EP2785626B1 - Safety brake with resetting means - Google Patents

Description

The invention relates to a method for returning a released for braking safety brake a driving body of an elevator system and a safety device in an elevator system.

The elevator system is installed in a building. It consists essentially of a cabin, which is connected via suspension means with a counterweight or with a second car. By means of a drive which acts selectively on the support means or directly on the car or the counterweight, the car is moved along, substantially vertical, guide rails. The elevator system is used to transport people and goods within the building, over single or multiple floors.
The elevator system includes devices for securing the elevator car in case of failure of the drive or the suspension means. For this purpose, safety brakes are usually used, which can decelerate the elevator car on the guide rails, if necessary.

Today, safety brakes are known with an electromechanical holding device, which can hold the safety brake in a standby position in an activated state and which releases the safety brake for braking in a deactivated state. EP1930282 discloses such a safety brake. To reset this safety brake electromechanical holding device must apply a release force to overcome a clearance. To reset the overcoming of the air gap requires a correspondingly dimensioned electromechanical device.
Other safety brakes are equipped with electromechanical release devices. Here, the safety brake, for example, mechanically locked, held in the ready position and it is released by means of an activation signal for braking. With a subsequent movement of the elevator car, or the driving body, the safety brake is automatically placed in a braking position. EP1733992 shows, for example, such a safety brake. This device requires a secure power supply, which allows a safe release of the safety brake even with prolonged interruption of a power grid.

US 2011/226560 discloses another example of a method and apparatus for returning a safety brake of a vehicle.

The invention aims to provide a method and a corresponding safety device to a safety brake, for example, in case of prolonged power interruption or after another non-safety shutdown, to put back into operation. Of course, the method should ensure safety of the elevator system at all times.

The solutions described below allow this task to be solved.

According to one aspect of the invention, the elevator installation is equipped with a safety device. This includes a safety brake, which is equipped with a safety switch which interrupts a brake safety circuit when the safety brake is released for braking. The safety device further includes a brake safety control, which releases the safety brake when needed for braking when on the one hand a fault or a critical event is detected in the elevator system or on the other hand, when an uncritically rated event occurs. An event assessed as uncritical is, for example, a power interruption in the building or a shutdown of an elevator for a long time or else an event carried out for the purpose of a test. When the safety brake is released for braking, the brake safety controller preferably stores the cause or the event of releasing the safety brake. As soon as the elevator control recognizes, on the one hand, that an elevator safety circuit or the brake safety circuit is interrupted and, on the other hand, an uncritical cause of the release of the safety brake is signaled by the brake safety control, the elevator control initiates an automatic reset of the safety brake. Automatic means that essentially without human intervention, the process of resetting the safety brake is initiated.

According to one aspect of the invention, the safety brake of a driving body of the elevator installation is provided with a preferably electromechanical holding device, which releases the safety brake for braking in a deactivated state. After release of the safety brake, the safety brake is preferably reset by, in a first step, the carriage is moved in a first direction of travel. As a result, the safety brake is at least partially tensioned or at least tensioned. At the same time, or in the time range before or after this first movement, the safety brake holding device is activated to prepare it for holding the safety brake in its standby position. Subsequently, the drive body is moved in a direction opposite to the first direction of travel second direction of travel. As a result, the safety brake is brought into the ready position, where it is held by the activated holding device. This puts the safety brake back in your ready position. Advantageously, this reset can be done in an at least partially automated process. The procedure causes the safety brake first, regardless of a current engagement state, comes in a clamping area. In the clamping area, a bias voltage is generated in the safety brake which allows a return of the holding device and the brake elements of the safety brake in the ready position.

For example, if the safety brake is activated as a result of a prolonged power failure in the building, i. the holding device has been disabled, so for example, a brake element of the safety brake has been delivered to the rail. However, since no cabin movement, or no movement of one of the cars, takes place-since there is no energy in the building-the safety brake is not actually engaged. That's why the safety brake is not cocked. However, since in safety brakes of the aforementioned type a reset of the holding or the safety brake in the standby position can be done by a relative movement between the safety brake and the brake rail, this deferral can not grab because the safety brakes is not yet curious. By the purposeful driving movements carried out according to this aspect of the invention, the safety brake is tensioned in a first movement and returned to the ready position in a second movement.

Preferably, a downward traveling direction is used as the first traveling direction, and as the second traveling direction, an upward traveling direction is accordingly used. This is advantageous because many elevator systems are provided only with a safety brake to secure a crash of the vehicle. With the choice of the downward direction of travel as the first direction of travel thus a selection is determined, which is for all Elevator systems is applicable accordingly. In addition, then, for moving in the second direction of travel, a maximum breakaway force is available, since usually in such an operating situation, the elevator car is empty and thus a preponderance of the counterweight is available for movement.

