CA3231355A1 - Insert element for guiding a rope or cable, rope or cable guide roller and method of manufacturing an insert element - Google Patents

Abstract

Insert element (1) for guiding a rope or cable, in particular for a cableway installation. The insert element (1) comprises a surface layer (2) with a first surface layer side (6), which is designed to come into contact with a rope or cable to be guided, and a second surface layer side (7) opposite the first surface layer side (6), and an indicator element (3), which is arranged on and/or in the surface layer (2). The indicator element (3) is designed to indicate a state of wear of the insert element (1). Furthermore, a pulley comprising the insert element (1) and a method for manufacturing the insert element (1) are provided.

Description

Insert element for guiding a rope or cable, rope or cable guide roller and method of manufacturing an insert element The present invention relates to an insert element for guiding a rope or cable, a rope or cable guide roller and a method for manufacturing the insert element.
Insert elements, sometimes also called linings, are used for rope pulleys or also for deflection pulleys of a ropeway, be it an aerial ropeway, a rail ropeway or a drag lift. The purpose of the insert elements is to support and guide a rope or ca-ble. Furthermore, insert elements also have a sound-absorbing and vibration-damping effect. Due to the provision of such elements in sensitive systems such as ropeways, the wear of such insert elements must be monitored regularly in or-der to be able to replace them in good time before they fail. Such monitoring is usually carried out by trained personnel inspecting the insert elements. The shape of the insert element is measured using a gauge or caliper and compared with an initial state. Based on a deviation of the shape of the insert element from its initial state, a wear condition can be inferred. Due to the often difficult-to-reach insert el-ements (for example on the supports of a cable car), monitoring the insert ele-ments is labor-intensive, difficult, time-consuming and therefore expensive.
It is therefore the object of the present invention to simplify the monitoring of an in-sert element.
This object is solved with an insert element with the features of claim 1, with a rope or cable guide pulley with the features of claim 13 and with a method for manufacturing the insert element with the features of claim 14. Preferred embodi-ments are given in the dependent claims.
According to one aspect of the invention, an insert element for guiding a rope or cable, in particular for a cableway installation, is provided, comprising a surface layer with a first surface layer side which is designed to come into contact with a rope or cable to be guided, and a second surface layer side opposite the first sur-face layer side, and an indicator element which is arranged on and/or in the sur-face layer, and wherein the indicator element is designed to indicate a state of wear of the insert element.
According to one aspect of the present invention, the insert element can also be used in pulleys for lifts, elevators, cranes, etc. Basically, wherever a cable or rope is guided, runs along or is deflected. The invention also relates to so-called wear strips, which can be provided as lockable strips instead of one-piece, closed rope pulley insert elements. For example, such wearable bands can protect a rope or cable from direct contact with a building or other structures. The rope or cable may be a load-bearing structure. In particular, the cable or cord may be non-current-carrying (i.e. power supply) elements. Such a dual function would be counterpro-ductive, as a cable used for power supply should not be used to carry a load at the same time. Nevertheless, test currents or similar can be conducted through the ca-ble or rope.
According to one aspect of the invention, insert elements, linings or linings for rope pulleys protect the rope or cable on the one hand and the rope pulley itself or ra-ther the usually metallic rope pulley sheaves that form it on the other.
Furthermore, the bearing of the rope pulley and the supporting structure can also be protected.
Furthermore, insert elements can also provide increased comfort when guiding the rope through a pulley by ensuring mechanically and acoustically quiet running.
For this purpose, the insert element can be made of a softer and/or more elastic mate-rial than the pulley on which the insert element can be provided. Accordingly, the insert element can be made as a one-piece ring, for example from an elastomer or rubber. The insert element can be realized with or without flexible textile fabric or flexible wire mesh inserts. For high loads, the insert element can be made of a plastic, which can comprise polyurethane as the base polymer and can belong to the category of thermoplastics or thermosets.
In contrast to the prior art, with the insert element according to the invention it is not necessary for a person to be in the immediate vicinity of the insert element in

- 2 -order to check the state of wear of the insert element. Rather, it is sufficient for the insert element to be inspected from a distance, since the indicator element can be used to easily recognize the state of wear of the insert element. For example, when used in ropeway systems, it may be sufficient to inspect an insert element from the ground, for example using binoculars, and thus obtain immediate infor-mation about the state of wear. This can significantly reduce the time required for inspection, so that the wear condition of an insert element can be checked, for ex-ample, as it passes by during an operating run. In this way, the previously known time-consuming and risky work of checking the insert elements can be reduced or avoided and at the same time it can be ensured that the state of wear can be ob-jectively determined independently of the person carrying out the inspection thanks to the objective display by the indicator element. This ensures that the in-sert element is always replaced at the same time. In contrast, purely visual and in-dividual inspection by a person does not guarantee that several insert elements are assessed objectively at the same time. Consequently, by using the insert ele-ment according to one aspect of the present invention, replacement intervals of the insert elements can be standardized.
The insert element can be a separate part and designed to be fixed in a roller. The roller, in turn, can be held rotatably on a structure such as a support. For example, the pulley can be rotatably mounted on the structure by means of a plain bearing or roller bearing. A rope or cable can be placed on the insert element and sup-ported and/or guided by it. A cable guide direction can designate the direction in which the cable to be guided extends. The insert element can also be designed to protect the cable against lateral displacement transverse to the cable guide direc-tion. For this purpose, the insert element can have a lower strength than the pul-ley. In other words, the insert element can be formed from an elastic material that at least partially surrounds the cable to be guided. In order to improve a guiding property, the insert element can at least partially adapt to the shape of the rope to be guided.
Preferably, the insert element is designed as a single piece. In other words, the in-sert element cannot be disassembled into its components in a non-destructive

