HK1240563B - A rescue apparatus and an elevator - Google Patents

Description

Rescue equipment and elevators

Technical Field

The subject matter described herein relates to a rescue device for an elevator, ie a device for rescuing elevator passengers from an elevator car.

Background Art

Sometimes an operational anomaly, such as a power failure, can cause the elevator car to stop between landings, outside the appropriate stopping area. One solution to remedy this situation is to manually disengage the traction machinery brake using the handbrake release lever. Disengagement of the machinery brake allows the elevator car to move toward the nearest landing by means of gravity.

The brake lever can be located, for example, in the elevator landing area, outside the elevator shaft. The brake lever is connected to the traction machinery brake via a brake-break wire (mechanical cable) so that when the brake lever is turned, the brake-break wire mechanically pulls the machinery brake.

The maintenance personnel keeps the mechanical brake disengaged by pulling the brake lever, visually observes the movement of the elevator car, and when the elevator car reaches the door area, returns the brake lever to the original position to stop the elevator car. When in the door area, the elevator car floor is at the same level as the landing floor, so that passengers can leave the elevator car and go to the landing.

This brake-disconnect mechanism must be located not too far from the traction machinery brake; otherwise, the length of the brake-disconnect cable can cause problems. As the length of the brake-disconnect cable increases, so does the force required to turn the brake lever. Dirt, corrosion, and the like can easily block the movement of very long brake-disconnect cables, complicating the brake-disconnect process/rescue operation.

On the other hand, sometimes it is beneficial to locate the handbrake disconnect interface (e.g., brake lever) away from the traction machine brake. For example, in some elevators, it is desirable to locate the handbrake disconnect interface at the lowest landing, while the traction machine/machine brake is located at the upper part of the elevator shaft.

A smooth rescue operation requires some experience in the use of brake levers. Therefore, there is a need for equipment that is easier to use but offers the same uncompromising safety.

Purpose of the Invention

In view of the above, the object of the present invention is to introduce an improved rescue device for an elevator that provides for flexible placement of a manual brake disconnect interface (hereinafter referred to as a "remote control unit") relative to the traction machinery brake. The present invention therefore discloses a rescue device according to a first aspect, an elevator according to a second aspect, and a conversion kit according to a third aspect. Preferred embodiments of the invention are described in the dependent claims. Some inventive embodiments and inventive combinations of various embodiments are presented in the description and drawings of this application.

Summary of the Invention

One aspect of the present invention is a rescue device for an elevator. The rescue device includes a brake control unit having input terminals for connection to a power supply, output terminals for connection to a magnetizing coil of an electromagnetic brake, and at least one controllable brake disconnect switch. The at least one controllable brake disconnect switch is associated with at least one of the input terminals and is adapted to prevent current from being supplied from the power supply to the magnetizing coil in a first switching state and to allow current from being supplied to the magnetizing coil in a second switching state. The rescue device also includes a control cable and a remote control panel. The control cable includes one or more control signal lines. The remote control panel is coupled to the brake control unit via the control cable. The remote control panel includes a manually operated drive switch. The manually operated drive switch is coupled to a control pole of the brake disconnect switch via a control signal line of the control cable.

Another aspect of the present invention is an elevator comprising an elevator car and a traction machine configured to drive the elevator car in an elevator shaft between landings based on service requests from elevator passengers, the traction machine including one or more electromagnetic brakes. The elevator includes a rescue device according to the present disclosure.

Another aspect of the present invention is a retrofit kit comprising a rescue device according to the present disclosure, which is suitable for being fitted into an elevator according to the present disclosure. This means that the rescue device according to the present disclosure can be introduced into old elevator installations to update the rescue functionality.

The disclosed rescue device has a simple structure; therefore, its operation can be analyzed in detail to achieve a high level of safety. The rescue device is also suitable for installation in various elevators because the position of the remote control unit relative to the brake control unit can be selected essentially freely. For example, unlike conventional brake levers using mechanical brake disconnect cables, the length of the control cable is not a limiting factor. In a preferred embodiment, the controllable brake disconnect switch of the brake control unit is a safety relay. This relay has mechanical contacts with a high isolation distance, thus ensuring high reliability during the magnetizing coil current interruption process. Consequently, reliable operation of the traction machinery brake is achieved even during rescue operations.

