Abstract:
A low-noise liquid distribution system for delivering a liquid to a user on demand includes a reservoir and a tank oriented in an inverted position over the reservoir for distributing liquid from the tank to the reservoir. A vent tube has an inlet end that is located outside of the tank and an outlet end that is located in the tank above the liquid level. With this arrangement, when an opening of the tank and the vent tube are at, or immersed below, a level of liquid in the reservoir, the liquid is held within the tank by a combination of vacuum pressure acting on the liquid in the tank and atmospheric pressure acting on the liquid in the reservoir. However, when at least the vent tube is above the level of liquid in the reservoir, the vacuum within the tank is broken as air travels into the tank by way of the vent tube. Accordingly, liquid in the tank is delivered to the reservoir without the formation of air bubbles and their associated noise.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]    This application claims the benefit of U.S. Provisional Application No. 60/265,454 filed on Jan. 31, 2001 and entitled “Noise-Reducing Water Distribution System”, the disclosure of which is hereby incorporated by reference. 
     
    
     
       BACKGROUND OF THE INVENTION  
         [0002]    This invention relates to liquid storage tanks, and more particularly to a low-noise or noiseless water distribution system for water tanks or the like.  
           [0003]    Water distribution systems can be found in products that are in wide use in offices and homes throughout the world, such as water coolers, humidifiers, automatic pet waterers, and so on. As shown in FIGS. 1 and 2, a prior art water distribution system  10  comprises an inverted water tank  12  and a reservoir  14  positioned below the water tank. A valve  16  or other control mechanism may also be provided for controlling the distribution of water  18  from the reservoir  14 .  
           [0004]    In operation, the level  20  of water  18  in the reservoir is initially at approximately the same level as the inlet  22  of the water tank  12 , as shown in FIG. 2. The combination of atmospheric pressure, as represented by arrows  24 , acting on the surface  20  of the water in the reservoir  14  and the vacuum pressure, as represented by arrows  26 , acting on a surface  28  of the water in the tank  12  holds the remaining water in the tank  12  and prevents the reservoir from being overfilled. When water is removed from the reservoir  14 , such as by opening the valve  16 , water is discharged from the reservoir  14  under gravity in a direction as shown by arrow  30  in FIG. 1. As the level  20  of water or liquid in the reservoir descends below the inlet  22 , air flows into the water tank  12 , as represented by arrow  32  and water bubbles  34 , to thereby break the vacuum in the water tank. Consequently, water flows under gravity from the tank  12  to the reservoir  14 , as represented by arrow  36 . Upon closing the valve  16 , the level  20  of the reservoir rises until it reaches the height of the water tank inlet  22 . When the vacuum in the water tank  12  is broken, the inrush of air bubbling to through the water can be unacceptably loud, particularly in a quiet room. It would therefore be desirable to provide a water distribution system for water coolers, humidifiers or the like that reduces or eliminates the noise associated with dispensing the water.  
         BRIEF SUMMARY OF THE INVENTION  
         [0005]    In accordance with one aspect of the invention, a low-noise liquid distribution system for delivering a liquid to a user comprises a reservoir and a tank oriented in an inverted position over the reservoir for delivering liquid in the tank to the reservoir. The reservoir includes a reservoir lower wall and a reservoir continuous side wall that extends upwardly from the reservoir lower wall to thereby form, together with the reservoir lower wall, a reservoir interior that is exposed to atmosphere for holding and distributing a first quantity of liquid to a user. The tank includes a tank upper wall, a tank continuous side wall extending downwardly from the tank upper wall, and a tank lower wall extending from the tank continuous side wall to thereby form, together with the tank upper wall and the tank continuous side wall, a tank interior into which liquid is received. An opening is located in at least one of the tank walls for distributing a second quantity of liquid under gravity to the reservoir. The tank further includes a vent tube with an inlet end that is located outside of the tank and an outlet end that is located in the tank hollow interior. With this arrangement, when the opening and the vent tube are at, or immersed below, a level of liquid in the reservoir, the second quantity of liquid is held within the tank hollow interior by a combination of vacuum pressure acting on the liquid in the tank hollow interior and atmospheric pressure acting on the liquid in the reservoir. However, when at least the vent tube is above the level of liquid in the reservoir, the vacuum within the tank hollow interior is broken and air flows into the tank through the vent tube to thereby deliver the second quantity of liquid to the reservoir without formation of air bubbles and their associated noise.  
