Tangential grinding machine particularly for railway rails

A tangential grinding machine, particularly for railway rails, comprising a rotating member (4), for rotation about a transverse axis, a plurality of abrasive sectors (5) having curved transverse profiles conforming to the original profiles of the rails and mounted on supports radially movable on said rotating member, elements which radially move said supports in order to move said abrasive sectors outwards toward said rail by an extent 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, characterised in that between the rotating member (4) provided with abrasive sectors (5) and the machine structure (1) slidable on the rail (3) there is interposed an articulated frame (8) having spaced-apart shoulders (9) joined by longitudinal members (10) for supporting said rotating member (4) with the transverse axis and provided with means (15, 16, 17) which cause said rotating member (4) with transverse axis to undergo transverse oscillations about a longitudinal axis substantially coinciding with the axis of curvature of the corresponding band of the rail (3) to be ground.