GB2340381A

GB2340381A - A Safety Helmet with Variable Hearing Protection

Info

Publication number: GB2340381A
Application number: GB9820262A
Authority: GB
Inventors: Mark Playle
Original assignee: Individual
Current assignee: Individual
Priority date: 1998-08-14
Filing date: 1998-09-18
Publication date: 2000-02-23
Also published as: GB9820262D0; GB9817601D0

Abstract

A protective helmet (15) comprises a rigid shell (1), an inner lining (2) containing at least one inflatable cell (3R,3L), and inflation /deflation means. The inflation of the cells (3R,3L) transports the ear cups (10R, 10L) towards the ears to provide variable hearing protection. The cups (10R, 10L) may also be pads or material forming the inner barrier of the lining (2). The inflation/deflation means comprises a pump (5) and self-acting valves (6,19).Actuation of the pump (5) causes fluid (8) to flow out through valve (6).The valves (6,19) control the flow of air into and out of the pump (5). Deflation of the cells (3R,3L) is achieved by valve means (7).The fluid (8) may be air, a liquid, or a compressed gas. The pump (5) may be driven manually or electrically. The inflation means may be located elsewhere on the wearer or vehicle. The ear cups (10R, 10L) may themselves be the inflatable cells, and may also include micro-speakers.

Description

2340381 AN IMPROVED SAFETY HELMET This invention relates to protective

helmets and hard-hats fitted with integral inflatable cells, inflation and deflation means, and sound insulation barriers.

More particularly it relates to protective helmets and hard-hats typically having a rigid shell, an inner resilient lining, for example crash-helmets; improved by integrally comprising inflatable cells, and sound insulation materials movably positionabie adjacent to the ears. And further incorporating means of inflation, means of deflation, and means of fluid control. The user of the helmet (the wearer) having control over the adjustment of inflatable cells, thereby achieving sound protection and comfort in any ambient sound circumstance, even whenever the helmet is in use.

Helmets and protective hats ( hard-hats) are well known types of headgear used to protect the wearers head from impact by collision with moving and stationary objects, and in the case of crash-helmets to protect the wearer from injury caused by relative movement and collision with objects injurious to the health. Typical activities where these helmets are regularly used being motorcycling, hover-craft racing, aircraft flying, motor-sports, mining, jet-skiing, defence, and the construction and building activities. The shape of helmets vary from those that protect the top of the head from failing objects for example on a building site ( the hard-hat), to open-face, and full-face types that give all-round protection to the wearers head for example those used when operating certain motor vehicles, motorcycles, and transportation craft. The types of helmet previously described, and applicable to this invention, are pictorially identified in Figures 1, 2 and 3 of the accompanying drawings.

Persons wearing these well known types of helmet, achieve protection from ambient, environmental noise and sound is by various methods dependent upon the type of helmet. Additional devices are required that either clip to, or are otherwise attached to the helmet. Examples of well-known ear protection devices being earmuffs ( ear-defenders) often worn outside of the hard hat, and ear-plugs worn in the ears.

Drawbacks of wearing these types of ear protector are that there is no allowance for adjusting the amount of sound protection. All present types providing a fixed amount of sound deadening regardless of the sound intensity, therefore disabling the wearer from hearing ambient sounds even when it is quiet. Additionally two hands are often required to put ear-muffs on the head, and ear-plugs fitted within a helmet require that the wearer removes their protective helmet before the ear-plugs can be inserted or removed.

Accordingly it is a primary objective of this invention to provide an improved protective helmet. A further objective of this invention is to provide an protective helmet of the types previously described, comprising a rigid protective shell, an inner resilient liner, improved by incorporating a self-contained means of variably adjusting the effect of sound insulation adjacent to the ears, even whenever the helmet is in use. In other terms; - improved by incorporating a self-contained means of allowing the wearer to variably adjusting the amount of sound able to reach his or her ears, even whenever the helmet is in use. Additionally a further objective of the said invention is to provide all the merits of the well-known helmets already described including impact protection, vision protection, hearing protection, means of adjusting the amount of sound able to be heard, improved retention on the head, improved comfort and fit, all in a self-contained improved helmet.

Other objects of the invention, along with numerous features and advantages, will become more clear from the summary of the invention, and the detailed description of the preferred embodiments, described below and further in this document.

Accordingly the objects of the invention referred to above, are achieved by way of summary, in a protective helmet typically comprising a rigid shell, and a resilient lining disposed therein. To the sides of the helmet, usually partially in place of the lining, are fitted inflatable cells disposed adjacent to the ears whenever the helmet is in use. Pumping means are integrally provided to enable expansion of inflatable cells, thereby moving sound insulation barrier materials of various shape and form into variable and adjustable proximity of the ears. Self-acting valves are provided to enable incremental inflation, maintain the inflation, and permit deflation of the inflatable cells. Adjustability of the inflatable cells being achieved by inflation of, or deflation of the inflatable cells, thereby varying the air-gap between the sides of the head and ears, and the sound insulation barriers. Further adjustability, described in the embodiments, is achieved using a compressive material, the porosity ( in terms of sound transmission), of which is variable by varying the compressive forces applied to the material.

The well known helmet types referred to in this invention are herewith identified by way of pictorial representation as shown in the accompanying drawings.

Figure 1. Shows a view looking onto one side of a typical full-face type protective helmet 21, as referred to in this invention.

Figure 2. Shows a view looking onto one side of a typical open-face type protective helmet 22, as referred to in this invention.

Figure 3. Shows a view looking onto one side of a helmet or hard-hat with sides extended to cover the ears 23, as referred to in this invention.

In all types of helmets described, namely those identified by numerals 21, 22, and 23, the entire range of embodiments, and variations in form and design, described in this invention, are applicable to all of these helmet types.