According to one embodiment, the brake control unit includes two controllable brake disconnect switches, each of which is adapted to independently block the supply of current to the magnetizing coil, and the remote control panel includes two manually operated drive switches, one of which is coupled to a control electrode of the first brake disconnect switch via a first control signal line, and the other drive switch is coupled to a control electrode of the second brake disconnect switch via a second control signal line. This means that the magnetizing coil current can be interrupted by two independent components (brake disconnect switches) that are independently controlled (via separate control signal lines, using the drive switches). Therefore, if one of the brake disconnect switches becomes stuck in the closed position for some reason, the other brake disconnect switch remains operable and the brakes can be applied by interrupting the magnetizing coil current.

According to one embodiment, the brake control unit comprises a switch state indicator for indicating a switch state of the brake disconnect switch.

According to one embodiment, the remote control panel comprises a manually operated mode selector switch connected in series with one or more actuation switches. This means that a rescue operation using the actuation switches is not possible until the mode selector switch is turned to the rescue position.

According to one embodiment, the power supply is a backup power supply. This means that by supplying current to the magnetizing coil from the backup power supply, rescue operations are also possible during mains outages.

According to one embodiment, the power supply is a DC backup power supply, and the main circuit includes a DC/DC converter for supplying power from the backup power supply to the magnetizing coil. This means that the DC/DC converter can be used to convert the low voltage of the DC backup power supply to a higher voltage for the magnetizing coil. In a preferred embodiment, the DC backup power supply is a battery.

According to one embodiment, the power supply is mains power. In a preferred embodiment, both the mains power and the backup power supply can be connected to the input terminal. In an embodiment, the control unit is configured so that power is supplied from the backup power supply only in the event of a mains power outage, otherwise power is supplied from the mains power.

According to one embodiment, the brake control unit further includes passage terminals for an output cable of the normal-mode brake control device, and a disconnect switch mounted between the passage terminals and the output terminals. A control electrode of the disconnect switch is coupled to a mode selector switch in the remote control panel via a control signal line, such that the disconnect switch is operable to selectively disconnect or connect the passage terminals from the output terminals based on the state of the mode selector switch. This means that by switching the mode selector switch to the rescue mode, the normal-mode brake disconnect device can be disconnected from the current supply circuit for the magnetizing coil in the rescue mode. Therefore, even if the normal-mode brake disconnect device malfunctions (for example, if the output of the normal-mode brake disconnect switch shorts), a rescue operation is still possible.

According to one embodiment, the disconnect switch is a transfer switch having a first input coupled to the access terminal, a second input coupled to the rescue current, and an output coupled to the output terminal. This means that when the mode selector switch is switched to normal mode, the brake control unit is also disconnected from the normal brake disconnect device during normal elevator operation. This reduces the possibility of failure of the brake control unit.

According to one embodiment, the mode selector switch has contacts in the elevator safety chain. When the mode selector switch is in rescue mode, the safety chain contacts of the mode selector switch are configured to be in an open state, and when the mode selector switch is in normal mode, the safety chain contacts of the mode selector switch are configured to be in a closed state. This means that by turning the mode selector switch to rescue mode (which interrupts the elevator safety chain), normal elevator operation can be prevented during a rescue operation.

According to one embodiment, the rescue device includes a controllable dynamic brake switch having terminals for coupling to the stator windings of a permanent magnet motor. The dynamic brake switch is adapted to generate a braking current from the electromotive force of the permanent magnet motor in a closed state, wherein a control electrode of the dynamic brake switch is coupled to the elevator safety chain such that the dynamic brake switch is in a closed state when the elevator safety chain is interrupted. This means that by switching the mode selector switch to rescue mode, dynamic braking can be activated from a remote control unit, thereby interrupting the elevator safety chain. Consequently, dynamic braking can also be used to reduce elevator car speed/acceleration during rescue operations, resulting in longer opening/closing intervals for the traction machinery brake (e.g., the brake opening/closing frequency can be reduced without triggering the safety device activation due to overspeed, which means that rescue operations are easier to perform).

