Elevator Brake Wedge Grooves for Secure Low-Friction Films

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Solution Overview

Problem

Elevator brake wedges face reliability and durability issues due to mechanical wear and difficulty in bonding low-friction materials, with existing solutions like linear roller bearings being complex and expensive, and adhesive bonding being unreliable.

Innovation Solution

The elevator brake wedge incorporates grooves in the safety wedges to secure low-friction films using compression forces, eliminating the need for adhesion by integrating grooves that hold the low-friction material in place through mechanical interlocking.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If adhesive bonding is used to attach low-friction films to brake wedges, then the low-friction guiding surfaces can be achieved, but the bond strength deteriorates during usage and reliability decreases

Engineering Contradiction:
Improvebond strengthVSAvoidbonding process complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent replaces the chemical bonding system (adhesive bonding) with a mechanical retention system (grooves). The low-friction film is secured to the brake wedge through physical grooves that mechanically interlock with the film, eliminating reliance on adhesive bond strength which deteriorates during usage. This mechanical retention method provides more reliable and durable attachment.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The brake wedge surface is designed with grooves that create a porous or textured structure to mechanically retain the low-friction film. These grooves allow the film to be physically secured through interlocking rather than chemical adhesion, solving the problem of bond strength deterioration while maintaining the low-friction surface functionality.

Inventive Principle:
Principle #31Porous materials

2Reliability

If linear roller bearing assemblies are introduced between guiding surfaces, then friction is reduced and movement is facilitated, but the device becomes overly thick, complex and expensive

Engineering Contradiction:
Improveengagement and disengagement reliabilityVSAvoidbearing assembly complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent uses a thin low-friction film instead of a thick roller bearing assembly. The film is applied directly to the brake wedge surface within grooves, providing the necessary low-friction guiding surface while maintaining a thin profile. This eliminates the excessive thickness and complexity associated with roller bearing assemblies while achieving the same functional goal of facilitating reliable wedge movement.

Inventive Principle:
Principle #30Flexible shells and thin films

3Duration of action of stationary object

If conventional brake wedge surfaces are used without low-friction features, then the structure remains simple, but mechanical wear increases and durability decreases

Engineering Contradiction:
Improveguiding surface durabilityVSAvoidmanufacturing complexity
Core Design Contradiction:
Duration of action of stationary objectVSEase of manufacture

Solution Approach 1:

The patent applies low-friction film material locally to specific grooved areas of the brake wedge rather than treating the entire surface. This localized application provides wear protection and low-friction properties exactly where needed (at the guiding surfaces) while keeping the rest of the wedge structure simple and easy to manufacture. The grooves are formed only in the regions requiring low-friction contact.

Inventive Principle:
Principle #3Local quality

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

This approach enhances the reliability and durability of the low-friction surfaces by securing the films without adhesion, ensuring secure engagement and disengagement of the wedges, thus improving the brake's operational efficiency and reducing maintenance costs.

Implementation Method 1

a low friction element (film) that is adhesive bonded to the wedge to provide the necessary low friction guiding surfaces

Methodology Applied
Scientific EffectLow friction: Lubrication

Implementation Method 2

grooves are provided in the backsides of elevator brake safety wedges and by pressing or injecting low friction material into the grooves to form pads or films

Methodology Applied
Scientific EffectMechanical interlocking: Mechanical Fastener

Data Source

PatentEP3354613B1Elevator brake wedge having low friction film securing grooves
Publication Date: 2026.03.11 OTIS ELEVATOR CO
  • EP3354613B1 patent drawingFigure 1~2
  • EP3354613B1 patent drawingFigure 3~4
  • EP3354613B1 patent drawingFigure 5~8

AI summary

An elevator brake wedge is provided and includes an elongate body (40) having first and second generally opposed major surfaces (41,42) and first and second generally opposed minor surfaces (43, 44). The second minor surface (44) has a greater length than the first minor surface (43). Each of the first and second major surfaces (41, 42) extends between corresponding first and second ends of the first and second minor surfaces (43, 44), respectively. The second major surface (42) defines low-friction film securing grooves (45) extending from a plane of the second major surface (42) into the elongate body (40).