Adjustable Fall Protection Device with Gear-Driven Payout Mechanism
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Solution Overview
Problem
Existing fall protection devices, such as self-retracting lanyards, lack the ability to adjust the length of line payout, limiting their versatility across different applications and environments, and cannot effectively switch between fall arrest and restraint modes without separate devices.
Innovation Solution
A fall protection device with an adjustable mechanism that includes a rotatable hub, central gear, and interacting gears and pivots, allowing for customizable line payout length through a knob-activated engagement mechanism, enabling the device to function as both a fall arrest and restraint system.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a fixed-length self-retracting lanyard is used, then the device structure is simple and reliable, but the device cannot adapt to different applications requiring different line payout lengths
Solution Approach 1:
The patent implements a dynamic adjustment mechanism that allows the maximum payout length to be changed based on application requirements. The adjustment mechanism includes a star wheel, pawl, and indicator system that enables users to set different payout lengths by rotating the star wheel, which moves the pawl engagement point along the drum circumference. This transforms a static device into a dynamic one that adapts to various working conditions.
Solution Approach 2:
The patent creates a universal fall protection device that can function as both a self-retracting lanyard (SRL) and a restraint device by allowing adjustment of the payout length. The same basic device structure serves multiple functions: when adjusted to longer lengths it operates as an SRL, and when adjusted to shorter lengths it functions as a restraint device, eliminating the need for separate specialized devices.
2Adaptability or versatility
If separate devices are used for fall arrest and restraint applications, then each device is optimized for its specific function, but the user needs to carry and manage multiple devices
Solution Approach 1:
The patent designs a single device that performs both fall arrest and restraint functions by allowing adjustment of the maximum payout length. The device includes a harness, drum, line, and adjustment mechanism that enables it to operate in SRL mode (longer payout) or restraint mode (shorter payout), replacing the need for two separate specialized devices and simplifying user operations.
3Adaptability or versatility
If the line payout length is fixed at maximum, then the device provides maximum fall protection distance, but it cannot be used in applications where the fall hazard is closer to the anchor point
Solution Approach 1:
The patent implements a dynamic adjustment mechanism featuring a star wheel with graduated markings, a movable pawl, and an indicator system. Users rotate the star wheel to change the pawl engagement position on the drum, thereby adjusting the maximum payout length. The indicator aligns with markings on the star wheel to show the current setting, providing a simple yet effective way to adapt the device to different working distances from anchor points to fall hazards.
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
Enables flexible line payout adjustment and dual functionality, ensuring safety in various environments by allowing a single device to be used for both fall arrest and restraint applications, with adjustable settings for different hazard distances.
Implementation Method 1
a central gear configured to rotate with the hub about the central rotation axis
Implementation Method 2
at least one gear attached to the housing and configured to interact with the central gear
Implementation Method 3
a pivot having a track configured to interact with the at least one gear and pivot as the at least one gear rotates
Implementation Method 4
an arm of the pivot configured to urge at least a portion of the engagement mechanism causing it to move into an engagement position, to thereby prevent further rotation of the hub
Data Source
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AI summary
A fall protection device, including: a housing; a hub rotatable with respect to the housing; a line wrapped around the hub and configured to pay out from and retract into the housing, an engagement mechanism configured to prevent rotation of the hub and further payout of the line; and an adjustment mechanism configured to adjust a length of the line paid out from the housing, the adjustment mechanism comprising: (i) at least one gear attached to the housing; (ii) a pivot having a track configured to interact with the at least one gear and pivot as the at least one gear rotates; and (iii) an arm configured to urge at least a portion of the engagement mechanism causing it to move into an engagement position, to thereby prevent further rotation of the hub and payout of the line from the fall protection device.