GB2478950A

GB2478950A - A composite element

Info

Publication number: GB2478950A
Application number: GB1004939A
Authority: GB
Inventors: Jeremy Gibson Harris; Michael J Franklin
Original assignee: Crawley Creatures Ltd
Current assignee: Crawley Creatures Ltd
Priority date: 2010-03-24
Filing date: 2010-03-24
Publication date: 2011-09-28
Also published as: GB201004939D0

Abstract

A composite element (10) comprising a first layer (12) and a second layer (14), a heating element (16) located in-between the first layer and the second layer, and a liquid dispensing system (18, 20, 22, 24, 26) for dispensing liquid onto the outer surface of the first layer. Further non-conductive layers may be located between the heating element and first and second layers, the outer layers preferably comprising a carbon composite material. The dispensing system may consist of one or more apertures passing through the first and second layers and connecting to a liquid reservoir, wherein an aperture is controllable to affect the flow of liquid from the reservoir through the apertures to an outer surface of the composite element. The heating element and apertures are preferably controlled by wireless means. The composite element may be formed into an anthropometric form or a component of a vehicle and may dispense simulated perspiration, lubricant of antifreeze.

Description

A Composite Element The present invention relates to a composite element comprising a heating element and a liquid dispensing system, in particular wirelessly controllable in use. The present invention also relates to a composite element comprising a heating element and a liquid dispensing system formed into an anthropometric form. The present invention also relates to a composite element comprising a heating element and a liquid dispensing system formed into a component part for an air, land or water vehicle. The present invention also relates to a method for heating and providing liquid to a surface of a composite element, which in particular is formed into an anthropometric form and a component part for an air, land or water vehicle Early systems for attempting to simulate perspiration by a human form, and in particular by a human head form, involved creating a human head form which was capable of being heated. The simulation of perspiration was created by putting a wet cloth in contact with the head form. Where the head form is being used to test protective goggles of respirators, the wet cloth is typically placed across the eyes of the head form underneath the protective goggles or respirator. The head form also comprised a camera placed in one eye. The head form was then heated, which resulted in water from the wet cloth forming vapour to simulate perspiration, the amount of fogging or misting within the goggles or respirator was then calculated from the fogging or misting of the camera.

Such systems have a number of limitations which include the inability to create perspiration in predefined areas at predefined rates in order to access the results. The head forms were formed from a rigid material which was quite dissimilar to human skin and therefore did not behave as such. Thus the protective goggles or respirators being tested usually could not sit, fit and seal on the head form in the same way as the protective goggles or respirators would sit, fit and seal on a real human head.

In such systems the heating elements tended to be metal pads either located on the surface of the head form or inside the skull of the head form. Where the heating elements are located on the surface of the head form they are able to come into contact with the simulated perspiration which if not properly protected results in shorting of the system. Where the heating elements are located inside the skull of the head form they need to create more heat for that lost as the heat moves through the head form to the surface of the skull. In addition such systems are generally controlled using wires meaning that the head form needs to be connected to the controller by wires. This results in the controller needing to be located close to the head form, and move with the head form.

According to an aspect of the present invention there is provided a composite element comprising: i) a first layer having an inner surface and an outer surface; ii) a second layer having an inner surface and an outer surface; iii) a heating element located in-between the first layer and the second layer; and iv) a liquid dispensing system for dispensing liquid onto the outer surface of the first layer.

This is particularly advantageous because a lightweight composite material such as carbon fibre, Kevlar RTM or a glass fibre can be used to form the layers with a lightweight heating element located in between such that the heating element is completely contained within the layers of composite material but which still heats the composite material. The heating element may be simulating extreme body temperature of a human or animal and it may be to present ice formation on a land, air or water vehicle. This also has the additional advantage that a liquid can be dispersed onto the outer surface of the composite material wherein the liquid does not come into contact with the heating element or the electronics/electrical wires controlling the heating element. The liquid may be simulating perspiration or it may be providing lubricant and anti-freeze on a component part of a land, air or water vehicle.

