Hand Tool Holder Positioning via Spindle Stop and Sensor Feedback

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Solution Overview

Problem

Conventional hand machine tools, such as jigsaws and eccentric sanders, lack a reliable mechanism to stop the tool holder at a precise position for tool changes, transportation, and parking, leading to difficulties in operation and storage due to protruding tools and inefficient space usage.

Innovation Solution

The hand machine tool incorporates a stop position mechanism that allows the tool holder to be blocked and adjusted for tool changes, transportation, and parking, using a spindle stop and actuating device, with position detection via sensors and control devices to ensure precise stopping, enabling the tool holder to be securely locked in place for these purposes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the tool holder is allowed to move freely for operation, then the tool can reach workpieces effectively, but the tool holder cannot be securely positioned for tool changes or storage

Engineering Contradiction:
Improvetool holder accessibilityVSAvoidtool holder positioning stability
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent implements a spindle stop mechanism that automatically positions the tool holder at predetermined locations (such as a retracted position) before tool changes or storage operations. This preliminary positioning action ensures the tool holder is securely located in advance, providing stability for tool changes while maintaining operational flexibility during cutting cycles.

Inventive Principle:
Principle #10Preliminary action

2Productivity

If the tool protrudes from the housing for effective cutting, then cutting performance is improved, but the hand machine tool occupies more space during transportation and storage

Engineering Contradiction:
Improvecutting performanceVSAvoidtool holder projection
Core Design Contradiction:
ProductivityVSVolume of moving object

Solution Approach 1:

The patent employs a dynamically adjustable tool holder that can change its position along the longitudinal axis. During cutting operations, the tool holder extends to provide adequate cutting performance. During transportation and storage, the tool holder automatically or manually retracts to a compact position, minimizing the overall volume of the hand machine tool and optimizing space utilization.

Inventive Principle:
Principle #15Dynamics

3Device complexity

If manual adjustment mechanisms are used for tool holder positioning, then device complexity is reduced, but positioning precision and repeatability are insufficient

Engineering Contradiction:
Improvepositioning mechanismVSAvoidtool holder stop position accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent replaces purely manual mechanical adjustment mechanisms with an automated positioning system that uses sensors (such as Hall sensors or optical encoders) to detect the tool holder position and a control unit to actuate the spindle stop mechanism. This substitution maintains relatively simple mechanical components while dramatically improving positioning precision and repeatability through electronic control and feedback.

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

Data Source

PatentEP2359986B1Manually operated tool machine with a position detection means for its tool holder
Publication Date: 2016.03.30 FESTOOL GMBH
  • EP2359986B1 patent drawingFigure 1~2
  • EP2359986B1 patent drawingFigure 3~5
  • EP2359986B1 patent drawingFigure 6a~7b

AI summary

The tool (10a) has a drive (22a) including a motor (11a) for driving a tool holder (14a) to an oscillation movement (21) and/or a rotation movement relative to a housing (28a). A control device controls the drive. A position detection unit detects a position signal based on a position of the holder. The control device stops the motor at a preset or adjustable stop-position (AP) i.e. tool exchange-position, of the holder based on the position signal. A balancing weight is connected with the holder and arranged against an eccentric position of a tool (15a) e.g. saw blade.