Rear Load Carrier Connection Device with Pivoting Retaining Elements

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Solution Overview

Problem

Existing rear load carriers for motor vehicles face issues with undefined pressing force application and adaptation to different trailer hitch sizes, leading to insecure and cumbersome attachment to trailer hitches.

Innovation Solution

The connection device features pivotally connected retaining elements above the swivel axes, with articulated design allowing end sections to move towards each other and apply a defined pressing force against the trailer hitch, along with adjustable swivel bolts and an intermediate lever mechanism for secure and quick attachment, ensuring a stable and frictional fit.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the retaining elements are pivotally connected above the swivel axes with articulated design, then the pressing force application becomes defined and secure, but the device complexity increases

Engineering Contradiction:
Improveattachment securityVSAvoidconnection device structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The retaining element is divided into two functional sections: an upper section above the swivel axis that pivots outward to apply pressing force, and a lower section below the swivel axis that forms the receptacle. This segmentation allows each section to perform its specific function independently, achieving defined force application while maintaining structural clarity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The retaining element is designed as a dynamic component that can pivot about the swivel axis. The upper section pivots outward during attachment to engage the connection head, then returns to a centered position in the holding state. This dynamic behavior enables secure attachment without requiring complex static structures.

Inventive Principle:
Principle #15Dynamics

2Adaptability or versatility

If the swivel bolt is arranged in an oblong hole allowing translational movement, then the connection device can adapt to different connection head sizes, but the pressing force application becomes undefined

Engineering Contradiction:
Improveadaptation to different trailer hitch sizesVSAvoidattachment security
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The swivel bolt is mounted on the retaining element rather than being fixed to the housing body, allowing it to pivot dynamically with the retaining element. This dynamic mounting enables the bolt to adapt to different connection head positions while the upper section of the retaining element maintains defined pressing force application through its pivotal motion above the swivel axis.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The retaining element is segmented into an upper force-applying section and a lower receptacle-forming section. The upper section pivots about the swivel axis to apply defined pressing force, while the lower section forms the receptacle that can accommodate different connection head sizes. This segmentation separates the adaptation function from the force application function.

Inventive Principle:
Principle #1Segmentation

3Device complexity

If the operating device applies pressing force at the height of the swivel axis, then the mechanism is simple, but the pressing force is applied in an undefined way

Engineering Contradiction:
Improveoperating device structureVSAvoidforce application definition
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The pressing force application is moved from the horizontal plane (at the swivel axis height) to the vertical dimension (above the swivel axis). The upper section of the retaining element pivots above the swivel axis, creating a moment arm that defines the force application point. This dimensional change provides geometric definition to the force application while keeping the operating device relatively simple.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

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 design provides a secure, quick, and adaptable attachment to trailer hitches of varying sizes, preventing unintentional twisting or rotation, and ensuring a defined positioning and force application, enhancing the safety and ease of use of the rear load carrier.

Implementation Method 1

The retaining elements are pivotable about a swivel axis... in the holding position, the swivel axis to the housing body is arranged approximately centrally to the connection head in the height direction... the retaining elements fixingly engage around a connection head located in the receptacle

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP3650274B1Rear load carrier
Publication Date: 2020.12.23 CARMAN ENTERPRISE
  • EP3650274B1 patent drawingFigure 1
  • EP3650274B1 patent drawingFigure 2
  • EP3650274B1 patent drawingFigure 3

AI summary

Rear load carrier (1) for mounting on a motor vehicle with a supporting frame (2) which has a connection device (4) for fastening to a trailer hitch on the vehicle side, the connection device (4) comprising a housing body (9) open towards the underside, two retaining elements (10, 11) which form a downwardly open receptacle between them for a connection head (6) of the trailer hitch and are each mounted on the housing body (9) so as to be pivotable about a swivel axis (X1, X2), and an operating device (18) coupled to the retaining elements (10, 11) for pivoting them relative to one another between an insertion position in which the retaining elements (10, 11) are pivoted apart such that the connection device (4) can be placed on or removed from the connection head (6) and a holding position in which the retaining elements (10, 11) fixingly engage around a connection head (6) located in the receptacle.