Compressible Liner for Impact Protection

Abstract

A compressible liner for impact protection, which may be installed in a helmet worn by a person. The compressible liner may also be applied to other impact protection situations, for example to baby capsules and child safety seats, as well as offering customised zones of impact protection. The compressible liner may have a relatively low density foam inner layer fused to a relatively high density foam outer layer. The inner layer may have many cone shaped protuberances which project into matching recesses of the outer layer. The compressible liner provides an initial low resistance to the impact for a desired part of the human body. As the impact progresses the level of resistance provided by the compressible liner increases in a controlled manner so that controlled deceleration of the part of the body is occurring throughout the impact for a desired impact protection zone of the compressible liner.

1 . An apparatus for impact protection for at least a part of a human body comprising:
 a compressible liner with an inner layer and an outer layer, wherein the inner layer has a contact surface and a first joining surface, wherein the first joining surface includes a plurality of protuberances;   wherein the outer layer has a second joining surface and an outer surface, wherein the second joining surface includes a plurality of recesses adapted to receive the protuberances of the inner layer;   wherein the inner layer includes a first material of a first compressibility and the outer layer includes a second material of a second compressibility; and   wherein the first compressibility is greater than the second compressibility.   
     
     
         2 . An apparatus according to  claim 1 , wherein:
 at least part of the contact surface of the inner layer of the compressible liner is adapted to be immediately adjacent or to engage with part of the human body.   
     
     
         3 . An apparatus according to  claim 1 , wherein:
 the protuberances are conical.   
     
     
         4 . An apparatus according to  claim 1 , wherein:
 said inner layer is formed from one or more inner layer segments.   
     
     
         5 . An apparatus according to  claim 4 , wherein:
 the first compressibility is different between one or more inner layer segments.   
     
     
         6 . An apparatus according to  claim 1 , wherein:
 said outer layer is formed from one or more outer layer segments.   
     
     
         7 . An apparatus according to  claim 6 , wherein:
 the second compressibility is different between one or more outer layer segments.   
     
     
         8 . An apparatus according to  claim 1 , wherein:
 one or more of the first material and the second material are foam.   
     
     
         9 . An apparatus according to  claim 8 , wherein:
 said foam includes expanded polystyrene.   
     
     
         10 . An apparatus according to  claim 9 , wherein:
 the first material has a density in the range of 15 to 50 kgm −3 .   
     
     
         11 . An apparatus according to  claim 10 , wherein:
 the first material has a density in the range of 25 to 35 kgm −3  and the second material has a density in the range of 35 to 50 kgm −3 .   
     
     
         12 . An apparatus according to  claim 10 , wherein:
 the first material has a density in the range of 15 to 25 kgm −3  and the second material has a density in the range of 35 to 45 kgm −3 .   
     
     
         13 . An apparatus according to  claim 9 , wherein:
 the second material has a density in the range of 35 to 90 kgm −3 .   
     
     
         14 . An apparatus according to  claim 13 , wherein:
 the second material has a density in the range of 35 to 55 kgm −3 .   
     
     
         15 . An apparatus according to  claim 1 , wherein:
 one or more of the first material and the second material are viscoelastic or thixotropic.   
     
     
         16 . An apparatus according to  claim 1 , wherein:
 a penetration of one or more protuberances into the outer layer is in the range of 50 to 100%.   
     
     
         17 . An apparatus according to  claim 1 , wherein:
 an apex of one or more protuberances is contiguous with the outer surface.   
     
     
         18 . An apparatus according to  claim 1 , wherein:
 the distance between adjacent bases of the protuberances is in the range of 0 to 20 mm.   
     
     
         19 . An apparatus according to  claim 18 , wherein:
 the distance between adjacent bases of the protuberances is in the range of 5 to 15 mm.   
     
     
         20 . An apparatus according to  claim 1 , wherein:
 the maximum transverse dimension of a base of the protuberances is in the range of 15 to 22 mm.   
     
     
         21 . An apparatus according to  claim 1 , wherein:
 the compressible liner has a thickness in the range of 15 to 45 mm;   a height of one or more protuberances from the base of the respective protuberance is in the range of 20 to 25 mm; and   a distance from the base of one or more protuberances to the contact surface is in the range of 5 to 10 mm.   
     
     
         22 . An apparatus according to  claim 1 , wherein:
 the inner layer is visible through the outer layer.   
     
     
         23 . An apparatus according to  claim 1 , wherein:
 the compressible liner comprises a removable and replaceable fitting.   
     
     
         24 . An apparatus according to  claim 1 , wherein:
 one of the inner and outer layer comprises a strip from which a line of protuberances project.   
     
     
         25 . An apparatus according to  claim 24 , wherein:
 said layer is the inner layer.   
     
     
         26 . An apparatus according to  claim 24 , wherein:
 a plurality of said strips are connected to the compressible liner so as to form a one-piece component.   
     
     
         27 . An apparatus according to  claim 1 , wherein:
 the compressible liner is installed within or forms an article selected from the group including: a vehicle cabin liner, a baby capsule, a child safety seat, a seat, a head rest and a body armour.   
     
     
         28 . An apparatus according to  claim 1 , wherein:
 the compressible liner is installed within or forms a helmet.   
     
     
         29 . A method of impact protection for at least a part of the human body by providing apparatus having:
 an initial low resistance to an impact to at least a part of a human body; and then progressively increasing the level of resistance to the impact to at least a part of the human body as the impact progresses.   
     
     
         30 . An apparatus for impact protection of at least part of an article, the apparatus comprising:
 a compressible inner with a stiffness gradient;   wherein the stiffness gradient during an impact varies from a low stiffness adjacent to the article to a higher stiffness through the thickness of the compressible liner.