Abstract:
Bird bath incorporates water reservoir and filter disposed above reservoir. Pump circulates water from reservoir to a bowl. Water from bowl received from water surface directed to filter. Agitator causes particles in bowl bottom to be directed to filter. Cascading shower aerates water. Filter captures particles and sanitizes water.

Description:
RELATED APPLICATIONS 
     This present application is related to a provisional application serial No. 60/339,064 filed on Oct. 22, 2001, entitled “METHOD AND APPARATUS FOR RECIRCULATING FILTERED BIRD-BATH”, by G. Desatoff, currently pending, for which the priority date for this application is hereby claimed. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Technical Field 
     This invention pertains to the field of birdbaths. 
     2. Description of the Prior Art 
     Birdbaths are not new. In fact, use of birdbaths as ornamental fixtures has become quite commonplace over the past few decades. The traditional birdbath comprises little more than a shallow bowl mounted on top of a pedestal. In this simple configuration, water is poured into the shallow bowl. Once the shallow bowl is filled with water, it is naturally attractive to non-domesticated birds. Those birds bathe in the water as well as consume water from the bowl. 
     As one might expect, water poured into the shallow bowl could easily become stagnant. This leads to the proliferation of harmful bacteria and the attraction of mosquitoes. These are just some of the undesirable aspects of the traditional birdbath. 
     The next step in birdbath evolution addressed the problem of water stagnating in the shallow bowl. That solution introduced a pump disposed in a reservoir of water to create a recirculating birdbath. These prior art recirculating birdbaths reduced the potential for water stagnation by constantly aerating the water supply. 
     Clearly, recirculating birdbaths helped to reduce water stagnation, but they were not entirely effective. One of the main reasons that recirculating birdbaths were not as effective as they could have been is that the water supply would accumulate organic waste left by birds using the birdbath. The organic waste would eventually decompose in the water supply; again rendering the water supply biologically hazardous. 
     Use of chlorine or other disinfectants was not a suitable means of sanitizing the water supply because sunlight often breaks down these compounds. And because the birds consume water from the birdbath, use of chemical disinfectants requires that the toxicity level of the compound be accurately controlled so that the birds visiting the birdbath would not be otherwise harmed. 
     The next inventive step in birdbath evolution comprised the introduction of a filter to help reduce the level of organic waste suspended in the water supply. The effectiveness of these filtered recirculating birdbaths was again less than expected. The reason for this was that the filters in these filtered recirculating birdbaths could not be easily cleaned because in many cases the filters are made integral to the pump assembly. Because the filters in these prior art birdbaths are so inaccessible, they are rarely cleaned. And even when these filters are cleaned, these filters are designed to capture particulate matter and do nothing to help sanitize or disinfect the water supply used in the birdbath. 
     One prior art design was conceived to prolong the useful operating life of the filter. In this prior art design, gravel was disposed in the base of the shallow bowl constituting the birdbath. The purpose of this gravel layer was to reduce the overall size of particulate matter deposited by birds using the birdbath. The gravel layer effectively helped to reduce the overall size of the particulate matter, but this really did not solve the problem at hand. The filter used to remove the particulate matter from the water supply would still become clogged over time. The only real benefit offered by the gravel layer was to prevent premature saturation of the filter due to excessively large particulate matter deposited in the water supply by defecating birds. 
     SUMMARY OF THE INVENTION 
     The present invention comprises a method for providing water to a birdbath comprising the steps of receiving water from a reservoir and directing the water under pressure to a birdbath bowl. According to this illustrative method, water may be received in the birdbath bowl where a bird may then use the water for bathing or internal consumption. The water may then be directed downward out of the bowl. Once the water leaves the bowl, one example method of the present invention provides that the water be directed to a filter that is disposed above the reservoir. Once the water is filtered, it may then be returned to the reservoir. 