According to one embodiment, the control cable includes a power line coupled to a backup power source, and the remote control unit includes an indicator of the backup power source status. This means that the operating status of the backup power source (e.g., a battery) can be monitored from the remote control unit. This is particularly useful if the backup power source is located in the elevator shaft and the remote control unit is located at the landing floor, outside the elevator shaft.

According to one embodiment, the brake control unit includes a solid-state switch associated with the output terminal for selectively preventing or enabling power to the magnetizing coil. This means that the solid-state switch can also be used to interrupt/restore power to the magnetizing coil. The mechanical brake disconnect switch is only necessary in selected operating situations (e.g., when releasing the actuation switch in the remote control unit). If the mechanical brake disconnect switch is used only when necessary, and the solid-state switch is used otherwise, the number of switching events of the mechanical brake disconnect switch can be reduced, and its lifespan can be increased.

According to one embodiment, the brake control unit includes safety logic having an output coupled to a control electrode of a solid-state switch and an input coupled to a switch state indicator for receiving information about the switch state of the brake disconnect switch. The safety logic includes a logic element configured to compare the received switch states of the brake disconnect switches and, if one of the brake disconnect switches remains in the closed state while the other brake disconnect switch changes from the closed state to the open state and then back to the closed state, block the supply of power to the output terminal. This means that the current supply to the magnetizing coil is blocked by the solid-state switch, so if both brake disconnect switches remain open between consecutive rescue operations, the brake will not disconnect (for example, if one brake disconnect switch opens, thereby interrupting the current supply to the magnetizing coil, the other brake disconnect switch must also open before the current supply to the magnetizing coil can be restored). In this way, it is possible to detect whether one of the brake disconnect switches has failed and is stuck in the closed position, thereby improving the safety of the rescue device.

According to one embodiment, the brake control unit includes a modulator coupled to a control electrode of a solid-state switch. The modulator is configured to adjust the output terminal voltage by modulating the solid-state switch. This means that after the brake is released, the output terminal voltage/magnetizing current can be reduced. When the brake is released, a lower magnetizing coil current is sufficient to keep the brake released. Therefore, by reducing the magnetizing current to a lower value (but this lower value is sufficient to keep the brake released), the power loss in the magnetizing coil can be reduced, and the increase in brake coil temperature can be reduced.

According to one embodiment, the remote control unit is arranged in the landing. This means that rescue operations can also be performed from the landing, outside the elevator shaft.

According to one embodiment, the traction machine, normal mode brake controller, brake control unit and backup power supply are arranged in close proximity to each other in the well. This means that only short power cables are required between them, which simplifies electrification and reduces possible EMC disturbances.

BRIEF DESCRIPTION OF THE DRAWINGS

Hereinafter, with reference to the accompanying drawings, the present invention will be described in more detail by means of some examples of its embodiments, which in themselves do not limit the scope of application of the invention, wherein

FIG1 shows a schematic diagram of an elevator according to an embodiment.

FIG2 shows a circuit diagram of a rescue device according to an embodiment.

FIG. 3 illustrates basic operating elements of an electromagnetic brake according to one embodiment.

FIG4 shows an elevator drive according to one embodiment.

DETAILED DESCRIPTION

For the sake of clarity, only those features that are considered necessary for understanding the present invention are shown in Figures 1 to 4. Therefore, for example, some components/functions that are well-known in the corresponding field may not be shown.

In the description, like reference numerals are used for like items throughout.

FIG1 is a schematic diagram of an elevator according to an exemplary embodiment. The elevator includes an elevator car 31 and an elevator drive. The main components of the elevator drive are further illustrated in FIG4 . The elevator drive includes a traction machine 23 and a frequency converter 40. As is known in the art, the traction machine 23 is configured to drive the elevator car 31 in an elevator shaft 33 between landings 34 based on service requests from elevator passengers.

