A method for condition monitoring of ropes of an elevator and elevator

Abstract

The invention relates to a method for condition monitoring of ropes (2) of an elevator (1), which elevator (1) comprises an elevator car (3), and one or more cambered rope wheels (4,6) around which a row of ropes5 (2) pass, the method comprising monitoring (200) by an elevator control system (10), during driving (100) of the elevator (1), the position of each rope (2) in width direction (w) of the row within the monitoring area (A1) using a contactless monitoring equipment (50,60); and detecting (300) if position of a rope portion (P) in width direction (w) of the row fulfills10 one or more criteria indicating abnormal displacement of the rope portion (P). The method moreover comprises stopping (500A) driving (400) of the elevator when the rope portion (P) is at least partially within an inspection area (A2) or driving (500B) the elevator with crawling speed when the rope portion (P) is at least partially within and inspection area15 (A2); and inspecting (600) condition of the rope portion (P) when it is stopped at least partially within said inspection area (A2) or moves with crawling speed within the inspection area (A2). The invention also relates to an elevator (1) implementing the method.

Description

[0001] A METHOD FOR CONDITION MONITORING OF ROPES OF AN ELEVATOR AND ELEVATOR

[0002] Field of the invention

[0003] The invention relates to monitoring condition of elevator ropes, wherein the elevator is in particular an elevator for transporting passengers and / or goods.

[0004] Background of the invention

[0005] Conventional elevators have plurality of hoisting ropes connected to the elevator car. The hoisting ropes typically pass as a row around a traction wheel and possibly also around guide wheels, which do not drive the ropes but only divert the route of the ropes. The traction wheel and the guide wheels are typically provided with a shape for keeping the ropes in a certain position in axial direction of the wheel in question. In an elevator having traditional steel ropes, the ropes pass inside grooves of the rotatable traction wheel. There are also elevators where the ropes are guided by a cambered shape of the rim of the wheel. This suits well for belt-shaped ropes. Cambered shape is a gentle and simple way to guide the ropes and may be desired for instance when the ropes have sensitive surface structure and / or sensitive internal structure.

[0006] In solutions utilizing cambered rope wheels (also later referred to as rope having crowning shape) for guidance, the intended placement of the rope is in the middle of the cambered area, but normally the rope is allowed to move sideways a little bit. It may happen that the rope gets too far displaced from the peak of the crowning shape. Running of a rope far outside its intended course is potential to cause different dangerous problems such as damaging the rope itself or other components of the elevator. Thus, there is a need to prevent the rope from running outside its intended course, or in some other way prevent the situation from developing this far.

[0007] Safety solutions have been suggested for stopping the elevator operation if a rope is displaced from its intended position over a limit position. Such a solution has been suggested in document EP2947034A1, for instance. In this document, a solution is disclosed with mechanical sensing members sensing displacement of ropes over limit positions. Also, a contactless monitoring solution is disclosed. This is implemented using sensors sensing electromagnetic radiation reflected from ropes displaced over limit positions. In response to displacement of ropes beyond a limit position, stopping of elevator drive machinery is triggered.

[0008] There are various reasons that may cause displacement of a rope guided by a cambered wheel. Some displacement is normal. For instance, changes of elevator drive direction cause typically minor displacement, which doesn't require reacting.

[0009] It has been concluded that also damage, wear or degradation of internal structures or surface structures of the rope can cause displacement, which may need to be reacted to before the issue develops worse.

[0010] With a composite rope, an internal damage of a load bearing member of the rope, such as delamination of a composite structure of a load bearing member of the rope, can for example cause a local change in stress distribution within the rope which can change of the balance position where the delaminated portion of the rope gets positioned on a crowning shape. It has been concluded that as a precaution for this kind of issues, it would be advantageous to give early attention to the individual rope, which has started to run aside of its intended course even though the position has not reached a dangerous limit. The attention could involve inspecting, maintenance or even replacing the individual rope.

[0011] One drawback of known solutions has been that after noticing abnormal displacement, the subsequent steps have not been optimally efficient. The subsequent steps have taken some time, and the accuracy, simplicity and ease of taking them, have not been optimized.

[0012] Brief description of the invention

[0013] The object of the invention is to introduce an improved method for condition monitoring of ropes of an elevator, and an elevator.

[0014] An object is to introduce a new solution by which one or more of the above-mentioned problems of prior art and / or drawbacks discussed or implied elsewhere in the description can be alleviated.

[0015] An object is, inter alia, to provide a solution whereby issues of rope structure can be brought into attention early and reacted to reliably, swiftly and with short down time of the elevator. The attention can be performed as a quick, reliable and well focused inspection of the correct portion of the rope.

[0016] An object is, in particular, to provide a solution facilitating condition monitoring of ropes of an elevator utilizing rope guidance by one or more cambered rope wheels.

[0017] An object is, in particular, to provide a solution suitable for ropes having composite load bearing members.

[0018] It is brought forward a new method for condition monitoring of ropes of an elevator, which elevator comprises an elevator car, and one or more cambered rope wheels around which the ropes pass, and wherein the ropes are connected to the elevator car, the method comprising driving (100) the elevator, in particular by rotating a drive wheel around which the ropes pass, such that the ropes move as a row via a monitoring area (Al) wherein the row is formed by plurality of ropes positioned side by side as viewed in thickness direction t, the row having a thickness direction and width direction w; monitoring (200) by an elevator control system, during said driving (100), the position of each rope in width direction of the row within the monitoring area (Al) using a contactless monitoring equipment;

[0019] detecting (300) if position of a rope portion (P) in width direction of the row fulfills one or more criteria indicating abnormal displacement of the rope portion (P); and

[0020] the method moreover comprises after said detecting (300), in particular if position of the rope portion (P) of any of the ropes in width direction of the row fulfills said one or more criteria,

[0021] driving (400) the elevator such that the rope portion (P) is moved towards an inspection area (A2); and

[0022] stopping (0A) the driving (400) of the elevator when the rope portion (P) is at least partially within the inspection area (A2);

[0023] or

[0024] driving (0B) the elevator with crawling speed when the rope portion (P) is at least partially within the inspection area (A2); and inspecting (0) condition of the rope portion (P) when it is stopped at least partially within said inspection area (A2) or moves with crawling speed within the inspection area (A2).

[0025] With this kind of solution one or more of the above-mentioned objects can be facilitated.

[0026] Preferable further details of the method are introduced in the following, which further details can be combined with the method individually or in any combination.

[0027] In a preferred embodiment, the ropes are belts and the one or more wheels around which the ropes pass comprise a drive wheel rotatable by a motor and / or a non-driven rope wheel, the ropes passing around the drive wheel and / or the non-driven rope wheel such that the wide side of each rope rests against a crowning shape of the drive wheel and / or nondriven rope wheel. In a preferred embodiment, the inspection area (Al) is apart from said monitoring area (A2).

[0028] In a preferred embodiment, the monitoring area Al and the inspection area A2 are a distance apart as measured along the path of the ropes, said distance preferably being more than 1 meter and / or the monitoring equipment is apart from the inspecting device.

