DE102014101381A1 - Measuring system and measuring method for testing the safety gear of an elevator - Google Patents

Abstract

The invention relates to a method and a system (10) for determining a characteristic of no safety gear (26) of a cable lift (100). For carrying out the method, in a first step (S1), a catching force FFang of the safety gear (26) is determined at rated speed vnenn a downward travel of an unloaded elevator car (18) with unladen weight mFK, wherein a braking deceleration aFang_leer> 1 g is reached; In a second step (S2), a test speed vtest> vnenn is determined as a function of the catching force FFang at which a predeterminable test load of the safety gear (26) and of the cable lift (100) occurs; In a third step (S3), a test run is carried out with the determined test speed vtest with the lift car (18) unloaded, with empty weight mFK, whereby a relative position change Δs of the lift car (18) to the counterweight (16) is recorded; In a fourth step (S4), a judgment is made as to whether the recorded relative position change Δs satisfies an achievement of the predetermined test load of the cable lift (100) and the desired characteristic value K is determined. The proposed measuring device comprises at least one elevator car distance measuring device (30) and a second counterweight distance measuring device (52) and / or a counterweight acceleration sensor (32), a relative position detection device (52) and an analysis device (54) for determining the characteristic value K.

Description

The invention relates to a measuring system and a measuring method for determining a characteristic None safety gear of a cable lift according to the preamble of the independent claims.

STATE OF THE ART

In general, a cable lift comprises a guided in a hoistway cabin, which is connected via a cable, which is guided by a traction sheave and connected to a counterweight. The counterweight typically has the mass of the elevator car plus half the rated load of the elevator. The elevator car is guided along a cabin guide, in particular a guide linkage in an elevator shaft. At the cabin a safety gear is provided to prevent the crash of a cabin, for example, in case of cable breakage or failure of a brake. If the permissible speed of the elevator car is exceeded, a centrifugal or speed controller triggers the safety gear. Friction linings between the safety gear and the track brakes the movement of the car.

After installing a cable lift, various tests must be carried out to ensure safe operation. In addition, tests of safety-relevant parts must be carried out during repetitive tests during operation on the basis of test regulations, such as the Lifts Directive. A central test instruction is aimed at testing the safety gear, in which the effectiveness of the safety gear is checked as the central safety device of the cable lift.

After EN 528 When operating the safety gear, no acceleration forces> 3 g may occur in order not to injure persons in the lift.

The safety gears must be checked at regular intervals, and in particular when placed on the market. For the test, it has hitherto been customary for weights to be introduced into the elevator car which are of the order of magnitude of the rated load of the elevator and for which the safety gear has been manually released during nominal speed driving in order to measure the braking deceleration or the response of the safety gear , Since the cabin is loaded with high load, braking delays <1 g regularly occur.

Such testing requires the teaching and loading of test weights, the handling of which is tedious and cumbersome. It requires a high staff and logistical effort to approach the corresponding weights, which make up several 100 kg, to the elevator and transported away again. Furthermore, the high mass and the high braking forces that are exerted on the essential parts of the elevator, in particular the safety gear, the cable, the car holder, the brake device and the traction sheave, are excessive, so that a high mechanical load and wear is expected from the test.

Based on the previous test methods for safety gears, a test method is proposed below, in which a characteristic value K of the safety gear is detected by a weightless test during a cabin cruise at increased speed and thus the reliability of the safety gear can be determined.

The basis of a safety gear check is to ensure the absorption of high kinetic energy to ensure that the safety gear functions reliably in extreme cases. Thus, when a load of additional mass in an elevator car is not ensured that a comparable safety gear in different lifts at the same loadings to the same extent can be tested for their functionality.

Will a cable lift, as in the 1 is shown schematically, with a load m _L 20 loaded, and is a deceleration, for example by means of the safety gear with a delay of a _{Fang_L} <1 g, the mass of the counterweight plays m _GG 16 a crucial role that significantly influences the energy consumed by the safety gear. The rope 14 that the cabin 18 with the counterweight 16 connects, as is usual with cable lifts, on a traction sheave 12 guided. The catch force that a safety gear at the in 1 has to take into account the following constellation: F _Fang = (m _FK + m _L - m _GG ) · g + (m _FK + m _L + m _GG ) · a _{Fang_L} (1)

Here, a _{Fang_L describes} the delay caused by the safety gear.

wobei F_Fang die von der Fangvorrichtung ausgeübte Fangkraft darstellt, m_FK die Masse der Aufzugskabine 18, m_L die Masse der zugeladenen Last, m_GG die Masse des Gegengewichts und g die Erdbeschleunigung 9,81 m/s².Accordingly, the delay applied by the safety gear is given by:

where F _{Fang represents} the force exerted by the safety gear, m _FK the mass of the elevator car 18 , m _{L is} the mass of the loaded load, m _{GG is} the mass of the counterweight and g is the gravitational acceleration 9,81 m / s ² .

, wobei eine Nenngeschwindigkeit v_nenn der Aufzugskabine angenommen wird. Hierdurch ergibt sich ein Verzögerungsweg s_L von:

der bei obigen Werten einen Verzögerungsweg von 85 mm bei einer Nenngeschwindigkeit von v_nenn = 1 m/s resultiert.Assuming a typical 3000N trapping force, the mass of an elevator car of 1000kg, the mass of the counterweight of _1500kg and a payload of _1250kg , there will be a delay of, for example, a _{catch_L} = _{0.6g of} the safety gear. With this delay, the delay path s _L results as:

, wherein a rated speed _vnenn the elevator car is assumed. This results in a delay path s _L of:

the above values at _nominal a delay path of 85 mm at a nominal speed of v = 1 m / s results.

was in unserem Beispiel eine verzehrte Energie von 2.500 J ergibt.If one considers the energetic conditions of the test of the safety gear when the load is loaded, the following absorbed energy of the safety gear, which is converted into heat, results according to the calculation rule energy = force × travel:

which gives a consumed energy of 2,500 J in our example.

