HK1171212B - Elevator rescue system - Google Patents

Description

Elevator rescue system

Technical Field

The present invention relates to an elevator rescue system for moving an elevator car to a landing position (disambiguation position) in a rescue operation.

Background

Modern elevators include rescue functionality to move the elevator car to a landing in an emergency and to allow passengers to land safely. An emergency situation is for example a loss of power due to a service interruption from the utility power grid. In this case, the elevator technician is called to perform a rescue operation, which involves moving the elevator car by releasing the brake that abruptly stops the elevator car in the event of an emergency. Electromagnetic brakes are commonly used in modern elevators, requiring a large amount of electric power for releasing the brake and performing rescue operations. This power is typically stored in batteries dedicated for rescue. Batteries used to store a sufficient amount of electrical energy are costly, large and cumbersome, and the required rescue functionality imposes undesirable limitations on the design of the overall elevator system. In addition, elevator rescue operations are often cumbersome because the rescue operation equipment, including the rescue operation battery and brake release circuit, is not easily accessible to elevator technicians. This results in longer rescue times, which in turn results in increased power requirements, since the rescue operation equipment must remain functional for an extended period of time.

Accordingly, it would be beneficial to provide an elevator rescue system that has low power requirements and is easy for elevator technicians to operate.

Exemplary embodiments of the present invention include an elevator rescue system for moving an elevator car to a landing position in a rescue operation. This elevator rescue system includes: a rescue apparatus coupled to a braking system of the elevator, the rescue apparatus comprising a rescue power source, wherein the rescue apparatus is disposed proximate to the braking system of the elevator; the operation panel comprises a manual rescue operation switch and is arranged far away from the rescue device; and a rescue operation signal transmission path between the rescue device and the operation panel.

Exemplary embodiments of the invention also include a method of moving an elevator car to a landing position in a rescue operation, the method comprising establishing a rescue signal transmission path between a rescue device and an operating panel, wherein the rescue device is coupled to a braking system of the elevator, the rescue device being disposed in proximity to the braking system of the elevator, and wherein the operating panel comprises a manual rescue operation switch, the operating panel being disposed remotely from the rescue device. The method further includes initiating rescue operation in response to receiving a signal from the manual rescue indication switch indicating a rescue operation initiation command.

Drawings

Embodiments of the invention are described in more detail below with reference to the accompanying drawings, in which:

fig. 1 shows a block diagram of a portion of an elevator system, the portion including an elevator rescue system.

Detailed Description

Fig. 1 shows a block diagram of a portion of an exemplary elevator installation. Said part comprising an exemplary embodiment of an elevator rescue system according to the invention. The elevator system comprises a drive 2 and a brake 4 for moving and stopping an elevator car (not shown). The elevator system may comprise an elevator car and a counterweight such that the drive 2 and the brake 4 move the elevator car and the counterweight simultaneously. The elevator can be a machine roomless elevator and the elevator car as well as the counterweight can be suspended in a two-to-one roping arrangement. The elevator system may also be a traction elevator system, wherein the drive 2 comprises a traction sheave for transmitting motion to one or more suspension members, such as ropes or a conveyor belt. However, the invention is applicable to a wide range of different kinds of elevator systems, e.g. traction elevators or hoisting elevators or hydraulic elevators, as well as different kinds of suspension/roping arrangements.

The elevator system also includes a drive and brake control 8 coupled to the drive 2 and the indicator 4. The drive and brake control 8 is also coupled to the power supply 6. A power supply 6 provides power to the elevator system. It may be coupled directly or indirectly to the power grid. Accordingly, the power supply 6 may provide AC power having 110-. Alternatively, a pre-conversion of the power received from the electricity network may be performed and the converted power may be provided to the elevator system by the power supply 6.

The elevator system also comprises a speed sensor 10, a door zone sensor 12 and an overspeed detector 14. It also includes rescue apparatus 16, rescue apparatus 16 in turn including switch controller 18, switch 20, and battery 22. A battery 22 is coupled to the power source 6 and the switch 20. Switch 20 is also coupled to brake 4 and switch controller 18 of rescue apparatus 16.

The elevator system also comprises an elevator control 24 coupled to the power supply 6. The elevator system further comprises an operating panel 26, the operating panel 26 being coupled to the power supply 6 and comprising a rescue controller 27, a rescue switch 28 and a battery 30.

