Abstrict A framework residing in a cat litter box with sprockets, chains,
and chain guides allowing a blade and basket mechanism to move horizontally
through a cat litter box removing the cat excrement. The blade and
basket are then elevated to a point at which they dump the cat excrement
into an inclined chute. The cat excrement travels down the chute
and into a disposable receptacle such as a plastic bag.
Claims I claim:
1. A Self cleaning cat litter box comprising:
a) a structural framework attached to or residing in a cat litter
box, said framework having chain guides attached to said framework
b) an axle with sprockets, attached to said framework in a manner
to allow rotation
c) a means for applying rotational force to said axle
d) chains circulating through said chain guides and said sprockets
e) a blade attached between the chains and a straining basket pivotally
attached to said blade
g) a means of conveying contents of the straining basket to a disposal
receptacle.
2. Apparatus as in claim 1 wherein said blade has multiple perforations.
3. Apparatus as in claim 1 wherein said straining basket is composed
of wire mesh.
4. Apparatus as in claim 1 wherein said straining basket is composed
of tines.
5. Apparatus as in claim 1 wherein said blade has basket pivot
resistance or restricting means attached.
Description BACKGROUND
Field of Invention
This invention relates to the cleaning of solid waste and cat urine
saturated litter clump from a cat box.
The current general practice is to manually clean the cat litter
box. Two predominant methods exist depending on the type of cat
litter used. Cat owners that use cat litter material that does not
clump urine will periodically remove solid waste from the litter
material and eventually discard the litter material after an extended
period. Cat owners using the never urine clumping cat litter will
manually remove the clumped urine and solid waste from the litter
box.
Many cat owners find the task of manually searching the kitty litter
for cat excrement obnoxious. There are health risks from exposure
to cat excrement as some cat diseases are communicable to humans.
Patents showing mechanical devices for cleaning cat litter boxes
include U.S. Pat. Nos. 5048465; 5048464; 4934317; 4854267;
4846104; 4574735; 4190525; 4120264; and 3937182. No mechanical
device for cleaning cat litter boxes has gained widespread acceptance.
Most of the patented devices rely on non conventional cat litter
box construction which use cylindrical, circular, or partially circular
containers (U.S. Pat. Nos. 5048464; 4934317; 4846104; 4574735;
4190525 and 4120264). Such devices greatly restrict the operating
area the cat has to maneuver in or must be very large to provide
a comparable operating area. Devices that are similar to standard
cat litter box constructions employ mechanisms such as filter belts
that deposit waste into a receptacle at one side of the box (U.S.
Pat. No. 3937182) or a rake that deposits the waste in a receptacle
at one side of the box (U.S. Pat. No. 5048465). Devices such as
that disclosed in U.S. Pat. No. 4854267 lift and tip the entire
container while at the same time raising a screen through the material
to remove wastes and store them in a separate receptacle. None of
the devices have an effective means of removing urine clumps that
have adhered to the floor of the cat litter box. The newer super
or ultra clumping litter material not only binds with itself when
wet but also forms a strong bond to a surface it comes into contact
with when binding. In the rotating drum devices the urine clump
may remain adhered to the wall. In other devices a layer of the
urine clump will remain attached to the surface it has adhered to
and/or may be fragmented by the cleaning device.
OBJECTS AND ADVANTAGES OF THE INVENTION
It is an object of the invention to provide a self cleaning cat
litter box with form factor and litter surface area similar to current
cat litter boxes.
It is an object of the invention to effectively remove urine clumps
that have adhered to the floor of the cat litter box.
It is an object of the invention to minimize the spread of airborne
particulates during the cleaning process.
It is an object of the invention to place the cat excrement in
a disposable container (e.g. plastic bag) so that when the waste
is eventually removed there is little to no human exposure.
It is an object of the invention to provide for the ability to
have the cat excrement deposited directly into a user provided receptacle
(e.g. toilet).
It is an object of the invention to make it extremely simple in
design so as to make it inexpensive to manufacture and greatly reduce
the potential for mechanical failures.
An advantage of the self cleaning cat litter box is its ability
to remove clumped urine attached to the floor of the cat litter
box. The blade, blade attachment method, and chain slack act in
a manner that pitches the blade downward and under the clump severing
its surface attachment without disbursing the clump. It is then
collected by the wire mesh basket. Prior art devices do not have
tapered, partially pivoting contact devices and consequently will
either leave a layer of the clump attached to the container wall
or disburse the clump leaving small fragments of the clump in the
litter box.
An advantage of the self cleaning cat litter box is that human
exposure to airborne contaminants is reduced. The domed enclosure
not only protects the user from possible injury during mechanical
operation but contains airborne particulates during the cleaning
process. The excrement is deposited in a plastic bag minimizing
further spread of contaminants. When the bag is eventually removed
for disposal the neck may be clamped before removal to prevent airborne
contamination.
