GB2186194A - Ventilated safety helmet - Google Patents

Abstract

A full-face visored safety helmet, as worn by motor cyclists, includes a first mask (23), attached to the chin guard of the helmet to engage the user's face at a position above his nostrils, a second mask 28 also attached to the chin guard to engage the user's face between his mouth and his nostrils, and/or a one-way valve 31 within a chamber 21 attached to the inside of the chin guard to duct exhaled air out through the chin guard to the surrounding atmosphere and thereby prevent misting up of the visor. <IMAGE>

Description

SPECIFICATION Ventilated safety helment Field of the Invention The invention relates to full-face safety helmets.

A full-face safety helmet is a helmet in which the helmet shell extends down around the wearer's ears and also extends forward to encase the wearers mouth and to form a chin guard.

Review of Art Known to the Applicant Full-face safety helmets are worn by motor cyclists (amongst other potential users) and almost always incorporate a transparent visor which, in use, covers the relatively small face opening of the helmet. The visor is usually unperforated. The helmet shell is usually extensively padded to fit tightly on the wearer's head. For these reasons, the visored helmet can become uncomfortably hot and also tends to mist up inside.

For these reasons it is common to see motor cyclists travelling with their visors partly or fully raised. This, however, can be dangerous.

Few, if any, visors are designed to stay up properly when the motor cyclist is moving at speed. In such conditions the air pressure around the base of the raised visor can tend to pull the helmet off the wearer's head and can generate unpleasant wind noise. More annoying still, and potentially more dangerous, is that there is nothing to stop insects and grit being carried into the motor cyclist's eyes when travelling with the visor partly or fully raised; and certain designs of visor in certain partly or fully raised positions can create air flows which positively encourage this.

UK Patent Specification No 2 048 056 (International Helmets AG) shows one attempt to overcome this problem of misting up. Here the full-face helmet described and illustrated incorporates an air mask (Figure 2), mounted on the chin guard inside the helmet, and shaped and positioned to fit over the mouth and nose of the helmet wearer; and a spoiler (6) depending from the chin guard. The mask is so shaped that it tends to direct exhaled breath from the wearer's mouth and nostrils down into the region of the spoiler, and when the helmet is travelling forward with its wearer at speed then the air flow around the spoiler creates a region of low pressure at the bottom of the helmet which encourages the exhaled breath to pass out of the helmet.

This arrangement may well work satisfactorily when the helmet wearer is travelling at speed. But it depends upon such travel to work at all. If the helmet wearer is stationary for example when waiting at traffic lights, or is not travelling at speed (for example when he walks into a building without wanting to raise his visor) then the air flow around the spoiler is insufficient to create the required air extraction from within the helmet.

UK Patent Specification No 1 576 647 (Stadium Limited) illustrates another attempt to overcome this same problem. A visored fullface helmet again incorporates an air mask, like the helmet just referred to, fixed to the chin guard inside the helmet so as to engage the helmet wearer's face closely in the region above his mouth and nostrils. Exhaled breath from the mouth and nostrils is unable to find its way above the mask (and hence onto the inside of the visor) because of this close fit between mask and face. The bottom of the helmet, conventionally, is open to the atmosphere and so the exhaled air will pass to the surrounding atmosphere rather than recirculating inside the helmet and misting up the visor.

This last-mentioned arrangement should theoretically work, irrespective of whether or not the helmet wearer is travelling at speed.

In practice, however, it is found that the everpresent difference in temperature between the air inside the helmet and in front of the wearer's face above the mask, and the air impinging on the outside of the visor, causes the visor to mist up. In simple terms, however closely the mask seals against the wearer's nose and cheeks, the portion of the wearer's face above the mask will always tend to sweat in a modern fully-padded enclosed safety helmet; and this alone causes the visor to mist up.

There is thus a continuing problem to which the known art provides no entirely satisfactory solution. The first of the two known arrangements specifically revealed above will only work at all when the helmet wearer is travelling at speed. The second, whilst theoretically workable irrespective of the movement of the helmet wearer, fails to take account of the simple fact outlined at the end of the preceding paragraph.

Summary of the Invention The invention is based on the analysis of the prior art as set out above.

According to the invention a full-face visored safety helmet incorporates, in use, a mask attached to the chin guard inside the helmet so as to divide off, in use, the space within the helmet into two regions, a first region below the mask and including the helmet wearer's mouth and nostrils, and a second region above the mask; the first region of the helmet, in use, is substantially open to atmosphere; and the chin guard a) incorporates a one-way valve means to duct air from the first region, specifically air in the form of breath exhaled from the wearer's mouth and nostrils, out through the chin guard to the surrounding atmosphere and/or b) has a second mask fitted to the inside of the chin guard to engage, in use, the region of the wearer's face between his mouth and nostrils so that there is defined between the two masks a duct through which air, specifically air exhaled from the wearer's nostrils, will tend to be directed down into the bottom region of the helmet and there drawn into the wearer's mouth and/or carried out of the helmet into the surrounding atmosphere.

