Pipette Ejection Mechanism Using Curved Support for Reduced Force

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Solution Overview

Problem

Existing pipettes face challenges with high construction volume and require significant force to eject pipette tips, especially when handling viscous fluids, leading to potential contamination and user fatigue.

Innovation Solution

A pipette design featuring a rotatably mounted curved support and a sensing element on an ejection rod, which converts rotary motion into linear motion to facilitate easy ejection of pipette tips with reduced force requirements, incorporating a form-fit connection mechanism with a locking sleeve for secure attachment and release.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a conventional ejection apparatus is used to eject pipette tips, then the pipette tip can be removed, but significant force is required especially when handling viscous fluids, leading to user fatigue and potential contamination

Engineering Contradiction:

Improveforce required for tip ejectionVSAvoidcontamination risk

Core Design Contradiction:

Ease of operationVSObject-affected harmful factors

Solution Approach 1:

A curved support element is introduced as an intermediary between the operating element and the ejection rod. This curved support converts the user's rotational input motion into amplified linear ejection motion, acting as a mechanical mediator that reduces the direct force requirement on the user while maintaining effective ejection capability

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The curved support element utilizes a curved geometric path to transform rotational motion into linear motion. The curved trajectory provides mechanical advantage, allowing a small rotational movement of the operating element to generate a larger linear displacement and reduced force requirement for tip ejection

Inventive Principle:

Principle #14Spheroidality (Curvature)

2Ease of operation

If the pipette design is expanded to include additional ejection mechanisms, then tip ejection capability is improved, but the construction volume of the pipette increases

Engineering Contradiction:

Improvetip ejection functionalityVSAvoidpipette construction volume

Core Design Contradiction:

Ease of operationVSVolume of moving object

Solution Approach 1:

The operating element serves multiple functions: it controls both the ejection of the pipette tip and the operation of the drive apparatus. This multi-functionality eliminates the need for separate control mechanisms, maintaining enhanced tip ejection capability while minimizing the increase in pipette volume

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The curved support element is positioned within the existing pipette housing structure, and the ejection rod operates within the confines of the pipette tip assembly. The components are nested within each other's spatial envelopes, allowing the ejection mechanism to be integrated without significantly increasing the overall pipette volume

Inventive Principle:

Principle #7Nested doll (Nesting)

3Reliability

If a locking mechanism is added to secure the pipette tip, then attachment security is improved, but the device complexity increases

Engineering Contradiction:

Improvetip attachment securityVSAvoidconnection mechanism complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The locking mechanism automatically engages when the pipette tip is inserted onto the nipple, and automatically releases when the operating element is rotated for ejection. This self-acting mechanism provides reliable attachment security without requiring additional control inputs from the user, maintaining simplicity despite the added locking function

Inventive Principle:

Principle #25Self-service

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 design achieves a compact pipette construction with reduced force needed for tip ejection and secure attachment, preventing tip displacement during use with viscous fluids, thus enhancing user convenience and preventing contamination.

Implementation Method 1

a first sensing element on an ejection rod and guided on a first curve on the perimeter of the curved support... The ejection apparatus is configured to rotate the curved support out of a start position by rotating the operating element, wherein the first curve displaces the first sensing element downward so that the ejection rod presses a pipette tip which is held on the nipple off of the nipple

Methodology Applied

Scientific EffectMechanical motion conversion (rotary to linear): Mechanical Advantage

Data Source

PatentUS11426720B2Pipette for use with a pipette tip

Publication Date: 2022.08.30 EPPENDORF AG

AI summary

A pipette comprises a pipette housing comprising an upper end and a lower end, a nipple configured to contact and retain a pipette tip, a drive apparatus configured to aspirate a liquid specimen into the pipette tip and expel the liquid specimen from the pipette tip, and an ejection apparatus. The ejection apparatus comprises a curved support rotatably mounted within the pipette housing, an ejection rod, a first sensing element positioned on the ejection rod and configured to be guided on a first curve on a perimeter of the curved support, and an operating element coupled to the curved support and configured to rotate relative to the pipette housing. The ejection apparatus is configured to rotate the curved support out of a start position by rotating the operating element. The first curve displaces the first sensing element downward a the ejection rod moves the pipette tip off of the nipple.