Electric Cutting Tool Emergency Stop via Body Conductivity Detection
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Solution Overview
Problem
Existing safety devices for electric cutting tools, such as pruning shears and chain saws, face issues like discomfort from conductive clothing, risk of wire severance, and unreliable operation due to wear and tear or insulating substances, which can render the safety system inoperative.
Innovation Solution
A safety cutting tool design that uses the operator's body conductivity to detect contact with the cutting element, employing insulated manual contact electrodes and a monitoring circuit to trigger an emergency stop, eliminating the need for conductive clothing and beacons, and ensuring reliable detection of potential injuries.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conductive clothing or beacons are used to detect contact with cutting element, then safety detection capability is improved, but operator comfort deteriorates and reliability worsens due to wear and tear or wire severance
Solution Approach 1:
The patent extracts the conductive clothing and beacon accessories from the safety system, eliminating the need for operators to wear or attach external items. The safety function is integrated directly into the tool itself through contact electrodes on the handle, improving comfort while maintaining detection capability
Solution Approach 2:
The patent introduces insulated contact electrodes as intermediaries between the operator's hand and the safety detection system. These electrodes detect contact through the operator's body conductivity without requiring conductive clothing, solving both comfort and reliability issues
2Reliability
If wired connection between conductive clothing and cutting tool is used, then contact detection is achieved, but risk of wire severance increases reducing reliability
Solution Approach 1:
The patent removes the external wired connection between conductive clothing and the tool by integrating the contact detection function directly into the tool handle. This eliminates the vulnerable wire link that could be severed during operation
Solution Approach 2:
The tool performs its own safety detection function through integrated contact electrodes on the handle, eliminating the need for external accessories and connections. The system is self-sufficient and does not require external conductive clothing or beacons
3Reliability
If conductive gloves are used for safety detection, then contact detection capability is improved, but discomfort from wearing gloves increases reducing ease of operation
Solution Approach 1:
The patent eliminates the need for conductive gloves by integrating contact detection electrodes directly into the tool handle. The electrodes make contact through the operator's hand naturally grasping the handle, removing the requirement for specialized protective clothing
Solution Approach 2:
The insulated contact electrodes on the handle serve as intermediaries that detect contact through the operator's body conductivity without requiring conductive gloves. The electrodes are positioned to be touched when the operator normally grasps the handle
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 reliable and comfortable safety mechanism that automatically stops the cutting tool to prevent injuries by accurately detecting contact with the cutting element, reducing the risk of severe injuries and operational disruptions.
Implementation Method 1
uses the operator's body conductivity to detect contact with the cutting element
Data Source
AI summary
A safety cutting tool has an electrically conductive cutting element, an electrically controlled actuating motor drivingly connected to the cutting element, a gripping handle electrically insulated from the cutting element and adapted to receive a hand of an operator therein, a cutting trigger control electrically insulated from the cutting element and adapted to be actuated by the hand of the operator, and an emergency stop device that is able to respond to a contact of the operator with the cutting element. The emergency stop device includes a first manual contact, electrode and a second manual contact electrode with an electrical monitoring circuit connected thereto.