Needle Safety Protector Hub Rotation Adjustment Mechanism
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Solution Overview
Problem
Existing needle safety protector devices fail to correctly align the cut surface of an injection needle during assembly, leading to potential medical accidents due to incorrect orientation of the needle hub when fastened to a syringe, which can result in improper injection direction.
Innovation Solution
A device with tooth protrusions arranged at equal intervals on the inner surface of a hub coupling hole and on the needle hub, allowing for cross-over rotation to correct the cut surface direction of the injection needle, ensuring it is aligned to a predetermined direction during fastening.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the needle hub is fastened to the needle safety protector using a simple groove and hole structure, then the assembly process is simple, but the rotation direction of the injection needle cannot be controlled, leading to incorrect cut surface orientation
Solution Approach 1:
The patent applies asymmetry by providing asymmetric tooth protrusions on the inner surface of the hub coupling hole and corresponding asymmetric tooth grooves on the needle hub. These asymmetric features engage with each other to prevent rotation in incorrect directions, ensuring the cut surface of the injection needle is oriented in the correct direction while maintaining a relatively simple assembly process.
Solution Approach 2:
The patent uses curved tooth protrusions and tooth grooves that engage with each other through a cross-over rotation mechanism. The curved geometry allows the needle hub to be inserted and then rotated to a predetermined direction, where the curved features lock together to prevent further rotation, thereby controlling the orientation of the injection needle.
2Manufacturing precision
If force-fitting method is used to prevent rotation of the needle hub, then rotation can be prevented, but it is difficult to fit the needle hub tightly and rotation adjusting is variable depending on the degree of force-fitting
Solution Approach 1:
The patent employs curved tooth protrusions and tooth grooves that engage through a controlled cross-over rotation. This curved geometry provides a mechanical advantage that enables tight fitting and precise rotation control without requiring excessive force, making the fitting process more consistent and less variable compared to simple force-fitting methods.
3Productivity
If the needle hub is fastened without a rotation adjusting mechanism, then the assembly process is fast, but the cut surface direction of the injection needle cannot be corrected to a predetermined direction
Solution Approach 1:
The curved tooth protrusions and tooth grooves are designed to engage through a limited cross-over rotation, allowing the needle hub to be quickly inserted and then automatically guided to the correct orientation. This mechanism enables both fast assembly and precise orientation control, as the curved features naturally guide the needle hub to the predetermined direction during the fastening process.
Solution Approach 2:
The asymmetric tooth protrusions and tooth grooves are designed to self-align during assembly. When the needle hub is inserted into the hub coupling hole, the curved features automatically engage and guide the rotation to the correct orientation without requiring external adjustment mechanisms, thereby maintaining assembly speed while ensuring precise cut surface orientation.
Data Source
AI summary
A device for adjusting the tightening angle of a needle safety protector is proposed. The device is configured to provide an injection needle in an integrated state with a needle hub for preventing reuse of the injection needle and to fasten the needle hub to a needle safety protector that is disposed of in a folded state after use, a fastening structure is improved such that rotation is possible by a predetermined angle when the needle safety protector is rotated. Accordingly, an injection is safely performed by correcting the injection needle to the reference direction. In addition, even when a syringe is assembled by deviating from a reference angle during the mass production with the automatic line, the wrong angle is corrected in use.