The invention summarised in the previous pages of this document will now be described by way of example with reference to the accompanying drawings. Preferred embodiments of the improved protective helmet of the invention identified generally by reference numeral 15 are depicted in Figures 4 through to, and including Figure 21.

Figure 4. Shows a schematic view of one preferred embodiment of the invention, here shown integral with the full-face type helmet, vertical sectional side view through the helmet. Figure 5. Shows a schematic view of one preferred embodiment of the invention, here shown integral with the full-face type helmet, vertical sectional view from the front of the helmet. ( de-pressurised Figure 6. Shows a schematic view of one preferred embodiment of the invention, here shown integral with the full- face type helmet, vertical sectional view from the front of the helmet. ( pressurised Figure 7. Shows a schematic view of another preferred embodiment of the invention, here shown integral with the full-face type helmet, vertical sectional side view through the helmet.

Figure 8. Shows a schematic view of one preferred embodiment of the invention, here shown integral with the full-face type helmet, vertical sectional view from the front of the helmet. ( de-pressurised Figure 9. Shows a schematic view of one preferred embodiment of the invention, here shown integral with the full-face type helmet, vertical sectional view from the front of the helmet. ( pressurised Figure 10. Shows a schematic view of another preferred embodiment of the invention, here shown integral with the full-face type helmet, vertical sectional side view through the helmet, Figure 11. Shows a schematic view of one preferred embodiment of the invention, here shown integral with the full-face type helmet, vertical sectional view from the front of the helmet- ( de- pressurised Figure 12. Shows a schematic view of one preferred embodiment of the invention, here shown integral with the full-face type helmet, vertical sectional view from the front of the helmet. ( pressurised Figure 13. Shows a schematic view of another preferred embodiment of the invention, here shown integral with the full-face type helmet, vertical sectional side view through the helmet. Figure 14. Shows a schematic view of one preferred embodiment of the invention, here shown integral with the full-face type helmet, vertical sectional view from the front of the helmet. ( de-pressurised Figure 15. Shows a schematic view of one preferred embodiment of the invention, here shown integral with the full-face type helmet, vertical sectional view from the front of the helmet. ( pressurised Figure 16. Shows a schematic view of another preferred embodiment of the invention, here shown integral with the full-face type helmet, vertical sectional side view through the helmet. Figure 17. Shows a schematic view of one preferred embodiment of the invention, here shown integral with the full- face type helmet, vertical sectional view from the front of the helmet. ( de-pressurised Figure 18. Shows a schematic view of one preferred embodiment of the invention, here shown integral with the full-face type helmet, vertical sectional view from the front of the helmet. ( pressurised Figure 19. Shows a simplified view of one preferred embodiment of the invention, here shown positioned upon the human head. ( de-pressurised) Figure 20. Shows a simplified view of one preferred embodiment of the invention, here shown positioned upon the human head. ( device partially pressuhsed) Figure 21. Shows a simplified view of one preferred embodiment of the invention, here shown positioned upon the human head. ( device fully pressurised) In all types of said helmets described, namely those identified by numerals 21, 22, and 23, the entire range of embodiments, and variations in form and design, described in this invention, are applicable to all of the helmet types identified.

For the purpose of limiting the size of document relating to this invention, preferred embodiments are shown pertaining to the helmet of the full-face type, however all forms of embodiments of this invention described in drawing pages 2/9, 3/9, 4/9, 5/9, 6/9, 7/9, 8/9, and 9/9, apply to helmet types identified on drawing page 1/9, namely those helmet types denoted by numerals 21, 22, and 23.

Detailed descriptions of the preferred embodiments are set out below, referring now to the Figures, and in particular to Figures 4, 5, and 6, views are shown of one preferred embodiment of the improved protective helmet of the invention identified generally by reference numeral 15.

As best shown in Figures 4, 5, and 6. Generally, the improved protective helmet 15 is comprised of a rigid shell 1, typically constructed from moulded thermoplastic, an example material being polycarbonate, or in more expensive helmets the shell WM material being typically a composite of glass-fibre, kevlar, and sometimes carbon- I fibre in varying proportions. The shell material however may be formed of any material capable of affording a rigid impact protective layer to the human head. A liner 2 consisting of one or more layers, and comprising resilient and cushioning materials is usually positioned internally within the shell 1, and typically in most cases these layers comprising expanded polystyrene, foamed rubber, and soft feltlike materials adjacent to the head. The lining materials however may be formed of any material conformable to the shape of the head, and offering means of dispersing, and damping the forces of impact, and knocks etc.

