GB2414413A - Face mask with visor - Google Patents

Abstract

A combined half mask respirator and eye protector is provided, portions of the mask 10 above the respirator being open to provide air circulation behind a lens 21 and reduce misting of the lens 21. A face seal 32 for the respirator of elastomeric material inhibits air leakage from the respirator to behind the lens 21, and outlet from the respirator is controlled by a flap valve 18 which offers minimal flow resistance, also for preventing development of overpressure in the respirator and leakage of air to behind the lens 21.

Description

1;ACE MASK

FIELD OF'I'IIE INVENTION

s The present invention relates to a face mask particularly, but not exclusively, for model makers, wood-woriers, and those engaged in dc'-ityourself household maintenance.

BACKGROUND TO TllE INVENTION

Inexpensive disposable moulded or ther21lotornled face masks that cover the nose and mouth are conventionally constructed of layers of fibrous sheet material and have found numerous applications in dirty or dusty environments, particularly in industry and for those who are engaged in model making or do-it-yourself tasks.

They have also found use in areas of medicine such as surgical masks. These masks are held on the face by one or more elastic hands or straps attached mechanically (such as by stapling), or by thermal fusing to the sides of the trace mask to hold the mask to the face and to accoT1lpl2sh sealing of the mask over the nose and mouth. A mask of this type should completely seal around the nose and moutl1 and allows no 20 air to pass between the mask and the face. Such masks are shown, for example, in US4641645 (Tayebi) Too often, however, due to the softness and flexibility of fibrous sheet materials fro2n which masks are molded, complete sealing around the . . .. bridge L'f Ihc nose and mouth is not: achieved. :.

:. 25 Model makers and do-it-yourself enthusiasts work with mainly wood and ., plastic US221g various ma21ufactur2ng methods. Many activities in industry, involve substances that people need to be protected against. Very fine aerosols or respirable dusts may be released by grinding, drilling and milling, as well as by painting and clea212mg processes. Respirators are commonly used to protect against health issues that may be caused by release ol such part2clcs. Respirators may he classified - 2 according to which of two key types of contaminant from which they provide protection: Particulates - most commonly used to protect against dusts. However anti particulate respirators are also used to guard against fumes and mists created through mechanical processes SUC}I as sanding, welding or spray painting that introduce fine particles into the air.

Gases anti vapours - This equipment protects against gaseous contaminants that can range froTn TlOXiOUS acidic gases, including sulphur dioxide and alkaline gases such as ammoma, to less perceptible gases that displace oxygen and create 0 hazards of hypoxia and, eventually, asphyxiation.

The most commonly used protective equipment by model makers is active against particulates. Wood dust cause a health risk due to allergic reactions and can affect the lungs, and also the eyes and skin. Exposure to some woods can cause is extrinsic allergic alveolitis - a disease with "flu-like" symptoms, which can cause progressive lung damage. Exposure to wood dust can cause rhinitis (runny nose), violent sneezing, blocked nose, nosebleeds, and, very rarely, nasal cancer. The most common ei'f'ects arise t'roTl1 irritation. In eyes the ei'f'ects can include soreness, watering and conjunctivitis. .

:: . 20 . Ilalf t'ace and full face respirator masks are also known. For example, US-- 5924420 (ReTschel, et al., Minnesota Mining and Manufacturing) is concerned Wit}l the problem of increasing visibility for users of t'ull-t:ace respirator masks. The proposed solution is to provide a full face respirator mask that comprises: (a) a rigid 2.5 plastic lens that has a transparent viewing portion and a port portion, the port portion 6. . being disposed beneath the viewing portion when the mask is viewed from a front elevation; (b) an exhalation port disposed in the port portion of the rigid plastic lens; (c) first and second air intake ports dTsposeci in the port portion of the rigid plastic fens on opposing sides Lathe exhalation port; (d) first and secontl connectors that are integral with the rigid plastic lens in its pots portion, the first arId second connectors being configured for receiving first and second filter cartridges and being located on - 3 thc port portion to allow intake air to be directed to the first and second intake ports, respectively; and (e) a face seal disposed on the till face respirator mask to seal the respirator over the wearer's eyes, nose, and mouth.

