EP3042874B1 - Lift belt monitoring - Google Patents

Description

FIELD OF THE INVENTION

The invention relates to a device for monitoring elevator belts, for example by means of resistance measurement by four-wire measurement, a monitored elevator installation and a method for monitoring elevator belts.

BACKGROUND

Lifting cables for lifts are u.a. designed as flat bands or straps, as they have a twist-free rolling and unwinding and a relatively high load capacity.

For carrying capacity of the tension cables or the entire elevator belt, it is for example in the document WO 2005/094249 A2 have been proposed to monitor the electrical cable resistance. The traction cables are electrically contacted by means of so-called connecting elements, which penetrate with their end the protective jacket over the traction cable. A so-called clamp element on the back provides back pressure.

WO 2000/58706 A2 describes the use of a so-called Kelvin bridge for measuring a suspension rope resistance. In this case, the ends of a supporting cable are connected to a power source, and the current flowing through the carrying cable tension is measured.

SUMMARY OF THE INVENTION

A first aspect relates to a device for monitoring an elevator belt with at least two electrically conductive tension cables embedded in an electrically insulating jacket by means of resistance measurement. The traction cables run against each other electrically isolated and lying parallel to each other in a common plane in the jacket. The device comprises a contacting device with at least one contacting device with contact elements and a resistance measuring system which, with the aid of the contact elements, makes electrical contact with the tension cables of the Elevator belt is connectable. The at least one contacting device is equipped with contact elements for each of the at least two tension cables for stripping-free contact contacting of the tension cables by the electrically insulating jacket. The resistance measuring system is adapted to determine the electrical resistance of at least one pull rope by means of four-wire measurement, ie with separate contacting for current flow and voltage measurement. In such a four-wire measurement, the feeding of a measuring auxiliary current via the Stromflusskontaktierung and thus the flow of the measuring auxiliary current along the at least one traction cable is realized. About the Spannungsmessungskontaktierung the at least one pull rope a falling voltage can be tapped off. The electrical tension cable resistance can be determined with the aid of the falling electrical voltage and the known measuring auxiliary current.

A further aspect relates to an elevator installation, comprising at least one elevator cage, a conveyor for the at least one elevator cage and a device for monitoring the elevator belt of the type mentioned above. The conveyor has at least one elevator belt with a plurality of tension cables which are fastened to the elevator cage.

Another aspect relates to a method for monitoring elevator belts with at least two electrically conductive tension cables embedded in an electrically insulating jacket by means of resistance measurement. The traction cables run against each other electrically isolated and lying parallel to each other in a common plane in the jacket. The method is performed by means of a monitoring device, wherein the monitoring device comprises a resistance measuring system. The resistance measuring system is electrically connected by means of stripping-free contact contacting with the tension cables through the electrically insulating jacket. With the aid of a contacting device with at least one contacting device with contact elements for each of the at least two traction cables, the electrical connection of the traction cables of the elevator belt with the resistance measuring system is provided. The method comprises the following steps with the resistance measuring system to determine the electrical resistance of at least one traction cable by means of four-conductor measurement, ie with separate contacting for current flow and voltage measurement: feeding a measuring auxiliary current via the Stromflusskontaktierung and thus the flow of the measuring auxiliary current along the at least a pull rope. Grasping the falling electrical voltage of at least one pull rope on the voltage measurement contact. Determining the electrical cable resistance with the help of the falling voltage and the known measuring auxiliary current.

Other features will be apparent from the disclosed apparatus and methods, or will become apparent to those skilled in the art from the following description of the examples and the accompanying drawings.

GENERAL EXPLANATION, ALSO CONCERNING OPTIONAL EMBODIMENTS OF THE INVENTION

A characteristic of a stripping-free contact contacting lies in the non-cohesive connection of the contact elements, e.g. Pins, with the ropes. The electrical contact is essentially maintained by the elasticity of the hawser strand and the counter-pressure of the haulage sheathing. This pressure-counter-pressure state can be subject to temporal and environmental changes, whereby the quality of the electrical contact of the contact elements to the traction cable can change over time.

The inventors have realized that a combination of two techniques, namely the stripping-free contact contacting of the tension cables and the resistance determination of the tension cables by means of four-conductor measurement, provides a simple method of contacting pull cables which is robust to the above-mentioned temporal changes. With the four-wire measurement, namely, a possible influence of the contact resistance on the measurement result can be kept low.

The described device is provided for monitoring an elevator belt with at least two electrically conductive tension cables embedded in an electrically insulating jacket. The traction cables run against each other electrically isolated and lying parallel to each other in a common plane in the jacket. The monitoring of an elevator belt is done by measuring the electrical resistance of the traction cables embedded in them.

The tension cables may be formed as individual strands, for example of steel, or as wire cables of a plurality of such strands. The traction cables are, for example, ropes comprising 6 strands of 7 wires each. A 6 × 19 standard rope has 6 strands each having 19 wires. In some stranded ropes, the strands are pressed onto an insert made of a plastic rod so that the plastic completely fills the interior between the strands, which stabilizes the strands and prevents their contact. The wire ropes are classified according to DIN EN 12385 according to their structure.

When using the ropes for the promotion of people, the usual visual and tactile rope inspection is not sufficient and embedded in the present embodiments in an elevator belt also not possible. In lifts, therefore, parallel supporting ropes and safety gears are used to prevent a crash. The ropes can, for example, also be tested in the pass with magnetic methods with which internal wire breaks can be discovered.

Due to the stranding of the wires, they can completely support the wind after a few turns away from their breakage. Some of the wires may be broken before safety is compromised. The number of broken wires of the pull ropes can be monitored with the described device.

The device comprises a contacting device with at least one contacting device at one end or at both ends of the elevator belt and a resistance measuring system which can be electrically connected to the tension cables of the elevator belt with the aid of the contacting device. The at least one contacting device is equipped with contact elements for each of the at least two tension cables for stripping-free contact contacting of the tension cables by the electrically insulating jacket. The contacting is, for example, a tapping contact by means of thorns which penetrate the jacket, and thus tapping the tension cables without stripping, i. electrically contact the passing tow rope.

The resistance measuring system is adapted to measure the electrical resistance of at least one pull rope by means of four-wire measurement, i. with separate contact for current flow and voltage measurement to determine.

In the four-wire measurement, a measuring auxiliary current is supplied via the current flow contact, ie via the contact elements, which are connected, for example, to a current source which supplies a constant regulated current. Thus, the flow of the auxiliary measuring current is achieved along the train rope to be measured. By knowing the current flowing through the resistance to be determined, the voltage dropping at the resistance to be determined can be measured virtually without current using a voltmeter with high internal resistance (ie an internal resistance which corresponds to a multiple of the resistance to be determined).