Disposed to the sides of the improved helmet 15, usually within the shell 1, are fitted inflatable cells 3. Two groups of inflatable cells 3 are identified, one group to the left, one group to the right as shown, denoted by numerals 3L and 3R, each said group comprising at least one inflatable cell. On certain types of helmet where the thickness of the lining 2 is restrictive, it is planned to permit the inflatable cells 3R and 3L to be housed within bulges of the shell 1, or to extend through the shell 1, thereby being deployed within bulges noticeable from the exterior of the shell 1. Pockets are provided in the lining 2 to house the inflatable cells 3R and 3L, giving adequate space for their expansion. The inflatable cells 3R and 3L are so disposed to be in close proximity to the ears, being adjacent to the ears whenever the helmet 15 is fully positioned on the human head. By controlling the inflation pressure of the inflatable cells 3R and 3L, it will be shown that fine control is imparted to sound insulation barriers 4 and associated compressive layers 10 R and 10L. This fine infinitely incremental, and decremental positional control of sound insulation barriers in close proximity to the ears being a vital aspect of this invention. For it is by controlling the inflation and deflation of these inflatable cells, and hence controlling the position of sound insulation barriers that the invention achieves some of its objectives. Inflation and hence expansion of the inflatable cells 3R and 3L, is usually achieved by pump 5 means, and associated self- acting valves 6 and 19. Actuation of the pump 5, is performed by the wearer, repeatedly squashing a squeezable bulb type pump or by repeatedly pressing a tactile membrane type pump accessible from the exterior of the helmet. The pump 5 operates similarly to the well-known displacement pump mechanism generally as follows: Squeezing the squeezable portion of the pump 5, displaces fluid 8 out of the outlet port and valve 6. Loosening one's grip will allow the squeezable portion to return to its original shape, in doing so drawing fluid 8 from a reservoir ( in this case the atmosphere), the fluid drawn in at inlet port and valve 19 Spring-like assistance may be utilised to aid replenishment of the squeezable portion of the pump 5, the associated self-acting valve means controlling the flow of fluid 8 in and out of the squeezable portion ( bulb) of the pump 5. The self-acting valves 6 & 19 incorporated into the pump body as described, will where the need dictates be positioned elsewhere, for example positioned in-line with the passageways 9. The positions, number, and type, of pump 5, and valve means 6 and 19, however are arbitrary, the essential features being the provision an inflation device, of a type already well known.

It is also envisaged that a small electrically driven pump, battery power source, and control switches of the well known type, mounted integral to the helmet could be used to achieve a similar effect. An alternative means of inflation is described later where the pump 5 is substituted for a compressed gas source, whereby a small gas cylinder simultaneously provides the inflation fluid 8 of which it is filled, and additionally means of moving the fluid 8 without integral pumping means being required.

In the embodiments described within this document, the inflation device, whether manual pump, electrically driven pump, or compressed gas source, with associated valves is described as being an integral part of the helmet. Certain circumstances may dictate, for example market requirements and constraints, that the inflation device ( with or without associated valves), be located elsewhere. For example the said apparatus may be attached interior, or exterior to the helmet, wom on the wearers person, slung from the wearers person, or attached to the vehicle being used. The power source may also be similarly remotely located, for example being derived from the vehicles battery. The option however over the inflation method is arbitrary and down to individual preference. The inflation means 5 generally being incorporated into the improved helmet 15, to provide means of moving the fluid 8 from one location to another. The fluid 8 used in this embodiment is air, other gases and fluids are dealt with later.

Self-acting valves 6 and 19 typically of the well known non-retum type permit the pump 5 to displace the fluid 8 from one location to another. The self-acting valves 6 and 19, allowing the passage of fluid 8 in one direction, but substantially block its passage in the opposite direction. Thereby actuation of the pump 5 causing fluid 8 to flow from a reservoir ( in this case the atmosphere) along passageways 9, and into the inflatable cells 3R and 3L causing their expansion. The particular number, arrangement, and design of the inflatable cells 3R, 3L and fluid passageways 9 are a matter of choice for those skilled in the art. The valves 6, and 7, ensure that inflation of the inflatable cells 3R and 3L is maintained for as long as desired, and until deflated by the wearer.

In all of the preferred embodiments the expansion of the inflatable cells 3R and 3L is by sliding, folding, concertina, or elastic means, whereby the volume of fluid 8 introduced into the inflatable cells 3R and 3L is accommodated by elastic deformation of a peripheral elastic seal element, concertina, bellow, z section seal, or by bladder or balloon-like expansion. The arrangement, number, layout, pattern, and design of the inflatable cells 3R and 3L being a matter of choice for those skilled in the art. It is also known that relative movement of a piston and cylinder like arrangement would be construed as an inflatable cell under the scope of this invention. Attached to, or incorporated into, and sometimes inherent to, the inflatable cells 3R and 3L are sound insulation barriers 4. These sound insulation barriers 4 providing means of substantially blocking the passage of sound able to be perceived by the wearers ears within the helmet 15. The sound insulation barriers 4 will here forth be referred to as "acoustic barriers". Said acoustic barriers 4 typically having a concave shape to fit around, and accommodate the ear, although other types are described later. The main function of the acoustic barriers 4, being to protect the ears from injurious sounds by variably shielding the ears from ambient sound, by reducing the transmission, insulating, and absorbing the sound thereby preventing damage to the hearing.

Additional functions of the acoustic barriers 4 being to help retain the helmet on the head, to provide means of incorporating electrically actuatable closeable voids, to provide means of accommodating microspeakers or other communication device, to shield the ears from external sounds thereby ensuring that desired sounds from said communication devices are able to be heard, and to improve the comfort, fit, and feel of the helmet.

For example, materials and/or fluid filled cells formed into a cupped, dished, pancake, annular, or irregular pad shape would constitute an acoustic barrier under the scope of this invention. For example, foams, felts, rubbers, plastics, cotton, woodpulp, powder matrix, fibre matrix, natural fibres, man-made fibres, cells with a sponge-like matrix, closedcell foam rubbers, open-cell foam rubbers, silicon, gas filled cells, fluid filled cells, evacuated cells ( vacuums), and multi-compartment cells; formed into shapes that could be described as being cupped, concave, a flattened cup, dished, saucer like, pancake like, or pad like, would all be construed as constituting an acoustic barrier 4 under this invention. Indeed, almost any materials, regardless of shape or form, moved into adjustable proximity to, in contact with, or surrounding the ear, deployed in ways described within this document would constitute an acousfic barrier under this invention.