Preferably the heating element is sandwiched between the inner surface of the first layer and the inner surface of the second layer.

Preferably a third layer is located in-between the first layer and the heating element and a fourth layer is located in-between the second layer and the heating element.

Preferably the first and second layers comprise a carbon composite material and wherein the third and fourth layers comprise an electrically non-conductive material. A suitable non-conductive material for the third and fourth layers is a glass fibre epoxy composite material.

This is advantageous because a composite material such as carbon fibre is capable of conducting electricity, therefore an electrical (but not thermal) insulating layer, such as a glass fibre epoxy composite, provided between the heating element, through which electricity is passing, and the carbon fibre prevents electricity from being conducted into the carbon fibre or the electrically conductive composite material.

Preferably the heating element comprises a resistive heating element.

Preferably the resistive heating element comprises a wire, in an alternative the heating element comprises a tape or ribbon.

Preferably the wire, tape or ribbon comprises a nickel wire, tape or ribbon, in an alternative the wire, tape or ribbon comprises a tungsten wire, tape or ribbon.

Preferably electricity is passed through the wire in use, wherein the wire has a resistance such that heat is generated in the wire and conducted out through the first and second layers.

Preferably the heat output of the heating element is wirelessly controlled in use, in an alternative it is Bluetooth RTM or IR controlled in use.

This is particularly advantageous because it allows for control of the heat output of the heating element without the need of wires connecting the heating element to the controller. This means that the composite element can be spaced apart from the controller. This is very advantageous when the composite element is formed into anthropometric form for testing safety equipment wherein the safety equipment is being tested under harsh conditions or is remote from the controller which would not be suitable for external cabling for example through the safety equipment being tested to the controller.

This is also advantageous when the composite element is formed into a component part for a land, air or water vehicle, such as an unmanned vehicle where the controller is located remote from the vehicle.

Preferably the liquid dispensing system comprises an aperture through the first and second layers and wherein the sealed aperture is connected to a liquid reservoir in use and wherein the flow of liquid from the liquid reservoir through the aperture is controllable by a control means. Preferably the aperture is 2 to 3 mm in diameter.

Preferably the aperture is connected to the liquid reservoir, in use, via a pump.

Preferably the liquid dispensing system comprises a plurality of apertures, preferably the number of apertures replicates the perspiration zones of a human, typically 1 to 15 apertures per perspiration zone.

Preferably the aperture(s) are each provided with a hydrophilic or wicking pad, preferably the hydrophilic or wicking pad comprises a cotton wick, expanded polyethylene (PE) or expanded polytetrafluoroethylene (PTFE).

Preferably the control means controlling the flow of liquid from the liquid reservoir and through the sealed aperture is wirelessly controlled in use, in an alternative it is Bluetooth RTM or IR controlled in use.

Preferably the liquid comprises simulated perspiration.

Preferably the liquid comprises a lubricant.

Preferably the liquid comprises antifreeze.

Preferably the composite element is formed into an anthropometric form.

Preferably the anthropometric form is adapted to simulate at least the head of an animal or human body. Preferably the apparatus further comprises a synthetic skin adapted to cover all of part of the anthropometric form. This is particularly advantageous as the synthetic skin simulates real skin and allows for the apparatus to seal to the synthetic skin in the same way as it would seal on real skin.

Preferably the apparatus further comprises a detection means.

Preferably the apparatus further comprises at least one eye socket.

Preferably the detection means is located in the at least one eye socket.

Preferably the detection means comprises a camera.

Preferably the detection means comprises a vision acquisition system.

Preferably the detection means comprises a temperature sensor.

Preferably the detection means comprises a humidity sensor.

Preferably the detection means comprises a moisture sensor.

Preferably the apparatus further comprises a mouth cavity.

Preferably the mouth cavity is provided with a breathing tube to simulate respiration.

This is particularly advantageous as in a full respirator rather than goggles water in the breath of the human or animal will also contribute to any fogging or misting of the respirator as well as the perspiration to give a more realistic simulation.

