Abstract:
A reservoir system for an operating unit, such as a humidifier, includes a removable water tank configured to provide the operating unit with water. The removable water tank includes a primary reservoir for holding water, with an opening in the removable water tank fluidically connecting the primary reservoir with a secondary reservoir in the operating unit. A plunger is slidably disposed in the opening and movable between an open position in which the opening fluidically connects the primary reservoir to the secondary reservoir, and a closed position that seals the opening to fluidically disconnect the primary reservoir from the secondary reservoir. A float member in the secondary reservoir includes a buoyant main body and is configured to generate a force upon the plunger to urge the plunger into the open position according to the height of water in the secondary reservoir.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of U.S. Provisional Application No. 61/794,353, filed Mar. 15, 2013, the contents of which are incorporated herein by reference. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    Various embodiments of the invention relate to a removable top fill water tank for use in association with an operating unit, and in particular for use in a humidifier. 
         [0004]    2. Description of the Related Art 
         [0005]    Portable humidifiers provide an economical appliance for improving indoor environmental conditions. Small humidifiers are convenient because they can be easily moved or stored. Such convenience is especially pertinent to locations with changing climates. Humidifiers can be used when the air is dry and stored away when the air is humid. 
         [0006]    Typical portable humidifiers are designed to operate most efficiently with a specific amount of water. For example, wick-type humidifiers have a certain water level that is optimal for operation of the humidifier. Wick-type humidifiers typically include a wick and a fan. The wick sits in a pool of water held in a tray and the water is absorbed by the wick. Thus, if the water level is too low, the air blows through less of the dampened wick, resulting in less water output. On the other hand, if the water level is too high, the air is not able to blow over enough of the wick to capture a significant amount of water. 
         [0007]    As the humidifier operates, the water level decreases. In order to keep the water at the optimum level, a water tank is utilized. The water tank continuously feeds water to the humidifier to maintain an optimal water level. The water tank also enables the humidifier to operate over extended periods of time by replenishing the water in the tray of the humidifier. 
         [0008]    A typical humidifier water tank is a sealed container with an outlet valve in the bottom. The outlet valve is usually spring-loaded and opens upon placement of the tank onto the tray. When the tank is first placed over the empty water tray of the humidifier the water flows down into the tray. As the water leaves the tank, the pressure at the top of the sealed tank decreases. The pressure continues to decrease as water leaves the tank until the pressure is low enough to hold the water in the tank. Air is then sucked into the tank restoring the pressure and allowing the water to flow out again. This process continues with water flowing out of the tank in cycles while the tray is filled. Once the water level in the tray reaches its maximum height, it covers the outlet of the water tank. Consequently, air is prevented from being sucked into the tank because the air path to the tank outlet is blocked by the water in the tray. This keeps the pressure in the water tank low and stops the water from flowing out. The water flow does not resume until the water level in the tank has fallen to a point that allows air to be sucked into the tank in order to restore the pressure therein. 
         [0009]    Humidifier water tanks include openings so that they can be refilled. The opening has a cap such that it can be opened and closed. Typically, the opening and its cap are provided in the bottom of the tank. In some cases, the outlet valve is integrated in the cap of the opening. Having the tank opening in the bottom of the tank requires the user to remove the water tank from the humidifier and flip it over before pouring more water into the tank. Many users find this to be a nuisance, especially when refilling repeatedly in a short period of time or when the tank is large. However, such tanks are intended to be operated this way. If the opening were provided in the top of the tank, the user would still be required to remove the tank before refilling it. Removing the tank closes the spring-loaded outlet valve, and the cap can then be removed and the tank refilled. However, at some point the user would undoubtedly attempt to fill the tank while it was placed on the tray. As soon as the user opened the cap enough to allow air to pass into the tank, the tank would effectively become a hose, with an opening in the top, and an opening in the bottom at the spring-loaded outlet valve. The water would continuously flow out of the tank, overflow the tray and making a mess. That is, by removing the cap the low back-pressure in the tank is destroyed and thus cannot hold the water back within the tank. Nonetheless, many users find water tanks with openings in their bottoms to be a nuisance. 
         [0010]    There is thus a need for a removable tank which can be filled from the top either while remaining on the operating unit, e.g., a humidifier, or after being removed from the operating unit. 