The energy conservation law of mechanics applies to the individual components of the cable lift. Before the start of the fishing test, the counterweight has a kinetic energy of: E _{kin1_GG} = 1 / 2m · _gg (V _nominal) ² (7) and the elevator car has a kinetic energy of E _{kin1_FK} = 1/2 · (m _FK + m _L ) · (v _nenn ) ² (8) on. Upon completion of the braking operation, the counterweight exhibits an increase in the potential energy of: E _{pot2_GG} = m _GG · g · s _L (9) and the elevator car has a change in the potential energy of: E _{pot2_FK} = (m _FK + m _L ) · g · (-s _L ) (10)

Considering the above formula (5) for the braking distance s _L results in an energy balance, which reflects the difference of the two kinetic energies minus the difference of the change of the two potential energies according to the following formula:

It is clearly evident that the mass of the counterweight and the mass of the driver's cab while traveling at nominal velocity v _nominal crucial to the mass of consumed energy the safety gear contributes so that with the same Massenzuladung m _L in different lifts with different counterweights and cab weights different to consuming energy of the braking device occur. Thus, for a defined load z. B. 125% of the rated load of an elevator car can never be ensured that the same braking energy are tested. The previous test method with load of additional masses thus leads to different elevations to different results, since the mass of the counterweight and the mass of the elevator car is an essential role in the determination of the consumable braking energy or the achievable acceleration forces by the safety gear. A test, as was customary in the prior art, provides no comparable results and depends on the design and construction of the respective cable lift.

was mit obigen Werten eine zu verzehrende Energie der Fangvorrichtung von 750 N bei Nennfahrt ergibt.The basis for a new, improved examination procedure is the following considerations:
Considering a check of the catching force of an unloaded elevator car in a first measuring procedure, acceleration forces a _catch > 1 g can be achieved when the safety gear is triggered, since the mass of the elevator car is substantially smaller than during loading so that higher deceleration accelerations are achieved when the safety gear is triggered can be. If higher deceleration accelerations than 1 g are achieved, then the influence of the counterweight can be neglected, since this is thrown up during a trapping process and does not exert a counterweight on the rope. The counterweight is thus in the short-term weightless state, and the safety gear only delays the weight of the elevator car. This then results in a force acting on the cabin catching force of F _catch = m _FK · g + m _FK · a _{catch_leer} (12) which gives a _catch force F _catch of 3,000 N in the case of a mass of the elevator car m _FK = 1,000 kg and a brake deceleration of a _{catch_leer} = 2 g measurable, for example, by a position determination, since the influence of the counterweight can be neglected. To determine the catch delay, for example, an accelerometer can be used, or by an optical elevator tester, as shown in the EP 2221268 is described, are used. Knowing the capture force a _{Fang_leer} the safety gear in the unloaded state can be calculated how fast the car must go to consume in a second fishing a brake energy to be tested, so that the required mechanical load of the brake device and the other components can be tested safely , Thus, in the case of an empty elevator car and in the process with the rated speed of v _nom = 1 m / s, an energy is consumed by:

which, with the above values, gives an energy to be consumed by the safety gear of 750 N at nominal speed.

When the elevator car moved in a second step with an increased speed, for example with a velocity v _140% 140% of the rated speed v _call, wherein a speed limiter, which triggers the safety gear on the elevator car in case of speed, so there is a catch energy at elevated Speed (assuming the deceleration remains with a _catch > 1 g, so that the mass of the counterweight is irrelevant) of

The energy consumed at the increased speed can thus be increased and depends on the initially determined catch force and the square of the increased travel speed:

In our example with an excessive speed of v = 140% = 1.4 m / s results in a catch energy of 1,400 J.

Thus, as long as the achievable catch delay when triggering the catcher and empty cabin a _{catch is} > 1 g, set by setting different speeds of the elevator car different trapping energies so that the effectiveness of the safety gear regardless of the mass of the counterweight or the achievable acceleration by the Safety gear can be tested. Thus, when driving at excessive speed and when the cab is empty, a characteristic value of the safety gear or a catch energy to be checked can be determined, which is independent of the design of the elevator car.

As a result, it can be stated that a test with weights added, so that the deceleration due to the high mass is usually a <1 g, and the mass of the counterweight plays a crucial role, provides different lifts for different test conditions and thus is disadvantageous. It can be stated that a test of the safety gear according to the conventional method, in which driven at rated speed and only increased deceleration of the elevator car braking delays a _catch <1 g are achieved, converted part of the braking energy from the safety gear into heat and another Part is used to raise the counterweight and thus to save potential energy. Thus, a safety gear which provides a high deceleration effect, and thus achieves a short deceleration path, converts a small amount of energy into heat, with only a small amount of energy flowing into a positional change of the counterweight. With a relatively weak safety gear, which requires a long deceleration path, more energy flows into the lifting of the counterweight, whereby a high amount of heat energy has to be absorbed by the long deceleration path. The amount of energy that is converted into heat by the safety gear during the test is thus highly dependent on the catching delay. Thus, the load on the safety gear in the test with an overload of, for example, 125% of the nominal cabin load is disadvantageous, since the load for the components to be tested varies very differently. So it is a fallacy that the same load on lifts will set the same conditions for the safety gear. Another disadvantage is that in a safety test with overload high mechanical loads of the catch housing can occur and cause damage. In an emergency, a safety gear could be severely damaged, so that it fails in an emergency.

The actual Standard EN-81 demands that a cab loaded with 100% rated load be allowed to decelerate at least 0.2 g and not more than 1 g without the influence of the rope. As the above example shows, with an empty cab and an excessive speed, accelerations of 1 g to no more than 2.5 g can be achieved, with the counterweight and the rope exerting no influence, and thus the entire kinetic energy must be consumed by the safety gear , which leads to comparable results in the catch test.

In the 3 is an example of a diagram of the catch force in safety gear, which can apply an acceleration of 8 to 38 m / s ² in an empty cab, shown. A weak safety gear which only reaches a low deceleration, if the elevator car is loaded with increased mass, would have to absorb a thermal energy of E _Fang = 3,000 J. A strong high deceleration gear would consume about 50% less energy.

Thus, the previous test method can not provide a uniform standard for different elevator configurations. The safety gear overload test gives no information about how much the safety gear is actually decelerating. Thus, the risk of incorrect settings of the safety gear is given, so that it triggers accidentally in a normal operation, the safety gear, or set too hard safety gear can pose a risk of injury to passengers. In a test with an empty elevator car and a rated speed of 140%, a catch test can be established without any influence of the counterweight and therefore independent of the type of lift. Thus, the behavior of the safety gear in an emergency can be effective and comparable check.

The object of the invention is therefore to propose a test method and a measuring system that, regardless of the design and the mass ratios of the cable lift results in the same characteristic values K of safety gear to be tested. Thus, a simpler, cheaper and more reliable test can be carried out without the additional load of additional weights.

