Asymmetric Thimble Rods for Elevator Traveling Cable Suspension

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Solution Overview

Problem

Conventional suspending apparatuses for traveling cables in elevators with large strokes face issues such as increased size and weight due to interference between rope sockets, and they do not effectively manage bending stress and lifting mechanisms, particularly for high-rise applications.

Innovation Solution

The design incorporates thimble rods of different lengths to prevent socket interference and a sway prevention mechanism using plate steel and hat-shaped fittings to reduce the need for larger components, along with a supporting bracket for easy lifting of the traveling cable to the hoistway midpoint, utilizing simple members to manage weight and stress.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If conventional rope sockets are used for suspending wire ropes in large-stroke elevators, then the suspending apparatus can support the load, but the rope sockets interfere with each other causing increased size and weight

Engineering Contradiction:
Improveload support capabilityVSAvoidweight of suspending apparatus
Core Design Contradiction:
StrengthVSWeight of stationary object

Solution Approach 1:

The patent applies asymmetry by making the thimble rods have different lengths (first thimble rod longer than the second thimble rod) to create asymmetric suspension geometry. This asymmetric configuration optimizes the spatial arrangement of rope sockets, preventing their interference while maintaining load support capability, thereby reducing the overall size and weight of the suspending apparatus.

Inventive Principle:
Principle #4Asymmetry

2Ease of operation

If larger rope sockets are used to avoid interference, then socket interference is prevented, but the suspending apparatus size and weight increase

Engineering Contradiction:
Improvesocket installationVSAvoidsize of suspending apparatus
Core Design Contradiction:
Ease of operationVSVolume of stationary object

Solution Approach 1:

The asymmetric length configuration of thimble rods positions the rope sockets at optimized distances from the suspension point, preventing spatial interference between sockets without requiring larger socket dimensions. This maintains ease of operation while minimizing apparatus volume.

Inventive Principle:
Principle #4Asymmetry

3Weight of stationary object

If the suspending apparatus is made smaller to reduce weight, then weight is reduced, but the load-bearing strength may be compromised

Engineering Contradiction:
Improveweight of suspending apparatusVSAvoidload-bearing capacity
Core Design Contradiction:
Weight of stationary objectVSStrength

Solution Approach 1:

The asymmetric thimble rod configuration optimizes the mechanical leverage and load distribution in the suspending system. The different lengths create an optimized force triangle that maintains load-bearing capacity while allowing for smaller component dimensions and reduced overall weight.

Inventive Principle:
Principle #4Asymmetry

4Device complexity

If conventional symmetric thimble rods are used, then the structure is simple, but socket interference occurs in large-stroke applications

Engineering Contradiction:
Improvestructure simplicityVSAvoidsocket installation
Core Design Contradiction:
Device complexityVSEase of operation

Solution Approach 1:

The patent introduces minimal complexity by varying only the thimble rod lengths while maintaining the overall symmetric structure of the suspending apparatus. This selective asymmetric modification prevents socket interference without requiring complete structural redesign, thus maintaining relative simplicity while improving functionality.

Inventive Principle:
Principle #4Asymmetry

Data Source

PatentEP2460754B1Suspending apparatus of traveling cable for elevator and elevator apparatus
Publication Date: 2014.11.19 HITACHI LTD
  • EP2460754B1 patent drawingFigure 1
  • EP2460754B1 patent drawingFigure 2A~2B
  • EP2460754B1 patent drawingFigure 3A~3B

AI summary

In a suspending apparatus of traveling cable for elevator, in order to realize a small and reliable suspending apparatus even for an elevator with a large stroke, the traveling cable (10) is configured to feed power to a car and exchange signals with the car. The traveling cable (10) includes a plurality of suspending wire ropes (10L, 10R) embedded therein. Each of the suspending wire ropes (10L, 10R) is incorporated into one of rope sockets (20L, 20R), respectively, and each of the rope sockets (20L, 20R) incorporating the suspending wire rope is fastened to one of thimble rods (30L, 30R), respectively, so that one end of the traveling cable is suspended from a hoistway side suspension apparatus (100) and the other end of the traveling cable is suspended from a car side suspending apparatus (200). The thimble rods (30L, 30R) is configured to have a different length from each other so as not to cause interference between the rope sockets (20L, 20R) to which a plurality of suspending wire ropes (10L, 10R) are attached. The suspending apparatus includes a traveling cable sway prevention mechanism (130) provided below a drawing point (10a) of the suspending wire ropes to suppress bending stress applied to the thimble rods due to rolling of the traveling cable.