Retracting Lifeline System with Abrasion-Resistant Tie-Back Anchoring
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Solution Overview
Problem
Current retracting lifeline systems face issues with sudden stop forces during falls, which can cause injury, and have a substantial length of lifeline outside the housing that creates tripping hazards and undesirable free fall distances, especially when tie-back anchoring is used.
Innovation Solution
A retracting lifeline system with a lifeline that has an initial ultimate tensile load of at least 8000 pounds, is abrasion-resistant, and can be fully retracted within the housing, featuring an energy-absorbing system and a stop mechanism to prevent further retraction, allowing tie-back anchoring at any point without the need for a protective sleeve, reducing tripping hazards.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a substantial length of lifeline is maintained outside the housing to enable tie-back anchoring, then tie-back capability is improved, but tripping hazards and free fall distance increase
Solution Approach 1:
The lifeline is nested within the housing when not in use, with only a minimal necessary length extending outward. The lifeline can be fully retracted into the housing and deployed as needed, eliminating the need for a substantial permanent external length while maintaining tie-back capability when required.
Solution Approach 2:
The system transitions from a static configuration with fixed external lifeline length to a dynamic system where the lifeline length outside the housing can be adjusted. The lifeline can be retracted fully or extended as needed, allowing the external length to change based on operational requirements rather than being fixed at a substantial length.
2Reliability
If high-strength materials and braking mechanisms are used to stop falls, then fall arrest capability is improved, but sudden stop forces causing injury increase
Solution Approach 1:
An energy absorbing mechanism is incorporated into the system that activates during fall arrest to cushion the sudden stop. This mechanism absorbs impact energy and extends the deceleration time, reducing the peak forces transmitted to the user while maintaining reliable fall arrest capability.
3Strength
If a protective sleeve is used to encase the lifeline for tie-back, then abrasion resistance is improved, but the sleeve prevents retraction into the housing
Solution Approach 1:
Instead of enclosing the entire lifeline in a protective sleeve, abrasion resistance is provided only at the specific location where the lifeline exits the housing and is subject to wear. This localized protection allows the rest of the lifeline to remain flexible and fully retractable into the housing while still providing protection where needed.
Solution Approach 2:
The protective feature is segmented from the entire lifeline length and applied only to the specific section requiring protection. This allows different portions of the lifeline to have different properties - the exit section has enhanced abrasion resistance while the remainder maintains full retraction capability.
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 system effectively absorbs fall energies, reduces the risk of injury from sudden stops, and eliminates tripping hazards by allowing secure tie-back anchoring without external lifeline lengths, enhancing user safety and mobility.
Implementation Method 1
The system effectively absorbs fall energies, reduces the risk of injury from sudden stops
Data Source
AI summary
A retracting lifeline system, includes: a housing, a first connector attached to the housing, a lifeline, and a hub to which the lifeline is attached at a first end of the lifeline and around which the lifeline is coiled within the housing. The housing includes an opening through which the lifeline exits the housing. The hub is tensioned to rotate in a first direction to cause retracting of the lifeline and coiling of the lifeline around the hub. The retracting lifeline system further includes a second connector attached to a second end of the lifeline. At least a section of the lifeline has an initial ultimate tensile load of at least 8000 pounds and is abrasion resistant (that is, satisfying the abrasion test requirement set forth in the ANSI/ASSE Z359.13 2009 standard) such that the section of the lifeline is available for tie-back anchoring using the second connector. The section of the lifeline is at least partially retractable within the housing.