Syringe Cap Guide Part Axial Alignment
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Solution Overview
Problem
Conventional syringe caps can be mounted at an oblique angle to the syringe body, leading to difficulties in storage, transportation, and proper sealing, especially in auto-injector systems, where the injection needle may pierce the inner layer, causing damage and compromising sealing performance.
Innovation Solution
A syringe design featuring a cap with an elastic cylindrical body and an external cylindrical body that includes a guide part to align the injection needle axially during mounting, using a guide part with a cylindrical shape coaxial with the external cylindrical body to prevent tilting and ensure proper alignment, and a locking mechanism to secure the cap in place.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the injection needle is inserted into the cap without a guide part, then the cap can be easily mounted, but the cap may be mounted at an oblique angle causing sealing failure and damage
Solution Approach 1:
The guide part acts as an intermediary element between the injection needle and the elastic cylindrical body. It provides a cylindrical surface that the injection needle contacts during insertion, guiding the needle along the axial direction and preventing oblique insertion that would cause sealing failure or damage to the inner layer.
Solution Approach 2:
The guide part enables the injection needle to self-align during insertion. By providing a cylindrical contact surface with dimensions matching the holding part, the guide part allows the needle to naturally follow the axial direction without requiring external alignment tools or complex mounting procedures.
2Reliability
If the cap is mounted at an oblique angle, then the injection needle may pierce the inner layer portion, but adding a guide part increases device complexity
Solution Approach 1:
The cap is segmented into distinct functional parts: the outer layer portion (shield), the inner layer portion (sheath), and the guide part. This segmentation allows each component to perform its specific function - the guide part prevents oblique insertion, the inner layer provides sealing, and the outer layer offers protection - without requiring complex integration between them.
Solution Approach 2:
The guide part performs the preliminary action of guiding and aligning the injection needle before the needle reaches the inner layer portion. By establishing proper axial alignment during the insertion process, the guide part prevents the needle from piercing the inner layer at an oblique angle, thereby maintaining sealing performance without adding complex locking or adjustment mechanisms.
3Ease of operation
If the guide part inner diameter is larger than the holding part outer diameter, then the injection needle can be easily inserted, but the guide part cannot effectively guide the needle axially
Solution Approach 1:
The guide part employs local quality by having its inner diameter substantially equal to the outer diameter of the holding part. This precise dimensional relationship creates a snug fit that provides effective guidance and axial alignment during insertion, while still allowing the injection needle to pass through without excessive friction or difficulty.
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 cap is securely mounted without tilting, maintaining sealing performance and preventing damage during storage, transportation, and use in auto-injector systems, ensuring accurate and reliable operation.
Implementation Method 1
an inner layer portion (sheath) having elasticity
Implementation Method 2
a guide part that guides the injection needle toward a certain direction by coming into contact with a part of the syringe body
Implementation Method 3
an external cylindrical body for covering the circumference of the elastic cylindrical body and holding the elastic cylindrical body in such a manner as to prevent movement of the elastic cylindrical body
Data Source
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AI summary
An object is to provide a syringe that is capable of preventing a cap from being mounted to a syringe body at an oblique angle. The cap includes an elastic cylindrical body for receiving an injection needle therein and sealing a holding part, and an external cylindrical body for covering the circumference of the elastic cylindrical body and holding the elastic cylindrical body in such a manner as to prevent movement of the elastic cylindrical body. The external cylindrical body includes an opening part having a dimension configured to be larger than the holding part of the syringe body, and a guide part that guides the injection needle toward a certain direction by coming into contact with a part of the syringe body when the injection needle is received inside the elastic cylindrical body.