Abstract:
A heated humidifier including an autofeed mechanism disposed within a humidifier chamber. The autofeed mechanism includes a housing, a float, a stem, and a sealing body. The housing defines an inlet, an outlet, a first chamber connected to the inlet, and a second chamber connected to the outlet and the first chamber by a channel. The float moves within the second chamber with the stem projecting therefrom and through the channel. The sealing body is within the first chamber and cooperates with the stem. In an open state, the sealing body is displaced from the channel to permit filling of the humidifier chamber. In a closed state, the sealing body seals the channel to prevent liquid flow to the outlet. A location of the sealing body relative to the channel is controlled by the float as a function of a humidifier chamber liquid level.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a continuation of U.S. patent application Ser. No. 11/405,341, filed Apr. 17, 2006, now U.S. Pat. No. 7,614,420, issued Nov. 10, 2009, and entitled “Autofeed Mechanism for Heated Humidified Chamber”; and entire teachings of which are incorporated herein by reference. 
     
    
     TECHNICAL FIELD 
       [0002]    The present disclosure generally relates to an automatic flow and level control device, especially for an autofeed mechanism particularly suited for controlling the fluid level in a heated humidifier chamber. 
       BACKGROUND 
       [0003]    Automatic flow control devices have been around for hundreds, if not thousands, of years. A large portion of automatic flow control devices are dedicated to maintaining a predetermined fluid level in a reservoir, or tank. Such level maintaining automatic flow control valves have often incorporated elements that float on the surface of the fluid to indicate when the desired fluid level has been obtained. Perhaps the most famous level maintaining automatic flow control valve is that found in the storage tank of a water closet, or toilet. The water closer tank control valve includes a float mounted on a lever that is connected to a shut-off device in the water supply line. When the water in the tank rises to the desired level, the float positions the lever such that it closes the shut-off device, and accordingly the flow of water. 
         [0004]    Such float-and-lever control devices appear relatively simple, yet as any homeowner knows, are plagued with problems. Additionally, float-and-lever control devices are not particularly well suited for miniaturization to small-scale application. Further, the level of control offered is relatively crude and not suitable for applications requiring precise level control. Still further, its reliance on an almost constantly submerged lever that must pivot in at least one location is not appropriate for critical applications. Such float-and-lever control devices are found in U.S. Pat. Nos. 3,049,144, 5,655,232, and 5,934,881. 
         [0005]    Some automatic flow control devices have recognized the limitations imposed by the lever in the float-and-lever configuration and have incorporated an untethered float configuration. Such untethered configurations are found in U.S. Pat. Nos. 2,169,462; 2,920,644; 2,928,663; and 6,129,836. Still, many such untethered designs suffered from large size requirements and were not suitable for critical applications. 
         [0006]    The present disclosure incorporates two free moving elements that cooperate across a seat connecting two distinct chambers. This configuration supports miniaturization of the automatic flow control device as well as robust operating capabilities, while capable of maintaining the fluid in a reservoir at a predetermined level with great precision. 
       SUMMARY 
       [0007]    In some configurations, aspects of the present disclosure advance the state of the art with a variety of new capabilities and overcomes many of the shortcomings of prior devices in new and novel ways. The present disclosure overcomes the shortcomings and limitations of the prior art in any of a number of generally effective configurations. The instant disclosure demonstrates such capabilities and overcomes many of the shortcomings of prior methods in new and novel ways. 
         [0008]    Some aspects of the present disclosure relate to a heated humidifier including a humidifier chamber and an autofeed mechanism. The autofeed mechanism is disposed within the humidifier chamber and includes a housing, a float, a stem, and a sealing body. The housing defines an inlet, an outlet, a first chamber, and a second chamber. The inlet is fluidly closed to the humidifier chamber, whereas the outlet is fluidly open to the humidifier chamber. The first chamber of the housing is fluidly connected to the inlet, whereas the second chamber is fluidly connected to the outlet. Finally, a channel is provided that fluidly connects the first and second chambers. The float is movably disposed in the second chamber. The stem projects from the float and through the channel. Finally, the sealing body is disposed within the first chamber and cooperates with the stem opposite the float. In this regard, the autofeed mechanism is configured to provide an open state and a closed state. In the open state, the sealing body is displaced from the channel to permit filling of the humidifier chamber via liquid flow from the inlet to the outlet. In the closed state, the sealing body seals the channel to prevent liquid flow from the inlet to the outlet. With this construction, a location of the sealing body relative to the channel is controlled by the float as a function of a liquid level within the humidifier chamber. Thus, the autofeed mechanism controls dispensement of liquid into the humidifier chamber as a function of the height or level of liquid within the humidifier chamber itself. In some constructions, the housing defines third and fourth chambers, with a float controlling movement of a sealing body between the third and fourth chambers providing additional control over liquid flow through the autofeed mechanism. 