Preferably, the holding device of the safety brake, before the movement of the driving body in the second direction of travel, activated. Because of this prior activation of the holding device, a precise timing of the activation can be omitted. Since the holding device reaches its activated state at some point in the course of the cabin movement, it is held directly when switched on beforehand. It is particularly advantageous if the holding device of the safety brake is already activated before movement of the driving body in the first direction of travel. This makes a preparatory testing and preparation algorithm easy to design.

Preferably, the movement of the driving body is carried out in the first direction of travel until the safety brake at least partially clamped on a braking surface provided for braking. The braking surface provided for braking is usually a brake rail, or a guide web of a guide rail, which is also the brake rail. This first movement of the driving body ensures that the safety brake has a minimal preload, or that it is at least partially clamped on the brake rail.

Preferably, the carried out at least partially clamping the safety brake on the braking surface provided for braking is determined by either a travel of the vehicle body, preferably by measuring a rotational movement of the traction sheave, determined and compared with a path target value. As soon as the drive body has traveled a certain travel path-which is usually determined experimentally-it can be assumed that a partial clamping of the safety brake has taken place. Conventional elevator drives already have measuring systems such as tachometers or incremental encoders on the drive shaft in order to determine a travel path on the basis of the rotational movement of the traction sheave. This version is correspondingly low.

Alternatively or additionally, a drive torque of the drive machine, preferably be determined by measuring the drive current, this drive torque is compared with a desired torque. As soon as the drive torque reaches or exceeds a predefined value, it can be assumed that an at least partial clamping of the safety brake has taken place. This design is particularly reliable because the drive torque gives an immediate indication of the clamping done.

Alternatively, a time duration for the movement of the drive body in the first direction of travel can also be determined and compared with a limit time value. Again, the required period of time is preferably determined experimentally. This design is particularly cost effective because no special sensors are required.

Preferably, following the first movement of the color body, the movement of the drive body in the second direction of travel is carried out. This second movement is carried out until the brake safety circuit is closed and the vehicle has traveled a predefined route. Closing the brake safety circuit usually indicates that the safety brake is in its ready position again. In addition, it is ensured by the covered route that all components of the safety brake and possibly the entire body are free.

Alternatively or additionally, the drive torque of the drive machine is monitored and the movement of the drive body in the second direction of travel is terminated when the drive torque reaches an indicator value. Usually, a considerable drive torque is required for the movement of the drive body in the second direction of travel, since the safety brake must be moved out of its clamping position. The measurement can now be used to determine when the drive torque or the starting torque exceeds a peak value and then returns to a substantially constant value or into the range of the indicator value.

Preferably, termination criteria are defined which abort or at least interrupt the movement of the drive body in the second direction of travel when, for example, the drive torque of the drive machine reaches or exceeds a maximum limit value. A time limit can be added to this limit. This means that the movement of the driving body is interrupted in the second direction of travel, if the drive torque of the prime mover exceeds a working limit during a predefined time limit. Alternatively, a limit period for the time limit of the second movement may be specified.

Preferably, the movement of the driving body in the second direction of travel is also aborted when a limit positions of the driving body in the elevator shaft is run over or, of course, when an unsafe condition of the elevator system is detected. In some cases, if, for example, an electronic speed limiter detects too high a speed, the safety brake holding device is deactivated again, which in any case leads to an immediate actuation of the safety brake, regardless of the current reset status. This allows special events to be considered for the provision. Thus, for example, an energy failure in the building take place accidentally when the elevator car, or the car is at the top or bottom in an extreme position or in a limit position near a shaft end in the elevator shaft. Since the elevator car is in this situation already close to the shaft end, of course, no major movement can be performed in one of the directions. In such individual cases, a possible damage is prevented by the termination criteria.

Preferably, the resetting steps are selectively repeated if, after completion or after termination of the movement of the drive body in the second direction of travel, the brake safety circuit is not closed. This can be helpful if, for example, in the case of a first reset attempt, a starting torque is not sufficient to tear the driving body or the safety brake off. The reset procedure can then be initiated again selectively. This can be repeated, for example, two to three times. If, after these repeated attempts, the deferral can not be completed successfully, the automatic reset is preferably aborted. The reset procedure can then be initiated, for example, only by an authorized person, such as a service technician.

Preferably, the readiness position of the safety brake is monitored and a brake safety circuit of the elevator system is closed when the safety brake in its standby position and the holding device are activated. On the other hand will or the brake safety circuit of the elevator system remains interrupted as long as the safety brake or the holding device is not in its ready position. This ensures that the elevator system can not go into normal operation as long as the safety brake is not in its ready position.

