Soil cultivating implements

#Usually, when working the soil by means of a soil cultivating implement it is not possible to remove stones and similar hard objects contained in the soil out of the worked layer of soil without utilising further measures. Various proposals have been made in the past to collect the stones and other hard objects contained in the worked layer of soil with the aid of all kinds of measures and to remove them subsequently. The measures required to do this and are frequently complicated and expensive, while it is still necessary to transport the collected stones and the like from the field.

#According to the present invention there is provided a soil cultivating implement that includes a plurality of working members each lying substantially parallel to a plane extending in the intended direction of operative travel of the implement and at a spacing between immediately adjacent members such that in operation, during movement of the members across the ground, stones and the like are pressed into the subsoil. Such an implement is capable of providing in a simple and effective manner a layer of arable land free of stones and similar hard objects, since by providing working members lying substantially parallel to a plane extending in the intended direction of operative travel and disposed at such a small distance from one another that stones and the like are pressed into the subsoil during the passage of the members across the ground, during this movement of the implement large stones and the like contained in the layer of soil being worked are urged towards the bottom of the layer of arable soil, where they are pressed into the subsoil, the arable layer thus obtained being substantially free of such stones and similar hard objects whose size has an adverse effect on the growth of plants.

#The invention also provides a method of removing stones from a layer of arable earth by urging the stones by mechanical means out of the layer of arable earth and into a subjacent layer.

#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:

#FIG. 1 is a plan view, partly broken away, of a first form of soil cultivating implement,

#FIG. 2 is a sectional side view taken on the line II--II in FIG. 1,

#The soil cultivating implement shown in FIGS. 1 and 2 has a frame that includes a frame beam 1 extending transversely of the intended direction of operative travel A of the implement and having vertical plates 2 and 3 secured to its ends. Near the lower edges of the plates 2 and 3 a rotary shaft 4 is mounted in bearings, this shaft 4 extending in a direction transverse of the direction of travel A and hence parallel to the frame beam 1. The rotary shaft 4 has secured to it at equal intervals circular plates or supports 5. At equal circumferential angles each support is provided with three cultivating members 6 formed by hooklike knives. The rotary shaft 4, the supports 5 and the cultivating members 6 constitute a rotor 7.

#Between the plates 2 and 3 at the level of the frame beam 1 and to the rear thereof an angle-section iron 8 extends substantially parallel to the frame beam 1. At relative distances of about 30 mms bars 9 of resilinet material such as spring steel, together forming a sieve 10, are secured to the angle-section iron 8 and extend rearwardly therefrom, the bars 9 lying in the direction of travel A. Each bar 9 has a substantially circular cross-section, the diameter being of the order of from 10 to 20 mms. From FIG. 2 it will be apparent that away from the angle-section iron 8 the bars 9 initially extend in a horizontal direction to the rear, whereafter each bar has an arcuate portion that is substantially concentric with the rotary shaft 4. From the lower end of this arcuate portion each bar 9 curves upwardly and finally forwardly, surrounding the lower and rear portions of the curved wall of a shaft or tube 11 and terminating above the tube 11. By means of stub shafts the tube 11 is journalled in bearing secured to the plates 2 and 3. On it outer side the plate 2 is reinforced by means of a stay 12, which extends away from the frame beam 1 up to the tube 11. The tube 11 is provided with working members in the form of discs 13 each having a thickness of about 10 mms and being at a distance of about 30 mms from one another disposed such that on either side of each disc 13 one of the bars 9 of the sieve 10 curves around the tube 11. Although this is not shown, the tube 11 may have an angular cross-section and the discs 13 can be slipped by means of intermediate pieces onto the tube 11, which considerably facilitates mounting. Each disc 13 lies substantially parallel to a plane extending in the direction of operative travel A.

#In the embodiment shown each disc 13 has a generally circular circumference. The tube 11, whose longitudinal center line constitutes a common rotary axis for the discs 13, is located at a lower level than the rotary shaft 4 of the rotor 7 and is located at a distance behind the rotary shaft 4 which is smaller than the diameter of the path described by the free ends of the cultivating members 6 of the rotor 7, formed by the hook-like knives (FIG. 2). The discs 13 in this embodiment have a diameter which is smaller than half the diameter of the path described by the free ends of the cultivating members 6 of the rotor 7. At the circumference each of the discs 13 has projections 14, located at equal distances from one another around the circumference and having an angular shape.