Three-Point Machine Room Suspension for Stable Construction Elevators

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Solution Overview

Problem

Construction elevator devices face challenges in maintaining stability of the machine room unit due to suspension at two points and wide-range roping arrangements, which interfere with working platforms and make it difficult to balance and position pulleys effectively.

Innovation Solution

A construction elevator device with three machine room unit hoisters installed on a support member, ensuring equal distances from the center of gravity and positioning suspension points outside the working platform, preventing interference and tilting, while reducing the weight of the hoisters by accounting for their weight.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If two hoisters are used to hoist the machine room unit, then the machine room unit can be suspended, but stability of the machine room unit cannot be maintained

Engineering Contradiction:
Improvestability of machine room unitVSAvoidnumber of hoisters
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent positions the three hoisters at specific locations on the support structure, ensuring that each hoister is strategically placed to contribute to stable suspension. The hoisters are arranged with specific spacing relationships (e.g., distance between first and second hoisters differs from distance between second and third hoisters) to optimize stability while maintaining balanced load distribution on the machine room unit.

Inventive Principle:
Principle #3Local quality

2Power

If 1:X roping is used with multiple pulleys, then mechanical advantage is achieved, but it requires rope arrangement over a wide range which interferes with working platform placement

Engineering Contradiction:
Improvemechanical advantageVSAvoidrope arrangement range
Core Design Contradiction:
PowerVSArea of stationary object

Solution Approach 1:

The patent extracts the hoisting mechanism from the machine room unit itself and relocates it to the support structure. By installing hoisters directly on the support structure rather than on the machine room unit, the system eliminates the need for extensive rope arrangements through multiple pulleys on the machine room unit, thereby clearing the space needed for working platform placement while maintaining the desired mechanical advantage.

Inventive Principle:
Principle #2Taking out (Extraction)

3Ease of operation

If machine room unit hoisters are installed on the machine room unit, then hoisting is achieved, but the weight of the machine room unit increases requiring more driving force

Engineering Contradiction:
Improvehoisting capabilityVSAvoidweight of machine room unit
Core Design Contradiction:
Ease of operationVSWeight of moving object

Solution Approach 1:

The patent extracts the hoisting mechanism from the machine room unit and relocates it to the support structure. The hoisters are installed on the support structure rather than on the machine room unit itself, thereby reducing the weight of the moving machine room unit while maintaining full hoisting capability. The support structure, being stationary, can bear the hoister weights without affecting the machine room unit's weight or required driving force.

Inventive Principle:
Principle #2Taking out (Extraction)

Data Source

PatentEP4122864B1Construction elevator device
Publication Date: 2026.02.18 HITACHI LTD
  • EP4122864B1 patent drawingFigure 1
  • EP4122864B1 patent drawingFigure 2
  • EP4122864B1 patent drawingFigure 3

AI summary

The present invention includes machine room unit hoisters 9a, 9b, 9c by which a machine room unit 6 is suspended from a support member provided in a hoistway so as to be movable in an ascending/descending direction. The machine room unit hoisters 9a, 9b, 9c suspend the machine room unit 6 at suspension points 21a, 21b, 21c. The machine room unit hoisters 9a, 9b, 9c are provided, supported by the support member. When viewed from a virtual horizontal plane over the machine room unit 6, distances from a center G of gravity of the machine room unit 6 to each of the suspension points are substantially equal and the center G of gravity is positioned within a region enclosed by virtual straight lines connecting each of the suspension points 21a, 21b, 21c. When viewed from a virtual horizontal plane over a working platform 5, the respective suspension points 21a, 21b, 21c of the machine room unit 6 are positioned outside a contour of the working platform 5.