Syringe Assembly Automatic Needle Retraction Mechanism
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Solution Overview
Problem
Traditional single-use syringes can be reused, leading to increased infection risks and are cumbersome to recycle, with the needle being prone to accidental exposure and injury.
Innovation Solution
A syringe assembly design featuring a plunger assembly with a spring mechanism that automatically retracts the needle and plunger into the syringe body after use, preventing reuse and enhancing safety by using a sealing plug and fixing valve to ensure secure closure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If traditional single-use syringe design is used, then the syringe can be easily manufactured and operated, but the needle remains exposed after use leading to reuse risks and accidental injuries
Solution Approach 1:
The syringe assembly is pre-configured with the needle contained within the protective housing and the plunger positioned to enable automatic retraction. Before use, the needle is safely enclosed, and the mechanism is set up so that upon activation (pushing the plunger through the liquid), the retraction automatically occurs, preventing needle exposure before it can cause harm
Solution Approach 2:
The needle is extracted from the exposed state and placed into a protected state by being retracted into the syringe body housing after use. This separates the needle from the external environment, eliminating the hazard of accidental sticking while maintaining the functional integrity of the syringe during operation
2Device complexity
If traditional single-use syringe is designed without retraction mechanism, then the device complexity is low, but the syringe can be reused leading to infection risks
Solution Approach 1:
The syringe employs a dynamic retraction mechanism where the needle and plunger automatically move from an extended operational position to a retracted protective position after use. The spring-loaded system transforms the static syringe structure into a dynamic one that automatically changes configuration based on usage state, preventing reuse while maintaining simplicity
Solution Approach 2:
The syringe assembly performs self-protection through automatic retraction of the needle and plunger into the housing after use. The spring mechanism and positioning structures enable the device to automatically secure itself in a locked, non-reusable state without requiring external intervention, ensuring reliability while keeping the mechanism simple
3Object-affected harmful factors
If a retraction mechanism is added to the syringe, then needle safety is improved, but the device complexity increases
Solution Approach 1:
The retraction mechanism is merged with the existing plunger and housing structures. The spring is integrated into the housing, the plunger serves dual purposes (both for liquid delivery and for triggering retraction), and the needle housing combines protective enclosure with the retraction guide. This integration minimizes additional components while achieving needle safety
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
The syringe assembly effectively prevents reuse and reduces infection risks by automatically retracting the needle and plunger, while ensuring secure sealing to prevent leakage during use.
Implementation Method 1
a spring arranged around the plunger body and located between the first stepped part and the second stepped part
Implementation Method 2
the spring is in a compressed state... when the syringe assembly is in a destroyed position, the spring is in a free state
Data Source
AI summary
A syringe assembly includes a plunger assembly, a syringe body, and a needle. The plunger assembly includes a plunger rod, a spring, a plunger base, and a plunger plug. The plunger rod includes a first end member having a first stepped part positioned in an inner wall thereof, a second end member, and a first accommodating room. The plunger base includes a plunger body, a projection, a second stepped part, a plunger member, and a locating member. The plunger body is received in the first accommodating room, and the projection abuts against the first end member. The spring is arranged around the plunger body and positioned between the first stepped part and the second stepped part. The plunger plug is mounted to the second end member, and defines a fixing groove. The syringe body includes a needle cannula, a needle base, a fixing pole, and a fixing valve. The plunger assembly is received in the needle cannula. The needle base is mounted to the needle cannula. The fixing valve is received in the needle base. The fixing pole is received in the fixing valve and protrudes out of the needle base. The needle is received in the fixing pole. The syringe assembly of the present invention is prevented from reuse and accidently damage because the needle can retract into the plunger rod using restoring force of the spring.