Power Tool Tethering Attachment with Energy-Absorbing Coil

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Solution Overview

Problem

Conventional power tools lack adequate locations for tethering attachments, leading to inadequate protection against kinetic energy transfer during falls, which can damage internal components even without direct impact.

Innovation Solution

A tethering attachment assembly featuring a resilient metallic coil element with a U-shaped hook design, covered by a sleeve that tears to expose the coil upon excessive force, providing energy absorption and notification of potential damage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a conventional lanyard is attached directly to the tool handle, then the tool can be tethered, but the kinetic energy from a fall is transferred directly to the tool housing causing damage

Engineering Contradiction:

Improvetool protectionVSAvoidkinetic energy transfer

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent incorporates an energy-absorbing mechanism (coil spring) into the tethering attachment assembly that is pre-configured to absorb kinetic energy during a fall event. This cushioning element is positioned between the lanyard attachment point and the tool housing, so that when a fall occurs, the spring compresses to absorb the impact energy before it can be transferred to the tool housing, thereby protecting internal components from damage

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

2Stability of the object's composition

If the coil element is made resilient to retain its state under force, then it provides consistent tethering, but it cannot absorb excessive energy from high falls

Engineering Contradiction:

Improvecoil element stateVSAvoidenergy absorption capacity

Core Design Contradiction:

Stability of the object's compositionVSLoss of energy

Solution Approach 1:

The patent designs the coil spring with specific material and geometric parameters that allow it to exhibit resilient behavior under normal operating forces while reaching a plastic deformation threshold under excessive force. The spring is engineered with controlled wire diameter, coil diameter, and number of turns to create a force-deflection curve that provides stable tethering during normal use but transitions to permanent deformation when the force exceeds the energy absorption capacity, thereby indicating a fall event has occurred

Inventive Principle:

Principle #35Parameter changes

3Loss of information

If the coil element is permanently deformable upon excessive force, then it can indicate fall damage, but it loses its tethering function

Engineering Contradiction:

Improvefall detectionVSAvoidtethering function

Core Design Contradiction:

Loss of informationVSReliability

Solution Approach 1:

The patent accepts that permanent deformation of the coil spring is an inevitable consequence of absorbing excessive fall energy, but converts this harmful effect into a beneficial indicator function. The permanent deformation serves as a visible indicator to the user that a fall event has occurred and the tethering attachment may be compromised. This allows the system to provide both energy absorption and fall detection functions, with the deformed spring state communicating critical information about the tool's safety status

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

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

Effectively absorbs kinetic energy during falls, protecting the tool and notifying the user of potential damage through permanent deformation of the coil element.

Implementation Method 1

a coil element including metallic material that substantially resiliently retains its state with application of force up to a limit, and is permanently plastically deformable upon application of force exceeding the limit

Methodology Applied

Scientific EffectElasticity: Elasticity

Implementation Method 2

Methodology Applied

Scientific EffectPlasticity: Plasticity

Data Source

PatentUS10136722B1Impact-absorbing tethering attachment

Publication Date: 2018.11.27 BLACK & DECKER CORP

AI summary

A power tool is provided with a housing and a tethering attachment assembly attached to the housing and adapted to facilitate connection of a lanyard to the power tool. The tethering attachment assembly includes a substantially U-shaped hook portion including a coil element comprising metallic material that substantially resiliently retains its state with application of force up to a limit, and is permanently plastically deformable upon application of force exceeding the limit, and two extended portions extending from ends of the coil element and attached to the housing.