Hand-Held Cutting Tool Speed Modes for Precision and Quick Severing
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Solution Overview
Problem
Hand-held gardening, forestry, and construction tools lack user-friendly features for efficient and versatile operation, particularly in terms of speed control and ease of use across different materials like wood, grass, and metal.
Innovation Solution
A hand-held tool with a movable, rotatable cutting tool driven by an electric motor and controlled by a user-adjustable motor control device, featuring two operating modes: a sensitive first mode for precise cutting and a high-speed second mode for quick severing, allowing for multi-functional processing without the need for a gearbox.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a single operating mode with linear speed control is used, then the device structure remains simple, but the versatility and user-friendliness for different materials and tasks is reduced
Solution Approach 1:
The control device provides two different operating modes with dynamically different speed-position characteristics. Mode 1 offers sensitive speed control for precise cutting of tough materials, while Mode 2 provides rapid speed response for quick cutting of softer materials. This dynamic adaptability allows the same device to handle diverse materials and tasks effectively.
Solution Approach 2:
The patent changes the control parameter characteristics by implementing two distinct operating modes with different speed-position relationships. Mode 1 uses a linear increase characteristic for sensitive control, while Mode 2 uses a different characteristic for rapid response. This parameter variation enables the device to adapt to different material properties and cutting requirements.
2Speed
If the motor control element is adjusted to maximum position for high speed cutting, then quick severing is achieved, but sensitive speed control is lost
Solution Approach 1:
The system dynamically switches between two operating modes depending on the cutting task. In Mode 1, the linear speed increase provides sensitive control for precise operations. In Mode 2, the rapid speed response enables quick cutting without requiring full throttle adjustment. This dynamic mode switching resolves the contradiction between speed and control sensitivity.
Solution Approach 2:
The operating range is segmented into two distinct modes, each optimized for specific cutting scenarios. Mode 1 handles precision cutting requiring sensitive control, while Mode 2 handles rapid cutting tasks. This segmentation allows the operator to select the appropriate mode based on the specific task, avoiding the need to compromise between speed and control sensitivity.
3Adaptability or versatility
If the motor control element adjustment range is increased for broader speed control, then versatile speed settings are achieved, but the response time to reach target speed increases
Solution Approach 1:
The control system dynamically adapts its response characteristics based on the selected operating mode. Mode 1 provides broad speed control range with linear progression for precise adjustment. Mode 2 prioritizes rapid response by implementing a different speed-position relationship that reaches target speeds faster. This dynamic adaptation resolves the time-range trade-off.
Solution Approach 2:
The patent changes the control parameter characteristics by implementing two distinct operating modes with different speed-position relationships. Mode 1 uses a linear increase characteristic for sensitive control across a broad range. Mode 2 uses a different characteristic optimized for rapid response. This parameter variation enables the device to adapt to different material properties and cutting requirements.
Data Source
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AI summary
The invention relates to a hand-held garden, forestry, and/or construction tool (1), wherein the garden, forestry, and/or construction tool (1) comprises: - a cutting tool (2), wherein the cutting tool (2) is designed for cutting through a workpiece, - an electric drive motor (3), wherein the drive motor (3) is designed for driving the cutting tool (2), - a motor control element (4), wherein the motor control element (4) is user-adjustable over an adjustment range (SB) from a minimum position (minST) to a maximum position (maxST), and - a control device (5), wherein the control device (5) is designed for controlling a target speed (nsoll) of the drive motor (3) as a function of a position (ST) of the motor control element (4) in at least a first operating mode (BM1) and a second operating mode (BM2), - wherein in the first operating mode (BM1) the target speed (nsoll) is controlled over at least one section (AS,AS') increases by a minimum of 0.5 times the setting range (SB) with increasing position (ST), wherein the increase (ZU1, ZU1') changes by a maximum of 60% over the section (AS, AS'), and . wherein in the second operating mode (BM2) the target speed (nsoll) from a maximum of 50% of the setting range (SB) with increasing position (ST) is a minimum of 0.9 times a maximum target speed (maxnsoll2) of the second operating mode (BM2).