         [0009]    Yet other aspects in accordance in accordance with principles of the present disclosure relate to a method of controlling the flow of liquid into a heated humidifier chamber. An autofeed mechanism is provided within the humidifier chamber as described above. Liquid is dispensed from a source apart from the humidifier chamber into the inlet of the autofeed mechanism such that the liquid flows into the first chamber. The autofeed mechanism is operated in an open state such that the liquid fills the first chamber, rises through the channel and into the second chamber, and then is dispensed into the humidifier chamber via the outlet. In this regard, a liquid level in the humidifier chamber rises with continued dispensement of the liquid from the outlet. The autofeed mechanism is transitioned from the open state to the closed state when the liquid level in the humidifier chamber reaches a predetermined level so as to interrupt the dispensement of liquid into the humidifier chamber. To this end, the predetermined level in the humidifier chamber is transposed to the second chamber via fluid connection of the humidifier chamber and the outlet, resulting in the float buoyantly moving away from the channel to promote the sealing body sealing against the channel. 
         [0010]    Variations, modifications, alternatives, and alterations of the various embodiments, arrangements, and configurations described herein may be used alone or in combination with one another as will become more readily apparent to those with skill in the art with reference to the following detailed description of the preferred embodiments and the accompanying figures and drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]    Without limiting the scope of the present disclosure as claimed below and referring now to the drawings and figures: 
           [0012]      FIG. 1  is a partial cross sectional view of an autofeed mechanism in accordance with the present disclosure, not to scale; 
           [0013]      FIG. 2  is an exploded assembly view of several components of the autofeed mechanism of  FIG. 1 , not to scale; 
           [0014]      FIG. 3  is a cross sectional view of the primary stem portion and the primary seat, taken along section lines  3 - 3  in  FIG. 2 , not to scale; 
           [0015]      FIG. 4  is a partial cross sectional view of an embodiment of the autofeed mechanism in operation, not to scale; 
           [0016]      FIG. 5  is a partial cross sectional view of an embodiment of the autofeed mechanism in operation, not to scale; 
           [0017]      FIG. 6  is a partial cross sectional view of an embodiment of the autofeed mechanism in operation, not to scale; 
           [0018]      FIG. 7  is a partial cross sectional view of an embodiment of the autofeed mechanism in operation, not to scale; 
           [0019]      FIG. 8  is a partial cross sectional view of an embodiment of the autofeed mechanism in accordance with the present disclosure, not to scale; 
           [0020]      FIG. 9  is a top plan view of the primary float, not to scale; 
           [0021]      FIG. 10  is a cross sectional view of the primary float of  FIG. 9  taken along section line  10 - 10 , not to scale; 
           [0022]      FIG. 11  is a partial cross sectional view of an autofeed mechanism in accordance with the present disclosure, not to scale; 
           [0023]      FIG. 12  is an exploded assembly view of several components of the autofeed mechanism of  FIG. 1 , not to scale; 
           [0024]      FIG. 13  is a cross sectional view of the primary stem portion and the primary seat, taken along section lines  13 - 13  in  FIG. 12 , not to scale; 
           [0025]      FIG. 14  is a partial cross sectional view of an embodiment of the autofeed mechanism in operation, not to scale; 
           [0026]      FIG. 15  is a partial cross sectional view of an embodiment of the autofeed mechanism in operation, not to scale; 
           [0027]      FIG. 16  is a partial cross sectional view of an embodiment of the autofeed mechanism in operation, not to scale; 
           [0028]      FIG. 17  is a partial cross sectional view of an embodiment of the autofeed mechanism in operation, not to scale; and 
           [0029]      FIGS. 18-26  illustrate features of other embodiments of the present disclosure. 
