Abstract:
A waste management system including a vessel having an opening into a recess defined at least partially by a bottom wall. A separation device is included having a porous surface disposed substantially laterally across the recess, and spaced-apart from, and adjacent the bottom wall. The waste management system further includes a plurality of substantially non-porous particulate material disposed atop the separation device in a manner spaced above the bottom wall such that liquids impinged upon the particulate materials are caused to pass directly therethrough and separate therefrom for collection on the bottom wall.

Description:
FIELD OF THE INVENTION 
     The present invention pertains to an apparatus for improved cat waste containment and management. More specifically, the invention pertains to a cat litter box and litter combination for improved cat waste management. 
     BACKGROUND OF THE INVENTION 
     Although there have been many cat litter boxes developed over the years, there still remain some fundamental problems with conventional cat waste containment and management. For the most part, advances in cat waste management have focused on two main areas: the design of the cat box and the properties of the litter material used in the cat box. 
     Many recent additions to cat litter box design have been primarily cosmetic; however, there have been some improvements in utility. The basic litter box is generally a receptacle for receiving litter (and subsequently cat waste). Improvements in litter box design have included the addition of sieves which aid the removal of solid waste. That is, many cat boxes allow the contaminated litter to be sieved back into the box for reuse, while the solid waste is removed. Some designs also allow excess liquid waste to pass through a metal screen (below the litter) into a storage container for direct chemical treatment (e.g. lime in the storage container). Despite these advancements, there remain some fundamental problems associated with waste handling. For example, chemical treatment cleanup and disposal is messy and labor intensive. As well, storage containers are typically open trays that are unwieldy, where the likelihood of spillage of urine is high. 
     With respect to the litter material, sand was initially used. Clay-type particulate litters eventually replaced sand since they were more absorbent and cheaper to produce. More recent advances in litter technology have included clumping clay litter that forms agglomerates (clumps) when wetted (with urine). When sieve-type litter boxes (as described above) or shovels are employed to remove solid waste, these clumps are easily removed. 
     Despite these advances, there still remain problems associated with clay litters. Agitation of clay litters produces copious amounts of dust. This commonly occurs when, for example, removing spent litter, placing new litter, or especially when sieving the litter. This clay dust is not only messy; but it is also an inhalation hazard. Oftentimes pet owners need to wear dust masks when handling clay litters. Although there have been attempts at producing “dust free” clumping clay litters, these ventures have been unsuccessful. 
     Another problem associated with clay type litters is inherent in their function. That is, they are designed to absorb not only the pet urine, but its associated powerful odor. As with most animal life, cats urinate frequently, commonly many times a day. This requires that the litter be changed often to avoid saturation. Thus, even though clay litters are absorbent, their small particulate size limits their function. 
     When clay litters are used with litter boxes having collection trays for excess urine, the litter often needs to be saturated before any urine will pass into the tray. This obviates the tray as an effective collection (or deodorizing) element, because avoidance of litter saturation is desirable (due to associated smell and unsanitary conditions). 
     To overcome this odor problem, deodorizing agents have been added to clay litter formulations. Still, the dust problems remain as well as the need for frequent litter changes to avoid urine saturation. 
     What is therefore needed is improved apparatus for cat waste containment and management. More specifically, a litter box and novel litter that together cooperate to overcome the above described problems. 
     SUMMARY OF THE INVENTION 
     The present invention addresses the above-described problems associated with conventional cat litter boxes and clay litters. The invention accomplishes this through a combination of litter box design and a novel litter material. Rather than using a litter material that absorbs liquids, the present invention applies a litter that repels liquids (such as cat urine). In combination with the cat box, the litter allows passage of liquid waste into a unique storage container designed for easy disposal. The litter can be rinsed with water periodically so that residual excreta on the litter is washed into the storage container, making litter changes much less frequent. 
     Another aspect of the invention relates to a cat waste management system which includes a liquid-repellant litter material and a cat litter box for receiving solid and liquid cat excreta. The cat litter box includes a separation device which facilitate the separation of liquid from the liquid-repellent litter material. 
