Electric Bar End Shifter Vertical Thumb Operation

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Solution Overview

Problem

Existing bicycle shift control devices for time trial bicycles, particularly those with bull horn handlebars and aero bars, lack efficient and ergonomic solutions for operating shifters, often requiring riders to move their hands laterally, which can increase air resistance and reduce stability.

Innovation Solution

The development of an electric bar end shifter with two independent electrical shift switches mounted on the free ends of aero bars, allowing for vertical operation, reducing the need for lateral hand movement and minimizing space requirements, with each switch controlling a different shift direction to prevent mistaken operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If traditional mechanical bar-end shifters are used, then lateral hand movement is required for operation, but this increases air resistance and reduces stability in time trial bicycles

Engineering Contradiction:
Improvehand movement requirementVSAvoidair resistance
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The patent transitions from lateral hand movement (horizontal dimension) to vertical thumb movement (vertical dimension) for shifter operation. The first and second shift operating members are designed to pivot vertically about horizontal pivot axes, allowing riders to operate shifters using thumb motion in the vertical plane rather than requiring lateral hand movement in the horizontal plane. This dimensional change eliminates the need for hand repositioning that increases air resistance.

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

2Productivity

If multiple electrical switches are provided at multiple handlebar locations, then shift responsiveness is enhanced, but device complexity increases

Engineering Contradiction:
Improveshift responsivenessVSAvoidnumber of switches
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent combines two shift operating functions (first shift direction and second shift direction) into a single integrated bar-end shifter unit. The first shift operating member and second shift operating member are both mounted on the same base member at one handlebar location, merging multiple switching functions into one compact device. This reduces the total number of separate switches and installations while maintaining quick access and responsiveness.

Inventive Principle:
Principle #5Merging (Combining)

3Object-affected harmful factors

If bar-end shifters are added to the free ends of aero bars, then aerodynamic position is maintained, but space for finger operation becomes limited

Engineering Contradiction:
Improveaerodynamic positionVSAvoidfinger operation space
Core Design Contradiction:
Object-affected harmful factorsVSEase of operation

Solution Approach 1:

The patent inverts the traditional finger-operated shifter design by using thumb-operated pivot members instead. The first and second shift operating members are designed to be manipulated by the rider's thumb rather than fingers, allowing operation in the limited space at the aero bar end while maintaining the aerodynamic tuck position. The vertical pivoting motion requires minimal lateral space.

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

4Area of stationary object

If two shift operating members are mounted on the same base member, then space requirements are reduced, but the risk of mistaken operation increases

Engineering Contradiction:
Improvemounting spaceVSAvoidshifting accuracy
Core Design Contradiction:
Area of stationary objectVSReliability

Solution Approach 1:

The patent employs asymmetric design in the arrangement and configuration of the first and second shift operating members. The members are positioned at different locations and orientations on the base member, with distinct pivot axes and operating directions. This asymmetric configuration makes it visually and tactually clear which member controls which shift direction, preventing mistaken operation while maintaining compact mounting space.

Inventive Principle:
Principle #4Asymmetry

Data Source

PatentEP2253531B1Electrical bicycle shift control device
Publication Date: 2013.12.18 SHIMANO INC
  • EP2253531B1 patent drawingFigure 1
  • EP2253531B1 patent drawingFigure 2~4
  • EP2253531B1 patent drawingFigure 5~7

AI summary

An electrical bicycle shift control device is provided with a base member (20), a first shift operating member (21) and a second shift operating member (22). The handlebar mounting portion is configured to be fixedly mounted to a free end of a bicycle handlebar. The base member includes a handlebar mounting portion (50) that is configured to be fixedly mounted a handlebar. The first shift operating member (21) is pivotally coupled the base member from a rest position to a shift position in a first shift operating direction. The second shift operating member (22) is mounted on the first shift operating member to move with the first shift operating member with respect to the base member. The second shift operating member is independently movable relative the first shift operating member from a rest position to a shift position in a second shift operating direction that is different to the first shift operating direction.