       
    
    
     DETAILED DESCRIPTION 
       [0030]    The autofeed mechanism for a heated humidifier chamber  10  of the instant disclosure enables a significant advance in the state of the art. Embodiments accomplish this by new and novel arrangements of elements that are configured in unique and novel ways and which demonstrate previously unavailable but preferred and desirable capabilities. The detailed description set forth below in connection with the drawings is intended merely as a description of embodiments of the disclosure, and is not intended to represent the only form in which the present disclosure may be constructed or utilized. The description sets forth the designs, functions, means, and methods of implementing the disclosure in connection with the illustrated embodiments. It is to be understood, however, that the same or equivalent functions and features may be accomplished by different embodiments that are also intended to be encompassed within the spirit and scope of the disclosure. 
         [0031]    Referring generally to  FIGS. 1 through 17 , aspects of the instant disclosure relate to an autofeed mechanism  10  for controlling the flow of a fluid to a heated humidifier chamber. It should be understood that the figures are not to scale. In fact, they are highly enlarged versions of the autofeed mechanism that would be used on a heated humidifier chamber. Further, one skilled in the art will realize that the inlets and outlets will have to be sized to allow venting of air from the chamber until the balls seat. An alternative embodiment would be to place, in the primary chamber, a hydrophobic vent. These vents are well-known to those skilled in the art and a preferred hydrophobic vent is a Gore-Tex™. that is found in the industry. The autofeed mechanism  10  includes a body  100  defining at least a primary housing  200  with a primary inlet chamber  210  and a primary float chamber  220 , as seen in  FIG. 1 . 
         [0032]    A primary seat  240 , in cooperation with a primary float  250  and a primary ball  230 , allows selective fluid communication between the primary inlet chamber  210  and the primary float chamber  220 . 
         [0033]    The basic operation of the autofeed mechanism  10  will now be briefly described, followed by a detailed disclosure of the various components of the autofeed mechanism  10 . With continued reference to  FIG. 1 , the fluid first enters the primary fluid inlet  270 , either under pressure or via gravity. The fluid then passes into the primary inlet chamber  210 , where the primary ball  230  is housed. The fluid fills the primary chamber  210  and then enters the primary float chamber  220  by passing through the primary seat  240 , which is partially blocked by a portion of the primary float  250 . The fluid then travels laterally and exits the primary float chamber  220  via the primary fluid exit  280 . The fluid generally then fills a humidifier chamber  400 . This first filling of the autofeed mechanism  10  is illustrated in  FIG. 4 . 
         [0034]    A few aspects of the structure of the autofeed mechanism  10  warrant review before proceeding with the sequence of operation of the mechanism  10 . First, with respect to the primary inlet chamber  210 , it has an inlet chamber base surface  212 , seen best in  FIG. 1  that may be thought of as the floor, or bottom, of the primary inlet chamber  210 . 
         [0035]    Second, with respect to the primary seat  240 , best illustrated in exploded view  FIG. 2 , it has a primary seat channel  242  with a distal end  243  open to the primary float chamber  220  and a proximal end  244  open to the primary inlet chamber  210 . The distance from the distal end  243  to the proximal end  244  defines a primary channel length  245 . Additionally, the primary seat channel  242  has an opening cross sectional area  246 , illustrated in  FIG. 3  representing a cross sectional view of the primary seat channel  242  taken along section line  3 - 3  of  FIG. 2 . 
         [0036]    Third, with respect to the primary float  250 , it has a float portion  258 , identified in  FIG. 2 , located in the primary float chamber  220 , and a stem portion  252 , also identified in  FIG. 2 , projecting toward the primary seat  240  and substantially parallel with the primary seat channel  242 . The primary float chamber  220  is configured to allow the primary float  250  to move within the chamber  220  when acted upon by the fluid and/or the primary ball  230 . Further, the stem portion  252  cooperates with the primary seat  240  so that it may move within the primary seat channel  242  with the movement of the primary float  250 . The stem portion  252  has a distal end  253  at the connection to the float portion  258  and a proximal end  254  nearest the primary seat  240  with the distance between the distal end  253  and the proximal end  254  defining a stem length  255 . The stem portion  252  has a stem cross sectional area  256  less than the primary seat channel opening cross sectional area  246  thereby permitting the fluid to flow through primary seat channel  242  when the stem portion  252  is in the primary seat channel  242 . 
