Cap Assembly Segmentation for Drug Delivery Safety Lock

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Solution Overview

Problem

Drug delivery devices, particularly pen-type injectors, face challenges in providing a secure and safe fastening mechanism for protective caps, which can lead to unintentional disassembly and contamination, posing safety risks, especially for physically impaired or unauthorized users.

Innovation Solution

A cap assembly with a cup-shaped receptacle and an interlock member that engages with the drug delivery device's dispensing end, providing a dual fastening mechanism to prevent self-acting disassembly, featuring a low pull-off force for easy assembly and a higher force for secure attachment, ensuring safety and preventing unintentional removal.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the cap is designed with a low pull-off force for easy removal, then ease of operation is improved, but reliability deteriorates due to unintentional disassembly

Engineering Contradiction:
Improveease of cap removalVSAvoidprevention of unintentional disassembly
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The cap assembly is segmented into two functional parts: a cap body that provides easy-on/easy-off functionality and an interlock member that provides secure locking. The cap body can be easily attached and removed, while the interlock member remains engaged with the cartridge holder to prevent unintentional disassembly. This segmentation allows each component to optimize for its specific function without compromising the other.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The interlock member acts as an intermediary element between the cap body and the cartridge holder. It provides a mechanical locking interface that mediates between the ease of cap removal and the need for secure attachment. The interlock member engages with the cartridge holder to prevent unintentional disassembly while allowing the cap body to be easily attached and removed by the user.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If the cap is designed with a high pull-off force for secure attachment, then reliability is improved, but ease of operation deteriorates for physically impaired users

Engineering Contradiction:
Improvesecure fastening of capVSAvoiddifficulty of cap removal
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The cap assembly is segmented into two functional parts: a cap body that provides easy-on/easy-off functionality and an interlock member that provides secure locking. The cap body can be easily attached and removed, while the interlock member remains engaged with the cartridge holder to prevent unintentional disassembly. This segmentation allows each component to optimize for its specific function without compromising the other.

Inventive Principle:
Principle #1Segmentation

3Reliability

If the cap assembly includes an interlock member for safety locking, then reliability is improved, but device complexity increases

Engineering Contradiction:
Improvesafety lock mechanismVSAvoidstructural complexity of cap assembly
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The interlock member is merged with the cap body to form an integrated cap assembly. This combining of functions reduces the number of separate components and simplifies the overall structure. The interlock member and cap body work together as a unified system, providing both easy operation and secure locking without requiring multiple independent mechanisms.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The interlock member serves multiple functions: it provides safety locking by engaging with the cartridge holder, prevents unintentional disassembly, and maintains a simple integrated structure with the cap body. This multi-functionality reduces the need for additional components and simplifies the overall device design while achieving reliable safety protection.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentEP2758103B1Cap assembly for a drug delivery device
Publication Date: 2016.06.29 SANOFI AVENTIS DEUT GMBH
  • EP2758103B1 patent drawingFigure 1
  • EP2758103B1 patent drawingFigure 2
  • EP2758103B1 patent drawingFigure 3

AI summary

The present invention relates to a cap assembly for a drug delivery device comprising: - a cap body (26) to protect and to receive a distal dispensing end (14; 50) of the drug delivery device (10), - an interlock member (24; 40) operably engaged with the cap body (26) and being further adapted to releasably engage with a distal end section (21) of the device's dispensing end (14; 50) to provide a safety lock for the cap body (26).