Foam Pump Restrictor-Based Lost Motion for Adjustable Dosage

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Solution Overview

Problem

Existing foam dispenser systems lack the ability to adjust the volume of foam output without replacing the pump or modifying its stroke, limiting user control over the dosage of foam dispensed.

Innovation Solution

The integration of a connector with a flexible portion and a restrictor between the connector and the piston in foam dispenser systems, allowing for 'lost motion' between the actuator and the pistons, which adjusts the stroke length and output dose by varying the position and configuration of the restrictor.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a restrictor is positioned between the connector and piston to create lost motion, then the foam output volume is adjustable, but the device complexity increases

Engineering Contradiction:
Improvefoam output volume adjustmentVSAvoiddevice complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

A restrictor element is introduced as an intermediary component between the connector and piston. This restrictor creates a controlled lost motion mechanism that reduces the effective stroke length of the piston, thereby adjusting the foam output volume without requiring pump replacement or complex modifications to the existing pump structure.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The connector is divided into multiple functional portions: a first portion that connects to the actuator, a second portion that connects to the piston, and an intermediate section where the restrictor is positioned. This segmentation allows the lost motion mechanism to be integrated into the existing connector without replacing the entire component, thus managing device complexity.

Inventive Principle:
Principle #1Segmentation

2Quantity of substance

If the connector stroke is greater than the piston stroke to produce partial dose, then the foam output is reduced, but the manufacturing precision requirements increase

Engineering Contradiction:
Improvefoam output volumeVSAvoidmanufacturing precision
Core Design Contradiction:
Quantity of substanceVSManufacturing precision

Solution Approach 1:

The restrictor element modifies the effective stroke length parameter of the piston by introducing a controlled lost motion distance. This changes the relationship between connector stroke and piston stroke, allowing the system to deliver partial doses (reduced foam output volume) while using standard manufacturing tolerances for the connector and piston components.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3331409B1Pumps with restrictor-based lost motion
Publication Date: 2019.07.10 GOJO IND INC
  • EP3331409B1 patent drawingFigure 1
  • EP3331409B1 patent drawingFigure 2
  • EP3331409B1 patent drawingFigure 3A~4B

AI summary

The present application discloses liquid dispensers, refill units for liquid dispensers, liquid pumps, lost motion devices, and methods for installing a refill unit and lost motion device. In certain embodiments, a liquid dispenser of the present application comprises a container for holding a liquid, a pump housing connected to the container, a liquid or air chamber, and a piston movable in the liquid or air chamber. A connector is linked to the piston. The connector has a flexible portion for connecting to the piston and an attachment portion for attaching to an actuator of the dispenser. A restrictor is positioned between the flexible portion of the connector and the piston. Movement of the connector a first distance in a first direction results in lost motion between the actuator and the piston and continued movement of the connector a second distance in the first direction moves the piston with the actuator.