         [0037]    Fourth, with respect to the primary ball  230 , it has a diameter  232  and is located in the primary inlet chamber  210  such that the center of the primary ball  230  is substantially collinear with a central axis of the primary float stem portion  252 . As previously mentioned, the primary ball  230  is acted upon by the primary float stem portion  252  thereby forcing the primary ball  230  against a ball support  214 , until a predetermined fluid level is reached that begins to float the primary float  250  thereby reducing its action on the primary ball  230  and allowing the primary ball  230  to float away from the ball support  214 , or the buoyant force of the primary ball  230  and the fluidic forces overtake the action of the primary float  250  causing it to move away from the primary seat  240 , as seen in  FIG. 6 . The ball support  214  is a projection extending from the inlet chamber base surface  212  a support length  217  distance thus allowing fluid entering the primary inlet chamber  210  to pass the primary ball  230  and exit to the primary float chamber  220  and the primary fluid exit  280  by passing through the primary seat  240  around the stem portion  252 . Eventually the fluid level reaches a predetermined primary fluid elevation  500  at which the action of the primary float  250  on the primary ball  230  has been reduced to the point that the primary ball  230  floats away from the ball support  214  and seals the primary seat channel proximal end  244 , thereby preventing the fluid from flowing from the primary inlet chamber  210  to the primary float chamber  220  thus stopping the flow of fluid, as seen in  FIG. 7 . 
         [0038]    Now, referring again to the sequence of operation,  FIG. 4  illustrates the initial filling of the primary inlet chamber  210  whereby the primary float  250  is not influenced by the fluid and the weight of the primary float  250  keeps the primary ball  230  against the ball support  214  and away from the primary seat  240 . As one with skill in the art will recognize, to keep the primary ball  230  against the ball support  214  the weight of the primary ball  230  must overcome the buoyant force developed due to the total submersion of the primary ball  230  and any fluidic forces. 
         [0039]    Next,  FIG. 5  illustrates a subsequent situation in which the fluid has now filled the primary inlet chamber  210  and the humidifier chamber  400  and the primary float chamber  220  up to the normal elevation of the float portion base surface  259 , labeled in  FIG. 2 . Whether or not the primary float  250  begins to float at this fluid elevation depends on the construction of the primary float  250 . A hollow primary float  250 , or one of low density, may float at this elevation, whereas a solid primary float  250 , or one of high density, may require a higher fluid elevation to begin to float. However, it is important to note that the operation of the present disclosure is not dependent upon the actual floating of the primary float  250 , but rather a reduction in action on the primary ball  230  such that it may cooperate with the primary seat  240  to stop the flow of fluid. Thus, the primary float  250  functions as a counterbalance and need only counter the primary ball  230  buoyant force and any present fluidic forces. Further, the density of the primary float  250  and the primary ball  230 , as well as the size and geometry of the primary float  250  and primary ball  230 , may be changed to accommodate the range of elevations and pressures anticipated. 
         [0040]      FIG. 6  illustrates the next level in which the primary ball  230  has moved away from the ball support  214  and the elevation of the primary float  250  has increased. Finally,  FIG. 7  illustrates the primary ball  230  seated against the primary seat  240  thus stopping the flow of fluid and maintaining the fluid elevation at the primary predetermined fluid level  500 . 
         [0041]    Referring again to  FIGS. 1 and 2 , in one particular embodiment the orthogonal distance from the inlet chamber base surface  212  to the primary seat channel distal end  243  is less than the total of the support length  217 , the primary ball diameter  232 , and the stem length  255 . This embodiment ensures the presence of a gap between the primary seat channel proximal end  244  and a float portion base surface  259  to ensure that the float portion base surface  259  does not block the primary seat channel  242  and to facilitate the flow of fluid into the primary float chamber  220 . In an alternative embodiment seen in  FIGS. 8 ,  9 , and  10 , the orthogonal distance from the inlet chamber base surface  212  to the primary seat channel distal end  243  is substantially equal to the total of the support length  217 , the primary ball diameter  232 , and the stem length  255 , and a float portion base surface  259  is formed with at least one flow channel  260  to facilitate the flow of fluid from the primary seat channel  242  into the primary float chamber  220 . In this embodiment, the primary float portion base surface  259  may rest directly on the primary seat  240  and not impede the fluid flow because the fluid exits the primary seat channel  242  into at least one flow channel  260  and directs the fluid to the primary float chamber  220 . 
