PUMP DISPENSER

摘要

Lotion pump has a stepped piston telescoping inside a stepped body to define a pumping chamber. The piston has in the wall of the piston inlet and discharge apertures, one above the other, to the pumping chamber. A stem integral with the actuator spout has a sealing head inside the piston which shuttles back and forth between positions at which it covers one aperture or the other. Shuttling is implemented by lost-motion between the actuator spout/stem and piston. A spring urges the stem up at all times.