Two-Stopper Elevator Shaft Door Lock for Controlled Emergency Access

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Solution Overview

Problem

Existing emergency release mechanisms for elevator shaft doors pose a safety risk as they allow unauthorized access to the elevator shaft, potentially leading to accidents during emergency situations.

Innovation Solution

A safety locking device for elevator shaft doors that includes a first stopper for the closed configuration, a second stopper for a semi-open configuration, and a counter-stopper to engage with both, allowing controlled opening to a semi-open position for safe access.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the shaft door lock is released using the emergency release mechanism, then the shaft door can be opened for emergency access, but the person operating the mechanism risks falling down the elevator shaft or suffering injuries

Engineering Contradiction:
Improveemergency accessVSAvoidsafety risk
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The door opening process is segmented into two distinct phases: a first phase where the door opens from the closed position to a semi-open intermediate position, and a second phase where it can open fully. The safety locking device provides separate locking configurations for these phases - a first locked configuration that prevents opening beyond the semi-open position, and a second locked configuration that prevents opening from the closed position. This segmentation allows emergency access while maintaining safety by requiring intentional action to proceed beyond the safe intermediate position.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The shaft door lock automatically engages the first stopper at the semi-open intermediate position during the opening process, performing a preliminary safety action before the door can be fully opened. This preliminary engagement of the first locked configuration prevents accidental falls by stopping the door at a safe intermediate position, requiring the operator to consciously disengage it to proceed with full opening.

Inventive Principle:
Principle #10Preliminary action

2Adaptability or versatility

If the shaft door is fully opened for emergency access, then complete access to the shaft is achieved, but the risk of accidental falls and injuries increases

Engineering Contradiction:
Improveaccess capabilityVSAvoidsafety risk
Core Design Contradiction:
Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The door opening process is segmented into two distinct phases: a first phase where the door opens from the closed position to a semi-open intermediate position, and a second phase where it can open fully. The safety locking device provides separate locking configurations for these phases - a first locked configuration that prevents opening beyond the semi-open position, and a second locked configuration that prevents opening from the closed position. This segmentation allows emergency access while maintaining safety by requiring intentional action to proceed beyond the safe intermediate position.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The semi-open intermediate position acts as an intermediary state between the closed and fully open positions. At this intermediate position, the first stopper engages with the counter-stopper to create the first locked configuration, providing a safe stopping point that allows emergency personnel to access the shaft without the door being fully open. This intermediary position mediates between the need for access and the need for safety.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Device complexity

If the shaft door lock uses only a single locked configuration, then the structure is simpler, but it cannot provide controlled stopping at intermediate positions for safety

Engineering Contradiction:
Improvelocking mechanismVSAvoidsafety control
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The locking mechanism is segmented into two distinct locked configurations: a first locked configuration that engages at the semi-open intermediate position, and a second locked configuration that engages at the closed position. The shaft door lock includes a first stopper for the intermediate position and a second stopper for the closed position, with corresponding locking configurations. This segmentation provides reliable safety control at critical positions while maintaining reasonable structural simplicity through the use of stoppers and counter-stoppers rather than complex locking mechanisms.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The shaft door lock system provides self-service safety control through the automatic engagement of stoppers and counter-stoppers at predetermined positions. As the door opens or closes, the stoppers automatically engage with the counter-stopper to create locked configurations without requiring external intervention. This self-service mechanism ensures reliable safety control while minimizing the complexity of additional control systems.

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP4452816B1Safety locking device for a shaft door of an elevator and method for opening a shaft door of an elevator using a safety looking device
Publication Date: 2025.09.24 INVENTIO AG
  • EP4452816B1 patent drawingFigure 1A~2B
  • EP4452816B1 patent drawingFigure 3A~4B
  • EP4452816B1 patent drawingFigure 5A~6B

AI summary

The present disclosure provides a safety locking device (240, 340, 440, 540, 640, 740) for a shaft door (230, 330, 430, 530, 630, 730) of an elevator and a method for opening a shaft door (230, 330, 430, 530, 630, 730) of an elevator using a safety locking device (240, 340, 440, 540, 640, 740). The safety locking device (240, 340, 440, 540, 640, 740) for a shaft door (230, 330, 430, 530, 630, 730) of an elevator, the safety locking device (240, 340, 440, 540, 640, 740) comprising a shaft door lock (L) having a first stopper (S1) for stopping the shaft door (230, 330, 430, 530, 630, 730) at a first position corresponding to a closed configuration of the shaft door (230, 330, 430, 530, 630, 730), the shaft door lock (L) having a first locked configuration for locking the shaft door (230, 330, 430, 530, 630, 730) at the first position; an emergency release mechanism (R) for manually releasing the shaft door lock (L) from the first locked configuration, thereby allowing the shaft door (230, 330, 430, 530, 630, 730) to move, from the fist position, in an opening direction for opening the shaft door (230, 330, 430, 530, 630, 730), characterized in that the shaft door lock (L) further has a second stopper (S2) for stopping the shaft door (230, 330, 430, 530, 630, 730) at a second position corresponding to a semi-open configuration of the shaft door (230, 330, 430, 530, 630, 730) being between the closed configuration and an open configuration of the shaft door (230, 330, 430, 530, 630, 730), the shaft door lock (L) having a second locked configuration for locking the shaft door (230, 330, 430, 530, 630, 730) at the second position; and in that the shaft door lock (L) further comprises at least one counter-stopper (C1, C2) configured to engage with the first stopper (S1) for stopping the shaft door (230, 330, 430, 530, 630, 730) at the first position and with the second stopper (S2) for stopping the shaft door (230, 330, 430, 530, 630, 730) at the second position.