         [0042]    Referring again to  FIGS. 1 and 2 , the cooperation between the primary float  250 , the primary seat  240 , the primary ball  230 , and the ball support  214  is essential. As previously disclosed, the center of the primary ball  230  is substantially collinear with a central axis of the primary float stem portion  252 . In a further embodiment, the ball support  214  is substantially collinear with the center of the primary ball  230  and with a central axis of the stem portion  252 . While the ball support  214  is generally described as projecting from the primary inlet chamber base surface  212 , one with skill in the art will recognize that it may equally be a recess formed in the primary inlet chamber base surface  212 , or merely a tightly confined area to control the motion of the primary ball  230 . 
         [0043]    The primary float stem portion  252  is designed to be releasably received by the primary seat channel  242 , yet permit the flow of fluid between the stem portion  252  and the seat channel  242 . Therefore, the stem cross sectional area  256  must be less than the primary seat channel opening cross sectional area  246 , as seen in  FIG. 3 . In one particular embodiment, the stem cross sectional area  256  is at least ten percent less than the primary seat channel opening cross sectional area  246 . 
         [0044]    Further, the primary seat channel distal end  244  must be configured to cooperate with the primary ball  230  to ensure that the primary ball  230  creates a liquid-tight seal against the primary seat  240 . As such, in one particular embodiment the primary seat channel opening cross sectional area  246  at the primary seat channel proximal end  244  is at least ten percent less than the maximum cross sectional area of the primary ball  230 . One with skill in the art will appreciate that despite the use of the word “ball,” the primary ball  230  need not be spherical in shape, in fact, it may be any object that will create a seal against the primary seat  240  and can be displaced by the primary float  250 . In fact, the primary ball  230  may be virtually any geometric shape, including, but not limited to, a conical shape or a flat shape such as a film or disk. 
         [0045]    Now, with the embodiments of  FIGS. 1-10  disclosed, a dual housing embodiment will be disclosed. Referring generally to  FIGS. 11 through 17 , the instant embodiment incorporates a second autofeed system to introduce a redundancy, or fail-safe, into the autofeed mechanism  10  of the present disclosure. In this embodiment the autofeed mechanism  10  includes a body  100  defining a primary housing  200  and a secondary housing  300 . The elements of the secondary housing  300  are substantially identical to those of the primary housing  200 , only now with reference numerals in the 300&#39;s rather than the 200&#39;s, and incorporating reference to “secondary” in the element description, rather than the references to “primary” associated with the elements of the primary housing  200 . Therefore, the prior disclosure with respect to the primary housing  200  will not be repeated here, it is incorporated by reference with respect to  FIGS. 11 ,  12 , and  13 , in lieu of  FIGS. 1 ,  2 , and  3 , and the secondary housing  300  elements. 
         [0046]    The setup of the secondary housing  300  may be identical to the primary housing  200  with the elevation of the primary float chamber base surface  222  equal to that of the secondary float chamber base surface  322 , however it is preferred to have the housings  200 ,  300  setup to alert an observer of a failure in the primary housing  200 . Therefore, as seen in  FIGS. 11 and 12 , the secondary float chamber base surface  322  is higher in elevation than the primary float chamber base surface  222  and the secondary ball support length  317  is greater than the primary ball support length  217  thus establishing a secondary fluid level  600  that is higher in elevation than the primary fluid level  500 , thereby providing a visual indication that the components of the primary housing  200  are not properly functioning. In this embodiment, the primary fluid exit  280  is in fluid communication with the secondary fluid inlet  370 . A failed primary float can be indicated by an elevated water level that is established by raising the base of the secondary float chamber. The elevated water level can also be established by changing the configuration of the secondary float. This will change the affect on the buoyancy and therefore delay the elevation of the secondary float leading to higher water level in the chamber. Since the design of this autofeed places a ball in the direct flow path upstream to the seat, the design is resistant to leakage due to elevated water levels in the feed bag. In other words, in the typical design the higher the water bag, the more water pressure on the seat and the greater the chance of dislodging the mechanism that seals the seat. With this design, the higher water pressure actually does the opposite and forces the ball further onto the seat. This will result in the humidifier chamber not getting water, but it will also ensure that the patient does not get drowned by the water in the bag. 
