Patent Publication Number: US-2019193987-A1

Title: Call device for elevator system

Description:
TECHNICAL FIELD 
     The invention concerns in general the technical field of elevators. More particularly, the invention concerns elevator call device. 
     BACKGROUND 
     Elevator calling is typically arranged so that a call device, such a call button, is arranged in a hall from where passengers enter an elevator car. A typical location of the call device is a wall next to elevator doors. The call device is communicatively coupled to an elevator control device, aka elevator controller, which is an entity taking care of at least some control operations of the elevator system. Among others, the elevator control device is configured to receive elevator calls from the call device and to generate control signals, such as control signals for a hoisting device, in order to instruct the elevator car to move. Naturally, the control device is provided with electricity through applicable power wiring. 
     As may be seen from the short description above an implementation of the call device system in the elevator system requires wiring and especially in modernization situations, in which an elevator is to be installed in an old building, the wiring may turn out to be challenging, expensive and time-consuming. 
     To solve the above-mentioned challenges some prior art solutions are introduced. For example, a document WO 2007/030109 discloses an arrangement in which a wireless call button is introduced. The wireless call button is configured to transmit a unique wireless signal when a passenger presses a call button for indicating a need for elevator service. The call button is also implemented so that it does not require wiring for bringing power to the call button, but the power generation is arranged with a piezo electric power generator in the call button. In other words, when the passenger presses the button the piezo electric power generator generates the power for the other modules in the call device, such as for wireless transmitter to transmit the call signal. 
     The drawback with the known solutions are that they are not reliable to use, and it may turn out that the pushing of the button does not generate enough energy for performing the desired task. 
     Hence, there is need to develop further solutions in the area. 
     SUMMARY 
     The following presents a simplified summary in order to provide basic understanding of some aspects of various invention embodiments. The summary is not an extensive overview of the invention. It is neither intended to identify key or critical elements of the invention nor to delineate the scope of the invention. The following summary merely presents some concepts of the invention in a simplified form as a prelude to a more detailed description of exemplifying embodiments of the invention. 
     An objective of the invention is to present an elevator call device for generating an elevator call signal. Another objective of the invention is that the elevator call device is configured to operate in a wireless manner at least in part. 
     The objectives of the invention are reached by an elevator call device as defined by the respective independent claims. 
     According to a first aspect, an elevator call device is provided, the elevator call device comprising: a processing unit for controlling a generation of an elevator call; an energy storage for storing electrical energy; a coupler for obtaining electrical energy from an external source for charging the energy storage; and a switch controllable with a call indicator device for activating the processing unit to generate the elevator call signal with the electrical energy from the energy storage. 
     The coupler may be configured to obtain the electrical energy from the external source through one of the following: galvanic connection, inductive connection. 
     The external source may be one of the following: power cable providing power to an elevator car, a battery carried by the elevator car, a generator generating electrical energy from a kinetic energy of at least one door of the elevator car, a generator generating electrical energy from a kinetic energy of the elevator car, an inductive loop arranged between the elevator car and an entity electrically coupled to the energy storage. 
     The elevator call device may further comprise a communication module, wherein the activation of the processing unit is configured cause a transmit of the generated elevator call signal by the communication module. 
     Moreover, the energy storage may be a capacitor unit comprising at least one supercapacitor. 
     According to a second aspect, a method for generating an elevator call signal with an elevator call device is provided, wherein the elevator call device comprising: a processing unit, an energy storage for storing electrical energy, a coupler for obtaining electrical energy from an external source for charging the energy storage, and a switch, wherein the method comprises: activating the processing unit to generate the elevator call signal with the electrical energy from the energy storage in response to a control of the switch with the call indicator device. 
     In the method, the electrical energy may be obtained, by the coupler, from the external source through one of the following: galvanic connection, inductive connection. 
     Moreover, the method may comprise transmitting the generated elevator call signal by a communication module of the elevator call device in response to the activation of the processing unit. 
     The expression “a number of” refers herein to any positive integer starting from one, e.g. to one, two, or three. 
     The expression “a plurality of” refers herein to any positive integer starting from two, e.g. to two, three, or four. 
     Various exemplifying and non-limiting embodiments of the invention both as to constructions and to methods of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific exemplifying and non-limiting embodiments when read in connection with the accompanying drawings. 
     The verbs “to comprise” and “to include” are used in this document as open limitations that neither exclude nor require the existence of unrecited features. The features recited in dependent claims are mutually freely combinable unless otherwise explicitly stated. Furthermore, it is to be understood that the use of “a” or “an”, i.e. a singular form, throughout this document does not exclude a plurality. 
