Spring Return Adjustment Wheel for Pipette Volume Control

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing electronic pipette adjustment methods, such as arrow keys and incrementally rotating adjustment wheels, are inefficient for precise and rapid adjustments, often leading to ergonomic issues and poor control sensitivity, especially when changing readings significantly.

Innovation Solution

A spring return adjustment wheel with two stages of movement, where initial rotation is light and gradually increases in force, allowing for distinct slow and fast adjustments, detected by magnetic or optic sensors, enabling sensitive and fast control with visual and auditory feedback.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If an incrementally rotating adjustment wheel is used, then the adjustment can be made in small steps, but the adjustment speed is slow and cannot achieve fast changes to specific values

Engineering Contradiction:
Improveadjustment precisionVSAvoidadjustment speed
Core Design Contradiction:
Measurement precisionVSSpeed

Solution Approach 1:

The adjustment wheel is designed with two distinct rotational modes: incremental rotation for precise small adjustments and free-wheeling rotation for fast adjustments. The mechanism dynamically switches between these modes based on the user's rotation speed and force, allowing both precision and speed to be achieved in different operational contexts.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The adjustment wheel's rotation range is segmented into two distinct phases: a first rotation range with incremental adjustment for precision, and a second rotation range with free-wheeling rotation for speed. This segmentation allows the system to optimize for different parameters in different operational phases.

Inventive Principle:
Principle #1Segmentation

2Productivity

If the adjustment wheel is rotated fast in pulses to speed up adjustment, then the reading changes quickly, but it easily exceeds or falls short of the wanted reading requiring additional iteration

Engineering Contradiction:
Improveadjustment efficiencyVSAvoidreading accuracy
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The adjustment mechanism dynamically adapts its response based on the user's input characteristics. During fast rotation, the system accumulates adjustment increments and applies them smoothly, preventing overshoot. During slow rotation, it applies increments immediately for precise control. This dynamic adaptation eliminates the need for iterative corrections.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system provides continuous feedback through the display showing the current reading and adjustment progress. This feedback allows users to monitor their adjustment in real-time and make informed decisions about when to stop rotating, preventing overshoot and reducing the need for iterative corrections.

Inventive Principle:
Principle #23Feedback

3Ease of operation

If arrow keys are used for volume adjustment, then the adjustment can be controlled, but the adjustment is not fast when the target value is far from the initial reading

Engineering Contradiction:
Improveadjustment controllabilityVSAvoidadjustment time
Core Design Contradiction:
Ease of operationVSLoss of time

Solution Approach 1:

The adjustment wheel responds dynamically to the user's rotation speed. When rotated quickly, it accumulates multiple adjustment increments, enabling fast traversal across large value ranges. When rotated slowly, it provides fine-grained control for precise adjustments. This dynamic behavior resolves the trade-off between speed and controllability.

Inventive Principle:
Principle #15Dynamics

4Device complexity

If the adjustment wheel is placed in connection with the display, then it can be integrated into the control interface, but the keys are ergonomically poorly located

Engineering Contradiction:
Improveinterface integrationVSAvoidergonomic location
Core Design Contradiction:
Device complexityVSEase of operation

Solution Approach 1:

The adjustment wheel is extracted from the display area and relocated to the upper part of the pipette body, separating the adjustment control from the display. This repositioning places the adjustment wheel in an ergonomically optimal location that is easily accessible by the thumb of the hand holding the pipette, while the display remains visible for monitoring.

Inventive Principle:
Principle #2Taking out (Extraction)

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

Enables precise, fast, and interactive adjustments, allowing for seamless operation in manual/measurement modes with ergonomic placement and independent control of piston movement, enhancing usability and precision in titration modes.

Implementation Method 1

The angle of rotation of the adjustment wheel can be detected for example by a magnetic sensor

Methodology Applied
Scientific EffectMagnetic sensor detection: Magnetic Field

Implementation Method 2

The angle of rotation of the adjustment wheel can be detected for example by a magnetic sensor or an optic reader head arrangement

Methodology Applied
Scientific EffectOptic detection: Optical Fibre

Implementation Method 3

members for returning the adjustment wheel to its initial position when released. This can be achieved with a spring return adjustment wheel solution

Methodology Applied
Scientific EffectSpring elastic force: Spring

Data Source

PatentEP2830771B1Pipette with adjustement wheel
Publication Date: 2020.05.27 SARTORIUS BIOHIT LIQUID HANDLING OY
  • EP2830771B1 patent drawingFigure 1
  • EP2830771B1 patent drawingFigure 2~3

AI summary

An electrical pipette that includes an adjustment wheel, which comprises a primary spring defining a first adjustment area and a secondary spring defining a second adjustment area after the first adjustment area in a turning direction of the adjustment wheel. The force required for turning the adjustment wheel within the first adjustment area is smaller than within the second adjustment area, and the springs are arranged to return the adjustment wheel to its original position when the adjustment wheel is released.