Apparatus for loosening soil

An apparatus arranged to be pulled by a drive vehicle, such as a tractor, over the surface of a field for loosening soil in preparation for agricultural use, comprising an elongated cross-beam extending generally horizontally and transversely of the direction of travel of said apparatus, a drive shaft mounted on and extending in generally parallel relation with said cross-beam, means for driving said drive shaft, at least two upwardly extending swing levers each having a first end mounted on said drive shaft and a second end spaced outwardly and downwardly from said drive shaft, said swing levers spaced apart along the axis of rotation of said drive shaft, a loosening bit attached to each said swing lever, each said loosening bit having a first end and a second end with the first end of said loosening bit attached to the second end of said swing lever and the second end of said loosening bit extending downwardly therefrom so that said loosening bit can extend into the soil for effecting a loosening action, wherein the improvement comprises a disc rigidly connected to each said swing lever and eccentrically mounted on said drive shaft so that said disc rotates with said drive shaft, said drive shaft spaced rearwardly and upwardly from said cross-beam, a guide rod for each said swing lever with said guide rod pivotally connected at one end to said swing lever intermediate the first and second ends thereof and means connected to said cross-beam for pivotally connecting the other end of said guide rod to said cross-beam forwardly of said swing lever, said swing levers and soil loosening bits extending downwardly in the rearward direction from said dicsc, a soil engaging blade attached to the second end of each said soil loosening bit and extending transversely outwardly and generally horizontally from both sides of said blade, said soil engaging blades each have a front edge facing in the direction of travel of said apparatus and an oppositely directed trailing edge, said front edge is V-shaped in horizontal plan with the apex of the V-shaped front edge aligned forwardly of said loosening bit and the sides of the V-shaped front edge sloping from the apex in the opposite direction from the direction of travel of said apparatus, the combination of the eccentric connection of said swing levers over said discs to said drive shaft, the downward and rearward orientation of said levers and loosening bits, and the pivotal connection of said swing levers via said guide rods to said cross-beam causes said soil engaging blades at the second ends of said loosening bits to describe a substantially closed non-circular arcuate path having a major axis extending generally in the direction of travel of said apparatus and a minor axis extending tranversely of the major axis, the ratio of the length of the major axis of the closed arcuate path to the length of the minor axis of the closed arcuate path is 2:1, the angle between the major axis of the closed arcuate path and the surface of the field over which the apparatus travels is in the range of 25 degrees and 40 degrees, the major axis slopes upwardly in the direction opposite to the direction of travel of the apparatus, each said soil engaging blade has an upwardly facing surface arranged at an angle to the surface of the field over which the apparatus travels in the range of from one-half the angle between the major axis of the closed arcuate path and the surface of the field over which said apparatus travels to the angle between the major axis of the closed arcuate path and the surface of the field over which the apparatus travels, said means for driving said drive shaft comprises an input shaft located approximately midway between the ends of said cross-beam, said drive shaft comprising a gear box connected to said input shaft, a first drive section extending from said gear box outwardly toward one end of and in generally parallel relation with said cross-beam, a second drive shaft section extending from said gear box outwardly toward the other end of and in generally parallel relation with said cross-beam, at least one said disc connected to each of said first and second drive shaft sections, and said at least one disc on said first drive shaft section being spaced 45 degrees apart from the corresponding said at least one disc on said second drive shaft relative to the axis of said drive shaft.