Patent Description:
Masks providing a substantially air-tight seal between a wearer and the mask are used in a variety of fields (e.g. gas masks, diving masks, respiratory therapy masks). Some of these masks use headgear including one or more straps to secure the mask against the face of the wearer.

Respiratory masks are used to provide respiratory therapy to the airways of a person suffering from any of a number of respiratory illnesses or conditions. Such therapies may include but are not limited to continuous positive airway pressure (CPAP) therapy and non-invasive ventilation (NIV) therapy.

CPAP therapy can be used to treat obstructive sleep apnea (OSA), a condition in which a patient's airway intermittently collapses, during sleep, preventing the patient from breathing for a period of time. The cessation of breathing, or apnea, results in the patient awakening. Repetitive and frequent apneas may result in the patient rarely achieving a full and restorative night's sleep.

CPAP therapy involves the delivery of a supply of continuous positive air pressure to the airway of the patient via a respiratory mask. The continuous positive pressure acts as a splint within the patient's airway, which secures the airway in an open position such that the patient's breathing and sleep are not interrupted.

Respiratory masks typically comprise a patient interface and a headgear, wherein the patient interface is configured to deliver the supply of continuous positive air pressure to the patient's airway via a seal or cushion that forms an airtight seal in or around the patient's nose and/or mouth. Respiratory masks are available in a range of styles including full-face, nasal, direct nasal and oral masks, which create an airtight seal with the nose and/or mouth. The seal or cushion is held in place on the patient's face by the headgear. In order to maintain an airtight seal, the headgear should provide support to the patient interface such that it is held in a stable position relative to the patient's face during use. Such respiratory masks may also be used to deliver NIV and other therapies.

<CIT>) discloses a respiratory mask system comprising a mask interface comprising a frame for a headgear assembly. The frame comprises a body comprising a first surface and a substantially opposing second surface. The body further comprises a gas inlet and optionally an outlet vent. The gas inlet may be substantially elliptical in shape. The frame may comprise a recessed region for receiving a yoke of a headgear assembly to attach the headgear to the mask interface. The respiratory mask system may also comprise a yoke for attaching to the frame.

<CIT>) discloses a nasal mask having a seal housing and a flexible nasal seal connected or connectable to the seal housing to define a mask cavity. The nasal seal extends between a face- contacting side and an outer side. The nasal seal has a contacting surface having an edge that defines a nose-receiving opening into the mask cavity and which is configured to seal about the user's nose. The nasal seal also has an under-nose support fixedly connected into the seal and which is configured to extend within the mask cavity and having a contact surface that is oriented to contact at least a portion of the under-nose surface of the user.

<CIT>) a headgear for securing a mask to a user's face is described. The headgear requires a first load force to elongate the headgear and, when fitted to a user, applies a balanced fit force that substantially equals a load force applied to the headgear during respiratory therapy. In some embodiments, the headgear includes an elastic portion configured to provide a retraction force, a non-elastic portion configured to be inelastic in comparison to the elastic portion, and a restriction mechanism connected to the non-elastic portion and to the elastic portion. The restriction mechanism is configured to apply a first resistance force to the user's head on elongation of the headgear and a second resistance force to the user's head on retraction of the headgear.

<CIT>) discloses a directional lock or a headgear or interface assembly comprising one or more directional locks that include a catch arrangement for initiating or assisting in movement of a lock member of the direction lock. In some configurations, the catch arrangement assists movement of the lock member in only a portion of a range of travel of the lock member. In some configurations, the directional lock comprises a housing and a sleeve and the catch arrangement comprises a catch arm carried by the sleeve. The catch arm includes a catch end that contacts the lock member, which can be a lock washer in some configurations.

<CIT>) discloses a patient interface system to treat sleep disordered breathing of a patient with pressurized gas, comprising: a patient interface; at least one strap; at least one retractor fixedly attached to the patient interface, said at least one retractor connected to the at least one strap and configured to retract the at least one strap without patient actuation; and at least one pad to cushion a rearward portion of the patient's head, said at least one pad having an opening, wherein said at least one strap passes through said opening to allow the at least one pad to move freely relative to said at least one strap.

The systems, methods and devices described herein have innovative aspects, no single one of which is indispensable or solely responsible for their desirable attributes.

A headgear for a respiratory mask comprises at least one strap comprising a filament, a directional lock having an engaged configuration and a disengaged configuration with respect to the filament, and a disengaging member operable to hold the lock in the disengaged configuration.

The headgear further comprises an actuator configured to act on the disengaging member to cause the disengaging member to hold the lock in the disengaged configuration.

In some configurations, the actuator is selectively operable to act on the disengaging member. In some such configurations, the actuator is coupled to one of a movable bar or button or a handle.

In some configurations, the actuator is configured to automatically act on the disengaging member when a user pulls a mask away from the user's face. In some such configurations, the actuator comprises an arm coupled to the at least one strap and configured to be movable relative to the respiratory mask.

In some configurations, the disengaging member is normally biased away from holding the lock in its disengaged configuration.

In some configurations, the at least one strap comprises a first strap portion and a second strap portion, wherein the filament is attached to one of the first strap portion and the second strap portion and the first strap portion and the second strap portion are movable relative to one another to vary a length of the at least one strap.

In some configurations, the at least one strap extends between a head-engaging portion and a mask-engaging portion of the headgear.

In some configurations, a headgear for a respiratory mask comprises at least one strap comprising a filament, a directional lock configured to limit movement of the filament in a direction until a minimum force in said direction is applied to the filament, and a disengaging member that is operable to reduce the minimum force required to move the filament in said direction.

In some configurations, the disengaging member is normally biased away from a position in which the minimum force is reduced.

In some configurations, the minimum force of the directional lock is between about <NUM> Newtons and <NUM> Newtons. In some configurations, two or more directional locks with a minimum force between <NUM> Newtons and <NUM> Newtons may be combined to yield an overall minimum force between <NUM> and <NUM> Newtons, or between <NUM> and <NUM> Newtons.

In some configurations, the headgear further comprises at least one strap that does not include a filament.

In some configurations, the headgear further comprises an actuator configured to operate the disengaging member.

In some configurations, the actuator is selectively operable to act on the disengaging member. In some such configurations, the actuator is coupled to one of a movable bar, a button or a handle.

In some configurations, the actuator is configured to automatically act on the disengaging member when a user pulls the mask away from the user's face. In some such configurations, the actuator comprises an arm coupled to the at least one strap and configured to be movable relative to the respiratory mask.

In some configurations, a mask assembly comprises any of the above-described headgear. The mask assembly further comprises a mask. The mask comprises a frame and a cushion module having a housing and a seal. The mask further comprises a connection arrangement configured to connect the cushion module to the frame. The connection arrangement comprises at least one protrusion located on one of the cushion module and the frame and at least one recess located on the other of the cushion module and the frame. The at least one protrusion is configured to engage the at least one recess to secure the cushion module to the frame.

In some configurations, the cushion module comprises a cylindrical wall defining an opening that receives a collar of the frame.

In some configurations, the at least one protrusion extends in a circumferential direction on the cylindrical wall and the at least one recess extends in a circumferential direction on the collar.

In some configurations, the cylindrical wall extends into a breathing chamber of the cushion module from an outer wall of the housing.

In some configurations, an alignment feature comprises a recess defined by one of the cushion module and the frame and a protrusion defined by the other of the cushion module and the frame. The protrusion is configured to engage the recess to facilitate rotational alignment of the cushion module relative to the frame.

In some configurations, the headgear comprises a yoke configured to connect the headgear to the mask.

In some configurations, the yoke comprises a central portion and at least one arm extending from the central portion. The at least one arm is configured to connect to the at least one strap of the headgear.

In some configurations, the frame comprises a lip and the yoke comprises at least one hooked connection finger configured to selectively engage the lip to secure the yoke to the frame.

In some configurations, the lip extends along a perimeter of the frame.

In some configurations, the lip extends from a front surface of the frame.

In some configurations, the at least one hooked connection finger is located adjacent a junction between the at least one arm and the central portion.

In some configurations, a recess is located adjacent to and configured to facilitate deflection of the at least one hooked connection finger.

In some configurations, a gap is located adjacent to and configured to facilitate deflection of the at least one hooked connection finger and/or to decouple movement of the at least one arm and the at least one hooked connection finger.

In some configurations, the gap extends entirely through a rear wall of the yoke.

In some configurations, the at least one strap comprises a plurality of straps and the at least one arm comprises a plurality of arms.

In some configurations, the number of straps is different than the number of arms.

In some configurations, a mask assembly includes a cushion module comprising a housing, a seal for sealing with a patient's face, an inlet opening to the cushion module and a plurality of exhaust vent holes located on the housing above the inlet opening. The mask assembly also includes a frame comprising at least one protrusion that engages the inlet opening of the cushion module to attach the frame to the cushion module. The frame has a conduit connector portion for connecting to a conduit through which respiratory gas is delivered. The conduit connector portion extends below the inlet opening when the frame is attached to the cushion module. A yoke is configured to attach to the frame. The yoke comprises a central portion that substantially aligns with the inlet opening of the cushion module when the yoke is attached to the frame and arms that extend laterally from the central portion.

In some configurations, an entirety of the central portion of the yoke is located below the plurality of exhaust vent holes when the yoke and the cushion module are attached to the frame.

In some configurations, an entirety of the yoke is located below the uppermost extent of the plurality of exhaust vent holes when the yoke and the cushion module are attached to the frame.

In some configurations, a maximum width of the frame is less than or equal to a maximum width of the central portion of the yoke.

In some configurations, the at least one hooked connection finger comprises a hooked connection finger located adjacent a junction between the each of the arms and the central portion.

In some configurations, a gap is located adjacent to each of the hooked connection fingers and configured to facilitate deflection of the associated hooked connection finger and/or to decouple movement of each of the arms and the associated hooked connection finger.

Throughout the drawings, reference numbers can be reused to indicate general correspondence between reference elements. The drawings are provided to illustrate example embodiments described herein and are not intended to limit the scope of the disclosure.

Embodiments of systems, components and methods of assembly and manufacture will now be described with reference to the accompanying figures, wherein like numerals refer to like or similar elements throughout. Although several embodiments, examples and illustrations are disclosed below, it will be understood by those of ordinary skill in the art that the inventions described herein extends beyond the specifically disclosed embodiments, examples and illustrations, and can include other uses of the inventions and obvious modifications and equivalents thereof. The terminology used in the description presented herein is not intended to be interpreted in any limited or restrictive manner simply because it is being used in conjunction with a detailed description of certain specific embodiments of the inventions. In addition, embodiments of the inventions can comprise several novel features and no single feature is solely responsible for its desirable attributes or is essential to practicing the inventions herein described.

Certain terminology may be used in the following description for the purpose of reference only, and thus are not intended to be limiting. For example, terms such as "above" and "below" refer to directions in the drawings to which reference is made. Terms such as "horizontal," "vertical," "front," "back," "left," "right," "rear," and "side" describe the orientation and/or location of portions of the components or elements within a consistent but arbitrary frame of reference which is made clear by reference to the text and the associated drawings describing the components or elements under discussion, which in the context of a patient interface is often in an as-worn orientation with the user's head in an upright orientation. Moreover, terms such as "first," "second," "third," and so on may be used to describe separate components. Such terminology may include the words specifically mentioned above, derivatives thereof, and words of similar import.

Conditional language used herein, such as, among others, "can," "could," "might," "may," "e.g.," and the like, unless specifically stated otherwise, or otherwise understood within the context as used, is generally intended to convey that certain embodiments include, while other embodiments do not include, certain features, elements and/or states. Thus, such conditional language is not generally intended to imply that features, elements and/or states are in any way required for one or more embodiments or that one or more embodiments necessarily include logic for deciding, with or without author input or prompting, whether these features, elements and/or states are included or are to be performed in any particular embodiment.