Drive and brake control 8, speed sensor 10, door zone sensor 12, overspeed detector 14, rescue device 16, elevator control 24, and operator panel 26 are connected by a communication network 34, communication network 34 being a Control Area Network (CAN) bus in the exemplary embodiment of fig. 1. For accessing the communication network 34, the above-mentioned elements each comprise a network access point. For example, the operation panel 26 includes a CAN bus access point 26A. These access points are able to encode/decode data to be transmitted over the CAN bus in data packets conforming to the CAN bus standard and to control CAN-compliant access to the CAN bus. In the exemplary embodiment of fig. 1, the CAN bus 34 is organized using a ring topology. Link 32 connecting operator panel network access point 26A and rescue device network access point 16A is an exemplary portion of the ring topology. However, the communication network may be configured in a variety of different topologies, such as a star topology or a wire bus topology, as is known to those skilled in the art. The CAN bus allows all devices of the elevator system having CAN bus access points to exchange information according to a communication protocol common to all these entities.

It is noted that the CAN bus 34 may connect a large number of other components. Examples of these components are elevator call buttons at a separate landing, floor request buttons in the elevator car, elevator car position displays in the elevator car and at a separate landing, door closing sensors, etc. The CAN bus CAN also connect a plurality of elevator installations, e.g. a plurality of adjacent elevators, in order to allow joint elevator control, which coordinates the individual operations of a plurality of elevators.

It is also noted that power for low power applications may be transmitted via the CAN bus. For example, the door zone sensor 12 or the overspeed detector 14 or a floor request button (not shown) in the elevator CAN be supplied with power via the CAN bus 34. However, the driver 2 and the brake 4 require more power for their operation than CAN be transmitted over the CAN bus. Thus, the driver 2 and the brake 4 are not considered low power devices, and at least all electronic devices are considered low power applications.

Normal operation, i.e., non-emergency operation, of the exemplary elevator system of fig. 1 is as follows. As an example, consider the situation when a passenger enters an elevator car at a first floor, such as the bottom floor, and presses a floor request button on a second floor, such as floor 5. This passenger request is transmitted to the elevator control 24 via the CAN bus. The elevator control 24 then provides information on how the brake 4 and the drive 2 should be operated so that the elevator car starts moving in the direction of the requested landing. The operating control information is transmitted via the CAN bus 34 to the drive and brake control 8, where the information is processed. The control information is used to determine which "amount" of power is transferred from the power source 6 to the driver 2 and the brake 4. Different "amounts" of power may relate to different voltages, different currents, or different periods of power supply. To initiate movement of the elevator, an initial power level may be provided to the drive 2 by the drive and brake control 8, in association with appropriate power delivered to the brakes 4, in order to release the brakes 4. Thus, the elevator car begins to move toward the requested elevator landing. The speed of the elevator car is detected by a speed sensor 10. An exemplary embodiment of the speed sensor 10 is an optical sensor comprising a plate with an aperture, said plate being attached to the drive shaft of the driver 2, and a combination of a light emitter and a light receiver, which are positioned at respective sides of the plate, and the number of rotations is calculated by counting the number of times light is received through the aperture of the plate. In addition, the door zone sensors 12 can detect the relative positioning of the elevator car with respect to the individual landing. To this end, the elevator car and the individual landing may comprise interactive devices such that when the elevator car is in the vicinity of the elevator car landing, either the landing part of the door zone sensor 12 is able to detect the car part of the door zone sensor 12 or the car part of the door zone sensor 12 is able to detect the landing part of the door zone sensor 12. The interaction may be an optical interaction or a magnetic interaction or any other form of interaction suitable for proximity detection.

Based on the previously transmitted control information and the information received from the speed sensor 10 and the door zone sensor 12, the elevator control 24 continuously determines updated control information and transmits said control information to the drive and brake control 8 via the CAN bus 34. In this way a control loop is established in which the elevator control 24 reacts to the signals from the speed sensor 10 and the door zone sensor 12 by controlling the drive and brake control 8 such that the drive 2 and the brake 4 achieve the desired behavior of the elevator car. In the above example, the elevator car is moved to the landing requested by the passenger and stopped when the floor of the elevator car is level with the requested landing.

It is noted that the elevator control 24 may alternatively be integrated in the drive and brake control 8.

The rescue operation of the elevator system is described below. Switching from the normal mode of operation to the rescue mode of operation may be triggered by a variety of different events. For example, a loss of power from the power supply 6 may terminate the normal operating mode. As a consequence of the loss of power from the power supply 6, no power will be supplied to the driver 2 and the brake 4 via the drive and brake control 8. Since the brake 4 is an electromagnetic brake in the exemplary embodiment of the elevator system, a loss of power will cause the brakes to be applied. In addition, no power will be supplied to the drive 2, so that the elevator car and the counterweight will stop. In another example, one of the safety chains of the elevator system may be interrupted, which causes a switch to the rescue operation mode. A safety chain may be defined as a series of checks of safety-related functionality that are performed periodically in order to ensure safe operation of the elevator system at any time. If one of these checks fails, a rescue mode of operation may be activated. In this case the connection between the power source 6 and the drive 2 and the brake 4 via the drive and brake control 8 is interrupted, so that the elevator car stops.

