Force Sensor Stem Anchoring Slots for Adhesion

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Solution Overview

Problem

Existing force measuring devices face challenges in effectively transmitting forces, particularly tensile forces, due to smooth cylindrical surfaces that lead to poor adhesion and potential damage or measurement errors when used in systems like game controllers or airbags.

Innovation Solution

Incorporating slots on the rigid rod surface that are perpendicular or parallel to the deformable membrane, which serve as anchoring means to enhance adhesion with the element being measured, improving force transmission and preventing damage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If a smooth cylindrical rod is used, then the device structure is simple, but the adhesion with the element is poor leading to force transmission failures

Engineering Contradiction:
Improveadhesion strengthVSAvoidrod structure complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The rod surface is modified locally by adding slots at specific positions rather than changing the entire rod structure. The slots are positioned at the ends of the rod where adhesion is most critical for force transmission, while the middle portion remains smooth and cylindrical. This localized modification improves adhesion strength without significantly increasing overall device complexity.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The rod surface is segmented by introducing slots that divide the continuous cylindrical surface into distinct sections. These slots create anchor points that enhance adhesion by providing mechanical interlocking with the element, while the rod itself remains a single integrated component. The segmentation is applied selectively at critical locations rather than throughout the entire rod.

Inventive Principle:
Principle #1Segmentation

2Reliability

If slots are added to the rod surface, then adhesion and force transmission improve, but the rod structure becomes more complex

Engineering Contradiction:
Improveforce transmission reliabilityVSAvoidrod structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

Slots are added only at the ends of the rod where force transmission and adhesion are most critical, while the middle portion remains smooth. This localized approach improves reliability at critical points without unnecessarily complicating the entire rod structure. The slots are positioned to provide maximum anchoring effect with minimum structural modification.

Inventive Principle:
Principle #3Local quality

3Measurement precision

If the rod has a smooth surface, then manufacturing is simple, but tensile forces cause separation and measurement errors

Engineering Contradiction:
Improveforce measurement accuracyVSAvoidrod manufacturing simplicity
Core Design Contradiction:
Measurement precisionVSEase of manufacture

Solution Approach 1:

The rod manufacturing process is simplified by adding slots only at the ends rather than modifying the entire surface. The slots can be created using standard machining operations such as drilling or milling at the rod ends, which are routine manufacturing steps. This localized modification maintains ease of manufacture while significantly improving measurement precision by preventing separation under tensile loads.

Inventive Principle:
Principle #3Local quality

4Strength

If anchoring means are added to the rod, then adhesion improves, but the device complexity increases

Engineering Contradiction:
Improveanchoring strengthVSAvoidoverall device complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The anchoring function is implemented locally at the rod ends through slots rather than requiring a completely different rod structure. The slots provide mechanical interlocking and adhesion enhancement at the critical interface with the element, while the rest of the device remains unchanged. This localized anchoring solution improves strength without significantly increasing overall device complexity.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP1877748B1Force measuring device having a rigid stem
Publication Date: 2010.08.04 COMMISSARIAT A LENERGIE ATOMIQUE ET AUX ENERGIES ALTERNATIVES
  • EP1877748B1 patent drawingFigure 1~2B
  • EP1877748B1 patent drawingFigure 3~6
  • EP1877748B1 patent drawingFigure 7~10

AI summary

The invention relates to a force measuring device having a rigid stem (10) joined to an essentially flat deformable diaphragm (12) comprising means (16) for detecting a deformation of the diaphragm (12). A portion of the stem (10) comes in contact with an element (20) capable of being subjected to the action of a force (F). The stem (10) has slots forming anchoring means (17) for interacting with the element (20). The invention is for use, in particular, in improving the transmission of loads to the deformable diaphragm.