Abstrict A cat litter sifting device for use with clumping litter includes
a pair of nesting pans, the inner one of which has a plurality of
holes sized and spaced apart to pass unclumped litter but which
trap substantially all clumped litter and fecal matter. The inner
pan has uniform bottom and side walls and is closely fitted in the
outer pan so that there are substantially no gaps for trapping litter
between the pans.
Claims What is claimed:
1. A cat litter sifting device for use with clumping cat litter
comprising inner and outer rectangular open topped rigid pans, said
inner and outer pans each having a bottom and outwardly flared side
walls, a long and a short axis and outwardly flared flanges along
a top edge of the side walls with the flange on the inner pan overlying
the flange on the outer pan when the pans are nested, said inner
pan having handholds formed in the flange midway of its long axis,
said outer pan being imperforate, said inner pan having a plurality
of holes in its bottom and partly up its side walls that are sized
and spaced apart a distance to pass unclumped litter but which trap
substantially all solid and liquid waste clumps formed by a cat
using the device as a relief station, said holes being substantially
evenly spaced apart. a distance equal to the width: of the holes,
said bottom and side walls of said inner pan being of a substantially
uniform thickness of between about 1/8 and 1/4 inch that nest flush
with the bottom and side walls of the outer pan so that there are
substantially no gaps for trapping litter between the pans and so
that the amount of litter in the holes is minimal.
2. The device of claim 1 wherein the holes are generally circular
and have a diameter between about 1/4 and 3/16 inch.
Description BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a cat litter sifting device for
use with litter which clumps when wetted, allowing for physical
removal of the wetted litter along with fecal matter.
2. Brief Description of the Prior Art
Cats can be trained to urinate and defecate in a specially provided
litter box filled with absorbent material. The urine soaked litter
can be separated from the clean litter with the fecal matter if
the litter clumps when it is wetted into agglomerates that are sufficiently
large and stable to be removed like feces. Litters that agglomerate
when they are wetted are called clumping or scoopable litters.
If the litter is not of the clumping kind, in a few days, the urine
odor will become so strong that the entire contents of the litter
box must be discarded. On the other hand if the litter clumps so
that the urine balls can be removed with the solid waste, the remaining
litter need not be discarded. If this is done on a daily basis,
the litter box can be kept sweet smelling without wasting litter,
resulting in savings to the pet owner.
Some clumping litters form very well defined agglomerates that
do not break apart easily. Other scoopable litters, however, form
more fragile agglomerates that require very gentle handling to avoid
breaking the clumps into fragments, some of which may remain behind
leading to the buildup of unpleasant urine odors.
The most common tool for cleaning urine balls and feces from clumping
cat litter is a perforated scoop, which when used to dig around
a litter box raises a cloud of dust and may become fouled such that
it must be washed. The process of scooping the litter and washing
the scoop is moderately unpleasant and, while necessary for good
litter box hygiene, tends to be put off so that in practice it may
not be done on a daily basis.
SUMMARY OF THE INVENTION
In view of the above, it is an object of the present invention
to provide an easy and effective way to remove urine balls and solid
waste from scoopable cat litter in a manner that avoids breaking
up the clumps, portions of which may otherwise be left behind as
an undesirable contaminant. It is another object to provide a litter
sifting device that does not raise a cloud of dust and is not soiled
in ordinary use so that it does not require frequent washing. It
is also an object to provide a cat litter sifting device, whose
ease of operation promotes daily use. Other objects and features
of the invention will be in part apparent and in part pointed out
hereinafter.
In accordance with the invention, a cat litter sifting device for
use with clumping cat litter has an inner and an outer open topped
pan. The inner pan has a plurality of holes sized and spaced apart
a distance to pass unclumped litter but which trap substantially
all solid and liquid waste clumps formed by a cat using the device
as a relief station. The inner pan has a bottom and side walls of
uniform thickness and is closely nested in the outer pan so that
there are substantially no gaps for trapping litter between the
pans and so that the amount of litter in the holes is minimal when
the pans are nested.
The invention summarized above comprises the constructions hereinafter
described, the scope of the invention being indicated by the subjoined
claims.
BRIEF DESCRIPTION OF THE DRAWINGS
In the accompanying drawings, in which one of various possible
embodiments of the invention are illustrated, corresponding reference
characters refer to corresponding parts throughout the several views
of the drawings in which:
FIG. 1 is a side elevation partly in section of a cat litter sifting
device in accordance with the present invention, said device having
nesting inner and outer pans wherein the inner pan is perforated;
FIG. 2 is a side elevation partly in section of the device wherein
the inner pan is shown sifting the cat litter as it is lifted from
the outer pan;
FIG. 3 is a side elevation of the outer pan;
FIG. 4 is a top plan view of the outer pan;
FIG. 5 is a side elevation of the inner pan; and,
FIG. 6 is top plan view of the inner pan.
DETAILED DESCRIPTION OF THE INVENTION
Referring to the drawings more particularly by reference character,
reference numeral 10 refers to a cat litter sifting device in accordance
with the present invention. Device 10 is for use with a clumping
cat litter 12. Such litters need not be thrown out because of the
development of odor if solid and liquid waste clumps are removed
at frequent intervals, preferably daily.