           [0006]    In accordance with a further aspect of the invention, a liquid holding and distribution tank for a liquid distribution system comprises an upper wall, a continuous side wall extending downwardly from the upper wall, and a lower wall extending from the continuous side wall to thereby form, together with the upper wall and the continuous side wall, a hollow interior into which liquid is received. An opening is located in one of the walls for distributing a quantity of liquid from the tank under gravity to the reservoir. The tank further comprises a vent tube with an inlet end that is located outside of the tank and an outlet end that is located in the hollow interior. With this arrangement, air flow through the vent tube prevents formation of air bubbles in the opening when the quantity of liquid exits the tank through the opening.  
       
    
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS  
       [0007]    The foregoing summary, as well as the following detailed description of preferred embodiments of the invention, will be better understood when read in conjunction with the appended drawings. For the purpose of illustrating the invention, there is shown in the drawings embodiments which are presently preferred. It should be understood, however, that the invention is not limited to the precise arrangements and instrumentalities shown.  
         [0008]    In the drawings:  
         [0009]    [0009]FIG. 1 is a schematic sectional view of a prior art water distribution system with an inverted water tank in the process of filling a reservoir;  
         [0010]    [0010]FIG. 2 is a schematic sectional view of the prior art water distribution system of FIG. 1 with the reservoir in a filled condition;  
         [0011]    [0011]FIG. 3 is a schematic sectional view of a liquid distribution system in accordance with an embodiment of the present invention and including a liquid holding tank in the process of filling a reservoir;  
         [0012]    [0012]FIG. 4 is a schematic sectional view of the liquid distribution system of FIG. 3 with the reservoir in a filled condition;  
         [0013]    [0013]FIG. 5 is a schematic sectional view of a liquid distribution system in accordance with a further embodiment of the present invention;  
         [0014]    [0014]FIG. 6 is a schematic sectional view of a liquid distribution system in accordance with an even further embodiment of the present invention;  
         [0015]    [0015]FIG. 7 is a schematic sectional view of a liquid distribution system in accordance with yet a further embodiment of the present invention;  
         [0016]    [0016]FIG. 8 is a schematic sectional view of a liquid distribution system in accordance with a further embodiment of the present invention;  
         [0017]    [0017]FIG. 9 is a schematic sectional view of a lower tank portion that can be used with each of the liquid distribution system embodiments; and  
         [0018]    [0018]FIG. 10 is a schematic sectional view of a modified lower tank portion that can be used with each of the liquid distribution system embodiments. 
     
    
       [0019]    It is noted that the drawings are intended to represent only typical embodiments of the invention and therefore should not be construed as limiting the scope thereof. The invention will now be described in greater detail with reference to the drawings, wherein like parts throughout the drawing figures are represented by like numerals.  
       DETAILED DESCRIPTION OF THE INVENTION  
       [0020]    Referring now to the drawings, and to FIGS. 3 and 4 in particular, a liquid distribution system  40  in accordance with the present invention comprises an inverted tank  42  and a reservoir  44  positioned below the tank. A valve  46  or other control mechanism may also be provided for controlling the distribution of liquid  48  from the reservoir  44 . Although in some applications the valve  46  is preferable, such as in water coolers, it will be understood that the valve  46  can be eliminated in other applications, such as in automatic waterers for animals where the liquid is lifted or otherwise removed from the reservoir, as shown by way of example in FIGS.  6 - 10 .  
         [0021]    The inverted tank  42  preferably has an upper wall  50 , a continuous side wall  52  extending downwardly from the upper wall, a lower wall  54  extending generally downwardly and inwardly from the side wall  52 , and a neck portion  56  that extends generally downwardly from the lower wall  54 , to thereby form a hollow interior  58  into which the liquid  48 , such as water, can be received. An opening or mouth  60  (shown in dashed line) is formed at a lower end of the neck portion  56  for transferring liquid into and out of the tank  42 . A vent tube  62  preferably extends through the lower wall  54  and into the tank interior  58 . The vent tube  62  can be integrally formed with the tank  42 , or can be formed separately and sealingly connected to the tank  42  through ultrasonic welding, adhesives, mechanical couplings, or other well-known mounting means. Preferably, an inlet end  64  of the vent tube  62  is higher than the mouth  60  of the inverted tank  42 , and an outlet end  66  of the vent tube is normally higher than a level  68  of liquid  48  in the inverted tank.  
