Elevator Car Ceiling Latch for Secure Emergency Access

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing elevator systems face challenges with complex and insecure closure mechanisms for covers in emergency situations, particularly in elevator cars without a machine room above the shaft, where maintenance and evacuation openings are cumbersome and often not securely locked.

Innovation Solution

A closure system for elevator car covers featuring a rotatable bolt with a bolt receptacle and an adjustment contour, allowing easy and secure opening and closing through a rotational mechanism, enhanced by projections and recesses for additional stability and safety, and optionally including a protective shield to prevent unauthorized access.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a traditional locking mechanism is used for the cover, then security is improved, but operation complexity increases

Engineering Contradiction:

Improvesecure closureVSAvoidopening and closing operation

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

The closure mechanism is designed to automatically engage and lock when the cover is closed, without requiring manual manipulation of separate locking components. The bolt and receptacle with projection automatically align and secure upon closure, making the system self-securing while maintaining simplicity.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The patent replaces complex mechanical locking systems with a simplified cam-based mechanism. The adjustment contour acts as a cam that converts linear pressing motion into rotational motion of the bolt, eliminating the need for threads, keys, or multiple moving parts while maintaining secure locking.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Ease of operation

If a simple closure mechanism is used, then ease of operation is improved, but security and reliability deteriorate

Engineering Contradiction:

Improveopening and closing operationVSAvoidsecure closure

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

The adjustment contour is designed with a curved cam profile that provides mechanical advantage. The curvature of the cam surface converts a small pressing force into a large locking force, ensuring secure closure while requiring minimal operator effort. The rounded geometry also facilitates smooth operation.

Inventive Principle:

Principle #14Spheroidality (Curvature)

Solution Approach 2:

The patent combines the closing action and locking action into a single integrated motion. Pressing the cover closed simultaneously engages the bolt with the receptacle and secures it through the cam action, eliminating separate locking steps while maintaining high reliability.

Inventive Principle:

Principle #5Merging (Combining)

3Ease of operation

If a rotatable bolt mechanism is used, then ease of operation is improved, but vulnerability to vibrations and unintentional opening increases

Engineering Contradiction:

Improverotational operationVSAvoidvibrations

Core Design Contradiction:

Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The cam-based adjustment contour is designed to pre-load the bolt into the receptacle, creating a preliminary locking force that resists subsequent vibrations. The cam profile ensures the bolt is firmly seated against the receptacle wall before any external forces act on the system, preventing unintentional disengagement.

Inventive Principle:

Principle #9Preliminary anti-action

Solution Approach 2:

Instead of designing a mechanism that prevents rotation, the patent uses the reverse approach: it allows easy rotational operation for opening/closing but designs the closed position to be self-locking and vibration-resistant through the cam geometry. The system is asymmetric in its behavior: easy to operate one way, secure in the other.

Inventive Principle:

Principle #13The other way round (Inversion)

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

Enables simple and safe operation of elevator car covers, ensuring secure closure and preventing unintentional opening, even under conditions like vibrations, thereby facilitating maintenance and emergency access.

Implementation Method 1

the bolt is rotated out of the overlap with the first projection by means of the adjustment contour by pressure against the underside of the bolt receptacle

Methodology Applied

Scientific EffectMechanical Force: Mechanical Force

Data Source

PatentEP4667407A1Elevator car for an elevator system with openable ceiling

Publication Date: 2025.12.24 THYSSENKRUPP ELEVATOR INNOVATION AND OPERATIONS GMBH

Figure 1~2
Figure 3a~3b
Figure 3c~5

AI summary

The following descriptions relate to a car (3) having an interior with a ceiling (10), wherein the ceiling (10) has an opening (12) and a first cover (13.1) for selectively opening or closing the opening (12) and a closure (14) for holding the first cover (13.1) against at least one fixed or fixable first counter element, wherein the closure (14) has: a rotatable latch (14.1) arranged on the first cover (13.1); a bolt receptacle (14.2) arranged on the first counter element with a first projection (17.1) for engaging the bolt (14.1), wherein the bolt (14.1) is subjected to force to a rotational position overlapping with the first projection (17.1) and a tool engagement (16) facing the interior for rotating the bolt (14.1) against the force, wherein the bolt receptacle (14.2) has an adjustment contour (19) such that the bolt (14.1) is rotated out of the overlap by pressure against the underside of the bolt receptacle (14.2) using the adjustment contour (19).