Patent ID: 6626332
Filing Date: 2003-09-30
Classification: A47K,B05B

Abstract:
A method for the controlled portion-wise delivery of foam in a device for producing and metering foam that is prepared from a foamable liquid by supplying compressed air to produce a coarse-bubbled foam which is refined and homogenised in a downstream foamer, wherein, in a compressed air cylinder, a forward stroke of an air piston is used for foam production and a backward stroke is used for blowing the foam out of a foam delivery bore, characterized in that an air flow produced by the backward stroke of the air piston is introduced into a region of the foam delivery bore as an excess pressure in a first phase and as a negative pressure in a second phase, the foam present in the delivery bore being substantially blown out in the first phase and a residual foam portion which remains expanding under negative pressure and collapsing in the second phase.