Helmet shell

Abstract

A helmet includes a helmet shell having an outer surface, an inner surface, and a plurality of slit openings. Each slit opening extends along a portion of the helmet shell. The slit openings include a pair of top slit openings that each extend longitudinally along a top portion of the helmet shell, where each top slit opening has a first length. The pair of top slit opening are spaced apart and define a flexible helmet portion spaced between the pair of top slit openings. The flexible helmet portion extends along the first length from a first end of the flexible helmet portion to a second end of the flexible helmet portion opposite to the first end, and the flexible helmet portion has a stiffness that varies along the first length from the first end to the second end.

1 . A helmet, comprising:
 a helmet shell comprising an outer surface, an inner surface, and a plurality of slit openings, wherein each slit opening extends along a portion of the helmet shell;   the plurality of slit openings comprising a pair of top slit openings that each extend longitudinally along a top portion of the helmet shell, each top slit opening of the pair of top slit openings has a first length;   the pair of top slit opening being spaced apart and defining a flexible helmet portion spaced between the pair of top slit openings; and   wherein the flexible helmet portion extends along the first length from a first end of the flexible helmet portion to a second end of the flexible helmet portion opposite to the first end, and the flexible helmet portion has a stiffness that varies along the first length from the first end to the second end.   
     
     
         2 . The helmet of  claim 1 , wherein the stiffness of the flexible helmet portion comprises:
 a first stiffness at the first end and at the second end of the flexible helmet portion,   a second stiffness at a middle portion of the flexible helmet portion between the first end and the second end, and   a third stiffness at an intermediate portion of the flexible helmet portion between the first end and the middle portion.   
     
     
         3 . The helmet of  claim 2 , wherein the first stiffness is greater than the second stiffness, and the third stiffness is greater than the second stiffness and less than the first stiffness. 
     
     
         4 . The helmet of  claim 1 , wherein the helmet comprises a plurality channels recessed in the outer surface of the helmet shell, the plurality of channels comprising a pair of top channels along the top portion of the helmet shell, and the pair of top slit openings reside within the pair of top channels. 
     
     
         5 . The helmet of  claim 1 , wherein the pair of top slit openings are arranged substantially parallel to each other along the top portion of the helmet shell. 
     
     
         6 . The helmet of  claim 1 , wherein the pair of top slit openings are symmetrical with each other across a lateral centerline of the helmet shell. 
     
     
         7 . The helmet of  claim 1 , wherein the pair of top slit openings are linear. 
     
     
         8 . The helmet of  claim 1 , wherein each of the top slit openings comprise a laterally outward curve. 
     
     
         9 . The helmet of  claim 4 , wherein the top slit opening of each top channel of the pair of top channels extends along a majority of a length of the pair of top channels. 
     
     
         10 . The helmet of  claim 1 , wherein the helmet shell comprises a central recession in the outer surface of the helmet shell in a crown region between the pair of top slit openings. 
     
     
         11 . The helmet of  claim 1 , wherein the plurality of slit openings further comprises:
 a pair of left side slit openings extending along a left side of the helmet shell toward a rear of the helmet shell, and   a pair of right side slit openings extending along a right side of the helmet shell toward the rear of the helmet shell.   
     
     
         12 . The helmet of  claim 11 , wherein:
 each left side slit opening of the pair of left side slit openings has a second length;   the pair of left side slit opening are spaced apart and define a second flexible helmet portion spaced between the pair of left side slit openings; and   the second flexible helmet portion extends along the second length from a first end of the second flexible helmet portion to a second end of the second flexible helmet portion opposite to the first end, and the second flexible helmet portion has a stiffness that varies along the second length from the first end to the second end of the second flexible helmet portion.   
     
     
         13 . The helmet of  claim 12 , wherein the stiffness of the second flexible helmet portion comprises:
 a first stiffness at the first end and at the second end of the second flexible helmet portion,   a second stiffness at a middle portion of the second flexible helmet portion between the first end and the second end, and   a third stiffness at an intermediate portion of the second flexible helmet portion between the first end and the middle portion.   
     
     
         14 . The helmet of  claim 13 , wherein the first stiffness is greater than the second stiffness, and the third stiffness is greater than the second stiffness and less than the first stiffness. 
     
     
         15 . The helmet of  claim 11 , wherein:
 the helmet comprises a plurality channels recessed in the outer surface of the helmet shell,   the plurality of channels comprising a pair of left side channels along the left side of the helmet shell and a pair of right side channels along the right side of the helmet shell,   the pair of left side slit openings reside within the pair of left side channels, and   the pair of right side slit openings reside within the pair of right side channels.   
     
