Gardening Tool Clutch Mechanism for Overload Protection
Solution Overview
Problem
Hedge trimmers often experience motor and transmission overload when the blade becomes blocked, leading to a decrease in the tool's working life due to inability to stop the high power driving mechanism in time.
Innovation Solution
A transmission system with a first clutch member, a movable member, a bias member, and a second clutch member that disengages when an overload condition is detected, protecting the system by allowing the first clutch member to rotate relative to the second clutch member, thus preventing further damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If high power is used to drive the blade member, then cutting performance is improved, but the motor and transmission device experience overload when blocked, decreasing working life
Solution Approach 1:
A clutch mechanism is introduced as an intermediary between the motor and the blade member. The clutch includes a driving member connected to the motor, a driven member connected to the blade member, and a movable member that can disengage the driving and driven members when overload occurs. This intermediary allows the high-power transmission while providing automatic protection against overload damage.
Solution Approach 2:
The clutch mechanism transforms the rigid direct drive connection into a dynamic system with movable components. The movable member can shift positions to engage or disengage the clutch, allowing the system to adapt its power transmission state based on operating conditions. This dynamic capability enables automatic overload protection while maintaining normal high-power operation.
2Ease of operation
If the blade member is blocked by something hard, then cutting operation stops, but the motor and transmission device continue to experience overload, causing damage
Solution Approach 1:
The clutch mechanism provides self-service automatic protection without requiring user intervention. When the blade member is blocked, the increased load automatically causes the movable member to disengage the clutch, stopping power transmission. The system serves itself by detecting and responding to overload conditions through the mechanical interaction of the clutch components.
Solution Approach 2:
The clutch mechanism creates a mechanical feedback loop where the load condition on the blade member is transmitted back to the motor through the movable member. When overload occurs, the feedback causes the movable member to shift position and disengage the clutch, automatically reducing the load on the motor and preventing damage.
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 effectively prevents motor and transmission overload by disengaging the clutch members during blockages, thereby extending the lifespan of the gardening tool and ensuring safe operation.
Implementation Method 1
The spring member bends to a first direction and engages with the plurality of gear teeth in the first state so as to couple the first clutch member and the second clutch member for rotation together, and the spring member bends to a second direction and disengages with the plurality of gear teeth in the second state so as to uncouple the second clutch member from the first clutch member
Data Source
AI summary
A gardening tool includes a motor, a working assembly for performing a function of the gardening tool, and a transmission system for causing the motor to drive the working assembly. The transmission system includes a first clutch member, a movable member that is moveable from a first position to a second position, a bias member for biasing the movable member to the first position, and a second clutch member configured to rotate with the first clutch member when the movable member is biased to the first position and to rotate relative to the first clutch member when the movable member is located at the second position.