Forward Extended Fork Legs for Rider Clearance

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Solution Overview

Problem

Conventional fork leg arrangements in riding vehicles, such as bicycles, do not provide sufficient clearance for a rider's lower body, particularly in competitive racing scenarios where greater knee and leg room is required, especially when crouching.

Innovation Solution

A steering apparatus with dual forward extended fork legs that include a steering column, first and second fork legs extending along both sides of the column, and top fork portions that extend upwardly and forwardly to support a steering handle bar, with lower and upper crowns having angled bores to stabilize and position the fork legs in a non-converging manner, providing increased vertical and horizontal space.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If conventional fork leg arrangements are used, then the steering structure is simple and compact, but the clearance for rider's knees and legs is insufficient

Engineering Contradiction:
Improveclearance for rider's lower bodyVSAvoidfork leg arrangement complexity
Core Design Contradiction:
Area of stationary objectVSDevice complexity

Solution Approach 1:

The fork legs are extended forward in the horizontal dimension rather than only vertically, creating additional space in the forward direction. The top fork portions extend 1 to 12 inches forward of the steering column axis, providing clearance for the rider's lower body without increasing vertical height or overall structural complexity

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Area of stationary object

If fork legs are extended forward to provide clearance, then rider's leg room is improved, but the positioning and stability of the steering handle bar becomes more difficult

Engineering Contradiction:
Improveleg room clearanceVSAvoidsteering handle bar positioning
Core Design Contradiction:
Area of stationary objectVSStability of the object's composition

Solution Approach 1:

The fork leg structure is divided into distinct segments: the lower fork portion, the bent section, and the top fork portion. This segmentation allows each part to perform its specific function - the bent section provides the forward extension for clearance while the top fork portions maintain proper positioning for handle bar attachment

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The bent section of the fork leg acts as an intermediary element between the lower fork portion and the top fork portion. This intermediate bent section enables the top fork portions to extend forward while maintaining structural integrity and proper positioning for the steering handle bar

Inventive Principle:
Principle #24Intermediary (Mediator)

3Area of stationary object

If the top fork portions extend forward, then clearance for crouching position is improved, but the manufacturing complexity of the fork legs increases

Engineering Contradiction:
Improveclearance for crouching positionVSAvoidfork leg manufacturing
Core Design Contradiction:
Area of stationary objectVSEase of manufacture

Solution Approach 1:

The fork legs incorporate bent sections with smooth curvatures rather than sharp angles or complex geometries. This curved design provides the necessary forward extension for clearance while maintaining manufacturability through standard bending and forming processes

Inventive Principle:
Principle #14Spheroidality (Curvature)

Data Source

PatentEP3411286B1Steering apparatus with forward extended fork legs
Publication Date: 2020.09.02 MARUI SHINJI
  • EP3411286B1 patent drawingFigure 1A~1B
  • EP3411286B1 patent drawingFigure 2
  • EP3411286B1 patent drawingFigure 3

AI summary

A steering apparatus with forward extended fork legs includes left and right fork legs that extend from a wheel axle all the way up to a handlebar. Top fork portions support a handlebar in a more forward location. A mid-fork portion of each fork leg is positioned in front of the steering column to provide more clearance room for the rider's knees, e top ends of the fork legs are positioned a forward distance in front of the vertical axis defined by the steering column. Each fork leg may be tilted forward with respect to the steering column and may also include a forward bend to direct portions of each fork leg towards the front.