Split-Mold Connector for Watertight Catheter Attachment

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Solution Overview

Problem

Conventional clip designs for removably attaching members suffer from mold complexity and increased manufacturing costs due to the need for a continuous mold surface to prevent mold parting lines, which complicates the mold structure and reduces molding speed.

Innovation Solution

A clip design featuring a two-sided split mold structure for the suction part and a separate mold for the leg part, allowing for a simpler mold configuration and improved watertightness without parting lines, using a combination of a grommet and pin with a packing or elastic wall for enhanced sealing and flexibility.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a traditional three-piece connector system is used to attach a catheter to a needle hub, then the components can be manufactured separately with standard tolerances, but the assembly requires multiple separate parts that increase device complexity and potential failure points

Engineering Contradiction:
ImproveManufacturing ease of connector componentsVSAvoidNumber of separate connector components
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

The patent combines the distal end of the catheter and the hub of the needle into a single integrated connector component. This merger eliminates the need for separate connector parts while maintaining the ability to manufacture the component using standard tolerances and processes, thereby reducing device complexity without sacrificing manufacturing ease.

Inventive Principle:
Principle #5Merging (Combining)

2Reliability

If a secure attachment mechanism is implemented to prevent disconnection during use, then connection reliability is improved, but the mechanism may require additional parts or complex engagement features

Engineering Contradiction:
ImproveConnection reliability of catheter to needle hubVSAvoidComplexity of attachment mechanism
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The integrated connector employs asymmetric engagement features where the catheter distal end and needle hub have complementary but non-symmetric geometries. This asymmetric design provides secure, reliable attachment that prevents disconnection during use while avoiding the need for complex multi-component mechanisms, as the secure connection is achieved through the geometric interlocking of the integrated single-piece structure.

Inventive Principle:
Principle #4Asymmetry

3Ease of manufacture

If the catheter and needle hub are designed as separate components, then manufacturing and assembly are simplified, but the connection interface may create dead space that increases fluid retention and infection risk

Engineering Contradiction:
ImproveManufacturing simplicity of separate componentsVSAvoidFluid retention and infection risk at connection interface
Core Design Contradiction:
Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

By merging the catheter distal end and needle hub into a single integrated component, the patent eliminates the connection interface between separate parts. This merger removes the dead space that would otherwise exist at the junction of separate components, thereby reducing fluid retention and infection risk while maintaining manufacturing simplicity through standard tolerances and processes.

Inventive Principle:
Principle #5Merging (Combining)

4Object-affected harmful factors

If an integrated single-piece connector is used to eliminate dead space and improve hygiene, then fluid retention and infection risk are reduced, but manufacturing precision requirements increase

Engineering Contradiction:
ImproveFluid retention and infection riskVSAvoidPrecision requirements for integrated connector
Core Design Contradiction:
Object-affected harmful factorsVSManufacturing precision

Solution Approach 1:

The patent addresses the manufacturing precision challenge by optimizing the geometric parameters of the integrated connector's engagement features. Through careful parameter selection and tolerance specification, the design achieves the dual goals of eliminating dead space to reduce infection risk while remaining manufacturable with standard precision capabilities.

Inventive Principle:
Principle #35Parameter changes

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 maintains excellent watertightness while simplifying the mold structure, reducing manufacturing costs, and allowing for easy absorption of variations in plate thickness and pressure contact, with improved usability and stability in fastening and detachment.

Implementation Method 1

a suction part (15) protruding around the head part (10) in a form of an umbrella or dish foam the lower circumference of the head part (10)

Methodology Applied
Scientific EffectSuction: Suction

Data Source

PatentEP3273075B1clip
Publication Date: 2021.06.09 NIFCO INC
  • EP3273075B1 patent drawingFigure 1A~1C
  • EP3273075B1 patent drawingFigure 2A~2C
  • EP3273075B1 patent drawingFigure 3A~3C

AI summary

This clip 4 is used for, for example, attaching and constraining one member 8 to the other member 7 in a detachable manner, and is provided with a head disposed so as to block off a through hole of one of the members among through holes 8a, 7b formed through the two members, and a leg which is inserted in the through hole, and which engages the back side of the other member. The clip 4 is at least provided with a first member 1 having a head 10, a suction part 15 protruding from the circumference of the head, and an insertion hole 13 in the axial direction, and a second member 2 having a head 20 overlaid so as to have a watertight structure with the head 10 of the first member, and the leg 24 formed perpendicularly with respect to the head, and inserted in the insertion hole 13.