[0029] In a preferred embodiment, the ropes pass via a machine room, and said inspection area (Al) and said monitoring area (A2) are inside the machine room.

[0030] In a preferred embodiment, the ropes are hoisting ropes suspending the car and a counterweight on opposite sides of a rope wheel arrangement comprising said one or more rope wheels.

[0031] In a preferred embodiment, the ropes are moved in said driving (100) towards the monitoring area (Al), in particular such that they move from the one or more cambered wheels towards the monitoring area (Al) i.e. such that they arrive in the monitoring area Al after passing around the one or more cambered wheels. This is however not necessary because the displacement can be seen also in the opposite driving direction, or the monitoring area can be at the point of a cambered wheel.

[0032] In a preferred embodiment, the method comprises

[0033] determining (301) a first car position value representing a first car position, wherein the car is or was when the aforementioned rope portion is or was in the monitoring area, and

[0034] determining (302) on the basis of said first car position value, a second car position value representing a second car position, wherein the car is when the rope portion is at least partially within the inspection area.

[0035] In a preferred embodiment, the aforementioned determining (302) can comprise calculating the second car position value on the basis of said first car position value or obtaining the second car position value from a table presenting second car position values as a function of first car position values.

[0036] In a preferred embodiment, the method comprises registering (304) in a memory of the control system the first car position value after said determining (301) and the second car position value after said determining (301).

[0037] In a preferred embodiment, said one or more criteria include that position of the rope portion (P) in width direction of the row of ropes reaches or has reached a threshold position in width direction of the row.

[0038] In a preferred embodiment, there is a separate pair of threshold positions per each rope, in particular the rope being between the pair of threshold positions.

[0039] In a preferred embodiment, the method comprises identifying (303) the rope comprising the portion (P) detected to fulfill said one or more criteria, and registering identification information associated with the identified rope in a memory of the control system.

[0040] In a preferred embodiment, in said stopping (0A) the elevator car is stopped in the second car position and / or in said driving (OB), the elevator is driven with crawling speed over said second car position. In a preferred embodiment, said monitoring (200) is performed in contactless manner.

[0041] In a preferred embodiment, the contactless monitoring equipment is in particular suitable for monitoring position of each rope in width direction of the row within a monitoring area (Al) in contactless manner. Preferably, the contactless monitoring equipment comprises an imaging device such as a camera or video recorder configured to capture images or video of the row of ropes and / or the individual ropes thereof extending via the monitoring area (Al), and the control system is configured to analyze the images or video captured with the imaging device ; or the contactless monitoring equipment is a light curtain system and the control system is configured to analyze signals of the light curtain system. In a preferred embodiment, the method comprises capturing with an imaging device such as a camera or video recorder images or video of the row of ropes and / or the individual ropes thereof, in particular when positioned within the monitoring area (Al); and analyzing by the control system the images or video captured with the imaging device, said analyzing comprising the detecting (300).

[0042] In a preferred embodiment, the light curtain system comprises

[0043] a light emitter arrangement comprising light emitters arranged to produce, in particular to emit, a plurality of spaced apart light beam portions oriented to pass in thickness direction (t) of the row of ropes, such that there is a separate pair of said light beam portions per each individual rope of the row, each rope being positioned in width direction of the row between one of said pairs of light beam portions ; and

[0044] a light sensor arrangement comprising plurality of light sensors for sensing light of light emitter arrangement ; and

[0045] said plurality of light sensors comprises per each said light beam portion a light sensor for sensing light of the light beam portion for sensing light of the light beam portion to which light sensor the light beam portion is directed to pass, wherein each said rope, when moved in width direction of the row away from its position between the pair of light beam portions such that it crosses the path of a light beam portion, is arranged to block passing of light of said light beam portion to a light sensor ; and

[0046] the control system is configured to monitor sensor signals of said plurality of light sensors. In a preferred embodiment, the monitoring (200) comprises collecting, and preferably moreover storing in a memory of an elevator control system, rope position data of individual ropes of the row in function of car position or possibly in function of some other parameter directly proportional with car position, in particular in function of a car position value or a value of a parameter directly proportional with car position value, respectively. Said rope position data of individual ropes preferably presents rope position of individual ropes numerically or as a curve in function of car position or said other parameter. The car position is preferably being presented numerically, i.e. as numerical values.

[0047] In a preferred embodiment, the method comprises using, in particular by the elevator control system (e.g. by one or more computers thereof), an algorithm for the detecting (300), which algorithm is configured to process the position data collected. In a preferred embodiment, the inspecting (600) is performed with an inspecting device, preferably an ultrasound scanner.

[0048] In a preferred embodiment, the inspecting (600) comprises ultrasound scanning internal structures of the portion (P) of rope.

[0049] In a preferred embodiment, said ultrasound scanning comprises emitting ultrasound from a lateral side of the portion (P) of rope into a load bearing member or members of the rope and receiving echoes of the ultrasound emitted into said load bearing member(s)

[0050] In a preferred embodiment, said ultrasound scanning comprises creating one or more cross sectional views of the load bearing member or members of the rope based on echoes received from the load bearing member(s) thereof.

[0051] In a preferred embodiment, the method is computer-implemented. In a preferred embodiment, the control system of the elevator comprises one or more computers. The control system is preferably configured to perform one or more of the steps (100-600), preferably at least the steps (100-500A;100-500B), possibly all of said steps 100-600.

[0052] In a preferred embodiment, the crawling speed of the elevator is a constant speed.

[0053] In a preferred embodiment, the crawling speed of the elevator is a speed slower than the maximum speed of the elevator during said driving (100). The crawling speed is preferably slower than 0.5 m / s, more preferably slower than 0.1 m / s. The maximum speed of the elevator during said driving (100) is preferably higher than 0.5, more preferably higher than 5 m / s.

[0054] In a preferred embodiment, each of the ropes comprise one or more load-bearing members made of composite material comprising reinforcing fibers, preferably carbon fibers or alternatively some other fibers, embedded in a matrix, which matrix comprises polymer material. Said polymer material is preferably epoxy.

[0055] It is also brought forward a new elevator comprising an elevator car, ropes connected to the elevator car, and one or more cambered wheels around which the ropes pass, and a contactless monitoring equipment for monitoring position of each rope in width direction of the row within a monitoring area (Al) in contactless manner, the elevator comprising an elevator control system configured

[0056] to drive (100) the elevator, in particular by rotating a drive wheel around which the ropes pass, such that the ropes move as a row via a monitoring area (Al) wherein the row is formed by plurality of ropes positioned side by side as viewed in thickness direction t, the row having a thickness direction and width direction w; and

[0057] to monitor the position of each rope in width direction of the row within the monitoring area (Al) while the elevator is driven using the contactless monitoring equipment; and to detect (300) if position of a rope portion (P) in width direction of the row fulfills one or more criteria indicating abnormal displacement of the rope portion (P); and thereafter

[0058] to drive (400) the elevator such that the rope portion (P) is moved towards an inspection area (A2); and

[0059] to stop (500A) the driving (400) of the elevator when the rope portion (P) is at least partially within the inspection area (A2); or to drive (500B) the elevator with crawling speed when the rope portion (P) is at least partially within the inspection area (A2). With this kind of solution one or more of the above-mentioned objects can be facilitated.

