US Patent 11172777 Mobile expandable hard sided package security drop box

A package drop box includes a base, a cap, and a retention bracket. The base has an open top. The cap has an open bottom. In a first position, the cap is fitted over the base such that a bottom edge of the cap is proximate a bottom edge of the base. In the second position, the bottom edge of the cap is proximate a top edge of the base. The retention bracket is configured to secure to the base. The retention bracket is configured to extend up a back of the base from the surface supporting the package drop box, extend along the surface away from the back of the base, and extend vertically upward from the surface supporting the package drop box at a predetermined distance from the back of the base.