Abstract:
A self-cleaning litter box assembly for litter using pets, which is capable of providing new litter and disposing of soiled litter for extended periods while minimizing human contact. The apparatus comprises, a receptacle with a receiving area, a central area, and a disposal area, a continuous litter support material, such as a roll of membranous material containing or supporting litter, and a traversing mechanism mounted to the receptacle for advancing the litter support material from the receiving area through the central area and on to the disposal area. Following litter soiling in the central area, the membrane is advanced to a disposable waste receptacle. After the roll of litter support material is completely used, the waste receptacle is disposed of. To renew the system one merely loads a fresh cartridge of litter support material into the device and inserts a new waste receptacle into the disposal area and operation continues.

Description:
FIELD OF THE INVENTION  
         [0001]    The invention relates to a self-freshening litter box for litter using pets. More specifically, the device is constructed and arranged to replenish and dispose of soiled pet litter by employing a continuous litter support material, e.g. a roll of membranous material, which unrolls to reveal pet litter distributed thereon. Following litter soiling the membrane is advanced into a waste receptacle while simultaneously providing a fresh litter surface for subsequent use.  
         BACKGROUND OF THE INVENTION  
         [0002]    Domestic pets, for example ferrets, skunks, rabbits, and particularly cats, require the use of a litter box to maintain sanitary conditions in the home. Litter boxes have the disadvantage of producing unpleasant odors when the litter product is not changed on a routine basis. While not limited to a particular litter product, litter products useful in the instant invention may include various clays, wood chips, sawdust, straw, clumping materials, shredded polymers and mixtures thereof.  
           [0003]    Used litter also creates health hazards for the occupants in the house.  
           [0004]    General practice for most pet owners is to place litter in a plastic box. After an extended period of use by the pet, the pet owner discards the litter. However, many pet owners find it necessary to periodically remove the pet&#39;s solid waste from the litter before discarding the entire contents to prevent the pet from tracking the waste out of the box upon its subsequent visits to the litter box.  
           [0005]    The changing of soiled litter or manually separating solid waste from the used litter is an unpleasant and undesirable task contributing to the reluctance of pet owners to frequently change the litter. Pet litter not maintained on a routine basis may pose a greater health risk to humans or pets. Insects, such as houseflies, may transfer disease from the animal waste in the litter box to areas contacted by humans.  
           [0006]    Toxoplasmosis, an infection of mammals, birds and reptiles, also common to humans and especially dangerous to pregnant women, can be transmitted by breathing contaminated dust particles from litter or handling soiled litter and cat feces during daily maintenance of the litter box.  
         DESCRIPTION OF THE PRIOR ART  
         [0007]    A number of patented devices exist for separating solid waste from litter; some of these devices are automated while others utilize the physical characteristics of the litter to carry out the separation.  
           [0008]    U.S. Pat. No. 5,188,062 issued to Joy utilizes a disposable container filled with alternating layers of litter and paper attached to a motorized rotational device. When the litter is soiled the rotational device pulls the paper covered with the soiled litter into a disposable container. During operation, the sides of the disposable container can become errantly soiled. Because the disposable container remains in place for up to 7 days until the container is emptied, it may create an odor and bacteria problem. Additionally, because the litter is not contained, dust from the litter may become airborne when being pulled into or removed via the disposal container, thereby creating additional health hazards.  
           [0009]    U.S. Pat. Nos. 5,048,465 and 6,289,847 issued to Carlisi utilize a tray for holding clumping litter. Also included is a rake member which moves laterally along the tray through the litter collecting solid waste. The solid waste is thereafter deposited into a collection module. Pet owners using this device must still replenish litter at the same frequency as a non-automatic litter box. During operation, the rake mechanism contacts waste material and is likely to accumulate residual waste, posing both sanitary and odor disadvantages. In addition, errant soiling of the exposed sides of the box require manual cleaning and create bacterial hazards.  
           [0010]    U.S. Pat. No. 5,460,122 issued to Reinartz utilizes a flexible floor mat covered with litter. After the litter is soiled the mat is retracted to a vertical position pushing the litter off the mat into a container below. A hopper mounted above redistributes fresh litter on the mat as it returns to its original position.  
