Abstract:
A breathing assistance apparatus has a lid and latch assembly configured for one-handed operation. The apparatus also includes a hinge assembly that separates when over-rotated but that reengages upon closing of the lid onto the main body of the apparatus.

Description:
INCORPORATION BY REFERENCE TO ANY PRIORITY APPLICATIONS 
     Any and all applications for which a foreign or domestic priority claim is identified in the Application Data Sheet as filed with the present application are hereby incorporated by reference under 37 CFR 1.57. The present application is a continuation of PCT International Application No. PCT/NZ2013/000175, filed Sep. 23, 2013, which claims priority to U.S. Provisional Application No. 61/705,340, filed Sep. 25, 2012, the entirety of each of which is hereby incorporated by reference herein. 
    
    
     BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The present invention generally relates to respiratory devices. More particularly, the present invention relates to respiratory devices in which respiratory gases are supplied at a positive pressure after passing over a surface of liquid in a reservoir. 
     Description of the Related Art 
     CPAP treatment of obstructive sleep apnea involves the delivery of pressurized, breathable gas, usually air, to a user&#39;s airways using a conduit and a user interface, such as a mask. The gas pressures employed for CPAP typically range from about 4 cm H2O to about 28 cm H2O at flow rates of up to about 180 L/min (measured at the user interface), depend upon the requirements of the user. The pressurized gas acts as a pneumatic splint for the airway of the user. As such, the pressurized gas reduces the likelihood of collapsing of the airway. 
     SUMMARY OF THE INVENTION 
     CPAP machines include an airflow generator to supply the pressurized gas and many CPAP machines include a heated water bath or other source of water for humidification of the pressurized gas. CPAP machines often are used in bedrooms or other sleeping quarters and are placed on nightstands, for example. As such, reducing the footprint of CPAP machines is desirable. In addition, given the limited space of nightstand tops, CPAP machines often are pushed as close to a wall as possible. 
     Because of the cramped spaces in which CPAP machines are used, easy manipulation of a lid or other component used to enclose a water reservoir or the like is desired. Preferably, the lid or other such component can be easily pivoted about hinges. More preferably, the hinges are configured to be generally flush with, or recessed into, the adjoining outer surfaces Even more preferably, the hinges provide a restraint against forces generated by air pressure within the machine (e.g., vertical forces with a generally horizontal lid) while allowing detachment of the lid when the lid is overextended during opening. 
     Moreover, to improve the ability to access the water reservoir, the lid preferably carries a latch mechanism such that a user can open the lid with a single hand. In other words, the latch can be operated and the lid can be opened with a single hand and, preferably, with the single hand in a single position. Such configurations are a welcomed improvement over configurations requiring one hand to operate the latch and another hand to subsequently raise the lid. 
     In some configurations, a breathing assistance apparatus comprises a lid and a main body with the lid and the main body selectively enclosing a cavity. The lid comprises a button member and at least one hinge assembly. 
     In some configurations, the lid further comprises a component adapted to be engaged with one or more fingertips while the button member is depressed. 
     In some configurations, the button member is spring biased away from the at least one hinge assembly. 
     In some configurations, the at least one hinge assembly allows pivotal movement of the lid relative to the main body. 
     In some configurations, the hinge assembly comprises at least one post and at least one support, the supports overlying the post and the post being positioned inboard of an outer perimeter of the lid. 
     Preferably, the hinge assembly comprises a clip extending along at least an axial length of the post, the clip being positioned on an opposite side of the post from the supports such that the post is captured between the clip and the supports. 
     In some configurations, the at least one hinge assembly comprises a guide structure and cam structure, the guide structure and the cam structure configured to cause sliding movement of the post during rotation of the post. 
     In some configurations, the guide structure comprises a guide surface, wherein in use the guide surface contacts the cam structure to move the lid from a detached state to an attached state relative to the main body via the sliding movement of the post as a result of closing motion of the lid. 
     Preferably, the sliding movement only occurs when the lid is moved from a disengage state to an engaged state with respect to the main body. 
     Preferably, the sliding movement of the post is substantially horizontal with the supports being positioned at least vertically above the post with the lid in the closed position. 