[0060] Preferable further details of the method and elevator are introduced in the following, which further details can be combined with the method and the elevator individually or in any combination.

[0061] In a preferred embodiment, the elevator comprises an inspecting device. The elevator control system is or may be configured to inspect (600) condition of the rope portion (P) when it is stopped at least partially within said inspection area (A2) or moves with crawling speed within the inspection area (A2) using an inspecting device.

[0062] In a preferred embodiment, the monitoring equipment, is mounted stationary and / or in a permanent position.

[0063] In a preferred embodiment, the ropes are belts.

[0064] In a preferred embodiment, ropes are belts and the one or more wheels around which the ropes pass comprise a drive wheel rotatable by a motor and / or a non-driven rope wheel, the ropes passing around the drive wheel and / or the non-driven rope wheel such that the wide side of each rope rests against a crowning shape (4a) of the drive wheel and / or nondriven rope wheel. In a preferred embodiment, the inspection area (Al) is apart from said monitoring area (A2).

[0065] In a preferred embodiment, each of the ropes comprise one or more load-bearing members made of composite material comprising reinforcing fibers, preferably carbon fibers or alternatively some other fibers, embedded in a matrix, which matrix comprises polymer material. Said polymer material is preferably epoxy. Preferably, the load bearing member(s) are embedded in a coating. The load bearing members [when more than one] are then preferably adjacent each other in width direction of the rope and isolated from each other by the coating. The coating is preferably made of material comprising polymer, such as of rubber or polyurethane or silicone, for instance.

[0066] Generally, the car preferably comprises an interior wherein passenger and / or goods can be transported.

[0067] Generally, the control system is preferably configured to perform any one or plurality of the steps of the method defined above or in any of the claims of the application.

[0068] In a preferred embodiment, when the method comprises the step of collecting, and preferably also the preferred step of storing in a memory of an elevator control system, rope position data of individual ropes, the control system is preferably configured to perform this / these step(s). The control system is then preferably also configured to perform the aforementioned step of using of the algorithm (if / when present).

[0069] Brief description of the drawings

[0070] In the following, the present invention will be described in more detail by way of example and with reference to the attached drawings, in which Figures 1-5 illustrate an elevator according to an embodiment at subsequent phases of an embodiment of the method for condition monitoring of ropes of an elevator. Figure lb illustrates an enlarged view of Figure 1 showing preferred details of the elevator and the method.

[0071] Figure 6 illustrates schematically a cross-sectional view of the ropes 2 passing around a rope wheel of Figures 1-5.

[0072] Figures 7 and 8 illustrate preferred details of the structure of the ropes. Figures 9 and 10 illustrate preferred details of a first kind of preferred embodiment of a contactless monitoring equipment.

[0073] Figures 11 illustrates preferred details of a second kind of preferred embodiment of a contactless monitoring equipment.

[0074] Figure 12 illustrates an image or video captured with the imaging device of Figure 11.

[0075] Figures 13 and 14 illustrate preferred further details of the contactless monitoring equipment of Figure 11.

[0076] Figure 15 illustrates an image or video captured with the imaging device of Figure 13.

[0077] Figure 16 illustrates an example of rope position data.

[0078] Figure 17 illustrates a member attached to a rope for facilitating testing of the method and the condition monitoring function of the elevator. Detailed description

[0079] Figures 1-5 illustrate an elevator 1 according to an embodiment at subsequent phases of an embodiment of the method for condition monitoring of ropes 2 of an elevator 1.

[0080] The elevator 1 comprises an elevator car 3, and a rope wheel arrangement comprising one or more cambered rope wheels 4,6 around which the ropes 2 pass. The elevator in question being a counterweighted elevator, the ropes 2 are connected on a first side of said rope wheel arrangement to the elevator car 3 and on a second side of said rope wheels 4,6 to a counterweight 7. The ropes 2 suspend the car 3 and counterweight 7 on opposite sides of the rope wheel arrangement.

[0081] For facilitating guidance by crowning, in the preferred embodiment of Figures 1-5, the ropes 2 are preferably belts. The width of the rope 2 is then greater than its thickness the width / thickness ratio of the rope 2 being preferably greater than 2. Figure 6 illustrates schematically a cross section of the ropes 2 [internal parts of the ropes not shown] and the rope wheel 4,6 of Figures 1-5. The drive wheel 4 / rope wheel 6 comprises crowning shapes 4a adjacent each other, one rope 2 being placed to rest against each of them. The one or more wheels 4,6 around which the ropes 2 pass comprise a drive wheel 4 rotatable by a motor 5 and a non-driven rope wheel 6, the ropes 2 pass around the drive wheel 4 such that the wide side [i.e. the side facing in thickness direction t of the rope 2 and / or the row] of each rope 2 rests against a crowning shape 4a of the drive wheel 4. The non-driven rope wheel 6 can also be provided for guiding the ropes by crowning.

[0082] The method comprises driving 100 the elevator 1, in particular by rotating a drive wheel 4 around which the ropes 2 pass, such that the ropes 2 move as a row via a monitoring area Al wherein the row is formed by plurality of ropes 2 positioned side by side as viewed in thickness direction t, the row having a thickness direction and width direction w. Progress of this driving 100 is illustrated in Figures 1-5, the arrows al, a2 and a3 showing direction of movement of car 3, ropes 2 and the drive wheel 4 rotation direction, respectively.

[0083] Figures 1-5 moreover illustrate a rope portion P of one of the ropes 2, which rope portion P in this example contains a structural anomaly affecting its behavior at a cambered rope wheel 4,6 while being guided by a crowning. In the example, the portion P drawn with thick line thickness in drawings 1-5 will be displaced on the cambered rope wheels 4,6 in an amount regarded abnormal and in particular such that its position in width direction w of the row fulfills one or more criteria set for abnormal displacement. In the driving 100, the portion P moves passing around the drive wheel 4, and thereafter via the monitoring area Al. In the example, the ropes 2 are moved in said driving 100 such that they move from the one or more cambered wheels 4,6 towards the monitoring area Al i.e. such that they arrive in the monitoring area Al after passing around the one or more cambered wheels 4,6.Any portion of any of the ropes 2, if displaced due to a structural anomaly affecting its behavior at a cambered rope wheel 4,6 while being guided by a crowning shape, is likely displaced in axial direction of the cambered rope wheel 4,6 from the path it would take without the structural anomaly. This displacement can be noticed and reacted to. It is not preferable to react to a very slight displacement. Said one or more criteria can be set so that a desired sensitivity is achieved. Said one or more criteria preferably include that the position of the rope portion of rope 2 in width direction of the row reaches or has reached a threshold positions L1,L2; L1',L2'; L1",L2" in width direction w of the row. This kind of criterium is simple to provide (however also alternative or additional criteria can be provided as will be later explained). There is preferably a separate pair of threshold positions L1,L2; L1',L2'; L1",L2" per each rope 2, in particular each rope 2 being between a pair of threshold positions L1,L2; L1',L2'; L1",L2".

