Safety valve for a timepiece

A crown head for a timepiece, in particular for a diving watch, comprising:

• a cap comprising a cover and an axial skirt;
• a tube which is designed to be secured in a case of the timepiece;
• a sealing gasket disposed between the tube and the axial skirt;
• a central pipe which is designed to be engaged with the tube, the central pipe and the cap forming an assembly which can be placed in different axial positions relative to the tube;
• a safety valve comprising a discharge channel which is designed to be able to be in fluid communication with the inside of the case when the valve is in an open configuration, in order to discharge excess fluid, said safety valve also comprising a piston fitted inside the central pipe and an elastic member designed to cooperate with the piston at a first end of the piston, which is configured to be displaced axially according to pressure variations inside the case;
• and
• blocking means which prevent separation of the cap and the tube, wherein the blocking means comprise a shoulder arranged on an inner wall of the tube, and comprising a support surface against which part of the piston can abut, and a rim which is provided at the base of the central pipe, and is designed to abut against a shoulder provided on the piston,
• wherein the safety valve also comprises a pressure regulator arranged inside the discharge channel and facing a second end of the piston in order to control the output speed of the fluid, the second end of the piston being opposite to the first end in an axial direction.