A frequency converter 40 and a traction machine 23 are mounted near the top of an elevator shaft 33. The traction machine 23 includes a permanent magnet motor 22 and a rotating traction sheave (not shown) mounted to the axis of the permanent magnet motor 22. The frequency converter 40 is connected to the stator 21 of the permanent magnet motor 22 for supplying power to the permanent magnet motor 22. The elevator car 31 and the counterweight (not shown) are suspended by traction ropes (not shown). The traction ropes extend through the traction sheave of the traction machine 23. The permanent magnet motor 22 drives the traction sheave, causing the elevator car 31 and the counterweight to move in opposite directions within the elevator shaft 33.

Alternatively, the traction machine 23 and the frequency converter 40 can be located in the elevator shaft. The elevator system can also have separate traction and suspension cables. In this case, the traction cable can extend from the traction sheave of the traction machine 23 located in the shaft. Furthermore, the suspension cable can be connected to at least one pulley near the shaft top. The term "cable" is understood to refer to conventional round ropes and belts. Alternatively, the traction machine 23 and the frequency converter 40 can be located in a machine room separate from the shaft 33.

The elevator according to the present disclosure can also be implemented without a counterweight.

The hoisting machine 23 in Figure 1 includes two electromagnetic brakes 7 for braking the movement of the traction sheave. Figure 3 shows one of the brakes 7. The electromagnetic brake 7 includes a fixed brake body 35 fixed to the fixed body of the hoisting machine 23, and an armature 36 arranged to move relative to the brake body 35. A spring 37 is installed between the brake body 35 and the armature 36 to apply a thrust between them. An electromagnet with a magnetizing coil 6 is installed inside the brake body 35. The armature is driven against a braking surface 38 of the rotating part of the hoisting machine 23 by the thrust of the spring 37, thereby applying the brake 7. The brake 7 is released by energizing the magnetizing coil 6. When energized, the magnetizing coil 6 induces an attractive force between the brake body 35 and the armature 36. This attractive force further causes the armature 36 to disengage from the braking surface 38 against the thrust of the spring 37.

The normal mode brake controller 17 is connected to the magnetizing coil 6 of the brake 7 to selectively open or close the brake 7 during normal elevator operation. The normal mode brake controller 17 is located in the frequency converter 40, close to the traction machine 23 and the brake 7. In some alternative embodiments, the normal mode brake controller 17 is located in a control panel installed in the elevator landing 34. In normal mode, the brake 7 is opened when a new elevator run begins and is used to hold the elevator car 31 stationary at the end of the run. The brake 7 is controlled to open by supplying the desired amount of current to the magnetizing coil 6. The brake 7 is applied by interrupting the current supply.

In the event of a functional failure, the operation of the elevator car 31 may be interrupted in such a way that the elevator car 31 becomes stuck outside the landing 34, and the elevator passengers in the elevator car 31 are therefore unable to leave the elevator car 31. The functional failure may be caused, for example, by a power outage of the mains 3A, or by an operating error or malfunction of the elevator control system. For this reason, the elevator of FIG1 has a rescue device for performing a rescue operation, in which maintenance personnel return the stuck elevator car safely to the landing 34 so that the passengers can leave the car 31. This is performed by disengaging the brake 7 to move the elevator car 31 by means of gravity.

The rescue device includes a brake control unit 1, a remote control unit 12, and a backup battery 3B. The brake control unit 1 and backup battery 3B are located in the elevator shaft 33, close to the hoisting machine 23, the brake 7, and the normal-mode brake controller 17. The remote control unit 12 is located outside the elevator shaft 33, within a control panel 39 mounted to the landing door frame at the shaft entrance. The remote control unit 12 is coupled to the brake control unit 1 via a control cable 10.

Figure 2 shows a circuit diagram of the rescue device of Figure 1 . The brake control unit 1 has an input terminal 2A connected to a mains supply 3A, and an input terminal 2B connected to a backup battery 3B. Mains supply 3A can be, for example, a 230V AC voltage network. The brake control unit 1 also has an output terminal 4 connected to the magnetizing coils 6 of two electromagnetic brakes 7 . The brake control unit 1 also has a solid-state switch in the form of an IGBT transistor 25 associated with the output terminal 4 for selectively preventing or enabling power to the magnetizing coils 6 .

