Excavator Pin Grabber Quick Coupler Coaxial Actuation

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Solution Overview

Problem

Existing tool coupler assemblies for machines like excavators and backhoes often add weight and cost due to offset designs, which can reduce breakout forces and increase tip radius, limiting their versatility and functionality.

Innovation Solution

A tool coupler assembly with a power linkage actuator featuring clevis-type collars with notch openings for engaging pins, allowing for quick and secure connection of tools, and maintaining engagement through arcuate tongue and groove configurations for slidable coaxial rotation, enabling efficient tool switching without disengagement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If an offset design is used in the tool coupler assembly, then the tool can be securely connected to the linkage, but the tip radius increases and breakout forces decrease

Engineering Contradiction:
Improvesecure connectionVSAvoidtip radius
Core Design Contradiction:
ReliabilityVSLength of moving object

Solution Approach 1:

Instead of offsetting the pin positions relative to the frame (conventional approach), the patent inverts the approach by positioning the pins coaxially with the tool pivot axis and using a power linkage actuator that rotates coaxially about the same axis. This inversion eliminates the offset design while maintaining secure connection through the coaxial power linkage actuator that engages both pins simultaneously.

Inventive Principle:
Principle #13The other way round (Inversion)

2Reliability

If an offset design is used in the tool coupler assembly, then the tool can be securely connected to the linkage, but the breakout forces are reduced

Engineering Contradiction:
Improvesecure connectionVSAvoidbreakout forces
Core Design Contradiction:
ReliabilityVSForce

Solution Approach 1:

The patent inverts the conventional offset design by using coaxial pin positioning and a coaxially rotating power linkage actuator. This inversion allows the actuator to apply force directly along the coaxial axis, maximizing breakout forces by eliminating the mechanical disadvantage introduced by offset designs.

Inventive Principle:
Principle #13The other way round (Inversion)

Solution Approach 2:

The patent merges the rotation axis of the power linkage actuator with the tool pivot axis, creating a coaxial configuration. This merging of axes allows the actuator to efficiently transmit force to both pins simultaneously, maximizing breakout forces while maintaining secure connection.

Inventive Principle:
Principle #5Merging (Combining)

3Adaptability or versatility

If a traditional tool coupler assembly with frame and hooks is used, then tools can be connected to the machine, but the weight and cost increase

Engineering Contradiction:
Improvetool interchangeabilityVSAvoidcoupler assembly weight
Core Design Contradiction:
Adaptability or versatilityVSWeight of moving object

Solution Approach 1:

The power linkage actuator serves multiple functions: it acts as both the connection mechanism and the locking mechanism, eliminating the need for separate hooks and latches. This multi-functionality reduces the number of components, thereby reducing weight and cost while maintaining tool interchangeability.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent combines the functions of the frame, hooks, and locking mechanism into a single integrated power linkage actuator system. By merging these separate components into one, the overall weight and cost of the coupler assembly are reduced while maintaining the ability to interchange tools.

Inventive Principle:
Principle #5Merging (Combining)

4Productivity

If quick coupling is implemented without proper locking mechanism, then tool changing speed increases, but connection reliability decreases

Engineering Contradiction:
Improvetool changing speedVSAvoidconnection reliability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The power linkage actuator automatically locks into position when rotated to engage the pins, using its own rotational motion to create the locking action. This self-service locking mechanism ensures connection reliability without requiring separate locking components or additional manual operations, maintaining quick tool changing speed.

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP3241949B1Integrated excavator pin grabber quick coupler
Publication Date: 2021.06.02 CATERPILLAR INC
  • EP3241949B1 patent drawingFigure 1
  • EP3241949B1 patent drawingFigure 2
  • EP3241949B1 patent drawingFigure 3

AI summary

A tool coupler assembly (40) may include a power linkage assembly, and the power linkage assembly may include a first power link (31). The first power link (31) may include a first end configured for pivotal connection to a tool (18), and a second, opposite end configured for pivotal connection to one end of a tool control actuator (30). The tool control actuator (30) may be connected at an opposite end to a first end of a tool support member (24) of a machine (10), wherein operation of the tool control actuator (30) pivots the tool (18) about a tool pivot axis (32) coaxial with a tool engagement interface (23) at a second end of the tool support member (24). A power linkage actuator (70) may be pivotally connected at a first end (78) for coaxial rotation with the tool engagement interface (23) at the second end of the tool support member (24), and at a second end (76) for coaxial rotation with the first end of the first power link (31).