HK1166486B - Operational state monitoring of load-bearing devices in a lift assembly - Google Patents

Description

The present invention relates to a lifting system which includes at least one monitoring device or device for monitoring the condition of the lifting equipment or equipment for the lifting cabin or counterweight in a lifting system.

A lift system normally consists of a lifting cab and at least one counterweight, which are moved in opposite directions in a lift shaft. The lifting cab and at least one counterweight are carried in or along guide rails, supported by at least one support which is guided by a propulsion drive. The support usually consists of one or more coated steel ropes, one or more artificial fibre ropes, one or more flag or profile straps (keil-ribbon straps) or a parallel combination of the above-mentioned versions, each support being guided by a separate propulsion drive.

The same problem may arise with counterweight if the lifting cab should be mounted on the shaft-floor buffers. This elevation of a load, be it the lifting cab or the lifting balance, to one side of the drive-wheel without allowing the opposite load to descend freely on the other side of the drive-wheel, is unforeseeable and may lead to dangerous (dirty) falls or reversal of the opposite load.

As a result, monitoring devices have been developed to detect a loose, unloaded load bearing medium, based, for example, as revealed in the European publication EP-A1-1 953 108 on spring-proof storage of the entire drive and a diversion unit with at least two additional rolls for the load bearing medium.

The document WO 2006/082460 provides a fall-stop device which prevents the counterweight from falling in the event of a break in the load bearing medium. The fall-stop device is attached to the counterweight and triggers the fixing of the counterweight as soon as a force threshold is exceeded. If the solution according to WO 2006/082460 results in a crack or loosening of the load bearing medium, a spring-loaded axis is moved which triggers the fall-stop device.

Document DE 10 2006 027989 A1 identifies a sensor device which monitors individual load-bearing equipment, in this case chains, and which is independent of the drive elements, rolls and other load-bearing parts of the lifting equipment described.

Document FR 2 618 420 shows a device for monitoring a single load bearing medium at its rolling coil, whereby a switch is operated to shut off the drive in the event of a loose load bearing medium. The device according to FR 2 618 420 therefore monitors the loose load bearing of a single cable and not the loose load bearing of the entire load bearing string.

The International Publication WO-A1-2007/144456 reveals, however, a direct, even spring-protected, attachment of the support itself. A spring release at the fixed support point of the support, thus triggering a switch to shut down the drive, is caused by its release. The disadvantage of this solution is that it is only suitable for lifts with low lifting height and that it is not detected at the directly affected support sections between the drive train and the lifting gearbox or between the drive train and the counterweight.

The technical disadvantages of these two solutions are, on the one hand, the construction work and, on the other hand, the difficulty of detecting a reliable trigger value.

The present invention is intended to propose a device for monitoring the working condition of the lifting equipment, which is simpler, less time-consuming and therefore more cost-effective to set up and avoid the aforementioned disadvantages of the state of the art, in particular to ensure improved detection of a lifting equipment that has become loose as a result of an accident.

The solution to the problem consists first of all in the design and arrangement of a monitoring device which is not located at the fixed mounting points of the load bearing equipment or at the storage of the entire drive unit, but at a rolling coil for the load bearing equipment.

According to a first basic variant of the monitoring device of the invention, a rolling pin is provided for the load carrier in the section of the load carrier between the drive shaft and a first point of attachment of the load carrier to the lifting cab. Hereinafter, the term 'point of attachment of the load carrier to the lifting cab or point of attachment of the load carrier to the counterweight' shall generally be understood to mean the roll or rolls of load carrier through which the load carrier is carried in order to support the lifting cab or counterweight. The lift carrier may in principle be carried by a load carrier which is carried only by an upper roll. This roll is usually centred but also eccentric or eccentric on the upper roll or lifting cab.The weight of the lifting material is approximately 180° of its circumference. In order to prevent the lifting material from being over-bent and over-strained, the weight of the lifting material must therefore be relatively large in diameter. Therefore, lifting arrangements for the lifting cabin or the counterweight with at least two smaller lifting rolls - or pairs of them - are often implemented as so-called underwing.In any case, the first point of contact of the lifting medium with the lifting medium or the first point of contact of the lifting medium with the counterweight is the individual rolls or, in the case of the last described rolls (whether at the bottom or the top of the lifting medium or the counterweight), the first point of contact of the next drive shaft with regard to the length of the counterweight.A second support point of the load-bearing equipment at the lifting cab or a second support point of the load-bearing equipment at the counterweight is only applicable to the different load-bearing arrangements and is the load-bearing roller further away from the drive shaft.