A DC/DC converter 16 is coupled between input terminal 2B and solid-state switch 25. DC/DC converter 16 supplies current from backup battery 3B to the input of IGBT transistor 25. Simultaneously, DC/DC converter 16 converts the voltage of battery 3B to the higher DC voltage required to magnetize coil 6. During normal elevator operation, battery 3B is charged using battery charger 43.

Brake control unit 1 includes two controllable brake disconnect switches 8A, 8B, and 9A, 9B in the form of safety relays. Both relays have two safety contacts 8A, 8B, and 9A, 9B. Safety contacts 8A, 8B, and 9A, 9B are associated with corresponding input terminals 2A and 2B. Each safety relay 8A, 8B, and 9A, 9B is adapted to block the supply of current to the corresponding magnetizing coil 6 independently of the other safety relay. This means that if one of the safety relays 8A, 8B, and 9A, 9B has its safety contacts stuck in the closed position, the other safety relay 8A, 8B, and 9A, 9B remains operational and can apply brake 7 by interrupting the current to magnetizing coil 6.

Safety contacts 8A, 8B; 9A, 9B are normally open (N.O.) contacts. They are attached to the main circuit of the brake control unit 1 so that in the open state, they prevent the supply of current to the magnetizing coil 6, and in the closed state, they allow the supply of current to the magnetizing coil 6.

The control cable 10 includes control signal lines 11A, 11B, 11C. As disclosed below, a control signal is transmitted from a remote control panel 12 to the brake control unit 1 via the control signal lines 11A, 11B, 11C.

The remote control unit 12 includes two manually operated drive switches 13A and 13B. One of the drive switches, 13B, is coupled to the control electrode 8C of the first brake release switches 8A and 8B via a first control signal line 11B, and the other drive switch is coupled to the control electrode 9C of the second brake release switches 9A and 9B via a second control signal line 11A. The remote control unit 12 also includes a manually operated mode selector switch having a contact 15A connected in series with the drive switches 13A and 13B. The mode selector switch 15 has two modes (positions): a normal mode (activating normal elevator operation) and a rescue mode (activating rescue operation). Mode selector switch contact 15A is closed in the rescue mode and open in the normal mode. When mode selector switch contact 15A is closed, the drive switches 13A and 13B receive a DC power supply voltage VCC. The DC power supply voltage VCC is supplied from the backup battery 3B via a control cable 11D.

When drive switch contacts 13A and 13B are manually closed (by operating a manual pushbutton), control voltage VCC is connected via control cables 11A and 11B to control coils 8C and 9C of the brake release switch safety relay, closing safety contacts 8A, 8B, and 9A, 9B. This has two effects: First, current can flow from mains 3A to IGBT transistor 25 through safety contacts 8A and 9A and diode bridge rectifier 41. Simultaneously, the closing of safety contacts 8B and 9B connects the control voltage of DC/DC converter 16, enabling operation of the DC/DC converter.

The remote control unit 12 includes an indicator 24 of the VCC voltage state, which also indicates the state of the backup battery 3B. The indicator 24 can be, for example, an LED. With the aid of the indicator 24, it is possible to check the condition of the backup battery 3B without entering the elevator shaft 33.

The remote control unit 12 also has an overspeed switch 42. The overspeed switch 42 is opened at a predetermined overspeed lever, so that the safety relay contacts 8A, 8B; 9A, 9B are opened.

Modulator 27 is coupled to the control electrode of IGBT transistor 25. Modulator 27 switches IGBT transistor 25 on and off at a high switching frequency according to a specific switching pattern to regulate the voltage at output terminal 4. Thus, the voltage at output terminal 4 can be reduced to avoid excessive power loss in magnetizing coil 6. On the other hand, the voltage at output terminal 4 can be temporarily increased to ensure proper opening of mechanical brake 7. As will be appreciated by those skilled in the art, the switching pattern depends on the modulation method used. Suitable modulation methods known in the art include, for example, pulse width modulation, frequency modulation, and hysteresis modulation.

