Patent ID: 7762423

Claim:
A flow control element for use with a drinking cup cap, the cap having a spout aperture and a depending first mating member in fluid communication with the spout aperture, said flow control element comprising: a first stack having an upper portion and a lower portion, said upper portion being configured to be removably sealed adjacent to the spout aperture, wherein said upper portion and said lower portion each have an outer dimension, said outer dimension of said upper portion is smaller than said outer dimension of said lower portion, said lower portion can be frictionally received and sealed in a lower portion of the first mating member, said upper portion extends upwardly in the first mating member toward the spout aperture without being in contact with the cap when said lower portion is sealed in the first mating member, and said upper portion having a sidewall, said sidewall having a first valve, said first valve having a first valve face that is arcuate when viewed in vertical section taken along the axis of flow of said first stack and that defines an arcuate valve slit, said arcuate valve slit having a substantially vertical orientation, the elongated extent of said arcuate valve slit following along the curvature of the arc of the first valve face and along the axis of flow of liquid through said first stack, said first valve being to provide selective fluid communication through the arcuate valve slit with the spout aperture and prevent such fluid communication without said first valve coming into contact with the cap.