The term "plurality" refers to two or more of an item. Recitations of quantities, dimensions, sizes, formulations, parameters, shapes and other characteristics should be construed as if the term "about" or "approximately" precedes the quantity, dimension, size, formulation, parameter, shape or other characteristic. The terms "about" or "approximately" mean that quantities, dimensions, sizes, formulations, parameters, shapes and other characteristics need not be exact, but may be approximated and/or larger or smaller, as desired, reflecting acceptable tolerances, conversion factors, rounding off, measurement error and the like and other factors known to those of skill in the art. Recitations of quantities, dimensions, sizes, formulations, parameters, shapes and other characteristics should also be construed as if the term "substantially" precedes the quantity, dimension, size, formulation, parameter, shape or other characteristic. The term "substantially" means that the recited characteristic, parameter, or value need not be achieved exactly, but that deviations or variations, including for example, tolerances, measurement error, measurement accuracy limitations and other factors known to those of skill in the art, may occur in amounts that do not preclude the effect the characteristic was intended to provide.

Numerical data may be expressed or presented herein in a range format. It is to be understood that such a range format is used merely for convenience and brevity and thus should be interpreted flexibly to include not only the numerical values explicitly recited as the limits of the range, but also interpreted to include all of the individual numerical values or sub-ranges encompassed within that range as if each numerical value and sub-range is explicitly recited. As an illustration, a numerical range of "<NUM> to <NUM>" should be interpreted to include not only the explicitly recited values of about <NUM> to about <NUM>, but should also be interpreted to also include individual values and sub-ranges within the indicated range. Thus, included in this numerical range are individual values such as <NUM>, <NUM> and <NUM> and sub-ranges such as "<NUM> to <NUM>," "<NUM> to <NUM>" and "<NUM> to <NUM>," etc. This same principle applies to ranges reciting only one numerical value (e.g., "greater than <NUM>") and should apply regardless of the breadth of the range or the characteristics being described.

A plurality of items may be presented in a common list for convenience. Furthermore, where the terms "and" and "or" are used in conjunction with a list of items, they are to be interpreted broadly, in that any one or more of the listed items may be used alone or in combination with other listed items. The term "alternatively" refers to selection of one of two or more alternatives, and is not intended to limit the selection to only those listed alternatives or to only one of the listed alternatives at a time, unless the context clearly indicates otherwise.

Reference to any prior art in this specification is not, and should not be taken as, an acknowledgement or any form of suggestion that that prior art forms part of the common general knowledge in the field of endeavor in any country in the world.

The invention may also be said broadly to consist in the parts, elements and features referred to or indicated in the specification of the application, individually or collectively, in any or all combinations of two or more of said parts, elements or features.

It should be noted that various changes and modifications to the presently preferred embodiments described herein will be apparent to those skilled in the art.

The present disclosure relates to a respiratory interface assembly or respiratory mask assembly incorporating one or more retention or lock arrangements configured to retain the interface assembly in an adjusted position (e.g., automatically adjusted), which may be a position that is sized to fit a particular user of the interface assembly, and a release arrangement (e.g., a manual release) configured to release the retention or lock arrangement(s) and permit the interface assembly to move from the adjusted position against little to no force - or a force that is less than (e.g., significantly less than) a retention or lock force of the retention or lock arrangement(s).

<FIG> illustrate one example of a respiratory interface system or respiratory mask system <NUM> for the delivery of respiratory therapy to a patient. The mask system <NUM> may comprise an interface, such as a mask <NUM>. In the illustrated arrangement, the mask <NUM> comprises a seal, or seal module, and a frame, as described in further detail herein. The illustrated mask system <NUM> also includes a headgear assembly <NUM> (which can be referred to simply as "headgear" herein). The mask <NUM> and headgear <NUM> may comprise a connection system to attach the headgear <NUM> to the mask <NUM>. Various forms of connection systems may be used to attach the headgear <NUM> to the mask <NUM>. Similarly, the mask <NUM> may be coupled to at least one and possibly multiple different types of headgear.

The mask <NUM> may comprise a seal <NUM> and a frame <NUM>. The seal <NUM> can be configured for sealing around and/or underneath a patient's mouth and/or nose. In the illustrated arrangement, the seal <NUM> is a nasal seal configured to deliver the flow of breathing gases only to the user's nose. In particular, the illustrated seal <NUM> includes a pair of nasal pillows configured to create a seal with the user's nares and a secondary sealing portion that surrounds the nasal pillows and is configured to create a secondary seal with one or more of an underside of the user's nose, side portions of the user's nose and the user's upper lip. However, features of the present disclosure can be implemented with other mask systems having other types of mask seals, such as full-face seals, for example and without limitation. The frame <NUM> is configured for supporting the seal <NUM> and attaching the seal <NUM> to the headgear <NUM>. The frame <NUM> may also comprise a gas inlet <NUM> (<FIG>) configured to attach to a gas conduit <NUM> for delivering a flow of breathing gas to the patient via the mask <NUM>. The seal <NUM> can include an attachment frame or clip <NUM>, which in some arrangements can include a first portion 122a and a second portion 122b that capture a rim of the seal <NUM> between them. The clip <NUM> is configured to selectively connect to the frame <NUM>, such as by a snap-fit, friction fit or other suitable arrangement. The frame <NUM> can include a vent <NUM>, which is configured to exhaust gases from an interior of the seal <NUM>. Optionally, the mask <NUM> can include a vent insert or diffuser <NUM> that covers the vent <NUM> to control the exhaust flow.

The headgear <NUM> of the respiratory mask system <NUM> is used to hold the mask <NUM> to the patient's face. The headgear <NUM> is typically attached to the mask <NUM> and wraps around the rear of the patient's head to hold the mask <NUM> in sealed contact with the patient's face.

In one form, the headgear assembly <NUM> may comprise a yoke or collector <NUM>, which is configured to attach to the mask <NUM>, as described in greater detail herein.

The yoke <NUM> may be configured to attach to straps of the headgear <NUM> such that the straps and yoke <NUM> cooperate to form a closed loop that surrounds the head of the user. In the illustrated embodiment, the headgear <NUM> comprises an assembly of straps, including a rear strap <NUM> configured to wrap behind a patient's head, an upper strap <NUM> configured to wrap over the top of a patient's head, and a pair of front straps <NUM> (<FIG>) configured to extend along the patient's cheeks during use. In one form, each front strap <NUM> is attached to the rear strap <NUM> of the headgear assembly <NUM>, e.g., to a free end <NUM> of the rear strap <NUM> or a connector coupled to the free end <NUM>, by a rear connector <NUM>. In another form, the rear strap <NUM> comprises side extensions that form front straps to extend along the patient's cheeks during use.

In one form, the headgear <NUM> can be adjustable (e.g. manually adjustable, automatically adjustable) and/or can incorporate one or more locks (e.g. directional locks <NUM>) that allow the headgear <NUM> to reduce in length with a relatively low amount of resistance and resist an increase in length of the headgear <NUM>. In some configurations, a locking force of the directional locks <NUM> can be overcome to allow lengthening of the headgear <NUM> for donning of the interface assembly <NUM>. In some forms, the yoke <NUM> may form a collector for filaments used in an automatically adjustable headgear system. In this form, the yoke <NUM> may incorporate one or more directional locks <NUM>, each of which can comprise one or more lock elements, which can be referred to herein as lock washers or washers. The lock washers are configured to frictionally engage with the filament during elongation of the headgear <NUM>, but allow relatively friction-free movement during retraction of the headgear <NUM>. In some configurations, the headgear <NUM>, or interface assembly <NUM>, includes a release mechanism or arrangement that is configured to release or hold open the directional locks <NUM> to allow for low-friction movement while a control or other actuator is operated by a user, and provide high-friction resistance if the control or actuator is not engaged.

The directional locks <NUM> may be incorporated into the ends of the yoke/collector <NUM> and the body of the yoke/collector <NUM> may be substantially hollow to receive the filaments within the body. The headgear <NUM> or any portion thereof can be configured in accordance with any of the embodiments disclosed in Applicant's <CIT>, <CIT>, and <CIT>,.

With reference to <FIG>, each front strap <NUM> may comprise a free end to which may be attached a connector <NUM>. Each connector <NUM> may engage with a complementary strap connector <NUM> located on the yoke <NUM>. Preferably, the yoke <NUM> is substantially elongate and comprises a strap connector <NUM> located at or near each end of the yoke <NUM>.

The connection between the front straps <NUM> and yoke <NUM> may be any suitable form of connection, such as a snap-fit connection, a screw and thread type connection, or a hooked connection. In one form, as shown in <FIG>, each strap connector <NUM> comprises a cap <NUM> located at each end of the yoke <NUM>. Each cap <NUM> may comprise an opening, such as an aperture or recess, configured to receive the connector <NUM> of the front strap <NUM> in a snap-fit arrangement to attach the yoke <NUM> to the front straps <NUM> of the headgear assembly <NUM>.

As mentioned above, the yoke <NUM> may also be configured to attach to the frame <NUM> of the mask <NUM>. In one form, the frame <NUM> may comprise a recessed region configured to receive at least a portion of the yoke <NUM> therein when the yoke <NUM> and frame <NUM> are attached together. A cover sleeve, or front portion <NUM> can be configured to facilitate the removable connection of the yoke <NUM> with the frame <NUM>.

<FIG> illustrate another example embodiment of a yoke <NUM> and cushion or seal <NUM> coupled to a frame <NUM>. The yoke <NUM>, seal <NUM>, and/or frame <NUM> can be similar to the yoke <NUM>, cushion or seal <NUM>, and/or frame <NUM>, respectively, except as otherwise described below. The frame <NUM> includes a yoke channel <NUM> configured to receive the yoke <NUM> in use. The yoke channel <NUM> is formed or defined by an upper wall <NUM>, rear wall <NUM>, and lower wall <NUM>. The yoke <NUM> has increased asymmetry between upper and lower edges of the yoke <NUM>, for example, compared to the yoke <NUM>. In the illustrated embodiment, the upper edge of the yoke <NUM> is straighter than the lower edge. The asymmetry advantageously provides improved visual cues as to the correct orientation for assembly of the yoke <NUM> to the frame <NUM> and helps inhibit incorrect assembly.

As shown in <FIG>, the yoke channel <NUM> includes connector recesses <NUM> in the upper <NUM> and lower <NUM> walls. In the illustrated embodiment, a connector recess <NUM> is positioned at, adjacent, or proximate each lateral end of the yoke channel <NUM>. The connector recesses <NUM> at least partially define or form retention lips <NUM> at or along front edges of the yoke channel <NUM> (e.g., at or along front edges of internally facing surfaces of the upper wall <NUM> and lower wall <NUM>). The yoke <NUM> includes connector protrusions <NUM> protruding rearwardly from upper, lower, and/or rear surfaces of the yoke <NUM>. In the illustrated embodiment, the yoke <NUM> includes a connector protrusion <NUM> on each side of a center of the yoke <NUM>. In the illustrated embodiment, the yoke <NUM> includes a yoke front <NUM> and yoke back <NUM> that are coupled together, as described in greater detail herein, and the connector protrusions <NUM> are formed in the yoke back <NUM>. The connector recesses <NUM> are configured to receive the connector protrusions <NUM> when the frame <NUM> and yoke <NUM> are coupled together to form a snap-fit connection between the frame <NUM> and yoke <NUM>. When the frame <NUM> and yoke <NUM> are coupled together, the retention lips <NUM> engage the yoke <NUM> forward of the connector protrusions <NUM> to contribute to the snap -fit connection and retain the yoke <NUM> in the yoke channel <NUM>. In the illustrated embodiment, the connector protrusions <NUM> and connector recesses <NUM> have a square or rectangular profile, which inhibits the yoke <NUM> from rotating out of the yoke channel <NUM>, for example, in the direction indicated by the arrow in <FIG>.