The present invention describes a monitoring device which is mounted on a rotating coil, i.e. either on the rotating coils and/or on rotating coils which do not have a rotating function.

For the sake of clarity, the present application defines two fixed anchorages for a load bearing device, usually fixed at two fixed anchorages, where the load bearing device is fixed, for example, in the upper part of the lift shaft. The load bearing device is, for example, guided by a drive shaft, usually placed approximately in the middle between these fixed load bearing device anchorages, and thus forms two loops. One of these loops supports the lifting scale with at least one drawbar, the other with at least one drawbar to support the counterweight. The load bearing device thus forms several sections of load bearing equipment or parts of load bearing equipment, which vary in their respective load bearing capacity when the lifting system is in operation. The load bearing equipment is thus located between the contact or loading points (for example, a cross section) of the load bearing device and the opposite loading point (for example, a cross section) of the load bearing equipment.(first) load-bearing material contact point at the counterweight. A second load-bearing material section of the entire load-bearing material is formed between the (first) load-bearing material roller or the (first) load-bearing material contact point at the counterweight (or, depending on the type of suspension, between a second load-bearing material roller or a second load-bearing material contact point at the counterweight) and the drive shaft. This second load-bearing material section is also referred to as the counterweight load-bearing material section. A third load-bearing material section of the entire load-bearing material is formed between the load-bearing material roller or the load-bearing material contact point at the lifting cabin or the lifting cabin. This second load-bearing material section is also referred to as the load-bearing material section.Err1:Expecting ',' delimiter: line 1 column 776 (char 775)Err1:Expecting ',' delimiter: line 1 column 44 (char 43)

The shift coil referred to at the beginning of paragraph [009] - which redirects the load between the drive unit and the first point of contact of the load at the lifting cab - is moved by means of a force storage device under defined pre-tension so that a sensor gives a signal when the load is discharged from the load due to the movement of the shift coils in their storage. This signal is used preferably to stop the drive unit and the drive unit or to indicate a reversal of its rotation. The shift coil is in normal operation, i.e. below the load direction of the loaded load, at a stop.

The present invention is based on the invention of a new device for monitoring the rolling stock, which is a sensor, which is activated in normal operation. However, as soon as the rolling stock is pushed away from the load-bearing position by the force storage device, the signal changes. Because the load is moved from one end to the other, the detection accuracy increases and the load is quickly transferred to the lowest or highest position, so that the load can be lifted to the maximum position.

A first further design variant of the basic variant described provides for a rolling coil according to the invention on both sides of the drive shaft, i.e. both on the load-bearing section between the drive shaft and the first point of attachment of the load-bearing device to the lifting cab, and on the load-bearing section between the drive shaft and the first point of attachment of the load-bearing device to the counterweight, which can be avoided not only by applying the counterweight to the shaft floor buffers or by clamping the counterweight when it moves downwards, but also by applying the lift shaft to the corresponding counterweight buffers to avoid further upward movement of the respective counterweight (s).

Another design variant concerns a lift system in which the lift cabin is isolated from the support, i.e. the lift cabin is on the rolls supporting it in a loop formed by the support. In the case of parallel support vehicles, preferably two rolls of the invention, each at the lower edges of the lift cabin, with a force storage element and a sensor, are arranged. This ensures that a relief or relaxation in the lift is detectable and a signal to stop the drive and the drive or to the direction of the drive is produced. In particular, it is advantageous for this design variant that the monitoring device operates independently of the weight of the load.