     In order to provide more effective aeration of the water, one derivative method of the present invention provides that the water may be cascaded into a shower that may then be directed into the bowl. In yet another variation of the illustrative method, water in the bottom of the bowl may be agitated so that any particulate matter that may otherwise accumulate there may be forced out of the bowl. In yet another alternative method, water that is directed downward out of the bowl may be captured from a region proximate to the surface of the water that may be in the bowl. 
     The methods of the present invention may be embodied in a birdbath that also comprises the present invention. According to one example embodiment, a birdbath may comprise a bowl for holding water that a bird may enjoy. Water may be discharged out of the bowl in a manner such that it is directed downward away from the bowl. The birdbath may further comprise a pedestal for supporting the bowl. The pedestal itself may comprise a reservoir for holding a volume of water that may be used to replenish any water that is held in the bowl. 
     The pedestal, according to the illustrative embodiment taught here, further comprises a pump that may be used for drawing water from the reservoir and delivering it under pressure to the bowl. To recover water from the bowl, the pedestal comprises a filter that is disposed above the reservoir that may receive water emanating from the bowl and then direct the water to the reservoir. 
     According to one alternative embodiment of the present invention, the birdbath bowl may further comprise a sprinkler assembly. Typically, the sprinkler assembly receives water from the pump and creates a cascading shower that may be directed into the bowl. In yet another embodiment of the present invention, the birdbath bowl may further comprise an agitator jet. The agitator jet is typically directed in a manner that causes the water in the base of the bowl to become turbulent causing any particulate matter that may accumulate there to become suspended in the water that may be held in the bowl. In yet another alternative embodiment of this invention, the birdbath bowl may comprise a combined sprinkler-agitator assembly that is capable of creating the cascading shower and agitating the water that may be present in the bowl. In any of these example embodiment, the agitation may be accomplished by energy received from pressurized water that may be received from the pump comprising the pedestal of the present invention. 
     In some case, the agitator jet may need to be disposed below the water line of water that may be held in the bowl. In these cases, water that may be stored in the bowl may be siphoned back into the reservoir through the agitating jet. To prevent this undesirable effect, the present invention may further comprise a back-flow preventer. According to one example embodiment, the back-flow preventer may be disposed between the pump and the bowl. 
     In order to maintain a particular water level for any water that may be present in the bowl, the bowl may further comprise a return riser. The return riser serves to establish a water level for the water that may be held in the bowl and also causes water proximate to the water&#39;s surface to be expelled from the bottom of the bowl. 
     The filter, according to one embodiment of the present invention, may be particulate filter. In yet another alternative embodiment of the present invention, the filter comprises a sanitizing filter. One alternative embodiment of a pedestal comprises a filter slot that allows for easy access to the filter that is disposed above the reservoir. 
     Supporting the filter above the reservoir may be accomplished by using a filter support grate that may further comprise the pedestal. The support grate, which itself may be supported by a ledge integral to the pedestal, supports the filter above the reservoir. In some embodiments of the present invention, the pump may be supported above a sump region that may further comprise the reservoir. In such embodiments, the pump may be supported by a pump support grate. The pump support grate may itself be supported above the sump region by a ledge integral to the pedestal. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The foregoing aspects are better understood from the following detailed description of one embodiment of the invention with reference to the drawings, in which: 
     FIG. 1 is a cross-section of one illustrative embodiment of a birdbath according to the present invention; 
     FIG. 1A is a pictorial depiction of the capillary action found at the entry of a return riser comprising one example embodiment of the present invention; 
     FIG. 2 is a pictorial view depicting the structure of a split support grate used in one example embodiment of the present invention; 
     FIG. 3 is a pictorial representation of the top view of a shallow bowl according to one example embodiment of the present intention; and 
     FIG. 4 is a cross-section of a simplified pedestal according to another example embodiment of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     What is lacking in the known art is a method and apparatus to filter the water supply in a birdbath in a manner that is both convenient and sanitizes the water supply to prevent either stagnation or other forms of biological infestation. The present invention responds to these objectives. Generally, the present invention comprises a method for filtering water used in a birdbath by passing the water through a filter disposed above a reservoir of water. Once the water is filtered, it is returned to the reservoir. The act of filtering the water may comprise either removal of particulate matter from the water, sanitization of the water, or both. 