In some embodiments, the yoke <NUM> has an oval or substantially oval cross-section, for example, as shown in <FIG>. This shape advantageously reduces the size or bulk of the yoke <NUM> and/or provides an improved aesthetic appearance. The lock washer housings <NUM>, discussed in greater detail herein, can have a D-shaped, substantially D-shaped, U-shaped, or substantially U-shaped cross-section, for example as shown in <FIG> and <FIG>, to allow for and/or contribute to the overall oval or substantially oval cross-section of the yoke <NUM>. The washer housings <NUM> can be positioned in opposite vertical orientations relative to each other. In other words, one of the washer housings <NUM>, e.g., the left washer housing <NUM> as shown in <FIG>, can be oriented as an upward-facing U-shape and the other washer housing <NUM>, e.g., the right washer housing <NUM> in <FIG>, can be oriented as a downward-facing U-shape. This arrangement and orientation can advantageously help allow receptacles or collectors for the excess portion of the filaments used in an automatically adjustable headgear system, which can be referred to herein as line tracks <NUM>, <NUM>, to extend above and below the left and right washer housings <NUM>, respectively, as discussed in greater detail herein. As shown in <FIG>, in the illustrated embodiment, the yoke <NUM>, or a central portion of the yoke <NUM>, has a depth D that is the same as or similar to or corresponds to a depth of the yoke channel <NUM> such that the yoke <NUM> does not protrude, or does not substantially protrude, from the yoke channel <NUM>. This advantageously reduces the overall size of the frame <NUM> and yoke <NUM> assembly.

As shown in <FIG> and <FIG>, in the illustrated embodiment, a rear or back surface of the yoke <NUM> includes a rearward step on each side or lateral end of the central portion of the yoke <NUM> such that the yoke <NUM> has a stepped depth. In other words, lateral portions of the yoke <NUM>, which are positioned laterally outside of the yoke channel <NUM> when the yoke <NUM> is coupled to the frame <NUM>, have a greater depth than the depth D of the central portion of the yoke <NUM>, which is positioned in the yoke channel <NUM> when the yoke <NUM> is coupled to the frame <NUM>. The steps form or define frame abutment surfaces <NUM> at the transitions between the central portion and lateral portions of the yoke <NUM>. When the yoke <NUM> is coupled to the frame <NUM>, each of the frame abutment surfaces <NUM> abuts or is positioned adjacent or proximate one of the lateral edges <NUM> of the frame <NUM> as shown in <FIG>. The frame abutment surfaces <NUM> and lateral edges <NUM> help properly align the yoke <NUM> with the frame <NUM> during assembly. The frame abutment surfaces <NUM> and lateral edges <NUM> also or alternatively provide a more secure connection between the yoke <NUM> and frame <NUM>. The reduced depth of the central portion of the yoke <NUM> advantageously reduces the overall size of the frame <NUM> and yoke <NUM> assembly.

As shown in <FIG>, in the illustrated embodiment, the yoke <NUM> includes a yoke front <NUM> and a yoke back <NUM>. The yoke <NUM> can also include two end caps <NUM> (as shown in <FIG>), one at each lateral end of the yoke <NUM>. In the illustrated embodiment, the yoke front <NUM> and yoke back <NUM> are formed as separate components that are coupled together. In the embodiment of <FIG>, a split line <NUM> (shown in <FIG>) between the yoke front <NUM> and yoke back <NUM> is centered or generally centered. This can improve ease of manufacturing.

The yoke front <NUM> and yoke back <NUM> can be coupled together via a snap fit. In the illustrated embodiment, the yoke front <NUM> includes a yoke fastener <NUM> projecting rearwardly from a rear surface of the yoke front <NUM>. In the illustrated embodiment, the yoke fastener <NUM> is positioned centrally or generally centrally in a vertical and/or lateral direction with respect to the yoke front <NUM> and is elongate in the lateral direction. The yoke back <NUM> includes a fastener aperture <NUM> that is sized, shaped, and positioned to receive the yoke fastener <NUM> to form a snap-fit connection when the yoke front <NUM> and yoke back <NUM> are coupled together. The central connection between the yoke front <NUM> and yoke back <NUM> via the yoke fastener <NUM> and fastener aperture <NUM> provides more rigidity to the connection between the yoke front <NUM> and yoke back <NUM> and/or provides support against or inhibits twisting between the yoke front <NUM> and yoke back <NUM>. In some embodiments, the yoke front <NUM> instead includes the fastener aperture <NUM> and the yoke back <NUM> includes the yoke fastener <NUM>. In some embodiments, the fastener aperture <NUM> includes one or more fastener bumps <NUM> extending along (e.g., laterally along) upper and/or lower edges of the fastener aperture <NUM> and protruding into the fastener aperture <NUM> from the upper and/or lower edges. The yoke fastener <NUM> includes one or more corresponding notches <NUM> (shown in <FIG>) extending along (e.g., laterally along) upper and/or lower surfaces of the yoke fastener <NUM> that are sized, shaped, and positioned to receive the fastener bump(s) <NUM> to form a snap-fit connection. In some embodiments, the fastener aperture <NUM> includes one or more notches <NUM> and the yoke fastener <NUM> includes one or more fastener bumps <NUM>.

<FIG> illustrate a variation of the yoke <NUM> in which the yoke back <NUM> includes a fastener recess <NUM>' instead of a fastener aperture <NUM>. The fastener recess <NUM>' does not extend all the way through the thickness of the yoke back <NUM>. The yoke front <NUM> includes a rearwardly-extending yoke fastener <NUM>'. The fastener recess <NUM>' is sized, shaped, and positioned to receive the yoke fastener <NUM>' to form a friction fit or interference fit connection when the yoke front <NUM> and yoke back <NUM> are coupled together. In some such embodiments, the fastener recess <NUM>' includes one or more interference bumps <NUM>' on the upper and/or lower surfaces or edges of the fastener recess <NUM>'. In the illustrated embodiment, the interference bumps <NUM>' are elongate and extend an entire depth of the fastener recess <NUM>'. The interference bumps <NUM>' interfere with and help create a friction or interference fit between the fastener recess <NUM>' and the yoke fastener <NUM>' to help secure the yoke front <NUM> and yoke back <NUM> together. This configuration can advantageously allow for easier manufacturing, provide a neater finish (without an aperture in the yoke back <NUM>), and/or inhibit the ingress of dirt or other debris into the line tracks <NUM>, <NUM> (due to the lack of aperture, which allows the yoke <NUM> to be fully enclosed along its length), which can help maintain the function of the automatic headgear adjustment mechanism.

In the embodiment of <FIG>, the yoke back <NUM> includes an upper alignment bead 612a protruding forward from the yoke back <NUM> and extending along a length of the yoke back <NUM> adjacent or proximate the upper surface of the yoke back <NUM>, and/or a lower alignment bead 612b protruding forward from the yoke back <NUM> and extending a length of the yoke back <NUM> adjacent or proximate the lower surface of the yoke back <NUM>. The yoke front <NUM> includes an upper alignment groove 614a in a rear surface of the yoke front <NUM> extending along a length of the yoke front <NUM> adjacent or proximate the upper surface of the yoke front <NUM>, and/or a lower alignment groove 614b in the rear surface of the yoke front <NUM> extending a length of the yoke front <NUM> adjacent or proximate the lower surface of the yoke front <NUM>. The upper and/or lower alignment grooves 614a, 614b receive the upper and/or lower alignment beads 612a, 612b, respectively, when the yoke front <NUM> and yoke back <NUM> are coupled together. The alignment beads 612a, 612b and alignment grooves 614a, 614b help correctly align the yoke front <NUM> and yoke back <NUM>. The alignment beads 612a, 612b and alignment grooves 614a, 614b can also or alternatively resist or support against torsion, e.g., between the yoke front <NUM> and yoke back <NUM>. In some embodiments, the alignment beads 612a, 612b and alignment grooves 614a, 614b can be positively engaged with each other, for example, in the form of a friction fit or snap fit connection.

The end caps <NUM> can help secure the yoke front <NUM> and yoke back <NUM> together by clipping over or snap fitting over or onto the lateral ends of the yoke front <NUM> and yoke back <NUM>. The end caps <NUM> can also allow for connection of a front strap (e.g., front strap <NUM>) of a headgear (e.g., headgear <NUM>) to the yoke <NUM>. In some embodiments, each end cap <NUM> is over-molded onto a braided portion of the front strap.

As shown in <FIG>, the lateral ends of the yoke front <NUM> and yoke back <NUM> include or are formed by end cap inserts <NUM>. The end cap inserts <NUM> can be integrally formed with or attached to the lateral ends of the yoke front <NUM> and yoke back <NUM>. The end cap inserts <NUM> have a reduced dimension or profile compared to the lateral portions of the yoke <NUM>. The end caps <NUM> have internal cavities <NUM> that receive the end cap inserts <NUM>. During assembly, the end caps <NUM> can be connected over or snapped onto the end cap inserts <NUM> in a rotational or hinged manner, as shown in <FIG>.

As shown in <FIG>, each end cap <NUM> includes a retention hole <NUM> on one side (e.g., in a rear side in the illustrated embodiment) and a retention notch <NUM> on an opposite side (e.g., a front side in the illustrated embodiment). In other embodiments, the position of the retention hole <NUM> and retention notch <NUM> can be reversed. The positioning of the retention hole <NUM> in the rear of the end cap <NUM> in the illustrated embodiment advantageously hides the retention hole <NUM> in use, which provides an improved aesthetic appearance. The retention notch <NUM> extends from the end cap cavity <NUM> forward into the end cap <NUM>. The end cap inserts <NUM> include a first retention feature <NUM> on one of the front and back surfaces (e.g., extending rearwardly from the yoke back <NUM> portion of the end cap insert <NUM> in the illustrated embodiment) and a second retention feature <NUM> on an opposite surface (e.g., extending forward from the yoke front <NUM> portion of the end cap insert <NUM> in the illustrated embodiment). To attach the end cap <NUM> to the yoke <NUM>, e.g., to the end cap insert <NUM>, the retention hole <NUM> is engaged with the first retention feature <NUM> as shown in <FIG>. The first retention feature <NUM> then acts as a hinge or pivot point, and the end cap <NUM> is pivoted over the end cap insert <NUM> in the direction indicated by the arrow in <FIG> until the second retention feature <NUM> and retention notch <NUM> engage, e.g., in a bump or snap fit connection. The hinged connection can provide a strong connection between the yoke <NUM> and end caps <NUM> with a reduced end cap insert <NUM> length L (indicated in <FIG>). The end caps <NUM> can therefore taper more steeply. The reduced length of the end cap inserts <NUM>, end caps <NUM>, and/or overall yoke <NUM> can advantageously reduce or minimize the yoke <NUM> contacting or digging into the patient's face.

In the illustrated embodiment, the first retention feature <NUM> is or includes an oval or stadium shaped post extending rearward from the yoke back <NUM>. The first retention feature <NUM> has a length or depth selected such that an outer or rearmost surface of the first retention feature <NUM> is flush or substantially flush with the rear surface of the yoke back <NUM>. This increases the contact area and interaction between the end caps <NUM> and end cap inserts <NUM> and increases the retention forces. The connection between the end caps <NUM> and end cap inserts <NUM> can therefore resist greater torsional forces along the length of the yoke <NUM> and/or rotational forces about the joint.