           [0011]    During operation, the mat, sidewalls of the box, and the disposal box contact pet waste and may require manual cleaning to avoid odor and bacteria problems. Additionally, because the litter is not contained when being scraped into the disposal container, dust from the litter may become airborne during operation and create additional health hazards.  
           [0012]    U.S. Pat. No. 4,844,011 issued to Strickland utilizes a rubber continuous conveyer covered with litter. After the litter is soiled the conveyer rotates and a rubber scraper pushes the soiled litter off the conveyer into a disposal container. Thereafter, a hopper mounted above the conveyer redistributes fresh litter on the conveyor.  
           [0013]    During operation of the device, the conveyor and the rake mechanism contact pet waste and are likely to accumulate residual waste, posing both sanitary and odor disadvantages.  
           [0014]    U.S. Pat. No. 5,003,920 issued to Miksitz utilizes a litter supply bin mounted above a litter trough. Litter is distributed on the trough by oscillating movement of the supply bin. Continued oscillations of the supply bin push the spent litter in the trough to a collection receptacle. The collection receptacle may include a washing apparatus to spray water into the spent litter and carry the litter and animal waste to a sewer system.  
           [0015]    There are many disadvantages associated with this system. Errant soiling and saturated litter in the trough area may create odor and sanitary problems. The design incorporating the washing apparatus requires a water supply and a sewer drain, and therefore lacks portability. In addition, not all types of litters are water-soluble and may create a clogging problem in drains.  
           [0016]    Another example of an animal litter device is disclosed in U.S. Pat. No. 5,673,648 issued to Ayle. The device utilizes a bottom tray filled with clumping litter. To separate the solid waste from the unused litter the pet owner attaches a top cover having a waste chute and a slide rail separator. A waste storage bag is attached to the waste chute and the entire device is lifted with a shaking motion. The slide rail diverts solid waste to the storage bag while the unused litter falls through the slide rail for redistribution on the bottom tray.  
           [0017]    This device has many shortcomings. To operate the device, the entire litter box must be lifted to separate clumped litter from used litter. In addition to the litter box, extra parts such as the top cover, the chute and slide rail separator come into contact with the soiled litter causing residual soiling and sanitary problems. Lastly, some types of litters may not be as easily separated from clumps of solid waste as others, thereby creating operational difficulties.  
           [0018]    U.S. Pat. No. 4,801,006 utilizes a prepacked animal litter box, which contains multiple layers of litter absorbent contained in disposable bags. The bags are set within a cardboard box so that when one bag is used and subsequently discarded, its removal uncovers a succeeding disposable bag of litter. This device requires manual cleaning to maintain sanitary conditions and offers very little advantage over litter poured into a plastic box.  
           [0019]    The above noted devices do not provide sufficient odor or bacteria control, and generally require handling of the used litter or manual cleaning of the litter containing area. In addition, many of the devices lack control of dust from the litter that may become airborne and create health hazards for the pet or the pet owner.  
           [0020]    Accordingly, there is a need for a self-cleaning device which is capable of manual or automatic operation. The device should protect the owner from exposure to animal waste or contaminated surfaces as well as airborne litter dust.  
         SUMMARY OF THE INVENTION  
         [0021]    The present invention is directed towards a self-freshening litter box assembly for litter using pets, which is capable of providing new litter and disposing of soiled litter for extended periods while minimizing human contact. The apparatus comprises a receptacle with a receiving area, a central area and a disposal area, a continuous litter support material illustrated by, but not limited to a spirally wound roll of membrane material containing litter and a traversing mechanism mounted to the receptacle for advancing the litter support material from the receiving area through the central area and on to the disposal area. The receiving area is constructed and arranged for facilitating the installation of the rotationally mounted roll of litter support material, which, when unrolled, reveals litter in the central area. Following litter soiling in the central area, the membrane is advanced to a disposable waste receptacle, or in the alternative, folded to cover the waste to be compressed by pinch rollers and advanced to a disposable waste receptacle. After the roll of litter support material is completely used, the waste receptacle is disposed of. To renew the system one merely loads a fresh cartridge of litter support material into the device and inserts a new waste receptacle into the disposal area and operation continues.  