         [0022]    The reservoir  44  includes a lower wall  80  and a continuous side wall  82  that extends upwardly from the lower wall  80  to form an interior  84  into which the liquid  48  is received and held until the reservoir liquid level drops, such as when the valve  46  is opened in some applications such as water coolers, or when liquid is otherwise removed from the reservoir in other applications such as humidifiers and automatic pet waterers. The interior  84  of the reservoir  44  is preferably open to atmosphere such that atmospheric pressure, as represented by arrows  88 , acts on the surface of the liquid  48  in the reservoir.  
         [0023]    In operation, the liquid  18  in the reservoir is initially at approximately the same level as the inlet end  64  of the vent tube  62  and preferably at the same or at a higher level than the mouth  60  of the inverted tank  42 , as shown in FIG. 4, which effectively seals the interior  58  of the tank  42  from atmosphere. The combination of atmospheric pressure, as represented by arrows  88 , acting on the surface  90  of the liquid in the reservoir  44  and the vacuum pressure, as represented by arrows  92 , acting on the surface  68  of the liquid in the tank  42  holds the liquid in the tank  42  and prevents the reservoir  44  from being overfilled. In use, the level  90  of liquid  48  in the reservoir  44  drops below the level of the mouth  60 , such as when the valve  46  is opened to discharge liquid from the reservoir  44  under gravity in a direction as shown by arrow  94  in FIG. 3, or when the liquid is lifted or otherwise removed from the tank as previously described. As the level  90  of liquid  48  in the reservoir descends below the inlet end  64  of the vent tube  62 , air flows into the inverted tank  42 , as represented by arrows  96 , to thereby break the vacuum in the inverted tank. Since the air entering in and traveling through the vent tube  62  is not in direct contact with the liquid  48  in the inverted tank  42 , the generation of air bubbles and their consequent noise is eliminated. Accordingly, liquid flows under gravity from the inverted tank  42  to the reservoir  44 , as represented by arrow  98 . Since the inlet end  64  of the vent tube  62  is at the same height or higher than the mouth  60  of the tank  42 , the liquid in the reservoir will not normally descend below the level of the mouth and the liquid in the tank  42  will flow relatively smoothly into the reservoir  44  without generating air bubbles at the mouth. Upon closing the valve  46 , the level  90  of liquid  48  in the reservoir continues to rise until it reaches the height of the inlet end  64  of the vent tube  62  to thereby seal the interior  58  from outside atmosphere. The combination of atmospheric pressure acting on the surface  90  of the liquid in the reservoir  44  and the vacuum pressure acting on the surface  68  of the liquid in the tank  42  again holds the remaining liquid in the tank  42  and prevents the reservoir  44  from being overfilled.  
         [0024]    Referring now to FIG. 5, a liquid distribution system  100  in accordance with a further embodiment of the invention is illustrated, wherein like parts in the previous embodiment are represented by like numerals. The liquid distribution system  100  is similar in construction to the liquid distribution system  40 , with the exception of a first valve  102  associated with the neck  56  of the tank  42 , a second valve  104  associated with the vent tube  62 , and protrusions  106  and  108  provided on the reservoir  44  to open the valves  102  and  104 , respectively, when the tank  42  is inverted and properly positioned or aligned with respect to the reservoir  44 . Each valve  102 ,  104  is preferably of conventional construction and includes a valve seat  112  that is fixed against movement in the neck  56  and the vent tube  62 , and a sealing member  110  that is normally seated against the valve seat  112  under pressure from a spring (not shown) or other bias means. A stem or rod  114  extends from the sealing member  110  for contacting one of the protrusions  106 ,  108  to thereby unseat the sealing member when the tank  42  is inverted and properly positioned or aligned with respect to the reservoir  44 .  
         [0025]    With this construction, the normally closed valves seal the liquid within the tank to thereby prevent the ingress of contaminants into the tank and the egress of liquid from the tank during storage, transportation, and inversion of the tank during installation over the reservoir  44 . Although the valves  102  and  104  are shown located adjacent the mouth  60  and inlet end  64 , respectively, it will be understood that the valves can be located anywhere along the vent tube  62  and the neck  56  or other tank access opening. It will be further understood that the valves  102  and  104  can be replaced with other types of valves, so long as they function to hold liquid in the tank during storage, transportation and inversion of the tank, and allow flow of liquid out of the tank when inverted.  
         [0026]    Although the above-described embodiments illustrate the vent tube extending through the bottom wall  54  of the inverted tank, it will be understood that the vent tube can extend through the top wall and/or the side wall, as illustrated in FIG. 6. As shown, a liquid distribution system  120  in accordance with a further embodiment of the invention is illustrated, wherein like parts in the previous embodiments are represented by like numerals. The liquid distribution system  120  includes inverted tanks  122  and  124  associated with a reservoir  44 .  
