Helmet

Abstract

A helmet, comprising: at least one protective layer; a head mount, configured to be mounted on the top of the head of a wearer of the helmet, wherein the head mount is suspended within a cavity formed by the at least one protective layer such that, in normal use and under an impact to the helmet below a threshold force, an air gap is provided that separates the head mount and the at least one protective layer, and, under an impact above the threshold force, the one or more protective layers contacts the head mount; and a sliding interface provided between the head mount and the at least one protective layer, configured such that the at least one protective layer is able to slide relative to the head mount as the at least one protective layer contacts the head mount under an impact to the helmet above the threshold force.

1 . A helmet, comprising:
 at least one protective layer;   a head mount, configured to be mounted on the top of the head of a wearer of the helmet, wherein the head mount is suspended within a cavity formed by the at least one protective layer such that, in normal use and under an impact to the helmet below a threshold force, an air gap is provided that separates the head mount and the at least one protective layer, and, under an impact above the threshold force, the one or more protective layers contacts the head mount; and   a sliding interface provided between the head mount and the at least one protective layer, configured such that the at least one protective layer is able to slide relative to the head mount as the at least one protective layer contacts the head mount under an impact to the helmet above the threshold force.   
     
     
         2 . The helmet of  claim 1 , wherein the sliding interface is provided, at least partially, by a layer of low friction material attached to, or integrated with, a surface of the at least one protective layer facing the head mount. 
     
     
         3 . The helmet of  claim 2 , wherein the layer of low friction material is moulded to the surface of the at least one protective layer facing the head mount. 
     
     
         4 . The helmet of  claim 1 , wherein the sliding interface is provided, at least partially, by a layer of low friction material attached to, or integrated with, a surface of the head mount facing the at least one protective layer. 
     
     
         5 . The helmet of  claim 2  wherein the low friction material is formed from a waxy polymer and/or a fabric. 
     
     
         6 . The helmet of  claim 1 , wherein the sliding interface is provided, at least partially, by a lubricating material on, or integrated with, a surface of the at least one protective layer facing the head mount. 
     
     
         7 . The helmet of  claim 6 , wherein the lubricating material is one of a polysiloxane-containing material, a mixture of an olefin polymer and a lubricant, and an ultra high molecular weight (UHMW) polymer. 
     
     
         8 . The helmet of  claim 1 , wherein the head mount is connected to the at least one protective layer by connectors. 
     
     
         9 . The helmet of  claim 8 , wherein the sliding interface is provided, at least partially, by a layer of low friction material attached to, or integrated with, a surface of the at least one protective layer facing the head mount; and wherein the low friction layer is also connected to the rest of the helmet by the connectors. 
     
     
         10 . The helmet of  claim 8 , wherein the sliding interface is provided, at least partially, by a layer of low friction material attached to, or integrated with, a surface of the at least one protective layer facing the head mount; and wherein the connectors are connected to the at least one protective layer via the low friction layer. 
     
     
         11 . The helmet of  claim 8 , wherein the connectors are deformable to allow the head mount to rotate relative to the at least one protective layer. 
     
     
         12 . The helmet of  claim 1 , wherein the head mount comprises one or more straps. 
     
     
         13 . The helmet of  claim 1 , wherein the head mount comprises a head ring that is configured to engage at least the forehead of a wearer of the helmet. 
     
     
         14 . The helmet of  claim 1 , wherein the at least one protective layer includes an energy absorbing layer. 
     
     
         15 . The helmet of  claim 1 , wherein the at least one protective layer includes a hard outer shell. 
     
     
         16 . The helmet of  claim 15 , wherein, in the absence of an impact on the helmet, the separation between the outer shell and the head mount at a location corresponding to the top of the head of a wearer provided by the air gap is at least 10 mm, optionally at least 15 mm, optionally at least 20 mm, optionally at least 30 mm, optionally at least 40 mm.