FOAM PUMPS, REFILL UNITS AND DISPENSERS WITH DIFFERENTIAL BORE SUCK-BACK MECHANISM

• Main Authors: HARRIS, Donald R, GLASGOW, Seth Andrew, CIAVARELLA, Nick E
• Format: Patent
• Language: English; French; German
• Published: 20.09.2023
• Subjects: APPLYING LIQUIDS OR OTHER FLUENT MATERIALS TO SURFACES, IN GENERAL; ATOMISING APPARATUS; COFFEE MILLS; DOMESTIC ARTICLES OR APPLIANCES; FURNITURE; HUMAN NECESSITIES; MEASURING; MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUIDLEVEL; METERING BY VOLUME; NOZZLES; PERFORMING OPERATIONS; PHYSICS; SANITARY EQUIPMENT NOT OTHERWISE PROVIDED FOR; SPICE MILLS; SPRAYING APPARATUS; SPRAYING OR ATOMISING IN GENERAL; SUCTION CLEANERS IN GENERAL; TESTING; TOILET ACCESSORIES; TRANSPORTING

An exemplary system for dispensing foam includes a container holding a foamable liquid, a pump, and a suck-back device. The suck back device has a housing having a small bore with first diameter and a large bore with a second diameter; a dual body piston with a first piston that reciprocates in the small bore and a second piston that reciprocates in the large bore; a flow restrictor located proximate the dual body piston, a suck back chamber formed at least in part by the large bore and the second piston, and a foam outlet. The flow restrictor is configured so that fluid flow into the suck back device causes the suck back chamber to compress and when the fluid flow stops, a biasing member causes the suck back chamber to expand and suck back residual foam into the suck back chamber.