The decision to switch from the normal operation mode to the rescue operation mode can be made, for example, by the elevator control 24. Since the elevator control 24 is coupled to the power supply 6, it is able to detect a loss of power. The elevator control 24 may also be responsible for performing safety chain checks. If the elevator control 24 determines that power is lost or the safety chain is broken or another predefined event of performing a switch to the rescue operation mode, the elevator control 24 will issue a corresponding message via the CAN bus 34. In reaction to this signal indicating a switch to the rescue operation mode, the elevator system, in particular the drive and brake control 8, is disconnected from the power supply 6. Rescue operation mode is performed using the battery of rescue apparatus 16 and the power stored in battery 30 of operation panel 26. This separation ensures that undesirable effects caused by power supply inconsistencies do not occur during rescue operations. It is noted that the message indicating the loss of power and/or interrupting the safety chain and/or another predefined event may be generated and allocated by parts of the elevator system other than the elevator control 24, as long as these parts are suitable for detecting such events.

In the exemplary embodiment described in connection with fig. 1, the rescue operation is controlled by an operation panel 26. To this end, the operation panel 26 includes a rescue controller 27. The rescue controller 27 is supplied with electric power from a battery 30 of the operation panel 26. After the rescue operation mode has been initiated, the rescue controller 27 of the operation panel 26 issues a message to the nodes of the CAN bus to turn off the respective associated devices. For example, indicating to the speed sensor 10 that the speed of the elevator car is not to be measured until other indications are received. The operator panel 26 is also adapted to provide power to the CAN bus 34 in order to keep the communication network active. The power is provided by a battery 30. At this point, however, the operating panel 26 stops providing power for low power applications, such as the speed sensor 10, that are not connected to the power supply 6 and that also receive power via the CAN bus 34 in normal operation. In the particular embodiment of fig. 1, transmission link 32 between rescue device 16 and operating panel 26 is still supported, i.e., switch controller 18 is still provided with power from battery 30 of operating panel 26. Thus, it is ensured that switch controller 18 of rescue device 16 keeps switch 20 open, so that brake 4 stays in the applied state, which is transferred to operation panel 26. Thus, any kind of movement of the elevator car is prohibited until the elevator technician manually operates the rescue switch 28 of the operation panel 26.

In the exemplary embodiment, rescue switch 28 includes three positions, namely a normal operating position, a rescue operating position, and a stop position. Rescue switch 28 is manually operable. Since the rescue switch is required to be in the normal operation position for the normal operation of the elevator system, the rescue switch is still in the normal operation position when the elevator operator touches the operation panel to perform the rescue operation. To begin the process of moving the elevator car to a safe landing position, the elevator technician switches the rescue switch 28 to a rescue operation position. In response to the operation of rescue switch 28, rescue controller 27 of operation panel 26 issues activation signals to all devices involved in the actual rescue operation via CAN bus 34. In the present embodiment, rescue apparatus 16, door zone sensor 12 and overspeed detector 14 are activated and supplied with power from battery 30 via CAN bus 34 to be operable.

The elevator car is then moved to a safe landing position, as described below. Rescue controller 27 of operation panel 26 issues a message to switch controller 18 of rescue apparatus 16 to release brake 4. In response, the switch controller 18 closes the switch 20 so that power is provided to the brakes 4 by the battery 22. In the case of a sufficient weight difference between the elevator car and the counterweight, the elevator car and the counterweight will start to move. The direction of movement depends on which elements-the counterweight or the elevator car containing the load/passengers-are heavier. For the sake of illustration, it is assumed that the counterweight is heavier than the elevator car carrying a small load, such as a passenger. In this case the release of the brake 4 will move the elevator car upwards, since the counterweight is heavier than the elevator car. For practical reasons the landing position is selected as the landing position that is closest to the current position of the elevator car in the upward direction.

With the brake 4 in the released position, the elevator car remains accelerating. The elevator car speed is monitored by an overspeed detector 14. When the elevator car reaches a critical speed, the overspeed detector 14 sends a message to the operating panel 26 via the CAN bus 34. In the context of a rescue operation, a critical speed may be defined as the maximum elevator car speed that still allows a sudden stop of the elevator car without any potentially dangerous impact on the passengers. In response to the message from overspeed detector 14, rescue controller 27 of operation panel 26 generates a message for the rescue apparatus indicating that brake 4 should be applied again. In response thereto, the switch controller 18 opens the switch 20 so that the power supply from the battery 22 to the brake 4 is interrupted. Thus, the brake 4 is applied and the elevator car is stopped. The overspeed detector 14 then indicates in a message to the operating panel 26 that the speed of the elevator car has dropped below the critical speed. Therefore, rescue controller 27 of operation panel 26 sends a message to rescue device 16 over CAN bus 34 indicating that brake 4 should be released again. Correspondingly, the elevator car will pass through a circulation that is accelerated by the weight difference of the elevator car and the counterweight and stopped by the application of the brake 4. The speed of the elevator car follows a sawtooth-like function over time, repeatedly exhibiting a substantially linear increase in speed before the critical speed is reached and a substantially immediate stopping of the elevator car.

