Viscoelastic Switch Actuator Damping Vibration in Handheld Power Tools
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Solution Overview
Problem
Hand-held rotary power tools transmit excessive vibrations and noise to the user's hand during operation, leading to user fatigue and a negative experience due to the rigid housing structure.
Innovation Solution
A switch actuator made of viscoelastic material is mounted in the grip zone of the tool housing, providing damping of vibrations and noise while allowing for on/off switch operation, and is retained via a flexible connection with the housing, reducing the transmission of vibrations to the user's hand.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the tool housing is made rigid to provide structural support and grip, then structural strength is improved, but vibration transmission to the user's hand increases
Solution Approach 1:
The switch actuator serves as an intermediary element between the rigid tool housing and the user's hand. It is mounted on the exterior surface of the housing in the grip zone and provides a compliant interface that absorbs vibrations before they reach the user's hand, while still allowing reliable switch actuation.
Solution Approach 2:
The patent changes the material parameter of the switch actuator to have different mechanical properties than the housing. The actuator is made of a softer, more compliant material with higher damping characteristics, creating a contrast in rigidity that allows vibration absorption while maintaining structural integrity of the overall tool.
2Object-affected harmful factors
If a separate active dampener is added to reduce vibration, then vibration damping is improved, but device complexity and cost increase
Solution Approach 1:
The switch actuator is designed to combine multiple functions into a single component: it provides switch actuation functionality and simultaneously serves as a vibration dampener. This integration eliminates the need for a separate active dampener, reducing component count, assembly complexity, and cost while achieving effective vibration reduction.
Solution Approach 2:
The switch actuator is designed as a multi-functional element that performs both switching operation and vibration damping. By making the actuator universal in its functionality, the patent eliminates redundant components and simplifies the overall device structure while addressing multiple problems simultaneously.
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
The viscoelastic switch actuator effectively reduces vibration and noise transmission to the user's hand, enhancing the user experience by minimizing fatigue and eliminating the need for additional dampening components, thus lowering costs and simplifying assembly.
Implementation Method 1
The switch actuator is formed of a viscoelastic material, and is more flexible and elastic than the tool housing which is formed of a rigid plastic or metal
Implementation Method 2
protuberances formed on sides surfaces of the rib are in contact with, and compressed by, the surface of the slot
Data Source
AI summary
A hand-held rotary power tool includes a housing that provides a manual grip zone that is grasped by the user during operation of the tool. The housing includes a switch opening that overlies an electrical switch that controls operation of a tool motor. The tool includes a switch actuator that is disposed in tool housing so as to be accessible to a user of the tool via the switch opening and is operable to control the position of the switch. The switch actuator is configured to damp tool noise and transmission of tool vibration to the tool housing.