A further object of the present invention is to propose a system and a method with which the effectiveness of the catch test can be determined in an unloaded elevator car, so that a test of the safety gear is gentler, faster and cheaper to carry out.

The present object is achieved by a measuring system and a method according to the independent claims. Advantageous embodiments are the subject of the dependent claims.

DISCLOSURE OF THE INVENTION

According to the invention, the measuring system for determining a characteristic value K of a safety gear of a cable lift comprises at least one distance measuring device for determining a distance s of an elevator car and / or a counterweight to a fixed point, in particular an elevator shaft excavation. The system further comprises a second distance measuring device and / or an acceleration sensor, a relative position detection device for detecting a relative position change Δs between elevator car and counterweight at the conclusion of a trip of the elevator car by braking action of the safety gear, and an analysis device for determining at least one characteristic value K of the safety gear, preferably one _Catch energy E _Fang , when the elevator car and the counterweight have reached standstill, based on the course of the relative position change Δs between the elevator car and the counterweight.

In other words, the measuring system comprises a distance measuring device for determining a distance s of an elevator car and / or a counterweight to a fixed point, so that the kinematic behavior of the elevator car, ie position, speed and acceleration of the elevator car during the safety test can be detected. Also, a distance measuring device picks up position, acceleration and counterweight speed during the capture test. The second distance measuring device or an acceleration sensor are intended to determine the kinematic behavior of the counterweight or the elevator car, wherein a relative position means can determine a relative position change Δs between elevator car and counterweight at the conclusion of the ride of the elevator car under the action of the braking device. This allows the relative position change of counterweight to the elevator car to be quantified during the course of the catching test. An analysis device determines a characteristic value K, in particular the catch energy E _Fang , which is reached by the safety gear as soon as the elevator car and counterweight come to a standstill after completion of the test drive, on the basis of this relative position change Δs between the elevator car and the counterweight.

In other words, a measuring system is proposed, which reaches in operation at an overspeed of the cabin ride, so that the counterweight by the influence of an increased catch delay a _catch loses> 1 g in the short term rope tension and jumps up. The height of the counterweight's upward speed provides a measure of the catching delay in order to determine, based on the catching delay, the energy to be consumed for a given speed of the elevator car, which is picked up by the safety gear. Thus, by the measuring system without the influence of the counterweight, a test of the functioning of the safety gear can be determined, which does not depend on the construction of the elevator.

In an advantageous embodiment, the distance measuring device, an optical distance measuring device, for example, one already from the EP 2221268 A1 be known distance measuring device, which is arranged at the fixed point, in particular in the hoistway pit room or on the elevator car, and which emits an optical measuring beam, which attaches to a preferably removable optical reflector is reflected on a lower or upper side of the elevator car and / or the counterweight, wherein preferably the optical distance measuring device comprises adjusting means for preferably self-aligning alignment of the optical measuring beam to the reflector. By an optical distance measuring device, a non-contact determination of the position, the speed and the acceleration of the elevator car or the counterweight can be made. If two optical distance measuring devices are used, one for the elevator car and one for the counterweight, the relative position change Δs can be easily determined. In this way, all kinematic parameters can be determined in the course of testing the safety gear in order to determine the characteristic value K of the safety gear clearly. The optical distance measuring device can be housed, for example, in a portable measuring device that can be temporarily arranged in the hoistway pit or on the roof of the elevator car, so that it can be easily transported for measurement purposes and attached by a single person. The procurement of heavy weights and the associated logistical effort are not necessary.

In an advantageous embodiment, the system may comprise an acceleration sensor arranged on the counterweight, for example a magnetically attachable sensor, and the distance measuring device may be set up to measure the distance s between the elevator car and the fixed point, the relative position determining device being set up on the basis of the course of the distance s of the elevator car relative to the fixed point and an acceleration value a _GG of the acceleration sensor arranged on the counterweight to determine the relative position change Δs. Thus, the position, speed and acceleration of the elevator car can be recorded by a distance measuring device, wherein an acceleration sensor a _{GG is} arranged on the counterweight, and based on the acceleration values that occur at the counterweight, the relative position change Δs together with the analysis of the distance s between the elevator car and Fixed point are used to determine the characteristic of the safety gear. An acceleration sensor can be easily attached to a counterweight and, for example, can be magnetically attached, and reliably record the data in the rough conditions in the elevator shaft.

In a further development of the invention, a gyrometer and / or an acceleration sensor can be arranged on the elevator car, which can determine a tilting of the elevator car, and the analysis device can be set up to determine an uneven braking action of the safety gear on the basis of the determined tilting. A gyrometer or another acceleration sensor can on the one hand detect the vertical acceleration of the elevator car directly, on the other hand also determine horizontal tilting of the elevator car in the elevator shaft by a two- or three-axis determination, and thus make uneven operation of the safety gear detectable. For example, if one of several safety gears responds more than the others, then twisting or tilting of the elevator car inevitably results in the course of the safety test, so that uneven operation due to wear on one or more safety gears can be identified. Thus, more accurate data on the effectiveness of all safety gear on the elevator car can be determined.

In an advantageous development, the acceleration sensor and / or the gyrometer and the distance measuring device may comprise an internal data memory for temporal measured value recording, wherein the analysis device is set up to determine the characteristic value K after completion of a measuring process, a time assignment of the measured values of acceleration sensor and / or gyrometer and Distance measuring device to perform by cross-correlation. If one or more acceleration sensors or gyroscopes are used, and in addition a distance measuring device, which is arranged in particular in the hoistway pit area or on the roof of the elevator car, then the recorded data must be synchronized with one another in terms of time. This can be done, for example, in that both the acceleration sensor / gyrometer and the distance measuring device have their own internal clock and store the recorded measured values in a time sequence, wherein in a postprocessing step the analysis device correlates the time-based measured values of the acceleration sensor / gyrometer and the distance measuring device with one another in a temporal relationship which is done via a cross-correlation.

