TRACTION BELT MISALIGNMENT INDICATOR

Abstract

 A traction belt (18) for an elevator system (10) comprises a running surface (30) for contacting a pulley (20) and two side surfaces (28) neighbouring the running surface (30), wherein at least one of the side surfaces (30) comprises an outer layer (34) adapted for being rubbed off, when the side surface (28) touches a flange (48) of the pulley (20), such that a differently looking area (40) of the traction belt (18) becomes visible.

Description

[0001] The present invention relates to a traction belt and a pulley for an elevator system as well as to the elevator system. Furthermore, the invention relates to a use of a layer of a side surface of a traction belt and/or a coating on an inner surface of a flange of a pulley for determining a misalignment of the traction belt.

[0002] Elevator systems comprise an elevator cabin that is vertically moved in a shaft with a drive. In particular for higher shafts, the cabin is moved with the aid of a traction means. The traction means usually runs over a drive pulley and a number of deflection pulleys, which inter alia may be attached to the cabin and the counter weight.

[0003] Traction belts are usually very sensible with respect to misalignment of the pulleys. For a proper operation of the elevator system, a misalignment of a traction belt with respect to the pulleys is only tolerated within a specific limit. When the misalignment leaves the limit, undesired sounds or a jumping of a profiled traction belt may be possible. A jumping of the traction belt may refer to a situation, when the profile of the traction belt profile leaves the corresponding profile of a pulley and runs over the pulley in a not intended way.

[0004] To prevent a jumping of the traction belt, one or more of the deflection pulleys may be provided with flanges, i.e. may be flanged pulleys. However, this may result in further sounds and a higher wear of the traction means.

[0005] There may be a need for better determining a misalignment of a traction belt. There also may be a need for easier detecting wear of a traction belt caused by misalignment.

[0006] Such needs may be met with the subject-matter of the independent claims. Advantageous embodiments are defined in the dependent claims.

[0007] Ideas underlying embodiments of the present invention may be interpreted as being based, inter alia, on the following observations and recognitions.

[0008] An aspect of the invention relates to a traction belt for an elevator system. The traction belt may comprise an elongated cross-section, for example may have a substantial rectangular outer shape. Furthermore, the traction belt may comprise one or more metal strands that are encased in elastomer material. An elevator system may be any kind of system for moving an elevator cabin vertically in a shaft. Usually, the elevator system comprises a drive, such as an electrical motor, which via a drive pulley moves the traction belt, which runs over further deflection pulleys attached to the elevator cabin, the shaft, counter weights, etc.

[0009] According to an embodiment of the invention, the traction belt comprises a running surface for contacting a pulley and two side surfaces neighbouring the running surface. The running surface may be opposite to a back surface of the traction belt, which is substantially parallel to the running surface. The side surfaces may interconnect the running surface with the back surface. The side surfaces may be substantially parallel and/or substantially orthogonal to the running surface.

[0010] According to an embodiment of the invention, at least one of the side surfaces comprises an outer layer adapted for being rubbed off the side surface, when the side surface touches a flange of the pulley, such that a differently looking area of the traction belt becomes visible. The outer layer may be a part of the elastomer material of the traction belt or may be a coating on the elastomer material. Also, the differently looking area may be a part of the elastomer material of the traction belt or may be a further coating on the side surface.

[0011] The outer layer on the differently looking area may be seen as an indicator that may be used during approval or service, whether the pulleys are correctly aligned with respect to the traction belt.

[0012] In the case, the traction belt is properly aligned with respect to the pulley, the side surfaces of the traction belt do not touch the flanges of the pulley, which are primary a security device for preventing the traction belt to completely jump of the pulley. In this case, the outer layer is not subjected to abrasive wear, i.e. is not rubbed off. In this case, the outer layer stays intact. For a person looking at the side surface, no color or pattern change is visible, the whole side surface of the traction belt has the same color or at least the same pattern.

