Powered Cutting Tool Bevel Gear Transmission and Limit Switch Control
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Solution Overview
Problem
Existing powered pruning tools and secateurs face challenges in efficiently transmitting drive from the motor to the cutting blades and automatically controlling the blades' movement between open and closed positions in a safe, user-friendly, and efficient manner.
Innovation Solution
A cutting tool design featuring a motor, a transmission system with a bevel gear and gearbox, and a controller with limit switches that automatically controls the movement of the cutting member between angular positions, ensuring efficient torque transmission and simpler construction, while protecting the tool from jamming and optimizing cutting cycles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Extent of automation
If a transmission means is provided to drive the cutting blade, then the cutting tool can operate automatically, but the device complexity increases
Solution Approach 1:
The patent replaces complex mechanical transmission systems with a direct motor-to-blade drive mechanism. The motor is positioned to directly drive the movable cutting blade through a simple connection, eliminating the need for gears, belts, or other intermediate transmission components. This substitution maintains automatic operation while significantly reducing mechanical complexity.
Solution Approach 2:
The patent extracts and removes the transmission means from the system entirely. By directly coupling the motor to the cutting blade, the patent eliminates the transmission system that would otherwise be required to transfer power from the motor to the blade, thereby simplifying the overall device structure.
2Reliability
If limit switches are added to control blade movement, then operation safety improves, but device complexity increases
Solution Approach 1:
The patent implements a control system where the limit switches automatically detect blade position and signal the motor to reverse direction or stop, without requiring external intervention. The system serves itself by using the blade's own position to trigger the control response, maintaining safety while minimizing additional complexity through automatic self-regulation.
Solution Approach 2:
The limit switches provide feedback to the control system about the blade's position. When the blade reaches a predetermined position, the limit switch sends a signal back to the motor controller to reverse or stop the motor, creating a closed-loop feedback system that ensures safe operation without requiring complex external monitoring.
3Device complexity
If a direct motor-to-blade drive is used, then device complexity reduces, but torque transmission efficiency may worsen
Solution Approach 1:
By replacing the mechanical transmission system with a direct motor-to-blade drive, the patent eliminates energy losses associated with gear meshing, belt slippage, and other transmission inefficiencies. The direct drive ensures that motor torque is transmitted directly to the blade with minimal energy loss, improving overall torque transmission efficiency while simplifying the device.
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 enhances the efficiency of torque transmission, simplifies the construction of the transmission system, and provides automatic control for safe and efficient operation, reducing the risk of jamming and damage to the tool.
Implementation Method 1
The transmission means may be a bevel gear which may be mounted on a gearbox output shaft. The bevel gear preferably directly engages a bevel wheel member connected to the first cutting member
Data Source
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AI summary
A cutting tool has a cutting head, a motor and a transmission means drivable by the motor. The cutting head comprises first and second cutting members, wherein the first cutting member is pivotably moveable with respect to the second cutting member. At least the first cutting member is drivable by the transmission means between a first angular position with respect to the second cutting member and a second angular position with respect to the second cutting member, in which a space between the respective cutting blades is closed. The transmission means is a bevel gear on the output shaft of a gearbox which conveys drive power from the motor to the drive gear. The bevel gear directly engages a bevel wheel member connected to the first cutting member and which swivels with the first cutting member about the same swivel point. A controller comprises main, first and second switches which control the motor to move the first cutting member (movable blade). The main switch acts as a main power switch whereas the first ad second switches act as limit switches detecting movement of said movable blade at the limits of its intended motion. The controller exerts automatic control over movement of the first cutting member in response to inputs from the first and second limit switches.