     Preferably, the separation device employed to separate the liquids from the liquid-repellent litter material include a filter layer disposed below and supporting the liquid-repellant litter material in the litter box. A sloped region of the box receives and supports the filter layer, whereby liquids impinged upon the liquid-repellent litter material flow through the filter layer and into a recessed separation region below said filter layer of the littler box. Generally, the filter layer is a screen, the mesh of which is small enough that the liquid-repellent litter material will not pass through. In a preferred embodiment, the screen is also made of a liquid-repellent material, so that it is resistant to urine permeation. Preferably the liquid-repellent material from which the screen comprises is polyethylene. 
     In one configuration, the litter box includes a drainage aperture in the recessed region of the cat litter box through which liquids traverse after passing over the liquid repellent material and through said filter layer. A removable storage container is preferably disposed below the drainage aperture into which the drained liquids collect. 
     In one specific implementation, the storage container is an essentially closed structure with a collection port aligned below and under the drainage aperture for collection of the drained liquids. The removable storage container further includes a disposal opening for emptying liquids from the removable storage container. 
     In another embodiment, the removable storage container further include a handle, proximate to said collection port and said disposal opening. The handle is used for engaging the vessel with the cat litter box, removing the vessel from the cat litter box, and carrying the storage container during transport to a site for disposal of the liquid waste. Preferably, the removable storage container slideably engages the cat litter box. 
     In another aspect of the waste management system of the present invention litter material is liquid repellant as opposed to absorbent as with traditional litter material. Preferably, the liquid-repellent litter material comprises polyethylene. Also preferably, the liquid repellent litter material comprises a collection of individual particles having a mean diameter of between about {fraction (1/16)} and ½ inches, and more preferably about ⅛ inch. The litter can have a shape chosen from the group consisting of spheres, cylinders, cubes, etc. In a particularly preferred embodiment, the liquid-repellent litter material comprises pelletized polyethylene. Unlike conventional clay litters, the liquid repellent litter of the present invention need not be changed for between about 30 and 60 days. 
     These and other features and advantages of the present invention will be described in more detail below with reference to the associated drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a front perspective view of a waste management system constructed in accordance with the present invention. 
     FIG. 2 is a side perspective view of the waste management system of FIG.  1 . 
     FIG. 3 is a rear perspective view of the waste management system of FIG.  1 . 
     FIG. 4 is a bottom perspective view of the litter box of the waste management system of FIG.  1 . 
     FIG. 5 is a top plan view of the waste management system of FIG. 1, and illustrating the separation screen thereof 
     FIG. 6 is a top plan view of the separation screen device of FIG.  5 . 
     FIG. 7 is a top plan view of a removable storage container for the waste management system of FIG.  1 . 
     FIG. 8 is a side perspective view of the removable storage container of FIG.  7 . 
     FIG. 9 is a cross-sectional side elevation view of the removable storage container of FIG.  7 . 
     FIG. 10 is a side elevation view, in cross-section, of the waste management system taken along the plane of the line  10 — 10  in FIG.  5 . 
     FIG. 11 is a fragmentary, enlarged, side elevation view, in cross-section, of the waste management system of FIG.  10 . 
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     In the following detailed description of the present invention, numerous specific embodiments are set forth in order to provide a thorough understanding of the invention. However, as will be apparent to those skilled in the art, the present invention may be practiced without these specific details or by using alternate elements or processes. In other instances well-known processes, procedures and components have not been described in detail so as not to unnecessarily obscure aspects of the present invention. 
     Referring now to FIGS. 1-5, a cat waste management system, generally designated  100 , is provided which includes a cat litter box  101  for receiving solid and liquid excreta, and a liquid-repellant litter material  131  disposed in the litter box. A separation device  126  supporting the litter material  131  is configured to separate the disposed liquids from the liquid-repellent litter material for drainage of the liquid thereof. 
     Accordingly, the present invention addresses the problems associated with conventional cat litter boxes and clay litters through a novel combination of litter box design and a litter composition. Rather than using a litter material that absorbs liquids or fluids, the litter material of the present invention repels liquids (such as cat urine), causing it to quickly and gravitationally flow directly downward. Into a storage container designed for easy disposal. The litter can be rinsed with water periodically so that residual excreta on the litter is washed into the storage container, making the litter reusable and subject to fewer changes. 