- 3 -manner. This can ensure high stability and simple manufacture of the insert ele-ment. In particular, with a one-piece or integral insert element, a defined position-ing (for example during a central production of the insert element) is ensured, so that the indicator element always has the same relative position, for example to the surface layer, with several insert elements. This can ensure a consistent deter-mination of wear on the insert element.
The surface layer can be a volume layer that extends in all three spatial directions.
In particular, in a cross-section transverse to the direction in which the cable is guided, the surface layer can have a first surface layer side and a second opposite surface layer side. A surface of the surface layer on the first surface layer side and a surface of the surface layer on the second surface layer side can be many times larger than the side surfaces of the surface layer. The first side of the surface layer can have such a shape that the rope or cable can be reliably guided through the insert element. To this end, the first surface layer side can, for example, have a shape that is complementary to the rope or cable to be guided. Preferably, the first surface layer side has such a shape that the rope is at least partially accommo-dated in the surface layer. For this purpose, the surface layer can be recessed on the first surface layer side, for example, and/or have an area that is formed from a different (e.g. softer) material.
The indicator element can be influenced and/or changed by an operation (i.e.
by the contact between the rope and the surface layer and/or the indicator layer) in such a way that a wear condition of the insert element, in particular of the surface layer, can be indicated by the indicator element (for example a condition of the in-dicator element). The indicator element can, for example, be a further layer that is arranged, for example, on the second surface layer side of the surface layer.
The indicator element can then become visible as a result of wear on the surface layer, so that it can be quickly and easily determined from the outside looking at the first surface layer side that the surface layer or the insert element is in a certain state of wear. In the case of a ring-shaped core element, for example, the state of wear can be determined by looking at the outside in the radial direction of the core ele-ment (i.e. the contact side between the core element and the rope or cable).
For

- 4 -this purpose, the indicator element can, for example, have a different color from the surface layer. For example, the surface layer can be black and the indicator el-ement white. This ensures that the high contrast makes it quick and easy to recog-nize that the indicator layer has come into contact with the surface of the core ele-ment.
According to a further aspect of the present invention, the indicator element can be a strip which is provided on the first surface layer side of the surface layer at least in the region in which the rope is guided through the surface layer. For example, the indicator element can be a strip-like element which is located transversely to the direction in which the rope is guided and/or along the direction in which the rope is guided in or on the first side of the surface layer. In this case, the indicator element can also have a different color from the surface layer. During operation, the surface layer and the indicator element can be abraded. In this case, the indi-cator element can have a lower material thickness than the surface layer, so that at some point during abrasion the indicator element has disappeared (i.e. is no longer visible), so that when viewed on the first surface layer side it can be recog-nized whether the indicator element is still present there or not.
Furthermore, the indicator element or the indicator elements may have a tapering or widening shape pointing away from the first surface layer side. The visible indicator element can thus be thicker or thinner depending on the wear. The indicator element can thus indicate whether and/or to what extent the surface layer is worn. Particularly in the embodiment in which the indicator element extends transversely to the rope guide direction, it is easy to recognize in which area of the first surface layer side a par-ticularly large abrasion by the rope or cable has taken place. In this way, it is also possible to draw conclusions about an operating condition (for example, eccentric guidance of the rope, uneven loading of the core element, etc.). As a result, opera-tion can be further optimized and safety increased.
Preferably, several indicator elements can be provided in or on the surface layer.
For example, several indicator elements can be provided as layers parallel to the first surface layer side in a way that builds on one another. Each indicator layer can have a different color. It is conceivable, for example, that the indicator element

- 5 -closest to the first surface layer side has a green color, the next indicator element has an orange color and the next indicator element has a red color. In the present embodiment, the insert element can therefore have a total of three indicator ele-ments, each of which is designed as a separate layer. During operation, the sur-face layer is then at least partially worn away first, so that the first (green) indicator element becomes visible. The indicator element can thus indicate that the surface layer is already worn, but that further operation of the insert element is still possi-ble (by the green color of the first indicator element). If the first indicator element is also worn, the second indicator element (yellow layer) appears and indicates that the insert element will soon be worn and needs to be replaced. As soon as the red indicator element becomes visible, the indicator element indicates that the insert element now needs to be replaced. Similarly, the insert element can have a large number of different layers as indicator elements so that close monitoring of the in-sert element is possible. It is also conceivable that the indicator element extends variably relative to the first surface layer side. In this way, a visible pattern can be created on the first side of the surface layer when the surface layer is worn.
The pattern can change depending on the sealing state. For example, the indicator ele-ment can extend in a wavelike manner relative to the first side of the surface layer.
The variable arrangement of the indicator element means that a state of wear can only be detected by specialist personnel and/or image recognition systems and not by passengers or visitors. This prevents untrained persons from misinterpreting the indicator element.
On the one hand, the above insert element reduces the potential danger for the personnel who have to inspect the insert elements, and on the other hand it re-duces the effort involved in determining the wear of the insert element. For exam-ple, the insert element can be checked from a certain distance during an opera-tional journey.
Preferably, the indicator element covers the first surface layer side and/or the sec-ond surface layer side at least partially or in sections.

