GB2487966A

GB2487966A - Body armour

Info

Publication number: GB2487966A
Application number: GB201102436A
Authority: GB
Inventors: Andrew Vian Smith; Edward Pennington-Ridge
Original assignee: Individual
Current assignee: Individual
Priority date: 2011-02-09
Filing date: 2011-02-09
Publication date: 2012-08-15
Also published as: GB201102436D0

Abstract

The invention provides an item of body armour with active cooling to increase wearer comfort without necessitating increased weight or loss of protective performance. The body armour has an interior layer and an outer ballistic layer b for resisting penetration of handgun projectiles. The interior layer comprises a compressible open cell foam panel c. When the open cell foam panel c is compressed the air trapped within it is expelled out and away from the wearer; subsequent expansion of the foam panel c causes warm, moist air from around the wearer's body to be taken up into the voids within the foam. The compression and expansion of the foam may be caused by movement of the wearer, such as breathing, bending over, walking, running etc. Alternatively, mechanical means may be used to effect this cycle.

Description

Body Armour

Field of the invention

This invention provides an improved system to provide projectile, knife, or spike resistant protection for individuals to wear as body-armour. The system incorporates active cooling to increase wearer comfort without necessitating increased weight or loss of protective performance.

Background to the invention

Most conventional body armour consists of sealed Kevlar panels (sealed to stop water ingress) that are soft, i.e. flexible. Typically, these soft armour panels are designed to stop tow-velocity projectiles and shrapnel, e.g. handgun ammunition or projectiles travelling at velocities under or approximately equal to 500 MIs (metres per second).

These soft panels may be covered in key areas by trauma, or rifle, or SAPI plates or panels made using ceramics, steel, or a combination of very hard materials, in order to stop high velocity projectiles, e.g. rifle ammunition.

Summary of the invention

The inventors of the present invention have established that a problem with conventional body armour is that the wearer can get too hot as body heat is trapped within the armour.

The present invention (embodied in the CoolCor&" system) uses the same basic theme as conventional body armour but allows warm air and moisture to be pumped away from the users body core via the expansion and contraction of an open cell foam that may be treated with an anti bacterial agent.

The present invention provides a system for cooling the wearer of ballistic protection without weight or performance penalties.

Thus, the present invention provides an item of body armour having an interior layer and an outer ballistic layer for resisting penetration of low velocity (e.g. handgun) projectiles, the interior layer comprising an air pocket panel having at least one compressible air pocket therein. The air pocket panel preferably comprises a compressible open cell foam panel.

The invention thus provides body armour through which air gasses and liquids (e.g. water or water vapour) are actively pumped. The pumping action is as a result of compression and expansion of the open cell foam, and may be powered by movements of the users body or by other means such as a battery powered pump, solar powered pump, or other pumping mechanisms.

The body armour is thus not only breathable, but heat and moisture are actively pumped away from the user's body, and cool surrounding air is drawn in.

As cool air is drawn through the damp open cell foam, a significant evaporative cooling effect takes place such that the entire system acts as a solar fridge with pump.

In some embodiments the cooling system can be switched on and off by many simple means, meaning that the armour can be used effectively in cold environments.

Because the user is cooler and more comfortable, he or she can work more effectively, carrying less water, perspiring less and working without the added burdens of heat stress.

The interior layer of the armour, i.e. innermost layer, or layer closer to the body of a wearer than the ballistic layer, has an open-cell polymer foam component. As the open cell foam is compressed, the air within the foam cells is exposed to higher pressure due to a decrease in volume of the cells. This decrease in volume pumps air out of the foam and away from the body core. As the open cell foam expands warm air surrounding the users body is drawn into the foam and held ready to be pumped away from the body core. The foam may be compressed by movements of the wearer such as breathing, leaning forward or backwards, walking, running or other physical activity.

The inventors have established that increases in body temperature will cause a proportional increase in the speed of hysterysis of the foam component, leading to a proportional venting of heat away form the body core. As the foam increases in temperature, heat will be vented away from the body core more rapidly. Conversely in colder conditions the foam will demonstrate limited hysterysis and heat movement away from the body core will be minimised.

The open cell foam may be removable from the item of body armour for washing or replacement. The open cell foam may be washed by being soaked in a cleaning liquid and then wrung out before being refitted to the body armour. The open cell foam may be retained within the body armour by e.g. a fabric pocket, zips, velcroTM, magnets, or by any other means.