Err1:Expecting ',' delimiter: line 1 column 374 (char 373)

In order to prevent the sensors on the drive being able to interpret the maximum displacement of a load-bearing section and the resulting discharge as a failure, the drive is preferably placed between the drive and another fixed counter-roller for the load-bearing medium or between two additional fixed counter-rollers for the load-bearing medium.

The latter design variant with a stroke between the load-bearing sections is cost-effective because only two rolling roller bearings of the invention can detect failure, either in the lift cab or in the counterweight.

The cost-efficiency of the latter design variant can, however, be improved by equipping the drive with a rolling coil of the invention on one side only. Preferably, however, in order to keep the detection of faults on both the lift cabin side and the counterweight side, the drive can be arranged in its longitudinal direction freely moving. The latter can be achieved by a gear bar or even by a long-hole guide.

The drive can also be optionally equipped at its ends with normal fixed rolling coils without a force-storage element pushing the rolling coil against the load bearing material, because the load bearing material itself provides a tension. The drive, which is aimed against the resistance of the two load bearing sections, is then forced to move from a central position when a load bearing section is discharged.

In the case of elevators in which at least two parallel load-bearing structures support the lifting cab or counterweight, the screw described above may be placed between these two load-bearing structures with rolls, allowing the loosening of one of the two load-bearing structures in relation to the tension of the intact, working load-bearing structure to be detected, either in the parallel cab side load-bearing sections or in the parallel counterweighted load-bearing structures.

In the case of the latter type of suspension of the lifting cab or counterweight with two parallel supporting elements, four rolling coils are preferably placed at the bottom of the lifting cab or counterweight in a rolling coil profile support. This rolling coil profile support may be fixed at the bottom or also at the top of the lifting cab and is preferably formed by two longitudinal profiles with a connecting step, i.e. H-shaped, but preferably the two longitudinal bearings are connected not by one but by two connecting steps. At least two of the four rolling coils, preferably the two on the shorter side of the lifting cab or counterweight, are used as control devices, such as the one described above, with a force sensor and a retractor.

The roll-over profile support is further equipped, in accordance with the invention, with at least one load torque sensor, located approximately in the centre of each of the two longitudinal profiles, to supplement the monitoring of the working condition of the load-bearing equipment. The load torque sensors, such as bend sensors, are capable of measuring simultaneously whether the lifting cabin is in operation in the parallel loops of the load-bearing equipment or is stuck in the lift shaft on the downstream or on the floor buffers. However, a different measurement signal from the two load-bearing torque sensors, for example a load-bearing part load ratio exceeding 40%, indicates that the load-bearing equipment has an accumulation error of approximately 39%, or that the load-bearing equipment is moving away from the load-bearing equipment or is moving away from the load-bearing equipment in a similar way, or that the load-bearing equipment is moving away from the load-bearing equipment in a similar way, but still has a corresponding load-bearing ratio, or that the load-bearing equipment is moving away from the load-bearing equipment in a similar way, or that the load-bearing equipment is moving away from the load-bearing equipment in a similar way, or that the load-bearing equipment is moving away from the load-bearing equipment in a similar way, or that the load-bearing equipment is moving away from the load-bearing equipment in a similar way, or that the load-bearing equipment is moving away from the load-bearing equipment in a similar way or that is moving away from the load-bearing equipment.

The addition of the torque sensors to the monitoring of the operating condition of the load-bearing equipment by means of the roll-over monitor devices described above, which in principle measure the torque of the profile bearing, is particularly useful in cases where monitoring by the roll-over monitor devices alone would not detect the failure, for example when the load-bearing equipment itself becomes stuck and the roll-over monitor is still under a voltage greater than its own voltage.

A further advantage of combining the rollover monitoring device of the invention with the load torque sensor monitoring device of the invention is that, in addition to the fact that more types of incident can be detected than before, the load sensors normally located in the shaft floor buffers can be eliminated.

The roll-over monitor according to the invention, if located at the lower edge of the lifting cab or counterweight or in the roll-over profile holder described above, is preferably so designed that the roll-over coil displacement or compression and expansion of the force storage element takes place in a direction which is at a 45-degree angle to the lower edge and the side wall of the lifting cab or to the lower edge and the sides of the counterweight.

