WO2018127272A1

WO2018127272A1 - Elevator with overspeed governor rope monitoring

Info

Publication number: WO2018127272A1
Application number: PCT/EP2017/050067
Authority: WO
Inventors: Simo Sairanen; Henri WENLIN; Jani MÄKINEN
Original assignee: Kone Corporation
Priority date: 2017-01-03
Filing date: 2017-01-03
Publication date: 2018-07-12

Abstract

The invention relates to an elevator comprising at least one elevator car driving in at least one elevator shaft via an elevator drive machine (16) controlled by an elevator control (28), which elevator comprises an overspeed governor (OSG) having an OSG rope (20) running between a governor pulleys (22, 24) in the shaft top and shaft bottom, whereby the OSG rope (20) is fixed to the elevator car. The elevator (10) comprises an OSG rope monitoring device (21) comprising at least one, preferably two detector elements (32, 34) surrounding the OSG rope (20), whereby the at least one detector element (32, 34) is connected with at least one sensor device (36, 38). The sensor device (36, 38) is configured to issue a contact signal if the detector element (32, 34) is in contact with at least one wire (46) protruding from the surface (23) of the OSG rope (20). The OSG monitoring device (21) further comprises an electric fault circuit (40) connected to the elevator control (28) which electric fault circuit (40) is configured to issue a fault signal (52) if the at least one sensor device (36, 38) issues a contact signal (47).

Description

Elevator with overspeed governor rope monitoring

The present invention relates to an elevator having at least one elevator car driving in at least one elevator shaft via an elevator drive machine controlled by an elevator control. The elevator comprises an overspeed governor having an overspeed governor rope (OSG rope) running between governor pulleys in the shaft top and in the shaft bottom. The overspeed governor rope is fixed at a connection point to the elevator car. When the car drives along the elevator shaft, the OSG rope runs between the two governor pulleys and rotates them. One of the governor pulleys comprises a detector which monitors the rotation velocity of the overspeed governor pulley and activates a gripping device located at the elevator car to grip the guide rails in case of overspeed. Several cases have been reported over the years where overspeed governor ropes have been stuck at one of the governor pulleys or at any other component located along the run of the OLSG rope. This stucking is caused by wires or wire strands projecting from the surface of the OSG rope.

It is object of the present invention to provide an elevator wherein the probability of an overspeed governor rope stucking at a component of the overspeed governor or another component of the elevator is reduced.

The object is solved with an elevator according to claim 1 as well as with a method for detecting wear in an overspeed governor rope according to claim 12. Preferred embodiments of the invention are subject-matter of the corresponding dependent claims. Advantageous embodiments are also described in the description part as well as in the drawings.

According to the invention, the elevator comprises an OSG rope monitoring device which is configured to monitor the condition of the OSG rope. The OSG monitoring device comprises at least one, preferably two, detector elements surrounding the OSG rope whereby in case of two detector elements, these are being placed in a defined mutual distance along the OSG rope. The detector element is connected with at least one sensor device which is configured to issue a contact signal if the detector element is contacted by a wire of the OSG rope protruding from the surface of the OSG rope. The OSG monitoring device further comprises an electric fault circuit connected with the sensor device as well as with the elevator control. The electric fault circuit is configured to issue a fault signal if the sensor device issues a contact signal. With this device, it can be reliably determined whether a wire is protruding from the surface of the OSG rope and is tending to stuck the OSG rope over the time when coming into contact with any of the components of the overspeed governor. If such a wire is protruding from the OSG rope, the detector element in connection with the sensor device issues a contact signal and the electric fault circuit can issue a fault signal which for example leads to a message in a remote monitoring centre and which optionally leads to the elevator control being triggered to drive the elevator car to the next stop and to open the door to release the passengers. Thereafter, the elevator could be put out of service. With this measure, the invention is able to keep the condition of the overspeed governor rope such that it does not tend to stuck with any component of the OSG or of the elevator.

