Oar Handle Asymmetric Cross-Section Reduces Hand Compression

Solution Overview

Problem

Rowing and sculling oar handles made of wood with cylindrical shapes cause blisters and injuries due to unnatural, repetitive, and high-force grip, leading to compression of the hands during feathering and stroking motions.

Innovation Solution

A rowing or sculling oar handle with an axial cross-sectional shape that has a greater horizontal extent than vertical extent, featuring an oval shape with vertically misaligned portions and an abutment on the underside to reduce hand compression, allowing the thumb to contact a surface and distribute force more naturally.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a cylindrical handle shape is used, then the handle is simple to manufacture and provides a conventional grip, but the flesh of the hands is compressed in an unnatural way causing blisters and injuries

Engineering Contradiction:

Improvehandle manufacturing simplicityVSAvoidhand compression and injury

Core Design Contradiction:

Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The patent applies asymmetry by changing the handle cross-section from a symmetric cylindrical shape to an asymmetric shape with a flat underside and rounded top. This asymmetric geometry allows the thumb to rest on the flat surface while fingers wrap around the curved portion, distributing grip forces more naturally across the hand anatomy and reducing compression on vulnerable areas.

Inventive Principle:

Principle #4Asymmetry

Solution Approach 2:

The patent applies local quality by providing different surface characteristics at different locations on the handle. The underside features a flat abutment surface for thumb contact, while the top portion has a rounded contour for finger accommodation. This localized differentiation of surface geometry optimizes the grip interface at each specific contact point, reducing overall hand stress.

Inventive Principle:

Principle #3Local quality

2Ease of operation

If a roughened wooden surface is used, then grip is improved in wet conditions, but the repetitive high-force grip causes blisters and skin injuries

Engineering Contradiction:

Improvegrip in wet conditionsVSAvoidskin injuries and blisters

Core Design Contradiction:

Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The patent applies local quality by providing different surface characteristics at different locations on the handle. The underside features a flat abutment surface for thumb contact, while the top portion has a rounded contour for finger accommodation. This localized differentiation of surface geometry optimizes the grip interface at each specific contact point, reducing overall hand stress.

Inventive Principle:

Principle #3Local quality

3Power

If the handle is oriented for a stroke with traditional cylindrical shape, then the power from legs, torso and arms is transmitted through the grip, but the unnatural compression causes repetitive strain injuries

Engineering Contradiction:

Improvepower transmission through gripVSAvoidrepetitive strain injury

Core Design Contradiction:

PowerVSObject-affected harmful factors

Solution Approach 1:

The patent applies asymmetry by changing the handle cross-section from a symmetric cylindrical shape to an asymmetric shape with a flat underside and rounded top. This asymmetric geometry allows the thumb to rest on the flat surface while fingers wrap around the curved portion, distributing grip forces more naturally across the hand anatomy and reducing compression on vulnerable areas.

Inventive Principle:

Principle #4Asymmetry

Data Source

PatentUS7399213B2Rowing or sculling oar handle

Publication Date: 2008.07.15 WEBB EMILY

AI summary

A rowing or sculling oar handle in which when the handle is orientated for a stroke it has an axial cross-sectional shape with a greater horizontal extent than vertical extent, and in which an underside of the axial cross-sectional shape is provided with an abutment.