VAPOUR DISPENSING DEVICE.

摘要

A vapour dispensing device in which a flowable substance (5) to be vaporised is dispensed from a reservoir (4) onto an emanator pad (9). The reservoir is provided with an outlet (6) and an air inlet (7). These are positioned in relationship to the emanator pad such that some of the substance leaving outlet 6 is conveyed by the emanator pad into the vicinity of the air inlet. When the pad adjacent to the air inlet is wetted, it becomes impermeable to air. As no further air can enter the reservoir (4), the vacuum in the head space prevents the dispensing of further substance from the outlet (6). This causes a drying of the emanator pad (9) which then becomes air permeable allowing further flow from the reservoir. This effectively provides a negative feedback arrangement which regulates the flow from the reservoir.