METHOD FOR MOVING AN ELEVATOR CAR OF AN ELEVATOR FOR EVACUATING PASSENGERS AND BRAKE OPENING DEVICE FOR MOVING AN ELEVATOR CAR OF AN ELEVATOR FOR EVACUATING PASSENGERS

Abstract

A method for moving an elevator car of an elevator for evacuating passengers from the elevator car in the event of a power failure, wherein a brake blocks a vertical movement of the elevator car, includes the steps of: applying an electrical pulse or a plurality of electrical pulses to the brake of the elevator car to release the brake and unblock the vertical movement of the elevator car, the brake being released for as long as the particular electrical pulse is applied to the brake; determining a covered height which the elevator car has covered during the application of the particular electrical pulse; comparing the determined covered height with a predetermined distance; and terminating the application of the particular electrical pulse to the brake when the determined covered height is equal to or greater than the predetermined distance.

Claims

1-13. (canceled)

14. A method for moving an elevator car of an elevator for evacuating passengers from the elevator car in an event of a power failure, wherein a brake blocks a vertical movement of the elevator car, the method comprising the steps of: applying an electrical pulse to the brake of the elevator car to release the brake and unblock vertical movement of the elevator car, wherein the brake is released for as long as the electric pulse is applied to the brake; determining a covered height of vertical movement that the elevator car has covered during the application of the electrical pulse; comparing the determined covered height with a predetermined distance; and terminating the application of the electrical pulse to the brake when the determined covered height is equal to or greater than the predetermined distance.

15. The method according to claim 14 including determining a speed of the elevator car during the vertical movement, comparing the speed of the elevator car with a predetermined speed, and terminating the application of the electrical pulse to the brake when the determined speed is equal to or greater than the predetermined speed.

16. The method according to claim 14 including determining a period since the application of the electrical pulse to the brake, comparing the determined period with a predetermined period, and terminating the application of the electrical pulse to the brake when the determined period is equal to or greater than the predetermined period.

17. The method according to claim 14 wherein the electrical pulse is a square pulse.

18. The method according to claim 14 wherein the electrical pulse is a voltage pulse.

19. The method according to claim 14 including generating the electrical pulse using a controller.

20. The method according to claim 14 including generating the electrical pulse using a microcontroller.

21. A brake opening device for moving an elevator car of an elevator for evacuating passengers from the elevator car in an event of a power failure by opening a brake blocking a vertical movement of the elevator car, the brake opening device comprising: a pulse generating device adapted to apply an electrical pulse to the brake to release the brake and unblock the vertical movement of the elevator car, wherein the brake is released for as long as the electric pulse is applied to the brake; a determination device determining a covered height of vertical movement of the elevator car that the elevator car has covered during the application of the electrical pulse; and wherein the brake opening devices compares the determined covered height with a predetermined distance and terminates the application of the electrical pulse to the brake when the determined covered height is equal to or greater than the predetermined distance.

22. The brake opening device according to claim 21 wherein the brake opening device determines a speed of the elevator car during the vertical movement, compares the determined speed of the elevator car with a predetermined speed, and terminates the application of the electrical pulse to the brake when the determined speed is equal to or greater than the predetermined speed.

23. The brake opening device according to claim 21 wherein the brake opening device determines a period since the application of the electrical pulse to the brake, compares the determined period with a predetermined period, and terminates the application of the electrical pulse to the brake when the determined period is equal to or greater than the predetermined period.

24. The brake opening device according to claim 21 wherein the electrical pulse is a square pulse.

25. The brake opening device according to claim 21 wherein the electrical pulse is a voltage pulse.

26. The brake opening device according to claim 21 wherein the pulse generating device is a controller.

27. The brake opening device according to claim 21 wherein the pulse generating device is a microcontroller.

28. An elevator for carrying passengers, the elevator comprising: an elevator car accommodating the passengers; a brake blocking a vertical movement of the elevator car; and the brake opening device according to claim 21 operating the brake.

Description

DESCRIPTION OF THE DRAWINGS

[0053] FIG. 1a is a distance-time diagram for a first embodiment of the method according to the invention;

[0054] FIG. 1b is a speed-time diagram for the first embodiment of the method according to the invention;

[0055] FIG. 2a is a distance-time diagram for a second embodiment of the method according to the invention;

[0056] FIG. 2b is a speed-time diagram for the second embodiment of the method according to the invention;

[0057] FIG. 3a is a distance-time diagram for a third embodiment of the method according to the invention;

[0058] FIG. 3b is a speed-time diagram for the third embodiment of the method according to the invention; and

[0059] FIG. 4 is a schematic view of an embodiment of the elevator according to the invention.