The roll-over monitor according to the invention may be mounted on the upper edge of the lifting cab, with or without the roll-over profile support described above; arrangements in which the lifting cab or counterweight is suspended on a single roll are also possible with force storage elements designed accordingly; and one or more roll-over monitors according to the invention may be mounted on an overhanging roller located at a centre fixing point in the lift shaft.

In another possible design variant, the roll is stored in a hinged housing with defined spring protection.

The force storage element may be a conventional pressure spring, which is carried in a housing or on a bolt, but gas pressure springs or sheet or plate springs, where a contact sensor detects the displacement of a single sheet or plate, are also considered.

The sensor measurement is preferably made at an adjustable time interval, which prevents the sensor (s) from detecting individual peak torques and subsequent discharges as an incident due to systemic elasticity, even though no such event is present. Such short-term peak torques or discharges may occur, for example, because of a short-term entrapment or release, or a heavy load in the lift cabin falls from a pile, or for example, passengers or children jump synchronously in the lift cabin.

Further or advantageous features of a lifting system in accordance with the invention are the subject of the dependent claims.

Figures are used to illustrate the invention in a symbolic and illustrative manner. Figures are described in a coherent and comprehensive manner. The same reference marks mean the same components, and the reference marks with different indices indicate functionally identical or similar components.

It shows Fig. 1 a schematic representation of a lift system with one monitoring device at each of the fixed mounting points of the vehicle according to the state of the art;Fig. 2 a schematic representation of a lift system according to the invention with one monitoring device according to the invention on carrying coils of the lift cab;Fig. 3 a schematic detailed representation of a coil of the invention;Fig. 4 a schematic representation of a coil of the invention on the bottom of a lift cab;Fig. 5 another design variant of a lift system according to the invention with two coils of the invention;Fig. 6 a further design variant of a lift system according to the invention with two coils of the invention;Fig. 6 a monitoring device according to the invention with two coils of the invention on a carrying rod.

Figure 1 shows a lifting system 100 as known from the state of the art. In a lift shaft 1 a lifting cabin 2 is placed in a conductive position, connected by a support 3 to a conductive counterweight 4. The support 3 is driven when in operation by a drive 5 of a drive unit 6 located in the uppermost area of the lift shaft 1, for example in the shaft head 12 or in the engine room 12. The lifting cabin 2 and the counterweight 4 are guided by means of guide rails 7a, 7b and 7c, extending over the shaft height respectively.

The lift shaft 1 is composed of shaft side walls 15a and 15b, a shaft ceiling 13 and a shaft floor 14 on which a shaft floor buffer 22a is located for counterweight 4 and two shaft floor buffers 22b and 22c for the lift shaft 2.

The load carrier 3 is attached to a fixed anchorage or centre of support 18a on the shaft deck 13 and is directed parallel to the shaft side wall 15a to a support roller 17a for counterweight 4 and from there back via the drive shaft 5 to a support roller 17b for the lifting cab 2 and to a second fixed anchorage or centre of support 18b on the shaft deck 13.

Each of these monitoring devices 16a and 16b is formed at the load centre point 18a and 18b respectively by the arrangement of a spring 19 which takes up the load of load medium 3 in each case. In the event of a downward movement and the application of counterweight 4 to the shaft floor buffer 22a, the drive 5 continues its counterclockwise rotation and raises the lifting cab 2 further without the lifting cab 2 being balanced by the counterweight 4 counterload. The detection of the discharge of the spring 3 is therefore carried out at a shaft-side load medium section 303a between the attachment point 18a and the load medium 17a and a (upper) impact point of the load medium 3 on the shaft floor buffer. This means that the counterweight 3 is moved counterweight 303 instead of the last weight of the shaft 4 (for the detection of the counterweight of the shaft 5a) but is sometimes removed at the right of the load medium 3 and the lower load medium 3 (for the detection of the impact point 303 and 303a) This means that the impact of the load medium 3 is removed from the last weight of the shaft 4 instead of the impact point 303 (for the detection of the impact of the load medium 5a) but is sometimes eliminated at the right of the shaft 3 and the lower load medium 3 (for the detection of the impact of the impact of the load medium 303a) due to the previous impact of the 303 and the 5a) but is sometimes removed at the opposite of the load medium 303 (for the detection of the load medium 5a)

The spring 19 of the known monitoring device 16a then pushes a transmission element 20 to a terminal switch 21 which turns off the drive 6 due to the decreasing traction load from the load carrier 3.

