Safety Injection Needle with Elastic Flip Mechanism
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Solution Overview
Problem
Current safety injection needles face difficulties in easy snap-fitting, stability, and material wastage, requiring excessive force for sheath fitting, prone to disengagement, and increased production costs due to enlarged needle hubs for locking mechanisms.
Innovation Solution
A safety injection needle design featuring dual needle hub hooks on the sidewall cooperating with elastic root portion snaps in a safety protective cover, allowing easy fitting with minimal force and providing strong anti-pull resistance, reducing product volume and costs while maintaining stability and safety.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a lateral safety sheath structure with hook body is used to protect the needle tube, then protection function is achieved, but excessive force is required for fitting and operation becomes difficult
Solution Approach 1:
The patent inverts the traditional snap-fitting direction by having the safety sheath's snap engage with the needle hub's hook from the inside outward, rather than the conventional external snapping mechanism. This inversion allows the elastic root portion to naturally push the snap into the hook during sheath insertion, reducing fitting force to approximately 0.5N and enabling comfortable single-hand operation while maintaining reliable protection function
Solution Approach 2:
The elastic root portion automatically generates the force needed to push the snap into engagement with the hook during the sheath insertion process, eliminating the need for additional manual force or complex mechanisms. The structure serves itself by using its own elastic deformation to achieve the fitting action, significantly reducing operation difficulty
2Ease of manufacture
If snap-fitting mechanism is used to connect safety sheath and needle tube, then assembly is simplified, but disengagement occurs under external force reducing stability
Solution Approach 1:
The patent employs asymmetric geometry where the hook has a specific shape with a hook opening that selectively receives the snap, while the snap's engagement surface is designed to match the hook's asymmetric profile. This asymmetric pairing creates a connection that is easy to assemble in one direction but resistant to disengagement under external force, resolving the contradiction between assembly simplicity and connection stability
Solution Approach 2:
The elastic root portion is pre-configured to exert a continuous pushing force on the snap, maintaining constant engagement pressure against the hook. This preliminary anti-action counteracts any external forces that might attempt to disengage the connection, preventing separation while maintaining simple snap-fitting assembly
3Reliability
If needle hub is enlarged to include locking mechanism, then locking function is improved, but product volume increases and production costs rise
Solution Approach 1:
The patent extracts the locking function from the needle hub body and implements it through a separate, minimal hook structure attached to the needle hub. This extraction allows the needle hub to maintain its original small size while the detached hook provides the necessary locking engagement with the safety sheath's snap, avoiding volume increase and additional production costs
Solution Approach 2:
The locking mechanism is segmented into two separate components: a small hook attached to the needle hub and a snap integrated into the safety sheath. This segmentation allows each component to be optimized independently, with the hook being minimal in size and the snap providing the locking function within the sheath structure, thereby avoiding enlargement of the needle hub while maintaining reliable locking function
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
Enables comfortable single-hand operation with reduced force requirement, enhanced stability, and minimized material usage, achieving ideal safety and environmental sustainability with efficient assembly and reduced disengagement risk.
Implementation Method 1
two symmetrically-distributed protective cover snaps 203 with elastic root portions 2031 are disposed in the hollow inner cavity of the safety protective cover 2
Data Source
AI summary
Disclosed is a safety injection needle. An injection needle (1) consists of a needle hub (101) and a needle tube (102). The needle hub (101) is connected to a safety protective cover (2) by means of an elastic flip mechanism (4). Two symmetrically-distributed needle hub hooks (103) are provided on a side wall of the needle hub (101). Two symmetrically-distributed protective cover snaps (203) are provided in a hollow inner cavity of the safety protective cover (2). The two protective cover snaps (203) cooperates with the two needle hub hooks (103). Protective cover snap stoppers (204) are provided on outer sides of the two protective cover snaps (203). The injection needle employs the two needle hub hooks (103) which are disposed on the side wall of the needle hub (101) and cooperate with the two protective cover snaps (203) disposed in the inner cavity of the safety protective cover (2). The snap-fitting process of the protective cover snaps (203) and the needle hub hooks (103) is easy, simple and convenient, a required thrust is only about 0.5 N, and a single-hand operation can be achieved. The protective cover snap stoppers (204) disposed on the outer sides of the protective cover snaps (203) can effectively prevent disengagement of the protective cover snaps (203) from the needle hub hooks (103).