Needle Safety Shield Locking Mechanism
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Solution Overview
Problem
Existing safety devices for medical needles lack a secure locking mechanism to prevent unexpected opening, compromising sterility and safety, especially during storage and emergency situations, and often require hooks that decrease protection and increase storage space.
Innovation Solution
A safety device featuring a ring and shield with a locking unit that engages via pegs and recesses, and a releasing unit with a deflecting surface to facilitate intuitive unlocking, allowing for secure closure and easy opening without the need for additional hooks, ensuring the shield remains locked until intentionally opened.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a locking unit with pegs and recesses is implemented, then reliability is improved by preventing unexpected opening, but device complexity increases
Solution Approach 1:
The locking mechanism is segmented into distinct functional elements: pegs on the shield and corresponding recesses on the ring. This segmentation allows each component to perform its specific locking function while maintaining overall system simplicity. The peg-recess interface provides reliable locking without requiring complex mechanisms.
Solution Approach 2:
The locking unit operates through self-service mechanics where the pegs automatically engage with the recesses when the shield is in the closed position, and the releasing unit automatically disengages them during protective cap removal. No additional actuation or complex control systems are needed - the mechanism serves itself through its geometric design and mechanical interactions.
2Reliability
If hooks are added to lock the shield in final position, then reliability is improved, but device complexity and storage space requirements increase
Solution Approach 1:
The locking unit with pegs and recesses serves multiple functions: it locks the shield in the closed position during storage, maintains shielding during the procedure when the protective cap is removed, and can be easily released during protective cap removal. This single multi-functional mechanism replaces what would otherwise require multiple separate hooks and locking features, simplifying the overall device design while improving reliability.
3Reliability
If the protective cap is made to securely hold the shield, then reliability is improved, but ease of operation deteriorates due to difficulty in removal
Solution Approach 1:
The system transitions from a static friction-based hold to a dynamic mechanical locking system. The locking unit with pegs and recesses provides secure retention during storage, but the releasing unit creates a dynamic disengagement mechanism during removal. As the protective cap is pulled, the deflecting surface actively pushes the peg out of the recess, making removal easier while maintaining secure hold during storage.
Solution Approach 2:
The releasing unit acts as an intermediary mechanism between the protective cap and the locking unit. Instead of directly pulling the shield or overcoming strong friction, the user's removal action is transmitted through the deflecting surface, which mediates the force to automatically disengage the peg from the recess. This intermediary mechanism simplifies the operation while maintaining secure retention.
Data Source
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AI summary
A safety device (20) for a needle (14) of a medical device, the safety device (20) comprising: - a ring (30) arranged to be fixed with regard to the needle (14) - a shield (40) arranged to be mounted on the ring (30) by a pivot link so as to define a closed position in which the shield (40) covers the needle (14) and an open position - a protective cap (50) configured to surround the needle (14) and to accommodate at least part of the shield (40) in the closed position wherein the ring (30) and the shield (40) further comprise a locking unit adapted to lock the shield (40) to the ring (30) in the closed position, and wherein the protective cap (50) and the shield (40) comprise a releasing unit adapted to release the locking unit during a portion of a removal movement of the protective cap (50).