Adjustable Drawbar Spring Restraint for Trailer Load Moments

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Solution Overview

Problem

Existing trailers with pivotally mounted drawbars require separate springs with specific spring constants for each draw fork, making them inefficient and costly to adapt to different load moments.

Innovation Solution

A trailer design featuring a pivotably mounted drawbar with a restraint device that includes a spring device and an adjustment mechanism, allowing the spring constant to be adjusted and the pivoting position of the drawbar to be changed, ensuring the spring preload matches the load moment without requiring multiple springs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If separate springs with specific spring constants are used for each drawbar, then the drawbar load moment can be compensated, but the device complexity and cost increase

Engineering Contradiction:
Improvedrawbar load moment compensationVSAvoidmultiple springs with different constants
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

A single spring device is designed to serve multiple drawbars with different load moments through an adjustment mechanism. The spring constant remains fixed, but the effective leverage is changed by adjusting the distance between the attachment point on the drawbar and the pivot axis, allowing one spring to compensate for various load moments that previously required multiple specialized springs.

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

Solution Approach 2:

The attachment point of the spring to the drawbar is made adjustable rather than fixed. This dynamic adjustment capability allows the system to adapt to different drawbar configurations and load moments by changing the geometric parameters (distance from pivot axis), transforming a static single-function spring into a dynamic multi-function component.

Inventive Principle:
Principle #15Dynamics

2Ease of operation

If the spring preload is adjusted to match the load moment, then the drawbar pivoting position can be optimized, but the adjustment mechanism increases device complexity

Engineering Contradiction:
Improvedrawbar pivoting position adjustmentVSAvoidadjustment mechanism
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

Instead of adjusting the spring constant (which would require changing the physical spring), the system adjusts the geometric parameter - the distance between the spring attachment point on the drawbar and the pivot axis. This parameter change effectively modifies the leverage and spring preload influence, allowing optimization of drawbar pivoting position without complex spring replacement mechanisms.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The adjustment functionality is extracted as a separate, simple mechanism that only needs to change the attachment point position. This separates the adjustment function from the spring itself, allowing the spring to remain a simple, reliable component while the adjustment mechanism handles the complexity of adapting to different load conditions.

Inventive Principle:
Principle #2Taking out (Extraction)

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 allows for adaptable and efficient operation across varying load conditions, reducing wear and noise while maintaining a fixed position of the stop point relative to the drawbar, thus eliminating the need for multiple springs and enhancing usability.

Implementation Method 1

The restraint device has at least one spring device with a first end and a second end. The spring device can, in principle, compensate for a load moment of the drawbar.

Methodology Applied
Scientific EffectSpring: Spring

Data Source

PatentEP4331873A1Trailer
Publication Date: 2024.03.06 EPSILON KRAN
  • EP4331873A1 patent drawingFigure 1a~1b
  • EP4331873A1 patent drawingFigure 2
  • EP4331873A1 patent drawingFigure 3a

AI summary

Trailer (1) with a vehicle frame (2) and a drawbar (3) pivotably mounted on the vehicle frame (2), with a restraint device (9) for the drawbar (3), wherein the restraint device (9) allows at least one pivot position of the drawbar (3) relative to the vehicle frame (2) to be adjusted, wherein the restraint device (9) comprises at least one spring device (10) with a first end (11) and a second end (12), wherein the spring device (10) is connectable to or connected with the vehicle frame (2) at its first end (11), and an adjustment device (13) arranged on the drawbar (3) with at least one stop point (14), wherein the spring device (10) is connectable to or connected with the at least one stop point (14) at its second end (12).wherein a position of at least one stop point (14) relative to the drawbar (3) is adjustable and the position of the at least one stop point (14) relative to the drawbar (3) can be adjusted and fixed with the adjusting device (13) independently of the pivot position of the drawbar (3) relative to the vehicle frame (2).