Preferably the breathing tube is connected to a humidifier. This is advantageous as it allows the artificial breath to be humidified to more realistically simulate real human or animal breath.

Preferably the apparatus further comprises a climatic chamber in which the anthropometric form is located within.

Preferably the climatic chamber provides for external control of temperature and humidity. This is advantageous as it allows the tester to determine if the external climate is different from the internal climate of the goggles or respirator or other apparatus being tested whether this would have an effect on the misting or fogging of the apparatus being tested.

Preferably the apparatus is provided with goggles or a respirator of other protective head wear.

Preferably the level of misting or fogging inside the goggles or respirator or other protective head wear resulting from the artificial perspiration or respiration is measured by the detection means.

Alternatively the composite element is formed into a component part for a UAV (unmanned aerial vehicle).

Alternatively the composite element is formed into a component part for an aircraft.

Alternatively the composite element is formed into an automotive component for a land vehicle.

The present invention provides an apparatus and method to provide a lightweight heated surface to a composite component especially one of a compound form. The heated component could be applied to simulated body forms to UAV, aircraft and automotive components for example.

In addition a liquid dispersal system for depositing sweat or antifreeze, for example onto the components surface, with both temperature and liquid dispersal being controlled wirelessly by a remote computer.

The present invention will now be described by way of example only with reference to the accompanying drawings, wherein: Figure 1 is a schematic chart of the apparatus of an embodiment of the present invention.

Figure 1 shows a full schematic diagram of the individual components which can be included in the composite element.

The composite element 10 has a first layer 12 and a second layer 14 with a heating element 16 sandwiched in between. The heating element 16 is a nickel element wire.

In an alternative embodiment the heating element 16 is a nickel element ribbon or tape and in a further alternative embodiment the heating element 16 is a tungsten element wire, ribbon or tape. The composite element 10 is also provided with a number of apertures 18 acting as hydrophilic liquid dispense points for dispensing fluid on to the outer surface of the first layer 12 of the composite element 10. The number of apertures 18 acting as hydrophilic liquid dispense points replicate the number required to simulate perspiration zones in a human in one embodiment, in an alternative embodiment the number and positioning are calculated to provide for efficient lubrication or anti-freezing of the outer surface of the composite element 10. The apertures are typically 2 to 3 mm in diameter. Each of the hydrophilic liquid dispense points 18 are provided with a hydrophilic or wicking pad. The hydrophilic or wicking pad is formed from a cotton wick, or in an alternative embodiment expanded PE or PTFE. The hydrophilic or wicking pad is then connected to a pump 20 via tubing 22.

The pump 20 is also connected to a liquid reservoir 24 by tubing 26. The pump 20 and the heating element 16 are connected electrically to a wireless control board 28. The wireless control board 28 is then wirelessly connected by wi-fi to a computer, which will work typically over a range of 30 metres. In an alternative embodiment the pump 20 and the heating element 16 are connected electrically to a Bluetooth RTM or IR controller. The Bluetooth RTM or IR controller is then wirelessly connected by Bluetooth RTM or IR to a computer. In a further alternative the pump 20 and the heating element 16 are simply hardwired to a computer.

In order to make a composite element 10 of the present invention the first thing to determine is the heat output i.e. temperature range required by the heater element 16.

The surface area of the composite element 10 to be heated then needs to be calculated, and from this the required wattage of the heating element 16 can then be determined. A wire is then laid out over the surface area of the composite element 10 to determine the overall length of wire needed. Once the length of the wire has been determined the resistance of the wire can then be calculated and the thickness of wire needed can be determined to give the correct heat output i.e. temperature range typically 37.5 degrees but up to around 50 to 50 degrees. It may be that a number of heated zones are required each of which are controllable individually, in which case the process above simply needs to be repeated to each zone.

