Motor-Driven Rope Unwinding Mechanism for Fall Protection
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Solution Overview
Problem
Conventional fall protection devices require a line to pull down the connecting hook, hindering work on the factory floor and being complex to operate, as they often necessitate a lifting platform to reach the connection hook.
Innovation Solution
A fall protection device with a drive mechanism featuring a motor-driven rope unwinding system, including a drive wheel and freewheel, which allows the connecting hook to be lowered via a button press, eliminating the need for a line and enabling easy connection, while a pressure wheel and adjustable contact pressure enhance force transmission, and a three-phase motor with reversible rotation and speed control limits rope retraction speed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a line is used to pull down the connecting hook, then the connecting hook can be reached, but the line constantly hinders work on the factory floor and the device complexity increases
Solution Approach 1:
The patent removes the external line from the system by integrating a motor-driven unwinding mechanism directly into the fall protection device. The motor (140) with drive wheel (210) and freewheel (200) internally generates the rope movement, eliminating the need for separate manual pulling lines and reducing overall device complexity.
Solution Approach 2:
The patent replaces the manual mechanical line-pulling system with an electric motor-driven system. The motor (140) electronically controls rope unwinding and retraction, substituting complex manual mechanical operations with a controlled electric drive system that simplifies user interaction.
2Ease of operation
If a lifting platform is used to reach the connection hook, then the connecting hook can be accessed, but the solution becomes particularly complex
Solution Approach 1:
The patent extracts the rope unwinding function from external equipment (lifting platform) and integrates it directly into the fall protection device itself. The motor-driven drive mechanism (140, 210, 200) provides internal rope movement capability, eliminating the need for external lifting platforms.
Solution Approach 2:
The fall protection device is enhanced with multi-functionality by incorporating the motor-driven unwinding mechanism. The same device now performs both fall protection and controlled rope deployment/retraction functions, eliminating the need for separate lifting equipment.
3Ease of operation
If the rope is allowed to unwind freely, then the person can connect easily, but the rope may rise too quickly during retraction causing safety issues
Solution Approach 1:
The patent implements speed control through the motor control circuit (160) that regulates the motor (140) operation during rope retraction. The system monitors and controls the winding speed to prevent excessive rope retraction velocity, ensuring safe operation while maintaining ease of use.
Solution Approach 2:
The patent changes the operational parameters of the motor-driven system by setting predetermined speed limits for rope retraction. The motor control circuit adjusts the winding speed parameter to optimize both ease of operation and safety, preventing the rope from rising too quickly during retraction.
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 seamless and efficient operation by allowing the connecting hook to be lowered at the push of a button, reducing operational complexity and hindrances on the factory floor, while ensuring safe and controlled rope management during falls and retraction.
Implementation Method 1
a return spring which is to be tensioned when the rope is unwound from the drum
Implementation Method 2
the rope is passed through a gap between the drive wheel and the pressure wheel and is in frictional contact with both wheels in the gap
Implementation Method 3
the contact pressure of the pressure wheel is preferably adjustable
Implementation Method 4
the lever can be biased by spring force in order to press the pressure wheel onto the rope
Data Source
Figure 1~2
Figure 3A~3
Figure 4
AI summary
The invention relates to a crash safety device having a safety rope (105) wound onto a drum, a recuperating spring tensioned by the drum during the winding of the rope, and a locking device for blocking the drum from rotation in the rope unwinding direction during the crash of a person secured by the rope. A rope drive mechanism is provided in order to unwind the rope (105) from the drum and to slowly move the rope end having a hook (290) attached thereto toward such that a person can hook onto the safety rope (105). The drive mechanism has a motor (140) driving a rope drive wheel (210) via a freewheel (200) for lowering the rope end having the hook (290). In order to rewind the rope, the motor (140) is operated in a reverse direction of rotation at a controlled rotational speed in order to limit the speed at which the rope (105) is pulled up by the tensioned recuperating spring.