Pivoting Foot Platform Decouples Drive Arm Angle for Elliptical Trainers
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Solution Overview
Problem
Rear-drive elliptical cycles with fixed foot platforms restrict foot angle adjustment, leading to uncomfortable extreme angles that can cause injuries and limit the minimum drive arm length, resulting in a larger and heavier frame.
Innovation Solution
A pivoting foot platform decouples the foot angle from the drive arm angle, allowing dynamic adjustment and incorporating forward and rearward motion limits, which can be adjustable or locked, to enhance comfort and reduce frame size.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a fixed foot platform is rigidly attached to the drive arm, then the structure is simple and stable, but the foot angle becomes extreme and uncomfortable causing injuries
Solution Approach 1:
The foot platform system is segmented into two independent components: the drive arm and the foot platform, connected through a pivot mechanism. This allows the foot platform to rotate independently relative to the drive arm, decoupling the foot angle from the drive arm angle and enabling comfortable foot positioning throughout the pedaling stroke.
Solution Approach 2:
The foot platform is made dynamically adjustable through a pivot mechanism that allows rotation during operation. The platform can be positioned at different angles throughout the pedaling stroke and locked at desired positions, transforming from a static fixed angle to a dynamic adjustable angle system.
2Manufacturing precision
If a longer drive arm is used to achieve desired foot path, then the foot path accuracy is improved, but the frame length and weight increase
Solution Approach 1:
The pivoting foot platform enables the system to achieve the desired elliptical foot path with a shorter drive arm by allowing dynamic angle adjustment. The pivot mechanism compensates for the reduced leverage of a shorter arm through angular optimization, maintaining foot path accuracy while reducing frame dimensions.
Solution Approach 2:
The system changes the operational parameters by introducing an additional degree of freedom (pivot angle) that allows optimization of the drive arm length. By adjusting the pivot angle throughout the stroke, the system achieves equivalent foot path geometry with shorter drive arm dimensions.
3Length of moving object
If a shorter drive arm is used to reduce frame size, then the frame length and weight are reduced, but the foot angle becomes extreme and uncomfortable
Solution Approach 1:
By segmenting the foot platform from the drive arm through a pivot connection, the system allows the foot platform to independently adjust its angle. This decoupling enables the use of a shorter drive arm while maintaining comfortable foot angles through independent platform rotation.
4Device complexity
If the foot platform is fixed to the drive arm, then the mechanism complexity is reduced, but the adaptability for different rider preferences is limited
Solution Approach 1:
The foot platform incorporates a pivot mechanism with adjustable positioning capability, allowing riders to customize their preferred foot angle. The platform can be set to different angular positions and locked in place, providing adaptability for different rider preferences while adding only minimal mechanical complexity.
Data Source
AI summary
An apparatus including a frame; a drive wheel coupled to the frame; first and second foot links operably coupled to said drive wheel to transfer power to said drive wheel so as to propel the apparatus; and each of said first and second foot links including a pivoting foot platform for receiving an operator's foot, said pivoting foot platform pivotally coupled to one of said first and second foot links so as to allow angular travel of the pivoting foot platform, the apparatus including one or more features to limit the angular travel of said pivoting foot platform.