Preferably, before the movement of the driving body in the first direction of travel of the elevator safety circuit is checked and the movement in the first direction of travel is carried out only if predetermined parts of the elevator safety circuit are found to be in order. This ensures the safety of the elevator installation and any users in the vicinity of the elevator installation. The elevator safety circuit is open, for example, if accesses to the elevator shaft are not closed or if important functional parts, such as a cable tension, a buffer device, a position detection device or the speed measuring device, etc. are not functional. Preferably, the predetermined parts of the elevator safety circuit with the exception of the brake safety circuit all other parts of the elevator safety circuit. The brake safety circuit is preferably bridged, since it is naturally open, since the safety brake is no longer in its standby position when the holding device is deactivated. Thus, it is necessary to exclude this part of the elevator safety circuit in the judgment to start the reset.

Preferably, in a first step, prior to performing the reset steps, an error status of a brake controller is interrogated, and depending on the error status, the appropriate procedure is selected.
The reset steps can be initiated automatically, for example, if the holding device has been deactivated as a result of the evaluated as uncritical event and at the same time the safety circuit of the elevator system called the essential parts of the elevator system as safe. Uncritical events are, for example, a deliberate deactivation of the holding device as a result of a power failure in order to save energy in a stationary elevator system or if a deactivation of the holding device takes place as a result of a self-test. The automatic initiation of the reset steps means that a controller, for example the elevator control, generates and executes a corresponding travel command by the drive of the elevator is controlled accordingly.
On the other hand, the reset steps can also be initiated manually if the holding device has not been deactivated as a result of an event assessed as uncritical or if the safety circuit of the elevator installation does not designate the system as safe. This means that an assessment of an authorized or authorized person is required. This person assesses the condition of the elevator, arranges necessary repairs or even carries them out at best. After the state of the elevator installation is judged by the authorized person to be safe, he can initiate the provision of the safety device, or the safety brake via appropriate commands, in which case either these reset steps are performed directly by the authorized person or he only release for automatic initiation the reset steps are. By this method, the safety of the elevator system is always best possible and at the same time the elevator system is not unnecessarily put out of service.

Preferably, the manual initiation of the reset steps, as previously explained by an authorized person. In this case, an authorization of the authorized person is advantageously checked to determine whether the person is actually authorized to carry out the required activities professionally. For this purpose, for example, an authorization code must be entered in the brake control or in the elevator control. In a simple test, the controller can determine if this authorization code is compliant. This authorization code may be a code noted in the service documents or it may correspond to a part of an identification number of the brake controller.

Alternatively, a predefined command and action cycle can be used to verify authority. This is, for example, a two-time operation of an elevator call button followed by an actuation of a control button within a predetermined time.

Alternatively, a preferably personal key may be connected to the brake control or the elevator control. The key may be a mechanical key allowing access to certain functions of the elevator. It can also be an electronic key, such as an electronic card, etc. which allows access to certain functions of the elevator. The different solutions make it possible to achieve a level of safety and availability matched to the lift system.

Preferably, the manual initiation of the reset steps involves manual confirmation of the status of the brake control. This means that the authorized person must acknowledge the status or error status stored in the brake control system - of course after a professional assessment and repair. Subsequently, preferably by the authorized person, a manual movement of the vehicle by means of actuating the elevator drive in a first direction of travel and a subsequent manual movement of the vehicle in the second direction opposite to the first direction of travel. In this case, the authorized person has complete control over the state of movement. He can cancel the rides at any time immediately if irregularities are detected.

Preferably, the required control functions are divided between the elevator control and the brake control. Thus, the brake control, which advantageously also includes or is connected to a so-called electronic speed limiter, for example, the control of the holding device, a device for bridging the brake safety circuit and a communication interface to the elevator control. The brake control deactivates the holding device of the safety brake in the event of an error, eg overspeed, and opens the associated part of the safety circuit of the elevator. But it disables, for example, the holding device of the safety brake as well, if the power supply is interrupted for a predetermined longer time or if other judged uncritical events occur. The brake controller stores this triggering event as non-critical in a nonvolatile memory.
The elevator control includes the parts required to control the elevator, in particular being able to control the elevator drive for moving the carousels of the elevator and being able to communicate with the brake control. After switching off the entire elevator, for example, when a power grid of the building is turned off, the entire elevator is in a de-energized state and the brake control by definition disables the holding device of the safety brake.

