Bicycle helmet with ventilation plate

Abstract

A bicycle helmet includes a front portion, a rear portion, an overall length, and an overall width. The bicycle helmet includes a liner having a plurality of vents at the front portion of the bicycle helmet and being impact-absorbing. The bicycle helmet further includes a shell over an outer surface of the liner at the front portion of the bicycle helmet, and a plate over the outer surface of the liner at the rear portion of the bicycle helmet. The plate is devoid of vents in a narrow region starting at approximately 45% to 65% of the overall length from a front of the bicycle helmet and extending to a rear of the bicycle helmet. The narrow region is laterally centered on the bicycle helmet and has a width of approximately 30% to 50% of the overall width.

1 . A bicycle helmet having a front portion, a rear portion, an overall length, and an overall width, the bicycle helmet comprising:
 a liner including a plurality of vents at the front portion of the bicycle helmet and being impact-absorbing;   a shell over an outer surface of the liner at the front portion of the bicycle helmet; and   a plate over the outer surface of the liner at the rear portion of the bicycle helmet, the plate being devoid of vents in a narrow region starting approximately 45% to 65% of the overall length from a front of the bicycle helmet and extending to a rear of the bicycle helmet, the narrow region being laterally centered on the bicycle helmet and having a width of approximately 30% to 50% of the overall width.   
     
     
         2 . The bicycle helmet of  claim 1 , wherein the plate defines airflow channels behind the front portion of the bicycle helmet. 
     
     
         3 . The bicycle helmet of  claim 1 , wherein the liner includes two center rails, two parietal rails, and two temporal rails that together define the plurality of vents at the front portion of the bicycle helmet, and wherein the plate provides a connection between rear ends of the center rails and the parietal rails. 
     
     
         4 . The bicycle helmet of  claim 3 , wherein reinforcing struts extend between adjacent pairs of the two center rails and the two parietal rails at the front portion of the bicycle helmet. 
     
     
         5 . The bicycle helmet of  claim 3 , wherein the plate is positioned adjacent outer surfaces of the two center rails and defines airflow channels underneath the plate. 
     
     
         6 . The bicycle helmet of  claim 5 , wherein the airflow channels under the plate include a center channel disposed between the two center rails, and wherein at a first portion of the bicycle helmet, the center channel has a first area in cross section that is approximately 70%-100% of a first combined cross-sectional area of the two center rails. 
     
     
         7 . The bicycle helmet of  claim 6 , wherein at the first area, the two center rails have a thickness of approximately 25 millimeters and have an averaged width of approximately 21 millimeters, and wherein the center channel has a thickness of approximately 25 millimeters and a width of approximately 36 millimeters. 
     
     
         8 . The bicycle helmet of  claim 6 , wherein at a second portion of the bicycle helmet disposed rearward of the first portion, the center channel has a second area in cross section that is approximately 65%-95% of a second combined cross-sectional area of the two center rails. 
     
     
         9 . The bicycle helmet of  claim 8 , wherein at the second portion, the two center rails have a thickness of approximately 25 millimeters and have an averaged width of approximately 20 millimeters, and wherein the center channel has a thickness of approximately 25 millimeters and a width of approximately 30 millimeters. 
     
     
         10 . The bicycle helmet of  claim 1 , wherein the liner comprises expanded polystyrene. 
     
     
         11 . The bicycle helmet of  claim 1 , wherein the plate is approximately 1 millimeter to 5 millimeters in thickness. 
     
     
         12 . The bicycle helmet of  claim 1 , wherein the plate comprises at least one of an injection molded material, a composite reinforced polymer, an ultra-high molecular weight polyethylene, a fiberglass fabric and epoxy matrix, a polypropylene weave composite, fiberglass, carbon, or a polycarbonate material folded onto itself with a midlayer for support and adhesion. 
     
     
         13 . The bicycle helmet of  claim 1 , wherein the plate further includes a wider region. 
     
     
         14 . The bicycle helmet of  claim 13 , wherein the overall length of the bicycle helmet is approximately 270 millimeters and the overall width of the bicycle helmet is approximately 210 millimeters, wherein the narrow region has a length of approximately 118 millimeters and a width of approximately 86 millimeters, and wherein the wider region has a length of approximately 85 millimeters and a width of approximately 174 millimeters. 
     
     
         15 . The bicycle helmet of  claim 13 , wherein both the narrow region and the wider region extend to the rear of the bicycle helmet. 
     
     
         16 . The bicycle helmet of  claim 13 , wherein the wider region starts at approximately 55% to 80% of the overall length from the front of the bicycle helmet. 
     
     
         17 . The bicycle helmet of  claim 1 , wherein the narrow region extends less than or equal to approximately 44% of the overall length of the bicycle helmet. 
     
     
         18 . A bicycle helmet having a front portion, a rear portion, an overall length, and an overall width, the bicycle helmet comprising:
 a liner including a plurality of rails defining vents at the front portion of the bicycle helmet, and a plurality of struts extending between the plurality of rails;   a shell over an outer surface of the liner at the front portion of the bicycle helmet; and   a plate over the outer surface of the liner at the rear portion of the bicycle helmet, the plate being devoid of vents and defining air channels beneath the plate and between the plurality of rails, wherein the plate extends approximately from a center of the bicycle helmet to a rear of the bicycle helmet.   
     
     
         19 . The bicycle helmet of  claim 18 , wherein the liner includes two center rails, two parietal rails, and two temporal rails that together define the plurality of vents at the front portion of the bicycle helmet, and wherein the plate provides a connection between rear ends of the two center rails and the two parietal rails. 
     
     
         20 . The bicycle helmet of  claim 18 , wherein the plate comprises at least one of an injection molded material, a composite reinforced polymer, an ultra-high molecular weight polyethylene, a fiberglass fabric and epoxy matrix, a polypropylene weave composite, fiberglass, carbon, or a polycarbonate material folded onto itself with a midlayer for support and adhesion.