METHOD FOR MONITORING ELEVATOR SYSTEM SUSPENSION APPARATUS

Abstract

A method monitors at least one suspension apparatus in an elevator system, wherein the suspension apparatus includes at least one electrically conducting tension load carrying member that is surrounded by an electrically insulating jacket. The method includes the steps of: repeated determination of a value of an electrical characteristic of at least one tension load carrying member or of a group of tension load carrying members; establishment of a mean value on the basis of the determined values; and comparison of the mean value established with a reference value.

Claims

1-15. (canceled)

16. A method for monitoring at least one suspension apparatus in an elevator system, wherein the suspension apparatus includes at least one electrically conducting tension load carrying member that is surrounded by an electrically insulating jacket, the method comprising the steps of: determination of a value of an electrical characteristic of the at least one tension load carrying member a predetermined number of times; establishment of a mean value on the basis of the determined values; comparison of the established mean value with a reference value; and transmitting to an elevator controller of the elevator system a signal based upon the comparison and representing a state of the suspension apparatus.

17. The method in accordance with claim 16 wherein the electrical characteristic is an electrical resistance of the at least one tension load carrying member.

18. The method in accordance with claim 16 wherein the predetermined number of times is between two and at least ten.

19. The method in accordance with claim 16 wherein the predetermined number of times is carried out within a range of a minute to a week.

20. The method in accordance with claim 16 wherein the predetermined number of times is carried out during at least two different states of the elevator system.

21. The method in accordance with claim 20 wherein the two different states of the elevator system differ while the elevator system is in a driving state of an elevator car suspended by the suspension apparatus.

22. The method in accordance with claim 20 wherein the two different states of the elevator system differ in a loading of an elevator car suspended by the suspension apparatus.

23. The method in accordance with claim 20 wherein the two different states of the elevator system differ in a position of an elevator car suspended by the suspension apparatus in a shaft of the elevator system.

24. The method in accordance with claim 16 wherein the determination times are carried out at regular intervals.

25. The method in accordance with claim 16 wherein during the establishment of the mean value an arithmetic mean is established.

26. The method in accordance with claim 16 wherein during the establishment of the mean value a moving mean value is established.

27. The method in accordance with claim 16 wherein during the establishment of the mean value a weighted mean is established.

28. The method in accordance with claim 16 wherein the suspension apparatus includes at least three of the electrically conducting tension load carrying member in a common one of the electrically insulating jacket.

29. The method in accordance with claim 16 wherein the suspension apparatus has only one of the electrically conducting tension load carrying member in the electrically insulating jacket.

30. The method in accordance with claim 16 wherein the suspension apparatus has only two of the electrically conducting tension load carrying member in a common one of the electrically insulating jacket.

31. A method for monitoring at least one suspension apparatus in an elevator system, wherein the suspension apparatus includes a plurality of electrically conducting tension load carrying members surrounded by a common electrically insulating jacket, the method comprising the steps of: determination of a value of an electrical characteristic of the tension load carrying members a predetermined number of times; establishment of a mean value on the basis of the determined values; comparison of the established mean value with a reference value; and transmitting to an elevator controller of the elevator system a signal based upon the comparison and representing a state of the suspension apparatus.

Description

DESCRIPTION OF THE DRAWINGS

[0022] With the aid of figures the invention is described symbolically and in an exemplary manner in more detail. Here:

[0023] FIG. 1 shows an exemplary form of embodiment of an elevator system;

[0024] FIG. 2 shows an exemplary form of embodiment of a suspension means; and

[0025] FIG. 3a shows an exemplary form of embodiment of a suspension means; and

[0026] FIG. 3b shows an exemplary form of embodiment of a suspension means.

DETAILED DESCRIPTION

[0027] The elevator system 40 represented in a schematic and exemplary manner in FIG. 1 features an elevator car 41, a counterweight 42 and a suspension means or suspension apparatus 1, together with a drive pulley 43 with an associated drive motor 44. The drive pulley 43 drives the suspension means 1 and thus moves the elevator car 41 and the counterweight 42 in opposition. The drive motor 44 is controlled by an elevator controller 45. The car 41 is configured to accommodate people or goods, and to transport these between floors of a building. Car 41 and counterweight 42 are guided along guides (not represented). In the example the car 41 and the counterweight 42 are each suspended on load-bearing rollers 46. Here the suspension means 1 is secured to a first suspension means attachment device 47, and is then firstly guided around the load-bearing roller 46 of the counterweight 42. The suspension means 1 is then laid over the drive pulley 43, around the load-bearing roller 46 of the car 41, and is finally connected by means of a second suspension means attachment device 47 to a fixed point. This means that the suspension means 1 runs with a higher speed in accordance with a transfer factor over the drive 43, 44, than the car 41 or counterweight 42 move. In the example the transfer factor is 2:1.