With such an arrangement, it is not essential for the first-mentioned mask to engage closely against the helmet wearer's nose and cheeks. Indeed if it does not do so, then the tendency of warm air from the upper parts of the wearer's face (i.e. the parts above the said mask) to be drawn down below the mask and into the bottom region of the helmet, is enhanced. Whether such a helmet incorporates the one-way breath outlet, or the "two-mask" arrangement (or both), the visor can remain closed under all normal conditions without unduly misting up.

Preferably the helmet has its chin guard perforated and incorporates means to duct air, entering the helmet through the perforations, to the base region of the inside of the visor.

Such an arrangement is disclosed in my pending UK Patent Application No 85 29337 also entitled VENTILATED SAFETY HELMET and filed on 28th November 1985. In use, as explained in that Patent Application, when the helmet wearer is travelling forward there is a positive air flow to the inside face of the visor which helps to keep the visor from misting over and to keep the wearer's face from becoming unduly hot. Because the air enters at the base of the visor, the air flow up the inside face of the visor is similar to that of the flow of demisting air up the inside face of a vehicle windscreen and is thus of proven efficiency. And, as explained in my previous Patent Application, the risk of insects or grit entering the wearer's eyes is greatly reduced if not virtually eliminated.

In an arrangement such as that just outlined, where the chin guard is perforated and air enters the perforations and is ducted to the base region of the inside face of the visor, and where the helmet incorporates a one-way outlet through the chin guard as provided for in one form of the broadest aspect of the present invention, then the air-inlet perforations and the one-way outlet may be formed in the same geneal region of the chin guard.

When the helmet is viewed from outside, this gives a pleasing appearance, more so than if separate regions of the chin guard were to be vented for each of these two functions.

Where, in the case just outlined, and as envisaged in my previous Application No 85 29337, the air-inlet perforations lead initially into a plenum chamber within the helmet, then the one-way outlet may with advantage be incorporated into that plenum chamber for effi ciency of construction and also to minimise the number of components fixed to the inside of the chin guard (because in the event of an accident, the chin guard may deform sufficiently to impinge on the wearer's chin, and in such a case the less components there are carried with it the better).

Advantageously the first-mentioned mask-the one whose level is generally above the wearer's nostrils as well as being above his mouth-is fixed to the top of the chin guard inside the helmet. The top of the chin guard (i.e. the region bounding the bottom portion of the face opening and receiving, when the visor is down, the base of the visor) is conventionally heavily padded and the padding continues round into the side regions of the helmet.As it is not necessary, in a helmet embodying the present invention, for the mask to come well up the nose of the helmet wearer (in contrast to the arrangement especially of Patent Specification No 1 576 647) then to use the inside of the top of the chin guard in this way gives an extremely efficient seal for the mask; and this contributes to its overall efficiency without the need for a close sealing engagement against the wearer's face.

Preferably indeed the mask is substantially planar, or at least is dished upwards (in use and with the helmet worn normally) to only a limited extent, with the exception of its nosebridging portion. This again contrasts with the arrangement of Specification No 1 576 647 (and of the other prior art Specification specifically discussed above) where both masks have to be largely preformed and moulded in order to cover most of the wearer,s nose as well as covering his mouth. A mask for use in a helmet embodying the present invention can, by contrast, be made from inherently flat fabric and/or flexible plastics materials and thus incur far lower manufacturing costs. It also has the undeniable safety feature that it leaves a far greater portion of the wearer's vision free of obstruction in comparison with the prior art masks referred to.

The mask, a chin guard region incorporating a one-way breath outlet and/or a second mask of the kind defined in the broadest aspect of the invention, constitute of course essential integers for putting the invention into practice. As such, they could be supplied as a kit (or in respectively separate entities) for fitting to existing helmets.

Brief Description of the Drawings The accompanying drawings show, by way of example only, the best way currently known to the applicant of putting the invention into practice. In these drawings: Figure 1 shows in plan the chin guard region of a full-face safety helmet; Figure 2 shows the same region in sectioned side elevation; Figure 3, drawn to a reduced scale, shows in perspective the first mask-the nose-bridging mask-of the helmet; and Figure 4, again reduced like Figure 3, shows the second mask-the mouth-bridging mask-of the helmet.

The helmet whose parts are illustrated is a full-face visored safety helmet of the kind specifically described and illustrated in my previous UK Patent Application No 85 29337 filed 28th November 1985. It incorporates all the features of the helmet described and illustrated in that previous Application. The reader is specifically referred to the Specification, including the drawings, of the previous Application before proceeding further to read this present specification, and to note that in the drawings of the present specification, the reference numerals used in the drawing of Application No 85 29337 have been used again for corresponding parts.

Referring now to the present drawings, the fabric-covered foamed plastics padding 18 which lines the helmet shell 11 continues along each opposite inside face of the chin guard region of the helmet and continues also across the inside face of the front of the chin guard; but it is reduced, as indicated in the run between the two reference numerals 19 in Figure 1, in thickness across the chin guard inside front region.

