ES3035954T3 - Exhalation valve assembly for a wearable protective device - Google Patents

Abstract

An exhalation valve assembly for a portable protective device, said assembly comprising a valve support for receiving a valve member, in use, a valve cap (4), and a releasable mounting mechanism for releasably mounting said valve cap to said valve support so as to substantially cover said valve member, said mounting mechanism comprising a bayonet locking mechanism having a first part (110c) located on said valve support and a second part (20a, 20b, 20c) located on said valve cap (4), said first and second parts being configured to engage in a locked configuration when said valve cap (4) is rotated, in use, with respect to said valve support from an unlocked configuration.

Description

DESCRIPTION

Exhalation valve assembly for a wearable protective device

This invention relates generally to a face respirator mask incorporating an exhalation valve and a removable cover for said exhalation valve.

Many different types of face respirator masks are known for protecting the wearer against inhalation of hazardous vapors, preventing cross-infection, and the like. One such known mask comprises a resiliently flexible, e.g., rubberized, mask body configured to fit over the nose and mouth of the wearer during use and includes a generally central opening, in which an opening defining an airway is provided and which contains an array of radial support members, over which a flexible diaphragm configured to define a one-way exhalation valve is provided. The mask body is further provided with a pair of openings in opposite faces or “cheek”-shaped portions thereof, for receiving respective filter cartridges. In use, when a wearer inhales, the diaphragm seals the central opening and inhaled air is forced to pass through the filter cartridges to the wearer’s nose and mouth. When the user exhales, the force of the airflow causes the edges of the diaphragm to flex away from the support elements of the central opening, allowing exhaled air to pass through them and exit the mask.

It is necessary to cover the protective device over the diaphragm that forms the exhalation valve to prevent it from being damaged and/or clogged with debris, for example. However, it is equally important to allow periodic access to the diaphragm and its removal so that it and the corresponding exhalation airway components can be cleaned and then reassembled for future use. Therefore, a removable cover is generally provided for this purpose.

In prior art devices, such a removable cover is typically configured to grip and remove the face mask (in a linear direction). However, given the flexible nature of the mask body and the degree of deformation that can occur when a user secures the mask to their face, the valve cover can be inadvertently detached and removed with relative ease.

US2929376 describes a regulator in a respiratory apparatus comprising a housing open at one end, said housing forming a chamber with an inlet for respirable gas; valve means at said inlet biased in the closing direction by the pressure of said respirable gas and arranged to control the flow of respirable gas into said chamber; a diaphragm closing the open end of said housing and exposed on one side to the pressure of the gas in said chamber and on the other side to the pressure of a surrounding medium, said diaphragm being movable in response to differences in such pressures; means operative when said diaphragm moves inwardly relative to said housing, for opening said valve means and admitting respirable gas; a mouthpiece formed at the end of the housing opposite said diaphragm through which said respirable gas may be inhaled and spent gas exhaled; and an exhalation valve carried by said diaphragm and closing and opening therein, said exhalation valve being movable toward the open position, when the pressure in said chamber exceeds the pressure of the surrounding medium by a predetermined amount.

GB530289 describes an exhalation valve for gas masks, particularly for horses, comprising a threaded pin arranged in the centre of a bar connecting the annular valve seat and carrying the rubber or similar valve disc, and a nut-shaped screen screwed onto the pin from the inside, to clamp the flanged edge of the mask opening between the screen and the valve seat.

WO2006118599 describes a sealing device for positive pressure testing that is attached to a respiratory face mask and includes an outer frame integrally attached to a movable lid by a flexible linkage that biases the lid into an open position for operational use of the face mask against a manually applied force to move the lid into a sealed position for positive pressure testing to ensure proper fit of the face mask on the wearer. The method for positive pressure testing includes flexibly moving the sealing device from the open position to the sealing position such that the sealing surface of the lid tightly closes the exhalation valve assembly. The wearer then exhales into the mask to test the seal of the mask. When the test is complete, the sealing device is released and the inherent biasing force moves the lid from the sealing position to the open position.