         [0027]    The inverted tank  122  has a vent tube  126  with an inlet end  128  that is preferably at the same height as or above the mouth  60  and an outlet end  130  that extends into the top wall  50  of the inverted tank  122  for fluid communication with the interior of the tank  122 . The vent tube  126  has a bend  132  between the inlet and outlet ends  128  and  130 , respectively. The vent tube  126  can be integrally formed with the tank  122  or can be formed separately and joined to the tank in a well-known manner.  
         [0028]    Likewise, the inverted tank  124  has a vent tube  136  with an inlet end  138  that is preferably at the same height as or above the mouth  60  and an outlet end  140  that is positioned in the interior of the tank  124  near the top wall  50 . As shown, a middle portion  142  of the vent tube  136  enters the side wall  52  of the inverted tank  124  and may be S-shaped or otherwise formed to dampen or control fluid flow through the vent tube, and thus dampen or control liquid flow from the inverted tank  124  to the reservoir  44 . The vent tube  136  can be integrally formed with the tank  124  or can be formed separately and joined to the tank in a well-known manner.  
         [0029]    Although in this embodiment two tanks are associated with the reservoir  44 , it will be understood that one or more of the tanks  42 ,  122 , and/or  124  can be provided. In addition, it will be understood that plural reservoirs can be associated with a single tank.  
         [0030]    Referring now to FIG. 7, a liquid distribution system  150  in accordance with a further embodiment of the invention is illustrated, wherein like parts in the previous embodiments are represented by like numerals. The liquid distribution system  150  includes an inverted tank  152  associated with a reservoir  44 .  
         [0031]    The inverted tank  152  has a vent tube  154  that is integrally molded with a side wall  52  of the tank. The vent tube  154  has an inlet end  156  that is preferably above the mouth  60 , such as at an intersection of the bottom wall  54  and side wall  52 , and an outlet end  158  that is adjacent the top wall  50  inside the tank  152 .  
         [0032]    With reference now to FIG. 8, a liquid distribution system  160  in accordance with an even further embodiment of the invention is illustrated, wherein like parts in the previous embodiment are represented by like numerals. The liquid distribution system  160  includes an inverted tank  162  that is similar in construction to the inverted tank  152  previously described, with the exception that a neck portion  164  extends generally horizontally and an opening or mouth  166  extends generally vertically when the tank  152  is mounted in the inverted position. With this construction, the flow of liquid  48  from the tank  162  to the reservoir  44  will tend to be more laminar than in the previous embodiments, resulting in smoother and quieter operation. The inlet end  156  of the vent tube  154  is preferably positioned at or above the highest exit point  168  of the mouth  166  in order to create and break the vacuum effect, as previously described. Although the particular orientation of the mouth  166  has been described for use with the integrally molded vent tube  154 , it will be understood that the mouth  60  of the previous embodiments may be similarly constructed.  
         [0033]    In accordance with a further embodiment of the invention, and with reference to FIGS. 9 and 10, each of the previous embodiments can be further modified by orienting an opening or mouth  170  of the inverted tank at an angle  172  between horizontal and vertical, such as by tilting the tank, as shown in FIG. 9, or by forming the mouth at an angle  172 , as shown in FIG. 10. The inlet end of the vent tube (not shown in FIGS. 9 and 10) is preferably positioned at or above the highest exit point  174  of the mouth  170  in order to create and break the vacuum effect, as previously described. With this arrangement, the flow of liquid from the tank to the reservoir will tend to be more laminar, resulting in smoother and quieter operation.  
         [0034]    It will be understood that various terms of orientation and/or position as may be used throughout the specification, such as upper, lower, side, upward, downward, and their respective derivatives and equivalent terms are intended to denote relative, rather than absolute orientations and/or positions.  
         [0035]    It will be 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 should be appreciated that the tank of the present invention may find applicability with a wide variety of liquid distribution systems, including, but not limited to, water cooler bottles, humidifier water tanks, water bottles for automatic waterers used for pets or other animals, and so on. It will be further appreciated that the tank can be formed in a wide variety of sizes, shapes, configurations such as multiple tank openings located in one or more of the tank walls, and materials to accommodate a wide variety of applications. It will be understood, therefore, that this invention is not limited to the particular embodiments and applications disclosed, but it is intended to cover modifications within the spirit and scope of the present invention as defined by the appended claims.