- 6 -In the case where the indicator element is designed as a volume layer, the indica-tor element can cover the surface layer at least in the area where the rope or cable comes into contact with the surface layer. In other words, in this case the indicator element can be arranged on the first side of the surface layer. Alternatively, or ad-ditionally, the indicator layer can be provided on the second surface layer side (i.e.
on the side of the surface layer facing away from the rope or cable) and extend over the second surface layer side. In this case, the indicator layer only appears when the surface layer is worn. Alternatively, or additionally, the indicator layer can also cover the first side of the surface layer and/or the second side of the surface layer in sections. In this case, the indicator element can be arranged as strip ele-ments (e.g. transverse to or along the rope guide direction). The indicator element can thus be arranged depending on the use of the insert element. For example, a sectional arrangement of the indicator element can be advantageous in a case where the cable or rope comes into contact with the surface layer in a previously known area. On the other hand, a flat arrangement of the indicator element can be provided in a case where it is not clear in advance where wear will occur. The lat-ter can be the case, for example, with large-area insert elements. This means that the insert element can always be provided appropriately for the intended use.
It is also conceivable to provide the indicator element within the surface layer.
For ex-ample, at half the material thickness of the surface layer. This means, for example, that a wear condition can be indicated when the insert element is half worn.
Con-sequently, reliable monitoring of the expected service life of the insert element can be provided.
Preferably, the surface layer comprises SBR, NR, NBR, EPDM, CSM, BR and/or FKM.
This means that the surface layer can have sufficient elasticity to ensure that the cable or rope is guided securely and that the necessary soundproofing and vibra-tion damping effects are achieved. Furthermore, the materials SBR (styrene-buta-diene rubber), NR (natural rubber), NBR (acrylonitrile-butadiene rubber), EPDM

(ethylene-propylene-diene rubber), CSM (hypalon), BR (polybutadiene rubber) and/or FKM (fluororubber) are easy to process, so that the surface layer can be

- 7 -produced easily and in a suitable form. In particular, the insert element can be a vulcanization product. In addition, the above-mentioned materials are inexpensive and therefore make the manufacturing process of the insert element efficient.
Fur-thermore, the surface layer may comprise a mixture of the above materials. The above materials or blends thereof may each constitute the base polymer and may be augmented by additives such as carbon black, etc. In this way, the desired properties (such as color) that are required for the intended use of the insert ele-ment can be easily achieved.
Preferably, the indicator element comprises PE, PP, TPE, PA and/or PETP.
With the above materials, the indicator element can have suitable properties in or-der, on the one hand, to be able to suitably indicate the state of wear and, on the other hand, to have sufficient strength in order, for example, to guide the rope or cable safely and suitably in the event of contact with it and still indicate the state of wear of the insert element. In other words, the indicator layer can comprise PE
(polyethylene), PP (polypropylene), TPE (thermoplastic elastomers), PA (polyam-ides) and/or PETP (polyethylene terephthalate). Furthermore, the indicator ele-ment can also comprise mixtures of the above materials. The above materials could merely represent the base polymer and comprise further additives, such as carbon black and so on. Consequently, the indicator element can also be suitably adapted to the respective area of use of the insert element and have sufficient strength and resistance for long-term operation.
Preferably, the indicator element and the surface layer have different properties, such as in particular hardness, density, tensile strength, elongation at break, abra-sion, rebound elasticity, compression set, tear propagation resistance, glass tran-sition temperature, electrical conductivity and/or swelling.
The surface layer preferably has a Shore-A hardness of greater than 81 Shore.
In contrast, the indicator element can have a Shore-A hardness of less than 80 Shore. It has been found that in the above-mentioned range, a particularly high en-ergy efficiency (especially with regard to the deformation of the insert element) can

- 8 -be achieved when using the insert element in a guide roller for a cableway system.
The fact that the indicator element has a lower hardness compared to the surface layer can ensure that the indicator element is eroded faster than the surface layer on contact with the rope or cable, so that a state of wear can be clearly and easily recognized even from a certain distance. The hardness can, for example, be de-termined in accordance with DIN 53505, DIN EN ISO 868 or analogue.
The density of the indicator element is preferably lower than the density of the sur-face layer. Preferably, the density of the indicator element is less than 1.25 g/cm3 and the density of the surface layer is preferably greater than 1.25 g/cm3 .
This en-sures that the wear condition of the insert element can be clearly indicated.
The density can preferably be determined in accordance with the EN ISO 1183-1 standard. Preferably, the surface layer has a density in the range of 1.26 g/cm3 to 1.28 g/cm3 . This ensures that the weight of the insert element is in a suitable range for use in particular in conjunction with a pulley for a cableway system. In this case, particularly efficient operation of the pulley is possible.
The tensile strength can indicate the maximum mechanical tensile stress that a material can withstand before it fails (e.g. tears). Preferably, the surface layer has a tensile strength of greater than 15 N/mm2 . In contrast, the indicator element can have a tensile strength of less than 15 N/mm2 . In this range, it can be ensured that the surface layer has sufficient resistance to failure. This can ensure the re-quired safety when guiding a rope or cable. In contrast, a lower tensile strength is sufficient for the indicator element, as this is only partially used, if at all, to guide the rope or cable. The areas shown above can be used to form a particularly effi-cient insert element, as the indicator element can be equipped with a lower tear re-sistance and is therefore less expensive.
Elongation at break can be a characteristic value that indicates a permanent elon-gation of a component in relation to its initial length when the component is loaded by a force. In other words, the elongation at break can indicate the deformation ca-pacity of a component. Preferably, the elongation at break can be determined in accordance with the DIN 53504-S2 standard. Preferably, the surface layer has an