       SUMMARY OF THE INVENTION 
       [0011]    In a preferred embodiment a reservoir system for an operating unit, such as a humidifier, is provided. The reservoir system includes a removable water tank configured to operationally engage with the operating unit so as to provide the operating unit with water. The removable water tank includes a primary reservoir for holding water, an opening in the removable water tank to fluidically connect the primary reservoir in the removable water tank with a secondary reservoir in the operating unit, a plunger slidably disposed with respect to the opening. The plunger is movable between an open position in which the opening fluidically connects the primary reservoir to the secondary reservoir, and a closed position that seals the opening to fluidically disconnect the primary reservoir from the secondary reservoir. A float member in the secondary reservoir includes a buoyant main body and is configured to generate a force upon the plunger to urge the plunger into the open position according to the height of water in the secondary reservoir. 
         [0012]    In specific embodiments the float member includes a lever coupled to the buoyant main body and an engaging member that pivotably secures the float member within the secondary reservoir. A torque is generated by the buoyant main body with respect to the engaging member to provide a corresponding torque to the lever, and the lever is configured to mechanically contact the plunger, thereby urging the plunger into the open position as a function of water level in the secondary reservoir. In such embodiments the plunger may include an elongated portion that passes through the opening, with a first enlarged portion at one end of the elongated portion for plugging the opening and a second enlarged portion at another end of the elongated portion for contacting the lever. In a particular embodiment the second enlarged portion has a substantially planar surface for contacting the lever, and the lever has a rounded surface for contacting this planar surface. 
         [0013]    In certain embodiments the engaging member is pivotably connected to a wall that extends from the removable tank below the primary reservoir. In yet other embodiments the plunger includes an elastic element that biases the plunger into the closed position. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0014]    The various aspects and embodiments disclosed herein will be better understood when read in conjunction with the appended drawings, wherein like reference numerals refer to like components. For the purposes of illustrating aspects of the present application, there are shown in the drawings certain preferred embodiments. It should be understood, however, that the application is not limited to the precise arrangement, structures, features, embodiments, aspects, and devices shown, and the arrangements, structures, features, embodiments, aspects and devices shown may be used singularly or in combination with other arrangements, structures, features, embodiments, aspects and devices. The drawings are not necessarily drawn to scale and are not in any way intended to limit the scope of this invention, but are merely presented to clarify illustrated embodiments of the invention. In these drawings: 
           [0015]      FIG. 1  is cross-sectional perspective view of an embodiment water tank disposed on an associated operating unit. 
           [0016]      FIG. 2  is a detailed cross-sectional view of a plunger shown in  FIG. 1 . 
           [0017]      FIG. 3  is a detailed perspective view of a float member shown in  FIG. 1 . 
           [0018]      FIG. 4  is a detailed cross-sectional view of the float member and plunger shown in  FIG. 1  while in an open position. 
           [0019]      FIG. 5  is a detailed cross-sectional view of the float member and plunger shown in  FIG. 1  while in a closed position. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0020]    Various embodiments provide a removable water tank which can be filled from the top of the tank without fear of causing overflow in the base operating unit to which the tank feeds water. The tank can be filled either when the tank is positioned on the associated operating unit, e.g., a humidifier, or after the tank has been removed from the operating unit. This offers added convenience for a user servicing the operating unit. 
         [0021]      FIG. 1  illustrates an embodiment water tank  100  functionally engaged with an associated operating unit  5 , such as a humidifier. Water tank  100  provides a removable top fill tank and includes an upper chamber  102  that serves as a primary water reservoir for the operating unit  5 , an opening  104  at a bottom  106  of the upper chamber  102 , and a plunger  110  coupled to the opening  104  via an elastic element  112 . The tank  100  can further include a bottom section  108  configured to allow the tank  100  to be securely positioned within the operating unit  5 . For example, the bottom section  108  of the tank  100  can include side walls  109  to engage retaining weirs  7  located at the bottom of the main housing  9  of the operating unit  5 . Additionally or alternatively, when the tank  100  is assembled to the operating unit  5 , the bottom side  106  of the upper chamber  102  can engage the structure of the main housing  9  of the operating unit  5 , and a gap is provided between the side walls  109  of the bottom section  108  of the tank  100  and the bottom of the operating unit  5  so that water can flow out the tank  100 . In the specific embodiment depicted in  FIG. 1 , the bottom section  108  provides or forms a portion of a secondary reservoir that is used by the operating unit  5  for its intended operations, such as to moisten a wick or the like, and water flows from the primary reservoir  102  into this secondary reservoir  108  via the opening  104 . When assembled, water freely can flow from the bottom section  108  of the tank  100  to active elements in the main housing  9  of the operating unit  5 , such as a wick, a heating element, an ultrasonic atomizer or the like. Other configurations of the bottom section  108  of the tank  100  can also accomplish the same effect, e.g., by including through holes on the side walls  109  of the bottom section  108 . Also, the structure at the bottom of the operating unit  5  can include one or more openings to allow water to freely flow between the bottom section  108  of the tank  100  and the main housing  9  of the operating unit  5 . 
