Interchangeable Syringe Carriages for Fast Plunger Rod Coupling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing systems for coupling plunger rods to syringe assemblies are inefficient for small batches and require time-consuming manual adjustments for different sizes, and automated machines have a large footprint and are impractical for flexible use.
Innovation Solution
A machine with interchangeable carriages and an actuating device that moves a cradle from a first to a second position to couple plunger rods to syringe assemblies, using pressure plates, friction elements, and servomotors for efficient coupling, accommodating different sizes and reducing manual intervention.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a fully automated machine is used for coupling plunger rods to syringe assemblies, then productivity is improved for large batches, but device complexity and footprint increase, making it impractical for small batches and different sizes
Solution Approach 1:
The automated machine is divided into modular functional units: a carriage system with interchangeable carriages for different syringe sizes, a cradle for positioning, an actuating device for coupling, and a pressure plate application system. Each module can be independently selected or adjusted based on batch size and syringe dimensions, allowing the system to scale from small to large batches without requiring a completely different machine.
Solution Approach 2:
The machine incorporates adjustable and interchangeable components rather than fixed structures. Carriages can be swapped to accommodate different syringe assembly sizes, the cradle position can be adjusted via the actuating device, and the pressure plate force can be dynamically controlled. This dynamic adaptability allows the same machine to efficiently handle varying batch sizes and syringe specifications.
2Adaptability or versatility
If manual adjustment is used for different syringe sizes, then adaptability is improved, but loss of time increases due to changeover procedures
Solution Approach 1:
Multiple carriages designed for different syringe assembly sizes are prepared in advance and stored on the machine. When a changeover is needed, the operator simply selects and installs the pre-configured carriage matching the required size, eliminating the need for manual adjustments during changeover. This preliminary preparation of various carriage configurations significantly reduces changeover time while maintaining full adaptability to different syringe sizes.
Solution Approach 2:
The machine employs a universal carriage interface and standardized cradle design that can accommodate multiple syringe sizes through interchangeable carriages rather than size-specific adjustment mechanisms. This multi-functional approach allows a single machine to handle various syringe dimensions using the same basic structure with simple carriage swaps, rather than requiring complex adjustment procedures for each size.
3Strength
If excessive pressure is applied during plunger rod coupling, then coupling strength is improved, but harmful factors increase due to premature fluid expulsion and compromised container closure integrity
Solution Approach 1:
The actuating device incorporates a feedback-controlled mechanism that monitors the coupling process and automatically adjusts the applied force. As the plunger rod engages with the syringe assembly, the system detects resistance changes and modulates the actuating force accordingly, ensuring sufficient coupling strength without exceeding the threshold that would cause fluid expulsion or damage the container closure. This closed-loop control prevents both under-coupling and over-pressurization.
Solution Approach 2:
The machine includes a pressure plate with a controlled descent mechanism that applies force gradually rather than abruptly. Before the plunger rod fully engages, the system pre-positions components and begins applying minimal force, then incrementally increases pressure as engagement progresses. This cushioning approach prevents sudden force spikes that could compromise container integrity while still achieving the necessary coupling strength through controlled, progressive loading.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A machine for coupling a plunger rod to a syringe assembly may include a carriage including a cradle having a seat portion sized to receive a syringe assembly and an aperture portion disposed above the seat portion and sized to receive a plunger rod. An actuating device may be operatively coupled to the carriage and adapted to move the cradle from a first position to a second position to couple the plunger rod to the syringe assembly. The carriage may be selected from separate and interchangeable first and second carriages, wherein the first carriage includes a cradle adapted to receive a syringe assembly of a first size and the second carriage including a cradle sized to receive a syringe assembly of a second size that is different from the first size.