HK1066781B - Safety circuit for elevator doors - Google Patents

Description

The subject of the invention is an elevator system as defined in claim 1.

For the safety of users of the elevator system and passengers in the buildings containing the elevator system, it is of great importance that the respective position of the elevator door and the elevator door is aligned with the position of the elevator cabin; that is, the elevator door and the cabin door may only be opened if the elevator is stopped at one of the designated exit and climb stages, i.e. the height of a building.

The safety contacts are closed when the locking devices are in their locking position and the locking doors are closed. The safety contacts are integrated into a safety circuit which is itself closed only in closed safety contacts. The safety circuit is so connected to the lifting system that the lifting devices are only open when the operation is in a closed safety circuit or when the lifting circuit is in a specialised heating or cooling mode. This is so that the safety circuit can be opened and disconnected by means of a safety control or a heating circuit or a service circuit, so that the lifting system can be operated only in a closed safety circuit or under a special heating or cooling mode.

Each elevator system with such conventional monitoring has several disadvantages, which are described in more detail below. In any case, a safety circuit is subject to inherent problems, including the length of the connections, the voltage drop in the safety circuit and the relatively high installation effort.Despite a surveillance system with a safety circuit, unsafe or dangerous situations cannot be avoided; on the one hand, the safety contacts can be crossed individually or together with relative ease, which is practically equivalent to the absence of safety precautions; on the other hand, although an open hatch door prevents the cabin from moving, if the cabin is not directly next to the open hatch door, there is still a risk of falling through the open hatch door.Intelligent or situational responses, for example in an open safety circuit, are not possible because the cabin is always shut down; in particular, it is not possible to avoid unintentional locking of people in the cabin.The monitoring system does not allow a specific diagnosis; that is, in an open safety circuit, it is only possible to determine that at least one safety contact and thus at least one locking device or at least one shaft door is open.It is not possible to determine which or which safety contacts are open.Preliminary maintenance is not possible because no indication of the safety status is given; it is therefore not possible to anticipate the maintenance of the lift system and to protect the safety of the doors in time,However, the system must be replaced at a time when the lift system can be easily decommissioned, except in the context of a periodic review, but in many cases the lift system is decommissioned without any need. The availability of the lift is limited because an open safety contact always leads to the lift system being disabled, even if another solution, for example not to drive the affected section of the shaft, is possible.

Although a functionally improved solution can be achieved by using a data bus to collect or transfer safety-related data relating to the position of the shaft doors, since the data is safety-related, a safety bus must be used.

The purpose of the invention is thus to create an improved lifting system of the type described at the outset which avoids the disadvantages of the state of the art in terms of safety measures for the position of the hatch doors and which is relatively inexpensive.

The solution to this problem is given by the features of the characteristic part of claim 1, as described in the invention.

Beneficial upgrades of the lift system of the invention are defined by dependent claims 2 to 10.

The lift system of the invention has a new monitoring system with a standard data bus. The data concerning the position of the shaft doors are collected and transferred via this data bus. Instead of a security data bus, a standard data bus with standard bus nodes is used, which may be the data bus already present for the transfer of process data in the lift shaft. The use of a relatively expensive security data bus, including the necessary cumbersome security bus nodes, which would be required due to the security of the data to be transferred, is avoided by taking measures to ensure the security of the data transmitted to the security data owner when the bus is not in operation.

The locking sensor is connected to the conventional data bus, which transmits the information obtained to the control or monitoring unit and the control or monitoring unit then evaluates the information obtained. This is done by the control or monitoring unit periodically, for example at intervals of 20 ms, interrogating the locking sensors. A communication interruption in the area of the data bus or bus nodes can thus be detected within a very short time. Further locking is detected very quickly, depending on the size of the associated sensor interface or interfaces, and at regular intervals, for example, when the control or monitoring unit is opened correctly or when the control unit is closed, and the test data can be observed within 24 hours (or at least 8 hours) before the test is performed, and at a minimum within 24 hours (or if the test is performed within 8 hours), and at a maximum interval of 8 hours (or if the control or monitoring unit is not operated correctly or if the test is performed within a period of 8 hours), and the data can be examined in a random and repeated manner, for each test.

For floors with low traffic, the locking sensor and the corresponding interface should preferably be designed with a safety focus, especially for floors where the lift may not be self-controlled, for example because a living unit such as a penthouse can be accessed directly from the lift shaft.

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If necessary for safety reasons, additional means of detecting the condition, in particular the position of the locking doors, may be provided in addition to the locking sensors, such means transmitting information on the position or condition of the locking door to the control either via the existing data bus or by providing a safety-oriented design with an additional safety bus including a safety node.

The shaft doors are preferably self-locking; that is, they close automatically as soon as they are not actively kept open. The locks are also self-locking when the shaft door is closed.

For safety reasons, the locking devices used to lock the shaft doors shall preferably be designed so that they can only be unlocked, opened or closed by a cabin door provided for in the lift cab, or that they can be unlocked and pushed up by hand using a special tool.

The condition of the shaft door and its locking device is monitored by the locking sensor located at that shaft door.