In order to increase the evaporative cooling effect of the open cell foam, the open cell foam may be impregnated with water or another liquid such as alcohol or water-alcohol mix. The liquid may be injected into the open cell layer via a port or orifice in the item of body armour.

As an alternative to a compressible open cell foam, the air pocket panel may comprise one or more air pockets formed from a flexible material, the air pockets being biased towards an inflated configuration. The flexible material may itself have properties enabling it to return to a shape in which the air pocket is inflated (i.e. in the inflated configuration), or the air pocket may have one or more inserts or strengthening parts formed from a material demonstrating a shape memory or elastic effect, e.g. spring steel, carbon fibre, polyacetal, nylon, or any foamed material. In such embodiments the or each air pocket has an interior face (i.e. user-facing face) with a first one way valve or valves arranged to permit air to enter the air pocket and an exterior face (i.e. facing away from the user) with a second one way valve or valves arranged to permit air to exit the air pocket. In this way, repeated compression and subsequent expansion of the air pocket causes a pumping action which draws warm, moist air away from the user and replaces it with air from the surrounding environment.

In flexible air pocket embodiments there is preferably an open cell layer or mesh or fabric layer between the one or more air pockets and the user, e.g. a high air flow waterproof fabric layer. Alternatively, a known air flow under armour shirt (similar to a high tech string vest) may be worn under the item of body armour.

The ballistic layer preferably comprises a plurality of air flow channels extending there through, whereby compression of the open cell foam panel causes air to be expelled from the open cell foam panel through the plurality of air flow channels.

The air flow channels thus provide an escape route to the environment for heated air evacuated from the voids within the open cell foam panel when the panel is compressed.

The air flow channels may be offset so as to ensure that no straight line channel through the ballistic layer exists.

The ballistic layer is preferably flexible, i.e. soft. The ballistic layer may comprise a plurality of layers of a ballistic fabric impregnated with a waterproof polymer matrix, and the plurality of air flow channels may extend through each of the impregnated ballistic fabric layers. The ballistic fabric may comprise a woven fabric, or a fabric woven from fibres made of one of the following materials: nylon, polythene, an aramid, a para-aramid such as KevlarTM, an ultra-high-molecular-Weight polyethylene such as SpectraTM or Dyneema'TM, or any material suitable for use in ballistic resistant materials.

The ballistic layer may be formed in any of many different ways, including the following methods for manufacturing breathable panels of soft ballistic fabric that are waterproof.

A method of manufacturing a ballistic panel for preventing penetration of low velocity projectiles may include the steps of: providing a plate or mould tool having a plurality of outwardly extending spikes attached thereto; laying up a plurality of layers of a ballistic fabric on the plate or mould tool so that each layer of ballistic fabric is pierced by the plurality of spikes; impregnating the plurality of layers of ballistic fabric with a polymer; and removing the polymer-impregnated layers of ballistic fabric from the plate or mould tool, whereby voids formed by the spikes provide a plurality of air flow channels through the polymer-impregnated layers of ballistic fabric.

The layer of polymer impregnated layers may be produced in 2 or more layers and offset by at least the diameter of the spikes used, thereby ensuring that no straight line channel through the layers of polymer impregnated ballistic fabric exists.

The step of impregnating the plurality of layers of ballistic fabric with a polymer may comprise laying up a sheet of a solid polymer between two of the plurality of layers of ballistic fabric and curing the polymer so that it impregnates the layers of ballistic fabric. Alternatively, the step of impregnating the plurality of layers of ballistic fabric with a polymer may comprise injecting a liquid polymer into the layers of ballistic fabric and curing the polymer.ln one preferred embodiment one layer of the armour is made of an open pore material that holds panels of ballistic fabric that are treated in a way that removes the requirement for the material to be held in a waterproof pouch. Any woven fabric material with high comparative tensile strength including Nylon, other Aramids, KevlarTM, SpectraTM, DyneemaTM, Polythene, is herein referred to as ballistic fabric. It is Well understood in the art that many fibres used in the art of ballistic resistance demonstrate a reduction in ballistic performance when exposed to water or other contaminants.

In one preferred embodiment the vented armour plate (hard plate panel, described below) and/or soft insert (ballistic panel) are encased in Goretex or other breathable fabric.

