Wheelchair Wheel Winder Gearing System for Fatigue Reduction
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Solution Overview
Problem
Current wheelchair propulsion devices that rely on hand rails around the outer rim of wheels can be strenuous for users, particularly on hills or long journeys, and may put excessive strain on the arms, shoulders, and elbow joints.
Innovation Solution
A hand propulsion device, known as the wheel winder, is attached to the rear axle of wheelchairs, allowing propulsion through circular motions on the outer rims with an extendable and retractable design, featuring a gearing system and a pawl switch for forward, rear, locked, and neutral positions, and a quick release mechanism for easy attachment and detachment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If hand rails around the outer rim of wheelchair wheels are used for propulsion, then the wheelchair can be self-propelled, but it causes excessive strain on the arms, shoulders, and elbow joints and creates user fatigue on hills or long journeys
Solution Approach 1:
The patent introduces a windlass mechanism as an intermediary device between the user's hands and the wheelchair wheel. This mechanism includes a handle that rotates within the wheel rim, connected through a drum and rope system to the wheel's outer rim. The user applies force to the handle in a circular motion rather than directly pushing the wheel, distributing the mechanical load through the gearing system and reducing strain on the user's joints and muscles.
Solution Approach 2:
The patent implements a dynamic propulsion system where the handle can rotate freely within the wheel rim, and the rope winds and unwinds dynamically as the wheel rotates. The gearing system allows the mechanical advantage to change dynamically based on the wheel's position and the user's applied force, optimizing propulsion efficiency while reducing peak loads on the user's body.
2Ease of operation
If the wheel winder is extended to the outer wheel rim for propulsion, then circular motion propulsion is enabled, but the device complexity increases with extendable and retractable mechanisms
Solution Approach 1:
The patent combines multiple functions into a single integrated mechanism. The handle serves both as the user interface for circular motion input and as part of the winding mechanism for the propulsion rope. The drum is integrated into the wheel structure, and the gearing system is combined with the handle rotation mechanism, eliminating the need for separate extendable and retractable components while achieving the same functional result.
3Adaptability or versatility
If the wheel winder is made retractable to be close to the wheel axle, then access through doorways and transportation is improved, but the propulsion effectiveness may be reduced
Solution Approach 1:
The patent divides the wheel winder into separable components: the handle assembly can be detached from the drum mechanism. This allows the handle to be removed for easy storage and transportation, while the drum remains attached to the wheel for continued propulsion function. The segmentation enables the device to adapt to different usage scenarios without compromising propulsion effectiveness when the handle is reattached.
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
The wheel winder reduces user fatigue by providing a more efficient and comfortable propulsion method, allowing for adjustable force and speed control, and can be easily detached for access through doorways and transportation.
Implementation Method 1
2—The ball bearing to keep the wheel winder head unit mechanism in place when fitted to a socket.
Implementation Method 2
4—Spring loaded Pawl on the wheel winder mechanism to shift from forwards to backwards, locked position & neutral.
Implementation Method 3
5—The arm & of the gears of the wheel winder that is attached to a switch on the outside side of the wheel winder which controls a total of 8 gears
Implementation Method 4
8—A soft grip handle to enable the user of the wheel winder to propel ones self by holding onto and rotating the wheel winder in circular motions around the rotation area of the wheelchair wheel.
Data Source
AI summary
A manual wheelchair propulsion device (FIGS. 5, 6&7), attached to wheelchairs through the axles of the rear wheels (FIGS. 14, 15, 16&17), attached through the wheel winder unit with a quick release head with ball Joint to lock in position (FIGS. 1, 2) to an adaptable socket either manufactured into the axle of the wheelchair wheel or attached rigidly with supports later (FIGS. 14, 15&17) with a retractable arm (FIGS. 5&6) with eight gears and one neutral (FIGS. 3, 12&13) used in a circular motion to manually propel ones self.