[0013] In the case, the traction belt is not properly aligned with respect to the pulley, at least one or both sides start to touch the flanges of the pulley and the outer layer is subjected to abrasive wear. At least a part of the outer layer is rubbed off and the differently looking area beneath becomes visible. Now, for a person looking at the side, a color or pattern change is visible.

[0014] Since the outer layer is provided on the side surface of the traction belt, the outer layer does not influence the friction properties between the running surface of the belt and the running surface of the pulley.

[0015] It has to be noted that both side surfaces may be provided with an outer layer and a differently looking area as described in the above and in the following.

[0016] According to an embodiment of the invention, the outer layer and the differently looking area are made from a material of the traction belt, for example from an elastomer material of the traction belt, which provides the running surface and/or which surrounds metal strands of the traction belt. For example, the outer layer may have a different color as a central part or core of the traction belt, which provides the different color area. Furthermore, it may be possible that the differently looking area is a layer of material sandwiched between the outer layer and the central part or core of the traction means.

[0017] In both cases, wear on the side surface causes the outer layer to be rubbed off, such that the differently looking material below becomes visible.

[0018] When the outer layer and/or the differently looking area are made of the same material as a central part or a core of the traction belt, the traction belt together with the indicator may be produced in one step during extrusion of the traction belt. For example, the outer layer and the differently looking area may be made with differently colored extrusion granulate.

[0019] According to an embodiment of the invention, the outer layer is a coating on the traction belt, such as paint. For example, the coating may be made with paint of a different color as the elastomer material of the traction belt, which may provide the differently looking and in this case differently colored area.

[0020] A coating may be renewed, after the misalignment of the one or more pulleys has been corrected. For example, a paint stick may be used for applying the coating again on the side surface of the traction, in particular in areas, where the coating has been rubbed off.

[0021] According to an embodiment of the invention, the differently looking area is a coating on the traction belt. In this case, both of the outer layer and the differently looking area may be coatings with different colors and/or different patterns. The coating of the outer layer may be made of a material that is rubbed off more easily than the material of the coating of the differently looking area.

[0022] According to an embodiment of the invention, the outer layer and the differently looking area have different colors. In general, also black and white may be colors. Furthermore, it may be possible that the outer layer and the differently looking area provide different patterns. When the pattern of the outer layer is rubbed off, the pattern of the differently looking area becomes visible.

[0023] According to an embodiment of the invention, the outer layer and the differently looking area are provided along a section of the traction belt longer than 50% of the traction belt. It may be that the side surfaces of the traction belt are provided with the indicator over nearly all of the extension of the traction belt. In this case, even specific pulleys, which are misaligned, may be identified, since only specific parts of the traction belt have a rubbed off outer layer.

[0024] According to an embodiment of the invention, the running surface is flat. The traction belt may be a flat belt, for example with a rectangular cross-section. In the case of a flat belt, the belt may be centred with a bulged pulley.

[0025] According to an embodiment of the invention, the running surface is profiled. A profiled traction belt may have grooves and/or protrusions that run parallel to the extension of the traction belt. In this case, the pulley may have a complementary running surface. In particular in the case of a profiled belt, that has a repeating profile (i.e. equally formed grooves and/or protrusions), the traction belt may slip within the profile due to misalignment, which however may not be seen. In this case, a visual indicator showing the misalignment may be very helpful.

[0026] There are different possibilities, how the profile of the running surface may be formed. For example, the running surface may have V-shaped grooves, which may run in V-shaped grooves in the pulley. Furthermore, the running surface may have round protrusions running in round grooves in the pulley.

[0027] A further aspect of the invention relates to a pulley for an elevator system. On the other hand, a misalignment indicator may be provided on the pulley. This indicator also may be based on abrasive wear between a side surface of the traction belt and a flange of the pulley. For example, the pulley may be the drive pulley, a deflection pulley attached to the cabin and/or a deflection pulley attached to the shaft.