About the voltage measurement contact of the to-be-measured pull rope, i. the contact elements, which are connected for example to a DC voltage meter, a falling voltage can be tapped off. The electrical tension cable resistance can be determined with the aid of the falling electrical voltage and the known measuring auxiliary current. The monitoring device has a connecting line which electrically connects the contact elements to the resistance measuring system, which may also be located further away in these cases. The resistance measuring system determines the falling voltage and then calculates from this voltage and the known measuring auxiliary current the resistance of the pull rope or the tension cables between the voltage measurement contacts of the at least one contacting device.

The connecting cable is designed as a flat cable, i. the wires of the connecting lead are in a well-defined relationship to each other, namely parallel spaced apart in a plane. The contact elements of the contacting device each electrically contact a pull rope of the elevator belt with a wire of the flat cable, and the flat cable has as many wires as the elevator belt has pull cables.

In some embodiments, the contacting device comprises two contacting devices, wherein a contacting device is provided for each end of the elevator belt. Thus, the contacting device is spatially extended over the entire length of the elevator belt and the measuring auxiliary current can flow between these two contacting devices. By tapping the voltage at the voltage measurement contacting in the contacting devices together with the known measuring auxiliary current, the electrical resistance of the tension cables can be measured or calculated directly.
In some embodiments, the contacting device comprises only one contacting device, wherein the contacting device is provided at one end of the elevator belt. In this case, the measuring system of the monitoring device measures the electrical resistance of pull ropes of the elevator belt which are electrically connected to one another at the opposite end of the elevator belt, ie at least two pull ropes at a time. By contacting at one end of the elevator belt and the electrical connection at the other end of the elevator belt said pull cables are connected in series.
In alternative embodiments, a plurality of tension cables are connected to each other, whereby the number of required contact elements is reduced. As a result, the Zugseil resistors can not be separated but determined only in this composite. In this way, a chain of tension cables can be formed, which requires only two contact elements for measuring voltage. The two outer traction cables are current-and voltage-contacted while the inner traction cables on alternate sides are in electrical contact with each other and so a long conductor form.
In some embodiments, the at least one contacting device serves both the current flow contact and the voltage measurement contact. The contacting device has contact elements for current contacting and for voltage contacting, for example Contact pins that can penetrate a plastic or cable sheath. The contact elements for power contacting are electrically connected to the output of the power source, for example via one or more cables. The contact elements for voltage contact are electrically connected to the input of the voltmeter.
In some embodiments, the at least one contacting device comprises at least two sub-devices; A power contacting subdevice and a voltage-contacting subdevice. The power contacting subdevice has contact elements electrically connected to the current flow to the output of the power source. The voltage-contacting subdevice has contact elements electrically connected to the input of the voltmeter for voltage measurement.
In some embodiments, the at least two sub-devices are spatially, ie structurally, separated from each other, in other embodiments, the contacting device comprises the at least two sub-devices in a common housing.

In some embodiments, the wires of the flat cable are contacted stripping of the contact elements. This means that electrical contact between the contact elements and the wires of the flat cable can be made without first removing the cable insulation. Thus, traction cables and flat cable cores are electrically connected to each other stripping free, and always a traction cable with a core of the flat cable.

In some embodiments, the contact elements of the contacting device are designed as contact pins. The mandrels penetrate when pressurized by the sheath of the elevator belt and / or the sheath of the flat cable and make an electrical contact with the running inside the traction cables or wires. In some other embodiments, the contact elements are designed as contact blades or contact pins or contact pins.

In some embodiments, the contact pins are formed as individual mandrels. They each contact one wire of the flat cable with a pull rope of the elevator belt. One and the same single mandrel penetrates coming from one side of the vein of the flat cable and penetrates at least partially into a pull rope. The penetration or penetration leads, for example, to a displacement and displacement of the strands in the elevator belt and / or in the flat cable. Therefore, the contacting devices are attached to the end of the elevator belt, i. behind the suspension, where no more pulling forces act.

In some embodiments, the contact elements are designed as double arbors. They are arranged between the elevator belt and the flat cable and their partial mandrels extend in opposite directions.

The double mandrels are therefore to be understood as nails with two tips and may have a diamond-shaped longitudinal sectional area. The double mandrels may alternatively comprise two individual partial mandrels, which are electrically connected to each other in the middle between the mandrels. In this case, an insulating layer can be located between the mandrels, which is selectively bridged with a connecting piece of a partial mandrel to the other.

A double mandrel contacts a respective strand of the flat cable with a pull rope of the elevator belt. A partial mandrel penetrates the wire insulation of the flat cable and is thus electrically connected to an underlying core of the flat cable. The opposite part of the mandrel penetrates the shell of the elevator belt and is thus electrically connected to an underlying pull rope of the elevator belt. Since the two partial arbors are electrically connected to each other, the pairs of traction cable and flat cable core are electrically connected to each other, both stripping free.

In some embodiments, the flat cable is disposed at right angles to the hoop and tensions in the contacting area, i. in the region of the elevator belt where the contacting device is arranged, a plane parallel to the plane of the elevator belt. In other words, the flat cable is at an angle of 90 ° on the elevator belt and is penetrated in this position by the contact pins of the contacting either completely or at least partially and the wires of the flat cable are thus in electrical contact with the tension cables of the elevator.

In some embodiments, the contact elements are arranged in at least two rows and the contact elements have a diameter which is greater than the distance between two tension cables. This results in a "matrix arrangement" which allows contact elements having a maximum diameter of more than one Zugseilabstand.

For example, in a series of contact elements only every second pull rope is contacted and the intermediate pull cords are contacted in one or more further rows of contact elements. In this way, a two-dimensional structure can be formed which approximates the "dense sphere packing" in two dimensions. The contact elements may taper from their tip to their attachment, where, as mentioned above, they can reach a maximum width or a maximum diameter of more than one tension distance. This conical shape causes an increased pressure on the stranding of the strands, whereby the electrical contact is improved.

The described device for monitoring the elevator belt in its various embodiments and configurations may be integrated in an elevator installation. In addition to the monitoring device, such an elevator installation also has at least one elevator cage for the transport of persons and / or loads and a conveyor device for moving the at least one elevator cage. The conveyor comprises at least one elevator belt to which the at least one elevator cage is attached. The elevator belt comprises at least two tension cables which carry the weight of the elevator cage and the persons and / or loads to be transported.

In some embodiments, by rotating a drive roller of the conveyor, the length of the elevator belt on one side of the drive roller is shortened and correspondingly lengthened on the other side. By this shortening or extension of the Aufzuggurtgurtstücks between the drive roller and the elevator belt suspension of the elevator cage is within a Elevator shaft of the elevator system moves up or down. Alternatively, in other embodiments, the elevator cage may be moved up and down by rolling up and down the elevator belt.

The method described is provided for monitoring elevator belts with at least two electrically conductive tension cables embedded in an electrically insulating jacket by means of resistance measurement. In this case, the traction cables are electrically insulated from each other in parallel to each other in a common plane lying in the jacket.

