Bead breaker group for a tire mounting-demounting machine

A method for bead breaking a tire of a tired wheel, comprising the following steps:

• a) prearranging a tire mounting-demounting machine comprising a base, a wheel-holder table rotatably supported by said base and a column extending upward starting from said base, comprising at least one bead breaker group supported by said column, said bead breaker group comprising:
• a support and at least one bead breaker tool mounted for rotation around a pin borne by said support, and wherein said bead breaker tool is substantially flat and comprises:
• at least one peripheral portion configured as an abutment front against a flange of a rim of a tired wheel to be bead broken;
• and
• at least one portion having curved peripheral edge substantially coaxial with the pin and intended to act as an engagement-penetration zone between the flange of a rim and the bead of a tire to be bead broken,
• the distance between said abutment front and said pin being less than the distance between said pin and said at least one engagement-penetration zone, said bead breaker tool being configured as a sectioned roller lacking a segment thereof, thereby having a rectilinear front, and
• b) prearranging, on said wheel-holder table, a tired wheel having a rim and a tire;
• c) moving a bead breaker group so as to move said at least one portion configured as an abutment front in abutment against a flange of a rim of the tired wheel to be bead broken;
• d) rotating said wheel-holder table, thus also causing the rotation via driving of said tool with consequent engagement-penetration of said engagement-penetration zone between the flange of the rim and the bead of the tire.

A method for bead breaking a tire, comprising the following steps:

• a) prearranging a tire mounting-demounting machine comprising a base, a wheel-holder table rotatably supported by said base and a column extended upward starting from said base, comprising at least one bead breaker group supported by said column, said bead breaker group including:
• a support and at least one bead breaker tool mounted for rotation around a pin borne by said support, and wherein said bead breaker tool is substantially flat and comprises:
• at least one peripheral portion configured as an abutment front against a flange of a rim of a tired wheel to be bead broken;
• and
• at least one portion having curved peripheral edge substantially coaxial with the pin and intended to act as an engagement-penetration zone between the flange of a rim and the bead of a tire to be bead broken,
• the distance between said abutment front and said pin being less than the distance between said pin and said at least one engagement-penetration zone, said bead breaker tool being configured as a sectioned roller lacking a segment thereof, thereby having a rectilinear front,
• said bead breaker group further comprising at least one actuator means intended to control angular movements of said tool around said pin and secured on one side to said support and on the other side to said bead breaker tool,
• b) prearranging a tired wheel including a tire and a rim on said wheel-holder table;
• c) moving a bead breaker group so as to move said at least one portion configured as an abutment front in abutment against a flange of a rim of the tired wheel to be bead broken;
• d) driving said at least one actuator means for operating an angular engagement-insertion movement of said tool between said flange of the rim and the bead of the tire;
• and
• e) rotating said wheel-holder table.