The locking sensors may be used, for example, locking device contacts, micro-switches, inductive sensors, capacitive sensors or optical sensors.

The control of the lift system shall preferably be trained to evaluate the query of the locking sensors to trigger one or more predefined responses, in particular to detect and locate a fault, to trigger a service call, to stop an elevator cab or to perform any other situationally appropriate response when a shaft door is detected to be open.

The control may also be trained to evaluate the query of the locking sensors to correct detected transmission errors by evaluating multiple data packets.

In the case of the safety of the lift system, it is particularly advantageous to monitor the cabin door in addition to the monitoring of the shaft doors, which allows a statement to be made on the functioning of the shaft doors and/or the locking sensors of the shaft doors by means of a coincidence test of the signals of the shaft doors on the one hand and the cabin door on the other.

The main advantages of the arrangement according to the invention are: The safety of the elevator system is increased compared to an elevator system with a safety circuit in the safety system. Although the bridging of contacts is possible by software, it is detectable and can be removed after a predefined time. The safety also remains if, for example, a fault occurs or a service is performed.The monitoring system allows specific diagnostics because a fault can be immediately located and transmitted remotely.A precautionary maintenance is possible because the condition of the elevator, especially the sensors, can be analyzed.The availability of the elevator is increased.

The safety of the lift system can be further improved by the following measures: The cabin door monitoring can be implemented in a safety-oriented manner, which increases the significance of the coincidence test, and the sensor attached to the cabin door, the connected data bus and the bus nodes must be trained in a safety-oriented manner.

The following is a description of the invention by means of an example of an embodiment and with reference to the drawing. Fig. 1 an elevator system of the invention with a monitoring system, in a highly simplified and schematic representation.

The elevator system 10 shown in Figure 1 is designed to operate three floors A, B, C. There is a shaft door 11 on each of the floors A, B, C. The shaft door 11 is used to separate an elevator shaft in which an elevator shaft 12 can move up and down from the surrounding space with a cabin door 13 in the shaft. The movement of the elevator shaft 12 is carried out by means of a drive unit 14 and is controlled by a controller 16. In principle, the shaft door should only be available if the elevator shaft 12 is on the corresponding controller. The shaft door is controlled for this purpose by the gate 13 of the elevator shaft 12 with a cabin door 12 connected in a way that it is easily accessible by a sensor device designed to prevent the movement of the elevator shaft. The shaft door is also designed to be in contact with the controller, in particular the controller 16 and the controller 12 of the bus. The shaft door is connected to the controller 16 in a way that it is able to control the direction of the elevator shaft. The shaft door is designed to be in contact with the controller 16 and the controller 12 of the bus.

The lifting system 10 described above shall operate as follows:

A locking sensor 20 or locking device contact 20 associated with each locking device 18 or opening door 20 provides data or information on the condition of the locking device 18 or opening door. The data bus 22 transmits this data or information to the controller 16 which periodically evaluates the data or information received. The controller 16 interrogates the locking sensors 20 at short intervals of, for example, 20 ms, so that a communication disruption in the area of the data bus 22 or the bus nodes can be detected very quickly.

In addition to the continuous test described above, a further test is carried out at longer intervals. When the lift cab 12 has finished the approach to one of the floors A, B or C, the cab door opens. The shaft door 11 of the floor to which it is being carried is normally unlocked and opened by the cab door 13. The further test is carried out approximately once every 8 to 24 hours. The locking contact is tested 20. If it is found to be in order, a corresponding entry is made in a table, recording the condition 'contact in order' and the time of the test. The entry in the table enables the test to be carried out.

If the shaft door 11 opens but behaves unintentionally when opening, this indicates a minor fault in itself, for example wear or contamination in the area of the doors and/or the locking device 18 In this case the lifting system 10 may remain in operation at least temporarily, but it is advisable to provide for prompt close inspection and review by service personnel.

If the locking contact 20 does not open, it must be assumed that the contact is defective, but the locking has been released and the hatch door has been opened. In this case, the lifting cabin 12 must not be put into operation; the lifting system 10 must be taken out of operation and it is essential to call the service personnel. In this case, an unintended opening of the affected hatch door can no longer be detected.

Before leaving a floor, the shaft door and the locking device 18 are generally closed by the cabin door 13 and the locking is completed. This is done by checking whether the locking contact 20 indicates on the shaft side that the shaft door 11 is closed. At the same time, the closing condition of the cabin door 13 is monitored for safety purposes, allowing a coincidence check of the two locking operations and thus increasing safety. If the result of these two tests is positive, the lift cabin 12 can be started.

If, on the other hand, at least one of the tests mentioned is negative, a recovery test may be carried out, which involves several closing and opening of the doors. If the recovery test results in the closing and locking of the shaft door 11, the lifting system 10 may remain in operation, but a service should be considered, at least if repeated recovery attempts are required.

However, if the shaft door 11 is still open after the recovery test, the lifting system shall be shut off and service personnel shall be called.