     In some configurations, the at least one support defines an opening that permits the at least one post to pass through the opening such that in use the lid can be moved from a detached state to an attached state relative to the main body. 
     In some configurations, a method of opening a lid of a breathing apparatus comprises moving a button member toward an engagement component to unlatch the lid and then rotating the lid to an opened position without the user having to reposition a hand. 
     In some configurations, a method of engaging a lid on a main body of a breathing apparatus comprises placing a post alongside at least one support member with the lid in an open position, pivoting the lid toward a closed position such that at least one engaging structures formed on the lid and at least one engaging structure formed on the main body cause the lid to translate into an engaged structure with the lid being pivotable while in the engaged structure. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       These and other features, aspects and advantages of the present invention will be described with reference to the following drawings. 
         FIG. 1  is a rear perspective view of a breathing assistance apparatus that is arranged and configured in accordance with certain features, aspects and advantages of the present invention. 
         FIG. 2  is an enlarged rear top perspective view of a hinge of the breathing assistance apparatus of  FIG. 1  with a lid in a closed position. 
         FIG. 3  is an enlarged front perspective view of the hinge of  FIG. 2  showing the lid in an opened position. 
         FIG. 4  is a sectioned perspective view of the hinge of  FIG. 2  showing the lid in a partially closed position. 
         FIG. 5  is a front perspective view of the lid of the breathing assistance apparatus of  FIG. 1 , which lid is arranged and configured in accordance with certain features, aspects and advantages of the present invention. 
         FIG. 6  is a rear bottom perspective view of a latch member of the lid of  FIG. 5 . 
         FIG. 7  is a rear bottom perspective view of the latch member of  FIG. 6  shown assembled to the lid. 
         FIGS. 8A-8D  are side views of a guide structure of the hinge of  FIG. 2  in several positions from opened to closed. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       FIG. 1  illustrates a breathing assistance apparatus  100  that is arranged and configured in accordance with certain features, aspects and advantages of the present invention. The apparatus  100  comprises a main body  102  and a lid  104 . Together, the main body  102  and the lid  104  define a housing  106  that encloses, or generally encases, a reservoir, tub, tank or other body of liquid (not shown) within a cavity. 
     The illustrated body  102  comprises at least one outer surface  110 . In the illustrated configuration, the body  102  comprises four generally planar outer surfaces  110  that are connected by rounded corners  112 . Other configurations are possible. 
     The lid  104  is connected to the body  102  with hinge assemblies  114 . In the illustrated configuration, the lid  104  is connected to a rear of the main body  102  using two hinge assemblies. The lid  104  can be connected to other surfaces. In addition, the lid  104  can be connected to the main body  102  using as few as one hinge assembly  114  or more than two hinge assemblies  114 . Preferably, the hinge assemblies  114  are constructed such that, with the lid  104  in the closed position (e.g., as shown in  FIG. 1 ), the hinge assemblies  114  are generally flush with or recessed into the rear outer surface  110 . In some configurations, the hinge assemblies  114  are constructed such that the hinge assemblies do not protrude rearward of the rear outer surface  110 . In some configurations, some of the hinge features may protrude very slightly from one or more surrounding surface of the rear outer surface or other surrounding portion of the apparatus. In some configurations, the lid  104  comprises an outer perimeter  116  and the hinge assemblies  114  do not protrude significantly outward of the outer perimeter  116  of the lid  104 . 
     With reference to  FIG. 2 , the hinge assemblies  114  comprise at least one post  120  and at least one support  122 . Preferably, the at least one post  120  is mounted such that the post is recessed and located inside of the outer perimeter  116  of the lid. The illustrated configuration comprises a single post  120  that is connected to two supports  122 . In some configurations, the at least one post  120  is mounted to the lid  104  while the at least one support  122  is mounted to the main body  102 . In some configurations, the at least one post  120  can be mounted to the main body  102  while the at least one support  122  can be mounted to the lid  104 . 