    
    
     
       BRIEF DESCRIPTION OF FIGURES 
       The embodiments of the invention are illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings. 
         FIG. 1  illustrates schematically an example of an elevator system into which the present invention may be implemented to. 
         FIG. 2  illustrates schematically an example of a call device according to an embodiment of the invention. 
         FIG. 3  illustrates schematically an example of an implementation for charging an energy storage of a call device. 
         FIG. 4  illustrates schematically a further example of the invention according to an embodiment. 
         FIG. 5  illustrates schematically an example of a method according to an embodiment of the invention. 
     
    
    
     DESCRIPTION OF THE EXEMPLIFYING EMBODIMENTS 
     The specific examples provided in the description given below should not be construed as limiting the scope and/or the applicability of the appended claims. 
     Lists and groups of examples provided in the description given below are not exhaustive unless otherwise explicitly stated. 
       FIG. 1  schematically illustrates an example of an elevator system into which the present invention may be implemented to. The elevator system is implemented for carrying passengers from one floor to another in a space the elevator system is implemented to. In the exemplifying  FIG. 1  a number of the floors is two. The elevator system may comprise an elevator control device  110  which may be communicatively coupled to one or more other entities, such as to an elevator call device  120  residing e.g. on every floor, a hoisting machine  130 , hall display  140 , and so on for communicating with the other entities. Some non-limiting examples of the communication between the entities may e.g. be control signals instructing an entity to perform a certain task or data acquisition signals for obtaining e.g. measurement data from one or more sensors. The communicative coupling between the elevator control device  110  and the call device  120  according to the present invention is implemented in a wireless manner. The wireless communication technology used in this context may be any applicable short-range communication technology, such as Wi-Fi, or wide-area communication technology, such as a technology utilizing mobile communication network having a coverage within the area of the elevator. Moreover, the call device  120  may be implemented so that it comprises an energy storage which may be charged from external entity as will be discussed. The energy storage refers to an electrical component, or a plurality of those, for example. The electrical component may e.g. be a capacitor, such as a so-called supercapacitor, as a non-limiting example. All in all, the present invention enables an implementation of the elevator call device in a wireless manner as a whole or at least in part. 
       FIG. 2  illustrates an example of the call device  120  according to an embodiment of the invention. The example shown in  FIG. 2  does not necessarily illustrate all necessary components and elements need to implement the call device  120  as a whole, but at least those entities are disclosed, which are needed to describe at least some aspects of the present invention. In the embodiment as disclosed in  FIG. 2  the call device  120  comprises a processing unit  210  including one or more processors for controlling at least some operations of the call device  120 , when the processing unit  210  is configured to execute at least one portion of a computer program code. The processing unit  210  may be communicatively coupled to memory unit  220  storing data, such as computer program code, parameters and data input and output thereto and therefrom. The memory unit  220  may include one or more memory elements of any suitable type for storing the data, as mentioned. The call device  120  according to the embodiment comprises an internal energy storage  230  which may be charged from an external energy source to the call device  120 . According to the embodiment the energy storage  230  may be charged by means of a coupler  240 . The coupler  240  shall be understood as a device, which provides means for obtaining electrical energy from external energy source either directly or indirectly e.g. through an interaction between the coupler  240  and an external device to the call device  120 . The energy stored in the energy storage  230  may be provided to the processing unit  210 . The processing unit  210  may be activated, for example, in response to a call indication given by a passenger through a call indicator device  250 , which may e.g. be a push button. In other words, in response to a receipt of the indication, i.e. an elevator call, the call indicator device  250  may be configured to control a switch so that when the call is given the switch  260  electrically connects the processing unit  210  to a ground for activating an operation of the processing unit  210 , and hence the call device  120 . In other words, the processing unit  210  wakes up in response call indication, and is configured to perform so that the elevator call may be delivered to an elevator control device  110 . For example, the processing unit  210  may be configured to generate a call signal and instruct a communication module  270  to transmit the call signal to the elevator control device  110  e.g. through an antenna. The communication module  270  may e.g. be a modem implementing a wireless communication technology, such as Wi-Fi. Preferably, it is a low energy device in the context of the present invention. Alternatively or in addition, the communication module  270  may perform the communication in a wired manner in case the elevator environment supports the wired communication i.e. the necessary wiring is in place. 
