GB2631534A - A protective face mask - Google Patents

Abstract

A positive pressure face fit test valve mountable over an exhalation valve 13 of a particulate respirator comprises a valve cap with at least one opening 33 therethrough rotationally mountable over a grill exhalation port body with at least one opening 31 therethrough and rotatable between an open condition in which the respective openings 31,33 are at least partially aligned and a closed condition in which the respective openings 31,33 are not aligned, sealing the exhalation valve for the user to conduct a positive pressure face fit leak test – without interfering with the normal function of the mask and minimising the chance that the face fit test can be actuated accidentally. The mask further comprises a mask body defining at least one inhalation pathway with filter elements and at least one exhalation valve, an outer frame removably attachable relative to the mask body and at least one head strap attachable to the outer frame and/or the mask body.

Description

A PROTECTIVE FACE MASK

Technical Field of the Invention

The present invention relates generally to the field of protective or safety masks to be worn by a user over their nose and mouth and more particularly to a protective face mask with a positive pressure lace lit test valve.

Background to the Invention

Protective face masks of certain classes are fitted with flexible flap valves to control the flow of air into and out of the mask. Such a mask is initially placed on the wearer's head and the retaining straps are adjusted as required to comfortably seal the mask against the wearer's face. The wearer then tests the integrity of the seal provided by the face mask before entering into a contaminated area or using hazardous materials by a method such as a positive pressure test.

One technique for the positive pressure testing of the integrity of the seal of the face mask is for the wearer to block the passage of air through the exhalation valve and then exhale into the mask. While the test response of individual masks can vary, a proper fitting mask should produce a high internal pressure. If the wearer feels a flow of air at one or more release points without first experiencing a significant build-up of pressure inside the mask, the fit is not proper. If the face mask seal passes the test, the wearer unblocks the exhalation valve and is ready to use the mask. When a sealing test failure occurs, the wearer must adjust the fit of the face mask and perform the test again until the test is successfully completed.

As explained in the Background portion of United Slates Patent Publication No. US2010132714, US Patent No. 5,299,448 to Maryyanek et al., provides a positive pressure test apparatus for a facepieee respirator having a flexible flap valve is disclosed that includes a cover, a central bore and a plunger. The plunger includes a button portion and an opposed flange portion that are connected by a stem. The is positioned for movement along the central bore in cover. The cover encloses flange portion and defines a plurality of vents. Flange portion has a frustoconical shape designed to cover the effective area of fluid communication through the exhalation valve. Flange portion includes a base or sealing interface that has a diameter that is significantly larger than the diameter of central bore. Button extends out from cover in the rest position and is pushed inwardly until flush with a surface of cover in the depressed position.

This apparatus has a rest position where the exhalation valve is open and a depressed position where flange portion seals the exhalation valve. A biasing means engages button portion and a shoulder in central bore and biases test apparatus to the rest position. Range portion seals the area of the exhalation valve in the facepiece respirator when button portion is depressed.

This apparatus is limited by the interface between the rim of the frustoconical flange element and the facepiece respirator to maintain a complete seal around the effective area of the exhalation valve and also by safety considerations. Maintaining the seal requires the proper angular orientation of the frustoconical flange base relative to the exhalation valve. Depending upon the materials used in apparatus and the exhalation valve, the flexing of stem or cover as a result of the downward pressure by the wearer to depress button, could angularly distort central bore and cause a breach of the intended sealing interface. Further, apparatus is a complex device that is dependent upon separate biasing means positioned in the central bore to disengage button 22 from the depressed position, flush with the surface of cover, to the rest position, where it projects outwardly from surface. Thus, if plunger were to jam in the depressed position, the wearer could not manually access button in order to break the seal of the exhalation valve.

US2010132714 then goes on to provide an alternative construction to prevent such jamming, in which after the face mask is positioned on the head of the wearer and the retaining straps adjusted for fit, sealing device is depressed to test the seal between the head of the wearer and face mask. To initiate the test process, the wearer or another individual moves cap by manually pushing top portion, against the biasing force of flexible link and relative to outer frame along the central longitudinal axis towards exhalation valve assembly. Link member aligns the movement of cap from the open position to the sealing position of device such that sealing surface 32 contacts and seals the border area of flap valve against predefined border area of valve scat to securely close exhalation valve.

It would therefore be an advance in the art to provide a mask with a positive pressure face fit test valve which solves any one or more of the abovementioned problems.

Existing design solutions currently on the market do not satisfy the above requirements and the new design below solves all of the cun-ent issues.

