US Patent 8152025 Valving for a refillable reusable mixer bottle

A self-contained mixing and dispensing container having at least two chambers, includes a valving combination of two oppositely installed one-way valves by which fluid may be transferred from one chamber to another by deforming one chamber. One of the valves permits the transfer of fluid and the other valve, communicates with the ambient atmosphere, to permit air into the deformed chamber to replace the removed fluid.