CN112274794A

CN112274794A - Face mask

Info

Publication number: CN112274794A
Application number: CN202010704286.7A
Authority: CN
Inventors: R·A·H·雷克斯; 陈伟忠; 潘雯
Original assignee: Koninklijke Philips NV
Current assignee: Koninklijke Philips NV
Priority date: 2019-07-22
Filing date: 2020-07-21
Publication date: 2021-01-29
Anticipated expiration: 2040-07-21
Also published as: EP3846913A1; CN213374825U; CN112274794B; WO2021013663A1; EP3846913B1; KR102391451B1; JP2022530695A; KR20210057823A

Abstract

A mask has a shell and a filter member. A fan module is used, thereby defining an active mask. When the mask is worn by a user, a mask cavity is defined inside the filter member and a chamber is defined between the shell and the filter member. The battery module is positioned within the cavity.

Description

Face mask

Technical Field

The present invention relates to a mask for providing contaminant filtration.

Background

Air pollution is a global problem. The World Health Organization (WHO) estimates that 400 million people die of air pollution each year. Part of this problem is the outdoor air quality in cities. Nearly 300 cities affected by smoke do not meet the national air quality standards.

The official outdoor air quality standard defines particulate matter concentration as mass per unit volume (e.g., μ g/m)³). One particular problem is contamination of particles smaller than 2.5 μm in diameter (referred to as "PM 2.5") because they are able to penetrate into the gas exchange regions of the lungs (alveoli), and very small particles (R) ((R))<100nm) may pass through the lung and affect other organs.

Since this problem is not significantly improved in the short term, a common method of dealing with this problem is to wear a mask, which provides cleaner air by filtration, and in recent years, the market for masks in china and other areas has increased dramatically.

Such a mask may be made of a material that acts as a contaminant particle filter, or may have a filter for only a portion of the mask surface, and the filter may be replaced when it becomes clogged.

However, during use, the temperature and relative humidity inside the mask increase and, in addition, a pressure differential inside the mask relative to the outside causes breathing discomfort. This can be partially mitigated by providing an outlet valve or check valve which allows exhaled air to escape from the mask with little resistance, but requires inhaled air to be drawn through the filter. To improve comfort and effectiveness, a fan may be added to the mask that draws air through the filter and/or provides assistance during exhalation.

One possible benefit to the wearer of the use of a fan-powered mask is the reduction of light pressure on the lungs caused by inhaling against the resistance of the filter in a conventional unpowered mask. Furthermore, in conventional unpowered masks, inhalation also results in a slight pressure drop within the mask, resulting in leakage of contaminants into the mask, which may be dangerous if the contaminants are toxic substances.

Therefore, the fan assisted mask can improve breathing comfort by reducing temperature, humidity and breathing resistance.

In one arrangement, an inlet (i.e. suction) fan may be used to provide continuous intake of air. In this way, the slight pressure on the lungs caused by inhaling against the resistance of the filter in conventional unpowered masks is relieved. A steady flow of air may then be provided to the face, and a slight positive pressure may be provided, for example, to ensure that any leakage is outward rather than inward. However, this adds additional resistance to breathing during exhalation.

In another arrangement, an exhaust (i.e., exhalation) fan may be used to provide a continuous release of air. Instead, this provides breathing assistance when exhaling. The exhalation fan may be used in conjunction with a series check valve so that no air flow through the fan enters the inlet hood.

The fan again establishes a continuous flow of air through the mask. Air is drawn through the filter into the hood cavity by flow induced by the fan or by suction. This improves the comfort of the wearer.

Another option is to provide both an inlet fan and an exhaust fan and to synchronize the timing of the control of the fans with the user's breathing cycle. The respiratory cycle may be measured based on pressure (or differential pressure) measurements. This improves control over temperature and humidity and reduces respiratory resistance during inspiration and expiration.

Thus, several types of masks are available for preventing routine exposure to airborne contaminants, including passive masks, passive masks with exhalation valves, and masks with at least one active fan.

