WO2011098761A1

WO2011098761A1 - Headwear

Info

Publication number: WO2011098761A1
Application number: PCT/GB2011/000174
Authority: WO
Inventors: Julian Joshua Preston-Powers
Original assignee: Julian Joshua Preston-Powers
Priority date: 2010-02-09
Filing date: 2011-02-09
Publication date: 2011-08-18
Also published as: GB2489389A; GB201214240D0; GB201002055D0

Abstract

Headwear comprises gas storage means connected to means for distributing the gas from the gas storage means to other parts of the headwear at a reduced temperature.

Description

Headwear

TECHNICAL FIELD The present invention relates to headwear comprising an internal cooling device. Such headwear is particularly suited to use as or in conjunction with safety headwear, such as motorcycle helmets.

BACKGROUND

It has long been recognised that deterioration in the comfort, mental acuity and cognizance of wearers of protective headwear is improved when normothermic state is maintained. Cooling has also been noted to be particularly effective when applied directly to the head as a network of small veins dissipates heat from the cranium through emissary capillaries.

The human skull has many small holes passing through it, known as emissary foramina, through which veins transport (hot) blood from the scalp into the venous sinuses. The blood transported to the surface of the head is cooled by the surrounding environment and by sweat evaporating from the surface of the skin, before re-entering the skull at a lower temperature, to help keep the brain cool. This explains how cooling the head at the surface can produce significant cooling within the human brain, even at significant depths within the skull, more quickly than would be expected to be achieved through mere thermal conduction.

A typical motorcycle safety helmet may be a full-face motorcycle safety helmet (that is, a helmet which substantially fully encloses the wearer's head and face and extends around the region in front of the wearer's mouth and chin). The helmet includes a helmet main body which has an opening through which the rider can see, and a visor which is selectively raisable and lowerable either to expose the rider's face, or to enclose the rider's face so as to deflect wind and debris.

The helmet main body is a layered shell which encloses a rider's head when worn. The main body comprises a relatively thin rigid outer shell , a relatively thick layer of impact absorbing material and an inner comfort layer. The inner comfort layer is provided between the impact absorbing material and a user's head, to provide a comfortable tactile surface against the wearer's head when worn, and to provide softer localised padding so that the helmet will fit tightly and comfortably in place during normal use.

The inner comfort layer typically provides an air gap or channel to allow for ventilation around the wearer's head, and may take the form of a removable washable liner.

Motorcycle helmet design necessarily represents a trade-off between the level of safety and protection which the helmet can provide in an impact and the practicality with which the helmet can be worn when riding a motorcycle. Theoretically, the impact absorbing material could be provided as a very thick construction, in one or more layers of varying degrees of density, so as to provide extensive progressive cushioning to the wearer's head during an impact.

On the other hand, the helmet has to be of an overall size and shape that the motorcycle rider can wear it without undue interference from wind resistance and wind noise, and it must not be too heavy. Motorcycle helmet design has increasingly been driven towards smaller, more lightweight design, as newer materials have enabled existing safety standards to be met and surpassed with progressively more compact and lightweight configurations.

Nevertheless, despite advances in helmet safety design, those who wear such motorcycle safety helmets still suffer great build-up of heat within the safety helmet. One problem in this regard is that even with recent claims of improvement in the cooling of motorcycle helmets, for instance, due to the energy absorbent layer of expanded polystyrene being in close proximity to the scalp, which is critical for best fit and performance, significant cooling has been hard to achieve.

United States patent publication US 5 950 234 A l , to Leong et al, discloses a cooling pack head covering. The cooling pack is intended to be worn so as to cover the scalp of a patient undergoing chemotherapy treatment. It is contemplated that the cooling pack may be a chemical cold pack, in which chemicals in a container become cold when they are mixed together by breaking a barrier which otherwise separates them. The cooling pack is generally circular and has a "V" shaped notch formed therein to enable the pack to be wrapped around and secured to a patient's head, in a generally bowl shape. It is contemplated that, if an American football helmet were to be used, then the cooling pack might be formed in multiple parts to fit in the helmet, with the objective of cooling the wearer's scalp to a temperature which will minimise hair loss. The cooling pack must be activated before being put on, and has no means by which to activate the cooling pack whilst being worn.

Further United States patent publication US 5 469579 A l , to Tremblay et al, discloses a head cooling device for mounting over a person's head, generally within headgear or a safety helmet, such as the construction hats worn on building sites. The head cooling device is configured to sit within the hat or helmet of a wearer, and to contain ice cubes therein.

As the ice cubes melt, the head cooling device allows the melting water to pass one drop at a time onto the wearer's scalp, so as to absorb and extract heat from the wearer's head. US patent publication US 5 755 756 A l, to Freedman, Jr. et al, discloses a hypothermia- inducing resuscitation unit which includes a helmet adapted to be mounted on the head of a patient. A coolant source is pumped from external of the helmet into a bladder which is inflatable to achieve a tight fit over the head of a patient, and to provide cooling to the patient's head.