WO2006037000 describes a respirator exhalation unit comprising a negative pressure valve and a selectively actuatable positive pressure valve assembly. The position of the positive pressure valve assembly can be selectively adjusted to convert the exhalation unit for use in multiple operating modes, such as a negative pressure mode, a supplied air mode, and a self-contained breathing apparatus (SCBA) mode. In addition, a closed circuit breathing apparatus (CCBA) adapter assembly can be connected to the exhalation unit for conversion to a CCBA mode of operation. Furthermore, the negative pressure valve divides the interior of the exhalation unit into two chambers, one of which functions as a dead space that protects the user from exposure to any harmful contaminants at the end of exhalation.

US4850346 describes breathing apparatus, for example, a half-mask respirator. A mask is provided with three ports of common dimensions, on any of which inhalation or exhalation fittings housing inhalation or exhalation valves can be mounted. Chemical and mechanical filtration cartridges usable alternately or in combination are described. Disposable chemical filtration cartridges are described having a novel closure and sealing structure. Bayonet-type couplings for coupling the filter housings to the inhalation breathing fittings and an audible device to indicate that the filter housings are properly coupled are described. The breathing valve is a thin, umbrella-shaped disc valve having a multiplicity of radiating ribs that bias the valve to the closed position.

Therefore, it would be desirable to provide a wearable protective device that includes an exhalation valve, in which a removable cover is provided that addresses this problem.

In accordance with the present invention, there is provided a respirator mask including an exhalation valve assembly, comprising a valve holder for receiving a valve element; a valve cover comprising an open-ended receptacle having side walls defining an enclosed space and a cover at one end thereof; wherein the valve cover comprises two outer cover sections, a first raised cover section and a second lower cover section, the first and second cover sections defining a vertical through hole therebetween; and a releasable mounting mechanism for releasably mounting the valve cover to the valve holder to substantially cover the valve element, the mounting mechanism comprising a bayonet locking mechanism having a first portion located on the valve holder and a second portion located on the valve cover, the first and second portions being configured to engage in a locked configuration when the valve cover is rotated relative to the valve holder from an unlocked configuration.

The mounting mechanism comprises at least three spaced locking elements on the valve stem, each locking element defining a locking edge, and at least three spaced openings in the valve stem, the location of the openings corresponding substantially to the location on the valve stem of the locking elements when the valve stem is positioned thereon, to substantially cover the valve stem such that the locking edge of each locking element engages a locking edge of a respective opening in the valve stem.

The valve cover openings extend over at least 50% of the axial length of the side walls of the open-ended receptacle having side walls defining the enclosed space.

The first part of the bayonet locking mechanism is provided on each locking edge of the locking element and the second part of the bayonet locking mechanism is provided on each locking edge of the valve cover openings.

The first part of the bayonet locking mechanism comprises a notch located along the locking edge of the locking elements, and the second part of the bayonet locking mechanism comprises a projection located along each length of the locking edge of the valve cover openings.

The locking edge on at least one face of the notch has a substantially convex curved profile along the direction of travel of the valve cover relative to the valve stem during its rotation from the non-locked configuration to the locked configuration.

The locking elements are located adjacent to substantially diametrically opposite edges of the valve holder and the valve cover openings are located adjacent to corresponding substantially diametrically opposite edges of the valve cover.

An inner edge of each notch is stepped or tapered with a relatively high slope, and the locking edge on at least one face of the notch is provided with a relatively shallow tapered profile.

The valve cover openings may extend between 50 and 75% of the axial length of the sidewalls. In an alternative illustrative embodiment, the valve cover openings may extend over more than 75% of the axial length of the sidewalls.