The acoustic barriers 4, will optionally incorporate ports ( closeable voids) that are actuatable by electrical means thereby instantaneously opening a channel to the environment exterior to the acoustic barriers 4, thereby providing means of permitting sounds from the external environment to be heard without adjusting the inflation pressure. The said channel to the exterior environment being through the sides of the acoustic barrier 4, or through passageways provided in the shell 1, and the lining 2. This facility will be available for use regardless of the inflation pressure of the inflatable cells 3R and 3L, and useable whenever the helmet is in use. This facility would be of greatest usefulness when for example, the operator is using a noisy piece of equipment, the operator knows when it is noisy, and knows when it is quiet, as he/she is operating the equipment. Thus whenever it is noisy the operator will have inflated the inflatable cells 3R and 3L to achieve comfort and sound protection, additionally he/she would ensure that the closeable void is closed, thereby providing sound protection. Whenever he switches the noise source off, for example to speak, or listen to a colleague, the operation of a switch integral to the helmet 15, opens the closeable void enabling him or her to hear. Operating the switch again closes the closeable void allowing the wearer to restart the noise source and carry on with his or her activity, - without adjustments being made to the inflatable cells 3R and 3L. This facility will especially be provided where it is not possible to incorporate communication devices into the helmet 15, due for example to the type of helmet, or the type of activity being performed by the wearer. This closeable void facility would require electrical actuation means, switching means, power supply means ( battery), and means of transmitting electric current. Additionally small holes in the shell 1, and / or lining 2 may be provided in the sides of the helmet 15 enabling sounds to enter the acoustic barriers 4 whenever the closeable void is opened.

Attached to the said acoustic barriers 4 are compressible layers 1 OR and 1 OL, these compressible layers 1 OR and 10L provide a soft interface where the acoustic barriers come into close proximity of the head, and also as best shown in Figures 19, 20, and 21 the compressible layers 1OR and 10L provide additional means of variable sound transmittance.

It should be noted that information regarding inflation means, deflation means, fluids, storage vessels, valves, fluid control means, passageways, etc. etc. is not provided in Figures 19, 20, and 21 as these aspects are detailed in the preferred embodiments described elsewhere in this document. All alternative arrangements described in those preferred embodiments being selectable and applicable to the preferred embodiments relating to Figures 19, 20, and 21.

Figures 19, 20, and 21 demonstrate the effect of progressively inflating the inflatable cells 3R and 3L. Inflation may be stopped at any point, thus there is an infinite number of inflation pressures and hence positions that can be achieved. Figures 19, 20, and 21 however show only 3 positions - Figure 19 deflated, Figure 20 partially inflated, and Figure 21 fully inflated.

The compressible layers I OR and 1 OL are typically comprised of compressive cellular or porous materials. For example, an open-cell foam rubber, foam rubber with a collapsible membrane covering, or other resilient materials usually containing high proportions of gas, typically air, will readily compress when pushed into contact with the head 20, providing their main function detailed below. Figure 19 shows the air-gap between the head 20 the acoustic barriers 4, and associated compressible layers 1OR and 10L. Figure 19 shows an initial position whereby the inflatable cells are deflated and the acoustic barriers 4 are withdrawn from the ears. This stage allows the helmet to be put on the head 20, the helmet 15 is useable in this state however little gain in terms of retaining the helmet 15 on the head 20, or in hearing protection is provided. Figure 20 shows partial inflation of the inflatable cells 3R and 3L, causing the acoustic barriers 4, and compressible layers 1 OR and 10L to almost contact the head 20, - a small air-gap is apparent allowing a reduced percentage of ambient sound to reach the ears, additionally the helmet 15 is beginning to hold the head 20. Further inflation by methods described causes the inflatable cells 3R and 3L to push the acoustic barriers 4 and associated compressible layers 1 OR and 10L against the sides of the head, or against the ears. As previously described the inflation of the cells 3R and 3L is infinitely variable between constraints, hence there are many inflation pressures not shown, that exist, between Figures 19, 20, and 21. Figure 21 shows the inflatable cells fully extended, their expansion compressing the compressible layer 1 OR and 1 OL, thereby excluding ambient sounds.

The compressible layers 1 OR and 1 OL whilst permitting a degree of sound to pass when uncompressed, will increasingly block the passage of sound as they are increasingly compressed. Thus the acoustic barriers 4 are moved into infinitely incremental and adjustable proximity of the ears, by the action of the inflatable cells 3R and 31---thereby achieving variable hearing protection by varying the air-gap between the sides of the head 20 and the thickness of the compressible layer 1 OR and 10L. It is however obvious, following the disclosure of this invention that, inflation to a set constant pressure, or deflation to a specific pressure will lead to a fixed level of hearing protection.

Deflation of the inflatable cells 3R and 31---is achieved by pressurerelief valve means 7, permitting controlled deflation of the inflatable cells 3R and 3L. In most cases, except where the pump is used to evacuate the inflatable cells 3R and 3L, it is the elastic expansion caused by inflation, and energy stored within the elastic membrane material forming the cells that is used to provide deflation of the inflatable cells 3R and 3L, similar by way of example, to an inflated balloon deflating when its inflation nozzle is opened to a region of lower pressure.

It is envisaged, especially where liquids are used for inflation, to aid the deflation process by inclusion of additional elastic ties within the cells, thereby creating a greater contraction force available for deflation. As the fluid used for this preferred embodiment is air, the air is controllably released by pressure-release valve means 7, and vented to the atmosphere. Intermediate increments of adjustability are achieved by releasing a percentage of the fluid by means of pressure- release valve means 7. Closing the valve 7 before complete deflation has occurred, giving intermediate levels of inflation and hence intermediate and fine incremental adjustability of the degree of comfort, fit, retention, and sound exclusion. Closing the pressu re-re lease valve 7 allows inflation to be performed again as previously described.