SUMMARY OF THE INVENTION

According to a first aspect of the present invention, there is provided headwear comprising a circumcranial network of porous tubing or membrane attached to a small compressed gas canister with a trigger to initiate a release of compressed gas within the safety helmet whilst being worn on a wearer's head. An ancilliary benefit of this invention is that a section of porous tubing could be routed along the upper frontal edge of the helmet near the visor in order to remove fog build-up that is dangerous to the helmet wearer on the inside of the visor. Preferably, the trigger is arranged to nearer the front of the safety helmet so that the wearer can initiate the release of the cooling gas by pushing a button when needed. The trigger could also be thermostatically controlled to trigger in response to detection of potentially dangerous levels of heat build-up in the headwear. This would be especially beneficial in extremely hot climates. Most preferably, the headwear is a motorcycle safety helmet but the system could be applied to all forms of safety helmets. In one form, the trigger includes a plunger for opening the hole in the membrane. In another form, the membrane or trigger comprises a shape memory alloy, or a shape memory structure, in a first memorized state and is configured to open holes in the membrane in response to a change in the tempreture inside the helmet. In yet further preferred embodiments, the trigger comprises a shape memory alloy, or a shape memory structure, in a first memorized state and is configured to initiate the reaction in response to a change in the shape memory state to a second memorized state.

In even further preferred embodiments, the trigger comprises an element of thermoreactive material for initiating the release of gas in response to a signal generated by said detection.

According to a second aspect of the present invention, there is provided headwear comprising a gas expansion cooling device for cooling a wearer's head and a trigger to initiate release of the gas from a pressurized container into a decompression region adjacent to or in a region of the headwear that is configured to enclose the head of a wearer.

In preferred embodiments of the motorcycle safety helmet of the fourth or fifth aspect, the cooling gas that may in that case be distributed in tubing layer arranged to encompass substantially all or a part of the head of a wearer.

In an embodiment of the present invention, cooling of the gas is achieved wholly or partly by means of a vortex tube which is incorporated in the headwear.

A vortex tube, known also as the "Ranque Vortex Tube", the "Hilsch Tube ", the "Ranque- Hilsch Tube", and "Maxwell 's Demon", uses compressed air as a power source, has no moving parts, and produces hot air from one end and cold air from the other. The volume and temperature of these two airstreams are adjustable with a valve built into the hot air exhaust. Temperatures as low as -50°F (-46°C) and as high as +260°F (127°C) are possible.

Compressed air is supplied to the vortex tube and passes through nozzles that are tangent to an internal counterbore. These nozzles set the air in a vortex motion. This spinning stream of air turns 90° and passes down the hot tube in the form of a spinning shell, similar to a tornado. A valve at one end of the tube allows some of the warmed air to escape. What does not escape, heads back down the tube as a second vortex inside the low-pressure area of the larger vortex. This inner vortex loses heat and exhausts through the other end as cold air. A motorcycle safety helmet which includes, incorporates or embodies headwear according to the present invention is able to provide significant cooling to the rider without the need to remove the helmet from time to time to cool down the scalp.

Deterioration of mental acuity and vision could be immediately improved with the press of a button and accidents may be avoided.

BRIEF DESCRIPTION OF THE DRAWINGS

To enable a better understanding of the present invention, and to show how the same may be carried into effect, reference will now be made, by way of example only, to the accompanying drawings, in which :-

Figure 1 is a cross-sectional side view, showing a diagrammatic representation of the key constructional elements of a motorcycle safely helmet main body;

Figure 2 is an enlarged cross-sectional view of a portion of the motorcycle main body of Figure 2, indicating diagrammatically the manner in which forces are distributed and absorbed in the motorcycle safety helmet during an impact; and Figure 3 is a rear view of the helmet showing the gas distribution network.

DETAILED DESCRIPTION

It will be appreciated that although the illustrated embodiments of the motorcycle safety helmet of the present invention are illustrated as full-face safety helmets, other known forms of motorcycle safety helmet may be adapted to incorporate a suitable cooling system triggering device, according to the principles set forth herein. Specifically, endothermic reactors and triggering devices arranged in accordance with the principles of the present invention may be applied to so-called open-face or three-quarter helmets, which still provide protection over the ears of a wearer but leave the lower face and chin exposed; half-helmets, which provide protection only to the top of the wearer's head; and flip-face helmets, which have a flip-up chin bar and visor, allowing the helmet to convert between a full-face configuration and an open-face configuration.

The rigid outer shell 10 is typically 3 to 5 mm thick and is normally either an injection- moulded thermoplastic or a pressure-moulded thermoset reinforced with glass or Kevlar fibres. Polycarbonate outer shells are widely used. The specific material and type of construction selected for the rigid outer shell is, however, not critical to achieving the advantages obtainable with the present invention.

The inner comfort layer 30 is provided usually as a combination of soft padding and a breathable mesh, to ensure that the motorcycle safety helmet is a comfortable fit during normal use, and to ensure that it is held appropriately in place on the user's head, to prevent the helmet from moving around and interfering with the concentration and vision of the motorcyclist.

