Motor Grader Bit Retention Lock for Square-Drive Attachment

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Solution Overview

Problem

Existing retention systems for attaching work tools or wear members to motor graders and similar equipment do not allow the use of a square driver and require excessive material, making them inefficient and costly.

Innovation Solution

A retention system that includes a lock and retainer assembly with a shank receiving aperture and a lock receiving aperture, allowing rotation of the lock to secure the work tool or wear member using a square driver, minimizing material usage and allowing for easy attachment and detachment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a pin retention system is used to attach work tools to the adaptor board, then the work tool can be held securely, but the adaptor board requires excessive material and width to accommodate the pin through the shank

Engineering Contradiction:

Improvesecure attachment of work toolVSAvoidadaptor board material

Core Design Contradiction:

ReliabilityVSWeight of stationary object

Solution Approach 1:

The patent extracts the pin from the retention system and replaces it with a lock mechanism that rotates within a lock receiving aperture. This eliminates the need for a thru-hole through the shank and reduces the adaptor board width requirement while maintaining secure attachment capability

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

Instead of passing a pin through the shank from one side to the other, the invention inverts the approach by having the lock rotate within a confined aperture in the adaptor board, engaging the shank from a single side and eliminating the need for excessive board width

Inventive Principle:

Principle #13The other way round (Inversion)

2Ease of manufacture

If a pin retention system is used, then the work tool can be attached, but a square driver cannot be used for attachment

Engineering Contradiction:

Improveattachment capabilityVSAvoidcompatibility with square driver

Core Design Contradiction:

Ease of manufactureVSAdaptability or versatility

Solution Approach 1:

The lock mechanism incorporates a drive portion with a square drive interface that accepts a square driver, making the attachment system universal and compatible with commonly available tools in the field while maintaining secure attachment capability

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Ease of operation

If the adaptor board is made wider to accommodate the pin system, then the pin can fit through the shank, but more material is required

Engineering Contradiction:

Improvepin insertion capabilityVSAvoidadaptor board material

Core Design Contradiction:

Ease of operationVSQuantity of substance

Solution Approach 1:

The lock mechanism is nested within a lock receiving aperture in the adaptor board, with the lock rotating within confined spaces. This nesting approach allows pin insertion capability through a compact design that minimizes adaptor board material while maintaining functionality

Inventive Principle:

Principle #7Nested doll (Nesting)

Data Source

PatentUS11414842B2Retention system for motor grader bits

Publication Date: 2022.08.16 CATERPILLAR INC

AI summary

A work tool or a wear member includes a working portion or a wear portion, and a shank extending from the working portion or the wear portion, defining a longitudinal axis, and a first lock receiving groove that defines an axis of rotation that is perpendicular to the longitudinal axis of the shank.