Auto-Injector Housing Composite Shell Impact Resistance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing auto-injector housings lack sufficient impact resistance and protection against mechanical shocks, which can lead to breakage or unintended activation of the actuating mechanism when dropped, compromising safety and hygiene.
Innovation Solution
A housing part comprising a shell form body made of a hard, incompressible material with an over-coating of a softer, compressible thermoplastic elastomer that extends into windows, providing enhanced impact absorption and protection while maintaining structural integrity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the housing is made of hard, incompressible material, then structural strength is improved, but impact resistance deteriorates
Solution Approach 1:
The housing combines a hard, incompressible shell form body (e.g., polycarbonate) with a softer, compressible over-coating material (e.g., thermoplastic elastomer). This composite structure allows the hard shell to provide structural strength while the compressible over-coating absorbs impact energy, resolving the contradiction between structural strength and impact resistance.
Solution Approach 2:
The over-coating material is applied selectively to specific regions of the housing that are most susceptible to impact, such as the outer surface and areas around windows. This localized application provides impact resistance where needed while maintaining the overall structural integrity and minimizing the trade-off between hardness and impact absorption.
2Reliability
If the over-coating covers the entire outer shell surface, then impact protection is improved, but manufacturing complexity increases
Solution Approach 1:
Instead of applying over-coating to the entire housing surface, the invention selectively applies it to specific regions that require impact protection, such as the outer shell surface and window areas. This localized approach provides adequate protection while simplifying the manufacturing process compared to full-surface coating.
Solution Approach 2:
The over-coating is applied to cover the essential protective areas (outer surface and windows) without requiring complete coverage of every surface. This partial action provides sufficient impact protection while reducing manufacturing complexity and material usage.
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 significantly improves the impact resistance and protection of auto-injector housings, preventing breakage and unintended activation, ensuring safe and hygienic operation even upon mechanical impact, such as dropping.
Implementation Method 1
an over-coating formed of a relatively softer or more compressible material, the over-coating covering at least part of the outer shell surface of the shell form body
Data Source
Figure 1
Figure 2
Figure 3A
AI summary
Provided is a housing part for an auto-injector comprising a shell form body defining inner and outer shell surfaces and comprising a relatively hard or generally incompressible material; an over-coating formed of a relatively softer or more compressible material, the over-coating covering at least part of the outer shell surface of the shell form body; and at least one window defined in the shell form body, wherein the over-coating extends into the at least one window. Also provided is a housing comprising the housing part, and an auto- injector comprising the housing.