Summary of the Invention

According to one aspect of the invention, there is provided a protective mask comprising: i. a mask body defining at least one inhalation pathway therethrough relative to which one or more filter elements are provided; ii. at least one exhalation valve mounted to the mask body; iii. an outer frame removably attachable relative to the mask body; iv. at least one head strap attachable to the outer frame and/or the mask body; and v. a positive pressure face fit test valve mountable relative to the at least one exhalation valve and comprising a grill exhalation port body with at least one opening therethrough and a valve cap with at least one opening therethrough which is mountable over the grill exhalation port body and rotatable between an open condition in which the at least one opening through the valve cap is at least partially aligned with the at least one opening through the grill exhalation port body and a closed condition in which the at least one opening through the valve cap is not aligned with the at least one opening through the grill exhalation port body, sealing the test valve.

Providing a protective mask with these features gives the user a reliable mechanism to undertake a positive pressure face fit test as and when needed but which does not otherwise interfere with the normal function of the mask. The configuration also minimises the chance that the positive pressure face fit test can be actuated accidentally.

The at least one inhalation pathway is preferably a one-way inhalation pathway. The at least one exhalation valve preferably provides a one-way exhalation pathway.

The protective mask of an embodiment may be more correctly referred to as a particulate respirator. The protective mask may he provided for any purpose but in particular, is a master protect the wearer against inhalation of particulate material. The protective mask may he a half-face mask. The protective mask may have any rating, for example Pl, P2 or P3. The protective mask may include one or more HEPA filters or filter elements.

The protective mask comprises a mask body defining at least one inhalation 10 pathway therethrough relative to which one or filter elements are provided. The mask body will preferably abut the wearer's face when the mask is worn.

The mask body may be manufactured from any material. A material such as thermoplastic elastomer (TPE) is preferred, particularly a low allergen TPE. TPE and preferably be manufactured to be flexible, particularly in portions of the mask body which abut the wearer's face. This may assist with allowing the mask body to conform to different face contours.

The mask body will preferably be shaped to fit over a wearer's nose and mouth and extend downwardly over the wearer's chin. The mask body may preferably sealed to the wearer's face under force applied by the at least one head strap.

A volume is preferably defined within the mask body to receive the wearer's nose and mouth but to remain spaced therefrom.

The mask body may include a central ridge running from the top of the mask body to the bottom of the mask body and extending substantially down the centre of the mask body, separating a pair of side, cheek portions. As mentioned above, a lower part of the mask body may preferably sealed to the wearer's face under the wearer's chin.

The mask body defines at least one inhalation pathway. An inhalation pathway may be provided into the mask on at least one, and preferably both sides. In one embodiment, an inhalation pathway may extend through each of the cheek portions of 30 the mask body. An opening may be provided as a part of the at least one inhalation pathway. The opening may he provided with a one-way valve assembly allowing air to be drawn into the mask body when the wearer inhales.

A shaped recess may be provided about the opening. The shaped recess may be partially conical with the opening provided at the smaller end thereof. The shaped recess may seat one or more filter elements relative to the mask body. Preferably, the one or more filter elements are provided relative to the mask body over the opening such that any air drawn into the mask body will be drawn into the mask body through the one or more filter elements.

The one or more filter elements may comprise a filter and in some cases, a pre-10 filter. As mentioned above, the filter element may be a HEPA filter element. The one or more filter elements are preferably replaceable. Replacement of the one or more filter elements may require disassembly of the mask body from the outer filter frame.

The one or more filter elements are preferably held in place relative to the mask body by the juxtaposed outer filter frame. The outer filter frame may in some circumstances be attached to the mask body to sandwich the one or more filter elements between the mask body and the outer filter frame.

The protective mask may include at least one exhalation valve mounted to the mask body. The at least one exhalation valve is preferably mounted to the mask body in a lower part of the mask body. The at least one exhalation valve is preferably mounted to the chin portion of the mask body. The at least one exhalation valve is preferably downward facing. Providing a downward facing exhalation valve means that it is less likely that exhalation fumes steam or fog any glasses or goggles worn by the wearer of the mask.

The at least one exhalation valve preferably comprises a valve body mounted in a shaped opening in the mask body. The at least one exhalation valve is preferably a one-way exit valve for air. In one form, the valve body may be cylindrical and at least partially hollow. A valve diaphragm is preferably fitted relative to the valve body and allows exhalation to escape the volume defined within the mask body when the wearer breathes out. The valve diaphragm is preferably flexible and resilient. The valve body may have any shape but is preferably substantially circular. The valve diaphragm will usually correspond to the shape of the valve body in order to seal the valve body.

The protective mask may include an outer frame removably attachable relative to the mask body. The outer frame may have any configuration. In a simple form, the outer frame may be a planar portion configured to overlie the mask body approximately centrally and relative to which other components of the protective mask may he mounted. For example the outer frame may mount to an attachment strap and the other components of the mask may mount to the outer frame including the mask body, filter elements and one or more cheek parts and a lower grill exhalation port body. In a more complex form, the outer frame may be configured as an outer filter frame.