The padding 18 (as illustrated in Figure 2 of the drawings of Application No 85 29337) abuts the lip 14, 16 defining the bottom of the helmet opening, across the chin guard front inside surface. From the points 19 onwards, referring again now to the present drawings, it departs from the curve of the lip 14, 16 as shown in Figure 2 of the present drawings. Because of this, the top of the padding as it lines the chin guard region makes an ideal surface to seal against a removable air mask 23 fixed to the top of the chin guard with VELCRO (VELCRO is a trade mark) strips or other suitable fixing means (referenced 24).

This mask 23, when fixed in place, spans the helmet internally and seals in a substantially airtight manner against the padding 18.

The mask is formed from an initially flat fabric and/or plastics material, which may be padded slightly, and is very nearly substantially planar but for its nose-bridging region 25. It is in fact dished upwards (when viewed as in Figure 2, i.e. with the helmet in its normally intended attitude of use) but it is only relatively slightly dished. Its front curved periphery incorporates cutouts 26 to enable the mask to seat in a substantially airtight manner around the ends of the tubular vents 22 which admit air to the base region of the inside face of the visor 12 when the helmet wearer is travelling forward at speed (as outlined in my previous Patent Application No 85 29337).

In use, and as illustrated in Figure 2 of the present drawings, the mask 23 effectively divides the interior of the helmet into two regions, a first region including the helmet wearer's nostrils and mouth, and a second region above the mask 23 and including such areas of his cheeks, eyes and forehead which are not covered by the remainder of the padding 18.

Also, as shown clearly in Figure 2, although the bridge portion 25 of the mask 23 does locate against the helmet wearer's nose, the remainder of the back periphery 27 of the mask does not engage closely the wearer's face in the region below his eyes and above his mouth and nostrils. Indeed in the embodiment illustrated, in use, the portions 27 are spaced some slight distance from the wearer's cheeks. The profile of the back periphery 27, 25, 27 of the mask is deliberately so cut-and is sufficiently inherently relatively rigid-that when the bridge portion 25 engages the wearer's nose then the portions 27 will automatically be lifted slightly clear of the wearer's face along virtually the whole of their respective lengths.

A second mask 28 is also fixed removably to the inside of the chin guard of the helmet shell 11 with VELCRO strips or a suitable equivalent fixing means. This second mask is made of material similar to that of the first mask 23 and, like the first mask, is preformed to a curved shape. In this case, however, the second mask is altogether more noticably curved than the first, as the drawings illustrate between them.

The second mask 28 is fixed removably to the inside of the front of the chin guard, so that it is spaced below the first mask 23, and so that in use (referring to Figure 2) it engages the helmet wearer's face in the region between his mouth and his nostrils. It does not span the full width of the helmet internally, as Figure 1 makes clear. Nor does it extend to the full width or more of the wearer,s mouth, as Figure 2 shows. And it defines with the first mask 23 effectively a channel, curving downwardly to the bottom region of the inside of the helmet, when the helmet is being worn.

The plenum chamber 21 fixed to the inside of the front of the chin guard is perforated, as indicated at 29, across substantially its entire circular back face. The perforations allow air exhaled from the wearer's mouth (and ducted into the region of his mouth from his nostrils by the channel defined between the two masks 23, 28) to enter the plenum chamber 21. A one-way membrane valve (not illustrated) of known kind inside plenum chamber 21 allows this exhaled air to pass through the chin guard to the surrounding atmosphere via a vent 31 whilst preventing any intake of air in the opposite direction.

Within the plenum chamber 21, the air is ducted from the perforations 29 to the outlet 31 through a tube (not illustrated) which prevents that air from mixing with the incoming air entering through vents 19 and being ducted via tubes 22 to the inside face of the visor. But it might be possible for these two streams of air to be allowed to mix, and still retain a workable arrangement. Other modifications will become apparent to those skilled in the field to which the invention relates.

Claims (7)

1. A full-face visored safety helmet which incorporates a mask attached to the chin guard and located inside the helmet so as to divide off the space within the helmet into two regions, a first region below the mask and including the helmet wearer's mouth and nostrils, and a second region above the mask; the first region being open to atmosphere; and in which a) the chin guard incorporates a one-way valve means to duct air from the first region out through the chin guard to the surrounding atmosphere, and/or b) there is a second mask fitted to the inside of the chin guard to engage, in use, the region of the wearer's face between his mouth and nostrils so that there is defined between the two masks a duct through which air, specifically air exhaled from the wearer's nostrils, will tend to be directed down into the bottom region of the helmet and there drawn into the wearer's mouth and/or carried out of the helmet into the surrounding atmosphere.

2. A helmet according to Claim 1, wherein the chin guard is perforated and means are provided to duct air, entering the helmet through the perforations, to the base region of the inside of the visor.

3. A helmet according to Claim 2, wherein the perforations in the chin guard are formed in the same general region as the one-way valve means.

4. A helmet according to Claim 1, wherein the mask which divides the space inside the helmet into two regions is substantially planar, with the exception of its nose-bridging portion.

5. A full-faced visored safety helmet substantially as hereinbefore described with reference to and as shown in the accompanying drawings.

6. A safety helmet as claimed in Claim 1 of Patent Application No 85 29337 including an additional mask fitted to the inside of the chin guard.

7. A safety helmet as claimed in Claim 1 of Patent Application No 85 29337, wherein the chin guard incorporates a one-way valve.