Preferably, in one embodiment of the invention, only one detector element is provided in the OSG monitoring device whereby in this case, preferably the electric fault circuit is configured to issue a fault signal only if the contact signal is issued by the sensor device over a minimum predetermined minimum time period. Via this measure, it could be ensured that a fault signal is given only when either one long wire strand or wire protrudes from the surface over a certain minimum length which leads to the

corresponding minimum contact period with the detector element or when several successive protruding wires contact the detector element continuously so that the summarized length of contact receives the predetermined minimum time period. Thus, via this measure, it could be ensured that a fault signal is only given when the overspeed governor rope has been worn down to a certain extent, i.e. one wire protruding over a larger length or several wires protruding successively.

In another embodiment, two or more detector elements are located in a predetermined mutual distance along the length of the overspeed governor rope. This distance is preferably comparably short as for example between 0,5 cm and 10 cm, particularly between 1 cm and 5 cm. A fault signal is only given if the sensor devices or the at least one sensor device issues a contact signal for both of the detector elements

simultaneously. Also this embodiment ensures that either one wire is protruding from the surface over a length as being able to contact both detector elements simultaneously or several successive wires are protruding from the surface of the OSG rope contact both detector elements simultaneously. This leads to the issuing of a fault signal by the electric fault circuit and accordingly to the measures which are mentioned above.

Of course, the issuing of a fault signal could also lead to other safety measures which are per se known to the skilled person as e.g. immediate stop of the elevator car by de- energizing the elevator drive machine and/or activation of the elevator brakes by de- energizing the brake coils. Anyway, preferably, the elevator car is driven to the next stop as to release passengers currently travelling with the elevator car before optionally deactivating the elevator. It is generally sufficient to deactivate the elevator only after the passengers in the elevator car are released. In this connection, also messages can be given to the passengers via a display or loudspeaker as to leave the elevator car.

Preferably, the detector elements are configured as detector rings which are most preferably closed and surround the overspeed governor rope totally. Preferably, the detector ring surrounds the overspeed governor rope concentrically so that the distance of the detector ring from the rope surface is identical over all sectors of the overspeed governor rope.

The sensor device connected with the detector element is preferably an electric sensor device which is configured to measure a voltage and/or current running between a measuring circuit electrically contacted with the detector ring and the OSG rope. Of course, in which case the detector element is electrically conducting, preferably made of metal, at least in a part surrounding the overspeed governor rope. The measuring of an electric contact between the detector element and the overspeed governor rope is technically easy and very reliable as even a slight contact of a wire with the detector element immediately leads to the flow of current or to the change of the voltage level of the detector element.

Preferably, a voltage can be applied to the detector element, in which case the contact of a wire or wire strand with the detector element immediately leads to a drop of the voltage and/or a current flow from the detector element to the OSG rope. Alternatively or additionally, the sensor device may be a mechanical sensor which registers a force imposed by a protruding wire or wire strand to the detector element which mechanical force could be for example transmitted via a piezo-element or any other electromechanical transducer into an electric signal.

Of course, the detector element can be connected with an electric sensor device as well as with a mechanical sensor device so that via the strength of the mechanical force imparted from the wire(s) to the detector element, it can be determined how much a wire of the OSG rope protrudes from the surface of the overspeed governor rope or how many wires or strands are protruding therefrom.

In case an electric sensor device is used, the detector element is connected with a voltage source having a voltage between 24 and 500 V, whereby low voltages are safer in use and handling.

In case several detector elements are used, preferably each detector element has its own sensor device, although it is possible to use one sensor device for several detector elements, in which case the sensor device should be able to differentiate between the different detector elements, e.g. having different channels.

Preferably, the detector element is a detector ring made of a sheet metal which is easy to produce and easy to mount in a corresponding location around the OSG rope.. Thus, in case of the use of two detector rings, two of these sheet metal plates can be located spaced apart by isolating elements. Each of these sheet metal parts are then connected to a voltage source and with an electric sensor device.

Although it is preferred to have a closed detector sing, it may be advantageous to have a gap in the detector ring, that allows the insertion of the OSG rope, so that the detector ring can be mounted from the side to surround the OSG rope. Of course, preferably also detector elements may be used which comprise several parts which form a closed ring only after being mounted to each other. Also in this case the detector element can be mounted around an OSG rope, without de-roping of the rope (which is necessary with a fully closed detector ring).

The sensor device(s) and the electric fault circuit may be implemented as one integrated circuit or being separate units. These components furthermore can be implemented in the elevator control or in separate units connected with the elevator control.

