Tool-Free Wheel Hub Assembly with Spring-Loaded Retainer

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Solution Overview

Problem

Existing wheel assemblies for refuse carts are difficult to remove for maintenance, repair, or transportation without specialized tools, and are prone to accidental removal by vandals due to complex and tool-dependent designs.

Innovation Solution

A hand-maneuverable release mechanism is integrated into the wheel and hub assembly, allowing users to remove the wheel without tools by manipulating a tab to displace the retaining element, providing an additional layer of security against unauthorized removal.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If a hammered push-on hat fastener is used to mount the wheel to the axle, then the wheel is securely held in place, but the wheel becomes difficult to remove and requires special tools or destruction for removal

Engineering Contradiction:
Improvewheel retention strengthVSAvoidwheel removal ease
Core Design Contradiction:
StrengthVSEase of operation

Solution Approach 1:

The fastener transitions from a static hammered configuration to a dynamic spring-loaded configuration that can be easily actuated. The spring biasing element allows the retaining element to be pushed into and out of engagement with the axle groove through manual pressure on the tab, enabling easy removal while maintaining secure retention during normal use.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The spring biasing element automatically maintains the retaining element in the engaged position with the axle groove, providing self-locking retention without requiring additional fastening steps. The system self-regulates the retention force through spring pressure, eliminating the need for complex tool-based removal mechanisms.

Inventive Principle:
Principle #25Self-service

2Ease of operation

If a snap-on wheel assembly is used to simplify wheel mounting, then the wheel can be easily installed, but the assembly becomes unduly complex and visually unappealing

Engineering Contradiction:
Improvewheel mounting easeVSAvoidassembly complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

Multiple functions are merged into a single integrated fastener assembly: the retaining element engages the axle groove, the spring biasing element maintains engagement pressure, and the tab provides manual actuation. This unified structure achieves easy wheel mounting while avoiding the undue complexity of separate snap-on components.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The fastener assembly serves multiple purposes: it secures the wheel to the axle during operation, provides easy manual removal capability, and maintains a clean integrated appearance. The single structure performs retention, release, and aesthetic functions simultaneously, avoiding the need for separate complex assemblies.

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

3Reliability

If a tool passageway covered by a membrane is used to prevent unwanted removal, then security against vandalism is improved, but the mechanism becomes less effective once the membrane is punctured

Engineering Contradiction:
Improveprotection against unwanted removalVSAvoidwheel removal accessibility
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The tab acts as an intermediary control element that provides manual access to the retaining mechanism without requiring tool passage. Users can directly manipulate the tab to actuate the spring and retaining element, eliminating the need for membrane-covered tool passageways and their associated security vulnerabilities.

Inventive Principle:
Principle #24Intermediary (Mediator)

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

Facilitates efficient removal and installation of wheel assemblies, enhances security against accidental removal, and simplifies maintenance and distribution processes.

Implementation Method 1

The biasing element is within the conduit and is configured to bias the retaining element towards the axle bore

Methodology Applied
Scientific EffectSpring: Spring

Implementation Method 2

The hand-maneuverable release mechanism is configured to displace the retaining element away from the axle bore. The release mechanism includes a tab, a lifter connected to the tab, and a connector coupled to the tab and coupled to the lifter. The tab is configured to be manipulated by a hand of a user.

Methodology Applied
Scientific EffectMechanical Advantage: Mechanical Advantage

Data Source

PatentEP2812193B1Wheel and hub assemblies removable without tools
Publication Date: 2020.07.15 GEO PLASTICS
  • EP2812193B1 patent drawingFigure 1
  • EP2812193B1 patent drawingFigure 2A
  • EP2812193B1 patent drawingFigure 2B

AI summary

A hub or wheel assembly includes a retaining element, biasing element, and hand- maneuverable release mechanism. The housing includes an axle bore configured to receive an axle and a pin sleeve including a first end in fluid communication with the axle bore, a second end, and a conduit between the first end and the second end. The retaining element is within the conduit and is configured to operatively engage a groove in an axle. The biasing element is within the conduit and is configured to bias the retaining element towards the axle bore. The hand-maneuverable release mechanism is configured to displace the retaining element away from the axle bore.