Abstract:
A disposable liner for placing in a litter box protects the litter box from soil deposited by cats and other pets. The liner has side and end walls projecting upwardly from a floor. Each of the longer side walls has a discontinuity that serves as a fold feature allowing the liner to be folded along a fold line into a folded configuration with the two sections of the floor on either side of the fold in facing relationship. In the folded configuration, the side walls overlap to form a partially closed space for retaining pet waste prior to disposal of the lining.

Description:
CLAIM OF PRIOR APPLICATION FILING DATE 
       [0001]    This is a regular application filed under 35 U.S.C. § 111(a) claiming priority under 35 U.S.C. § 119(e) (1), of provisional application Ser. No. 61/039,333, filed Mar. 25, 2008. This regular application incorporates by reference, the provisional application in its entirety. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    The invention solves a significant problem in handling and disposing of pet wastes, particularly cat wastes. 
         [0003]    Cats have been companion animals for millennia. They are friendly creatures that require minimal care, in that they typically eat what they need (as opposed to dogs, who usually eat what they want), and can be trained to excrete urine and feces in a particular place. Normally, cats kept indoors are now trained to excrete in a litter box. 
         [0004]    A litter box is a small tray usually 8-10 in. wide and 12-14 in. long, with perhaps 2-3 in. high walls. An absorbent material such as bentonite or chopped cellulose (litter) is placed in the litter box. The cat&#39;s excretions soak into the litter. Current litter formulations to some extent neutralize the odor and prevent the cat from tracking excretions around the dwelling. These features may be inherent in the litter material, or may result from additives in the litter formulation. 
         [0005]    In spite of the advances in this area, to prevent unpleasant odors and to prevent a cat from tracking excretions, it is still necessary to frequently remove and dispose of the litter. This is a messy and repetitive task for the cat owner. 
         [0006]    Loose litter has other problems as well. First of all, the cat may track the litter around the house, creating a mess and possibly staining rugs and floors. 
         [0007]    Secondly, some types of loose litter such as silica bentonite may not be healthy for either cats or their owners. A cat is prone to licking its fur and paws. When or if such litter adheres to its body, the cat will ingest some of the litter while licking itself. The ingested litter may then swell in the digestive tract, creating blockages that are potentially dangerous health problems for the animal. 
       BRIEF DESCRIPTION OF THE INVENTION 
       [0008]    A disposable litter box liner formed of a flexible sheet material has the general shape of a pan. The liner has a rectangular floor sized to fit within a litter box. Two side walls extend upwardly from edges of the floor. Two end walls extend upwardly from edges of the floor between the two side walls, and are fastened to the side walls in the shape of a pan. 
         [0009]    Preferably, each side wall has between the end walls, a discontinuity that forms a fold feature that allows folding of the liner on a fold line on the floor to place the surfaces of the floor on either side of the fold line in an approximate facing relationship. The folded surfaces of the floor in cooperation with the side walls, form a space for retaining loose pet waste in the course of disposal. 
         [0010]    The discontinuity in the side walls may take the form of gussets or of overlapping wall segments. 
         [0011]    The liner&#39;s end walls may have upwardly extending tabs that serve as handles. 
         [0012]    The liner&#39;s walls may slant outwardly from the floor to allow a number of liners to compactly nest together. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0013]      FIG. 1  is a perspective view of the litter box liner invention in its normal usage configuration. 
           [0014]      FIG. 2  is a perspective view of the invention in its folded configuration. 
           [0015]      FIG. 3  is a side elevation view of an alternative embodiment of a side wall of the invention. 
           [0016]      FIG. 4  is an edge view of the construction of sheet material suitable for forming the invention. 
           [0017]      FIG. 5  is an end elevation view of a stack of liners illustrating how they nest with each other. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0018]      FIG. 1  shows a litter box liner  10  comprising one or more sheets of material formed by folding or molding into a rectangular tray or pan shape. Liner  10  has opposite facing long side walls  12  and opposite facing shorter end walls  15  and a floor  24 . In the embodiment of  FIGS. 1-3 , each of the walls  12  and  15  are attached at their ends to the two adjacent walls  12  or  15  and to floor  24 . 
         [0019]    Liner  10  is sized to fit inside a litter box. Litter boxes almost always have first and second facing sides of equal length that are shorter than the third and fourth sides. Several different sizes for litter boxes exist. The dimensions of a liner  10  should approximately match the litter box holding it, so as to support the walls  12  and  15 . 
         [0020]    Liner  10  receives feces and urine that a cat for example deposits, to thereby prevent soiling of the litter box itself. “Loose soil” or “loose waste” includes cat feces unattached to floor  24 . 
         [0021]    The liner  10  preferably comprises a sheet material having a first moisture-resistant outer (lower) ply or layer and a second moisture-absorbent inner (upper) ply or layer that faces upward and inward to form the interior of liner  10 . The upper ply absorbs urine and watery or runny fecal matter. The moisture-resistant outer ply or layer prevents fluid from escaping an individual liner  10 . Preferred sheet material is flexible and easily bent. 
