Abstract: A tool can be made up of two or more rotors, each of them formed by a rotary axis of rotation and at least one helix-shaped blade, the axes of rotation parallel to each other and parallel to the ground or lawn and separated by a distance less than the sum of the radii of the helices of each one of the rotors. The blade(s) of one of the rotors has/have the shape of a right handed helix and the blade(s) corresponding to the other rotor show(s) the shape of a left handed helix, and one of the rotors consists of a driving rotor and the other consists of a driven rotor. The machine derived incorporates at least one double-helicoidal tool connected to at least one of the machine's wheels.

Abstract: The tool is made up of two rotors (1, 2), each one of them formed by a rotary axis of rotation (4, 4?) and at least one helix-shaped blade (5, 6), the axes of rotation (4, 4?) parallel to each other and parallel to the ground or lawn and separated by a distance less than the sum of the radii of the helices of each one of the rotors (1, 2). The blade(s) (5, 6) of one of the rotors (1, 2) has/have the shape of a right handed helix and the blade(s) (6, 5) corresponding to the other rotor (2, 1) show(s) the shape of a left handed helix, and one of the rotors (1, 2) consists of a driving rotor (1) and the other consists of a driven rotor (2). The machine derived incorporates at lest one double-helicoidal tool connected to at least one of the machine's wheels (14).