The method is carried out by means of a monitoring device comprising a resistance measuring system. The monitoring device additionally has a contacting device with at least one contacting device which, with contact elements for each of the at least two traction ropes, produces a stripping-free contact contact with the traction ropes of the elevator belt through the electrically insulating jacket. Contact contacting here means a non-fixed contact, so by removing the contact again releasable connections.

A contacting device is arranged either at one end of the elevator belt or at both ends of the elevator belt. By the contact elements, the traction cables of the elevator belt are electrically connected to the resistance measuring system via the contacting device.

The method for monitoring elevator belts comprises several steps in order to be able to ensure the carrying capacity of the elevator belt. The carrying capacity of the elevator belt is determined by the resistance of the tension cables running in the belt. In the case of damage to the tension cables, the measured resistance increases. These damages can be breaks of single wires, over strands, up to the break of a whole pull rope. To determine the resistance of at least one electrically conductive pull rope, a four conductor measurement is performed, i. a resistance measurement with separate contacting for current flow and voltage measurement.

A measuring auxiliary current is fed via the Stromflusskontaktierung in the at least one traction cable, for example, so that the traction cable is traversed over the entire supporting length of the elevator belt of this measuring auxiliary flow, ie at least in the piece of the elevator belt between the attachment points of the elevator belt lies. An electrical voltage is tapped at the voltage measurement contacts. This electrical voltage is tapped at a position on the elevator belt within the Stromflusskontaktierungen, but outside the attachment points of the elevator belt to the elevator system, ie at positions where no tensile forces act. With a known and constant measuring auxiliary current, the tension cable resistance according to the linear relationship U = R * I corresponds to the measured voltage (with a constant factor, the measuring auxiliary current). Even with time-varying measuring auxiliary current with knowledge of the two values of current and voltage at a certain time, the Zugseil-resistance can be determined.

In some embodiments, the method of monitoring elevator belts employs a monitor having one or more of the features described above.

BRIEF DESCRIPTION OF THE DRAWING

Fig. 1

eine Ausführungsform einer Aufzugsanlage mit einer Fördereinrichtung für einen Aufzugskorb und einer Überwachungseinrichtung für einen Aufzugsgurt,

Fig. 2

eine Ausführungsform einer Aufzugsfördereinrichtung sowie einer Überwachungseinrichtung samt Messsystem mit jeweils einer Kontaktierungsvorrichtung an den beiden Enden des Aufzugsgurts,

Fig. 3

eine andere Ausführungsform ähnlich derjenigen von Fig. 2, bei der jedoch die Kontaktierungsvorrichtung nur an einem Ende des Aufzugsgurts vorgesehen ist und bei der Enden der Zugseile am anderen Aufzugsgurt-Ende elektrisch miteinander verbunden sind,

Fig. 4

eine andere Ansicht mit weiteren Merkmalen der Überwachungseinrichtungen von Fig. 2 und 3;

Fig. 5

ein Flussdiagramm eines Überwachungsverfahrens, das z.B. bei den Überwachungseinrichtungen von Fig. 1 bis 4 durchgeführt werden kann,

Fig. 6

eine Ausführungsform eines Vierleitermessungsaufbaus zum Ermitteln eines Zugseil-Widerstands bei unbekannten Zuleitungswiderständen, die z.B. bei dem Verfahren gemäß Fig. 5 und/oder bei den Überwachungseinrichtungen von Fig. 1 bis 4 Verwendung finden kann,

Fig. 7

eine detailliertere Ansicht der Kontaktierung des Zugseils aus Figur 6,

Fig. 8

eine Ausführungsform einer Kontaktierungseinrichtung mit jeweils einer Kontaktierungsvorrichtung für Stromfluss- und Spannungsmessungs-Kontaktierung an beiden Enden des Aufzugsgurts, entsprechend Fig. 2,

Fig. 9

eine Ausführungsform einer Kontaktierungseinrichtung mit einer Kontaktierungsvorrichtung für Stromfluss- und Spannungsmessungs-Kontaktierung an nur einem Ende des Aufzugsgurts mit elektrischer Zugseil-Verbindung am anderen Ende, entsprechend Fig. 3,

Fig. 10

eine andere Ansicht der Ausführungsform von Fig. 9, bei der nur eine KontaktierungsTeilvorrichtung dargestellt ist, nämlich diejenige zur Spannungsmessungskontaktierung, sowie deren Verbindung zum Spannungsmessgerät,

Fig. 11

eine Ausführungsform der in den obigen Figuren dargestellten Kontaktierungsvorrichtung mit Doppeldorn-Kontaktelementen,

Fig. 12

eine andere Ausführungsform der in den Figuren 1 - 10 dargestellten Kontaktierungsvorrichtung, die im Unterschied zu Fig. 11 Einzeldorne aufweist, wobei in der Figur nur eine Kontaktierungs-Teilvorrichtung dargestellt ist,

Fig. 13

einen Schnitt der Kontaktierungs-Teilvorrichtung aus Figur 12 entlang der Linie A-A,

Fig. 14

einen vergrößerten Ausschnitt von Figur 12,

Fig. 15

einen Schnitt der Kontaktierungs-Teilvorrichtung aus Figur 12 entlang der Linie B-B.

In the following examples are also explained with reference to the accompanying drawings; show:

Fig. 1

an embodiment of an elevator installation with a conveyor for a lift cage and a monitoring device for an elevator belt,

Fig. 2

an embodiment of an elevator conveyor and a monitoring device including measuring system, each with a contacting device at the two ends of the elevator belt,

Fig. 3

another embodiment similar to that of Fig. 2 in which, however, the contacting device is provided only at one end of the elevator belt and at the ends of the traction cables at the other end of the elevator belt are electrically connected to each other,

Fig. 4

another view with further features of the monitoring devices of Fig. 2 and 3 ;

Fig. 5

a flowchart of a monitoring method, for example, in the monitoring devices of Fig. 1 to 4 can be carried out,

Fig. 6

an embodiment of a four-conductor measurement structure for determining a Zugseil resistor at unknown supply line resistances, for example, in the method according to Fig. 5 and / or at the surveillance facilities of Fig. 1 to 4 Can be used

Fig. 7

a more detailed view of the contact of the pull rope FIG. 6 .

Fig. 8

an embodiment of a contacting device, each with a contacting device for current flow and voltage measurement contacting at both ends of the elevator belt, respectively Fig. 2 .

Fig. 9

an embodiment of a contacting device with a contacting device for current flow and voltage measurement contacting at only one end of the elevator belt with electrical traction cable connection at the other end, respectively Fig. 3 .

Fig. 10

another view of the embodiment of Fig. 9 in which only one contacting device is shown, namely that for voltage measurement contacting, as well as its connection to the voltage measuring device,

Fig. 11

An embodiment of the contacting device shown in the above figures with double mandrel contact elements,

Fig. 12

another embodiment of the in the Figures 1-10 illustrated contacting device, in contrast to Fig. 11 Having individual mandrels, wherein in the figure only one contacting sub-device is shown,

Fig. 13

a section of the contacting part of device FIG. 12 along the line AA,

Fig. 14

an enlarged section of FIG. 12 .

