Perforator cap in particular for flexible tube

An assembly for the closure of a tube, said assembly comprising:

• a cap comprising a punch adapted to cut a seal, said seal being adapted to seal a neck of a tube head, said cap comprising two different positions in which said cap is fixed to said neck, said positions comprising a first position, known as the standby position, and a second position, known as the use position, and,
• a ring movably fixed to said cap,
• said assembly being configured to allow a passage from an extended position of the assembly, with the aim of said punch being protected by said ring in the standby position of said cap, to a retracted position of the assembly, with the aim of said seal being pierced by said punch in the use position of said cap, the change of the assembly from the extended position of the assembly to the retracted position of the assembly being effectuated by a sliding of the cap through the ring, said ring comprising at least one projecting element configured to cooperate with at least one groove of said cap for the change of the assembly from the extended position to the retracted position, said cap comprising a first thread configured to screw said cap onto said neck, in the use position of the cap.