         [0022]    The plunger  110  is shown in  FIG. 2  and includes an elongated portion  114  having a cross-section that is smaller than the cross-sectional diameter of the opening  104 . The elongated portion  114  moves up and down through the opening  104  while permitting water to flow between the upper chamber  102  and the bottom section  108 . The plunger  110  further includes a first enlarged portion  116  disposed at an upper end of the elongated portion  114 . The first enlarged portion  116  has a cross-sectional dimension that is larger than the elongated portion  114 , e.g., a cross-section sufficiently large to block the opening  104  (and thus the water flow) when the plunger  110  is fitted into and mechanically engages with and seals against the opening  104 . The plunger  110  may further include a second enlarged portion  118  disposed at the lower end of the elongated portion  114 , which is configured, for example, as a flat disk as shown in  FIG. 2 , although other suitable shapes are certainly possible, such as a generally spherical shape. The elongated portion  114  has a length sufficient to traverse the opening  104 , such that in operation the second enlarged portion  118  is disposed within the bottom section  108  of the tank  100  (i.e., below the opening  104 ). 
         [0023]    As shown in  FIGS. 1 and 3 , the tank  100  further includes a float member  120  disposed under the bottom  106  of tank  100  and within the secondary reservoir used by the operating unit  5 , such as within the bottom section  108 . The float member  120  includes a main body  122  and a lever  124  extending from the main body  122 . The float member  120  is retained in the bottom section  108  by any suitable pivoting mechanism. As illustrated in  FIG. 3 , the float member  120  can include two engaging members  126  that extend in a substantially parallel manner from opposite sides of the main body  122 . The engaging members  126  rotatably engage the side walls of the bottom section  108  of the tank  100  (or a similar structure provided by the operating unit  5 ). By way of example, the engaging members  126  can include small outward protrusions  127  to engage with corresponding depressions on the two opposing side walls of the bottom section  108  of the tank  100 . The two contacting points  127  between the engaging members  126  and the side walls define a pivotal axis about which the float member  120  can rotate. Thus, a top surface  125  of the lever member  124  can exert an upward pushing force on the plunger  110  via the second enlarged surface  118  through a torque generated by the main body  122 . The magnitude of the pushing force can depend on the weight or weight distribution of the main body  122  and the distance from the center of gravity of the main body  122  to the pivoting axis  127 , as well as the weight or weight distribution of the lever member  124  and the distance from the top surface  125  of the lever member  124  to the pivoting axis  127 . 
         [0024]    The float member  120 , or at least the main body  122  of the float member  120 , can float in water. For example, the float member  120  can be made of a material having a density which is less than that of water, such as plastic, wood, etc. Additionally or alternatively, the float member  120  can be made with a hollow interior, a foamed structure, etc., such that its overall density is less than that of water. 
         [0025]    The operation of the removable tank is explained as follows in connection with  FIGS. 4 and 5 . When the tank  100  is removed from the operating unit  5 , e.g., to fill tank  100  with water, the plunger  110  is in a down, sealed or closed position where the first enlarged portion  116  of the plunger  110  seals the opening  104 . This can be accomplished by selecting an appropriate spring force or bias for the elastic element  112  to pull the first enlarged portion  116  of the plunger  110  down onto the mouth of the opening  104  and thus fluidly sealing the opening  104 ; alternatively, the gravitational weight of the plunger  110  may be sufficient to provide such a sealing force. On the other hand, when the tank  100  is filled and functionally engaged with the operating unit  5 , the second enlarged portion  118  of the plunger  110  is positioned above and contacts the tip  125  of the lever member  124  of the float member  120 . Due to the upward pushing force applied on the plunger  110  by the tip  125  of the lever member  124 , the plunger  110  is urged upward, thereby unsealing or opening the opening  104  and allowing water  1  from the tank  100  to flow into the bottom section  108  of the tank and thus into the operating unit  5 . That is, the torque generated by the weight of main body  122  with respect to the pivoting axis  127  is applied to the second enlarged portion  118  via the lever member  124 , and this torque exceeds the sealing force provided by the elastic member  112 , the weight of the plunger  110  or both, thus forcing the plunger  110  into an open state with respect to opening  104 . 
