Segmented Plunger Front Opening for Dispenser

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Solution Overview

Problem

Existing dispensers face issues with liquid material adhesion to syringe walls and backward flow, leading to reduced discharge efficiency and waste, especially when dealing with high viscosity liquids under high pressure.

Innovation Solution

A plunger design with a thin-wall hollow structure, featuring a large diameter body with ring-like contact surfaces and a front opening that functions as both a pressure receiving area and a buffer passage, allowing for efficient liquid discharge while minimizing adhesion and backward flow.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a plunger with flanges is used to press the liquid material uniformly, then liquid adhesion to syringe walls is prevented, but air is sucked into the lower side of the upper flange causing discharge instability

Engineering Contradiction:
Improvedischarge stabilityVSAvoidair suction
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The front opening is divided into multiple openings (first opening and second opening) separated by a bridging member. This segmentation prevents air suction while maintaining uniform liquid pressing, as the liquid material flows through multiple paths rather than creating a vacuum that would draw air in.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The bridging member acts as an intermediary structure between the first and second openings. It provides structural support to prevent plunger collapse while allowing liquid material to pass through both openings, thereby preventing air suction without compromising discharge stability.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If the front opening diameter is increased to improve liquid discharge, then discharge efficiency increases, but plunger rigidity decreases

Engineering Contradiction:
Improvedischarge efficiencyVSAvoidplunger rigidity
Core Design Contradiction:
ProductivityVSStrength

Solution Approach 1:

The front opening is segmented into multiple smaller openings (first opening and second opening) divided by a bridging member. This segmentation maintains plunger rigidity by providing structural support through the bridging member while still achieving effective liquid discharge through multiple flow paths.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The bridging member provides localized structural reinforcement in the front opening region. This allows the plunger to maintain rigidity at critical structural points while still achieving adequate liquid discharge efficiency through the distributed opening configuration.

Inventive Principle:
Principle #3Local quality

3Productivity

If pressurized air is supplied at high pressure to improve discharge speed, then productivity increases, but liquid material adhesion to syringe walls increases

Engineering Contradiction:
Improvedischarge speedVSAvoidliquid adhesion
Core Design Contradiction:
ProductivityVSLoss of substance

Solution Approach 1:

The segmented front opening configuration distributes the liquid material flow across multiple paths. This distribution reduces the velocity and pressure concentration at any single point, thereby reducing liquid material adhesion to syringe walls while maintaining overall discharge speed through the combined flow of multiple openings.

Inventive Principle:
Principle #1Segmentation

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The plunger effectively prevents liquid adhesion to the syringe walls and reduces response delays, enabling high-tact discharge with minimal waste, even with high viscosity liquids.

Implementation Method 1

a front surface of the plunger is held in a close contact state with an inner peripheral surface of the syringe

Methodology Applied
Scientific EffectSurface tension: Surface Tension

Implementation Method 2

pressurized air is supplied as an air pulse to press a liquid material with the air pulse

Methodology Applied
Scientific EffectPressure gradient: Pressure Gradient

Data Source

PatentEP3718644B1Plunger for dispenser, dispenser, and method for dispensing liquid material
Publication Date: 2022.06.01 MUSASHI ENG INC
  • EP3718644B1 patent drawingFigure 1
  • EP3718644B1 patent drawingFigure 2
  • EP3718644B1 patent drawingFigure 3

AI summary

The present invention provides a plunger (20) for a dispenser, the plunger including a large diameter body portion (23) provided with ring-shaped contact surfaces (24, 25) that contact an inner wall surface of a syringe, a rear opening (26) formed in a backside of the large diameter body portion (23), and a small diameter body portion (22) provided with a front opening (28), wherein the front opening (28) is formed in a size allowing a liquid material to be directly pressed by pressurized air, and allowing at least the plunger (20) to move following a fall in water head position, which is caused with discharge and consumption of the liquid material. With those features, the liquid material can be prevented from adhering to the inner wall surface of the syringe, and the liquid material in the syringe can be prevented from flowing backwards.