WO2009138713A1

WO2009138713A1 - Cooling system for a garment

Info

Publication number: WO2009138713A1
Application number: PCT/GB2009/001123
Authority: WO
Inventors: Matthew Searle
Original assignee: Bcb International Limited
Priority date: 2008-05-16
Filing date: 2009-05-06
Publication date: 2009-11-19
Also published as: GB0808949D0

Abstract

The present invention relates to an apparatus that can be worn on the human body and in that, in operation, acts to cool the human body. The present invention comprises a wearable apparatus for cooling the human body which comprises an airflow creation means, a controller for controlling the created airflow, at least one duct connected to the airflow creation means, wherein the duct comprises a porous portion configured to direct a flow of air to a region of the human body and wherein in operation the controller means controls the airflow to intermittently allow air to flow through the duct.

Description

COOLING SYSTEM FOR A GARMENT

The present invention relates to an apparatus that can be worn on the human body and that, in operation, acts to cool the human body. The present invention also relates to a method of cooling the human body.

Excessive exposure to heat can result in hyperthermia which occurs when the body produces or absorbs more heat than it can dissipate. The heat-regulating mechanisms of the body eventually become overwhelmed and unable to effectively deal with the heat, and body temperature climbs uncontrollably. This is a medical emergency that requires immediate medical attention. A person wearing a protective garment, such as for example, a vest incorporating body armour, may have a higher risk of hyperthermia as protective garments are often heavy and have low moisture permeability which prevents evaporation of sweat.

A known armoured vest includes a cooling system comprising a fan, which on activation creates a continuous flow of air up the front and back of the vest to evaporate sweat and cool the wearer. However, the air quickly becomes saturated with sweat so sweat is only evaporated from the area around the air entry point and the cooling capability is thus limited.

The present invention provides an improved wearable apparatus for cooling the human body.

The present invention relates to a wearable apparatus for cooling the human body, comprising:

air flow creation means,

a controller for controlling the created air flow,

at least one duct connected to the air flow creation means,

wherein the duct comprises a porous portion configured to direct a flow of air to a region of the human body and

wherein in operation the controlling means controls the air flow to intermittently allow air to flow through the duct. The apparatus of the invention provides intermittent flow of air onto the region of the body and increases the perceived cooling effect for the wearer compared to a continuous flow of air. Embodiments of the invention may also provide lower energy consumption compared to continuous air flow. The increased perceived cooling effect is because in normal circumstances the wearer becomes used to a continuous flow and ceases to perceive its cooling effect. In contrast, intermittent cooling maintains the stimulation of skin thermoreceptors and thereby the perception of cooling.

Preferably the wearable apparatus comprises a plurality of ducts, each comprising a porous portion configured to direct a flow of air to a particular region of the human body, and wherein in operation the controller sequentially directs the air flow to one or more of the plurality of ducts to provide intermittent air flow through any particular duct. The apparatus thereby enables multiple areas of the body to be intermittently cooled by the air flow. The total area of the body made up by the multiple areas can thus be cooled using less energy than if all the multiple areas were continuously cooled. The flow may be directed to one or more ducts at any particular time. Repeatedly moving the location of the air cooling also results in the evaporation of sweat over a larger surface area of the body than would be seen with one constant supply that quickly becomes saturated.

More preferably, wherein in operation when the air flow is directed to a particular duct or ducts, the controller varies the air flow rate through the duct or ducts. The air flow through a particular duct can thus be varied to provide optimal cooling effect by, for example, providing a gradually increasing flow rate.

The controller may comprise one from the group consisting of: a disc valve; a sleeve valve; and a solenoid valve. The controller preferably comprises a sleeve valve having,

an inner rotatable portion, with one or more cut-out areas, and

an outer portion connected to the one or more ducts,

wherein the sleeve valve is configured such that during rotation of the inner portion the cut-out(s) is(are) periodically aligned with a duct(s) to allow air to flow intermittently through the duct(s). Such a sleeve valve can provide good performance with low power consumption.