Providing a sealed respirator and glasses combined in an open mask, so protecting the areas listed above would be beneficial for such a 'central' user group with moderate exposure. The mask would prevent the dust from al'fectng the face and eyes, through the Ions. The respirator would protect the nose and lungs, as they are sealed. Ilowever, it has been realized that there are drawbacks in a fully sealed respirator. Heat build-up and breathing resistance are two of the principal reasons why peopic refuse to wear respirators. To overcome these dit'ticultes, many masks are equipped with an exhalation valve that reduces breathing resistance and heat build-up.

Integrated eye protectors and respirators can leak exhalett err into the region of the eye protection and steam up the insides of the lens. This restricts vision and has imphcalrons for working especially with machinery and sharp tools.

SUMMARY OF THE INVENTION

It is an object of the invention to provide a t'ace mask that can provide users in a middle category of exposure, including many model makers and do-it-yourself' cmthusiists, with birth eye protection against flying objects and respiratory protection for and whicl1 does not sulkier fiom undue misting even . : , 2s In the present invention these flaws have been substantially addressed by providing a face mask comprising a half mask negative pressure respirator that tits around the nose and mouth and a lens supported above the rcsprator tier providing eye protection, por-toTls ot'thc mask car-rymg the lens being open to the surrounding air. - 4 -

The present invention relates to a mask that is a combination of a half face negative pressure respirator and impact resistant safety lenses. Embodiments of the mask are also designed to fit comfortably around a standard pair of ear defenders, to protect the user from dust both being Inhaled and from irritating the eyes, from flying objects hitting the eyes and face, from the steaming up ot'the inside of the lenses.

Embodiments of the present mask are designed to overcome the problems of using a respirator, satiety glasses and ear defenders together. There are a number of lo problems with equipment currently available. With separate glasses or goggles, the nose area of the respirator and the glasses interfere with the fitting of each other. The glasses -,r goggles tend to rise up on the respirator and not sit correctly on the t'ace. A second problem is the Amos of the glasses interfering with the ear defenders. 'I'he ear def nders have a strong grip and they push the arms of the glasses into the head of' l the wearer making the wearing of them uncont'ortable.

BRIEF DESCRIPTION OF THE DRAWINGS

How the invention may be put into ef'f'ect will now be described, by way of . :: 20 example only, with reference to the accompanying drawings, in which: . . . . Iig. I is a view t'rom the t'ront and obhquely below s}lowing a face mask according to the invention; Figure 2 Is a view of the musk of Fig I from the rear and ot't'set to the side; :.

Fig 3 is an exploded view of the mask froth the t'ront; and . . 2s Fig. 4 is an exploded view of the mask from the rear. .

DETAII,EI) DESCRIPTION ()F PREFERRED EMBODIMENT

Fig. I shows a t'ace mask according to the Invcntion, having a body 10, an area 1 2 for a lens 2 1 which is located above a breathing circuit area 2() that receives breathing air from filter cartridges 14, 16 and a t'orwardly f'acmg air outlet 18. - 5

Features of the mask body 10 which are important for its intended performance appear in Fig. 5. It is moulded of mineral filled polypropylene which combines lightness with good mechanical properties such as flexural modulus stit'filess and impact strengtil and resistance to alkali and UV anti both injection moulding and vacuum forming may be used. The thin sheet-like main areas are bounded by up.standilig (as viewed in fig. 5) base wall l()a lower side walls lOb arid l()c upper side walls l()d and lOe and Lop wall l()f that stiffen the mask body against flexing under load. A flange IOg extends across the top of the mask at a small spacing frolic top wall 101 and together they serve to stit'i'en the top of the mask. An nvertcd lo generally V-shaped wall 3() extends across the mask and meets the walls lOb lOc partway along their length. The wall 30 together with the lower portions of the walls lob I() c and the wall l()a define the shape of the breathing circuit area 20 that surrounds the nose and mouth and provide stt'fness at that area. Bosses 5() 52 through the walls l()b lOc open into the breathing circuit area as also does a Is centrally located aperture 68 t'or an exhalation valve. An aperture l()h is provided for a lens and apertures I ()i and I Ol at the upper sides of the mask receive at the ends of an upper fastening band that passes behind the user's head. Apeltures (not shown are also provided for a lower t'astening band.

. 20 As best seen In Figs. 2 and 4 a face seal 32 of thin sfliconc rubber or other . .. elastomeric material has a groove on its toward face which fits onto the walls 30 . IOa lOb lOc defining the breathing circuit area 20 with a chin rest and regions closely confonning to the nose. The lace seal is made slightly undersized so that it is tensioned to fit onto the walls alid is air- tightly retained thereoll. It is apertured to . : 25 either side at 34 tor air inlet via bosses 5() 52 and centrally at 36 for the exhalation . .: valve. At the top corners of the mask there can be seen attachments 38 for the upper head band. Tile headband supports the top of the mask on the face.

