The present invention relates to an inspection control system of an elevator system and a method for switching an elevator system between a normal operating mode and an inspection operating mode. The invention further relates to an elevator system having such an inspection control system.
An elevator system serves to transport people within buildings, wherein an elevator car is moved between different floors in an elevator shaft. In order to be able to guarantee the safety of passengers or service personnel, safety-relevant current states of a number of its components should be monitored within an elevator system. There are usually many serviceable and/or maintenance-requiring components in the elevator shaft. For the maintenance of such components or for carrying out regular inspection and maintenance work, the elevator system is put into an inspection operating mode or maintenance mode in which operation of the elevator car is blocked or the elevator car may move at a walking speed by manual control or can be moved only between specific positions within the elevator shaft.
In order to be able to carry out inspection and maintenance work in an elevator shaft, a service technician has to get into an elevator shaft via a shaft door, wherein a maintenance switch usually has to be operated before entering the elevator shaft, which is usually located inside the elevator shaft next to the shaft door. The maintenance switch can, for example, be referred to as an emergency stop switch which, when activated, can interrupt a so-called safety chain—also known as a safety circuit. The safety chain is a serially connected circuit having a discrete number of switches that are configured to indicate the status of the doors and the position of the elevator car. A door switch is typically provided on a car door and on each of a plurality of shaft doors, which switch is closed as long as the respective door is closed. Several door switches are connected in series as components of the safety chain, so that the safety chain as a whole is only closed when all door switches are closed. In this case, it can be assumed that all car and shaft doors are currently closed. The shaft doors are thus coupled with such a safety chain of the elevator system. If one of the shaft doors or door switches can be opened, the elevator car must not move or must no longer move. This can be implemented, for example, by interrupting a power supply to a drive of the elevator car.
An example of safety chains for elevator systems and their operation is given, for example, in EP 2214998 A1 (see WO 2009/073001 A1). The safety chain is a series circuit that comprises switches and contacts. The safety chain actuates relays that control the current to the electric motor and the brake. Some parts of the safety chain can be bridged, other parts can be inserted to change the safety monitoring for special operating modes during inspection, maintenance, and rescue operations.
For inspection and maintenance work, an easily accessible operating device is generally available in the shaft pit as an operating device in order to be able to control the elevator car manually during maintenance work. This device must be switched on by a changeover switch. After completing maintenance work and after leaving the elevator shaft, the inspection or maintenance mode can be ended by actuating, e.g. deactivating, the controller and the maintenance switch, and by closing or locking the shaft door and, as a result, the elevator system can be returned into regular drive operation in which the elevator controller can move the elevator car by closing the safety chain. In regular drive operation, the elevator car can be moved, for example, despite the presence of personnel in the elevator shaft. It is particularly dangerous that the safety chain is closed because of a software, control or switch contact error if, after an inspection/maintenance work, the operating device has already been deactivated but the maintenance switch has not yet been switched on. Such a case could often occur if the operating device is located in a deep shaft pit and the maintenance switch is arranged in a higher position next to a shaft door/maintenance hatch of the operating device. In this case a service technician who is in a shaft pit should normally first climb up a ladder after maintenance work to turn on the maintenance switch, then go back into the shaft pit and switch the elevator system from maintenance operation to normal operation using the operating device. Afterwards he has to climb up the ladder again, open a shaft door and step out of the shaft. Since it is too much effort or the technician has inadvertently not adhered to the sequence of operations, the elevator system could be put into normal operation with the maintenance switch not switched on while the technician is still in the shaft. If possible, such a dangerous scenario should be avoided.
EP 2033927 A1 relates to a safety device of an elevator system. If an elevator car with an open car door leaves a door zone or reaches a door zone at an impermissible acceleration or speed, a control signal for braking the elevator car is generated.
EP 1159218 A1 (see WO00/51929A1) describes an elevator safety system, wherein an electronic safety controller can communicate with a plurality of bus nodes via a safety bus. The electronic safety controller processes the data received from the bus nodes and determines whether there is an unsafe state, and if so, the safety controller sends a stop signal to the drive and brake unit and also sends a status signal to the elevator controller.
EP 2214998 A1 discloses a system for recognizing the presence of a person within an elevator shaft. The system comprises a passive infrared detector positioned for detecting infrared radiation from within the elevator shaft and a local processor that compares an infrared profile generated by signals from the passive infrared detector with a reference infrared profile to determine if a person is present in the elevator shaft.
DE 110201101050918 T5 (see WO 2013/084279 A1) relates to an elevator safety operating device which controls the operation of the elevator from a safety standpoint. Two reset switches 11 and 12 are disclosed which can set an elevator system from a maintenance operating mode to an automatic operating mode. The elevator safety operating device can determine the presence of a service technician with the aid of the reset switches. Before a safety chain can then immediately be connected to an electric motor, it must first be checked whether an already closed safety chain of the elevator system has really been completely closed. Such reset switches can be arranged inside or outside the shaft of the elevator system.
