Steering Column Locking Device Asymmetric Tooth Offset
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional steering column locking devices face issues with restricted retaining forces in the closed state, leading to potential uncontrolled shifting during crashes, and require high friction or force to close properly due to direct tooth tip orientation, which complicates adjustment and safety.
Innovation Solution
A locking device with toothings and countertoothings that extend transversely, featuring a V-form tip orientation and offset teeth positions to prevent direct tip alignment, ensuring engagement in all adjustment positions and maintaining secure retention without excessive friction, utilizing a tensioning arrangement with a clamping plate and counterlocking part for reliable height and inclination adjustment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the tips of the teeth of opposing toothings are directly oriented toward one another (tooth to tooth position), then the locking device structure is simple, but the teeth strike one another when the tensioning arrangement is being closed, such that the locking device cannot be closed properly and may lead to uncontrolled shifting during crashes
Solution Approach 1:
The patent applies asymmetry by offsetting the tooth positions between the two toothings relative to each other. Instead of having teeth directly opposite each other (symmetrical arrangement), the teeth are positioned asymmetrically so that when one toothing is in a certain position, the other toothing is offset by a fraction of the tooth pitch. This prevents direct tooth-to-tooth alignment and eliminates the striking problem during closing operation.
2Force
If packets of plates crossing one another are provided to arrest the shell tube, then the retaining force in the closed state can be increased, but a relatively large number of plates is required and a relatively high friction force must be overcome in order to adjust the steering column
Solution Approach 1:
The patent replaces the mechanical friction-based plate packet system with a tooth engagement system. Instead of relying on friction between multiple plates to provide retaining force, the invention uses the geometric interlocking of offset teeth that engage in a controlled manner. This substitution eliminates the need to overcome high friction forces during adjustment while providing reliable retention through positive tooth engagement.
Solution Approach 2:
The patent segments the continuous friction-based retention into discrete tooth engagement points. By dividing the retention function into individual tooth interactions rather than continuous plate friction, the system achieves retention through multiple localized engagement points without requiring the cumulative friction of many plates, thereby reducing the force needed for adjustment.
3Reliability
If magnets are provided on the two opposing tooth bars to repel the free tips of the teeth, then the hazard of tooth tip striking is reduced, but relatively high magnetic forces must be exerted, which entails considerable expenditures
Solution Approach 1:
The patent extracts and removes the magnetic repulsion system entirely, replacing it with a purely mechanical offset tooth design. By taking out the magnetic components and their associated complexity and costs, the invention achieves the same hazard prevention function through the geometric offset arrangement of teeth, which passively prevents tip-to-tip alignment without requiring active magnetic forces.
Data Source
AI summary
A locking device of a steering column adjustable in at least one adjustment direction (46) comprises at least one locking part (20, 21) associated with the adjustment direction (46) or one of the adjustment directions, at least one counterlocking part (14, 15) associated with this adjustment direction (46) and an openable and closable tensioning arrangement, in the opened state of which first and second toothings (38, 39) of locking parts (20, 21) are spaced apart from first and second countertoothings (40, 41) of the counterlocking part (14, 15), and in the closed state of which the locking part (20, 21) and the counterlocking part (14, 15) engage each other's teeth. The planes (47, 48; 49, 50) of the tips of teeth (42, 43; 44, 45) of the first and second toothings (38, 39) or first and second countertoothings (40, 41) are disposed in a V shape relative to one another and between the teeth (42, 43; 44, 45) of the first and second toothing (38, 39) or the first and second countertoothing (40, 41) is present an offset (v) in the adjustment direction (46), which is a fraction of the distance (a) between successive teeth (42 to 45).