In one preferred embodiment the ballistic fabric layers may be infused with a flexible waterproof polymer As will be clear to experts in the field there are numerous flexible waterproof polymers which may be used in order to seal the ballistic fabric layers. In one preferred embodiment each panel of ballistic fabric is created by laying up multiple layers of ballistic fabric on a plate to whose surface is attached a plurality of solid or hollow projections which may be sharpened or pointed at one or both ends.

After laying up multiple layers of ballistic fabric on the spike plate a waterproof polymer material may be added to the layers of ballistic fabric by any means known to the art, including wet lay up, vacuum infusion, vacuum bagging or other method of soaking a material in a liquid resin.

In a further embodiment the ballistic fabric panel may be laid up on a plate to whose surface is attached a plurality of solid or hollow projections which may be sharpened or pointed at one or both ends as follows. One or more layers of ballistic fabric followed by one or more layers of a solid polymer followed by one or more layers of ballistic fabric, repeated until the required number of ballistic fabric layers is achieved.

With the required number of ballistic fabric layers in place, the stack of interlaced ballistic fabric and solid polymer layers may be placed under compression by any means known to the art, including vacuum, mechanical press, autoclave press, hydrostatic bag, or other means of compression known to the art.

In one preferred embodiment the compressed stack of ballistic fabric and polymer layers may be exposed to an external stimuli including heat, cold, LJV light, or other methods known to the art of causing a polymer to soften, cure or otherwise alter its state causing the ballistic fabric layers to become sealed and bonded together.

In another embodiment a stack of multiple ballistic fabric layers may be held within an injection mould tool or other moulding tool familiar to other experts in the field. This mould tool may contain a plurality of solid or hollow projections which may be sharpened or pointed at one or both ends positioned so as to fully pierce the ballistic fabric layers.

The mould or tool may be injected with a rigid or flexible polymer material infusing the ballistic fabric layers with rigid or flexible polymer.

In another embodiment, a stack of ballistic fabric layers may be treated in any of the ways now described to the art including laid up on a plate or a mould tool to whose surface is attached a plurality of solid or hollow projections which may be sharpened or pointed at one or both ends. The ballistic fabric stack may then be infused with a polymer material or other material demonstrating sheer thickening or sheer hardening properties.

An alternative method of manufacturing a ballistic panel for preventing penetration of low velocity projectiles includes the steps of: laying up a plurality of layers of a ballistic fabric to form a stack; impregnating the stack with a polymer; applying a pressure difference across the stack to generate a plurality of air flow channels through the polymer-impregnated stack; and curing the polymer.

In such an embodiment a stack of ballistic fabric layers may be infused with solid or liquid polymers which may or may not demonstrate sheer thickening or sheer hardening properties.

The stack of ballistic fabric layers may then be exposed to pressure or vacuum causing a flow of air or other gas through the stack of infused or otherwise coated ballistic fabric layers.

The air or other gas flowing through the ballistic fabric and polymer stack will create channels through which air or other gasses or liquids will flow easily.

The channels or voids created in the ballistic fabric stack will be entirely sealed from the ballistic fabric in such a way that, after the stack has been cured or hardened by any method already understood by the art, gasses or fluids may easily pass through the ballistic fabric stack without contaminating the materials from which it is made.

The body armour of the present invention may further comprise one or more hard plate panels for resisting penetration of high velocity projectiles, each of the one or more hard plate panels having a plurality of air flow channels therethrough.

Preferably, each of the one or more hard plate panels comprises a plurality of rigid elements arranged in an array such that there is an air flow channel between neighbouring rigid elements.

The array of rigid elements is preferably formed in a non-planar shape that may be arranged to approximate the female form. Thus, the hard plate panels may be formed and moulded to follow breast contours to allow comfortable active cooling ballistic body protection to be made for females.

In one preferred embodiment one layer of the armour system is formed by such hard plate panels constructed using a plurality of ceramic spheres or spheres of any suitable material, including those used in the prior art such as steel, tungsten, tungsten alloys, boron carbide, zirconium, alumina, silicon nitride, silicon carbide, or ruby sapphire.

In one preferred embodiment spherical rigid elements are arranged in a manner whereby channels allowing the free flow of air are created due to the arrangement of the spherical elements. That is, in such embodiments neighbouring spherical rigid elements are in contact, the air flow channels being formed by voids between the spherical rigid elements.

The rigid elements (e.g. spheres) may be laid up on a bed of solid or hollow projections which may be sharpened or pointed at one or both ends.

The rigid elements (e.g. spheres) may be woven into a layer of ballistic fabric.

