Respirators

Abstract

A respirator (10) having an oral-nasal unit (12) with a peripheral seal that seals around the nose and mouth of a wearer's face and having an inlet aperture (40) connectable to a supply of breathable air, and an outlet aperture (42). The unit having a rigid insert (106) with an exterior profile adapted to seat against a correspondingly shaped interior surface of the unit (12); an outlet conduit (112) with a tube adapted to extend through the exhale aperture (40) of the unit (12); and a wing portion (110) with a through aperture (122) registering with the unit's inlet aperture (40). The outlet conduit (112) having a bayonet connector (130, 132) that enables the unit to interchangeably and detachably connect to, a connector formed as part of an exhale aperture of a full-face mask, or of a harness assembly (102). The bayonet connector forms an airtight seal between the two.

Claims

1. A respirator comprising: an oral-nasal unit comprising a first peripheral seal adapted, in use, to form a first seal around a nose and mouth of a wearer's face and having an inlet aperture in fluid communication, in use, with a supply of breathable air, and an outlet aperture; a relatively rigid insert comprising: an exterior profile adapted to seat against a correspondingly shaped interior surface of the oral-nasal unit; an outlet conduit comprising a tube adapted to extend through the outlet aperture of the oral-nasal unit; and a wing portion comprising a through aperture registering with the inlet aperture of the oral-nasal unit, wherein the outlet conduit of the relatively rigid insert includes an exhale valve assembly, wherein the respirator is configured to selectively interchange for use between a full-face configuration and a half-face configuration, wherein, in only the half-face configuration, a harness assembly, having at least one strap for coupling the oral-nasal unit to a wearer's head, is coupled to the oral-nasal unit, wherein, in the half-face and full-face configurations, the first peripheral seal is configured to form the first seal between the oral-nasal unit and the wearer's face, wherein, in only the full-face configuration, a full-face mask is coupled to a front surface of the oral-nasal unit and a second peripheral seal is configured to form a second seal at least partially around a perimeter of a user's face between the full-face mask and the wearer's face wherein the full-face mask includes a bayonet connector formed as a part of an integral conduit, the bayonet connector configured to engage the exhale valve assembly.

2. The respirator of claim 1, wherein the inlet aperture of the oral-nasal unit communicates with the supply of breathable air provided via any one or more of the group consisting of: a filtration unit; a filter cartridge; bottled air; and a breathable air supply tube.

3. The respirator of claim 2, wherein the full-face mask comprises a secondary inlet connectable, in use, to the supply of breathable air.

4. The respirator of claim 2, wherein the inlet aperture of the oral-nasal unit communicates with an interior volume of the full-face mask.

5. The respirator of claim 1, wherein the inlet aperture of the oral-nasal unit communicates with an interior volume of the full-face mask.

6. The respirator of claim 1, wherein the first peripheral seal and the second peripheral seal each comprise a three-dimensional profile and at least one resiliently deformable lip, which deforms, in use, to form respective ones of the first and second seal.

7. The respirator of claim 1, wherein the oral-nasal unit comprises a unitary molding manufactured from a resiliently deformable material.

8. The respirator of claim 1, wherein the oral-nasal unit comprises one or more fixing points to which, in use, a retaining strap or harness is detachably affixable.

9. The respirator of claim 1, wherein the oral-nasal unit comprises a harness attachment having an aperture for receiving the outlet conduit.

10. The respirator of claim 1, further comprising the full-face mask, wherein the full-face mask comprises a transparent visor portion.

11. The respirator of claim 1, wherein the outlet aperture comprises a one-way valve.

12. The respirator of claim 1, wherein the inlet aperture comprises a temporary shut-off valve adapted to selectively close the inlet aperture when there is no filter cartridge and/or air supply tube connected thereto.

13. The respirator of claim 12, wherein the full-face mask comprises a secondary inlet connectable, in use, to the supply of breathable air.

