Patent ID: 6062212
Filing Date: 2000-05-16
Classification: A61M,B01F,B05B

Abstract:
Dispensing apparatus comprising a housing defining a dispensing outlet, a perforate membrane having a front face exposed at the outlet and a rear face contacted in use by liquid to be dispensed, vibrating means connected to the housing and operable to vibrate the membrane to dispense droplets of the liquid through the membrane, liquid supply means connected to the housing and having an outlet valve, and delivery means operable at successive actuations of the delivery means to deliver a respective metered quantity of the liquid from the liquid supply means via the outlet valve into contact with the rear face of the membrane and means for operating the vibrating means for an operating period greater than a dispensing period required for the metered quantity to be dispensed though the membrane whereby in use all of the dispensed liquid is consumed prior to the next successive actuation of the delivery means, such that the liquid is isolated from the ambient air between successive actuations of the delivery means.