Additionally the pressure-relief valve is provided to permit rapid deflation of the inflatable cells 3R and 3L, which amongst other reasons, would be used in the event of an accident occurring to the wearer, permitting the helmet to be quickly removed, perhaps by a third party.

Dependent upon the model of helmet, its intended performance, intended usage, and market constraints, numerous variations in the layout of the embodiments of the invention are envisaged, and will be apparent to those skilled in their particular field.

A slightly different arrangement of this invention is shown in figures 7, 8, and 9 where the inflatable cells 3R and 3L act upon an inner resilient lining 18, the liner material itself forming the compressive layers 1OR and 10L in the regions of the ears. Although the lining 18 is depicted as a single part it is envisaged that the area adjacent to, and peripheral to the ears is of a material having more sound insulation. Examples of the properties in this case being to provide flexibility, retention, wear resistance, coolness, ease of deformation, comfort, resilience, breathability, and sound insulation amongst others. The deformable lining adjacent to the ears may comprise a sealed pad or pancake-like shaped cells filled with a fluid of suitable viscosity to provide sound deadening to the wearer as the inflatable cells 3R and 3L are inflated in ways described within this document. Figure 9 demonstrates the deflection of the lining material which prDvides hearing protection as it is brought into close proximity and ultimately contact with the ears in a way similar to that previously described. The inflation means, fluid control means, valve means, and deflation means are similar to those described elsewhere within this document.

A slightly different arrangement of this invention is shown in figures 10,11 and 12 where the inflatable cells 3R and 3L are themselves the acoustic barriers, the inflatable cells 3R and 3L are so constructed to inherently possess sound deadening properties. These properties are achieved in inflatable cells 3R and 3L filled with a sponge-like porous matrix, pervious to the inflation fluid 8. Alternatively, and additionally the inflation fluid 8 itself would provide sound deadening properties when combined with good design of the inflation cell 3R and 3L membrane materials and thicknesses. Introducing fluid 8 into the inflatable cells 3R and 3L in ways described elsewhere within this document, the cells 3R and 3L perhaps constructed from variable thicknesses of elastic membrane material inflate until contacted with the ears, after which, further inflation causes side-ways expansion onto the sides of the head, thereby excluding sound from the ears. Alternatively the inflatable cells 3R and 3L might comprise sealed pancake or saucer like shaped cells filled with fluid of suitable viscosity incorporated into one or more of the inflatable cells 3R and 3L membrane surfaces. The inflation means, fluid control means, valve means, and deflation means, are similar to those described elsewhere within this document.

A slightly different arrangement of this invention is shown in figures 13, 14 and 15 where the inflatable cells 3R and 3L act upon an inner resilient lining 18, with lining pockets in the regions of the ears, the liner material itself forming peripheral compressive layers 1 OR and 1 OL in the regions of the ears. The inflatable cells 3R and 3L also form the acoustic barriers by inherently possessing sound deadening properties by virtue or their construction, perhaps comprising sealed pancake like or saucer like shaped cells filled with a fluid of suitable viscosity incorporated into one or more of the surfaces comprising the cells. Alternatively the membrane material may be sufficiently increased in thickness adjacent to, and peripheral to the ears so as to provide sound insulation to the wearer. The inflation means, fluid control means, valve means, and deflation means are similar to those described elsewhere within this document.

A slightly different arrangement of this invention is shown in figures 16, 17 and 18 where the inflation fluid 8 is a liquid. This embodiment describes inflatable cells 3R and 3L which are elastic cells, filled and inflated by a liquid. It is important to state that all types, forms, and embodiments of inflatable cell 3R and 3L described elsewhere in this document can be used with the liquid filled system herewith now described. It is further stated that any features not mentioned in this embodiment are interchangeable with features described in embodiments elsewhere in this document. Incorporated into this embodiment are fitted additional self-acting valves, a bladder type fluid reservoir 13 and a reservoir pocket 12. Inflation and hence expansion of the inflatable cells 3R and 3L, is usually achieved by pump 5 means, and associated self-acting valves 6 and 19. The pumping principle, being of the well-known displacement type is very similar to that previously described for pumping air. Actuation of the pump 5, is performed by the wearer, repeatedly squashing a squeezable bulb type pump or by repeatedly pressing a tactile membrane type pump accessible from the exterior of the helmet. Squeezing the squeezable portion of the pump 5, displaces fluid 8 out of the outlet port and valve 6. Loosening one's grip will allow the squeezable portion to return to its original shape, in doing so it draws fluid 8 from the reservoir 13, the fluid drawn in at inlet port and valve 19. Spring-like assistance may be utilised to aid replenishment of the squeezable portion of the pump 5 ( bulb), the associated selfacting valve means controlling the flow of fluid 8 in and out of the squeezable portion ( bulb) of the pump 5. It is also envisaged that a small electrically driven pump, battery power source, and control switches mounted integral to and even internal to the helmet could be used to achieve a similar effect. The pumping means 5 being incorporated into the improved helmet 15, to provide means of moving the fluid 8 from one location to another. Self-acting valves 6 and 19 typically of the well known non-retum valve type permit the pump to displace the fluid 8 from one location to another.