The present invention generally relates to active masks. They are battery powered devices and battery life is critical. In particular, it is desirable to obtain the longest battery life from a given battery quality. One problem is that the performance of the battery depends on the temperature. This is particularly problematic for masks, as they are used outdoors and are required to be used throughout the year.

Disclosure of Invention

The invention is defined by the claims.

According to an example of an aspect of the present invention, there is provided a mask comprising:

a housing;

a filter member for mounting inside the housing, wherein a mask cavity is defined between the filter member and a user's face and a chamber is defined between the housing and the filter member when the mask is worn by the user;

a fan module to generate flow between the mask cavity and the ambient environment; and

a battery module is provided with a battery cell and a battery cell,

wherein a battery module is located within the chamber.

Accordingly, the present invention relates to a mask design having a two-layer structure of a filter member and a shell. The filter member is flexible (so that it can conform to the contours of the user's face).

The mask is designed to form a chamber between the filter member and the shell. A portion of the wearer's exhaled air passes through the chamber. As a result, the chamber is also maintained at a higher temperature during cold periods as the user's breath continuously replenishes the air content in the chamber. By placing the battery module within the chamber, the battery module is exposed to higher temperatures and therefore has a longer life under such conditions.

The battery module is preferably located in the path of the user's exhaled air when the mask is worn by the user. In this way, the heat of the user's exhalation gases is directly used to heat the battery module.

The battery module is located, for example, in the front region of the mask. This means that it is the approximate area in front of the mouth and nose, not the top, bottom or sides of the mask. In this way, it is in the path of air exhaled from the nose or mouth of the user.

The battery module and the fan module are, for example, independent units installed separately from each other. By separating the fan module and the battery module (which powers the fan module), concentration of heavy components at individual locations of the mask is avoided.

The mask body, for example, includes opposing side edges adapted to face at least partially laterally outward when the mask is worn by a user, the fan assembly being mounted at one of the opposing side edges and the battery module being mounted at the other of the opposing side edges.

By providing the fan module and the battery module on opposite sides, the balance is improved.

The fan module preferably includes an exhaust fan for exhausting air from the mask cavity. However, only a portion of the exhaled air passes through the fan; another part passes through the chamber and thereby increases the chamber temperature. Thus, even if an expiratory fan is used, the exhaled air can still be used for battery heating.

The fan module may include a centrifugal fan having an axial inlet in communication with the interior of the mask cavity and a radial outlet outside the mask cavity. The centrifugal fan is compact and the radial outlet can be easily hidden from view to provide a desired aesthetic appearance.

The battery module is for example part of a control unit which further comprises a fan control circuit for the fan module.

An electrical connector is preferably disposed between the fan module and the battery module, within the cavity. The electrical connections form, for example, a bridge between the opposite sides of the mask. The battery module (or control unit) is for example attached to the inner surface of the housing or removably attached to the filter member.

The filter member may comprise a first connector portion and the fan module may comprise a second connector portion for connecting to the first connector portion to releasably secure the fan module to the filter member. Thus, the fan module may be detached from the filter member, so that the filter member may be replaced or cleaned without replacing the fan module.

The first and second connector portions are, for example, push-fit together to enable the filter member to be attached to and detached from the fan module. This makes assembly and disassembly easy.

The housing has an opening, for example, and the fan module extends through the chamber and through the opening in the housing. This is one way of mounting the module with a housing that is mounted on the fan module. This provides a simple assembly method.

The fan module may comprise a third connector portion and the housing may comprise a fourth connector portion for connecting to the third connector portion to secure the housing to the fan module, wherein the fan module protrudes through the opening.

This further coupling between the fan module and the housing, such as the inner edge around the opening in the housing, provides a positional location of the fan module relative to the position of the housing. Thus, the air flow characteristics into and out of the fan module remain consistent regardless of any shape adjustment of the flexible filter member. The set of connector portions also prevents leakage and improves user comfort.

The third connector portion may be a push-fit with the fourth connector portion.

