Needle Shield Puller Cap Assembly With Slit Grip
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Solution Overview
Problem
Existing automatic injector devices face challenges in efficiently removing protective needle shields due to complex designs, high installation forces, and potential damage to the needle or shifting of the protective shield, which can affect the sealing integrity.
Innovation Solution
A puller assembly comprising a one-piece molded grip component with a tubular body and a cap, featuring a slit for size adjustment and articulating sections, along with a cap having a softer gripping periphery, allows for secure gripping and removal of the needle shield within a range of axial tolerances without applying excessive force, thereby maintaining the needle seal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a two-piece cap assembly with resilient fingers and serrated ribs is used to grip the rigid needle shield, then the gripping capability is improved, but the device complexity increases and manufacturing becomes more difficult
Solution Approach 1:
The patent combines the cap and grip component into a single integrated unit. The grip component is formed as one piece with the cap, eliminating the need for separate resilient fingers and serrated ribs that were previously required in two-piece assemblies. This merging maintains gripping capability while significantly reducing assembly complexity.
Solution Approach 2:
The grip component incorporates a slit that allows it to be segmented or split during installation, enabling it to expand and contract for gripping the needle shield. This single-piece segmentation approach achieves the same function as multiple separate components but with simpler manufacturing and assembly.
2Strength
If high forces are applied during installation of the cap assembly to secure gripping, then the gripping strength is improved, but the risk of bending the needle or shifting the protective shield increases
Solution Approach 1:
The grip component is designed with a slit that provides dynamic flexibility during installation. The component can elastically deform to accommodate the needle shield and then maintain a secure grip without requiring excessive installation forces. This dynamic behavior allows the grip to adapt to slight variations in needle shield positioning while maintaining reliable sealing.
Solution Approach 2:
The grip component's physical state changes during installation - it transitions from a relaxed state to an engaged state where the slit closes and the component expands to grip the needle shield. This parameter change allows the same component to provide both easy installation and strong gripping without requiring high forces that could damage the needle or shield.
3Adaptability or versatility
If the cap assembly is designed to accommodate a range of axial tolerances in needle shield positioning, then the adaptability is improved, but the device complexity increases
Solution Approach 1:
The grip component with its slit design provides inherent dynamic adjustment capability. As the component is installed and engages the needle shield, the slit allows the component to flex and adapt to slight variations in axial positioning. This dynamic adaptation enables the same design to accommodate tolerance variations without requiring complex adjustment mechanisms or multiple design variants.
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 puller assembly effectively grips and removes the needle shield across varying tolerances without compromising the seal, reducing manufacturing complexity and the risk of shield damage, thus enhancing user convenience and maintaining the needle's sterility.
Implementation Method 1
a grip component (25) formed of an elastomeric material and having a one-piece molded construction... the body (32) including a plurality of rigid arcuate sections... hinge regions (49, 50) interconnecting the arcuate sections
Implementation Method 2
Each of the body sections (44-46) includes a groove (75) along its outer radial periphery... a ramped distal edge (76) leading into the groove (75)... configured to engage the needle shield
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
A puller assembly for removing a shield from around a needle of a syringe. The puller assembly includes a grip component and a cap. The grip component has a tubular body defining an interior hollow which axially receives the shield. The tubular body has a slit that allows it to be forcibly shifted from a first arrangement to a second arrangement to change the size of the interior hollow. The tubular body includes a radial inner face with at least one radial inward projection for directly engaging the shield. The cap is grippable by a user. The grip component is held by the cap when inserted within a cavity of the cap during manufacturing installation, and when so held at least one radial inward projection of the grip component engages the shield for removal of the shield from around the needle when the cap is moved. A method of mounting a puller assembly to a shield around a needle is also disclosed.