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 . referring generally to fig1 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 fig1 . 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 . 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 fig1 , 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 fig4 . 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 fig1 that may be thought of as the floor , or bottom , of the primary inlet chamber 210 . second , with respect to the primary seat 240 , best illustrated in exploded view fig2 , 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 fig3 representing a cross sectional view of the primary seat channel 242 taken along section line 3 - 3 of fig2 . third , with respect to the primary float 250 , it has a float portion 258 , identified in fig2 , located in the primary float chamber 220 , and a stem portion 252 , also identified in fig2 , 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 . 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 fig6 . 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 fig7 . now , referring again to the sequence of operation , fig4 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 . next , fig5 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 fig2 . 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 . fig6 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 , fig7 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 . referring again to fig1 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 fig8 , 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 . referring again to fig1 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 . 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 fig3 . 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 . 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 . now , with the embodiments of fig1 - 10 disclosed , a dual housing embodiment will be disclosed . referring generally to fig1 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 fig1 , 12 , and 13 , in lieu of fig1 , 2 , and 3 , and the secondary housing 300 elements . 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 fig1 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 . now , referring to the sequence of operation , fig1 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 . next , fig1 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 . fig1 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 fig1 . 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 fig1 , 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 . 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 . 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 . 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 . 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 .
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 .