After a reconnection of the power supply to the elevator, the elevator control detects an interruption of the safety circuit at the safety brake, whereby a start of the elevator is prevented. The brake controller checks its own safety status and detects on the one hand - for example by means of a self-test function - that the function of the controller and the example integrated electronic speed limiter is given and further notes that the shutdown cause was uncritical, since a corresponding entry in the non-volatile memory is deposited. The brake control transmits this information to the elevator control, which now initiates the deferral of the safety brake. The elevator control checks the status of the rest of the safety circuit and then triggers the corresponding reset steps.

The presented method and the corresponding safety device makes it possible to provide a safe elevator installation which can work with minimal energy resources and which nevertheless is quickly available again in the case of special events or after special events.

The explained embodiments and solutions can be varied and supplemented by the person skilled in the art. He selects the solutions preferred for a particular asset and merges them together.

In the following exemplary embodiments are explained with reference to examples and schematic embodiments.

Fig. 1

eine schematische Ansicht einer Aufzugsanlage in der Seitenansicht,

Fig. 2

eine schematische Ansicht der Aufzugsanlage im Querschnitt,

Fig. 3

ein schematischer Ablaufplan einer Rückstellung einer Sicherheitsbremse,

Fig. 4

ein schematischer Ablaufplan zur Einleitung einer Rückstellung,

Fig. 5

ein schematischer Ablaufplan zur manuellen Einleitung einer Rückstellung,

Fig. 6

eine schematische Darstellung eines elektrisch verknüpften Sicherheitssystems,

Fig. 7s

eine Seitenansicht einer Ausführung einer Sicherheitsbremse in einer ersten, unbetätigten Position,

Fig. 7f

eine Frontansicht zur Sicherheitsbremse von Fig. 8s,

Fig. 8s

eine Seitenansicht der Sicherheitsbremse von Fig. 8s in einer zweiten, betätigten Position, und

Fig. 8f

eine Frontansicht zur Sicherheitsbremse von Fig. 9s

Show it:

Fig. 1

a schematic view of an elevator system in the side view,

Fig. 2

a schematic view of the elevator installation in cross section,

Fig. 3

a schematic flow chart of a provision of a safety brake,

Fig. 4

a schematic flow chart for initiating a provision,

Fig. 5

a schematic flow chart for manually initiating a provision,

Fig. 6

a schematic representation of an electrically linked security system,

Fig. 7s

a side view of an embodiment of a safety brake in a first, unactuated position,

Fig. 7f

a front view of the safety brake of Fig. 8s .

Fig. 8s

a side view of the safety brake of Fig. 8s in a second, actuated position, and

Fig. 8f

a front view of the safety brake of Fig. 9s

In the figures, the same reference numerals are used across the figures for equivalent parts.

Fig. 1 shows an elevator system 1 in an overall view. The elevator installation 1 is installed in a building and serves to transport persons or goods within the building. The elevator installation includes an elevator car 2, which can move up and down along guide rails 6. The elevator car 2 is provided for this purpose with guide shoes 8, which leads the elevator car as closely as possible a predetermined route along. The elevator car 2 is accessible from the building via shaft doors 12. A drive 5 serves to drive and hold the elevator car 2. The drive 5 is arranged, for example, in the upper area of the building and the car 2 hangs with support means 4, for example, carrying ropes or carrying strap on the drive 5. The support means 4 are on the drive 5 on led to a counterweight 3. The counterweight compensates for a mass fraction of the elevator car 2, so that the drive 5 has to compensate for the main thing only an imbalance between the car 2 and counterweight 3. The drive 5 is arranged in the example in the upper part of the building. It could, of course, also be arranged at another location in the building, or in the area of the car 2 or the counterweight 3.

The elevator installation 1 is controlled by an elevator control 10. The elevator control 10 receives user requests, optimizes the operation of the elevator system and controls, usually via a drive control 9, the drive 5. The drive 5 is equipped with an encoder or incremental encoder 14. Thus, a rotational movement of an axis of the drive can be detected and transmitted to the drive control 9 for the purpose of controlling the drive. This incremental encoder 14 can also be used to detect the travel path of the elevator car 2 and thus to control and control the same. The elevator control 10 also monitors the safety status of the elevator installation and interrupts the operation when an unsafe operating condition occurs. This monitoring is usually with Use of an elevator safety circuit in which all safety-relevant functions are integrated. In such monitoring, or in this elevator safety circuit, for example, shaft door contacts 13 are included, which monitor a correct closure of the shaft doors 12 and it also, for example, limit positions of the car 2, 3 monitored in the elevator shaft by means of lower and upper limit switch 16, 17.

