Autoinjector Needle Guard Lock Assembly for Robust Cap Removal
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Solution Overview
Problem
Medicament delivery devices, such as autoinjectors, often have needle guard locks that are flimsy and can be broken easily, and there is a need for improved lock mechanisms to prevent needle stick injuries and restrict movement of the medicament delivery member guard before cap removal.
Innovation Solution
A robust medicament delivery member guard lock assembly with a housing, a medicament delivery member guard, a lock activation sleeve, and a medicament delivery member guard lock, featuring a flexible arm pivotally attached to a base, which allows for a robust needle guard lock mechanism that prevents accidental retraction and simplifies cap removal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a needle guard lock is made robust to prevent breaking, then the strength and reliability of the lock is improved, but the device complexity increases
Solution Approach 1:
The lock mechanism employs a flexible arm that can dynamically change its state between locked and unlocked positions. The flexible arm pivots between a first position where it engages with the needle guard to prevent retraction, and a second position where it releases the guard. This dynamic flexibility allows a robust lock structure to provide reliable engagement while accommodating movement during operation, resolving the contradiction between strength and complexity.
Solution Approach 2:
The lock mechanism is divided into distinct functional segments: a base providing structural support, a flexible arm providing the locking action, and engagement features on the needle guard. This segmentation allows each component to be optimized independently - the base can be robust for strength, while the flexible arm provides the necessary movement. The modular structure reduces overall complexity by assigning specific functions to separate elements.
2Ease of operation
If a flexible arm is used in the lock mechanism to allow movement, then the ease of operation is improved, but the strength of the lock may be reduced
Solution Approach 1:
The flexible arm's physical parameters are optimized to balance flexibility and strength. The arm's dimensions, material properties, and pivot point location are designed so that it has sufficient flexibility to allow smooth movement during operation, while maintaining adequate structural strength to provide reliable locking engagement. This parameter optimization resolves the contradiction between ease of operation and lock strength.
3Object-affected harmful factors
If the lock mechanism restricts guard movement before cap removal, then safety is improved, but the device complexity increases
Solution Approach 1:
The lock mechanism applies preliminary anti-action by automatically engaging the flexible arm in the locked position before cap removal. This preliminary locking action prevents any unintended needle guard retraction that could cause needle stick injuries. The mechanism proactively establishes the safe state without requiring additional user actions or complex control systems, thus improving safety while minimizing complexity.
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 provides a robust needle guard lock that prevents accidental retraction and simplifies cap removal, enhancing user safety and ease of use, particularly for devices delivering high viscosity liquids.
Implementation Method 1
The medicament delivery member guard lock comprises a base and a flexible arm pivotally attached to the base, wherein the arm comprises a proximal part and a distal part, wherein the arm is attached to the base between the proximal part and the distal part
Implementation Method 2
wherein the proximal part of the arm is arranged adjacent to the recess or slit in the housing
Data Source
AI summary
The application describes lock mechanisms for medicament delivery devices. The lock mechanisms extend from a proximal end to a distal end in an axial direction relative to a longitudinal axis, the lock mechanisms can have a housing, a medicament delivery member guard and a cap. The lock mechanisms can also include a protrusion extending in a radial direction relative to the longitudinal axis and a recess or cut-out. Various related medicament delivery devices, medicament delivery device components, sub-assemblies and methods are also described.