Elevator Braking Device Using Buckling Beams for Consistent Force
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Solution Overview
Problem
Existing elevator brake systems face issues with inconsistent force application and hysteresis due to spring arrangements, which affect the reliability and efficiency of braking in over-speed conditions.
Innovation Solution
The use of buckling beams made from flexible materials, such as metal or carbon, which are pre-tensioned and arranged to provide a consistent braking force by urging the brake member into engagement with the guiderail, reducing mass and space requirements while minimizing hysteresis.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If spring arrangements are used to urge brake components into engagement with the guiderail, then braking force is applied, but the force varies with spring deflection and hysteresis occurs due to internal friction
Solution Approach 1:
The patent changes the physical state and geometric parameters of the elastic elements by pre-deflecting them into curved shapes during manufacturing. This pre-deflection creates a buckled configuration that, when compressed, provides a more consistent force output over the braking stroke compared to standard spring arrangements whose force varies continuously with deflection.
Solution Approach 2:
The elastic elements are pre-deflected into curved shapes before installation, creating an initial buckled state. This preliminary action ensures that when the brake is activated, the elements already have the optimal geometric configuration to provide consistent force, eliminating the need for complex real-time adjustments and reducing hysteresis effects.
2Force
If traditional spring arrangements are used, then braking force is applied, but mass and space requirements increase
Solution Approach 1:
The patent uses thin, flexible elastic elements that are pre-deflected into buckled configurations. These thin-film-like structures provide the necessary elastic force while occupying minimal space and having low mass, replacing traditional bulky spring assemblies with sleek, curved geometric shapes that achieve the same function with reduced material volume.
Solution Approach 2:
The elastic elements are given curved, buckled geometries rather than straight configurations. This curvature allows the thin elements to store elastic energy efficiently and provide consistent force over a range of deflections, achieving high force output from low-mass, space-efficient curved structures.
3Force
If disk-shaped springs are stacked under compression, then braking force is applied, but hysteresis occurs due to internal friction between disks and contact friction
Solution Approach 1:
The patent extracts the essential function of elastic force storage from complex multi-component spring assemblies and implements it through simple, pre-deflected curved elements. By removing the stacked disk configuration and internal friction interfaces, the design eliminates the source of hysteresis while retaining the force application function.
Solution Approach 2:
The elastic elements are pre-deflected into optimal curved shapes during manufacturing, establishing the correct geometric configuration before use. This preliminary action ensures that during braking operation, the elements follow a predictable force-deflection path with minimal hysteresis, as they are already in the optimal stress state when activated.
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 buckling beam configuration ensures a nearly constant braking force over the entire stroke, reducing mass and space requirements, and eliminates hysteresis, leading to improved braking performance and efficiency in elevator systems.
Implementation Method 1
The plurality of buckling beams are situated between the brake member and the brake member support to urge the brake member away from the brake member support and apply a braking force
Data Source
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AI summary
An elevator brake device (30) includes a housing (32) that supports a brake member (34). The brake member (34) has a braking surface (36). The brake member (34) is moveable between a disengaged position and an engaged position. A plurality of buckling beams are situated to urge the brake member (34) to apply a braking force.