| abstract |
The present invention relates to a method of manufacturing tyres and an apparatus for producing elastomeric compounds. The apparatus comprises a mixer (1) provided with a pair of rotors (2, 3) housed in a mixing chamber (4) and a pressure piston (7) movable between a raised position spaced apart from the pair of rotors (2, 3) and "r" lower end-of-stroke positions different from each other, which are close to the pair of rotors (2, 3), wherein "r" is equal to or greater than two. Based on the compound to be produced, "q" lower end-of-stroke positions are selected among the possible "r" lower end-of-stroke positions of the pressure piston (7), wherein "q" is equal to or greater than one. During mixing, the pressure piston (7) is moved "m" times from the raised position to the selected "q" lower end-of-stroke positions and vice versa, where "m" is equal to or greater than one. |