     The at least one post  120  can be secured to the lid  104  using one or more standoffs  124 . In the illustrated construction, the standoffs  124  are positioned between the two supports  122 . The standoffs reduce the deflection of the post  120  in the region of the supports  122 . In some configurations, the portion  126  of the post  120  extending between the standoffs  124  can be omitted. In the illustrated configuration, however, the portion  126  of the post  120  can be secured by a clip  130 . The clip  130  can have a recess that accommodates the post  120  or any other suitable configuration. 
     A force generated by the clip  130  on the post  120  in the illustrated configuration is opposed by forces generated by the supports  122 , for example. The clip  130  can contact an opposite side of the post  120  relative a contact region between the supports  122  and the post  120 . In some configurations, the clip  130  can be configured to deflect away from the post  120  during assembly of the post  120  and the clip  130 . For example, the clip  130  can be a deflectable finger that extends rearward from the main body  102 . The supports  122  can have a recess that defines a rearwardly-opening mouth that receives at least a portion of a circumference of the post  120 . Accordingly, movement of the post  120  in the directions shown by the arrow can result in attachment and detachment of the post  120  relative to the supports  122  and the clip  130 . The rearwardly-opening mouth of the supports  122  also results in a structure that overlies the post  120  such that vertical movement of the post  120  relative to the supports  122  is not possible with the post  120  fully received within the mouths of the supports  122 . As such, the lid  104  is unlikely to separate from the main body  102  during therapy. 
     With reference to  FIG. 3 , the lid  104  and the main body  102  can include structures that guide the post  120  and the clip  130  and supports  122  into connection. In some configurations, the structures facilitate movement of the at least one post  120  into the mouth of the supports  122  and into engagement with the clip  130  when the lid  104  is brought toward the closed position on the main body  102 . In the illustrated configuration, two guide structures  140  are positioned outboard of the two supports  122 . Other configurations also are possible. 
     With reference to  FIG. 4 , the guide structure  140  comprises a recess  142  that receives a cam structure  144 . The cam structure  144  is received within the recess  142  such that, with the lid  104  moved to the fully closed position on the main body  102 , the cam structure  144  does not prevent the lid  104  from fully closing. The cam structure  144  tapers toward a point with a sloping surface  146  such that the thickness of the cam structure  144  increases from back to front while the guide structure has an opposing surface  150 . The sloping surface  146  and the opposing surface  150  engage each other such that the sloping surface  146  and the opposing surface  150  resists movement of the lid  104  relative to the main body  102  in the detachment direction (see  FIG. 2 ) when the lid  104  is in an at least partially closed position. 
     Moreover, as the lid  104  is rotated toward a closed position (e.g.,  FIG. 1 ), the sloping surface  146  and the opposing surface  150  act to draw the lid  104  forward into the attachment position (e.g., the at least one post  120  connected to the supports  122  and the clip  130 ). Thus, rotation of the lid  104  can result in the hinge assemblies  114  being operatively connected from a detached state. In some configurations, the difference in thicknesses of the sloping surface  146  and the opposing surface  150  from initial contact to fully closed is substantially the same as a distance from the outer surface of the post  120  and the first contact with the supports  122  such that as the sloping and opposing surfaces  146 ,  150  are moved into full engagement along their lengths, the post  120  is pulled into position within the supports  122  and the clip  130 . 
     Notably, with the lid  104  in the open position (e.g.,  FIG. 3 ) relative to the main body  102 , sufficient space exists between the sloping surface  146  and the opposing surface  150  such that the lid  104  can be separated from the main body  102  with the application of force. Advantageously, such a construction allows separation between the lid  104  and the main body  102  by disconnection of the posts  120  from the supports  122  and the clips  130 . Such a separation can protect the apparatus  100  from damage resulting from forces that result from over-opening of the lid or from possible misuse of the apparatus  100 . Accordingly, the ability to separate the lid  104  from the main body  102  can protect the apparatus  100  from permanent damage. As discussed above, the lid  104  can be easily reconnected by placing the posts  120  alongside the supports  122  and rotating the lid  104  toward a closed position, which results in the sloping surface  146  of the cam structure  144  and the opposing surface  150  of the guide structure drawing the components back together. 