In the illustrated embodiment, the second retention feature <NUM> is or includes a raised tab extending forward from the yoke front <NUM>. The second retention feature <NUM> has a reduced length or depth compared to the first retention feature <NUM>, which allows the end cap <NUM> to pass over the second retention feature <NUM> during assembly. In the illustrated embodiment, the second retention feature <NUM> has a chamfered lead-in 617a on one edge, e.g., on the lateral (relative to the yoke <NUM>) edge in the illustrated embodiment, which allows the end cap <NUM> to be hinged or pivoted over and/or onto the second retention feature <NUM> more easily.

In some embodiments, the end caps <NUM> can be over-molded onto an end of a braided element of an automatic headgear adjustment mechanism, for example, braided elements as shown and described in <CIT>, and PCT Application No. <CIT>, The core elements or filaments <NUM> can extend within the braided elements. The end caps <NUM> can connect the braided element, and therefore the headgear, to the yoke <NUM> and create a closed loop headgear system.

As described herein, in some embodiments, the yoke <NUM> may form a collector or line track <NUM>, <NUM> for core elements, such as filaments <NUM>, used in an automatically adjustable or self-adjusting headgear system. In some configurations, the yoke <NUM> can provide a separate space (e.g., line track <NUM>, <NUM>) for each of the filaments <NUM>. As shown in <FIG>, the yoke front <NUM> includes an upper line track <NUM> and a lower line track <NUM>. A line track divider <NUM> protrudes rearwardly from a rear or internal surface of the yoke front <NUM>. The line track divider <NUM> extends generally at a diagonal across a portion of the length of the yoke front <NUM> to transition from a relative upper location to a relative lower location relative to the yoke <NUM>. In the illustrated embodiment, a divider wall <NUM> extends between each of the washer housings <NUM> and the opposing line track. The divider wall <NUM> separates the opposing line track from the washer housing <NUM> so that a free end of the filament <NUM> is inhibited from being caught in the opposing washer housing <NUM> during retraction. In the illustrated embodiment, the line tracks <NUM>, <NUM> are not symmetrically mirrored due to the asymmetry of the upper and lower edges of the yoke <NUM>.

<FIG> illustrates a variation of the yoke <NUM> in which the line tracks <NUM>, <NUM> extend into and terminate within the end caps <NUM>. The lengths of the line tracks <NUM>, <NUM> are therefore extended beyond the ends of the yoke front <NUM> and yoke back <NUM>. This increases the length of filament <NUM> that can be stored within the yoke <NUM>, which increases the range of adjustment or variability in the size of the headgear. The headgear assembly <NUM> defines a headgear loop that extends around a user's head in use. The filament <NUM> forms part of a headgear adjustment mechanism that allows a total length of the headgear loop to be extended during donning and doffing of the mask system. In some such embodiments, the length of each of the line tracks <NUM>, <NUM> can be increased or extended by about <NUM>. In such embodiments, the total length of the headgear loop, in an extended state, can therefore increase by about <NUM>.

<FIG> show an embodiment of a directional lock <NUM> comprising a housing <NUM>, a first and a second lock element (e.g., washer <NUM>, <NUM>) and a core member or filament <NUM>. The housing <NUM> comprises a first and a second chamber <NUM>, <NUM> wherein the first and second chambers <NUM>, <NUM> are configured to house the first and second lock washers <NUM>, <NUM>, respectively. Washers <NUM> may be made out of a material that provides at least some resistance to wear from friction (e.g. polypropylene, high-density polyethylene, aluminum, steel). In the illustrated arrangement, the first and second chambers <NUM>, <NUM> are separated by an internal wall <NUM> of the housing <NUM>. However, in other arrangements, the first and second chambers <NUM>, <NUM> are not necessarily physically separate spaces, but can, for example, be portions of a chamber. The housing <NUM> has two end walls <NUM>, which along with the internal wall <NUM>, have an elongate core opening <NUM> for the core member or filament <NUM> to pass through. The core member or filament <NUM> may be an elongate thread, fiber, string, wire, or filament, e.g. a nylon, polyethylene, polypropylene fiber, or a metal (e.g. aluminum, copper, silver) wire. Advantageously, a material may be chosen that provides at least some resistance to friction, fraying and splaying. Other shapes or geometries may be used, including a rectangular cross-section (e.g. a ribbon, band or belt) or multiple threads, fibers, strings, wires or filaments (e.g. a cable or braided or twisted wires). All of these may be referred to as the core member <NUM>. The material or materials of the core member may be chosen to be substantially non-elastic, thus allowing the core member <NUM> to remain substantially the same length under elongative strain. The core openings <NUM> may be substantially aligned with each other. The core opening <NUM> of the end wall <NUM> shown on the right side of the figures may be larger than one or both of the core opening <NUM> of the internal wall <NUM> and the end wall <NUM> shown on the left of the figures. This allows for manipulation or deflection of the path of the core member <NUM> through the housing <NUM>. The first and second chambers <NUM>, <NUM> are each delimited by the internal wall <NUM>, one of the end walls <NUM> and a pair of side walls <NUM>; wherein the side walls <NUM> extend between the end walls <NUM> of the housing <NUM>. The first and second chambers <NUM>, <NUM> are configured to be open at one or both of a top and a bottom of the housing <NUM>.

Each of the first and second chambers <NUM>, <NUM> has a pair of washer retainers <NUM> that are aligned on opposing side walls <NUM> of the housing <NUM>. Each pair of washer retainers <NUM> is configured to pivotally retain one of the first or second lock washers <NUM>, <NUM> within the respective first or second chamber <NUM>, <NUM>. The washer retainers comprise a circular bush <NUM> and an elongate slot <NUM>, wherein circular bushes <NUM> intersect with the bottom of the housing such that an entrance is formed. The entrance is configured to allow the first and/or second lock washers <NUM>, <NUM> to be received into the washer retainers <NUM>. The slot <NUM> extends radially from the circular bush <NUM> towards the top of the housing <NUM>.

The first and second washers <NUM>, <NUM> each comprise a cylindrical shaft <NUM> and an arm <NUM> that extends from their respective shaft <NUM>. The cylindrical shaft <NUM> is substantially the same width W, as the housing <NUM> and the arm <NUM> is narrower to fit within the first and second chambers <NUM>, <NUM>. In the illustrated arrangement, the arm <NUM> comprises a first section <NUM> and a second section <NUM>, wherein the first section <NUM> extends radially or perpendicularly from the cylindrical shaft <NUM> and the second section <NUM> extends at an obtuse angle from the end of the first section <NUM>. The first section <NUM> of the arm <NUM> of the first washer <NUM> is shorter than the first section <NUM> of the arm <NUM> of the second washer <NUM>. The angle between the first and second sections <NUM>, <NUM> of the arm <NUM> of the first washer <NUM> is greater than the corresponding angle of the second washer <NUM>. The angles can be selected such that the second section <NUM> of one or both of the first and second washers <NUM>, <NUM> lies substantially flat against the corresponding wall (e.g., internal wall <NUM> and end wall <NUM>, respectively) of the housing <NUM> in one position of the washers <NUM>, <NUM>. The second section <NUM> of the arm <NUM> comprises a centrally located circular aperture <NUM> configured to receive the core member <NUM>. The first and second chambers <NUM>, <NUM> differ in size according to the size of the washer that is to be housed within it, i.e. the first chamber <NUM> is smaller than the second chamber <NUM> because the first washer <NUM> is smaller than the second washer <NUM>.

The cylindrical shafts <NUM> of the first and second lock washers <NUM>, <NUM> have a diameter substantially the same as that of the circular bushes <NUM> of the washer retainer <NUM>, and are configured to be received and retained by the circular bush <NUM> in a snap-fit configuration. The snap-fit configuration is provided by the entrance of the circular bush <NUM> being narrower than the diameter of the cylindrical shaft <NUM>. The slots <NUM> of the washer retainers <NUM> are configured to allow the entrance to be flexed open to increase the ease with which the first and second lock washers <NUM>, <NUM> can be pushed through the entrances and assembled to the housing <NUM>. Once assembled within the first and second chambers <NUM>, <NUM> of the housing <NUM>, the first and second washers <NUM>, <NUM> can pivot back and forward around a central axis that runs through the cylindrical shaft <NUM>.

The core member <NUM> may be configured to pass through the core openings <NUM> of the housing <NUM> and the apertures <NUM> of the first and second washers <NUM>, <NUM>. Application of a tension force to the core member <NUM> causes the first and second lock washers <NUM>, <NUM> to pivot back and/or forward between a locked position and/or open position. <FIG> and <FIG> show the directional lock in a locked configuration in which a force is applied to the core member <NUM> in a direction towards the left side of the figure (as indicated by the arrow). In an embodiment, the force applied to the core member <NUM> in this configuration causes the first and second lock washers <NUM>, <NUM> to pivot in an anti-clockwise direction, such that the path of the core member <NUM> through the directional lock <NUM> is non-linear or tortuous and/or an increased frictional force is applied to resist movement of the core member <NUM>, e.g. due to an increase of the area in contact between core member <NUM> and first and second lock washers <NUM>, <NUM> and an increase in contact pressure. <FIG> and <FIG> show the directional lock in an open or unlocked configuration in which a force is applied to the core member <NUM> in a direction towards the right side of the figure (as indicated by the arrow). In this configuration, the first and second lock washers <NUM>, <NUM> may be pivoted in a clockwise direction such that the circular apertures <NUM> and core openings <NUM> are aligned in a substantially straight line. This provides a smooth and low-friction path and/or reduced contact pressure for the core member <NUM> to be pulled substantially freely through the directional lock <NUM>. Based on the different amount of frictional force exerted on core member <NUM> in the closed position and the open position, the amount of force required to move core member <NUM> through the directional lock <NUM> may be varied.

While the illustrated embodiment of directional lock <NUM> utilizes first and second lock washers <NUM>, <NUM>, fewer or more lock washers could be used. The number of lock washers, the type, length and thickness of core member <NUM>, and the geometry of lock washers <NUM> are design parameters that can be varied to determine an amount of force necessary to overcome directional lock <NUM> while in the closed configuration ("yield force") and an amount of force necessary to open the lock while in the open configuration ("opening force").

Additional particulars of the operation of the directional locks <NUM> are described above and in Applicant's patent application No. <CIT>,.

With reference to <FIG>, several arrangements for securing a respiratory interface, such as a respiratory mask, to the head of a wearer and to facilitate convenient removal of the interface are described in further detail. In <FIG>, the respiratory interface is a full-face mask having an upper headgear strap and a lower headgear strap on each side of the user's head that connect the mask to a rear portion of a headgear. One or more directional locks can be incorporated into the mask, headgear or other portion of the interface assembly that are configured to provide a locking or retention force tending to inhibit or prevent elongation of the interface assembly and to permit retraction of the interface assembly against a resistance that is less (e.g., significantly less) than the locking or retention force. Preferably, the directional lock(s) are configured to provide very little or substantially no resistance to retraction of the interface assembly. In the illustrated arrangements, the interface assembly incorporates a release mechanism or arrangement that permits a user to manually release the directional lock(s) to facilitate elongation of the interface assembly. Although the illustrated release mechanisms or arrangements are applied to a full-face mask having upper and lower headgear straps, the release mechanisms or arrangements can be used with, or can be modified for use with, other types of masks and headgear arrangements, such as the nasal masks and two-strap headgear arrangements of <FIG>, among others.

