Percussion Driver Drill Clutch Miniaturization via Radial Nesting

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

The existing percussion driver drills face challenges in miniaturization due to the axial length increase caused by the separate positioning of the clutch and vibration mechanisms, which results in interference and increased tool length.

Innovation Solution

The percussion driver drill design incorporates a clutch mechanism outside the vibration mechanism, with a cam mechanism and a switch member configuration that allows the clutch mechanism to be positioned outside without interference, enabling axial miniaturization by using a pin member to connect the switch member and slider member through a gap in the engageable members and around the coil spring, allowing independent operation and minimizing structural modifications.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the clutch mechanism and vibration mechanism are positioned separately in the axial direction to avoid interference, then the mechanisms can operate independently, but the axial length of the tool increases

Engineering Contradiction:
Improveindependent operation of mechanismsVSAvoidaxial length of tool
Core Design Contradiction:
ReliabilityVSLength of moving object

Solution Approach 1:

The patent repositions the clutch mechanism from a separate axial location to a radial position outside the tubular portion, where it can operate independently of the vibration mechanism without increasing axial length. The coupling member extends radially to connect the switch member to the slider member, utilizing the radial dimension to resolve spatial interference while maintaining functional independence.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The clutch mechanism is positioned outside the tubular portion while still being integrated into the overall tool structure. The coupling member passes through the tubular portion to connect components, creating a nested arrangement where the clutch mechanism operates in the radial direction while the vibration mechanism remains within the tubular portion, eliminating axial interference.

Inventive Principle:
Principle #7Nested doll (Nesting)

2Length of moving object

If the clutch mechanism is positioned outside the vibration mechanism, then axial miniaturization is enabled, but structural complexity increases due to the need for coupling members and gap navigation

Engineering Contradiction:
Improveaxial length of toolVSAvoidstructural complexity
Core Design Contradiction:
Length of moving objectVSDevice complexity

Solution Approach 1:

The coupling member serves as an intermediary element that connects the switch member to the slider member across the radial boundary. It passes through the gap between engageable members and detours around the coil spring, providing a simple mechanical linkage that avoids the need for complex mounting structures while enabling the clutch mechanism to operate independently outside the tubular portion.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If the coupling member passes through the gap between engageable members and detours around the coil spring, then interference with clutch components is avoided, but the coupling path becomes more complex

Engineering Contradiction:
Improveavoidance of interferenceVSAvoidcoupling path complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The coupling member is designed to extract or bypass the coil spring by detouring around it, rather than requiring the spring to be relocated or the coupling path to cut through it. This extraction approach allows the coupling member to navigate the radial space efficiently, connecting the switch member to the slider member while avoiding interference with clutch components and the coil spring's compression space.

Inventive Principle:
Principle #2Taking out (Extraction)

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

This configuration allows for substantial miniaturization of the percussion driver drill by eliminating interference between the clutch and vibration mechanisms, reducing the axial length while maintaining operational effectiveness and structural integrity.

Implementation Method 1

a coil spring disposed frontwardly of the plurality of engageable members and configured to press the plurality of engageable members against the end face of the internal gear

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

The cam mechanism is provided inside the tubular portion and configured to selectively impart an axial vibratory motion to the spindle

Methodology Applied
Scientific EffectCam mechanism: Cam

Data Source

PatentEP2508303B1Percussion driver drill
Publication Date: 2016.02.24 MAKITA CORP
  • EP2508303B1 patent drawingFigure 1
  • EP2508303B1 patent drawingFigure 2
  • EP2508303B1 patent drawingFigure 3

AI summary

In a clutch mechanism (90) of a percussion driver drill, a plurality of engageable members (99) held in a gear case (9, 10) is configured to be engageable with an end face of a final-stage internal gear (23C), and a coil spring (97) is configured to press the engageable members (99) against the end face of the internal gear (23C). The coil spring (97) is disposed frontwardly of the engageable members (99) between a switch member (76) and an operating member (79) of a vibration mechanism (50). A coupling member (85) connected with the switch member (76) and the operating member (79) is disposed to pass through a gap between the plurality of engageable members (99) and detour around a rear end of the coil spring (97).