beschrieben. Die Kreuzkorrelationsfunktion ermöglicht die Zuordnung von Signalwerten unterschiedlicher Zeitskalen zueinander, sofern die Signale einem gemeinsamen Einfluss unterliegen, hier beispielsweise dem Einfluss der Bremswirkung, die Aufzugskabine und Gegengewicht in gleicher Art beeinflussen. Somit können Beschleunigungswerte des Gegengewichts mit Beschleunigungswerten der Aufzugskabine zeitlich korreliert werden, auch wenn beide mit unterschiedlichen und unabhängigen Zeitbasen aufgezeichnet sind, um die beiden Zeitskalen zueinander zuzuordnen. Hierdurch kann eine asynchrone zeitliche Aufnahme von Beschleunigungswerten des Gegengewichts und Positions- bzw. Beschleunigungswerten der Aufzugskabine vorgenommen werden, die nachträglich in der Analyseeinrichtung durch Kreuzkorrelation miteinander verbunden werden können. Hierdurch ist es möglich, zwei oder mehrere Sensoren unabhängig voneinander im System anzubringen und deren Daten in einer gemeinsamen Analyse miteinander zu vergleichen, so dass eine Verkabelung oder ein zeitsynchroner Datenaustausch während des Prüfvorgangs nicht notwendig ist.A cross-correlation allows the correlation of two time-dependent signals at different time shifts between two signals x (t) and y (t) and is represented by a correlation function:

described. The cross-correlation function allows the assignment of signal values of different time scales to each other, provided that the signals are subject to a common influence, here, for example, influence the influence of the braking effect, the elevator car and counterweight in the same way. Thus, acceleration values of the counterweight can be correlated in time with acceleration values of the elevator car, even if both are recorded with different and independent time bases in order to assign the two time scales to one another. In this way, an asynchronous time recording of acceleration values of the counterweight and position or acceleration values of the elevator car can be made, which can subsequently be connected to one another in the analysis device by cross-correlation. This makes it possible to attach two or more sensors independently of each other in the system and to compare their data in a joint analysis with each other, so that a cabling or a time-synchronous data exchange during the testing process is not necessary.

According to the aforementioned embodiment, it may be advantageous for the acceleration sensor and / or the gyrometer to be temporarily connectable to the analysis device via a contact unit for data exchange, wherein the analysis device is preferably included in the distance measuring device designed as a transportable device. This embodiment proposes that after completion of a capture test, the time-based measured values of acceleration sensor or gyrometer attached to the elevator car and / or the counterweight, with the analysis of a contact unit, such as a USB port, connectors, Bluetooth or other temporarily connectable Contact connections for data exchange are connectable. The analysis device may be located in a portable device in which the distance measuring device is installed, so that in the portable distance measuring device device, the overall analysis can be performed.

As an alternative to the above-mentioned summary of the measured values of the various sensors, data transmission between the acceleration sensor and / or the gyrometer and the distance measuring device can take place wirelessly, in particular by radio transmission via radio antennas. Here, for example, on the basis of a single time scale synchronous time during the execution of the Fangprüfung or based on multiple time scales and a subsequent correlation step, a non-contact data exchange takes place, so that acceleration and position data are available based on the same time scale. The data exchange can expediently take place via a radio transmission, for example via WLAN, NFC, Bluetooth or the like.

In an advantageous development, at least one, in particular a plurality of force measuring devices can be included which are set up to measure a weight force m _{FK of} the elevator car and / or a weight force m _{GG of} the counterweight and which are connected to the analysis device for determining the characteristic value K of the safety gear are. To determine the characteristic value K, in particular the catching force E _Fang , knowledge is advantageous at least via the mass of the elevator car m _FK but also of the counterweight m _GG . To determine these masses, these can either be entered manually or measured directly. For this purpose, it is advisable to provide one or in particular a plurality of force measuring devices, preferably load cells, which can be placed on the buffers of the elevator car or the counterweight, and to determine their mass directly upon lowering the counterweight or the elevator car. Thus, even if the technical specifications of the elevator are not present, the mass parameters can be measured, so that an exact determination of the catching force of the safety gear is made possible even with structural changes to the cabin or counterweight.

• – in einem ersten Schritt (S1) eine Fangkraft F_Fang der Fangvorrichtung bei Nenngeschwindigkeit v_nenn einer Abwärtsfahrt einer unbeladenen Aufzugskabine mit Leergewicht m_FK ermittelt, wobei eine Bremsverzögerung a_{Fang_leer} > 1 g zu erreichen ist;
• – In einem zweiten Schritt (S2) wird eine Testgeschwindigkeit v_test > v_nenn in Abhängigkeit der Fangkraft F_Fang und/oder einer Bremsverzögerung a_{Fang_leer} bestimmt, bei der eine vorbestimmbare Prüfbelastung der Fangvorrichtung und des Seilaufzugs auftritt;
• – In einem dritten Schritt (S3) wird eine weitere Testfahrt mit der bestimmten Testgeschwindigkeit v_test > v_nenn bei unbeladener Aufzugskabine mit Leergewicht m_FK durchgeführt, wobei eine Relativpositionsveränderung Δs von Aufzugskabine zum Gegengewicht aufgenommen wird;
• – Schließlich wird in einem vierten Schritt (S4) eine Beurteilung durchgeführt, ob die aufgenommene Relativpositionsveränderung Δs einem Erreichen der vorbestimmten Prüfbelastung des Seilaufzugs genügt, und der gewünschte Kennwert K wird ermittelt.

In a secondary aspect, the invention proposes a method for characterizing a safety gear of a cable lift, which can preferably be carried out using a system according to one of the aforementioned system claims. For this purpose is

• - in a first step (S1) a fielding force F _catch of the safety device at rated speed v _call determines a downward travel of an elevator car unloaded with tare m _FK, wherein a braking deceleration a _{Fang_leer>} 1 g to reach;
• - In a second step (S2), a test speed v _test> V _nominal, depending on the fielding force F _catch and / or a braking deceleration a _{Fang_leer} determined at which a predeterminable test loading of the catch device and the rope elevator occurs;
• - In a third step (S3), a further test drive is carried out with the determined test speed v _test > _vnenn with unloaded elevator car with empty weight m _FK , wherein a relative position change Δs is taken from the elevator car to the counterweight;
• Finally, in a fourth step (S4), a judgment is made as to whether the recorded relative position change Δs satisfies an achievement of the predetermined test load of the cable lift, and the desired characteristic value K is determined.

The method described above determines in a first step, a catching force or a catching delay of the safety gear during a downward travel of an unloaded elevator car with the rated speed and the empty weight m _FK . If the braking deceleration a _{Fang_leer} > 1 g, then the influence of the counterweight does not matter because it flies upwards due to the inertia and exerts no influence during the braking process. Depending on the determined catch force or the braking deceleration, a further test speed v _test can be determined in a second step in order to achieve a predetermined test load or predetermined load energy of the safety gear. In a third step, a _{test run is} carried out with this test speed v _test in order to expose the catching energy or the test load to the safety gear. In this case, in a fourth step, a relative position change .DELTA.s between high-flying counterweight and the elevator car is determined to verify that the desired load is reached or the acceleration forces and braking energies are achieved, and thus the safety gear and the other elevator components meets the assumed characteristic value.

