Steering Column Locking Cam With Dual-Hardness Elastomer
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Solution Overview
Problem
Existing locking mechanisms for adjustable motor vehicle steering columns suffer from high friction, leading to difficulty in operation and sudden unlocking, resulting in wear and discomfort for the driver.
Innovation Solution
A locking device utilizing cam and cam follower discs made of materials with different hardnesses, featuring progressively decreasing ramps and elastomer components to reduce friction and provide a smooth unlocking process, ensuring a pleasant and reliable user experience.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the locking elements are tightened together to increase column locking force, then the locking strength is improved, but the friction between locking elements increases making lever operation more difficult
Solution Approach 1:
A cam mechanism is introduced as an intermediary between the lever and the locking elements. The cam converts the rotational motion of the lever into controlled linear motion that separates the locking elements, reducing friction during operation while maintaining locking strength when engaged.
Solution Approach 2:
The cam surface is designed with curved profiles that progressively control the separation of locking elements. The curved geometry allows for smooth, progressive movement that reduces sudden friction spikes and enables easier lever operation while maintaining effective locking force.
2Ease of operation
If rolling elements are inserted between locking elements to reduce friction, then ease of operation is improved, but wear of parts increases significantly
Solution Approach 1:
The patent replaces the rolling element mechanism with a cam-based mechanical system. The cam's controlled separation action reduces friction without requiring rolling elements, thereby eliminating the wear problems associated with rolling elements while maintaining ease of operation.
3Reliability
If the locking elements are designed for tight engagement, then locking reliability is improved, but sudden unlocking occurs during operation
Solution Approach 1:
The cam surfaces are designed with progressive curved profiles that control the engagement and disengagement of locking elements. The curvature ensures gradual separation during unlocking, preventing sudden release while maintaining reliable locking when engaged.
Solution Approach 2:
The cam mechanism introduces dynamic control over the locking elements' engagement and disengagement. The cam's rotational motion creates a controlled, progressive separation that smooths the unlocking process while maintaining firm locking when the cam is in its engaged position.
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 device achieves reduced friction and consistent effort during unlocking, preventing sudden column release, thus enhancing user comfort and mechanism longevity.
Implementation Method 1
the materials of different hardnesses are chosen from the group of materials consisting of a metal, an elastomer, a rubber and a plastic
Implementation Method 2
one of the materials of the cam has a Shore hardness of between 10 Shore A and 100 Shore A
Data Source
Figure 1~3
Figure 4~6
AI summary
The invention relates to a locking device for an adjustable vehicle steering column comprising: - a jaw for receiving a steering column, - means for locking the column relative to the jaw comprising: - a shaft, - a locking lever rotatably movable relative to the jaw between an active locking position of the column and an unlocking position, - a cam fixed to one of the lever and the jaw, and - a counter-cam fixed to the other of the lever and the jaw, movable relative to the cam along a locking path. The cam comprises, along the locking path, at least two parts (61, 62) formed of two materials of different hardnesses suitable for cooperating successively with the counter-cam.