Disposable Injection Needle Sleeve Locking Against Reuse
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Solution Overview
Problem
Conventional injection needles have exposed needle tips, increasing infection risk and potential for cross-infection due to secondary use, and suffer from unstable assembly with insulin injection pens.
Innovation Solution
A disposable injection needle design featuring a tube needle protected by a second sleeve that retracts inward upon use, guided by an elastic element and rotational mechanisms to prevent exposure, with blocking members and fasteners ensuring the needle remains covered after use.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the needle tip is exposed continuously after removing the big sleeve and small sleeve, then the injection can be performed, but the infection probability increases and cross-infection can occur
Solution Approach 1:
The small sleeve is designed to be movable rather than fixed, allowing it to dynamically transition between retracted and extended positions. During injection, the small sleeve retracts to expose the needle tip for easy injection. After use, it can be pushed back to cover the needle tip, preventing exposure and potential infection. This dynamic mechanism resolves the contradiction between accessibility during use and safety after use.
Solution Approach 2:
The elastic element acts as an intermediary mechanism between the small sleeve and the user's manual operation. It provides the necessary force to return the small sleeve to its retracted position after injection, ensuring the needle tip is automatically covered without requiring additional manual intervention. This intermediary force mechanism ensures consistent safety while maintaining ease of operation.
2Ease of manufacture
If the big sleeve is designed to slide freely outside the needle mount, then assembly is simple, but the assembling becomes unstable and working conditions deteriorate
Solution Approach 1:
The sleeve system is segmented into a big sleeve and a small sleeve with distinct functions. The big sleeve provides outer protection and easy assembly, while the small sleeve handles the needle exposure and retraction. This segmentation allows each component to be optimized independently - the big sleeve remains simple for assembly, while the small sleeve provides the necessary stability through its engagement mechanism with the needle mount.
Solution Approach 2:
The small sleeve is nested inside the big sleeve, creating a layered structure. The small sleeve engages with the needle mount while remaining contained within the big sleeve's framework. This nesting arrangement provides stability by ensuring the small sleeve cannot move independently of the big sleeve, preventing instability during operation while maintaining assembly simplicity.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Prevents accidental needle exposure and secondary use, enhancing safety and stability during assembly with insulin pens.
Implementation Method 1
an elastic element adapted to provide elastic force for the second sleeve to move axially toward outside the receiving space
Data Source
Figure 1a~2e
Figure 3a~4e
Figure 5~7c
AI summary
The present disclosure relates to a disposable injection needle, including: a needle mount, having a tube needle; a first sleeve, one end of which is suitable for connecting to the needle mount to form receiving space, and the other end of which is provided with a first opening; a second sleeve, one end of which is located inside the receiving space, and the other end of which having a second opening extends out from the first opening, wherein the second sleeve is axially slideable; an elastic element adapted to allow the second sleeve to move axially toward outside the receiving space, wherein: the second sleeve is provided with a sleeve guiding portion, and the needle mount is provided with a guiding engagement portion, the sleeve guiding portion engages with the guiding engagement portion to guide the circumferential rotation of the second sleeve based on axial movement of the second sleeve toward inside of the receiving space; the first sleeve is provided with a blocking member and the second sleeve is provided with a fastener, wherein the blocking member and the fastener are arranged to allow the fastener to pass through the blocking member in the axial direction toward the second opening, and to prevent the fastener from passing through the blocking member in the axial direction away from the second opening to prevent the tube needle from being exposed via the second opening.