US Patent 7798101 Apparatus and method to remove animal waste from litter

An apparatus and method for separating animal waste from litter are provided. In one form, the apparatus includes a drum that contains litter and a helical rake that is rotatable in the drum. The rake can rotate relative to the drum to reduce power requirements for the rotary rake drive. Preferably, the drum is also rotatable by turning of the rake in the drum, but only for a limited, fixed angular distance which also reduces peak power requirements for the rotary drive motor for the rake.