In this exemplary embodiment, this repetitive movement pattern is changed when the elevator car approaches a safe landing position. When the door zone sensor 12 detects an elevator car near the landing's intended floor landing, it sends a corresponding message to the operating panel 26 via the CAN bus 34. In response, rescue controller 27 of operation panel 26 sends a message to rescue device 16 requesting switch controller 18 to close/keep switch 20 open for a short interval and then reopen switch 20 so that brake 4 is in the released state for only a short interval before reapplying. Then, the rescue controller 27 of the operation panel 26 waits for an update from the door zone sensor 12 indicating the current distance of the floor of the elevator car to the floor landing. Depending on that distance the rescue controller 27 requests the rescue device for a suitably short interval of movement of the elevator car so that it is ensured that the elevator car does not cross the target position. The rescue algorithm executed in the rescue controller 27 of the operating panel 26 is adapted to respond to the distance between the floor of the elevator car and the target landing position indicated by the door zone sensor 12, so that it is possible for the elevator car to stop exactly at the desired floor level. This enables even a safe landing of a disabled passenger sitting in a wheelchair.

The control of the rescue operation performed in the rescue controller 27 of the operation panel 26 may be implemented in various different ways. Regardless of the specific algorithm, a control loop is established in which rescue controller 27 of operating panel 26 receives messages relating to the state of the elevator car, e.g. from door zone sensor 12 and overspeed detector 14, via CAN bus 34, and sends control messages to rescue apparatus 16. The particular rescue operation algorithm may also depend on the devices available during the rescue operation and the particular configuration of these devices. For example, the speed sensor 10 may be activated and used during a rescue operation. In this case, the speed sensor 10 periodically transmits elevator car speed information to the operating panel 26 via the CAN bus 34. Since there are more information available to rescue controller 27 of operation panel 26 than provided by overspeed detector 14, which provides only a piece of binary information (whether a critical speed is exceeded or not), there are more options for designing the control algorithm for the rescue operation. Specifically, the predicted elevator car speed may be calculated in advance, and preventive control measures may be taken by the rescue controller 27 of the operation panel 26. This is particularly useful when switch 20 of rescue apparatus 16 is not only an on-off switch but allows at least one intermediate state. This intermediate state caused by a specific control signal of the switch controller 18 causes a fraction of the maximum possible power to be supplied from the battery 22 to the brakes 4, which in turn causes a partial release of the brakes 4. In other words, the brake 4 will be applied with a fraction of its maximum braking force. In this way, multiple acceleration/deceleration rates may be achieved. Providing a speed sensor 10 for a rescue operation and/or providing a switch 20 that is not just on and off allows finer control of the rescue operation and more uniform movement of the elevator car during the rescue operation.

Up to this point, the rescue operation has been described as a process triggered by manual operation of the rescue switch 28 and thereafter machine control. This is advantageous insofar as not only trained elevator technicians, but virtually everyone, such as a back office manager often present in a building, can perform rescue operations. In an alternative embodiment, the control algorithm executed by rescue controller 27, which may be applied to operator panel 26, is monitored manually. For this purpose, rescue switch 28 may be placed in a stop position. The corresponding positioning of rescue switch 28 will direct rescue controller 27 of operating panel 26 to generate a message that will be sent over CAN bus 34 to switch controller 18 of rescue apparatus 16 to open switch 20. In order for an elevator technician handling rescue switch 28 to make an informed decision, operating panel 26 may be equipped with a display that displays elevator car status data to the elevator technician. Such data may be exemplarily acquired by the speed sensor 10 and/or the door zone sensor 12 and/or the overspeed detector 14. Such a display may be an LED array or an LCD screen or any other component suitable for communicating elevator car status information to a user. Accordingly, the elevator technician has the option of overriding the rescue algorithm executed by rescue controller 27 of operator panel 26. As one example, this allows elevator technicians to brake the elevator car at a lower speed than the speed that the automatic control would have been had, which may be desirable when the elevator car is carrying extremely sensitive loads, such as patients in hospitals.