- 9 -elongation at break of at least 120%. In contrast, the indicator element has an elongation at break of at least 200%. This ensures that safe operation of the insert element is guaranteed without the risk of premature failure, even if the indicator el-ement is involved in guiding the rope or cable.
Abrasion (also known as abrasion or erosion) can refer to a loss of material on the surface of components. Abrasion can be caused by mechanical stress, such as friction, and/or by environmental influences. Very small particles can usually be produced when material is removed from the component. In materials science, abrasion can also be referred to as wear. Preferably, the abrasion is determined as a volume according to the ISO 4649 - Method A standard. Preferably, the sur-face layer has an abrasion of greater than 160 mm3 . In contrast, the indicator ele-ment has an abrasion of preferably less than 160 mm3 . Furthermore, the abrasion of the surface layer and the indicator element can be limited to a maximum of mm3 . This can also ensure permanent operation of the insert element. This is par-ticularly advantageous if the indicator element is located in the material of the sur-face layer. Furthermore, the upper limit on abrasion can prevent excessive mate-rial from entering the environment.
The rebound resilience can be used to assess the elasticity behavior of elastomers under impact stress. Preferably, the surface layer has a rebound resilience of at least 40 %. In contrast, the indicator element preferably has a rebound resilience of less than 40 %. Preferably, the rebound resilience is determined in accordance with the DIN 53512 standard. Furthermore, the surface layer and the indicator ele-ment can have a rebound resilience of at least 25 %. This ensures that the rope or cable is guided securely on the insert element without bouncing off it, thus ena-bling the rope to be guided securely.
Compression set is a measure of how elastomers behave during prolonged con-stant compression set and subsequent relaxation. Preferably, the compression set is determined over 24 hours at 70 C and 20 % deformation in accordance with the ISO 815 type B standard. Preferably, the surface layer can have a compression set of less than 20%. In contrast, the indicator element can have a compression

- 10 -set of at least 20%. This ensures that the rope is guided securely even if the insert element is subjected to prolonged loading. Furthermore, it can be ensured that the indicator element reliably indicates a state of wear of the core element. A
particu-larly durable core element can be provided in the above area.
The volume resistivity can be a measure of how well a component conducts elec-trical current. The volume resistivity results from the measured volume resistivity multiplied by the measurement area divided by the sample length. Preferably, the volume resistivity is determined in accordance with the IEC 62631-3-2 standard.
Preferably, the surface layer has a volume resistivity of less than 6.7*1013 Ohm*cm. In contrast, the indicator layer preferably has a volume resistivity of at least 5 times 1014 Ohm*cm. This ensures that the indicator element is electrically non-conductive. This is advantageous if, for example, a conductive surface layer is used (e.g. with a volume resistivity of 1.9 times 105 Ohm*cm). In this case, it is possible to detect when the rope is in contact with the insert element only via the indicator element, and thus the electrical resistance increases significantly.
In other words, a voltage can be applied to a rope or cable to be guided, which can be measured at a conductive surface layer. As soon as the surface layer is worn and the rope or cable is only in contact with the insert element via the indicator el-ement, an increased resistance can be detected. This allows the conclusion to be drawn that the surface layer is worn. Alternatively, this configuration can also be designed the other way round, so that the surface layer is non-conductive and the indicator element establishes an electrically conductive connection between a de-tector element (e.g. sensor element) and the cable to be guided. In this case, it is also possible to detect (in this case by establishing an electrical connection) that the surface layer is worn.
The tear propagation resistance can for example be determined in accordance with ONORM C 9446:2007 02 01. The tear propagation resistance can be the maximum force required to produce a crack in the material and can be related to the thickness of the material. A ratio of the tear propagation resistance of the sur-face layer to the tear propagation resistance of the indicator element can prefera-

-11 -bly be in a range of 0.7 to 1.9. It has been found that in this range, the indicator el-ement can be reliably held in the surface layer or on the surface layer, even if the surface layer is already largely worn. This ensures that the indicator element relia-bly indicates the state of wear even if the surface layer is worn to an advanced stage. Furthermore, the rope or cable can be reliably supported by the indicator el-ement even if the wear of the surface layer is already in an advanced stage.
The glass transition temperature can preferably be determined in accordance with the ISO 11357-2 standard. Preferably, the surface layer has a glass transition tern-perature of at least 70 C. In contrast, the indicator element can have a lower glass transition temperature. The glass transition temperature can be a temperature above which a polymer changes to a rubbery to viscous state. In other words, if the glass transition temperature is exceeded, the surface layer can abruptly change its properties, which are necessary for guiding a rope. It is therefore ad-vantageous if the surface layer has a sufficiently high glass transition temperature to ensure that the rope is guided safely through the core element even during con-tinuous operation. In contrast, the indicator element can have a lower glass transi-tion temperature, as the indicator element is not primarily responsible for guiding the rope, particularly in the case where the indicator element is only provided in sections or partially on the surface layer. Consequently, an efficient interaction of the surface layer and the indicator element can be achieved. Furthermore, due to the above determined glass transition temperature of the surface layer, the insert element can also be used with fast rotating pulleys (i.e. with higher heat genera-tion during operation).
Preferably, the indicator element comprises a fabric, at least a thread, fluorescent material, colored liquid, in particular ink, and/or a film.
The fabric can, for example, be a textile surface fabric that comprises at least two thread systems and is provided extensively in the surface layer or on the surface layer. If the surface layer is worn to such an extent that the fabric is visible from the outside, the wear condition of the insert element can be determined. The fabric can also be made of wires, cord or other elements, for example. Preferably, the