     With reference now to  FIG. 5 , a release and handle assembly  160  of the lid  104  will be described. As illustrated, the release and handle assembly  160  comprises at least one button member  162  that is mounted on the lid  104 . In some configurations, the button member  162  is mounted for movement toward and away from the hinge assemblies  162 . In some configurations, the button member  162  can be mounted along a side of the lid  104  that is adjacent to the side of the lid  104  having the hinge assemblies  162 . In the illustrated configuration, the button member  162  is mounted on an opposing side of the lid  104  relative to the hinge assemblies  114  and capable of movement toward and away from the hinge assemblies  114 . 
     The button member  162  is illustrated in  FIG. 6 . The button member comprises an exterior surface  164 , which is best shown in  FIG. 5 . The exterior surface  164  is sufficiently large for contact with a finger or thumb. As also illustrated in  FIG. 5 , the lid  104  can comprise a component  166  that is used to raise the lid  104 . In the illustrated configuration, the component  166  is a recessed region that has a wall  170  extending generally parallel with the exterior surface  164 . Preferably, the recessed region  166  is sufficiently large as to accommodate at least tips of fingers. In some configurations, the component  166  is one or more lip, ridge, protrusion, recess or the like. Accordingly, the component  166  (e.g., having the wall  170 ) and the exterior surface  164  can allow a simple squeezing action to accomplish both an unlatching of the button member  162  as well as providing a grasping action to allow movement of the lid  104  away from the main body  102 . 
     With reference again to  FIG. 6 , the illustrated button member  162  comprises two outer posts  172 . The posts  172  are sized and configured to engage with biasing members, such as compression springs or the like, for example but without limitation. The posts  172  are received within corresponding housings  174  that are formed in the lid  104 . The housings  174  can contain the biasing members and the posts  172  can slide into and out of the housings  174  against the biasing force of the biasing members. 
     The illustrated button member  162  also comprises at least one tab  176 . In the illustrated configuration, the button member  162  comprises two tabs  176 . The tabs  176  are bayonet shaped with a barb  180  at the end. As shown in  FIG. 7 , the tabs  176  can engage a structure  182  formed in the lid  104 . Thus, the tabs  176  in cooperation with the structure reduce the likelihood of the button member  162  coming out of a recess of the lid  104  while allowing inward depression of the button member  162  relative to the lid  104 . 
     The structure  182  also comprises a passage  184  that receives a finger  186  mounted to, or formed on, the button member  162 . The passage  184  facilitates generally only linear translation of the button member  162  relative to the lid  104 . In other words, the passage  184  receives the finger  186  and the finger  186  is generally limited by the passage  184  to substantially linear movement. 
     The finger  186  supports a locking post  190 . The locking post  190  can engage with a structure formed on the main body  102 . In some configurations, the locking post  190  engages with a structure formed on an inner surface of the main body  102  such that the depression of the button member  162  results in separation between the locking post  190  and the structure with which it normally engages. Releasing of the button member  162  results in the biasing members moving the locking post  190  into position for reengagement with the structure with which it normally engages. 
       FIGS. 8A-8D  illustrate the lid  104  in several positions relative to the main body  102 .  FIG. 8A  illustrates the lid  104  in a first opened position.  FIGS. 8B and 8C  illustrate the lid  104  in progressively further closed positions relative to the first opened position of  FIG. 8A .  FIG. 8D  illustrates the lid  104  in a closed position. In particular,  FIGS. 8A-8D  further illustrate the interaction between the sloping surface, or cam surface,  146  of the cam structure  144  and the opposing surface (also referred to as a guide surface or cam follower surface)  150  of the lid recess  142  as the lid  104  moves from an opened position to a closed position. As described herein, the cam structure  144  and the recess  142  can interact to move the lid  104  from a detached position relative to the main body  102  to an attached position relative to the main body  102  when the lid  104  is moved from an opened position to a closed position. 