The elevator car 2 and, if necessary, the counterweight 3 is further equipped with a braking system which is suitable for securing and / or decelerating the elevator car 2 during an unexpected movement or at overspeed. The brake system comprises in the example two identical safety brakes 20, 20 ', which are mounted on both sides of the drive body 2, 3 on the same. The safety brakes 20, 20 'are arranged in the example below the car 2 and they are electrically controlled by a brake controller 11. This brake control 11 preferably also includes an electronic speed or Fahrkurvenbegrenzer the driving movements of the elevator car 2 monitored. A mechanical speed limiter, as it is commonly used, can therefore be omitted.

Fig. 2 shows the elevator system of Fig. 1 in a schematic plan view. The brake system includes the two safety brakes 20, 20 '. The two safety brakes 20, 20 'are coupled in this example by means of a synchronization rod 15, so that the two safety brakes 20, 20' are necessarily actuated together. Thus, an unintentional one-sided braking can be avoided. The two safety brakes 20, 20 'are preferably of identical or mirror-symmetrical design and they act on the, arranged on both sides of the car 2, brake rails 7 a. The brake rails 7 are identical to the guide rails 6 in the example.
On the synchronization rod 15 can also be dispensed with. However, then electrical synchronization means are recommended which ensure a simultaneous triggering of both sides of the elevator car arranged safety brakes 20, 20 '.

In the Fig. 7 and 8th is a possible example of a safety brake 20, 20 'shown and explained below. The two safety brakes 20, 20 'are functionally identical, Therefore, only the safety brake 20 will be discussed below. The safety brake 20 has a brake housing 21 with brake member 22. The brake housing 21 is by a holding device 28 in a standby position ( Fig. 7s, 7f ) held. The holding device 28 is fixed by means of a holding magnet 29. This position of the holding device 28 is controlled by a first brake contact 24. The first brake contact 24 includes in the example a contact bridge 25 and contact points 26, which are guided to a brake safety circuit 23. Alternatively or additionally, the ready position of the safety brake 20 can also be controlled via a second brake contact 27. This second brake contact 27 monitored in the example, the brake member 22 and also this second brake contact 27 is, at most in series with the first brake contact 24, connected to the brake safety circuit 23. The holding magnet 29 is connected to the brake controller 11 and corresponding power sources 30 and is controlled by the brake controller 11.

As soon as the brake control 11 deactivates the holding magnet 29 ( Fig. 8s, 8f ), the safety brake 20 is moved to its braking position, wherein the brake member 22 is brought into contact with the brake or guide rail 6, 7. If the elevator car continues to move in relation to the brake or guide rail 6, 7, this leads to a further engagement of the safety brake 20 and finally to the safe braking of the elevator car 2. With the deactivation of the holding magnet 29, or the holding device 28 is the first Brake contact 24 is interrupted, by the movement of the brake housing 21 and the brake member 22 and the optional second brake contact 27 is interrupted and the brake safety circuit 23 is interrupted, whereby an operation of the elevator system 1 is suspended.

Fig. 6 shows a possible circuit diagram of an electrically linked brake system. The brake contacts 24, 27 of the two safety brakes 20, 20 'are connected in series in the example and performed as a brake safety circuit 23 to the brake control 11. In the brake control 11, the state of the brake safety circuit 23 is evaluated and integrated into the elevator safety circuit 19. The brake control 11 includes an electronic speed limiter 18, which on the one hand monitors a driving operation and a general condition of the elevator installation. The holding magnets 29 of the two safety brakes 20, 20 'are in the example also connected in series and guided to the brake control 11, from where the holding magnets 29 controlled and from a power source 30 can be energized. By the serial circuit is achieved that in case of an interruption of the electrical line both necessarily, or all holding magnets 29 of the safety brakes 20 are deactivated. The serial circuit is preferably implemented in the brake controller 11. That is, the holding magnets 29 of the two safety brakes 20, 20 'are connected separately to the brake control and the serial circuit is executed in the brake control 11.

If necessary, the electronic speed limiter 18 can interrupt both the elevator safety circuit 19 and the holding circuit of the holding magnet 29, whereby the safety brake 20 is released for braking.

If, for example, the overspeed governor 18 detects an excessively high driving speed in a first case, it interrupts the holding circuit of the holding magnet 29, whereby the elevator car 2 is braked. At the same time it interrupts the elevator safety circuit 19 by opening a first breaker 31, whereupon the elevator control 10 decelerates and stops the drive 5 of the elevator installation. The speed limiter 18 stores the cause of the operation as relevant or critically and provides the corresponding error status signal S1 in a non-volatile memory.

