Foam dispenser

摘要

A foam assembly connectable to a liquid container includes a main pump body, a resiliently deformable piston dome, an air chamber, a liquid chamber, a mixing zone and a porous member. The main pump body has an exit nozzle with the porous member therein. The air chamber and the liquid chamber are each defined by the piston dome and the main pump body. The liquid chamber has a liquid inlet valve and a liquid outlet valve. The mixing zone is in flow communication with the air chamber and the liquid chamber. The volume of the air chamber and the liquid chamber are each dependent on the position of piston dome and during an activation stroke the piston moves from the at rest position to the depressed position and responsively the volume of the air chamber and the volume of the liquid chamber are reduced.

主权项

1. A mixing tube for use in a foam assembly wherein the foam assembly has an air chamber, a liquid chamber, a means for pressurizing the air chamber and the liquid chamber, and a porous member, the mixing tube comprising:
an elongate mixing channel having an upstream end and a downstream end, the elongate mixing channel having a cross sectional area substantially the same from the upstream end to the downstream end; an exit zone at the downstream end of the elongate mixing channel, the exit zone is a chamfer expanding to a cross sectional area that is larger than the cross sectional area of the elongate mixing channel and continuously increases to a downstream end of the exit zone, and the downstream end of the exit zone being configured to be upstream of the porous member; wherein the elongate mixing channel has a length greater than the exit zone; and wherein the mixing tube is configured such that when positioned in the foam assembly, the upstream end of the elongate mixing channel is in flow communication with the liquid chamber, the elongate mixing channel is in flow communication with the air chamber and air from the air chamber is injected into the mixing channel spaced upstream of the downstream end thereof such that liquid combined with air passes through the substantially the same cross sectional area of the elongate mixing channel and then into the expanding cross sectional area of the exit zone.