By the first test drive with rated speed v _nenn the maximum catch force or the braking deceleration of the safety gear is determined. Based on these values, a test braking energy that the safety gear and the entire system has to absorb can be determined by determining a test speed v _test . In a further trip with this test speed v _test all relevant components of the elevator are subjected to these energies, so that a reliable test of the safety gear can be performed. The system can be carried out without additional loads and only by determining the relative position between elevator car and counterweight. A basic requirement is that the safety gear allows braking delays of a _catch > 1 g, so that the counterweight is irrelevant, this being ensured by observing the relative position change. The system can be checked in a short time with a minimum of hardware and only by a single person.

In an advantageous development, the relative position change Δs of the elevator car to the counterweight can be determined by correlation of measured values of an optical distance device, which measures a distance s of the elevator car from a fixed point, and a second distance measuring device, the distance between a fixed point and the counterweight or one at the counterweight arranged acceleration sensor can be determined, preferably in a post-processing step, the measured values of the movement of the elevator car and counterweight by means of cross-correlation are assigned to each other in time. The combination of the time-based measurements of the kinematic behavior of the elevator car and counterweight can be processed by means of cross-correlation in a post-processing step, so that no real-time data comparison between the various sensors is necessary. This simplifies the measurement recording and makes it possible, for example, to carry out a plurality of measurement runs, with an evaluation only having to be carried out at the end. By means of the cross-correlation, the time bases of the different measured values can be assigned to one another with high accuracy.

In an advantageous development, the determined catching force F _catch can be compared with an archived catching force F _{catch_old} from a database, and a deviation of the catching forces can be determined and evaluated. For this purpose, the distance measuring device or the analysis device may include a database of already determined measured values of the catching force or the catching energy at the same speeds in order to indicate an aging process or a wear.

In an advantageous variant of the measuring method, to determine the relative position change .DELTA.s at least one distance s between the elevator car and / or the counterweight and a fixed reference point, in particular the elevator shaft mine chamber, can be determined by means of an optical distance measuring device. If the distance measuring device is not based on a mechanical travel sensor but on an optical scanning of the distance, then the kinematic behavior of the elevator car and / or the counterweight can be detected with high precision and with little measurement effort. The measuring process can be carried out quickly and temporarily set up or dismantled without major effort of the measuring apparatus. Thus, the measuring method can be performed quickly and easily.

In an advantageous embodiment of the method, at least one vertical acceleration component a _{FK of} the elevator car and / or a _{GG of} the counterweight can be detected and evaluated by an acceleration sensor to determine the relative position change .DELTA.s. In this embodiment, the relative position change Δs is determined depending on at least one vertical acceleration component detected at the elevator car or the counterweight. This allows a simplified determination of the relative position change, since an acceleration detected by a central sensor can be who does not need a reference position. As a result, in particular the relative movement of the counterweight relative to the elevator car can be easily detected.

In an advantageous development of the measuring method, a rotational or twisting movement of the elevator car along the guide rail can be detected by means of a gyrometer or acceleration sensor in order to determine an uneven effect of the safety gear. Thus, an acceleration sensor can be designed as a two- or three-axis sensor, which detects, for example, a vertical acceleration component and detects parallel thereto one or two lying in a horizontal plane components that provide information about whether two or more safety gear evenly decelerate the elevator car or not. As a result, the uniform and non-uniform effect of the safety gear can be detected and, for example, an uneven wear of the various safety gear can be determined. A detected vertical acceleration component of the elevator car may be used to improve the accuracy of a distance determined by a distance measuring device.

In a further advantageous embodiment, for determining the weight force m _{FK of} the elevator car and / or weight force m _{GG of} the counterweight, at least one force measuring device, preferably at least one load cell, can be provided which measures the weight force by lowering the elevator car and / or the counterweight on a buffer. For the exact determination of the braking deceleration and the consumed braking energy of the safety gear, it is important to know the masses, in particular the elevator car m _FK and the counterweight m _GG . These can be entered manually, for example, since they are already known during the installation of the elevator system. An accurate determination of the weights which can be detected independently of preliminary information can be carried out by a force measuring device, preferably one or more load cells, which are placed on the buffers of the elevator system in the shaft pit, for example, whereby the elevator car and / or the counterweight can be placed on the load cells to determine their masses. Thus, deviating masses are detected, in particular in structural changes of the elevator system, so that an exact determination of the characteristic of the catcher is possible.

According to the above embodiment, which propose the use of one or more force measuring devices for determining the weight of counterweight and elevator car, it may further be advantageous that in a further step, a load scale of the cable elevator is calibrated, whereby by increasing loading of the elevator car and recording the Weight of the elevator car by the force measuring device and the load scale calibration of the load scale can be made. Usually cable lifts have load scales that monitor a loading state of the elevator car and can make a warning signal or a deactivation of the elevator system in the event of an overload. To calibrate such a load scale, it was previously necessary to load at least two or more known weights in the elevator car to compare the known weight with the display of the load scale so as to calibrate the load scale. By using force measuring devices, the method can also be used to perform a calibration of the load scale, this one or more weight measuring steps in the process are feasible.

In principle, the method is suitable for determining a characteristic value of a safety gear. Furthermore, it may be possible in a further method step, when driving with an unloaded elevator car, to determine a characteristic value of a service brake by analyzing the course of the distance s between the elevator car and a fixed point. Thus, when operating the elevator car at a normal speed v _nominal, the service brake can be activated and its deceleration can be checked by measuring the distance by means of the distance measuring device. As a result, the effectiveness of the service brake can be determined and, for example, in the case of wear or due to aging, an indication of the condition of the service brake can be output.

Thus, the method can be used not only to determine a characteristic for the safety gear, but also for the verification of a load scale or the state of the service brake. As a result, an easily usable and quickly installable measuring system and measuring method can be performed in order to be able to check in particular safety-relevant parameters of a cable lift system.

DRAWINGS

Further advantages result from the present description of the drawing. In the drawings, embodiments of the invention are shown. The drawing, the description and the claims contain numerous features in combination. The person skilled in the art will expediently also consider the features individually and combine them into meaningful further combinations.

