Collapsible helmet and corresponding production method

A collapsible helmet deployable for protecting a head of a user, the helmet comprising:

• an arcuate layered structure configured to have a collapsed state and openable therefrom into a honeycomb protective configuration for encompassing at least an upper part of the head, said arcuate layered structure spanning an angular range from a first end to a second end in both said collapsed state and in said protective configuration,
• said arcuate layered structure being formed at least in part from a plurality of arcuate segments each having an angular span less than said angular range, each segment having a plurality of layers, each of said layers being joined to adjacent layers along lines of attachment, said lines of attachment being staggered between successive of said layers so as to define, when opened, a honeycomb structure with an extensional cell direction, said extensional cell direction being a radial direction for a mid-region of each of said arcuate segments,
• said arcuate layered structure including at least two of said arcuate segments deployed sequentially between said first end and said second end so that said extensional cell directions form an angle of no more than 45 degrees to radial directions of said arcuate layered structure across said angular range;
• a pair of arcuate end plates bonded to outer surfaces of said arcuate layered structure, opposite ends of each of said arcuate end plates carrying complementary parts of an engagement configuration,
• wherein, in a collapsed stated of the helmet, said arcuate end plates are brought together with said arcuate layered structure between them,
• and wherein, when said honeycomb structure is open, said engagement configurations at ends of said arcuate end plates engage so that said arcuate end plates form a rigid loop encircling a bottom edge of the helmet, wherein, in said rigid loop, said arcuate end plates form a locking angle between them greater than 180 degrees around which said honeycomb structure is stretched.

A collapsible helmet deployable for protecting a head of a user, the helmet comprising:

• an arcuate layered structure openable into a honeycomb protective configuration for encompassing at least an upper part of the head, said arcuate layered structure being formed from layers joined to adjacent layers along staggered lines of attachment so as to define, when opened, a honeycomb structure;
• and
• a pair of arcuate end plates bonded to outer surfaces of said arcuate layered structure, opposite ends of each of said arcuate end plates carrying complementary parts of an engagement configuration,
• wherein, in a collapsed stated of the helmet, said arcuate end plates are brought together with said arcuate layered structure between them,
• and wherein, when said honeycomb structure is open, each said engagement configurations at ends of said arcuate end plates engages so that said arcuate end plates form a rigid loop encircling a bottom edge of the helmet.