Elevator Door Seal with Dual Tubes to Limit Lateral Force

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Solution Overview

Problem

Existing elevator door seals exert excessive lateral forces on the door mechanism due to high pressure requirements, leading to premature wear and increased complexity and cost.

Innovation Solution

A door seal system comprising a first tube and a second tube made of elastically deformable material, where the first tube is pressurized to bridge the door gap and the second tube allows pressure equalization, reducing lateral forces through compressibility and compensating for gap variations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If high pressure is used to inflate the door seal securely, then the sealing effect is improved, but the lateral forces on the door increase significantly

Engineering Contradiction:
Improvesealing effectVSAvoidlateral forces on door
Core Design Contradiction:
ReliabilityVSForce

Solution Approach 1:

The door seal is divided into two separate tubes: a first tube that is pressurized to bridge the door gap and provide sealing, and a second tube that is compressible with pressure equalization openings to accommodate gap variations without transmitting excessive lateral forces. This segmentation allows each tube to perform its specific function independently, resolving the contradiction between secure sealing and force reduction.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The second tube acts as an intermediary element between the pressurized first tube and the door. It receives the sealing force from the first tube but dissipates it through its compressibility and pressure equalization openings, preventing the full lateral force from being transmitted to the door while still maintaining the seal.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If the door seal is designed to bridge the door gap at its widest point with additional reserve, then the sealing reliability is improved, but the lateral forces on the door increase

Engineering Contradiction:
Improvesealing reliabilityVSAvoidlateral forces on door
Core Design Contradiction:
ReliabilityVSForce

Solution Approach 1:

The door seal system applies different mechanical properties to different parts: the first tube uses high pressure and rigidity to bridge the gap at its widest point, while the second tube uses compressibility and pressure equalization to accommodate local variations in gap width without generating excessive lateral forces. This local differentiation of properties resolves the contradiction between sealing reliability and force reduction.

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

The system effectively seals the door gap while minimizing stress on the door mechanism, allowing for simpler and less costly manufacturing with reduced wear and improved durability.

Implementation Method 1

The first hose has a pressure port for pressurizing the first hose with fluid pressure and is deformable by changing the fluid pressure between an initial shape and an end shape that is larger in the bridging direction compared to the initial shape

Methodology Applied
Scientific EffectFluid pressure: Pressure Increase

Implementation Method 2

The second hose has at least one pressure equalization opening designed to allow pressure equalization between the interior and the surrounding environment of the second hose when it is compressed

Methodology Applied
Scientific EffectPressure equalization: Pressure Gradient

Implementation Method 3

The door seal comprises at least a first tube and a second tube made of an elastically deformable sealing material

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Data Source

PatentEP4493502B1Door seal for an elevator car
Publication Date: 2025.12.03 INVENTIO AG
  • EP4493502B1 patent drawingFigure 1
  • EP4493502B1 patent drawingFigure 2~3
  • EP4493502B1 patent drawingFigure 4~5

AI summary

The invention relates to a door seal (8) for a lift car (3), the door seal comprising: at least one first tube (10) and one second tube (11) made of an elastically deformable sealing material; the door seal being mountable on a car wall (4) and/or door (6) of the lift car in such a way that the first and the second tube, when the door closes a door opening (5) in the car wall, are arranged opposite one another within a door gap (9) in a bridging direction (13) and run at least in part around the door opening; the first tube having a pressure connection (14) and being deformable between a starting form and an end form, which is enlarged in the bridging direction compared to the starting form, by being exposed to a fluid pressure; the second tube having at least one pressure compensation opening (16), which is designed to allow a pressure compensation between an interior and a surrounding environment of the second tube when the second tube is compressed.