     As discussed above an activation of the call indicator device  250  e.g. by a passenger causes a discharging of the energy storage  230  at least in part so that the processing unit  210 , in the described embodiment, wakes up from a sleep or idle mode. The processing unit  210  may be configured so that the activation causes the processing unit  210  to operate in a predetermined manner, i.e. so that an elevator call signal is generated and delivered to the elevator control device  110  through the communication module  270 . The communication module  270  is at least configured to transmit generated signals, but in some embodiment of the invention the communication module  270  may also implement a functionality of a receiver, if two-way communication is implemented in the call device  120 . 
     According to some embodiment of the invention the processing unit  210  may be configured to monitor charging level of the energy storage  230 . This may be implemented so that the processing unit  210  may e.g. utilize an electrical energy of the energy storage  230  for performing the monitoring function. The monitoring function may be implemented as a watchdog functionality i.e. the processing unit  210  may be configured to generate an inquiry to the energy storage for obtaining data representing energy level of the energy storage  230  under a predetermined scheme, based e.g. on time. In response to a detection that the energy level of the energy storage is below a reference level, the processing unit  210  may be configured to perform an action to cause the charging of the energy storage. As discussed above, the action to cause the charging may e.g. be that electrical energy is obtained from external energy source either directly or indirectly e.g. through an interaction between the coupler  240  and an external device to the call device  120 . An example of the action to cause the charging may e.g. be a generation of an elevator call when the electrical energy for charging is obtained from the elevator car, for example. 
     Next some aspects relating to the energy storage  230  and its charging are discussed. Firstly, in some embodiment of the invention the energy storage  230  is advantageously a capacitor unit comprising one or more capacitors. The capacitors in the capacitor unit may e.g. be so called supercapacitors, which have an advantage that they have high energy density and their charging and discharging is fast. Additionally, they tolerate high number of charging and discharging cycles which is advantageous feature in the application environment of the present invention. 
     Next some non-limiting examples with respect to charging of the energy storage, such as the capacitor unit comprising one or more supercapacitors, are discussed. As mentioned the elevator call device  120  comprises a coupler  240  which comprises means for obtaining electrical energy from external energy source either directly or indirectly e.g. through an interaction between the coupler  240  and an external device to the call device  120 . According to a first non-limiting example the coupler  240  may be implemented so that it provides a port  310  for charging the energy storage  230  from an external entity. In the example of  FIG. 3  the external entity is an elevator car  350 , which may be equipped with a counter-port  320  to the port  310  of the coupler  240 . According to an embodiment the ports  310 ,  320  may be configured to form a galvanic connection, and in that manner to establish a conductive path from the elevator car  350  to the energy storage  230  through the coupler  240 . The embodiment shown in  FIG. 3  enables the charging of the energy storage  230  from a power of the elevator car  350 . The power of the elevator car  350  may e.g. be brought in with the hoisting system e.g. so that a power cable is arranged to provide the electricity to the elevator car  350 , which electricity may be conveyed to the energy storage  230  in the described manner. Alternatively or in addition, the elevator car  350  may carry a power source, such as a battery, which may be charged in an elevator shaft. The power source may provide the energy to the energy storage  230  when the ports  310 ,  320  are conductively coupled to each other. The conductive coupling may e.g. be established e.g. at landing i.e. when the elevator car arrives to at least one floor and stops there. The ports  310 ,  320  are adjusted to contact each other during the stop and the energy storage  230  may be charged. The ports  310 ,  320  may be of any type which may establish the conductive path as described. In some implementation they may have flexible character in order enable a smooth arrival of the elevator car, and, thus, an establishment of the conductive path between the port  310  and the counter-port  320 . As mentioned the ports may establish the conductive path with a galvanic connection, but in some embodiment of the invention the connection may be implemented with an inductive coupling. 
     According to another embodiment the energy storage  230  may be charged by changing a kinetic energy generated by the elevator system, or any applicable external energy source, to an electrical energy. The source of the kinetic energy may e.g. be any moving entity in the elevator system into which a suitable generator device is installed. An example of the source may be elevator door or doors, which are typically opened and closed when the elevator car arrives at a floor level. By installing the generator device within the door frame so that the kinetic energy generated by the opening or closing motion of the door may be collected and converted to an electrical energy it is possible to be conveyed to the energy storage  230  accordingly. For example, the generator device may be wired so that it forms a conductive path to the energy storage  230  through the coupler  240  by utilizing the port  310  and the counter-port  320  when the elevator car arrives at the floor in question. 
     Moreover, the kinetic energy transformed to electrical energy may also originate from an external source to the elevator system. For example, the external source may be any device or system within the building in which the elevator is installed to. For example, the kinetic energy may be obtained from doors of the building, other people flow systems, such as escalators in the building in question, and so on. 