Fig. 15

a section of the contacting part of device FIG. 12 along the line BB .

The figures and the description of the figures relate to examples of the invention and not to the invention itself.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

In general, the monitored elevator belt has more than two pull ropes, of which in some of the figures only a smaller number, e.g. two or four is shown.

An elevator installation 1 in a building according to Fig. 1 has a conveyor 2, which has, inter alia, a lift cage 6 for the transport of persons and / or loads. The elevator installation 1 comprises an elevator shaft with guide rails for the elevator cage 6. The components of the conveyor device 2 are described in the description of FIGS Figures 2 and 3 explained in more detail.

The elevator cage 6 is connected via an elevator belt 7 to the drive of the conveyor 2. With the help of a counterweight 13 (see Figures 2 and 3 ), the elevator cage can be moved along in the elevator shaft, thus transporting the persons and / or the charged loads into the various floors of the building.

The elevator installation 1 furthermore has a monitoring device 3 in order to check the carrying capacity of the elevator belt 7. The elevator belt 7 comprises a plurality of tension cables 8, of which in FIG. 1 two are shown. The traction cables 8 are in a common plastic sheath 31 (s. FIG. 15 ) arranged. These traction ropes 8 carry the weight of the elevator cage 6 together with the persons to be transported and / or loads.

Due to the continuous tensile and rolling stress of the tension cables 8, they may wear over time or damage, i. the wires and / or wire strands forming the traction cables 8 may break at one or more points and thus jeopardize the carrying capacity of the entire elevator belt 7.

The plastic jacket 31 protects the traction cables 8 from external influences, such as moisture, and increases the traction of the elevator belt 7, whereby a reliable conveyance of the elevator cage 6 by the drive of the conveyor 2 is ensured. On the other hand, however, this protective jacket 31 prevents an inspection of the traction cables 8 for damage due to optical observations, such as, for example, by surveillance cameras or by maintenance personnel.

The elevator installation 1 is therefore provided with the already mentioned monitoring device 3, which checks the integrity of the tension cables 8 by means of resistance measurement by a measuring system 4. If one or more wires of one of the traction cables 8 are broken, the electrical resistance of this traction cable 8 increases. The measuring system 4 is set up to register such resistance increases.

In order to determine the electrical resistance of the traction cables 8 of the elevator belt 7, the traction cables 8 are electrically contacted via a contacting device 5 and electrically connected to the measuring system 4 via the wires 11 of a connecting line 10. An electric current is fed to the traction cables 8 and the voltage dropping across them is measured by the measuring system 4. In the in FIG. 1 As shown, the two traction cables 8 at one end of the Lifting belts 7 form an electrical connection 9 and form a series connection, whereby they only have to be electrically contacted at one end in order to determine the common resistance.

By the structure described here, the resistance can be determined, which is a measure of the carrying capacity of the tension cables 8, and thus any damage occurring to the conveyor 2 can be detected and corrected before danger to persons and / or loads.

An embodiment of an elevator conveyor 2 and a monitoring device 3 together with the measuring system 4, each with a contacting device 50 or 50 'at the two ends of the elevator belt 7 is in Fig. 2 shown.

An exemplary embodiment of a conveyor 2 according to Fig. 2 has an elevator cage 6 and a counterweight 13. The elevator cage 6 and the counterweight 13 are attached to an elevator belt 7, which is fastened via the suspensions 12 to the elevator installation 1 or to the surrounding building. These suspensions 12 absorb the tensile forces of the elevator belt 7 and divert them to the building.

The elevator belt 7 is guided between the two suspensions 12 via three rollers, namely an elevator basket support roller 14, a drive roller 18 and a counterweight support roller 16. The support rollers 14 and 16 are respectively mounted on associated axes 15 and 17. The drive roller 18 has a drive axle 19 on which it is mounted. The drive roller 18 is driven by a drive, for example an electric motor.

By rotating the drive roller 18, the length of the elevator belt 7 is shortened on one side of the drive roller 18 and extended accordingly on the other side. As a result of this shortening or lengthening of the elevator belt section between the drive roller 18 and the suspension 12, the elevator carrier roller 14 and thus the elevator cage 6 fastened thereto are moved up or down within an elevator shaft of an elevator installation 1.

In the in FIG. 2 shown embodiment of a conveyor 2, the two ends of the elevator belt 7 are contacted by a contacting device 5 electrically. End of the elevator belt 7 here refers to the piece of the elevator belt 7 beyond the suspensions 12, ie where there are no tensile forces through the elevator cage 6 and / or the counterweight 13 on the traction cables 8 of the elevator belt 7 act. The suspensions 12 are to be understood as a strain relief for the elevator belt 7, so to speak.

The contacting device 5 is divided into two contacting devices 50 and 50 'at the respective ends of the elevator belt 7. Each of the two contacting devices 50, 50 'has two contact points for each pull rope 8 of the elevator belt 7, one for power supply and one for voltage measurement. These current flow and voltage measurement contacts are electrically connected via a connecting line 10 to a measuring system 4 for traction cable resistance measurement.

In a further exemplary embodiment of a conveyor 2 according to Fig. 3 hang like in FIG. 2 , the elevator cage 6 and the counterweight 13 on an elevator belt 7, which is attached via the suspensions 12 to the elevator installation 1 or to the surrounding building. The structure and operation of the elevator is similar to the embodiment in the description in connection with Fig. 2 is explained. The monitoring device 3 of the exemplary elevator installation 1, however, has a different structure.

The traction cables 8 of the elevator belt 7 have at one end in pairs an electrical connection 9, whereby always two traction cables 8 form a series circuit. At the other end, the traction cables 8 are contacted by a contacting device 5 electrically. In the in FIG. 3 In the illustrated embodiment, the contacting device 50 coincides with the contacting device 5. The contacting device 50 has two contacts per pull rope 8, as in connection with Fig. 2 is described. Both contacts are connected via a connecting line 10 with a measuring system 4 for measuring resistance, see Fig. 4 ,

Further features of the monitoring devices 3 of Fig. 2 and 3 are in Fig. 4 shown. The measuring system 4 has a controllable constant current source 20, which serves to supply the elevator belt 7, more precisely the traction cables 8 embedded therein, with a constant measuring auxiliary current. The poles of the constant current source 20 are electrically connected via the wires 11 of a connecting line 10 with Stromflusskontaktierungen at the ends of the traction cables 8, see FIG. 2 , At the ends here means beyond the suspensions 12, ie without tensile load by the elevator cage. 6

The voltage measurement contacts at the ends, i. Beyond the suspensions 12, the tension cables 8 falling voltage is read out via the wires 11 of a connecting line 10 via a tension measuring device 21. The connecting line 10 can be the same as for the power supply via the Stromflusskontaktierung.