In one particular embodiment, a continuous exchange of inspection messages may be established between rescue device 16 and operating panel 26. This continuous exchange will indicate to each of the two devices that the other device is still operational and working and ready to receive and process messages and/or user input. On the other hand, switch controller 18 of rescue device 16 ensures that any control messages from operation panel 26, whether caused by operation of manual rescue switch 28 or by messages from speed sensor 10 or door zone sensor 12 or overspeed detector 14, will safely reach rescue device 16. On the other hand, the rescue controller 27 of the operating panel 26 ensures that the switch controller 18 of the rescue device 16 will be able to react quickly to control messages sent over the CAN bus 34. These check messages may include timestamps that control the communication latency introduced by the transmission of the messages over the CAN bus 34. The strict time-out requirement of these check messages may ensure that a rescue operation is only performed when a timely reaction to user input or updated elevator car status information is guaranteed. The continuous exchange of check messages can be extended to other devices that are critical to passenger safety in rescue operations, such as overspeed detector 14. The communication network protocol, in particular the CAN protocol, may be adapted in a way to allow such check messages and timeout requirements. When the successful cross-check of the safety-critical device is no longer successful, the switch controller 18 of the rescue device 16 will open the switch 20 in order to apply the brake 4. This decision can be made by the switch controller 18 itself or can be triggered by a corresponding message from the rescue controller 27 of the operating panel 26. The rescue operation can continue when a timely exchange of check messages is again achieved.

In an alternative embodiment, control of rescue operations may be performed by a rescue controller included in rescue apparatus 16. This alternative rescue controller and switch controller 18 may form one control module or may form separate entities capable of exchanging information. This means that messages from speed sensor and/or door zone sensor 12 and/or overspeed detector 14 are received by rescue apparatus 16 and an alternative rescue controller determines control information for switch 20 based on these messages. Only the state of manual rescue switch 28 is transmitted from the operation panel to rescue device 16. Additionally, CAN bus 34 may be powered by battery 22 of rescue apparatus 16 through a corresponding circuit. In addition, operating panel 26 may be provided with power from battery 22 via CAN bus 34 in order to detect the position of rescue switch 28 and communicate that information to rescue apparatus 16. In this case, operation panel 26 need not be equipped with a battery, so that all of the power used in rescue operation can be provided solely by battery 22 of rescue device 16. Between the start of an emergency and the manual operation of rescue switch 28 to the rescue operation position, rescue device 16 may keep operation panel 26 activated and constantly exchange status check messages with operation panel 26 via CAN bus 34 in order to ensure that the manual operation of rescue switch 28 is timely communicated to rescue device 16. The rescue algorithm may be performed by a rescue controller of rescue apparatus 16.

As mentioned above, in a situation in which the elevator car comprising the load is substantially as heavy as the counterweight, the release of the brake 4 may not be sufficient to start the movement of the elevator car. In order to still be able to perform a rescue operation, battery 22 of rescue device 16 may be connected to drive 2 or to another drive via a second switch of rescue device 16. This second switch may also be controlled by switch controller 18, which switch controller 18 in turn is controlled by a rescue operation control message generated by rescue controller 27, e.g. operation panel 26, and transmitted via CAN bus 34. In this way the drive 2/the further drive and the brake 4 can work together to move the elevator car to a safe landing position. An elevator car weight sensor may be used as a means to indicate this weight equality. Also the output from the speed sensor 10 showing an approximate zero speed of the elevator car after the expiration of the normal time frame during which the elevator car usually starts moving after the release of the brake can be used as an indicator that this situation exists.

The positioning of the elements of the elevator system of fig. 1 is discussed below. In many elevator installations, the drive 2 and the brake 4 are located in the upper part of the elevator system. For example, they may be located in a machine room above the elevator hoistway. In a machine roomless elevator system, the drive 2 and brake 4 may be located in the overhead space of the elevator hoistway, which is defined as the space between the top of the elevator car in its uppermost operating position and the ceiling of the hoistway. The drive 2 may be coupled by a drive shaft to one or more traction sheaves, which interact with one or more suspension members for driving the elevator car and counterweight, which suspend the elevator car and counterweight. A brake 4 can also be connected to the drive shaft, which brake is adapted to stop the rotation of the drive shaft, thereby braking the elevator car. In such a machine roomless elevator system, rescue device 16 may also be located in the overhead space of the hoistway. This allows a very short distance between the battery 22 and the brake 4. The short distance between battery 22 and brake 4 reduces losses associated with power transmission during rescue operation, since a large amount of power is required to drive the electromagnetic brake. This in turn allows for a smaller battery 22 that is lighter, easier to locate in overhead space, smaller, and less expensive. The operator panel 26 may be located anywhere that is readily accessible to an elevator technician initiating and supervising the rescue operation. For example, the operator panel 26 may be associated with an elevator call panel at the bottom floor of a building. However, the operator panel 26 may be located behind the upper lock door. In another exemplary embodiment, the operation panel 26 is provided in a facility management room located on the bottom floor or basement of a building.

