EP2516313B1 - Monitoring a supporting and traction means of an elevator system - Google Patents

Description

The present invention relates to an elevator installation, in which at least one elevator car or at least one counterweight is moved in opposite directions in an elevator shaft, wherein the at least one elevator car and the at least one counterweight run along guide rails, carried by one or more carrying and propelling means and driven by a traction sheave of a drive unit.

In elevator systems, the use of carrying and blowing agents has proven to be advantageous, which consist of at least one current-conducting steel cable and non-conductive sheaths or made of specialty plastics ropes, in which a conductor is incorporated. As a result, a test current can be applied for monitoring the individual supporting cable or the individual supporting cables - also called cords. In the circuit thus formed or in a plurality of circuits thus formed, the current flow or the current intensity, the voltage, the electrical resistance or the electrical conductivity is measured and thus provides information about the integrity or the degree of wear of the carrier and propellant.

For example, the published patent application DE-Al-39 34 654 a serial connection of all individual cords and an ammeter, or, instead of an ammeter, an electronic circuit in which the base resistance of an emitter-connected transistor is measured.

The patent US B2-7,123,030 discloses a calculation of the electrical resistance by a measurement of the current voltage by means of a so-called Kelvin bridge and a comparison of the thus determined voltage value with an input reference value.

The international publication WO-A2-2005 / 094250 discloses a temperature-dependent measurement of the electrical resistance or the electrical conductivity, in which the different environmental and thus also assumed carrier temperature is taken into account, which can be very different, especially in high elevator shafts.

Another international publication WO-A2-2005 / 094248 discloses special interconnections of the individual cords, to avoid electric fields and to avoid transversal ions between the individual cords.

A European publication EP-A1-1 275 608 An application of the same applicant as the present application discloses monitoring of the sheath by applying a positive pole of a DC source to the cords, so that in case of a defective sheath a ground contact is made.

In all these known monitoring of the carrying and blowing agent, however, is disadvantageous that the information about the wear and tear or the present incident of the carrying and propellant is present only as an overall result. In particular, cross shorts between cords, for example, can severely distort the overall result.

A problem now is to eliminate the mentioned disadvantages of conventional monitoring devices and to propose a monitoring device for carrier and propellant, which provides more accurate or qualitatively classifiable information about the condition and Thus, a higher level of security for the elevator system is achieved, or costly to early replacement of the carrier and propellant can be avoided.

An exemplary arrangement comprises a circuit which can be applied to the carrying and blowing agent and comprises at least two electrical resistors or resistance elements having different resistance characteristics. In individual cases, this may be the resistance value itself, but in principle also the tolerance, the maximum power loss, the temperature coefficient or taking into account the same, the dielectric strength, the stability, the (parasitic) inductance, the (parasitic ) Capacity to handle the noise or impulse load or combinations thereof.

An arrangement according to the invention thus provides a support and propellant having at least one conductive cord. This supporting and blowing agent is substantially, advantageously coated with an electrically insulating material such as rubber or a polyurethane. At each of the conductive ends of the cord, different resistances are connected to each other. Additionally or alternatively, a further, of the first two mutually different resistors, in turn, different resistance at the contact point according to the invention arranged at which the carrying and blowing agent passes during operation.

This contact point may for example be an arbitrary deflection roller, be it a stationary roller arranged in the elevator shaft or else the or one of the deflection rollers of the counterweight or the elevator car. However, as a contact point where the carrying and blowing agent passes, there is also a so-called retainer, ie a derailment protection in consideration, the deflection rollers usually have. But also supporting roles of the counterweight or the Elevator cabin and in principle also the traction sheave and metallic shaft components come into consideration. The contact point may be a metallic surface which may be coated, for example, with a highly conductive material such as copper or brass. Also brush contacts, for example in the form of carbon fiber brushes, copper brushes or the like can be used. The use of brushes has the advantage that the brushes cling to a surface of the carrier and propellant, that is, for example, that they exactly follow a contoured or shaped surface, so that the entire surface is detected. It is essential, however, primarily that the contact point is conductive and can be advantageously grounded - in the case of operating the monitoring device with DC - or a voltage to the contact point can be applied - in the case of operating the monitoring device with AC - and in principle a contact to the conductive part or the conductive parts of a carrying and blowing agent is possible when this conductive part of the carrying and blowing agent comes into contact with this contact point.

