COLLAPSIBLE PUMP CHAMBER HAVING PREDETERMINED COLLAPSING PATTERN

摘要

A collapsible pump chamber, e.g., a bellows (40), for use with a liquid dispensing pump device is provided. The collapsible pump chamber includes a collapsing side wall which defines an internal volumetric portion of the pump chamber. The collapsing side wall has a structure which collapses in a predetermined pattern as the pump device is actuated. For example, the predetermined pattern of collapse could result in an initially relatively small volumetric change in internal volume per given stroke length followed by an increased volumetric change in internal volume per given stroke length. Thus, the pump device would initially provide very good control over the amount of product dispensed; giving precise control during a partial actuation. However, the same pump device would also be capable of delivering a large volume of product during a complete actuation.