Indexed Mower Handle Assembly for Ergonomic Height Adjustment

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Solution Overview

Problem

Typical walk-behind lawn mowers have a handle that is fixed at a single operative position, which does not accommodate operators of varying heights, leading to discomfort during use.

Innovation Solution

A handle adjustment assembly that includes indexing mechanisms with teeth and lugs, allowing the handle to be adjusted to multiple operative positions and a stored position, enabling users to set the handle height comfortably and store the mower vertically without interference.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a fixed handle position is used, then the structure is simple and reliable, but it does not accommodate operators of varying heights leading to discomfort

Engineering Contradiction:

Improvehandle position adaptabilityVSAvoidhandle adjustment mechanism complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The handle assembly transitions from a fixed static structure to a dynamic adjustable structure. The indexing mechanism allows the handle to be positioned at multiple discrete angles (at least three different orientations), enabling operators to adjust the handle to their comfort level while maintaining structural reliability through positive engagement of indexing lugs with indexing slots.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The handle adjustment mechanism is segmented into discrete positional increments rather than continuous adjustment. The indexing system divides the adjustment range into specific angular positions, with each position secured by indexing lugs engaging with corresponding slots, providing both adaptability and structural integrity.

Inventive Principle:

Principle #1Segmentation

2Ease of operation

If a fixed handle position is used, then the manufacturing is simple, but it cannot provide ergonomic flexibility for different users

Engineering Contradiction:

Improvehandle adjustment easeVSAvoidindexing mechanism complexity

Core Design Contradiction:

Ease of operationVSDevice complexity

Solution Approach 1:

The indexing mechanism is designed to be self-servicing through spring-loaded indexing lugs that automatically engage with indexing slots when the handle is positioned at the desired angle. The springs provide automatic engagement force, eliminating the need for additional locking mechanisms or complex adjustment procedures, thereby maintaining ease of operation despite the added functionality.

Inventive Principle:

Principle #25Self-service

3Adaptability or versatility

If multiple handle positions are provided, then ergonomic flexibility is improved, but the handling complexity increases

Engineering Contradiction:

Improvehandle position optionsVSAvoidhandle adjustment operation

Core Design Contradiction:

Adaptability or versatilityVSEase of operation

Solution Approach 1:

The manual adjustment and locking mechanism is replaced with an automatic spring-loaded indexing system. When the handle is moved to a desired position, the spring-loaded lugs automatically engage with the corresponding indexing slots, providing secure positioning without requiring manual locking operations. This substitution maintains ease of operation while enabling multiple handle positions.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Data Source

PatentUS11707018B2Adjustable handle assembly for a walk-behind mower

Publication Date: 2023.07.25 MTD PRODUCTS INC

AI summary

A handle adjustment assembly is attached to a walk-behind lawn mower, wherein the handle adjustment assembly is rotatably adjustable relative to a deck of the mower to allow the handle to be adjusted to multiple different heights relative to the ground at distinct operative positions. The handle adjustment assembly is also rotatable to allow the handle to be adjusted to a stored position adjacent to the deck, wherein the mower can be stored in a substantially vertical orientation.