The rigid elements (e.g. spheres) may be covered by sheets of ballistic fabric on one or more sides, i.e. the rigid elements may be enclosed within a pocket of ballistic fabric.

The spheres may be held in place to prevent movement upon impact of projectile using other materials. For example, the array of rigid elements (e.g. spheres) may be encased in a polymer matrix comprising a plurality of air flow channels therethrough.

As an alternative to spheres, hard plate elements of any shape may be used where channels or pockets allowing free flow of air are created when a plurality of hard plate elements are arranged in a particular manner. Hard plate elements may be made of any suitable material, including those used in the prior art such as steel, tungsten, tungsten alloys, boron carbide, zirconium, alumina, silicon nitride, silicon carbide, or ruby sapphire.

In one preferred method of manufacture one or multiple layers of spheres or hard plate elements are held in place on a bed of solid or hollow projections which may be sharpened or pointed at one or both ends. The spheres or hard plate elements are then bonded in place by surrounding the elements with polycarbonate softened to above its glass transition temperature.

In one preferred embodiment a softened sheet of polycarbonate is pressed into the surface of the layer or layers of spheres or hard plate elements such that the polycarbonate flows around the hard plate elements holding each hard plate element in contact with other hard plate elements.

ln one preferred embodiment liquid polycarbonate is injected around the spheres or hard plate elements held in place within a mould tool containing a plurality of solid or hollow projections such that upon removing the finished plate from the mould tool the plate consists of a plurality of hard plate elements encased in solid polycarbonate with air channels between the hard plate elements.

In one preferred embodiment any other liquid polymer material may be poured, cast, trowelled, injected, vacuum infused or otherwise introduced into the layer or layers of spheres or hard plate elements held in place by a flat or curved plate whose surface is interrupted by a plurality of solid or hollow projections which may be sharpened or pointed at one or both ends.

In another embodiment a layer or layers of spheres or hard plate elements are arranged such that they are held securely in place by their tessellation and geometry interacting with an edge boundary. The spheres or hard plate elements are arranged in such a way that voids or pockets allowing free flow of air or liquids are created. The layer or layers of spheres or hard plate elements are then coated or covered with any polymer material, liquid metal, other liquid substance, or granular adhesive or polymer material such that all voids created previously are filled and the elements are bound securely together. Any material demonstrating adhesive properties when cured or hardened by any means including heat, cold, light of any wavelength including UV, catalyst, cooling, or other means of hardening may be used in place of the materials mentioned as will be understood by experts in the art.

Before the polymer material or other liquid substance fully hardens or cures the complete construction may be exposed to pressure or vacuum such that excess polymer is blown or drawn or otherwise moved away from voids between the spheres or hard plate elements.

In one preferred embodiment the layer or layers of spheres or hard plate elements may be built up on a permeable sheet such as a sheet of expanded metal lath. Any liquid or solid granular polymer or otherwise adhesive material known to the prior art may be poured, trowelled, or otherwise applied such that it fills all voids between the spheres or hard plate elements.

The liquid polymer or other adhesive material may now be allowed to drain through the spheres or hard plate elements such that voids between the spheres or hard plate elements are created but sufficient adhesive material clings to the surface of the spheres or hard plate elements to effectively bond them together.

The bonded spheres or hard plate elements with air channels pockets or voids may now be exposed to a stimuli to fully cure the polymer or other adhesive material. External stimuli may include heat, cold, UV or light of other wavelengths or other mechanism of material hardening understood by the art.

In one embodiment, air channels may be created within a monolithic ceramic plate via the lost wax casting process or other method understood by the art. In another embodiment, a plurality of through-thickness channels may be formed in the or each ceramic hard plate element when it is in the green' (not fired) state. The channels may be produced by any means, including drilling, casting or by pressing the green ceramic plate into a mould having a plurality of outwardly extending projections such that the channels are formed in the green plate by the projections. Alternatively, a plurality of through-thickness channels may be formed in the or each ceramic hard plate element after firing, e.g. by drilling.

In one preferred embodiment, air may be pumped through the channels in the spheres or hard plate elements, away from the users body for direct cooling, and toward the user's body through a damp layer of open cell foam for evaporative cooling.

The one or more hard plates (CoolCoreTM hard plate) are thus constructed using rigid (e.g. ceramic) elements arranged such that there are air channels through the hard plate. The CoolCoreTM hard plates may be vented in any other way, such as a compound ceramic material cast around a wax former and then the wax is lost during a firing process to leave a plurality of open channels through the plate.