The brake control unit 1 comprises a switch state indicator 14 for indicating the switch state of the safety contacts 8A, 8B; 9A, 9B. The switch state indicator 14 comprises optical couplers 14A, 14B coupled to the safety contacts 8B, 9B.

Brake control unit 1 also includes safety logic 26. Safety logic 26 has an output coupled to modulator 27 to selectively enable or block a control signal to the gate of IGBT transistor 25. Safety logic 26's inputs are coupled to the outputs of optocouplers 14A and 14B. Safety logic 26 comprises a logic circuit, which may be in the form of a discrete IC, a microcontroller, and/or an FPGA, for example. The logic circuit is configured to compare the switch states of safety contacts 8B and 9B and, if one of safety relay contacts 8B and 9B remains closed while the other changes from closed to open and then back to closed, block current from flowing through IGBT transistor 25. This specialized logic makes it possible to detect if one of brake disconnect switches 8A, 8B, 9A, 9B has failed and is stuck in the closed position. Furthermore, in such an event, brake 7 is prevented from disengaging, ensuring elevator safety.

Current is supplied from the normal-mode brake control device 17 to the magnetizing coil 6 via the brake control unit 1. In rescue mode, the normal-mode brake control device 17 is isolated from the magnetizing coil 6, and the brake control unit 1 is connected to the magnetizing coil 6 so that the brake control unit 1 can supply current to the magnetizing coil 6 without any interference from the normal-mode brake control device 17. Therefore, in normal mode, the brake control unit 1 is isolated from the magnetizing coil 6, and the normal-mode brake control device 17 is connected to the magnetizing coil 6 so that the normal-mode brake control device 17 can supply current to the magnetizing coil 6 without any interference from the brake control unit 1. This isolation function is implemented in the brake control unit 1 disclosed below.

The current supply cable for the normal-mode brake control unit 1 is connected to the bypass terminal 5 of the brake control unit 1. The current supply cable for the magnetizing coil 6 is further connected to the output terminal 4 of the brake control unit 1. The brake control unit 1 includes a changeover switch 18 having a first input 18A, a second input 18B, and an output 18C. First input 18A is coupled to the bypass terminal 5, and second input 18B is coupled to the rescue current supply, for example, to the current path from input terminals 2A and 2B. In the embodiment of FIG2 , second input 18B is coupled to the emitter of an IGBT transistor 25. Output 18C of the changeover switch 18 is coupled to output terminal 4.

The control electrode 18D of the disconnect switch is coupled to a manually operated mode selection switch 15A in the remote control panel 12 via a control signal line 11C.

When the mode selection switch 15A is turned to the normal operation state (off state), current is supplied from the normal mode brake control device 17, through the first input 18A of the changeover switch 18, and further via the output terminal 4 to the magnetizing coil 6. At the same time, the second input 18B remains off, thereby isolating the magnetizing coil 6 from the IGBT transistor 25.

When the mode selection switch 15A is turned to the rescue operation state (closed state), current is supplied from the input terminals 2A and 2B, through the IGBT transistor 25 and the second input 18B, and further via the output terminal 4 to the magnetizing coil 6. At the same time, the first input 18A remains open, isolating the magnetizing coil 6 from the normal mode brake control device 17.

One of the mode selector switch contacts 15B is located in the elevator safety chain 19. In this disclosure, the term "elevator safety chain" should be broadly interpreted to encompass both the traditional series-connected circuit of elevator safety contacts and the modern programmable electronic safety devices enabled by new elevator safety codes. Switch contact 15B is closed during normal elevator operation and opens in rescue mode. Opening switch contact 15B interrupts elevator safety chain 19. When interrupted, safety chain 19 prevents normal elevator operation, thereby enhancing the safety of rescue operations.

