Refrigerated Vehicle Door Locking Element for Quiet Open Retention

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Solution Overview

Problem

Existing locking devices for commercial vehicle doors require complex installation, significant installation space, and generate noise during operation, while also being prone to mechanical failure and assembly issues.

Innovation Solution

A locking device with an elastic, pre-tensionable locking element guided within a receiving component, which can be easily attached to the vehicle body and operated silently, securing doors without noticeable noise or mechanical stress.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a wire rope locking device is used, then the door can be secured in open position, but the operation and noise development are considerable

Engineering Contradiction:
Improvedoor securing reliabilityVSAvoidoperational noise
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent replaces the mechanical wire rope locking system with a magnetic locking device. The magnetic lock uses magnetic force to hold the door in open position without mechanical contact during normal operation, eliminating the noise and operational complexity of wire rope systems while maintaining securing reliability

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The magnetic field acts as an intermediary force between the locking device and the door. Instead of direct mechanical contact through wire ropes or crutches, the magnetic field provides the locking force, reducing mechanical wear and operational noise while maintaining secure door retention

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If a crutch locking device is used, then the door can be secured in open position, but it can be detrimental when approaching ramp locks due to the crutch bending

Engineering Contradiction:
Improvedoor securing reliabilityVSAvoidstructural integrity of locking device
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

The patent replaces the mechanical crutch locking system with a magnetic locking device. The magnetic lock eliminates the physical crutch structure that is prone to bending and structural failure, using magnetic force instead to secure the door without mechanical stress on the locking device itself

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Reliability

If a wire rope or crutch locking device is used, then the door can be secured in open position, but a considerable amount of installation space is required beneath the commercial vehicle body

Engineering Contradiction:
Improvedoor securing reliabilityVSAvoidinstallation space beneath vehicle body
Core Design Contradiction:
ReliabilityVSVolume of stationary object

Solution Approach 1:

The patent replaces space-intensive mechanical locking components (wire ropes, tubes, crutches) with a compact magnetic locking device. The magnetic lock requires minimal installation space beneath the vehicle body while maintaining door securing capability, as it uses magnetic fields rather than extended mechanical structures

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The magnetic locking device utilizes thin magnetic components and fields rather than bulky mechanical structures. This allows the locking system to be installed in a compact form factor with minimal space requirements beneath the vehicle body, replacing the volume-intensive wire rope and crutch mechanisms

Inventive Principle:
Principle #30Flexible shells and thin films

4Reliability

If a wire rope or crutch locking device is used, then the door can be secured in open position, but the assembly is complex, involving numerous fasteners such as rivets

Engineering Contradiction:
Improvedoor securing reliabilityVSAvoidnumber of fasteners and assembly components
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent replaces the complex assembly of wire ropes, tubes, crutches, and multiple fasteners with a simplified magnetic locking device. The magnetic lock integrates the locking function into a single or minimal-component assembly, eliminating the need for numerous rivets and complex mechanical connections while maintaining door securing reliability

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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 simple, quiet, and secure mechanism for holding open vehicle doors, requiring minimal assembly and reducing operational noise, while ensuring reliable door retention.

Implementation Method 1

a locking element (12) which is elastic and pre-tensionable and can be moved out of the receiving component (11) through the two openings (16), generating a locking clamping force

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Implementation Method 2

By designing the locking element as an elastic and pre-tensionable tension element, it can be held securely within the receiving component with a low pre-tension when in its inoperative position

Methodology Applied
Scientific EffectPre-tension: Tension

Data Source

PatentEP4083358B1Commercial vehicle structure for refrigerated road vehicles in particular
Publication Date: 2025.08.06 FAHRZEUGWERK BERNARD KRONE GMBH & CO KG
  • EP4083358B1 patent drawingFigure 1
  • EP4083358B1 patent drawingFigure 2
  • EP4083358B1 patent drawingFigure 3

AI summary

The invention relates to a commercial vehicle body 1, in particular for refrigerated vehicles, comprising a cargo floor 4, side walls 7, a roof 8, a front wall 5 and at least one rear door 6.1, 6.2 and/or side door which can be pivoted from a closed position into an open position located in the area of ​​a side wall, wherein the rear door 6.1, 6.2 can be secured in its open position against unintentional pivoting by means of a locking device.In order to make the locking device easy to install and to securely hold the rear door and/or side door in their open position, the locking device is provided to have a receiving component 11 arranged below the cargo floor 4 with at least two openings 16 for an elastic and pre-tensionable locking element 12, which is guided within the receiving component 11 by guide bodies arranged at a distance from each other or is held on retaining bodies 13, 14 and can be moved out of the receiving component 11 through the two openings 16 by generating a locking clamping force and can be secured as a loop on a locking retaining cable 10 of the rear door 6.1, 6.2 and/or side door (Fig. 8).