Bicycle Fork Suspension With Air Cushion to Resist Bottoming
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Solution Overview
Problem
Conventional bicycle suspension systems often fail to fully absorb the impact of larger obstacles, leading to 'bottoming out' and force transmission to the rider, as they are tuned for smaller obstacles, and require complex valve arrangements for progressive damping, which increases cost and maintenance.
Innovation Solution
A suspension system incorporating a first and second tube with a gas-filled chamber, a one-way valve, and an adjustable blocker to control gas flow, providing progressive resistance and energy absorption near full compression, allowing for adjustable damping and reduced maintenance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the suspension is tuned for small obstacles, then it performs well on typical terrain, but it bottoms out on larger obstacles transmitting force to the rider
Solution Approach 1:
The suspension system dynamically adjusts its damping characteristics through a progressive air spring mechanism. As compression increases, the air pressure in the chamber increases non-linearly, automatically providing softer initial response for small obstacles and stiffer resistance for large obstacles, eliminating the need for fixed tuning compromises
Solution Approach 2:
The system changes the spring constant parameter dynamically through compression. The air spring's effective spring rate increases as volume decreases and pressure increases during compression, transforming the suspension from linear to progressive behavior to handle both small and large obstacles effectively
2Reliability
If conventional valves are used to achieve progressive damping, then bottoming is avoided, but device complexity and cost increase
Solution Approach 1:
The invention uses pneumatic principles with an air-filled chamber as the primary damping mechanism. The compressible air provides progressive resistance naturally through pressure-volume relationships, eliminating the need for complex mechanical valve arrangements while achieving the same bottoming prevention effect
Solution Approach 2:
The air spring system is self-regulating and self-adjusting. The air pressure automatically increases with compression to provide progressive damping without requiring external control mechanisms, valves, or complex regulation systems, simplifying the overall device structure
3Ease of operation
If incompressible fluid is used for damping, then damping control is achieved, but serviceability and convenience decrease
Solution Approach 1:
The system uses pneumatic (gas-based) damping instead of hydraulic (incompressible fluid) damping. This substitution improves serviceability because gas can be easily replenished or replaced without dealing with fluid contamination, leaks, or complex filtration systems, while still achieving effective damping control through air pressure regulation
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 system effectively resists hard bottoming during severe compression, providing adjustable damping and reduced maintenance by using a gas-filled chamber with one-way valves and an adjustable blocker, enhancing the bicycle's ability to absorb impacts across various terrains.
Implementation Method 1
a spring is damped under compression and rebound by controlling the flow of a substantially incompressible fluid... a damping device that uses gas may be more convenient to service
Implementation Method 2
The barrier may include the first substantially one-way valve, which valve may allow the gas to flow from the second chamber to the first chamber
Implementation Method 3
The adjustable blocker may be capable of controlling the rate at which the gas flows through the at least one orifice during movement of the barrier towards the closed end of the first tube
Implementation Method 4
The hollow rod may have an interior cavity and an open end and may define at least one orifice which allows the gas to flow between the first chamber and the interior cavity
Data Source
AI summary
A front fork of a bicycle may include a suspension system that includes a damper. The damper may include a hollow tube with orifices that may be partially blocked by an adjustable blocker. A free end of the adjuster that adjusts the blocker may maintain its axial position in any rotational position. Ambient air may be introduced through a valve and retained in the suspension system. The suspension may include a mechanical spring in a chamber away from the valve that introduces the ambient air.