As is apparent in Figs 3 and 4 a head pad 76 fits to the top of the mask between the flanges I()t; I()g and is held In position by Velcro (RTM) I:astenels. It is covered with Coolmax (RTM) which is a l'abric developed by Du Pont to wick sweat - 6 away from the skin anal to provide a barrier for inhibiting Sweat from leaking onto the forehead. The lens 2() is made of polycarhorIate which combines transparcrIcy and impact strength and is surrounded by an clastorncric seal or gasket 78 by which It tits into the aperture defined by wall I ()h and which allows the lens 2() to be removed for replacement. The lens seal, 78 grips on to the mask and the le'Is 2()holding the two together. When the ICnS needs to be removed the user pushes it out from the Inside of the mask. The lens is designed to be replaced, as during use the ICES may become scratched or damaged. A one-way exhalation valve has a rear support 72 that fits into the aperture 68 and retains flap member 70 behind front cover 74. At the sides of the 0 mask, air entry into the breathing circuit 2() is controlled by Rap valves 64 held iT1 positron by retainers 66.

To either sidle of the mask removable intake filter units arc detincd by cover members 42, 44 and base mcTTIbers 46, 48 between which arc located filter clemerIts s 43, 45, the cover members and base members being ultrasonically welded together grid the filters bomg simple dust filters carbon filters or a combination of both depending OTT the airborne contaTniT,ants with which the mask is likely to be challenged. The filters are push, bayonet or screw tits onto the spigots 5(), 52, with air-tightlless mirltaiTlcd by O-rillgs 54, 56, and with clips 6() (Fig 3) snapping into slots 62 ITI the sidewalls l()a, I()b to hold the filters In their working positions. In an . . cmbodimerIt, the filters filter out particles above 5 microns such as dust, and the organic vapours such as paint fumes. These may be fixed on to the mask with a 2. simple thread, by way of exaTnplc, which only requires a 18()-degree twist to lock in place. As previously explained there arc location clips to tell the user that the filter is . 2s iT1 position and also to line the filicr up with the contours of the mask. The filters arc : changed when they become significantly contaminated as with other t'ilters.

In use, the mask is sealed around the nose Grid mouth by the t:ace seal 32, and Owing to the very low working pressuTc of the outlet or exhalation flay valve, sigTliticaTlt overprcssuT e ITI the breathing circuit regToTI 2() does not develop.

ConscqucTItly, escape of moist exhaled air into the region beyond the t:acc seal 32 and behind the lens 2() is minimal. Furthermore, at least the sides of the mask beyond the seal 32 arc open for air circulatun behind the lens 2() so that perspiration can evaporate and for these reasons the mask is relatively resistant to misting up of the lens even when the user is engaged in manual work. The air passes through s inhalation valves which only open one way towards the user's mouth and nose, so the filters don't have any exhaust air going through them which would cause the filters to heat up, making tor a more uncomfortable product. The air then goes out of the mask through the exhalation valve on the front of the mask. 'I'his is positioned downwards so as not to breathe on the lens or eye area and mist the lens up. The exhaust valve is 0 also a one-way design so as not to allow the valve to open when the user is breathing in.

I'he mask has been dcsgnetl to be durable and with all parts removable and replaceable. If a lens or seal is damaged or has wont out, a replacement part can easily be substituted. There are many parts to the mask to enable it to function fully.

This also enables the user to dismantle the mask fully for general cleaning and mantcnancc.

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Claims (4)

- S- CLAIMS

1. A face mask comprising a half mask respirator for fitting gas-tghtly around the nose and moutl1 and a lens supported above the respirator for providing eye protection, portions of the mask supporting the lens above the respirator being open to the surrounding air.

2. The mask of claim 1, wherein the mask is termed of a generally sheetlike plastics body having rearwardly tracing walls defining an outline of the respirator, and lo a face seal is a push fit onto said walls.

3. 'he mask ot'claim I or 2, wherein an outlet from the respirator is controlled by a unidirectional flap valve.

is

4. A combined half mask respirator and eye protector substantially as hereinbef'ore described with ret'erence to and as illustrated in the accompanying drawings. -

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