Needleless Connector Plunger Valve for Low-Drag Flow

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Solution Overview

Problem

Conventional needleless connectors with collapsible valves face issues such as increased flow path drag, reduced flow rates, and liquid stagnation, particularly when injecting medicinal liquids under low pressure, and require additional mechanisms that increase the connector's size and complexity.

Innovation Solution

A needleless connector design featuring a plunger valve with a notched groove and a slit valve, where the plunger valve deforms to increase the flow path volume upon insertion and restore to decrease it upon removal, guided by a skirt-shaped section and housing grooves, reducing drag and stagnation while maintaining a compact size.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a collapsible valve is used to push liquid toward the tip end, then liquid drawn into the needleless connector is reduced, but the internal flow path becomes narrower and flow path drag increases

Engineering Contradiction:
Improveliquid drawn into connectorVSAvoidflow path drag
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The flow path is divided into multiple sections: a first flow path section with larger diameter, a second flow path section with smaller diameter, and a third flow path section with larger diameter. This segmentation allows the flow path to be narrow only where necessary (second section) while maintaining larger diameter sections (first and third sections) to reduce overall flow resistance and drag.

Inventive Principle:
Principle #1Segmentation

2Reliability

If the flow path is narrowed to reduce liquid stagnation, then liquid drawn into the connector is reduced, but high pressure is needed for injection and flow rate decreases

Engineering Contradiction:
Improveliquid stagnationVSAvoidflow rate
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The flow path is segmented into sections with different diameters. The first and third flow path sections have larger diameters to maintain high flow rates and reduce stagnation, while the second section has a smaller diameter to push liquid toward the tip end and reduce liquid drawn into the connector.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different sections of the flow path have different diameters tailored to their specific functions. The larger diameter sections provide low resistance for high flow rates, while the smaller diameter section provides the pushing action needed to prevent liquid from being drawn into the connector.

Inventive Principle:
Principle #3Local quality

3Ease of operation

If a guide mechanism and detachment prevention mechanism are added, then the plunger valve can smoothly deform and restore, but the diameter and height of the insertion port increase

Engineering Contradiction:
Improvevalve deformationVSAvoidinsertion port size
Core Design Contradiction:
Ease of operationVSVolume of moving object

Solution Approach 1:

The guide mechanism and detachment prevention mechanism are merged into a single integrated structure. The guide mechanism includes both the guiding function for smooth valve deformation and the detachment prevention function, eliminating the need for separate mechanisms and keeping the insertion port compact.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The guide mechanism is designed to perform multiple functions simultaneously: guiding the plunger valve during deformation, preventing detachment, and maintaining a compact insertion port size. This multi-functionality reduces the overall complexity and size of the insertion port.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 design ensures a smooth flow of medicinal liquids with reduced drag and stagnation, maintaining high flow rates without the need for increased pressure, and prevents detachment of the slit valve, thus enhancing the functionality and efficiency of the connector.

Implementation Method 1

The plunger valve is configured to be deformed such that the volume of the flow path increases, when a male connector is inserted in the insertion port, and restore such that the volume of the flow path decreases, when a male connector inserted in the insertion port is removed

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Data Source

PatentEP4623983A1Needleless connector
Publication Date: 2025.10.01 NIPRO CORP
  • EP4623983A1 patent drawingFigure 1
  • EP4623983A1 patent drawingFigure 2
  • EP4623983A1 patent drawingFigure 3

AI summary

A needleless connector includes a housing 103 and a plunger valve 101 housed in the housing. The plunger valve 101 has a cylindrical wall section 113, a head section 111 formed closer to an insertion port than is the cylindrical wall section 113, and a middle section 112 formed between the head section 111 and the cylindrical wall section 113. The plunger valve 101 is configured to be deformed such that the volume of a flow path increases, when a male connector is inserted, and restore such that the volume of the flow path decreases, when a male connector is removed. The head section 111 has a notched groove 151 having a radial depth that gradually becomes smaller from a top vertex portion thereof toward the middle section 112.