Saw Tool Linkage That Redirects Braking Torque Away From the User

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Solution Overview

Problem

Conventional sawing devices face issues with operational reliability due to the risk of serious injuries when the tool is braked, as the braking torque can cause the tool to pivot towards the user, leading to further injury and potential damage.

Innovation Solution

A multi-joint arrangement that absorbs and redirects forces during tool braking, maintaining pivotability and preventing the tool from pivoting towards the user, while allowing it to pivot away from the work area, thereby enhancing operational reliability and minimizing injury risk.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the tool is braked in a short time to reduce injury to the user, then the braking torque is supported in the tilting joint, but the tool is pivoted in the feed direction towards the user, resulting in serious injuries

Engineering Contradiction:
Improveoperational reliabilityVSAvoidinjury risk to user
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The support structure is divided into multiple segments (first support section, second support section, third support section) connected by support joints, allowing each segment to independently manage different force components during braking, preventing unified pivoting towards the user

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The multi-joint support arrangement acts as an intermediary mechanism between the tool and the base, absorbing and redirecting braking forces through multiple joints rather than allowing direct transmission to the tilting joint, thus preventing harmful pivoting motion

Inventive Principle:
Principle #24Intermediary (Mediator)

2Loss of time

If the tool is braked quickly to improve safety, then the braking process is faster, but the tool pivoting towards the user causes further injury

Engineering Contradiction:
Improvebraking timeVSAvoidextent of injury
Core Design Contradiction:
Loss of timeVSObject-affected harmful factors

Solution Approach 1:

The multi-joint support arrangement is pre-configured to absorb and redirect braking forces before they can cause harmful pivoting, cushioning the effect of rapid braking and preventing the tool from moving towards the user during the braking process

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

3Ease of operation

If the tool is allowed to pivot freely to maintain operational flexibility, then the tool can be positioned easily, but the tool may pivot towards the user during braking, reducing operational reliability

Engineering Contradiction:
Improvetool positioningVSAvoidoperational reliability during braking
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The support structure provides dynamic response to braking forces through multiple joints that can independently adjust, allowing the tool to be easily positioned during normal operation while automatically restraining harmful pivoting motion when braking occurs

Inventive Principle:
Principle #15Dynamics

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 multi-joint arrangement effectively redirects braking forces, ensuring the tool is not pivoted towards the user during braking, thus reducing the risk of injury and maintaining operational reliability by allowing safe pivoting away from the work area.

Implementation Method 1

A multi-joint arrangement (6) is designed to absorb and/or redirect forces occurring when braking the tool rotational movement (9)

Methodology Applied
Scientific EffectMechanical Force: Mechanical Force

Implementation Method 2

The moment of inertia of the saw blade is converted into a linear force that drives the saw blade upwards

Methodology Applied
Scientific EffectMoment of Inertia: Moment of Inertia

Data Source

PatentEP3996888B1Tool device
Publication Date: 2023.10.11 FESTOOL GMBH
  • EP3996888B1 patent drawingFigure 1
  • EP3996888B1 patent drawingFigure 2
  • EP3996888B1 patent drawingFigure 3

AI summary

The invention relates to a tool device (10), in particular a saw device, having a tool (1) for machining a workpiece (4) located in a working region, the tool device comprising: a tool braking apparatus (5) for braking a tool rotational motion (9) of the tool (1); and a multi-bar linkage (6), by means of which the tool (1) can be pivoted selectively into the working region (3) in a feeding direction (7) or out of the working region in a lead-away direction (8). The multi-bar linkage (6) is designed to absorb and/or deflect forces occurring during braking of the tool rotational motion (9), while maintaining the pivotability of the tool (1), such that the tool (1) is not pivoted in the feeding direction (7) by the forces occurring during braking of the tool rotational motion (9) or is pivoted in the lead-away direction (8) by the forces occurring during braking of the tool rotational motion (9).