Lift Landing Door Panel Anti-Derailment Mechanism

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Solution Overview

Problem

Landing doors in elevators lack sufficient safety measures to prevent unauthorized opening or derailment when the cabin is not present, posing a risk to users due to potential gaps large enough for adults or children to pass through.

Innovation Solution

A door assembly with an upper and lower translation guide, a transversal component, and a bolt system that secures the door panel in place, preventing derailment and forced opening by using a retention loop and elastic means to maintain the bolt in a retention configuration, ensuring increased resistance to intrusion and safety.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a traditional lock acting only at the top is used to keep the panel closed, then the structure is simple, but the panel can be moved from the bottom to cause partial rotation creating abusive access

Engineering Contradiction:
Improvedoor securityVSAvoidlocking mechanism
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The locking function is segmented into multiple independent components: a top lock acting at the upper part of the panel, and a bolt acting at the lower part. This segmentation ensures that even if one locking mechanism fails or is bypassed, the other remains effective, thereby preventing unauthorized access while maintaining manageable complexity through modular design

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The locking mechanism transitions from a single-point (top-only) constraint to a multi-dimensional constraint system. The bolt introduces a lower constraint point, creating a distributed locking system that prevents rotation and displacement in multiple directions, thereby enhancing security without requiring overly complex mechanisms

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Ease of operation

If the panel is allowed to slide in the longitudinal slot, then the door can open and close, but the panel may derail due to stress directed towards the lift shaft

Engineering Contradiction:
Improvedoor movementVSAvoidpanel stability
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The translational guides are designed with differentiated local qualities: the upper guide provides standard sliding support, while the lower guide incorporates a protrusion that engages with a corresponding feature on the panel. This localized structural enhancement at the lower guide prevents derailment under stress while preserving smooth operation during normal opening and closing cycles

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The protrusion in the lower translational guide acts as an intermediary element between the guide structure and the panel. This intermediate feature provides additional mechanical support and constraint, preventing the panel from derailing outward while allowing controlled movement during operation, thereby enhancing reliability without compromising ease of operation

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If the panels are positioned close together, then the access opening is properly closed, but forcing the door causes reciprocal distancing creating gaps for passage

Engineering Contradiction:
Improveclosure integrityVSAvoidpanel constraint system
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The lower edges of adjacent panels are merged with a common structural element - the lower translational guide with its protrusion feature. This merging creates a unified constraint system that simultaneously secures both panels, preventing them from being forced apart while maintaining proper closure integrity. The combined structure provides mutual support without requiring separate complex constraint mechanisms for each panel

Inventive Principle:
Principle #5Merging (Combining)

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 solution effectively prevents unauthorized access and movement of the door panel, providing enhanced safety by ensuring the door remains securely closed, even under stress, thus preventing falls from significant heights.

Implementation Method 1

elastic means configured so as to maintain the bolt in the retention configuration

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP3022146B1Landing door for a lift
Publication Date: 2018.06.13 SEMATIC SPA
  • EP3022146B1 patent drawingFigure 1
  • EP3022146B1 patent drawingFigure 2~3(d)
  • EP3022146B1 patent drawingFigure 4~5

AI summary

Door assembly (1) for the landing door of a lift, comprising an upper translation guide; a lower translation guide (2), parallel to the upper translation guide and defining a longitudinal slot (4), at least one door panel (6, 6')/ which acts in conjunction with the upper translation guide and which comprises an end portion (8, 8') inserted in a slidable manner in the longitudinal slot (4) between two end-stroke positions. Such assembly comprises a transversal component (10), which extends in a direction (Y) incident to the sliding direction of the panel and which projects at least partially into the longitudinal slot (4), a panel component (12), translatable with the door panel (6) and defining a retention loop (14) which, in a first end- stroke position, receives the transversal component (10) to prevent the derailing of said panel (6), and a bolt (16), joined to the door panel (6) and movable in relation thereto to keep the panel in the first end- stroke position, the bolt (16) acting in conjunction with the panel component (12) to block the transversal component (10) in the retention loop (14).