Abstract: A rotor (5) particularly for mixing machines of internal type (1) for elastomers and plastomers, equipped with at least one pair of blades (6) each projecting from the cylindrical hub of rotor (5) starting from flank (5c) of the rotor and set helically thereon, in which at least one of such blades (6) has at least one split delimited by two blade sections (6a, 6'a; 6b, 6'b; 8a, 8'a; 8b, 8'b; 10a, 10'a) located parallel to one another, one section (6a, 6b, 8a, 8b, 10a) having one of its ends located at flank (5c) of rotor (5) and at least one section (6a, 6'b, 8'a, 8'b, 10'a) being separated from the previous one or located on the same helix or on parallel helices to create at least one passage opening (7) capable of bringing about diversion of the flow of material during mixing.

Abstract: A closed mixer having rotors whose axial separation is adjustable, comprising an external casing containing a mixing chamber housing two rotors with projecting lobes operating at a limited distance from one another, and caused to rotate by a motor unit via transmission means, wherein the rotors are equipped with end shafts, having a relatively small diameter, rotatably supported within opposite heads of the external casing by means of supports housed within elements which can move and be locked in a number of positions, as a result of moving which elements the distance between the axes of the rotors can be varied, there being provided holding means between the rotors and the heads of the chambers across which they extend, in order to ensure that the axial separation of the rotors is held in the various positions.