| 摘要 |
The present invention provides a manually operated dispensing system for dispensing a liquid product in atomized or foam form. More particularly, the present invention provides an improved manually operated pump to for use in such dispensing systems which incorporates at least one collapsible bellows as a pump chamber. The use of a bellows as the air chamber in an air/liquid pump mechanism allows the pressure/volume profile of the air supply to be tailored to supply the desired air/liquid ratio throughout the travel of the pump mechanism. The shape of the air bellows is preferably selected to provide an is initially large volume reduction in the air chamber as the bellows collapses to provide a rapid rise in air pressure available for dispensing. In a preferred embodiment, dual bellows are utilized (one for liquid, one for air) in a concentric arrangement to allow the pressure/volume profile for each to be tailored to achieve the desired spray or foam characteristics. Inlet and outlet valves are unitarily formed with the liquid bellows and the use of a pre-compression mechanism for the liquid outlet valve allows the air pressure to build to the level required for satisfactory performance before the liquid begins to flow. |