Show it:

1 in a schematic representation of a cable lift 100 with physical characterization of the masses and accelerations to illustrate the physical conditions underlying the measuring method;

2 schematically another cable lift system 100 that serves to illustrate the principle underlying the measuring method;

3 the representation of recorded catch energies of braking devices with different deceleration values;

4 a first embodiment of a measuring system according to the invention;

5 schematically a block diagram of an embodiment of an inventive measuring system;

6 a further embodiment of a measuring system according to the invention;

7 schematically a further embodiment of a measuring system according to the invention;

8th schematically an embodiment of a measuring method according to the invention.

In the figures, similar elements are numbered with like reference numerals.

In 1 is schematically a cable lift system 100 shown in which an elevator car 18 over a rope 14 with a counterweight 16 are connected. The rope 14 is about a traction sheave 12 guided, which is driven by a drive motor, not shown, to an up and down movement of the elevator car 18 make. In the elevator car 18 is a schematically illustrated elevator load 20 arranged. The elevator car 18 has a weight m _FK , and the elevator load located therein 20 an additional weight m _L These weights are over the rope 14 to the counterweight 16 led that the mass has m _GG . The total mass of the system is taken from the traction sheave 12 carried. Typically, the mass of the counterweight m _GG corresponds to the value of the mass m _{FK of} the elevator plus about 50% of the nominal load which the elevator car is to transport, and thus compensates for an average loading of the elevator car. When assuming that the elevator car 18 As it moves downwards, accelerations result from the weight force g = 9.81 m / s ² and the acceleration a by the traction sheave motor 12 put together. The total power of the elevator car 18 with mass 20 thus results with (m _Fk + m _L ) · (g + a). On the other hand, the counterweight acts with the weight force m _GG · g downwards and the counterforce m _GG · a upwards.

In 2 is starting from the 1 a more realistic representation of an elevator system 100 shown in which a safety gear 266 comprising two safety brakes 26a . 26b the elevator car 18 using guide rollers 24a . 24b along an elevator cabin guide 22 is guided, can decelerate in an emergency. The braking deceleration is a _catch coming from the safety gear 26a . 26b can be exercised, greater than the gravitational acceleration g so would in the case of gripping the safety gear 26 the counterweight 16 be thrown upward, and move by a distance Δs higher than the taut rope 14 it is possible. For example, if it is determined starting from the elevator pit mine area 28 the distance s to the elevator car 18 and looking at the distance between the hoistway mine 28 and counterweight 16 or a relative position change or acceleration of the counterweight 16 , so it can be on the height Δs of the free parabolic movement of the "flying" counterweight 16 shut down. In the case of a flying counterweight 16 only becomes the elevator car 18 from the safety gear 26 braked without the influence of the counterweight 16 plays a role. Because the elevator car 18 with significantly more than the acceleration of gravity a _catch> 1 g is delayed, is the counterweight 16 in free parabolic flight with an initial velocity in the upward direction. By a combination of a distance measurement, for example a laser measuring device for determining the distance s from the hoistway pit area 28 to the cabin 18 and an acceleration measurement on the counterweight 16 can the altitude can be determined. Thus, the altitude Δs of the counterweight results during a journey of the elevator car 18 v with 140% of a rated speed _nom = 1 m / s with: Δs = - 1 / 2gt ² + v _140% t (18).

The total duration of the flight can be specified with t _tot :

The result is Δs at the apex of the parabolic flight with:

In the above example, with an excessive speed v = 140% = 1.4 m / s, an altitude of approximately 10 cm would result, with the total flight duration amounting to approximately t _ges = 0.14 s. It acts on the traction sheave 12 a total force, which is as follows: F _TS = m _GG · g + m _GG · a _GG + m _FK · g + m _FK · a _FK (21).

Thus, the load on the elevator system is significantly higher than in the conventional load test, wherein a proof of strength can be provided by setting a test speed higher than the rated speed at unloaded elevator car 18 is achieved.

In the 3 is exemplified represented the energy consumed by safety gear as a function of the braking deceleration applied by the safety gear, if the braking deceleration of 8 to 28 m / s ² vary. It can clearly be seen that weak safety gears, which can provide only a slight braking deceleration, must consume a significantly higher braking energy than strong safety gears that can perform an abrupt braking operation. This is because when calculating the energy, the deceleration force is reciprocally proportional, with a weak safety gear having to deal with 50% more energy than a strong safety gear. For this reason, a check of the safety gear with overload on the one hand lead to an overload of the entire system and the safety gear. On the other hand, no comparable results are achieved because the influence of the counterweight is included. On the other hand, when driving with an unloaded elevator and an overspeed, the deceleration performance of the safety gear and its consumed energy can be directly determined.

In the 4 is a first embodiment of a measuring device according to the invention 10 shown. Starting from the elevator 100 who in 3 is shown in 4 the distance s through an optical measuring beam 48 an optical distance measuring device 30 standing in the pit shaft room 28 as a fixed point 58 is arranged, determined. The optical measuring beam 48 frequency-pulsed laser beam and is attached to an optical reflector 38 standing on the bottom of the elevator car 18 is attached, reflected. The distance measuring device measures its transit times or phase position, so that precise distance information and thus also speed and also acceleration information as a time derivative of the distance values of the elevator car 18 can be determined. For an exact alignment of the measuring beam 48 are at the distance measuring device 56 adjusting 40 attached to the measuring device opposite the reflector 38 to be able to align. At the counterweight 16 is an accelerometer sensor 32 arranged by means of a radio antenna 34 Acceleration values measured in real time to the distance measuring device 56 can transmit. This also has a radio antenna 34 to receive the acceleration values. The distance measuring device comprises an analysis device, which by means of the acceleration values of the counterweight 16 and by the measuring beam 48 certain distance s of the elevator car 18 determines a relative position of the counterweight to the elevator car, and braking deceleration and the catch energy of the safety gear 26 can determine.

In 5 is a block diagram schematically an embodiment of a measuring device 10 shown. This includes a distance measuring device 56 as an optical distance measuring device 30 is designed and the distance to an elevator car 18 or to a counterweight 16 from a fixed point 58 , for example mine area 28 by means of an optical measuring beam 48 can determine. The distance measuring device 56 is with a relative position detection device 52 connected to the Relative position Δs between counterweight 16 and elevator car 18 can determine. Temporarily connected to this is via a contact device 68 For example, a USB port, an acceleration sensor 32 , which is a vertical acceleration component of the counterweight 16 or the elevator car 18 can capture. After determining the relative position change Δs when activating the safety gear 26 can by means of an analysis device 54 the characteristic value K, in particular the deceleration values of the safety gear 26 or that of the safety gear 26 recorded braking energy can be determined.

