Protective apparel and helmet

Abstract

An item of protective apparel comprising: first and second components ( 41, 42 ) that are configured to move relative to one another; and a sliding interface provided between the first and second components; wherein the sliding interface comprises first and second surfaces ( 41, 42 ) that oppose one another and are configured to slide relative to each other; the first surface has at least a first region ( 45 ) which is divided into at least first and second areas ( 47, 48 ) that are configured such that at least one of the static coefficient of friction and the dynamic coefficient of friction for the first area against the second surface is different from the second area against the second surface; the first surface has a second region configured such that the static and/or dynamic coefficient of friction of the first surface against the second surface is different in the first region from the second region ( 46 ); the second region is divided into at least first and second areas ( 49, 50 ) that are configured such that at least one of the static coefficient of friction and the dynamic coefficient of friction for the first area against the second surface is different from the second area against the second surface; and the arrangement of the first and second areas in the first region is different from the arrangement of the first and second areas in the second region.

1 . An item of protective apparel comprising:
 first and second components that are configured to move relative to one another; and   a sliding interface provided between the first and second components;   wherein the sliding interface comprises first and second surfaces that oppose one another and are configured to slide relative to each other;   the first surface has at least a first region which is divided into at least first and second areas that are configured such that at least one of the static coefficient of friction and the dynamic coefficient of friction for the first area against the second surface is different from the second area against the second surface;   the first surface has a second region configured such that the static and/or dynamic coefficient of friction of the first surface against the second surface is different in the first region from the second region;   the second region is divided into at least first and second areas that are configured such that at least one of the static coefficient of friction and the dynamic coefficient of friction for the first area against the second surface is different from the second area against the second surface; and   the arrangement of the first and second areas in the first region is different from the arrangement of the first and second areas in the second region.   
     
     
         2 . An item of protective apparel according to  claim 1 , wherein the first and second areas are evenly distributed across the first region. 
     
     
         3 . An item of protective apparel according to  claim 1 , wherein the first and second areas are provided in a repeating pattern across the first region. 
     
     
         4 . An item of protective apparel according to  claim 1 , in which the ratio of the first area to the second area is selected such that the area-weighted average of the static and/or dynamic coefficient of friction of the first surface against the second surface in the first region is a desired level. 
     
     
         5 . An item of protective apparel according to  claim 1 , wherein, in at least one of the first and second areas of a region of the first surface, a coating is provided that changes the static and/or dynamic coefficient of friction against the second surface in comparison to the first surface without a coating. 
     
     
         6 . An item of protective apparel according to  claim 5 , wherein the coating is configured to increase the static and/or dynamic coefficient of friction against the second surface in comparison to the first surface without a coating. 
     
     
         7 . An item of protective apparel according to  claim 5 , wherein the coating is configured to reduce the static and/or dynamic coefficient of friction against the second surface in comparison to the first surface without a coating. 
     
     
         8 . An item of protective apparel according to  claim 1 , wherein in at least one of the first and second areas of a region of the first surface, the surface is abraded in order to increase the static and/or dynamic coefficient of friction against the second surface in comparison to the unabraded first surface. 
     
     
         9 . An item of protective apparel according to  claim 1 , wherein at least one of the first and second areas of a region of the first surface is provided with plural protrusions that engage with the second surface to increase the effective static and/or dynamic coefficient of friction in comparison to the first surface without protrusions. 
     
     
         10 . An item of protective apparel according to  claim 1 , wherein the component on which the first surface is provided is formed as a layer formed from different materials in the first and second areas respectively. 
     
     
         11 . An item of protective apparel according to  claim 1 , wherein the component on which the first surface is provided is formed from a base layer made from a first material, covered by a layer of a second material; and
 the first areas correspond to openings in the layer of second material exposing the first material to provide part of the first surface.   
     
     
         12 . An item of protective apparel according to  claim 1 , wherein the item is a helmet; and
 the first and second components are first and second shells, respectively, configured such that in response to an oblique impact on the helmet the first shell can move relative to the second shell by sliding at the sliding interface.   
     