These and other aspects of the present invention will become apparent from the following specific description, in which embodiments of the present invention are described by way of example only and with reference to the accompanying drawings, where:

Figure 1 is a perspective view of an exhalation valve and cover according to an illustrative embodiment of the present invention;

Figure 2 is an exploded perspective view of a respiratory face mask incorporating the exhalation valve and cover of Figure 1;

Figure 3 is a schematic front view of the respiratory face mask of Figure 2, in its fully assembled configuration, but with the cover removed;

Figure 3a is a schematic side view of the respiratory face mask of Figure 3;

Figure 3b is a schematic partial front view of a portion of the locking mechanism used in the exhalation valve of Figure 1;

Figure 3c is a schematic partial side view of a portion of the locking mechanism used in the exhalation valve of Figure 1;

Figure 4 is a front view of the respiratory face mask of Figure 2 in its fully assembled configuration, including the cover in its unlatched configuration;

Figure 5 is a front view of the respiratory face mask of Figure 4, with the cover in its locked configuration;

Figure 6 is a partial side view of an exhalation valve according to an illustrative embodiment of the present invention, with the cover in its unlocked configuration; and

Figure 7 is a partial side view of the exhalation valve of Figure 6, with the cover in its locked configuration.

Referring to Figure 2 of the drawings, a respiratory mask including an exhalation valve according to an illustrative embodiment of the present invention comprises a rubberized mask body 6, a rigid inner body 1, a strap ring 2, a diaphragm 3, and an exhalation valve cage (or cover) 4. Each of these elements fits together to form a complete respiratory mask having side openings 36a for receiving a respective disposable filter cartridge (not shown). In its assembled form, the inner body 1 is sealed and fixed within the mask body 6, but the strap ring 2, the diaphragm 3, and the valve cover 4 can be removed and replaced as needed.

Referring to Figure 3 of the drawings, a generally central, substantially circular opening 6a is provided in a front face 6b of the mask body 6, the mask body 6 being formed of an elastically deformable material, for example rubber or the like. The inner body 1 defines a substantially rigid plate 1a defining a generally central, substantially circular collar 1b projecting outwardly from the opening 6a in the mask body 6. The collar 1b is traversed by six substantially equiangularly spaced support struts 8 extending substantially radially from a generally central bore 9. A pair of openings are provided in opposite faces of the mask body 6 and are configured to removably receive respective disposable filter cartridges of any known configuration.

Turning to Figure 2 of the drawings, a flexible diaphragm 3 is provided over the opening defined by collar 1b and is supported by struts 8, and secured by a rearwardly projecting pin which is formed integrally with diaphragm 3 and configured to be received within bore 9.

Referring further to Figures 3a to 3c of the drawings, three generally L-shaped locking elements 110 are formed integrally with the inner body and located adjacent the circumferential edge of the collar 1b. Each locking element 110 comprises an elongated leg portion 110a and a shorter flange portion 110b at its distal end extending substantially orthogonal to the longitudinal axis of the leg portion 110a to create the substantially L-shaped locking element 110. Each locking element 110 extends, from the proximal end of the respective leg portion 110a, outwardly and at a slight angle to the front face of the rigid plate 1a, and the flange portion 110b of each locking element 110 extends radially outwardly relative to the opening 6a and substantially parallel to the major plane of the rigid plate 1a, as shown more clearly in Figure 3b of the drawings.

As shown particularly in Figure 3c of the drawings, the free edge of the flange portion 110b of each locking element 110 is profiled to include a notch 110c at an intermediate distance along its lateral length. The notch 110c is defined by stepped or tapered inner edges and a curved, convex profile leading to a shallower taper at a location laterally distant from the notch 110c.