In another case, if the overspeed governor 18 detects that the brake safety circuit 23 has opened without obvious cause, it interrupts the holding circuit of the holding magnet 29 and the elevator safety circuit 19, thus stopping the elevator system. This ensures that in the event of accidental release of one of the safety brakes 20, 20 ', the second safety brake 20', 20 is also actuated immediately. This prevents one-sided deceleration. The speed limiter 18 stores the cause of the operation as relevant or critical and provides the corresponding error status signal S1 in the non-volatile memory.

If the speed limiter 18 determines in a further case that, for example, the stationary elevator installation is or is to be shut down for a long time, it also interrupts the holding circuit of the holding magnet 29, even though there is no relevant fault in the elevator installation. As a result, the holding device 28 is released and the safety brake 20 is moved to the braking position, but without braking, because the elevator car is stationary and thus the safety brake 20 is not further tensioned. The speed limiter 18 stores the cause of the operation as irrelevant, and provides the corresponding error status signal S1 in the nonvolatile memory.

Further, the electronic speed limiter 18, upon request, the brake safety circuit 23 bridge with a bridge contact 32 to allow a controlled movement of the elevator car 2 according to need.

Accordingly, in this last illustrated case, the safety brake 20 is delivered to a brake ready position and the holding device 28 is deactivated. Accordingly, the brake safety circuit 23 is interrupted and of course the elevator safety circuit 19 is interrupted, on the one hand by the brake safety circuit 23 but also by opening the first breaker 31st

If, in this case, the energy supply of the building or of the elevator installation is switched on again, the elevator control 10, after passing through any self-test and initialization routines, determines that the elevator safety circuit 19, in particular in the area of the cabin safety system, is interrupted. The elevator control starts now, as in Fig. 4 At the same time, with the switching on of the power supply, the brake controller 11 has undergone any internal tests and initialization routines and has determined that according to the stored error status signal S1, the cause of the operation was determined to be irrelevant or uncritical and that a function of the brake controller S2 itself is judged to be intact. The elevator control queries in the event analysis F the error status signal S1 and the function readiness message S2 and determines the further course of action. If the signal S1 transmits the message "uncritical" and the signal S2 has the message "pass function test", the elevator control 10 starts, provided that spare parts of the elevator safety circuit 19 are in order, an automatic reset A, which in the following Fig. 3 is explained in more detail. Otherwise, further operation of the elevator system will be interrupted until a manual reset M occurs, as described later with reference to FIG Fig. 5 is explained in more detail.

After a start of automatic reset A ( Fig. 3 In the example, the functionality S2 of the brake control system 11 and other parts of the elevator safety circuit 19 are checked R0.1 and if the result is "yes" an optional display D2 or announcement is issued in the area of floors or in the car 2, for example indicates that a return trip will be made shortly. Subsequently, the brake controller 11 closes, after appropriate instruction from the elevator control 10, the first breaker 31 of the elevator safety circuit 19 and temporarily bridges the brake safety circuit 23. At the same time the holding device 28 of the safety brake is activated R1 by a second breaker 33 of the holding device closed and the holding magnet 29 is energized to prepare the holding device 28 for holding the safety brake 20 in the standby position.

Subsequently, the elevator control 10 gives corresponding movement commands to the car 2 or occasionally the counterweight 3 to move in a first direction of travel with preferably low speed R2. Thus, the safety brake, which was delivered before the movement only to the rails 6, 7 but not really curious, at least partially stretched or tightened. This movement in the first direction of travel is preferably carried out until the safety brake is at least partially clamped on the braking surface of a brake or guide rail provided for braking R2.1. The clamping R2.1 that has taken place can be determined, for example, by determining a travel path of the drive body, if necessary by means of the signals from the incremental encoder 14, and comparing it with a desired travel path. Alternatively or additionally, it is also possible to determine a drive torque of the drive machine, preferably by measuring the drive current, and to compare it with a desired torque, or it can also simply determine a time duration for the movement of the drive body in the first drive direction and compare it to a limit time value ,

Subsequent to the first movement R2 in the first direction of travel, the elevator control 10 indicates a reversal of the direction of travel and the drive 5 accordingly moves the elevator car or the counterweight in the opposite second direction of travel R3.

Due to the movement R2 in the first direction of travel, the safety brake was clamped to the rail. Case by case, depending on the design of the safety brake 20 could thus also the holding device 28 are already spent in the holding position. By the second movement R3, the safety brake is returned to the actual operating position. This second movement R3 in the second direction of travel is basically continued until the safety brake is reset R3.1. This can usually be easily determined, for example, by checking whether the brake safety circuit 23 is closed, ie the safety brake 20 is in the standby position or by measuring a travel distance or, as a particularly reliable option, by measuring the drive torque of the drive engine. As soon as the drive torque reaches an indicator value, which generally corresponds to the constant moment of movement of the empty car, the safety brake 20 is no longer in free contact.

