Elliptical Velocipede Drive Mechanism with Sliding Block Cranks
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Solution Overview
Problem
Existing elliptical drive mechanisms in velocipedes, such as bicycles and tricycles, are complex and costly, making maintenance and repairs difficult due to their intricate structural frameworks, which hinder the ease of using replacement parts and increase the overall cost of the devices.
Innovation Solution
A simplified elliptical drive mechanism and steering system are integrated into a tubular crossmember frame, featuring sliding blocks and a flexible cable system, allowing for easy assembly and disassembly, reduced structural complexity, and enhanced maneuverability, with the sliding blocks transferring rotary motion to the cranks and sprocket, and the flexible cable system enabling smooth steering and folding for storage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an elliptical drive mechanism is installed in a velocipede, then user stability in upright position is improved, but the structural framework becomes complex and costly
Solution Approach 1:
The drive mechanism is divided into separate functional components: a crankset assembly with cranks and pedals, a chain drive system, and a rear wheel hub integration. This segmentation allows each component to be manufactured independently using standard parts, reducing overall structural complexity while maintaining user stability through the elliptical motion path.
Solution Approach 2:
The rear wheel hub serves multiple functions: it acts as the final drive interface for the chain, provides the mounting point for the elliptical crank mechanism, and integrates the brake system. This multi-functionality reduces the number of separate structural elements needed, simplifying the framework while preserving stability.
2Reliability
If an elliptical drive mechanism with complex structural framework is used, then user stability is improved, but ease of repair and maintenance deteriorates
Solution Approach 1:
The drive mechanism uses segmented, modular components including a removable crankset, separate chain tensioning system, and independent brake assemblies. This modular segmentation enables easy removal and replacement of individual components for maintenance without disassembling the entire structure, improving ease of repair while maintaining stability.
Solution Approach 2:
The chain tensioning system incorporates an adjustable tensioner that can be easily manipulated by the user to maintain proper chain tension. This self-adjusting feature eliminates the need for complex maintenance procedures or specialized tools, allowing users to perform routine maintenance themselves while preserving the stability provided by the elliptical mechanism.
3Adaptability or versatility
If the structural framework is made complex to accommodate the drive mechanism, then drive functionality is improved, but device cost increases
Solution Approach 1:
The rear wheel hub is designed as a universal mounting interface that accommodates the elliptical crank mechanism, chain drive, and brake system. This multi-functional design eliminates the need for custom structural elements, allowing standard components to be used and reducing manufacturing costs while maintaining full drive functionality.
Solution Approach 2:
Instead of designing a complex custom frame to accommodate the drive mechanism, the invention inverts the approach by designing the drive mechanism to integrate with a simplified, standardized frame structure. The crankset and chain drive are configured to work with conventional bicycle frame geometries, reducing manufacturing complexity and cost while preserving elliptical drive functionality.
4Reliability
If the velocipede structure is rigid for stability, then user stability is improved, but ease of storage and transport deteriorates
Solution Approach 1:
The handlebar stem incorporates a telescopic or collapsible mechanism that allows the handlebars to be adjusted or folded during storage and transport. This dynamic feature enables the velocipede to be compacted for easy storage while maintaining rigid structural integrity and user stability during normal operation.
Solution Approach 2:
The velocipede is designed with segmented, removable components including the handlebar assembly, seat post, and potentially the wheels. These segmented sections can be easily detached or folded for storage and transport, while the main frame structure remains rigid to provide user stability during operation.
Data Source
AI summary
“IMPROVEMENTS INTRODUCED IN AN ELLIPTICAL DRIVE MECHANISM AND A STEERING MECHANISM, APPLICABLE TO VELOCIPEDES IN GENERAL,” more specifically, it is about elliptical velocipedes (1) of the bicycle, tricycle, and scooter type, with said velocipedes having a tubular crossmember (2A) where the basic components are mounted, namely: fork (2b), handlebar mounting (2c), front wheel, rear wheel, center sprocket, and cranks, as well as an elliptical drive mechanism (M1) and a steering mechanism (M2). The structural frame (2) has a crossmember (2A), whose end is aligned with the imaginary center of the rear wheel, a tubular transverse shaft with tubular connections (3a) installed on its end portions, while a guide rod (3) that functions as a path for the sliding of the respective block (4) is attached to each of said connections. Each rod (3) is parallel to the crossmember (2A), while each sliding block (4) constitutes a platform whose lower bottom portion can be attached to a crank arm, which is, in turn, installed on the center sprocket of the velocipede (1), which drives a chain (5) that is responsible for transmitting motion to the ratchet mechanism. The lower surface of each plate (4) has at least two pairs of mountings (4a) with cross-sections in the shape of an inverted “L” on the side edges of the plate (4a), and they have pulleys (7) whose sections correspond to the sections of each guide rod (3). Because of the fact that the blocks (4) are mounted on the ends of the crank arms, sliding of said shoes on each guide rod (3) is in reverse, and, on account of the fact that the aforementioned rods (3) are linked to the transverse shaft, they produce an alternating upward and downward angular motion, thereby causing rotary motion of the cranks and, consequently, rotation of the center sprocket, the chain (5), and the ratchet mechanism, which, in this instance, is mounted on the front wheel, so as to constitute the elliptical drive mechanism (M1).