This latter contact between the point of contact, for example, the pulley, and the conductive part or parts of the carrying and propellant may arise, for example, if individual wires of the cords break and subsequently pierce through the sheath. These broken wires strip along the point of contact and thus make electrical contact during the contact time. Thus, by evaluating the resulting total resistance or a corresponding current characteristic variable, both an interruption of a cords, a cross or short circuit between cords or damage to the casing, or a piercing of individual wires can be determined.

In a separate approach, this contact between the contact point and conductive parts of the carrier and propellant alone for the indication of a support and Propellant damage can be used. In this solution can even be dispensed with a resistor, unless several different resistors are arranged at different contact points. In an advantageous embodiment, this contact point is a sliding contact, or a contact point which is arranged, for example, at a small distance to the carrying and blowing agent. This contact point can be any part of the elevator installation on which the suspension element has passed. This can be, for example, a machine console in the region of the drive machine or it can be a component of the cabin or it can also be a safety bar or retainer. This contact point is advantageously arranged in a distance range of about 1mm to 15mm. In an advantageous embodiment, this distance can be adjusted. This ensures that only real damage to the support and propellant lead to a contact, while small Verschleissspuren be ignored. The contact point is of course designed to be electrically conductive.

Alternatively, the said contact between the contact point, for example, the deflection roller, and the conductive part or the conductive parts of the support and propellant may also be realized by, for example, the conductive cord of the support and propellant not completely, but only substantially not coated with conductive plastic. There remain juxtaposed conductive points or even entire free parts of the cross-sectional circumference, which extend over the entire unwinding length of the support and propellant and can be in electrical contact with the deflection roller. Another way to make the contact between the cord and the pulley or the contact point with the third resistor is the incorporation of conductive strands in the sheath of the support and propellant. In principle, a carrier and propellant with a conductive sheath is possible, but then preferably an insulation layer between the conductive cord and the conductive sheath.

Another variant provides a support and propellant, which has a plurality of parallel conductive cords. This supporting and blowing agent is also encased substantially. At the conductive ends of the cord respectively different, the individual cords associated resistor elements, or characteristic resistors are connected. In addition, if necessary, a single further, in turn of the other resistors different resistance arranged, as explained above using the example of a single cord is arranged at the contact point according to the invention, at which the carrying and blowing agent passes during operation.

The mutually different resistors or resistance elements, which are arranged at the ends of the conductive cord or at the ends of the support and propellant, are preferably integrated into contacting elements, as described for example in European Publication EP-A1-127 56 08 have been disclosed. The contacting elements disclosed in these documents can be arranged not only at the ends of the carrier and propellant, but optionally also between them. Further contacting elements into which the two mutually different resistances at the ends of the conductive cord or at the ends of the carrying and blowing agent are preferably integrated, are for example in the publications WO-A2-2005 / 094249 . WO-A2-2005 / 094250 or WO-A2-2006 / 127059 disclosed. The different resistance elements may also be connected to the ends of the carrying and blowing means or integrated into these ends. Other arrangements of the resistors are possible. Thus, they can be integrated in the connecting line between the contacting element and a corresponding measuring device.

The mutually different resistors or resistance elements are in such a way with a measuring device or connected to a corresponding current source, that depending on the respective error possibility specific total resistances, currents or - with constant held current source - specific voltages to the overall circuit result. The respective measured values can be clearly assigned to a respective damage event. The measurement can be queried both permanently and at intervals or only as needed before and / or during each trip as a corresponding condition for a ride release.