Preferably the duct(s) is(are) adjustable in length so the wearer can adjust the duct to provide air flow to the desired region of the body. The adjustability of the duct length also allows the apparatus to be comfortably worn by wearers of differing body size.

The porous area of the duct may comprise one or more openings in the duct. One or more of the openings may be covered with a layer of air-permeable fabric to create diffuse air flow out of the duct.

To further increase the cooling capability of the invention the apparatus may further comprise a liquid reservoir and means to direct a misted layer of liquid onto a region of the body to which airflow is directed.

The apparatus of the invention can advantageously be incorporated into a garment and in particular into a protective garment, such as a protective vest.

The present invention also relates to a system comprising a protective garment and an undergarment worn underneath the protective garment wherein the undergarment has a perforated area that corresponds to the regions where air flow is to be directed. The undergarment beneficially provides extra comfort for the wearer, for example in the form of padding, without compromising the cooling capability.

The apparatus of the invention may also be attached to or incorporated into a separate garment that is worn between the protective garment and the undergarment or alternatively worn as a stand-alone cooling garment.

The garment preferably comprises at least one spacer section to space the duct(s) from the body of the wearer. The at least one spacer section is preferably foam, or more preferably reticulated foam.

The invention also relates to a method of cooling a human body, comprising the steps of:

a) first directing an air flow from an air flow creation means through a first duct to a first region of the body, and b) subsequently directing the airflow from the air flow creation means through a second duct to a second region of the body; and repeating steps a and b.

As described above with reference to claim 1 , this method has the advantage that the cooling provided to areas a and b is intermittent, thereby increasing the perceived cooling effect for the wearer and also leading to an increased physiological cooling effect compared to continuous air flow. Preferably the method may also comprise the step of misting fluid onto the body to increase the cooling effect of the method.

A further aspect of the invention relates to a wearable apparatus for cooling a human body comprising:

a liquid reservoir,

a pump and distribution means,

wherein the distribution means is configured to mist liquid onto at least one portion of the human body.

Preferably the apparatus also comprises air supply means to supply a flow of air directed to the portion(s) of the human body onto which the liquid is misted.

Exemplary embodiments of the invention will now be described with reference to the accompanying figures.

Brief description of drawings

Figure 1 schematically shows an embodiment of the apparatus of the invention incorporated into a protective vest.

Figure 2 schematically shows an alternative embodiment of the apparatus of the invention incorporated into a protective vest.

Figure 3 schematically shows a cross section through a protective vest incorporating an embodiment of the apparatus of the invention. Figure 4 schematically shows a cross section through the vest of figure 3 in a folded configuration.

Figure 5 schematically shows an embodiment of an air flow creation means and a sleeve valve as distributor.

Figure 6 schematically shows an embodiment of a combined air and water supply means.

Figure 7 schematically shows an embodiment of an undergarment in accordance with the invention.

Description

Figure 1 shows a representation of a body-facing portion of a protective vest 1. Air supply unit 2 is demountably fitted to a side of the vest to allow unrestricted movement, the side of the vest being the part of the vest extending under the arm of the user. The air supply unit 2 is preferably fitted to the vest via quick release fitting. This allows quick and easy replacement should the air supply unit fail. The air supply unit comprises a power source (not shown), preferably in the form of one or more batteries or a fuel cell. The battery(s) are preferably rechargeable. The power source may also comprise one or more photovoltaic cells. The air supply unit 2 also includes air flow creation means (not shown) in the form of, for example, a blower or a fan and more particularly a radial blower, axial fan or double axial fan. The double axial fan may be counter-rotating. Air supply unit 2 also comprises a distributor (not shown) to distribute the air flow. The distributor may be in the form of a disc valve, sleeve valve or a manifold with solenoid valves. The unit 2 is activated using switch 2a. The air supply unit 2 may comprise a filter unit (not shown) to filter indrawn air, the filter preferably being replaceable.

In this particular embodiment three ducts 3 are connected to unit 2.The ducts are preferably made of elastomeric material. The ducts 3 each comprise a porous portion, configured to direct a flow of air to a region of the back or chest of the wearer. In this particular embodiment the porous portion of each duct comprises multiple openings 4. The openings are preferably configured act as microjets to provide directed positive air flow to the body. The jets of air from the openings are preferably sufficient to disturb the boundary layer of air in contact with the skin and thereby assist in the evaporation of sweat.

