Demountable filter for a bottle or the like

摘要

A small filter cartridge is particularly adapted to be attached to the neck of a conventional plastic soft drink bottle to filter contaminated water contained in the bottle by passing the water through the filter as it is discharged from the bottle. The flexible bottle walls are squeezed to pressurize the water and facilitate flow through the filter element. The filter includes a uniquely positioned check valve which allows pressure equalization of the bottle interior in a simple and efficient manner. The filter is attached directly to the neck of the bottle and embodiments are disclosed in which the element is inserted completely within the bottle and mounted entirely outside the bottle.