Apparatus and method for monitoring shaft doors

Abstract

The invention relates to a lift installation having at least one shaft door and an apparatus for monitoring movements for opening the shaft door, comprising a first self-powered counter which is intended for counting the movements and, irrespective of the power supply being intact, in the case of one of these movements, increments a first counter value, and also comprising a second counter which is intended for counting the movements and, with the power supply intact, in the case of one of these movements, increments a second counter value, and further comprising a comparator circuit which retrieves, and compares, the first and the second counter values, and can generate a signal based on the comparison of the counter values, and to a method for monitoring movements for opening the shaft door, according to which the comparator circuit transmits request signals to the first counting and memory circuit and to the second counting and memory circuit, and therefore communication of the associated counter values to the comparator circuit is triggered, and the first counter value is communicated to the comparator circuit, and the second counter value is communicated to the comparator circuit, and the first counter value is compared with the second counter value by means of an algorithm of the comparator circuit.

Description

technical field [0001] The invention relates to a device and a method for monitoring a shaft door of an elevator installation. Background technique [0002] The monitoring of the shaft doors is used to ensure the safety of persons staying in the elevator installation. [0003] Elevator installations usually have an elevator shaft with a plurality of shaft doors and an elevator car that can travel in the elevator shaft. Each shaft door is secured by a latching device. To detect unlocking, a shaft door contact is provided on the latching device. The shaft door contacts of several shaft doors are connected in series in a closed circuit and form part of a safety circuit. The closed circuit is supplied with a base voltage. When one of the shaft doors is unlocked (which is not part of normal use of the elevator car), the safety circuit is interrupted by the corresponding shaft door contact. After such an unlocking, it must be assumed that the person is in a position outside t...

AI Technical Summary

Problems solved by technology

[0005] The problem with this type of disposal is that the equipment for monitoring the shaft doors does not work in the event of a prolonged power outage (basic voltage in the safety circuit cannot be maintained by the battery)

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