These and other aspects of the invention are apparent from and will be elucidated with reference to the embodiments described hereinafter.

Drawings

For a better understanding of the present invention, and to show more clearly how it may be carried into effect, reference will now be made, by way of example only, to the accompanying drawings, in which:

FIG. 1 shows an example of a mask design to which the present invention may be applied;

FIG. 2 shows the design of FIG. 1 in an assembled state from one front side;

FIG. 3 shows the design of FIG. 1 in an assembled state from the opposite front side;

FIG. 4 is used to illustrate the manner in which components are attached to the wearer and shows an alternative design;

FIG. 5 shows battery temperature measurements and ambient temperature for a mask design according to the present invention;

FIG. 6 shows the outlet of a centrifugal fan;

FIG. 7 shows a first cross-sectional view of the design of the third and fourth connector portions;

FIG. 8 shows a second cross-sectional view of the design of FIG. 7; and

fig. 9 shows a possible design of the first and second connector parts.

Detailed Description

The present invention will be described with reference to the accompanying drawings.

It should be understood that the detailed description and specific examples, while indicating exemplary embodiments of the devices, systems and methods, are intended for purposes of illustration only and are not intended to limit the scope of the invention. These and other features, aspects, and advantages of the apparatus, systems, and methods of the present invention will become better understood with regard to the following description, appended claims, and accompanying drawings. It should be understood that the figures are merely schematic and are not drawn to scale. It should also be understood that the same reference numerals are used throughout the figures to indicate the same or similar parts.

The present invention provides a mask having a shell and a filter member contained within the shell. A fan module is used, thereby defining an active mask. When the mask is worn by a user, a mask cavity is defined inside the filter member (i.e., between the filter member and the user's face), and a chamber is defined between the shell and the filter member. The battery module is located in the cavity.

Fig. 1 shows an example of a mask design according to the present invention. The mask 10 is shown in exploded view and includes a shell 12 that serves as the mask body and a filter member 14 mounted inside the shell (i.e., on the side of the shell that faces the user's face). The housing is rigid or semi-rigid, with ear straps 13, while the filter member 14 is formed of fabric, for example, and is therefore easily deformable so that the outer edge can match the shape of the wearer's face.

The housing is porous so that air can flow through the housing. The shell improves the appearance of the mask. The housing may be made of a material that is itself porous, for example, it may be an air mesh, a polyurethane layer, a cotton blend fabric, or other porous material. However, it may alternatively be made of a non-porous material (e.g. a plastics material), but with openings to allow air flow. The gap between the housing and the filter member around the housing edge may alternatively or additionally be used to enable air flow.

The present invention is based on the recognition that a chamber 15 is defined between the housing 12 and the filter member 14 and can be used to provide protection for the battery, in particular by increasing the temperature of the battery in the winter season. The chamber 15 is an air chamber around the battery in which hot air is partially trapped. Furthermore, the placement of the battery is preferably selected so that it is in the path of the exhaled air of the user and is thus most efficiently heated by the exhaled air.

The filter member 14 is sealed around the connector module 16. The connector module 16 is intended to be connected to a fan module 20, in particular to a corresponding connector portion 17 of the fan module. The connection may be circular so that it allows relative rotation between the fan module 20 and the filter member 14. The fan module includes a centrifugal fan. The centrifugal fan has a small form factor and is able to overcome the flow resistance of the check valve.

The fan module is typically used to generate a flow between the mask cavity and the ambient environment (i.e., air outside of the housing 12).

In this particular example, the connector module 16 includes a check valve. Connector module 16 and fan module 20 may be considered together to form a fan assembly, and the two modules may be manually connected together and separated, such as by a simple push-fit. For example, a lip around one portion may mate with a recess around the other portion.

The control module 18 is coupled to the exterior of the filter member 14. The control module includes a fan module 20 of the fan assembly and a control unit 22. The control unit includes a battery module and other control circuits. The control unit 22 is located inside the housing (i.e. on the side facing the user's face) and outside the filter member (i.e. on the side facing away from the user's face), and is thus located in the chamber 15 defined between these two parts.

