Portable Escape Descent Control Using Weight-Adaptive Braking
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Solution Overview
Problem
Existing emergency escape devices for high-rise buildings face issues with inconsistent descending speed, complexity, and safety concerns due to fluid-based speed control systems, which are cumbersome and prone to malfunctions, especially in high-temperature environments and high-rise settings.
Innovation Solution
A portable emergency escape device utilizing a DC motor with a braking resistor and a constant speed control unit that adjusts resistance based on user weight to maintain a constant descending speed, preventing body rotation and allowing for controlled descent speed, supported by multiple wires for simultaneous use.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If a reduction gear is used to control descending speed, then the descending speed is reduced, but the descending speed is not constant causing user unease and instability
Solution Approach 1:
The patent employs a feedback control system where a sensor detects the actual descending speed and feeds this information back to a controller. The controller adjusts the motor's output torque in real-time to maintain a constant descending speed, resolving the instability issue caused by simple reduction gearing.
Solution Approach 2:
The patent replaces the purely mechanical reduction gear system with an electromechanical system that uses a motor and electronic control. This substitution allows for precise, dynamic adjustment of descending speed through electronic feedback control, achieving constant speed that mechanical gears alone cannot provide.
2Speed
If a flow control valve is used to control descending speed, then constant speed descent is achieved, but the device becomes large and complicated with fluid leakage risks
Solution Approach 1:
The patent replaces the fluid-based flow control valve system with an electromechanical motor control system. This substitution eliminates the complexity and leakage risks associated with fluid systems while achieving the same constant speed control function through electronic feedback and motor torque regulation.
Solution Approach 2:
The patent extracts and eliminates the fluid control components (flow control valves, hydraulic lines, piston cylinders) from the system, retaining only the essential mechanical structure while using an electric motor and electronic controller to achieve speed control. This simplifies the overall device structure.
3Speed
If a flow control valve is used to control descending speed, then constant speed descent is achieved, but the device becomes large and heavy
Solution Approach 1:
The patent removes the heavy fluid control components (valves, hydraulic systems, large piston cylinders) and replaces them with a compact electromechanical system. The motor and electronic controller occupy significantly less space and weigh less than the equivalent fluid control system, reducing overall device weight.
Solution Approach 2:
The patent changes the control mechanism from fluid-based to electric-based, utilizing electrical parameters (voltage, current, resistance) instead of fluid parameters (flow rate, pressure). This parameter change enables a more compact and lighter control system while maintaining the constant speed descent function.
4Speed
If a fluid-based speed control system is used, then descending speed can be controlled, but malfunction occurs when fluid leaks due to high temperature exposure
Solution Approach 1:
The patent replaces the temperature-sensitive fluid control system with a temperature-resistant electromechanical system. The electric motor and electronic controller are not susceptible to fluid leakage issues caused by high temperature, maintaining reliable operation in fire emergency conditions where temperatures may be elevated.
Solution Approach 2:
The patent uses solid-state electronic components and a motor that do not rely on sealed fluid systems. These components are inherently more resistant to high temperature damage and do not suffer from leakage problems, providing reliable operation in extreme temperature environments without requiring complex thermal protection systems.
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
Ensures safe, constant descending speed regardless of user weight, prevents wire damage, allows for stable posture correction before descent, and enables multiple users to escape quickly and safely, even in high-rise settings.
Implementation Method 1
a braking force generation unit that generates a braking force when the DC motor rotates in a reverse direction
Implementation Method 2
a braking resistor connected in parallel to both ends of the power input terminal of the DC motor, and configured to have a resistance value determining a descending speed
Data Source
AI summary
The present invention discloses a portable emergency escape device comprising a casing, a drum rotatably installed inside the casing and around which a wire is wound, a reduction gear connected to the drum, a DC motor having a rotation shaft connected to the reduction gear, a safety belt worn by a user, a braking resistor for determining a descent speed, and a constant speed control unit connected to the braking resistor. The braking resistor is connected between both ends of a power input terminal of the DC motor, and the braking resistor can control a resistance value. And, the constant speed control unit changes the resistance value of the braking resistor in response to the user's weight to maintain the descent speed constant regardless of the user's weight.