Furthermore, to the analysis device 54 a force measuring device 46 also via a USB port 68 and a two-axis gyrometer 36 or a two-axis acceleration sensor also via a contact device 68 be temporarily connected for data synchronization and, if necessary, battery charging. The ones from the sensors 32 . 36 and 46 received data values may be considered in a post-processing method in the analysis, wherein time-based values, such as the values of the vertical acceleration sensor 32 or the position sensors 36 by means of a cross-correlation with the distance values of the distance measuring device 56 be reconciled in order to simulate and analyze the transient movement sequence. By means of the force measuring device 46 can the masses of counterweight 16 or elevator car 18 be determined, which determines the braking energy of the safety gear 26 necessary. Through the gyrometer 36 can twist the elevator car 18 When braking are detected, uneven behavior of individual safety gears 26 to be able to identify.

In the 6 and 7 two further embodiments of measuring devices are shown, which are basically those of 4 resemble. In all cases, the distance of the elevator car 18 from the elevator shaft mine room 28 as a fixed point 58 by means of an optical distance measuring device 56 certainly. In the 6 is further shown that by load cells 46a the mass of the counterweight 16 can be determined, and on a set of load cells 46b betting on 42 for resilient interception of the cabin 18 can be arranged, the mass of the elevator car 18 be determined. Thus, regardless of stored elevator system data, the masses of counterweight can be 16 and elevator car 18 determine exactly so that a calculation of the characteristic value K is possible even without knowledge of stored elevator data.

Furthermore, the force measuring devices 46b for example, for the calibration of a load scale 50 who are in the elevator car 18 is used. For this purpose, when discontinuing the elevator car 18 on the force measuring device 46b successively additional weights 20 in the elevator car 18 loaded, and the function and display of the force measuring device 50 to calibrate. Thus, a linearity and hysteresis error of the load scale 50 be determined. Depending on the construction of the load scale 50 For example, a measuring procedure can be carried out in which the elevator car 18 at different speeds on the force measuring devices 46b the buffer 42 is driven.

Furthermore, it is possible in different phases of a measurement process, the effectiveness of a service brake 60 , for example, on a traction sheave 12 attacks with the proposed measuring device. The acceleration sensor 32 at the counterweight 16 has an online data store and stores acceleration values with its own time base. After completion of the measuring process, the cross-correlation of the acceleration values of the sensor 32 with distance values s, that of the distance measuring devices 56 An analysis of the dynamic behavior of the elevator system will be made.

In the 7 is another variant of a measuring system 10 illustrated in which instead of an acceleration value two optically scanned distance values of elevator car 18 and counterweight 16 by means of two optical distance measuring devices 30 be recorded. These are each at the bottom of the elevator car 18 and the counterweight 16 reflector mirror 38a . 38b arranged, and two optical distance measuring devices 56 , which are connected to each other via a data link, independently determine the distances of counterweight 16 and elevator car 18 to the elevator shaft mine. Thus, the position, speed and acceleration of the two components of the cable system can be synchronized in time 100 determined and the effectiveness of the safety gear 26 , the brake 60 be determined.

Finally, in 8th The sequence of a measuring method for determining a core value of a safety gear is shown schematically, in which in a first step S1 a catching force F _catch at a nominal speed v _nominal in a downward travel of an unloaded elevator car 18 with empty weight m _{FK is} determined. This is the safety gear 26 triggered by the overspeed or manually, resulting in a braking deceleration a _{Fang_leer} > 1 g, so that the counterweight 16 in the free parabolic flight after located at the top. In a second step S2, an increased test speed v _{test is} determined by analyzing the braking deceleration a _{Fang_leer} with the a predetermined test load with the safety gear 26 of the cable lift 100 occurs. In the third step S3, a test drive with the test speed v _test , z. B. with v _test = v _140% , ie 140% of the rated speed v _nenn with unloaded elevator car with empty weight m _FK Leer performed, with a relative position change .DELTA.s of elevator car 18 and counterweight 16 is recorded to determine if the expected deceleration values arrive and the corresponding energies and loads occur. In a fourth step S4, a judgment is made as to whether the recorded relative position change Δs is a reaching of the predetermined test load of the elevator 100 is enough and the characteristic K is determined.

With the help of the measuring system according to the invention 10 and measuring method may further the effectiveness of the service brake 60 in empty cab 18 be judged in the upward direction, as with a nominal load 20 loaded cab 18 in the downward direction. Furthermore, the state of the elevator buffers 42 can be determined and a buffer characteristic can be created.

Thus, without supply of additional weights and with low personnel and technical effort, the state of the safety gear 26 be checked, this being independent of the design of the elevator system 100 can be determined.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• EP 2221268 [0017]
• EP 2221268 A1 [0032]

Cited non-patent literature

• EN 528 [0004]
• Standard EN-81 [0023]

Claims (17)

