Radial Clutch Device for Rapid Power Tool Mode Switching

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Solution Overview

Problem

Current power tools, such as electric hammers, have complex transmission mechanisms and clutches that are large in size and have a long stroke, making it difficult for users to quickly switch between work models due to the same engaging and disengaging direction, and often fail to engage properly during the engagement process.

Innovation Solution

A clutch device with a guiding element, sliding clutch elements, an elastic element, and a rotating element that allows for synchronized rotation and movement of driving elements to engage or disengage with the transmission element, facilitating quick switching between torque and impact force output modes by adjusting the position of the driving elements relative to the rotating axis.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the clutch has a long stroke to facilitate engagement and disengagement, then the clutch can engage properly, but the tool size increases and switching speed decreases

Engineering Contradiction:
Improveengagement reliabilityVSAvoidclutch stroke length
Core Design Contradiction:
ReliabilityVSLength of moving object

Solution Approach 1:

The patent changes the engagement direction from axial (parallel to rotating axis) to radial (perpendicular to rotating axis). The driving element moves radially outward to engage with the transmission element, and radially inward to disengage. This dimensional change allows for a shorter axial stroke while maintaining reliable engagement through the radial movement mechanism.

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

2Device complexity

If the engaging and disengaging direction is the same, then the clutch structure is simple, but the user cannot switch work models quickly

Engineering Contradiction:
Improveclutch structure complexityVSAvoidswitching time
Core Design Contradiction:
Device complexityVSLoss of time

Solution Approach 1:

The patent implements dynamic switching by allowing the driving element to move radially in response to rotational position. The engagement state changes dynamically based on the rotational phase of the driving element relative to the transmission element, enabling rapid switching between torque and impact modes without complex mechanical reconfiguration.

Inventive Principle:
Principle #15Dynamics

3Volume of moving object

If the clutch size is reduced, then the tool becomes more compact, but the engagement reliability decreases

Engineering Contradiction:
Improveclutch device volumeVSAvoidengagement reliability
Core Design Contradiction:
Volume of moving objectVSReliability

Solution Approach 1:

By transitioning from axial engagement to radial engagement, the patent reduces the axial dimension of the clutch device, making it more compact. The radial movement allows for effective engagement within a smaller overall volume while maintaining reliability through the direct radial contact between the driving element's engagement portion and the transmission element.

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

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

Enables efficient and rapid switching between rotating and impacting modes, reducing the size and complexity of the transmission mechanism while ensuring reliable engagement and disengagement, thereby improving user convenience and tool performance.

Implementation Method 1

an elastic element including a first connecting leg and a second connecting leg which are respectively connected with the first clutch element and the second clutch element

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentUS10518399B2Clutch device and power tool with clutch device
Publication Date: 2019.12.31 CHERVON HK LTD WANCHAI
  • US10518399B2 patent drawing
  • US10518399B2 patent drawing
  • US10518399B2 patent drawing

AI summary

A clutch device includes a guiding element, a first clutch element being capable of sliding relative to the guiding element, a second clutch element being capable of sliding relative to the guiding element, an elastic element including a first connecting leg and a second connecting leg which are respectively connected with the first clutch element and the second clutch element, and a rotating element being capable of rotating about a first axis relative to the guiding element. The rotating element includes a first supporting portion for contacting with the first connecting leg, which is disposed at a first axial position of the first axis, and a second supporting portion for contacting with the second connecting leg, which is disposed at a second axial position of the first axis.