The invention also relates to a method for detecting wear in an OSG rope, wherein at least one detector element is placed in a location along the length of the OSG rope as to surround the rope. The detector element is configured to sense wires projecting from the surface of the OSG rope via mechanical and/or electric contact with the projecting wire. This contact is sensed by a sensor device issuing a contact signal. In case of such a contact (and contact signal) a fault signal is issued by an electric fault circuit of the OSG rope monitoring device which is in electric contact with the detector element or the sensor device.

This fault signal is issued by the electric fault circuit either when one detector element is contacted over a predetermined minimum time period by at least one protruding wire of the OSG rope or when at least two detector elements are used and a contact with at least one wire protruding from the surface of the OSG rope is detected with both detector elements simultaneously.

Both alternatives show that the OSG rope is worn to a certain degree which increases the possibility of the OSG rope stucking with a component of the OSG or of the elevator, which situation could affect safety. Of course, also three or four detector elements may be used which anyway do not bring a lot of additional information with regard to the use of two detector elements. Via the inventive method, the skilled person is able to detect a certain degree of wear of the overspeed governor rope which might inflict the danger of the overspeed governor rope stucking to any components of the elevator, the elevator car or of the overspeed governor, for example the governor pulleys.

The corresponding minimum time period for the contact with one detector element can be calculated according to the travel velocity of the elevator car and to the allowed maximum length of the wire protruding from the surface of the overspeed governor rope. It usually is in the area of 0.1 to 10 ms in a case of a car velocity of 1 m/s.

It shall be clear that the method of the invention can be used in connection with the above-mentioned elevator or that the above-mentioned elevator is configured to use the method as described herein.

Preferably, the detector element, preferably detector ring, is arranged to surround the overspeed governor rope concentrically. Via this measure, it is obtained that the distance between the detector element and the overspeed governor rope is identical to all sides respectively sectors of the overspeed governor rope.

Following terms are used in synonym : OSG - overspeed governor;

The invention is hereinafter described via an exemplary embodiment in connection with the enclosed schematic drawings. In these drawings

Fig . 1 an elevator with an OSG rope monitoring device,

Figs. 2a-d two detector elements of the OSG rope monitoring device along a running

OSG rope with one protruding wire, with the rope passing through the two detector elements,

Figs. 2e-g two detector elements along a running OSG rope with several protruding strands passing through the two detector elements, and

Fig . 3 shows a runtime diagram of the electric contact of a first detector element and a second detector element and the resulting fault signal of the electric fault circuit of the OSG rope monitoring device. Fig. 1 shows an elevator 10 having an elevator car 12 suspended on hoisting ropes 14 running around the traction sheave of an elevator drive machine 16. Also a

counterweight 18 can optionally be suspended on the hoisting ropes 14. The elevator can also have separate hosting ropes and suspension ropes. The elevator car 12 is connected at one connection point with the OSG rope 20 of an overspeed governor 21, which OSG rope 20 is running between an upper governor pulley 22 located in the top of the elevator shaft and a lower governor pulley 24 located in the bottom of the elevator shaft. One of these pulleys could also be tensioned with a tensioning device, for example a tension weight. A speed monitoring device is located in connection with one of the governor pulleys 22, 24 to check the rotational speed of the pulley. Accordingly, a gripping device 26 of the elevator car 12 is activated to grip the guide rails in the elevator shaft (not shown) when a threshold value of the rotational speed is exceeded.

The elevator drive machine 16 is controlled by an elevator control 28. The elevator 10 further comprises an OSG rope monitoring device 30 having two ring-like detector elements, i.e. detector rings 32, 34 made preferably of sheet metal, which are electrically contacted to electrical sensor devices 36, 38 of the OSG rope monitoring device 30. The electrical sensor device 36, 38 are connected to an electric fault circuit 40 of the OSG rope monitoring device 30 which is possibly integrated in the elevator control 28 as shown in the figure. Of course, the electric fault circuit 40 could also be located separately from the elevator control 28 in which case it should be electrically connected therewith. The electric fault circuit 40 is connected, optionally via the elevator control 28 with a public communication network 42, for example the Internet and from there to a remote monitoring center 48. The elevator control 28 is connected via control line 44 with the elevator drive machine 16 and its elevator brakes (not shown).

