Auto-Injector Compression Connection Mechanism
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Manual injection devices pose challenges such as requiring continuous user effort, potential for underdosing, high injection forces, and discomfort due to trembling, while auto-injectors face issues in secure connection and proper placement of needle shields, which can lead to premature activation and medicament wastage.
Innovation Solution
A compression connection means using an annular mounting sleeve with a spring bias, latch arms, and a needle shroud to securely attach the front-end device to the back-end device, ensuring proper placement and preventing premature activation by detecting needle shield contact with the skin.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a bayonet type fitting is used to connect front and rear assemblies, then easy insertion and withdrawal is achieved, but secure connection and prevention of premature activation may be compromised
Solution Approach 1:
The patent combines a bayonet-type fitting for easy insertion with a compression connection mechanism featuring a mounting sleeve and latch arms for secure connection. The latch arms engage with the syringe barrel and are retained by the mounting sleeve, creating a dual-mechanism connection that maintains both ease of operation and connection reliability.
Solution Approach 2:
The connection mechanism is segmented into distinct functional components: the bayonet fitting for initial engagement, the compression spring for applying force, the mounting sleeve for retention, and the latch arms for securing. This segmentation allows each component to perform its specific function optimally while working together as an integrated system.
2Reliability
If the needle shield is not properly placed, then premature activation is prevented, but proper detection and control of shield placement adds device complexity
Solution Approach 1:
The system uses the existing compression connection mechanism to serve dual purposes: connecting the syringe and simultaneously detecting needle shield placement. The compression spring and mounting sleeve automatically detect when the shield is properly positioned through the mechanical interaction during assembly, eliminating the need for separate detection sensors or complex control systems.
Solution Approach 2:
The compression connection mechanism performs multiple functions: it secures the syringe barrel to the drive assembly, detects needle shield placement, and prevents premature activation. This multi-functionality reduces overall device complexity by eliminating the need for dedicated detection mechanisms.
3Device complexity
If manual injection devices are used, then device simplicity is maintained, but user comfort and dosing accuracy deteriorate due to continuous effort and trembling
Solution Approach 1:
The auto-injector device performs the injection action automatically without requiring continuous user effort. The compression spring provides the driving force to advance the plunger and deliver the medicament, while the mechanical connection mechanisms ensure proper positioning and activation. This eliminates user-induced trembling and ensures complete dose delivery.
Solution Approach 2:
The device is prepared in advance with the syringe pre-loaded and the compression spring pre-loaded. The needle is shielded before use, and all components are positioned ready for activation. This preliminary preparation eliminates the need for continuous user manipulation during the injection process.
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 simplifies the assembly of auto-injectors, reduces the risk of underdosing and medicament wastage, and enhances user safety by ensuring proper needle placement and activation only when the shield is in contact with the skin, thereby improving the reliability and efficiency of medicament delivery.
Implementation Method 1
a mounting sleeve spring (1.7.1) biasing the mounting sleeve towards a locked position
Data Source
Figure 1A~1B
Figure 2A~2B
Figure 3A
AI summary
The invention relates to a compression connection means for an auto-injector (A), wherein the compression connection means adapted to attach a front-end device(1) of the auto-injector (A) to a back-end device (3) of the auto-injector (A) comprises - an annular mounting sleeve (1.11) that is axially displaceable parallel to a longitudinal axis (X) between a locked position (L) and an unlocked position, - a mounting sleeve spring (1.7.1) biasing the mounting sleeve (1.11) towards a locked position (L), - at least one latch arm (1.1.2) connected to one of either the front-end device (1) or the back-end device(3), wherein the latch arm (1.1.2) is deflectable in a radial direction, wherein the mounting sleeve (1.11) in the locked position (L) is arranged to prevent the radial deflection of the latch arm (1.1.2) and wherein the mounting sleeve (1.11) in the unlocked position allows for a radial deflection of the latch arm (1.1.2), so as to allow the latch arm (1.1.2) to be deflected on assembly or disassembly of the front-end device (1) to the back-end device (3) and to latch to or unlatch from the other of the front-end device (1) or the back-end device (3).