Control device for vulcanization chambers in vulcanization presses and process put into practice by said control device

A control device for extending a flexible substantially sleeve-shaped vulcanization chamber in a tire vulcanization press from an axially-expanded condition to a radially expanded condition and vice versa, comprising:

• a fluid-operated actuator housed in a vulcanization press bed;
• an elongated drive rod coaxially projecting from said fluid-operated actuator and mounted for movement in the direction of its longitudinal axis;
• a lower piston housed in the actuator for moving said drive rod from a minimally drawn-out position to a maximally drawn-out position relative to said actuator;
• a movable disc detachably mounted to a distal end of the drive rod and sealingly secured to an upper end edge of said vulcanization chamber;
• a fixed disc, detachably mounted to the fluid-operated actuator and sealingly secured to a lower end edge of said vulcanization chamber;
• first stop means to limit the positioning of the drive rod to the maximally drawn-out position;
• second stop means to limit the positioning of the drive rod to the minimally drawn-out position;
• a grasping head carried by said distal end of the drive rod and having first quick coupling means for detachably engaging the movable disc to the rod;
• a grasping ring carried by said fluid-operated actuator and having second quick coupling means for detachably engaging said fixed disc;
• said first stop means comprising said sleeve-shaped vulcanization chamber, the wall thereof reacting to tensile stress between the movable and fixed sealing discs so as to stop the movement of the drive rod at the maximally drawn-out position;
• said second stop means comprising at least two semi-cylindrical elements positioned adjacent the drive rod at opposite sides thereof, so as to define a tubular locating sleeve which is slidably passed through by the drive rod, said locating sleeve having a lower end abutting a locating seat carried by the fluid-operated actuator and an upper end acting as an abutment seat for limiting a drive rod retraction stroke to said minimally drawn-out position.