Alternatively the ducts could comprise one or more openings, the openings being covered with a layer of air-permeable fabric to create diffuse air flow out of the duct 3 towards the body.

At least one section of spacer material 8, preferably comprising foam and more preferably in the form of reticulated foam, is positioned between the ducts to space the ducts from the body of the wearer and to prevent the ducts being crushed. The spacer foam also acts to create air ways to the exterior of the garment through which air saturated with moisture, eg sweat, can be vented to the atmosphere. The spacer foam may be positioned between each pair of ducts.

In operation the user wears the vest on their upper body with the ducts positioned on the inside of the vest. The air supply unit is activated by switch 2a. On activation of switch 2a, the power source supplies power to the air flow creation means and an air flow is created. The power source also supplies power to the distributor which operates to direct the air flow to one or more ducts for a predetermined period of time t, and once time t has elapsed the distributor operates to direct the air flow to one or more different ducts for time t. This process is repeated until the switch is activated to turn switch 2a off. The distributor thereby provides intermittent flow to each of the ducts and the wearer obtains the benefit of spatially intermittent air flow. The time t for which air flow is supplied to a particular duct or ducts may be varied. The air flow rate may be constant over time t or may be varied over time t, caused for example by varying the power supply to the air flow creation means. The air flow rate may be adjusted automatically by means of a programmable controller in unit 2 or may be adjustable by the user.

A high flow rate can also be used to create jets of air from the openings, sufficient to disturb the boundary layer of air in contact with the skin and assist in the evaporation of sweat. Figure 2 shows an embodiment with an alternative configuration of the ducts 3 and air supply unit 2. For conciseness reference numerals are used consistently to denote the same features throughout. The air supply unit 2 is fitted to the lower part of the front or back portion of the vest 1 and eight ducts 3 are each configured to direct air flow to a particular region of the chest or back of the wearer.

In an alternative embodiment the apparatus may comprise five ducts.

The duct system, comprising the ducts 3, may be integrally fabricated by thermoforming, and preferably by vacuum forming. The system is preferably formed in two parts each having the necessary channels before joining the two parts to form the duct system.

Figure 3 schematically shows a cross section through a protective vest fitted with the apparatus of the invention. The vest comprises soft armour 5 and hard armour 6. When worn the front and back sections of the vest are releasably fastened together by fastener portion 7, using Velcro (TM) as an exemplary fastener. As shown in figure 1 , the air supply unit 2 is demountably fitted to the side of the vest. The ducts 3 extend across the front and rear of the vest so air can be directed to both the chest and back of the wearer. The ducts are connected via flexible portions 3a to the air supply unit 2. The flexible portions 3a allow the vest to be folded when not in use as shown in figure 4, thereby taking up less space when being transported etc.

Preferably the ducts are made adjustable in length by including, for example, a folded or concertinaed section which can be pulled and compressed to elongate and shorten the duct.

Figure 5 shows air flow creation means in the form of fan 20, and a distributor in the form of sleeve valve 21. The sleeve valve comprises an inner rotating sleeve 21a (indicated by perforated lines) and an outer sleeve 21b. The inner sleeve is driven to by motor 23 via driving gear 24 and driven gear 25. The inner sleeve 21a has a plurality of openings or orifices or cut-outs 22 positioned a different points on the circumference of the inner sleeve. The outer sleeve 21b has multiple exit ports in the form of openings 27 to which, in use, the ducts are connected. Motor 23 drives the inner sleeve preferably at between 0.1 and 6 rpm. As the inner sleeve rotates different openings 22 line up with the exit ports 27 to allow air to pass to the duct connected to the particular exit port 27 as can be seen at 26.

