| 摘要 |
In an aerosol dispenser, a valve assembly comprises a generally conventional arrangement of a valve body (1) in a cup (4), a valve stem (9) in the valve body (1), and an actuator body (20) for depressing the valve stem (9) against a spring (10) to release atomised liquid through an outlet passage (21) and an atomising orifice (26). In addition to such conventional parts, a variable volume expansion chamber (30) is provided in the actuator body (20), and this communicates with the outlet passage (21). Upon shut-off, at the end of a dispensing operation, the volume of the expansion chamber (30) expands, to allow the expansion of foam (liquid/gas mixture) trapped at least in the outlet passage (21). Since the foam is allowed to expand in this controlled manner, spitting of liquid droplets at shut-off is prevented or inhibited. |