[0028] According to an embodiment of the invention, the pulley comprises a running surface for contacting the traction belt and two flanges neighbouring the running surface. The flanges may be substantially parallel and may border the inner part of the pulley with the running surface. At least one of the flanges comprises a coating on an inner surface adapted for being rubbed off the inner surface, when the inner surface touches the traction belt. The pulley may be a flanged pulley with flanges preventing the traction belt from jumping of the pulley, when it is misaligned. It has to be noted that both inner side surfaces of the flanges may be covered with such a coating.

[0029] When the traction belt touches the flanges, the coating will be rubbed off and the uncoated inner surface below the coating, which may look differently as the coating, becomes visible. A person looking at the inner surfaces can see, when the coating has been rubbed off at least partially and may conclude that the traction belt and the pulley are misaligned.

[0030] The coating on the inner surface of the flange of the pulley may be used as indicator, whether the traction belt has touched the flange. However, in this case, it may not be possible to determine the segment of the traction belt, which has touched the flange of the pulley.

[0031] According to an embodiment of the invention, the coating has a color different from a color of the flange. For example, the coating may be based on a paint with a different color than the inner surface.

[0032] According to an embodiment of the invention, the running surface is profiled. When the pulley is a pulley for a profiled belt, the running surface of the pulley also may be profiled as described above and below. For example, the running surface has V-shaped grooves or circular grooves.

[0033] A further aspect of the invention relates to an elevator system as described in the above and in the below, which comprises a traction belt and/or at least one pulley as described in the above and in the following.

[0034] According to an embodiment of the invention, the elevator system comprises an elevator cabin in an elevator shaft, a drive for moving the elevator cabin inside the shaft and a traction belt running over a drive pulley attached to the drive and over at least one deflection pulley attached to the elevator cabin and/or the elevator shaft. The traction belt may be a traction belt with a cover layer covering a differently looking area. At least one pulley of the drive pulleys and the at least one deflection pulleys may be a flanged pulley with a coating on an inner surface of one or both of the flanges.

[0035] A further aspect of the invention relates to a use of an outer layer on a differently looking area on a side surface of a traction belt and/or a coating on an inner surface of a flange of a pulley for determining a misalignment of the traction belt of an elevator system. It has to be understood that features of the traction belt, the pulley and/or the elevator system may be features of the use and vice versa.

[0036] In the following, advantageous embodiments of the invention will be described with reference to the enclosed drawings. However, neither the drawings nor the description shall be interpreted as limiting the invention.

Fig. 1 schematically shows an elevator system according to an embodiment of the invention.

Fig. 2 schematically shows a perspective view of a traction belt according to an embodiment of the invention.

Fig. 3 schematically shows a cross-sectional view of a traction belt according to an embodiment of the invention.

Fig. 4 schematically shows a view of a pulley according to an embodiment of the invention.

Fig. 5 schematically shows a cross-sectional view of a traction belt and a pulley according to an embodiment of the invention.

Fig. 6 schematically shows a cross-sectional view of a traction belt and a pulley according to an embodiment of the invention.

[0037] The figures are only schematic and not to scale. Same reference signs refer to same or similar features.

[0038] Fig. 1 shows an elevator system 10 with an elevator cabin 12 movable vertically in an elevator shaft 14. The elevator cabin 12 is moved by a drive 16, which moves a traction belt 18 that runs around a drive pulley 20, 20a on the drive 16 and deflection pulleys 20, 20b attached to the elevator cabin 12. A further deflection pulley 20, 20b is attached to a counter weight 22, which is lowered, when the elevator cabin is raised and vice versa. With its ends, the traction belt 18 is attached to the elevator shaft at fixation points 24.

[0039] When one of the pulleys 20 is misaligned, this may cause unwanted sounds and a higher wear of the traction belt 18. The following drawings show embodiments of traction belts 18 and pulleys 20 that may be used with the elevator system 10 of Fig. 1. These embodiments all comprise a visual indicator for determining a misalignment of a pulley. For example after installation or during inspection, a person may look at this visual indicator provided on the traction belt and/or one or more pulleys and may determine, whether a pulley has to be aligned more accurately.

