Cutting Tool Intermediate Shaft Forward Positioning
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Solution Overview
Problem
Battery-powered circular saws have an unfavorable weight balance due to the rear placement of the battery, leading to increased load on the operator's hands and degraded handling and operability.
Innovation Solution
The cutting tool design includes a two-stage reduction mechanism with an intermediate shaft positioned forwardly, a main handle and front handle, a lighting device, a blow nozzle, a lock lever, and a wrench holder, all positioned forwardly to shift the gravity center forward, improving balance and reducing operator fatigue.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the battery is mounted to the rear end of the handle, then the battery-powered circular saw can operate without power cord connection, but the gravity center shifts rearwardly causing unfavorable weight balance and increased load on operator's hands
Solution Approach 1:
The patent positions the battery in the front portion of the tool body, opposite to the conventional rear mounting, to create a counterbalancing effect. This repositioning shifts the gravity center forward, counteracting the rearward weight bias and achieving more favorable weight balance for improved handling and reduced operator fatigue
2Adaptability or versatility
If the battery is mounted to the rear end of the handle, then the battery-powered circular saw can operate without power cord connection, but the gravity center shifts rearwardly causing increased load on operator's hands
Solution Approach 1:
By repositioning the battery to the front portion of the tool body, the patent creates a counterbalancing weight distribution that reduces the net force required by the operator to hold and control the tool, thereby decreasing the load on the operator's hands while maintaining portable operation capability
3Ease of operation
If the intermediate shaft is positioned forwardly of the reference plane, then the gravity center shifts forward improving weight balance, but the reduction gear mechanism becomes more complex
Solution Approach 1:
The patent positions the intermediate shaft forwardly of the reference plane that passes through the motor output shaft and spindle, utilizing spatial reconfiguration in the longitudinal dimension. This dimensional adjustment shifts the gravity center forward to improve weight balance while integrating the additional shaft into the existing reduction gear structure
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
This configuration enhances the balance and operability of the cutting tool, reducing the load on the operator's hands and improving handling efficiency by positioning the weight gravity center forward, thus addressing the weight imbalance issue.
Implementation Method 1
The reduction gear section serves to transmit rotation of the electric motor to a spindle, to which the cutting blade is mounted, after reduction of the rotational speed through engagement between reduction gears
Data Source
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AI summary
A cutting tool (1) includes a base (2) and a tool unit (10) coupled to the base (2) and movable together with the base (2) in a cut proceeding direction for cutting a workpiece (W). The tool unit (10) includes an electric motor (12) having an output shaft (12a), a reduction gear section (20), and a spindle (29) having a cutting blade (13) mounted thereto. The reduction gear section (20) is coupled between the output shaft (12a) and the spindle (29), so that the rotation of the output shaft (12a) is transmitted to the spindle (29) via the reduction gear section (20). The reduction gear section (20) has an intermediate shaft (23), a first reduction gear mechanism provided between the output shaft (12a) and the intermediate shaft (23), and a second reduction gear mechanism provided between the intermediate shaft (23) and the spindle (29). The intermediate shaft (23) is positioned forwardly of the output shaft (12a) and the spindle (29) in the cut proceeding direction at least when the tool unit (10) is positioned for cutting the workpiece (W).