Method and system for applying a sealing agent to the surface of an internal cavity of a pneumatic tire

A system for applying a sealing agent to an inner surface of a cavity of a pneumatic tire, the system comprising:

• an applicator device configured to apply the sealing agent to the inner surface and to move itself into and out of the inner cavity;
• a sealing agent supply circuit connected to the applicator device and comprising:
• a tank defined by a casing having a variable volume collection chamber;
• a heating element actuatable to maintain a temperature of the sealing agent at a reference value;
• a pumping device that supplies the sealing agent to the applicator device;
• a movable piston which axially delimits the collection chamber;
• an extractor element configured to move with a reciprocating motion to draw the sealing agent into the collection chamber and to supply the sealing agent to the pumping device;
• a level sensor configured to determine positions of a piston position control device relative thereto and corresponding to an amount of sealing agent contained within the tank, said positions comprising a beginning of depletion position of the tank and a completely empty position of the tank;
• and
• a control unit configured to control the extractor element and/or the heating element as a function of said positions, wherein once the beginning of depletion position has been reached, the control unit is configured to direct the extractor element according to sequences having a number of extraction cycles, and further one or more of:
• imposing stop intervals that increase a duration between one sequence and the next;
• and/or
• gradually decreasing the number of extraction cycles of the extractor element between one sequence and the next.