The mask body will preferably be provided with one or more fixture points to attach the outer filter frame relative to the mask body. In one form, the outer filter frame may be provided with one or more slot openings with a circular central portion provided in the outer filter frame. The one or more slot openings may preferably receive a corresponding T-shaped key provided on the mask body. Rotation of the T-shaped key after the T-shaped key has been received through the corresponding slot opening may cause abutment of the underside of the T-shaped key against an outer side of the outer filter frame to hold the outer filter frame to the mask body. Aligning the T-shaped key with the slot opening may allow removal or separation of the outer filter frame from the mask body. In one embodiment, a pair of fixture points are provided, one on either cheek portion of the mask body.

The outer filter frame may have a clamshell configuration with a pair of cheek parts and a lower grill exhalation port body. Each of the cheek parts may be provided with a grill or louvres in positions to at least partially overlie the one or more filter elements.

The pair of cheek parts and lower grill exhalation port body are preferably connected together through the provision of a central mount portion. Each of the cheek parts may be mounted to the central mount along an elongate hinge line which allows the cheek parts to be moved relative to the central mount. The grill exhalation port body may he mounted to a lower end of the central mount. The grill exhalation port body may he mounted to the central mount using a flexible hinge. The flexible hinge may he formed from plastic or similar material allowing the grill exhalation port body to he moved relative to the central mount. The flexible hinge may include an arched portion provided between the central mount and the grill exhalation port body.

The central mount may he generally rectangular when viewed from the front.

The cheek portions may preferably be hinged to either side of the central mount and the grill exhalation port body is preferably hinged to a lower end of the central mount.

An underside of the central mount may be provided with one or more engagement assembly is to engage or at least abut an outer side of the mask body to assist with alignment of the outer filter frame relative to the mask body.

In one form, the engagement assembly may include a pair of spaced apart ridges or extensions extending from an underside of the central mount and toward the mask body. The spaced apart ridges or extensions may preferably define a gap therehetween. A central ridge of the mask body is preferably received into the gap at least partially, when the outer filter frame is assembled onto the mask body. As mentioned, this will assist with alignment of the outer filter frame with the mask body. The cheek portions of the outer filter frame may then he folded over the corresponding portions of the mask body. The fixture point may be engaged to hold the outer filter frame and the mask body together. The grill exhalation port body may be folded over the at least one exhalation valve mounted to the mask body. The grill exhalation port body is preferably attached over the at least one exhalation valve mounted to the mask body and seals over the at least one exhalation valve so that exhaled breath is forced to leave the mask through the grill exhalation port body and the positive pressure face lit test valve.

A lower portion of the outer filter frame may preferably be releasably attached to the mask body by the grill exhalation port body.

At least one, and preferably a number of head strap attachment loops are provided on the outer filter frame. Preferably, a pair of head strap attachment loops are provided on each cheek portion, namely an upper attachment loop and a lower attachment loop.

At least one head strap may be provided attachable to the outer filter frame and/or the mask body. In a preferred embodiment, a head strap is provided to extend through the head strap attachment loops to hold the mask relative to the wearer's face. An upper head strap and a lower head strap may be provided. The head strap may be adjustable. The head straps may include a fastening system such as Velcro for example to change the effective length of the head strap to adjust the force with which the protective mask is held to the wearer's face.

The protective mask comprises a positive pressure face fit test valve mountable relative to the at least one exhalation port. The positive pressure face fit test valve preferably includes the grill exhalation port body provided on the outer filter frame and a valve cap provided relative to the grill exhalation port body.

The grill exhalation port body may have any shape configured to engage with the at least one exhalation valve on the mask body. As mentioned above, the grill exhalation port body will typically attach to the mask body over the at least one exhalation valve.

hi one form, the grill exhalation port body includes a circular portion to mount the valve cap relative thereto and to allow rotation of the valve cap relative to the grill exhalation port body.

The grill exhalation port body may be circular when viewed in plan. Preferably, the grill exhalation port body is cylindrical, with a preferably circular outer wall and a side wall extending from the periphery of the outer wall.

The outer wall may be continuous. The outer wall preferably includes one or more guide formations to provide or define the limit of movement of the valve cap relative to the grill exhalation port body. In one form, the guide formation may include a depression or depressed portion formed into the outer wall of the grill exhalation port body. The depression may be generally arcuate in shape. At least one nubbin may be provided in the depression, preferably on a base wall of the depression. More than one nubbin may be provided. The nubbin preferably extends upwardly from within the depression. The nubbin may be shaped. In particular, the nubbin may include arcuate corners or transition zones to allow interaction of the nuhhin with a nuhhin lock provided on the valve cap. In use, a nubbin lock provided on the valve cap may receive a portion of the nubbin thereinto when the valve cap is in the open and/or more preferably the closed position to releasably hold the valve cap in that position. The engagement between the nubbin lock and the nubbin may also provide audible and/or tactile feedback of the engagement between the nubbin and the nubbin lock and thereby, the position of the valve cap relative to the grill exhalation port body.

