Pin Grabber Coupler Tertiary Lock for Secure Tool Attachment

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Solution Overview

Problem

Existing pin grabber couplers face challenges in securely connecting tools with level tool pins or shifted center of gravity, especially when the tool or machine is positioned unfavorably.

Innovation Solution

The pin grabber coupler incorporates a frame with a hook, a secondary lock assembly, and a tertiary lock. The tertiary lock is triggered by the tool pin entering the concavity, automatically locking onto the tool before engaging the secondary and primary locks, ensuring secure attachment without slipping.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a traditional pin grabber coupler is used, then the coupling process can be completed remotely, but tools with level pins or shifted center of gravity may slip out during the locking process

Engineering Contradiction:
Improveremote coupling capabilityVSAvoidtool retention security
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The coupler jaw is pre-positioned in an open state ready to receive the tool pin, and the locking mechanism is pre-configured to engage automatically once the pin is inserted. This preliminary preparation ensures that as soon as the tool is hooked, the locking action follows immediately without requiring additional manual intervention, preventing tools with level pins or shifted center of gravity from slipping out during the locking process.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If the coupler jaw is designed to fully curl up to the locking position, then secure locking is achieved, but tools positioned at unfavorable orientations or positions become difficult to couple

Engineering Contradiction:
Improvelocking securityVSAvoidcoupling difficulty
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The coupler jaw is designed with dynamic movement capability, allowing it to curl up fully to the locking position when needed. The jaw can adjust its position and orientation dynamically during the coupling process to accommodate tools at various orientations and positions. This dynamic adjustment ensures that even tools in unfavorable positions can be securely locked once the jaw curls up to the correct locking position.

Inventive Principle:
Principle #15Dynamics

3Reliability

If multiple locking mechanisms are added to prevent tool slippage, then tool retention is improved, but the device complexity increases

Engineering Contradiction:
Improvetool retentionVSAvoidcoupler structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The locking mechanism is merged with the jaw structure itself, where the jaw serves dual functions: both as the gripping element that curls up to lock the tool pin and as part of the locking mechanism. The blocking member is integrated into the jaw assembly, eliminating the need for separate, independent locking components. This merging approach maintains high tool retention reliability while avoiding excessive device complexity.

Inventive Principle:
Principle #5Merging (Combining)

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 configuration allows for secure and efficient attachment of tools with varying orientations and positions, reducing the risk of tools slipping out during the locking process.

Implementation Method 1

a bias member and a detent. The bias member may be disposed on the pivot axis P and may be configured to exert a biasing force on the tertiary lock to urge the tertiary lock to the locked TL position

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

The detent is configured to exert, when in the hold position, a holding force against the latch that is greater than the biasing force exerted by the bias member

Methodology Applied
Scientific EffectSpring force: Spring

Data Source

PatentEP4374013B1Pin grabber coupler
Publication Date: 2025.05.21 CATERPILLAR SARL
  • EP4374013B1 patent drawingFigure 1
  • EP4374013B1 patent drawingFigure 2
  • EP4374013B1 patent drawingFigure 3

AI summary

A pin grabber coupler (122) and method for locking and unlocking a tool (124) to a machine (100) is disclosed. The pin grabber coupler (122) may comprise a tertiary lock (148) configured to pivot between an unlocked TL position (198) and a locked TL position (196). The tertiary lock (148) may include a first and second shoulders (200, 202), a leg (204), a tab (206), a latch (208), a bias member (210) and a detent (212). The bias member (210) may be configured to exert a biasing force on the tertiary lock (148) to urge the tertiary lock (148) to the locked TL position (196). The detent (212) may be configured to exert, when in a hold position (214), a holding force against the latch (208) that is greater than the biasing force exerted by the bias member (210). When the detent (212) is in a release position (216), the holding force applied by the detent (212) against the latch (208) is less than the biasing force applied by the bias member (210).