Determination of the state of a suspension means

Patent metadata

Field	Value
Publication number	US-12434944-B2
Application number	US-202017593040-A
Country	US
Kind code	B2
Filing date	Mar 16, 2020
Priority date	Mar 29, 2019
Publication date	Oct 7, 2025
Grant date	Oct 7, 2025

Abstract

A method and an apparatus monitor the physical state of a suspension means that is connected to an elevator car and can move the same. The support means has markings along its length that divide the support means into segments. The strain difference of the suspension means is monitored segment by segment using a first strain at a first load and a second strain at a second load being determined by a signal processing unit from a distance between two selected markings detected by a detection device, and a strain difference representing the elastic behavior of the segment is calculated from the two strains, wherein the load acting on the suspension means between the two selected markings is measured by a load measuring device.

First claim

The invention claimed is:

1. A method for monitoring a physical state of a suspension means for moving an elevator car, the suspension means being connected to and suspending the elevator car, the suspension means being divided into segments by markings along a length of the suspension means, the method comprising the steps of:
detecting the markings with a detection device;
monitoring a strain difference of the suspension means segment by segment by determining using a signal processing unit a first strain at a first load acting on the suspension means and a second strain at a second load acting on the suspension means from a distance between two selected ones of the detected markings, wherein the first load and the second load acting on the suspension means between the two selected markings are measured by a load measuring device;
calculating the strain difference representing an elastic behavior of a one of the segments that is between the two selected markings from the first strain and the second strain;
performing the monitoring and the calculating for additional ones of the segments; and
generating an alarm signal when any one of the calculated strain differences indicates that the suspension means is at a point of discard.

2. The method according to claim 1 including determining when the suspension means is at the point of discard by at least one of:
comparing each of the calculated strain differences with a predetermined strain difference limit value;
calculating a cross-sectional loss in each of the segments from the calculated strain difference of the segment and comparing the cross-sectional losses with a predetermined limit value for a maximum permissible cross-sectional loss; and
calculating a breaking load loss from each of the calculated strain differences and comparing the breaking load losses with a predetermined limit value for a maximum permissible breaking load loss.

3. The method according to claim 2 including calculating the strain difference for a plurality of the segments, comparing the calculated strain differences with one another, creating a hierarchy of the segments with regard to the calculated strain differences, selecting ones of the segments according to the hierarchy such that the strain differences of ones of the segments having an increased calculated strain difference are calculated more frequently than the strain differences of ones of the segments having an unchanged calculated strain difference.

4. The method according to claim 1 including providing a detectability criterion with regard to a detectability of the markings by the detection device as being not readable or difficult to read, and when a one of the markings does not meet the detectability criterion selecting a next one of the markings along the length of the suspension means that meets the detectability criterion.

5. The method according to claim 1 wherein when the suspension means is first put into operation, measuring and storing a strain difference in a new state of each of the segments, and during subsequent operation of the suspension means periodically comparing the calculated strain difference of individual ones of the segments with a respective one of the strain differences in the new state.

6. An apparatus for performing the method according to claim 1 , the apparatus comprising:
the suspension means divided into the segments by the markings;
the load measuring device for measuring the first load and the second loads acting on the suspension means;
the signal processing unit for monitoring the strain differences by determining the first strain and the second strain and calculating the strain differences; and
the detection device for detecting the markings.

7. The apparatus according to claim 6 wherein the signal processing unit selects one of the segments and the two makings corresponding to the selected segment according to a predetermined criteria, and the signal processing unit transmits the selection of the one segment to the detection device to detect the corresponding two markings.

8. The apparatus according to claim 6 wherein each of the markings has a unique identification that is distinguishable by the detection device from the identifications of all others of the markings.

9. The apparatus according to claim 6 wherein each of the segments is delimited by a corresponding two of the markings arranged successively along the length of the suspension means.

10. The apparatus according to claim 6 wherein at least one of the segments is delimited by two of the markings and wherein at least another of the markings is arranged between the two markings.

11. An elevator system comprising:
the apparatus according to claim 6 ; and
an elevator car connected to and suspended by the suspension means.

12. The elevator system according to claim 11 including an updated digital twin data record containing physical components of the elevator installation in digital form as component model data records having characterizing properties, and wherein the signal processing unit exchanges data with the updated digital twin data record.

13. The elevator system according to claim 12 wherein the data being exchanged includes data transmitted by the signal processing unit to the updated digital twin data record being the calculated strain differences of the segments which, as the characterizing properties, are transferred to assigned virtual segments of a suspension means of the updated digital twin data record depicted as a digital component model data record and replace corresponding previous characterizing properties of the segments.

14. The elevator system according to claim 13 wherein the updated digital twin data record is adapted to carry out static and dynamic simulations for determining the point of discard or remaining service life of the suspension means, and the simulation results are transmitted to at least one of a control unit of the elevator system and an output unit of the elevator system.

15. A method for monitoring a physical state of a suspension means for moving an elevator car in an elevator system, the suspension means being connected to and suspending the elevator car, the suspension means being divided into segments by markings along a length of the suspension means, the method comprising the steps of:
selecting one of segments;
determining by a signal processing unit a first strain at a first load acting on the suspension means and a second strain at a second load acting on the suspension means from a distance between two of the markings detected by the detection device that delimit the selected one segment, wherein the first load and the second load acting on the suspension means between the two markings are measured by a load measuring device;
calculating a strain difference representing an elastic behavior of the selected one segment between the two markings from the first strain and the second strain;
generating an alarm signal when the calculated strain difference indicates that the suspension means is at a point of discard and transmitting the alarm signal to at least one of a control unit of the elevator system and an output unit of the elevator system; and
performing the method steps for at least another of the segments of the suspension means.

Assignees

• Inventio Ag

Inventors

• Dold Florian
• Zapf Volker

Classifications

• B66B7/1238

  by optical techniques · CPC title

• B66B3/002

  Indicators · CPC title

• B66B7/1215 Primary

  specially adapted for ropes or cables · CPC title