Abstract: A tangential grinding machine slidable on rails to be ground includes a base structure mounted on wheels slidable on the rails to be ground; a grinding unit freely slidable along the cross-members of the base structure, the grinding unit having a frame rigidly movable vertically relative to the base structure towards and away from the rail, the frame being rigidly coupled to at least two longitudinally aligned plates supporting a grinding wheel with a rotatable axis transverse to the rail longitudinal axis; and a bar hinged at its ends to the base structure and to the grinding unit respectively, there being connected to the frame supporting the plates a gear motor provided with a vertical axis worm gear, the end of which rests on the grinding unit, a control unit being associated with the gear motor to control frame descent following wear of the grinding wheel.

Abstract: A tangential grinding machine slidable on rails to be ground includes a base structure mounted on wheels slidable on the rails to be ground; a grinding unit freely slidable along the cross-members of the base structure, the grinding unit having a frame rigidly movable vertically relative to the base structure towards and away from the rail, the frame being rigidly coupled to at least two longitudinally aligned plates supporting a grinding wheel with a rotatable axis transverse to the rail longitudinal axis; and a bar hinged at its ends to the base structure and to the grinding unit respectively, there being connected to the frame supporting the plates a gear motor provided with a vertical axis worm gear, the end of which rests on the grinding unit, a control unit being associated with the gear motor to control frame descent following wear of the grinding wheel.

Abstract: A tangential grinding machine for railway rails has a rotating member, a plurality of abrasive sectors mounted on supports radially movable on the rotating member, elements which radially move the supports in order to move the abrasive sectors outwards by an extend which compensates their wear, and a plurality of sensors which when a predetermined degree of wear of the abrasive sectors is attained are activated to act under the control of an electronic unit on the radially movable supports, in order to restore the original grinding surface of the abrasive sectors which have undergone wear. In between the rotating member and the machine structure slidable on the rail there is interposed an articulated frame provided with a mechanism to cause the rotating member to undergo transverse oscillations about a longitudinal axis substantially coinciding with the axis of curvature of the corresponding band of the rail to be ground.