Machine used to mount and dismount tyres of motor vehicle wheels

The present invention relates to a machine used to mount and dismount tyres of motor vehicle wheels, which comprises means for the automatic blocking, when acting on the tyre bead, of the telescopic rods representing the support arms of the bead tools. Moreover, in this machine the arms (5) are pivoted in such a way that when acting on the tyre bead, the tools make an arc of a circle tangent to the edge of the rim and directed towards the bottom of the rim groove.