Bicycle Spring Damper Device with Segmented Pressure Valves

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Solution Overview

Problem

Existing spring damper devices for bicycles suffer from breakdowns due to small pressure differences, leading to potential damage, and at high pressure differences, they can cause strong pressure forces and reduced sensitivity, especially at higher speeds, resulting in loss of traction.

Innovation Solution

A spring damper device with three pressure-limiting valves that open at different pressure differences to control damping forces, including a third valve for overload protection, allowing for adjustable damping characteristics and compact design, and a lever for clear operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a single pressure relief valve is used in existing spring damper devices, then the device structure is simple, but the device suffers from breakdowns at small pressure differences and cannot provide adequate overload protection at high speeds

Engineering Contradiction:
Improveprevention of breakdownVSAvoidnumber of valves
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The single pressure relief valve is segmented into three separate valves (first, second, and third valves), each with different opening pressure differences. This segmentation allows each valve to handle specific pressure ranges, preventing breakdowns while maintaining manageable device complexity through modular design

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention changes the parameter of valve opening pressure difference by providing three valves with progressively higher opening pressure differences. This parameter variation enables the system to respond appropriately to different pressure conditions, providing reliable breakdown prevention without excessive complexity

Inventive Principle:
Principle #35Parameter changes

2Reliability

If the pressure relief valve opens at high pressure differences to avoid breakdowns, then breakdowns are prevented, but extremely strong pressure forces occur and the bicycle chassis reacts insensitively at higher speeds

Engineering Contradiction:
Improveprevention of breakdownVSAvoidsensitivity of chassis response
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The pressure relief function is segmented across three valves with different opening characteristics. The first valve opens at lower pressure differences to maintain chassis sensitivity, while the second and third valves provide progressive overload protection at higher pressures, resolving the contradiction between breakdown prevention and responsive operation

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

By changing the opening pressure difference parameter for each valve, the system achieves both sensitivity at normal operation (first valve) and protection at extreme conditions (second and third valves), eliminating the need to choose between one or the other

Inventive Principle:
Principle #35Parameter changes

3Ease of operation

If a single pressure relief valve opens at small pressure differences to maintain sensitivity, then the chassis responds sensitively, but the device can still break down under extreme pressure conditions

Engineering Contradiction:
Improvesensitivity of chassis responseVSAvoidprevention of breakdown
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The pressure relief function is divided into three segmented valves that activate at different pressure thresholds. This segmentation allows the first valve to maintain sensitivity at low pressures while the second and third valves provide progressive protection against breakdowns at extreme pressures

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The second and third valves provide beforehand cushioning by being pre-configured to open at higher pressure differences, preventing breakdowns before they occur while allowing the first valve to maintain normal operational sensitivity

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

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 device provides better control over damping forces, preventing breakdowns and maintaining sensitivity at various speeds, with adjustable settings for different riding conditions and enhanced overload protection.

Implementation Method 1

A spring device, which is an air or steel spring device, is usually provided for the suspension of a rear wheel swing arm of a bicycle, in order to cushion impact forces

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

The valves control a volume flow of a fluid between the damping chambers when the spring device is tensioned in the spring direction, which in turn controls the damping forces of the damping device

Methodology Applied
Scientific EffectPressure difference: Pressure Gradient

Implementation Method 3

a valve body is displaced by a pressure of the fluid into an open position away from the damper piston against the spring force of the valve slide

Methodology Applied
Scientific EffectFluid flow:

Implementation Method 4

a valve body is displaced by a pressure of the fluid into an open position away from the damper piston against the spring force of the valve slide

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP2565491B8Spring damper device for a bicycle
Publication Date: 2018.12.26 FOX FACTORY SWITZERLAND GMBH

AI summary

The spring-damper device (1) has fixable housing (2) on which a spring device is supported. The spring device is stretchable over damper main portion (12) of a damping device connectable with to-be-damped element clamped in a spring direction. The damper main portion is rigidly connected to the housing damper piston (24) which spatially separates the damper main portion into damper chambers. Several valves are provided for controlling volume flow of fluid between damping chambers during the clamping of the spring device in the spring direction.