The lifting cab side monitoring device 16b works in an analogous way to avoid a further lifting of counterweight 4 if lifting cab 2 is installed. An example of calculation shows another disadvantage of the state-of-the-art solution with this lifting cab side monitoring device 16b: the spring force 19 must be designed so that it does not release at a load of empty lifting cab 2 (e.g. 300 kg) plus the load of the load between the monitoring device 16b and the lifting rod 17b (e.g. 100 kg) plus the load of the load between the lifting rod 17b and the drive shaft 5 (100 kg), i.e. at an assumed 500 kg.This is the only way, for example, to ensure that the empty lifting cabin 2 is locked in the highest position of the shaft, i.e. with the lowest possible load. A spring force of about 400 hp would therefore be chosen in favour of a not too sensitive trigger.the monitoring device 16b will not be able to detect the release of carrier 3.

State-of-the-art monitoring systems, which operate over the entire load of the vehicle in the load carrier 3, are therefore not suitable for elevator systems 100 with high lift heights h and are also an obstacle to modern lightweight elevator cabin construction.

Figure 2 shows a schematic of a lifting system 100a according to the invention, whereby the monitoring devices 16c and 16d are combined with the overhead contact winding 23a and 23b instead of the overhead contact winding 18c and 18d. If the lifting cabin 2 should swing downwards on the shaft floor buffers 22b and 22c, the overhead contact winding monitoring devices 16c and 16d will detect the loosening of the load-bearing loop carried by the lifting cabin 2.

In Fig. 3 the inventive roll-over monitor 16c is shown schematically from Fig. 2. The roll-over coil 23a is mounted in the support 3 and in normal operation with a 24 axle support at a 25 stroke. On a frame 29 attached to the lift cabin 2 a control housing 27 is mounted for a force storage element 26 and a sensor 28. The sensor 28 is in contact with the 25 stroke in the normal operating position. When a discharge of the 3 stroke occurs, the force storage element 26 pushes the 23 stroke and the 25 stroke away from the sensor 28. The sensor 28 is thus deactivated at the first 25 stroke irregularities and not until a path to a stop is described.

The forward tensile force of the force storage element 26 applied to the rolling coil 23a by the coupling 25 and the axle support 24 is less than the load of the empty lifting cab 2 and is not affected by the weight of the load carrier 3.

Figure 4 shows a schematic representation of the invention of two parallel roll-over monitors 16e and 16f with a roll-over profile holder 30 at a parallel underslope of the lifting cab 2 with a first support 3a via roll-overs 23c and 23d and a second support 3b via roll-overs 23e and 23f. The roll-over profile holder 30 is located at the bottom of the lifting cab 2 and consists of two longitudinal profiles 31a and 31b connected by two connecting steps 32a and 32b. At least one load sensor 33a and 33b is approximately halfway between each of the longitudinal profiles 31a and 31b.

The load torque sensors 33a and 33b are capable of measuring a lifting cab 2 by dropping its load, while the monitoring devices 16e and 16f are capable of doing so. However, the load torque sensors 33a and 33b provide a measurement signal when the rolling roller profile carrier 30 is twisted due to unequal stresses in the load carriers 3a and 3b. The output of a control signal to stop the lifting system is preferably triggered when the load torque measurement of one lifting cab 33a or 33b begins to exceed 60% of the cab and the load torque measurement of the other lifting cab 33b or 33a begins to exceed 40%.

