Excavator Tool Coupling Sleeve Lock for Fast Tool Changes

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Solution Overview

Problem

The process of removing and replacing work tools from arm assemblies on machines like hydraulic excavators is time-consuming and difficult, with quick couplers adding weight and compromising machine capabilities.

Innovation Solution

An apparatus with a coupling system featuring a pin member and actuator that moves between retracted and extended positions, assisted by a locking sleeve to securely engage and disengage work tools with arm assemblies, allowing for efficient tool exchange without altering the machine's weight or length.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of time

If quick couplers are used to enable quick engagement of work tools, then the time required for tool replacement is reduced, but the weight of the stick end increases and the stick height/length is increased

Engineering Contradiction:
Improvetool replacement timeVSAvoidstick end weight
Core Design Contradiction:
Loss of timeVSWeight of moving object

Solution Approach 1:

The coupling system is divided into separate components: a coupling body mounted on the stick, a tool engagement means on the work tool, and a locking mechanism. This segmentation allows the stick itself to remain lightweight while the coupling components are distributed and optimized independently, reducing the overall weight penalty compared to a single integrated quick coupler assembly.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The locking mechanism is positioned within or around the coupling body, with the locking sleeve or latch mechanism nested within the coupling assembly. This nesting allows the locking components to occupy space within the existing coupling structure rather than adding external bulk, thereby minimizing increases in stick height and length while providing secure tool engagement.

Inventive Principle:
Principle #7Nested doll (Nesting)

2Ease of operation

If quick couplers are used to enable quick engagement of work tools, then the effort required for removing and replacing tools is reduced, but the stick height/length is increased

Engineering Contradiction:
Improvetool replacement effortVSAvoidstick height/length
Core Design Contradiction:
Ease of operationVSLength of stationary object

Solution Approach 1:

The manual mechanical coupling process is replaced with a system that uses hydraulic actuators or spring-loaded locking mechanisms to automatically engage and secure the tool. This substitution reduces the physical effort required by the operator while the compact design of the actuator and locking mechanism minimizes the increase in stick dimensions.

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

Solution Approach 2:

The coupling system incorporates movable components such as a retractable coupling member or a spring-loaded locking mechanism that dynamically adjusts during the engagement process. This allows the system to provide full locking force only when needed, maintaining a compact profile during storage or transport while enabling easy tool replacement during operation.

Inventive Principle:
Principle #15Dynamics

3Reliability

If a locking mechanism is added to prevent accidental detachment of the work tool, then the reliability of the coupling is improved, but the device complexity is increased

Engineering Contradiction:
Improvecoupling reliabilityVSAvoidcoupling system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The locking mechanism is designed to automatically engage and lock when the tool is inserted into the coupling body, using spring-loaded latches or over-center locking mechanisms that self-actuate upon engagement. This self-service approach ensures reliable tool retention without requiring additional control systems, sensors, or complex actuation mechanisms, thereby maintaining simplicity while improving reliability.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The locking mechanism is integrated into the coupling body structure, with the locking components combined with the existing coupling elements rather than being separate additions. For example, the locking sleeve may be part of the coupling body, or the locking latches may be incorporated into the tool engagement means, merging multiple functions into unified components and reducing overall system complexity.

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP3173535B1Apparatus and method for coupling work tool to a machine
Publication Date: 2021.09.08 CATERPILLAR WORK TOOLS
  • EP3173535B1 patent drawingFigure 1
  • EP3173535B1 patent drawingFigure 2
  • EP3173535B1 patent drawingFigure 3

AI summary

An apparatus for coupling a work tool to an arm assembly of a machine is disclosed. The work tool includes first and second tool engagement means and the arm assembly comprising first and second arms. The apparatus includes a first coupling means adapted to engage with the first arm and the first tool engagement means; and a second coupling means adapted to engage with the second arm and the second tool engagement means. The apparatus further includes an actuator coupled to and arranged to move the first and second coupling means between a retracted position and an extended position. Further a locking sleeve is mounted at least partially around the actuator. The locking sleeve is moveable into a locked position to prevent the first and second coupling means from moving into the retracted position from the extended position.