[0060] The drawings are merely schematic and not true to scale. Like reference signs refer to like or equivalent features in the various drawings.

DETAILED DESCRIPTION

[0061] FIG. 1 is a distance-time diagram for a first embodiment of the method according to the invention. FIG. 1b is a speed-time diagram for the first embodiment of the method according to the invention.

[0062] In the event of a power failure, the elevator car 10 of an elevator 5 (see FIG. 4) is automatically braked by a brake 18 or a plurality of brakes and further movements of the elevator car 10 along the height of the elevator shaft 15 are blocked. The brake 18 or brakes are de-energized in the locked or blocked state. If the elevator car 10 has not been braked to the height of a floor, the elevator car 10 must be moved to the height or level of a floor or some other exit option so that the passengers can be evacuated from the elevator car 10 or can safely leave the elevator car 10.

[0063] For this purpose, the brake 18 (or the brakes) of the elevator car 10 is repeatedly released by electrical pulses, so that the elevator car 10 can move gradually along the height of the elevator shaft 15 during the particular release of the brake 18. The electrical pulses are usually triggered manually, i.e. by an operator or maintenance person.

[0064] While the electrical pulse is applied or being applied to the brake 18, the brake 18 remains opened and the elevator car 10 can move by gravity. Alternatively or additionally, the elevator car 10 can be weighted with weights and/or pulled with cables in the direction of the elevator shaft 15.

[0065] The electrical pulse can be applied to the brake 18 or generated by a controller or a microcontroller. The controller can be a controller or microcontroller which takes on further tasks for controlling the movement of the elevator car 10 in normal circumstances. However, it is also conceivable that a special controller or microcontroller is present. The pulse-generating device 30 or the controller can be a device with a particularly high level of reliability, so that errors when applying the electrical pulse or when terminating the electrical pulse are substantially ruled out. In particular, individual components of the pulse-generating device 30 or the controller, or of an entire brake opening device 20 formed therewith, can be designed as safe components that, for example, meet a safety integrity level (SIL) SIL-2, SIL-3 or even SIL-4, e.g., as defined in IEC 61508 published by the International Electrotechnical Commission.

[0066] The length of time or the periods or time spans of the electrical pulses can be of different sizes.

[0067] The electrical pulse can be a voltage pulse. This means that the voltage which is applied to the brake 18 during the electrical pulse is higher than the voltage which is applied to the brake 18 outside of the electrical pulse. However, it is also conceivable that the electrical pulse is a current pulse.

[0068] The electrical pulse can in particular be a square pulse. This means that the electrical pulse is either at its maximum level or at its minimum level (e.g. zero level). Values in between occur only very briefly, if at all.

[0069] The electrical pulse can thus be a square voltage pulse.

[0070] It is also possible that the electrical pulse is the interruption of a current signal or voltage signal, the current signal or the voltage signal normally being applied to the brake 18 during the power failure. The electrical pulse then interrupts the current signal or voltage signal which ensures the closure of the brake 18, and in this way opens the brake 18.

[0071] The brake opening device 20 comprises a pulse-generating device 30 and a determination device 40. The pulse-generating device 30 is designed for applying the electrical pulse to a brake 18 of the elevator car 10 to release the brake 18, the brake 18 being released for as long as the electric pulse is applied to the brake 18. The determination device 40 is designed to determine or detect a distance covered by the elevator car 10 during a vertical movement of the elevator car 10 while the particular electrical pulse is being applied to the brake 18. The speed of the elevator car 10 can also be determined or calculated by means of the determination device 40. It is also possible for the determination device 40 to determine the period since the application of the electrical pulse. The brake opening device 20 can function as a pulse electric brake opening device (PEBO).

[0072] The application of the electrical pulse to the brake 18 is terminated when the elevator car 10 has moved a predetermined distance d.sub.max along the elevator shaft 15 while the brake 18 is released by the application of the electrical pulse. After the application of the electrical pulse to the brake 18 has been terminated, the brake 18 closes again and thus brakes the elevator car 10 so that the elevator car 10 can no longer move until the brake 18 is released again.

