Abstrict A cat litter box has a solid bottom, vertical sides and a top with
an opening to admit a cat. The height of the vertical sides is such
that a cat can reach the top with its forepaws by standing on its
hindlegs. The box is low enough that a cat would have easy access
to the box, yet is deep enough to prevent the escape of litter or
excreta from the box during use by a cat.
Claims What is claimed is:
1. An improved cat litter box comprising:
a solid bottom wall molded with continuous side walls extending
generally vertically upwardly from side edges of said bottom wall,
a peripheral lip projecting generally horizontally inwardly from
the top edge of said side walls to define an opening for providing
access to an interior of the box defined by said side walls and
said bottom wall,
said side walls defining a width, a length, and a height of the
box, said height of the box being more than one-half of the length
of the box and being more than three-quarters of the width of the
box, the height of the box being at least about 12 inches whereby
an adult domestic cat can enter the interior of the box substantially
only by jumping thereinto over said lip, and litter and excreta
are retained in the box.
2. A litter box as in claim 1 formed from upper and lower molded
portions, said lower portion comprising said bottom wall and a portion
of a vertical extent of said side walls, the upper portion comprising
the remainder of the vertical extent of said side walls and said
lip.
3. A litter box as in claim 2 wherein each of said upper and lower
portions define about half the height of the box.
4. A litter box as in claim 2 further comprising fastening means
for securing said upper and lower portions together, said fastening
means being selectively removable whereby the upper and lower portions
may be fully disengaged.
5. A litter box as in claim 4 wherein said fastening means comprise
a plurality of resilient plastic clips.
6. A litter box as in claim 2 wherein said upper and lower portions
are formed so as to have complimentary shapes whereby said upper
and lower portions may be nested together for shipping, with said
upper section within said lower section.
7. A litter box as in claim 1 wherein the height of the box is
at least about 14", wherein a width of said box is 16",
wherein a length of said box is 22", and wherein the width
of said lip is at least 1.5".
8. A litter box as in claim 1 wherein at least said side walls
are formed from a translucent material whereby a cat can observe
the interior of the box in advance of entry.
9. An improved cat litter box comprising:
a lower section molded as a unit having a solid bottom wall integral
with continuous side walls extending generally vertically upwardly
from side edges of said bottom wall, and
an upper section removably fixed to said lower section and including
side wall extensions and a peripheral lip projecting generally horizontally
inwardly at least 1.5" from the top edges of said side wall
extensions to define an opening for providing access to the interior
of said box defined by said side walls, said side wall extensions,
and said bottom wall,
said side walls and said wall extensions, defining a width, a length,
and a height of the box, said height of said box being more than
one-half of the length of said box and being more than three-quarters
of the width of said box, the height of said box being at least
about three times a usual and customary depth of kitty litter disposed
within the interior of said box whereby an adult domestic cat can
enter the interior of said box substantially only by jumping thereinto
over said lip, and litter and excreta are retained in said box.
10. A litter box as in claim 9 wherein each of said upper and
lower sections defines about half the height of the box.
11. A litter box as in claim 9 further comprising a plurality
of resilient plastic clips for securing said upper and lower sections
together, said plastic clips being selectively removable whereby
the upper and lower sections may be fully disengaged.
12. A litter box as in claim 9 wherein said upper and lower sections
are formed so as to have complimentary shapes whereby said upper
and lower sections may be nested together for shipping, with said
upper section within said lower section.
13. A litter box as in claim 9 wherein the height of the box is
at least about 14", wherein a width of said box is 16",
and wherein a length of said box is 22".
14. A litter box as in claim 9 wherein at least said side walls
are formed from a translucent material whereby a cat can observe
the interior of the box in advance of entry.
Description FIELD OF THE INVENTION
The present invention relates to an improved cat litter box. Many
patents have been issued for a wide range of containers for cat
litter. Almost without exception, these litter boxes have had structures
that facilitated entry by the cat, requiring the cat to exert a
minimum of effort to enter and use the box. As a result, these litter
boxes have not been able to retain the litter in the box when the
cat seeks to bury its excreta. As all cat owners know, it is an
instinctive reaction for cats to scratch the litter after relieving
themselves. Frequently the litter is thrown out of the box by vigorous
scratching. Moreover, male cats are particularly prone to spray
their urine out of conventional litter boxes.
What is required for a clean and efficient litter box is one that
cats cannot throw the litter from and from which no urine or faeces
escapes. Preferably such a litter box should also prevent litter
from being tracked out of the box on the cat's feet.
DISCUSSION OF THE PRIOR ART
As mentioned above, there are many patents extant for cat litter
boxes. Searches of the prior art have produced dozens of such patents.
In the United States Patent Office Classification System, Class
119 and its various subclasses seem to be entirely devoted to cat
litter boxes. These patent documents extend over a period of many
years with many attempts made to come up with the ideal litter box.
Such efforts range from Lowe, Jr. U.S. Pat. No. 3310031 of Mar.
21 1967 to McCauley U.S. Pat. No. 5329878 of Jul. 19 1994.
