Wheel Nut Assembly with Ratchet Locking and Tamper-Evident Cap

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Solution Overview

Problem

Existing wheel nut systems fail to provide a tamper-evident and aesthetically appealing solution that ensures the nuts remain securely fastened to the wheel hub, as they often require additional components or complex mechanisms to prevent loosening.

Innovation Solution

A wheel nut assembly featuring a wheel stud with axial ribs and a ratchet arm mechanism, combined with a retaining cap that securely fastens over the nut, providing visual indication of secure fastening and aesthetic appeal through various design configurations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a ratchet arm mechanism is used to prevent nut loosening, then the reliability of wheel retention is improved, but the device complexity increases

Engineering Contradiction:
Improvewheel nut retention securityVSAvoidnut assembly structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The ratchet arm is nested within the cylindrical wall of the nut assembly, with the resilient element and locking mechanism integrated into the existing nut structure. The ratchet arm pivots within the cylindrical wall and engages with the stud's external surface features, creating a compact nested arrangement that prevents loosening without adding external complexity.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The resilient element automatically urges the ratchet arm into engagement with the stud's axial ribs or external surface, creating a self-activating locking mechanism. When the nut is tightened, the ratchet arm automatically engages with the stud features, and the resilient element maintains constant engagement pressure without requiring external actuation.

Inventive Principle:
Principle #25Self-service

2Reliability

If a retaining cap with aesthetic cover is provided, then the visual indication of secure fastening and aesthetic appeal are improved, but the device complexity increases

Engineering Contradiction:
Improvetamper evident indicationVSAvoidnut assembly structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The retaining cap, aesthetic cover, and locking mechanism are merged into a single integrated assembly. The cap features both the functional locking elements (internal grooves or ribs for engaging the stud) and the aesthetic outer cover as unified components, eliminating the need for separate retaining and cosmetic elements.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The retaining cap serves multiple functions simultaneously: it provides structural retention through internal engagement features with the stud, offers aesthetic appearance through its outer cover design, and provides tamper-evident indication through visible positioning on the wheel assembly. The aesthetic cover also serves as the outer protective layer for the locking mechanism.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Reliability

If an unlocking mechanism requiring pressure and rotation is used, then the tamper proof security is improved, but the ease of operation decreases

Engineering Contradiction:
Improvetamper proof securityVSAvoidnut removal convenience
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The unlocking mechanism is pre-configured with the resilient element already urging the ratchet arm into the locked position. The user simply needs to apply pressure and rotate the nut assembly, which automatically disengages the ratchet arm from the stud's axial ribs through the pre-positioned unlocking features, eliminating complex multi-step unlocking procedures.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The unlocking mechanism transitions from a static locked state to a dynamic unlocking state through applied pressure and rotation. The resilient element allows the ratchet arm to flex and disengage when pressure is applied, and the rotation motion converts the static engagement into dynamic disengagement, providing easy one-handed operation while maintaining security.

Inventive Principle:
Principle #15Dynamics

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 ensures the wheel nut remains securely fastened to the hub, offering a tamper-evident and aesthetically pleasing design that is cost-effective and easy to implement, with the ratchet mechanism allowing for secure locking and easy removal.

Implementation Method 1

a ratchet arm resiliently urged against the ribs on the stud

Methodology Applied
Scientific EffectRatchet mechanism: Ratchet

Implementation Method 2

a ratchet arm resiliently urged against the ribs on the stud

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 3

an unlocking mechanism associated with said ratchet arm to disengage said ratchet arm from the ribs of the stud

Methodology Applied
Scientific EffectSpring force: Spring

Data Source

PatentEP2499004B1Wheel nut assembly
Publication Date: 2020.05.20 FERMAN MICHAEL
  • EP2499004B1 patent drawingFigure 1
  • EP2499004B1 patent drawingFigure 2
  • EP2499004B1 patent drawingFigure 3~4

AI summary

A wheel nut assembly for fixing a wheel to a vehicle hub which includes a wheel nut with an internal thread; a wheel stud having an external thread to co- operate with the internal thread of said wheel nut and having an end portion adapted to project beyond the wheel nut which end portion includes axial grooves o ribs on its external surface; a retaining cap with internal grooves or ribs complementary to the external ribs or grooves on said wheel stud adapted to fit over said wheel stud and said wheel nut; and means to secure the retaining cap to said wheel nut. The retaining cap prevents rotation of the nut once it has been tightened In some embodiments an aesthetic cover is provided to improve the appearance of the wheel. This aesthetic cover may also be used to lock the retaining cap to the nu and provide an indication that the nut is securely fastened.