Multi-Specimen Fixture Star for Stable Bath Level and Alignment

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Solution Overview

Problem

Mechanical testing systems face challenges such as temperature fluctuations and specimen alignment issues due to liquid evaporation and the need for frequent liquid replenishment, which can damage specimens and require significant time to change specimen lengths, limiting the efficiency and accuracy of multi-specimen testing.

Innovation Solution

A multi-specimen test fixture star with a bath chamber, supply reservoir, fluid channel, liquid level sensor, and valve system that maintains a stable liquid level and allows for efficient liquid replenishment, along with a non-circularly symmetric design that accommodates more specimens and facilitates easy repositioning without losing rotational alignment, ensuring consistent load distribution and reducing the need for frequent realignment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If liquid is repeatedly added to the bath to replenish evaporation, then the liquid level is maintained, but temperature fluctuations occur and specimen damage risk increases

Engineering Contradiction:
Improveliquid levelVSAvoidtemperature stability
Core Design Contradiction:
Quantity of substanceVSReliability

Solution Approach 1:

The patent pre-heats the replenishment liquid in a separate reservoir before adding it to the bath. This preliminary heating action ensures that the temperature of the added liquid matches the bath temperature, preventing thermal shock and temperature fluctuations that would otherwise occur when cold liquid is added to compensate for evaporation.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent introduces an intermediary heating system between the liquid source and the bath. This intermediary component (heating element or heat exchanger) mediates the temperature difference between the replenishment liquid and the bath, allowing liquid level maintenance without compromising temperature stability.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Adaptability or versatility

If specimen length is changed for different test procedures, then test versatility is improved, but alignment time increases significantly

Engineering Contradiction:
Improvespecimen length variationVSAvoidalignment time
Core Design Contradiction:
Adaptability or versatilityVSLoss of time

Solution Approach 1:

The patent segments the fixture into modular components that can be independently adjusted. This segmentation allows different specimen lengths to be accommodated by adjusting individual segments rather than requiring complete disassembly and realignment of the entire fixture, significantly reducing the time required to change specimen configurations.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent incorporates dynamic adjustment mechanisms that allow the fixture to be quickly reconfigured for different specimen lengths. These mechanisms enable continuous or stepless adjustment of fixture positions, eliminating the need for time-consuming manual alignment procedures required by fixed-position fixtures.

Inventive Principle:
Principle #15Dynamics

3Stability of the object's composition

If radially symmetric fixture configuration is used, then uniform deformation is achieved, but fixture size increases with more specimens

Engineering Contradiction:
Improveuniform deformationVSAvoidfixture size
Core Design Contradiction:
Stability of the object's compositionVSArea of stationary object

Solution Approach 1:

The patent transitions from a traditional radially symmetric fixture configuration to an asymmetric design. This asymmetric configuration optimizes the spatial arrangement of specimen holders, allowing more specimens to be accommodated within a smaller overall footprint while maintaining uniform deformation characteristics through carefully designed load distribution mechanisms.

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

The patent utilizes three-dimensional spatial optimization rather than simple radial expansion. By arranging specimen holders in multiple levels and utilizing vertical space, the fixture accommodates more specimens without proportionally increasing the horizontal footprint, effectively solving the space constraint problem.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

4Stability of the object's composition

If circular MSF geometry is used, then uniform load distribution is achieved, but visual observation of specimens is obscured

Engineering Contradiction:
Improveload distributionVSAvoidvisual observation
Core Design Contradiction:
Stability of the object's compositionVSIllumination intensity

Solution Approach 1:

The patent replaces the circular symmetric geometry with an asymmetric configuration that opens up viewing angles. This asymmetric design maintains uniform load distribution through alternative structural arrangements while eliminating the visual obstruction problem caused by the circular form factor, allowing better illumination and observation of all specimens.

Inventive Principle:
Principle #4Asymmetry

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 system maintains a stable bath liquid level, reduces temperature fluctuations, and allows for efficient testing of various specimen lengths, increasing testing capacity and reducing the time required for specimen alignment, thereby enhancing the efficiency and accuracy of mechanical characterization and fatigue testing.

Implementation Method 1

The liquid level sensor is disposed at one of the bath chamber and the supply reservoir and is configured to sense a liquid level

Methodology Applied
Scientific EffectLiquid level sensing:

Implementation Method 2

The valve is configured to fluidically couple a source of the liquid to the supply reservoir and is responsive to a sensed liquid level as determined by the liquid level sensor

Methodology Applied
Scientific EffectFluid flow control: Valve

Implementation Method 3

The bath chamber may include a heating surface

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentEP3733293B1Apparatus for multi-specimen test instrument
Publication Date: 2021.11.03 TA INSTRUMENTS WATERS LLC
  • EP3733293B1 patent drawingFigure 1A
  • EP3733293B1 patent drawingFigure 1B~2
  • EP3733293B1 patent drawingFigure 3

AI summary

Described are a test device, a multi-specimen test fixture star and a multi-specimen test fixture. The test device includes a bath chamber that is automatically replenished with bath liquid throughout an extended test period. The multi-specimen test fixture star is non-circularly symmetric and can be used, for example, in a rectangular bath chamber to hold a greater number of test specimens than a circularly symmetric test fixture star. The multi-specimen text fixture includes, in part, a multi-specimen text fixture star and a shaft having one or more keyways and enables the test fixture star to be repositioned along the shaft without loss of rotational alignment to the shaft.