Expandable Trailer Frame with Offset Longitudinal Members

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Solution Overview

Problem

Existing vehicle trailers face challenges in achieving economic production while maintaining mechanical stability and optimizing load space, with limitations in design flexibility and material usage.

Innovation Solution

The vehicle trailer design features a rear roller positioned below a front side member, allowing lateral offset and vertical overlap of longitudinal members, which reduces the overall frame height, lowers the center of gravity, and increases usable load space, while using a U-profile to guide rollers both upwards and downwards, eliminating the need for additional rollers and providing design freedom.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If the front and rear longitudinal members are arranged one above the other, then the structure is compact, but the mechanical stability is reduced and the center of gravity is raised

Engineering Contradiction:
Improvemechanical stabilityVSAvoidframe height
Core Design Contradiction:
Stability of the object's compositionVSLength of stationary object

Solution Approach 1:

The patent transitions from a vertical stacking arrangement (one above the other) to a lateral offset arrangement with vertical overlap. This dimensional reconfiguration allows the longitudinal members to overlap in height while being positioned side-by-side, thereby reducing overall frame height while maintaining structural stability and lowering the center of gravity.

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

2Strength

If longitudinal members are made higher to increase mechanical stability, then stability improves, but the loading area height increases disadvantageously

Engineering Contradiction:
Improvemechanical stabilityVSAvoidloading area height
Core Design Contradiction:
StrengthVSLength of stationary object

Solution Approach 1:

By arranging longitudinal members laterally offset with vertical overlap, the patent enables the use of taller, more stable members without proportionally increasing the overall frame height. The overlapping configuration allows the stability benefits of taller members to be achieved while maintaining a compact overall structure that preserves loading area height.

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

3Reliability

If a large number of front rollers are provided to guide the rear section, then reliability improves, but device complexity and cost increase

Engineering Contradiction:
Improveguiding reliabilityVSAvoidnumber of rollers
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines the guiding functions of multiple rollers into a single integrated U-profile structure. This U-profile channel guides the front rollers both upwards and downwards, consolidating what would require multiple separate guiding elements into one component, thereby reducing complexity while maintaining guiding reliability.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The U-profile serves multiple functions simultaneously: it guides front rollers in both vertical directions (upwards and downwards), provides structural support, and eliminates the need for separate guide structures. This multi-functionality reduces the overall number of components required while maintaining reliable guidance.

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

4Stability of the object's composition

If traverses are provided on the rear section to hold front rollers, then the structure is stable, but production complexity and cost increase

Engineering Contradiction:
Improvestructural stabilityVSAvoidproduction complexity
Core Design Contradiction:
Stability of the object's compositionVSEase of manufacture

Solution Approach 1:

The patent extracts the roller-holding function from dedicated traverses and integrates it directly into the rear side members. By forming the roller mounting locations as part of the main longitudinal members rather than separate traverses, the design simplifies production while maintaining structural stability and providing design flexibility.

Inventive Principle:
Principle #2Taking out (Extraction)

Data Source

PatentEP3093220B1Expandable vehicle trailer
Publication Date: 2018.06.06 SYST TRAILERS FAHRZEUGBAU
  • EP3093220B1 patent drawingFigure 1~3

AI summary

In an expandable vehicle trailer (1) comprising a front section (2) that can be coupled to a towing vehicle and has front longitudinal members (5), and a rear section (3) that has wheels (4) and rear longitudinal members (9) and coupling elements (14) for connecting a further trailer, wherein the two sections (2, 3) are slidably relative to each other and are guided for slidability by means of rollers (16, 18), and which can be locked in both a first, collapsed arrangement and a second, extended arrangement, and wherein front rollers (16) are arranged near the front end of the rear section (3) and are each guided in a horizontally oriented, laterally open U-profile (17), and rear rollers (18) are arranged near the rear end of the front section (2), the invention proposesthat the rear longitudinal beams (9) are laterally offset from the front longitudinal beams (5) and are arranged to overlap each other vertically, and that the front rollers (16) are held on the rear longitudinal beams (9).