     According to another embodiment of the present invention the kinetic energy may origin from a motion of the elevator car  350  in an elevator shaft. An example of such an arrangement is schematically illustrated in  FIG. 4 . Since the elevator car travels in the elevator shaft a known route it is possible to arrange a generation of an electrical energy from the kinetic energy of the elevator car  350 . This kind of implementation may be achieved with such an elevator system into which a number of generator devices is arranged so that the electrical energy may be generated from the kinetic energy of the elevator car  350  with an interaction of at least one first generator element  410  and at least one second generator element  420 . The at least one first generator element  410  may be mounted in the elevator shaft, whereas the at least one second generator element  420  is mounted on an outer wall of the elevator car  350  so that the first and the second generator element may interact together for generating the electrical energy when the elevator car  350  travels in the shaft. For example, the first generator entity may e.g. be based on a rotating wheel mounted to a guide rail of the elevator, which rotating wheel is configured to touch the elevator car, i.e. the second generator element  420  when the elevator car  350  passes by the wheel. The wheel causes the generation of the electricity e.g. in a dynamo-like manner, which electricity may be conveyed to the energy storage  230 . The at least one first generator element  410  may be coupled either directly or indirectly, e.g. through another circuit, or the coupler, to one or more call devices  120  residing in a hall with an applicable wiring  120 . Hence, in response to the motion of the elevator car  350  in the shaft electricity may be generated by the generator device and the generated electricity may be conveyed to the energy storage  230  of the call device  120 . In some preferred embodiments of the invention the first generator element  410  is advantageously implemented in the call device  120  so that there is no need to establish the wiring  430  in the elevator system. In such an embodiment a call device assembly and mounting may be implemented so that the backside of the call device  120  comprises the first generator element  410 , which backside extends to the elevator shaft so that the interaction between the first generator element  410  and the second generator element  420  may be achieved in at least some position of the elevator car  350  in the elevator shaft. 
     A further non-limiting example of the invention may be that the electrical energy is generated by means of inductive coupling. For example, the elevator shaft may be equipped with one or more coils, whereas the elevator car  350  is equipped with magnets. Now, when the magnets residing e.g. on an outer wall of the elevator car  350  passes by the coil, a current is induced in the coil and it may be conveyed to the energy storage  230 . The magnet, or a plurality of magnets, may e.g. be permanent magnets, for example. The inductive coupling is especially applicable when the elevator car  350  is parked on a position for charging for a period of time being enough for inductively charging the energy storage  230 . 
       FIG. 5  schematically illustrates a method according to the present invention. The method may be implemented by an elevator call device  120  as described above, which may be configured to interact with one or more external entities as described. In the method an elevator call signal may be generated with the elevator call device  120  so that a processing unit  210  may be activated  510  to generate the elevator call signal with the electrical energy from the energy storage  230  in response to a control of the switch  260  with the call indicator device  250 . The electrical energy may be obtained, by the coupler  240  or with the coupler  240 , from the external source through one of the following: galvanic connection, inductive connection. Further, the method may comprise a step in which the generated elevator call signal is transmitted, by a communication module  270  of the elevator call device  120 , in response to the activation of the processing unit  210 . 
     In the description of at least some embodiments of the invention it is mainly referred to an implementation wherein the call indicator device  250  is a push button controlling the switch  260 . However, the present invention is not limited to such a call indicator device  250  only, but any similar call indicator device  250  may be used, which may generate a signal for controlling a discharge of the energy storage  230  in response to a generation of elevator call. Some non-limiting examples of the call indicator device  250  may be sensors, such as a camera or a microphone, configured to trigger an elevator call in response to a detection of a predetermined event, such as a person attending in a certain area. 
     Further, the implementation of the present invention may be arranged so that the call indicator device  250 , when applicable, is configured to obtain electrical energy from the energy storage  230 . This may be necessary if it is desired that the call indicator device  250  is e.g. illuminated for being better visible in dark. This kind of arrangement may be established with a design of the elevator call device and the circuitry therein. Naturally, the powering of the call indicator device  250  is implementation specific, and in case the call indicator device  250  is required to be active, such as is the case with camera, the powering of the device is a necessity. 
     Having a wireless call device according to the present invention gives a freedom to mount the call device in an optimal location because there is no need to take into account wiring aspects of the elevator system. This may improve user satisfaction with respect to elevator usage. 
     The specific examples provided in the description given above should not be construed as limiting the applicability and/or the interpretation of the appended claims. Lists and groups of examples provided in the description given above are not exhaustive unless otherwise explicitly stated.