- 12 -fabric also has a stabilizing effect, so that radial forces acting on the insert element can be absorbed by the fabric. This allows the insert element to be thinner, which can save production costs. Furthermore, the insert element can also be used for small rolls.
The at least one thread can be arranged in or on the surface layer in such a way that the thread comes to light (i.e. becomes visible from the outside) when the sur-face layer is worn. This allows conclusions to be drawn about the state of wear of the insert element. The thread can be arranged straight or curved in the surface layer. Preferably, the thread can have a distinctive color (for example, a lighter color than the surface layer) so that it can be easily identified even from a greater distance.
The fluorescent material can be used to detect the state of wear of the insert ele-ment. Furthermore, the fluorescent material can have the additional property that an emission of light takes place after excitation of the material. Photons can be emitted when light is emitted. For example, an insert element to be examined can be irradiated with a light source so that any fluorescent material recognizable on the surface emits light accordingly. This means that an insert element can be checked for wear even in the dark. This can simplify the maintenance of an insert element. The fluorescent material can be applied to or in the indicator element in the form of paint or lacquer. The light source used to excite the fluorescent mate-rial can be a UV light source, for example. In principle, any fluorescent material is suitable for use in conjunction with the indicator element.
The colored liquid can for example be arranged in capsules in the surface layer. In the event of wear or abrasion of the surface layer, these capsules can be dam-aged so that the liquid comes to the surface of the insert element. This makes it easy to recognize that the insert element has reached a certain state of wear.
In this embodiment, it is advantageous that even with minor abrasions, the liquid is distributed over a large area of the surface of the insert element, so that even with minor damage to the surface layer, it is easy and straighfforward to recognize that

- 13 -a certain state of wear has been reached. The capsule with the liquid can be ar-ranged in the surface layer at a certain distance in the radial direction from the first surface layer side. Furthermore, differently colored liquids can also be provided depending on a position in the insert element (for example, depending on a dis-tance from the first surface layer side). Thus, the different colors appearing on the surface of the insert element can be used to determine how far wear of the insert element has progressed.
The foil can be a plastic foil or an aluminum foil, which is arranged parallel to the first surface layer side in the insert element. If the surface layer is worn, the foil can be partially or completely exposed and thus indicate the wear condition of the insert element. It is also conceivable to mix an aluminum powder into the surface layer, which becomes visible when the surface layer is worn. This makes it particu-larly easy to realize the indicator element.
Preferably, the insert element comprises at least one conductivity sensor, which is designed to detect a voltage applied to a rope or cable passing through the insert element.
This embodiment can be realized in two ways: Firstly, the surface layer can be an insulating material, as is the case with aerial tramways, for example. In this case, the cable running through the insert element is used to transport a signal (e.g. a telephone signal). If the insert elements were not insulated, this signal would be disturbed and would not reach the receiver in a suitable form. In contrast, the indi-cator element can be designed to be conductive. If the surface layer is rubbed off to such an extent that the cable passing through the insert element comes into contact with the indicator element, a circuit can be closed and the signal con-ducted through the cable can be detected by the sensor on the insert element.
This means that remote monitoring can also be used to determine whether an in-sert element is worn or not. Furthermore, this system can also detect the exact po-sition of the worn core element in a larger system. On the other hand, it is possible that the surface layer is designed to be conductive and the indicator element is provided in the surface layer or on the second side of the surface layer and has an

- 14 -insulating property. If the surface layer is worn, tension can be transmitted from the rope passing through the insert element to the insert element as long as the surface layer has a certain thickness. If the surface layer is worn and the abrasion is so great that the rope is in contact with the indicator element (e.g. with the indi-cator layer), the rope is insulated and tension can no longer be measured. In this case, it is also possible to detect that the core element is worn.
Preferably, the indicator element comprises at least one metal rod and/or a wire.
For example, the metal rod can be located in the surface layer at right angles to the direction in which the cable is guided. If the surface layer is worn or abraded to such an extent that the wire reaches the surface (i.e. the first side of the surface layer), it can be determined that the surface layer is worn. This offers the ad-vantage that no further abrasion is possible or at least greatly reduced by the metal rod, as the metal rod has a significantly higher strength than the surface layer. For this purpose, the metal rod can be arranged in a predetermined position (i.e. at a predetermined distance from the first surface layer side) in the surface layer at which it is desired that the insert element is replaced. In this way, a wear limit of the insert element can be defined in a simple manner, which nevertheless allows continued operation of the insert element.
Similarly, a wire can be arranged in or on the surface layer and thus have a similar effect to the metal rod. Furthermore, different wires separated from each other can be arranged in different positions within the surface layer. For example, each wire can have a different distance from the first side of the surface layer. The wires can differ in color, for example. If the surface layer is abraded to such an extent that a wire comes into contact with the surface of the surface layer, the wire can be rec-ognized and a wear condition can be indicated. During further operation, the wire (in contrast to the metal rod) can be worn further, i.e. removed from the insert ele-ment (until the next wire appears). Different wear states can be indicated by differ-ent colors of the different wires. It is also conceivable to apply a voltage to each wire and measure this separately for each wire. If the applied voltage can be measured, it can be assumed that the insert element is still intact. If, on the other

- 15 -hand, no voltage can be measured on one or more wires, it can be assumed that these wires have already been removed from the insert element by reducing the material thickness of the surface layer. Since the distance of the individual wires to each other and to the first surface layer side is known, an abrasion depth or a state of wear can be precisely defined according to the intervals at which the wires are provided in the insert element. Furthermore, this wear condition can also be determined by remote and/or automated maintenance. This means that detailed monitoring of a system, which for example comprises a large number of system el-ements, is easily possible. It is also conceivable to provide an automated system for monitoring the wear condition of at least one insert element. The monitoring system can, for example, automatically issue an alarm when a predetermined wear condition is reached. This can ensure that a worn insert element is detected and replaced in good time.
Preferably, the insert element comprises a plurality of indicator elements which are distributed in a radial direction of the insert element, and wherein each indicator el-ement has different properties.
The radial direction of the insert element can refer to an insert element that has a ring-like shape. Nevertheless, the insert element can also be a flat body. In any case, the radial direction may be a direction that is orthogonal to the first overlay side and extends to the second overlay side. The provision of several indicator el-ements is similar to the provision of different wires at different distances from the first cladding layer side in the above embodiment. In other words, different wear conditions can also be realized with other indicator elements by providing the indi-cator elements at different distances from the first surface layer side.
Preferably, a ratio of the material thickness of the surface layer and the material thickness of the indicator element in a radial direction of the insert element is in a range from 0.01 to 0.7, preferably in a range from 0.07 to 0.5, more preferably in a range from 0.1 to 0.3.

