Elevator Door Unlocking Zone for Safe Exit After Safety Stops
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Solution Overview
Problem
Passengers are often trapped in an elevator car due to the prevention of door opening when a safety switch is triggered, even if the car is stopped a short distance from the landing, which is undesirable.
Innovation Solution
An elevator system that allows the door to open if the car is within an 'unlocking zone' where the car and landing floors are aligned or misaligned by a defined amount, using safety switches and a position reference system to determine the car's position and safety status, and includes a warning device for misalignment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the elevator door and landing door are prevented from opening when a safety switch is triggered, then safety is improved, but passengers may be trapped in the elevator car
Solution Approach 1:
The patent applies local quality by creating different door opening policies for different spatial locations. The unlocking zone is defined as a specific region where door opening is permitted even when safety switches are triggered, while other regions maintain the traditional restricted policy. This spatial differentiation allows the system to provide safe exit capability locally without compromising overall safety.
Solution Approach 2:
The patent implements preliminary action by pre-defining the unlocking zone boundaries and criteria before any emergency situation occurs. The controller is programmed with advance knowledge of which positions constitute the unlocking zone, allowing it to make immediate door opening decisions when safety switches are triggered, without requiring real-time complex calculations or manual intervention.
2Adaptability or versatility
If the elevator car is stopped a short distance from the landing, then positioning flexibility is improved, but passengers cannot exit the elevator car
Solution Approach 1:
The patent applies local quality by creating different door opening policies for different spatial locations. The unlocking zone is defined as a specific region where door opening is permitted even when safety switches are triggered, while other regions maintain the traditional restricted policy. This spatial differentiation allows the system to provide safe exit capability locally without compromising overall safety.
Solution Approach 2:
The patent implements dynamics by making the door opening capability dynamic rather than static. Instead of having a fixed policy that either always allows or always prevents door opening when safety switches are triggered, the system dynamically adjusts the door opening permission based on the real-time position of the elevator car relative to the predefined unlocking zone boundaries.
3Ease of operation
If the unlocking zone allows misalignment between car floor and landing floor, then passenger exit capability is improved, but alignment precision requirements are relaxed
Solution Approach 1:
The patent applies parameter changes by modifying the acceptable range of floor alignment parameters. Instead of requiring precise alignment within a narrow tolerance band, the unlocking zone definition incorporates a misalignment threshold parameter that allows the car floor and landing floor to be misaligned by up to a predetermined distance while still permitting door opening. This parameter adjustment enables passenger exit capability under relaxed alignment conditions.
Data Source
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AI summary
An elevator system (201) comprising a hoistway (217) comprising landing (225A-225C), which comprises a landing door (227A-227C), an elevator car (203), comprising an elevator car door (229), arranged to move within the hoistway (217), a first safety switch (231; 233) configured to indicate a potential hazard in the elevator system (201) and a controller (215). The controller (215) is configured, when the first safety switch (231; 233) is triggered, to stop movement of the elevator car (203) and determine whether the elevator car (203) is located anywhere within an unlocking zone (253) in the hoistway. The controller is further configured, if it is determined that the elevator car (203) is located anywhere in the unlocking zone (253), to allow the elevator car door (229) and landing door (227A-227C) to be opened.