The self-acting valves 6 and 19, allowing the passage of fluid 8 in one direction, but substantially block its passage in the opposite direction. Thereby actuation of the pump 5 causing fluid 8 to flow from the reservoir 13 along passageways 9, and into the inflatable cells 3R and 3L causing their expansion. The valves 6, 7 and 19, ensuring that inflation of the inflatable cells 3R and 3L is maintained for as long as desired, and until deflated by the wearer. The fluid 8 may be any liquid of suitable viscosity to enable easy pumping, most liquids having the effect of shielding the ears from sound. An alternative type of fluid 8 would be one having thixotropic properties. The purpose in utilising these types of fluid 8 being to impart inherent sound deadening properties to the inflatable cells 3R and 3L from externally generated sounds. Several examples of suitable fluids 8 being liquid silicon, oils, multi-grade oils, gels, brine, emulsions etc. however this list is not exhaustive, the choice of liquid 8 being from the vast variety of liquids readily available to those experienced in their particular field. The fluid 8, in this case a liquid will be pumped from a reservoir 13 into the inflatable cells 3R and 3L in a fashion very similar to that already well known and described. Deflation of the inflatable cells 3R and 3L differs to that foregone as the liquid used for inflabon must be contained, for this purpose a reservoir 13 of the bladder or collapsible bag type is situated within a suitable housing or pocket 12 to provide room for expansion of the reservoir 13. Deflating the inflatable cells 3R and 3L is achieved by operating the pressure-release valve 7, channeling the pressurised fluid 8 along passageways 9 into the bladder reservoir 13. Operation of the pressure-release valve 7 permits contraction of the elastic membrane material of the inflatable cells 3R and 3L expelling the fluid 8 into the reservoir 13. The bladder type reservoir, free to fill within the pocket / void housing 12 accepts the introduced volume of fluid without significant increase in pressure. Closing the pressure-release valve 7 allows inflation to be performed again as previously described.

An alternative arrangement is two-way pumping, where the pump 5 is used to move fluid 8 to and from, one location to another, the said locations being the inflatable cells 3R and 3L and the reservoir 13. This method may be more easily achieved by using dedicated pumps, one for inflabon, the other for deflation.

A slightly different arrangement of inflation means is that of incorporating a small compressed gas cylinder into the helmet 15 in substitution of the pump 5. The cylinder in this alternative embodiment being of the type usually professionally filled, and usually disposable, however exceptions are present where the cylinders are returned for refill or exchange. The pump 5 in this case would not be required, as the energy required to move the fluid 8 would be stored as a positive internal pressure within the cylinder. The fluid 8 used to inflate the inflatable cells 3R and 3L in this case would be the gas within the cylinder, controllably released from the cylinder and channeled through passageways 9 into the inflatable cells 3R and 3L in ways previously described, and for the functions also previously described. The inflabon of the inflatable cells 3R and 3L will be maintained by valve acUon until released by the wearer, in a manner as previously described elsewhere. The means of controllably releasing the gas from the cylinder being of the well known gas regulation valve thereby permitting precise control over the inflation of the inflatable cells 3R and 3L in order to achieve the objectives and functions of the helmet 15 as previously described. Whenever the compressed gas is exhausted, the cylinder is intended to be removed and either refilled or replaced. Deflation of the inflatable cells 3R and 3L would be achieved in a similar fashion to the air filled system in Figures 4, 5, and 6 whereby the gas is released to the atmosphere. Several examples of suitable small compressed gas cylinders being compressed carbon-dioxide gas, low pressure oxygen, inert non-toxic gases, and even compressed air. In fact there are many gases that would be suitable provided they are not injurious by inhalabon or toxic to the wearer or the environment, and are well known to those experienced in their particular field.

An alternative means of providing a compressed gas for the purposes of providing inflation for the reasons previously described, is by deployment of a suitable do-it-yourself refillable vessel integral to the helmet 15 in place of the pump 5 or in substitution to the disposable cylinder previously described. This vessel would require valve means for connection to an external pump, or pressurised gas source for refilling the vessel, the vessel being intended to remain integral to the helmet at all times. Thus the refillable vessel would be replenished by the user, by supplying pressurised gas, typically air from a garage forecourt tyre inflation pump. hand pump, foot pump, or gas cylinder to pressurise the vessel. The helmet 15 would require valve means either extending through the shell of the helmet 15, or valve means ergonomically positioned so as to be accessible to enable pressurisation of the integral vessel. These valve means would be similar to the well known self-acting valves commonly found in vehicle pneumatic tyres. Following inflation of the vessel, the helmet 15 would be used in a similar fashion to the compressed gas cylinder previously described.

Regardless of the preferred embodiment, the helmet 15, equipped with one or more of the multitude of forms described within, allows convenient and expeditious usage and operation of its facilities, providing the wearer with an improved safety helmet.

Though the embodiments previously described are preferred, numerous changes and modifications which do not deviate from the true scope of the invention are apparent, being too exhaustive to mention, and will be apparent to those skilled in the art. Accordingly, all such changes and modifications are intended to be covered by the following claims.

0

Claims

1. A protective helmet with variable hearing protection comprising a rigid shell exterior to an inner lining containing at least one inflatable cell disposed to each side of said helmet; and including integral inflation means whereby actuation of said inflation means causes movement of fluid from said inflation means to said inflatable cells causing their expansion, thereby transporting ear cups to the ears. Said protective helmet further including means of maintaining the inflation of, and means of deflating said inflatable cells thereby enabling withdrawal of said ear cups from the ears, even whenever said helmet is in use.

2. A protective helmet with variable hearing protection comprising a rigid shell exterior to an inner lining containing at least one inflatable cell disposed to each side of said helmet; and including integral inflation means whereby actuation of said inflation means causes movement of fluid from said inflation means to said inflatable cells causing their expansion, thereby transporting ear pads into intimate proximity of the ears. Said protective helmet further including means of maintaining the inflation of, and means of deflating said inflatable cells thereby enabling withdrawal of said ear pads from the ears, even whenever said helmet is in use.