The controllable constant current source 20 and the voltage measuring device 21 are each connected via interfaces to a data bus 24. Furthermore, a processor 22 and a data memory 23 are connected to this data bus 24. In the data memory 23, for example, information about the various Zugseil resistors, the measured voltage waveforms and reference values for resistors and associated load capacities for traction ropes 8 are stored. The processor 22 controls the current source 20 within fixed intervals for current and voltage, so that a suitable measuring auxiliary current is applied to the tension cables 8. "Suitable" means that the measuring auxiliary current is sufficiently large to produce a voltage drop measurable with the given voltmeter 21 with the desired accuracy, without on the other hand causing damage due to current flow, e.g. caused by heat development.

About an IO unit (input / output unit), which is also connected to the data bus 24, information about the current Zugseil resistors are displayed on a graphical user interface 25. In case of damage, such as the breaking of a pull rope 8 or the breakage of one or more strands of a pull rope 8, alarm can be triggered. Thereafter, the elevator cage 6 can be brought into a parking position and the conveyor 2 inspected and repaired before persons or loads are damaged by a crash due to a broken or broken traction cable 8.

The flowchart of Fig. 5 shows a monitoring method, for example, in the monitoring devices 3 of Fig. 1 to 4 can be carried out.

When commissioning an elevator system 1, the current flow of a measuring auxiliary current (s. Fig. 4 ) is switched on by the tension cables 8 of an elevator belt 7 as well as the voltage measurement of the voltage dropping on the tension cables 8, see step 5.1 in FIG FIG. 5 , The power supply and voltage measurement happens, such as in Fig. 4 watch over a uniform measuring system 4.

From the combination of the known measuring auxiliary current and the measured voltage, which drops along the traction cables 8, a Zugseil resistance can be determined, which the step 5.2 in FIG. 5 equivalent.

As long as the determined resistance of the traction cables 8 is within the nominal values, the resistance measurement, ie the voltage measurement along the traction cables 8, is repeated continuously over a defined time interval. This corresponds to the yes answer loop of step 5.3 in FIG. 5 which leads back to step 5.2.

In the event that a set value interval for the Zugseil-resistors is exceeded, for example, by a broken pull rope 8 or a plurality of broken wire strands of a pull rope 8, this loop is left. This corresponds to the no answer of step 5.3 in FIG. 5 ,

If the resistance of a pull rope 8 beyond the allowable set points, for example, twice as high as a stored reference value, which indicates damage to the pull rope 8 and therefore to a possible loss of capacity, an alarm is triggered and shut down the elevator to make repairs what step 5.4 in FIG. 5 equivalent.

Fig. 6 shows an embodiment of a four-wire measurement assembly for detecting a _{rope-pull cable} resistance R for unknown lead resistances R _11, R _12, R ₁₃ and R _14, for example, in the method according Fig. 5 and / or at the surveillance facilities of Fig. 1 to 4 , Can be used. The so-called "supply line resistance" is composed of the contact resistance of the electrical pull cable contacting and the resistance of the respective connecting line 10 to the voltage measuring device 21 or to the current source 20.

The ends of the pull cable 8 are contacted with the wires 11 of a connecting line 10 and electrically connected to a controllable constant current source 20. Within this Stromflußkontaktierung a voltage meter 21 is connected with a very high internal resistance parallel to the pull cable 8. Within the current flow contact, this means that the voltage measurement contact is in each case on the current-carrying side of the current flow contact of the pull cable 8.

The voltage measuring device 21 is connected via wires 11 of a connecting line 10 with the voltage measurement contacts of the pull cable 8. The connecting lines 10 may be the same line or two separate lines. The same applies to the two-sided connections to the contacts of the pull rope 8, i. the four-wire measuring circuit can be realized with only one, two or even four independent connection lines 10. In any case, four wires 11 per pull rope 8 are required.

The fact that the measuring auxiliary current flows through the entire length of the traction cable 8 which is to be measured, and that the voltage measuring device 21 with a very high internal resistance is connected in parallel to the part of the traction cable 8 to be measured exhibits a current flow of almost 100% due to the traction cable resistance R _{pull rope} instead.

Since lead resistance R _11, the tow rope resistance R _{traction cable} and lead resistance R connected in series _14, the current flow through the traction cable resistance R is _Zugseit which is freely adjustable and therefore known equal to the applied measuring auxiliary power, within an area.

The lead resistances R ₁₂ and R ₁₃ are very small compared to the internal resistance of the voltmeter 21 and can be neglected.

bestimmt werden.With the aid of the circuit set forth above, the tow _{rope-traction cable} resistance R R ₁₁ can in spite of unknown lead resistances R _12, R ₁₃ and R ₁₄ are very accurately to the simple connection of measuring auxiliary current and the measured voltage, namely $R_{\mathit{rope}}=\frac{U_{\mathit{measuring}}}{I_{\mathit{Help}}}.$

be determined.

Fig. 7 Figure 12 shows a more detailed view of the current flow contact and voltage measurement contacting of a pull rope 8 in the four conductor measurement setup for determining the pull rope resistance R _{pull rope} Fig. 6 ,

The traction cable 8, which is composed of a plurality of stranded strands, which in turn are formed of stranded wires, is contacted at its ends by contact elements 26, which form the current contact and the voltage contact. These contact elements 26 are part of the contacting device 5, more precisely the contacting devices 50, 50 ', and establish an electrical connection between the measuring system 4 and the traction cable 8 in an elevator belt 7.

The contact elements 26 penetrate through the jacket 31 of the elevator belt 7 in the pull cable 8 and provide by means of the contacting device 5, an electrical contact, that is. a non-cohesive electrical connection, between the pull cable 8 and the connecting line 10, forth.

The controllable constant current source 20 and the voltage measuring device 21 of the measuring system 4 are, as in connection with Fig. 6 described electrically connected via leads 11 of one or more connecting line (s) 10 with the Stromfluss- or voltage measurement contacts, which are produced by the contact elements 26.

Figure 8 shows an exemplary embodiment of a contacting device 5, each with a contacting device 50 and 50 'for current flow and voltage measurement contacting at both ends of the elevator belt, respectively Fig. 2 , As mentioned above, the elevator belt 7 to be monitored has more than two tension cables, two of which are shown here.

At the respective ends of the elevator belt 7 contacting devices 50 and 50 'for current flow through the tension cables 8 and voltage measurement are attached. The respective contacts for current flow and voltage measurement can be arranged in a common contacting device 50, 50 'or in respectively separate subassemblies 500' and 500 ".The dashed lines indicate that the contacting devices 50 and 50 'can be unified or spatially separated ,

In the in Figure 8 In the exemplary embodiment illustrated, the two contacting devices 50, 50 'each form a unit. The illustration (shown by dashed line) in each case two sub-devices 500 ', 500 "for current or voltage contacting serves the functional distinction of the contact elements 26, which on the one hand provide the Stromflusskontaktierung and on the other hand the Spannungsmessungskontaktierung the tension cables 8 through the contacting device 5.