- 16 -It was found that in a first area there is optimum interaction between the surface layer and the indicator element. This is particularly true if the indicator element is designed as an indicator layer. The first-mentioned area is particularly advanta-geous with regard to the occurrence of stresses between the two layers, as the two layer thicknesses are in such a ratio to each other that no stress peaks occur at the interface between the surface layer and the indicator layer. This ensures the durability of the insert element.
In the second area mentioned, the advantage is that even if several indicator ele-ments are provided (in the second ratio specified above, the material thicknesses of all existing indicator layers are added together), sufficient cohesion of all individ-ual layers is ensured.
Furthermore, it was found that in the last defined area, a state of wear of the insert element is indicated long enough by the in the last area so that maintenance per-sonnel can take note of it. This means that a state of wear of the insert element can be reliably indicated over a sufficient period of time and can also be reliably detected.
Preferably, the insert element comprises a fabric layer which is designed to absorb radial forces, wherein a ratio of the material thickness of the surface layer and the material thickness of the fabric layer in a radial direction of the insert element is in a range from 0.8 to 9, preferably in a range from 1 to 8, more preferably in a range from 2 to 6.
The first area mentioned above offers the advantage that the insert element can be used in a wide range of applications. For example, the insert element can also be used in systems in which a large radial force acts on the insert element.
Even in such a case, safe operation can be realized.
In the second area mentioned above, the fabric layer is just as thick as the surface layer or thinner. The advantage here is that an overall thinner insert element can be provided and sufficient abrasion reserves can be realized by the surface layer.

-17-At the same time, the insert element offers sufficient resistance to absorb radial forces.
It was found that the latter area represents an optimum, particularly when operat-ing cable car systems. Here, the radial forces occurring in cable car systems can be sufficiently absorbed and yet a sufficiently thin insert element can be provided so that efficient operation is possible.
Preferably, the surface layer has on its first surface layer side a cross-section transverse to a cable or cable guide direction, a guide region and two protective regions adjacent to the guide region, wherein the guide region has a depression which is recessed by a depression spacing relative to at least one of the shoulder regions, and wherein a ratio of a width of both shoulder regions in the cross-sec-tion transverse to the cable or cable guide direction and the depression spacing is in a range from 0.2 to 5, preferably in a range from 0.4 to 3, more preferably in a range from 0.7 to 2.5. cable guide direction and the recess spacing is in a range from 0.2 to 5, preferably in a range from 0.4 to 3, more preferably in a range from 0.7 to 2.5.
This means that the first side of the surface layer can be structured in such a way that the cable can be guided through the surface layer in a defined manner.
Pref-erably, the recess is round and has the recess spacing as a radius. This allows the first side of the surface layer to be complementary to a cable or rope to be guided, which improves the guidance. The specified ratios indicate a ratio of the depth of the recess to a width of the insert element transverse to the cable guide direction.
The first ratio offers the advantage that any type of rope or cable is compatible with the insert element without any problems. For example, even very thick ropes can be suitably guided through the insert element. Furthermore, the range of use of the insert element in the first area defined above is very large, so that the insert element can be used in a variety of applications. In the second range defined above, there is the advantage that even in applications in which forces are applied to the insert element transversely to the radial direction of the insert element and to the direction in which the rope is guided, the insert element has sufficient

- 18 -strength or resistance to such acting forces due to the shoulder areas, so that per-manent operation is possible. In other words, the force acting on the shoulder ar-eas depends on the depth to which the rope sinks into the recess of the insert ele-ment. Thus, the second area defined above provides optimum lateral stiffness while at the same time efficiently guiding the rope. The last area defined above of-fers the advantage that an optimal lateral guidance property for the rope or calf is provided by the insert element, whereby the insert element can be realized with minimal use of material.
According to a further aspect of the present invention, there is provided a rope or cable guide pulley comprising an insert member comprising a surface layer having a first surface layer side adapted to come into contact with a rope or cable to be guided and a second surface layer side opposite the first surface layer side, and an indicator member arranged on and/or in the surface layer side, and wherein the indicator member is adapted to indicate a wear condition of the insert member, and a bearing portion for rotatably supporting the rope or cable guide pulley.
Such a pulley can be used, for example, in cable cars, elevators, cranes etc.
to de-flect and/or guide a rope or cable. The insert element can also be designed ac-cording to one of the above insert elements.
According to a further aspect of the present invention, there is provided a method of manufacturing a core member for guiding a rope or cable, in particular accord-ing to any of the above aspects, the method comprising the steps of:
Provision of an indicator element, Application of the indicator element in or on a surface layer, and Vulcanization of the indicator element and the surface layer, whereby the indicator element can indicate a state of wear of the insert ele-ment.
Furthermore, the method can include a step of cutting or milling a groove into the first face of the surface layer. The groove can extend in the direction of the cable guide. The indicator element (for example a different colored tape) can be inserted