Turning to Figure 2 of the drawings, the strap ring 2 defines a generally central cavity 2a defining an opening 2b, which houses the collar 1b of the inner body 1, on which the diaphragm 3 is mounted, when the respiratory mask is fully assembled for use. The opening 2b is framed by a substantially circular rim 2c defining the inner circumferential edge of the cavity 2a. The valve cage or cover 4 comprises a generally cylindrical and substantially rigid cover 4a, which may be transparent and formed, for example, of plastics material. The cylindrical cover is circumferentially sized so as to fit within the cavity 2a of the strap ring 2 when the respiratory mask is fully assembled for use. The cover is provided with an outer shell having a first raised convex portion 4b and a second substantially flat lower portion 4c, defining a generally central upper opening 4d therebetween. A vertical support member 4e is provided vertically across the opening 4d between the raised and lower cover portions 4b, 4c. The side edges of the cover 4a are provided with cut-out portions in the form of substantially rectangular openings 20a, 20b, 20c extending laterally from an outer edge of a respective cover portion and a location close to an opposite longitudinal edge of the cover 4a, i.e. close to the circumferential edge of the strap ring cavity 2a when the respirator mask is fully assembled for use, and spanning almost the entire length of the cylindrical cover portion 4a of the cover.

The lower edge of each of the rectangular openings 20a, 20b, 20c is provided with a respective tooth or rib 13 at a location that is offset along its length.

It will be appreciated, for example, from Figures 1, 4, 6 and 7 of the drawings, that the relative locations of the openings 20a, 20b, 20c in the cage cover or valve cover 4 generally correspond to the relative locations of the locking elements 110 provided on the inner body 1 and the circumference of the cover 4a, at least where the location of the openings 20a, 20b, 20c is such that the locking elements 110 can be received within the cover at these respective locations when the respiratory mask is fully assembled for use.

Additional openings 22 may be provided at circumferential locations around the face of the cover 4a, as needed, to further decrease breathing resistance, as will be discussed in more detail below.

In use, the valve cage 4 may be placed over the exhalation valve of the respiratory mask (defined outwardly by the diaphragm 3) and twisted relative to the locking elements 110 to lock the valve cage (in the form of a cover) onto the exhalation valve assembly. The locking mechanism is in the form of a bayonet locking mechanism, with the notch 110c on each of the flange portions 110b of the respective locking elements 110 forming the female receptor of the locking mechanism and the tooth or rib 13 on the inner edge of each of the openings 20a, 20b, 20c forming the male portion of the mechanism.

Thus, referring to Figures 6 and 7 of the drawings, each opening 20a, 20b, 20c has a raised tooth 13 at the innermost edge of the opening with respect to the main body 6 of the respiratory mask, when in a fully assembled configuration for use. The raised tooth 13 of each opening 20a, 20b, 20c corresponds to a notch 110c in the flange portion 110b of each locking element 110.

Referring to Figure 6 of the drawings, when the exhalation valve is in the unlocked configuration, the three locking elements 110 are loosely housed within cavities defined by the rectangular openings 20a, 20b, 20c of the valve cage 4. The valve cage 4 may therefore be lifted from the assembly, releasing the strap ring 2 and allowing the exhalation valve to be disassembled. This may be necessary, for example, to remove and clean the diaphragm 3, a task which generally needs to be performed on a regular basis.

Converting the exhalation valve from the non-locked configuration to the locked configuration requires a substantially 45° rotation of the valve cage, forcing the inner edge of the openings 20a, 20b, 20c along the tapered, convex edge of the respective flange portions 110b of the locking elements 110 until each tooth 13 reaches a respective notch 110c and the stepped, opposing edge of the notch 110c prevents further rotation of the valve cage 4 relative to the inner body without the application of a much greater force.

Referring to Figure 7 of the drawings, when the exhalation valve is in the locked configuration, each raised tooth 13 lies within each notch 110c in each respective flange portion 110b of the locking elements 110, preventing the valve cage 4 from rotating and subsequently being lifted out of the assembly. The shallow, curved, tapered profile of the forward inner edge of each opening 20a, 20b, 20c (in the direction of travel of the cover when rotated from the unlocked to the locked configuration) enables the locking action to be effected with relatively little force. However, the steeper, stepped edges immediately adjacent to each notch 110c mean that a much greater force is required to unlock the valve cage 4 and remove it, thus minimizing its accidental removal during use.