The side wall of the preferred grill exhalation port body is preferably provided with the at least one opening therethrough. Preferably a number of openings are provided spaced about the side wall. The openings are preferably equally spaced. In a preferred form, the side wall may include alternating solid portions and openings spaced around the sidewall.

At least one slot, and preferably a number of slots may be provided on an outer side of the grill exhalation port body. The slot or slots may preferably be provided about a lower end of the side wall. The slot or slots may preferably receive a corresponding tab provided on an inner side of the valve cap to attach the valve cap to the grill exhalation port body and allow rotation of the valve cap relative to the grill exhalation port body.

An inner side of the side wall of the grill exhalation port body may preferably include at least one, and preferably more than one engagement tab, to engage with a part of the exhalation valve and/or mask body to attach the grill exhalation port body to the exhalation valve and/or mask body. In a preferred embodiment, a number of engagement tabs are provided spaced about an inner rim of the side wall.

A lower edge of the side wall may be provided with at least one, and typically a plurality of abutment formations to abut the exhalation valve and/or mask body when the grill exhalation port body is attached relative thereto. The abutment formations will preferably minimise or prevent any rotation of the grill exhalation port body relative to the at least one exhalation valve or mask body when the valve cap is rotated between the open position and the closed position. The tolerance between the valve cap and the grill exhalation port body will necessarily be tight, forming at least a friction fit, so that a seal can be formed between the components when in the closed position to prevent air passing through the positive pressure face fit test valve. Due to the tight tolerance, relative movement of the valve cap and the grill exhalation port body in the high friction contact between the components attempts to cause sympathetic rotation of the grill exhalation port body when the valve cap is rotated. This in turn could decrease the effectiveness of the test valve. The abutment formations will resist and preferably prevent any sympathetic rotation of the grill exhalation port body when the valve cap is rotated. The resistance to sympathetic rotation will preferably also be assisted by the pair of spaced apart ridges or extension extending from the underside of the central mount of the outer filter frame which preferably receive a central ridge of the mask body thereinto as explained above.

The abutment formations may take any form which is configured to resist rotation and/or to anchor the grill exhalation port body relative to the at least one exhalation valve or mask body. For example, the abutment formations may be r include one or more wedges, teeth or fingers which extend from a lower edge of the side wall to abut the at least one exhalation valve or mask body. Preferably, a plurality of spaced apart abutment formations is provided about a lower edge of the grill exhalation port body.

The positive pressure face fit test valve also includes a valve cap. The internal shape of the valve cap preferably corresponds to an outer shape of the grill exhalation port body. In one form, the valve cap is preferably cylindrical including a substantially circular outer wall and a side wall depending from the periphery of the outer wall. The outer wall preferably includes at least one, and more preferably a number of openings.

The openings will preferably be spaced about the side wall. The openings will preferably be substantially equally spaced about the side wall. In a particularly preferred form, the side wall will include alternating solid portions and openings about the side wall.

In the closed condition, the solid portions of the side wall of the valve cap are preferably aligned with the at least one opening in the side wall of the grill exhalation port body, to close and seal the openings, thus sealing the positive pressure face fit test valve. in the open condition, the at least one opening in the side wall of the valve cap is at least partially aligned with the at least one opening in the side wall of the grill exhalation port body to allow exhalation through the positive pressure face fit test valve as normal as the wearer exhales. I 1

At least one engagement tab is preferably provided on an inner side of the side wall of the valve cap to engage with a slot provided in an outer side of the grill exhalation port body. This engagement will preferably attach the valve cap relative to the grill exhalation port body and also allow rotation, preferably guiding rotation. More than one engagement tab may be provided.

As mentioned above, a nuhhin lock may he provided on an inner side of the outer wall of the valve cap. The nuhhin lock will preferably at least partially correspond in shape to the shape of the nubbin. The nubbin lock may include at least one side wall defining a receiving depression in an end of the nubbin lock which faces the nubbin.

When the valve cap is rotated, particularly to the closed condition, the nubbin lock will preferably move on top of the nuhhin to engage the nubbin and hold the valve cap in position. The abutment formations and/or the pair of spaced apart ridges or extensions extending from the underside of the central mount of the outer filter frame are preferably also effective to minimise, and preferably substantially prevent rotation of the grill exhalation port body when the nubbin lock is engaged with and disengaged from the nubbin.

The protective mask may he provided in different configurations, for example including an eye covering or goggle portion which may be mounted relative to the outer frame and/or outer filter frame and which may mount one or more attachment straps.

Detailed Description of the Invention

In order that the invention may be more clearly understood one or more embodiments thereof will now he described, by way of example only, with reference to the accompanying drawings, of which: Figure 1 is an axonometric side view of a mask according to an embodiment with the test valve in an open condition.

Figure 2 is an axonometric side view of the mask illustrated in Figure 1 with the test valve in the closed condition.

Figure 3 is an axonometric exploded view of the mask illustrated in Figure 1.

Figure 4 is an exploded front view of the mask illustrated in Figure 1.