[0028] A free end 1.1 of the suspension means or suspension apparatus 1 is provided with a contact device 2 for purposes of making temporary or permanent electrical contact with the tension load carrying members, and thus for purposes of monitoring the suspension means 1. In the example represented such a contact device 2 is arranged at both ends 1.1 of the suspension means 1. In an alternative form of embodiment, not represented, only one contact device 2 is arranged at one of the ends 1.1 of the suspension means, and the tension load carrying members are connected with one another at the other end 1.1 of the suspension means. The suspension means ends 1.1 are no longer loaded by the tensile force in the suspension means 1, since the said tensile force is already previously directed via the suspension means attachment devices 47 into the building. The contact devices 2 are therefore arranged in a region of the suspension means 1 that is not rolled over, and outside the loaded region of the suspension means 1.

[0029] In the example the contact device 2 is connected at one end 1.1 of the suspension means or suspension apparatus with a monitoring device 3. The monitoring device 3 thereby interconnects the tension load carrying members of the suspension means 1 as electrical resistances in an electrical connection for purposes of determining electrical resistances. The monitoring device 3 is also connected with the elevator controller 45. This connection can, for example, be designed as a parallel relay or as a BUS system. By this means a signal or a measured value from the monitoring device 3, can be transmitted to the elevator controller 45, in order to take account of the state of the suspension means 1, as determined by the monitoring device 3, in controlling the elevator 40.

[0030] By means of the monitoring device 3 an electrical characteristic of at least one tension load carrying member is repeatedly determined. A mean value is then established on the basis of the values determined, and the said established mean value is compared with a reference value. If a difference between the established mean value and the reference value is greater than a predefined threshold value, a signal can, for example, be sent to the elevator controller 45, which has as a consequence, for example, the discontinuation of a warning signal, or an immobilization of the elevator system.

[0031] The elevator system 40 shown in FIG. 1 is an example. Other transfer factors and arrangements, such as, for example, elevator systems without a counterweight, are possible. The contact device 2 for purposes of making contact with the suspension means or suspension apparatus 1 is then arranged in accordance with the positioning of the suspension means attachment devices 47.

[0032] FIG. 2 represents a section of an exemplary form of embodiment of a suspension means or suspension apparatus 1. The suspension means 1 comprises a plurality of electrically conducting tension load carrying members 5 arranged parallel to one another, which are encased in a jacket 6. For purposes of making electrical contact with the tension load carrying members 5 the jacket 6 can, for example, be pierced or removed, or electrical contact can also be made with the tension load carrying members 5 on their end faces with a contact device 2. Furthermore, contact elements can also be fitted to the tension load carrying members 5, which then can be connected in a simple manner with the contact device.

[0033] In this example the suspension means or suspension apparatus is fitted with longitudinal ribs on a traction face. Such longitudinal ribs improve the traction characteristics of the suspension means 1 on the drive pulley 43, and at the same time ease the lateral guidance of the suspension means 1 on the drive pulley 43. The suspension means 1 can, however, be configured in another manner, for example, without longitudinal ribs, or with another number, or another arrangement, of the tension load carrying members 5. It is essential for the invention that the tension load carrying members 5 are configured so as to be electrically conducting.

[0034] FIG. 3a represents a cross-section of a further exemplary form of embodiment of a suspension means or suspension apparatus 1. The suspension means 1 comprises an electrically conducting tension load carrying member 5, which is encased in a jacket 6. For purposes of making electrical contact with the tension load carrying member 5 the jacket 6 can, for example, be pierced or removed, or electrical contact can also be made with the tension load carrying members 5 on their end faces with a contact device 2.

[0035] FIG. 3b represents a cross-section of a further exemplary form of embodiment of a suspension means or suspension apparatus 1. The suspension means 1 comprises two electrically conducting tension load carrying members 5, which are encased in a jacket 6. Here one tension load carrying member 5 is advantageously embodied in an S-twist, and the other tension load carrying member 5 in a Z-twist. By this means it is achieved that the torques that occur under load compensate one another, so that under load the suspension means is not pulled out of the groove of the drive pulley. For purposes of making electrical contact with the tension load-carrying members 5 the jacket 6 can, for example, be pierced or removed, or electrical contact can also be made with the tension load-carrying members 5 on their end faces with a contact device 2.

[0036] In accordance with the provisions of the patent statutes, the present invention has been described in what is considered to represent its preferred embodiment. However, it should be noted that the invention can be practiced otherwise than as specifically illustrated and described without departing from its spirit or scope.