Power Tool Mode Detection via Switch State Analysis

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Solution Overview

Problem

Existing power tools lack an efficient method to easily determine the currently-selected operation mode, requiring additional switches and complex mechanisms to manage different drive modes.

Innovation Solution

A power tool design incorporating a control device with a switch detecting section, operation mode determining section, and drive control section that directly detects the on/off states of switches, allowing for seamless mode switching and motor control without additional switches, using an operation mode switching member and indicating section for user feedback.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If additional switches are added to detect operation mode, then mode detection capability is improved, but device complexity increases

Engineering Contradiction:
Improvemode detection capabilityVSAvoiddevice complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The existing first and second switches serve dual purposes: they control motor operation and simultaneously indicate operation mode. The control device detects which switch is in the on-state to determine the current mode, eliminating the need for separate detection switches. This self-service approach resolves the contradiction by improving mode detection without adding components.

Inventive Principle:
Principle #25Self-service

2Adaptability or versatility

If multiple switches are used to control different modes, then operation mode versatility is improved, but ease of operation deteriorates

Engineering Contradiction:
Improveoperation mode versatilityVSAvoidease of operation
Core Design Contradiction:
Adaptability or versatilityVSEase of operation

Solution Approach 1:

The first and second switches are designed to perform multiple functions: they control motor start/stop operations and simultaneously serve as mode selection indicators. The control device interprets the state of these switches to determine operation mode (first mode when first switch is on, second mode when second switch is on). This multi-functionality resolves the contradiction by providing mode versatility while maintaining simple, familiar switch operation.

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

Data Source

PatentEP2233252B1Power tool
Publication Date: 2014.12.24 MAKITA CORP
  • EP2233252B1 patent drawingFigure 1
  • EP2233252B1 patent drawingFigure 2
  • EP2233252B1 patent drawingFigure 3

AI summary

It is an object of the invention to easily determine a currently-selected operation mode in a power tool which offers several operation modes. A representative electric hammer drill 101 embodying a power tool according to the invention has a controller 171 for at least controlling a driving motor 111. The controller 171 includes a switch detecting circuit 173 that detects the on or off state of each of first and second switches 141, 146 when power is on, a computing/driving section 174 that determines a current operation mode based on results of detection of the switch detecting circuit 173, and a motor control section 176 and a drive circuit 177 that output a drive control signal to the driving motor 111 when the switch in the off state is turned on after the computing/driving section 174 determines the operation mode.