Furthermore, design variants of such a monitoring device can be realized, which, in combination with only one or more cords and the corresponding number of mutually different resistances, not only that they according to the invention have a contacting point at which the carrying and blowing agent passes, but they can, if necessary, be configured with multiple Kontaktierungs-points.

As already mentioned, the following cases come into consideration: cord breakage, short circuit (short circuit between two cords), breakdown or combinations thereof.

Basically, with such a designed monitoring device, it is possible to determine the "quality" of an impending cord break because the resistivity of a single cord increases as its cross-sectional area decreases as a result of increasing breakage of the individual strands. However, it is preferable to select the mutually different resistances at the ends of the cord on the order of a factor larger than the specific resistance of the cord, which factor is in a range of 500 to 1,500, but preferably about 1,000 is. In this way, a reliable independence of the measurement signal of the mutually different resistors from the resistivity of the cord guaranteed, which varies not only in function of the cross-sectional area, but also due to temperature differences that can be considerable in a high elevator shaft.

The fact that in an alternative in addition to the detection of the total resistance of the at least two mutually different resistances in between the inventive contact point to a third, in turn of the at least two resistors different resistance is arranged, it is possible a cord breakage, a cross-circuit or a breakdown of a Locate cords to the contact point or combinations thereof. The location may be related to the affected cord or it may be with reference to control data of the elevator installation and a time of contact registration at the point of contact. This is done on the basis of the known information, where the contact point is fixed, or the known elevator car position, or a time measurement from in-drive-setting of the elevator system, so that on the basis of the operating speed of the elevator system, the distance traveled by the carrying and propellant is calculable. This known or calculated position information is set at the occurrence of a measurement signal at the third resistance arranged in the contact point or at the occurrence of a change in the measurement signal of this third resistance and the occurrence of a change in the measurement signals in the at least two first resistances thus the position of damage to the carrying and propellant. The acquisition or calculation of these described values preferably takes place in a processor-assisted and automatic manner and can be displayed on a display or monitor. The processor is also preferably capable of storing the occurrences of damage and thus creating a damage clutter image.

In particular, in such a monitoring device for a carrier and propellant with multiple cords, or a corresponding elevator system, it is it is also possible, preferably also by means of the supporting processor, to evaluate the extent of damage of the entire carrier and propellant with regard to the number of defective locations and with regard to the extent of a respective individual defective location and thus issue a staggered warning message. For example, it can be realized that a carrier and propellant with, for example, 12 cords, one of which is broken, or only rarely and with low intensity cross-circuiting, can still be used without hesitation for a certain period of time. This certain grace period is detected by the processor and shortened again or leads to a shutdown of the elevator system, if the extent of damage should expand accordingly or another damage event should be added.

The following tables show by way of example what measurements or damage cases can occur by way of example. The following Table 1 shows possible measurements of the total resistance in an exemplified circuit example of an exemplary monitor for two cords A and B. By way of example, one end of the first cord A has a resistance of 1 ohm and at the other end of this first cord A, by way of example Resistor of 1.1 ohms arranged. At the second Cord B, by way of example, identical resistors are arranged, however, in mirror image, ie at the one end of the second cord B, a further resistor of 1.1 ohm is for example arranged and at the other end of this second cord B a further resistor of 1 ohm is arranged by way of example , At the contact point (P), past which the carrying and blowing agent, a fifth resistor of 1.5 ohms is arranged by way of example. The voltage source is assumed to be a DC source with a voltage of, for example, 1 volt.