The exemplary embodiment of the invention as described above allows for high energy efficient rescue operations to be performed, which elevator technicians can start and supervise from an easily accessible location. The electrical losses associated with this power transfer are kept low due to the proximity between the rescue power supply and the braking system. This energy saving effect is particularly sufficient because the commonly used electromagnetic elevator brakes are high power devices which require a large amount of power to be transmitted to them each time they are activated. Furthermore, in a typical rescue operation, the brakes are continuously released and reapplied, which results in many instances of power transmission. Since the provision of a rescue operation signal transmission path between the rescue device and the operation panel allows remote control of the rescue operation, the positioning of the rescue device can be chosen at will in order to minimize losses associated with the transmission of power during the rescue operation. The accessibility of the rescue device does not have to be considered as a design criterion. In addition, the operating panel, which may serve as the sole remote control of the rescue device, can be realized to have a small size and can be positioned in virtually any location deemed to be readily accessible in an emergency situation.

With regard to the feature that the rescue device is arranged in the vicinity of the brake system of the elevator, the term "vicinity" can be defined geometrically or electrically. In geometrical terms "near" may be understood to describe a distance spanning less than 50% of the floors of the elevator system, in particular less than 25% of the floors of the elevator system. In this context, all floors of the elevator system can be considered. Alternatively, only the bottom floor and all floors above, i.e. all floors except the basement platform, may be considered. The braking system and the rescue device can be located at the same floor, in particular at substantially the same height. In the lateral dimension, the brake and rescue device may not be separated by a distance that exceeds the maximum lateral extent of the hoistway, e.g., the diagonal of a square hoistway. Electrically, "proximity" may be defined in terms of electrical losses associated with the transfer of power from the power source to the braking system. In this electrical context, an arrangement may be referred to as "near" when the loss of the power line between the power source and the braking system is reduced by more than 50%, in particular more than 75%, compared to a situation where the power source is located at the bottom floor of a building and the braking system is located substantially at the top of the elevator hoistway. For a fair comparison, the same cable may be assumed when power transmission losses are considered. To illustrate the large potential for power savings associated with such a nearby arrangement of power supply and brake system, the following numerical example is given. An exemplary building may have 10 floors with a cable length of 50m between the floor and the top of the hoistway. The brake may consume 250W. The voltage provided by the power supply may be 48V. Accordingly, the brake current may exceed 5.2A (due to transmission losses). At such high current values, the reduction of the cable length has a significant impact in terms of power savings. Similarly, the term "remote" may be understood to mean a distance spanning more than 50% of the floors of the elevator system, in particular more than 75% of the floors, in particular substantially all the floors of the elevator system. The elevator floors considered can again include or exclude basement floors.

It is noted that the elevator rescue system is part of an elevator system. Thus, an elevator rescue system can include devices that are not used during normal operation of the elevator as well as devices that are used during normal operation of the elevator. In other words, the use of a particular part of the elevator system during normal operation does not prevent this part from being part of the elevator rescue system. In addition, portions of the elevator rescue system may have functionality for uses other than rescue operations. For example, the operating panel may comprise all functionalities that are normally considered as a so-called service panel, e.g. functionalities for performing brake tests of the elevator system.

In another embodiment of the invention, the rescue operation signal transmission path is part of an elevator control communication network comprising a plurality of nodes. Modern elevator installations comprise a communication network for collecting information that underlies elevator control and for allocating elevator status information, e.g. for display to users/passengers. The rescue operation signal transmission path being part of this elevator control communication network thus allows the use of existing resources for enabling communication between the operation panel and the rescue device in a rescue situation. Therefore, no communication infrastructure exclusively dedicated to rescue operation functionality must be included in the elevator rescue system. In this elevator control communication network, the rescue operation signal transmission path may be a direct link between two nodes. However, the rescue operation message may be routed through one or more intermediate nodes such that the rescue operation signal transmission path includes a plurality of branch lines. The elevator control communication network may be a wired communication network or a wireless communication network.

The elevator control communication network may comprise a CAN bus, wherein the rescue operation signal transmission path is part of the CAN bus. The CAN bus standard provides a well-defined set of communication protocols. However, extensions to these protocols are possible. Thus, an elevator control communication network comprising a CAN bus has the advantage of providing a means of embedding rescue operation communication in an existing and reliable framework, wherein existing resources CAN be efficiently used.

