Single Lever Coupling Device with Four-Bar Linkage

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Solution Overview

Problem

Existing coupling devices for load carriers on trailers are complex to operate and prone to errors, often requiring multiple movements and sequences to secure the load carrier, which can lead to incorrect operation and potential damage.

Innovation Solution

A coupling device with a single lever actuated by a four-bar linkage that simplifies the tensioning process, allowing the clamping bracket to be pivoted and tensioned with a single movement, and includes a compensating mechanism for different ball diameters, ensuring secure attachment with high clamping forces and a locking mechanism for stability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a single lever with four-bar linkage is used for actuation, then ease of operation is improved, but device complexity increases

Engineering Contradiction:
Improveease of operationVSAvoiddevice complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

Multiple actuation functions (pivoting the clamping bracket, engaging the locking mechanism, and actuating the compensating mechanism) are merged into a single lever operation through the four-bar linkage, allowing all actions to be performed with one continuous movement

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The four-bar linkage acts as an intermediary mechanism that translates the simple rotational movement of the single lever into the complex coordinated movements required for clamping bracket pivoting, locking engagement, and ball diameter compensation

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If multiple movements and sequences are required for securing, then clamping reliability is improved, but ease of operation deteriorates

Engineering Contradiction:
Improveclamping reliabilityVSAvoidease of operation
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The compensating mechanism is preliminarily positioned to accommodate different ball diameters before the actual clamping action occurs, ensuring that the clamping bracket engages correctly regardless of the specific ball size

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The single continuous lever movement maintains continuous useful action throughout the entire clamping process, eliminating idle positions or separate discrete actions that would interrupt the clamping sequence

Inventive Principle:
Principle #20Continuity of useful action

3Adaptability or versatility

If a compensating mechanism for different ball diameters is included, then adaptability is improved, but device complexity increases

Engineering Contradiction:
ImproveadaptabilityVSAvoiddevice complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The compensating mechanism is designed to universally accommodate various ball diameters within a standardized range, allowing the same coupling device to work with different trailer hitch sizes without requiring model-specific configurations

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

Solution Approach 2:

The compensating mechanism adjusts its geometry or position based on the detected ball diameter, dynamically changing its parameters to maintain optimal clamping force and alignment across different ball sizes

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

The solution enables secure and easy attachment of the load carrier to the trailer hitch with a single hand movement, avoiding operating errors and providing high clamping forces, while accommodating various ball diameters, ensuring reliable and efficient operation.

Implementation Method 1

a single lever (10) serving as an operating element, by which, by a pivoting movement about a pivot axis, the clamping bracket (21) is pivoted in and tensioned via a four-bar linkage (44)

Methodology Applied
Scientific EffectFour-bar linkage: Four-Bar Linkage

Implementation Method 2

Due to the design of part of the four-bar linkage (44) in connection with the contact point on the head of the trailer hitch as a toggle lever, high clamping forces can be achieved

Methodology Applied
Scientific EffectMechanical advantage: Mechanical Advantage

Data Source

PatentEP2540532B1Coupling device for a load bearing device
Publication Date: 2015.05.06 I RACKS
  • EP2540532B1 patent drawingFigure 1
  • EP2540532B1 patent drawingFigure 2
  • EP2540532B1 patent drawingFigure 3

AI summary

The device (2) has a clamping bracket (21) pivoted and clamped around a pivot axis by pivoting movement of a lever (10), where the lever is used as a control element. The pivoting movement of the lever is converted into pivoting movement of the clamping bracket up to a locating point via a four-joint while converting the pivoting movement of the lever into the clamping movement of the clamping bracket. A transmission element (36) is arranged eccentrically with respect to the pivot axis of the lever.