<FIG> illustrate a mask assembly that may comprise a cushion module <NUM>, a mask frame <NUM> and a headgear arrangement <NUM>, which in the illustrated arrangement includes a yoke <NUM>. <FIG> illustrate various views of the mask assembly with the straps <NUM> and rear portion <NUM> of the headgear <NUM> omitted. The yoke <NUM> may be attached to a rear portion <NUM> of the headgear <NUM> via one or more upper straps <NUM> and/or one or more lower straps <NUM>. In the illustrated arrangement, the headgear <NUM> includes an upper strap <NUM> and a lower strap <NUM> on each side of the mask assembly. Advantageously, upper straps <NUM> and/or lower straps <NUM> may be coupled to yoke <NUM> using one or more manually releasable or disengageable locks, such as disengageable locks 2048a, 2048b. An actuator, or disengagement element <NUM>, may be linked to the one or more disengageable locks 2048a, 2048b to allow for manual release or disengagement of the locks 2048a, 2048b. Headgear attachment posts, including lower headgear attachment posts 2012a, 2012b and upper headgear attachment posts 2012c, 2012d, may be provided to connect the straps <NUM> of the headgear <NUM> to the yoke <NUM>. The yoke <NUM>, the mask frame <NUM> and the cushion module <NUM> may be distinct components that can be taken apart and reassembled. In other configurations, any combination of the yoke <NUM>, the mask frame <NUM> and the cushion module <NUM> can be integrated with one another. Thus, although yoke <NUM> is described as forming a portion of the headgear <NUM> herein, in other configurations the yoke <NUM> can be integrated with or formed as a portion of the mask frame <NUM> or the cushion module <NUM>.

In general, the mask assembly of <FIG> is similar in construction to the mask assemblies of <FIG>, except that the mask assembly of <FIG> is implemented in a full-face form rather than the nasal masks of <FIG>. The mask assembly of <FIG> includes the frame <NUM> that is configured for connection with the cushion module <NUM> and the yoke <NUM>. The frame <NUM> is configured to connect with a gas conduit (not shown) to deliver a flow of breathing gases to the user via the cushion module <NUM>. The illustrated frame <NUM> has a central portion <NUM>, which defines an interior passage configured to communicate the flow of breathing gases from the gas conduit to the cushion module <NUM>. The central portion <NUM> of the frame <NUM> and/or the interior passage extends in a vertical direction and overlies a central portion <NUM> of the cushion module <NUM> when the mask assembly is viewed from the front. A plurality of arms <NUM> sweeps in a rearward direction from the central portion <NUM> of the frame <NUM> and approximately follows the shape of the cushion module <NUM>. In the illustrated arrangement, the frame <NUM> has four arms <NUM>, which includes an upper right arm, an upper left arm, a lower right arm and a lower left arm. The upper arms <NUM> and the lower arms <NUM> can diverge from one another in a front-to-back direction. The illustrated upper arms <NUM> extend in an upward direction away from the lower arms <NUM> in a front-to-back direction. The lower arms <NUM> can have a generally or substantially horizontal orientation. Such an arrangement can accommodate a vent <NUM> of the cushion module <NUM> and/or orient the headgear straps <NUM> in a desirable direction to comfortably achieve a satisfactory seal.

The cushion module <NUM> can include a relatively rigid housing <NUM> and a relatively soft cushion or seal <NUM>. In the illustrated arrangement, the housing <NUM> maintains a desired shape of the cushion module <NUM>, allows for connection to the frame <NUM> and defines at least a portion of a breathing chamber of the cushion module <NUM>. The cushion or seal <NUM> is removably or permanently coupled to the housing <NUM> and is configured to create a seal against the user's face to seal the breathing chamber. In the illustrated arrangement, the housing <NUM> also includes the exhaust vent <NUM>, which permits venting of expired gases from the breathing chamber and provides a restricted leak path configured to maintain a positive pressure within the breathing chamber. The exhaust vent <NUM> is located above the inlet opening. The exhaust vent comprises a plurality of vent holes through the housing <NUM>. In other arrangements, the exhaust vent <NUM> could be located elsewhere, such as within the frame <NUM>, for example.

The yoke <NUM> is configured to be removably coupled to the frame <NUM>, such that the headgear <NUM> can be coupled to the cushion module <NUM> via the frame <NUM>. The yoke <NUM> has a shape that is similar to the shape of the frame <NUM> when viewed from the front. The yoke <NUM> includes a central portion <NUM> that overlies a portion or an entirety of the central portion <NUM> of the frame <NUM>. The yoke <NUM> also includes a plurality of arms <NUM> that sweeps in a rearward direction from the central portion <NUM>. In some configurations, the number of arms <NUM> of the yoke <NUM> is equal to the number of arms <NUM> of the frame <NUM>. In the illustrated arrangement, the yoke <NUM> includes left and right upper arms <NUM> and left and right lower arms <NUM> that correspond with a respective one of the upper and lower arms <NUM> of the frame <NUM>. In some configurations, the arms <NUM> of the yoke <NUM> are longer than the corresponding arms <NUM> of the frame <NUM> and, therefore, extend in a rearward direction beyond the ends of the corresponding arms <NUM> of the frame <NUM>. The arms <NUM> of the yoke <NUM> can extend beyond the housing <NUM> of the cushion module <NUM> such that ends of the arms <NUM> are located adjacent or rearward of the seal <NUM>.

The frame <NUM> can include one or more walls or lips <NUM> extending outwardly from a forward surface of the arm(s) <NUM> and adjacent to the arms <NUM> of the yoke <NUM>. The walls <NUM> can be configured to couple the yoke <NUM> to the frame <NUM>, such as with a snap-fit arrangement, or can serve to inhibit or prevent rotation of the yoke <NUM> relative to the frame <NUM> about one or more axes. In the illustrated arrangement, a single wall <NUM> extends along the central portion <NUM> and upper arms <NUM> and additional single walls <NUM> extend between each of the upper and lower arms <NUM> on each of the left and right sides of the frame <NUM>.

The yoke <NUM> may comprise a front piece <NUM> and a rear piece <NUM> that are removably or permanently coupled to one another in a manner similar to yokes <NUM> and <NUM> described with respect to <FIG>. The yoke <NUM> can define an interior space configured to receive excess portions of core member(s) or filament(s) (e.g., filaments <NUM>, <NUM>) utilized by the directional lock(s) 2048a, 2048b. Although not illustrated, the yoke <NUM> can divide the interior space into separate sections for each of the filaments.

As described above, the yoke <NUM> or other portion of the mask assembly of <FIG> can include or support one or more actuators or disengagement elements <NUM>. The disengagement element <NUM> may be configured to release, unlock or open one or more disengageable locks, such as disengageable locks 2048a, 2048b. In the illustrated arrangement, actuation of the disengagement element <NUM> prevents the directional locks from moving to a locked position in response to elongation of the headgear <NUM> or overall mask assembly. Thus, the disengagement element <NUM> allows for deliberate or manual deactivation of the directional locks. In other words, the normal operation of the directional locks (e.g., moving to a locked position in response to elongation of the headgear <NUM>) is temporarily suspended while the disengagement element <NUM> is actuated. However, the disengagement element <NUM> is contemplated for use with other types of headgear locking arrangements. When used with other types of locks, the disengagement element <NUM> may be configured to physically move the lock to a released position upon actuation to facilitate elongation of the headgear <NUM> or overall mask assembly. The specific operation of the disengagement element <NUM> can be configured for the specific locks utilized so as to achieve the aim of permitting manual or deliberate release of the lock(s) to permit elongation of the headgear <NUM> or overall mask assembly with reduced effort.

The disengagement element <NUM> may be provided in different forms or shapes (e.g. a button, lever or handle) and be provided on different locations of the yoke <NUM> or another portion of the mask assembly. Advantageously, in one arrangement the disengagement element <NUM> is located at least partially on a front side of the yoke <NUM> or mask and/or at least partially on a top side of the yoke or mask so that a user gripping the mask can naturally or intuitively exert a force onto the disengagement element <NUM> (e.g. by squeezing or pinching the disengagement element <NUM> toward the yoke <NUM>) in the process of donning or doffing the mask assembly. <FIG> illustrate the disengagement element <NUM> in a released position and an actuated position, respectively.

In the illustrated arrangement, the disengagement element <NUM> is in the form of an elongate button or bar that extends along and is spaced-apart from an upper edge of the yoke <NUM>. The disengagement element <NUM> can be curved in a manner similar to the yoke <NUM> such that the lateral ends of the disengagement element <NUM> are positioned rearwardly of the center portion. Such an arrangement can provide an attractive appearance as well as provide access to the disengagement element <NUM> from the center and the sides of the mask assembly. In other arrangements, the disengagement element <NUM> can be positioned along a lower edge of the yoke <NUM>.

Other arrangements are possible in which the disengagement element(s) <NUM> is positioned relative to the yoke <NUM> such that a user can actuate the disengagement element(s) <NUM> in the process of grasping the yoke <NUM> or mask, thus intuitively triggering the release of the one or more disengageable locks (e.g., disengageable lock 2048a, 2048b). For example, a pair of opposed disengagement elements <NUM> could be positioned such that a user could squeeze the elements <NUM> towards one another (e.g., in a horizontal, vertical or other direction relative to the orientation shown in the figures). In such an arrangement, each disengagement element <NUM> could operate one or more disengageable locks (e.g., 2048a, 2048b).

In the illustrated arrangement, the disengagement element <NUM> is coupled to the yoke <NUM> in a manner that restricts or guides the relative movement of the disengagement element <NUM>. In particular, the disengagement element <NUM> includes a first guide element 2044a and the yoke <NUM> includes a second guide element 2044b (<FIG>). The first guide element 2044a is captured for sliding movement within the second guide element 2044b, or vice-versa, to at least substantially restrict movement of the disengagement element <NUM> to translation relative to the yoke <NUM>. However, in other arrangements other types of movement may be permitted, such as rotational movement, for example. In the illustrated arrangement, the first guide element 2044a is an elongate, flat plate or bar and the second guide element 2044b is a partially or fully-enclosed slot having a shape that corresponds to the shape of the first guide element 2044a. However, these arrangements could be reversed. The slot can be defined by the yoke <NUM> or by a separate structure attached to the yoke <NUM>. The illustrated arrangement advantageously permits movement of the disengagement element <NUM> toward and away from the upper edge of the yoke <NUM>, but inhibits or substantially prevents relative movement in other directions, to provide for smooth and/or consistent actuation of the disengagement element <NUM>.

In some arrangements, a biasing element, such as a spring or other elastic element <NUM> may be included, e.g. between the disengaging element <NUM> and the yoke <NUM> and configured to bias the disengaging element <NUM> toward or to the unactuated position in which the disengageable locks 2048a, 2048b are locked or permitted to move to a locked or engaged position. In the illustrated arrangement, a portion of the disengagement element <NUM> protrudes from the slot (second guide element 2044b) through an access opening in the yoke <NUM> and forms a structure that engages one end of a biasing element <NUM> (<FIG>). The yoke <NUM> includes a structure that engages the other end of the biasing element <NUM>.

The number of disengageable locks utilized in a given mask assembly may be varied based on a variety of relevant factors, such as the type of mask or interface, the number of headgear straps connected to the mask, and the desired doffing and donning procedure, among other possibilities. In the illustrated arrangement, each of the lower straps <NUM> of the headgear <NUM> features a disengageable lock 2048a, 2048b, whereas the upper straps <NUM> do not include a disengageable lock. However, in the illustrated arrangement, the upper straps <NUM> include directional locks (as described below) that work in a manner that is similar to or the same as the directional locks <NUM> described with reference to <FIG>. In a full-face mask, the lower straps of the headgear often require greater extension than the upper straps of the headgear for comfortable donning or doffing of the full-face mask. Thus, in some configurations, only the lower headgear straps may be provided with manually or deliberately disengageable locks. In addition, the tension in the lower straps during operation tends to be larger than the tension in the upper straps. Thus, in arrangements that incorporate directional locks (or other automatic locks), the locking force of the locks in the lower straps may be greater than a locking force of the upper straps. Thus, it can be more beneficial to provide for manual or deliberate release of the locks in the lower straps, which have a higher locking force and, thus, a greater resist to elongation than the locks of the upper straps. Providing for manual or deliberate release in only a portion of the straps (e.g., the lower straps) can reduce complexity of the system and lower the overall cost compared to arrangements in which each strap is provided with a disengageable lock. However, if desired, disengageable locks can be provided in any of the straps or portions of the headgear. Thus, in some configurations, the upper straps <NUM> may be attached with a disengageable lock on one or both sides. In addition, in some configurations, the lower straps <NUM> may be attached without a disengageable lock. As discussed, in some configurations, all of the upper and lower straps <NUM> may be attached using disengageable locks. Furthermore, in some configurations disengageable locks may be provided in the rear, top, or side of the headgear to enable elongation of various headgear sections during donning and doffing.