In one preferred embodiment the face of the open cell foam closest to the body may be highly breathable to allow free air flow and the remaining surfaces of the foam be sealed to prevent air flow. Thus, the body armour of the present invention may, in some embodiments, have an impermeable membrane between the open cell foam panel and the ballistic layer, and a valve having an open configuration in which it provides fluid communication between the open cell foam panel and the atmosphere and a closed configuration in which fluid communication between the open cell foam panel and the atmosphere is prevented, whereby when the valve is in the open configuration compression of the open cell foam panel causes air to be expelled from the open cell foam panel into the atmosphere via the valve.

The valve, or plurality of valves, allow exit of air from the sealed portion of the foam layer.

The body armour may comprise a user control arranged to switch the valve between the open configuration and closed configuration. Alternatively, the device may comprise a temperature sensor arranged to detect the temperature of a user wearing the item of body armour, and a control unit arranged to switch the valve into the open configuration if the temperature sensor detects that the temperature of the user exceeds a threshold temperature.

Thus, the valve or valves may be opened or closed by the user or by feedback from a device monitoring the core temperature of the user. In this way the user may choose to open the valve on the open cell foam layer to allow warm air to be pumped through the valve and away form the body core, the user may close the valve to maintain core temperature. This embodiment of the invention will allow use of the art in cold conditions where movement of warm air away form the body core may not be desirable.

In one preferred embodiment the valve or valves may be opened closed, or held parbally open without any input or feedback from the user. A simple heat sensitive valve containing a bi-metallic strip or other temperature sensing device known to the art may be used to effect the opening and closing of the valve or valves.

In one preferred embodiment the valve or valves may be powered, being a solenoid valve or other powered valve, operated by disposable battery or connected to photovoltaic solar array to ensure that the battery is kept fully charged when exposed to light.

In the above description features described as being suitable for resisting impact by low velocity projectiles may be defined as being capable of resisting an impact velocity of 500 mis or less in testing, as defined in NATO armour testing standards STANAG 2920.

Alternatively and/or in addition, low velocity' may be defined as any velocity currently protected against using soft armour.

In the above description features described as being suitable for resisting impact by high velocity projectiles may be defined as being capable of resisting an impact velocity of more than 500m/s in testing. Alternatively, and/or in addition, high velocity' may be defined as a velocity currently protected against using hard plate armour.

Any of the optional and/or preferable features described above may, where appropriate, be applied to any aspects of the invention, either on their own or in any combination.

Brief description of the drawings

Embodiments of the present invention will now be described with reference to the appended drawings, in which: Figs. 1 -4 show cross-sections through items of body armour according to four embodiments of the present invention; and Figs. 5 and 6 show cross sections through shaped and contoured hard plate panels from items of body armour according to two embodiments of the present invention.

Description of the embodiments

Fig 1 shows a section through the CoolCore" armour system in an iteration in which the hard plate (d) is made of a single layer of spheres held in a polymer matrix and backed with a compound layer (b) of ballistic fabric and polymer matrix with air channels (not shown) therethrough, all inside a breathable cover (a). Beneath this is the main layer of compound ballistic fabric (b) with air channels (through holes, not shown) therethrough. Beneath this is a layer of open cell foam (c).

Fig 2 shows a section through the CoolCoreTM armour system in an iteration in which the hard plate (d) is made of two layers of nested spheres held in a polymer matrix and backed with a compound layer (b) of ballistic fabric and polymer matrix with air channels (not shown) therethrough, all inside a breathable cover (a). Beneath this is the main layer of compound ballistic fabric (b) with air channels (through holes, not shown) therethrough. Beneath this is a layer of open cell foam (c).

Fig 3 shows a section through the CoolCore'TM armour system in an iteration in which the hard plate (d) is made of a single layer of spheres held in a polymer matrix and backed with a compound layer (b) of ballistic fabric and polymer matrix with air channels (not shown) therethrough, all inside a breathable cover (a). Beneath this are two main layers of compound ballistic fabric (b) with air channels (through holes, not shown) therethrough separated by a thin layer of open cell foam (c), so allowing the channels (holes) through the ballistic fabric layers (b) to be offset. Beneath this is a layer of open cell foam (c).