3. A protective helmet with variable hearing protection comprising a rigid shell exterior to an inner lining containing at least one inflatable cell disposed to each side of said helmet; and including integral inflation means whereby actuation of said inflation means causes movement of fluid from said inflation means to said inflatable cells causing their expansion, thereby transporting barrier materials inherent to said inflatable cells into intimate proximity of the ears. Said protective helmet further including means of maintaining the inflation of, and means of deflating said inflatable cells thereby enabling withdrawal of said barrier materials from the ears, even whenever said helmet is in use.

4. A protective helmet as claimed in Claims 1, 2, and 3 further including integral means of providing fine and adjustable control over the amount of said fluid introduced into said inflatable cells ( controllable inflation), and the amount of said fluid removed therefrom ( controllable deflation).

5. A protective helmet as claimed in Claim 4 further including passageways connecting said inflatable cells to said inflation means, whereby actuation of said inflation means causes fluid to move along said passageways from said inflation means to said inflatable cells.

6. A protective helmet as claimed in Claim 5 wherein said inflation of said inflatable cells is accommodated by expansion of said inflatable cells.

7. A protective helmet as claimed in Claim 6 wherein said expansion of said inflatable cells is accommodated by balloon-like deformation.

8. A protective helmet as claimed in Claim 6 wherein said expansion of said inflatable cells is accommodated by bladder-like deformation.

9. A protective helmet as claimed in Claim 6 wherein said expansion of said inflatable cells is accommodated by deformation of a sealing element.

10. A protective helmet as claimed in Claim 6 wherein said expansion of said inflatable cells is accommodated by concertina-like deformation.

11. A protective helmet as claimed in Claim 6 wherein said expansion of said inflatable cells is accommodated by deformation of a z-section seal.

12- A protective helmet as claimed in Claim 6 wherein said expansion of said inflatable cells is accommodated by the relative movement of two or more parts sliding relative to each other.

D3

13. A protective helmet as claimed in Claim 12 wherein said relative movement of sliding parts is similar to a piston within a cylinder.

14. A protective helmet as claimed in Claims 7 8 9 10 and 11 wherein said deformation is elastic.

15. A protective helmet as claimed in Claim 6 wherein said expansion of said inflatable cells causes elastic deformation of said inflatable cells membrane materials thereby providing means of evacuating said inflatable cells.

16. A protective helmet as claimed in Claim 6 wherein said expansion of said inflatable cells causes stretching of elastic ties disposed within said inflatable cells causing contraction forces to be set-up within the inflated cells, thereby providing means of evacuating said inflatable cells.

17. A protective helmet as claimed in Claim 1 wherein said ear cups are disposed to inner juxtaposition of said inflatable cells.

18. A protective helmet as claimed in Claim 5 wherein said inflation means is by at least one pump ergonomically positioned so as to be actuatable whenever said helmet is in use.

19. A protective helmet as claimed in Claim 18 wherein said inflation means is accompanied by action of automatic valve means.

20. A protective helmet as claimed in Claims 12 3 and 4 wherein said means of maintaining the inflation of said inflatable cells is by action of automatic valve means.

21. A protective helmet as claimed in Claim 2 wherein said ear pads are disposed to inner juxtaposition of said inflatable cells.

9 Lt

22. A protective helmet as claimed in Claims 19 and 20 wherein said automatic valve means are devices which permit fluid to flow by yielding to pressure in one direction, but which substantially block the reflux of fluid in the opposite direction.

23. A protective helmet as claimed in Claim 22 wherein said automatic valve means are check-valves.

24. A protective helmet as claimed in Claim 5 wherein said means of fine and adjustable control of deflation is achieved by actuation of at least one pressure-relief valve thereby permitting controlled evacuation of said inflatable cells.

25. A protective helmet as claimed in Claim 24 wherein repeatedly releasing small quantities of fluid by actuation of said pressure-relief valve facilitates controlled deflation. A fixed inflation being achieved by halting the release of fluid whenever required by closure of said pressure-relief valve.

26. A protective helmet as claimed in Claim 24 wherein releasing large quantities of fluid by continued actuation of said pressure-relief valve facilitates rapid deflation.

27. A protective helmet as claimed in Claims 4 and 5 further including passageways connecting said inflatable cells to fluid storage means, whereby actuation of said deflation means causes fluid to move along said passageways from said inflatable cells to said storage means.

28. A protective helmet as claimed in Claim 27 wherein said deflation means is by at least one pump ergonomically positioned so as to be actuatable whenever said helmet is in use.

29. A protective helmet as claimed in Claim 28 wherein said means of deflation is achieved by pumping said fluid from said inflatable cells to said storage means.

096

30. A protective helmet as claimed in Claims 27 and 29 wherein said storage means is the atmosphere.

31. A protective helmet as claimed in Claim 29 wherein said storage means is an integral reservoir.

32. A protective helmet as claimed in Claim 31 wherein said reservoir is of the bladder type.

33. A protective helmet as claimed in Claim 5 where said inflation means is a compressed gas cylinder releasably secured to said helmet so as to be removable for replacement whenever said cylinder is exhausted.

34. A protective helmet as claimed in Claim 33 wherein said inflation by compressed gas cylinder is controlled by pressure-regulation and release valve.

35. A protective helmet as claimed in Claim 34 wherein said compressed gas cylinder is replenished either by exchange for a refilled cylinder or by refilling the cylinder so removed.

36. A protective helmet as claimed in Claim 34 where said cylinder is a sodastream bulb.

37. A protective helmet as claimed in Claim 5 wherein said inflation means is a pressure vessel integral to said helmet so as to be pressurised whenever required from an external pressurised gas source.

38. A protective helmet as claimed in Claim 37 wherein said pressure vessel is connected to valve means accessible from the exterior of said helmet so as to permit replenishment from an external pressurised gas source.

ju

39. A protective helmet as claimed in Claims 37 and 38 wherein said inflation by integral pressure vessel is controlled by pressureregulation and release valve.