In the process according to Fig. 3 is exemplary, especially the movement in the second direction of travel, monitored by each trip aborted R3.2, when an unsafe condition of the elevator system is detected. This monitoring preferably applies during each travel movement. Thus, in particular, the drive is aborted when, for example, the drive torque of the prime mover reaches a maximum limit, when the drive torque of the prime mover exceeds a working limit during a time limit, when a limit period is reached, when limit positions of the drive body in the elevator shaft are run over or if the elevator safety circuit 19 detects another unsafe condition. In these cases, a manual reset M is usually initiated or requested.

The essential steps of the reset R of the safety brake 20 thus include activating R1 of the safety brake holding means to prepare it for holding the safety brake in a standby position, moving the vehicle in a first driving direction R2 to at least partially tension or retract the safety brake tensioning and moving the driving body in a second driving direction R3 opposite to the first driving direction in order to bring the safety brake into the ready position, where it is held by the activated holding device.

By way of example, in the example of Fig. 3 the reset steps R selectively repeated R4, if after completion of the movement of the drive body in the second direction of travel, the brake safety circuit is still not closed, but no fault has been detected in the elevator system. Since safety brakes can certainly require a high energy recovery, or force, a first attempt may not be enough.

As already mentioned, the determination of unsafe conditions or deviations from the expected behavior leads to a cancellation or non-start of the automatic reset A. In these cases, a manual reset M must be carried out as described in Fig. 5 is shown schematically. For this purpose, an authorized person 35 is offered. This service is provided via known service channels, either electronically targeted by the elevator control or, for example, by telephone from affected persons. In a first step, the authorized person performs the necessary expert diagnoses of the elevator installation and initiates any repairs M1. As soon as at least the primary functions and the safety of the elevator installation are given, the authorized person carries out, for example, the reset steps R by manual control. He turns on the holding circuit of the holding device 28 and at most bypasses the brake safety circuit 23. Then he moves the elevator car, for example, by using a so-called inspection control in the first direction until it detects a low clamping resistance. Subsequently, he moves the elevator car backwards, counter to the first direction of travel, until the elevator car runs free. Afterwards, of course, he takes appropriate final checks on the elevator installation before releasing the elevator installation again for normal use.

Alternatively, the authorized person 35 starts the reset by inputting an authorization code 36 to the elevator controller. The authorization code 36 signals the elevator controller 10 that the person 35 is actually authorized to initiate a corresponding chain of commands. The authorization code 36 may correspond, for example, to a part of an identification number of the brake control. Alternatively, a predefined command and action cycle can be executed. This is, for example, a command via an operating keyboard of the elevator control followed by a reset command of the elevator control within a time window of for example 10 seconds. These authorization checks prevent obvious mistakes.

Alternatively, the authorization code 36 includes a preferably personal key 34 which is connected to the brake controller 11 or the elevator controller 10. The key may be a mechanical key allowing access to certain functions of the elevator. It may also be an electronic key, such as an electronic card, etc., which allows access to certain functions of the elevator. By using the key 34, the wearer of the same is identifiable.

After entering the authorization code 36, the brake controller 11 or the elevator control 10 checks authorization M3 and, if successful, initiates the automatic reset A as described above. In any case, a negative test result again leads to an abort of the automatic reset.

The illustrated embodiments and processes can be varied by the person skilled in the art. The assignment of individual functions to elevator control 10 or brake control 11 can be reversed or all functions can be combined in one control group. The authorization check M3 can also be used for other sub-steps of lift maintenance, such as to authorize the performance of test activities on the brake control 11 or the safety brakes 20.

Claims (14)

1. Method of resetting a safety brake (20, 20'), which is released for braking, of a travel body (2, 3) of a lift installation (1) with a preferably electromechanical retaining device (28) which in a deactivated state releases the safety brake (20, 20') for braking, the method comprising at least the resetting steps (R) of:

   - activating (R1) the retaining device (28) of the safety brake (20, 20') in order to prepare it for holding the safety brake in a readiness setting,

   - moving (R2) the travel body (2, 3) in a first travel direction in order to at least partly tighten or re-tighten the safety brake (20, 20') and