     The cat litter box  101 , which is part of the preferred cat waste management system  100  of the present invention, includes a rectangular-shaped main body  104 . This main body  104  includes a front wall  107 , a rear wall  109 , two side walls  111 , and a bottom wall  113  integrally formed to hold and contain the litter material  131  (see FIG. 10) therein. In this particular design, the front wall  107  defines an “opening”  115  to facilitate entry of a cat or the like into the litter box. Note that front wall  107  has a lowest elevation point  118  in its middle. While the main body  104  is generally rectangular, one skilled in the art would understand that the shape can be of any number of acceptable shapes or dimensions. Likewise, litter box  101  can be made of any number of materials. Preferably, main body  104  of litter box  101  is a one-piece injection molded plastic article, but this need not be the case. 
     Peripherally extending around the uppermost perimeter of main body  104  is an upper lip portion  102  which eases handling thereof. Depending downwardly from and disposed on the corners of the bottom wall  113  of the main body  104  are front legs  105 A,  105 B and rear legs  108 A,  108 B (see FIG.  4 ). These appendages cooperate to vertically space the main body  104  above the ground. 
     Since the granulated litter material  131  does not absorb the liquid wastes, but actually repels it, the litter material essentially functions as a porous barrier to gravitationally drain the liquid straight to the bottom wall  113  of the main body, while retaining the solid wastes thereatop. In order to prevent saturation of the litter with the liquid wastes, in accordance with the present invention, the waste management system  100  includes a porous separation device  126  which supports and maintains the granulated litter material  131  above and out of contact with the bottom wall (FIGS. 5,  10  and  11 ). This allows liquid wastes to pass vertically through the litter material  131  (in the direction of arrows  120  in FIG.  10 ), and separate therefrom for collection at the bottom wall  113 . Thus, the separation device  126  spaces the litter material  131  from the bottom wall so that contact with the liquid wastes is minimized. 
     The separation device  126  is sufficiently porous to allow the passage of the liquid wastes therethrough. Preferably, separation device  126  includes a framed screen mesh material (see FIG.  6 ). To retain the litter material  131  thereatop, while permitting the passage the liquid waste therethrough, the transverse cross-sectional dimension of the passages of the mesh are sized sufficiently smaller than that of the individual granulated litter material  131 . In a preferred embodiment, the screen may include a liquid-repellent material coating so that it is resistant to urine permeation. Moreover, the screen may include dispensing nubs  134  (FIG. 11) at each mesh intersection which facilitate separation of the liquid wastes from the screen material. 
     As best viewed in the top plan view of FIG. 5, the coverage area of the screen material  127  is sufficient to cover the entire horizontal surface area of the bottom wall  113 , in order to support and maintain granulated litter material  131  above and out of contact with bottom wall  113 . To support and space the screen material  127  above the bottom wall, a plurality of strategically spaced support ridges  114  (to be described below) depend upwardly from the bottom wall  113  (FIGS.  5  and  11 ). When the separation device is weighted with the granulated litter material  131 , the flexible screen material  127  contacts and is supported by the ridges  114 . These ridges can be of any height depending upon the desired spacing from the bottom wall  113 . Preferably, the height is in the range of about ⅛ inch to about {fraction (3/16)} inch. 
     To mount the separation device  126  to the litter box  101 , the frame  129  is sized to engage and cooperate with the box when the screen is supported atop the support ridges  114 . Thus, the peripheral dimensions of frame  129  are such that its outer perimeter fits snugly against and engages the inner surfaces of front wall  107 , rear wall  109 , and side walls  111 . The separation device is further retained in place by a plurality of spaced-apart, elongated locking nubs or clips  112  (FIGS. 1-3,  5  and  11 ) disposed along the inner lowermost perimeter of the walls of main body  104 . These clips  112  extend inwardly from the interior walls by about ⅛ inch to about {fraction (3/16)} inch so that the frame  129  must be press-fit over and downwardly below the clips to retain the separation device into place. To reduce slack, the spacing of the bottom of the nub or clip  112  from the support ridges  114  (FIG. 11) is substantially similar to the height to the frame  129 , preferably in the range of about ⅛ inch to about {fraction (3/16)} inch. Accordingly, once in place, the screen prevents litter material  131  from passing through to bottom wall  113 . 