The one or more disengageable locks 2048a, 2048b may be connected to the disengagement element <NUM> either directly or via an actuation arrangement configured to transfer motion from the disengagement element <NUM> to the disengageable locks 2048a, 2048b. The actuation arrangement can be referred to herein as a linking member <NUM>. In some configurations, the linking member <NUM> can be a substantially non-elastic string, cable or wire that is tensioned by a movement of disengagement element <NUM>, thereby capable of transmitting force from disengagement element <NUM> to the one or more disengageable locks 2048a, 2048b. In some configurations, the linking member <NUM> may be or include a Bowden cable or an arrangement similar to a Bowden cable, which includes an inner cable and a guide member or fixed guide path such that movement at one end of the cable results in corresponding movement at the other end of the cable. In some configurations, the linking member <NUM> is a pull only arrangement that transmits a pulling force from the disengagement element <NUM> to the disengageable locks 2048a, 2048b and utilizes a return biasing element to move the linking member <NUM> in the return direction. In other configurations, the linking member <NUM> can be a push-pull arrangement that can transmit a pushing or pulling force, if desired. The illustrated linking members <NUM> do not include a continuous outer housing common to many Bowden cable arrangements, but instead are guided along a fixed length path defined by one or more guide features, such as a central guide 2047a, intermediate guides 2047b, and lateral guides <NUM> (generally or collectively <NUM>). The guides <NUM> are configured to define or alter a path of the linking member <NUM> between the disengaging element <NUM> and the disengageable locks 2048a, 2048b. In the illustrated arrangement, the guides <NUM> are eyelets through which the linking member <NUM> passes. In the illustrated arrangement, a single linking member <NUM> is connected to and actuates both disengageable locks 2048a, 2048b. However, in another embodiment, each disengageable lock 2048a, 2048b can be actuated by a dedicated linking member <NUM> or a single linking member <NUM> can be split into multiple sub-members to control multiple disengageable locks. Although cables are shown herein, the linking member <NUM> could be of any suitable arrangement, such as one or more rods, linkages, etc..

With reference to <FIG>, <FIG>, <FIG> and <FIG>, an example of a disengageable lock 2048a is illustrated in detail. The disengageable lock 2048b can be of the same or similar arrangement (e.g., a mirror image) as the disengageable lock 2048a. Furthermore, the basic components and operation of the disengageable lock 2048a can be the same as or similar to the above-described directional locks <NUM>, with the notable exceptions of the disengagement feature and the shape of the lock washers <NUM> as described herein. The disengageable lock 2048a may comprise one or more washers <NUM>, a bias spring <NUM> and a channel <NUM> that receives a disengagement member <NUM>. In the illustrated arrangement, the channel <NUM> is defined by the yoke <NUM>; however, in other arrangements the channel <NUM> could be defined by a structure separate from and assembled to the yoke <NUM>. The disengagement member <NUM> is attached to the linking member <NUM> at a linking member connection <NUM>. One or more lock elements or lock washers <NUM> may be received within a washer housing <NUM>. In the illustrated arrangement, multiple (e.g., five) lock washers <NUM> are provided. However, the actual number may be varied based on, among other factors, the desired locking force of the lock 2048a.

The disengagement member <NUM> may be free to slide within channel <NUM>. The disengagement member <NUM> is movable to selectively engage the lock washers <NUM> to move the lock washers <NUM> to, or retain the lock washers <NUM> in (block the lock washers <NUM> from moving away from), the released or unlocked position. As described above, in the released or unlocked position of the lock washers <NUM>, movement of the filament (not shown, e.g., <NUM>, <NUM>) in the elongation direction of the associated strap <NUM> is not resisted or is permitted with significantly reduced resistance relative to the locked position of the lock washers <NUM>. The disengagement member <NUM> is moved to the actuated position (engaging or blocking the lock washers <NUM>) or actuated by the disengagement element <NUM> via the linking member <NUM>. This position may be referred to as the unlocked or open position of the disengagement mechanism or disengageable lock 2048a and is illustrated in <FIG> and <FIG>. The bias spring <NUM>, or another suitable biasing arrangement, is configured to return the disengagement member <NUM> to the unactuated position in which the lock washers <NUM> are free to move and operate as normal (free to move to a locked position in response to movement in an elongation direction). This position may be referred to as the locked, engaged, operable or normal position of the disengagement mechanism or disengageable lock 2048a and is illustrated in <FIG> and <FIG>.

In the unactuated position of disengagement member <NUM>, the washers <NUM> are permitted to move between an unlocked and a locked position in response to retraction and elongation movement, respectively, of the strap <NUM> or headgear <NUM>. As discussed with reference to <FIG>, if the washers <NUM> are permitted to move or pivot, the movement of filament or core member <NUM> in the elongation direction may be restricted (e.g., inhibited or prevented) by friction between core member <NUM> and washers <NUM>. Conversely, if the washers <NUM> are held in the unlocked position, the friction between core member <NUM> and washers <NUM> is reduced and movement of core member <NUM> in the elongation direction becomes easier relative to the locked position.

With reference to <FIG> and <FIG>, each of the washers <NUM> may comprise one or more protrusions 1821a, 1821b. These protrusions 1821a, 1821b may define engagement surfaces configured for selective engagement with the disengagement member <NUM> to move the washers <NUM> to the unlocked position or block the washers <NUM> from moving away from the unlocked position, and thus allow the relatively free movement of the core member <NUM> in the elongation direction (as well as the retraction direction). The disengagement member <NUM> can include an appropriate number of actuators 2054a, 2054b configured to contact the protrusions 1821a, 1821b. In the illustrated arrangement, the actuators 2054a, 2054b are in the form of tabs or arms that extend from a main body portion of the disengagement member <NUM>. In the illustrated arrangement, a protrusion 1821a, 1821b is located on each side of the washer <NUM> such that a balanced force is applied to each side of the washer <NUM> by the corresponding actuators 2054a, 2054b of the disengagement member <NUM>, which are similarly provided on each side of the disengagement member <NUM>, to provide for smooth pivoting movement of the washer <NUM> and reduce or prevent binding.

<FIG> illustrates an alternative washer <NUM> that includes only one protrusion 1821a. In the arrangement of <FIG>, the single protrusion 1821a is centrally-located relative to the pivoting structure engaged by the housing <NUM> to reduce or prevent binding. However, in some configurations, an off-center protrusion <NUM> or protrusions can be employed and binding can be resisted by other methods or structures, such as the pivoting arrangement, for example. Other arrangements, including multiple protrusions, and other geometries, may be used in addition to or in the alternative of protrusions 1821a.

With reference to <FIG>, a lock <NUM> that is in some aspects similar to disengageable locks 2048a, 2048b is illustrated that incorporates washers <NUM> in a washer housing <NUM>, but does not incorporate a disengageable mechanism. In some configurations, the basic components and operation of the lock <NUM> can be the same as or similar to the above-described directional locks <NUM>, except as described herein. The illustrated lock <NUM> includes multiple washers <NUM>. In particular, in the illustrated arrangement, the lock <NUM> includes three washers. In some configurations, each of the locks <NUM> include a lesser number of washers than each of the disengageable locks 2048a, 2048b. In some such configurations, one or more locks <NUM> are employed in each upper strap <NUM> of the headgear <NUM> and one or more locks 2048a, 2048b are employed in each lower strap <NUM> of the headgear <NUM>. It will be appreciated that any desired combination of disengageable locks 2048a, 2048b and non-disengageable locks <NUM> may be used in the same mask assembly.

With reference to <FIG>, another embodiment of a mask assembly is disclosed that may be similar in certain aspects to the mask assembly illustrated in <FIG>, but includes a disengagement element in the form of a disengagement handle <NUM> instead of the disengagement bar <NUM> of <FIG>. Accordingly, features that are not described in detail herein can be the same as or similar to corresponding features disclosed herein, or can be of another suitable arrangement. The disengagement handle <NUM> may be attached to yoke <NUM> and may be directly or indirectly connected to the disengagement member <NUM> so that pulling on handle <NUM> transmits a force to disengagement member <NUM>. In the illustrated arrangement, the disengagement handle <NUM> is directly connected to the disengagement member <NUM>. In other arrangements, the disengagement handle <NUM> can be integrated with the disengagement member <NUM> or can be connected to the disengagement member <NUM> by intervening structure so as to gain a mechanical advantage, change the direction or type of motion, or avoid interference with other structures, among other possibilities. In an embodiment, disengagement handle <NUM> may be configured so that a wearer of the mask can grasp and pull the handle away from his face, thereby moving the disengagement member <NUM> to the actuated position, as illustrated in <FIG>. With particular reference to <FIG> and <FIG>, disengagement handle <NUM> can curve downwardly from the side portions to the central or forward portion such that an upper surface of the central portion is concave. Such an arrangement provides an intuitive portion of the disengagement handle <NUM> for the user to grasp. As disclosed herein, when the disengagement member <NUM> is in the actuated position, the disengageable locks 2048a, 2048b are disengaged such that the locks 2048a, 2048b do not significantly resist elongation movement of the lower straps <NUM> of the headgear <NUM>. Upon the user releasing the disengagement handle <NUM>, the bias spring <NUM> may return the disengagement member <NUM> to its unactuated position, as illustrated in <FIG>, thus also retracting disengagement handle <NUM>. In such a position, the disengageable locks 2048a, 2048b operate normally and inhibit or prevent elongation movement of the lower straps <NUM> of the headgear <NUM>.

With reference to <FIG>, another mask assembly is disclosed that may be similar in certain aspects to the other mask assemblies disclosed herein with respect to <FIG>, but includes a disengagement arm <NUM> attached to yoke <NUM> in place of, or in addition to, the disengagement handle <NUM> or the disengagement bar <NUM>. Accordingly, features that are not described in detail herein can be the same as or similar to corresponding features disclosed herein, or can be of another suitable arrangement. The illustrated mask assembly includes one disengagement arm <NUM> on one side of the yoke <NUM> and configured to interact with one of the lower straps <NUM> of the headgear <NUM> and the disengagement member <NUM> of the disengageable lock 2048a. In some configurations, another disengagement arm (which can be a mirror image of the disengagement arm <NUM>) can be employed on the opposite lower strap <NUM> of the headgear <NUM> and configured to interact with the other lower disengeageable lock 2048b. Alternatively, a linking member or other motion transfer arrangement can be configured to link both locks 2048a, 2048b to movement of a single disengagement arm <NUM>. In other arrangements, disengagement arms <NUM> can be employed on any or all straps <NUM> of the headgear <NUM>.

The disengagement arm <NUM> is movable relative to the yoke <NUM>. In some configurations, the disengagement arm <NUM> is configured to pivot relative to or is pivotally supported by the yoke <NUM>. In the illustrated arrangement, the yoke <NUM> includes a pivot <NUM> in the form of at least one protrusion configured to be engaged by, received in, or held within a complementary feature of the disengagement arm <NUM>. The protrusion can be cylindrical as illustrated. Preferably, the yoke <NUM> includes a pivot <NUM> on each of a side facing away from the user and a side facing towards the user. Accordingly, the disengagement arm <NUM> may be configured to pivot, rotate or swivel around a pivot axis defined by the pivot <NUM>.