When the user wears the mask, the control unit 22, and thus the battery module, is located in the path of the user's exhaled air. For this purpose, it is positioned in the front region of the mask. The fan module of the design shown is offset to one side and the control unit is offset to the opposite side. However, both are generally located in front of the user's mouth and/or nose. The mask has side regions that overlie the cheeks of the user and are connected to ear straps 13, a top region that extends over the nose of the user, a bottom region that extends under the mouth (and chin) of the user, and a front region that bounds the top, bottom and side regions. A battery module is located in the front region. The front area of the housing may for example be considered to be an area corresponding to 50% or even 33% of the total surface area of the housing. The front region is symmetrical about a vertical center line and has a width of less than 60% or 50% of the total width of the housing, for example. For example, the height of the front region is less than 60% or 50% of the total height of the housing.

The control unit 22 includes, for example, a sensor. Note that the control circuitry may alternatively be located on the fan module side and integrated into the fan module. Thus, various additional circuit elements and battery modules may be divided between the fan module and the control unit in different ways.

There may be a single module containing all the components. In the more preferred example shown, the battery module is separate and remote from the fan module. This means that the weight of the component can be divided between different positions to provide better balance of the mask and reduce local loads.

This also means that the battery module is in a region that is not directly exposed to the exhaust flow driven by the fan (i.e., the flow through the fan), but is exposed to exhaled air that has passed through the filter. The battery module is therefore located in a chamber which is at least partially insulated and is thus able to maintain the higher temperatures caused by the gases exhaled by the user. For example, the air may have a lower moisture content due to the action of the filter member.

Thereby, the battery module of the control unit is protected from the surroundings by the housing 12 and is exposed to the breathing air of the user downstream of the filter member. This enables the battery module to be maintained at a high temperature with respect to the ambient environment.

The connector module 16 is permanently secured to the filter element 14 for disposal with the filter element 14 when the filter is replaced. The fan module 20 of the fan assembly is reusable and includes (at least) a fan drive circuit and a fan impeller.

Housing 12 has an opening 24 that receives fan module 20 of the fan assembly.

The inner surface of the housing may also have a receiving docking area for the control unit 22, or there may be a receiving docking area 26 on the outer surface of the filter member for positioning the control unit 22 (as shown in fig. 1). The control unit may be connected to the filter member or housing by magnetic coupling and, or alternatively, by mechanical alignment features.

An electrical connector 28 in the form of a bridge provides an electrical connection between the control unit 22 and the fan module 20 of the fan assembly for transmitting power and control signals.

The fan module 20 and control unit 22 of the fan assembly are located on opposite sides of the mask, i.e. one on each side of the wearer's nose. This provides a balanced weight distribution. By providing two modules, the weight of each individual part is reduced, thereby reducing the load at any one location.

In a preferred design, the fan module is an exhaust fan. In one of the simplest designs, it operates continuously to provide a continuous supply of air to the face (using air drawn through the mask filter). This provides temperature and humidity control. However, it may be operated in synchronism with the wearer's breathing (with appropriate breathing sensing), and it may be controlled bi-directionally. Alternatively, there may be separate inlet and exhaust fans, for example one for each side.

Preferably an exhaust fan is used. This means that the fan does not require a filter to reduce the air flow just before or after the fan. The user also finds the air blown on the face uncomfortable. The fan should be made waterproof because the exhaled air is humid and condensation can form at the air outlet and the fan.

Since the invention is particularly concerned with the location of the battery modules, all known fan control options can be applied.

Fig. 2 shows the design of fig. 1 in an assembled state from one front side, and fig. 3 shows the design of fig. 1 in an assembled state from the opposite front side.

The mask shown is designed in a V-shape when viewed from above. Thus, it has two opposing sides, and a ridge between the opposing sides.

Fig. 4 is intended to illustrate the manner in which the components are connected to the wearer and shows another design in which the control circuitry is on the fan module side and only the battery module 23 is on the opposite side.