         [0022]    To form a liner  10 , the sheet material is first cut into the appropriate shape, and then is folded along generally orthogonal intersecting bend lines to define side walls  12  and end walls  15 . Preferably, walls  12  and  15  slant upwards and outwards from floor  24  to each form an obtuse interior angle with floor  24  of perhaps 95-105°. 
         [0023]    A number of possibilities exist for folding and attaching the ends of walls  12  and  15  to each other to form liner  10 .  FIG. 1  shows one arrangement with ends of walls  12  having integral tabs  18  bent at about 90° to contact the adjacent end surfaces of walls  15  and fasten thereto with staples or adhesive. 
         [0024]    The upper edges of end walls  15  may comprise tabs or projections  21  extending above the plane defined by the upper edges of the adjacent side walls  12 . Tabs  21  may have cutouts or openings  27  to form handles for lifting a liner  10  from a litter box. The extra spacing of these openings  21  from floor  24  reduces the likelihood that the surrounding sheet material may be soiled by the animal during use. 
         [0025]    The structure of liner  10  shown in  FIG. 1  simplifies disposal when soiled. Each side wall  12  includes a discontinuity in the form of a fold feature that allows liner  10  to easily fold along a fold line  33  on floor  24  to collapse or close liner  10  into a configuration substantially as shown in  FIG. 2 . In this folded configuration, parts of floor  24  on each side of fold line  33  are in approximate facing relationship. The side walls  12  and the floor  24  cooperate to form a partially closed space for containing loose soil. In this configuration with tabs  21  close to each other, loose soil lying on the surface of floor  24  rolls or slides to the crease in floor  24  along fold line  33  formed by folding. 
         [0026]    In the embodiment of  FIGS. 1 and 2 , the centers of walls  12  have gussets  30  that serve as the fold feature. Gussets  30  add extra sheet material to side walls  12 , particularly along the upper edges, and extend to near floor  24  in an approximate V shape. Fold line  33  extends on floor  24  between gussets  30 . 
         [0027]    Folding liner  10  to juxtapose tabs  21  also forms a crease along fold line  33 . During folding in this way, gussets  30  collapse and in so doing, assist folding along fold line  33 .  FIG. 2  shows a liner  10  folded along fold line  33 . Scoring along fold line  33  may allow easier folding. Gussets  30  close the space formed by folded liner  10  at the ends of fold line  33  to reduce the possibility of loose soil falling from folded liner  10 . The two halves of liner  10  on either side of fold line  33  may each bend slightly as tabs  21  near each other and segments  12 A contact floor  24 . 
         [0028]    Gussets  30  may comprise sheet material thinner and more flexible than that comprising other parts of liner  10 , and may be bonded onto walls  12 . Or liner  10  may comprises walls  12  non-integral from and bonded to floor  24 , in which case gussets  30  may be integral with walls  12 . 
         [0029]      FIG. 3  shows a side elevation view of a liner  10 ′ having a second configuration for a wall  12  with a fold feature. ( FIG. 3  shows only one wall  12 .) The wall  12  of  FIG. 3  has a pair of overlapping walls segments  12 A and  12 B that serve as a fold feature to assist folding a liner  10 ′ into a configuration similar to that of  FIG. 2 . Wall segment  12 A is adjacent to the inside surface of wall segment  12 B where segments  12 A and  12 B overlap. At fold line  33 , an edge  13  of segment  12 A slants up and back so that the upper edge of segment  12 A is shorter than the lower edge of segment  12 A (where segment  12 A intersects floor  24 ). Fold line  33  in  FIG. 3  is perpendicular to the plane of the paper and thus shows as a point. 
         [0030]    In overlapping segment  12 A, wall segment  12 B extends past edge  13  to a substantially vertical edge  14 . In  FIG. 3 , the right edge  13  of wall  12 A is shown as a dotted line because wall  12 B is interposed between wall  12 A and the viewer where walls  12 A and  12 B overlap. Because no connection exists between the adjacent ends  13  and  14  of segments  12 A and  12 B, wall  12  adds little resistance to bending of floor  24  along fold line  33 . 
         [0031]    When liner  10 ′ is folded along line  33  for disposal, the overlap of segments  12 A and  12 B limits the escape of loose soil a cat has previously deposited in liner  10 ′. The slanted edge  13  on each segment  12 A seals against floor  24  when in the folded configuration to hold loose soil material within the space formed by folded liner  10 ′. The two halves of liner  10 ′ on either side of fold line  33  may each bend slightly as tabs  21  near each other and segments  12 A contact floor  24 . 
         [0032]      FIG. 4  shows an edge view of one preferred structure for the sheet material comprising floor  24  and likely, the entire liner  10 . A base sheet  38  may comprise beverage cardboard on the order of 5-15 mils (0.13-0.4 mm.) thick. The inner surface of base sheet  38  has a thin moisture-resistant coating  35 . An absorbent inner ply  37  on the order of 5-15 mils (0.13-0.4 mm.) thick adheres to coating  35 . Inner ply  37  may have an upper surface with a relatively rough or nubby texture that appeals to and attracts cats. 
         [0033]    At least two sources for suitable material for ply  37  exist: 
         [0000]    Absorbent Technologies, Inc., Beaverton, Oreg. 97008 has a product called “Zeba.”
 
Archer Daniels Midland Co., Decatur Ill. 62526 has a product called Lysorb 218.
 
         [0034]      FIG. 5  shows how the angled walls  12  and  15  allow a number of the liners  10  to form a compact nested stack that can be placed in a litter box. This nesting allows a number of nested liners  10  to provide additional support of the top liner  10  in a nest. Likely, a cat owner will remove a liner  10  each day or after the liner  10  is soiled, exposing a fresh liner  10  beneath the one removed. Ply  38  prevents liquid deposited on the top liner  10  from leaking to liners  10  beneath it.