Syringe Centering Element for Metering Accuracy
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Solution Overview
Problem
Existing syringe and metering device systems face challenges in achieving accurate metering due to non-circular syringe cylinder shapes, leading to metering errors, tilting issues, and reduced seal tightness, which affect the precision and reliability of liquid dispensing.
Innovation Solution
The introduction of a syringe design featuring a centering element with a cylindrical piston movement area and a centering region with a larger internal diameter, allowing for accurate centering and alignment, which corrects non-circular shapes and prevents tilting, thereby enhancing metering accuracy and reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a conventional syringe design without a centering region is used, then the syringe structure is simpler, but the syringe cylinder assumes a non-circular shape leading to metering errors and tilting
Solution Approach 1:
The syringe cylinder is divided into distinct functional regions: a centering region with a first internal diameter and a piston movement area with a second internal diameter. This segmentation allows the centering region to assume a circular shape for accurate alignment, while the piston movement area maintains its smaller diameter for sealing, thereby resolving the contradiction between structural simplicity and metering precision.
Solution Approach 2:
The centering region is given a specific local quality of having a larger internal diameter compared to the piston movement area. This local modification ensures that only the centering region assumes a circular shape under compression forces, providing the necessary alignment precision without requiring the entire syringe cylinder to be circular, thus maintaining structural efficiency.
2Shape
If the syringe cylinder is compressed axially to correct non-circular shape, then the circularity and alignment improve, but the seal tightness between piston and cylinder deteriorates
Solution Approach 1:
By dividing the syringe cylinder into a centering region and a piston movement area, the compression forces are localized to the centering region. This segmentation ensures that the circular shape correction occurs only where needed, while the piston movement area maintains its original dimensions and sealing properties, thereby resolving the contradiction between shape correction and seal integrity.
Solution Approach 2:
The centering region is given the local quality of being more compliant to axial compression, allowing it to assume a circular shape, while the piston movement area maintains its structural integrity for sealing. This localized differentiation resolves the contradiction by applying shape correction only where it is needed without compromising the sealing function.
3Measurement precision
If a centering region with larger internal diameter is introduced, then accurate centering and alignment are achieved, but the device complexity increases
Solution Approach 1:
The centering region is integrated directly into the syringe cylinder structure as an inherent feature rather than a separate component. This merging approach achieves accurate centering and alignment functions while minimizing device complexity, as the centering capability is built into the basic syringe design without requiring additional centering devices or complex assembly steps.
Data Source
AI summary
Syringe for use with a metering device comprising a centering element with an axial through-passage in a receiver for a syringe cylinder and an axially displaceable piston receiver for a syringe piston, comprisingsyringe cylindersyringe piston,the syringe cylinder comprising an outlet at the bottom,centering flange at the top on the external periphery for inserting into the receiver,cylindrical piston movement area connected to the outlet, with a first internal diameter, in which the syringe piston is sealingly guided, andat least at a distance of at least 3 mm from the upper end of the syringe cylinder a centering region for inserting the centering element, which has a second internal diameter, which exceeds the first internal diameter and is at least 16.2 mm,the syringe piston at the upper end has a coupling piece for inserting into the piston receiver.