If a shaft door is opened without the elevator cabin 12 having approached the corresponding floor, it must be concluded that the shaft door was opened from the outside; this can be done either by an instructor with a special tool or unjustifiably by force, as it is impossible to open the shaft doors accidentally or by mis-handling. The opening of shaft 11 is detected only by the non-security data bus. The non-security recording of this condition of the shaft door 11 hours can be considered sufficient, but for the following reasons: first, the occurrence of such a door is extremely rare. Second, the instructor of the event organiser is instructed to ensure that all potential threats are avoided by the door being opened accidentally or by mis-handling.

If the opening of the shaft door 11 is not from the lift cab 12 the lift system shall immediately switch off from its normal operating mode and shall not return to its normal operating mode without verification that the shaft door 11 is actually closed.

The main advantages of the new elevator system are: The absence of numerous safety bus connections leads to a considerable reduction in the cost of the system.Each lock connector is read and checked individually.Not only is it determined that a malfunction or fault has occurred, but the malfunction or fault can be precisely located, which makes it possible to quickly diagnose it if it does.Not only malfunctions and errors, but also the causes of malfunction or failure, can be prevented.The locking contacts can be switched off, but the state of the locking sensors or locking contacts, in particular the impact and voltage drop, can be recorded before a malfunction occurs. This information enables precautionary maintenance of the locking contacts.In many cases, this prevents the occurrence of malfunctions and errors due to failed locking contacts.An unnoticed overlap of the locking contacts is not possible because the control would detect a signal change at an unforeseen time.This further increases the security of the locking door monitoring.In the event of a malfunction, the fact that open locking contacts can be located allows the lift cabin to be moved to the next possible floor without having to cross the affected locking door with the contact; in any case, passengers will be able to open and not remain locked for a longer period of time.Thereafter, various reactions may occur: the lift may remain on the floor on which the passengers have disembarked and service personnel are called; or, if the lift is below the floor with the defective locking contact, the lift may be driven to a position where its cabin roof is slightly below the open shaft door, eliminating the risk of a person falling into the shaft through the open shaft door; or the lift may be driven at low speed and preferably with an acoustic signal to the affected floor with the shaft door open.And if it succeeds, the elevator system is back online.

Claims (10)

1. Lift system (10) with a lift cage (12) movable in a lift shaft by a drive unit (14), a control (16) for controlling the drive unit (14), a data bus (22) connected with the control (16), shaft doors (11) for closing the lift shaft, locking devices (18) for locking the shaft doors (11) at the shaft side and lock sensors (20) for monitoring the setting of the locking devices (18), wherein the lock sensors (20) are connected with the control (16) by way of the data bus (22), characterised in that a lock sensor (20) is repeatedly automatically interrogated by the control (16) at short intervals in time by way of the data bus (22) in order to be able to establish communications interruptions or transmission errors in the transmission by way of the data bus (22), and the function of a locking sensor (22) is detected in that the state of the locking sensor (20) is repeatedly automatically interrogated at long intervals in time with open and closed shaft door and made available to the control (16) by way of the data bus (22).
2. Lift system (10) according to claim 1, characterised in that the locking device is self-shutting when the corresponding shaft door (11) is closed.
3. Lift system (10) according to claim 1 or 2, characterised in that the locking devices (18) used for locking the shaft doors (11) are preferably so constructed that they can be unlocked, opened or closed only by a cage door (13) provided at the lift cage (12) or that they can be unlocked by a special tool and slid open by hand.
4. Lift system (10) according to one of claims 1 to 3, characterised in that there is monitored, by way of the locking sensor (20) at one of the shaft doors (11), the state (for example the position) of the locking device (18) of these shaft doors (11) and the state (for example the setting) of the shaft doors (11).
5. Lift system (10) according to one of claims 1 to 4, characterised in that the locking sensor (20) is a locking device contact, a microswitch, an inductive sensor, a capacitive sensor or an optical sensor.
6. Lift system (10) according to one of claims 1 to 5, characterised in that the control (16) evaluates the interrogation of the locking sensors (20) in order to be able to trigger one or more of the following predefined reactions: recognition and localisation of a fault; triggering of a service call; or, if an open shaft door was recognised, stopping lift cage or carrying out a situation-adapted reaction.
7. Lift system (10) according to one of claims 1 to 6, characterised in that the control (16) evaluates the interrogation of the locking sensors (20) in order to correct ascertained transmission errors by evaluation of several data packets.
8. Lift system (10) according to one of claims 3 to 7, characterised in that in addition to monitoring of the shaft doors (11) the cage door is also monitored in order to make possible, by means of a coincidence check of the signals of shaft door (11) and cage door (13), a statement about the functional capability of the shaft door (11) and/or the locking sensor (20) of the shaft door (11).
9. Lift system (10) according to claim 8, characterised in that the monitoring of the cage door (13) is carried out by a safety bus in order to increase safety.
10. Lift system (10) according to claim 1, characterised in that in addition to the locking sensors (20) further means for detecting the state of the shaft doors (11) are present, which transmit information about the state of the shaft door by way of the data bus (22) or by way of a safety bus to the control (16).