[0084] In said driving 100 a large proportion of each rope 2 preferably is moved via the monitoring area Al at least once. The detection of abnormal displacement of the portion P may take place while the portion P is within the monitoring zone Al, i.e. without considerable delay, or after the portion P has passed via the monitoring area. The detecting 300 can be arranged to take place online or through a post analysis to be performed after collection of an amount of rope position data with the monitoring equipment 50,60. In the latter case, the method preferably comprises processing the rope position data collected. Figure 1 illustrates the elevator 1 at a moment when a rope portion P is being moved in said driving 100 towards the monitoring area Al, in particular such that the portion P arrives in the monitoring area Al after passing around the drive wheel 4. Figure 2 illustrates the elevator 1 at a moment when the rope portion P is at least partially within the monitoring area Al. Figure 3 illustrates the elevator 1 at a moment when the rope portion P has already moved via the monitoring area Al.

[0085] The method comprises monitoring 200 by an elevator control system 10, during said driving 100, the position of each rope 2 in width direction w of the row within the monitoring area Al using a contactless monitoring equipment 50,60 [not shown in Figures 1-5]. The contactless monitoring equipment 50,60 is suitable for monitoring position of each rope 2 in width direction w of the row within a monitoring area Al in contactless manner.

[0086] The method moreover comprises detecting 300 if position of a rope portion P of any of the ropes 2 in width direction w of the row fulfills one or more criteria indicating abnormal displacement of the rope portion P. The method moreover comprises, after said detecting, if position of the rope portion P of any of the ropes 2 in width direction w of the row fulfills said one or more criteria,

[0087] driving 400 the elevator 1 such that the rope portion P is moved towards an inspection area A2; and

[0088] either stopping 500A the driving 400 of the elevator 1 when the rope portion P is at least partially [however preferably fully] within the inspection area A2; or

[0089] driving 500B the elevator with crawling speed when the rope portion P is at least partially within the inspection area A2; and inspecting 600 condition of the rope portion P when it is stopped within said inspection area A2 or moves with crawling speed within the inspection area A2.

[0090] Thus, the portion P can be brought at least partially within the inspection area A2 and a well focused inspection of this rope portion P now known to be relevant, can be performed.

[0091] Said driving 400 has been illustrated in Figure 4. Figure 5 illustrates the elevator 1 when the rope portion P is within the inspection area A2. For facilitating that in the driving 400 the portion P can be brought at least partially within the inspection area A2, the method preferably comprises determining 301 a first car position value Fl representing a first car position, wherein the car 3 is or was when the aforementioned rope portion P is or was in the monitoring area Al, and determining 302 on the basis of said first car position value Fl, a second car position value F2 representing a second car position, wherein the car 3 is when the rope portion P is at least partially within the inspection area A2.

[0092] In said stopping 500A the elevator car 3 is stopped in the second car position, i.e. the elevator 1 is stopped such that the car 3 stops in the second car position, i.e. in a position where the car position value equals to said second car position value F2. In the alternative involving said crawling speed, in said driving 500B, the elevator is driven with crawling speed over said second car position, i.e. the elevator 1 is driven such that the car 3 moves over said second car position i.e. over a position where the car position value equals to said second car position value F2.

[0093] The aforementioned determining 301 of the first car position value Fl can comprise obtaining the first car position value Fl from the elevator control system. The elevator control system 10 can be configured to store and indicate the first car position value Fl prevailing at the moment when the position of a rope portion P in width direction w of the row fulfil Is / or fulfilled the one or more criteria indicating abnormal displacement of the rope portion P.

[0094] The aforementioned determining 302 on the basis of said first car position value Fl, a second car position value F2, can comprise calculating the second car position value F2 by addition to first car position value Fl or subtraction from first car position value Fl, a value indicating the distance between the monitoring area Al and the inspection area A2 along the path of the ropes 2. In an alternative, this determining on the basis of said first car position value Fl, a second car position value F2, can comprise obtaining the second car position value F2 from a table presenting second car position values as a function of first car position values. Such a table can be prepared by calculating second car position values F2 for multiple first car position values as described above or alternatively such a table can be prepared by testing.

[0095] The method preferably comprises registering 304 in a memory of the control system 10 the first car position value Fl after said determining 301 and the second car position value F2 after said determining 301. The method preferably comprises identifying 303 the rope 2 comprising the portion P detected to fulfill said one or more criteria, and registering identification information associated with the identified rope in a memory of the control system 10.

[0096] In the method and elevator 1, the inspection area Al is apart from said monitoring area A2. Thus, the monitoring equipment 50,60 can be mounted stationary and / or in a permanent position, which is advantageously chosen, such as in proximity of one of the cambered rope wheels 4,6. The inspection can thus be performed in a different location, which suits well for inspection, e.g. in terms of accessibility by a service person and / or inspection equipment without danger and without disturbing the monitoring equipment or difficulties and tightness caused by presence of the monitoring equipment 50,60 beside the ropes 2. This is however not necessary, because alternatively the areas Al and A2 could at least partially overlap with each other.

[0097] Preferably, the ropes pass via a machine room M, and said inspection area Al and said monitoring area A2 are inside the machine room M. A machine room M provides a safe space for the inspection and a position where a cambered drive wheel 4 and / or rope wheel 6 are preferably located whereby the monitoring area Al can be in close proximity to a position where abnormal rope displacement is likely visible if caused by structural anomaly when it passes around a cambered wheel 4,6.

[0098] In the preferred embodiment, the method is computer-implemented, preferably such that a control system 10 of the elevator 1 comprises one or more computers, and the control system 10 is configured to perform one or more of the steps 100-600, preferably at least the steps 100-500, possibly all of said steps 100-600.

[0099] Figures 7 and 8 illustrate a preferred structure of the rope 2. In this case, the rope 2 comprises plurality of load bearing members 2a adjacent each other in width direction w of the rope 2, which is also the width direction w of the row of ropes 2. Alternatively, the rope 2 could comprise a single larger [wider] load bearing member 2a. Each load bearing member 2a is an elongated member extending parallel with the longitudinal direction of the rope 2 as a structure that continues unbroken throughout the length of the rope 2. The load bearing members 2a are embedded in a coating 2b. The load bearing members 2a are adjacent each other in width direction w of the rope 2 and isolated from each other by the coating 2b. The coating 2b is preferably made of material comprising polymer, such as of rubber or polyurethane or silicone, for example. In the preferred embodiment, the load bearing members 2a are made of composite material comprising reinforcing fibers, preferably carbon fibers or alternatively some other fibers [e.g. glass fibers], embedded in a matrix, which matrix comprises polymer material. Said polymer material is preferably epoxy. This kind of composite material structure can get damage, wear or degradation or internal structures or surface structures of the rope can cause displacement, which may need to be reacted to before the issue develops worse. By early reacting, developing of the structural issue of the rope 2 into a dangereous level can be prevented and / or developing of the displacement issue of the rope 2 into a dangerous level can be prevented.