Measuring system ( 10 ) for determining a characteristic value K of a safety gear ( 26 ) of a cable lift ( 100 ), comprising at least one distance measuring device ( 56 ) for determining a distance s of an elevator car ( 18 ) and / or a counterweight ( 16 ) to a fixed point ( 58 ), in particular a lift pit mine ( 28 ), characterized in that the system ( 10 ) a second distance measuring device ( 56 ) and / or an acceleration sensor ( 32 ), a relative position detection device ( 52 ) for detecting a relative position change Δs between the elevator car ( 18 ) and counterweight ( 16 ) upon completion of a downward movement of the elevator car ( 18 ) by braking action of the safety gear ( 26 ), and an analysis device ( 54 ) for determining at least one characteristic value K of the safety gear ( 26 ), preferably a catch energy E _catch , when the elevator car has reached standstill ( 18 ) and the counterweight ( 16 ) based on the course of the relative position change Δs between the elevator car ( 18 ) and counterweight ( 16 ). System ( 10 ) according to claim 1, characterized in that the distance measuring device ( 56 ) an optical distance measuring device ( 30 ), which is at the fixed point ( 58 ), in particular the elevator shaft mine ( 28 ) can be temporarily arranged, and their optical measuring beam ( 48 ) on a preferably removably mounted optical reflector ( 38 ) on a lower or upper side of the elevator car ( 18 ) and / or the counterweight ( 16 ), wherein preferably the optical distance measuring device ( 30 ) Adjustment means ( 40 ) for preferably self-aligning alignment of the optical measuring beam ( 48 ) to the reflector ( 38 ). System ( 10 ) according to one of the preceding claims, characterized in that one on the counterweight ( 16 ) arranged acceleration sensor ( 32 ) and the distance measuring device ( 56 ), the distance s between the elevator car ( 18 ) and the fixed point ( 58 ), and the relative position determining device ( 52 ) is set up, based on the course of the distance s of the elevator car ( 18 ) opposite the fixed point ( 28 ) and an acceleration value a _GG of the counterweight ( 16 ) arranged acceleration sensor ( 32 ) to determine the relative position change Δs. System ( 10 ) according to one of the preceding claims, characterized in that a gyrometer ( 36 ) and / or an acceleration sensor ( 32 ) at the elevator car ( 16 ) is arranged to tilt the elevator car ( 16 ) and the analysis facility ( 54 ) is set up, an uneven braking effect of the safety gear ( 26 ) on the basis of the determined tilt. System ( 10 ) according to one of the preceding claims, characterized in that the acceleration sensor ( 32 ) and / or the gyrometer ( 36 ) and the distance measuring device ( 56 ) comprises an internal data memory for time measurement recording, wherein the analysis device ( 54 ) is set up to determine the characteristic value K after completion of a measuring process, a temporal assignment of the measured values of the acceleration sensor ( 32 ) and / or gyrometers ( 36 ) and distance measuring device ( 56 ) by cross-correlation. System ( 10 ) according to claim 5, characterized in that the acceleration sensor ( 32 ) and / or the gyrometer ( 36 ) with the analysis device ( 54 ) via a contact unit ( 68 ) are temporarily connectable for data exchange, wherein the analysis device ( 54 ) preferably in the distance measuring device designed as a transportable device ( 56 ) is included. System ( 10 ) according to one of the preceding claims 1 to 4, characterized in that a data transmission between acceleration sensor ( 32 ) and / or gyrometers ( 36 ) and distance measuring device ( 56 ) wirelessly, in particular by radio transmission via radio antennae ( 34 ) he follows. System ( 10 ) according to one of the preceding claims, characterized in that at least one, in particular a plurality of force measuring devices ( 46 ), which are set up, a weight force m _{FK of} the elevator car ( 18 ) and / or a weight force m _{GG of} the counterweight ( 16 ) and with the analyzer ( 54 ) for determining the characteristic K of the safety gear ( 26 ) are connected. Method for characterizing a safety gear ( 26 ) of a cable lift ( 100 ), preferably using a system ( 10 ) according to one of the aforementioned system claims, in which; In a first step (S1) a catch force F _{catch of} the safety gear ( 26 ) at rated speed v, _indicating a descent of an unloaded elevator car ( 18 ) is determined with empty weight m _FK , wherein a braking deceleration a _{catch_leer} > 1 g can be achieved; - in a second step (S2) a test speed v _test> V _nominal, depending on the fielding force F _catch and / or a braking deceleration a _{Fang_leer} is determined, wherein a predeterminable test loading of the catch device ( 26 ) and the cable lift ( 100 ) occurs; - in a third step (S3) a test drive with the determined test speed v _test> V _nominal unloaded at the lift cage ( 18 ) with empty weight m _FK , wherein a relative position change Δs of elevator car ( 18 ) to the counterweight ( 16 ) is recorded; In a fourth step (S4), a judgment is made as to whether the recorded relative position change Δs corresponds to a reaching of the predetermined test load of the cable lift (FIG. 100 ) and the desired characteristic value is determined. Method according to Claim 9, characterized in that the relative position change Δs of the elevator car ( 18 ) to the counterweight ( 16 ) by correlation of measured values of an optical distance device ( 30a ), a distance s of the elevator car ( 18 ) from a fixed point ( 58 ) and a second distance measuring device ( 30b ), which is a distance between a fixed point ( 58 ) and the counterweight ( 16 ) or one at the counterweight ( 16 ) arranged acceleration sensor ( 32 ), wherein preferably in a post-processing step measured values of the movement of the elevator car ( 18 ) and counterweight ( 16 ) are temporally assigned to one another by means of cross-correlation. A method according to claim 9 or 10, characterized in that the determined catching force F _{catch is} compared with an archived catching force F _{catch_old} from a database, and a deviation of the catching forces is determined and evaluated. Method according to one of the preceding claims 9 to 11, characterized in that for determining the relative position change Δs at least one distance s between the elevator car ( 18 ) and / or the counterweight ( 16 ) and a fixed reference point ( 58 ), in particular the elevator shaft mine ( 28 ) by means of an optical distance measuring device ( 30 ) is determined. Method according to one of the preceding claims 9 to 12, characterized in that for determining the relative position change Δs at least one vertical acceleration component a _{FK of} the elevator car ( 18 ) and / or a _{GG of} the counterweight ( 16 ) by an acceleration sensor ( 32 ) is recorded and evaluated. Method according to one of claims 9 to 13, characterized in that a rotational movement of the elevator car ( 18 ) by means of a gyrometer ( 36 ) or acceleration sensor ( 32 ) is detected in order to prevent an uneven effect of the safety gear ( 26 ) to investigate. Method according to one of claims 9 to 14, characterized in that for determining the weight force m _{FK of} the elevator car ( 18 ) and / or weight force m _{GG of} the counterweight ( 16 ) at least one force measuring device ( 46 ), preferably at least one or more load cells are provided by lowering the elevator car ( 18 ) and / or the counterweight ( 16 ) on a buffer ( 42 . 44 ) measures the weight. A method according to claim 15, characterized in that in a further step, a load scale ( 50 ) of the cable lift ( 100 ) is calibrated, whereby by increasing loading of the elevator car ( 18 ) and recording the weight of the elevator car ( 18 ) by the force measuring device ( 46 ) and the load scale ( 50 ) a calibration of the load scale ( 50 ) is made. Method according to one of the preceding claims 9 to 16, characterized in that in a further step by driving the unloaded elevator car ( 18 ) a characteristic value of a service brake ( 60 ) by analyzing the course of the distance s between the elevator car ( 18 ) and fixed point ( 58 ) is determined.

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