     The present invention comprises a method for receiving water from the reservoir, pressurizing the water and delivering the water to a bathing bowl. This step of delivering the water to bathing bowl may further comprises creating a cascading shower that helps to aerate the water supply. 
     The present invention may further comprise steps for agitating the water present in the bowl in order to cause particulate matter that may have accumulated at the base of the bowl to float to the surface level of the water present therein. This step helps particulate matter suspended in the water or accumulated in the base of the bowl to migrate toward filters disposed above the water reservoir. 
     FIG. 1 is a cross-section of one illustrative embodiment of a birdbath according to the present invention. In this illustrative embodiment, a birdbath comprises a pedestal  10  that is used to support a bowl  15 . The pedestal  10  comprises the main reservoir  20  that is used to contain a volume of water. In this illustrative example, the main reservoir  20  is sized to accommodate five gallons of water. It should be noted, though, that the overall size of the birdbath can be varied according to specific architectural requirements or to accommodate specific application needs. Also, the bowl  15  and the pedestal  10  may be manufactured as one integral unit wherein alternative means for conveniently changing a filter can be provided. This type of alternative embodiment is described infra. 
     The cross-section of this illustrative embodiment depicts that a pump  25  is disposed in the volume of water contained in the reservoir  20 . In some embodiments, the pump  25  is supported away from the bottom of the pedestal by a pump support grate  30 . It should be noted that supporting the pump  25  away from the bottom of the pedestal  10  is entirely optional. The purpose of supporting the pump  25  away from the bottom of the pedestal  10  is to help preclude entry into the pump  25  of large particulate matter that may accumulate in the sump volume  22  of the pedestal  10 . Many embodiments of a birdbath according to the present invention actually dispose the pump  25  at the bottom of the pedestal  10  directly in the sump volume  22 . One such alternative example is described infra. 
     The pump  25  comprises a water intake  35 . In operation, water from the main reservoir  20  enters the pump  25  through the water intake  35 . The pump  25  imparts pressure onto the water and discharges the water through a pressure hose  40 . The pressure hose  40  delivers pressurized water from the pump  25  to a sprinkler assembly  45 . The pressurized water is discharged from the sprinkler assembly  45  to create a cascading shower of water. It should be noted that the sprinkler assembly  45  is purely optional and that any means to direct the pressurized water into the bowl  15  is an acceptable alternative embodiment of the present invention. 
     As water begins to fill the bowl  15 , the level of the water in the bowl (depicted as the bowl-water-level  50 ) will rise to a height established by a return riser  55 . The return riser  55  comprises a section of tubing that establishes a return-path  56  for water from the bowl  15  to return back into the pedestal  10 . The return riser  55  continues downward through the base of the bowl  15  and allows water to fall back into the pedestal  10 . 
     As water falls back into the pedestal  10 , it encounters a particulate filter  60 . The purpose of the particulate filter  60  is to remove contaminants from the water returning into the pedestal  10 . Water passing through the particulate filter  60  encounters a sanitizing filter  65 . The purpose of the sanitizing filter  65  is to neutralize biologically active matter suspended in the returning water. It should be noted that the illustrative embodiment described here comprises both the particulate filter  60  and the sanitizing filter  65 . However, in other embodiments, the particulate filter  60  may not be provided and only the sanitizing filter  65  comprises the invention. In yet other embodiments, the sanitizing filter  65  may be omitted and the invention comprises only the particulate filter  60 . 