[0073] In FIG. 1a, the time t is plotted on the x-axis and the distance d covered by the elevator car 10 along the elevator shaft 15 is plotted on the y-axis. As soon as the predetermined distance d.sub.max (also referred to as the maximum distance) has been covered by the elevator car 10 during the release of the brake 18 by applying a single electrical pulse, the application of the electrical pulse is terminated. As a result, the elevator car 10 is stopped by the brake 18. It is also possible that the application of the electrical pulse is not terminated until the predetermined distance is exceeded.

[0074] In FIG. 1b, the time t is plotted on the x-axis and the speed v of the elevator car 10 along the height or along the elevator shaft 15 is plotted on the y-axis.

[0075] After the application of the electrical pulse has been terminated, a predetermined or variable pause can follow in which no electrical pulse is applied to the brake 18. During this pause, the brake 18 remains in the blocked state. The variable pause can depend, for example, on how long the brake 18 was opened during the immediately preceding electrical pulse. If the brake 18 has been open for a longer period of time, the pause until the next electrical pulse can be longer. The variable pause can also depend on the distance covered during the immediately preceding electrical pulse. It is also conceivable that the variable pause depends on the distance covered within a given period of time (e.g. within the last minute).

[0076] The speed v of the elevator car 10 increases somewhat faster than linearly in FIG. 1b.

[0077] The course of the distance covered by the elevator car 10 shown in FIG. 1a and in FIG. 1b is typical when the weight of the counterweight of the elevator is much greater than the weight of the elevator car 10 with passengers.

[0078] FIG. 2a is a distance-time diagram for a second embodiment of the method according to the invention. FIG. 2b is a speed-time diagram for the second embodiment of the method according to the invention.

[0079] In FIG. 2a, the time t is plotted on the x-axis and the distance d covered by the elevator car 10 along the elevator shaft 15 is plotted on the y-axis. In FIG. 2b, the time t is plotted on the x-axis and the speed v of the elevator car 10 along the height or along the elevator shaft 15 is plotted on the y-axis.

[0080] A further termination condition for the termination of the electrical pulse can be present in the method or the brake opening device 20, namely that a predetermined maximum period t.sub.max or time span has been reached. This means that the maximum period or time span of the application of the electrical pulse is t.sub.max. The brake 18 is therefore not opened for longer than t.sub.max. This means that the application of the electrical pulse is terminated when the elevator car 10 has covered the predetermined maximum distance d.sub.max while the brake 18 is being opened or when the electrical pulse was applied to the brake 18 (at least) for the period or time span t.sub.max. When at least one of these two termination conditions is met, the application of the electrical pulse is terminated in the method or the brake opening device 20.

[0081] For this purpose, the time that has elapsed since the electrical pulse was applied is detected or determined and compared with the predetermined period t.sub.max. The further termination condition is fulfilled when the specific period is equal to or greater than the predetermined period t.sub.max.

[0082] The maximum or predetermined period or time span t.sub.max can, for example, be in the seconds range, for example 10 s. This ensures that the elevator car 10 does not move in height for longer than the period or time span t.sub.max in one go, i.e. without interruption. This consequently ensures that the passengers in the elevator car 10 are not frightened. With a release of any length or very long release of the brake 18, i.e. until the predetermined distance d.sub.max has necessarily been covered, the passengers could, under unfavorable circumstances, get the impression that the brake 18 is no longer working.

[0083] In the course shown in FIGS. 2a and 2b, the elevator car 10 is accelerated only very slowly and moves at a correspondingly low speed. The predetermined maximum distance d.sub.max is not covered during the electrical pulse. Nonetheless, the electrical impulse is terminated, since the maximum period or time span of the electrical pulse t.sub.max has been reached.

[0084] The course shown in FIG. 2a and in FIG. 2b occurs in particular when the weight of the elevator car 10 with passengers substantially corresponds to the weight of the counterweight.

[0085] The elevator car 10 can move up or down along the elevator shaft 15. This depends on the weight of the elevator car 10 with passengers compared to the weight of the counterweight. Further factors here are additional weights for moving the elevator car 10 and/or cables for moving the elevator car 10 if it does not move significantly on its own.

[0086] FIG. 3a is a distance-time diagram for a third embodiment of the method according to the invention. FIG. 3b is a speed-time diagram for the third embodiment of the method according to the invention.