Possible measurements of the total resistance are thus, - Table 1 - case of damage cord breakage none A B A + B none 1050 2100 ** 2100 ** 00 ** FROM 1048 - ** - ** - ** AB (before break) - 1624 ** 1524 ** 2200 ** AB (after break) - 1524 ** 1624 ** 2000 ** AP 0939 - ** 1700 ** - ** AP (before break) - 1162 ** - ** 2600 ** AP (after break) - 2100 ** - ** ∞ ** BP 0919 1635 ** - ** - ** cross circuit BP (before break) - - ** 1141 ** 2500 ** BP (after break) - - ** 2100 ** ∞ ** ABP 0912 * - ** - ** - ** ABP (before breakage) - * 1158 ** 1124 ** 2024 ** ABP (after break) - * 1388 ** 1488 ** ∞ ** The measured values denoted by *, for example, merely cause a warning and the measured values denoted by **, in turn, result in a shutdown of the elevator installation. Possible measured values of the current measured in an ammeter are - Table 2 - case of damage cord breakage none A B A + B none 0952 0476 ** 0476 ** 0000 ** FROM 0955 - ** - ** - ** AB (before break) - 0616 ** 0656 ** 0455 ** AB (after break) - 0656 ** 0616 ** 0500 ** AP 1064 - ** 0588 ** - ** AP (before break) - 0861 ** - ** 0385 ** AP (after break) - 0476 ** - ** 0000 ** BP 1088 0612 ** - ** - ** cross circuit BP (before break) - - ** 0876 ** 0400 ** BP (after break) - - ** 0476 ** 0000 ** ABP 1096 * - ** - ** - ** ABP (before breakage) - * 0863 ** 0890 ** 0494 ** ABP (after break) - * 0720 ** 0672 ** 0000 **

Also in a monitoring device, which are provided for carrying and blowing agent with multiple cords, the resistance elements, or resistors are preferably arranged in mirror image. That is, for example, in three cords, the mutually different resistances at the one, adjacent ends of the cords have the characteristics x, y, z, while the resistors at the other, adjacent ends of the cords have the characteristics z, y, x. The sum of the two resistors thus arranged on a single cord remains constant. Also, the sum of the resistances, which are arranged at one end preferably in a single, first contacting element for all cords in parallel, or the sum of their characteristics x + y + z is thus identical to the sum of the resistors at the other ends are also preferably arranged in parallel in a single, second contacting element for all cords, or with the sum of their characteristics z + y + x. This does not affect the usability of the measurement results obtained and brings the advantage of a more cost-effective mass production.

In order to avoid a falsification of the measurements, which can take place continuously, ie even when the elevator installation is stationary, only during a journey and / or before a journey, it is provided to discharge static charges of the elevator installation continuously or at least before a measurement is carried out by a grounding ,

The disclosed monitoring devices can preferably be combined with a bending change counter, so that a further information in the - preferably processor-assisted - monitoring device flows and thus the determination of the Ablegereife a carrying and propellant is even more reliable.

In the present application, different resistance elements have hitherto been disclosed. Instead of However, with resistors, a monitoring device can also be implemented additionally or completely with other electronic components, for example, with capacitors and coils. In this case, when an alternating voltage is applied, the frequency, the inductance, the capacitance or combinations thereof are preferably measured. Thus, in the following, an arrangement and measurement on several, mutually different "resistive elements" claimed, which may include as a collective term said electronic components. The measurement may relate to the following current characteristics: the resistance or / and one of the resistance characteristics listed in paragraph [0010], the amperage, the voltage, the frequency, the inductance, the capacitance or combinations thereof.

• Die Messwerte sind im Gegensatz zu einer einfachen Durchgangsprüfung quantifizier- und qualifizierbar und somit sind präzisere und gestaffelte Warnmeldungen generierbar.
• Die schadhaften Stellen sind an der Abwicklungslänge des Trag-und Treibmittels lokalisierbar.
• Es ist ein Schadenshäufungs-Bild erstellbar.
• Die Messwerte sind weitgehend unabhängig von dem spezifischen Widerstand eines Cords.
• Trotz dem Vorliegen eines allfälligen Querschlusses bleibt ein Cordbruch erkennbar.
• Geringe Anzahl von nur zwei Anschlussstellen durch die kombinierten Kontaktierungselemente.

