Detector Stylus Axial Displacement Detection Mechanism

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Solution Overview

Problem

Conventional detectors for measuring devices face increased manufacturing costs and size due to the need for additional components to prevent breakage during collisions, especially when the stylus is moved in the axial direction, as they lack the necessary displacement detection mechanism.

Innovation Solution

The detector incorporates a stylus with a proximal end inclined portion and an abutting member with a groove and extending portion, allowing the stylus to slide along the groove and convert axial force into rotational displacement detectable by the sensor, preventing breakage without additional components.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a contact switch is added to detect stylus displacement in the opposite direction, then the detector can prevent breakage caused by collision, but the number of components increases and manufacturing costs increase

Engineering Contradiction:
Improvebreakage preventionVSAvoidnumber of components
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the breakage prevention function into the existing sensor assembly by utilizing the differential transformation sensor's ability to detect displacement in both directions. The sensor assembly is configured to detect stylus displacement regardless of direction, eliminating the need for a separate contact switch while maintaining breakage prevention capability.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The differential transformation sensor is designed to serve multiple functions: it detects stylus displacement during normal measurement operations and also detects collision events for breakage prevention. This multi-functional design eliminates the need for additional dedicated components for collision detection.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Reliability

If a contact switch is added to detect stylus displacement, then the detector can prevent breakage, but the size of the detector increases

Engineering Contradiction:
Improvebreakage preventionVSAvoiddetector size
Core Design Contradiction:
ReliabilityVSVolume of moving object

Solution Approach 1:

The patent combines the breakage prevention detection capability within the existing sensor assembly structure. The differential transformation sensor is positioned and configured to detect stylus displacement in both measuring and opposite directions, eliminating the need for additional spatial accommodation for a separate contact switch and thereby maintaining compact detector size.

Inventive Principle:
Principle #5Merging (Combining)

3Adaptability or versatility

If the stylus is moved in the axial direction, then the detector can detect displacement, but the detector lacks the necessary detection mechanism for axial movement

Engineering Contradiction:
Improveaxial direction detection capabilityVSAvoiddetection mechanism
Core Design Contradiction:
Adaptability or versatilityVSDifficulty of detecting and measuring

Solution Approach 1:

The patent employs a dynamic conversion mechanism where axial displacement of the stylus is transformed into rotational displacement of the holding portion through the interaction between the stylus and the abutting member with the groove. This dynamic transformation enables the differential transformation sensor to detect axial movement by converting it into a detectable rotational signal.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The abutting member with its groove structure acts as an intermediary mechanism that converts axial stylus displacement into rotational motion of the holding portion. This intermediary structure enables the sensor to indirectly detect axial displacement through the rotational movement it can measure.

Inventive Principle:
Principle #24Intermediary (Mediator)

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

This configuration enables the detection of stylus displacement when moved axially, allowing for effective prevention of breakage without additional components, reducing manufacturing costs and detector size.

Implementation Method 1

a sensor that detects a rotational displacement of the holding portion

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

a plate spring 122...serves as a biasing member that biases the proximal end portion of the stylus 110 against the groove portion 121A

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP2312260B1Detector and measuring device
Publication Date: 2016.04.20 MITUTOYO CORP
  • EP2312260B1 patent drawingFigure 1
  • EP2312260B1 patent drawingFigure 2
  • EP2312260B1 patent drawingFigure 3A~3B

AI summary

A detector 4 includes a stylus 41, a holding portion 42 that holds a proximal end portion of the stylus 41, a body portion 43 that supports the holding portion 42 rotatably about a rotational axis, and a sensor 44 that detects a rotational displacement of the holding portion 42. The holding portion 42 includes an abutting member 421, on which the proximal end portion of the stylus 41 abuts, and a plate spring 422 that biases the proximal end portion of the stylus 41 against the abutting member 421. The abutting member 421 includes a groove portion 424A on which the proximal end portion of the stylus 41 abuts, and a semispherical portion 425A that extends toward the plate spring 422, compared with a bottom of the groove portion 424A. The stylus 41 includes a proximal end inclined portion 412 at the proximal end portion of the stylus 41. The proximal end inclined portion 412 is inclined toward the plate spring 422, with a decreasing distance from the rotational axis.