[0087] In FIG. 3a, the time t is plotted on the x-axis and the distance d covered by the elevator car 10 along the elevator shaft 15 is plotted on the y-axis. In FIG. 3b, the time t is plotted on the x-axis and the speed v of the elevator car 10 along the height or along the elevator shaft 15 is plotted on the y-axis.

[0088] A further termination condition can be the speed reached by the elevator car 10. When the speed of the elevator car 10 along the elevator shaft 15 reaches or has reached or exceeded a predetermined maximum speed or predetermined speed v.sub.max, the electrical pulse is terminated. As can be clearly seen in FIG. 3b, the electrical pulse or the application of the electrical pulse is terminated, although the predetermined distance d.sub.max, as can be seen in FIG. 3a, has not yet been covered.

[0089] This prevents the elevator car 10 from reaching too high a speed. This protects the brake 18 when the application of the electrical pulse is terminated. In addition, this limits the maximum negative acceleration that acts on the passengers in the elevator car 10 when braking the elevator car 10 when the brake 18 is closed.

[0090] It is possible that only the two termination conditions of covering the predetermined distance d.sub.max and the elapse of the predetermined period t.sub.max or time span of the application of the electrical pulse apply. It is also possible that only the two termination conditions of covering the predetermined distance d.sub.max and reaching the predetermined speed v.sub.max apply. With both of these possibilities, the electrical pulse is terminated as soon as one of the two termination conditions is met.

[0091] It is also possible that all three termination conditions apply at the same time, i.e. the termination conditions of covering the predetermined distance d.sub.max, the elapse of the predetermined period t.sub.max or time span of the application of the electrical pulse, and reaching the predetermined speed v.sub.max. As soon as at least one of the termination conditions is fulfilled, the electrical pulse or the application of the electrical pulse to the brake 18 is terminated.

[0092] The predetermined distance d.sub.max can be 10 cm or 5 cm, for example. The predetermined maximum speed v.sub.max can be 0.1 m/s, for example. The predefined period t.sub.max or time span can be 10 s, for example.

[0093] There can be a time span of, for example, 0.5 s or 1 s between the electrical pulses.

[0094] FIG. 4 is a schematic view of an embodiment of the elevator 5 according to the invention. The elevator 5 comprises an elevator car 10 for accommodating the passengers and a brake opening device 20 having the pulse generating device 30 and the determination device 40. The brake opening device 20 is connected via a connecting line to an electrical brake 18 of the elevator car 10, which can move up and down in the elevator shaft 15 when the brake 18 is released. In the de-energized state (i.e. also in the event of a power failure) the brake 18 is closed and brakes the elevator car 10. The brake 18 can be opened by the brake opening device 20 by means of an electrical pulse and remains open during the application of the electrical pulse. The duration of the application of the electrical pulse is determined by the distance covered by the elevator car 10 during the application of the electrical pulse. In addition, a predetermined speed (maximum speed) and/or the elapse of a predetermined period can determine the duration of the application of the electrical pulse.

[0095] The brake opening device 20 can be arranged in a technical space of the elevator 5. The application of an electrical pulse to the brake 18 can be triggered or started manually by an operator or technician, for example, by actuating an evacuation button of the brake opening device 20. The application of the electrical pulse is terminated when a termination condition (distance traveled) ora plurality of the termination conditions described above is/are fulfilled. The evacuation button can be pressed repeatedly until the elevator car 10 has moved gradually to a level or height at which the passengers can be safely evacuated from the elevator car 10. This can be indicated, for example, by an optical signal (LED) and/or an acoustic signal. The door or doors of the elevator car 10 can now be opened, and therefore the passengers can safely leave the elevator car 10.

[0096] During the power failure of a main supply, the brake opening device 20 can be supplied with power from a power supply independent of the main supply and/or from a generator.

[0097] Finally, it should be noted that terms such as “comprising,” “having,” etc. do not preclude other elements or steps and terms such as “a” or “an” do not preclude a plurality. Furthermore, it should be noted that features or steps that have been described with reference to one of the above embodiments may also be used in combination with other features or steps of other embodiments described above.

[0098] In accordance with the provisions of the patent statutes, the present invention has been described in what is considered to represent its preferred embodiment. However, it should be noted that the invention can be practiced otherwise than as specifically illustrated and described without departing from its spirit or scope.