Method and device for determining a deterioration state in a suspension member for an elevator

Patent metadata

Field	Value
Publication number	US-11014784-B2
Application number	US-201615748277-A
Country	US
Kind code	B2
Filing date	Jul 28, 2016
Priority date	Jul 31, 2015
Publication date	May 25, 2021
Grant date	May 25, 2021

Abstract

A method for determining a deterioration state in a suspension member arrangement having a suspension member including a plurality of electrically conductive cords includes the steps of: counting a number of bending cycles applied to the suspension member; measuring an electrical characteristic of the suspension member upon applying an electrical voltage to at least one of the cords; performing at least one of (a) determining a critical deterioration state upon monitoring both the bending cycles number and the electrical characteristic, and (b) determining an unexpected deterioration state based on deriving a current actual deterioration state of the suspension member based on the electrical characteristic and assuming a currently expected deterioration state based on the bending cycles number and comparing the current actual deterioration state with the currently expected deterioration state; initiating a defined procedure upon determining at least one of the critical deterioration state and the unexpected deterioration state.

First claim

The invention claimed is:

1. A method for determining a deterioration state in a suspension member arrangement for an elevator, the suspension member arrangement having a suspension member including a plurality of electrically conductive cords, the method comprising the steps of:
counting a number of bending cycles applied to the suspension member;
determining an electrical characteristic of the suspension member;
performing at least one of
(a) determining a critical deterioration state upon monitoring both the counted number of bending cycles applied to the suspension member and the determined electrical characteristic of the suspension member; and
(b) determining an unexpected deterioration state based on deriving a current actual deterioration state of the suspension member based on the determined electrical characteristic and assuming a currently expected deterioration state based on the counted number of bending cycles and comparing the current actual deterioration state with the currently expected deterioration state;

initiating a defined procedure for the elevator upon the determining at least one of the critical deterioration state and the unexpected deterioration state; and
wherein the suspension member is subdivided into several sections and wherein a number of section bending cycles applied to each section of the suspension member is counted for each of the sections and wherein the number of bending cycles applied to the suspension member is set to correspond to a maximum of all the numbers of section bending cycles counted for each of the sections of the suspension member.

2. The method according to claim 1 wherein the critical deterioration state is determined upon occurrence of at least one of:
the counted number of bending cycles applied to the suspension member exceeding an allowable maximum number; and
the determined electrical characteristic of the suspension member deviating from a reference characteristic by more than an allowable maximum deviation.

3. The method according to claim 2 wherein the allowable maximum deviation is at least one of determined taking into account the counted number of bending cycles applied to the suspension member and fixedly predetermined.

4. The method according to claim 2 wherein the allowable maximum number is at least one of determined taking into account the determined electrical characteristic of the suspension member and fixedly predetermined.

5. The method according to claim 2 wherein the reference characteristic is determined based upon measuring the electrical characteristic of the suspension member in a non-deteriorated condition.

6. The method according to claim 1 wherein the determining of the electrical characteristic of the suspension member comprises at least one of:
determining an electrical resistivity through the suspension member;
determining an electrical conductivity through the suspension member;
determining an inductivity through the suspension member;
determining the electrical characteristic using magnetic measurements applied to the suspension member; and
determining the electrical characteristic using phase measurements applied to the suspension member.

7. A method for determining a deterioration state in a suspension member arrangement for an elevator, the suspension member arrangement having a suspension member including a plurality of electrically conductive cords, the method comprising the steps of:
counting a number of bending cycles applied to the suspension member;
determining an electrical characteristic of the suspension member;
performing at least one of
(a) determining a critical deterioration state upon monitoring both the counted number of bending cycles applied to the suspension member and the determined electrical characteristic of the suspension member; and
(b) determining an unexpected deterioration state based on deriving a current actual deterioration state of the suspension member based on the determined electrical characteristic and assuming a currently expected deterioration state based on the counted number of bending cycles and comparing the current actual deterioration state with the currently expected deterioration state;

initiating a defined procedure for the elevator upon the determining at least one of the critical deterioration state and the unexpected deterioration state; and
wherein the determining of the electrical characteristic of the suspension member comprises at least one of:
electrical measurements indicating that at least one of the cords in the suspension member is broken;
electrical measurements indicating that an electrical connection between a voltage supply for applying the electrical voltage to the at least one cord and the at least one of the cord is interrupted;
electrical measurements indicating that the at least one cord is electrically connected to ground potential;
electrical measurements indicating that at least two of the cords in the suspension member are shorted together; and
electrical measurements indicating that an electrical conductivity through the at least one cord changed over time.

8. A method for determining a deterioration state in a suspension member arrangement for an elevator, the suspension member arrangement having a suspension member including a plurality of electrically conductive cords, the method comprising the steps of:
counting a number of bending cycles applied to the suspension member;
determining an electrical characteristic of the suspension member;
performing at least one of
(a) determining a critical deterioration state upon monitoring both the counted number of bending cycles applied to the suspension member and the determined electrical characteristic of the suspension member; and
(b) determining an unexpected deterioration state based on deriving a current actual deterioration state of the suspension member based on the determined electrical characteristic and assuming a currently expected deterioration state based on the counted number of bending cycles and comparing the current actual deterioration state with the currently expected deterioration state; and

initiating a defined procedure for the elevator upon the determining at least one of the critical deterioration state and the unexpected deterioration state; and
wherein, upon determining the electrical characteristic, an electric indicator current correlating to a net sum of all phases of a multi-phase alternating current is measured, wherein at least one of the phases of the multi-phase alternating current is applied to one of the cords of the suspension member.

9. The method according to claim 8 wherein the indicator current is measured using a measuring arrangement comprising a measuring device for contactless measuring of an electrical current in a conductor arrangement, the measuring device being one of a current transformer and a Hall effect current sensor.

10. A method for determining a deterioration state in a suspension member arrangement for an elevator, the suspension member arrangement having a suspension member including a plurality of electrically conductive cords, the method comprising the steps of:
counting a number of bending cycles applied to the suspension member;
determining an electrical characteristic of the suspension member;
performing at least one of
(a) determining a critical deterioration state upon monitoring both the counted number of bending cycles applied to the suspension member and the determined electrical characteristic of the suspension member; and
(b) determining an unexpected deterioration state based on deriving a current actual deterioration state of the suspension member based on the determined electrical chara

Assignees

• Inventio Ag

Inventors

• Henneau Philippe

Classifications

• B66B7/062

  Belts · CPC title

• B66B7/1215

  specially adapted for ropes or cables · CPC title

• G01R31/08

  Locating faults in cables, transmission lines, or networks · CPC title

• B66B7/1223 Primary

  by analysing electric variables · CPC title

• D10B2401/16

  antistatic; conductive · CPC title