Abstract: A sub-soiler has a plow bottom for subsoil for opening a furrow in a subsoil layer and raising subsoil so as to discharge the subsoil on the surface on one or both sides of the furrow and a plow bottom for top soil, located on the subsoil discharge side posterior to the plow bottom for subsoil, for breaking a top soil layer and dispersing subsoil clods discharged on the surface by the plow bottom for subsoil. Permeability of the soil at the furrow opened in the subsoil layer is improved by dispersing clods of the discharged subsoil and breaking up the top soil.

Abstract: A bottom cultivating machine including a laser emitter for emitting a plane signal of a laser beam, a laser detector which is secured to a frame and detects the plane signal to output an attitude control signal, a horizontal detector having a horizontal sensor which is secured to the frame and serves to detect the level of the front end portion of the bottom cultivating machine in a cultivation progress direction, and a controller for controlling the height of the bottom cultivating machine on the basis of the attitude control signal and controlling the attitude of the bottom cultivating machine on the basis of a signal output from the horizontal sensor by upwardly or downwardly moving a gage wheel or a heel which is provided at the rear portion of the bottom cultivating machine.

Abstract: A cultivating system including a tractor, a cultivating machine for performing a cultivating work in combination with the tractor, and a link mechanism for linking the tractor and the cultivating machine, includes a free-motion mechanism provided to at least one of the tractor, the cultivating machine and the link mechanism, and having a free motion permissible zone in which at least one of the tractor, the cultivating machine and the link mechanism is freely movable relatively to the others in accordance with variation of a cultivation attitude of the cultivating machine due to variation of a cultivation environment, a cultivation-condition control mechanism for detecting the free motion of at least one of the tractor, the cultivating machine and the link mechanism within the free motion permissible zone in accordance with the variation of the cultivation environment, and moving the cultivating machine in accordance with the free motion permissible zone so as to offset the variation of the attitude of said c

Abstract: An agricultural machine including a fixed mast secured to a frame body so as to be projected from a front end portion of the frame body, a movable mast which is pivotably mounted to the fixed mast so as to be arcuately movable in an agricultural working direction relatively to the fixed mast and has a mount portion to which a top link of a tractor is mounted, and a mode selecting mechanism provided between the movable mast and the fixed mast for changing and fixing a positional relationship between the movable mast and the fixed mast interlockingly with a lifting operation of the agricultural machine to thereby freely change a penetrating angle of the agricultural machine into the soil.

Abstract: A coulter adjusting device for use in a reversible plowing machine having a non-reversible mast frame, a bottom frame secured to the non-reversible mast frame in such a manner as to be rotatable or reversible relative to the non-reversible mast frame, a rotatable shaft for rotating or reversing the bottom frame, plural pairs of bottoms fixed to the bottom frame such that each pair of bottoms is secured to upper and lower sides of the bottom frame respectively, and coulters provided in correspondence with each pair of bottoms, at least one of the coulters being secured to the non-reversible mast frame, includes an adjusting mechanism the position of the coulter secured to the non-reversible mast frame by inclining the coulter on a plane perpendicular to a plowing direction by an angle corresponding to the plowing depth, or by moving the coulter in the plowing width direction by an amount corresponding to the tread of a tractor interlockingly with a reversing operation of the bottom frame.