Dual-Trigger Power Tool Control for Two-Handed Operation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Users may operate power tools without properly gripping the side handle, compromising safety and stability, despite the handle being mounted on the tool.
Innovation Solution
A power tool system with a side handle featuring a non-rotatable design and a controller that ensures both the main and auxiliary triggers are engaged within specific time thresholds to activate and maintain motor operation, providing tactile and audible feedback for proper grip and operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a side handle is mounted on the power tool, then user stability and safety are improved, but users may still operate the tool without properly gripping the side handle, compromising safety
Solution Approach 1:
The system incorporates trigger switches on both the main handle and side handle that provide feedback signals to a controller. The controller monitors the state of both triggers and only allows motor operation when both triggers are simultaneously engaged, ensuring proper two-handed grip. This feedback mechanism prevents single-handed operation while maintaining safety without significantly impacting ease of operation for legitimate two-handed use.
Solution Approach 2:
The system requires preliminary engagement of both triggers before the motor can operate. The controller checks the status of both main and side handle triggers in advance, and only permits motor activation when both are engaged. This preliminary verification ensures that users properly grip both handles before the tool becomes operational, addressing the safety concern before operation begins.
2Reliability
If the controller requires both main trigger and auxiliary trigger to be actuated within a time threshold, then safety is improved by preventing single-hand operation, but device complexity increases due to additional control logic and time threshold management
Solution Approach 1:
The controller continuously monitors the state of both triggers and uses feedback signals to determine whether both are engaged within the required time threshold. This feedback-based approach provides a systematic method for enforcing safety requirements while maintaining manageable control logic through clear state detection and response protocols.
Solution Approach 2:
The system dynamically adjusts its operation based on real-time trigger states and timing. The controller evaluates whether both triggers are actuated within the specified time threshold and dynamically controls motor activation accordingly. This dynamic approach allows the system to adapt to user actions while enforcing safety constraints without requiring overly complex predetermined sequences.
3Reliability
If the controller electronically brakes the motor within the time threshold, then safety is enhanced by quickly stopping motor operation when triggers are released, but energy consumption increases during braking operations
Solution Approach 1:
The electronic braking system converts the motor's kinetic energy into electrical energy during braking, which is then dissipated or recovered. Instead of simply applying mechanical friction brakes that waste energy as heat, the electronic brake uses the motor's back-EMF to create a braking torque while potentially recovering energy. This approach enhances safety by providing quick stopping capability while minimizing energy loss compared to traditional mechanical braking.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A power tool is provided including a housing; an electric motor disposed within the housing; a main trigger switch mounted on the housing; a side handle mounted on the housing, the side handle having an auxiliary trigger; and a controller disposed within the housing operable to control a flow of electric current from a power source to the electric motor. The controller activates the motor only if the main trigger and the auxiliary trigger are both actuated. If the one of the triggers is released while the other trigger is still engaged, the controller is configured to continue operating the motor only if the released trigger is reengaged within a time threshold, but otherwise discontinue operating the motor until both the main trigger and the auxiliary triggers are released and reengaged.