Self-cleaning litter box
View Patent ↗A self-cleaning litter box ( 50 ) provides various advantages over the prior art. In particular, in one embodiment, the self-cleaning litter box ( 50 ) is configured to use a one piece litter cartridge ( 20 ) having a litter compartment ( 26 ) and a waste compartment 24 . In another embodiment, the cartridge ( 20 ) is non-compartmentalized. In another embodiment, the system includes a rake assembly ( 56 ) configured with a drive assembly ( 58 ) that is protected from waste contamination. In accordance with the invention, the self-cleaning litter box ( 50 ) is configured to be used with all types of litter including crystal type litter.
1. A self cleaning litter box for use with a non-attached, one piece litter and waste storage cartridge having a floor, the self cleaning litter box comprising:
a rake assembly including a rake for combing at a constant height above the floor through said litter cartridge during a cleaning stroke from a home position to a waste position within the one piece litter cartridge during a cleaning stroke and returning from said waste position to said home position during a return stroke;
a chassis assembly for carrying said rake assembly, said chassis also configured to enable said rake to communicate with an interior portion of said non-attached litter cartridge when said chassis assembly is placed over said litter cartridge without any attachment thereto.
2. An automatic litter box machine used with a removable, single chamber cartridge having a floor and a litter, the litter box machine comprising:
a moveable rake for sifting through the litter at a constant height above the cartridge floor; and
a plurality of tines connected to the moveable rake, said rake tines having distal ends,
wherein the distal ends move through the litter in substantially one plane during a cleaning stroke from a home position to a waste position within the single chamber cartridge.
3. The litter box of claim 2 , wherein said distal ends of rake tines move in substantially one plane at all times.
4. An automatic litter box machine in combination with a single removable chamber litter tray, the litter box comprising:
a housing configured to lift vertically off the litter tray for replacement of the tray;
a moveable rake assembly connected within the housing with a linearly moving element having a forward travel direction and a rearward travel direction with respect to the housing and the tray;
a rotatably mounted machine lid with a closed position and an open position mounted to the housing, said lid configured to rotate from a closed position to an open position within a portion of the single chamber tray to cover stored waste at one end of the tray;
a separate lift arm mounted within the housing and configured to rotate, said lift arm having a pin to engage the machine lid;
wherein said linearly moving element engages the lift arm during the forward travel direction to rotate the lift arm in an upward direction, thereby causing the machine lid to rotate from the closed position to the open position in an upward direction; and
wherein the linearly moving element engages the lift arm during the rearward travel direction to rotate the lift arm in a downward direction thereby allowing the machine lid to rotate from the open position to the closed position.
5. A litter box having a removable single chamber litter tray with a floor, a moveable rake assembly, said rake assembly including a rake configured to sift through a litter in the tray to move an animal waste to a waste storage position within the tray, wherein said rake is comprised of a plurality of tines, and wherein said rake tines are angled backward by a substantial angle with respect to an axis perpendicular to the rake travel direction and a distal end of the tines maintain a constant height above the floor of the tray.
6. The litter box of claim 5 , wherein the rake tine angle is changeable, such that the tines are angled backward with respect to the rake travel direction for any direction of rake travel.
7. The litter box of claim 5 , wherein the rake has a pivot axis that allows the rake to rotate between a positive angle and a negative angle with respect to an axis perpendicular to the rake travel direction.
8. The litter box of claim 7 , wherein said pivot axis is located near the ends of said rake tines such that the tine ends do not substantially change height position within the litter during rake rotation.
9. The litter box of claim 5 , wherein the rake assembly is compatible with the removable litter tray.
10. The litter box of claim 5 , wherein said rake tines are u-shaped.
11. The litter box of claim 5 , wherein the tines are made from steel wire.
12. The litter box of claim 5 , wherein the spacing between tines is selected as a function of the maximum particle size of the litter and as a function of the rake back angle in order to effectively sift waste from the litter without causing excessive litter plowing.
13. The litter box of claim 7 , wherein said pivot axis is located below the litter level such that the rake will passively flip from one angle to the opposite angle upon reversal of the rake travel direction due to the resistive force of sifting through the litter.
14. The litter box of claim 7 , wherein the rake is made to flip from one angle to the opposite angle from an axis perpendicular to the rake travel direction at a pre-determined location along the travel path by introduction of a resistance located above the pivot axis.
15. A litter box with a single chamber removable litter tray with a floor and a moveable rake assembly, wherein said rake is configured to sift through a litter to move waste to a waste location within the tray, wherein said rake is comprised of a plurality of wire tines, and wherein said rake tines are formed with two legs, wherein the second leg is bent at an angle with respect to the first leg and wherein the distal ends of the rake tines engaging the litter remain at a constant height above the tray floor in all directions of travel.
16. The litter box of claim 15 , wherein the second leg is angled backward by a substantial angle with respect to the rake travel direction.
17. The litter box of claim 15 , wherein each pair of tines is formed from a single piece of wire bent into a u-shape.
18. A litter box having a removable single chamber litter tray with a floor, a moveable rake assembly, said rake assembly including a rake configured to sift through a litter in the box to move an animal waste, wherein said rake is comprised of a plurality of tines, and wherein said rake tines are angled backward by a substantial angle with respect to the rake travel direction, wherein the rake tine angle is changeable, such that the tines are angled backward with respect to the rake travel direction for any direction of rake travel, wherein the rake has a pivot axis that allows the rake to rotate between a positive angle and a negative angle with respect to an axis perpendicular to the rake travel direction, wherein said pivot axis is located near distal ends of said rake tines such that the tine ends do not substantially change height position within the litter during rake rotation.
19. A litter box having a removable single chamber litter tray with a floor, a moveable rake assembly, said rake assembly including a rake configured to sift through a litter in the box to remove an animal waste, wherein said rake is comprised of a plurality of tines, and wherein said rake tines are angled backward by a substantial angle with respect to the rake travel direction, wherein the rake has a pivot axis that allows the rake to rotate between a positive angle and a negative angle with respect to an axis perpendicular to the rake travel direction, wherein said pivot axis is located below the litter level such that the rake will passively flip from one angle to the opposite angle upon reversal of the rake travel direction due to the resistive force of sifting through the litter.