Elevator Brake Release Mechanism for Automatic Safety Disengagement
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Elevator systems face difficulties in releasing safeties from guide rails when the torque of the motor is insufficient, requiring manual intervention, as the forces involved in engaging the safeties exceed the motor's capability, making it challenging to move the elevator car once the safety is engaged.
Innovation Solution
A braking device with a first fixed brake member and a second moveable brake member, along with a brake release member that can selectively release the braking force by applying a controlled upward force on the elevator car, allowing the motor to disengage the safety from the guide rail through controlled relative movement between the brake members.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Extent of automation
If the motor torque is increased to release the safety from the guide rail, then the safety can be released automatically, but the motor size and cost increase
Solution Approach 1:
A brake release member is introduced as an intermediary component between the brake members and the guide rail. This member includes a friction surface that contacts the guide rail and can selectively release the brake by reducing frictional engagement, allowing the motor to release the safety without requiring excessive torque
Solution Approach 2:
The friction characteristics between the brake system and guide rail are dynamically changed through the brake release member. By adjusting the frictional engagement level, the system transitions from a high-friction engaged state to a low-friction released state, enabling automatic release with normal motor torque
2Force
If the brake members are tightly engaged against the guide rail for reliable braking, then the braking force increases, but the motor torque becomes insufficient to release the brake
Solution Approach 1:
The brake release member acts as a mediator that selectively controls the frictional engagement between the brake members and guide rail. During normal operation, it maintains tight engagement for reliable braking; during release, it reduces frictional resistance, allowing the motor to easily move the brake members away from the guide rail
Solution Approach 2:
The brake system transitions from a static tightly-engaged state to a dynamic release state through the brake release member. The member enables the system to adapt its frictional characteristics based on operational requirements, allowing easy release when needed while maintaining secure engagement during braking
3Reliability
If a fixed wedge brake member is used for applying braking force, then the braking reliability increases, but the ability to release the brake automatically decreases
Solution Approach 1:
The brake release member serves as an intermediary that works in conjunction with the fixed wedge brake member. It provides the necessary friction modulation capability without compromising the reliability of the fixed wedge structure, enabling automatic release while maintaining braking effectiveness
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 automatic and reliable release of the braking device, allowing the elevator car to return to service without manual intervention by utilizing the motor's torque to overcome the frictional forces and disengage the brake, ensuring efficient operation and reduced downtime.
Implementation Method 1
A brake release member adjacent the first brake member is received against the first side of the guide rail between the first brake member and the first side of the guide rail. The brake release member is moveable relative to the first brake member for selectively releasing the braking device from engagement with the guide rail.
Implementation Method 2
A first brake member configured to remain fixed relative to an elevator car for applying a braking force to a first side of a guide rail. A second brake member is moveable relative to the first brake member for applying a braking force to a second, opposite side of the guide rail.
Implementation Method 3
the forces associated with engaging the guide rail and stopping the elevator car are so large that they exceed the torque of the motor, which makes it difficult to move the car once the safety is engaged
Data Source
AI summary
An exemplary braking device for an elevator car includes a first brake member configured to remain fixed relative to an elevator car for applying a braking force to a first side of an element such as a guide rail. A second brake member is moveable relative to the first brake member for applying a braking force to a second side of the element. A brake release member adjacent the first brake member is received against the first side of the element between the first brake member and the first side of the guide rail. The brake release member is moveable relative to the first brake member for selectively releasing the braking device from engagement with the element.