Figure 5 is an exploded side view of the mask illustrated in Figure 1.

Figure 6 is a close-up view of the test valve of the mask indicated by reference letter 'A' in Figure 2 in the open condition.

Figure 7 is a close-up view of the test valve of the mask indicated by reference letter 'A' in Figure 2 in the closed condition.

Figure 8 is n axonometric view of the test valve of the mask indicated by reference letter 'A' in Figure 2 with the valve cap removed.

Figure 9 is an axonometric view of the test valve body of the test valve shown in Figures 6 and 7, with diaphragm removed.

Figure 10 is an axonometric view of the test valve body of the test valve shown in Figures 6 and 7, with diaphragm in place.

Figure 11 is a front view of the test valve illustrated in Figure 10.

Figure 12 is underside view of the valve grill exhalation port of the mask illustrated in Figure 1.

Figure 13 is an axonometric front view of the valve cap of the mask illustrated in Figure 1.

Figure 14 is an axonometric underside view of the valve cap illustrated in Figure 13.

As illustrated, a protective mask 10 is provided. The protective mask 10 comprises a mask body 11 defining a pair of inhalation pathways therethrough relative to which one or more filter elements 12 are provided. An exhalation valve 13 is mounted to the mask body 11. An outer filter frame 14 is removably attachable relative to the mask body 11 and a pair of headstraps 15 are attachable to the outer filter frame 14.

The mask body 11 may be manufactured from any material. A material such as thermoplastic clastomer (TPE) is preferred, particularly a low allergen TPE. TPE and preferably he manufactured to he flexible, particularly in portions of the mask body which abut the wearer's face. This may assist with allowing the mask body to conform to different face contours.

The mask body 11 is shaped to fit over a wearer's nose and mouth and extend downwardly over the wearer's chin. The mask body 11 will seal to the wearer's face under force applied by the head straps 15.

Due to the shape of the mask body 11, a volume is defined within the mask body 11 to receive the wearer's nose and mouth but to remain spaced therefrom.

As shown, the mask body II includes a central ridge 17 running from the top of the mask body 11 to the bottom of the mask body 1 land extending substantially down the centre of the mask body 11. separating a pair of side, cheek portions. As mentioned above, a lower part of the mask body may preferably seal to the wearer's face under the wearer's chin.

An inhalation pathway is defined through each of the cheek portions of the mask body 11. In the illustrated embodiment, an opening (obscured under filter element 18) is provided as a part of each inhalation pathway. The opening is provided with a one-way valve assembly allowing air to be drawn into the mask body 11 when the wearer inhales.

A partially conical shaped recess (obscured under filter element 18) is provided about the opening, with the opening provided at the smaller end thereof. An outer portion of the shaped recess seats one or more filter elements 18 relative to the mask body 11. The one or more filter elements 18 are provided relative to the mask body 11 over the opening such that any air drawn into the mask body 11 will be drawn into the mask body 11 through the one or more filter elements 18.

The filter elements 18 may comprise a filter and in some cases, a pre-filter. As 25 mentioned above, the filter element may be a HEPA filter element. The one or more filter elements 18 are preferably replaceable. Replacement of the one or more filter elements will require disassembly of the mask body 11 from the outer filter frame 14.

hi the illustrated embodiment, the filter elements 18 are held in place relative to the mask body 1I by the juxtaposed outer filter frame 14. The outer filter frame 14 is attached to the mask body 11 to sandwich the filter elements 18 between the mask body 11 and the outer filter frame 14.

As shown in Figure 5 in particular, the exhalation valve 13 is mounted to the mask body 11 in a lower part of the mask body II, preferably mounted to the chin portion of the mask body 11. In this location, the exhalation valve 13 is downward facing.

As shown in Figures 9 to 11, the exhalation valve 13 comprises a valve body 19 mounted in a shaped opening in the mask body 11. The exhalation valve 13 provides a one-way exit valve for air. In the illustrated form, the valve body 19 is cylindrical and at least partially hollow. A flexible and resilient valve diaphragm 20 is fitted relative to the valve body 19 and allows exhales breath to escape the volume defined within the mask body 11 when the wearer breathes out. The valve diaphragm 20 corresponds to the shape of the valve body 19 in order to seal the valve body 19.

The mask body 11 shown is also provided with one or more fixture points 21 to attach the outer filter frame 14 relative to the mask body 11. As shown, the outer filter frame 14 may he provided with one or more slot openings 22 with a circular central portion provided in the outer filter frame 14. The slot openings22 receive a corresponding T-shaped key of the fixture point 21 provided on the mask body 11. Rotation of the T-shaped key after the T-shaped key has been received through the corresponding slot opening 22 cause abutment of the underside of the T-shaped key against an outer side of the outer filter frame 14 as shown in Figures 1 and 2, to hold the outer filter frame 14 to the mask body 11. Aligning the T-shaped key with the slot opening 22 allows removal or separation of the outer filter frame 14 from the mask body 11. In one embodiment, a pair of fixture points 21 are provided, one on either check portion of the mask body 11.