The face 30 of the wearer is shown in cross-section from above.

The filter member 14 is connected to the housing 12 by fasteners 32. For example, the fasteners are push-fit snaps. The periphery of the filter member also carries an inwardly projecting seal 34 to form a substantially enclosed space between the filter member and the face 30.

When inhaling, air is drawn through the filter member 14 as indicated by arrows 36. The exhaust fan may be run during this time, providing flow 38, or the exhaust fan may be turned off to conserve power. When exhaling, the exhaust fan operates to generate flow 38, but there is also outward flow through the filter member, as indicated by arrows 40.

This flow 40 heats the chamber 15 between the filter member 14 and the housing 12.

The flow 36 may also continue (depending on the manner in which the fan is operated), but at this point the flow is not drawn in, but rather circulated out by the fan. Breathing comfort is improved, in particular because the fan removes exhaled air from the mask cavity and thus prevents rebreathing (recirculation) of previously exhaled and therefore stale air.

The fan module may, for example, include a fan, a one-way check valve, and a printed circuit board carrying control circuitry. The fan is located on top of the check valve.

In the example of fig. 4, connector module 16 and fan module 20 are again separable so that the filter member can be replaced (or cleaned) when the module is reused.

Fig. 5 shows a plot 42 of battery temperature measurements and a plot 44 of ambient temperature over time for a mask design according to the present invention. The mask is used in a-10 degree environment and is brought into the room and removed at time t 1.

In this example, the battery temperature is considered to be maintained at a temperature between 15 and 20 degrees above the ambient temperature.

In the preferred design shown, the fan module comprises a centrifugal fan having an axial inlet located inside the mask cavity and a radial outlet located outside the mask cavity.

Fig. 6 shows a front view of the mask and shows the radial outlets 50. For example, the location of the outlet is selected so that the outlet is not visible from the front and above the mask body, i.e., from the possible location of the eyes of another person. For example, the radial outlet may face downward or rearward (i.e., rearward toward the user).

In the basic design, the fan module 20 protrudes through an opening in the housing, but is a loose fit in the opening. It has been found that the movement of the fan module results in different flow characteristics, for example, because the outlet flow may hit the housing, thereby creating altered turbulence.

Accordingly, it is preferred to provide additional connections between fan module 20 and housing 12, particularly around the inner edge of opening 24 in housing 12. The use of a rim around the opening 24 in the housing also provides stability to the edges of the opening.

Fig. 7 shows one design example of the design of the connection device around the opening in the housing. Fig. 8 shows a cross-section along the line VII-VII to illustrate the connection between the fan module and the housing.

Fig. 7 shows the housing 12 with a primary structural layer 60.

The mask has four connector portions.

The filter member 14 comprises a first connector portion 16 (i.e. a connector module) and the fan module 20 comprises a second connector portion 17 for connecting to the first connector portion, thereby securing the fan module 20 to the filter member 14. These parts are shown in fig. 1 and fig. 7 and 8.

The fan module also has a third connector portion 70, as shown in fig. 8.

The housing 12 has a fourth connector portion 72 for connecting to the third connector portion 70 to secure the housing 12 to the fan module 20, which protrudes through the opening.

The fan module is thus connected to the filter in the manner already explained above, and there is a further coupling between the fan module and the housing. In this way, the fan module is fixed in position relative to the housing. Thus, the air flow characteristics into and out of the fan module remain consistent regardless of any shape adjustment of the flexible filter member.

The fourth connector portion 72 in the illustrated example comprises a ring around the inner edge of the opening 24. During mask assembly, fan module 20 is pushed through opening 24, and then it is locked in a fixed position.

Note that the connection is not intended to be released by the user, as the fan module and housing may remain attached while the filter member is removed for cleaning. However, the connection may be reversible, e.g., the user may have a different cover design.

