Foam producing pump with anti-drip feature
AssigneeJoseph S. Kanfer
InventorRichard C. Sayers
Life of this patent
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Abstract
A pump including a pump body having a head assembly slidably received therein; a mixing chamber in communication with an air source and a liquid source; wherein the head assembly is movable relative to the pump body to define a pump stroke, wherein the head assembly urges air from the air supply and liquid from the liquid supply into the mixing chamber to form a foam during the pump stroke; wherein the mixing chamber opens externally of the pump body and wherein during a portion of the stroke less than a complete stroke, the mixing chamber receives fluid and air to form a foam and discharge the foam externally of the pump and wherein during the remainder of the stroke, a blowing charge from the air source is urged through the mixing chamber and externally of the pump to evacuate any residual foam in the pump.
Claims11
A pump used in connection with a container filled with a liquid, the pump comprising:
- a) a pump body defining an air chamber and a liquid chamber separated by a seal;
- b) a cup slidably received within said pump body at said liquid chamber, said cup being in selective communication with the liquid, whereby said cup is filled with liquid when the pump is in an idle position;
- c) a head assembly slidably mounted within said pump body and sealingly engaging said air chamber;
- d) a plunger extending from said head assembly through said seal and into said cup and slidably received therein;
- and
- e) a mixing chamber in selective fluid communication with said liquid chamber and said air chamber, said mixing chamber opening externally of said head assembly, whereby operation of the pump causes liquid from the liquid chamber and air from the air chamber to mix in the mixing chamber to form a foam which is discharged from the head assembly;
- f) wherein said cup is spaced from an end of said pump body by a first spring adapted to urge said cup toward said plunger;
- g) wherein said plunger is adapted to bottom out in said cup to empty said liquid chamber;
- wherein said air chamber is sized to allow further inward movement of said head assembly after said plunger bottoms out, whereby said further inward movement of said head assembly compresses said spring and forces a blowing charge from said air chamber through said mixing chamber and said head assembly to evacuate any foam remaining therein.
A pump used in connection with a container filled with a liquid, the pump comprising:
- a pump body defining an air chamber;
- a cup housed within and moveable relative to said pump body, said cup defining a liquid chamber, said cup being in selective fluid communication with the container;
- a head assembly movable relative to the pump body and adapted to mix air from said air chamber and liquid from said liquid chamber, said mixture being dischargeable through a nozzle during a portion of a single pump stroke;
- a spring biasing said liquid chamber toward said head, such that movement of said head during said pump stroke evacuates said liquid chamber before evacuating all of the air in said air chamber, whereby compression of said spring during the remainder of said pump stroke discharges air from said air chamber through said nozzle.
Dependencies are inferred from the claim text.