The rescue device of FIG1 also includes dynamic brake switches 20A and 20B. These are used to brake the rotation of the hoisting machine 23 during the rescue operation, thereby stabilizing the movement of the elevator car. The connection principle of the dynamic brake switches 20A and 20B is shown in FIG4 . When closed, the dynamic brake switches generate a braking current from the electromotive force of the permanent magnet motor 22 of the hoisting machine 23.

The terminals of dynamic brake switches 20A and 20B are coupled to the stator winding 21 of a permanent magnet motor 22. In the embodiment of FIG4 , dynamic brake switches 20A and 20B are normally closed (NC) contacts of a contactor or relay. This means that dynamic braking is always possible even when no control voltage is available (e.g., during a power outage). Alternatively, a solid-state switch (such as an IGBT transistor, a MOSFET transistor, a gallium nitride transistor, a silicon carbide transistor, etc.) could be used instead of a mechanical switch. The control coil 20C of the dynamic brake contactor is coupled to the elevator safety chain 19. When the switch contact 15B is opened (e.g., during a rescue operation), the current to the control coil 20C is interrupted, initiating dynamic braking.

The invention has been described above with the aid of exemplary embodiments. It is obvious to a person skilled in the art that the invention is not limited to the embodiments described above and that many other applications are possible within the scope of the inventive concept defined by the claims.

Claims (19)