As shown, the outer filter frame 14 has a clamshell configuration with a pair of cheek parts 23 and a lower grill exhalation port body 24. Each of the cheek parts 23 is provided with a grill 25 in positions to at least partially overlie the one or more filter elements 18.

As best shown in Figure 12, the pair of check parts 23 and lower grill exhalation port body 24 of the illustrated embodiment are connected together through the provision of a central mount portion 26. Each of the cheek parts 23 are mounted to the central mount 26 along an elongate hinge line which allows the cheek parts 23 to be moved relative to the central mount 26. The grill exhalation port body 24 is mounted to a lower end of the central mount 26 using a flexible hinge 27. The flexible hinge 27 of this embodiment is formed from plastic or similar material allowing the grill exhalation port body 24 to be moved relative to the central mount 26. The flexible hinge 27 may include an arched portion provided between the central mount 26 and the grill exhalation port body 24.

The central mount 26 is generally rectangular when viewed from the front. The cheek portions 23 are hinged to either side of the central mount 26 and the grill exhalation port body 24 is preferably hinged to a lower end of the central mount 26.

An underside of the central mount 26 as shown in Figure 12, is provided with a pair of spaced apart extensions 28 extending from an underside of the central mount 26 and toward the mask body 11. The spaced apart extensions 28 define a gap 29 therehetween. The central ridge 17 of the mask body 22 is received into the gap 29 at least partially, when the outer filter frame 14 is assembled onto the mask body 11. As mentioned, this will assist with alignment of the outer filter frame 14 with the mask body 11.

The cheek portions 23 of the outer filter frame 14 can then be folded over the corresponding portions of the mask body 11. The fixture points 21 are engaged to hold the outer filter frame 14 and the mask body 11 together. The grill exhalation port body 24 can he folded over the exhalation valve 13 mounted to the mask body 11 and is attached over the exhalation valve 13. The grill exhalation port body 24 seals over the exhalation valve 13 so that exhaled breath is forced to leave the mask 10 through the grill exhalation port body 24 and the positive pressure face fit test valve 16.

As shown, a pair of head strap attachment loops 30 are provided on each cheek portion 23, namely an upper attachment loop and a lower attachment loop.

In the illustrated embodiment, a head strap 15 is provided to extend through the head strap attachment loops 30 to hold the mask 10 relative to the wearer's face. An upper head strap and a lower head strap are provided. Both head straps 15 are adjustable. The head straps may include a fastening system such as Velcro for example to change the effective length of the head strap 15 to adjust the force with which the protective mask 10 is held to the wearer's face.

As illustrated best in Figures 6 to 14, the protective face mask 10 also includes a positive pressure face fit test valve 16 ( 'A' in Figure 2) mountable over the exhalation valve 13. The illustrated positive pressure face fit test valve 16 comprises the grill exhalation port body 24 which has a number of openings 31 therethrough and a valve cap 32 with a number of openings 33 therethrough which is mountable over the grill exhalation port body 24. The valve cap 32 is rotatable relative to the grill exhalation port body 24 between an open condition in which the opening 33 through the valve cap 32 are at least partially aligned with the openings 31 through the grill exhalation port body 24 and a closed condition in which openings 33 through the valve cap 33 are not aligned with the openings 31 through the grill exhalation port body 24. Instead, solid parts 34 of the valve cap 32 cover the openings 31 in the grill exhalation port body 24, sealing the test valve 16.

The grill exhalation port body 24 may have any shape configured to engage with and seal over, the exhalation valve 13 on the mask body 11. As mentioned above, the grill exhalation port body 23 is attached to the mask body 11 and seals over the exhalation valve 13.

In the form shown in Figures 8 and 12 in particular, the grill exhalation port body 24 includes a circular body to mount the valve cap 32 relative thereto and to allow rotation of the valve cap 32 relative to the grill exhalation port body 24.

The grill exhalation port body 24 illustrated is circular when viewed in plan. The grill exhalation port body is cylindrical, with a circular outer wall 35 and a side wall 36 extending from the periphery of the outer wall 35.

The outer wall 35 includes a depression 37 to provide or define the limit of 30 movement of the valve cap 32 relative to the grill exhalation port body 24. The depression 37 is generally arcuate in shape. A nubbin 38 is provided in the depression 37 on a base wall of the depression 37. The nubbin 38 extends upwardly from within the depression 37. The nubbin 38 includes arcuate corners or transition zones to allow interaction of the nubbin 38 with a nubbin lock 39 provided on the valve cap 32. In use, the nubbin lock 39 provided on the valve cap 32 receives a portion of the nubbin 38 thereinto when the valve cap 32 is in the closed position to releasably hold the valve cap 32 in that position while a positive pressure test is performed. The opposite configuration could be used, with the nubbin used to releasably hold the valve cap 32 in an open position to prevent accidental movement of the valve cap to the closed condition.