   - moving (R3) the travel body (2, 3) in a second travel direction opposite the first travel direction in order to bring the safety brake (20, 20') into the readiness setting where it is held by the activated retaining device (28),

   wherein the retaining device (28) is activated before movement of the travel body (2, 3) in the second travel direction.
2. Method according to claim 1, wherein a downward travel direction is used as first travel direction and correspondingly an upward travel direction is used as second travel direction.
3. Method according to claim 1 or 2, wherein the retaining device (28) is activated before movement of the travel body (2, 3) in the first travel direction.
4. Method according to claim 3, wherein the movement of the travel body (2, 3) in the first travel direction is performed until the safety brake (20, 20') at least partly clamps (R2.1) on a brake surface, which is provided for the braking, of a brake rail or guide rail (6, 7).
5. Method according to claim 4, wherein the executed at least partial clamping (R2.1) of the safety brake (20, 20') on the brake surface provided for the braking is ascertained in that

   - a travel path of the travel body (2, 3) is detected, preferably by means of measuring a rotational movement of the drive pulley, and compared with a travel target preset and/or

   - a drive torque of a drive engine (5) is detected, preferably by means of measuring a drive current, and is compared with a target torque or

   - a time duration for movement of the travel body (2, 3) in the first travel direction is detected and compared with a limit time value.
6. Method according to any one of claims 3 to 5, wherein the movement of the travel body (2, 3) is carried out in the second travel direction until the safety brake is reset (R3.1), wherein this is ascertained when a brake safety circuit (23) is closed, and

   - the travel body (2, 3) has covered a pre-defined travel path and/or

   - the drive torque of the drive engine (5) attains an indicator value.
7. Method according to claim 6, wherein the movement of the travel body (2, 3) in the second travel direction is terminated (R3.2) when

   - the drive torque of the drive motor (5) has reached a maximum limit value or

   - the drive torque of the drive motor (5) has exceeded a working limit value during a time limit or

   - a limit time period is reached or

   - limit positions of the travel body (2, 3) in the lift shaft are passed or

   - a lift safety circuit (19) detects an unsafe state.
8. Method according to one of claims 6 and 7, wherein resetting steps (R) are selectively repeated (R4) if after conclusion of the movement of the travel body in the second travel direction the brake safety circuit (23) is not closed.
9. Method according to any one of claims 6 to 8, wherein the readiness setting of the safety brake (20, 20') is monitored and the brake safety circuit (23) of the lift installation is closed if the safety brake (20, 20') is in its readiness setting and the retaining device (28) is activated and the brake safety circuit (23) of the lift installation is interrupted if the safety brake (20, 20') or the retaining device (28) is not in the readiness setting thereof.
10. Method according to claim 7, wherein prior to movement of the travel body (2, 3) in the first travel direction the lift safety circuit (19) is checked (R0.1) and the movement in the first travel direction is performed only if predetermined parts of the lift safety circuit (19) are found to be in order, wherein the predetermined parts of the lift safety circuit (19) preferably include, with the exception of the brake safety circuit (23), all remaining parts of the lift safety circuit (19).
11. Method according to one of claims 7 and 10, wherein

    - the resetting steps (R) are automatically (A) initiated when the retaining device (28) was deactivated as a consequence of an event evaluated as non-critical, a functional readiness report (S2) of a brake control (11) is present and the safety circuit (19) of the lift installation designates the installation as safe, and

    - the resetting steps (R) are manually (M) initiated when the retaining device (28) has not been deactivated as a consequence of an event evaluated as non-critical, the functional readiness report (S2) of the brake control (11) is not present or the safety circuit (19) of the lift installation does not designate the installation as safe,

    wherein the functional readiness report (S2) of the brake control (11) is interrogated in a first step (R0.2) prior to performance of the resetting steps (R).
12. Method according to claim 11, wherein the manual initiation (M) of the resetting steps (R) is performed by an authorised person (35), wherein an authorisation is checked (M2) in that

    - a authorisation code (36) is input into the brake control (11) or into a lift control (10), wherein this authorisation code (36) corresponds with, for example, a part of an identification number of the brake control, or

    - a predefined command and action cycle is performed or

    - a preferably personal key (34) is connected with the brake control (11) or the lift control (10).
13. Method according to claim 11 or 12, wherein the manual initiation of the resetting steps includes:

    - manual confirmation of the status of the brake control and

    - a subsequent manual movement of the travel body in a first travel direction and

    - a subsequent manual movement of the travel body in a second travel direction opposite to the first travel direction,

    wherein the manual movement is performed by means of actuation of a lift drive.
14. Safety device in a lift installation, comprising

    - a safety brake (20, 20') with a preferably electromechanical retaining device (28) which in a deactivated state releases the safety brake (20, 20') for braking,

    - a lift control (10) which can initiate an automatic resetting (A) of the safety brake when the safety brake (20, 20') as a consequence of an event evaluated as non-critical has been released for braking, wherein the automatic resetting (A) comprises resetting of the safety brake released for braking, characterised in that this resetting takes place in accordance with one of the methods of claims 1 to 10.

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