Disposable Syringe Retractable Needle Collapse Mechanism
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Solution Overview
Problem
Current disposable syringes with retractable needles often have complex structures and high costs, and there is a risk of needle re-emergence after retraction, posing a biological risk due to accidental exposure.
Innovation Solution
A disposable syringe with a mechanism that irreversibly traps the needle inside the syringe after use, utilizing a collapse mechanism facilitated by a separation element and potentially assisted by a spring, preventing outward needle exit.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a retractable needle mechanism is implemented in disposable syringes, then safety against accidental punctures is improved, but device complexity and manufacturing cost increase
Solution Approach 1:
The syringe is divided into distinct functional segments: a barrel, a plunger, and a separately retractable needle assembly. The needle is initially detached from the barrel and held in a protective housing, allowing independent operation and retraction of the needle component. This segmentation enables the safety function without requiring complex integration throughout the entire syringe structure.
Solution Approach 2:
The needle is pre-positioned in a retracted state within its housing before use. The protective housing is pre-configured to contain the needle, and the mechanism is designed so that retraction automatically occurs upon engagement with the barrel or upon plunger activation. This preliminary positioning ensures safety is built-in from the start without requiring complex active control systems.
2Object-affected harmful factors
If the needle is made retractable, then protection against accidental exposure is improved, but the risk of needle re-emergence after retraction increases
Solution Approach 1:
The housing structure is designed with features that preemptively prevent needle re-emergence. The needle, once retracted, is mechanically constrained by the housing geometry, friction surfaces, or locking features that make re-extension impossible without deliberate disassembly. This preliminary anti-action is built into the passive structure, ensuring that even if the plunger is manipulated, the needle cannot accidentally exit the housing.
Solution Approach 2:
The needle assembly is nested within the protective housing, with the needle fitting inside a dedicated cavity. The housing acts as a container that completely encloses the needle in its retracted state. This nesting arrangement ensures that the needle is physically trapped within the housing structure, preventing any possibility of re-emergence while maintaining a compact and safe configuration.
3Reliability
If a complex retractable needle mechanism is used, then safety is improved, but ease of operation deteriorates
Solution Approach 1:
The retractable needle mechanism is designed to operate automatically through the natural actions of using the syringe. The needle retracts when the plunger is engaged or when the syringe is activated, without requiring separate manual intervention. The mechanism uses the existing operational forces (plunger movement, insertion motion) to trigger retraction, making the safety function self-activating and maintaining simplicity of use.
Solution Approach 2:
The needle retraction function is merged with the existing syringe operational sequence. The same plunger mechanism that delivers the medication also triggers needle retraction, or the needle retraction is combined with the barrel engagement process. This merging ensures that safety is achieved through actions already required for normal syringe operation, eliminating the need for additional steps or complex control systems.
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
Enhances safety by preventing needle re-emergence and reducing the risk of accidental punctures, particularly for medical personnel and the general public, by ensuring the needle remains trapped within the syringe.
Implementation Method 1
The present invention also describes a disposable syringe with retractable needle in which the retraction of the needle can possibly be facilitated due to the presence of a spring situated inside the syringe itself.
Data Source
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AI summary
Disposable syringe with retractable needle comprising a cylindrical body (1), a plunger (2) with grooves (3) and base (4), a needle (7) supported by a support (9), a housing (10) adapted for inserting said support (9) and surrounded by a seal gasket (6) which is integral with a head/support (5) of the plunger (2), a neck (8) arranged at the upper end of the cylindrical body (1), and a separation element (1 1) adapted to make the needle (7) collapse inside the cylindrical body (1) after the use of the syringe.