An advantage of the device is its simplicity of design and low
parts content which allow for inexpensive manufacture and high reliability.
DESCRIPTION OF DRAWINGS
FIG. 1 shows an isometric view of the self cleaning cat box.
FIG. 2A shows an exploded view of the blade, basket, and spool
guides; 2B shows a basket pivot resistance member; 2C shows an alternate
basket.
FIG. 3A to 3C are side views of the self cleaning cat box operation.
FIG. 4A shows a protective cover; 4B shows a lateral access restricting
guard.
FIG. 5A shows a hand crank power source; 5B shows a hand crank
and gear or sprocket power source.
SUMMARY OF THE INVENTION
Briefly, the preferred embodiment of the present invention includes
a blade and basket mechanism that is pulled by chains through a
cat litter box removing the cat excrement. The blade and basket
are then elevated to a point at which they dump the cat excrement
into an inclined chute. The cat excrement travels down the chute
and into a disposable receptacle such as a plastic bag.
DETAILED STATIC DESCRIPTION OF INVENTION
In accordance with the preferred embodiment of the present invention
FIG. 1 shows a self cleaning cat litter box. A structural frame
24 is attached to a cat litter box 19. The preferred embodiment
of frame 24 is comprised of vertical members 21 and horizontal
members 22 and 23; however, any other combination of flat, angle,
or channel members may be substituted to form rectangular, trapezoidal,
triangular or any suitable geometry for the structural frame. Chain
guides 15 are attached to frame 24. An axle 17 with sprockets 16
runs through holes in frame 24 or may be attached to frame 24 by
any other suitable means. Chains 14 wrap around the chain guides
15 and sprockets 16; however, a perforated belt or any other suitable
means may be substituted for chain 14. A blade 11 is attached between
chains 14 and a basket 12 is pivotally attached to blade 11. A chute
18 is oriented parallel to axle 17 and is inclined vertically with
one end of chute 18 being higher than the opposite end of chute
18. A power source 20 is attached to one end of axle 17. Power source
20 may be a motor, motor with gear reduction, a hand crank, an adjacent
hand crank with gear, sprocket, or chain and sprocket(s) reduction
means connecting it to axle 17 or any other suitable means of imparting
rotational force to axle 17.
FIG. 2A shows an exploded view of blade 11 basket 12 chain guides
15 and chain 14. Blade 11 is a horizontal member tapered towards
the front (leading edge) and having its extremes bent upwards or
with vertical members attached at its extremes. The preferred embodiment
of blade 11 has the vertical part of blade 11 tapered at the leading
edge to facilitate entry into the spool guides; however, a non tapered
version may be substituted. The horizontal part of blade 11 may
include perforations to reduce resistance and shifting of the cat
litter material during operation. The vertical parts of blade 11
have holes that allow the blade to be attached to chains 14 by screws,
rivets or any other suitable means. One embodiment of basket 12
is essentially a five sided rectangle 30 31 32 33 34 with the
front (leading side) missing; however, any suitable geometric shape
may be substituted. Basket 12 can be made from wire mesh or any
suitable material. The wire mesh may include a larger spacing mesh
for structural support with a finer spacing mesh attached for better
sifting ability. FIG. 2A shows the sides of basket 12 as separate
for clarity; however, basket 12 may actually be constructed from
either one or more than one continuous piece(s) that is bent to
form the desired geometry. Where needed the pieces of basket 12
may be connected to each other by ferrules or any other suitable
means. The leading edge of the basket or any part thereof may be
surrounded by an optional protective sheath of a suitable material
to offer protection from burns. The leading edge of side 31 may
be bent inwards (toward side 30) or extend further out and bent
inwards to enhance its ability to contain more cat excrement on
basket's 12 upward motion and/or to adjust the desired excrement
placement during the dump into chute 18. The preferred embodiment
shows basket 12 pivotally attached to blade 11 by rings traversing
the floor piece of basket 12 and traversing holes in blade 11; however,
hinges or any other suitable means of attachment may be substituted.
Chain guides 15 may be comprised of a stack of washers bounded on
both sides by fender washers to resemble a spool; however, any suitable
substitute may be used to achieve the appearance of a spool or part
of a spool and the functionality to guide the chain and blade along
a desired path. The fender washers or spool walls of chain guides
15 may be bowed outward from the spool to facilitate entry of the
blade into chain guide 15. Chain guides 15 that are not beneath
the cat litter may also be substituted with freely rotating sprockets.
FIG. 2B shows an optional resilient member(s) 35 that may be attached
to the horizontal part of blade 11 extending into basket 12 to limit
the forward pivot range of basket 12. Member(s) 35 may also be made
of a rigid or semi-rigid angled or perpendicular member(s) attached
to blade 11.
FIG. 2C shows an alternate basket 12. The shape is more oval and
the vast majority of members are oriented parallel to each other.
