Needle Assembly Axial Torsional Shielding Mechanism

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Solution Overview

Problem

Existing needle assemblies for injection devices often increase complexity and part count with shielding mechanisms, compromising sterility and safety, and existing packaging poses risks of needle stick injuries and sterility loss.

Innovation Solution

A single-use needle assembly with a needle hub and axially and torsionally biased shield that automatically retracts and locks, using a spring member for both movements, and a textured surface for pain masking, with a packaging design that maintains sterility and prevents accidental needle exposure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a needle shield is added to prevent accidental needle stick injuries, then safety is improved, but device complexity and part count increase

Engineering Contradiction:

ImprovesafetyVSAvoiddevice complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines the axial biasing function and torsional biasing function into a single spring member. The spring member has an axial component that biases the shield axially and a torsional component that biases the shield rotationally, reducing the part count from multiple springs to one integrated component while maintaining both safety functions.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The spring member serves multiple functions simultaneously: it provides axial biasing to return the shield to the extended position, provides torsional biasing to rotate the shield to the locked position, and acts as both a mechanical spring and a positioning element. This multi-functionality reduces the overall complexity of the shielding mechanism.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Reliability

If a needle shield with multiple biasing mechanisms is used to ensure safety, then reliability is improved, but manufacturing complexity increases

Engineering Contradiction:

ImprovesafetyVSAvoidmanufacturing complexity

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The spring member is designed as a single integrated component that combines both axial and torsional biasing capabilities. This eliminates the need to manufacture and assemble multiple separate springs, simplifying the manufacturing process while ensuring reliable safety functionality through the combined biasing actions.

Inventive Principle:

Principle #5Merging (Combining)

3Reliability

If a complex shielding mechanism is implemented, then safety is improved, but the number of components increases

Engineering Contradiction:

ImprovesafetyVSAvoidpart count

Core Design Contradiction:

ReliabilityVSQuantity of substance

Solution Approach 1:

The patent reduces the part count by merging the axial spring and torsional spring into a single spring member with integrated functionality. This single component performs what would traditionally require multiple separate parts, thereby reducing the overall quantity of components in the needle assembly while maintaining comprehensive safety coverage.

Inventive Principle:

Principle #5Merging (Combining)

4Ease of manufacture

If traditional packaging is used for needle assemblies, then ease of manufacture is improved, but sterility is compromised due to needle stick risks

Engineering Contradiction:

Improvepackaging simplicityVSAvoidsterility

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The needle shield is designed to automatically return to the extended position that covers the needle tip through the axial and torsional biasing of the spring member. This preliminary positioning ensures the needle is protected before use, and the packaging can be designed to maintain sterility by accommodating this pre-positioned shield state, reducing the risk of accidental needle exposure during packaging and storage.

Inventive Principle:

Principle #10Preliminary action

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 solution reduces complexity and part count, enhances safety by preventing needle stick injuries, maintains sterility, and allows for simple, safe packaging that prevents accidental needle exposure, while providing effective pain masking during use.

Implementation Method 1

the needle shield being axially biased towards the extended position

Methodology Applied

Scientific EffectSpring: Spring

Implementation Method 2

the needle shield is further arranged to be torsionally biased for relative rotational movement with respect to the needle hub

Methodology Applied

Scientific EffectTorsion spring: Torsion Spring

Data Source

PatentUS11497857B2Needle assembly

Publication Date: 2022.11.15 OWEN MUMFORD

AI summary

A needle assembly is disclosed, for use with an injection device. The needle assembly comprises a needle hub (20) having a needle (22) and a needle shield (40) arranged for relative axial movement with respect to the needle hub, between a retracted position in which the tip of the needle projects beyond a forward end of the shield and an extended position in which the tip of the needle does not project beyond the forward end of the shield. The needle shield (40) is axially biased towards the extended position. The needle shield (40) is further arranged to be torsionally biased for relative rotational movement with respect to the needle hub (20).