Elevator Door Emergency Brake with Rotating Blade
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Solution Overview
Problem
Conventional emergency brake devices for elevator doors fail to maintain strong contact between the guide rail and braking blade when the falling load is large, leading to sliding and loss of friction, and may not operate if the hoist wire or chain is cut or if the motor fails, resulting in accidents.
Innovation Solution
An emergency brake device with a braking blade that maintains contact with the guide rail through a braking force transmission system, including a pressing roller and elastic components, which generates a braking force when the door's lowering speed exceeds a specified threshold, ensuring continuous frictional engagement regardless of the load size or failure scenarios.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional emergency brake device uses a brake shoe that contacts the guide rail, then the door falling can be stopped under normal conditions, but when the falling load is large the device slides downward together with the door and the brake shoe opens to lose frictional force
Solution Approach 1:
The brake shoe is changed from a static component to a dynamic one that rotates around a rotation axis. When the door falls, the brake shoe rotates to maintain contact with the guide rail, adapting to the dynamic loading conditions and preventing the opening problem that occurs with fixed brake shoes
Solution Approach 2:
The orientation and position parameters of the brake shoe are changed through rotation around a vertical axis. This allows the brake shoe to maintain optimal contact angle and position with the guide rail under varying load conditions, ensuring continuous frictional engagement even when the falling load is large
2Reliability
If the hoist wire or chain is cut or motor fails, then the door may fall due to loss of tensile force, but conventional emergency brake devices may not operate in these scenarios
Solution Approach 1:
The emergency brake device uses its own operational state (rotation of the brake shoe) to detect and respond to failure conditions. The system self-activates when the door begins to fall, eliminating the need for separate detection systems while ensuring comprehensive safety coverage
Solution Approach 2:
The rotation of the brake shoe provides feedback about the door's motion state. When the door falls due to wire cutting or motor failure, the brake shoe rotates in response, creating a feedback mechanism that automatically activates the braking function based on the actual falling condition
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 effectively stops the elevator door by maintaining strong frictional contact with the guide rail, even under high loads, and automatically operates at specified speeds, preventing accidents without relying on the braking blade for smaller loads, thus enhancing safety and reliability.
Implementation Method 1
a braking blade movable tool that receives a braking force of the acceleration prevention device to bring a braking blade into contact with the guide rail
Implementation Method 2
the brake shoe 5 causes friction while in contact with an outer surface of the guide rail 4
Data Source
AI summary
An emergency brake device for occurrence of acceleration of an elevator door of the present inventive concept is fixedly installed at both lower ends of the elevator door and moves up along a guide rail, and may be configured comprising: a fixing bracket (110) secured to the elevator door; an acceleration prevention device (100) installed in a front inner side of the fixing bracket (110) and causing a braking force when a door downward speed of the elevator door accelerates above a regulation speed; a braking blade driving mechanism (150) which receives the braking force of the acceleration prevention device (100) and brings a braking blade (151) into contact with the guide rail (300), thereby stopping the door downward movement of the elevator door; and a braking force transmission system for transmitting the braking force between the acceleration prevention device (100) and the braking blade driving mechanism (150).