Trailer Hitch Sway Control Using Rigid Brackets and Trunnion Bars

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Solution Overview

Problem

Existing trailer hitch systems often fail to effectively control trailer sway and distribute weight evenly, leading to steering difficulties and increased stress during towing, especially on uneven roads and in emergency situations.

Innovation Solution

A trailer hitch system that includes spring bars with a trunnion connection to the hitch head and rigid brackets attached to the trailer tongue, providing an upward force to equalize load distribution and reduce sway, while allowing for adjustable attachment and metal-to-metal contact surfaces for improved friction and stability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If flexible members or chains are used to join spring bars to the trailer tongue, then the hitch system allows movement and adjustment, but the spring bars can swing back and forth like a pendulum and do not provide stabilizing support

Engineering Contradiction:
Improvemovement and adjustment capabilityVSAvoidspring bar stability
Core Design Contradiction:
Adaptability or versatilityVSStability of the object's composition

Solution Approach 1:

The patent uses a flexible bracket with a spring element that provides both flexibility for adjustment and stability for sway control. The spring bracket acts as a flexible member that maintains constant tension on the spring bar, preventing pendulum-like swinging while allowing necessary movement and adjustment during towing operations.

Inventive Principle:
Principle #30Flexible shells and thin films

2Stability of the object's composition

If rigid brackets are used to join spring bars to the trailer tongue, then stabilizing support is provided, but adjustment and accommodation of movement is limited

Engineering Contradiction:
Improvespring bar stabilityVSAvoidmovement and adjustment capability
Core Design Contradiction:
Stability of the object's compositionVSAdaptability or versatility

Solution Approach 1:

The patent employs a dynamic bracket design that transitions from a static rigid structure to a dynamic system with spring elements. The spring bracket can deflect and adjust its position to accommodate movement between the trailer tongue and spring bar while maintaining stabilizing support, effectively combining the benefits of both rigid and flexible connections.

Inventive Principle:
Principle #15Dynamics

3Device complexity

If most of the trailer tongue weight is carried on the back axle of the tow vehicle, then the hitch structure is simpler, but steering control becomes more difficult and the front end of the tow vehicle is raised

Engineering Contradiction:
Improvehitch structure simplicityVSAvoidsteering control
Core Design Contradiction:
Device complexityVSEase of operation

Solution Approach 1:

The patent implements a weight distribution system where spring bars extend from the hitch head toward the trailer tongue, applying upward force to counterbalance the tongue weight. This distributes the load across multiple axles rather than concentrating it on the back axle, lowering the front end of the tow vehicle and improving steering control while maintaining hitch structure simplicity.

Inventive Principle:
Principle #8Anti-weight (Counterweight)

4Stability of the object's composition

If spring arms are lifted or loaded to place an upward force on the hitch head, then load equalization is achieved, but the mechanism becomes more complex

Engineering Contradiction:
Improveload distributionVSAvoidequalizing mechanism complexity
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The patent uses a self-adjusting spring bracket system that automatically equalizes load distribution without requiring manual adjustment or complex mechanisms. The spring element naturally applies upward force to the hitch head through its elastic properties, achieving load equalization through the inherent characteristics of the spring material rather than through complex mechanical adjustment devices.

Inventive Principle:
Principle #25Self-service

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 system effectively reduces trailer sway and improves load distribution, enhancing steering control and maneuverability during towing, while minimizing the risk of hitch dragging and sway-related issues.

Implementation Method 1

spring bars with a trunnion connection to the hitch head and rigid brackets attached to the trailer tongue, providing an upward force to equalize load distribution

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

metal-to-metal contact surfaces for improved friction and stability

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentUS8833789B2Sway control hitch
Publication Date: 2014.09.16 DEXTER AXLE CO LLC
  • US8833789B2 patent drawing
  • US8833789B2 patent drawing
  • US8833789B2 patent drawing

AI summary

A trailer hitch system for equalizing trailer loads and reducing trailer sway. The trailer hitch system may include spring bars that may be attached to a hitch head using a trunnion style connection. The spring bars may be attached to the trailer using rigid brackets that reduce swinging of the spring bars. The rigid brackets may include an upward extending portion for attaching to the trailer tongue, and a lateral extending portion for receiving the spring bars thereupon. The brackets may have a contact surface on the lateral extending portion that may be free from a coating such that a metal on metal contact is made between the spring bars and the brackets. Portions of the brackets beyond the contact surface may be covered with a protective coating.