In the figure, a detail D of the overspeed governor rope 20 with the detector elements 32, 34 is shown in the top of the figure in an enlarged view (dotted rectangular) as to clarify the embodiment of the detector elements 32, 34 along the path of the overspeed governor rope 20 (as shown in the small dotted rectangular at the left lower side of the figure).

The function of the invention is shown in connection with Fig. 2. During the travel of the elevator car 12 along its shaft, the overspeed governor rope 20 runs through the detector elements 32, 34 fixed at the elevator shaft or any component of the elevator. Thus, if a strand or wire 46 of the overspeed governor rope 20 projects from its surface 23, it electrically and/or mechanically contacts the ring-like detector element 34, 32 at contact point 47. Thereby, it either generates an electric contact with the detector element 32, 34 which can be sensed by the corresponding electric sensor device 36, 38. The sensing device may alternatively or additionally comprise a mechanical which is able to detect a force, for example electrical-mechanical transducers. If only one of the detector elements 32, 34 contacts with a strand 46 of the overspeed governor rope 20, the electric fault circuit 40 receives one contact signal of an electric sensor device 36, 38. Only in case one strand 46 is long enough to contact both detector elements 32, 34, the electric fault circuit 40 issues a fault signal to the elevator control 28 as well as to the public communication network 42 which is connected with a remote monitoring centre 48 and/or it triggers the elevator control 28 to drive the elevator car in travelling direction (arrow) to the next stop 50 in travelling direction. This situation can be obtained e.g. with one wire or strand 46 long enough to contact both detector elements 32, 34 or with several wires 46a-ed contacting both detector elements simultaneously as shown in Fig. 2f. In this case, the electric fault circuit 40 which may in an easy embodiment comprise an AND logic issues the fault signal which leads to the driving of the car 12 to the next stop 50 in traveling direction (arrow) and to the opening of the car doors to release the passengers. Thereafter the elevator may be de-activated and to a maintenance signal may be sent to the remote monitoring center 48.

Thus, the invention is able to increase the safety of the elevator 10 essentially.

Fig. 3 shows an signal diagram of the components 36, 38, 40 of the OSG rope monitoring device. The horizontal axis shows the time in ms and the vertical axis a voltage level of the signal outputs of the sensor devices 36, 38 as well as of the electric fault circuit 40.

The two uppermost signal lines show the signals of the two sensor devices 36, 38. At the contact situations 47 the voltage level of the detector elements drops because of the contact with a strand/several strands which leads to contact signals of the sensor devices 36, 38 forwarded to the electric fault circuit 40. The signals of both sensor devices 36, 38 are lead to an AND logic in the electric fault circuit 40. This results in a fault signal 52 when in both sensor devices 36, 38 a contact signal 47 is issued simultaneously, which leads to the measures described above. In this connection it is to be mentioned that the diagram has been taken with an elevator velocity of 1 m/s whereby the distance between the dotted lines in horizontal direction corresponds to 10 ms.

It shall be clear for the skilled person that the invention is not delimited to the above- mentioned embodiments but may be varied within the scope of the appended patent claims. List of reference numbers elevator

elevator car

hoisting ropes

elevator drive machine

counterweight

OSG rope

overspeed governor - OSG

upper governor pulley

lower governor pulley

gripping device of the elevator car

elevator control

OSG rope monitoring device

first detector element - first detector ring

second detector element - second detector ring first sensor device

second sensor device

electric fault circuit - fault detection circuit

public communication network - Internet - phone network control line for elevator drive machine

protruding strand(s)/wire(s)

contact point / contact signal

remote monitoring center

floor or stop of the elevator

fault signal of the electric fault circuit

Claims

1. Elevator comprising at least one elevator car driving in at least one elevator shaft via an elevator drive machine (16) controlled by an elevator control (28), which elevator comprises an overspeed governor (OSG) having an OSG rope (20) running between a governor pulleys (22, 24) in the shaft top and shaft bottom,

whereby the OSG rope (20) is fixed to the elevator car,

characterized in that the elevator (10) comprises an OSG rope monitoring device (21) comprising at least one, preferably two detector elements (32, 34) surrounding the OSG rope (20),

whereby the at least one detector element (32, 34) is connected with at least one sensor device (36, 38),

and which sensor device (36, 38) is configured to issue a contact signal if the detector element (32, 34) is in contact with at least one wire (46) protruding from the surface (23) of the OSG rope (20), whereby the OSG monitoring device (21) further comprises an electric fault circuit (40) connected to the elevator control (28) which electric fault circuit (40) is configured to issue a fault signal (52) if the at least one sensor device (36, 38) issues a contact signal (47).