14. The respirator of claim 1 further comprising: a bayonet connector formed as part of an integral conduit, the bayonet connector configured to engage the exhale valve assembly.

15. The respirator of claim 14, wherein the bayonet connector is connectable, in use, from inside the relatively rigid insert and extending through the inlet aperture of the oral-nasal unit to which, in use, a filter cartridge and/or air supply tube is detachably affixable.

16. A respirator assembly comprising: an oral-nasal unit comprising: a first peripheral seal; a first inlet aperture disposed on a first side of the oral-nasal unit; a second inlet aperture disposed on a second side of the oral-nasal unit; and an outlet aperture, wherein each of the first inlet aperture and the second inlet aperture are in fluid communication with a supply of breathable air, a full-face mask comprising a transparent visor and a second peripheral seal extending around the periphery of the transparent visor; a harness assembly having at least one strap for coupling the oral-nasal unit to a wearer's head; a first filter coupled to the first inlet aperture; and a second filter coupled to the second inlet aperture, wherein the respirator is selectively interchangeable for use between a full-face configuration and a half-face configuration, wherein, in the half-face and full-face configurations, the first peripheral seal is configured to form a first seal between the oral-nasal unit and a wearer's face, and wherein, in only the full-face configuration, the full-face mask is coupled to a front of the oral-nasal unit and the second peripheral seal is configured to form a second seal between the full-face mask and the wearer's face.

Description

(1) Embodiments of the invention shall now be described, by way of example only, with reference to the accompanying drawings in which:

(2) FIG. 1 is a perspective view of a full-face respirator in accordance with the invention;

(3) FIGS. 2 and 3 are perspective views of the oral-nasal unit of the respirators described herein;

(4) FIG. 4 is a perspective view of the interior of the visor of FIG. 1;

(5) FIG. 5 is a partial cross-section of FIG. 1 on V-V;

(6) FIG. 6 is a perspective view from above of the respirator of FIG. 1 with one filter cartridge removed;

(7) FIGS. 7A and 7B are perspective views of the oral-nasal unit and head harness of a half-face respirator, respectively;

(8) FIG. 8 is an exploded view of the oral-nasal unit of the half-face respirator of FIG. 7A;

(9) FIG. 9 is an exploded view of the respirators described herein, showing a bayonet connection for affixing a filter cartridge to a respirator; and

(10) FIGS. 10A-10H and FIGS. 10K-10Q are schematic views showing the various components of a full-face respirator (FIG. 10I) and a half-face respirator (FIG. 10J), respectively in accordance with the invention.

(11) In FIG. 1, a full-face respirator 10 comprises a full-face mask 12 and oral-nasal unit 14 that are connected to one another to form a unit. The full face mask 12 comprises a transparent visor 16 manufactured from a tough, durable, optically clear polymer, such as ABS through which a wearer can see when wearing the respirator 10. The visor 16 provides protection to the wearer's face and eyes, and serves as an integral part of the respirator 10.

(12) The visor 16 comprises a profiled lip 18 to which a silicone rubber face seal 20 is sealingly affixed, for example, via a mechanical and/or adhesive connection (not visible). The face seal 20 has a three-dimensional profile that has been optimised to form an effective seal against the faces of a designated population of people, and it will be appreciated that different visor-seal combinations could be used to fit different groups of a given population of people.

(13) The face seal 20 has an inwardly turned lip portion 22, which allows the seal 20 to flex to seat correctly against the face of a wearer, thus forming an effective airtight seal.

(14) The respirator 10 is affixed to the wearer's head (not shown) in use, by a head harness (not shown), which connects to the respirator 10 via a set of adjustable straps (not shown) that connect to five, in the illustrated embodiment, strap buckles 24. The strap buckles 24 detachably affix, in the illustrated embodiment, to a corresponding set of tabs 26, which project rearward from the visor 16.