     
         13 . An item of protective apparel according to  claim 1 , wherein the item of protective apparel is a helmet that comprises first and second shells and is configured such that in response to an oblique impact on the helmet the first shell can move relative to the second shell; and
 first and second components are provided in a connector that connects the first and second shells together but permits movement of the first shell relative to the second shell by sliding at the sliding interface within the connector.   
     
     
         14 . (canceled) 
     
     
         15 . A helmet comprising:
 first and second shells that are configured such that, in response to an oblique impact on the helmet the first shell can move relative to the second shell; and   a sliding interface provided between the first and second shells;   wherein the sliding interface comprises first and second surfaces, that are each part of one of the respective shells, that oppose one another and are configured to slide relative to each other; and   the first surface has at least a first region and a second region that are configured such that at least one of the static coefficient of friction and the dynamic coefficient of friction for the first region against the second surface is different from the second region against the second surface.   
     
     
         16 . A helmet according to  claim 15 , wherein the wherein the first region is at least one of a frontal region, a posterior region, a left lateral region, a right lateral region, a crown region and a region corresponding to one of the lobes of the brain of a wearer of the helmet; and the second region is a different at least one of a frontal region, a posterior region, a left lateral region, a right lateral region, a crown region and a region corresponding to one of the lobes of the brain of a wearer of the helmet from the first region. 
     
     
         17 . A method of manufacturing a component of a helmet, comprising:
 forming a sheet of material into a shaped form that approximately conforms to the shape of a head, having a concave surface on one side of the shaped form and a convex surface on the other side of the shaped form;   securing the shaped form in a mould such that one of the concave and convex surfaces forms part of the mould;   co-moulding a second material to the shaped form within the mould;   wherein the other of the concave and convex surfaces than the one forming part of the mould has at least a first region which is divided into at least first and second areas that are configured such that at least one of the static coefficient of friction and the dynamic coefficient of friction for the first area against a surface of another component of the helmet slid against it is different from the second area against said surface of another component of the helmet.   
     
     
         18 . A method of manufacturing a component of a helmet according to  claim 17 ,
 wherein the step of securing the shaped form to the mould comprises using an adhesive-backed strip of material to hold the shaped form in place in the mould; and   the size and distribution of the first and second areas is selected relative to the size of the strip of adhesive-backed material such that, when the adhesive-backed strip is adhered to any part of the first region, part of it adheres to each of the first and second areas.   
     
     
         19 . A method of manufacturing a component of a helmet according to  claim 17 ,
 wherein the step of forming the shaped form comprises performing a shaping operation to a flat sheet of material; and   before performing the shaping operation, a coating is provided in at least one of the first and second areas of a region of the other of the concave and convex surfaces than the one used to form part of the mould, the coating configured to change the static and/or dynamic coefficient of friction against the surface of another component of the helmet in comparison to the surface without a coating.   
     
     
         20 . A method of manufacturing a component of a helmet according to  claim 17 ,
 wherein the step of forming the shaped form comprises performing a shaping operation to a flat sheet of material; and   before performing the shaping operation, one of the first and second areas of a region of the other of the concave and convex surfaces than the one used to form part of the mould is abraded in order to increase the static and/or dynamic coefficient of friction against the surface of another component of the helmet in comparison to the surface that has not been abraded.   
     
     
         21 . A method of manufacturing a component of a helmet according to  claim 17 ,
 wherein the step of forming the shaped form comprises performing a shaping operation to a flat sheet of material; and   in addition to shaping the flat sheet into the shaped form, the shaping operation forms plural protrusions in one of the first and second areas of a region of the other of the concave and convex surfaces than the one used to form part of the mould, the plural protrusions configured to engage with the surface of another component of the helmet to increase the effective static and/or dynamic coefficient of friction in comparison to the surface without protrusions.   
     
     
         22 . A method of manufacturing a helmet comprising the method of  claim 17 .