Cap Removal Mechanism for Liquid Injection Devices
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Solution Overview
Problem
Individuals with weak grips, such as the aged or those with rheumatism, face difficulty in removing the cap from liquid injection devices like auto injectors due to the requirement of pinching with fingers.
Innovation Solution
A packaging assembly with a cap removal mechanism featuring step parts that protrude outward, allowing easy engagement with engaging parts of the packaging body, facilitating cap removal without the need for strong finger grip.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the cap is removed by pinching with fingers, then the cap can be removed from the liquid injection device, but it becomes difficult for persons with weak grips such as aged persons or patients suffering from rheumatism
Solution Approach 1:
The packaging body acts as an intermediary tool to assist cap removal. The engaging part on the packaging body interacts with the step part on the cap, providing a mechanical advantage that enables persons with weak grips to remove the cap without directly pinching it with fingers.
Solution Approach 2:
The solution transitions from direct finger pinching (one-dimensional grip force) to a multi-dimensional mechanical interaction involving the engaging part and step part. This allows force application through a larger surface area and lever arm, reducing the grip strength requirement.
2Ease of operation
If the step part protrudes further outward than the side surface of the barrel part, then the step part can be easily engaged with the engaging parts, but the overall device dimensions increase
Solution Approach 1:
The step part is designed with localized protrusion only where needed for engagement with the packaging body's engaging part. This concentrated geometric feature provides the necessary mechanical advantage without requiring a uniform increase in the entire device dimensions.
Data Source
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AI summary
A packaging body for housing a liquid injection device including a barrel part capable of being filled with a liquid, a syringe having a needle for discharging the liquid, which is attached to a distal portion of the barrel part, a cap that covers the needle, and a housing that covers at least a base end part of the syringe, the liquid injection device having a step part protruding further outward than the side surface of the barrel part between an outer peripheral surface of the cap or the housing and the cap, the packaging body including a container including a housing space for housing the liquid injection device and an opening for removing the liquid injection device from the housing space, to which a sealing member for sealing the opening can be attached, and the container including an engaging part that engages with the step part so as to remove the cap from the liquid injection device.