[0100] Said monitoring 200 is performed preferably in contactless manner. There are alternative monitoring equipment available by which position of ropes can be monitored in contactless manner, i.e. such that the monitoring equipment does not contact the ropes.

[0101] In a first kind of preferred embodiment, the monitoring equipment 50 is a light curtain system and the control system 10 is configured to analyze signals of the light curtain system 50. Such an embodiment is illustrated in Figures 9-10. In this embodiment, the light curtain system 50 comprises a light emitter arrangement comprising light emitters el,e2 arranged to produce, in particular to emit a plurality of spaced apart light beam portions Lbl, Lb2 oriented to pass in thickness direction t of the row of ropes 2, such that there is a separate pair pl-p3 of said light beam portions Lbl, Lb2 per each individual rope 2 of the row, each rope 2 being positioned in width direction w of the row between one of said pairs pl-p3 of light beam portions Lbl, Lb2. The light curtain system 50 a light sensor arrangement comprising plurality of light sensors sl,s2; sl',s2'; sl",s2" for sensing light of the light emitter arrangement el,e2; and said plurality of light sensors sl,s2 comprises per each said light beam portion Lbl, Lb2 a light sensor sl,s2 for sensing light of the light beam portion Lbl, Lb2 for sensing light of the light beam portion Lbl, Lb2 to which light sensor sl,s2 the light beam portion Lbl, Lb2 is directed to pass, wherein each said rope 2, when moved in width direction w of the row away from its position between the pair pl-p3 of light beam portions Lbl, Lb2 such that it crosses the path of a light beam portion Lbl, Lb2, is arranged to block passing of light of said light beam portion Lbl, Lb2 to a light sensor sl,s2; sl',s2'; sl",s2". The control system 10 is configured to monitor sensor signals of said plurality of light sensors sl,s2; sl',s2'; si", s2".

[0102] The control system 10 is in particular configured to detect a predetermined change in the sensor signal of any of the light sensors sl,s2; sl',s2'; sl",s2" indicating that passing of light beam portion into the light sensor sl,s2; sl',s2'; sl",s2" is blocked, said predetermined change preferably being a cease of said signal, or a cease of said signal for at least a predetermined period of time.

[0103] Figure 9 illustrates a situation where a rope 2 [third from left] has moved in width direction w of the row away from its position between a pair p3 of light beam portions Lbl, Lb2 such that it has crossed the path of a light beam portion Lb2. This has blocked passing of light of said light beam portion Lb2to a light sensor s2". In the monitoring system 10 a single rope 2 is associated [by computer program for instance] with each light sensor sl,s2; sl',s2'; sl",s2". Thereby, the monitoring system 10 can identify simply the rope 2 that has caused a change in signals being monitored. Correspondingly, should the rope 2 move left in Figure 9 to block passing of light of light beam portion Lbl to the light sensor si". Generally, the light of said light emitters el,e2 can be any light, but preferably it is laser light or infrared light or led light.

[0104] Each said pair pl-p3 of light beam portions Lbl, Lb2 comprises a first light beam portion Lbl arranged to pass on a first side of a rope 2 to a first light sensor sl;sl';sl" a distance apart from the rope 2, and a second light beam portion Lb2 arranged to pass on second side of the rope 2 to a second light sensor s2;s2';s2" a distance apart from the rope 2. Said first light beam portion Lbl and second light beam portion Lb2 of each pair pl-p3 extend on opposite sides of the rope 2 a distance apart from the rope 2, defining threshold positions L1,L2; L1',L2'; Ll",L2" of the rope 2 in the width direction w.

[0105] The control system 10 is configured to identify and / or indicate the rope 2 associated with the light sensor sl,s2; sl',s2'; sl",s2" in the sensor signal of which a predetermined change was detected and to register a first car position value Fl representing the position of the car 3 [i.e. the first car position] of the elevator at the moment of occurrence of the predetermined change in the sensor signal of any of the light sensors. In a second kind of preferred embodiment, the monitoring equipment 60 comprises an imaging device C such as a camera or video recorder configured to capture images or video of the row of ropes 2 and / or the individual ropes 2 thereof extending via the monitoring area Al, and the control system 10 is configured to analyze the images or video captured with the imaging device C. Such an embodiment is illustrated in Figures 11-12. In this embodiment, the method comprises capturing with an imaging device C such as a camera or video recorder images or video of the row of ropes 2 and / or of the individual ropes 2 thereof, which ropes 2 in particular pass via the monitoring area Al; and analyzing by the control system 10 the images or video captured with the imaging device C, said analyzing comprising the detecting 300.

[0106] Said analyzing preferably comprises recognizing in the images patterns P, such as patterns of light emitted on said ropes 2, and analyzing one or more characteristics, such as preferably positions, of the recognized patterns P. Said recognizing is preferably performed by an image recognition software, in particular running on a computer of the control system 10.

[0107] The patterns to be recognized are preferably the shapes of the ropes 2 as it is the case in the embodiment of Figures 11-12 and 13-14. For facilitating the analyzing and recognizing, the method may comprise emitting light, in particular with one or more light sources 61 comprised in the monitoring equipment 60, on the ropes 2 while they move past the one or more light sources 61; and said analyzing comprises recognizing in the images patterns of light emitted on said ropes 2. Said emitting preferably then comprises emitting on a flank f of each of said ropes 3 at least one light beam b having a shape, such as a planar shape. Said light is preferably laser light, infrared light or light from a led device. In the latter case, said one or more light sources 61 are leds. Said beam b preferably has one or more planar sides sl,s2 or side portions, whereby it produces patterns which are easily recognizable.

[0108] As mentioned, the imaging device C can be for example a camera or a video recorder. Then the imaging device C can be an edge device, and it may be equipped with a computing means providing it some computing capabilities. The computing means can be then connected to a cloud for instance. Here, the computing means and the cloud are considered to be part of the elevator control system 10.

[0109] The monitoring 200 may comprise collecting 201 and storing 202 in a memory of an elevator control system 10 rope position data of individual ropes 2 of the row in function of car position or possibly in function of some other parameter directly proportional with car position, in particular in function of a car position value or a value of a parameter directly proportional with car position value respectively. Figure 16 illustrates an example of such rope position data. The rope position data of individual ropes 2 of the row is presented here as a curve in function of car position value. Figure 16 illustrates a situation where a portion of rope 2 has reached threshold L2". The first car position value Fl is in this example 104.

