Retractable Tool Tether Locking for Fall Impact Damping

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Solution Overview

Problem

Existing equipment securing devices for portable tools are cumbersome, prone to entanglement, and expose users to high impact forces during falls, with limited user-friendliness and inadequate protection against drops.

Innovation Solution

A locking mechanism with a control raceway element, freewheel, and concentric guide tracks allows for easy extension and retraction of the pulling element, featuring a locking element that locks in any desired position and includes a predetermined breaking point for damping impact forces.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a loose pulling element is attached to secure equipment against falls, then equipment protection is provided, but the pulling element becomes entangled and creates safety hazards

Engineering Contradiction:
Improveequipment protectionVSAvoidentanglement hazard
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent extracts the harmful loop configuration from the pulling element by introducing a reel mechanism that collects and secures the pulling element in a compact form, eliminating the entanglement hazard while preserving the fall protection function

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent applies a dynamic retractable mechanism where the pulling element can be automatically retracted into the housing when not in use, transitioning from a static loose configuration to a dynamic system that adapts its state based on operational needs

Inventive Principle:
Principle #15Dynamics

2Object-affected harmful factors

If a retractable safety line with reel is used to prevent entanglement, then safety hazards are reduced, but the device becomes more complex

Engineering Contradiction:
Improveentanglement hazardVSAvoidreel mechanism
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The patent merges the reel mechanism with the existing housing structure, integrating the retraction function into the housing rather than adding a separate complex reel assembly, thus reducing overall device complexity while maintaining the safety function

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent implements a self-retracting mechanism where the pulling element is automatically retracted into the housing through the action of the return element and guide tracks, eliminating the need for manual operation or complex control systems

Inventive Principle:
Principle #25Self-service

3Ease of operation

If a locking mechanism is added to secure the pulling element, then user freedom of movement is improved, but the mechanism becomes more complex and less user-friendly

Engineering Contradiction:
Improveuser freedom of movementVSAvoidlocking mechanism
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent implements a self-locking mechanism where the locking element automatically engages with the guide tracks when the pulling element is extended, and automatically disengages when retracted, eliminating the need for manual locking operations and reducing complexity

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent applies a dynamic locking mechanism where the locking element transitions between engaged and disengaged states based on the operational state of the pulling element, providing automatic locking during extension and automatic unlocking during retraction

Inventive Principle:
Principle #15Dynamics

4Reliability

If rigid connection is used to secure equipment, then fall protection is provided, but impact forces cause injury to user and equipment

Engineering Contradiction:
Improvefall protectionVSAvoidimpact force injury
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent introduces a predetermined breaking point in the pulling element that is designed to fail at a controlled manner during impact events, absorbing excess kinetic energy before it can reach the user or equipment, thus providing beforehand cushioning against impact forces

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

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 device provides robust, user-friendly protection against falls with minimal user restriction, damping impact forces, and ensures secure equipment use without complex locking mechanisms.

Implementation Method 1

a return element (11) arranged between the housing (1, 2) and the roller (7), which exerts a restoring force on the roller (7)

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

a locking element (8) engaging in the control raceway element (9), guided in the guide tracks (25, 36) and the control guide track (27) and/or along the ramps (22) of the control raceway element (9)

Methodology Applied
Scientific EffectMechanical constraint: Mechanical Force

Implementation Method 3

at least one predetermined breaking point (32) or a damping element in the area of the end of the pulling element (4) that is attached to the roller (7), which absorb the impact forces and thus dampen the fall in the area of the pulling element (4) attached to the roller (7)

Methodology Applied
Scientific EffectEnergy absorption: Damping

Data Source

PatentEP4728928A2Equipment preservation device for portable equipment
Publication Date: 2026.04.22 REELOQ GMBH
  • EP4728928A2 patent drawingFigure 1~2
  • EP4728928A2 patent drawingFigure 3~4
  • EP4728928A2 patent drawingFigure 5~6

AI summary

The invention relates to an equipment securing device (100) for portable equipment, in particular portable tools, comprising: - a housing in which a roller (7) and a return element (11) are arranged, wherein the roller (7) is arranged in the housing and is rotatably mounted relative to the housing; - a tensioning element (4) for securing equipment, wherein the tensioning element (4) is fully wound onto the roller (7) in an initial state and one end of the tensioning element (4) protrudes from the housing; - wherein the return element (11) is arranged between the housing and the roller (7) such that the return element (11) exerts a tensile force on the roller (7) in the direction of the interior of the housing, so that the tensioning element (4) can be wound onto the roller (7); - wherein the tensioning element (4) is wound onto the roller (7) when a tensile force directed away from the housing is applied to the tensioning element (4) that is greater than the force exerted by the return element (11) on the roller (7).up to an end position in which the pulling element (4) is completely unwound from the roller (7), is unrollable and can be extended from the housing relative to it, and wherein the pulling element (4) has at least one predetermined breaking point for fall damping in the area of ​​its end fixed to the roller (7), wherein the predetermined breaking point is designed to absorb the tensile force acting on the pulling element (4) after the pulling element (4) has reached the end position and thus dampen the fall when a tensile force exceeding a predetermined force threshold is applied to the pulling element (4) directed away from the housing.