Foldable Rear-View Mirror Assembly with Tangential Spring Compensation
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Solution Overview
Problem
Existing external fold rear-view mirrors for motor vehicles face issues with dimensional variations due to temperature changes and frequent folding cycles, leading to maladjustment and increased costs and weight due to the need for metallic components in the driving mechanism.
Innovation Solution
A fold rear-view mirror assembly that incorporates a ring gear assembly with a spring element positioned tangentially, allowing for flexible mechanical stops to absorb tolerances and stabilize mirror positioning, reducing the need for metallic materials and minimizing maladjustments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If metallic materials are used for the ring gear assembly and driving means, then dimensional stability and reliability are improved, but weight and cost increase
Solution Approach 1:
The patent changes the material parameter from metallic to plastic, and introduces a compensation mechanism that allows dimensional parameters to vary within acceptable ranges. The driving means are designed with tolerance compensation features that maintain functional reliability despite material-induced dimensional variations.
Solution Approach 2:
The patent employs composite construction by combining plastic materials for the ring gear assembly with metallic components only where absolutely necessary (such as mounting points or high-stress areas). This hybrid approach reduces overall weight while maintaining sufficient dimensional stability through the plastic components' inherent flexibility and tolerance.
2Reliability
If metallic materials are used for the ring gear assembly and driving means, then reliability is improved, but cost increases
Solution Approach 1:
The patent changes the material parameter from metallic to plastic, which significantly reduces manufacturing cost. The design incorporates tolerance compensation mechanisms that ensure functional reliability is maintained despite the lower material cost, achieving cost-effectiveness without sacrificing performance.
Solution Approach 2:
The patent uses inexpensive plastic materials for the ring gear assembly and driving means, replacing expensive metallic components. The design accounts for potential wear and dimensional changes by incorporating compensation features, allowing the use of more economical materials that can be replaced if necessary.
3Manufacturing precision
If metallic materials are used for the ring gear assembly, then dimensional stability is improved, but the mirror housing maladjustment occurs due to wearing
Solution Approach 1:
The patent changes from rigid metallic materials to more flexible plastic materials that can accommodate dimensional variations. The design incorporates compensation mechanisms that actively counteract wearing and dimensional changes, maintaining positioning accuracy over the product lifecycle despite material limitations.
Solution Approach 2:
The patent incorporates compensation features in advance that anticipate and counteract dimensional variations and wearing. These pre-designed compensation mechanisms ensure that positioning accuracy is maintained throughout the product life, preventing maladjustment before it occurs.
4Reliability
If metallic materials are used for the driving means, then reliability is improved, but vibration increases
Solution Approach 1:
The patent changes the material parameter from metallic to plastic, which inherently reduces vibration due to the damping properties of plastic materials. The design maintains operational stability through proper structural design and tolerance compensation, achieving lower vibration levels without sacrificing reliability.
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 solution effectively stabilizes mirror positioning and reduces maladjustments, maintaining correct operation across temperature variations while minimizing material costs and weight, and allows for efficient manual operation in case of motor component failure.
Implementation Method 1
a spring element (170) positioned in a direction that is substantially tangential to the ring gear assembly (210)... the spring element is adapted to cooperate with the ring gear assembly (210) such that... the mirror housing (110) is allowed to rotate relative to the base member (120)... where the spring element resiliently abuts a stop surface (175)
Data Source
AI summary
A foldable rear-view mirror assembly comprises a base member to be mounted on a motor vehicle, a mirror housing, a motor component, drive means comprising a ring gear assembly engaging the motor component with the base member for rotation of the mirror housing thereto between mirror operative and folded conditions, and a spring element positioned substantially tangential to the ring gear assembly to cooperate therewith such that in a first direction of rotation the mirror housing is allowed to rotate to the base member and in a second reverse direction of rotation the mirror housing is prevented from being rotated relative to the base member, where the spring element resiliently abuts a stop surface formed in the ring gear assembly.