Closable plastics drinking beaker unit - includes valve unit set at regulated pressure, lid having aperture in which cylindrical stop fits, and consists of two collars

摘要

The beaker lid (2) has an aperture (1) in which a cylindrical stop (3) fits, and consists of two collars (4,5). The distance between the collars is a fraction smaller than the distance of the surface of the lid. Elasticity of the stop enable the stop to deform to release the pressure. The hole in the lid is conical inward in shape.