[0110] The aforementioned collecting 201 position data enables use of an algorithm for the detecting 300 if position of a rope portion P in width direction w of the row fulfills one or more criteria indicating abnormal displacement of the rope portion P. Accordingly, the monitoring 200 may comprise using 203, in particular by the elevator control system 10 (e.g. by one or more computers thereof), an algorithm for the detecting 300 if position of a rope portion P in width direction w of the row fulfills one or more criteria indicating abnormal displacement of the rope portion P, which algorithm is configured process the position data collected, wherein the algorithm may be a computer program algorithm for example. Also in this case, the one or more criteria can include reaching of a threshold position L1,L2; L1',L2'; L1",L2" as described elsewhere in the application. However, the one or more criteria can alternatively or additionally include also one or more sophisticated criteria such as that one or more of that a displacement of a certain portion P of an rope 2 is detected repeatedly e.g. every time the rope portion P passes via the monitoring area Al, or that one of the ropes 2 is displaced differently than other ropes or that the portion P of a rope is displaced more than other portions of the rope in question or that position of a rope portion P changes in a predetermined manner (e.g. the curve shape or a characteristic thereof is of a predetermined kind or the rate of position change is of a predetermined kind, e.g. higher than a threshold rate) or a combination of two or more of these criteria. Also other alternative or additional sophisticated criteria can be set.

[0111] The inspecting 600 is preferably performed with an inspecting device 8, preferably an ultrasound scanner. Additionally or alternatively, the inspecting 600 may comprise visual inspection by a service person. In the preferred embodiment, as illustrated in Figure lb, the inspecting device is positioned beside the rope portion during said inspecting 600. The inspecting 600 preferably comprises ultrasound scanning internal structures of the portion P of rope 2. This can be implemented for instance correspondingly as in US patent application document US2018306752 Al. Preferably, said ultrasound scanning comprises emitting ultrasound from a lateral side of the portion P of rope 2 into a load bearing member 2a or members 2a of the rope 2 and receiving echoes of the ultrasound emitted into said load bearing members 2a.

[0112] Said ultrasound scanning preferably comprises creating one or more cross sectional views of the load bearing member or members of the rope 2 based on echoes received from the load bearing members thereof and / or creating from the portion P an echo strength graph based on echoes received from the load bearing member 2a or members 2a, the echo strength graph presenting echo strength versus thickness directional position of the load bearing members 2a. The method preferably further comprises analyzing the cross sectional views and / or echo strength graphs created.

[0113] In the embodiment of the method comprising said stopping 500A, in said stopping 500Athe car 3 is brought to standstill. Then in particular the ropes are also stopped and brought to standstill. The stopping 500A the elevator car 3 in the second car position preferably comprises moving the brakes of the elevator 1 into braking state, such as machine brakes of the elevator [not shown] for preventing car movement during inspecting 600. The machine brakes are preferably in their braking state arranged to keep the drive wheel 4 immovable.

[0114] In the embodiment of the method comprising said driving 500B the elevator with crawling speed, said crawling speed is preferably a constant speed slower than 0.5 m / s, more preferably slower than 0.1 m / s. A slow speed facilitates careful inspection of the portion P while it moves past an inspecting device 8, such as an ultrasound scanner. The maximum speed of the elevator during said driving 100 is preferably higher than 0.5 m / s, more preferably higher than 5 m / s, whereby the crawling speed is in particular slower than the speed of the elevator during said driving 100, as well as slower than the nominal speed of the elevator 1. In an embodiment of an elevator 1, the elevator 1 comprises an elevator car 3, ropes 2 connected to the elevator car 3, and one or more cambered wheels 4,6 around which the ropes 2 pass, and a contactless monitoring equipment 50,60 for monitoring position of each rope 2 in width direction w of the row within a monitoring area Al in contactless manner. The elevator 1 comprises an elevator control system 10 configured to drive 100 the elevator 1, in particular by rotating a drive wheel 4 around which the ropes 2 pass, such that the ropes 2 move as a row via a monitoring area Al wherein the row is formed by plurality of ropes 2 positioned side by side as viewed in thickness direction t, the row having a thickness direction and width direction w; and to monitor the position of each rope 2 in width direction w of the row within the monitoring area Al while the elevator 1 is driven using the contactless monitoring equipment 50,60; and to detect 300 if position of a rope portion P of any of the ropes 2 in width direction w of the row fulfills one or more criteria indicating abnormal displacement of the rope portion P; and thereafter to drive 400 the elevator 1 such that the rope portion P is moved towards an inspection area A2; and to stop 500A the driving 400 of the elevator when the rope portion P is at least partially within the inspection area A2; or to drive 500B the elevator with crawling speed when the rope portion P is at least partially within the inspection area A2.

[0115] The monitoring equipment 50,60 is preferably mounted stationary and / or in a permanent position. The elevator 1 preferably moreover comprises an inspecting device 8, and the elevator control system 10 is configured to inspect 600 condition of the rope portion P when it is stopped at least partially within said inspection area A2 or moves with crawling speed within the inspection area A2 using an inspecting device 8.

[0116] Preferred details of the elevator 1 has been described earlier above referring to Figures 1-15. The elevator 1 implements the method described anywhere above referring to Figures 1-15. The control system 10 is preferably configured to perform steps of the method described. When the method comprises collecting 201, and preferably moreover storing 202 in a memory of an elevator control system 10, rope position data of individual ropes 2, the control system 10 is preferably configured to perform these steps as well as the using 203 of the algorithm (if / when present).

[0117] It is also possible to test the condition monitoring function of the elevator 1 and the condition monitoring method. Preferably, said testing comprises attaching a member 70 on one or the ropes 2 such that it extends along the wide side 2s of the rope 2 which rests against the one or more cambered rope wheels 4,6, in particular against a crowning shape 4a thereof, and thereafter performing the steps of the method for condition monitoring of ropes 2. The member 70 is attached to a point of the side 2s which point is not against a rope wheel 4,6 so there is room for performing said attaching. Figure 17 illustrates an example of cross section of the rope 2 at a point where a member 70 has been attached to the side 2s of the rope 2. The member 70 is preferably attached asymmetrically on the rope side which side rests against the one or more cambered rope wheels 4,6 when passing around it / them. The member 70 is preferably attached in particular so that it covers more of one of the two halves of the rope side than the other of the two halves. The member is preferably a piece of tape attached by adhesive. During the driving 100, the elevator 1 is driven such that the side to which the member 70 has been attached passes around the one or more cambered rope wheels 4,6 such that the member 70 is passes between the rope 2 and the crowning shapes 4a of the one or more cambered rope wheels 4,6. Thus it causes displacement of the rope, which is then detectable by the monitoring equipment 50,60. Thus, an abnormal displacement can be caused to simulate an abnormal displacement caused by structural anomaly of the rope. Generally preferably, the monitoring arrangement 1 is utilized with a solution utilizing rope guidance with crowning shape of a wheel. However, this is not necessary since at least some of the advantages can be achievable also in context of other kind of rope guidance.

[0118] Generally preferably, although not necessarily, the ropes are belts, and most preferably the ropes are belts comprising one or more load bearing members made of composite material. However, at least some of the advantages can be achievable also with other kind of rope structure, such as with belts comprising other kind of load bearing members e.g. metal cords.