1. A rescue device for an elevator, the rescue device comprising: Braking control unit (1), the braking control unit having: Input terminals (2A, 2B) are used to connect to a power supply (3A, 3B). Output terminal (4) is used to connect to the magnetizing coil (6) of the electromagnetic brake (7). At least one controllable automatic disconnect switch (8A, 8B; 9A, 9B) is associated with at least one of the input terminals (2A, 2B) and is adapted to prevent the supply of current from the power source (3A, 3B) to the magnetizing coil (6) in the open state and to allow the supply of current from the power source (3A, 3B) to the magnetizing coil (6) in the closed state; The rescue device is characterized in that it comprises: Control cable (10), the control cable including one or more control signal lines; Remote control panel (12), which is coupled to the brake control unit (1) via the control cable (10); The remote control panel (12) includes manually operated drive switches (13A, 13B), which are coupled to the control poles (8C, 9C) of the brake disconnect switches (8A, 8B; 9A, 9B) via the control signal line. 2. The rescue device according to claim 1, wherein the brake control unit (1) includes a switch status indicator (14) for indicating the switch status of the brake disconnect switches (8A, 8B; 9A, 9B). 3. The rescue device according to claim 2, characterized in that the control signal line includes a first control signal line (11B) and a second control signal line (11A), the brake control unit (1) includes two controllable brake disconnect switches (8A, 8B; 9A, 9B), both controllable brake disconnect switches being adapted independently of each other to prevent the supply of current to the magnetizing coil (6), the brake disconnect switches (8A, 8B; 9A, 9B) including a first brake disconnect switch (8A, 8B) and a second brake disconnect switch (9A, 9B), and The remote control panel (12) includes two manually operated drive switches (13A, 13B). One of the drive switches (13A, 13B) is coupled to the control electrode (8C) of the first brake disconnect switch (8A, 8B) via the first control signal line (11B), and the other drive switch (13A, 13B) is coupled to the control electrode (9C) of the second brake disconnect switch (9A, 9B) via the second control signal line (11A). 4. The rescue device according to any one of the preceding claims, characterized in that the remote control panel (12) includes a manually operated mode selection switch (15A), the manually operated mode selection switch (15A) being connected in series with one or more drive switches (13A, 13B). 5. The rescue device according to any one of claims 1-3, characterized in that the power supply includes a backup power supply (3B). 6. The rescue device according to claim 5, wherein the backup power supply is a DC backup power supply (3B), and the braking control unit (1) includes a DC/DC converter (16) for supplying power from the backup power supply (3B) to the magnetizing coil (6). 7. The rescue device according to any one of claims 1-3 and 6, wherein the power source comprises mains power (3A). 8. The rescue device according to claim 4, characterized in that the control signal line includes a third control signal line (11C), and the brake control unit (1) further includes a pass terminal (5) for the output cable of the normal mode brake controller (17); and The brake control unit (1) includes a disconnect switch (18) mounted between the access terminal (5) and the output terminal (4); and The control electrode (18D) of the disconnect switch is coupled to the mode selection switch (15A) in the remote control panel (12) via the third control signal line (11C), so that the disconnect switch (18) can operate to selectively disconnect or connect the path terminal (5) from the output terminal (4) based on the state of the mode selection switch (15A). 9. The rescue device according to claim 8, wherein the disconnect switch (18) is a transfer switch having a first input (18A) coupled to the passage terminal, a second input (18B) coupled to the current supply during rescue, and an output (18C) coupled to the output terminal (4). 10. The rescue device according to claim 4, characterized in that the mode selection switch has a safety chain contact (15B) located in the elevator safety chain (19); and When the mode selector switch is in rescue mode, the safety chain contact (15B) of the mode selector switch is configured to be in the open state, and when the mode selector switch is in normal mode, the safety chain contact (15B) is configured to be in the closed state. 11. The rescue device according to claim 10, characterized in that the rescue device includes a controllable dynamic braking switch (20A, 20B), the controllable dynamic braking switch having a terminal for coupling to the stator winding (21) of a permanent magnet motor (22), the dynamic braking switch (20A, 20B) being adapted to generate a braking current from the electromotive force of the permanent magnet motor (22) in a closed state, wherein the control pole (20C) of the dynamic braking switch (20A, 20B) is coupled to the elevator safety chain (19) such that when the elevator safety chain (19) is interrupted, the dynamic braking switch (20A, 20B) is in a closed state. 12. The rescue device according to claim 5, characterized in that the control cable (10) includes a power line (11D) coupled to the backup power supply (3B); and The remote control panel (12) includes an indicator (24) for the status of the backup power supply. 13. The rescue device according to any one of claims 1-3, 6 and 8-12, characterized in that the braking control unit (1) includes a solid-state switch (25) associated with the output terminal (4) for selectively blocking or allowing power to be supplied to the magnetizing coil (6). 14. The rescue device according to claim 13, characterized in that the braking control unit (1) includes safety logic (26) and a switch status indicator (14) for indicating the switch status of the brake disconnect switches (8A, 8B; 9A, 9B), the safety logic having an output coupled to a control electrode of the solid-state switch (25) and an input coupled to the switch status indicator (14), the input being used to receive switch status information of the brake disconnect switches (8A, 8B; 9A, 9B), the safety logic (26) including: A logic element configured to compare the received switching states of the brake disconnect switches (8A, 8B; 9A, 9B) and, if one of the brake disconnect switches (8A, 8B; 9A, 9B) remains in the closed state while the other of the brake disconnect switches (8A, 8B; 9A, 9B) changes from the closed state to the open state and then returns to the closed state, prevents the supply of power to the output terminal (4). 15. The rescue device according to claim 13, characterized in that the braking control unit includes a modulator (27) coupled to the control electrode of the solid-state switch (25), and The modulator (27) is configured to adjust the output terminal voltage by modulating the solid-state switch (25). 16. An elevator comprising an elevator car (31) and a traction machine (23), the traction machine being configured to drive the elevator car (31) between floors (34) in an elevator shaft (33) in response to service requests from elevator passengers, the traction machine (23) comprising one or more electromagnetic brakes (7), characterized in that the elevator includes a rescue device according to any one of claims 1 to 15. 17. The elevator according to claim 16, wherein the remote control panel (12) is disposed in the landing (34). 18. The elevator according to claim 17, characterized in that the elevator includes a normal mode brake controller (17) for controlling the one or more electromagnetic brakes (7) during normal elevator operation, the power supply includes a backup power supply (3B), and the traction machine (23), the normal mode brake controller (17), the brake control unit (1) and the backup power supply (3B) are arranged in the elevator shaft (33) in very close proximity to each other. 19. A retrofit kit comprising a rescue device according to any one of claims 1-15, the rescue device being adapted for installation in an elevator according to any one of claims 16-18.