Helmet liner

Abstract

An adjustable liner for use with a protective helmet includes at least one bladder containing open cell foam within the bladder. The bladder is formed by a film that surrounds the foam. The film includes a port that regulates air transfer within the bladder of the liner. When a person dons the helmet having the liner for the first time, the liner's air port is open. When a wearer puts the helmet on his or her head, the foam compresses, thus causing air to escape from within the foam and bladder through the port. The port may then be closed so that air cannot re-enter the bladder or foam, and the foam is retained in its compressed form. When a new wearer wishes to don the same helmet, he or she may release the port to return the foam and bladder to its fully expanded form for a subsequent use.

What is claimed is: 
     
         1 . A helmet liner for use within a protective helmet, the helmet liner comprising:
 a bladder member formed by a protective film, the bladder member having at least one interior cavity;   an open cell foam contained within the at least one interior cavity of the bladder member; and   an air port positioned on the protective film, the air port selectively allowing for fluid communication between atmosphere and the at least one interior cavity of the bladder member.   
     
     
         2 . The helmet liner of  claim 1 , wherein the film is made of at least one of TPU and PVC. 
     
     
         3 . The helmet liner of  claim 1 , wherein air passively enters the air port when it is in the open position until the bladder member is full. 
     
     
         4 . The helmet liner of  claim 1 , wherein when the air port is closed, air does not enter or escape the bladder member. 
     
     
         5 . The helmet liner of  claim 1 , wherein the air port is an air bypass port. 
     
     
         6 . The helmet liner of  claim 1 , wherein the helmet liner is selectively attached to an interior portion of the protective helmet. 
     
     
         7 . The helmet liner of  claim 1 , wherein the helmet liner includes a plurality of bladders. 
     
     
         8 . The helmet liner of  claim 7 , wherein the plurality of bladders are in fluid communication with one another via a plurality of channels. 
     
     
         9 . A helmet liner for use within a protective helmet, the helmet liner comprising:
 a bladder member formed by a protective film;   a compressible material contained within the protective film; and   an air bypass port positioned on the protective film, the air bypass port in fluid communication with the bladder member.   
     
     
         10 . The helmet liner of  claim 9 , wherein the film is made of at least one of TPU and PVC. 
     
     
         11 . The helmet liner of  claim 9 , wherein air passively enters the air port when it is in the open position until the bladder member is full. 
     
     
         12 . The helmet liner of  claim 9 , wherein when the air port is closed, air does not enter or escape the bladder member. 
     
     
         13 . The helmet liner of  claim 9 , wherein the compressible material is open cell foam. 
     
     
         14 . The helmet liner of  claim 9 , wherein the helmet liner is selectively attached to an interior portion of the protective helmet. 
     
     
         15 . The helmet liner of  claim 9 , wherein the helmet liner includes a plurality of bladders. 
     
     
         16 . The helmet liner of  claim 15 , wherein the plurality of bladders are in fluid communication with one another via a plurality of channels. 
     
     
         17 . A method of fitting a protective helmet to a wearer's head, the method comprising the steps of:
 donning the helmet so that a helmet liner comprising a bladder member formed by a protective film and filled with low density foam abuts a portion of the wearer's head;   compressing the low density foam by the wearer's head applying a force to the helmet liner; and   closing an air port located on the protective film when the helmet liner fits the wearer's head.   
     
     
         18 . The method of  claim 17 , further comprising the step of opening the air port when the protective helmet is to be re-used so that the helmet liner returns to its shape and size prior to donning.