Tool Coupling Arrangement Using Bent Pin Fastening

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Solution Overview

Problem

Current methods for joining a handle and a tool head, such as press-fit or epoxy adhesive, face issues with precision requirements and durability due to material expansion, shrinkage, or degradation, leading to a compromised connection.

Innovation Solution

A coupling assembly comprising a plug member, a ferrule, and a pin member, where the plug member has an elongated passage for the tool head shank, and the ferrule has aligned openings, with the pin member extending through and bent to secure the shank, minimizing the need for tight manufacturing tolerances and enhancing durability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a press-fit method is used to join the tool head shank to the handle, then the connection is initially secure, but the connection reliability deteriorates over time due to wood absorption, shrinkage, or rot

Engineering Contradiction:

Improveconnection reliabilityVSAvoidconnection duration

Core Design Contradiction:

ReliabilityVSDuration of action of stationary object

Solution Approach 1:

The patent introduces a metal insert as an intermediary component between the tool head shank and the wooden handle. This metal insert serves as a stable mediator that does not absorb moisture or rot like wood, thereby maintaining connection reliability over time while the wooden handle undergoes environmental changes

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent anticipates future deterioration of the wooden handle by pre-installing a metal insert that will maintain its dimensions and strength over time. This beforehand cushioning ensures that even when the wood degrades, the critical connection point remains stable and reliable

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

2Reliability

If a press-fit method is used to join the tool head shank to the handle, then the initial connection is secure, but manufacturing precision requirements increase due to the need for proper cross-sectional area relationship

Engineering Contradiction:

Improveconnection securityVSAvoidbore diameter and shank cross-sectional area relationship

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The metal insert acts as an intermediary that standardizes the connection interface. Instead of requiring precise fitting between the shank and wooden handle, the insert provides a standardized recess that receives the shank, significantly reducing manufacturing precision requirements

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent changes the material parameter from wood to metal for the connection component. This parameter change allows for more consistent dimensional tolerances and easier manufacturing, as metal can be precisely formed and maintains its dimensions better than wood

Inventive Principle:

Principle #35Parameter changes

3Strength

If a nail or rivet fastener is used to join the handle and tool head, then the connection is mechanically secure, but durability is compromised due to introduction through the wood handle

Engineering Contradiction:

Improvemechanical connection strengthVSAvoidtool durability

Core Design Contradiction:

StrengthVSReliability

Solution Approach 1:

Instead of driving fasteners through the wooden handle (outside-in), the patent inverts the approach by installing the metal insert from the inside of the handle, creating a recess that receives the tool head shank. This inversion eliminates the need to penetrate the wooden handle with fasteners

Inventive Principle:

Principle #13The other way round (Inversion)

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

The solution provides a secure and durable connection that is less prone to failure due to material changes, as the ferrule is crimped onto the plug member, ensuring the tool head is retained effectively, and the handle is frictionally secured, improving the overall reliability of the assembly.

Implementation Method 1

the ferrule is crimped onto the plug member, ensuring the tool head is retained effectively

Methodology Applied

Scientific EffectCrimping: Deformation

Implementation Method 2

The ends of the pin member are bent at an angle to an axis extending through the elongated passage to secure the tool head shank to the plug member and ferrule

Methodology Applied

Scientific EffectBending: Deformation

Implementation Method 3

the handle is frictionally secured, improving the overall reliability of the assembly

Methodology Applied

Scientific EffectFriction: Friction

Data Source

PatentUS10307905B2Tool coupling arrangement

Publication Date: 2019.06.04 THE IAMS CO

AI summary

A coupling for an elongated handle and a tool head is disclosed. The coupling includes a plug member, a ferrule, and a pin member. The plug member further comprises an elongated passage formed therein receives a tool head shank of the tool head. The elongated passage is in communication with a pair of aligned plug member openings formed through the plug member. The ferrule includes a pair of aligned ferrule openings. When the plug member is partially received within the ferrule, the plug member openings align with the ferrule openings. The pin member extends through the aligned ferrule openings and the plug member openings and through an opening of the tool head shank when the tool head shank is mounted in the elongated passage. The ends of the pin member are bent at an angle to an axis extending through the elongated passage to secure the tool head shank to the plug member and ferrule.