           [0022]    It is therefore an objective of the present invention to provide a new and improved pet litter system and method for its use. The device includes means for replenishing pet litter while virtually eliminating contact or exposure to soiled litter. The device takes into consideration pet and human hygiene, convenience, reduction of human maintenance, and exposure to unsanitary conditions.  
           [0023]    A further objective of the present invention is to provide a pet litter system which can be self-cleaning, and automatically disposes of soiled litter, which is capable of either manual or automatic operation, and which allows for operation over extended periods without human attention.  
           [0024]    Yet an additional objective of the present invention is the introduction of replaceable rolls of litter material contained within a linear membrane of folded plastic or other medium designed to integrate with the litter system. Simultaneously, the membrane is advanced, opens to expose the litter, refolds to enclose the used litter, and continues to a disposal container.  
           [0025]    A still further objective of the present invention is odor repression with the sanitary disposal of animal waste within an advancing roll of plastic membrane into a disposal container.  
           [0026]    Another object of the present invention is to provide a litter box and disposal container that protects the pet and the pet owner from exposure to animal waste, contaminated surfaces and airborne litter dust.  
           [0027]    Yet another object of the present invention is to provide a totally renewable litter box that is easy to operate and reload.  
           [0028]    Other objects and advantages of this invention will become apparent from the following description taken in conjunction with the accompanying drawings wherein are set forth, by way of illustration and example, certain embodiments of this invention. The drawings constitute a part of this specification and include exemplary embodiments of the present invention and illustrate various objects and features thereof.  
       
    
    
     BRIEF DESCRIPTION OF THE FIGURES  
       [0029]    [0029]FIG. 1 is a perspective view of the present invention, a portion thereof being broken away;  
         [0030]    [0030]FIG. 2 is a partial cross sectional view through the receiving area of the present invention showing the relationship of the litter within the spooled membrane and the unfolding of the membrane to expose the litter;  
         [0031]    [0031]FIG. 3A is a cross sectional view through the central area of the present invention showing a tractor roller in cooperation with the membrane and the floating central member;  
         [0032]    [0032]FIG. 3B is a longitudinal cross sectional view through a tractor roller in the central area of the present invention further showing the cooperation of the roller and the membrane;  
         [0033]    [0033]FIG. 4 is a cross sectional view through the central area of the present invention showing the optional disposable rake as well as the path of the membrane as it refolds over the litter;  
         [0034]    [0034]FIG. 5 is a cross sectional view through the disposal area of the first embodiment showing the pinch rollers as well as the path of the membrane as it passes through the pinch rollers to the disposal box;  
         [0035]    [0035]FIG. 6 is a perspective view showing the litter cartridge opening to expose the litter;  
         [0036]    [0036]FIG. 7 is a cross sectional view through the disposal area of an alternative embodiment of the present invention showing the path of the membrane as it passes into the disposal area and is spirally wound around an axle member. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0037]    For the purposes of promoting an understanding of the principles of the invention, reference will now be made to the embodiment illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended, such alterations and further modifications in the illustrated device, and such further applications of the principles of the invention as illustrated therein being contemplated as would normally occur to one skilled in the art to which the invention relates.  
         [0038]    Now referring to FIG. 1 of the present invention, it can be seen that a litter box  1  capable of automated operation is shown. Located in the receiving area  10  is the receiving module  11 , generally rectangular in shape with one open side. Receiving module access means are provided, for example an optional hinged lid  14  pivots around hinges  15  and  16  to allow installation of litter cartridge  12 . Receiving module  11  being constructed and arranged to facilitate the installation of litter cartridge  12 , rotatably mounted on axis  13 .  
