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EP-4566978-B1 - SYSTEM AND METHOD FOR DETERMINING SUSPENSION MEMBER ELONGATION

EP4566978B1EP 4566978 B1EP4566978 B1EP 4566978B1EP-4566978-B1

Inventors

  • GUILANI, BARDIA
  • Alkan, Ergün
  • DIETHERT, ANDREAS J.

Dates

Publication Date
20260513
Application Date
20241206

Claims (12)

  1. An elevator system (20), comprising: at least one suspension member (26) that supports an elevator car (22) and facilitates movement of the elevator car (22) in a hoistway (34); a counterweight (28) coupled to the elevator car (22) with the at least one suspension member (26); and a first sensor (42) that detects a presence of one of the counterweight (28) and the elevator car (22); characterized in that the elevator system (20) further comprises a second sensor (44) that determines a position of the other of the counterweight (28) and the elevator car (22) within the hoistway (34) in response to a detection signal generated by the first sensor; and a control system that determines elongation of the at least one suspension member (26) based on a change in the position of the elevator car (22) or the counterweight (28) in the hoistway (34) over time as determined in response to the detection signal.
  2. The elevator system (20) of claim 1, wherein the first sensor (42) comprises a counterweight sensor that is positioned at a fixed location (48) in the hoistway (34) and detects a presence of the counterweight (28).
  3. The elevator system (20) of claim 2, wherein the second sensor (44) comprises a car sensor for an absolute position reference system (APRS) that determines a position of the elevator car (22).
  4. The elevator system (20) of claim 3, wherein the absolute position reference system (APRS) includes a code tape (52) extending along a wall (54) of the hoistway located next to the elevator car (22) and the car sensor comprises an absolute position sensor that moves with the elevator car (22) and interacts with the code tape (52) to determine a precise position of the elevator car (22) within the hoistway (34).
  5. The elevator system (20) of claim 4, wherein the absolute position reference system (APRS) records a precise position of the elevator car (22) within the hoistway (34) in response to each detection of the counterweight (28), preferably wherein the control system compares the precise position of the elevator car (22) in response to the detection signal generated by the counterweight sensor when the elevator car (22) is in an initial installation state to the precise position of the elevator car (22) in response to the detection signal generated by the counterweight sensor when the elevator car (22) is in a subsequent operational state to determine elongation.
  6. The elevator system (20) of claim 1, wherein the first sensor (42) comprises a car sensor that is positioned at a fixed location in the hoistway (34) and detects a presence of the elevator car (22).
  7. The elevator system of claim 6, wherein the second sensor (44) comprises a counterweight sensor to determine a position of the counterweight (28), preferably wherein the counterweight sensor comprises a reference tape (410) associated with one of the counterweight (28) and a hoistway wall and a camera associated with the other of the counterweight (28) and the hoistway wall, preferably wherein the fixed location comprises a lowest door zone, and wherein once the elevator car is stopped at the lowest door zone, the detection signal is generated to activate the camera.
  8. A method wherein an elevator car (22) is supported for movement within a hoistway (34) by at least one suspension member (26) and a counterweight (28) is coupled to the elevator car (22) with the at least one suspension member (26), the method comprising: detecting a presence of one of the counterweight (28) and the elevator car (22) with a first sensor (42); determining a position of the other of the elevator car (22) and counterweight (28) within the hoistway with a second sensor (44) in response to a detection signal generated by the first sensor (42); and determining elongation of the at least one suspension member (26) based on a change in the position of the elevator car (22) or counterweight (28) in the hoistway (34) over time as determined in response to the detection signal.
  9. The method of claim 8, including having the counterweight (28) and the elevator car (22) be in motion during generation of the detection signal.
  10. The method of claim 8, including having the counterweight (28) and the elevator stationary during generation of the detection signal.
  11. The method of claim 8, wherein the first sensor (42) comprises a counterweight sensor and the second sensor (44) comprises a car sensor for an absolute position reference system (ARPS) that determines a position of the elevator car (22), and including: positioning the first sensor (42) at a fixed location (48) in the hoistway (34) to detect the presence of the counterweight (28); extending a code tape (52) of the absolute position reference system (APRS) along a wall (54) of the hoistway located next to the elevator car (22) ; and mounting the car sensor to move with the elevator car (22) and interact with the code tape (52) to determine a precise position of the elevator car (22) within the hoistway (34).
  12. The method of claim 8, wherein the wherein the first sensor (42) comprises a car sensor and the second sensor (44) comprises a counterweight sensor to determine a position of the counterweight (28), and including: positioning the first sensor (42) at a fixed location in the hoistway (34) to detect the presence of the elevator car (22); providing the counterweight sensor as a reference tape (410) associated with one of the counterweight (28) and hoistway wall and a camera associated with the other of the counterweight (28) and hoistway wall; and once the elevator is stopped at the fixed location, generating the detection signal to activate the camera to read the reference tape.

