Steering Column Tilt Lock Mechanism With Preloaded Lash Elimination
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing adjustable steering column assemblies face issues with complex designs, increased part failure risk due to clearance between components, and inadequate locking mechanisms, particularly in secondary impacts.
Innovation Solution
A simplified steering column assembly design utilizing a pair of downwardly disposed plates with slots, an elongated member, a rotational member, and a biasing member, which reduces or eliminates lash and ensures smooth locking and unlocking through a preloaded rotational member engagement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a positive locking mechanism is added to hold the column in tilt position during secondary impact, then the reliability is improved, but the device complexity increases due to requiring many parts
Solution Approach 1:
The patent combines the locking mechanism with the existing tilt adjustment mechanism by integrating the lock into the slot structure where the elongated member moves. The lock is formed as part of the slot assembly rather than being a separate complex mechanism, merging multiple functions into a unified structure that reduces part count while maintaining reliability.
Solution Approach 2:
The locking function is segmented into discrete lock positions along the slot, with the lock engaging at specific intervals. This segmentation allows the column to be held at multiple predetermined tilt positions while using a simplified lock structure that engages with corresponding features in the slot, reducing overall complexity.
2Ease of manufacture
If clearance is provided between parts of the assembly (e.g., spring and bolt, or lock and bolt), then the ease of manufacture is improved, but the reliability deteriorates due to free motion causing lock disengagement failure
Solution Approach 1:
The spring is pre-loaded to maintain constant engagement between the lock and the elongated member throughout the adjustment range. This preliminary action ensures that the lock remains positively engaged with the member at all times, eliminating free motion and preventing disengagement failure while still allowing for manufacturing tolerances in the clearance design.
3Device complexity
If a simplified design with fewer parts is used, then the device complexity is reduced, but the reliability may worsen due to increased chance of part failure
Solution Approach 1:
The patent merges multiple components into integrated assemblies, such as combining the lock with the slot structure and integrating the spring mechanism with the tilt adjustment system. This reduction in part count simplifies the overall design while the integrated nature of the components improves reliability by reducing the number of potential failure points from multiple separate parts.
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 design achieves reliable locking and unlocking with fewer parts, reducing assembly complexity and enhancing stability during secondary impacts by minimizing clearance and ensuring secure positioning of the steering column.
Implementation Method 1
a biasing member, such as a spring, operably connected to the rotational member and adapted to bias the rotational member into engagement with the elongated member
Data Source
Figure 1~2
Figure 3
Figure 4~5
AI summary
A tilt assembly (30) for a steering column assembly (10) including a pair of downwardly disposed plates each having a slot (36); an elongated member adapted to be rotated, wherein the elongated member penetrates the slot (36) of each downwardly disposed plate and extends therebetween; a rotational member (50) located within each slot (36) and having an opening through which the elongated member is received; a biasing member (60) with a first end (62) and a second end (68), where at least one end engages with the rotational member (50). The biasing member (60) is adapted to drive rotation of the rotational member (50). When the tilt assembly (30) is in an unlocked position, the rotational member (50) is adapted to travel with respect to the slot (36), and when the tilt assembly (30) is in a locked position, the rotational member (50) is adapted to rotate and engage with a wail that is fixed with respect to the slot (36). The elongated member, rotational member (50), and biasing member (60) may be configured to eliminate lash. A steering column assembly (10) incorporating the tilt assembly (30) is also contemplated.