Steering Column Break-Away Lever Using Mechanical Fastening
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing adjustable steering columns with break-away levers face issues such as labor-intensive and expensive injection molding processes, erratic break-away loads due to variations in injection pressure and moisture, and reduced stiffness from using plastic materials, which affect the operator's experience and safety during collisions.
Innovation Solution
An adjustable steering column assembly with a lever arm that uses a securement member with a slot design, where the securement member is biased to engage and disengage the lever arm from an adjustment assembly member using a controlled force, allowing for a robust feel during normal operations and safe separation under high impact forces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If injection molding process is used to attach lever arm to adjustment assembly member, then lever arm can be secured to adjustment assembly member, but manufacturing process becomes labor-intensive and expensive with erratic break-away loads
Solution Approach 1:
The patent replaces the injection molding process with a mechanical fastening system consisting of a securement member (bolt or screw) that passes through the lever arm and adjustment assembly member. This mechanical system eliminates the need for complex injection molding operations, reduces manufacturing labor and cost, and provides consistent, controllable break-away loads through precise mechanical engagement.
2Strength
If plastic material is used to secure lever arm to adjustment assembly member, then lever arm is attached to adjustment assembly member, but stiffness is reduced affecting operator experience
Solution Approach 1:
The patent employs a composite construction where the lever arm and adjustment assembly member are secured through a mechanical fastening system rather than relying on plastic material alone. This allows the use of rigid materials for the lever arm and assembly member while the mechanical securement provides the necessary attachment strength without compromising stiffness, thereby maintaining a robust feel during normal operations.
3Strength
If securement member is tightly engaged to prevent lever arm disengagement, then lever arm remains securely attached during normal operations, but lever arm cannot separate under impact forces
Solution Approach 1:
The patent designs the securement member engagement with specific parameters that allow it to maintain strong attachment during normal operations while permitting disengagement under impact forces. The securement member is engaged with a biasing force that is sufficient for normal use but can be overcome by impact forces exceeding a threshold value, enabling the lever arm to separate from the adjustment assembly member during collisions.
4Strength
If adhesive bonding is used to attach lever arm to adjustment assembly member, then lever arm is secured to adjustment assembly member, but manufacturing variability increases and stiffness is reduced
Solution Approach 1:
The patent replaces adhesive bonding with a mechanical fastening system using a securement member that passes through both the lever arm and adjustment assembly member. This mechanical system eliminates the variability associated with adhesive bonding processes, provides consistent and reliable attachment, and maintains stiffness without requiring chemical bonding agents.
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 provides a robust feel during normal operations while ensuring the lever arm separates from the steering column under high impact forces, reducing manufacturing complexity and variability, and maintaining stiffness by eliminating the need for adhesive bonding and minimizing the force required for disengagement.
Implementation Method 1
At least one securement member is operably coupled with the lever arm and the adjustment assembly member and biases the first and second mounting interfaces into engagement
Data Source
AI summary
An adjustable steering column assembly having a repositionable steering column and a break-away lever arm. The lever arm has a first mounting interface and an adjustment assembly member operably coupled with the steering column has a second mounting interface. Engagement of the first and second mounting interfaces mounts the lever arm on the adjustment assembly member. Movement of the lever arm rotates the adjustment assembly member to facilitate the repositioning of the steering column. Applying a breakaway force exceeding a threshold value to the lever arm disengages the mounted lever arm from the adjustment assembly member by relative translational movement between the first and second mounting interfaces. Some embodiments employ a threaded fastener installed to a predetermined torque to bias the first and second mounting interfaces into engagement. The threaded fastener can be installed such that it may be non-frangibly disengaged by displacement through the open end of a slot.