     As described herein, the support  122  includes the recess  200  comprising the mouth  202 , which opens in a rearward direction in the illustrated arrangement. Preferably, the recess  200  is elongate in shape and extends in a generally fore-aft direction. In the illustrated arrangement, the recess  200  is generally or substantially horizontal or aligned with a bottom support surface of the main body  102  such that the recess  200  is generally or substantially horizontal when the apparatus  100  is rested on a flat surface. The recess  200  includes upper and lower guide surfaces  204  that extend forwardly from the mouth  202  to an end surface  206 . As described herein, the support  122  also assists in retaining the lid  104  on the main body  102  in response to forces within the housing  106  (e.g., forces resulting from internal pressure) tending to separate the lid  104  from the main body  102 . Thus, the upper portion of the end surface  206  and/or the upper guide surface  204  can form a retention surface that contacts the post  120  to retain the lid  104 , or at least a portion of the lid  104  near the support  122  and/or hinge  114  (e.g., a rearward portion), on the main body  102  in response to forces tending to separate the lid  104  from the main body  102 . 
     In the illustrated arrangement, the end surface  206  is curved (e.g., semi-circular) in shape from a side view and connects the upper guide surface  204  and the lower guide surface  204 . The illustrated support  122  is elongate in a lateral or side-to-side direction and, thus, defines a substantially semi-cylindrical shape in three dimensions. However, for convenience, the hinge  114 , guide structure  140  and cam structure  144  may be described herein in the context of the side views of  FIGS. 8A-8D  in two-dimensional terms. It will be appreciated that the described structures also have a width dimension relative to the apparatus  100  or a depth dimension relative to the side view of  FIGS. 8A-8D . 
     The illustrated end surface  206  is defined by a curve having a radius  208  from a center point  210  (or an axis in three dimensions). The recess  200  can have a longitudinal axis  212  that extends along a length of the recess  200  generally from the mouth  202  to the end surface  206  and, in the illustrated configuration, passes through the center point  210 . The axis  212  can be aligned with or parallel to one or both of the upper and lower guide surfaces  204  or can be centrally-located between the guide surfaces  204  (such as in the event of a tapered recess, for example and without limitation). In the illustrated configuration, the axis  212  is generally or substantially horizontal (or parallel to a bottom surface of the main body  102 ). However, in other configurations, the axis  212  could be non-horizontal or angled relative to the bottom surface of the main body  102 ). 
     As described herein, the post  120  preferably is cylindrical in shape or circular in shape from a side view, as illustrated in  FIGS. 8A-8D . The post  120  defines a center point  214  (or an axis in three dimensions) and a radius  216 . Preferably, the radius  216  of the post  120  is substantially equal to the radius  208  of the end surface  206  such that the post  120  can be snugly positioned against the end surface  206  and restrained in a vertical direction within recess  200  with the center points  210 ,  214  substantially aligned or coaxial with one another. 
     Preferably, the cam surface or sloping surface  146  of the cam structure  144  is positioned or oriented relative to the end surface  206  and/or center point  210  such that the post  120  is moved along the axis  212  of the recess  200  toward the end surface  206  as the lid  104  is moved from the opened toward the closed position. In the illustrated arrangement, a first distance  220  is defined between a first point or location  222  on the sloping surface  146  and the center point  210  and a second distance  224  is defined between a second point or location  226  on the sloping surface  146  and the center point  210 . Preferably, the first point  222  is located on an initial portion of the sloping surface  146  and the second point  226  is located on a subsequent portion of the sloping surface  146  such that the opposing surface  150  will contact the first point  222  before the second point  226  as the lid  104  is moved from an opened position to a closed position. The first point  222  can be at or near the location that is first contacted by the opposing surface  150  during closing of the lid  104  and the second point  226  can be at or near the furthest location along the sloping surface  146  contacted by the opposing surface  150  when the lid  104  is in the closed position. The first distance  220  preferably is smaller than the second distance  224 , which causes the movement of the post  120  along the axis  212  of the recess  200  as the lid  104  is moved from an opened position to a closed position and the opposing surface  150  moves along the sloping surface  146  in a direction from the first point  222  towards the second point  226 . 
