Foldable protective helmet

A protective helmet comprising a rigid or semi-rigid external shell comprising a plurality of rigid or semi-rigid flaps joined together, a compressively deformable internal liner acting as a shock absorber, the shock absorber comprising several elements associated with said flaps, including at least one central element and one or more peripheral elements,

• wherein 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,
• wherein only the peripheral elements 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 during relative displacement of the corresponding flaps,
• wherein a crown flap of the rigid or semi-rigid flaps is disposed at an upper extent of the rigid or semi-rigid flaps relative to the other flaps of the rigid or semi-rigid flaps, the central element being directly connected to the crown flap, and
• wherein the shock absorbing element associated with the crown has lateral extensions pointing towards the base of the helmet and define, at the level of said extensions, a plurality of notches oriented substantially parallel to each other into which protrusions of matching shape and corresponding number constituting part of the shock absorbing element associated with each elytron are capable of sliding or engaging.