Safety helmet with ventilation holes

Abstract

A safety helmet includes a shell body adapted to be worn on the head of the user. The shell body has an outer shell surface and an inner shell surface opposite to the outer shell surface. The shell body is formed with a plurality of ventilation holes that extend from the inner shell surface through the outer shell surface. Each ventilation hole has a hole axis that is inclined relative to a horizontal plane. Each ventilation hole is further confined by an upper hole-confining wall portion and a lower hole-confining wall portion that is disposed below the upper hole-confining wall portion relative to the hole axis. Each ventilation hole has an inner hole end proximate to the inner shell surface, and an outer hole end proximate to the outer shell surface. The upper hole-confining wall portion is disposed below the lower hole-confining wall portion relative to the horizontal plane.

I claim:  
     
         1 . A safety helmet comprising: 
 a shell body adapted to be worn on the head of the user, said shell body having an outer shell surface and an inner shell surface opposite to said outer shell surface, said shell body being formed with a plurality of ventilation holes that extend from said inner shell surface through said outer shell surface, each of said ventilation holes having a hole axis that is inclined relative to a horizontal plane, each of said ventilation holes being confined by an upper hole-confining wall portion and a lower hole-confining wall portion that is disposed below said upper hole-confining wall portion relative to the hole axis, each of said ventilation holes further having an inner hole end proximate to said inner shell surface and an outer hole end proximate to said outer shell surface, said upper hole-confining wall portion at said outer hole end being disposed below said lower hole-confining wall portion at said inner hole end relative to the horizontal plane.    
     
     
         2 . The safety helmet as claimed in  claim 1 , wherein the inner shell surface is formed with a plurality of wedge projections, each of said wedge projections having an end face, each of said ventilation holes being formed through a respective one of said wedge projections such that said inner hole end is disposed at said end face of the respective one of said wedge projections.  
     
     
         3 . The safety helmet as claimed in  claim 1 , wherein each of said ventilation holes has a circular cross-section transverse to the hole axis.  
     
     
         4 . The safety helmet as claimed in  claim 1 , wherein each of said ventilation holes has a rectangular cross-section transverse to the hole axis.  
     
     
         5 . The safety helmet as claimed in  claim 1 , further comprising an air-permeable liner mounted in said shell body.  
     
     
         6 . The safety helmet as claimed in  claim 5 , wherein said air-permeable liner is surrounded by said inner shell surface and is disposed below said lower hole-confining wall portion at said inner hole end of each of said ventilation holes.