Patent ID: 6286457
Filing Date: 2001-09-11
Classification: A01K

Abstract:
A self-cleaning litter box comprising:a rotatable drum adapted to contain litter; said drum being cylindrical and having front and back walls, an axis of rotation, and support means, and having a front opening in said front wall which serves as an access and egress suitable for a domestic pet to pass through, and a first opening in said back wall for both the removal of soiled litter and the addition of clean litter; wherein said axis of rotation of said drum is located along the centerline passing longitudinally through said drum;said drum being rotatably mounted on said support means comprising at least two bearings which facilitate the rotation of said drum;a spiral filter, having first and second ends, mounted on the inner surface of said drum; said filter being slotted, and adapted such that clean litter passes through said filter while clumped soiled litter and fecal matter is retained by said filter;a stationary back plate located parallel to the plane of said back wall of said drum, and being flush with said back wall of said drum, said back plate having a second opening therethrough to permit the passage of clumped soiled litter and fecal matter away from said drum;said back plate also having a third opening to permit the passage of clean litter into said drum, where said second and third openings are located at least 180.degree. apart;drive means for rotatably driving said drum; andswitch means for electively driving said drum by said drive means;wherein said spiral filter spans the length of said drum and at least 180.degree. of said inner surface of said drum; and wherein said filter has a spiral angle of at least 30.degree.;wherein said filter is configured such that it functions as a scoop, and so that as said drum is rotated through one fill revolution, said first end of said filter will contact the litter, and the length of said filter will pass through the litter effectively scooping clumped soiled litter and fecal matter therefrom, which is then retained by said filter;wherein, when said drum is at its rest position, said first end of said filter is located at least 10.degree. from the bottommost point on said drum and said second and third openings of said back plate are covered by said back wall of said drum;wherein at least a portion of said second opening in said back plate is located on one side of said drum in substantially the same plane as said axis of rotation of said drum;wherein, when said second opening in said back plate is in alignment with said first opening in said back wall of said drum, it allows passage of clumped soiled litter and fecal matter from said filter into disposable collection means through said aligned first opening and said second opening;wherein said third opening in said back plate is positioned at the base of a reservoir where excess clean litter may be stored; whereby clean litter from said reservoir may be dispensed into said drum when said third opening in said back plate is in alignment with said first opening in said back wall of said drum;wherein, when said drum is rotated about said axis of rotation, said filter effectively scoops clumped soiled litter and fecal matter from the bottommost region of the rotating drum, and collects the waste material on said filter, and when said third opening in said back plate and said first opening in said back wall of said drum come into alignment, clean litter is dispensed into said drum from said reservoir through said third opening of said back plate.