The overall configuration of the valve cage locking mechanism and the use of large side openings as part of the locking mechanism itself allow the cover to have a relatively large open area, thus minimizing breathing resistance.

In some illustrative embodiments of the invention, and as can be seen in Figure 3 of the drawings, two of the locking elements 110 and therefore two of the flange portions 110b have the same dimensions, while a third locking element 110 and therefore the respective third flange portion 110b are of a different, smaller dimension. This ensures that the valve cage 4 cannot be incorrectly mounted on the respiratory mask and that the corresponding openings 20a, 20b, 20c only engage the flange portions 110b in a single, specific orientation. There may also be etched markings on the surface of the strap ring 2, corresponding to a notch in the valve cage 4, which direct the user to the correct positions of the valve cage 4 when in the unlocked and locked configurations.

It will be apparent to one skilled in the art from the foregoing description that modifications and variations may be made to the described embodiments without departing from the scope of the invention as defined in the appended claims.

Claims (1)

A respiratory mask including an exhalation valve assembly, comprising: a valve support (1) for receiving a valve element (3); a valve cover (4) comprising: an open-ended receptacle (4a) having side walls defining an enclosed space and a cover (4b, 4c) at one end thereof; where the valve cover comprises two outer cover sections, a first raised cover section (4b) and a second lower cover section (4c), the first and second cover sections (4b, 4c) defining a vertical through hole (4d) therebetween; and a releasable mounting mechanism for releasably mounting the valve cover (4) to the valve holder (1) to substantially cover the valve element (3), the mounting mechanism comprising a bayonet locking mechanism having a first part (110) located on the valve holder (1) and a second part located on the valve cover (4), the first and second parts being configured to engage in a locked configuration when the valve cover is rotated relative to the valve holder from an unlocked configuration; where The mounting mechanism comprises: at least three locking elements (110) separated from each other in the valve support (1), each locking element (110) defining a locking edge (110b), and at least three spaced apart openings (20a, 20b, 20c) in the valve cover (4), the location of the openings (20a, 20b, 20c) corresponding substantially to the location on the valve support (1) of the locking elements (100) when the valve cover (4) is located thereon to substantially cover the valve element (3) such that the locking edge (110b) of each locking element (110) engages a locking edge of a respective opening (20a, 20b, 20c) in the valve cover (4), wherein the valve cover openings (20a, 20b, 20c) extend over at least 50% of the axial length of the side walls of the open-ended receptacle (4a) having side walls defining the enclosed space; the first part (110c) of the bayonet locking mechanism being provided at each locking edge (110b) of the locking element and the second part (13) of the bayonet locking mechanism being provided at each valve cover opening locking edge; wherein the first part of the bayonet locking mechanism comprises a notch (110c) located along the length of the locking edge (110b) of the locking elements (110), and the second part of the bayonet locking mechanism comprises a projection (13) located along each length of the locking edge of the openings (20a, 20b, 20c) in the valve cover (4); where the locking edge (110b) on at least one face of the notch (110c) has a substantially convex curved profile along the direction of travel of the valve cover (4) relative to the valve support (1) during its rotation from the non-locked configuration to the locked configuration; wherein the locking elements (110) are located adjacent to substantially diametrically opposite edges of the valve support (1) and the valve cover openings (20a, 20b, 20c) are located adjacent to corresponding substantially diametrically opposite edges of the valve cover (4); and wherein an inner edge of each notch (110c) is relatively steeply stepped or tapered, and the locking edge on at least one face of the notch (110c) is provided with a relatively shallow tapered profile. A respiratory mask according to claim 1, wherein the valve cover openings (20a, 20b, 20c) extend between 50 and 75% of the axial length of the side walls. A respiratory mask according to claim 1, wherein the valve cover openings (20a, 20b, 20c) extend over more than 75% of the axial length of said side walls.