     
         16 . A helmet shell, comprising:
 a shell body;   an outer surface of the shell body, an inner surface of the shell body, and a plurality of slit openings, wherein each slit opening extends along a portion of the helmet shell; and   the plurality of slit openings comprising:
 a pair of left side slit openings extending along a left side of the shell body toward a rear of the shell body, each left side slit opening of the pair of left side slit openings comprising a first length, and 
 a pair of right side slit openings extending along a right side of the shell body toward a rear of the shell body, each right side slit opening of the pair of right side slit openings comprising a second length; 
   wherein the pair of left side slit openings being spaced apart and defining a left flexible helmet portion between the pair of left side slit openings, the left flexible helmet portion extending along the first length from a first end of the left flexible helmet portion to a second end of the left flexible helmet portion opposite to the first end, and the left flexible helmet portion comprising a stiffness that varies along the first length from the first end to the second end; and   wherein the pair of right side slit openings being spaced apart and defining a right flexible helmet portion between the pair of right side slit openings, the right flexible helmet portion extending along the second length from a third end of the right flexible helmet portion to a fourth end of the right flexible helmet portion opposite to the third end, and the right flexible helmet portion comprising a stiffness that varies along the second length from the third end to the fourth end.   
     
     
         17 . The helmet shell of  claim 16 , wherein the stiffness of the left flexible helmet portion comprises:
 a first stiffness at the first end and at the second end of the left flexible helmet portion,   a second stiffness at a middle portion of the left flexible helmet portion between the first end and the second end, and   a third stiffness at an intermediate portion of the left flexible helmet portion between the first end and the middle portion.   
     
     
         18 . The helmet shell of  claim 17 , wherein the stiffness of the right flexible helmet portion comprises:
 the first stiffness at the third end and at the fourth end of the right flexible helmet portion,   the second stiffness at a second middle portion of the right flexible helmet portion between the third end and the fourth end, and   the third stiffness at a second intermediate portion of the right flexible helmet portion between the third end and the second middle portion.   
     
     
         19 . The helmet shell of  claim 17 , wherein the first stiffness is greater than the second stiffness, and the third stiffness is greater than the second stiffness and less than the first stiffness. 
     
     
         20 . The helmet shell of  claim 16 , wherein:
 the helmet shell comprises a plurality channels recessed in the outer surface of the helmet shell,   the plurality of channels comprising a pair of left side channels along the left side of the helmet shell and a pair of right side channels along the right side of the helmet shell,   the pair of left side slit openings reside within the pair of left side channels, and   the pair of right side slit openings reside within the pair of right side channels.   
     
     
         21 . The helmet shell of  claim 16 , wherein the pair of left side slit openings and the pair of right side slit openings are linear. 
     
     
         22 . A helmet shell, comprising:
 a shell body;   an outer surface and an inner surface of the shell body, and a plurality of slit openings extending along a portion of the helmet shell; and   the plurality of slit openings comprising a pair of rear slit openings at a rear of the helmet shell, the pair of rear slit openings partially surrounding a rear zone at the rear of the helmet shell and comprising a first length.   
     
     
         23 . The helmet shell of  claim 22 , wherein:
 the pair of rear slit openings are spaced apart and define a rear flexible helmet portion between the pair of rear slit openings,   the rear flexible helmet portion extending along the first length from a first end of the rear flexible helmet portion to a second end of the rear flexible helmet portion opposite to the first end,   the rear flexible helmet portion comprising a stiffness that varies along the first length from the first end to the second end.   
     
     
         24 . The helmet shell of  claim 23 , wherein the stiffness of the rear flexible helmet portion comprises:
 a first stiffness at the first end and at the second end of the rear flexible helmet portion,   a second stiffness at a middle portion of the rear flexible helmet portion between the first end and the second end, and   a third stiffness at an intermediate portion of the rear flexible helmet portion between the first end and the middle portion.   
     
     
         25 . The helmet shell of  claim 24 , wherein the first stiffness is greater than the second stiffness, and the third stiffness is greater than the second stiffness and less than the first stiffness. 
     
     
         26 . The helmet shell of  claim 22 , wherein the pair of rear slit openings are straight. 
     
     
         27 . The helmet shell of  claim 22 , wherein the pair of rear slit openings are symmetrical across a lateral centerline of the helmet shell.