Injection Device Fluid-Damped Delay Mechanism
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing injection devices face challenges in ensuring complete discharge of syringe contents and reliable release from the drive spring, often resulting in incomplete discharge or 'wet' injections due to manufacturing tolerance stack-ups, which can be costly to resolve with fine tolerances and fluid-damped delay mechanisms.
Innovation Solution
The use of a highly viscous fluid with a dynamic viscosity of 3000 centiPoise or more, such as DOW CORNING 111 Silicone Compound, to create a fluid-damped delay mechanism that compensates for tolerance variations, allowing complete discharge before syringe retraction without the need for fine manufacturing tolerances or seals, thereby preventing simulated wet injections.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a fluid-damped delay mechanism is used to ensure complete discharge, then discharge completeness is improved, but the device requires fine manufacturing tolerances and seals which increases manufacturing cost and complexity
Solution Approach 1:
The patent changes the physical parameter of the damping fluid to extremely high viscosity (3000 centiPoise or more), which fundamentally alters the damping mechanism's behavior. This high viscosity allows the fluid to provide sufficient delay effect without requiring precise dimensional tolerances or sealing mechanisms, thereby resolving the contradiction between reliability and manufacturing complexity
Solution Approach 2:
The patent incorporates the high viscosity damping fluid into the drive mechanism in advance, where it automatically provides the necessary delay effect during operation. This preliminary preparation of the damping mechanism eliminates the need for additional complex components like seals and precision-toleranced parts that would otherwise be required
2Reliability
If a fluid-damped delay mechanism is used to ensure complete discharge, then discharge completeness is improved, but manufacturing cost increases due to fine tolerances and seals
Solution Approach 1:
By changing the viscosity parameter of the damping fluid to 3000 centiPoise or more, the patent eliminates the need for expensive fine tolerances and sealing components, thereby significantly reducing manufacturing cost while maintaining discharge completeness
Solution Approach 2:
The patent employs a simple, inexpensive high viscosity fluid that can be easily manufactured and incorporated into the device, replacing expensive precision components and seals, making the device more cost-effective for disposable injection applications
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
Ensures complete discharge of syringe contents before retraction, reducing the risk of 'wet' injections and lowering manufacturing costs by eliminating the need for precise tolerances and seals, while maintaining a compact design with a reduced component count.
Implementation Method 1
a highly viscous fluid damping the movement of the first component relative to the second, so that the release of the syringe is delayed
Data Source
AI summary
An injection device (10; 110, 210) is described of the type that receives a syringe, extends it, discharges its contents and then retracts it automatically. The injection device makes use of a fluid-damped delay mechanism.