     In this example embodiment of the present invention, the particulate filter  60  comprises a polyester filter akin to those commonly used in an air conditioning return path. It should be noted that any suitable material may be used to impeded the passage of particulate matter suspended in the returning water. Also in this example of embodiment, the sanitizing filter  65  comprises an activated-carbon filter commonly used to filter drinking water. Again, and in the true spirit of the present invention, any suitable sanitizing filter can be used to cleanse the water returning from the bowl  15 . 
     Once the water passes the particulate filter  60 , if such a particulate filter is provided for in a particular embodiment of the present invention, and once the water is sanitized by a sanitizing filter  65  in those embodiments of the present invention that comprise the sanitizing filter, the water is discharged back into the main reservoir  20  comprising the pedestal  10  of this example embodiment. In this example embodiment, either the particulate filter  60  and/or the sanitizing filter  65  are supported by a filter grate  70 . The filter grate  70  is disposed slightly above the water level found in the main reservoir  20 . The water level in the main reservoir  20  is referred to as the reservoir-water-level  75 . 
     As already discussed, support grates are used to hold the pump  25  away from the sump volume  22  found in the lowest portion of the pedestal  10  and to fix either the particulate filter  60  and/or the sanitizing filter  65  above the reservoir-water-level  75 . The pump support grate  30  is supported vertically around its perimeter by a first contoured ledge  80 . The second contoured ledge  85  supports either filter above the reservoir-water-level  75 . In this example embodiment, the pedestal  10  comprises contoured ledges because the contoured ledges result in an aesthetically pleasing contoured profile at the pedestal&#39;s  10  external surface. 
     It should be noted that any means to support either the pump support grate  30  or the filter support grate  70  can be used in alternative embodiments of the present invention. It should also be noted that any supporting means used to support the pump support grate  30  or the filter support grate  70  need not necessarily support these grates around their entire perimeter. As an additional note, the example embodiment described here suggests that a pedestal and shallow bowl  15  is circular. The present invention should not be limited in scope to any particular geometric shapes that may comprise a birdbath according to the present invention. 
     Again referring to FIG. 1, birds  100  visiting the birdbath may bathe in the water or they may drink water found in the bowl  15 . As birds made do, biological wastes may be deposited in the water found in the bowl  15 . Particulate matter, i.e. excrement, will inevitably be deposited in the bowl  15 . Some particulate matter may float to the surface of the water found in the bowl  15  and other particulate matter may collect at the bottom of the bowl  15 . To prevent the collection of particulate matter at the bottom of the bowl  15 , the invention may further comprise an agitating jet  105  that emit a strong stream of water  110  toward the bottom of the bowl  15 . This strong stream of water  110  agitates the particulate matter collecting at the bottom of the bowl  15  forcing it to the water&#39;s surface. It should be noted that the present invention may comprise one or more agitating jets  105 . 
     One disadvantage exhibited by the invention in a configuration comprising an agitating jet  105  is siphon-drainage of the bowl  15  when the pump  25  is turned off. In the absence of the agitating jet  105 , the water level and the bowl will be maintained at the height of the return riser  55  when the pump  25  is turned off. In most example embodiments that comprise an agitating jet  105 , the agitating jet will be disposed below the height of the return riser  55 . When the pump  25  is turned off, the water level in the bowl  15  will recede to the level of the agitating jet  105  because of back-flow. To preclude this effect, the invention may further comprises a back-flow preventer  42  disposed in the line with the pressure hose  40 . The back-flow preventer  42  prevents siphoning of water present in the bowl  15  so that the water level can be maintained at the height of the return riser  55  when the pump  25  is turned off. 
     FIG. 1A is a pictorial depiction of the capillary action found at the entry of a return riser comprising one example embodiment of the present invention. Once particulate matter is either floating on the surface or has been forced to the surface by an agitating stream of water  110 , it passes into the water return path  56  formed by the return riser  55 . The return riser  55  exhibits a capillary effect with respect to water flowing from the bowl  15  into the return path  56 . This capillary effect allows particulate matter to flow freely over the perimeter of the return riser  55 . The agitating stream of water  110  promotes the passage of particular matter into the return path  56  because agitation of water in the bowl  15  causes irregularities in the surface tension of the water present in the bowl  15 . This, of course, causes variations in the level of capillary action. 