Lowe Jr. recognized that the box should be rectangular, and that
the walls at the ends of the box should project upwardly from the
side walls "to a substantial height thereabove", (column
2 lines 58 and 59).
Unfortunately, cats do not conform to the wishes of designers of
litter boxes. A box with low sides and high ends, and no shelf as
defined above, will not retain litter or urine. Litter will be sent
flying by vigorous scratching, and male cats will urinate over the
low sides.
Similarly, McCauley U.S. Pat. No. 5329878 provides a box for
a pot belly pig, a creature not known for its ability to jump. Thus
an inclined ramp is provided in one end of the box. Here again this
design would not meet the criteria for a cat litter box. Litter
and urine would not be retained in such a box if used by a cat.
Other United States Parents which have been studied in order to
assess the patentability of the present invention include the following:
______________________________________ U.S. Pat. No. Date Inventor
Title ______________________________________ 3085550 04/16/63
Crawford Cat Sanitary Container Enclosure 3771493 11/13/73 Chandor
Litter And Waste Receptacle For Small Pet Animals 3793989 02/26/74
Clark Deodorized Pet Relief Station 3831557 08/27/74 Elesh Cat
Litter Box 3990397 11/09/76 Lowe, Jr. Sanitary Pet Box Structure
4271544 06/09/81 Hammond Animal Commode 4279217 07/21/81 Behringer
Liner For A Litter Box 4541360 09/17/85 Higgins et al Disposable
Animal Litter Box 4548160 10/22/85 Feitelson Cat Litter Box 4553671
11/19/85 Cheesman Tear-open Compartmented Cat Litter Container 4627382
12/09/86 Muzzey Disposable Litter Box 4640225 02/03/87 Yananton
Odorless Animal Litter Unit 4646684 03/03/87 Embry Animal Waste
Container 4696257 09/29/87 Neary et al Self Drying Pet Litter
Box 4766845 08/30/88 Bavas Cat Litter Pan System 4771731 09/20/88
Derx et al Litter Box 4813376 03/21/89 Kaufman et al Cat Litter
Tray 4838202 06/13/89 Neu Animal Litter Container 4848274 07/18/89
Yananton Odorless Animal Litter Unit 4852518 08/01/89 Yananton
Odorless Animal Litter Unit 4858561 08/22/89 Springer Pet Litter
Enclosure 4.926794 05/22/90 Yamamoto Domestic Pets' Chamberpot
4972800 11/27/90 Bennett et al Pet Litter Box 5167204 12/01/92
Nussle Litter Box 5195464 03/23/93 Mutter Animal Litter Station
5211133 05/18/93 Foley Litter Saver Device 5218930 06/15/93
Casmira Litter Tray Apparatus 5220885 06/22/93 Goetz Litter Box
5272999 12/28/93 Nussle Litter Box ______________________________________
SUMMARY OF THE INVENTION
All of the above desirable characteristics are provided by the
litter box of the present invention. This improved litter box requires
cats to enter by using their natural jumping abilities, entering
through the top of the box, which has no side openings, and no doors
or flaps to admit cats, except by entry from above. The walls of
the litter box of the invention are sufficiently tall that a cat
standing inside on the litter is surrounded by an unbroken wall,
as high as the cat's shoulder when standing.
It will be appreciated by cat owners that cats are cautious creatures.
Accordingly, no cat will jump into a box if it cannot first see
into the box to determine the safety, and cleanliness of the interior
of the litter box. It has been determined that if the cat can stand
on its back legs with its forepaws on the top edge of the box, so
that it can inspect the interior of the box before entry, that the
cat will enter once it is satisfied that the box is acceptable to
it. The necessity of jumping over the wall of the box is no impediment
to cats. Even elderly cats of 20 plus years readily use the litter
box of the invention.
Thus the present invention is directed to an improved litter box
in which the exterior wall is approximately the height of the shoulder
of the average cat when standing on its back legs, and the interior
height above the normal bed of litter is greater than the height
of a cat's shoulder when standing on all four legs. A shelf or ledge
around the top of the walls is highly desirable for assisting the
cat to enter and exit the box. Typical dimensions of a box meeting
these criteria are: overall height of box 14.5 inches (36.8 cm),
width 16 inches (40.6 cm), length 22 inches (55.9 cm) and the shelf
around the top of the box 1.5 inches (3.8 cm), with an opening of
13 by 19 inches (33 cm by 48.3 cm) in the top of the box. The depth
of the litter bed would typically be 3 inches (7.6 cm).
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the improved cat litter box of
the present invention;
FIG. 2 is a top plan view of the litter box of FIG. 1;
FIG. 3 is a side elevation of the litter box of FIG. 1;
FIG. 4 is an end elevation of the litter box of FIG. 1;
FIG. 5 is a longitudinal section of the litter box of FIG. 1 on
the line 5--5 of FIG. 2;
FIG. 6 is a transverse cross-section on the line 6--6 of FIG. 2;
FIG. 7 is a partial section of the left hand side wall of FIG.
