Patent ID: 7578419

Claim:
A disposable pump for integration with a collapsible reservoir, comprising: a) a hollow pump body having a first end connecting to the reservoir and a second end for dispensing liquid; b) a seal-base inside the pump body dividing the pump body into a plunger chamber and a nozzle chamber, having a seal-base opening; c) a nozzle opening into air at the second end of the pump body, comprising an output hole small enough that liquid remains in the nozzle chamber and acts as a barrier to gas inflow; d) a plunger located in the plunger chamber in the pump body made of magnetic material, having a seal-head extending through the opening in the seal-base, reciprocally movable within the pump body from a first position nearer the first end of the pump body to a second position nearer the second end of the pump body; and e) a compression spring between the seal-base and the plunger, biasing the plunger into the first position; such that when the plunger is biased by the compression spring to the first position, the seal-head seals the seal-base opening by sealing against a side of the seal-base in the nozzle chamber, blocking flow of liquid.