The engagement between the nubbin lock 39 and the nubbin 38 may also provide audible and/or tactile feedback of the engagement between the nubbin 38 and the nubbin lock 39 and thereby, the position of the valve cap 32 relative to the grill exhalation port body 24.

The side wall 36 of the grill exhalation port body 24 is provided with a number of openings 31 therethrough. The openings 31 are provided equally spaced about the side wall 36, separated by alternating solid portions 40 spaced around the sidewall 36.

A number of slots 41 are provided on an outer side of the grill exhalation port body 24. The slots 41 are provided about a lower end of the side wall 35. The slots 41 receive a corresponding tab 42 provided on an inner side of the valve cap 32 to attach the valve cap 32 to the grill exhalation port body 24 and allow rotation of the valve cap 32 relative to the grill exhalation port body 24.

An inner side of the side wall 35 of the grill exhalation port body 24 includes a number of engagement tabs 43, to engage with a part of the exhalation valve 13 and/or mask body 11 to attach and seal the grill exhalation port body 24 to the exhalation valve 13 and/or mask body 11. As shown, a number of engagement tabs 43 are provided spaced about an inner rim of the side wall 35.

As shown in Figure 12 in particular, a lower edge of the side wall 35 is provided with a plurality of abutment fingers 42 to abut the exhalation valve 13 and/or mask 30 body 11 when the grill exhalation port body 24 is attached relative thereto. The abutment fingers 42 act to minimise or prevent any rotation of the grill exhalation port body 24 relative to the exhalation valve 13 or mask body 11 when the valve cap 32 is rotated between the open position and the closed position. The tolerance between the valve cap 32 and the grill exhalation port body 24 will necessarily be tight, forming at.

least a friction fit, so that a seal can he formed between the components when in the closed position to prevent air passing through the positive pressure face fit test valve 16. Due to the tight tolerance, relative movement of the valve cap 32 and the grill exhalation port body 24 in the high friction contact between the components attempts to cause sympathetic rotation of the grill exhalation port body 24 when the valve cap 32 is rotated. This in turn could decrease the effectiveness of the test valve 16. The abutment fingers 42 resist and preferably prevent any sympathetic rotation of the grill exhalation port body 24 when the valve cap 32is rotated. The resistance to sympathetic rotation will preferably also he assisted by the pair of spaced apart extensions 28 extending from the underside of the central mount 26 of the outer filter frame 14 which receive the central ridge 17 of the mask body 11 thereinto as explained above.

The internal shape of the valve cap 32 preferably corresponds to an outer shape of the grill exhalation port body 24. In the illustrated form, the valve cap 32 is preferably cylindrical including a substantially circular outer wall and a side wall depending from the periphery of the outer wall. The side wall includes alternating solid portions 34 and openings 33 about the side wall.

In the open condition illustrated in Figure 6, the openings 33 in the side wall of the valve cap 32 arc at least partially aligned with the openings 31 in the side wall of the grill exhalation port body 24 to allow exhalation through the positive pressure face fit test valve 16 as normal as the wearer exhales.

In the closed condition illustrated in Figure 7, the solid portions 34 of the side wall of the valve cap 32 are aligned with the openings 31 in the side wall of the grill exhalation port body 24, to close and seal the openings 32, thus sealing the positive pressure face fit test valve 16.

Engagement tabs 42 are provided on an inner side of the side wall of the valve cap 32 to engage with a respective slot 41 provided in an outer side of the grill exhalation port body 24. This engagement will attach the valve cap 32 relative to the grill exhalation port body 24 and also allow rotation, preferably guiding rotation.

As shown in Figure 14, the nubbin lock 39 provided on an inner side of the outer wall of the valve cap 32 will preferably at least partially correspond in shape to the shape of the nubbin 38. When the valve cap 32 is rotated, particularly to the closed condition, the nubbin lock 39 will preferably move on top of the nubbin 38 to engage the nubbin 38 and hold the valve cap 32 in position. The abutment fingers 42 and/or the pair of spaced apart extensions 28 extending from the underside of the central mount 26 of the outer filter frame 14 are preferably also effective to minimise, and preferably substantially prevent rotation of the grill exhalation port body 24 when the nubbin lock 39 is engaged with and disengaged from the nubbin 38.

The one or more embodiments are described above by way of example only. Many variations are possible without departing from the scope of protection afforded by the appended claims.