     Referring now to FIGS. 1-3 and  10 , the bottom wall  113  is locationally sloped for gravitational flow of the collected waste fluids toward a drainage aperture  123  for drainage thereof from the litter box  101 . The bottom wall, more preferably, is funnelshaped toward the drainage aperture  123 , which is positioned proximate a central portion of the front wall  107 . Thus, after the liquid wastes pass vertically through the litter material  131 , they are further discarded from the litter box  101  through drainage aperture  123  (in the direction of arrows  130  in FIG. 10) to prevent pooling at the bottom wall  113 . 
     To facilitate drainage toward the drainage aperture  123 , FIG. 5 best illustrates that the support ridges  114  are staggered and extend radially from the aperture. When the collected liquid wastes impinges upon the bottom wall, accordingly, these ridges not only support the separation device, but also direct the flow of liquids toward the aperture for discard thereof. 
     In accordance with another aspect of the present invention, the waste management system  100  of the present invention further includes a storage container, generally designated  103 , positioned below the litter box  101  to collect the liquid wastes as they are discarded through the drainage aperture  123 . As shown in FIGS. 1, and  7 - 10 , this substantially hollow storage container  103  includes a collection port  119  in flow communication with the drainage aperture  123  of the bottom wall  113  to enable free flow of the wastes into the container for storage thereof. More preferably, the drainage aperture  123  and the collection port  119  are coaxially aligned, substantially vertically, for gravitational flow more directly into the container  103  (in the direction of arrows  130  in FIG.  10 ). 
     FIGS. 11 best illustrates that the bottom facing surface  132  of bottom wall  113  includes an annular, downwardly depending nipple portion  133  upon which the drainage aperture  123  passes therethrough. To reduce spillage, this nipple portion  133  is adapted to insert and extend into the collection port  119  when the drainage aperture is coaxially aligned with the port. This assures that the liquid wastes funnel directly into the storage container  103  from the litter box  101 . 
     The outer diameter of the nipple portion  133  is similar to that of the inner diameter of the collection port  119  so that the nipple portion can extend freely into the collection port  119 . However, the tolerance between the diameters of the nipple portion and the collection port should not be so large as to allow significant lateral displacement between the litter box and the storage container. By way of example, when the outer diameter of the nipple portion  133  is in the range of about {fraction (11/4)} inch to about {fraction (11/2)} inch, and while the inner diameter of the collection port  119  is in the range of about {fraction (11/2)} inch to about {fraction (15/8)} inch, the preferred tolerance therebetween is in the range of about +/−{fraction (1/16)} inch to about +/−¼ inch. 
     This configuration is beneficial in that when the nipple portion  133  is engaged in the collection port  119  of the storage container  103 , the litter box  101  will be removably mounted to the storage container so that they cannot be laterally separated. Thus, only vertical displacement, and not lateral displacement, between litter box and the storage container of the waste management system  100  will cause the nipple portion  133  to disengage from insertion in the collection port  119 . 
     To prevent rotational displacement about the longitudinal axis of the collection port  119 , the nipple portion  133  and the collection port can be non-circular in shaped. In this manner, rotational alignment between the litter box and the storage container will also be required before insertion of the nipple portion  133  into the collection port  119 . Another technique is to provide a key and slot mechanism. 
     In yet another specific embodiment, the storage container  103  is sized and shaped to engage the litter box  101  in a manner preventing rotational displacement about the collection port longitudinal axis. As best viewed in FIGS. 8 and 10, an upper surface  135  of the storage container  103  which defines the collection port  119  is contoured to position substantially adjacent to the bottom surface  132  of the sloped bottom wall  113  of the litter box  101  when the storage container  103  is mounted to and aligned with the litter box. Accordingly, substantial rotational displacement between the litter box  101  and the storage container  103  about the collection port longitudinal axis will be prevented as the upper surface  135  of the storage container  103  slideably engages the bottom surface  132  of the litter box  101 . 