In summary, such a monitoring device provides the following advantages:

• In contrast to a simple continuity test, the measured values can be quantified and qualified and thus more precise and staggered warning messages can be generated.
• The damaged areas can be localized at the unwinding length of the carrying and blowing agent.
• It is a damage accumulation image buildable.
• The measurements are largely independent of the resistivity of a cord.
• Despite the presence of a possible cross-circuit a cord break remains recognizable.
• Low number of only two connection points through the combined contacting elements.

Further or advantageous embodiments of a monitoring device for a carrier and propellant in an elevator system form the subject of the other dependent claims.

The invention will be explained symbolically and by way of example with reference to figures. The figures become coherent and comprehensively described. The same reference symbols denote the same components, reference symbols with different indices indicate functionally identical or similar components.

Fig. 1

eine schematische Darstellung einer beispielhaften Aufzugsanlage mit einer Überwachungseinrichtung für das Trag- und Treibmittel gemäss Stand der Technik;

Fig. 2

eine schematische Darstellung einer ersten Ausgestaltungsvariante einer Überwachungseinrichtung für ein Trag- und Treibmittel mit einem Cord;

Fig. 2a

eine schematische Darstellung einer zweiten Ausgestaltungsvariante einer Überwachungseinrichtung für ein Trag- und Treibmittel mit zwei Cords, bei gleichzeitiger Darstellung eines Querschlusses zwischen den beiden Cords und eines bevorstehenden Cordbruchs eines Cords;

Fig. 3

eine schematische Darstellung einer anderen Ausgestaltungsvariante einer Überwachungseinrichtung für das Trag- und Treibmittel und

Fig. 4

eine schematische Darstellung einer weiteren Ausgestaltungsvariante einer Überwachungseinrichtung für das Trag- und Treibmittel.

It show here

Fig. 1

a schematic representation of an exemplary elevator system with a monitoring device for the supporting and blowing agent according to the prior art;

Fig. 2

a schematic representation of a first embodiment variant of a monitoring device for a support and propellant with a cord;

Fig. 2a

a schematic representation of a second embodiment variant of a monitoring device for a carrying and blowing agent with two cords, while representing a cross-circuit between the two cords and an imminent cord breakage of a cord;

Fig. 3

a schematic representation of another embodiment variant of a monitoring device for the support and propellant and

Fig. 4

a schematic representation of another embodiment variant of a monitoring device for the support and propellant.

The Fig. 1 shows an elevator system 100, as known from the prior art, for example in a illustrated 2: 1 suspension. In an elevator shaft 1, an elevator car 2 is movably arranged, which is connected via a support and propellant 3 with a movable counterweight 4. The support and propellant 3 is driven during operation by means of a traction sheave 5 of a drive unit 6, which are arranged in the uppermost region of the elevator shaft 1 in a machine room 12. The elevator car 2 and the counterweight 4 are guided by extending over the shaft height guide rails 7a and 7b and 7c.

The elevator car 2 can serve a top floor door 8, further floor doors 9 and 10 and a lowest floor door 11 at a delivery height h. The elevator shaft 1 is formed by shaft side walls 15a and 15b, a shaft ceiling 13 and a shaft bottom 14 on which a shaft bottom buffer 19a for the counterweight 4 and two shaft bottom buffers 19b and 19c for the elevator car 2 are arranged.

