Cable-Pull Hydraulic Upper Pump Layout for Compact Bicycle Braking
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Solution Overview
Problem
Existing cable disc brakes provide a poor braking experience and require more force, while hydraulic disc brakes are costly and require frequent maintenance, and existing solutions to combine both types face issues with increased volume, limited installation space, and unchanged cable length.
Innovation Solution
A combination of a cable-pull hydraulic upper pump and disc brake that includes parallel first and second cylinders with radial oil outlets and an oil passage hole, drive members, and brake cables, integrated with a handlebar stem to reduce cable and oil tube length, and an oil reservoir mechanism to adjust hydraulic fluid pressure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If a cable-to-hydraulic conversion structure is installed at the lower pump position, then hydraulic braking power is achieved, but the volume of the brake lower pump increases significantly
Solution Approach 1:
The patent inverts the conventional location of the cable-to-hydraulic conversion structure from the lower pump position to the upper pump position mounted on the handlebar stem. This inversion allows the conversion structure to be positioned where space is more abundant, avoiding the volume constraints at the lower pump location while still achieving hydraulic braking power.
Solution Approach 2:
The patent moves the conversion structure from a vertical arrangement (at the lower pump) to a horizontal arrangement on the handlebar stem. The upper pump extends horizontally with cylinders arranged side-by-side, utilizing the lateral space on the handlebar stem rather than increasing vertical volume at the lower pump position.
2Force
If a cable-to-hydraulic conversion structure is added, then hydraulic braking is achieved, but the installation space becomes limited
Solution Approach 1:
The patent inverts the conventional location of the cable-to-hydraulic conversion structure from the lower pump position to the upper pump position mounted on the handlebar stem. This inversion allows the conversion structure to be positioned where space is more abundant, avoiding the volume constraints at the lower pump location while still achieving hydraulic braking power.
Solution Approach 2:
The upper pump structure serves multiple functions: it acts as both the mounting structure for the hydraulic system and the conversion structure itself. The handlebar stem provides both structural support and mounting surfaces, eliminating the need for separate conversion components that would consume additional installation space.
3Length of moving object
If the cable length remains unchanged, then the original cable routing is maintained, but more braking force is required
Solution Approach 1:
The patent replaces the direct mechanical cable connection with a hydraulic system. The cable connects to the piston rod which moves within the cylinder, converting cable motion into hydraulic pressure through fluid displacement. This mechanical-to-hydraulic substitution amplifies the braking force while maintaining the same cable length.
Solution Approach 2:
The patent uses hydraulic fluid within the cylinder to transmit and amplify force. When the cable pulls the piston rod, it displaces hydraulic fluid which then transmits force to the brake lower pump, creating a force multiplication effect that reduces the required input force while keeping cable length unchanged.
4Device complexity
If hydraulic fluid pressure is not adjusted, then the system is simpler, but braking performance is inconsistent
Solution Approach 1:
The patent incorporates an oil reservoir mechanism that dynamically adjusts hydraulic fluid pressure by changing the volume of oil in the system. The oil reservoir can add or remove hydraulic fluid based on system needs, maintaining optimal pressure levels and consistent braking performance while managing fluid expansion and contraction during operation.
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 combination achieves smooth braking with less force, reduces costs and maintenance frequency, optimizes space usage, and integrates cable and hydraulic systems effectively, providing consistent brake cable lengths and reduced oil tube exposure.
Implementation Method 1
An elastic member has a first end thereof is fitted inside the hollow hole, and a second end of the elastic member is fitted against an inner wall of the end part to elastically position a normal position of the piston rod and provide an elastic resetting force after the piston rod moves.
Implementation Method 2
Two brake cables with their two respective first ends respectively connected to the two drive members to control movement of the two drive members, so that hydraulic fluid in the first cylinder flows out from the first oil outlet, and hydraulic fluid in the second cylinder flows out from the second oil outlet via the oil passage hole.
Data Source
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AI summary
A combination of cable-pull hydraulic upper pump (10) and cable-pull hydraulic disc brake includes a cable-pull hydraulic upper pump (10) which is used with a bicycle handlebar stem, and includes an upper pump (10) that has a first cylinder (101) and a second cylinder (102). The upper pump (10) includes a first oil outlet (104) and a second oil outlet (105) that radially connect to the first cylinder (101). An oil passage hole (106) is coaxially arranged with the second oil outlet (105) and connects the first cylinder (101) and the second cylinder (102). Two drive members (20) are installed in the first cylinder (101) and the second cylinder (102). Two brake cables (60) are connected to the two drive. The hydraulic fluid in the first cylinder (101) flows out from the first oil outlet (104). The hydraulic fluid in the second cylinder (102) flows out from the second oil outlet (105) via the oil passage hole (106).