Foldable Protective Helmet

A protective helmet comprising a rigid or semi-rigid external shell (1) comprising a plurality of rigid or semi-rigid flaps (2-5) joined together a compressively deformable internal liner acting as a shock absorber, itself comprising several elements (8-11) associated with said flaps, including at least one central element (8) and one or more peripheral elements (9-11), characterised:

• in that at least some of the flaps that constitute the external shell are capable of moving relative to each other at the level of their respective means of connection,
• and in that only the peripheral elements (9-11) that constitute the internal liner associated with the corresponding flaps are designed so that they retract inside the volume defined by the helmet and by said central element (8) during relative displacement of the corresponding flaps.