Serial Spring Elevator Brake for Redundant Soft Engagement
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Solution Overview
Problem
Elevator brakes with two movable plungers can cause hard stops, which are unpleasant and dangerous for passengers, and existing solutions do not adequately address this issue while maintaining safety redundancy.
Innovation Solution
An elevator brake system with two movable plungers and an actuator comprising springs and solenoids, where the springs urge the plungers into engagement and the solenoids provide a counterforce to release the brake, arranged in a serial configuration to ensure redundancy and prevent hard stops.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If two movable plungers are used for redundancy, then reliability is improved, but hard stops occur causing passenger discomfort and danger
Solution Approach 1:
The patent applies beforehand cushioning by introducing a cushioning element between the movable plunger and the brake disc. This cushioning element deformable under load absorbs the impact energy when the plunger engages with the brake disc, preventing hard stops while maintaining the redundant two-plunger configuration for reliability. The cushioning element is pre-positioned to deform during normal braking operation, thereby mitigating the harmful shock effect before it reaches the brake disc and shaft.
2Reliability
If two movable plungers are used simultaneously, then safety redundancy is improved, but both plungers engaging simultaneously causes hard emergency stop
Solution Approach 1:
The cushioning element is pre-installed in the engagement path of each plunger, ensuring that when both plungers engage simultaneously, the impact is absorbed through deformation of the cushioning element rather than direct contact between plungers and brake disc. This maintains safety redundancy while ensuring smooth brake engagement.
Solution Approach 2:
The patent changes the physical state and mechanical properties of the engagement interface by introducing a deformable cushioning element. This element alters the force transmission characteristics, allowing the brake system to accommodate simultaneous plunger engagement without generating harmful shock loads, thereby improving ease of operation while maintaining reliability.
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 system ensures reliable braking without hard stops, maintaining safety redundancy by allowing independent movement of the plungers, even if one plunger is malfunctioning, thereby enhancing elevator safety.
Implementation Method 1
Each of the at least two springs is configured for applying a spring force to at least one of the at least two movable plungers for urging the at least one movable plunger towards the at least one brake disc
Implementation Method 2
The at least one solenoid is configured for producing a counterforce directed against the spring forces applied by the springs
Data Source
AI summary
An elevator brake for braking rotation of a shaft includes a brake disc mounted to the shaft such as to rotate with the shaft; at least two movable plungers that are movable along the axial direction (A) for engaging the elevator brake or releasing the elevator brake; and an actuator, including at least two springs configured for applying a spring force to at least one of the at least two movable plungers for urging the at least one movable plunger towards the brake disc for engaging the elevator brake; and at least one solenoid configured for producing a counterforce directed against the spring forces applied by the springs such as to urge the movable plungers in the axial direction (A) away from the brake disc for releasing the elevator brake. The at least two springs are arranged in series with each other along the axial direction (A).