Figure 5 shows a schematic of a lifting system 100b in which the roll-over monitoring devices 16g and 16h are located on a drive 34a with roll-over controls 23g and 23h. The drive 34a is located in the lift shaft 1 and thus the roll-over control 23g represents a load centre 42a for the load medium 3 at a load-bearing section 303c and the roll-over control 23h represents a load centre 42b for the load medium 3 at a load-bearing section 303d. The roll-over control section 303c runs from drive 5 to a (first) load-bearing centre 40 at the load-bearing section 3, which in this case represents nothing more than the load-bearing section 17a. The roll-over control 23h represents a load-bearing centre 42a for the load-bearing medium 3 at a load-bearing section 303c and the roll-over control 23h represents a load-bearing centre 42b for the load-bearing medium 3 at a load-bearing section 303d. In this case, the roll-over control device 23a also runs from the drive 5 to a load-bearing centre 40 at the load-bearing section 3b, which in this case represents nothing more than the load-bearing section 17a. The roll-bearing centre 23a is located on the load-bearing device 23a, which is connected to the load-bearing section 23a. In this case, the roll-over control device 23a can also run from the load-bearing unit 2a to a load-bearing centre 2a, and the control device 23a can also run from the load-bearing centre 2a to a load-bearing centre 2a, and the control device 23a to a load-bearing centre 2 to a load-bearing centre 2a, and the control device 23a, and the control device 23a can also run from the controller 2 to a load-bearing centre 2 to a second load-bearing centre.

The 34a strip with the 23g and 23h rolls is placed between the load-bearing section 303c and the 303d section. The 34a strip is fixed in the lift shaft 1 with anchorages 36 but can, by means of a longitudinal hole 35, yield horizontally to the pressure which an intact load-bearing section 303c or 303d would exert reciprocally on the other load-bearing section 303d or 303c in the event of a failure.

The rollover monitoring devices 16g and 16h can be configured as before, but the sensor can also be mounted on the attachments 36 as an option.

In order to prevent the sensor at the mountings 36 or the sensors of the roll-over monitor 16g and 16h from detecting the voltage differences in load sections 303c and 303d during normal operation during a journey, i.e. the increasing or maximum discharge with simultaneous increasing or maximum discharge of the other load section 303d or 303c, the 34a thrust shall be arranged as shown between co-reels 37a-37d.

Figure 6 shows the schematic of the lifting cab 2 in a parallel underslung suspension as in Figure 4, with a first load medium 3c and a second load medium 3d, which are driven synchronously by drives 5a and 5b or by a common drive unit 6a. By means of a drive 34b, which presses the rolling coils 23i and 23j against the load media 3c and 3d, or by means of the rolling coil monitoring devices 16i and 16j, as previously disclosed, the figure realises a monitoring of the individual rolling coils 3c and 3d of a parallel load medium suspension.

The load-bearing section 303e extends from the drive 5a to a load-bearing rotor coil, which is covered in the side view of the lifting cab 2 shown by a load-bearing rotor coil 23k. This covered load-bearing rotor coil is thus a first point of attack of the load-bearing coil 3c at the lifting cab 2 and the visible load-bearing rotor coils 23k a second point of attack 41d of the load-bearing coil 3c at the lifting cab 2. The same applies by analogy to the load-bearing coil 3d, which has a load-bearing rotor coil 303f from the drive 5b to a load-bearing rotor coil which can be covered by a load-bearing rotor coil 231. Some of these rotors also extend on the side of the lift 2 from a load-bearing rotor coil 16 41c to a load-bearing coil 2 41c. The first and second rotor coils 16 16 and 16 16 16 can be viewed from a second rotor coil. The monitoring and control devices can be used to detect the rotors and the rotors.

As in Figure 5, to avoid the maximum discharge of load-bearing media 3c and 3d being recorded as an accidental loosening, counter-rollers 37e-37h are arranged as shown.

However, in order to achieve stable guidance in the counter-rollers 37e-37h and the counter-rollers 23i and 23j, rope according to the invention with a cross-section of approximately 3c and 3d may be used on the one hand, or a fresh cutting belt with a cross-section of approximately 23 or 23d, preferably with a threaded surface providing a wide guide, which may be rotated 90 degrees below the mean of a rotation of approximately 23 or 23 degrees, for example, and the rotation of the other two rollers may not be possible at the same time, and the rotation of the other two rollers may be carried out at a speed of approximately 60 degrees.