The contacting device 50 has a first set of Stromflußkontaktierungen I ₁₁ and I ₂₁ and a first set of Spannungsmessungskontaktierungen U ₁₁ and U ₂₁ ; In each case one Stromflußkontaktierung and a Spannungsmessungskontaktierung per traction cable 8. The Spannungsmessungskontaktierungen U ₁₁ and U ₂₁ are in this case on the current-carrying side of Stromflußkontaktierungen I ₁₁ and I _{21 of} the traction cables. 8

The contacting device 50 'has a second set of Stromflußkontaktierungen I ₁₂ and I ₂₂ and a second set of Spannungsmessungskontaktierungen U ₁₂ and U ₂₂ . The Spannungsmessungskontaktierungen U ₁₂ and U ₂₂ are in this case also on the current-carrying side of Stromflusskontaktierungen I ₁₂ and I _{22 of} the traction cables. 8

The current flow contacts and the voltage measurement pads are each connected via wires 11 of one or more leads 10 to a measuring system 4, as in connection with FIG Fig. 4 is explained in more detail.

The current flow I runs along the tension cables 8 from the first contacting device 50 to the second contacting device 50 '. The falling voltages in the current flow I, which are proportional to the Zugseil resistors are tapped via the voltage measurement contacts U ₁₁ and U ₁₂ and U ₂₁ and U ₂₂ . The dashed part of the traction cables 8 indicates the spatial extent of the traction cables 8 between the two contacting devices 50 and 50 ', which are arranged at the respective ends of the elevator belt 7.

The exemplary embodiment which is in Fig. 8 is shown, has measuring points, ie contact points, on each pull rope 8. In other embodiments, only one pull cable is electrically contacted, ie the current contacts I ₂₁ and I ₂₂ and the voltage contacts U ₂₁ and U ₂₂ fall away. The measurement of the one pull rope 8 is then used representatively for the whole lift belt 7.

In another exemplary embodiment of a contacting device 5 according to Fig. 9 For example, the contactor 50 for current flow and voltage measurement contacting is provided at only one end of the elevator belt 7. Thus fall here the contacting device 50 and the contacting device 5 together. At the other end of the elevator belt 7, the traction cables 8 in pairs on an electrical connection 9 and thus form a series circuit of two series-connected tension cables 8, respectively Fig. 3 ,

As in Fig. 8 For example, the contacting device 50 (provided here only at one end of the elevator belt 7) is shown as formed from two functionally different partial devices 500 'and 500 ", which together form a unit.

Analogous to Fig. 8 For example, subdevice 500 'has a set of current flow contacts I ₁₁ and I ₂₁ , while subdevice 500 "has a set of voltage measurement pads U ₁₁ and U _21. There is one current flow contact and one voltage measurement contact per pull cord 8. Voltage measurement contacts U ₁₁ and U ₂₁ lie here on the current-carrying side of Stromflußkontaktierungen I ₁₁ and I _{21 of} the traction cables 8, as in connection with the description of Fig. 8 is explained.

The current flow contacts and the voltage measurement pads are each connected via leads 11 of one or more leads 10 to a measurement system 4, as in connection with FIG Fig. 4 is explained in more detail.

By connecting the Stromflußkontaktierungen I ₁₁ and I ₂₁ to the in Fig. 4 described current source 20 is a current flow I of Stromflusskontaktierung I ₁₁ from a first pull rope 8 along to the other end of the elevator belt 7 and via the electrical connection 9 through a second pull cable 8 back to Stromflußkontaktierung I _{21 of} the contacting device 5 instead. Via the two voltage measurement contacts U ₁₁ and U ₂₁ , the voltage dropping across the series-connected tension cables 8 can be tapped off.

Fig. 10 shows a different view of the embodiment of Fig. 9 in which only one contacting subdevice 500 "is shown, namely that for voltage measurement contacting, as well as its connection to the voltage measuring device 21.

At one end of the elevator belt 7, a contacting device 5, which comprises only one contacting device 50, is arranged. In other words, the contacting device 50 and the contacting device 5 fall in the exemplary embodiment disclosed in US Pat Fig. 10 is shown, together. The contacting device 50 has two contacting sub-devices 500 'and 500 "for current or voltage contacting of the tension cables 8.

At the other end of the elevator belt 7, the traction cables 8 in pairs electrical connections 9, as in connection with Fig. 9 are described in more detail.

The current flow I through the tension cables 8 is, as in connection with Fig. 4 described, ensured by a controllable constant current source 20 of a measuring system 4. The power supply via the wires 11 of one or more connecting line (s) 10, which are connected via the contacting part device 500 "with the tension cables 8.

The current flow I through the paired electrically interconnected tension cables 8 takes place analogously to in connection with Fig. 9 described current flow I.

The voltage measurement contacts are here represented by the contact elements 26 of the contacting device 5. Each pull rope 8 is associated with a contact element 26.

The voltage dropping in each case on two voltage measurement contactings electrically connected in pairs by the two tensioned cables 8 is read out via the wires 11 of one or more connection leads 10 from a tension measuring device 21 of the measuring system 4.

As already mentioned above, the connection lines 10 for current supply and voltage measurement can be one and the same connection line 10, with sufficient number of cores, or separate connection lines 10.

Again, the dashed areas of the traction cables 8 indicate the spatial extent of the traction cables 8 between the two ends of the elevator belt 7.

The present explanations for the voltage contact to Fig. 10 apply accordingly also in connection with in Fig. 8 and 9 described embodiments.

An embodiment of the contacting device 50 or 50 'with double-pin contact elements illustrated in the above figures is shown in FIG Fig. 11 shown.

The contacting subdevice 500 "of the contacting device 50 is connected to a connecting line 10, which is realized as a flat cable 100.

The connecting line 10 is locked in a plane parallel to the plane which is spanned by the elevator belt 7 and perpendicular to the elevator belt 7 in the contacting device 50.

The contact elements 26, which electrically connect the traction cables 8 of the elevator belt 7 to the cores 11 of the connecting cable 10, are designed as double arbors in a contact element holder 30. For each pull rope 8, one contact element 26 is arranged per partial device 500 "for voltage measurement contacting or one contact element 26 per partial device 500 'for the current flow contact in the contacting device 50.

The double mandrel contact elements 26 each have a partial mandrel 27 or 27 'in the direction of the elevator belt 7 and a partial mandrel 28 or 28' in the direction of the connecting line 10. The partial mandrels 27 and 28 or 27 'and 28' are either made in one piece or at least electrically connected to each other. The partial mandrels 27, 27 'make contact with the tension cables 8 without stripping through the plastic jacket 31 of the elevator belt 7 and establish a physical contact between the tension cables 8 and the contact elements 26. The mandrels 28, 28 'contact the wires 11 also stripping through the cable sheath of the connecting line 10 and make a physical contact between the wires 11 and the contact elements 26 ago.

