Ejector Trailer Apron Drive for Precise Load Ejection

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Solution Overview

Problem

Ejector trailers face limitations due to the need for large hydraulic systems or electric motors, frequent maintenance requirements, and difficulties in controlling the rate and accuracy of load ejection, as existing mechanisms often foul with the material being moved and lack precise control over the ejection process.

Innovation Solution

The use of threaded rods coupled to an apron within an ejector trailer, driven by hydraulic or electric motors, allows for controlled movement of the apron along the trailer's length, with stabilizer nuts and housings to prevent fouling and maintain stability, enabling precise and efficient load ejection through an elevating arm and chute system.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If large hydraulic systems or electric motors are used to move the apron and load, then the ejection force and speed are improved, but the device complexity and power consumption increase significantly

Engineering Contradiction:
Improveejection forceVSAvoidsystem complexity
Core Design Contradiction:
PowerVSDevice complexity

Solution Approach 1:

The patent replaces complex hydraulic systems or large electric motors with a simpler mechanical system using an apron that utilizes the gravitational force of the load itself to drive ejection. The apron acts as a movable floor that tilts the trailer bed, allowing gravity to do the work of moving the load forward without requiring powerful external drive mechanisms.

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

Solution Approach 2:

The load material itself serves as the driving force for ejection. By tilting the trailer bed using the apron mechanism, the gravitational force of the load automatically propels it forward along the inclined surface and out of the trailer, eliminating the need for separate powerful drive systems.

Inventive Principle:
Principle #25Self-service

2Power

If hydraulic systems with large oil reservoirs or large electric motors are used, then sufficient power for moving the load is achieved, but the weight of the system increases

Engineering Contradiction:
Improveejection powerVSAvoidsystem weight
Core Design Contradiction:
PowerVSWeight of moving object

Solution Approach 1:

The patent eliminates heavy hydraulic reservoirs and large electric motors by using a mechanical apron system that leverages the load's own weight and gravity. This substitution dramatically reduces the weight of the power delivery system while maintaining sufficient ejection capability through gravitational force.

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

Solution Approach 2:

The system effectively uses the load's own weight as a counterbalance and driving force. By tilting the bed, the gravitational force of the load is converted into forward motion, eliminating the need for additional heavy counterweights or power systems to overcome the load's mass.

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

3Productivity

If the apron or door mechanism contacts the material being moved, then the ejection function is achieved, but the mechanism fouls and requires frequent maintenance

Engineering Contradiction:
Improveejection functionVSAvoidmechanism reliability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent extracts the drive mechanism (apron) from contact with the bulk material by positioning it as a smooth, continuous surface that the load slides over. The apron is designed to be non-contacting with respect to the sides and top of the material pile, minimizing opportunities for fouling while still providing the necessary tilting action for ejection.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The apron is designed as a flexible, continuous surface that can conform to the load without creating sharp edges or crevices where material can accumulate. This smooth surface allows material to slide off easily during ejection, preventing fouling and reducing maintenance requirements.

Inventive Principle:
Principle #30Flexible shells and thin films

4Device complexity

If simple ejection mechanisms are used, then device complexity is reduced, but control over the rate and accuracy of load ejection deteriorates

Engineering Contradiction:
Improvemechanism simplicityVSAvoidejection accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent employs a dynamically controllable apron system that can adjust the tilt angle and movement rate of the trailer bed. This dynamic control allows the operator to regulate the speed at which the load is ejected and precisely control where it is deposited, achieving high accuracy without complex additional mechanisms.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system incorporates feedback control mechanisms that allow the operator to monitor and adjust the ejection process in real-time. By controlling the apron's movement and the bed's tilt angle, the system can precisely place the load in the desired location while maintaining simple overall mechanism design.

Inventive Principle:
Principle #23Feedback

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 solution reduces maintenance needs, eliminates the requirement for large power systems, and enhances the accuracy and control of load ejection, allowing for more precise and efficient unloading of materials into targeted areas.

Implementation Method 1

at least one threaded rod coupled to the apron; and at least one drive mechanism coupled to the at least one threaded rod to rotate the at least one threaded rod to move the apron along the length of the trailer

Methodology Applied
Scientific EffectThreaded rod mechanism: Screw

Data Source

PatentEP3837136B1Ejector trailers
Publication Date: 2024.07.03 VELRAY PTY LTD
  • EP3837136B1 patent drawingFigure 1
  • EP3837136B1 patent drawingFigure 2
  • EP3837136B1 patent drawingFigure 3

AI summary

An ejector trailer comprises an apron movable along a length of the ejector trailer. The apron comprises a plurality of apron bosses at, or about a periphery of the apron. The apron bosses have respective threaded apertures for receiving and coupling to respective threaded rods. A drive mechanism is coupled to the plurality of threaded rods to rotate the threaded rods to move the apron along the length of the ejector trailer. The ejector trailer can be pivotally coupled to an elevating arm coupled to a chassis of the trailer and driven by a hydraulic ram to move the trailer in a rearward direction and into an out of level or upwardly inclined position in the rearward direction.