The motorcycle safety helmet main body 3 includes a gas cylinder 20. Extending from cylinder 20 is a serpentine arrangement of rubber tubing 22 which conveys cooled gas, released from cylinder 20, over the whole inner surface of the helmet.

Other known cooling gases, which might be utilised in place of liquefied or pressurised oxygen, are:

• liquefied or pressurised oxygen and hydrogen combined;

· nitrogen;

• helium

These gases could be released into the interior of the helmet, between the impact absorbing material 24 and the inner comfort layer 30, so as to provide cooling to the inside of the helmet as the gas expands. The gas expansion passage within the helmet could be appropriately configured so as to vent the expanded gas into the atmosphere after release and cooling of the helmet interior. Such form of cooling would, however, be more appropriate for alternative items of headwear than a motorcycle safety helmet, which is liable to suffer extreme impacts, as well as substantial temperature variations. Such gas expansion cooling, however, might find ready application to a headwear item suitable for use by paramedic teams in the initial treatment of head injury victims. The cooling of the internal region of the helmet not only provides immediate commencement of the cooling process when needed, but offers the significant advantage, in a motorcycle safety helmet application, of providing cooling to the motorcyclist's head without having to remove the motorcycle safety helmet. It is advisable not to move the victim of a motorcycle traffic accident, if safe and reasonable not to do so, in case they have suffered spinal or neck injuries. If they have, attempting to move the accident victim or to remove the motorcycle safety helmet could result in causing damage to the spinal column; motorcycle safety helmets should only be removed once an experienced medical practitioner has had opportunity to assess whether it is safe to remove the helmet. Whilst the invention has been described above with reference to specific exemplary embodiments, it is contemplated that practical applications will emerge in a number of areas. For example, helmets are worn in the majority of high-speed non-contact sports, such as motorcycle and motorcar racing, downhill skiing, etc. Similar safety helmets are also worn by the pilots of jet planes, as well as by police and military personnel. Helmets are also worn in certain contact sports, such as American football and ice hockey, although these sports necessarily involve significant amounts of contact, which could tend to induce triggering of the endothermic reactor in a non-critical event.

Claims

1. Headwear comprising gas storage means, means connected to the gas storage means to distribute the gas from the gas storage means to other parts of the headwear, and means to release gas at a reduced temperature from the gas storage means to the distribution means.

2. Headwear according to Claim 1 , wherein the release means includes a trigger to initiate inner helmet cooling around the scalp, while the helmet is being worn.

3. The headwear of Claim 1 or Claim 2, wherein the trigger is arranged to initiate the cooling reaction in response to the trigger or system activation button on the headwear.

4. The headwear of any of the preceding claims, wherein the trigger is arranged to initiate the reaction in response to an input on the headwear by the wearer.

5. The headwear of Claim any of the preceding claims, wherein the headwear is a helmet for protection of a wearer's head from impacts.

6. The headwear of Claim 5, wherein the headwear is a motorcycle safety helmet.

7. The headwear of Claim 4, wherein the trigger is arranged to initiate the reaction in response to a force or heat generated in the headwear by the temperature exceeding a threshold magnitude.

8. The headwear of Claim 7, wherein at least one of the reagents is contained in a layer of tubing arranged to encompass substantially all or a part of the head of a wearer.

9. The headwear of Claim 7, wherein the membrane or trigger comprises a shape memory alloy, or a shape memory structure, in a first memorized state and is configured to open a hole in the membrane in response to a change in the shape memory state to a second memorized state.

10. The headwear according to any preceding claim, wherein the trigger comprises a shape memory alloy, or a shape memory structure, in a first memorized state and is configured to initiate the reaction in response to a change in the shape memory state to a second memorized state.

1 1. The headwear according to Claim 2, wherein the trigger comprises an element of thermoreactive material for initiating the reaction in response to a signal generated by said detection.

12. The headwear according to any preceding claim, wherein the cooling device is configured to reduce the inner helmet temperature after active input from the rider.

13. Headwear comprising a gas-expansion cooling device for cooling a wearer's head and a trigger to initiate release of the gas from a pressurized container into a decompression region adjacent to or in a region of the headwear that is configured to enclose the head of a wearer.

14. Headwear comprising a reagent package arranged to remove heat energy from a wearer's head when activated by wearer activated trigger or button.

15. A motorcycle safety helmet comprising:

- a rigid outer shell;

- a layer of impact absorbing material inside the rigid outer shell;

- a cooling system, substantially contained inside the rigid outer shell, containing one or more gases which will react together in an endothermic reaction to absorb heat from inside the helmet; and

- a trigger arranged to initiate the endothermic reaction in the reactor, whilst being worn on a wearer's head, in response to detection of an excessive heat or input by the wearer.

16. A motorcycle safety helmet comprising:

- a rigid outer shell;

- a layer of impact absorbing material inside the rigid outer shell;

- a comfort cooling system, substantially contained inside the rigid outer shell, containing one or more gases which will react together in an endothermic reaction to absorb heat from inside the helmet; and - a trigger arranged to initiate the endothermic reaction in the reactor, whilst being worn on a wearer's head, in response to an input by the wearer of the helmet.