A SOWING MACHINE

Abstract: In a sowing machine with a seed box (17) and two or more rows of coulters (25), these are divided in a direction perpendicular to the direction of travel into a plurality of sections with their respective carrier frames (21), which are so suspended from a carrier beam (15) as to be movable up and down independently of each other. This enables all the coulters to penetrate into the ground in substantially the same depth, even if the surface of the ground is not quite plane.

Description: A sowing machine The invention relates to a sowing machine with a seed box and two or more rows of coulters. The coulters may be constructed as spring teeth, as spring-loaded feed boxes or as roller coulters. In the known sowing machines all the coulters are mounted on a frame which extends in the entire working width of the machine. These machines can meet the important re¬ quirement that all the grains are placed at the same depth in the ground only when the seedbed is quite plane. The object of the invention is to provide a sowing ma¬ chine of the present type which makes it possible to satisfy the requirement of a constant depth of covering even if the seedbed is irregular. This object is achieved in that the sowing machine is constructed as stated in the characterizing portion of of claim 1 since the independently movable sections cause all coulters to be pressed against the ground with sub¬ stantially the same pressure, irrespective of height variations in the surface of the ground. Claim 2 defines a simple embodiment of the means for keeping each individual carrier frame at a substantially constant height above the ground. The feature in claim 3 makes it possible to vary the coulter penetration depth independently of cerial and moment of time. Claims 4-7 define means for pressing the carrier frames against the ground with a certain force which may be adjusted as required. Minor irregularities in the form of mounds and hillocks may be smoothed out by such a smoothing beam as is stated in claim 8. The machine embodiment defined in claim 9 enables all coulters on the same carrier frame to penetrate into the ground in practically the same depth, and the struc¬ ture defined in claim 10 results in a uniform distance between the seed rows. The invention will be explained more fully below with reference to the drawing, in which fig. 1 is a schematic side view of an embodiment of the sowing machine of the invention mounted on a tractor, and fig. 2 is a schematic horizontal view, showing a car¬ rier frame with suspension and ground following drum as well as the relative positions of the coulters. In the drawing, 10 represents a rear wheel of an other- wise not shown tractor having a conventional three- point suspension 11, 12. A carrier beam 15 is suspended by means of arms 13 and 14 from the suspension, said carrier beam being incorporated in and forming the carrying member of the frame of a sowing machine. Plates 16 directed obliquely upwards and backwards from the carrier beam carry the seed box 17 of the machine. A plurality, e.g. eight, of vertical brackets 18 of U-shaped cross-section are equidistantly secured to the rear of the carrier beam 15, and one end of two parallel links 19 of the same length are pivotally mounted at the top and at the bottom, respectively, of each of the brackets; the other end of the links 19 is pivotally journalled in a bracket 20 extending upwardly and se¬ cured to a carrier frame 21. Each of these consist of two side members 22 and a plurality, in this case four, of equidistantly spaced cross members 23. Each cross member mounts two spring teeth 24 carrying at their end coulters 25 with holders 26 for tubes 27 through which grains or seeds are fed to the coulters from feed boxes 28 of the seed box 17. As shown in fig. 2, the spring teeth are so mounted on the cross members 23 that there is always the same distance, e.g. 6.25 cm, between two adjacent coulters, as seen in the transverse direction of the machine, i.e. in a direction perpendicular to the direction of travel. This applies not only to the coulters on the individual carrier frame, but also to all the coulters of the machine. A fork-shaped yoke 29 is pivotally mounted between the rearmost ends of the side members 22 of each carrier frame 21, and a ground following drum 30 is pivotally journalled between the legs of the yoke. In the embodi¬ ment shown, the drum consists of two end discs 31 with a serrated periphery and a plurality of axial rods 32 extending between the serrations of the two discs. An adjustable stop means (not shown) for the yoke 29 makes it possible to maintain the drum at various heights with respect to the carrier frame 21 during travel and thus to vary the penetration depth of the coulters. A bridge 33 secured on the side members 22 of each carrier frame supports an upstanding rod 34, which ex- tends up through a hole in the horizontal leg of an angle member 35 secured to the upper parallelogram link 19. A compression screw spring 37 surrounding the rod is fixed between this angle leg and an adjustable rest 5 36 secured to the rod, and the compression screw spring 37 thus affects the carrier frame with a downwardly directed force depending upon the position of the rest 36, Two arms 39 are pivotally journalled on the lower ends of two obliquely forwardly and downwardly directed brackets 10 38 secured at their respective sides of the carrier beam 15; the arms 39 carry between them a smoothing beam 40 which is caused to engage the ground by a compression screw spring 41. The screw spring 41 is placed on a slide rod 42 with a variable engagement to adjust the 15 spring tension. Moreover, the sowing machine is equipped in a generally known manner with a preferably forwardly directed wheel (not shown), which rolls on the ground during travel and serves to drive the distribution shafts of the machine 20 through a chain drive. The division of the coulters into sections which are placed on their respective parallelogram-suspended carrier frames enables each individual section to fol¬ low the surface of the ground, irrespective of irregu- 25 larities in the ground. The details of the sowing machine shown and described may be modified in many ways within the scope of the invention. The ground following drums 30 may e.g. be replaced by ground wheels and optionally be placed at 30 the front end of the carrier frames, and these may more¬ over be suspended from a single swing arm instead of two, in which case they must be equipped with wheels at both ends. Another possibility is to replace the parallelogram suspension by a guideway. The screw springs 37 and 41 may be replaced by hydraulic or pneumatic cylinders. Also the coulters may be constructed in several ways and may. e.g. have the shape of roller coulters.