The disengagement arm <NUM> is configured to directly or indirectly contact or otherwise engage the disengagement member <NUM> to move the disengagement member <NUM> from the unactuated position to the actuated position. In particular, when the disengagement arm <NUM> is rotated about the pivot <NUM> in a clockwise direction relative to the orientation shown in the figures, the disengagement arm <NUM> contacts an engagement portion 2055a of the disengagement member <NUM> and, if the disengagement arm <NUM> is rotated a sufficient amount, moves the disengagement member <NUM> to the actuated position. Accordingly, when disengagement arm <NUM> is moved from a substantially level or horizontal position as illustrated in <FIG> and <FIG> to a substantially inclined or raised position as illustrated in <FIG>, <FIG> and <FIG>, disengagement member <NUM> moves from the unactuated position to the actuated position. Conversely, when the disengagement arm <NUM> is returned to the level or horizontal position, the disengagement member <NUM> is able to return to the unactuated position or, when the force tending to rotate the disengagement arm <NUM> in the clockwise direction is removed, the bias spring <NUM> (or other biasing element) may move the disengagement member <NUM> from the actuated to the unactuated position whereby the disengagement arm <NUM> may be rotated back toward or to the substantially level position.

Although the disengagement arm <NUM> could be configured for direct manual manipulation by the user, in the illustrated arrangement the disengagement arm <NUM> is configured to engage a strap <NUM> of the headgear <NUM> and be actuated as a result of relative movement between the yoke <NUM>, mask frame <NUM> or cushion <NUM> and the headgear strap <NUM>. For example, to remove the mask assembly, the user can grasp the yoke <NUM>, mask frame <NUM> or cushion <NUM> (referred to collectively as the "mask" for convenience) and rotate at least the bottom of the mask upwardly and/or outwardly away from the user's face (e.g., chin). The straps <NUM> of the headgear <NUM> tend to stay in place on the user's head due to frictional contact with the user and because of tension on the headgear straps <NUM>. Accordingly, the movement of the mask initiated by the user causes clockwise movement of the disengagement arm <NUM> relative to the mask, which actuates the disengagement member <NUM>, as described above. As a result, one or both of the disengageable locks 2048a, 2048b are disengaged and at least the lower straps <NUM> of the headgear <NUM> are permitted to elongate with lowered or little resistance. Similarly, clockwise movement of the disengagement arm <NUM> relative to the mask is caused when the user places the rear portion <NUM> of the headgear on his or her head and rotates the bottom of the mask away from the face so that the mask can pass by the nose. Thus, one or both of the disengageable locks 2048a, 2048b are disengaged and at least the lower straps <NUM> of the headgear <NUM> are permitted to elongate with lowered or little resistance during donning of the mask assembly. Advantageously, the pivot <NUM> may be located below the lower headgear attachment posts 2012a, 2012b to reduce tension in the lower strap <NUM> exerting a torque on the disengagement arm <NUM>. The range of rotation of disengagement arm <NUM> may be limited by the range of linear travel of the disengagement member <NUM> and/or a contact between disengagement arm and yoke <NUM>. Alternatively, separate protrusions or any suitable mechanical stop may be implemented to limit the disengagement arm's rotation.

With reference to <FIG>, the disengagement arm <NUM> may comprise a headgear engaging feature <NUM>, a pivot connection <NUM>, a stop <NUM> and an engagement surface <NUM>. The headgear engaging feature <NUM> is configured to couple the disengagement arm <NUM> to a portion of the headgear <NUM>, such as a strap <NUM> (e.g., lower strap) of the headgear <NUM> so that the disengagement arm <NUM> moves relative to the yoke <NUM> or mask in response to relative movement between the headgear <NUM> and the yoke <NUM>, mask frame <NUM> or cushion module <NUM>, as described above. In the illustrated arrangement, the headgear engaging feature <NUM> is a loop or collar configured to surround a substantial portion or entirety of a strap <NUM> of the headgear <NUM>. The illustrated headgear engaging feature <NUM> has a small open section <NUM> to permit insertion of the strap <NUM> into the interior space of the loop or collar. The open section <NUM> provides the engaging feature <NUM> with a generally C-shaped cross-section. In other arrangements, the loop or collar may form a fully closed loop. Other suitable arrangements for coupling to the headgear <NUM> (or other portions of the mask that experience relative movement during donning or doffing) may also be used, such as a hook, rim or other connector (e.g. a snap-fit connector or other interlocking connector), into which a corresponding mating piece or connector from headgear <NUM> may be inserted, for example.

In some configurations, the headgear engaging feature <NUM> provides a removable connection between a headgear strap <NUM> and the disengagement arm <NUM>. In other configurations, the connection between headgear engaging feature <NUM> and the headgear <NUM> may be made permanent, for example by over-molding (e.g. with silicone rubber) the headgear engaging feature <NUM> and the headgear strap <NUM>.

The pivot connection <NUM> is configured to allow the disengagement arm <NUM> to removably or permanently connect with the yoke <NUM> for rotation about the pivot axis define by the pivots <NUM>. In the illustrated arrangement, the pivot connection <NUM> has an inner side portion and an outer side portion connected by a bridge portion. The inner side portion and the outer side portion have different shapes such that the overall pivot connection <NUM> is asymmetrical. In the illustrated arrangement, the inner side portion is configured to provide a secure connection with the corresponding pivot <NUM> of the yoke <NUM>. Accordingly, the inner side portion surrounds a greater portion of a periphery of the pivot <NUM> and has more material surrounding the recess that receives the pivot <NUM> to inhibit or prevent deformation that would permit unintended separation of the pivot connection <NUM> and the yoke <NUM>.

The outer side portion is configured to pivot about the corresponding pivot <NUM> of the yoke <NUM> and includes the engagement surface <NUM>, which is configured to selectively contact the engagement portion 2055a (<FIG>) and move the disengagement member <NUM>. Accordingly, in the illustrated arrangement, the outer side portion of the pivot connection <NUM> surrounds less of the periphery of the corresponding pivot <NUM> in comparison to the inner side portion. In addition, the outer side portion has less material surrounding the pivot <NUM> in comparison to the inner side portion.

The engagement surface <NUM> is located above the recess configured to receive the pivot <NUM>. In the illustrated arrangement, the engagement surface <NUM> is substantially planar (linear from a side view) and is angled away from the disengagement member <NUM> in a direction from a lower end to an upper end of the engagement surface <NUM>. However, other suitable shapes (e.g., single curve, multiple curves) can be employed for the engagement surface <NUM> depending, for example, on the desired rate of movement of the disengagement member <NUM> in response to movement of the disengagement arm <NUM> relative to the yoke <NUM>.

In the illustrated arrangement, the disengagement arm <NUM> includes a stop surface or a stop <NUM> that limits rotational movement of the disengagement arm <NUM> relative to the yoke <NUM>. The illustrated stop <NUM> is defined by the bridge portion of the pivot connection <NUM> and, in particular, by a leading edge of the bridge portion. Upon sufficient rotation of the disengagement arm <NUM> in the clockwise direction relative to the yoke <NUM>, the stop <NUM> of the disengagement arm <NUM> contacts the yoke <NUM> (e.g., an upper surface of the yoke <NUM>) to limit movement of the disengagement arm <NUM>. Such an arrangement inhibits or prevents excessive force from being applied to the disengagement member <NUM>. However, in other arrangements, the disengagement member <NUM> could be configured to define the stop point of rotation of the disengagement arm <NUM> and, thus, could be configured to handle the expected loads.

Advantageously, disengagement arm <NUM> may be shaped to correspond to a shape of the user's head along which the disengagement arm <NUM> extends and/or a desired path of the corresponding strap <NUM> or other portion of the headgear <NUM>. In the illustrated arrangement, a rearward portion (e.g., containing the headgear engaging feature <NUM>) of the disengagement arm <NUM> is slightly bent or curved inward relative to a forward portion (e.g., containing the pivot connection <NUM>) to follow the expected curvature of the user's face and/or desired path of the headgear strap <NUM>.

<FIG> illustrate a mask assembly <NUM> suitable for use with any of the retention or lock arrangements and release arrangements described above. The mask assembly <NUM> includes alternative arrangements for coupling the yoke <NUM> and the cushion module <NUM> to the frame <NUM> relative to the previously-disclosed assemblies. Accordingly, certain features of the retention or lock arrangements and the release arrangements are omitted for the sake of clarity. However, the mask assembly <NUM> can incorporate or can be modified to incorporate any of the retention or lock arrangements and/or release arrangement disclosed herein. Alternatively, the previously-disclosed mask assemblies can incorporate or can be modified to incorporate any of the coupling arrangements disclosed with respect to the mask assembly <NUM>. Moreover, in many respects, the yoke <NUM>, the cushion module <NUM> and the frame <NUM> are the same as or similar to one or more of the previously-described embodiments. Thus, features or components of the mask assembly <NUM> that are not described in detail below can be the same as or similar to corresponding features or components described previously, or can be of another suitable arrangement.

In the illustrated arrangement, the yoke <NUM>, the cushion module <NUM> and the frame <NUM> are distinct or separable components, which can be selectively assembled and disassembled. Allowing the yoke <NUM>, the cushion module <NUM> and the mask frame <NUM> to be easily separated from one another and reassembled may provide various advantages, including easier cleaning of the mask by the user, replacement of components, and allowing the mask to be disassembled for easier transportation and storage, among others.

The illustrated mask assembly <NUM> includes a first or yoke-to-frame connection arrangement that permits selective connection of the yoke <NUM> to the mask frame <NUM>. In particular, the illustrated mask frame <NUM> comprises a ridge or lip <NUM> that surrounds at least a portion of the perimeter of the frame <NUM> and provides a feature or structure onto which the yoke <NUM> can removably attach or clip. In the illustrated arrangement, the lip <NUM> is provided at least on each side of the frame <NUM>. However, in other arrangements, the lip <NUM> could define a complete closed-loop perimeter. Alternatively, the lip <NUM> could be provided in a number of discrete locations. That is, the lip <NUM> can be provided only in those locations corresponding to engagement features of the yoke <NUM>, which are described below. In the illustrated arrangement, the lip <NUM> is formed by an extension of a front wall of the mask frame <NUM> such that the forward surface of the lip <NUM> is flush with adjacent portions of the front wall of the mask frame <NUM>. The lip <NUM> may be unitarily-formed with the mask frame <NUM> (e.g. formed as a protrusion from mask frame <NUM>) or may be a separate structure that is attached to the mask frame <NUM> (e.g. mechanically coupled to or formed by an over-molded structure). Advantageously, the geometry of mask frame <NUM> and/or lip <NUM> may be asymmetrical, so as to inhibit or prevent rotation or pivoting of the yoke <NUM> and provide a single, stable orientation of yoke <NUM> relative to mask frame <NUM>.

With particular reference to <FIG>, as in prior embodiments, the illustrated yoke <NUM> comprises a first or front piece or portion <NUM> and a second or rear piece or portion <NUM>. The front piece <NUM> and the rear piece <NUM> can be permanently or removably coupled to one another. The front piece <NUM> and the rear piece <NUM> cooperate to define one or more interior spaces configured to receive components of a retention or lock arrangement, such as directional locks (<NUM> - <FIG>, <NUM> - <FIG>, and <NUM> - <FIG>). The yoke <NUM> includes a central portion <NUM> and a plurality of arms (e.g., four arms <NUM>) that sweep rearwardly from the central portion. The arms <NUM> are configured to connect to straps of the headgear. In some configurations, each arm <NUM> can be connected to a single headgear strap such that the number of straps equals the number of arms <NUM>. However, in other arrangements, multiple straps can be connected to a single arm <NUM> such that the number of straps is greater than the number of arms <NUM> or a single strap can be connected to multiple arms <NUM> (e.g., a strap can extend from a rear portion of the headgear to a first arm, from the first arm to a second arm and then return to the rear portion of the headgear) such that the number of straps is less than the number of arms <NUM>.

