Abstract: A bead release unit comprises an arm (1) which at one end carries a bead ease tool consisting of a curved plate body, whereas at its other end it is intended to be hinged to a supporting structure so that it can rotate between two positions in which it positions said tool respectively distant from and in contact with the tire of a wheel (wheel rim+tire) resting against a locator. The tool (6) is supported by said arm (1) by way of an articulated joint comprising two coplanar pins (8), (9) connected together, of which the first (8) is arranged transverse to the generating lines of said tool to enable this latter to rotate within a plane perpendicular to the plane of rotation of the arm (1), whereas the second (9) is substantially parallel to the generating lines of the tool to enable this latter to rotate within a plane transverse both to the plane of rotation of the arm and to the plane of rotation of the tool about said first pin.