Helmet adapted to its usage constraints

Abstract

A helmet for sporting activities. The helmet includes an outer shell and a lower portion, the outer shell designed to be positioned on a skull, the outer shell including an upper portion to cover at least the crown portion of the skull, the material forming the upper portion having mechanical properties suitable for the upper portion to satisfy a certification standard defined for the intended use of the helmet. The lower portion is affixed to the upper portion so as to form a single unitary element, the lower portion extending continuously so as to at least partially cover the lateral portions and rear portion of the skull, the lower portion being made of a material having a different modulus of elasticity than that of the material forming the upper portion.

1 . A helmet for protecting a user's head during participation in at least one of a plurality of sporting activities, said helmet comprising:
 an outer shell designed to be positioned on a skull, the outer shell including:
 an upper portion designed to cover at least a crown portion of the skull; 
 the upper portion made of a material having mechanical satisfying properties specified in a certification standard defined for use of the helmet during participation in the at least one of a plurality of sporting activities; and 
 a lower portion affixed to the upper portion so as to form a unified bi-injected or overmolded construction, the lower portion extending continuously so as to at least partially cover the lateral portions and rear portion of the skull, the lower portion being made of a material having a different modulus of elasticity than that of the material forming the upper portion. 
   
     
     
         2 . A helmet according to  claim 1 , wherein:
 the material forming the upper portion has mechanical properties suitable satisfying a certification standard for alpine skiing or snowboarding.   
     
     
         3 . A helmet according to  claim 1 , wherein:
 the Shore D hardness of the material forming the upper portion is between 50 and 75.   
     
     
         4 . A helmet according to  claim 1 , wherein:
 the modulus of elasticity of the material forming the upper portion is less than 1000 MPa.   
     
     
         5 . A helmet according to  claim 1 , wherein:
 the modulus of elasticity of the material forming the upper portion is less than the modulus of elasticity of the material forming the lower portion.   
     
     
         6 . A helmet according to  claim 1 , wherein:
 the upper portion is made of one of the following materials: PU, PP, SBS, SEBS.   
     
     
         7 . A helmet according to  claim 1 , wherein:
 the lower portion is made of one of the following materials: PU, ABS, PP, PC.   
     
     
         8 . A helmet according to  claim 1 , wherein:
 at least one of the upper portion and the lower portion has a wall thickness between one and three millimeters.   
     
     
         9 . A helmet according to  claim 1 , wherein:
 the outer shell comprises an excess thickness in an area of a junction zone between the upper portion and the lower portion.   
     
     
         10 . A helmet according to  claim 9 , wherein:
 the excess thickness projects into an inner volume of the outer shell.   
     
     
         11 . A helmet according to  claim 9 , wherein:
 the excess thickness of the junction zone is substantially equal to the sum of the average thicknesses of each assembly portion.   
     
     
         12 . A helmet according to  claim 9 , wherein:
 the junction zone has a width of less than thirty millimeters.   
     
     
         13 . A helmet according to  claim 1 , further comprising:
 a cap distinct from the outer shell, the cap being fixed to an inside of the outer shell.   
     
     
         14 . A helmet according to  claim 9 , further comprising:
 a cap distinct from the outer shell, the cap being fixed to an inside of the outer shell;   the excess thickness being received in a groove arranged in the cap.   
     
     
         15 . A method of manufacturing a helmet according to  claim 1 , said method comprising:
 affixing the lower portion to the upper portion to form a unified structure by bi-injecting or overmolding the lower and upper portions together to obtain the outer shell.   
     
     
         16 . A method for manufacturing a helmet for sporting activities, comprising:
 attaching a lower portion to an upper portion to form on outer shell of the helmet by one of the following:
 overmolding one of the lower and upper portions to another; 
 bi-material injecting the upper and lower portions.