- 19 -into the groove and then vulcanized together with the surface layer. In this way, the indicator element can be bonded to the surface layer. Preferably, the indicator element is located at the deepest point of the indentation in the surface layer. The recess can be designed in such a way that the rope or cable to be guided does not touch the deepest point of the recess at the start of operation of the insert element.
The cable or rope can only come into contact with the deepest point of the recess and abrade the indicator element as a result of wear or abrasion of the surface layer. If the indicator element is no longer visible, it can be defined that a certain state of wear has been reached. For example, when the indicator element is no longer visible, the insert element can be replaced.
The embodiment variants and advantages listed above in connection with the de-vice also apply analogously to the method and vice versa. Individual features of in-dividual embodiments can be combined with each other to form new embodi-ments. The advantages of the individual features then also apply to the new em-bodiment. In the following, embodiments to be preferred are described in detail with reference to the figures. They show:
Fig. la schematic and perspective view of an insert element according to an embodiment of the present invention, Fig. 2a cross-section of the insert element shown in Fig. 1 transverse to a cable guide direction, Fig. 3a schematic surface view of an insert element according to a further embodiment of the present invention, Fig. 4a schematic surface view of an insert element according to a further embodiment of the present invention, Fig. 5a schematic cross-section of an insert element of a further embodi-ment according to the present invention, and

- 20 -Fig. 6a schematic cross-section of an insert element according to a further embodiment of the present invention.
Fig. 1 is a schematic and perspective view of an insert element 1 according to an embodiment of the present invention. The insert element 1 according to the pre-sent embodiment has a ring-like shape and is only shown in sections in Fig. 1 for simplification. The insert element 1 has a surface layer 2. The surface layer 2 has a first surface layer side 6, which represents an outer side of the surface layer 2 (i.e. facing the environment), and a second surface layer side 7, which represents an inner side of the surface layer side 2. An indicator layer is provided on the sec-ond surface layer side 7 as an indicator element 3. Furthermore, the surface layer 2 has a cable guide area 5 and two shoulder areas 4 on its first surface layer side 6. The two shoulder areas 4 enclose the rope guide area 5 in their center. A
rope or cable to be guided (not shown in the figures) comes to rest in the rope guide area 5 so that the rope or cable comes into contact with the surface layer 2.
The cable guide area 5 has a recess 8, which is recessed radially inwards in relation to the shoulder areas 4. The cable is guided through the insert element 1 in a cable guide direction 10 (in Fig. 1 from right to left or from left to right). In other words, the cable can move in the cable guide direction 10. The insert element 1 can also move (i.e. rotate) according to the movement of the rope. For example, a pulley on which the insert element 1 is arranged can rotate. Guiding the rope can cause the surface layer 2 to wear, particularly since a relative speed between the rope and the core element is not equal to zero. The wear causes abrasion, which causes the surface layer 2 to lose material. If the surface layer 2 is worn down to such an extent that the indicator layer 3 appears (i.e. is visible from the outside in a surface view of the core element), the state of wear of the core element can be recognized from the outside. Accordingly, it can be determined that the insert element 1 needs to be replaced.
Fig. 2 is a section through the insert element 1 shown in Fig. 1 at right angles to the cable guide direction 10. In Fig. 2, the cable guide direction therefore runs into and out of the sheet plane. In Fig. 2, the recess 8 can be seen in the cable guide

- 21 -area 5. It can also be seen that the indentation 8 has a radius that defines the in-dentation. Furthermore, the radial direction 20 and an axial direction 30 are shown in Fig. 2. The indicator layer 3 of the present embodiment is bonded to the surface layer 2 by vulcanization. This can ensure that there is sufficient cohesion between the surface layer 2 and the indicator layer 3.
Fig. 3 is a surface view of an insert element 1 according to a further embodiment of the present invention. In this embodiment, the surface layer 2 also has two shoulder regions 4 and a rope guide region 5. However, in the present embodi-ment, the indicator element is not arranged as an indicator layer on the second surface layer side 7 of the surface layer 2, but as strip-like elements which extend in the axial direction parallel to one another and transversely to the cable guide di-rection 10. The indicator elements 3 extend both in the shoulder areas 4 and in the rope guide area. This means that wear can be indicated over the entire width of the core element 1. In the present embodiment, the indicator elements 3 are lo-cated on the surface of the core element 1 (i.e. on the first surface layer side 6), so that if the indicator elements 3 are no longer present, it can be concluded that a certain state of wear of the core element 1 has occurred.
In another embodiment not shown, further indicator elements are arranged inside the surface layer 2 in addition to the indicator elements 3 attached to the surface.
The indicator elements 3 differ in their color. More precisely, the indicator elements 3 that are arranged on the surface of the surface layer 2 (i.e. on the first surface layer side 6) differ from the indicator elements 3 that are arranged inside the sur-face layer 2. This means that different color coding can be used to easily and readily identify how far the wear of the insert element 1 has progressed.
Fig. 4 shows a surface view of an insert element 1 according to a further embodi-ment of the present invention. The present embodiment largely corresponds to the embodiment shown in Fig. 3, with the difference that the indicator elements 3 now run in the direction of the cable guide 10. In the present embodiment, one indicator element is arranged at the deepest point of the recess 8 in the cable guide area 5