As an example if a heat dissipation of 1 watt per square centimetre is required and the object has an area of 100 CmA2 then a heater of 100 watts is required. Taking the known resistances of the hearing wire and the supply voltage to the heater, the use of Ohm's law allows the calculation of the total length of heating element for any given wire resistance. In this instance a wire with a resistance of 1 Ohms per meter R=V/(WN) Where R = Resistance V=supply voltage W= watts So with a wire of 1 Ohm resistance a required heater output of 100 watts and a supply voltage of 24v we have 24/(100/24) =5.76 Ohms With a heater wire resistance of 1 Ohm a meter the surface would require 5.76 meters of wire. The wire diameter needs to be selected to ensure that there is enough wire to cover the zone at a spacing that gives an even heat distribution.

To produce the composite element 10 a fine layer 12 of composite material is provided which may be provided with a barrier layer of electrically non-conductive material if the composite material is a carbon composite such as carbon fibre or other electrically conductive material. Suitable composition materials include carbon fibre, Kevlar RTM and glass fibre, a suitable barrier layer is a non-electrically conductive composite material which includes glass fibre epoxy composite. A flexible mesh, typically a thin, open weave of around 5mm, stiffened fabric, is then used to provide a structure to bond the heating element 16 i.e. nickel element wire to. Once the heating element 16 is positioned further layers of composite material as appropriate are layered on top such that the heating element 16 is sandwiched in the composite element 10.

Claims

CLAIMS: 1. A composite element comprising: i) a first layer having an inner surface and an outer surface; ii) a second layer having an inner surface and an outer surface; iii) a heating element located in-between the first layer and the second layer; and iv) a liquid dispensing system for dispensing liquid onto the outer surface of the first layer.
2. A composite element as claimed in claim 1, wherein the heating element is sandwiched between the inner surface of the first layer and the inner surface of the second layer.
3. A composite element as claimed in claim 1 or claim 2, wherein a third layer is located in-between the first layer and the heating element and a fourth layer is located in-between the second layer and the heating element.
4. A composite element as claimed in claim 3, wherein the first and second layers comprise a carbon composite material and wherein the third and fourth layers comprise an electrically non-conductive material.
5. A composite element as claimed in any preceding claim, wherein the heating element comprises a resistive heating element.
6. A composite element as claimed in claim 5, wherein the resistive heating element comprises a wire.
7. A composite element as claimed in claim 6, wherein the wire comprises a nickel wire.
8. A composite element as claimed in claim 6 or claim 7, wherein electricity is passed through the wire in use, wherein the wire has a resistance such that heat is generated in the wire and conducted out through the first and second layers.
9. A composite element as claimed in any preceding claim, wherein the heat output of the heating element is wirelessly controlled in use.
10. A composite element as claimed in any preceding claim, wherein the liquid dispensing system comprises an aperture through the first and second layers and wherein the sealed aperture is connected to a liquid reservoir in use and wherein the flow of liquid from the liquid reservoir through the aperture is controllable by a control means.
11. A composite element as claimed in claim 10, wherein the aperture is connected to the liquid reservoir, in use, via a pump.
12. A composite element as claimed in any of claims 10 to 11, wherein the liquid dispensing system comprises a plurality of apertures.
13. A composite element as claimed in any of claims 10 to 12, wherein the aperture(s) are each provided with a hydrophilic or wicking pad.
14. A composite element as claimed in any of claims 10 to 13, wherein the control means controlling the flow of liquid from the liquid reservoir and through the sealed aperture is wirelessly controlled in use.
15. A composite element as claimed in any preceding claim, wherein the liquid comprises simulated perspiration.
16. A composite element as claimed in any of claims 1 to 14, wherein the liquid comprises a lubricant.
17. A composite element as claimed in any of claims 1 to 14, wherein the liquid comprises antifreeze.
18. A composite element as claimed in any preceding claim, formed into an anthropometric form.
19. A composite element as claimed in claim 18, wherein the anthropometric form is adapted to simulate at least the head of an animal or human body.
20. A composite element as claimed in any of claims 1 to 17, formed into a component part for a UAV.
21. A composite element as claimed in any of claims 1 to 17, formed into a component part for an aircraft.
22. A composite element as claimed in any of claims 1 to 17, formed into an automotive component for a land vehicle.

23 A composite element as hereinbefore described with reference to the accompanying figures.