Description

BACKGROUND Elevator systems are in widespread use for carrying passengers between various levels in buildings, for example. Some elevator systems are traction-based in which a suspension assembly, sometimes referred to as roping, suspends the elevator car and a counterweight. The suspension assembly also facilitates movement of the elevator car when needed. Traditional suspension assemblies include round steel ropes. Some elevator systems have included other types of suspension members, such as flat belts or other types of ropes that have tension members encased in a compressible polymer jacket. Elongation of suspension members, especially coated suspension members, is an indication of life/retained breaking strength. As elongation occurs on a very small scale, it can be challenging to measure repeatedly and accurately. JP H05262474 A relates to an elevator having position detectors on both the car and counterweight, which are connected by ropes via sheaves attached to the rotating shaft of a traction machine, a rotary encoder as a speed detection device, and an indication means for calculating the elongation of the rope. JP 2010 260682 A provides an elevator system comprising car position detecting means for detecting the position of a car, weight position detecting means for detecting the position of a counterweight, and calculation means for calculating the elongation of a main rope based on position information of the car and the counterweight, wherein the car position detecting means comprises a car position detector provided in the car, and a car shielding plate attached in advance to the hoistway wall side so as to face the car position detector at a balanced position between the car and the counterweight at a reference time. SUMMARY The invention is set out in appended set of claims. According to a first aspect of the present invention, an elevator system includes: at least one suspension member that supports an elevator car and facilitates movement of the elevator car in a hoistway; a counterweight coupled to the elevator car with the at least one suspension member; a first sensor that detects a presence of one of the counterweight and the elevator car; a second sensor that determines a position of the other of the counterweight and the elevator car within the hoistway in response to a detection signal generated by the first sensor; and a control system that determines elongation of the at least one suspension member based on a change in the position of the elevator car or the counterweight in the hoistway over time as determined in response to the detection signal. In an embodiment, the first sensor comprises a counterweight sensor that is positioned at a fixed location in the hoistway and detects a presence of the counterweight. In an embodiment, the second sensor comprises a car sensor for an absolute position reference system that determines a position of the elevator car. In an embodiment, the absolute position reference system includes a code tape extending along a wall of the hoistway located next to the elevator car and the car sensor comprises an absolute position sensor that moves with the elevator car and interacts with the code tape to determine a precise position of the elevator car within the hoistway. In an embodiment, the absolute position reference system records a precise position of the elevator car within the hoistway in response to each detection of the counterweight. In an embodiment, the control system compares the precise position of the elevator car in response to the detection signal generated by the counterweight sensor when the elevator car is in an initial installation state to the precise position of the elevator car in response to the detection signal generated by the counterweight sensor when the elevator car is in a subsequent operational state to determine elongation. In an embodiment, the first sensor comprises a car sensor that is positioned at a fixed location in the hoistway and detects a presence of the elevator car. In an embodiment, the second sensor comprises a counterweight sensor to determine a position of the counterweight. In an embodiment, the counterweight sensor comprises a reference tape associated with one of the counterweight and a hoistway wall and a camera associated with the other of the counterweight and the hoistway wall. In an embodiment, the fixed location comprises a lowest door zone, and wherein once the elevator car is stopped at the lowest door zone, the detection signal is generated to activate the camera. An illustrative example elevator system, which is not claimed in the present application, includes: at least one suspension member that supports an elevator car and facilitates movement of the elevator car in a hoistway; a counterweight coupled to the elevator car with the at least one suspension member; a first sensor assembly that detects a presence of one of the counterweight and the elevator car, wherein the first sensor assembly