Abstract: The invention relates to an apparatus for aerating a ground layer including a frame movable along a ground surface and a number of substantially vertically placed aerating pins movable in and out of the ground layer. Each pin is engaged by a pivot arm mounted on the frame for pivoting, and a guide arm is connected to the frame at a distance from the position where the pivot arm engages the frame. A drive element is provided for causing reciprocal pivoting of the pivot arm during the movement of the apparatus along the ground layer. The connections of the pivot arm to the frame and the aerating pin and the connections of the guide arm to the frame and the aerating pin substantially form corners of a parallelogram in the non-loaded state of the aerating pin. At least one of the sides of this parallelogram is changeable in length such that the bottom part of the pin is displaced relative to the top part of the pin in a direction opposed to the direction of movement of the frame.

Abstract: The invention relates to a soil treating device comprising at least one working element rotatably driven by a rotation shaft and a frame accommodating the working element and displaceable practically parallel to the ground, characterized in that the rotatable working element consists of a plurality of contact elements intended for ground working and fixed in a holder, wherein at least a part of the contact elements lies at different distances from the rotation shaft.