         [0039]    Located in the central area  20  is the central module  21  suitably attached and in communication with the open side of receiving module  11 . The central module  21  is generally channel shaped having a flat bottom surface, two upwardly standing sidewalls and open ends. Within the central module  21  it can be seen that there is an optional floating central member  22  having two upwardly standing sidewalls and a bottom surface. The four upper corners of the upwardly standing sidewalls of floating central member  22  being bent inward for guiding membrane  26 .  
         [0040]    Also located in the central area  20  are means for facilitating traverse of membrane  26 . Such means are illustrated by, but not limited to, four tractor rollers  23  rotatably mounted on four roller shafts  24  (FIG. 3B). Two tractor rollers  23  and two roller shafts  24  being located on each sidewall of central module  21 .  
         [0041]    The disposal area  30  contains the disposal module  31 , which is characterized as a compartment that is generally rectangular in shape with one open side. The open side of the disposal module  31  is suitably attached and in communication with the second open end of the central module  21 . The disposal module  31  may further include access means, for example in the form of a hinged lid  32  pivoting around hinges  33  and  44  to allow removal of the disposal box  40  (FIG. 5). The disposal module  31  is constructed and arranged to support three pinch rollers  34 ,  35 , and  36  rotatably mounted on roller shafts  37 ,  38 , and  39  respectively (FIG. 5).  
         [0042]    Now referring to FIG. 2 it can be seen that the lower surface of the membrane  26  is located juxtaposed to the outer surface of the floating central member  22  so as to allow the membrane  26  to traverse the floating central member  22 . The litter  25  is located juxtaposed to and covered by the inwardly folded upper surface of the membrane  26 . The upstanding walls of the floating central member  22  being shaped so that as the membrane  26  traverses the floating central member  22 , the membrane  26  is unfolded to expose litter  25  before entering the central area  20 .  
         [0043]    While a particular preferred embodiment has been shown, it is also understood that an absorbent mat may replace either the litter  25  or the combination of the membrane  26  and the litter  25 .  
         [0044]    [0044]FIG. 3A shows one of four locations in the central area  20  (FIG. 1) representative of the typical cooperation between the central module  21 , tractor rollers  23  and floating central member  22  for traversing membrane  26 . It can be seen that a longitudinal channel  28  located on the upstanding wall of floating central member  22  allows the membrane  26  passing therethrough to be driven by the rotatably mounted tractor roller  23  which is shown having upstanding pins or triangular protrusions on its outer periphery designed to engage optional tracking means, for example tractor openings  27  which are assembled in a linear array (FIG. 6) located adjacent to the outer edges of the membrane  26 .  
         [0045]    [0045]FIG. 3B further shows one of the four locations in the central area  20  (FIG. 1) representing the engaging tangent relationship between the central module  21 , tractor rollers  23 , roller shafts  24  and floating central member  22  for traversing the membrane  26 .  
         [0046]    The distance between the engaging tangent relationship of the rollers  23  and the membrane  26  is such that the membrane  26  will not rip or tear as it is traversed. In effect, the distance the tractor rollers  23  should be in adjacent or proximate relationship to the membrane  26  is dependant upon the thickness and shear strength of the membrane material. This relationship can be determined by routine experimentation. The tractor rollers  23  may be made of any suitable material such as rubber, plastic, metal or a combination thereof. In this manner the tractor rollers  23  are able to traverse and regulate the respective speed of the membrane  26  passing therethrough.  
         [0047]    The process described above may be driven by hand or by a geared motor activated and controlled either manually or by sensors and a control unit using means well known to those of ordinary skill in the art. Household current is the preferred energy source for the motor, although other sources such as batteries, a spring driven motor, or the like may be used.  
         [0048]    [0048]FIG. 4 represents an end view of central area  20  (FIG. 1) showing the refolding of the membrane  26  as it enters the disposal area  30  (FIG. 1). An optional disposable rake  28  is suitably attached and positioned so as to distribute animal waste and litter  25  as membrane  26  traverses. Also shown are the upstanding sidewalls of floating central member  22 , the corners of the sidewalls bent inward to allow the membrane  26  to be refolded to cover litter  25  as it traverses into the disposal area  30 .  