     Moreover, the front leg  105 A and rear leg  108 A cooperate with a guide rail  116  to form a retaining pocket  136  (FIG. 4) for aligned receipt of the storage container  103  therein in a retained manner. The guide rail  116  extends from the front to the rear of the litter box  101 , and is supported by a strut  125 . Preferably, the guide rail and the strut are integrally formed with and depend downwardly from the bottom surface  132  of the bottom wall  113 . This guide rail  116  cooperates with a guide edge  137  of the front leg  105 A to facilitated aligned engagement when the storage container  103  is being positioned and engaged in the retaining pocket  136  of the litter box  101 . To further facilitate guided receipt, a stop plate  138  extends between the rear leg  108 A and the middle rear leg  106 . Each of these rear legs  106  and  108 A defines a corner pocket portion  140 ,  141 , respectively, which together with the stop plate  138 , engage the rear portion of the storage container  103  to position it in the retaining pocket. Thus, when the storage container  103  is properly positioned in the retaining pocket, and the drainage aperture  123  and the collection port  119  are coaxially aligned, the storage container will be laterally locked to the litter box to prevent lateral displacement therebetween. More importantly, this design configuration prevents lateral separation between the nipple portion  133  of the litter box  101  and the collection port  119  of the storage container  103 . 
     Referring back to FIGS. 7-9, the storage container  103  is preferably constructed of a one-piece blow molded unit which further includes a handle  117  and a disposal opening  121  for discard of the collected liquid wastes therefrom. The disposal opening  121  is preferably at a front corner position of the storage container  103  so that during pouring of the liquid wastes from the container, the liquid flows only out of disposal opening  121  and not through the collection port  119 . FIG. 7 best illustrates that the disposal opening  121  triangular-shaped to facilitate pouring therefrom without splashing or extraneous dripping. 
     FIG. 8 best depicts that the handle  117  is provided by a channel formed in the container body. A user can therefore easily grasp the handle  117  by inserting their fingers through the channel to carry the container in the upright position shown in FIG.  9 . The handle  117  is also positioned at the front portion of storage container  103  so that when the storage container is carried upright, the collection port  119  and disposal opening  121  are located at the top position. Thus, during transport of the liquid waste  130 , accidental spillage from the collection port  119  or the disposal opening  121  are reduced. 
     As above mentioned, the upper surface  135  of the storage container  103  is sloped to conform with the slope of the bottom surface  132  of the litter box bottom wall  113 . The transverse cross-section dimension of the container is thus trapezoidal-shaped. This design, however, is beneficial since the container will be more stable when carried upright (FIG.  9 ). Since a larger percentage of volume of the liquid  130  is carried at the bottom portion of the storage container  103  than at the top portion thereof, when upright, the center of gravity is lowered for more stability during transport and handling. 
     Because the waste management system  100  of the invention uses a liquid-repellent litter material  131 , several advantages over conventional absorbent litters are realized. For one, the litter material need not be discarded and may be periodically cleaned for reuse. By way of example, during a typical waste cleaning operation, solid waste is initially removed (e.g. scooped) from litter material  131  and properly disposed. Then the litter material is rinsed with water to remove not only urine, but also any small amounts of solid excreta that remain on the litter material. As described, the rinse water flows into storage container  103  for easy disposal (via disposal opening  121 ) into a toilet or other proper disposal unit. Preferably this cleaning process is done daily. 
     Depending upon the material composition, the liquid repellent litter material may eventually retain some finite amount of odor from repeated exposure to urine or excrement. Thus, unlike conventional clay litters, the litter of the present invention does not require changing for between about 30 and 60 days. 
     Another advantage of the litter material of the present invention is that it does not generally break down into finer and finer particles. Thus, the litter is substantially dust free. Yet another benefit is that whenever stool or urine are to be analyzed for worms (for example), the instant waste management system  100  allows the pet owner to analyze the rinses from the entire litter material. Small worms or other parasites will be rinsed into the storage container for easy isolation and characterization. This feature is particularly useful to veterinarians as well. 
     The liquid repellent litter material  131  of the present invention is comprised of a collection of individual or granulated particles having a diameters ranging between about ⅛ inch and about ¼ inch. The litter particulates can have any shape as well, such as spheres, cylinders, squares, etc. It will be appreciated, however, that smoother surfaces are preferred to avoid deposition thereon and facilitate rinsing of excretia and urine therefrom. 
     Such liquid-repellent litter material are composed of inert, non-porous materials such as plastics, metals, non-porous rocks, ceramics, and plastics. More preferably, the liquid-repellent litter material comprises pelletized polyethylene. 
     Although various details have been omitted for clarity&#39;s sake, various design alternatives may be implemented. Therefore, the present examples are to be considered as illustrative and not restrictive, and the invention is not to be limited to the details given herein, but may be modified within the scope of the appended claims.