(15) The oral-nasal unit 14 is manufactured from a unitary silicone rubber moulding, and can be seen more clearly in FIGS. 2 and 3 of the drawings. The oral-nasal unit 14 comprises a hollow main body portion 30 having a generally tetrahedral shape with an open face 32 into which a wearer's mouth and nose are placed, in use. The open face 32 is surrounded by an integrally formed, inwardly turned-over peripheral lip 34 whose three-dimensional profile is optimised to fit a particular group of a given population. The lip 34 comprises side portions 36 that are deformable in use to conform to the shape of a wearer's cheeks, and a lower portion 38 that is deformable in use to conform to the shape of a wearer's chin and lower lip, thereby forming an airtight seal when pressed against the wearer's face. When correctly worn, the oral-nasal unit 14 forms a hollow interior volume between the wearer's face and the interior walls of the oral-nasal unit 14, which can be sealed-off from the interior of the full-face mask 12 or the surrounding atmosphere, as shall be described below.

(16) The oral-nasal unit comprises a pair of circular inlet apertures 40 through which inspired air enters the hollow interior volume, and a circular exhale aperture 42 through which exhaled air passes, in use.

(17) Turning now to FIGS. 4 and 5, the oral-nasal unit 14 is located within the full-face mask 12 and is connected thereto by a conduit portion 44 integrally formed with the visor 16. The conduit portion 44 comprises a frusto-conical tube having a bayonet-type fitting 46 at its inward end that engages with an exhale valve assembly 48. The exhale valve assembly 48 is also tubular and comprises a main body portion 50 that extends through the exhale aperture 42 of the oral-nasal unit 14 and into the open end of the conduit portion 44 of the visor 16. The exhale valve assembly 48 comprises a flange 52 that seats against an inner surface of the oral-nasal unit 12 such that when it is connected to the visor 16, the oral-nasal unit 14 is clamped between the flange 52 of the exhale valve assembly 48 and an inwardly-turned lip forming part of the bayonet-type fitting 46 of the conduit portion 44, to form an airtight seal.

(18) The exhale valve assembly 48 additionally comprises a flap valve diaphragm 54 that is retained by a retaining boss 56 that permits the diaphragm 54 to flex to allow exhaled air out of the respirator 10, but to prevent its inward flow.

(19) The outlet of the exhale valve assembly 48 communicates with an intermediate chamber 58 formed by the outer end of the conduit portion and an external cover plate 60, which clips to the front of the respirator 10, as can be seen in FIG. 1, which has a secondary outlet aperture 62 therein in fluid communication with the surrounding atmosphere. A secondary exhale filter (not shown) can be provided in the chamber 58, if desired, to filter exhaled air.

(20) When a wearer inhales, air is drawn into the interior of the oral-nasal unit 14 via the inlet apertures 40, which (in the full-face respirator 10 embodiment shown in FIGS. 1 and 6), communicate with the interior of the full-face mask 12. Thus, the oral-nasal unit 14 provides complete separation between the inhaled and exhaled air flows, thus preventing re-breathe, fogging of the visor 16 and undesirable moisture build-up within the respirator 10.

(21) The visor 16 additionally comprises three inhale apertures 70, each having a bayonet-type fitting to which a filter cartridge 72 can be affixed. One, two or three of the inhale apertures 70 can be used, depending on user requirements, however, in the illustrated embodiment, two filter cartridges 72 are used.

