Elevator Cab Sound Panels with Perforated Ventilation

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Solution Overview

Problem

Elevator cab noise reduction is inadequate, primarily due to the motion of the cab and machinery, which affects passenger comfort.

Innovation Solution

A panel assembly comprising an outer panel, perforated inner panels, and a ventilation passage with foam panels to absorb noise and facilitate airflow, with adjustable parameters such as panel thickness, perforation size, and foam placement to target specific frequency ranges.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If traditional solid panel structures are used in the elevator cab, then noise reduction is achieved, but ventilation is insufficient

Engineering Contradiction:

Improvenoise reductionVSAvoidventilation

Core Design Contradiction:

Object-affected harmful factorsVSEase of operation

Solution Approach 1:

The patent employs perforated panels with controlled porosity to allow air passage while maintaining noise reduction capabilities. The perforated structure enables ventilation functionality without significantly compromising the noise absorption performance of the panel assembly.

Inventive Principle:

Principle #31Porous materials

Solution Approach 2:

The patent introduces a porous absorptive material as an intermediary layer between the perforated panels and the cavity space. This intermediary material facilitates both ventilation airflow and enhanced noise absorption, resolving the contradiction between ventilation requirements and noise reduction goals.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Ease of operation

If perforated panels are used to enable ventilation, then airflow is improved, but noise reduction effectiveness decreases

Engineering Contradiction:

ImproveventilationVSAvoidnoise reduction

Core Design Contradiction:

Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The patent creates a composite panel assembly combining perforated panels with porous absorptive materials. This composite structure integrates the ventilation benefits of perforations with the noise absorption capabilities of porous materials, achieving both functions simultaneously with enhanced overall performance.

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The patent nests the porous absorptive material within the cavity defined by the perforated panels, creating a multi-layered nested structure. This nesting arrangement allows the inner porous material to enhance noise absorption while the outer perforated panels maintain ventilation pathways.

Inventive Principle:

Principle #7Nested doll (Nesting)

3Device complexity

If a single panel structure is used, then device complexity is low, but noise reduction across frequency ranges is insufficient

Engineering Contradiction:

Improvepanel structureVSAvoidnoise reduction

Core Design Contradiction:

Device complexityVSObject-affected harmful factors

Solution Approach 1:

The patent segments the panel structure into multiple functional components: perforated panels, porous absorptive materials, and cavity spaces. This segmentation allows each component to address specific noise frequency ranges and ventilation requirements, achieving broad-spectrum noise reduction while maintaining manageable structural complexity.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent transitions from a two-dimensional panel surface to a three-dimensional panel assembly with internal cavities and layered structures. This dimensional expansion enables enhanced noise reduction performance across multiple frequency ranges by creating resonant cavities and absorption paths without proportionally increasing overall complexity.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

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

Significantly reduces noise levels within the elevator cab while providing ventilation, enhancing passenger comfort and noise reduction across various frequency ranges.

Implementation Method 1

a foam panel located in the internal cavity

Methodology Applied

Scientific EffectAcoustic absorption: Acoustic Absorption

Implementation Method 2

a ventilation passage at least partially defined by the panels through which fluid is configured to flow

Methodology Applied

Scientific EffectFluid flow through porous/perforated structures: Permeation

Data Source

PatentEP3822214B1Sound absorbing panels for elevator

Publication Date: 2024.07.17 OTIS ELEVATOR CO

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AI summary

A panel assembly (25) for an elevator cab (10) includes an outer panel (26) that defines an exterior surface of the elevator cab (10). A first inner panel (28) is spaced from the outer panel (26) and at least partially defines a first cavity (32) with the outer panel (26). A foam panel (34) is located adjacent one of the outer panel (26) and the first inner panel (28). A first passage opening is associated with the first panel and is in fluid communication with a ventilation passage (40) at least partially defined by one of the inner panel (28) or the outer panel (26).