Claims: P a t e n t C l a i m s ? 1. A sowing machine with a seed box and two or more rows of coulters, c h a r a c t e r i z e d in that the coulters are divided in a direction transversely to the direct.ion of travel into groups which are placed 5 on their respective carrier frames, that the carrier frames are individually movable in a substantially ver¬ tical direction, and that means are provided to keep each individual carrier frame at a substantially con¬ stant height above the ground. 10 2. A sowing machine according to claim 1, c h a r a c ¬ t e r i z e d in that the said means are formed by a ground following drum or wheel or slide shoe mounted on each carrier frame. 3. A sowing machine according to claim 2, c h a r a c - 15 t e r i z e d in that the ground following drums or wheels or the slide shoes are adjustable in height. 4. A sowing machine according to claim 1, 2 or 3, c h a r a c t e r i z e d in that each carrier frame is subjected to a downwardly directed force by a press- 20 ure-exerting means. 5. A sowing machine according to claim 4, c h a r a c ¬ t e r i z e d in that the pressure-exerting means are formed by screw springs. 6. A sowing machine according to claim 4, c h a r a c • 25 t e r i z e d in that the pressure-exerting means are formed by hydraulic cylinders. 7. A sowing machine according to claim 4, c h a r a c ¬ t e r i z e d in that the pressure-exerting means are formed by weight blocks. 8. A sowing machine according to any of the preceding claims, c h a r a c t e r i z e d in that a smoothing beam is mounted in front of the coulters, said smooth¬ ing machine being spring-urged toward the ground and extending in the entire working width of the machine. 9. A sowing machine according to any of the preceding claims, c h a r a c t e r i z e d in that each carrier frame is parallelogram-suspended from the frame of the machine. 10. A sowing machine according to any of the preceding claims, c h a r a c t e r i z e d in that the coulters are so placed on the carrier frames offset with respect to each other in a direction perpendicular to the di¬ rection of travel that the distances between all coul¬ ters, as seen in the transverse direction, are substan¬ tially the same.

Inventors: LARSEN BOERGE, LARSEN, BOERGE
Applicants: TAARUP AS MASKINFAB, MASKINFABRIKEN TAARUP A/S
Application year: 1985
Main classification: A01C7
IPC codes: A01C7