Elevator Brake Disc Locking Bar for Field Adjustment Access

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Solution Overview

Problem

Clutch type elevator brakes are not adjustable in the field, requiring a mechanic to be on top of the elevator car for adjustments, which is inconvenient and inefficient.

Innovation Solution

A fail-safe bar with a variable diameter and circumferentially extending slots is used to prevent rotation of the brake disc, allowing for brake adjustments by inserting a bolt with threads into orifices in the brake disc, and a guard plate mechanism provides access to a brake adjustment screw, enabling secure and accessible adjustments without needing a mechanic on top of the elevator car.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a clutch type brake is used in the elevator machine, then the brake provides reliable stopping force, but the brake cannot be adjusted in the field and requires a mechanic to be on top of the elevator car for adjustments

Engineering Contradiction:
Improvebrake stopping forceVSAvoidbrake adjustability
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The brake system is segmented into adjustable components. The brake disc includes multiple orifices that can selectively receive different length bars, allowing the brake adjustment to be segmented into discrete positioning options. This enables field adjustment without requiring complex mechanisms or technician access to the top of the elevator car.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A bar with variable diameter acts as an intermediary component between the brake disc and the adjustment mechanism. The bar includes a first portion with a first diameter and a second portion with a second diameter, allowing it to engage with different orifices and provide stable positioning. This intermediary component enables reliable adjustment while maintaining brake performance.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of operation

If the brake disc is made rotatable for adjustment purposes, then field adjustment becomes possible, but the brake disc may rotate unintentionally during operation compromising safety

Engineering Contradiction:
Improvefield adjustabilityVSAvoidbrake disc stability
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The bar's diameter parameter changes along its length, with a first portion having a first diameter and a second portion having a second diameter. This parameter variation allows the bar to engage different orifices in the brake disc while providing interference fits that prevent rotation. The changing diameter creates stable engagement that eliminates unintended rotation while allowing intentional adjustment.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The bar features asymmetric geometry with different diameter portions. The first portion with the first diameter engages one set of orifices, while the second portion with the second diameter engages different orifices. This asymmetric design provides directional stability and prevents rotation in one direction while allowing controlled adjustment in the other direction.

Inventive Principle:
Principle #4Asymmetry

3Adaptability or versatility

If multiple orifices are provided in the brake disc for bar insertion, then adjustable positioning is enabled, but the structural integrity of the brake disc may be compromised

Engineering Contradiction:
Improvebrake positioning optionsVSAvoidbrake disc structural integrity
Core Design Contradiction:
Adaptability or versatilityVSStrength

Solution Approach 1:

The brake disc features local quality variations with different orifices positioned at specific locations and orientations. Each orifice is strategically placed to provide adjustment capability while minimizing impact on overall structural integrity. The local modifications are concentrated in specific areas rather than distributed throughout, preserving the bulk material strength.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

Multiple orifices are provided as copies of the same basic feature, but positioned differently in space. Rather than creating complex unique structures for each adjustment position, the design uses replicated orifice features that can accommodate the variable diameter bar. This copying approach provides versatility while using simple, structurally sound geometry.

Inventive Principle:
Principle #26Copying

Data Source

PatentEP3656725B1Fail safe bar for clutch type brake adjustment
Publication Date: 2023.11.22 OTIS ELEVATOR CO
  • EP3656725B1 patent drawingFigure 1
  • EP3656725B1 patent drawingFigure 2~3
  • EP3656725B1 patent drawingFigure 4

AI summary

Disclosed is an elevator machine (200) including: a plurality of stationary structures (210), including a proximate stationary structure (220) and a distal stationary structure (230), a brake support (240) that comprises the proximate stationary structure (220), a brake disc (250) rotably supported in the brake support (240) intermediate the plurality of stationary structures (210), the plurality of stationary structures (210) and the brake disc (250) each including a respective one of a plurality of orifices (255), and the plurality of orifices (255) being mutually aligned and offset from a rotational axis (257) of the brake disc (250) to removably receive an elongated bar (260), wherein when the bar (260) is positioned in the plurality of orifices (255), the brake disc (250) is prevented from rotating, thereby preventing vertical movement of an elevator car (103) in an elevator hoistway (117).