         [0049]    [0049]FIG. 5 shows the cooperation of the pinch rollers  34 ,  35  and  36  with the membrane  26  within the disposal area  30 . Pinch roller  34  is rotatably mounted on shaft  37  in a manner that allows it to rotate with the respective speed of the membrane  26  passing therethrough. Pinch roller  35  is a driven pinch roller rotatably mounted on shaft  38  for traversing membrane  26 . The spring biased pinch roller  36  is connected to the pivot plate  41  and is rotatably mounted on shaft  39 . Pinch roller  36  may either be an idle pinch roller allowing it to rotate with the respective speed of membrane  26  passing therethrough or in the alternative may be a driven roller for traversing membrane  26 . The pinch roller  36  is allowed to move upwardly and downwardly against the membrane  26 . The pivoting movement of pinch roller  36  is around the pivot point  42  which is spring biased by spring  43 . Also shown is the path of membrane  26  as it traverses through disposal area  30 . Membrane  26  passes under pinch roller  34 , travels upward and over the driving pinch roller  35  as the contents are compacted by pinch roller  36  and it is received into the disposal box  40 .  
         [0050]    Rollers  35  and  36  are shown having upstanding pins or triangular protrusions on their outer periphery that engage the membrane  26  or the optional tracking means, for example tractor openings  27  which are assembled in a linear array, or any suitable combination thereof. The distance between the engaging tangent relationships of the rollers  35  and  36  to the membrane  26  is such that the membrane  26  will not rip or tear as it is traversed. In effect, the distance the rollers  35  and  36  should be in adjacent or proximate relationship to the membrane  26  is dependant upon the thickness and shear strength membrane material. This relationship can be determined by routine experimentation. The pinch rollers  34 ,  35  and  36  can be made of any suitable material such as rubber, wood, plastic, metal or any suitable combination thereof.  
         [0051]    The process described above may be driven by hand or by a geared motor activated and controlled either manually or by sensors and a control unit using means well known to those of ordinary skill in the art. Household current is the preferred energy source for the motor, although other sources such as batteries, a spring driven motor, or the like may be used.  
         [0052]    [0052]FIG. 7 shows an alternative embodiment of the present invention wherein the pinch rollers  35  and  36  are replaced by an axle  44 . The axle  44  is a driven member rotatably mounted to the disposal module  31 . The axle  44  is constructed and arranged to spirally wind the membrane  26 . The axle  44  can be made of any suitable material such as rubber, wood, plastic, metal or any suitable combination thereof. In this manner the axle  44  is able to traverse and regulate the respective speed of the membrane  26  passing through the central area and into the disposal area  30 .  
         [0053]    The process described above may be driven by hand or by a geared motor activated and controlled either manually or by sensors and a control unit using means well known to those of ordinary skill in the art. Household current is the preferred energy source for the motor, although other sources such as batteries, a spring driven motor, or the like may be used.  
         [0054]    All patents and publications mentioned in this specification are indicative of the levels of those skilled in the art to which the invention pertains. All patents and publications are herein incorporated by reference to the same extent as if each individual publication was specifically and individually indicated to be incorporated by reference.  
         [0055]    It is to be understood that while a certain form of the invention is illustrated, it is not to be limited to the specific form or arrangement herein described and shown. It will be apparent to those skilled in the art that various changes may be made without departing from the scope of the invention and the invention is not to be considered limited to what is shown and described in the specification.  
         [0056]    One skilled in the art will readily appreciate that the present invention is well adapted to carry out the objectives and obtain the ends and advantages mentioned, as well as those inherent therein. The embodiments, methods, procedures and techniques described herein are presently representative of the preferred embodiments, are intended to be exemplary and are not intended as limitations on the scope. Changes therein and other uses will occur to those skilled in the art which are encompassed within the spirit of the invention and are defined by the scope of the appended claims. Although the invention has been described in connection with specific preferred embodiments, it should be understood that the invention as claimed should not be unduly limited to such specific embodiments. Indeed, various modifications of the described modes for carrying out the invention which are obvious to those skilled in the art are intended to be within the scope of the following claims.