[0040] Fig. 2 shows a traction belt 18 with a visual indicator 26 on its side surfaces 28. In general, the traction belt 18 has a substantially rectangular cross-section with a profiled running surface 30, a substantially flush back surface 32 and two narrower side surfaces 28, which also may be substantially flat. The traction belt may be made of elastomer material 33, in which a number of strands or cables 36, usually made of metal, are embedded. The running surface 30 may be profiled and, as shown in Fig. 2, may have V-shaped grooves 38.

[0041] The visual indicator 26 is provided in the form of an outer layer 34 on the side surfaces 28. The outer layer 34 may be made of the material 33 or may be a coating on this material 33.

[0042] The outer layer 34 is adapted for being rubbed off, when the traction belt 18 touches a pulley 20 in the case, the traction belt 18 is misaligned. The pulleys 20 and the traction belt 18 are designed in such a way that in the case of well alignment, a gap is provided between the side surface 28 and a flange of the pulley 20.

[0043] Fig. 2 shows that below the outer layer 34, a differently looking area 40 becomes visible, when the outer layer 34 is rubbed off, which is the case, when a misalignment between the pulley 20 and the traction belt 18 is higher than a threshold. The differently looking area 40 may have another color and/or other pattern as the outer layer 34.

[0044] Fig. 3 shows that the visual indicator 26 may comprise an outer layer 34 and an optional intermediate layer 42, which may be made of the same material 33 as the traction belt 18.

[0045] In the case of only the outer layer 34, the outer layer may have a different color as the material. In this case, the differently looking area 40 is provided by the material 33.

[0046] In the case of the outer layer 34 on the intermediate layer 42, the outer layer 34 and the intermediate layer may have different colors. The outer layer 34 may have the same color as the material 33 or may have a different color. In this case, the differently looking area 40 is provided by the intermediate layer 42.

[0047] In both cases, the layer 34 or the two layers 34, 42 may be made during extrusion of the traction belt 18, for example with differently colored granulates.

[0048] Fig. 4 shows a pulley 20 with a visual indicator 26 based on a coating 44 applied to the inner surfaces 46 of the flanges 48 of the pulley 20. The pulley 20 is a flanged pulley with a profiled running surface 50 that is arranged between the two flanges 48. In the case of Fig. 4, the pulley 20 fits to a V-shaped traction belt 18 as shown in Fig. 2 or 3 and also has a V-shaped running surface 50.

[0049] The coating 44 may be a paint coating with a different color than the material of the pulley 20 (usually metal).

[0050] In general, it has to be noted that the visual indicator 26 only may be provided of some of the pulleys 20a, 20b of Fig. 1. Furthermore, it is possible that the visual indicator is provided only on the pulleys 20 or only on the traction belt 18.

[0051] Furthermore, the visual indicator 26, i.e. the outer layer 34 and the optional intermediate layer 42, on the side surfaces 28 of the traction belt may be provided substantially completely along the length of the traction belt 18. The visual indicator 26, i.e. the coating 44, on the inner surfaces 46 of the pulley 20 may be provided substantially completely along the circumference of the pulley 20.

[0052] Fig. 5 shows a further embodiment with a flat traction belt 18 that has a flat running surface 30. In this case, the pulley 20 may have a bulged running surface 50 for centring the traction belt 18. The visual indicator 26 on the side surface 28 of the traction belt 18 is a single layer 34 in the form of a coating, for example a paint coating. The visual indicator 26 on the pulley 20 may be a coating as described with respect to Fig. 4.

[0053] Fig. 6 shows a further embodiment with a profiled traction belt 18 that has a running surface 30 with round protrusions 52. In this case, the pulley 20 may have round grooves on the running surface 50. The visual indicator 26 on the side surface 28 of the traction belt 28 is a single layer 34 made of a differently color elastomer material. The visual indicator 26 on the pulley 20 may be a coating as described with respect to Fig. 4.

