Device for controlled activation of a pressurized air supply for inflating tires

A device for controlled activation of the pressurized supply of air for inflating tires in machines for tire dealers comprising air feeders (1), at least one pair of regulators (3,4) for air pressure regulation to two predefined extreme values, a first regulator (3) to a minimum value and a second regulator (4) to a maximum value, the regulators being connected in parallel to each other to the air feeders (1), at least one dispenser (6) for dispensing pressurized inflation air connectable alternately to one of the regulators (3, 4), at least one selection valve (5), interposed between the first and second regulators (3, 4) and the dispenser (6) for selecting alternate connection of the dispenser to the regulators (3, 4), the selection valve (5) being kept, by a return element (8), normally connected to the first regulator (3) and forcibly temporarily connectable, in contrast with the return element (8), to the second regulator (4), interruption of direct actuation causing automatic reconnection of the selection valve (5) to the first regulator (3).