2. Elevator according to claim 1, wherein the OSG rope monitoring device (21) comprises one detector element (32, 34) and the electric fault circuit (40) is configured to issue a fault signal (52) only when the contact signal (47) appears over a minimum

predetermined time period.

3. Elevator according to claim 1, wherein the OSG rope monitoring device (21) comprises at least two detector elements (32, 34) and the electric fault circuit (40) is configured to issue a fault signal (52) when a contact signal (47) is detected at two detector elements (32, 34) simultaneously.

4. Elevator according to one of the preceding claims, wherein the sensor device (36, 38) is an electric sensor and is configured to measure a voltage and/or current running between a measuring circuit electrically contacted with the detector element (32, 34) and the OSG rope (20), whereby at least a part of the detector element (32, 34) is electrically conducting.

5. Elevator according to one of the preceding claims, wherein the detector elements (32, 34) are connected to a voltage source and the sensor device (36, 38) is configured to measure the voltage level of the detector element (32, 34) or the current flowing from the detector element (32, 34) to the OSG rope (20).

6. Elevator according to one of the preceding claims, wherein the sensor device (36, 38) is an mechanical sensor and is configured to measure a mechanical impact being imposed the detector element (32, 34) by the at least one protruding wire (46).

7. Elevator according to one of the preceding claims, comprising at least two detector elements (32, 34) which are connected with their own sensor device (36, 38),

respectively.

8. Elevator according to one of the preceding claims, wherein the elevator control (28) is upon receipt of a fault signal (52) configured to drive the car to the next stop in travelling direction of the elevator car and to de-activate the elevator after stopping and opening the car doors.

9. Elevator according to one of the preceding claims, wherein the mutual distance of at least two detector elements (32, 34) along the OSG rope (20) is between 0,5 and 10 cm, preferably between 1 and 5 cm.

10. Elevator according to one of the preceding claims, wherein the at least one detector element is a metal element (32, 34), preferably made of sheet metal.

11. Elevator according to one of the preceding claims, wherein the at least one detector element (32, 34) is a detector ring (32, 34) surrounding the OSG rope (20).

12. Method for detecting wear in an OSG rope (20) under use of an OSG rope monitoring device (21), wherein at least one detector element (32, 34) is placed in a location along the length of the OSG rope (20) as to surround the OSG rope (20), whereby the detector element (32, 34) is configured to sense rope wires (46) or strands projecting from the surface (23) of the OSG rope (20) by mechanical and/or electric contact with the detector element (32, 34), whereby a fault signal (52) is issued by an electric fault circuit (40) of the OSG rope monitoring device (21) when - either one detector element (32, 34) is contacted over a predetermined minimum time period,

- or at least two detector elements (32, 34) are used and a contact is detected at both detector elements (32, 34) simultaneously.

13. Method according to claim 12, wherein two detector elements (32, 34) are placed in a fixed mutual distance along the length of the OSG rope (20).,

14. Method according to claim 13, wherein the mutual distance is between 0,5 and 10 cm, preferably between 1 and 5 cm.

15. Method according to claim 12, 13 or 14, wherein a detector ring (32, 34) is used as the at least one detector element (32, 34), which detector ring (32, 34) is placed to surround the rope, preferably concentrically.

16. Method according to one of claims 12 to 15, wherein after issuing a fault signal (52) the elevator car (12) is stopped at the next floor (50) in driving direction of the elevator car (12) and optionally passengers are released by opening the car doors, whereafter the elevator (10) is put out of service.

17. Method according to one of claims 12 to 16, wherein the fault signal (52) is transmitted to a remote monitoring center (48).

18. Method according to one of claims 12 to 17, being performed in an elevator (10) according to one of claims 1 to 11.