- 22 -and one indicator element 3 in each of the shoulder areas 4. This means that a pe-riodically occurring uneven load on the insert element 1 due to uneven wear of the indicator elements 3 can also be detected.
Fig. 5 is a cross-section through an insert element 1 according to a further embod-iment of the present invention. The embodiment shown in Fig. 5 essentially corre-sponds to the embodiment shown in Fig. 2, with the difference that the indicator el-ement 3 is not formed as an indicator layer, but as a plurality of capsules contain-ing a colored liquid. The capsules 3 are arranged at different depths within the sur-face layer 2. In other words, the capsules 3 are arranged at different positions in the radial direction 20 of the insert element I. If the surface layer 2 is now worn by a cable or rope, the capsules can be damaged and the liquid can escape to the first surface layer side 6. The colored liquid can indicate that a certain state of wear of the insert element 1 has been reached.
Fig. 6 is a schematic cross-section of a further embodiment of the present inven-tion. The embodiment shown in Fig. 6 essentially corresponds to the embodiment shown in Fig. 3, with the difference that the indicator element 3 comprises wires extending in the cable guide direction 10, which are arranged inside the insert ele-ment 1. The wires 3 are arranged at different distances from the first surface layer side 6 of the surface layer 2 and can thus indicate different wear states of the in-sert element 1 by the wires 3 coming to the surface on the first surface layer side 6. In a further embodiment, a voltage can be applied to the wires 3 and measured by a sensor. Damage to a wire 3 (for example due to wear) can cause the voltage to change. In particular, each wire can be monitored individually and separately.
This means that remote diagnosis can be used to detect the extent to which the in-sert element is worn.
The rope guide direction can also be referred to as the circumferential direction for round insert elements. In a further embodiment not shown, the indicator element is formed as a structure on the surface of the surface layer (i.e. on the first surface layer side 6). For example, the indicator element 3 is an indentation in a rope guide area 5 and if the indentation is no longer present, it can be concluded that a

- 23 -certain wear condition has occurred. In a further embodiment not shown, the insert element comprises, in addition to the surface layer and the indicator element, a fabric layer designed to absorb radial forces.
Reference sign list:
1 Insert element 2 Surface layer 3 Indicator element 4 Shoulder area 5 Rope guide area 6 First surface layer side 7 Second surface layer side 8 Deepening 10 Cable guide direction Radial direction Axial direction

- 24 -

Claims (15)

Claims

1. insert element (1) for guiding a rope or cable, in particular for a cableway in-stallation, comprising a surface layer (2) with a first surface layer side (6), which is designed to come into contact with a rope or cable to be guided, and a second surface layer side (7) opposite the first surface layer side (6), and an indicator element (3), which is arranged on and/or in the surface layer (2), and wherein the indicator element (3) is designed to indicate a state of wear of the insert element (1).

2. insert element (1) according to claim 1, wherein the insert element is formed in one piece.

3. insert element (1) according to one of the preceding claims, wherein the indi-cator element (3) covers the first surface layer side (6) and/or the second surface layer side (7) at least partially or in sections.

4. insert element (1) according to any one of the preceding claims, wherein the surface layer (2) comprises SBR, NR, NBR, EPDM, CSM, BR and/or FKM.

5. insert element (1) according to any one of the preceding claims, wherein the indicator element (3) comprises PE, PP, TPE, PA and/or PETP.

6. insert element (1) according to one of the preceding claims, wherein the indi-cator element (3) and the surface layer (2) have different properties, such as in particular hardness, density, tear resistance, elongation at break, abrasion, rebound elasticity, compression set, tear propagation resistance, glass tran-sition temperature, electrical conductivity and/or swelling.

7. insert element (1) according to any one of the preceding claims, wherein the indicator element (3) comprises a fabric, at least one thread, fluorescent ma-terial, colored liquid, in particular ink and/or a foil.

8. insert element (1) according to any one of the preceding claims, further com-prising at least one conductivity sensor adapted to detect a voltage applied to a rope or cable passed through the insert element (1).

9. insert element (1) according to any one of the preceding claims, wherein the indicator element (3) comprises at least one metal rod and/or wire.

10. insert element (1) according to any of the preceding claims, wherein the insert element (1) comprises a plurality of indicator elements (3) distributed in a radial direction (20) of the insert element (1), and each indicator element (3) having different properties.

11. insert element (1) according to one of the preceding claims, wherein a ratio of the material thickness of the surface layer (2) and the material thickness of the indicator element (3) in a radial direction (20) of the insert element (1) is in a range from 0.01 to 0.7, preferably in a range from 0.07 to 0.5, more pref-erably in a range from 0.1 to 0.3.

12. insert element (1) according to one of the preceding claims, further compris-ing a fabric layer which is designed to absorb radial forces, wherein a ratio of the material thickness of the surface layer (2) and the material thickness of the fabric layer in a radial direction (20) of the insert element (1) is in a range from 0.8 to 9, preferably in a range from 1 to 8, more preferably in a range from 2 to 7.

13. insert element (1) according to any one of the preceding claims, wherein the surface layer (2) has a guide region (5) and two shoulder regions (4) adjacent to the guide region on its first surface layer side (6) in a cross-section transverse to a rope or cable guide direction, wherein the guide region (5) has a recess (8) which is deepened by a recess spacing relative to at least one of the shoulder regions (4), and wherein a ratio of a width of both shoulder regions (4) in the cross-section transverse to the rope or cable guide direction (10) and the recess spacing iS
in a range from 0.2 to 5, preferably in a range from 0.4 to 3, more preferably in a range from 0.7 to 2.5.

14. Rope or cable guide pulley comprising an insert element (1) comprising a surface layer (2) with a first surface layer side (6), which is designed to come into contact with a rope or cable to be guided, and a second surface layer side (7) opposite the first surface layer side (6), and an indicator element (3), which is arranged on and/or in the sur-face layer (2), and wherein the indicator element (3) is designed to indicate a state of wear of the insert element (1), and a bearing area for rotatable mounting of the rope or cable guide pulley.

15. Method of manufacturing an insert element (1) for guiding a rope or cable, in particular according to any one of claims 1 to 13, the method comprising:
Providing an indicator element (3), Application of the indicator element (3) in or on a surface layer (2), and Vulcanization of the indicator element (3) and the surface layer (2), wherein the indicator element (3) can indicate a state of wear of the insert el-ement (1).