[0119] Generally, the ropes 2 of the row extend preferably on the same plane [as illustrated] or at least substantially on the same plane, in particular when within the monitoring area Al. However, perfect alignment to be on the same plane is not necessary, since some variation of position of rope in thickness direction t of the row would not disturb operation of the solution considerably. However, the ropes 2 should be side by side as viewed in thickness direction t of the row, and preferably moreover such that the ropes 2 are a distance apart from each other as viewed in width direction w of the row. Thus, their width directional position can be monitored effectively by monitoring equipment 50,60.

[0120] Generally, preferably in the method and elevator one or more rope wheels 4 and / or 6 is provided for guiding the ropes by crowning, and there may be driven rope wheels 4 and / or non-driven rope wheels 6 provided for guiding the ropes by crowning.

[0121] Generally, the rope wheel arrangement comprising rope wheels 4,6 could alternatively comprise some other number of rope wheels than what is illustrated, such as only one rope wheel 4 or additional rope wheels in addition to those illustrated, for example.

[0122] Generally, the elevator control system 10 is considered broadly. In particular, the elevator control system 10 can comprise local units and / or remote units for performing tasks of the elevator control system 10. Said local units and / or remote units can comprise one or more computers or computer systems. Said local units and / or remote units can comprise one or more memory units for storing data, such as car position data and / or computer programs for performing tasks of the elevator control system 10. Said memory units can comprise a local memory, a cloud memory, or a remote memory, accessible in wired or wireless manner, for instance. Generally, in the preferred embodiments the monitoring area Al and the inspection area A2 are inside the machine room M. However, this is not necessary since one or both of them could be in an alternative location such as inside the hoistway of the elevator. Moreover, there could be more than one monitoring area Al and / or more than one inspection area A2. This may be advantageous e.g. for facilitating covering of the whole length or at least close to whole length of the ropes 2 with the monitoring. Also, this may be advantageous for facilitating ability to detect abnormal displacement caused by structural anomaly when it passes around a cambered wheel during driving in either of the two driving directions. Generally, in the preferred embodiments described and illustrated, the ropes 2 monitored are hoisting ropes. However, alternatively, the ropes 2 monitored could be compensation ropes of the elevator. In such a case, the ropes would be monitored in corresponding manner but the cambered rope wheels would be rope wheels mounted in the pit i.e. the bottom end of a hoistway.

[0123] Generally, the condition monitoring solution disclosed is advantageous in particular with ropes having load bearing members made of fiber reinforced composite, because this kind of ropes are costly to replace and unnecessary replacements are to be avoided, and because this kind of ropes may need to be locally inspected carefully so as to determine whether or not there are internal structural issues that would require rope replacement. However, at least some of the advantages of the condition monitoring solution disclosed can be achieved also with other kind of ropes.

[0124] Generally, the monitoring area Al is preferably close to one of said cambered rope wheels [in Figures the wheel 4], preferably in particular such that the distance d, as measured along the path of the ropes 2, between a contact point with a rim of a cambered rope wheel 4,6 and the monitoring area Al is shorter than 1 meter. In Figures, the distance d is non-zero which give room for components but preferably the distance d is relatively short if not zero. The distance d can be zero, whereby the monitoring 200 would be performed on a portion of rope resting against the cambered rope wheel 4,6. Short distance facilitates that the monitoring is directed to rope portion close to position where a structural anomaly can cause an abnormal displacement, whereby the portion requiring attention / inspection can be easily localized and the inspection can be simply focused to the rope portion containing the structural anomaly that caused the abnormal displacement. The length of the inspection area A2 as measured along the path of the ropes 2, is preferably longer than the distance d, however in general preferably longer than 1 meter, however preferably although not necessarily shorter than 2 meters. Thus, the rope portion containing the structural anomaly that caused the abnormal displacement will likely be at least partially within the inspection area A2 when the inspecting 600 is performed. Generally, the inspecting 600 can be performed with an inspecting device 8, such as an ultrasound scanner for example. Additionally or alternatively, the inspecting 600 may comprise visual inspection by a service person. The inspecting device 8 can be comprised in the elevator or be a temporary device brought to the site by the service person. Generally, the car position such as a car position value is easily obtainable in elevators. However, instead of the car position and / or the car position value, some other parameter could be utilized, which parameter is directly proportional with car position and / or the value of which is directly proportional with car position value, respectively.

[0125] It is to be understood that the above description and the accompanying Figures are only intended to teach the best way known to the inventors to make and use the invention. It will be apparent to a person skilled in the art that the inventive concept can be implemented in various ways. The above-described embodiments of the invention may thus be modified or varied, without departing from the invention, as appreciated by those skilled in the art in light of the above teachings. It is therefore to be understood that the invention and its embodiments are not limited to the examples described above but may vary within the scope of the claims.

Claims

Claims1. A method for condition monitoring of ropes (2) of an elevator (1), which elevator (1) comprises an elevator car (3), and one or more cambered rope wheels (4,6) around which the ropes (2) pass, and wherein the ropes (2) are connected to the elevator car (3), the method comprisingdriving (100) the elevator (1), in particular by rotating a drive wheel (4) around which the ropes (2) pass, such that the ropes 2 move as a row via a monitoring area (Al) wherein the row is formed by plurality of ropes (2) positioned side by side, the row having a thickness direction (t) and width direction (w);monitoring (200) by an elevator control system (10), during said driving (100), the position of each rope (2) in width direction (w) of the row within the monitoring area (Al) using a contactless monitoring equipment (50,60);detecting (300) if position of a rope portion (P) in width direction (w) of the row fulfills one or more criteria indicating abnormal displacement of the rope portion (P); andthe method moreover comprises after said detecting (300), in particular if position of the rope portion (P) of any of the ropes (2) in width direction (w) of the row fulfills said one or more criteria,driving (400) the elevator (1) such that the rope portion (P) is moved towards an inspection area (A2); andstopping (500A) the driving (400) of the elevator when the rope portion (P) is at least partially within the inspection area (A2);ordriving (500B) the elevator with crawling speed when the rope portion (P) is at least partially within the inspection area (A2); andinspecting (600) condition of the rope portion (P) when it is stopped at least partially within said inspection area (A2) or moves with crawling speed within the inspection area (A2).

2. Method according to any of the preceding claims, wherein ropes (2) are belts and the one or more wheels (4,6) around which the ropes (2) pass comprise a drive wheel (4) rotatable by a motor (5) and / or a non-driven rope wheel (6), the ropes (2) passing around the drive wheel (4) and / or the non-driven rope wheel (6) such that the wide side of each rope (2) rests against a crowning shape (4a) of the drive wheel (4) and / or non-driven rope wheel (6).

3. A method according to any of the preceding claims, wherein the inspection area (Al) is apart from said monitoring area (A2).

4. Method according to any of the preceding claims, wherein the ropes (2) pass via a machine room (M), and said inspection area (Al) and said monitoring area (A2) are inside the machine room (M).

