US Patent 8109237 Device for actuating automated litterbox

An improved automated litter box comprises a motorized comb or rake drive mechanism for removing clumps, a means for cycling the drive mechanism, and a cat proximity sensor for sensing the relative position of a cat about or within said litter chamber. The cat proximity sensor is capable of identifying the location of a cat outside the litter box or litter box or litter chamber. The cat proximity sensor comprises a passive or inductive transmitter for identification for modulating and demodulating a radio frequency (RF) signal; and an antenna for receiving and transmitting a radio frequency (RF) signal.