Foldable Bicycle Frame Single-Tube Suspension
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Solution Overview
Problem
Conventional foldable bicycles require complex folding systems and are often bulky and heavy, with dual-tube suspension systems that do not withstand strong forces effectively.
Innovation Solution
A foldable frame incorporating a single-tube suspension system made of lightweight materials, featuring three cylindrical members aligned vertically with a suspension spring and pin axle, and connected using screws and hinge joints, allowing for easy and compact folding without welding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a dual-tube suspension system is used in conventional foldable bicycles, then suspension performance is improved, but weight and volume increase
Solution Approach 1:
The patent extracts and removes one tube from the conventional dual-tube suspension system, retaining only the essential single tube with spring mechanism. This extraction eliminates redundant components while preserving core suspension functionality, directly reducing weight and volume as stated in the abstract.
Solution Approach 2:
The suspension system is segmented into distinct functional components: a single tube housing, spring mechanism, and locking system. This segmentation allows for optimized material usage and component layout, reducing overall system mass while maintaining suspension performance through precise functional decomposition.
2Reliability
If a dual-tube suspension system is used in conventional foldable bicycles, then suspension performance is improved, but volume increases
Solution Approach 1:
The single-tube suspension system employs a nested structure where the spring mechanism is contained within the tube, and components are arranged concentrically along the vertical axis. This nesting approach maximizes space utilization and minimizes the external volume of the suspension system while maintaining internal functionality.
Solution Approach 2:
The patent transitions from a multi-tube three-dimensional arrangement to a single-tube design with components aligned along one vertical dimension. This dimensional simplification reduces the spatial footprint and volume occupation of the suspension system while preserving essential suspension capabilities through vertical stacking of functional elements.
3Ease of operation
If conventional folding systems are used to reduce bicycle size, then foldability is improved, but structural strength deteriorates
Solution Approach 1:
The locking system is designed to pre-secure the cylindrical members in their operational positions before cycling begins. The spring mechanism is pre-loaded to maintain constant engagement force, ensuring structural integrity is established in advance rather than relying on forceful engagement during use.
Solution Approach 2:
The spring mechanism provides beforehand cushioning by maintaining constant contact and engagement force between the cylindrical members. This pre-loaded spring system compensates for any gaps or wear before significant loads are applied, preventing sudden structural failures and maintaining strength during folding and unfolding operations.
4Strength
If welding is used to connect frame parts, then structural strength is improved, but flexibility and ease of repair deteriorate
Solution Approach 1:
The frame is segmented into discrete, interchangeable components connected by mechanical locking systems rather than permanent welding. The cylindrical members, tube, and locking mechanisms are separate replaceable units that can be independently serviced, repaired, or replaced without affecting the entire frame structure.
Solution Approach 2:
The connection system transitions from static welded joints to dynamic mechanical locking connections that can be engaged and disengaged. This allows the frame to adapt between rigid locked states for strength and flexible separated states for repairability, with the locking system providing reversible connectivity.
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 single-tube suspension system reduces weight and volume, enhances durability and flexibility, and simplifies the folding process while maintaining structural integrity.
Implementation Method 1
The second cylindrical member further includes a suspension spring situated inside the interior space thereof such that when the first cylindrical member is pressed down towards the bottom of the second cylindrical member, the suspension spring can absorb the downward force from the first cylindrical member.
Data Source
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AI summary
A foldable frame for a bicycle, comprising a front locking system (109) for releasably connecting a handlebar (111) with a head tube (102), a pair of rear forks (104), pivotally connected with a crossbar (101), which can be folded towards a front wheel and a seat tube (103), pivotally connected with the crossbar (101), which can be folded up towards the crossbar (101).