Patent ID: 7500504

Claim:
A bead breaking unit for a tire changing machine, comprising an arm having a first end to which a bead breaking tool can be attached and a second end opposite the first, said first end being mobile between an idle position in which said bead breaking tool is placed away from a base of a tire changing machine, and a working position in which said bead breaking tool is placed in contact with a wheel to bead break; and an adjustment device for adjusting a trajectory of said bead breaking tool when the arm moves between said idle position and said working position, which are interposed between a base and said arm and suitable for defining at least one first operating configuration in which said trajectory is substantially curvilinear and at least a second operating configuration in which said trajectory is substantially rectilinear, wherein said adjustment device comprises at least one guide element positioned between said arm and said base, and said guide means comprising at least a first and a second slot formed in said guide element which are alternatively engageable by said portion of the arm.