Needle Shield Assembly with Nested Tapered Inner Body
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Solution Overview
Problem
Conventional needle shield assemblies for medicament delivery devices are bulky and inefficient in packaging and use due to their large diameter, which compromises the usability of syringes and auto-injectors, and existing solutions fail to adequately protect the needle from external forces that cause bending.
Innovation Solution
A needle shield assembly comprising an inner body with a larger proximal portion and a smaller distal portion, frictionally engaging the needle, and an outer body with projections and notches for secure engagement, constructed from different materials like rubber and plastic, allowing for a compact and secure design that prevents axial movement and rotation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional plastic cover is used to encase the rubber sheath, then the needle is protected from bending, but the assembly becomes bulky with a large diameter that compromises packaging efficiency and usability
Solution Approach 1:
The inner body is nested within the outer body, with the distal portion of the inner body fitting inside the outer body's cavity. This nested configuration allows the needle shield assembly to maintain a compact overall diameter while providing layered protection for the needle, resolving the contradiction between protection reliability and compact size.
Solution Approach 2:
The needle shield assembly is divided into two functional segments: an inner body for direct needle engagement and protection, and an outer body for structural support and constraint. This segmentation allows each component to be optimized for its specific function while maintaining a compact overall diameter, addressing both protection needs and space constraints.
2Object-affected harmful factors
If a rubber sheath is used to protect the needle, then the needle is covered, but external forces cause the rubber sheath and needle to bend
Solution Approach 1:
The needle shield assembly combines two different materials with complementary properties: a flexible inner body material that conforms to and protects the needle, and a rigid outer body material that resists external forces and maintains structural integrity. This composite structure provides both coverage and stability, preventing needle bending while maintaining needle straightness.
Solution Approach 2:
The protective function is segmented between the inner body (direct needle contact and coverage) and the outer body (structural support and force resistance). This segmentation allows the flexible inner body to provide coverage while the rigid outer body provides stability, resolving the contradiction between coverage and straightness maintenance.
3Volume of moving object
If the outer body diameter is reduced to improve packaging efficiency, then space is saved, but the structural integrity and protective capability are compromised
Solution Approach 1:
The nested configuration of the inner body within the outer body allows the assembly to maintain a compact outer diameter for efficient packaging while the combined structural integrity of both bodies provides adequate protective capability. The inner body's distal portion extends to provide protection at the needle tip without increasing the overall assembly diameter.
Solution Approach 2:
The shield assembly provides localized protection where needed: the distal portion of the inner body provides protection at the needle tip, while the outer body provides structural support at critical locations. This local quality approach maintains protective capability without requiring a uniformly large diameter throughout the entire assembly.
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 solution provides a compact and effective needle shield assembly that securely protects the needle, enhances packaging efficiency, and allows for optimal use in various medicament delivery devices without compromising the device's functionality.
Implementation Method 1
The distal portion of the inner body may be adapted to frictionally engage the needle
Data Source
AI summary
Described is a needle shield assembly comprising an inner body adapted to receive a needle and an outer body coupled to the inner body. The inner body comprises a proximal portion having a first outer diameter (D4) and a distal portion having a second outer diameter. The first outer diameter is larger than the second outer diameter. The outer body has a third outer diameter (D3) substantially equal to or less than the first outer diameter.