The support and propellant 3 is attached to a fixed attachment point or Tragmittelfixpunkt 16 a to the shaft ceiling 13 and guided parallel to the shaft side wall 15 a to a support roller 17 for the counterweight 4. From here again via the traction sheave 5, to a first deflection or support roller 18a and a second deflection or support roller 18b, the elevator car 2 unterschlingend, and to a second stationary attachment point or Tragmittelfixpunkt 16b on the shaft ceiling 13th

A first and a second contacting element 20a and 20b are respectively arranged at the respective ends of the carrying and propelling means 3 in the vicinity of the first stationary fastening point or supporting-medium fixing point 16a and in the vicinity of the second stationary fastening point or suspension-fixing point 16b. At the contacting elements 20a and 20b, a symbolically illustrated test circuit 23 with a test current IP can be applied, with the example, a simple continuity test of the supporting and propellant 3 can be realized.

The Fig. 2 schematically shows a monitoring device 200a in an elevator installation 100a. To a support and propellant 3a, which consists essentially of a cord 21 and a casing 22 which substantially encloses this cord 21, a respective contacting element 20c or 20d is connected to its respective ends. These contacting elements 20c and 20d preferably each have a resistor R1 or R2 integrated in them, through which a test circuit 23a with a voltage source Ua and a test current IPa can be applied. The test circuit 23a further comprises a ground 24 and a measuring device 25, and an optional connection to a contact point P - for example, a deflection roller over which the support and propellant 3a runs - with a third resistor R3. The resistors R1-R3 have different current and resistance characteristics, so that, depending on a respective damage event, the measuring device 25 measures a classifiable measured value which allows a diagnosis or a staggered warning or shutdown of the elevator installation 100a. Alternatively, the test circuit 23a can also be guided only by contacting the ends of the cord 21 and the contact point P. This makes it easy to detect damaged areas in the carrying and blowing agent. Also, the grounding 24 may take place at another suitable location of the plant. For example, the contact point P can be connected directly to earth. This can also be defined multiple contact points in the elevator system, which can recognize each for themselves defective locations in the carrying and propellant.

In the Fig. 2a is a monitoring device 200a 'in an elevator system 100a' shown symbolically. In contrast to the monitoring device 200a or the elevator system 100a from the Fig. 2 For example, a support and propulsion means 3 'has two cords 21' and 21 ", which are enveloped by a casing 22 '. A corner or a side of the elevator car 2 is shown in perspective and symbolically, so that it can be seen by way of example that the support and propellant 3 '- and preferably a second support and propellant, not shown in greater detail, on the opposite side of the elevator car 2 - the elevator car 2 is guided in an undercut manner via two deflection or support rollers 27a and 27b 27b form two optionally available contact points P1 and P2, which - symbolically represented - are each connected to a resistor RP 'and RP ".

As previously disclosed, the cords 21 'and 21 "at their respective ends are also advantageously connected to resistors RCa and RCa' for the cord 21 'and resistors RCb and RCb' for the cord 21". The characteristics of the resistors RCa, RCa ', RCb and RCb', and optionally the resistors RP ', RP "are all different from each other or the resistors RCa, RCb and RCa', RCb 'at the ends of the cords 21' and 21" are arranged in mirror image with respect to their parameters. That is, the characteristics of the resistors RCa and RCb ', RCb and RCa' may be identical. The ends of the suspension element are connected via the respective resistance elements RCa and RCb 'or RCb and RCa' to the measuring device 25 '.

Furthermore, in this Fig. 2a symbolically representing the damage event of a cross-circuit Qsch at the optional contact point P1, by indicating that the cords 21 'and 21 "are no longer spaced apart from one another in the casing 22' but approach each other, for example, by a damaged casing 22 ' that they get in contact with each other.

At the likewise optional contact point P2, the damage event of an impending cord break Cb is represented symbolically. The cord 21 'begins to untwist its individual strands 26 which protrude from the casing 22' and thus initiate contact with the deflecting or supporting roller 27b or on its holder. A monitoring of the contact points P1, P2 can be carried out in the illustrated manner self-responding without resistors RCa, RCa ', RCb and RCb'.

