US Patent 10206370 Pet litter box cleaning system

A disposable liner assembly to be placed in a pan for the successive sifting of litter and removal of animal waste, each sheet is arranged above and below one another such that the sifting apertures in the sheet are above and below the solid portions of a sheet below and above it to form an apertures closure. Some embodiments are provided with positioning apertures in each sheet make it easy to properly offset the thin flexible sheets relative to one another. The present invention also includes a shielded liner retainer to be removably placed over the pan to cover and clamp the liners in a fix position.