Device 10 includes inner and outer open topped pans 14 16 respectively,
preferably, but not necessarily, made of plastic. As shown in FIG.
1 inner pan 14 nests flush in outer pan 16 to keep litter 12 from
draining into outer pan 16 until inner pan 14 is raised. This keeps
the litter from agglomerating between the pans and sticking to the
inside of outer pan 16. Pans 14 16 may be rectangular in shape,
about 16 inches wide by 20 inches long and about 8 inches deep,
with bottom walls 18 20 respectively, and outwardly flared side
walls 22 24 respectively. In this form, device 10 looks like an
ordinary litter box when assembled as shown in FIG. 1 so that a
cat will not hesitate to use it. Pans 14 16 may be sold as a unit
or separately and inner pan 14 may be provided as a liner for already
existing outer pans 16.
Bottom wall 18 and side walls 22 of inner pan 14 are substantially
uniform in thickness and are preferably no greater than about 1/4
inch thick, more preferably no greater than about 1/8 inch thick.
A plurality of holes 26 preferably generally circular, are provided
in bottom 18 of inner pan 14 and, in the embodiment shown in the
drawings, are also provided in side walls 22 for a short distance
up the walls (e.g., no more than about 2 inches above bottom wall
18) so that the litter will not spill out when the inner pan is
used as a sifter. Holes 26 are spaced apart the width of the holes
and are sized such that the litter will drain out when inner pan
14 is lifted as shown in FIG. 2 while retaining urine balls 28 and
fecal matter 30 on bottom 18 of inner pan 14. The holes 26 in side
walls 22 allow for quicker sifting of the litter.
With small grain clumping cat litter formed from clay, holes 26
should be about 3/16 inch in diameter, spaced about 3/16 inch apart,
whereas with pellet clumping cat litter formed from paper, organics,
etc., holes 26 should be about 1/4 inch in diameter, spaced about
1/4 inch apart. It will be understood that the foregoing dimensions
for holes 26 are stated for the purpose of satisfying disclosure
requirements and not intended to be limiting. Moreover, while the
full benefits of the present invention (regarding conservation of
litter and avoiding urine odor) are only enjoyed with clumping cat
litters, it will be appreciated that device 10 can be used with
other litters that can be easily sifted through holes 26 such as
sand, pea gravel and so forth.
For ease of use, an outwardly flared flange 32 is formed around
the top edge of side walls 22 of inner pan 14. Flange 32 includes
opposing enlarged portions for use as handholds 34 for best balance
midway the long axis of the rectangular pan. Handholds along the
short axis are not preferred. As shown in the drawings, outer pan
16 also includes an outwardly flared flange 36 said flange 36 having
a downwardly extending lip 38. Flange 32 of inner pan 14 overlies
flange 36 of outer pan 16 when the pans are nested as shown in FIG.
1. As further shown, handholds 34 include a downwardly extending
lip 40 which nests over lip 38. In the form illustrated, nothing
sticks up above nested flanges 32 36 so that a cat can perch on
the edge of the litter pan in the usual manner.
In use, inner pan 14 is nested in outer pan 16 with bottom 18 and
side walls 22 of inner pan 14 flush with bottom 20 and side walls
24 of outer pan 16. The fit between the pans must be sufficiently
snug so that substantially no litter is trapped between the pans.
Inner pan 14 is then filled with a clumping cat litter to a depth
in accordance with the manufacturer's specifications, typically
in the range of 2 to 4 inches and preferably to a level above holes
26 (if any) in side walls 22. Because of the close fit between inner
and outer pans 14 16 substantially no litter will be between the
pans and a very thin plug of litter will be in holes 26 because
of the minimal thickness of bottom and side walls 18 22.
After a cat has used device 10 as a relief station, the clumpable
litter can be cleaned by simply lifting inner pan 14 by its handholds
34 during which operation the litter will sift through holes 26
and fall into outer pan 16. After the litter has been sifted, all
solid and liquid waste clumps may be dumped into a proper receiver
as, for example, by placing inner pan 14 in a trash bag and inverting
the pan. Holes 26 do not tend to clog since the litter in the hole,
if wetted by urine, is not thick enough to form a hard plug and,
if clogged, may be easily opened by tapping on inner pan 14. The
sifted litter is then transferred from outer pan 16 to a third litter
pan or some other container with no litter sticking to bottom 20
and side walls 24 of outer pan 16 obviating the need to wash the
outer pan. Inner pan 14 is then reinstailed in outer pan 16 the
old litter poured back into device 10 from the container in which
it has been temporarily stored and fresh litter added to bring the
litter up to the appropriate level. The whole operation can be accomplished
without raising a cloud of dust, an important consideration for
those with dust sensitivity.
As will be appreciated, the ease with which device 10 can be used
promotes frequent sifting of the litter, thus extending the useful
life of the litter without the development of offensive odors and
conserving resources.
In view of the above, it will be seen that the several objects
of the invention are achieved and other advantageous results attained.
As various changes could be made in the above construction without
departing from the scope of the invention, it is intended that all
matter contained in the above description or shown in the accompanying
drawings shall be interpreted as illustrative and not in a limiting
sense. |