Handlebar Adjustment Mechanism with Tool-Free Detent Locking

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Solution Overview

Problem

Existing handlebar adjustment mechanisms for devices like lawn mowers and tillage equipment are difficult to adjust without tools and often have play issues, with locking devices being complex and prone to catching debris.

Innovation Solution

A handlebar adjustment mechanism that allows for easy, tool-free adjustment with minimal play, featuring a locking lever with a dowel pin that engages with prismatic notches on a locking plate, secured by a spring, and covered by a recess to prevent debris entry.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If screw connections are used for adjusting the handlebar height, then the handlebar can be adjusted to different heights, but the adjustment requires tools and is difficult to perform

Engineering Contradiction:
Improveease of handlebar adjustmentVSAvoidcomplexity of adjustment mechanism
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The adjustment mechanism is segmented into discrete locking positions with notches on the locking plate, allowing the handlebar to be adjusted to specific predetermined heights without requiring complex continuous adjustment mechanisms or tools

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Instead of using a traditional screw connection where rotation moves the handlebar continuously, the invention inverts the approach by using a locking lever that engages with notches to lock the handlebar at specific positions, making adjustment simpler and tool-free

Inventive Principle:
Principle #13The other way round (Inversion)

2Reliability

If detent devices are used for locking the handlebar, then the handlebar can be fixed in pivot positions, but the devices have play and are annoying in use

Engineering Contradiction:
Improvelocking reliabilityVSAvoidsmoothness of operation
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The geometry of the notches is specifically designed with a prismatic shape that narrows toward the locking position, and the locking lever is dimensioned to fit tightly within these notches, minimizing play while maintaining reliable locking

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The spring automatically pushes the locking lever into engagement with the notches, providing self-locking functionality that eliminates play without requiring additional adjustment mechanisms or user intervention

Inventive Principle:
Principle #25Self-service

3Reliability

If complex locking devices with considerable width are used, then the handlebar can be locked securely, but grass and dirt residue can become trapped in the locking mechanism

Engineering Contradiction:
Improvelocking securityVSAvoiddebris accumulation
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The locking mechanism is extracted from the interior of the handlebar structure and positioned on its outer surface, allowing it to be covered by the handlebar cover and preventing debris from entering the mechanism while maintaining secure locking functionality

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The locking mechanism is nested within the handlebar structure by positioning it on the outer surface and covering it with the handlebar cover, creating a protected environment that prevents debris accumulation while maintaining locking security

Inventive Principle:
Principle #7Nested doll (Nesting)

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

Enables easy and tool-free adjustment of the handlebar to different heights with minimal play, maintaining operational efficiency and cleanliness by minimizing debris accumulation.

Implementation Method 1

which is provided at its end opposite the shaft (51) with a spring (16) which is pre-tensioned into the detent position

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

a dowel pin (15) which can engage, which is attached to the locking lever (50) with a shaft (51)

Methodology Applied
Scientific EffectMechanical Fastening: Mechanical Fastener

Implementation Method 3

the first end (12) of which carries a handle (20) and which is rotatable about a first axis of rotation (31) which extends essentially perpendicular to the longitudinal axis of the pole (10)

Methodology Applied
Scientific EffectRotation:

Data Source

PatentEP3420793B1Device for adjusting the position of a spar of a moving device
Publication Date: 2021.04.28 MTD PRODUCTS INC
  • EP3420793B1 patent drawingFigure 1
  • EP3420793B1 patent drawingFigure 2
  • EP3420793B1 patent drawingFigure 3

AI summary

A handlebar for moving and/or controlling a mobile device (20) comprises at least one handlebar (10) with a first end rotatably attached to one end of the device (20) and a second end carrying a handle, as well as an adjustment mechanism (30) by which the first end (12) of the handlebar is rotatably attached to the device (20) about a first axis of rotation (31) and adjustable to several pivot positions. The adjustment mechanism includes a handlebar mounting plate (32) arranged on the device (20) for rotatably attaching the first end of the handlebar (10) about the first axis of rotation.This first end is extended on the side of the axis of rotation opposite the handle by a detent plate (13) which carries first elements (14) of the adjustment mechanism which can be engaged with second elements (15, 50) of the adjustment mechanism arranged on the handle mounting plate and pivotable about a second axis of rotation (51), the second axis of rotation lying on a circular path of the rotation of the detent plate about the first axis of rotation.