Link Unit Automates Speed Selection in Impact Driver Mode Switching

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Solution Overview

Problem

Conventional electric power tools require manual manipulation of both mode and speed switching members, leading to cumbersome operation and potential performance decreases, especially when switching to high-speed modes like vibration drill or impact modes, as users often forget to switch to high-speed mode, resulting in temporary stops to adjust settings.

Innovation Solution

A link unit is introduced between the mode switching member and the speed switching member, ensuring that the speed switching member is automatically set to high-speed mode when the mode switching member selects a predetermined operation mode, eliminating the need for separate speed switching operations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a mode switching member and a speed switching member are provided separately, then the speed can be selected in each operation mode, but the operation becomes cumbersome and user-friendliness decreases

Engineering Contradiction:
Improvespeed selection capabilityVSAvoidoperation simplicity
Core Design Contradiction:
Adaptability or versatilityVSEase of operation

Solution Approach 1:

The patent combines the mode switching member and speed switching member into a single integrated switching mechanism. The mode switching member simultaneously controls both operation mode selection and speed selection, eliminating the need for separate speed switching operations. This merging resolves the contradiction by maintaining adaptability (speed selection in each mode) while improving ease of operation (single member control).

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The mode switching member is designed to perform multiple functions: selecting operation modes (drill, impact, vibration drill) and selecting speeds (high-speed, low-speed) within each mode. This multi-functionality allows the single switching member to provide comprehensive control, resolving the contradiction between versatility and operational simplicity.

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

2Adaptability or versatility

If separate mode switching and speed switching members are used, then comprehensive control is achieved, but productivity decreases due to temporary stops for adjustment

Engineering Contradiction:
Improvecontrol comprehensivenessVSAvoidwork continuity
Core Design Contradiction:
Adaptability or versatilityVSProductivity

Solution Approach 1:

By merging mode switching and speed switching into a single integrated mechanism, the patent eliminates the need for separate adjustment operations. Users can switch modes and speeds simultaneously with one operation, preventing work interruptions and maintaining productivity while achieving comprehensive control.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The integrated switching mechanism performs both mode selection and speed selection in a single preliminary action. When the user operates the mode switching member, the speed is automatically set appropriately for the selected mode, eliminating the need for subsequent speed adjustments and preventing work interruptions.

Inventive Principle:
Principle #10Preliminary action

3Adaptability or versatility

If two switching members are provided, then flexible operation mode selection is enabled, but device complexity increases

Engineering Contradiction:
Improveoperation mode selection flexibilityVSAvoidswitching mechanism complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent merges two separate switching members into one integrated switching mechanism. This consolidation reduces the number of components and simplifies the overall structure while maintaining the flexibility to select different operation modes and speeds through the single unified interface.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The single switching member is designed with multi-functionality to handle both mode selection and speed selection. This universal design reduces device complexity by eliminating redundant components while preserving comprehensive control capabilities through intelligent functional integration.

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

Data Source

PatentEP2554306B1Electric power tool
Publication Date: 2018.06.20 MAKITA CORP
  • EP2554306B1 patent drawingFigure 1
  • EP2554306B1 patent drawingFigure 2
  • EP2554306B1 patent drawingFigure 3

AI summary

In an impact driver, a link unit (a link sleeve (63) and first and second elongated protrusions (88A, 88B)) is provided between the mode switching ring (64) for selecting an operation mode and the slide button (34) for selecting the rotation speed. With the link unit, a switching operation of a slide button (34) to the high-speed side is performed in coordination with a selecting operation of a mode switching ring (64) to an impact mode or a vibration drill mode and the rotation speed is held at high speed.