Pump dispenser having a locking system with detents

摘要

Lotion pump has a stepped piston telescoping inside a stepped body to define a pumping chamber. The piston has in its wall inlet and discharge apertures, one above the other, to the pumping chamber. A stem integral with the actuator has a sealing head inside the piston which shuttles up and down 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. The actuator can be turned to lock the head over the discharge aperture by nullifying the lost-motion. Further turning can lock the stem in lockdown position. One-directional turnback can liberate the head and unlock the lockdown. Detents control sequence of unlocking.