Pipette Clamping Spring and Conical Pin Mechanism
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing pipette systems, particularly air cushion pipettes, suffer from dosing errors due to changes in air cushion length caused by liquid weight, temperature, pressure, and humidity, and face contamination risks from aerosols, while direct positive displacement pipettes require complex sensor systems for correct tip alignment.
Innovation Solution
A direct displacement pipette with a clamping device featuring a clamping spring and insertion bevel or groove that securely fastens the piston rod to the lifting rod, allowing for easy and secure connection of the pipette tip without the need for additional movement, and an electronic control device that determines the tip type based on frictional forces for accurate operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If air cushion pipettes are used, then liquid dispensing is achieved, but dosing errors occur due to changes in air cushion length caused by liquid weight, temperature, pressure, and humidity
Solution Approach 1:
The patent removes the air cushion component entirely by using a direct positive displacement mechanism where the piston directly contacts and displaces the liquid, eliminating the harmful effects of air cushion length changes caused by liquid weight, temperature, pressure, and humidity
Solution Approach 2:
The patent replaces the pneumatic air cushion system with a direct mechanical piston-liquid contact system, where the piston rod directly displaces the liquid without an intermediate air cushion, thereby achieving more reliable dosing accuracy
2Reliability
If air-cushion pipettes are used, then liquid dispensing is achieved, but contamination from aerosols becomes problematic
Solution Approach 1:
The patent eliminates the air cushion that generates aerosols by implementing direct piston-liquid contact, thereby preventing aerosol formation and contamination while maintaining liquid dispensing functionality
Solution Approach 2:
The patent substitutes the pneumatic displacement method with direct mechanical piston contact, where the piston rod directly pushes the liquid without creating aerosols, thus preventing contamination
3Ease of operation
If color-coding is used for pipette and pipette tip identification, then correct identification is facilitated, but misinterpretation by users can result in incorrect combination
Solution Approach 1:
The patent replaces subjective color-coding with an objective mechanical interference fit system where the conical pin and conical tip opening physically guide correct alignment, eliminating user interpretation errors while maintaining ease of operation
Solution Approach 2:
The pipette and pipette tip self-align through the conical interference fit mechanism, automatically ensuring correct combination without requiring user knowledge or interpretation of color codes
4Reliability
If a complex gripping device with control element is used to clamp the tip piston, then secure connection is achieved, but the connection process becomes complex and requires multiple steps
Solution Approach 1:
The patent extracts the complex multi-step control mechanism and replaces it with a simple conical interference fit system where the pin and conical tip opening automatically align and secure the connection in a single insertion motion
Solution Approach 2:
Instead of using a complex active clamping mechanism that requires control elements and multiple steps, the patent uses a passive geometric interlocking system where the conical shapes provide automatic alignment and securing upon insertion
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 provides a secure, easy-to-produce connection between the pipette and tip, reducing dosing errors and contamination risks, and eliminates the complexity of sensor systems by using tactile feedback and force measurement for accurate tip identification.
Implementation Method 1
a clamping device (30) seated on the outer circumference of the lifting rod (17), with at least one clamping spring (30.2, 30.3) having one leg engaging in the clamping slot (29.1, 29.2) and projecting into the axial bore (24) for clamping the piston rod (80)
Implementation Method 2
an electronic control device that determines the tip type based on frictional forces for accurate operation
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Pipette for use with a pipette tip comprising: • a pipette body, • a pin projecting outwards from the pipette body for clamping a seat area on the inner circumference of a tip cylinder of a pipette tip having a mounting opening at its upper end, wherein the pin (4) has a through-bore for inserting a piston rod of a tip piston of the pipette tip,• a drive device comprising a stroke rod aligned with the through-bore and guided longitudinally in the direction of the pin in a pipette housing, with an axial bore and a hole at the lower end for inserting the upper end of the piston rod and for moving a piston of the tip piston, which is guided sealingly in a piston running area between a tip opening at the lower end and the seat area of the tip cylinder; and • a clamping device comprising at least one clamping slot on the outer circumference of the stroke rod, open towards the axial bore, and a clamping spring located on the outer circumference of the stroke rod, the spring having at least one leg engaging in the clamping slot and projecting into the axial bore, for clamping the piston rod, which has an insertion chamfer and/or a clamping groove, in the axial bore of the stroke rod.