FIG. 3A shows a side view of the self cleaning cat litter box as
blade 11 and basket 12 have just entered the cat box 19 which has
cat excrement 41 in it. FIG. 3B shows blade 11 and basket 12 after
they have moved through the cat box and the cat excrement 41 is
now in basket 12. FIG. 3C shows the position of basket 12 as it
is pivoted by its contact with axle 17. Basket's 12 open side is
now the floor and cat excrement 41 falls by gravity out of basket
12 down chute 18 and into bag 42. Although the preferred embodiment
uses axle 17 as the means of tipping basket 12 an alternative may
be to place a protruding piece anywhere along the upper horizontal
path of basket 12 and adjust the placement of chute 18 accordingly.
FIG. 4A shows a protective cover that fits over frame 24 and rests
on the upper rim of box 19. An opening 46 is provided so the cat
may enter and a closure 47 may be pivotally attached at the bottom
of opening 46 as shown or, to the top of opening 46. The side opposite
the pivotal attachment of closure 47 may include a latch mechanism
and receptacle for the latch attached to cover 45 or frame 24 so
that the closure may be shut preventing access during operation
of the self cleaning cat litter box. Closure 47 may include a device
to prevent the self cleaning cat box from operating unless closure
47 is latched shut.
FIG. 4B shows a lateral guard 49 which is a substantially flat
piece oriented vertically along the vertical frame members 21. Guards
49 restrict the area the cat can use to that which can effectively
be cleaned by blade 11 and basket 12.
FIG. 5A shows an hand crank 51 attached directly to axle 17 as
an alternative to the motor and gear power source 20.
FIG. 5B shows a hand crank 51 and gears or sprockets 52 and 53
as an alternative power source. A circular piece of chain attached
to handle 51 may be substituted for sprocket 52 when a sprocket
is used for 53. When 52 and 53 are sprockets they may be connected
by a chain rather than by direct contact. Note blade 11 and basket
12 have been oriented in the opposite direction so that the familiar
clockwise rotational force may be applied to handle 51 in order
to operate the self cleaning cat litter box.
DETAILED OPERATIONAL DESCRIPTION OF INVENTION
FIGS. 3A, 3B, and 3C have been prepared to facilitate the operational
description of the invention. In the three figures the invention
is designed to accept a rotational force on axle 17 in a clockwise
direction; however, it could also be designed to accept a counterclockwise
rotation by simply attaching blade 11 and basket 12 in the opposite
direction.
A rotational force applied to axle 17 is transferred as a rotational
force to sprockets 16 which in turn moves chains 14 through spool
guides 15. In FIG. 3A the clockwise rotational force would result
in blade 11 and basket 12 moving from right to left across the cat
litter box. A certain amount of slack in chains 14 and the geometry
of blade 11 causes it to pitch slightly downward. This enables blade
11 to scrape the bottom of the cat litter box with its tapered end.
When blade 11 encounters clumped urine that has adhered to the floor
of the cat litter box it severs the attached urine clump from the
floor of the cat box and the clump is subsequently collected by
basket 12. Cat excrement distributed throughout the cat litter material
is collected by the basket as it moves through the cat litter box.
FIG. 3B shows basket 12 containing the cat excrement at the opposite
end of the cat litter box. Basket 12 then starts its upward journey.
When basket 12 encounters axle 17 it is pushed backwards and its
contents fall into inclined chute 18. The cat excrement then slides
down the chute and into a receptacle such as a plastic garbage bag
37. At some point after the dump the unit may either be manually
shut off or automatically shut off by either a mechanical, electronic,
photo electric or other suitable means. In the hand crank versions
shown in FIG. 5A and 5B the rotational force is provided manually
by the user.
CONCLUSION, RAMIFICATIONS AND SCOPE OF INVENTION
The described invention provides a simple device for cleaning animal
excrement from litter boxes while reducing both human exposure and
human work required.
While my invention contains many specificities and subordinate
devices and assemblies, these should not be construed as limitations
on the scope of invention or scope of use for the subordinate devices
or assemblies, but rather as an exemplification of one preferred
embodiment for one particular application. Many other variations
and applications are possible. Some examples of possible variations
are: The number of chain guides may be reduced if the axle with
sprockets is moved to one end of the apparatus and substituted in
place of one of the upper sets of chain guides. The chains may be
substituted with perforated belts and the blade and blade attachment
means modified so as to attach to the belts. Many variations of
the chute are possible including concave members and large diameter
plastic piping with various portion(s) cut away.
My description of the self cleaning cat litter box contains the
essential operating parts but this should not be construed to limit
ancillary or optional items that may be added to the invention.
For example multiple or different scraping and cleaning devices
may be attached between the chains at various intervals. Cat litter
material leveling or redistributing devices may also be attached
either between the chains or as a foot or hand actuated device to
lift one end of the invention. Additional openings and/or receptacles
may be provided to facilitate the storage and/or infusion of new
litter material into the apparatus. |