(22) As can be seen most clearly from FIG. 6, air enters the respirator 10 via the filters, as shown by arrows 74, and exits via the exhale valve, as shown by arrow 76. Although not shown in the illustrated embodiments, a connector conduit manufactured from a length of flexible tubing could be inserted between the inlet aperture 70 of the visor 16 and the corresponding inlet aperture 40 of the oral-nasal unit 14. Such a configuration would provide a double failsafe as there would be an effective seal between the users face and the visor, as well as a secondary seal between the oral-nasal unit and surrounding the user's nose and mouth. By making the connector conduit (not shown) from a flexible material, such as silicone rubber, it is possible to offer the oral-nasal unit 14 up to the visor and to connect its outlet aperture 42 to the exhale valve assembly of the visor and to rotate it into engagement therewith via the bayonet connector previously described. The connector conduit or conduits (not shown) could then be folded and bent into engagement with respective spigots (not shown) of the inlet aperture 70 of the visor 16 and the corresponding inlet aperture 40 of the oral-nasal unit 14, thereby forming a sealed passageway between the two for the passage of inhaled air. Suitably, the connector conduit comprises a resiliently deformable seal at either end thereof, which seals form an airtight seal between the inlet aperture 70 of the visor 16 and the corresponding inlet aperture 40 of the oral-nasal unit 14, respectively.

(23) A half-face respirator 100 is shown in FIGS. 7A, 7B, 8, 9, and 10J of the drawings, which comprises the same oral-nasal unit 14 as that described above. In this embodiment, however, there is no full-face mask 12, and so the oral-nasal unit 14 functions as the major air isolating component of the respirator 100. Nevertheless, most of the description that follows is applicable also to the full-face respirator 10 described previously.

(24) In FIGS. 7A and 7B, the half-face respirator 100 comprises an oral-nasal unit 14 connected to a harness assembly 102 to which a head harness (104A and B) is connected via adjustable, elasticated straps 160 (shown in FIG. 10J). The respirator 100 comprises a pair of filter cartridges 72 that connect to the inlet apertures 40 of the oral-nasal unit 14, through which the wearer inhales, in use. Exhaled air leaves the oral-nasal unit 14 via the exhale aperture 42, into an intermediate chamber 58 of the harness assembly 102 and out through a secondary outlet aperture 62 of the harness assembly 102.

(25) As can be seen from FIG. 8, the half-face respirator 100 is formed of a number of interlocking components, which facilitates breaking-down, cleaning, maintaining and replacing various components thereof during the life of the respirator 100.

(26) The oral-nasal unit 14 is connected to the harness assembly 102 by a relatively rigid, generally U-shaped plate 106 (when viewed from above), which seats against the correspondingly shaped surfaces of the interior of the oral-nasal unit 14. The plate 106 comprises a central portion 108 having a tubular extension 50 that forms part of the exhale valve assembly 54, and which extends through the exhale aperture 42 of the oral-nasal unit 14, as previously described. The oral-nasal unit 14 is thus sealingly clamped to the harness assembly 102 by connecting the tubular extension 50 to the harness assembly 102, i.e. by insertion and rotation.

(27) The U-shaped plate 106 additionally comprises integrally formed wing portions 110 each comprising a through aperture to which a filter connection bayonet tube 112 clips from the inside of the oral-nasal unit 14, as shown more clearly in FIG. 9.

(28) The bayonet tube 112 comprises a main body portion 114 and a flange 116 that seats against the exterior surface of the wing portion 108 of the U-shaped plate 106. As can be seen in inset 9c of FIG. 9, the flange 116 comprises a set of four clips 118, that clip into a correspondingly-shaped cut-out in the through aperture 122 of the side wing 110. The main body portion 114 extends through the aperture 122 and through the inlet aperture 40 of the oral-nasal unit 14, as shown by dashed line 124 in FIG. 9. The free end 126 of the main body portion 114 projects beyond the inlet aperture 40 of the oral-nasal unit 40 enabling the outlet 128 of the filter cartridge 72 to connect thereto via a bayonet-type connection.

(29) Referring to inset 9d of FIG. 9, the main body portion 114 of the bayonet tube 112 comprises a pair of diametrically opposes lugs 130, 132 at axially offset positions on the main body portion 114. The lugs 130, 132 extend around the exterior surface of the main body portion 114 through an angle C. The lugs 130, 132 are adapted to engage with corresponding ribs 136, 138 of the outlet 128 of the filter cartridge 72.

