Quick Coupler Over-Center Latching System

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing quick couplers for machines like excavators face issues with unexpected disconnection due to hydraulic failure, requiring additional safety measures like compression springs or manual locking pins to prevent latching issues.

Innovation Solution

The implementation of an over-center latching system in a quick coupler assembly that ensures latches remain locked even if the actuator fails, eliminating the need for compression springs and manual locking pins by using a frame with recesses and notches, securing latches, and a rocker assembly to maintain the latched position.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If compression springs are added to prevent piston retraction during hydraulic failure, then reliability is improved, but device complexity increases

Engineering Contradiction:
Improvelatching reliabilityVSAvoidcoupler complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent removes the compression spring from the system entirely. Instead of adding a spring to prevent piston retraction, the design uses the inherent mechanical advantage of the over-center latching mechanism and the rocker assembly to maintain the latched position even during hydraulic failure, thereby improving reliability without increasing complexity

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The system uses its own structural geometry (the over-center latching mechanism with rocker assembly) to provide the safety function that would otherwise require an external component like a compression spring. The latching mechanism itself ensures that once latched, it remains latched during hydraulic failure without needing additional active components

Inventive Principle:
Principle #25Self-service

2Reliability

If manual locking pins are installed to prevent latch movement during hydraulic failure, then reliability is improved, but ease of operation deteriorates

Engineering Contradiction:
Improvelatching reliabilityVSAvoidcoupler operation
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The over-center latching mechanism with rocker assembly is self-securing. Once the latches engage the pins, the mechanical geometry automatically prevents unintended unlatching during hydraulic failure, eliminating the need for manual locking pins and maintaining ease of operation

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The latching mechanism is designed so that the latched position is inherently stable and self-maintaining through the over-center geometry. This preliminary mechanical configuration ensures that no additional manual action is needed to secure the latches against hydraulic failure

Inventive Principle:
Principle #10Preliminary action

3Reliability

If over-center latching system with rocker assembly is implemented, then device complexity increases, but reliability improves

Engineering Contradiction:
Improvelatching reliabilityVSAvoidlatching system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines the over-center latching mechanism and the rocker assembly into a single integrated system. The rocker assembly serves dual purposes: it provides the mechanical advantage for latching and simultaneously acts as the safety mechanism that prevents unintended unlatching, merging multiple functions into one component to minimize overall complexity

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP2167738B1Quick coupler assembly for connecting an implement to an arm of a machine
Publication Date: 2014.05.14 CATERPILLAR INC
  • EP2167738B1 patent drawingFigure 1
  • EP2167738B1 patent drawingFigure 2
  • EP2167738B1 patent drawingFigure 3

AI summary

A quick coupler (10) for connecting and disconnecting an implement (2) such as a bucket to and from a machine such as an excavator. In an example, the quick coupler includes a frame (12) having recesses (30, 32) configured to receive pins (5, 5') located on the implement. The quick coupler includes first and second securing latches (42, 44) that are movable between latched and unlatched positions for removably latching the pins of the implement in the recesses. A rocker assembly (48) and a connector link (50) are provided for moving the second latch (44) between latched and unlatched positions.