Foam forming liquid dispensing device
AssigneeBecton, Dickinson and Company
InventorsMinh Quang Hoang, Jonathan Karl Burkholz, Donald Edward Hunt
Life of this patent
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Abstract
A foam dispensing apparatus of the present invention includes a reservoir containing a foamable liquid, with a closed headspace above a surface of the liquid. The apparatus also includes a source of a gas disposed to impose a gas pressure higher than ambient atmospheric pressure into the closed headspace. There is a mixing chamber having an inside diameter, an inlet and an outlet open to the ambient atmosphere with a flow restricter having a plurality of openings therein in gaseous communication with the closed headspace. The foam dispensing apparatus also includes a hydrophobic filter.
Claims13
A foam dispensing apparatus comprising:
- a reservoir containing a foamable liquid said reservoir having a closed headspace above a surface of the liquid;
- a source of a gas disposed to impose a gas pressure higher than ambient atmospheric pressure into said closed headspace;
- a mixing chamber having an inside diameter, an inlet and an outlet open to the ambient atmosphere,
- a first flow restricter having at least one opening therein in gaseous communication with said closed headspace, said first flow restricter being disposed at said inlet of said mixing chamber;
- an elongate delivery tube and an open passageway therethrough having a longitudinal axis extending from said inlet of said mixing chamber to below the surface of the foamable liquid disposed so that an application of the gas having higher pressure than atmospheric pressure to the headspace causes the liquid to flow through said tube past said first flow restricter and wherein the headspace gas having higher pressure than atmospheric pressure flows from said openings in said first flow restricter to mix with the foamable liquid and to expand to atmospheric pressure in said mixing chamber thereby to form a foam from the foamable liquid and discharge said foam from said outlet;
- and
- a hydrophobic filter disposed between the pressure source and the reservoir.
A foam dispensing apparatus comprising:
- a reservoir containing a foamable liquid, said reservoir having a closed headspace above a surface of the liquid;
- a source of a gas disposed to impose a gas pressure higher than ambient atmospheric pressure into said closed headspace;
- a mixing chamber having an inside diameter, an inlet and an outlet open to the ambient atmosphere;
- a substantially tubular flow restricter having a plurality of openings therein in gaseous communication with said closed headspace, said flow restricter being disposed at said inlet of said mixing chamber,
- said mixing chamber further comprising a secondary flow restricter at said outlet of said mixing chamber, said secondary flow restricter to restrict the expansion of bubbles formed as said foamable liquid having said higher pressure gas mixed therein expands to atmospheric pressure;
- an elongate delivery tube and an open passageway therethrough having a longitudinal axis extending from said inlet of said mixing chamber to below the surface of the foamable liquid disposed so that an application of the gas having higher pressure than atmospheric pressure to the headspace causes the liquid to flow through said tube past said flow restricter and wherein the headspace gas having higher pressure than atmospheric pressure flows from said openings in said flow restricter to mix with the foamable liquid and to expand to atmospheric pressure in said mixing chamber thereby to form a foam from the foamable liquid and discharge said foam from said outlet;
- and
- a hydrophobic filter located between the reservoir and the source of gas to prevent backflow of fluid into the source of gas.
Dependencies are inferred from the claim text.