(30) Referring now to insets 9a and 9b of FIG. 9, the outlet 128 of the filter cartridge comprises a pair of inwardly-projecting ribs 136, 138 that are axially offset by a distance corresponding to the axial offset of the lugs 130, 132. Each rib 136, 138 has an integrally-formed end stop 14 in the form of an axial abutment that prevents the lugs 130, 132 from sliding past a certain position. The ribs 136, 138 extend around the interior surface of the filter cartridge's outlet 128 through an angle A, leaving the remaining angle B as a clearance for the lugs 130, 132.

(31) The filter cartridge 72 can thus be offered up to the bayonet tube 112 at any angle whereby the first lug 130 lies within the clearance angle B of the first rib 138. Because the second lug 132 is axially offset relative to the first 130, the second lug 132 does not need to clear the first rib 138. The filter cartridge 72 can thus be pushed home and rotated. If the lugs 130, 132 engage the outer surfaces of the ribs 136, 138, the filter cartridge can be rotated until a clearance is located whereupon it will push into position. Further rotation of the filter cartridge 72 results in the lugs 130, 132 sliding over the ribs 136, 138 until they locate behind their respective ribs 136, 138 until, eventually, the lugs 130, 132 abut the end stops 140 indicating that the filter cartridge 72 has been correctly attached. If, say, the filter cartridge 72 is offered-up at an incorrect angle, because the lugs 130, 132 and ribs 136, 138 are axially offset, there is only one locking position, and so the filter cartridge 72 cannot be affixed incorrectly.

(32) The lugs 130, 132 and/or the ribs 136, 138 comprise an inclined surface and/or a detent, which respectively serve to clamp the flange 116, and hence the wings 110 into sealing engagement with the oral-nasal unit 14; and to provide a positive “click” to indicate correct alignment and to inhibit disconnection of the filter-cartridge 72.

(33) Finally, FIG. 10 shows a kit of parts in accordance with the invention, for forming a full-face respirator 10 or a half-face respirator 100 from a common set of components, which are suitably provided in a single package or kit 200.

(34) The kit comprises a common set of components, namely the oral-nasal unit 14 and the exhale valve components 106, 54, 56. A range of oral-nasal units 14 may be provided, for example, in different sizes and shapes and/or manufactured from different materials, such that each wearer can be individually fitted with a suitable oral-nasal unit appropriate to their face geometry. A set of components, including the visor 12 (which can also be provided in different sizes and shapes to fit different user's face geometries), face seal 22, face seal retaining clip 150 and the front cover components 152 can be attached to the common components to form the full-face respirator 10. A set of components, including the harness assembly components 102 can be added to the common components to form the half-face respirator 100. Further, consumable components, such as filter cartridges of various specifications can be included in the kit, or supplied separately.

(35) By providing a range of oral-nasal units and visors/face seals, each user can have an oral-nasal unit and visor correctly fitted. The ability to mix and match different oral-nasal units and visors/face seals in a single system represents a significant step forward in the design and provision of respirators because it affords much greater flexibility in designing and fitting respirators. As such, each user can be issued with an individual “PPE kit” comprising an individually-fitted oral-nasal unit that can be worn as a half-mask respirator, and an individually-fitted visor/face seal that enables the half-mask respirator to be converted into a full-face respirator as and when required.

(36) The invention is not restricted to the details of the foregoing embodiments, which are merely exemplary of the invention. For example, the shape and configuration of various components, their dimensions and materials of manufacture may be changed without departing from the invention. Moreover, the respirator may be provided as a half-mask respirator, a full-face respirator, or a kit that can form either or both. The bayonet-type connection for the filter cartridges may be omitted in certain embodiments of the respirator, and/or the bayonet-type connector may be used in other applications.

(37) The respirator is suitably a PPE device, which may be adapted for various applications, such as chemical handling, spray painting applications, fire-fighting activities, construction work (including woodworking and glass-fibre work) and so forth, but this is not an exhaustive list.