Press-Fit Rake Lever Assembly for Lower-Cost Steering Column Locking

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Solution Overview

Problem

Traditional adjustable steering column rake lever assemblies are costly due to the use of insert molding with metal inserts, which requires specialty suppliers and complex part logistics.

Innovation Solution

A rake lever assembly with a plastic injection molded rake lever and a metal stamping press fit, where the rake lever is rotatable to move between locked and unlocked positions, reducing the need for overmolding and powder metal pins, and incorporating anti-rotation and retention features.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If insert molding with metal inserts is used for the rake lever assembly, then the structural strength and durability are improved, but the manufacturing cost and process complexity increase

Engineering Contradiction:

Improvestructural strengthVSAvoidmanufacturing cost

Core Design Contradiction:

StrengthVSEase of manufacture

Solution Approach 1:

The patent combines the rake lever body and metal reinforcement into a single integrated component. The metal stamping is formed with integral tabs that are directly attached to the rake lever body, eliminating the need for separate insert molding processes and reducing assembly steps while maintaining structural strength.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The patent uses a composite structure combining plastic (rake lever body) and metal (stamping with tabs). This composite approach provides the strength benefits of metal inserts while avoiding the complexity of insert molding, as the metal component is designed to be attached through simpler means such as press-fit or mechanical attachment.

Inventive Principle:

Principle #40Composite materials

2Strength

If insert molding with metal inserts is used for the rake lever assembly, then the structural strength is improved, but the device complexity and part logistics increase

Engineering Contradiction:

Improvestructural strengthVSAvoidpart logistics

Core Design Contradiction:

StrengthVSDevice complexity

Solution Approach 1:

The patent merges the rake lever body and metal reinforcement into a single integrated component. The metal stamping is formed with integral tabs that are directly attached to the rake lever body, eliminating the need for separate insert molding processes and reducing assembly steps while maintaining structural strength.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The patent extracts the complex insert molding process from the manufacturing workflow. Instead of requiring specialty suppliers and complex part logistics for insert molding, the design uses a metal stamping with integral tabs that can be attached through simpler processes, effectively removing the problematic manufacturing step while retaining the structural benefits.

Inventive Principle:

Principle #2Taking out (Extraction)

3Reliability

If overmolding and powder metal pins are used for the rake lever assembly, then the retention and anti-rotation features are improved, but the manufacturing cost and process complexity increase

Engineering Contradiction:

Improveretention featureVSAvoidmanufacturing cost

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The patent replaces expensive overmolding and powder metal processes with simpler, more cost-effective manufacturing methods. The metal stamping with integral tabs provides the necessary retention and anti-rotation features through geometric design rather than complex manufacturing processes, achieving the same functional result at lower cost.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The patent changes the manufacturing parameters from complex processes (overmolding, powder metal) to simpler processes (metal stamping with integral tabs). This parameter change maintains the functional requirements for retention and anti-rotation while significantly reducing manufacturing complexity and cost.

Inventive Principle:

Principle #35Parameter changes

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 solution provides a cost-effective and efficient assembly that simplifies the manufacturing process, reduces material costs, and maintains the functionality of the steering column adjustment mechanism.

Implementation Method 1

a metal stamping press fit to the rake lever

Methodology Applied

Scientific EffectPress fit: Friction

Data Source

PatentUS11142236B2Injection molded rake lever assembly

Publication Date: 2021.10.12 STEERING SOLUTIONS IP HOLDING CORP

AI summary

A rake lever assembly for a steering column is provided. The steering column is adjustable in an unlocked position of the rake lever assembly and is in a fixed position in a locked position of the rake lever assembly. The rake lever assembly includes a rake lever, the lever being rotatable for moving the clamping arrangement between the locked position and the unlocked position. The rake lever assembly also includes a metal stamping press fit to the rake lever.