         [0026]    When water  1  enters the bottom section  108  of the tank  100  and at least partially immerses the float member  120 , an upward buoyancy force  2  is applied on the main body  122  of float member  120 . The upward buoyancy force  2  can be tuned by adjusting the size, material, shape or structure of the float member  120 . As the float member  120  is not freely floating but rotatably fixed at the pivot points  127 , the buoyancy force  2  applied on the main body  122  causes a reduction of the upward pushing force (or torque) exerted by the tip  125  of the lever member  124  on the plunger  110 . When a sufficient amount of water  1  enters the bottom section  108  of the tank  100 , e.g., when a desired working water level height inside secondary reservoir of the operating unit  5  is reached, the main body  122  of the float member  120  tilts up to a sufficient degree so as to cause the plunger  110  to return back to the sealed position under the urging of spring  112 , the gravitational weight of plunger  110  or both. Thereafter, when the water level decreases in the secondary reservoir  108  (due to the usage of water in the operating unit  5 ), the buoyancy force  2  on the float member  120  (and in particular the main body  122 ) causes the main body  122  to similarly go down, pivoting about the axis  127 , causing an increase in the upward pushing force (or torque) on the plunger  110 . When the water level decreases to a sufficiently low level, the plunger  110  will again be pushed into an open position by the upward pushing force, allowing water  1  (if any) remaining in the tank  100  to flow down through the opening  104 . The above cycle can repeat until the water is depleted in the tank  100 . 
         [0027]    When filling the tank  100  with water  1  without taking the tank  100  out of the operating unit  5 , the plunger  110  will initially be in the open position, and the water  1  being filled into tank  100  can enter the bottom section  108  of the tank  100  directly. When the water  1  in the operating unit  5  reaches a sufficient level, the plunger  110  returns to the closed position, sealing the opening  104 , as explained above. 
         [0028]    To facilitate effective transmission of the pushing force from the lever member  124  to the plunger  110 , the lever member  124  of the float member  120  can include a rounded tip  125  to engage the second enlarged portion  118  of the plunger  110 . For example, if the second enlarged portion  118  of the plunger  110  has a flat disk configuration, as shown in  FIGS. 4 and 5 , the rounded tip  125  of the lever member  124  can be shaped as a generally spherical bump protruding upwards from the lever member  124 . In this manner, the tip  125  of the lever member  124  can have continuous and smooth contact with the plunger  110  when the lever member  124  tilts at different angles under the torque provided by the main body  122 . Meanwhile, due to the point-like contact between the rounded contact surface  125  and the second enlarged portion  118 , the upward pushing force generated by this torque at the different tilting angles can remain approximately vertical, that is, substantially parallel to the longitudinal length of the elongated portion  114  of plunger  110 . 
         [0029]    Although the illustrated embodiments of the tank  100  include a bottom section  108 , it will be appreciated that such a bottom section  108  can be alternatively formed, partially or fully, by structures within the operating unit  5  itself. Additionally, the float member  120  can be pivotably installed on a suitable structure of the operating unit  5  instead of the bottom section  108  of the tank  100 , with the lever member  124  aligned with the plunger  110  of the tank  100  when the tank  100  is engaged with the operating unit  5 . Other variations and modifications of the structure of the removable tank  100  described herein are also apparent to those skilled in the art, and therefore are encompassed within the scope and spirits of the present invention. 
         [0030]    Those skilled in the art will recognize that the present invention has many applications, may be implemented in various manners and, as such is not to be limited by the foregoing embodiments and examples. Any number of the features of the different embodiments described herein may be combined into a single embodiment, the locations of particular elements can be altered and alternate embodiments having fewer than or more than all of the features herein described are possible. Functionality may also be, in whole or in part, distributed among multiple components, in manners now known or to become known. 
         [0031]    It will be further appreciated by those skilled in the art that changes could be made to the embodiments described above without departing from the broad inventive concept thereof. It is understood, therefore, that this invention is not limited to the particular embodiments disclosed, but it is intended to cover modifications within the spirit and scope of the present invention. While there has been shown and described fundamental features of the invention as applied to being exemplary embodiments thereof, it will be understood that omissions and substitutions and changes in the form and details of the disclosed invention may be made by those skilled in the art without departing from the spirit of the invention. Moreover, the scope of the present invention covers conventionally known, future developed variations and modifications to the components described herein as would be understood by those skilled in the art.