Autoinjector Collar Rib Locking Mechanism
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing autoinjectors face challenges in ensuring consistent and reliable administration of medications, particularly for users who may lack the dexterity or strength required to operate manual injection devices.
Innovation Solution
The autoinjector design features a telescopic needle shroud, a carrier for holding a medicament container, and a collar mechanism that interacts with a rib on the case to control the movement and locking of the needle shroud, ensuring proper injection and needle safety.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a spring mechanism is used to provide injection force, then the ease of operation is improved for users with limited strength, but the device complexity increases
Solution Approach 1:
The spring mechanism is pre-loaded and automatically activates to provide the injection force, eliminating the need for the user to manually apply force. The device serves itself by using the stored energy in the spring to drive the plunger and deliver the medicament, making it accessible to users with limited strength while managing complexity through automated operation.
Solution Approach 2:
The spring is pre-compressed during device assembly or activation, storing energy in advance before the injection is needed. This preliminary action allows the spring to automatically provide the necessary force during injection, improving ease of operation for users who cannot generate sufficient manual force, while the complexity is contained within the pre-configured mechanism.
2Reliability
If a collar mechanism with multiple engagement points is used to control needle shroud movement, then the reliability of injection delivery is improved, but the device complexity increases
Solution Approach 1:
The collar mechanism is divided into multiple engagement points or lobes that interact with corresponding features on the needle shroud and carrier. This segmentation allows the collar to control different stages of movement independently, ensuring reliable sequential operation of the injection mechanism while managing complexity through modular, repetitive structural elements.
Solution Approach 2:
The collar is designed to rotate or move dynamically through different positions, engaging and disengaging from various points on the needle shroud and carrier during the injection sequence. This dynamic operation ensures reliable control over the timing and sequence of needle deployment, medicament delivery, and needle retraction, while the complexity is managed through the predictable cyclic motion of the mechanism.
3Object-affected harmful factors
If the needle shroud is designed to telescope between extended and retracted positions, then the safety against needle stick injuries is improved, but the device complexity increases
Solution Approach 1:
The needle shroud is designed as a telescopic structure where the protective outer shroud nests over the needle during storage and transport, and can retract to expose the needle during injection. This nesting arrangement provides safety by enclosing the needle when not in use, preventing accidental needle stick injuries, while the complexity is managed through the compact nested configuration that utilizes existing structural spaces.
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
This design enhances the ease of use by reducing the need for manual force and dexterity, ensuring consistent dosing, and providing a secure mechanism to lock the needle in place after use, thereby reducing the risk of needle stick injuries.
Implementation Method 1
a drive spring biasing the plunger relative to the carrier
Implementation Method 2
a collar rotatably and slidably disposed in the case and coupled to the needle shroud and the carrier. The collar abuts the rib when the needle shroud is in the first extended position and the carrier is in the first axial position, and the collar disengages the rib when the needle shroud is in the retracted position and the carrier is in the second axial position
Data Source
AI summary
An autoinjector includes a case having a rib, a needle shroud telescopically coupled to the case, a carrier slidably arranged in the case and adapted to hold a medicament container, and a collar rotatably and slidably disposed in the case and coupled to the needle shroud and the carrier. The needle shroud is movable between a first extended position, a retracted position and a locked second extended position. The carrier is movable from a first axial position to a second axial position relative to the case. The collar abuts the rib when the needle shroud is in the first extended position and the carrier is in the first axial position, and the collar disengages the rib when the needle shroud is in the retracted position and the carrier is in the second axial position.