40. A protective helmet as claimed in Claim 18 and 28 wherein said pump is of the squeezable bulb type, actuated by at least one squeeze from the hand.

41. A protective helmet as claimed in Claim 18 and 28 wherein said pump is of the tactile membrane type, actuated by at least one press of a tactile membrane.

42. A protective helmet as claimed in Claim 18 and 28 wherein said pump is electrically driven.

43. A protective helmet as claimed in Claim 42 wherein said electrical pump is powered by battery disposed integral to said helmet.

44. A protective helmet as claimed in Claim 42 wherein said electrical pump is powered by battery attached to a vehicle being used by the wearer.

45. A protective helmet as claimed in Claim 3 wherein said barrier materials are constituent parts of said inflatable cells.

46. A protective helmet as claimed in Claim 1 wherein said ear cups are formed of materials generally of a concave, cupped, or dish-like shape.

47. A protective helmet as claimed in Claim 46 wherein said ear cups are made from materials having sound insulating properties.

48. A protective helmet as claimed in Claim 46 wherein said ear cups are largely hollow and include evacuated cells (vacuums).

49. A protective helmet as claimed in Claims 46 and 47 wherein said ear cups include at least one compressive layer disposed around the periphery of each cup.

-I

50. A protective helmet as claimed in Claim 49 wherein said peripheral compressive layer conforms to the shape of the head surrounding each ear whenever pushed into contact with the head by expansion of said inflatable cells.

51. A protective helmet as claimed in Claim 50 wherein said compressive layers provide further means of variably shielding the ears from ambient sounds.

52. A protective helmet as claimed in Claim 51 wherein said further means of variably shielding the ears is achieved by varying said inflation pressure thereby varying the force pushing said ear cups against the sides of the head, thereby varying the thickness of said compressive layers thereby making them more or less conducive to the passage of sound.

53. A protective helmet as claimed in Claim 17 wherein means of variably blocking the passage of sound to the ears is provided by positioning said ear cups at variable distances from the ears as required.

54. A protective helmet as claimed in Claim 21 wherein means of variably blocking the passage of sound to the ears is provided by positioning said ear pads at variable distances from the ears as required.

55. A protective helmet as claimed in Claim 54 wherein said ear pads are a constituent part of the lining of said helmet.

56. A protective helmet as claimed in Claim 45 wherein means of variably blocking the passage of sound to the ears is provided by positioning said barrier materials at variable distances from the ears as required.

57. A protective helmet as claimed in Claims 54 and 55 wherein said ear pads are pancake shaped materials capable of being pushed into intimate proximity and conformable contact with the ears.

D(

58. A protective helmet as claimed in Claim 57 wherein said ear pads are made from materials having sound insulating properties.

59. A protective helmet as claimed in Claim 57 wherein said ear pads are filled with a liquid.

60. A protective helmet as claimed in Claim 56 wherein said inflatable cells comprise at least one fluid filled cell incorporated into their membrane surfaces.

61. A protective helmet as claimed in Claim 56 wherein said inflatable cells inherently provide sound insulation.

62. A protective helmet as claimed in Claim 5 wherein said inflation fluid has ( acoustic) sound deadening or insulative properties.

63. A protective helmet as claimed in Claims 6, 56, and 57 wherein said expansion of said inflatable cells creates a clamping force upon the sides of the wearers head thereby increasing the retention of said helmet on the head.

64. A protective helmet as claimed in Claims 6, 52, and 53 wherein said expansion advances said ear cups enclosing the ears thereby increasing the forces required to dislodge said helmet from the head, said helmet retained by the ears.

65. A protective helmet as claimed in Claim 5 wherein said inflatable cells consist of a single cell or comprise multiple cells at equal or differing pressures.

66. A protective helmet as claimed in Claim 65 wherein said inflatable cells are inflated independently or as a group of cells.

67. A protective helmet as claimed in Claim 5 wherein said inflation means is located elsewhere on the wearers person.

1) Cl

68. A protective helmet as claimed in Claim 5 wherein said inflation means is slung from the wearers person.

69. A protective helmet as claimed in Claim 5 wherein said inflation means is attached to the vehicle being used.

70. A protective helmet as claimed in Claim 1 wherein said ear cups, accommodate communication devices for by way of example, micro-speakers, enabling selected sounds to be heard, even whenever said inflatable cells are inflated and said helmet is in use.

71. A protective helmet as daimed in Claim 2 wherein said ear pads accommodate communication devices for by way of example, micro-speakers, enabling selected sounds to be heard, even whenever said inflatable cells are inflated and said helmet is in use.

72. A protective helmet as claimed in Claim 3 wherein said inflatable cells accommodate communication devices for by way of example, microspeakers, enabling selected sounds to be heard, even whenever said inflatable cells are inflated and said helmet is in use.

73. A protective helmet as claimed in Claims 5, 6, 15, 16, 17, 18, 21, 25, 26, 30, 35, 39, 40, 41, 42, 44, 45, 52, 53, 54, 55, 56 wherein said fluid is air.

74. A protective helmet as claimed in Claims 5, 6, 15, 16, 17, 18, 21, 25, 26, 30, 35, 36, 39, 40, 41, 42, 44, 45, 52, 53, 54, 55, 56, 59 wherein said fluid is a gas other than air.

75. A protective helmet as daimed in Claims 5, 6, 15, 16, 17, 18, 21, 25, 26, 32, 40, 41, 42, 44, 45, 52, 53, 54, 55, 56, 59, 60, 62 wherein said fluid is a liquid.

JO

76. A protective helmet substantially as described herein with reference to Figures 4 to 21 of the accompanying drawings.