Quick Coupler Lever Stop for Safe Bucket Locking

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Solution Overview

Problem

Conventional quick couplers for public works machines are unsafe due to loose or broken locking mechanisms, leading to accidental release of attached tools, posing a significant danger on construction sites.

Innovation Solution

A coupler system with a lever mechanism and locking means, featuring a rear plate stop, pivotally mounted lug, and tension springs to secure the lever in a closed position, ensuring the coupler remains locked even if springs break, preventing accidental detachment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If locking means are provided to secure the quick coupler to the connection device, then the coupling reliability is improved, but if the locking means come loose or break, the bucket may be accidentally released causing safety hazards

Engineering Contradiction:
Improvecoupling reliabilityVSAvoidsafety hazard from accidental release
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent implements a stop mechanism (comprising a stop element on the lever and a corresponding stop surface on the coupler body) that prevents the lever from moving beyond its closed position. This beforehand cushioning mechanism ensures that even if the spring locking means fail, the lever cannot open the coupling, thus preventing accidental release and eliminating the safety hazard while maintaining coupling reliability

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

Solution Approach 2:

The stop mechanism acts as a preliminary anti-action against the potential harmful effect of lever over-travel. By physically blocking the lever's movement path before it can cause coupling release, the system preemptively counteracts the failure mode of the locking means, ensuring that spring failure does not lead to bucket release

Inventive Principle:
Principle #9Preliminary anti-action

2Ease of operation

If a lever mechanism with springs is used to lock the coupling, then the ease of operation is improved, but the device complexity increases

Engineering Contradiction:
Improveease of coupling and uncouplingVSAvoidcomplexity of locking mechanism
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent extracts the safety function from the complex spring-lever locking mechanism by adding a separate, simple stop mechanism. This separation allows the lever mechanism to remain relatively simple for ease of operation, while the stop mechanism provides the necessary safety constraint without significantly increasing overall device complexity

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The locking system is segmented into functional components: the lever mechanism for operation, the springs for locking force, and the stop mechanism for safety. This segmentation allows each component to be optimized independently - the lever and springs provide ease of operation, while the stop provides safety without requiring complex interconnections

Inventive Principle:
Principle #1Segmentation

3Ease of operation

If the lever is allowed to move freely to ensure easy operation, then the ease of operation is improved, but the reliability of maintaining closed position is reduced

Engineering Contradiction:
Improveease of lever movementVSAvoidreliability of closed position maintenance
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The stop mechanism provides beforehand cushioning by limiting the lever's movement range before it can compromise the closed position. The lever can still move freely within its operational range for ease of operation, but the stop prevents it from moving beyond the closed position, thus maintaining reliability without restricting necessary movement

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

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 provides enhanced safety by ensuring the coupler remains securely attached to the tool, reducing the risk of accidental release and falls, even under failure of locking components.

Implementation Method 1

the locking means comprise at least one spring, in particular two springs, which is/are fixed on the one hand to the body of the coupler, in particular a rear part of the body of the coupler, and on the other hand to a front end part of the lever

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

a lever mounted to move between a closed position in which it holds the journal or one of the journals in the rear receiving cavity and an open position in which it does not hold the journal

Methodology Applied
Scientific EffectMechanical Advantage: Mechanical Advantage

Data Source

PatentEP4636168A1Quick coupler for construction machines
Publication Date: 2025.10.22 KLAC IND SA
  • EP4636168A1 patent drawingFigure 1~2
  • EP4636168A1 patent drawingFigure 3~4
  • EP4636168A1 patent drawingFigure 5~6

AI summary

Coupler device comprising a coupler, or quick coupler, intended to be secured to a public works machine, such as an excavator, a connection device, intended to be secured to a tool, such as a bucket, coupling means intended to couple the quick coupler to the connection device and locking means intended to lock the coupling; the connection device comprising at least one trunnion, preferably two trunnions, in particular parallel to each other;the coupler comprising a base body in which is defined a rear receiving cavity of the or one of the journals, characterized in that it comprises a lever pivotally mounted between a closed position in which it holds the journal or one of the journals in the rear receiving cavity and an open position in which it does not hold the journal, the locking means being arranged to block or prevent rotation of the lever in the closed position.;