The fourth connector part may be a single component, but for ease of assembly the example shown has a fourth connector part with a first ring 74 located outside the housing and a second ring 76 located inside the housing. Structural layer 60 is sandwiched between the first and second rings. Thus, the first and second rings provide a termination for the opening 24 in the structural layer 60. The structural layer 60 may have some flexibility, but it is more rigid than the filter member.

The first ring 74 and the second ring 76 may be mechanically snapped together or glued or welded together (e.g., by ultrasonic). They are plastic parts. For example, they may be formed from a thermoplastic material suitable for ultrasonic welding, such as Acrylonitrile Butadiene Styrene (ABS). Other plastics, such as polypropylene or polycarbonate, may also be used.

The first connector portion 16 and the second connector portion 17 are push-fit together to enable the filter member to be attached to and detached from the fan module as described above. The third connector portion 70 is also a push-fit with the fourth connector portion 72. This allows the fan module to be easily assembled to the housing.

The third connector part 70 is for example a recess around the outer side wall of the fan module and the fourth connector part 72 comprises resilient lugs 78, more preferably a set of resilient lugs, for engaging with the recess. This provides a snap-fit connection. The recess may completely surround the outer sidewall or there may be only one set of recess portions at the location of the resilient lugs.

Figure 8 shows the arrangement of the lugs and recesses in more detail. The resilient lugs 78 are biased outwardly (i.e., toward the center of the opening). It is pushed back by inserting the fan module and then it springs back into the recess 70. There may be a set of lugs, for example three or more, around the opening. However, continuous lugs are also possible.

The appearance of the first ring 74 (which is visible) is consistent so that the lug design does not detract from the visual appearance. The second ring 76 has a tab-forming region in which the connection between the first and second rings is interrupted. In the example shown, the lugs are located at the ends of the folded legs, and the folded legs extend into cavities formed in the first ring 74, as shown in FIG. 8.

When the fan module is in place, it protrudes through the opening and the radial outlet 50 is located outside the housing, e.g., extending outwardly beyond the outermost surface of the first ring 74. Thus, the radial outlets are positioned to minimize obstruction to the outlet flow. Alternatively, however, as schematically illustrated in fig. 6, the radial outlets are positioned in a desired positional relationship with the flow deflecting member 80.

Possible designs of the third and fourth connector parts are described above. For completeness, fig. 9 shows a possible design of the first and second connector parts. In fig. 9, the third and fourth connector portions are only schematically represented as

units

70, 72.

Fan module 20 of the fan assembly includes a main housing 86, an outer housing 82, a fan control circuit board 84, and a fan motor 88. There is also a fan wheel (not shown).

In this example, the connector module 16 includes an annular channel 90 and the fan module includes a spring-biased engagement feature 92.

The left diagram of fig. 9 shows the connector module 16 and the fan module 20 separated, and the right diagram shows the connector module and the fan module coupled together. When coupled together, the features 92 engage the annular channel 90, thereby attaching the connector module to the fan module by a push-fit.

The connector module 16 is connected to the filter member 14, for example by ultrasonic welding, to form a seal around the connector module 16. In this example, the connector module 16 defines a check valve 94, such as a rubber flap valve.

The annular channel 90 forms a ring 96 with a larger diameter above the channel. When connector module 16 is pushed into fan module 20 (the arrows are intended only to show relative movement), features 92 are deflected radially outward by ring 96 and then snap back into channel 90.

Because the channel is annular, the two modules can rotate relative to each other. Thus, the connection can be made without requiring precise angular calibration. This also means that little force is applied to the filter member, for example no significant twisting forces that could damage the filter material.

In the illustrated example, the feature 92 includes a tab. The lug includes a support arm and a head. The head is designed to fit into the channel, and the support arms provide a radially inward spring bias. The main housing 86 is designed to provide room for the lugs to deflect outward as they ride on the ring 96 during coupling.

There may be only two diametrically opposed lugs, or more preferably a set of three lugs, or there may be more than three lugs. The annular channel need not be continuous. Fan module 20 has the correct orientation, particularly so that electrical connector bridge 28 is in the correct position. Thus, only some angular degrees of freedom for adjustment are required, rather than full angular control. Thus, the annular channel may comprise a set of annular channel portions (one for each lug), but they need not form a continuous channel.