6;
FIG. 8 is an enlarged fragmentary view of the joint of FIG. 7;
FIG. 9 is a section through the joining clip holding the upper
and lower sections of the litter box together; and
FIG. 10 is a side elevation of a second embodiment of the present
invention in which the proportions of the upper and lower portions
of the litter box are different than in FIG. 3.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The litter box of the present invention represents a simple yet
elegant solution to the problems associated with conventional litter
box designs. As shown in FIG. 1 the litter box 10 includes a solid
bottom 11 (FIG. 2), upright sides 12 13 14 and 15 and a shelf
16 forming an opening 17 in the top of the box 10.
Preferably the box 10 is formed of upper and lower portions U and
L which can, for example, be molded from a suitable translucent
plastic polymer. The upper and lower portions are of identical size
and shape, except for the opening 17 in the upper portion, and the
solid bottom 11 of the lower portion. Thus it would be possible
to mold both portions from the same mold by inserting a plate in
the mold for forming the opening 17 when molding the upper portion
U. The two halves of the litter box 10 are joined by a series of
clips 18 which are formed of resilient material that damps the halves
of the litter box together.
From the top view of FIG. 2 the shelf or rim 16 can be clearly
seen. Also raised panels 19 20 and 21 are shown in this view, which
serve to strengthen the bottom of the box 11 in a technique well
known to those skilled in the plastic molding art. FIGS. 2 3 and
4 are three views of the basically rectangular box 11 the specific
shape being chosen for moldability and strength, while permitting
the completed box to be molded in two halves from a single mold.
Since the upper and lower sections are of identical, but inverted
shape they may be nested for shipment by inverting the upper half
into the lower half. Obviously several complete boxes can be nested
together for shipping, and assembled at the point of sale.
The cross-sections of FIGS. 5 and 6 show the assembled components
of the litter box 11 held together by clips 18. Litter 22 is shown
in the box to a depth, for example, of 3 inches (7.6 cm).
As will be evident to those skilled in the art of plastic molding,
the litter box of the invention may also be molded as a solid box
having a top opening, and formed, for example, by blow molding from
polyethylene. Such a manufacturing process could form the box without
the opening 17 in the box as molded and the opening 17 would then
be cut in the top of the box to complete the litter box.
A further advantage of the two part litter box is the possibility
of removing the upper half so that the box may be used for an injured
cat which could not enter the assembled box by jumping over the
tall wall of the assembly. Similarly, the top may be removed for
training a kitten to use the box. Kittens quickly learn to jump
and the top could be reattached once the kitten had grown to a size
to enter over the top of the assembled box. The owner of the box
will also find it convenient to remove the upper portion from the
lower portion when replacing the litter in the box. It is much easier
to pour litter from the box once the upper portion has been removed.
A suitable litter is placed in the box typically to a depth of
3 inches (7.6 cm), when the litter box is put into use, as shown
in FIGS. 5 and 6. Experience has shown that the best type of litter
to use in a cat litter box is the dumping type of material, which
has the property of the particles adhering to each other when moistened.
Such litter is easy to maintain in clean condition by regular removal
of clumped material, and can be obtained in either odorless or scented
forms.
FIG. 9 shows the clip 18 as extruded, for example, from a suitable
resilient plastic material. When applied to the upper and lower
halves of the litter box, they are held securely together to prevent
the escape of litter or urine from the joint between the halves.
Obviously these clips would not be required for a one piece box.
FIG. 10 illustrates an alternative embodiment of the two piece
litter box, which for aesthetic reasons has the lower portion L
formed as taller than the upper portion U. The overall height of
the box is the same as the first embodiment. The joint between the
two portions is above the median height of the assembled box, for
example, 8.25 inches (21 cm) above the base, and the upper portion
is therefore 6.25 inches (15.8 cm), so the total height is still
14.5 inches (36.8 cm).
It is important, however, that the overall height of the box be
such that a cat standing on its hind legs can just reach the shelf
16 with its forepaws, and see into the box before jumping inside.
If the box is lower than this, then when litter is added there is
a risk that the cat when standing inside may urinate over the shelf,
or may be able to scatter litter over the shelf while burying its
excreta in the litter. The design of this litter box is predicated
on the facts that cats are inherent jumpers and climbers, cats are
also naturally curious, and can't resist jumping into boxes, cats
often have a need for privacy when eliminating, and finally a tall
box provides a sense of security for the cat while in the box.
These considerations led to the design of a litter box with entry
and exit achieved through an opening in the top of a tall four-sided
box. All prior art litter boxes assume that the cat must enter the
box by stepping over the side, just as a human would enter a room
through a door. The litter box of the present invention has been
designed around the way in which cats think, rather than imposing
anthropomorphic limitations in the design. The top only entry of
a tall box is entirely unknown in the prior art. All previous cat
litter box designs in which the box was open at the top were of
shallow proportions. None of the prior inventors recognized the
benefits of a tall box which the cat jumps into, and from which
no excreta and litter escapes. Incredibly, no-one prior to the present
inventors has recognized the importance of the dimensions of a cat
litter box as well as the necessity for top entry. If any litter
should be stuck to the cat's paws after using the box, the act of
jumping from the box contributes to removal of litter from the paws,
leaving almost all of it in the litter box. |