Wiper Arm Assembly Locking Catch Mechanism

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Wiper arm assemblies for vehicles face challenges in manufacturing cost and inadvertent disassembly due to permanent fixing methods and lack of secure locking mechanisms, leading to increased assembly costs and potential disassembly during handling or transport.

Innovation Solution

A wiper arm assembly design featuring a mounting head and wiper arm with a locking mechanism that engages upon rotation, using a spring to increase preload and snap into a shipping position, preventing disassembly by confronting locking surfaces that maintain engagement and prevent rotation back to the disassembled position.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the mounting head and wiper arm are permanently fixed together by a staked pin or rivet, then the assembly is secure and cannot be disassembled, but the manufacturing cost and assembly cost increase due to the added cost of the pin or rivet and the permanent fixing processes

Engineering Contradiction:

Improvesecure attachmentVSAvoidmanufacturing cost

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The locking mechanism is divided into separate components: a locking protrusion on the mounting head and a corresponding locking recess on the wiper arm. These segmented elements can be independently manufactured and then assembled together, eliminating the need for separate pins or rivets while maintaining secure attachment.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The locking function is merged into the basic structural components themselves. The mounting head and wiper arm incorporate locking features directly into their designs, combining the structural support function with the locking function, thereby eliminating the need for additional fastening components.

Inventive Principle:

Principle #5Merging (Combining)

2Ease of manufacture

If the mounting head and wiper arm are attached together to be disassembled after assembly in a preassembled position, then the manufacturing cost is reduced, but the bearing surfaces can slide relative to one another under minimal force during transport or handling, causing inadvertent disassembly

Engineering Contradiction:

Improvemanufacturing costVSAvoidresistance to inadvertent disassembly

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The locking protrusion and recess are designed to engage automatically when the mounting head and wiper arm are brought together during assembly. This preliminary engagement prevents any subsequent sliding or inadvertent disassembly during transport or handling, countering the harmful effect before it can occur.

Inventive Principle:

Principle #9Preliminary anti-action

Solution Approach 2:

The spring mechanism, which applies continuous pressure to maintain engagement, converts the potential harm of minimal forces during handling into a benefit by ensuring the locking surfaces remain firmly pressed together, actually increasing resistance to disassembly rather than allowing it.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

3Reliability

If the bearing surfaces are arranged to define interacting camming surfaces requiring increased tensile force to overcome, then the mounting head and wiper arm are prevented from disassembling, but the spring must be increased in length and the device complexity increases

Engineering Contradiction:

Improveprevention of disassemblyVSAvoidspring length and complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

Instead of using camming surfaces that require overcoming tensile force to maintain engagement, the design inverts the approach by using a locking protrusion and recess that naturally engage and lock the components together. The spring simply maintains pressure on these locked surfaces rather than having to overcome camming action, simplifying the spring design and reducing its required length.

Inventive Principle:

Principle #13The other way round (Inversion)

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 cost-effective, easy-to-assemble wiper arm assembly that remains securely attached during handling and transport, reducing the risk of inadvertent disassembly and ensuring a long, reliable service life.

Implementation Method 1

a spring arranged for operable attachment to the mounting head and the wiper arm, wherein the locking surface on the wiper arm is configured for engagement with the locking surface on the mounting head under a force imparted by the spring

Methodology Applied

Scientific EffectElasticity: Elasticity

Data Source

PatentUS7996952B2Wiper arm assembly having a locking catch

Publication Date: 2011.08.16 PGI NORTHSTAR LLC

AI summary

A wiper arm assembly and method of assembly thereof includes a mounting head and a wiper arm configured for relative rotation during assembly from a disassembled position to a shipping position, wherein the wiper arm and mounting head are locked against rotation toward the disassembled position once in the shipping position. The mounting head and wiper arm have locking surfaces configured for locked engagement with one another while in the shipping position. The locking surfaces are brought into engagement with one another by a force imparted by a spring while rotating the mounting head relative to the wiper arm from the disassembled position toward the shipping position. When in the shipping position, the locking surfaces confront each other and prevent the mounting head and the wiper arm from rotating back toward the disassembled position from the shipping position.