of the arms 8 are each provided with an obliquely downwardly and rearwardly extending support 49, between the bottom sides of which the hollow beam 14 is arranged, in such a way that the legs of the U-shaped portion are directed rearwardly and slightly downwardly. Between the crowns of plate-shaped tines or cams 13 there are arranged scrapers 51 by means of clamping plates 50 and the bolts 16. The scrapers 51 are formed by rods which, respectively, are provided near the tines or cams 13 and near the middle between the crowns of tines or cams. The respective scrapers 51 are trade of a material which preferably is resilient and which has an angular, preferably square, cross-section. From their mounting, the scrapers 51 extend over a straight portion slightly forwardly and downwardly to a point which is situated in the region of a point on the cylindrical carrier 12, which includes a circumferential angle of + 100 with the horizontal plane through the axis of rotation a of the roller. The portion in question merges via a flowing curve into a portion which extends in the direction of the cylindrical carrier 12 and which with its end rests at least substantially against the outer circumference of the cylindrical carrier, and in this point includes an angle with a tangential plane of + 300 (Figure 11). The point where the portion rests against the outer circumference of the cylindrical carrier 12 is located over a circumferential angle of + 450 with the vertical, respectively horizontal, plane through the axis of rotation a. In the last embodiment, the scraping effect is obtained by the three rod-shaped scrapers 51 which are situated between the respective crowns of tines or cams 13, and by means of the portion which rests against the outer circumference of the cylindrical carrier 12 and includes an angle of + 300 with a tangential plane through the point of contact it is possible to obtain an effective removal of the soil and the immediate application of this soil onto the ground. As is apparent from Figure 12, each time two scrapers 51 are situated along a crown of tines or cams 13, while the third scraper is present in the middle.

Claims: Claims 1. A soil cultivating machine comprising at least one roller provided with scrapers, characterized in that a scraper comprises a support which is situated at least partly at the front side of the roller and comprises a scraping portion located at the rear side of the roller. 2. A soil cultivating machine as claimed in claim 1, characterized in that one end of the scraping portion is arranged near the roller, while the other end is situated in a free position. 3. A soil cultivating machine comprising at least one roller provided with scrapers, characterized in that a scraping portion of the scraper has two ends, one end of which is arranged near the roller, while the other end is situated in a free position. 4. A soil cultivating machine as claimed in any one of the preceding claims, characterized in that a support for a scraping portion of the scraper is formed by a support arm which extends at least over half the circumference of the roller. 5. A soil cultivating machine as claimed in claim 4, characterized in that the support arm is attached in a point which, seen in top view, is situated in front of the axis of rotation of the roller. 6. A soil cultivating machine as claimed in claim 4 or 5, characterized in that the support arm comprises an at least substantially tangentially straight extending portion which in the region of the axis of rotation of the roller merges into a concentrically relative to the axis of rotation extending portion which end at the rear side of the roller. 7. A soil cultivating machine as claimed in claim 6, characterized in that the concentrically. relative to the axis of rotation of the roller extending portion terminates in a point where a radial through this point includes an angle of + 450 with a vertical plane through the axis of rotation of the roller. 8. A soil cultivating machine as claimed in any one of claims 4 - 7, characterized in that the free end of the support arm is provided with a scraping plate-shaped portion which comprises a portion that from the free end of the support arm extends obliquely upwardly and rearwardly, and reaches to near the crowns of cams of the roller. 9. A soil cultivating machine as claimed in claim 8, characterized in that the said portion of the plateshaped portion in the region of the front side of the free end of the support arm merges via a folding line into a V-shaped portion extending forwardly relative to the direction of rotation of the roller. 10. A soil cultivating machine as claimed in any one of claims 4 - 8 and claim 9, characterized in that the inner side of the support arm is located at a space from a cylindrical carrier of the roller, which space is at least substantially equal to the thickness of the Vshaped portion of the plate-shaped portion of the scraper. 11. A soil cultivating machine as claimed in any one of claims 8 - 10, characterized in that the free end of the plate-shaped portion is located below a horizontal plane through the axis of rotation of the roller. 12. A soil cultivating machine as claimed in any one of claims 4 - 11, characterized in that said beam is adjustable by means of an adjusting mechanism, which adjusting mechanism comprises a screw spindle extending at least substantially in the direction of rotation. 13. A soil cultivating machine as claimed in any one of the preceding claims, characterized in that the roller comprises cams which are provided with a portion that extends at least substantially parallel to the axis of rotation of the roller. 14. A soil cultivating machine comprising at least one roller provided with scrapers, characterized in that between the scrapers there are arranged cams which, relative to the direction of rotation of the roller, extend rearwardly and also comprise a portion extending at least substantially transverse to the direction of travel of the machine. 15. A soil cultivating machine as claimed in claim 13 or 14, characterized in that said portion is blade-shaped and extends V-shaped towards the ends. 16. A soil cultivating machine as claimed in claim 15, characterized in that said blade-shaped portion is arranged at a tangentially extending side of a cam 17. A soil cultivating machine as claimed in any one of claims 8 - 16, characterized in that the plate-shaped scraping portion of the scraper has a smaller width at the front and back side than near the middle. 18. A soil cultivating machine comprising at least one roller provided with scrapers, characterized in that the scraping portion of the scraper has a front end and a rear end of smaller width than near the middle. 19. A soil cultivating machine as claimed in any one of the preceding claims, characterized in that a scraper extends essentially alongside a cam arranged on a cylindrical carrier of the roller. 20. A soil cultivating machine comprising at least one roller provided with scrapers, characterized in that the roller is provided with cams and at least one scraper which is located essentially alongside a cam. 21. A soil cultivating machine as claimed in any one of the preceding claims, characterized in that a scraper is constituted by a rod. 22. A soil cultivating machine comprising at least one roller provided with scrapers, characterized in that a scraper comprises a rod. 23. A soil cultivating machine as claimed in claim 21 or 22, characerized in that the roller is provided with cams which are arranged in crowns and that on either side of a crown of cams there is located a rod-shaped scraper. 24. A soil cultivating machine as claimed in claim 23, characterized in that two rod-shaped scrapers, situated between two crowns of cams, are bent hairpin-shaped from one-piece material. 25. A soil cultivating machine as claimed in claim 24, characterized in that the bent portion of the hairpin is located at the rear side of the roller and the rod-shaped scrapers extend under the roller alongside the front side upwardly, the free ends being mounted to a carrier, and that each of the longitudinal portions of the hairpin from its attachment extends at least substantially tangentially and, in the region of the axis of rotation of the roller, merges into a concentrical portion. 26. A soil cultivating machine as claimed in any one of claims 21 - 23, characterized in that between two interspaced crowns of cams of the roller there are located three rod-shaped scrapers, two scrapers being present near the crowns of cams and one scraper being present near the middle between the crowns of cams. 27. A soil cultivating machine as claimed in any one of the preceding claims, characterized in that it comprises a plurality of soil cultivating members, which are rotatable about upwardly directed shafts and which are arranged in rows, the roller being arranged behind the soil cultivating members and, relative to the soil cultivating members, being adjustable and fixable in height in several positions.

Inventors: VAN DER LELY, OLAF
Applicants: C. VAN DER LELY N.V.
Application year: 1986
Main classification: A01B29
IPC codes: A01B29