The invention is based on the task of ensuring the work safety of an elevator system not only during maintenance/inspection or installation work, but also afterwards when the elevator system is switched back to a normal operating mode. Among other things, there may be a need for a security measure that can be used to ensure that service personnel can safely enter or leave an elevator shaft.
According to the invention, an inspection control system of an elevator system is provided which comprises an elevator car and an electric motor, wherein the electric motor is able to drive the elevator car to move in a shaft of the elevator system, and wherein the shaft comprises at least one shaft door. The shaft door can be opened either alone or together with a car door of the elevator car. The inspection control system comprises a safety chain which comprises at least one door contact switch for determining or monitoring an open and/or closed state of the shaft door or the car door and an operating device in the shaft connected in series. The operating device comprises a changeover switch for switching the elevator system into a normal or inspection operating mode. The safety chain is closed in order to drive the elevator car via the electric motor, whereby a current path can be established between an electrical supply source and the electric motor. The safety chain is accordingly interrupted in order to interrupt the current path and thus to stop the elevator car. To control the safety chain and/or the current path, the inspection control system also comprises a manual switch outside the elevator shaft and at least one control element. The series circuit of the safety chain can be electrically closed or interrupted by activating or deactivating the control element, while the current path to the electric motor remains permanently interrupted until the manual switch is actuated when the changeover switch of the operating device switches the elevator system from the inspection operating mode to the normal operating mode.
In particular, that or at least one of the control elements can be activated by actuating the manual switch. The control element or at least one of the control elements can advantageously be deactivated by switching the elevator system into the inspection operating mode by means of the changeover switch. Since the safety chain can be controlled from the outside of the elevator shaft with the help of a control element, it is possible that the elevator system is first switched to normal operating mode and then, when service personnel have confirmed an exit from the shaft, is set to normal operation.
When the elevator system is switched from the inspection operating mode to the normal operating mode by means of the changeover switch on the control panel, the safety chain is closed, but it remains initially separated from the electric motor. In other words, although the elevator system is in normal operating mode in this case, it is not yet directly set to normal operation. A distinction must be made here that a normal operating mode is not the same as normal operation. Switching the elevator system to a normal operating mode means that the elevator system is now suitable for normal operation, but has not yet been set to normal operation. The safety chain is only then connected to the electric motor for driving the elevator car after the manual switch outside the shaft has been manually confirmed at least once. If the drive or the electric motor is viewed as part of the safety chain, it should be understood that the safety chain as a whole remains permanently interrupted until a service technician has manually operated the manual switch. The elevator system is only put into normal operation when the safety chain has been closed as a whole. It can thus be ensured that the technician remaining in the shaft is protected before he has left the shaft. If the operating device is located in the shaft pit of the elevator shaft, the inspection control system can be of great help to the technician, in particular, if maintenance/inspection work has to be carried out in the shaft pit or if he wants to move the elevator car when he is in the shaft pit. The elevator system can therefore be reliably put into an inspection operating mode and a normal operating mode without a dangerous movement of the elevator car being possible in the presence of personnel in the shaft or under certain circumstances with a potential risk.
According to an advantageous embodiment of the preceding invention, the control element is a control relay which comprises a control unit and one or more switches. Such a relay could, for example, be a current relay and is able to switch over all switches of this relay at the same time when current flows through its control unit. The control relay can control an operating switch connected in series to the safety chain in order to establish or interrupt the current path to the electric motor. One or more switches from the control relay(s) can serve as the operating switch. Because the operating switch is opened or closed, the electric motor can be blocked or released for driving. If all switches of the safety chain are physically or electrically closed, the safety chain is still separated from the electric motor by the operating switch. Even if a software error or faulty signal communication occurs and consequently a function of an elevator controller fails, the safety chain can be reliably connected in series.
According to an alternative advantageous embodiment of the preceding invention, the control element comprises one or more electronic circuits for controlling the safety chain and/or the current path. That is, instead of the control relay or relays, a different type of electronic circuit can be used, such as a programmable electronic system in safety-related applications (PESSRAL), which has the same function as the control relay or relays.
According to another advantageous embodiment of the preceding invention, the operating device comprises a control switch. The operating device can only control the electric motor via the control switch in the inspection operating mode for driving the elevator car. A control switch can for example be a direction switch, via which the elevator car can be controlled for moving in an upward or downward direction. By means of the electric motor, the elevator car is therefore driven to move automatically in the normal operating mode, for example under an elevator controller, and in the inspection operating mode under manual operation by means of the operating device.
