Medicament Delivery Cap Assembly With Cam-Locked Shield Insertion
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Solution Overview
Problem
Existing medicament delivery devices face difficulties in the assembly of delivery member shields due to connector designs that make it challenging to insert the needle cover or rigid needle shield, leading to increased complexity.
Innovation Solution
A cap assembly with a tubular body and an elongated squeeze member featuring radial arms and a cam structure, allowing for easy insertion and secure engagement of the delivery member shield by axial displacement and rotation, facilitating simple mounting and removal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the connector legs are flexed towards each other when the connector is placed in the cap insert, then the needle cover/rigid needle shield is secured to the cap, but it becomes more difficult to insert the needle cover/rigid needle shield into the connector
Solution Approach 1:
The radial arms are pre-configured in a relaxed state that allows easy insertion of the delivery member shield. After insertion, the cam structure is activated to flex the radial arms towards each other, securing the shield in place. This separates the insertion phase from the securing phase, allowing each function to be optimized independently.
Solution Approach 2:
The radial arms are designed to be flexible rather than rigid, allowing them to dynamically change their configuration. They start in an open position for easy insertion, then transition to a closed position when the cam structure is activated, providing secure retention. This dynamic behavior resolves the contradiction between ease of insertion and secure securing.
2Reliability
If the radial arms are pressed into the channel by the inner walls of the tubular body, then the cross-sectional area of the channel is reduced for secure engagement, but the assembly process becomes more complex
Solution Approach 1:
The cap structure and the squeeze member are combined into an integrated assembly. The cam structure is built into the cap, and the radial arms are part of the squeeze member, eliminating the need for separate securing mechanisms and reducing overall device complexity while maintaining secure engagement.
Solution Approach 2:
The radial arms automatically press into the channel when the squeeze member is axially displaced, without requiring additional actuators or complex mechanisms. The cam structure leverages the axial motion itself to trigger the radial inward movement, making the system self-actuating and simpler in design.
3Ease of operation
If axial displacement of the squeeze member causes rotation relative to the cap, then the radial arms disengage from the radial recesses and are pressed into the channel, but the mechanism becomes more complex
Solution Approach 1:
The cam structure performs multiple functions simultaneously: it converts axial displacement to rotational motion, controls the disengagement of radial arms from radial recesses, and triggers the pressing of radial arms into the channel. This multi-functionality reduces the need for separate mechanisms, offsetting the added complexity with operational efficiency.
Solution Approach 2:
The cam structure utilizes curved surfaces to transform linear axial motion into rotational motion of the squeeze member. This curved geometry naturally guides the radial arms through their disengagement and engagement paths, providing a smooth and reliable mechanism without requiring complex linkages or multiple components.
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 cap assembly simplifies the assembly process by enabling easy engagement and disengagement of the delivery member shield, enhancing user convenience and reducing assembly complexity.
Implementation Method 1
the radial arms are pressed into the channel by the inner walls of the tubular body, reducing a cross-sectional area of the channel
Implementation Method 2
axial displacement of the squeeze member from a first position in which the proximal end face bears against the cam structure to a second position in which the squeeze member is received further by the cap causes rotation of the squeeze member relative to the cap
Data Source
Figure 1~2
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AI summary
A cap assembly for a medicament delivery device is disclosed. The cap assembly includes a cap configured to be mounted to a proximal end of the medicament delivery device, wherein the cap comprises a cam surface. The cap assembly further includes a squeezer comprising (i) a body defining a first longitudinally extending channel configured to receive a delivery member shield and (ii) a plurality of radial arms flexible in a radial direction. The cap assembly also includes a spinner comprising (i) a proximal end face configured to cooperate with the cam surface of the cap, (ii) a body defining a second longitudinally extending channel configured to receive the squeezer, and (iii) a plurality of holes in the body of the spinner configured to receive the plurality of radial arms of the squeezer.