In the Fig. 3 is another embodiment variant of a monitoring device 200b for an indicated elevator system 100b shown schematically. A support and propellant 3b has four cords 21a-21d, which are co-covered by a sheath 22a. At the ends of the cords 21a-21d there is respectively a contacting element 20e or 20f arranged. In each of these contacting elements 20e and 20f four resistors R1 ', R3', R5 'and R7' or R2 ', R4', R6 'and R8' are integrated, which is connected to a test circuit 23b with a voltage source Ub, a Test current IPb, a ground 24 'and a measuring device 25a are connected. Furthermore, an optional contact point P 'with a resistor R9' is connected to the test circuit 23b.

The resistors R1'-R9 'all have different current characteristics or are optionally arranged in mirror image. That is, for example, the resistor R1 'a current characteristic w, the resistor R3' a current characteristic x, the resistor R5 'a current characteristic y and the resistor R7' can have a current characteristic z, while the resistor R2 'The current characteristic z, the resistor R4' the current characteristic y, the resistor R6 ', the current characteristic x and the resistor R8', the current characteristic w has. The sums w + z, x + y, y + x, z + w and also w + x + y + z at the one adjacent ends of the cords 21a-21d and z + y + x + w at the other adjacent ends identical. The current characteristic of the resistor R9 'is different from w, x, y and z.

In the Fig. 4 schematically shows how a further embodiment variant of a monitoring device 200c is arranged for an indicated elevator installation 100c with a support and propellant 3c. The support and propellant 3c has 12 cords 21a'-211 ', which are all wrapped together by a sheath 22b. At the one adjacent ends of the cords 21a'-211 ', a contacting element 20g is arranged, into which resistors R1 ", R3", R5 ", R7", R9 ", R11", R13 ", R15", R17 ", R19" , R21 "and R23" are preferably integrated, each individual resistor associated with one of the cords 21a'-211 '. At the other adjacent ends of the cords 21a'-211 ', in turn, a second contacting element 20h is arranged, into which, analogous to the first contacting element 20g, resistors R2 ", R4", R6 ", R8", R10 ", R12", R14 " R16 ", R18", R20 ", R22" and R24 "are preferably also associated with each of the cords 21a'-211 '.

Analogous to Fig. 3 For example, the resistors R1 "-R24" are connected to a test circuit 23c having a test current IPc. The test circuit 23c further includes a voltage source Uc, a ground 24 "and a measuring device 25b. Also connected to the test circuit 23c is an optional pad P" with a resistor R25 ".

Also analogous to Fig. 3 , the resistors R1 "-R23" with odd reference number are preferably arranged with respect to their current characteristics in mirror image to the resistors R2 "-R24" with a straight reference number. The resistor R25 ", however, is preferably again selected differently from these twelve current characteristics.

The ground 24 can, as in the example of Fig. 2 designed to be arranged at any location of the system. Thus, advantageously, the contact point P can be connected directly to the ground. In this way, contact points in the elevator installation can also be defined, which each can detect defects in the support and propellant that are defective in interaction with the monitoring device.

Claims (9)