Figure 6 schematically shows a combined air and water supply system. The fan 20 and sleeve valve 21 are as described with reference to figure 5. The ducting 31 is preferably in the form of moulded rubber ducting which is preferably attached to an inner surface of a garment (not shown).To further improve the cooling performance, the apparatus comprises a reservoir 37 of cooling fluid, such as water, and pump 36 for the water. The pump 36 is connected to water distribution system 33 which comprises means for misting water onto the body, preferably in the form of microjets 34. The microjets 34 are preferably positioned in proximity to the air openings 32. The additional water provided to the body of the user improves the evaporative cooling effect.

Figure 7 schematically shows an undergarment 10 for wearing underneath the protective vest. The undergarment comprises a perforated section 11 , preferably a mesh material, with the remainder of the garment being preferably being made from a wicking material. The perforated section preferably corresponds substantially to the area of the body to which air is to be directed. The undergarment may comprise a perforated section front and back. The undergarment preferably also comprises padded sections 12 for the comfort of the wearer.

The apparatus of the invention may also be attached to a separate garment that is worn between the protective garment and the undergarment or alternatively worn as a stand-alone cooling garment.

The present invention also relates to an apparatus comprising one single duct, the duct being connected to an air supply unit, the air supply unit comprising a power source, air flow creation means and a controller. When the air supply unit is activated by being switched on, the controller repeatedly supplies and disconnects power to the air flow creation means thereby creating intermittent air flow to the duct and consequently the particular region of the body to which the duct directs air flow through its porous portion. Features described with respect to a particular embodiment are not limited to that embodiment and may be incorporated into other embodiments.

Claims

1. Wearable apparatus for cooling a human body comprising:

air flow creation means,

a controller for controlling the created air flow,

at least one duct connected to the air flow creation means,

wherein in operation the controlling means controls the air flow to intermittently allow air to flow through the duct.

2. Apparatus according to claim 1 , wherein the apparatus comprises a plurality of ducts, each comprising a porous portion configured to direct a flow of air to a particular region of the human body, and wherein in operation the controller sequentially directs the air flow to one or more of the plurality of ducts to provide intermittent air flow through any particular duct.

3. Apparatus according to claim 1 or 2, wherein in operation when the air flow is directed to a particular duct or ducts, the controller varies the air flow rate through the duct or ducts.

4. Apparatus according to claim 2 or 3, wherein the controller comprises one from the group consisting of: a disc valve; a sleeve valve; and a solenoid valve.

5. Apparatus according to any of claims 2 to 4,

wherein the controller comprises a sleeve valve having,

an inner rotatable portion, with one or more cut-out areas, and

an outer portion connected to the one or more ducts,

wherein the sleeve valve is configured such that during rotation of the inner portion the cut-out(s) is(are) periodically aligned with a duct(s) to allow air to flow intermittently through the duct(s).

6. Apparatus according to any preceding claim, wherein the duct(s) is(are) adjustable in length.

7. Apparatus according to any preceding claim, wherein the porous area of the duct(s) comprise at least one opening in the duct(s).

8. Apparatus according to claim 7, wherein the or each opening is configured to direct a jet of air to the body.

9. Apparatus according to claim 7, wherein at least one opening is covered with a layer of air-permeable fabric to create diffuse air flow out of the duct.

10. Apparatus according to any preceding claim, further comprising a liquid reservoir and means to direct a misted layer of liquid onto a region of the body to which airflow is directed.

11. A garment, preferably a protective garment, comprising the apparatus of any preceding claim.

12. A garment according to claim 11, wherein the garment comprises at least one spacer section to space the duct(s) from the body of the wearer.

13. A system comprising the garment of claim 11 or 12 and an undergarment worn underneath the garment

wherein the undergarment has a perforated area that corresponds to the regions where air flow is to be directed.

14. A method of cooling the human body comprising the steps of:

c) first directing an air flow from an air flow creation means through a first duct to a first region of the body, and d) subsequently directing the airflow from the air flow creation means through a second duct to a second region of the body; and repeating steps a and b.

15. The method according to claim 14 wherein step a and/or b also comprises misting liquid, preferably water, onto the body.

16. A wearable apparatus for cooling a human body substantially as hereinbefore described and with reference to the accompanying figures.