Vehicle Seat Fitting Wedge Segment Transition Area
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Solution Overview
Problem
Existing vehicle seat fittings face challenges in maintaining static strength while reducing the axial dimension of wedge segments, leading to concerns about stability during adjustment and dynamic loads.
Innovation Solution
The introduction of a transition area, such as a bevel or step, between the lateral surfaces and the inner or outer surfaces of the wedge segments, combined with an eccentric epicyclic gear system for continuous backrest adjustment, enhances static strength and reduces material usage by forming the toothed ring and wheel on the fitting parts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If the axial dimension of the wedge segment is reduced, then the fitting becomes more compact, but the static strength is expected to decrease
Solution Approach 1:
The invention transitions from a purely axial dimension reduction approach to incorporating radial dimension utilization through the transition area. The bevel or step configuration extends the load-bearing surface radially outward, compensating for the reduced axial dimension by utilizing the radial direction for strength enhancement.
Solution Approach 2:
The transition area employs curved surfaces (bevels or steps) instead of sharp edges, creating a gradual geometric transition that distributes stress more effectively. This curvature allows for optimized stress flow paths that maintain strength despite reduced axial dimensions.
2Area of stationary object
If the inner surface or outer surface width is reduced, then the wedge segment becomes more compact, but the support area for load bearing is reduced
Solution Approach 1:
The transition area projects radially outward to compensate for the reduced width of the inner or outer surface. By utilizing the radial dimension, the invention maintains adequate load-bearing capacity despite the reduced circumferential width, effectively trading axial/circumferential space for radial extension.
3Strength
If a transition area is added to the wedge segment, then static strength increases, but the manufacturing complexity increases
Solution Approach 1:
The transition area uses standard geometric features (bevels or steps) that can be manufactured using conventional machining processes. These curved or angled transitions are achieved through common operations such as facing, turning, or milling, avoiding the need for complex custom tooling or multi-step manufacturing sequences.
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 surprisingly increases static strength and allows for continuous adjustment of the backrest inclination without compromising stability, while saving material and space through optimized gear design and locking mechanisms.
Implementation Method 1
The use of an eccentric epicyclic gear system between the first fitting part and the second fitting part enables the inclination of the backrest to be adjusted continuously.
Implementation Method 2
The basic part of the locking of the eccentric epicyclic gear is provided by the friction between the eccentric and one of the two fitting parts
Implementation Method 3
The wedge segments which define the eccentric serve for both, locking and driving the rolling movement of toothed wheel and toothed ring.
Data Source
AI summary
A fitting for a vehicle seat includes a first fitting part, a second fitting part, and an eccentric, which is rotatably supported and is driven by a carrier and rotates in the circumferential direction, for driving a relative rolling motion of a spur gear and a ring gear. The eccentric has two wedge segments, which each have a convexly curved outer surface, a concavely curved inner surface, and two lateral surfaces. The lateral surfaces have a distance from each other and the inner surface and/or outer surface has a width that is less than the distance, and a transition area, which reduces the local axial dimension of the particular wedge segment from the distance to the width, is provided between at least one of the two lateral surfaces and the inner surface or the outer surface.