1. Monitoring device (200, 200a, 200a', 200b, 200c) for a supporting and drive means (3, 3', 3a-3c) of a lift installation (100, 100a, 100a', 100b, 100c), which supporting and drive means (3, 3', 3a-3c) includes at least one electrically conductive cord (21, 21', 21", 21a-21d, 21a'-211'), wherein the monitoring device includes a measuring device (25, 25', 25a, 25b) for determining a resultant resistance and contacting elements (20a - 20h) for connecting the monitoring device with the supporting and drive means (3, 3', 3a-3c), wherein a first contacting element (20a, 20c, 20e, 20g) for contacting a first end of the supporting and drive means (3, 3', 3a-3c) and a second contacting element (20b, 20d, 20f, 20h) for contacting a second end of the supporting and drive means (3, 3', 3a-3c) are provided, characterised in that the monitoring device includes a further contacting element, which can be connected with a contact point (P, P', P", P1, P2), at which the supporting and drive means (3, 3', 3a-3c) runs along, wherein the contact point (P, P', P", P1, P2) is a deflecting roller, a drive pulley or a wiper contact, so that the monitoring device can ascertain contact of the contact point (P, P', P", P1, P2) with the at least one electrically conductive cord (21, 21', 21", 21a-21d, 21a'-211') of the supporting and driving means (3, 3', 3a-3c).
2. Monitoring device (200, 200a, 200a', 200b, 200c) according to claim 1, characterised in that the contact point (P, P', P", P1, P2) is arranged at a spacing (s) of preferably 2 millimetres to 15 millimetres from the supporting and drive means so that contact of the at least one electrically conductive cord (21, 21', 21", 21a-21d, 21a'-211') is ascertained when electrical parts of the cord protrude from the surface of the cord in correspondence with the spacing and wipe the contact point (P, P', P", P1, P2).
3. Monitoring device (200, 200a, 200a', 200b, 200c) according to claim 1 or 2, characterised in that the further contacting element which can be connected with the contact point (P, P', P", P1, P2) includes a further resistance element (R3, R9', R25", RP', RP") by means of which the contact point (P, P', P", P1, P2) is connectible with the monitoring device.
4. Monitoring device (200a, 200a', 200b, 200c) according to any one of the preceding claims, characterised in that the monitoring device (200a, 200a', 200b, 200c) includes a processor by means of which a damage frequency pattern of the supporting and drive means (3', 3a-3c) of the lift installation (100, 100a', 100b, 100c) can be created.
5. Monitoring device (200a, 200a', 200b, 200c) according to claim 4, characterised in that a staggered warning report can be issued, or the lift installation (100, 100a', 100b, 100c) stopped, by the processor in dependence on the damage frequency pattern or the extent of damage.
6. Lift installation (100a', 100b, 100c) with a supporting and drive means (3', 3b, 3c), which includes at least two electrically conductive cords (21, 21', 21", 21a-21d, 21a'-211'), with a monitoring device (200a, 200a', 200b, 200c), which includes a measuring device (25', 25a, 25b) for determining a resultant resistance and which is connected with the supporting and driving means (3', 3b, 3c) preferably by way of a first contacting element (20e, 20g) for contacting a first end of the supporting and drive means (3', 3b, 3c) and a second contacting element (20f, 20h) for contacting a second end of the supporting and drive means (3', 3b, 3c), characterised in that the monitoring device includes a further contacting element connected with a contact point (P', P", P1, P2), at which the supporting and drive means (3', 3b, 3c) runs along, wherein the contact point (P', P", P1, P2) is a deflecting roller, a drive pulley or a wiper contact, and that the monitoring device ascertains contact of the contact point (P', P", P1, P2) with the at least one electrically conductive cord (21', 21", 21a-21d, 21a'-211') of the supporting and drive means (3', 3b, 3c).
7. Lift installation (100a', 100b, 100c) according to claim 6, characterised in that the contact point (P', P", P1, P2) is arranged at a spacing (s) of preferably 1 millimetre to 15 millimetres from the supporting and drive means so that a contact of the at least one electrically conductive cord (21', 21", 21a-21d, 21a'-211') is ascertained when electrical parts of the cord protrude from the surface of the cord in correspondence with the spacing.
8. Lift installation (100a', 100b, 100c) according to claim 6, characterised in that the contact point (P', P", P1, P2) is constructed as a brush contact, which is guided along a contoured surface of the supporting and drive means (3', 3b, 3c) in contact-making proximity so that a contact of the at least one electrically conductive cord (21', 21", 21a-21d, 21a'-211') is ascertained when electrical parts of the cord protrude.
9. Lift installation (100a', 100b, 100c) according to any one of claims 6 to 8, characterised in that the monitoring device (200a', 200b, 200c) can be combined with a reverse bending counter for the supporting and drive means (3', 3b, 3c).

Images