Automatic Bicycle Pedal Spring Stiffness Adjustment Mechanism
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Solution Overview
Problem
Existing automatic cycle pedals face issues with maintaining initial spring tension adjustment and preventing premature wear, leading to uncontrolled openings and potential cyclist imbalance or falls due to non-linear adjustment mechanisms and permanent deformation of spring branches.
Innovation Solution
The adjustment mechanism for spring stiffness is relocated to act on the fixed branch of the spring, positioned opposite to the movable jaw, with a threaded rod and nut system that locks in rotation, allowing for precise and linear adjustment of spring tension without affecting the movable jaw's operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the adjustment means act on the movable branch of the spring directly stressed by the movable jaw, then the spring tension can be adjusted, but the adjustment deviates from linear proportionality when the jaw opens and the initial setting is not retained
Solution Approach 1:
The spring is divided into two distinct branches: a movable branch that interacts with the movable jaw during operation, and a fixed branch that remains stationary and is exclusively used for adjustment. This segmentation allows the adjustment function to be separated from the movement function, ensuring that adjustments remain linear and accurate without being affected by jaw motion.
Solution Approach 2:
The adjustment function is extracted from the movable jaw assembly and relocated to the fixed jaw assembly. The adjustment means (threaded rod and nut) are mounted on the fixed jaw and act only on the fixed branch of the spring, removing the source of non-linearity and ensuring stable, retainable adjustment settings.
2Adaptability or versatility
If the adjustment means are mounted on the movable jaw, then the spring tension can be adjusted, but the permanent deformation of spring branches leads to premature wear and relaxation of spring tension
Solution Approach 1:
By separating the spring into movable and fixed branches with distinct functions, the fixed branch serves solely as an adjustment anchor point. This prevents the spring material from undergoing repeated stress cycles during jaw operation, eliminating permanent deformation and maintaining reliable spring tension over time.
Solution Approach 2:
The spring tension is adjusted in advance through the fixed branch before the pedal enters service. Once adjusted, the setting remains stable because the fixed branch does not participate in the dynamic operation of the pedal, preventing subsequent relaxation or deformation that would require frequent readjustment.
3Adaptability or versatility
If the adjustment means act on the movable branch during jaw operation, then spring tension can be modified, but frequent adjustments are required due to fatigue and deformation
Solution Approach 1:
The adjustment mechanism is extracted from the movable jaw assembly and mounted on the fixed jaw, acting exclusively on the fixed branch of the spring. This separation ensures that adjustments made through the threaded rod and nut system remain stable and do not require frequent repetition due to fatigue or deformation during pedal operation.
4Reliability
If the adjustment means are mounted through the fixed jaw on the opposite face, then the initial adjustment is maintained and spring lifespan is extended, but the device complexity increases
Solution Approach 1:
The adjustment means (threaded rod and nut) are integrated into the fixed jaw assembly, which is already a structural component of the pedal. This merging approach allows the adjustment function to be added without requiring separate mounting structures or additional complex mechanisms, thereby limiting the increase in device complexity.
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 configuration maintains desired spring tension, extends spring lifespan, and ensures stable and precise adjustment over time, preventing uncontrolled openings and improving cyclist safety.
Implementation Method 1
said movable jaw being urged by at least one elastic return spring so as to pivot between a locking position of said wedge and an open position allowing the introduction and release of said wedge
Implementation Method 2
the said member for adjusting the stiffness of the spring is mounted on the face of the pedal opposite to said movable jaw with respect to said longitudinal plane, through the fixed jaw, and acts on the fixed branch of said spring
Data Source
Figure 1~2
Figure 3~4
AI summary
Automatic bicycle pedal comprising a body (1) having an upper face (1a) and a lower face (1b) separated by a longitudinal plane (P) and each carrying a movable jaw (2a, 2b) and a fixed jaw (3a, 3b), the fixed jaws (3a, 3b) being mounted opposite the movable jaws (2a, 2b) and the two fixed and movable jaws defining between them a housing (10a, 10b) for a cleat attached to the sole of a shoe, said movable jaw (2a, 2b) being actuated by at least one elastic return spring (4a, 4b) so as to pivot between a locking position of said cleat and an opening position allowing the insertion and release of said cleat, said spring having, on the one hand, at least one movable arm actuated by the movable jaw (2a, 2b) and a fixed arm (42) not actuated by the movable jaw and being provided, on the other hand, a mechanism (5, 5a, 5b) for adjusting its stiffness,characterized in that said spring stiffness adjustment device (5) is mounted on the face of the pedal opposite said movable jaw (2a, 2b) with respect to the longitudinal plane (P), through the fixed jaw (3a, 3b), and acts on the fixed arm (42, 42a, 42b) of said spring.