     FIG. 2 is a pictorial view depicting the structure of a split support grate used in one example embodiment of the present invention. In the example embodiment of a pedestal as described here, the circular geometry of the pedestal and the use of contoured ledges to support the grates used to support the filters and pump precludes the use of one-piece support grates. Accordingly, each support grate is split into two semi circles  130 . Each semi circles is physically small enough to pass through the opening of the pedestal  10  and can then be positioned onto either the first or second contoured ledges ( 80  and  85  respectively). The support grates used in this example embodiment of the present invention are fabricated from a polystyrene plastic and comprise a mesh of approximately one-half of an inch. Again, the actual structure of the support grates is not pertinent to the utility of the invention as specified herein. Any suitable support mechanism may be applied. 
     FIG. 3 is a pictorial representation of the top view of a shallow bowl according to one example embodiment of the present intention. According to this example embodiment, the sprinkler assembly  45  is disposed approximately in the center of the shallow bowl  15 . Again, the actual location of the sprinkler assembly  45  can be varied. In this illustrative embodiment, the return riser  55  is offset from the center of the bowl  15 . Again, the actual placement of the return riser  55  can be varied. For the sake of manufacturing convenience, an agitating jet  105  is made as an appendage to the sprinkler assembly  45 . The actual placement of any agitating jet  105  can be varied in order to maximize the effectiveness of a water stream  110  emanating from the jet. Hence, agitating jets  105  may be placed anywhere in the bowl  15  either proximate to the center of the bowl or around its periphery or anywhere where the efficacy of water agitation can be maximized. 
     FIG. 4 is a cross-section of a simplified pedestal according to another example embodiment of the present invention. In this simplified version of the present invention, the pedestal  10  comprises a linear profile and further comprises a single support ledge  130 . In this simplified embodiment, the pump  25  is disposed at the bottom of the main reservoir  20 . Akin to the first illustrative embodiment described herein, the pump  25  receives water from the main reservoir  20  through an inlet  35 . The pump  25  discharges pressurized water through a pressure hose  40  that delivers the pressurized water to the shallow bowl  15 . In this illustrative embodiment, the pedestal  10  may further comprise a filter replacement slot  135 . The invention according to this illustrative embodiment further comprises a filter cartridge  140  that is disposed above the main reservoir  20  being supported by the single support ledge  130 . Accordingly, the filter cartridge  140  may be inserted through the filter replacement slot  135  in order to facilitate replacement of the filter system. In this alternative example embodiment, the filter cartridge  140  may comprise a particulate filter and/or a sanitizing filter commensurate with the specification thus far provided. 
     In this illustrative embodiment, replacement of the filter can be accomplished through the filter replacement slot  135 . In other embodiments that do not provide such a slot, the shallow bowl  15  must be removed to gain access to the filter disposed above the water reservoir. Hence, the shallow bowl must be a separate assembly so that it can be removed from the pedestal. In those embodiments that comprise the filter replacement slot  135 , the shallow bowl may be made integral with the pedestal forming a single piece birdbath. 
     Various materials can be utilized in the construction of a birdbath according to the methods and apparatus described herein. In one example embodiment, the shallow bowl  15  and the pedestal  10  comprises a baked ceramic material. Either the shallow bowl  15  or the pedestal  10  may be constructed of plastic, Bakelite, metal, fiberglass or any other suitable structural material. 
     Alternative Embodiments 
     While this invention has been described in terms of several preferred embodiments, it is contemplated that alternatives, modifications, permutations, and equivalents thereof will become apparent to those skilled in the art upon a reading of the specification and study of the drawings. It is therefore intended that the true spirit and scope of the present invention include all such alternatives, modifications, permutations, and equivalents. Some, but by no means all of the possible alternatives are described herein.