In another embodiment, an elevator rescue system is configured to provide power for low power applications via an elevator control communication network. This allows for the use of multiple devices, such as overspeed detectors, during rescue operations without having to equip the devices with individual power supplies. Accordingly, the number of batteries for rescue operation purposes in the entire elevator system can be kept low, which is advantageous in terms of reliability, maintenance and cost. A low power application may generally be all devices not associated with the movement of the elevator car, i.e. all devices except the elevator drive and the elevator brake which require a lot of power. Examples of low power devices are all electronic devices, such as control units, sensors and display devices.

In another embodiment, the elevator rescue system is configured to deactivate nodes of the elevator control communication network that are not associated with devices involved in the rescue operation. In this way, the communication network may be reduced to those parties relevant for the rescue operation, which results in less power intensive operation of the communication network during the rescue operation, which in turn allows for reduced battery size. The disabling may be via software control messages. Alternatively, it may be done via hardware, wherein when the elevator control communication network is organized in a star topology, the control node disconnects the link to the device not involved in the rescue operation.

It is also possible that the elevator rescue system is configured to narrow the elevator control communication network to the rescue operation signal transmission path until the manual rescue operation switch is operated. Since the activation and deactivation of specific communication network nodes is configured in an adaptive manner, further power savings can be achieved by ensuring only communication between the operation panel and the rescue device for the period between the start of an emergency and the start of an actual rescue operation triggered by the operation of the manual rescue operation switch.

In another embodiment, an elevator rescue system is configured to communicate a state of a manual rescue operation switch through a rescue operation signal transmission path. This allows to achieve a complete control of the rescue operation in the rescue device, which results in a very low communication burden on the rescue operation signal transmission path, since only one piece of information will be transmitted from the operation panel to the rescue device.

In another embodiment the elevator rescue system further comprises an elevator car speed sensor and/or an elevator car position sensor for determining a state of the elevator car, which state comprises elevator car speed information and/or elevator car position information. The collection of elevator car status information allows to check whether the rescue control causes the expected behavior of the elevator car. In this way, a control loop can be implemented. However, it is also possible that sufficient state information of the elevator car, e.g. the exact position and weight, is known at the point where the emergency situation occurs and that a rescue operation command sequence can be generated, which causes the elevator car to reach a safe landing position without a control loop. Although this is possible, an advantage of the implementation of the control loop is that the accuracy and timing requirements of the devices used are not as stringent.

The elevator rescue system may be configured to communicate the status of the elevator car over an elevator control communication network.

According to another embodiment, an elevator rescue system includes a controller configured to determine a braking control signal based on a state of an elevator car and a state of a manual rescue operation switch. The controller receives feedback on the effect of its control commands and can adapt these control commands accordingly. Thereby ensuring reliable, safe and efficient movement of the elevator car to the landing position. The controller may be associated with the operating panel or with the rescue device. Accordingly, the number of devices communicating over the elevator control communication network during a rescue operation is kept low. However, the controller may be provided at a location other than the operation panel or the rescue device. The elevator rescue system may also be configured to operate the brakes using power provided by the rescue power supply in response to the brake control signal.

In another embodiment, the controller is configured to automatically determine the brake control signal upon bringing the manual rescue indication switch into a rescue operation state. Thus, manual application and release of the brake is not required. The person performing the rescue operation switches the manual rescue switch on/off only once, wherein the subsequent rescue operation is realized by a control algorithm, for example a control algorithm realized by software. The controller may perform a rescue operation depending on the status information relating to the elevator car. Such status information may be provided by an elevator car speed sensor and/or an elevator car position sensor.

It is to be noted that the term "rescue operation" as used in the present invention denotes throughout the operation from the emergency stop of the elevator car to the arrival at the safe landing position. Further, the communication network may be characterized as being operable to enable information exchange via a communication protocol. Parts of the communication protocol, such as the access functionality, may be implemented in a node of the communication network. The term "controller" may be understood as a control unit in a non-limiting manner. It can be understood as the capacity of the computing functionality for control. The computing functionality may be distributed over a communication network, e.g., multiple sub-controllers in communication with each other, which may be associated with different nodes of the communication network. The computational functionality of the node may also be used to execute the control algorithm in whole or in part.

In another embodiment, the elevator rescue system is configured to establish a continuous exchange of information between the rescue device and the operating panel. The continuous information exchange may include a functionality check message for ensuring error-free operation of the rescue operation signal transmission path.

The elevator rescue system may be installed in a machine roomless elevator system.

The features and advantages described for the elevator rescue system are also applicable to the method of moving the elevator car to a landing position in a rescue operation. Accordingly, a detailed description of other various embodiments of the methods is omitted for the sake of brevity.

While the invention has been described with reference to exemplary embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed, but that the invention will include all embodiments falling within the scope of the appended claims.