The partial mandrels 27 and 28 lie in one plane and the partial mandrels 27 'and 28' lie in one plane. The spacing of these two planes corresponds to a multiple of the spacing of the centers of the wires 11 of the connecting line 10. In the exemplary embodiment shown here, this spacing of the planes is exactly the wire spacing of the flat cable 100. The distance between the center axes of the partial pins 27 and 27 'is a multiple In the exemplary embodiment shown here, this distance of the partial mandrels 27 and 27 'is exactly the Zugseilabstand. This distance is determined by the passage 32 of the plastic jacket of the elevator belt 7 between the two tension cables 8.

The connecting line 10 is, as in connection with Fig. 4 described, connected to a measuring system 4. The measuring system 4 causes the flow of current through the traction cables 8 and measures the voltage dropping on the traction cables 8 and determines therefrom the traction cable resistances.

One too Fig. 11 alternative embodiment of the contacting device 50 or 50 'shown in the above figures is in Fig. 12 shown. In contrast to Fig. 11 has these individual spines 29 on. Only one contacting subdevice 500 'or 500 "is shown here.

The individual mandrels 29 are arranged in a "matrix arrangement" with the following scheme: A row of thorns 29 contacts the second outermost passing traction cable 8 and from this traction cable, away from the connection line side of the contacting subdevice 500 'or 500 " 8, every other pull rope 8 to the middle of the elevator belt 7. Another row of mandrels 29 makes contact, from the connection line facing side of the contacting part device 500 'or 500 ", the second outermost passing pull rope 8 and from this pull rope 8, every second traction cable 8 to the middle of the elevator belt 7. Another row of thorns 29 contacts the remaining passing traction cables eighth

In the in Fig. 12 In the embodiment shown, the contacting partial device 500 'or 500 "for an elevator belt 7 is connected to twelve tension cables 8 in a common plastic jacket 31 with a flat cable 100 having twelve wires 11 perpendicular thereto.

This contacting subdevice 500 ', 500 "has three rows of contact elements 26, which in this case are divided into groups of three by way of example Fig. 12 maintains orientation and counting from the lead-side facing away from the contacting subdevice 500 'and 500 ", respectively, then a series of contact elements 26 contacts the second, fourth and sixth traction cables 8. A second row of two groups of contact elements 26 contacts the first, third, fifth, eighth, tenth and twelfth traction cables 8. A third row of contact elements 26 contacts the seventh, ninth and eleventh traction cables 8.

When counting the traction cables 8 of the elevator belt 7 as described above, the first traction cable 8 is electrically connected to the first wire 11 of the flat cable 100 by the contact elements 26 from left to right. The second traction cable 8 is connected to the seventh wire 11, the third traction cable 8 is the third vein 11, the fourth traction rope 8 is the ninth vein 11, the fifth traction rope 8 is the fifth vein 11, the sixth traction rope 8 is the eleventh vein 11, the seventh traction rope 8 is the second vein 11, the eighth tow rope 8 is with the eighth strand 11, the ninth tension rope 8 is with the fourth strand 11, the tenth tension rope 8 is with the tenth strand 11, the eleventh tension rope 8 is with the sixth strand 11 and the twelfth tension rope 8 is connected to the twelfth wire 11.

This "matrix arrangement" is due to the size of the contact elements 26, which have a diameter of more than one Zugseilabstand or more than one vein spacing.

The contacting device 5 has two parts, namely a bottom 35 and a cover 36. For mounting, the flat cable 100, i. the lead 10 is inserted all the way into the contacting subdevice 500 ', 500 ", whereupon it is clipped together with four plastic snaps 37. Thus, the flat cable 100 is locked in the contacting subdevice 500', 500".

In order to make the electrical contact between the tension cables 8 and wires 11 through the contact elements 26, the two contacting Teilvorrichtungshälften 35 and 36 with four clamping screws 33 and associated nuts 34 are pressed against each other. Due to the additional force, which starts from the clamping screws 33, the tension cables 8 and wires 11 are contacted berührungsierfrei contact by the contact elements 26.

Fig. 13 shows the section through the contacting subdevice 500 ', 500 "from FIG. 12 along the line AA.

Bottom 35 and cover 36 of the contacting subassembly 500 ', 500 "are replaced by the clamping screws 33 and associated nuts 34, as in connection with FIG Fig. 12 already described, compressed. Thus, the contact elements 26 (see X-circle) penetrate the wires 11 of the flat cable 100 and partially penetrate the traction cables 8 of the elevator belt 7. As a result, the contact elements 26 create an electrical connection between the two.

The Kunststoffschnapper 37 of the Kontaktierungseinrichtungsdeckels 36 are no longer in contact with Einrastschultern the Kontaktbierungsungsformernboden 35, since the bottom 35 and cover 36, by the clamping screws 33, are compressed to an increased extent.

On the upper side of the elevator belt 7, ie on the side facing the connecting line 10, the jacket 31 is thin. The jacket 31 on the underside of the elevator belt 7, ie on the side facing the bottom of the contacting device 5, has a pronounced running surface for rolling over the carrying rollers 14, 16 and drive rollers 18 of the conveyor 2 up, see Fig. 2 and 3 ,

A 20x enlarged section of the X marked circular area in Fig. 13 is in Fig. 14 shown.

The contact elements 26 in the contact element holder 30 are formed in this exemplary embodiment of a contacting subdevice 500 ', 500 "as individual mandrels 29, which in Fig. 14 be referred to as pins.

By the application of force from the clamping screws 33, the individual mandrels 29 have completely penetrated the wires 11 of the connection line 10. They have also contacted the tension cables 8 of the elevator belt 7 stripping-free by the jacket 31. The contact elements 26, i. the individual mandrels 29, establish an electrical connection between the wires 11 of the connecting cable 10 and the tension cables 8 of the elevator belt 7.

Due to the conical shape of the individual spikes 29, the stranding of the steel cables, that is to say the traction cables 8, are more extensively stretched. This leads to an improved electrical contact with respect to straight, for example nail-shaped, contact elements 26.

The PU layer of the jacket 31 is significantly thicker on the side facing away from the mandrel: On the one hand, it gives the elevator belt 7 good rolling properties, and on the other side it has a thin layer which has to be penetrated for contacting.

Fig. 15 shows the section through the contacting subdevice 500 '. 500 "off FIG. 12 along the line BB.

The jacket 31 of the elevator belt 7 has on the bottom 35 side facing a tread with comb structure. Each hump of this comb has the width of two tension cables 8 and serves the traction of the elevator belt 7 when winding and unwinding on the support and drive rollers 14,16 and 18 of the conveyor 2, see Figures 2 and 3 ,

On the cover 36 side facing the jacket 31 of the elevator belt 7 is as thin as possible to allow easy contacting of the tension cables 8 through the individual mandrels 29, which protrude from the contact holders 30.

