Mower Speed Control Assembly for Walking-Pace Adaptation

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Solution Overview

Problem

Existing lawn mowers lack an efficient mechanism to automatically adjust speed based on the user's walking pace, leading to inconsistent operation and user experience.

Innovation Solution

A speed control system for lawn mowers that includes a movable grip, a sensor to detect grip position, and a controller to adjust the drive system accordingly, allowing automatic speed control based on user input.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a speed control system with sensor and controller is added to detect grip position and adjust drive system, then the mower can automatically adjust speed to match user's walking pace, but the device complexity increases

Engineering Contradiction:

Improvespeed adaptation to user paceVSAvoidcontrol system complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent replaces complex mechanical speed control mechanisms with electronic sensing and control systems. A sensor detects the position of the grip on the handle, generates an output signal, and a controller processes this signal to automatically adjust the drive system, substituting mechanical linkages with electronic control to achieve speed adaptation.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent implements a feedback control loop where the sensor continuously monitors grip position, generates output signals, and the controller uses this feedback to automatically adjust the drive system speed, creating a closed-loop system that adapts to user walking pace in real-time.

Inventive Principle:

Principle #23Feedback

2Measurement precision

If a sensor and controller are integrated into the handle assembly to detect grip position, then speed control precision improves, but the manufacturing complexity increases

Engineering Contradiction:

Improvegrip position detection accuracyVSAvoidassembly integration difficulty

Core Design Contradiction:

Measurement precisionVSEase of manufacture

Solution Approach 1:

The patent merges the sensor, controller, and handle assembly into an integrated unit. The sensor is positioned within the handle assembly to directly detect grip position, and the controller is coupled to both the sensor and drive assembly, combining multiple functions into a unified structure that simplifies manufacturing while maintaining detection precision.

Inventive Principle:

Principle #5Merging (Combining)

3Ease of operation

If the grip is made moveable relative to the handle assembly to enable speed control input, then the ease of operation improves, but the reliability of the connection may worsen

Engineering Contradiction:

Improvespeed control input easeVSAvoidgrip connection stability

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

The patent introduces a sensor as an intermediary between the movable grip and the controller. The sensor detects grip position without requiring direct mechanical connection to the drive system, allowing the grip to move freely for easy operation while the sensor maintains reliable detection of position changes through non-contact or minimal-contact sensing.

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentUS12389824B2Speed control assembly

Publication Date: 2025.08.19 TECHTRONIC OUTDOOR PRODS TECH

AI summary

A mower including a handle assembly and a grip coupled to the handle assembly. The handle assembly includes a cross member. The grip is moveable longitudinally relative to the cross member. The mower also includes a sensor operable to generate an output signal based on a position of the grip relative to the cross member, and a drive assembly configured to operate based on the output signal.