According to another advantageous embodiment of the preceding invention, the safety chain has at least one further switch, which is provided for switching the safety chain, for deactivating the operating device, for preventing and/or for interrupting movement of the elevator car. Such an expansion option for the safety chain or the inspection control system can continue to ensure safety monitoring for the elevator system more reliably. The further switch can be an emergency stop switch, which is fastened, for example, to an inner wall of the elevator shaft or in the vicinity of a shaft door and/or is arranged on the operating device. By pressing the emergency stop switch, an immediate remedy can be obtained if the operating device fails and a hazard arises.
According to a second aspect of the invention, a method according to the invention for switching an elevator system between normal and inspection operation is provided, which comprises an elevator car and an electric motor, wherein the electric motor can drive the elevator car to move in a shaft of the elevator system, and wherein the shaft at least includes a shaft door. A safety chain is designed as a series circuit of at least one door contact switch and an operating device that is in the shaft, with an open and/or closed state of the shaft door being determined by the door contact switch. The elevator system is switched to a normal operating mode or an inspection operating mode by means of a changeover switch of the operating device. A current path is established between an electrical supply source and the electric motor by the closed safety chain for driving the elevator car and interrupted by the interrupted safety chain for stopping the elevator car. The safety chain and/or the current path can be controlled by a manual switch, which is arranged outside the shaft, and at least one control element in such a way that the series circuit of the safety chain is electrically closed or interrupted by activating or deactivating the control element, while the current path remains interrupted from the electric motor until the manual switch is actuated when the changeover switch of the operating device switches the elevator system from the inspection operating mode to the normal operating mode.
According to a third aspect of the invention, an elevator system according to the invention is provided with an inspection control system according to the invention or can be carried out by a method according to the invention.
It is pointed out that some of the possible features and advantages of the invention are described herein with reference to different embodiments of the inspection control system on the one hand and a method for switching an elevator system between a normal operating mode and an inspection operating mode on the other hand. A person skilled in the art will recognize that the features can be suitably combined, adapted, or replaced in order to arrive at further embodiments of the invention.
An advantageous embodiment of the invention will be described below with reference to the enclosed drawings, wherein neither the drawings nor the description is to be interpreted as limiting the invention. The drawings are only schematic and are not true to scale.
In which:
The inspection control system 2 can then switch and set the elevator system 1 to normal operation again. Now the technician releases the manual switch 7 or the manual switch 7 releases itself with a reset function. Current then no longer flows through the control unit S3 and it is deactivated, whereby the switches K3-1, K3-5 are closed and K3-2, K3-3 and K3-4 are opened. The safety chain 14 is again supplied from the power source 10a via the closed switch K3-1. The switching state of the safety chain 14 or the inspection control system 2 corresponds to the switching state shown in
In summary, an elevator system 1 which has an inspection control system 2 according to the invention or is controlled by this system is ensured when switching from an inspection operation to normal operation, because the elevator car 8 is prevented from moving if it is not determined whether a technician has left the shaft 5 of the elevator system 1 after an inspection work. This is independent of whether the safety chain 14 is closed or interrupted. Before manual actuation is carried out, it can also be understood that the drive of the elevator car 8, for example the electric motor 12, is always disconnected from an electrical supply source 10a, 10b.
Finally, it should be noted that terms such as “having,” “comprising,” etc. do not preclude other elements or steps, and terms such as “a” or “an” do not preclude a plurality of elements or steps. Furthermore, it should be noted that features or steps that have been described with reference to one of the above exemplary embodiments can also be used in combination with other features or steps of other exemplary embodiments described above.
It is pointed out that possible features and advantages of embodiments of the invention are described here partly with reference to a method according to the invention and partly with reference to a device according to the invention. A person skilled in the art will recognize that the individual features can be combined, modified, or exchanged in a suitable manner and that features described in particular for the method can be transferred analogously to the device and vice versa in order to arrive at further embodiments of the invention.
In accordance with the provisions of the patent statutes, the present invention has been described in what is considered to represent its preferred embodiment. However, it should be noted that the invention can be practiced otherwise than as specifically illustrated and described without departing from its spirit or scope.
1 elevator system
2 inspection control system
3 operating device
4 changeover switch
4
a inspection switch
5 shaft
5
a shaft pit
6 another or further switch
7 manual switch
8 elevator car
10
a a first power source
10
b a second power source
11 shaft door
12 electric motor
14 safety chain
15 door contact switch
16 control switch/direction switch
Kn-x a switch of the control relay (n=1 to 3, x=1 to 5)
S1-S3 control unit of the control relay
Number | Date | Country | Kind |
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18180696.9 | Jun 2018 | EP | regional |
Filing Document | Filing Date | Country | Kind |
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PCT/EP2019/066497 | 6/21/2019 | WO | 00 |