Fig 4 shows a section through the CoolCoretM armour system in an iteration in which the hard plate (d) is made of two layers of nested spheres held in a polymer matrix and backed with a compound layer (b) of ballistic fabric and polymer matrix with air channels (not shown) therethrough all inside a breathable cover (a). Beneath this are two main layers of compound ballistic fabric (b) with air channels (through holes, not shown) therethrough separated by a thin layer of open cell foam (c), so allowing the channels (holes) through the ballistic fabric layers (b) to be offset. Beneath this is a layer of open cell foam (c).

Fig 5 shows a section through a shaped hard plate of the CoolCoreTM armour system in an iteration in which the hard plate (d) is made of two layers of nested spheres held in a polymer matrix and backed with a compound layer (b) of ballistic fabric and polymer matrix, with the plate shaped to fit the female form.

Fig 6 shows a section through a shaped hard plate of the CoolCoretM armour system in an iteration in which the hard plate (d) is made of a single layer of spheres held in a polymer matrix and backed with a compound layer (b) of ballistic fabric and polymer matrix, with the plate shaped to fit the female form.

Claims

Claims 1. An item of body armour having an interior layer and an outer ballistic layer for resisting penetration of low velocity projectiles, the interior layer comprising an air pocket panel having at least one compressible air pocket therein.
2. An item of body armour according to claim 1, the air pocket panel comprising a compressible open cell foam panel.
3. An item of body armour according to claim 2, wherein the open cell foam panel is treated with an antibacterial agent.
4. An item of body armour according to any of claims 1 to 3, wherein the ballistic layer comprises a plurality of air flow channels extending therethrough, whereby compression of the open cell foam panel causes air to be expelled from the air pocket panel through the plurality of air flow channels.
5. An item of body armour according to claim 4, wherein the ballistic layer comprises a plurality of layers of a ballistic fabric impregnated with a waterproof polymer matrix, and the plurality of air flow channels extend through each of the impregnated ballistic fabric layers.
6. An item of body armour according to claim 4 or claim 5, wherein the ballistic fabric comprises a woven fabric.
7. An item of body armour according to any of claims 4 to 6, wherein the ballistic fabric comprises a fabric woven from fibres of one of the following: nylon, polythene, an aramid, a para-aramid such as KevlarTM, or an ultra-high-molecular-weight polyethylene such as SpectraTM or DyneematM.
8. An item of body armour according to any of claims 1 to 7, further comprising one or more hard plate panels for resisting penetration of high velocity projectiles, each of the one or more hard plate panels having a plurality of air flow channels extending therethrough.
9. An item of body armour according to claim 8, each of the one or more hard plate panels comprising a plurality of rigid elements arranged in an array such that the air flow channels are formed between neighbouring rigid elements.
10. An item of body armour according to claim 9, wherein the array of rigid elements is formed in a non-planar shape arranged to approximate the female form.
11. An item of body armour according to claim 9 or claim 101 wherein the rigid elements are each spherical.
12. An item of body armour according to claim 11, wherein neighbouring rigid elements are in contact, the air flow channels being formed by voids between the spherical rigid elements.
13. An item of body armour according to any of claims 9 to 12, wherein the rigid elements are formed from one of the following materials: ceramics, steel, tungsten, tungsten alloys, boron carbide, zirconium, alumina, silicon nitride, silicon carbide, or ruby sapphire.
14. An item of body armour according to any of claims 9 to 13, wherein the array of rigid elements is woven into a layer of ballistic fabric or encased within a pocket of ballistic fabric.
15. An item of body armour according to any of claims 9 to 14, wherein the array of rigid elements is encased in a polymer matrix comprising a plurality of air flow channels therethrough.
16. An item of body armour according to any of claims 1 to 3, comprising an impermeable membrane between the air pocket panel and the ballistic layer, and a valve having an open configuration in which it provides fluid communication between the open air pocket panel and the atmosphere and a closed configuration in which fluid communication between the air pocket panel and the atmosphere is prevented, whereby when the valve is in the open configuration compression of the air pocket panel causes air to be expelled from the air pocket panel into the atmosphere via the valve.
17. An item of body armour according to claim 15, comprising a user control arranged to switch the valve between the open configuration and closed configuration.
18. An item of body armour according to claim 16, comprising a temperature sensor arranged to detect the temperature of a user wearing the item of body armour, and a control unit arranged to switch the valve into the open configuration if the temperature sensor detects that the temperature of the user exceeds a threshold temperature.
19. An item of body armour substantially as herein described, with reference to the accompanying drawings.