The illustrated frame <NUM> defines an interior passage <NUM> configured to communicate the flow of breathing gases from a gas conduit (not shown) to the cushion module <NUM>. The frame <NUM> and/or the interior passage extend in a vertical direction and overlies a central portion of the cushion module <NUM> when the mask assembly is viewed from the front. An upper edge of the frame <NUM> terminates a relatively short distance above an inlet opening of the cushion module <NUM> and can include a downwardly-curved or concave upper surface configured to accommodate a vent <NUM> of the cushion module <NUM>. The mask frame <NUM> may be configured for connection to a gas conduit (not shown). In the illustrated arrangement, a conduit connector portion <NUM> is permanently or removably coupled to a lower end of the frame <NUM> and is configured to be directly or indirectly coupled to a gas conduit. The conduit connector portion <NUM> may also secure a valve member of an anti-asphyxiation valve (AAV) within the interior passage of the frame <NUM>.

<FIG> illustrates a rear piece <NUM> of the yoke <NUM>, which faces the frame <NUM>. The rear side of the yoke <NUM> includes a portion of the first or yoke-to-frame connection arrangement. In particular, the rear piece <NUM> of the yoke <NUM> includes one or more connection features, generally referred to as <NUM>, which are configured to engage with a portion of the frame <NUM>, such as the lip <NUM>. The illustrated connection features <NUM> are in the form of deflectable fingers or arms. In the illustrated arrangement, the yoke <NUM> includes four connection features 7612a, 7612b, 7612c, 7612d spaced around a periphery of a base portion or central portion <NUM> of the yoke <NUM>. The connection features 7612a, 7612b, 7612c, 7612d can be substantially similar or identical and, therefore, any description of a particular connection feature 7612a, 7612b, 7612c, 7612d or a connection feature <NUM> generally, can be applied to each connection feature 7612a, 7612b, 7612c, 7612d unless otherwise indicated.

Each of the connection features 7612a, 7612b, 7612c, 7612d is associated with one of the arms <NUM> of the yoke <NUM>. In particular, each of the connection features 7612a, 7612b, 7612c, 7612d is located at or adjacent a base of the associated arm <NUM> at or near a junction between the arm <NUM> and the central portion <NUM>. Such an arrangement hides the connection features 7612a, 7612b, 7612c, 7612d when the yoke <NUM> is assembled to the frame <NUM> and provides a clean and attractive appearance. In other arrangements, other numbers of connection features <NUM> may be provided. For example, one, two, three, five, six or more connection features <NUM> may be provided. The connection features <NUM> can be arranged in a radial configuration about the periphery of the central portion <NUM>. The connection features 7612a, 7612b, 7612c, 7612d may be unitary with the rear piece <NUM> made from a material that deforms elastically, such as e.g. polypropylene, high-density polyethylene, or polycarbonate.

The fingers or connection features 7612a, 7612b, 7612c, 7612d are hooked tabs extending in a rearward direction from the rear surface of the rear piece <NUM> of the yoke <NUM>. The fingers or tabs 7612a, 7612b, 7612c, 7612d have a first end connected to (e.g., unitarily formed with) the rear piece <NUM> of the yoke <NUM> and a second end that defines an inwardly-extending return, catch or projection <NUM> configured to engage the lip <NUM> of the frame <NUM>. In particular, each projection <NUM> defines a first interlock surface configured to contact a rearward surface of the lip <NUM>, which functions as a second interlock surface, such that each projection <NUM> and the lip <NUM> define a snap-fit or an interlock connection. The rearward-facing surface of projections <NUM>, or the leading surface relative to the assembly direction, can be chamfered, angled or sloped so that the fingers or connection features 7612a, 7612b, 7612c, 7612d are deflected outwardly by contact with and movement toward the lip <NUM> of the frame <NUM>. Once the projections <NUM> move past the lip <NUM>, the fingers or connection features 7612a, 7612b, 7612c, 7612d can elastically recover and move radially inward until the projections <NUM> engage the lip <NUM>. In alternate arrangements, the illustrated arrangement can be reversed such that the fingers or connection features 7612a, 7612b, 7612c, 7612d are located on the frame <NUM> and the lip <NUM> is located on the yoke <NUM>. Moreover, other types of structures providing cooperating interlocking surfaces can be used.

<FIG> illustrates the general direction of forces applied to the yoke <NUM> and the frame <NUM> during the connection or assembly process. For example, a first force may be applied on the yoke <NUM> substantially in the direction of arrow <NUM>. The first force may be applied through a user's hand pushing or pulling the yoke towards the frame <NUM>. A second force or counterforce is applied substantially in the opposite direction of the first force, as illustrated by arrow <NUM>. The connection feature <NUM> and lip <NUM> are compressed against each other and one or both may lightly deform or deflect (e.g. elastic deformation) to permit the connection feature <NUM> to move past the lip <NUM>. The path of motion of the deflection of connection feature <NUM> is substantially radially outward, as illustrated by arrow <NUM>. The deformation or deflection may be limited by a stop surface <NUM>, which in the illustrated arrangement is defined by the corresponding arm <NUM> of the yoke <NUM>. Advantageously, such an arrangement may limit the deflection of connection feature <NUM> to within a range of elastic deformation to reduce the risk of breakage and increase the useful life of the yoke <NUM> in comparison to arrangements that do not limit deflection of the connection features <NUM>. The stop surface <NUM> may be separated from the connection feature <NUM> by a gap <NUM>, which can extend partially or completely through the rearward wall of the rear piece <NUM> of the yoke <NUM>. The gap <NUM> can facilitate deflection of the connection feature <NUM> and/or decouple movement between the connection feature <NUM> and the associated arm <NUM> such that movement of the arm <NUM> does not move the connection feature <NUM> or at least does not result in sufficient movement to cause unintended disconnection of the connection feature <NUM> from the lip <NUM>. After connection feature <NUM> has passed lip <NUM>, the resilient nature of the connection feature <NUM> will allow it to elastically recover toward or to its relaxed position such that the projection <NUM> engages the lip <NUM> to secure the yoke <NUM> to the frame <NUM>.

With particular reference to <FIG> and <FIG>, the rear piece <NUM> of the yoke <NUM> can include a recess <NUM> associated with each of the fingers or connection features <NUM>. Each recess <NUM> is located adjacent the first end of the associated finger or connection feature <NUM> to facilitate deflection of the finger or connection feature <NUM>. Preferably, the recess <NUM> is immediately adjacent the finger or connection feature <NUM>. However, in other arrangements, the recess <NUM> is located close enough to the finger or connection feature <NUM> such that the deflection force required is lower than a design that does not include a recess <NUM>. In an alternative arrangement, a single recess could be associated with, or located adjacent, more than one or all of the fingers or connection features <NUM>. For example, a single recess could extend along one side of the central portion <NUM> and adjacent each of the fingers or connection features <NUM> on that side. Or, a single recess could circumscribe the central portion <NUM> and be located adjacent all of the fingers or connection features <NUM>.

The illustrated mask assembly <NUM> includes a second or cushion module-to-frame connection arrangement that permits selective connection of the cushion module <NUM> to the mask frame <NUM>. The mask frame <NUM> includes a rearwardly-extending cylindrical collar <NUM> configured to engage a corresponding opening <NUM> defined by a cylindrical wall <NUM> of the housing <NUM> of the cushion module <NUM>. The cylindrical wall <NUM> can extend inwardly from an outer wall of the housing <NUM> toward or into a breathing chamber of the cushion module <NUM>. In the illustrated arrangement, the collar <NUM> and the opening <NUM> define a circular or substantially circular perimeter. However, in other arrangements, the collar <NUM> and/or the opening <NUM> could have non-circular shapes, such as ovate or polygonal, for example. Accordingly, as used herein, the term "cylindrical" can include an extruded closed loop of any perimeter shape, unless indicated otherwise.

The illustrated mask frame <NUM> includes one or more recesses <NUM> configured to receive a corresponding protrusion <NUM> of the cushion module <NUM>. However, this arrangement could also be reversed such that the mask frame <NUM> includes one or more protrusions and the cushion module <NUM> includes corresponding recesses. The illustrated mask frame <NUM> includes a pair of part-annular recesses <NUM>, which extend in a circumferential direction and are located on opposing sides of the collar <NUM>. The cushion module <NUM> includes a corresponding pair of protrusions <NUM> that engage the recesses <NUM> in a snap-fit or interlocking manner. In other arrangements, the mask frame <NUM> and the cushion module <NUM> can include a lesser number (e.g., a single) or a greater number of recesses <NUM> and protrusions <NUM>. The interlocking connection of the recesses <NUM> and the protrusions <NUM> provide a retention force tending to inhibit or prevent unintentional separation of the cushion module <NUM> from the mask frame <NUM>. In addition, the recesses <NUM> and the protrusions <NUM> can provide feedback (e.g., tactile or audible feedback) to the user that connection between the cushion module <NUM> and the mask frame <NUM> is complete and/or can inhibit or prevent relative rotation between the cushion module <NUM> and the mask frame <NUM>.

In some configurations, the mask assembly <NUM> includes an alignment feature that facilitates proper rotational alignment between the cushion module <NUM> and the mask frame <NUM>. In some configurations, the alignment feature can also inhibit or prevent relative rotation between the cushion module <NUM> and the mask frame <NUM>. With reference to <FIG>, the collar <NUM> of the illustrated mask frame <NUM> includes a recess <NUM> configured to receive a corresponding protrusion <NUM> of the cushion module <NUM>. However, this arrangement could be reversed such that the protrusion is located on the mask frame <NUM> and the recess is located on the cushion module <NUM>.

In the illustrated arrangement, the side surfaces of the protrusion <NUM> contact corresponding side surfaces of the recess <NUM> to limit rotation of the cushion module <NUM> relative to the mask frame <NUM>. An outer shape defined by at least the side surfaces of the protrusion <NUM> substantially corresponds to the size and the shape defined by at least the side surfaces of the recess <NUM> such that any significant relative rotational movement is prevented. However, in other arrangements, a gap may be provided between the protrusion <NUM> and the recess <NUM> such that some amount of rotation may be permitted. In the illustrated arrangement, the recess <NUM> and the protrusion <NUM> each have a generally trapezoidal shape in the circumferential direction or otherwise have shapes that taper in width in a direction from the rear to the front so that the recess <NUM> acts as a lead-in for the protrusion <NUM> to ease assembly.

In some configurations, a forward-facing surface of the protrusion <NUM> contacts the rearward-facing surface of the recess <NUM> when the cushion module <NUM> is properly assembled to the mask frame <NUM>. With such an arrangement, contact between the forward-facing surface of the protrusion <NUM> and the rearward-facing surface of the recess <NUM> can provide an indication or feedback (e.g., tactile or audible feedback) to the user that the connection is complete. In addition or in the alternative, other portions of the cushion module <NUM> and the mask frame <NUM> can contact upon complete assembly, such as a forward-facing perimeter surface of the cylindrical wall <NUM>, for example.

Claim 1:
A headgear (<NUM>) for a respiratory mask, comprising:
at least one strap (<NUM>) comprising a filament (<NUM>,<NUM>);
a directional lock (<NUM>) having an engaged configuration and a disengaged configuration with respect to the filament (<NUM>,<NUM>); and
a disengaging member (<NUM>) operable to hold the lock in the disengaged configuration; and
an actuator (<NUM>) configured to act on the disengaging member (<NUM>) to cause the disengaging member to hold the lock in the disengaged configuration., and wherein actuation of the disengaging member (<NUM>) prevents the directional lock (<NUM>) from moving to the engaged configuration in response to elongation of the headgear (<NUM>).