Fixed Connector Protrusions for Impact Fastening Signal Stability

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Solution Overview

Problem

Impact fastening tools experience signal interruption and reduced service life due to intermittent impacts causing brushes or fixed connectors to momentarily separate from rotating electrodes, leading to abrasion issues.

Innovation Solution

A fixed connector with protrusion portions is used to maintain contact with the rotating electrode, absorbing swaying motion and generating a force to prevent disconnection, ensuring continuous signal transmission and reducing abrasion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a force is increased to press a brush against the rotating electrode to prevent bouncing, then signal transmission reliability is improved, but abrasion increases and service life is reduced

Engineering Contradiction:
Improvesignal transmission reliabilityVSAvoidservice life
Core Design Contradiction:
ReliabilityVSDuration of action of stationary object

Solution Approach 1:

The patent changes the physical parameters of the brush by forming protrusions on its surface, transforming it from a smooth flat surface to one with multiple contact points. This structural parameter change allows the brush to maintain reliable electrical contact without requiring excessive pressing force, thereby reducing abrasion while maintaining signal transmission reliability.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The brush surface is segmented into multiple protrusions rather than being a single flat surface. Each protrusion acts as an independent contact point, allowing the brush to accommodate vibrations and movements while maintaining continuous electrical contact. This segmentation distributes the contact stress across multiple points, reducing overall abrasion.

Inventive Principle:
Principle #1Segmentation

2Duration of action of stationary object

If the brush is pressed lightly against the rotating electrode, then abrasion is reduced and service life is extended, but signal transmission may be interrupted due to bouncing

Engineering Contradiction:
Improveservice lifeVSAvoidsignal transmission reliability
Core Design Contradiction:
Duration of action of stationary objectVSReliability

Solution Approach 1:

The brush structure is modified by adding protrusions that change its mechanical properties. These protrusions allow the brush to maintain contact under lighter pressing forces by conforming to the rotating electrode surface and accommodating relative movements, thus preventing bouncing while reducing wear.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The brush is designed with dynamic characteristics through its protrusion structure, allowing it to adapt to the dynamic conditions of impact fastening tool operation. The protrusions can independently respond to vibrations and movements, maintaining electrical contact without requiring excessive static pressing force.

Inventive Principle:
Principle #15Dynamics

3Reliability

If multiple coils forming rotary transformers are used to eliminate contact, then reliability is improved by preventing wear, but device complexity and size increase

Engineering Contradiction:
Improvecontactless transmission reliabilityVSAvoidnumber of parts
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent partially applies this principle by replacing the smooth brush surface with a protrusion-based mechanical structure, rather than completely replacing mechanical contact with electromagnetic fields. This intermediate approach maintains simple mechanical contact while improving performance through structural modification.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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 solution prevents signal interruption and extends the service life of the impact fastening tool by maintaining stable contact and reducing abrasion between the fixed connector and rotating electrode.

Implementation Method 1

deflection of the whole fixed connector can absorb the swaying motion

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

when a force that detaches one contact point of the fixed connector from the rotating electrode is applied on the one contact point, a force headed toward the rotating electrode is generated in the other contact point

Methodology Applied
Scientific EffectElastic recovery: Elastic Recovery

Data Source

PatentEP3189936B1Impact fastening tool and torque tester
Publication Date: 2019.11.27 YOKOTA IND
  • EP3189936B1 patent drawingFigure 1
  • EP3189936B1 patent drawingFigure 2
  • EP3189936B1 patent drawingFigure 3~4

AI summary

Provided are: an impact fastening tool (1) which prevents a torque detecting means (3) from missing a signal and extends service life by adopting a fixed connector (5) that prevents the trouble of being instantaneously separated (bounced) from a rotating electrode (4) by intermittent impacts and has a shape allowing the progression of friction to be delayed structurally; and a torque tester (6). Both end portions (50, 51) of the fixed connector (5) are fixed, and at least two protrusion portions (52, 53) are formed between the both end portions (50, 51). The rotating electrode (4) is disposed between one protrusion portion (52) and the other protrusion portion (53) such that the rotating electrode contacts the fixed connector (5) at two or more points or in a line form. A signal required for the torque detecting means (3) is transmitted through the contact between the rotating electrode (4) and the fixed connector (5).