Of course, the channels and lugs may be interchanged, with the channels on the fan module and the lugs on the connector module.

The features 92 are preferably metal to provide greater resiliency and durability than plastic features.

The use of a spring-biased connection rather than an interference fit allows for periodic filter replacement (or disconnection for cleaning).

The filter member 14 may be attached to the housing in any suitable manner, and the snap shown is by way of example only. Preferably, a push-fit connection is used, as this allows the filter member to be easily connected and disconnected from the housing.

The above description relates to one design of a mask, in particular having a fan module protruding from a filter member through an opening in a housing. However, other configurations are possible, such as the fan module being mounted outside the housing.

Variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage. If the term "adapted" is used in the claims or the description, it is to be noted that the term "adapted" is intended to be equivalent to the term "configured to". Any reference signs in the claims shall not be construed as limiting the scope.

Claims

1. A mask (10) comprising:

a housing (12);

a filter member (14) for mounting inside the housing (12), wherein a mask cavity is defined between the filter member (14) and the user's face, and a chamber (15) is defined between the housing (12) and the filter member (14) when the mask is worn (10) by the user;

a fan module (20) for generating a flow between the mask cavity and an ambient environment; and

a battery module (23) for storing a battery,

wherein the battery module (23) is positioned within the chamber (15).

2. The mask (10) of claim 1, wherein the battery module (23) is positioned in a path of exhaled air of the user when the mask (10) is worn by the user.

3. The face mask (10) of claim 1 or 2, wherein the battery module (23) is positioned at a front region of the face mask (10).

4. The mask (10) according to any one of claims 1 to 3, wherein the battery module (23) and the fan module (20) are separate units mounted separately from each other.

5. The mask (10) according to claim 4, wherein the mask body includes opposing sides adapted to face at least partially laterally outward when the mask (10) is worn by a user, the fan assembly (20) is mounted at one of the opposing sides, and the battery module (23) is mounted at the other of the opposing sides.

6. The mask (10) according to any one of claims 1 to 5, wherein the fan module (20) comprises an exhaust fan for exhausting air from the mask cavity.

7. The facepiece (10), according to claim 6, in which said fan module (20) comprises a centrifugal fan having an axial inlet communicating with the interior of said facepiece cavity and a radial outlet (50) outside said facepiece cavity.

8. The face mask (10) according to any one of claims 1 to 7, wherein the battery module (23) is part of a control unit (22), wherein the control unit (22) further comprises a control circuit for the fan module (20).

9. The mask (10) according to any one of claims 1 to 8, comprising an electrical connector (28) positioned within the chamber (15) between the fan module (20) and the battery module (23).

10. The face mask (10) according to claim 8 or 9, wherein the battery module (23) is:

is attached to the interior of the housing (12); or

Is removably attached to the filter member (14).

11. The mask (10) according to any one of claims 1 to 10, wherein the filter member (14) comprises a first connector portion (16) and the fan module (20) comprises a second connector portion (17) for connecting to the first connector portion (16) to thereby releasably secure the fan module (20) to the filter member (14).

12. The mask (10) according to claim 11, wherein the first and second connector portions (16, 17) are push-fit together, thereby enabling the filter member (14) to be attached to and detached from the fan module (20).

13. The mask (10) according to any one of claims 1 to 12, wherein the shell (12) has an opening (24), and wherein the fan module (20) extends through the chamber (15) and through the opening (24) in the shell (12).

14. The face mask (10) according to claim 13, wherein the fan module (20) includes a third connector portion (70) and the shell (12) includes a fourth connector portion (72) for connecting to the third connector portion (70) to thereby secure the shell (12) to the fan module (20), wherein the fan module (20) protrudes through the opening (24).

15. The mask (10) according to claim 14, wherein the third connector portion (70) and the fourth connector portion (72) are a push-fit.