The 34b drive, unlike Fig. 5, is mounted on a fixed gear in the lift shaft 1 with preferably two 39a and 39b notches. 38 A horizontal displacement of the 34b drive due to an unevenness in the load-bearing media 3c and 3d is therefore expressed in a rotation of the 39a and 39b notches.

This reveals the combination of the design variants of the monitoring devices according to the invention shown. Thus, the monitoring devices 16c-16f shown in Figures 2-4 can be combined in a single lifting system 100 with the monitoring devices 16g and 16h shown in Figure 5 and/or the monitoring devices 16i and 16j shown in Figure 6.

Claims (7)

1. Lift installation (100) having at least one lift car (2) and having at least one counterweight (4), the two of which can be displaced in opposite directions, by supporting means (3) guided over a traction sheave (5) of a drive (6), on at least one guide rail (7) in a lift shaft (1), and having at least one monitoring device (16) for detecting slackening of the supporting means (3), wherein the traction sheave (5) is arranged between two fixed-location supporting-means fastening points, and the supporting means (3) are guided over the traction sheave (5) and form two loops, and wherein the lift car (2) has at least one roller (17a, 17b, 23a, 23b, 23c, 23d, 23e, 23f), serving as a supporting roller or deflecting roller, supported in one of the two loops and the counterweight (4) is supported in the other of the two loops, characterized in that the monitoring device (16) is arranged on one of the rollers (17a, 17b, 23a, 23b, 23c, 23d, 23e, 23f), in that the roller (17a, 17b, 23a, 23b, 23c, 23d, 23e, 23f) is arranged on the lift car (2) and/or the counterweight (4), in that the monitoring device (16) has a sensor (28), which, in the normal operating state, is switched on, and in that the roller (17a, 17b, 23a, 23b, 23c, 23d, 23e, 23f) is mounted for displacement by way of an energy-store element (26) which is subjected to a defined level of prestressing, and therefore the sensor (28) emits a signal in the case of the supporting means (3) being relieved of loading on account of the roller (17a, 17b, 23a, 23b, 23c, 23d, 23e, 23f) being displaced in a bearing means.
2. Lift installation (100) according to Claim 1, characterized in that the roller (17a, 17b, 23a, 23b, 23c, 23d, 23e, 23f) can be pushed onto the supporting means (3) by a defined prestressing force of the energy-store element (26) which is smaller than the stressing of the supporting means (3) in the operating state and, in the case of the supporting means (3) being relieved of loading in the event of disruption, the deflecting roller (23) is arranged for displacement by the prestressing force of the energy-store element (26) such that the signal can be emitted by the sensor (28).
3. Lift installation (100) according to Claim 1, characterized in that, in the case of the supporting means (3) being relieved of loading, the energy-store element (26) pushes the roller (17a, 17b, 23a, 23b, 23c, 23d, 23e, 23f) and a stop (25) away from the sensor (28).
4. Lift installation (100) according to either of preceding Claims 1 and 2, characterized in that the lift car (2) and the counterweight (4) are supported by a first supporting means (3a) and a second supporting means (3b), and at least four deflecting rollers (23c-23f) are arranged on a deflecting-roller profile support (30) made up of two longitudinal profiles (31a, 31b) and at least one connecting crosspiece (32).
5. Lift installation (100) according to Claim 4, characterized in that at least one load-moment sensor (33a, 33b) is arranged in each of the longitudinal profiles (31 a, 31b).
6. Lift installation (100) according to Claim 5, characterized in that a signal can be emitted by the load-moment sensors (33a, 33b) as soon as a load-moment sensor (33) measures more than 60% of the supporting load of the lift car (2) or of the counterweight (4).
7. Lift installation (100) according to one of the preceding Claims 2 and 4-6, characterized in that sensor measurement takes place at adjustable time intervals.