Baby bottle assembly

A baby bottle assembly comprising

• a bottle defining a liquid chamber for holding a quantity of liquid having an open bottom portion, an open top portion, and a sidewall extending between the open bottom and the open top portions;
• wherein the sidewall has a top portion, a base portion, and middle portion extending between the top and base portions;
• a top closure member adapted for releasable engagement with the top portion of the bottle for closing the open top of the bottle;
• a bottom closure member adapted for releasable engagement with the base portion of the bottle for closing the open bottom of the bottle;
• wherein
• the bottom closure member has a raised portion, a top center annular sealing surface encircling the raised portion, a top sealing surface and at least one center air passage through the raised portion;
• a diaphragm positionable between the bottom closure member and the base portion of the bottle;
• wherein the diaphragm has a sealed position when there is positive pressure in the liquid chamber and an unsealed position when there is a negative pressure in the liquid chamber;
• wherein the diaphragm has a disc portion that is liquid impenetrable;
• wherein positioned on the disc portion and above the raised portion is a moveable sealing surface;
• wherein the moveable sealing element is flat with a circular perimeter;
• wherein the moveable sealing element has attachment points to the disc portion on opposite sides of the circular perimeter;
• wherein portion of the circular perimeter without attachment points is unattached and moveable;
• wherein the on the bottom of the disc portion is a diaphragm annular sealing surface that sealingly engages with the center annular sealing surface;
• wherein, in the sealed position, the at least one moveable sealing element seals the top sealing surface, thereby sealing the central air passage;
• wherein in the sealed position, the diaphragm air passageway and the central air passageway are sealed from the liquid chamber by the moveable sealing element;
• wherein in the sealed position, no liquid from the liquid chamber leaks from the bottom closure;
• and
• wherein in the unsealed position, the diaphragm air passageway proximate the moveable sealing element opens, and allows air to enter the liquid chamber.