Settable Fall Arrest Reel With Traveller-Triggered Line Limit
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing fall arrest devices do not effectively prevent users from falling and require additional locking mechanisms, increasing complexity and cost.
Innovation Solution
A fall arrest device with a traveller mechanism that activates the speed responsive engagement assembly when a predetermined length of safety line is paid out, eliminating the need for a separate locking mechanism and allowing for adjustable setting of the maximum length of safety line.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an additional locking mechanism is incorporated into the fall arrest device to prevent falls, then fall prevention capability is improved, but device complexity and cost increase
Solution Approach 1:
The patent combines the fall prevention function with the existing drum rotation control mechanism. The traveller mechanism integrates with the drum and speed responsive engagement assembly, using the drum's rotation to both pay out/retract the safety line and to trigger fall prevention when the traveller reaches the engagement assembly. This merging eliminates the need for a separate locking mechanism while maintaining fall prevention capability.
Solution Approach 2:
The drum serves multiple functions: it winds and pays out the safety line during normal operation, and it simultaneously acts as the trigger mechanism for fall prevention when the traveller reaches the engagement assembly. The speed responsive engagement assembly also serves dual purposes by controlling both normal drum rotation and preventing overspeed rotation during falls. This multi-functionality reduces the need for additional dedicated components.
2Reliability
If a separate locking mechanism is added to prevent falls, then safety is improved, but cost increases
Solution Approach 1:
The fall prevention function is merged with existing components rather than adding a separate locking mechanism. The traveller, drum, and speed responsive engagement assembly work together to provide both safety line control and fall prevention, eliminating the need for additional expensive components while maintaining safety.
3Reliability
If the maximum length of safety line is restricted to prevent falls, then fall likelihood is reduced, but user movement freedom is limited
Solution Approach 1:
The system dynamically adjusts between two states: during normal operation, the traveller moves freely along the drum allowing the user to move within the safety line length limit; when the traveller reaches the engagement assembly, the system automatically transitions to a locked state to prevent falls. This dynamic behavior provides both user freedom and safety without requiring manual intervention.
4Reliability
If the traveller is made load-bearing to ensure safety during fall arrest, then reliability is improved, but device weight increases
Solution Approach 1:
The traveller acts as an intermediary or actuator that triggers the fall arrest function without bearing the full load. When the traveller reaches the engagement assembly, it activates the speed responsive engagement assembly to lock the drum, transferring the load-bearing responsibility to the existing engagement assembly and drum structure rather than requiring the traveller itself to be load-bearing.
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 reduces complexity and cost by integrating a traveller that activates the engagement assembly without additional load-bearing components, enhancing safety and reliability by preventing falls and adjusting the safety line length to restrict users from hazardous edges.
Implementation Method 1
a traveller configured to move in response to rotation of the drum
Implementation Method 2
a speed responsive engagement assembly arranged to inhibit rotation of the drum above a predetermined rotational speed
Implementation Method 3
a drum configured to have a safety line wound thereon
Data Source
Figure 1
Figure 2
Figure 3A~4
AI summary
A fall arrest device (10) includes a drum (1) configured to have a safety line (2) wound thereon, a speed responsive engagement assembly (3, 4, 6) arranged to inhibit rotation of the drum (1) above a predetermined rotational speed, and a traveller (30) configured to move in response to rotation of the drum (1). The traveller (30) is configured to activate the speed responsive engagement assembly (3, 4, 6) when a predetermined length of safety line has been paid out. This allows a user to be restrained from the edge of a worksite or other location where a fall may occur.