Nested Bearing Linkage for Unlimited Bicycle Handlebar Rotation
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Solution Overview
Problem
Existing mechanical linkages for bicycles, such as those using Bowden cables, are unable to accommodate unlimited rotation of the front wheel and simultaneously control multiple mechanisms like brakes and gears, which is a limitation for 'freestyle' bicycles and other machines with multiple control systems.
Innovation Solution
A dual mechanical linkage system with nested bearings allows for independent rotation of handlebars and the frame, enabling the control of multiple mechanisms without interference, by using a first bearing connected to the handlebars and a second bearing located radially outward, connected to the frame, allowing for 360-degree turns without cable flexing or entanglement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If Bowden cables are used for mechanical linkages, then flexibility and rotation accommodation are improved, but the ability to control multiple mechanisms simultaneously deteriorates
Solution Approach 1:
The patent employs nested bearings where an inner bearing is positioned within an outer bearing, both sharing a common axis. The inner bearing accommodates rotation for one mechanical linkage while the outer bearing accommodates rotation for another linkage. This nesting arrangement allows multiple independent rotational movements to coexist in a compact space, enabling simultaneous control of multiple mechanisms without cable interference.
2Device complexity
If multiple mechanical linkages are implemented, then multi-mechanism control is improved, but spatial interference and complexity increase
Solution Approach 1:
The nested bearing configuration places the inner bearing within the outer bearing, both centered on the same axis. This vertical nesting eliminates horizontal spatial interference between linkages, allowing multiple control cables to pass through the same axial space without crossing or tangling, thus reducing the area occupied while maintaining multi-mechanism control.
Solution Approach 2:
The patent transitions from horizontal arrangement of multiple linkages to a vertical/axial arrangement by nesting bearings along the same axis. This dimensional reorganization allows multiple linkages to occupy the same radial space at different axial positions, eliminating spatial interference in the horizontal plane while maintaining independence of each linkage.
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
This solution enables the simultaneous control of multiple mechanisms like brakes and gears during unlimited handlebar rotation, preventing cable flexing and snagging, and allows for the use of non-flexible couplings, enhancing operational reliability and flexibility.
Implementation Method 1
a first bearing (15) having two parts (15A, 15B, 15C and 15D, 15E, 15F) relatively rotatable about the axis (X)
Data Source
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AI summary
Conventional linkages between bicycle handlebar-mounted controls and rear brakes and gears are unable to accommodate unlimited rotation of the handlebars as is required on some so-called "freestyle" bicycles. A prior attempt to solve the problem employs a linkage comprising a bearing having two parts that are relatively rotatable about an axis. However this proposal is unable to handle situations where there are two or more mechanisms to be controlled e.g. a rear brake and a gear. The problem is solved by using multiple bearings (15, 16, 17) that share a common axis (X-X) of rotation but are located at different radial positions with respect to the axis. This avoids interference between the different linkages and makes it possible to locate the linkages around a stem on which the front wheel fork of the bicycle is mounted. A possible suitable location may be within a head tube of the bicycle frame. The invention is not limited to use with bicycles and can be employed in robotic and other machines.