Nursing bottle utilizing air pressure to expel air from disposable liners and methods using same for feeding an infant

DETAILED DESCRIPTION Accordingly, it is an object of the present invention to provide nursing bottles, especially intended for human infants or animals, which utilize air pressure to collapse a liner and expel air from the liner, e.
g.
, expel air out of the liner via the nipple.
It is another object of the present invention to provide nursing bottles which utilize air pressure to prevent air from being drawn back into the liner while feeding of an infant.
It is another object of the present invention to provide nursing bottles which promotes upright feeding by keeping the nipple full of liquid during feeding.
It is another object of the present invention to provide nursing bottles which are easy to use and operate.
It is a further object of the present invention to provide nursing bottles which are economically and easily manufactured for widespread sale and use.
Certain of the foregoing and related objects are readily obtained in a nursing bottle comprising a body having an open end and an aperture, a flexible liner suspendable from the open end of the body so as to create a chamber between the liner and the body, a feeding nipple attachable to the open end of the body, and a check valve for regulating a flow of air through the aperture and into the chamber.
When fluid contained within the liner is removed during feeding, a vacuum is created in the chamber to readily draw air into the chamber through the valve so as to compensate for the volume of liquid removed from the liner, and when feeding stops the valve prevents air from exiting the chamber and air from being drawn through the nipple and into the liner.
Certain of the foregoing and related objects are also readily obtained in a nursing bottle for feeding an infant or an animal in which the bottle comprises a rigid body having an open end and an aperture, a flexible liner suspendable from the open end of the body so as to create a chamber between the liner and the body, a feeding nipple attachable to the open end of the body, and means for pumping air into the chamber, wherein the pump means is operable to pressurize the chamber and to expel air from the liner