Claims (25)

1. CLAIMS1. A protective face mask comprising: a. a mask body defining at least one inhalation pathway therethrough relative to which one or more filter elements are provided; b. at least one exhalation valve mounted relative to the mask body; c. an outer frame removably attachable relative to the mask body; d. at least one headstrap attachable to the outer filter frame and/or the mask body; and e. a positive pressure face fit test valve mountable relative to the at least one exhalation valve and comprising a grill exhalation port body with at least one opening therethrough and a valve cap with at least one opening therethrough which is mountable over the grill exhalation port body and rotatable between an open condition in which the at least one opening through the valve cap is at least partially aligned with the at least one opening through the grill exhalation port body and a closed condition in which the at least one opening through the valve cap is not aligned with the at least one opening through the grill exhalation port body, sealing the test valve.
2. 2. A protective face mask as claimed in claim 1 wherein the outer frame is an outer filter frame having a clamshell configuration with central mount portion and a pair of cheek parts and a lower grill exhalation port body mounted to the central mount using a flexible hinge, an underside of the central mount provided with one or more engagement assemblies to engage or at least abut an outer side of the mask body to assist with alignment of the outer filter frame relative to the mask body.
3. 3. A protective face mask as claimed in claim 2 wherein the one or more engagement assemblies include a pair of spaced apart ridges or extensions extending from an underside of the central mount and toward the mask body defining a gap therebetween into which a central ridge of the mask body is at least partially received, when the outer filter frame is assembled onto the mask body.
4. 4. The protective face mask as claimed in any one of the preceding claims wherein the grill exhalation port body engages and seals relative to the at least one exhalation valve on the mask body.
5. 5. The protective face mask as claimed in any one of the preceding claims wherein the grill exhalation port body is cylindrical, with a circular outer wall and a side wall extending from a periphery of the outer wall.
6. 6. The protective face mask as claimed in claim 5 wherein the outer wall comprises one or more guide formations to provide or define limits of movement of the valve cap relative to the grill exhalation port body.
7. 7. The protective face mask as claimed in claim 6 whcrcin the one or more guide formations includes a depression formed into the outer wall.
8. 8. The protective face mask as claimed in claim 7 further including at least one nubbin provided in the depression, extending upwardly from within the depression.
9. 9. The protective face mask as claimed in claim 8 further including a nubbin lock provided on the valve cap, engageable with the nubbin when the valve cap is in the open and/or the closed position to releasably hold the valve cap in that position.
10. 10. The protective face mask as claimed in any one of clams 5 to 10 wherein the sidcwall includes alternating solid portions and openings spaced around the sidcwall.
11. The protective face mask as claimed in any one of the preceding claims further including at least one slot provided on an outer side of the grill exhalation port body to receive a corresponding tab provided on an inner side of the valve cap to attach the valve cap to the grill exhalation port body and allow rotation of the valve cap relative to the grill exhalation port body.
12. 12. The protective face mask as claimed in any one of the preceding claims further including at least one engagement tab, to engage with a part of the exhalation valve and/or mask body to attach the grill exhalation port body to the exhalation valve and/or grill exhalation port body.
13. 13. The protective face mask as claimed in any one of the preceding claims further including at least one abutment formation provided about lower part of the grill exhalation port body to abut the exhalation valve and/or mask body when the grill exhalation port body is attached relative thereto.
14. 14. The protective face mask as claimed in claim 13 wherein a plurality of abutment formations is provided.
15. 15. The protective face mask as claimed in claim 14 wherein the abutment formations are or include one or more wedges, teeth or lingers which extend from a lower edge of the grill exhalation port body to abut the at least one exhalation valve or mask body.
16. 16. The protective face mask as claimed in any one of the preceding claims wherein the valve cap is cylindrical including a substantially circular outer wall and a side wall depending from a periphery of the outer wall.
17. 17. The protective face mask as claimed in claim 16 wherein the outer wall includes a number of openings alternating with solid portions about the side wall.
18. 18. The protective face mask as claimed in claim 16 or claim 17 wherein a nubbin lock is provided on an inner side of the outer wall of the valve cap to engage the nubbin and hold the valve cap in position.
19. 19. The protective face mask as claimed in any one of the preceding claims wherein the at least one inhalation pathway is a one-way inhalation pathway.
20. 20. The protective face mask as claimed in any one of the preceding claims wherein the at least one exhalation valve provides a one-way exhalation pathway which is covered by the positive pressure face fit test valve.
21. 21. The protective face mask as claimed in any one of the preceding claims wherein the one or more filter elements are held in place relative to the mask body by the juxtaposition of the outer filter frame.
22. 22. The protective face mask as claimed in any one of the preceding claims wherein the outer filter frame is releasably attached to the mask body to sandwich the one or more filter elements between the mask body and the outer filter frame.
23. 23. The protective face mask as claimed in any one of the preceding claims wherein the at least one exhalation valve is mounted to the mask body in a lower part of the mask body to be downward facing.
24. 24. The protective face mask as claimed in any one of the preceding claims wherein the at least one exhalation valve comprises a valve body mounted in a shaped opening in the mask body and a flexible and resilient valve diaphragm fitted relative to the valve body to allow exhaled breath to escape the mask body when the wearer breathes out.
25. 25. The protective face mask as claimed in any one of the preceding claims wherein a lower portion of the outer filter frame is releasably attached to the mask body by the grill exhalation port body.