Patent ID: 8127789

Claim:
An apparatus for retaining fluid in a liquid delivery tube comprising; a lower portion having a ball valve that permits only unidirectional flow of fluids and includes a valve chamber for housing a ball and having an inlet end and an outlet end being spaced apart sufficiently so that said ball is longitudinally, reciprocally movable within said chamber from a closed position at the inlet end of said chamber to an open position at the outlet end of said chamber; and an upper tubular portion that has an outside diameter that is tapered to its terminus to facilitate insertion into a liquid delivery tube, said tubular portion having an elongated, tapered passageway that communicates with said outlet end of the valve chamber to convey fluid from said chamber to said tube; and said valve chamber inlet end includes a valve seat having sidewalls that taper inwardly from said valve chamber such that the diameter of said valve seat is reduced toward the valve chamber inlet end to prevent said ball from becoming stuck therein, and wherein the spacing between said inlet end and said outlet end of said valve chamber is of a sufficient length so that as said ball moves from said open position to said closed position, a portion of the liquid in said delivery tube is permitted to pass back through said apparatus to reduce the amount of liquid in said tube, and wherein said liquid delivery tube is in the form of a straw having an upper end for delivering fluid to the mouth of a user and a bottom end to which said apparatus is attached.