Energy Dissipating Touch Fastener Links for Fall Arrest
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current energy dissipating devices used in fall prevention systems, such as safety lines for rock and wall climbing, often subject climbers to injurious arresting forces due to abrupt halting of free falls, as they rely on discrete connection points that break or tear under tensile force, leading to uneven energy dissipation and potential shock during disengagement.
Innovation Solution
The development of an energy dissipating link featuring elongated bases with permanently coupled touch fasteners that form a releasable closure with a shear plane, allowing for continuous and controlled disengagement under tensile overload, utilizing hundreds or thousands of re-engagable fastening elements to distribute and dissipate kinetic energy smoothly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If discrete connection points are used to dissipate energy by breaking or tearing under tensile force, then kinetic energy can be dissipated, but injurious arresting forces and shocks are generated due to abrupt and uneven energy dissipation
Solution Approach 1:
The energy dissipating device is segmented into multiple discrete connection points (stitches, welds, or attachment points) distributed along the webbing. Each connection point acts as an independent energy dissipation element that can fail separately, distributing the energy dissipation process across multiple locations rather than a single point, thereby reducing peak forces and shocks.
Solution Approach 2:
The device transitions from a static structure to a dynamic energy dissipation system where connection points progressively fail under tensile load. The sequential breaking or tearing of discrete connection points creates a controlled dynamic response that extends the energy dissipation time, reducing the rate of force application and minimizing abrupt arresting forces.
2Loss of energy
If folded and overlapping flexible material is used with discrete connection points, then energy dissipation is achieved, but the disengagement process is abrupt and creates shock
Solution Approach 1:
The closure system is segmented into multiple discrete connection points along the webbing. This segmentation allows the disengagement process to occur progressively at each connection point rather than all at once, creating a smoother, more controlled release that reduces shock and improves the ease of operation during energy dissipation events.
3Reliability
If conventional energy dissipators are used, then fall protection is provided, but the arresting force on the climber is injurious due to abrupt halting
Solution Approach 1:
The device employs dynamic energy dissipation through sequential failure of discrete connection points, extending the duration of the arresting process. This dynamic approach transforms the abrupt, high-force halt into a more gradual force application, maintaining fall protection reliability while reducing peak arresting forces to non-injurious levels.
Solution Approach 2:
The device converts the potentially harmful abrupt arresting force into a beneficial controlled energy dissipation process. By designing discrete connection points to fail in a controlled manner, the harmful sudden stop is transformed into a progressive energy absorption mechanism that protects the climber from injurious forces while maintaining effective fall arrest.
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
This solution effectively reduces the maximum arrest force experienced by climbers by ensuring a smooth and continuous disengagement of fastening elements, minimizing perceived shocks and maintaining consistent shear strength throughout the energy-dissipating process, thereby enhancing safety and comfort during fall arrests.
Implementation Method 1
the engaged touch fasteners loaded in shear in the shear plane... energy-dissipating shear disengagement of the first and second touch fasteners by a tensile overload
Data Source
Figure 1A~1B
Figure 2A~2B
Figure 3~4
AI summary
An energy dissipating link (200) includes: an elongated base (202) having first (204) and second (206) end portions; a first touch fastener (208a) permanently coupled to the base proximate the first base end portion; and a second (208b) touch fastener permanently coupled to the base proximate the second base end portion. The second touch fastener (208b) is engageable with the first touch fastener (208a) to form a releasable closure (212) defining a shear plane (214). With the first (208a) and second (208b) touch fasteners engaged to transmit a tensile load between the first (204) and second (206) end portions, and with the engaged touch fasteners loaded in shear, the base (202) includes a longitudinally slack idler section (216) between the first and second end portions. The idler section (216) is configured to transmit tensile load upon an energy-dissipating shear disengagement of the first (208a) and second (208b) touch fasteners.