Injection Needle Cap Removal Tools for Distortion-Free Force Testing
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Solution Overview
Problem
Conventional injector testing systems distort the cap during removal force measurements due to gripping forces, affecting accuracy and repeatability.
Innovation Solution
A cap removal tool with a cap removal surface that retains the cap without distortion, coupled with alignment tools and procedures to ensure precise alignment with the injector, using a base and adapter system for accurate force measurement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional gripping methods are used to measure cap removal force, then the cap can be held during measurement, but the gripping forces cause distortion in the cap, affecting measurement accuracy
Solution Approach 1:
The patent introduces a positioning plate with a cap retention feature that acts as an intermediary between the cap and the measurement system. This feature includes a cap retention surface with a contour that complements the cap geometry, allowing the cap to be retained without distortion during force measurement. The positioning plate mediates the interaction, eliminating direct gripping forces that cause distortion.
Solution Approach 2:
The positioning plate provides localized support to the cap at specific regions (flange, shoulder, or tip depending on cap type) rather than applying force across the entire cap structure. This localized support prevents distortion while maintaining proper alignment and retention during the removal force measurement.
2Measurement precision
If alignment tools and procedures are implemented for precise alignment, then measurement accuracy improves, but device complexity increases
Solution Approach 1:
The positioning plate is pre-configured with alignment features including alignment holes, alignment slots, and registration features that automatically guide and constrain the injector during positioning. This preliminary preparation of alignment infrastructure eliminates the need for complex real-time alignment procedures or sophisticated alignment tools during measurement.
Solution Approach 2:
The positioning plate's alignment features work passively to self-align the injector through mechanical constraints (alignment holes matching alignment pins, slots providing guided movement). The system uses its own geometric features to achieve precise alignment without requiring external alignment tools or complex adjustment mechanisms.
Data Source
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AI summary
Disclosed example cap removal tools include: a cap removal adapter having a cap removal aperture; and a base, comprising: first alignment features configured to align the cap removal tool with an actuator of the autoinjector testing system; and second alignment features configured to removably attach the cap removal adapter to the base and align the cap removal adapter with the actuator.