Claims (24)

1. An elevator rescue system for moving an elevator car to a landing position in a rescue operation, the elevator rescue system comprising:

a rescue device (16) coupled to a brake system (4) of an elevator, the rescue device (16) comprising a rescue power supply (22), wherein the rescue device (16) and the brake system (4) of the elevator are arranged in a machine room or in an overhead space of an elevator system;

an operating panel (26) including a manual rescue operating switch (28), the operating panel (26) being disposed remotely from the rescue device (16) at any location readily accessible to an elevator technician; and

a rescue operation signal transmission path (32) between the rescue device (16) and the operation panel (26).

2. Elevator rescue system according to claim 1, wherein the rescue operation signal transmission path (32) is part of an elevator control communication network (34) comprising a plurality of nodes.

3. Elevator rescue system according to claim 2, wherein the elevator control communication network (34) comprises a CAN bus, wherein the rescue operation signal transmission path (32) is part of the CAN bus.

4. An elevator rescue system as claimed in claim 2 or 3, configured to provide power for low power applications via the elevator control communication network (34).

5. Elevator rescue system according to claim 2 or 3, configured to deactivate nodes of the elevator control communication network (34) not associated with devices involved in the rescue operation.

6. An elevator rescue system as defined in claim 2 or 3, configured to narrow the elevator control communication network (34) to the rescue operation signal transmission path (32) until the manual rescue operation switch (28) is operated.

7. Elevator rescue system according to any one of claims 1-3, configured to communicate the state of the manual rescue operation switch (28) through the rescue operation signal transmission path (32).

8. Elevator rescue system according to any one of claims 1-3, further comprising an elevator car speed sensor (10) and/or an elevator car position sensor (12) for determining a status of the elevator car, which status comprises elevator car speed information and/or elevator car position information.

9. The elevator rescue system of claim 8 configured to communicate the status of the elevator car over the elevator control communication network (34).

10. The elevator rescue system of any of claims 1-3 and 9, further comprising a controller (27), the controller (27) configured to determine a braking control signal based on a state of the elevator car and a state of the manual rescue operation switch (28).

11. Elevator rescue system according to claim 10, wherein the controller (27) is associated with the operating panel (26) or with the rescue device (16).

12. An elevator rescue system as claimed in claim 10, configured to operate the brake system (4) with power provided by the rescue power supply (22) in response to the brake control signal.

13. Elevator rescue system according to claim 10, wherein the controller (27) is configured to automatically determine the brake control signal upon bringing the manual rescue operation switch (28) into a rescue operation state.

14. Elevator rescue system according to any of claims 1-3, 9 and 11-13, configured to establish a continuous information exchange between the rescue device (16) and the operating panel (26).

15. Elevator rescue system according to claim 14, wherein the continuous information exchange comprises a functionality check message for ensuring error-free operation of the rescue operation signal transmission path (32).

16. An elevator rescue system as defined in any of claims 1-3, 9 and 11-13 and 15, wherein the rescue power source (22) is adapted to provide the power required by the elevator rescue system in the rescue operation.

17. Elevator rescue system according to any one of claims 1-3, 9 and 11-13 and 15, wherein the operating panel (26) comprises an operating panel power supply (30), wherein the rescue power supply (22) and the operating panel power supply (30) are adapted to jointly provide the power required by the elevator rescue system in the rescue operation.

18. A machineroom-less elevator system comprising the elevator rescue system of any of claims 1-17.

19. A method of moving an elevator car to a landing position in a rescue operation, comprising:

a rescue operation signal transmission path between the rescue device (16) and the operation panel (26) is established,

wherein the rescue device (16) is coupled to a brake system (4) of an elevator and comprises a rescue power supply (22), wherein the rescue device (16) and the brake system (4) of the elevator are arranged in a machine room or in an overhead space of an elevator system, and

the operating panel (26) includes a manual rescue operating switch (28), the operating panel (26) being disposed remotely from the rescue device (16) at any location readily accessible to an elevator technician; and

the rescue operation is started in response to receiving a signal indicating a rescue operation start command from the manual rescue operation switch (28).

20. The method of claim 19, wherein the rescue operation signal transmission path (32) is part of an elevator control communication network (34) comprising a plurality of nodes.

21. The method of claim 19 or 20, further comprising: generating a brake control signal for performing the rescue operation, wherein the generation of the brake control signal is automatically achieved by a controller (27) upon receiving the signal indicating the rescue operation start command from the manual rescue operation switch (28).

22. The method of claim 21, wherein the controller is coupled to the elevator control communication network.

23. The method of claim 21, wherein the generation of the braking control signal is implemented in accordance with a rescue algorithm that is responsive to a condition of an elevator car of the elevator.

24. The method of claim 21, wherein the generation of the braking control signal is implemented in accordance with a rescue algorithm that is responsive to a distance between an elevator car position and a safe landing position.