Power Tool Switch Linkage for Longer Trigger Stroke
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Solution Overview
Problem
Existing power tools with microswitches have a short turn-on stroke, leading to poor user manipulation, increased vulnerability to accidental triggering due to vibrations, and a shortened switch lifespan due to structural damage.
Innovation Solution
The power tool incorporates a contact rod and pressing block configuration that increases the turn-on stroke, coupled with a reset and biasing element to buffer impact forces and protect the switch, enhancing safety and extending its lifespan.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a microswitch is used in the power tool, then the cost is reduced and safety is improved, but the turn-on stroke is too short for user manipulation and the switch is easily damaged by vibrations
Solution Approach 1:
The operating element's stroke is segmented into two independent parts: a first stroke portion that compresses the biasing element and a second stroke portion that actuates the microswitch. This segmentation allows the total stroke to be longer while the switch activation portion remains short, resolving the contradiction between user manipulation needs and switch protection.
Solution Approach 2:
The biasing element acts as an intermediary between the operating element and the microswitch. It absorbs the first portion of the stroke and transmits only the second portion to the switch, protecting the microswitch from excessive travel while maintaining a longer overall operating stroke for better user control.
2Device complexity
If the operating element stroke coincides with the microswitch stroke, then the structure is simple, but the user cannot accurately manipulate the power tool and the switch is easily turned off by vibrations
Solution Approach 1:
The stroke is divided into two functional segments: a compression stroke (first portion) that absorbs vibrations and a switching stroke (second portion) that actuates the microswitch. This segmentation prevents vibrations from directly actuating the switch while maintaining structural simplicity through the use of a single biasing element.
Solution Approach 2:
The biasing element provides beforehand cushioning by being pre-compressed during the first stroke portion. This cushioning effect absorbs vibration energy before it can reach the microswitch, preventing accidental triggering while maintaining a simple overall structure.
3Volume of moving object
If the microswitch has a short stroke, then the structure is compact, but the switch structure is easily damaged resulting in short service life
Solution Approach 1:
The biasing element serves as a protective intermediary that isolates the microswitch from direct impact forces. It absorbs shock and vibration through elastic deformation, reducing stress on the switch structure and extending its service life while maintaining compact dimensions.
Solution Approach 2:
The biasing element provides beforehand cushioning by being pre-loaded in compression. This cushioning protects the microswitch from impact forces before they can cause damage, extending the switch's service life without increasing the overall compact structure's volume.
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 solution provides a safer and more reliable operating experience by preventing accidental triggers and extending the switch's life, while maintaining a compact and simple structure.
Implementation Method 1
a biasing element, the other end of which is connected to the contact rod, the biasing element being configured to buffer an impact force applied to the switch
Data Source
Figure 1~2a
Figure 2b~3
Figure 4~5
AI summary
Provided is a power tool. The power tool includes a housing, an electric motor, a switch, an operating element, a contact rod, a pressing block, and a reset element. The electric motor is disposed in the housing. The switch includes a trigger point for controlling the electric motor to be turned on. The operating element is operated so that the switch is triggered. The contact rod is supported by the housing, where the operating element is capable of pushing the contact rod to move. The pressing block is elastically connected to the contact rod and capable of being driven by the contact rod to push the trigger point. The reset element is connected to the contact rod.