BEAD BREAKING UNIT

The bead breaking unit (1) for tyre changing machines comprises: - a bead breaking arm (6, 7) having a substantially horizontal longitudinal direction (L), a first extremity (6a) hinged to the base frame (3) of a tyre changing machine (2) around a substantially vertical rotation axis (A) and an opposite second extremity (7a) having a bead breaking tool (8) able to carry out the bead breaking of the tyre (P) of a wheel (R); - an operating actuator (9) for the movement of the bead breaking arm (6, 7) interposed between the base frame (3) and the bead breaking arm (6, 7); and - a control lever (11), associated with the bead breaking arm (6, 7) in the proximity of the second extremity (7a) and able to control the operating actuator (9), wherein the control lever (11) is hinged around a oscillation axis (B) substantially horizontal and parallel to the longitudinal direction (L) and is associated with return means (12) for the maintenance of the control lever (11) in a substantially vertical balance position, the operating actuator (9) being controlled in a first direction (F1) for the bead breaking of the tyre (P) when the control lever (11) is rotated towards the wheel (R) starting from the balance position.