Fall Protection Post with Dynamic Lifeline Height Adjustment
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Solution Overview
Problem
Existing fall protection systems face challenges in minimizing torque and damage to structures during falls, as they often result in high torque forces that can cause posts to tilt or tip over, leading to inadequate force absorption and increased risk of injury or equipment damage.
Innovation Solution
A post system with a connector to a structure and a support maintaining a lifeline at a first height, which lowers to a second height upon experiencing a threshold force, featuring a moveable member and an energy absorber with a metal strap that deforms and tears to absorb energy, reducing the effective length change ratio (ΔL/ΔH) to less than 1, thereby minimizing torque and damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the lifeline is maintained at a high position to facilitate user operation, then ease of operation is improved, but torque and damage to the structure worsen during falls
Solution Approach 1:
The support is designed to dynamically change position based on load conditions. During normal use, it maintains the lifeline at a high first height for ease of operation. During a fall, it automatically lowers to a second height to reduce torque on the structure, thus adapting the system behavior to different operational states
Solution Approach 2:
The system changes the height parameter of the lifeline support based on the force experienced. By transitioning between two discrete height positions (first height during normal use, second height during falls), the system optimizes both operational ease and structural protection
2Strength
If the effective length of the lifeline increases during falls to reduce force on the user, then force absorption is improved, but the ratio of length change to height change (ΔL/ΔH) increases causing more torque
Solution Approach 1:
The system controls the relationship between length change (ΔL) and height change (ΔH) by changing the support position. By lowering the support to a second height during falls, the system ensures that the ratio ΔL/ΔH remains less than 1, optimizing both force absorption and torque reduction
Solution Approach 2:
The movable support dynamically adjusts its position to control the geometric relationship between lifeline length and height. This dynamic adjustment ensures that during fall events, the system maintains an optimal ΔL/ΔH ratio that balances force absorption with torque minimization
3Stability of the object's composition
If the support structure is made more rigid to prevent tilting during falls, then stability is improved, but the force and damage to the structure worsen
Solution Approach 1:
Rather than making the post rigidly stable, the system uses a movable support that dynamically adjusts its position. This allows the system to maintain functional stability during normal use while reducing structural stress during falls by lowering the support to a second height
Solution Approach 2:
The system converts the potential harm of post tilting into a beneficial mechanism. By allowing controlled movement of the support rather than rigid resistance, the system reduces the torque transmitted to the structure, transforming what would be a harmful instability into a protective feature
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 reduces torque on structures and minimizes the increase in effective lifeline length upon threshold force, enhancing safety by limiting the vertical fall of users and reducing damage to roofs and other structures.
Implementation Method 1
an energy absorber with a metal strap that deforms and tears to absorb energy
Implementation Method 2
the metal strap that deforms and tears to absorb energy
Implementation Method 3
The moveable member may, for example, pivot from a first position to a second position upon the lifeline experiencing the threshold force to lower the lifeline to the second height
Implementation Method 4
The moveable member may, for example, be maintained in the first position by at least one breakable connector which breaks upon the lifeline experiencing the first threshold force to enable the moveable member to move
Data Source
AI summary
A post system for use in fall protection includes a connector to connect to a structure and a support in operative connection with a lifeline to maintain the lifeline at a first height above the structure. When a first threshold force is experienced on the lifeline, the support is operable to lower the lifeline to a second height which is lower than the first height. The ratio of a change in effective length of the lifeline resulting from the lowering of the lifeline to a change in height resulting from lowering of the lifeline (or the ΔL/ΔH ratio) is less than 1. The ratio of the change in effective length of the lifeline resulting from the lowering of the lifeline to the change in height resulting from lowering of the lifeline may also be less than 0.5 or less than 0.4.