     A distance  228  traveled by the center point  214  of the post  120  within the recess  200  when the lid  104  is closed preferably is substantially equal to a difference  230  between the second distance  224  and the first distance  220 . The distance  228  can be less than an overall length of the recess  200  because the post  120  can be at least partially located within the recess  200  prior to being drawn to the end surface  206  by the guide structure  140 . In other arrangements, the distance  228  could be substantially equal to a length of the recess  200 . Although the distances described immediately above are in relation to the center points  210  and  214 , the distances similarly could be measured relative to other points on locations on the recess  200  (e.g., end surface  206 ) and post  120 , respectively, if desired, such as in the context of non-circular (or non-cylindrical) recess or post shapes. 
       FIG. 8A  illustrates the lid  104  in a first open position relative to the main body  102 , which may be a fully opened position, such as when initiating a process of reattachment of the lid  104 . As illustrated, the opposing surface  150  is clear of the sloping surface  146  such that rearward movement (e.g., detachment) of the lid  104  is permitted. Advantageously, such an arrangement reduces the likelihood of permanent damage resulting from excessive opening forces applied to the lid  104 .  FIG. 8B  illustrates the lid  104  in a second open position that is further towards a closed position relative to the first open position of  FIG. 8A . In  FIG. 8B , the opposing surface  150  remains clear of the sloping surface  146 . That is, a vertical gap exists between a bottom of the opposing surface  150  and a top of the sloping surface  146 . 
       FIG. 8C  illustrates the lid  104  in a third open position that is further towards a closed position relative to the positions of  FIGS. 8A and 8B . In the position of  FIG. 8C , a leading portion or engagement portion  232  of the opposing surface  150  is engaged with or contacts an initial portion of the sloping surface  146 , which may be at or near the first point or location  222 . In the illustrated arrangement, the post  120  is spaced away from the end surface  206  of the recess  200 .  FIG. 8D  illustrates the lid  104  in a position that is further towards a closed position than the positions of  FIGS. 8A-8C . The position of  FIG. 8D  can be a fully closed position of the lid  104 . In the illustrated arrangement, at least the leading portion or engagement portion  232  of the opposing surface  150  is engaged with or contacts a subsequent portion of the sloping surface  146  spaced from the initial portion. The subsequent portion may be at or near the second point or location  226 . Preferably, the post  120  is snugly positioned against the end surface  206  in the position of  FIG. 8D . Thus, preferably, a distance between the engagement surface  232  and the center point  214  is preferably substantially equal to the second distance  224 . 
     As described herein, the interaction of the guide structure  140  and the cam structure  144  as illustrated in  FIGS. 8A-8D  may occur only during a reattachment or engagement procedure for the lid  104 . In normal opening and closing movement, sliding of the post  120  (or significant sliding of the post  120 ) within the recess  200  may not occur. Advantageously, such an arrangement reduces wear by reducing the amount of sliding movement between components during normal use. However, other arrangements are possible in which the sliding movement of the post  120  occurs more often than only during engagement of the lid  104 , such as during normal opening and closing of the lid  104 . 
     Although the illustrated opposing surface  150  has a similar size and shape as the sloping surface  146  and extends along a substantial portion of the sloping surface  146  when the lid  104  is in the closed position, other arrangements are also possible. For example, the opposing surface  150  could be a smaller surface, such as a cam follower surface, defining an engagement portion  232  that contacts only a point or small length of the sloping surface  146  in any one position. The engagement portion  232  could be rotatable such that it rolls along the sloping surface  146 , if desired. Moreover, as disclosed herein, the illustrated arrangements could be reversed such that the cam surface or sloping surface  146  is carried by the lid  104  and the opposing surface  150  (or cam follower with engagement portion  232 ) is carried by the main body  102 . 
     Unless the context clearly requires otherwise, throughout the description and the claims, the words “comprise”, “comprising”, and the like, are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense, that is to say, in the sense of “including, but not limited to”. 
     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 endeavour 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. 
     Where, in the foregoing description reference has been made to integers or components having known equivalents thereof, those integers are herein incorporated as if individually set forth. 
     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. Such changes and modifications may be made without departing from the spirit and scope of the invention and without diminishing its attendant advantages. It is therefore intended that such changes and modifications be included within the scope of the invention.