[0054] Finally, it should be noted that the term "comprising" does not exclude other elements or steps and the "a" or "an" does not exclude a plurality. Also elements described in association with different embodiments may be combined. It should also be noted that reference signs in the claims should not be construed as limiting the scope of the claims.

List of reference signs

[0055] 

10

elevator system

12

elevator cabin

14

elevator shaft

16

drive

18

traction belt

20

pulley

20a

drive pulley

20b

deflection pulley

22

counter weight

24

fixation point

26

visual indicator

28

side surface

30

running surface

32

back surface

33

elastomer material

34

outer layer

36

cable

38

groove

40

differently looking area

42

intermediate layer

44

coating

46

inner surface

48

flange

50

running surface

52

round protrusion

Claims

1. A traction belt (18) for an elevator system (10), the traction belt (18) comprising:

a running surface (30) for contacting a pulley (20);

two side surfaces (28) neighbouring the running surface (30);

wherein at least one of the side surfaces (30) comprises an outer layer (34) adapted for being rubbed off, when the side surface (28) touches a flange (48) of the pulley (20), such that a differently looking area (40) of the traction belt (18) becomes visible.

2. The traction belt (18) of claim 1,
wherein the outer layer (34) and the differently looking area (40, 42) are made from a material (33) of the traction belt (18).

3. The traction belt (18) of claim 1,
wherein the outer layer (34) is a coating on the traction belt (18); and/or
wherein the differently looking area (40) is a coating on the traction belt (18).

4. The traction belt (18) of one of the previous claims,
wherein the outer layer (34) and the differently looking area (40) have different colors.

5. The traction belt (18) of one of the previous claims,
wherein the outer layer (34) and the differently looking area (40) are provided along a section of the traction belt (18) longer than 50% of the traction belt.

6. The traction belt (18) of one of the previous claims,
wherein the running surface (30) is flat.

7. The traction belt (18) of one of claims 1 to 5,
wherein the running surface (30) is profiled.

8. The traction belt (18) of claim 7,
wherein the running surface (30) has V-shaped grooves; or
wherein the running surface (30) has round protrusions (52).

9. A pulley (20) for an elevator system (10), the pulley (20) comprising:

a running surface (50) for contacting a traction belt (18);

two flanges (48) neighbouring the running surface (50);

wherein at least one of the flanges (48) comprises a coating (44) on an inner surface (46) adapted for being rubbed off the inner surface (46), when the inner surface (46) touches the traction belt (18).

10. The pulley (20) of claim 9,
wherein the coating (44) has a color different from a color of the flange (48).

11. The pulley (20) of claim 9 or 10,
wherein the running surface (50) is profiled.

12. The pulley (20) of one of the claims 11,
wherein the running surface (50) has V-shaped grooves or circular grooves.

13. An elevator system (10), comprising:

an elevator cabin (12) in an elevator shaft (14);

a drive (16) for moving the elevator cabin (12) inside the elevator shaft ( 14);

a traction belt (18) running over a drive pulley (20a) attached to the drive (16) and over at least one deflection pulley (20b) attached to the elevator cabin (12) and/or the elevator shaft (14);

wherein the traction belt (18) is a traction belt according to one of the claims 1 to 8 and/or at least one pulley (20) of the drive pulleys and the at least one deflection pulleys is a pulley according to one of the claims 9 to 12.

14. The elevator system (10) of claim 13,
wherein the running surface (30) of the traction belt (18) is profiled;
wherein both side surfaces (28) of the traction belt (18) comprise an outer layer (34) covering a differently looking area (40) and which are provided along a section of the traction belt (18) longer than 50% of the traction belt (18).

15. A use of an outer layer (34) on a differently looking area (40) on a side surface (28) of a traction belt (18) and/or a coating (44) on an inner surface (46) of a flange (48) of a pulley (20) for determining a misalignment of the traction belt (18) of an elevator system (10).

Drawing