Autoinjector Safety Cap Locking for Intuitive Needle-End Use

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing autoinjectors face challenges with user confusion regarding activation ends, potential misuse due to misunderstanding which end to press, and the need for improved safety features to prevent accidental operation and maintain sterility, while also requiring efficient manufacturing and material usage.

Innovation Solution

An autoinjector design featuring a safety cap that locks the actuation unit until removed, maintaining sterility and preventing unintended actuation, with a non-circular safety cap shape ensuring correct orientation and a slide-fit mounting system for recapping, combined with a snap-fit casing for ease of use and efficient assembly.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a safety cap is provided at the front end to prevent accidental operation, then safety is improved, but the device complexity increases

Engineering Contradiction:
ImprovesafetyVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The safety cap is designed as a separate removable component that can be detached from the main body of the autoinjector. This segmentation allows the safety feature to be added without redesigning the entire device, thereby improving safety while minimizing the increase in overall device complexity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The safety cap functions as an extractable protective element that can be removed only when needed. By taking out the safety function as a separate removable component rather than integrating it permanently into the device structure, the design improves safety while keeping the core device relatively simple.

Inventive Principle:
Principle #2Taking out (Extraction)

2Ease of operation

If the safety cap is made removable to allow recapping, then ease of operation is improved, but the risk of misuse increases

Engineering Contradiction:
Improveease of operationVSAvoidmisuse prevention
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The safety cap employs asymmetric threading or engagement features that allow removal in only one direction and require specific orientation. This asymmetric design enables easy removal for legitimate recapping while preventing accidental or incorrect manipulation, thus balancing ease of operation with misuse prevention.

Inventive Principle:
Principle #4Asymmetry

3Reliability

If a locking mechanism is added to lock the actuation unit, then safety is improved, but the device complexity increases

Engineering Contradiction:
ImprovesafetyVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The locking mechanism is merged with the safety cap itself, where the cap's engagement with the actuation unit creates the lock. By combining the safety cap and locking function into a single integrated component rather than adding a separate locking mechanism, safety is improved while minimizing the increase in device complexity.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The locking mechanism is designed to engage and disengage automatically through the user's natural actions of capping or removing the safety cap. The cap itself performs the locking function without requiring additional user operations or complex mechanical interventions, thereby improving safety while keeping the system simple.

Inventive Principle:
Principle #25Self-service

4Productivity

If the autoinjector is designed for single use, then manufacturing efficiency is improved, but material usage increases

Engineering Contradiction:
Improvemanufacturing efficiencyVSAvoidmaterial usage
Core Design Contradiction:
ProductivityVSLoss of substance

Solution Approach 1:

The single-use design allows the entire device to be discarded after one use, eliminating the need for complex cleaning, sterilization, or component recovery processes. This approach improves manufacturing efficiency by simplifying production and quality control while the modular design optimizes material usage by allowing efficient disposal of the complete assembled unit.

Inventive Principle:
Principle #34Discarding and recovering

Data Source

PatentEP4554640B1autoinjector
Publication Date: 2026.04.08 ALK ABELLO AS
  • EP4554640B1 patent drawingFigure 1
  • EP4554640B1 patent drawingFigure 2A
  • EP4554640B1 patent drawingFigure 2B

AI summary

An autoinjector (1) is disclosed. The autoinjector comprises a main casing (10); a cartridge assembly (30) disposed within the main casing (10). The cartridge assembly may include a cartridge (3) land a needle (40). A power pack (100) is disposed within the main casing (10) for moving the cartridge (31) and the needle (40) from a storage position to an injection position when actuated. An actuation unit (50) comprises a cartridge container (52) and a needle cover (60) disposed between the cartridge container (52) and the main casing (10). The actuation unit (50) is operably coupled to the power pack (110) and retractable from a first position to an actuation position for actuating the power pack. The needle cover (60) is extendable to an extended position covering the needle (40) when the cartridge (31) and the needle (40) are in the injection position. A safety cap (20) is removable from a mounted position on a front end of the main casing (10) to expose a front portion of the actuation unit (50).