Rotary Locking Insulin Pen Needle With Dual Shield Protection

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Solution Overview

Problem

Existing insulin injection needles lack stability and reliability in their locking mechanisms, with rear-end protection often absent or poorly integrated with front-end protection, leading to potential safety hazards.

Innovation Solution

A rotational locking type safety insulin pen needle design featuring a rotating tube with a beveled rail and elastic arm, coupled with a front shield and spring mechanism, which ensures reliable locking protection by coordinating the front and rear shield positions through rotational movement upon needle insertion and withdrawal.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a simple protection structure is used, then the device complexity is reduced, but the reliability and stability of locking protection deteriorates

Engineering Contradiction:
Improvestructure simplicityVSAvoidlocking stability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent employs a nested structure where the front shield and rear shield are integrated within a single protective assembly. The rotating tube contains both shields in a compact arrangement, with the front shield positioned to cover the needle tip and the rear shield positioned to cover the connection interface. This nesting approach achieves reliable dual protection without significantly increasing overall device complexity.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The patent introduces a rotating tube that can dynamically transition between locked and unlocked positions. The rotation mechanism allows the protective shields to move from a retracted position during injection to an extended locked position after injection, providing adaptive protection that responds to the injection process stages.

Inventive Principle:
Principle #15Dynamics

2Reliability

If front-end protection is added, then the safety is improved, but the integration with rear-end protection deteriorates

Engineering Contradiction:
Improvefront-end protectionVSAvoidlinkage between protections
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

The patent merges the front-end needle tip protection and rear-end connection protection into a single integrated protective assembly. Both shields are mounted on the same rotating tube and are actuated simultaneously by the same rotational mechanism, ensuring coordinated operation and stable integration between the two protection functions.

Inventive Principle:
Principle #5Merging (Combining)

3Ease of operation

If a directional locking mechanism is used, then the ease of operation is improved, but the locking stability deteriorates

Engineering Contradiction:
Improvedirectional lockingVSAvoidlocking stability
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent employs asymmetric locking features on the rotating tube, including inclined surfaces and positioning protrusions that engage with corresponding features on the protective shields. This asymmetric design provides directional locking during rotation while maintaining stable engagement in the final locked position, combining ease of operation with reliable stabilization.

Inventive Principle:
Principle #4Asymmetry

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 provides robust, reliable locking protection for both the front and rear needle tips, maintaining simplicity and stability while ensuring safety, thus enhancing the overall safety and usability of insulin injection tools.

Implementation Method 1

A front spring, used to push the front shield to the protection position of the injection section

Methodology Applied
Scientific EffectSpring: Spring

Implementation Method 2

a rotating tube with a beveled rail and elastic arm, coupled with a front shield and spring mechanism, which ensures reliable locking protection by coordinating the front and rear shield positions through rotational movement

Methodology Applied
Scientific EffectMechanical Force: Mechanical Force

Data Source

PatentEP3815727B1Rotary locking safe insulin injection needle
Publication Date: 2025.11.19 SANDSTONE MEDICAL SUZHOU INC
  • EP3815727B1 patent drawingFigure 1~2
  • EP3815727B1 patent drawingFigure 3~4
  • EP3815727B1 patent drawingFigure 5~8

AI summary

A rotational locking type safety insulin pen needle comprises a needle body, an intermediate shield, a front shield and a spring, wherein: the intermediate shield is provided with a rotating tube and the rotating tube is provided with a beveled rail on the outer edge; relative to the beveled rail, the front shield is provided with a bevel acting part on the inner edge; the rotating tube is provided with an elastic arm in the front and the elastic arm is provided with a front protection stopper; relative to the front protection stopper, the front shield is provided with a guiding slot and a limit slot at intervals along the circumferential direction. The present invention uses the backward movement of the front shield when the needle is pushed to drive the rotation of the rotating tube and uses the coordination of the front protection stopper on the rotating tube with the guiding slot and limit slot on the front shield to change the coordination relationship between the front shield and the rotating tube, which effectively provides the reliable locking protection of the front shield after use.