A helmet for impact protection

Abstract

A helmet for protecting a wearer's head has a protective layer configured to, when the helmet is impacted by a force, absorb the normal component thereof by compression and rupture when the tangential component of the force exceeds a predefined threshold.

1 .- 15 . (canceled) 
     
     
         16 . A helmet for protecting a wearer's head comprising:
 a protective layer configured to, when the helmet is impacted by a force, absorb the normal component thereof by compression and rupture when the tangential component of the force exceeds a predefined threshold.   
     
     
         17 . The helmet according to  claim 16  wherein the protective layer comprises closed-cell foam configured to perform said absorbing and said rupturing. 
     
     
         18 . The helmet according to  claim 17  wherein the closed-cell foam comprises expanded beads. 
     
     
         19 . The helmet according to  claim 16 , wherein the protective layer comprises:
 a first layer; and   protuberances extending from the first layer; and   wherein the protuberances are configured to rupture from the first layer when exceeding the predefined threshold.   
     
     
         20 . The helmet according to  claim 19 , wherein the protective layer further comprises:
 a second layer covering the protuberances.   
     
     
         21 . The helmet according to  claim 20 , wherein the second layer also comprises protuberances configured to rupture from the second layer when exceeding the predefined threshold. 
     
     
         22 . The helmet according to  claim 21  wherein the protuberances of the first layer and the protuberances of the second layer face towards each other. 
     
     
         23 . The helmet according to  claim 20  wherein the first and second layer are connected with each other by the protuberances. 
     
     
         24 . The helmet according to  claim 22  wherein the protuberances of the first layer are interlinked with the protuberances of the second layer. 
     
     
         25 . The helmet according to  claim 20 , wherein the protuberances comprise at least one of the group of:
 a tubular protuberance;   a beam-shaped protuberance;   a conical protuberance with an elliptic or polygonal base.   
     
     
         26 . The helmet according to  claim 18 , wherein the protective layer comprises a mixture of the beads and second granules. 
     
     
         27 . The helmet according to  claim 26  wherein the protective layer is further arranged such that the rupturing initiates at a border between the beads and the granules. 
     
     
         28 . The helmet according to  claim 26  wherein the beads and granules have a diameter of around 0.5 mm to around 5 mm. 
     
     
         29 . The helmet according to  claim 26 , wherein the beads have a first density between 50 and 70 m −3 ·kg; and
 the granules correspond to second beads having a second density between 90 and 110 m −3 ·kg. 
 
     
     
         30 . The helmet according to  claim 26 , wherein the mixture comprises between 25 and 75 weight percent of the beads with the first density.