The individual spikes 29 pierce the flat cable 100 at the points at which the wires 11 run and thus contact the wires 11 of the connecting line 10 and the traction cables 8 of the elevator belt 7 simultaneously and without insulation.

Claims (13)

1. Device (3) for monitoring, by means of resistance measurement, a lift belt (7) having at least two electrically conductive traction ropes (8) which are embedded in an electrically insulating sheath (31), are electrically insulated from one another and run parallel to one another in a common plane horizontally in the sheath (31), comprising:

   a contact-making device (5) with at least one contact-making apparatus (50, 50') which is equipped with contact elements (26) for each of the at least two traction ropes (8) for making physical contact with the traction ropes (8) through the electrically insulating sheath (31) without stripping insulation;

   a resistance measurement system (4) which can be electrically connected to the traction ropes (8) of the lift belt (7) with the aid of the contact elements (26);

   characterized in that

   the resistance measurement system (4) is designed to determine the electrical resistance of at least one traction rope (8) by means of four-conductor measurement, that is to say with separate contact-connection for current flow and voltage measurement, by causing a measurement auxiliary current to be fed in by means of the current flow contact-connection and therefore causing the measurement auxiliary current to flow along the at least one traction rope (8), and tapping off an electrical voltage which is dropped across the at least one traction rope (8) by means of the voltage measurement contact-connection, and ascertaining the electrical traction rope resistance with the aid of said electrical voltage and the known measurement auxiliary current,

   the contact-making device (5) has at least one connection line (10) which serves to electrically connect the contact elements (26) to the resistance measurement system (4), and

   the connection line (10) is designed as a flat cable (100) and the contact elements (26) each make electrical contact with a traction rope (8) of the lift belt (7) by way of a wire (11) of the flat cable (100), and the flat cable (100) has a number of wires (11) which corresponds to the number of traction ropes (8) in the lift belt (7).
2. Monitoring device (3) according to Claim 1, wherein the contact-making device (5) comprises two contact-making apparatuses (50, 50'), one of which is intended to be arranged at one end and the other of which is intended to be arranged at the other end of the lift belt (7), so that the electrical resistance of traction ropes (8) between the two contact-making apparatuses (50, 50') can be measured.
3. Monitoring device (3) according to Claim 1, wherein the contact-making device (5) comprises a contact-making apparatus (50) which is intended to be arranged at only one end of the lift belt (7), and wherein the monitoring device (3) is designed to measure the electrical resistance of at least two traction ropes (8) of the lift belt (7) which are connected electrically in series with one another by means of electrical connection (9) at the other end of the lift belt (7).
4. Monitoring device (3) according to one of Claims 1 to 3, in which

   - the at least one contact-making apparatus (50 or 50, 50') serves both for current flow contact-connection and for voltage measurement contact-connection, or

   - the at least one contact-making apparatus (50 or 50, 50') comprises at least one current contact-connection component apparatus (500') for current flow contact-connection and at least one voltage contact-connection component apparatus (500") for voltage measurement contact-connection.
5. Monitoring device (3) according to one of Claims 1 to 4, wherein the contact elements (26) also make contact with the wires (11) of the flat cable (100) without stripping insulation.
6. Monitoring device (3) according to Claim 5, wherein the contact elements (26) are in the form of contact spikes.
7. Monitoring device (3) according to Claim 6, wherein the contact spikes are individual spikes (29) which are designed to jointly in each case contact-connect a wire (11) of the flat cable (100) to a traction rope (8) of the lift belt (7) by one and the same individual spike (29) piercing both the flat cable wire (11) and the traction rope (8) from one side, wherein the spike completely pierces the flat cable wire (11) and at least partially pierces the traction rope (8).
8. Monitoring device (3) according to Claim 6, wherein the contact spikes are twin spikes which are arranged between the lift belt (7) and the flat cable (100) and the two component spikes (27, 28 or 27', 28') of which extend in opposite directions, wherein the twin spikes are designed to in each case contact-connect a wire (11) of the flat cable (100) to a traction rope (8) of the lift belt (7) by one component spike (28, 28') at least partially piercing the flat cable wire (11) and the other component spike (27, 27') at least partially piercing the traction rope (8).
9. Monitoring device (3) according to one of Claims 1 to 8, wherein the flat cable (100) is arranged at a right angle in relation to the lift belt (7) and, in the contact-making region, lies in a plane parallel to the plane spanned by the lift belt (7).
10. Monitoring device (3) according to one of Claims 1 to 9, wherein the contact elements (26) are arranged in at least two rows, wherein the contact elements (26) have a diameter which is greater than the distance between in each case two traction ropes (8).
11. Lift system (1) comprising

    - at least one lift cage (6),

    - a conveyer device (2) for the at least one lift cage (6), wherein the conveyor device (2) has at least one lift belt (7) with a plurality of traction ropes (8) which are fastened to the lift cage (6), and

    - a device (3) for monitoring the lift belt (7) according to one Claims 1 to 10.
12. Method for monitoring lift belts (7) having at least two electrically conductive traction ropes (8) which are embedded in an electrically insulating sheath (31), are electrically insulated from one another and run parallel to one another in a common plane horizontally in the sheath (31) by means of resistance measurement, wherein the method is carried out with the aid of a monitoring device (3), wherein the monitoring device (3) comprises a resistance measurement system (4) which is electrically connected to the traction ropes (8) by way of their electrically insulating sheaths (31) by means of contact-connection without stripping insulation, specifically with the aid of a contact-making device (5) with at least one contact-making apparatus (50, 50') which has contact elements (26) for each of the at least two traction ropes (8), wherein a contact-making apparatus (50 or 50, 50') is arranged at one end or at both ends of the lift belt,
    characterized in that
    the method comprises the following steps in order to ascertain the electrical resistance of at least one electrically conductive traction rope (8) with the aid of four-conductor measurement, that is to say with separate contact-connection for current flow and voltage measurement:

    a measurement auxiliary current is fed into the at least one traction rope (8) by means of the current flow contact-connection, so that the said measurement auxiliary current flows through the at least one traction rope (8) over the length of the lift belt (7);

    an electrical voltage which is dropped across the at least one traction rope (8) is tapped off by means of the voltage measurement contact-connection;

    the electrical traction rope resistance is ascertained with the aid of the tapped-off electrical voltage and the known measurement auxiliary current;

    furthermore characterized in that

    the contact-making device (5) has at least one connection line (10) which serves to electrically connect the contact elements (26) to the resistance measurement system (4), and

    the connection line (10) is designed as a flat cable (100) and the contact elements (26) each make electrical contact with a traction rope (8) of the lift belt (7) by way of a wire (11) of the flat cable (100), and the flat cable (100) has a number of wires (11) which corresponds to the number of traction ropes (8) in the lift belt (7).
13. Method according to Claim 12, wherein the monitoring device (3) is designed according to one of Claims 1 to 10.

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