         [0047]    Now, referring to the sequence of operation,  FIG. 14  illustrates the initial filling of the primary inlet chamber  210  and the secondary inlet chamber  310  whereby the primary float  250  and the secondary float  350  are not influenced by the fluid and the weight of the primary float  250  keeps the primary ball  230  against the primary ball support  214  and away from the primary seat  240  and the weight of the secondary float  350  keeps the secondary ball  330  against the secondary ball support  314  and away from the secondary seat  340 . As one with skill in the art will recognize, to keep the primary ball  230  against the ball support  214  the weight of the primary ball  230  must overcome the buoyant force developed due to the total submersion of the primary ball  230  and any fluidic forces. 
         [0048]    Next,  FIG. 15  illustrates the situation in which the components of the primary housing  200  function properly and the primary ball  230  stops the flow of fluid through the primary seat  240 , thus maintaining the primary fluid level  500 . In this situation, the fluid level has not increased enough to reduce the action of the secondary float  350  on the secondary ball  330  to the point that the secondary ball  330  leaves the secondary ball support  314 . 
         [0049]      FIG. 16  illustrates a situation in which an impediment I is lodged between the primary ball  230  and the primary seat  240 , thus preventing the primary ball  230  from sealing against the primary seat  240 . In such a situation, the fluid level would continue to rise in an uncontrolled manner if not for the presence of the secondary housing  300 . Here, the fluid level rises until the force exerted on the secondary ball  330  by the secondary float  350  is reduced to the point that it is overcome by the buoyant force of the secondary ball  330  resulting in the secondary ball  330  leaving the secondary ball support  314 , as seen in  FIG. 16 . Eventually the secondary ball  330  closes the secondary seat channel proximal end  344  once the fluid level has reached the secondary fluid level  600 . The difference in elevation between the secondary fluid level  600  and the primary fluid level  500 , seen in  FIG. 17 , provides an indication to the operator that the autofeed mechanism  10  is not properly functioning and requires service. Any number of audio, visual, and tactile alarm indicators may be incorporated into the autofeed mechanism  10  to sense the change in normal fluid level and warn of malfunctions. 
         [0050]    One with skill in the art will recognize that the humidifier chamber  400  illustrated in the accompanying figures is merely schematic in nature. Further, the autofeed mechanism  10  and its components may be fabricated from a wide variety of materials, selected to reflect particular characteristic desired for operation with a variety of fluids, including, by way of example and not limitation, metals, plastic, glass, natural and synthetic rubbers, and composites of various types. 
         [0051]    Numerous alterations, modifications, and variations of the preferred embodiments disclosed herein will be apparent to those skilled in the art and they are all anticipated and contemplated to be within the spirit and scope of the instant disclosure. For example, although specific embodiments have been described in detail, those with skill in the art will understand that the preceding embodiments and variations can be modified to incorporate various types of substitute and or additional or alternative materials, relative arrangement of elements, and dimensional configurations. Accordingly, even though only few variations of the present disclosure are described herein, it is to be understood that the practice of such additional modifications and variations and the equivalents thereof, are within the spirit and scope of the disclosure as defined in the following claims. 
         [0052]    Although the present disclosure has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes can be made in form and detail without departing from the spirit and scope of the present disclosure. 
       INDUSTRIAL APPLICABILITY 
       [0053]    The autofeed mechanism for a heated humidifier chamber answers a long felt need for a novel flow control device that eliminates the problems commonly associated with lever actuated flow control systems. The mechanism is easy to manufacture and assemble due, in part, to the low number of moving components. The simple construction results in a significant advance over prior art autofeed devices. Further, the various components of the present disclosure are easily changed out to adjust the operating parameters of the mechanism, a feature lacking from the prior art.