Gas distribution garment

Abstract

A garment for cooling the body of a wearer is described which comprises a substantially gas impermeable first substrate and a gas-permeable second substrate attached to form a cavity. At least one of the first and second substrates comprising a plurality of raised protrusions on a surface within the cavity, and the gas permeable second substrate comprising a plurality of raised protrusions on the surface external to the cavity and proximate to the body of the wearer. The cavity is adapted to be connected to a gas supply such that the gas flows into the cavity and exits the cavity through the gas permeable second substrate. The cooling garment is light weight and conformable, and may be non-tethered for portability.

Description

FIELD OF THE INVENTION [0001] The present invention relates to a personal gas distribution garment, preferably a ventilated cooling garment. One embodiment is directed to a ventilated cooling garment for use by a wearer who is clad in a sealed overall suit and breathing system which is designed to protect the wearer from harmful chemical, biological or other environmental hazards. It is also a function of the ventilated cooling garment of the present invention that it may be adapted to use filtered ambient air as the ventilating cooling medium. Further desirable attributes of the garment are high cooling power, low weight, low bulk, good flexibility, and high water vapour permeability, all of which contribute to the comfort of the wearer. BACKGROUND OF THE INVENTION [0002] It is well known that subjecting a person to prolonged periods of inadequate heat dissipation leads to an increase in body temperature (heat stress), indicated by undesirable effects such as discomfort, increased ...

AI Technical Summary

Benefits of technology

[0007] The present invention is directed to a gas distribution garment system which can be used with sealed garments such as are used in hazardous or toxic environments, as well as in other applications where the subject is exposed to high heat stress situations such as fire-fighters, clean room operatives or hospital theatre operatives. In a preferred embodiment, a gas distribution cooling garment system most conveniently comprises a vest which delivers cooling air only to the torso, but may also be a jacket with sleeves, a coverall with sleeves and legs, or any other form which delivers cooling air to specific areas of the body. For optimum comfort and cooling efficiency it is desirable that the garment conforms closely to the body shape of the wearer.

[0012] A further object of the invention is to provide a cooling garment which comprises substrates having high water-vapour-permeability thereby minimising the build-up of perspiration on the wearer's body even when the garment is not supplied with cooling gas.

[0014] In one preferred embodiment, the garment is in the form of a vest, and in use the second substrate will form the inside of the vest such that gas exiting the cavity through the gas-permeable second substrate will flow over the torso of the wearer. The plurality of discrete elements on the surface of the second substrate external to the cavity provides a space between the substrate and either the body of the wearer or any other garment worn thereon. The height of the discrete elements are chosen such that the space between the wearer's body, or any other clothing worn next to the wearer's body, and the gas permeable second substrate is sufficiently wide to allow uniform flow of cooling gas but not so wide that it reduces the cooling effect of the gas. The in-plane spacing between the discrete elements is optimised to distribute the flow of gas exiting the cavity and give substantially uniform cooling of the torso.

[0015] The plurality of discrete elements on one or both surfaces of the substrates within the cavity provides a space between the surfaces thereby allowing optimal distribution of the cooling gas within the cavity, and therefore across the wearer's body.

[0017] The plurality of discrete elements contributes to increased conformability of the garment of the present invention by allowing flexing between protrusions compared with prior art garments which utilise mesh or mesh-like spacers. The flexibility of substrates suitable for use in the present invention, having a pattern or plurality of discrete elements thereon, is not substantially less than the flexibility of substrates without any discrete elements. In contrast, the three dimensional structures of the mesh or mesh-like spacers of the prior art lack flex points and they are generally bulky and stiff; therefore the use of these structures results in garments having poor flexibility and conformability.

[0018] Furthermore, the plurality of discrete elements also result in a garment construction having lower resistance to gas flow compared with garments of the prior art that utilise mesh or mesh like materials as spacers. Mesh spacers are constructed with material that can interfere with the air flow, whereas materials of the present invention have no intervening material between the discrete elements to interfere with air flow. The low resistance to gas flow afforded by the discrete elements facilitates the use of low power fans to supply cooling gas to the invention and obviates the need for the garment to be “tethered” to a power supply or a high pressure supply of cooling gas. Thus, a preferred embodiment comprises a “portable” or “non-tethered” gas distribution garment system which, as used herein, refers to a system which is not tethered to a (stationary) power supply or a high pressure gas supply. The cooling gas may be ambient air blown into the cavity by battery powered fans which may be optionally fitted with filter elements or other gas treatment systems to remove noxious or other undesirable contaminating components.

Problems solved by technology

It is well known that subjecting a person to prolonged periods of inadequate heat dissipation leads to an increase in body temperature (heat stress), indicated by undesirable effects such as discomfort, increased fatigue, decreased physical and intellectual performance and, in extreme cases, death.

Body core temperatures in excess of 38° C. will, for example, lead to impaired decision making and increased reaction times whereas core temperatures in excess of 40° C. can cause physiological damage and fatalities.

Personnel such as fire-crews, “hazmat” operatives such as those working on toxic or generally hazardous cleanup operations, and chemical plant operatives handling hazardous products are potential victims of such heat stress.

Such personnel have usually to wear virtually totally sealed garments which severely inhibit cooling effects that would naturally occur due to ambient air flow over the persons skin and clothing.

Given the multi-layer construction of the garment and the inclusion of the corrugated spacer layer the flexibility, fit and comfort of the garment would be severely compromised and would be unlikely to meet the desirability criteria defined supra.

Also, the relatively high resistance of the mesh fabrics to the flow of air necessitates a high pressure air source not readily available in a portable (or non-tethered) system.

Given the small areas over which the cooling air is vented relative to the total area of the torso, the cooling power of the garment disclosed in this reference is likely to be severely limited and not meet the cooling criteria previously defined.

One distinct shortcoming of such a system is the absence of any intermediate layer to control airflow within the cavity resulting in uneven air distribution.

A further shortcoming is the lack of a means for controlling air distribution between the inner air permeable layer and the body of the wearer.

The absence of such mechanisms may cause excessive cooling of some areas of the wearer's body, especially next to the air inlet port, while not supplying sufficient cooling in other areas.

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