5. Method according to any of the preceding claims, wherein the method comprisesdetermining (301) a first car position value (Fl) representing a first car position, wherein the car is or was when the aforementioned rope portion is or was in the monitoring area, and determining (302) on the basis of said first car position value (Fl), a second car position value (F2) representing a second car position, wherein the car is when the rope portion is at least partially within the inspection area.

6. Method according to any of the preceding claims, wherein the method comprises registering (304) in a memory of the control system (10) the first car position value (Fl) after said determining (301) and the second car position value (F2) after said determining (301).

7. Method according to any of the preceding claims, wherein said one or more criteria include that position of the rope portion (P) in width direction (w) of the row of ropes (2) reaches or has reached a threshold position (L1,L2; L1',L2'; L1",L2") in width direction (w) of the row.

8. Method according to any of the preceding claims, wherein there is a separate pair of threshold positions (L1,L2; L1',L2'; L1",L2") per each rope (2).

9. Method according to any of the preceding claims, wherein the method comprises identifying (303) the rope (2) comprising the portion (P) detected to fulfill said one or more criteria, and registering identification information associated with the identified rope in a memory of the control system (10).

10. Method according to any of the preceding claims, wherein in said stopping (500A) the elevator car is stopped in the second car position and / or in said driving (500B) the elevator is driven with crawling speed over said second car position.

11. Method according to any of the preceding claims, wherein the contactless monitoring equipment (50) comprises an imaging device (C) such as a camera or video recorder configured to capture images or video of the row of ropes (2) and / or theindividual ropes (2) thereof extending via the monitoring area (Al), and the control system (10) is configured to analyze the images or video captured with the imaging device (C); or the monitoring equipment (60) is a light curtain system and the control system (10) is configured to analyze signals of the light curtain system.

12. Method according to any of the preceding claims, wherein the light curtain system (60) comprisesa light emitter arrangement comprising light emitters (el,e2) arranged to produce, in particular to emit, a plurality of spaced apart light beam portions (Lbl, Lb2) oriented to pass in thickness direction (t) of the row of ropes (2), such that there is a separate pair (pl-p3) of said light beam portions (Lbl, Lb2) per each individual rope (2) of the row, each rope being positioned in width direction (w) of the row between one of said pairs (pl-p3) of light beam portions (Lbl, Lb2); anda light sensor arrangement comprising plurality of light sensors (sl,s2; sl',s2'; sl",s2") for sensing light of light emitter arrangement (el,e2); andsaid plurality of light sensors (sl,s2; sl',s2'; sl",s2") comprises per each said light beam portion (Lbl, Lb2) a light sensor (sl,s2; sl',s2'; sl",s2") for sensing light of the light beam portion (Lbl, Lb2) for sensing light of the light beam portion (Lbl, Lb2) to which light sensor (sl,s2) the light beam portion (Lbl, Lb2) is directed to pass, wherein each said rope (2), when moved in width direction (w) of the row away from its position between the pair (pl-p3) of light beam portions (Lbl, Lb2) such that it crosses the path of a light beam portion (Lbl, Lb2), is arranged to block passing of light of said light beam portion (Lbl, Lb2) to a light sensor (sl,s2; sl',s2'; sl",s2"); andthe control system (10) is configured to monitor sensor signals of said plurality of light sensors (sl,s2; sl',s2'; sl",s2").

13. Method according to any of the preceding claims, wherein the monitoring (200) comprises collecting (201), and preferably moreover storing (202) in a memory of an elevator control system (10), rope position data of individual ropes (2) of the row in function of car position or in function of some other parameter directly proportional with car position.

14. Method according to any of the preceding claims, wherein the method comprises using (203), in particular by the elevator control system (10), an algorithm for the detecting (300), which algorithm is configured to process the position data collected.

15. Method according to any of the preceding claims, wherein the inspecting (600) is performed with an inspecting device, preferably an ultrasound scanner.

16. Method according to any of the preceding claims, wherein the inspecting (600) comprises ultrasound scanning internal structures (2a) of the portion (P) of the rope (2).

17. Method according to any of the preceding claims, wherein the crawling speed of the elevator (1) is a constant speed slower than the maximum speed of the elevator (1) during said driving (100).

18. An elevator (1) comprising an elevator car (3), plurality of ropes (2) connected to the elevator car (3), and one or more cambered wheels (4,6) around which the ropes (2) pass, and a contactless monitoring equipment (50,60) for monitoring position of each rope(2) in width direction (w) of the row within a monitoring area (Al) in contactless manner, the elevator (1) comprising an elevator control system (10) configuredto drive (100) the elevator (1), in particular by rotating a drive wheel (4) around which the ropes (2) pass, such that the ropes (2) move as a row via a monitoring area (Al) wherein the row is formed by plurality of ropes (2) positioned side by side, the row having a thickness direction (t) and width direction (w); and to monitor (200) the position of each rope (2) in width direction (w) of the row within the monitoring area (Al) while the elevator (1) is driven using the contactless monitoring equipment (50,60); andto detect (300) if position of a rope portion (P) in width direction (w) of the row fulfills one or more criteria indicating abnormal displacement of the rope portion (P); and thereafter to drive (400) the elevator (1) such that the rope portion (P) is moved towards an inspection area (A2); andto stop (500A) the driving (400) of the elevator when the rope portion (P) is at least partially within the inspection area (A2); orto drive (500B) the elevator with crawling speed when the rope portion (P) is at least partially within the inspection area (A2).

19. An elevator or a method according to any of the preceding claims, wherein the elevator comprises an inspecting device (8), and the elevator control system (10) may be configured to inspect (600) condition of the rope portion (P) when it is stopped at least partially within said inspection area (A2) or moves with crawling speed within the inspection area (A2) using an inspecting device (8).

20. An elevator or a method according to any of the preceding claims, wherein the monitoring equipment 50,60 is mounted stationary and / or in a permanent position.

21. An elevator or a method according to any of the preceding claims, wherein ropes (2) are belts and the one or more wheels (4,6) around which the ropes (2) pass comprise a drive wheel (4) rotatable by a motor (5) and / or a non-driven rope wheel (6), the ropes (2) passing around the drive wheel (4) and / or the nondriven rope wheel (6) such that the wide side of each rope (2) rests against a crowning shape (4a) of the drive wheel (4) and / or the non-driven rope wheel (6).

22. An elevator or a method according to any of the preceding claims, wherein the inspection area (Al) is apart from said monitoring area (A2).

23. An elevator or a method according to any of the preceding claims, wherein each of the ropes (2) comprise one or more load-bearing members (2a) made of composite material comprising reinforcing fibers, preferably carbon fibers or alternatively some other fibers, embedded in a matrix, which matrix comprises polymer material. Said polymer material is preferably epoxy.

24. An elevator or a method according to any of the preceding claims, wherein the control system (10) of the elevator comprises one or more computers, the control system (10) being configured to perform one or more of the steps (100-600), preferably at least the steps (100-500A;100-500B).

Images