Method and device for monitoring the state of a cable and press clamp

Abstract

The invention relates to a method for monitoring the state of a cable (2), in particular a wire cable, comprising the steps of: providing a reference surface quality of an end-side cross-section (3) of a cable (2), in particular a wire cable; determining a current surface quality of the end-side cross-section (3); determining a state and / or a state change of the cable (2) by comparing the reference surface quality and the currently determined surface quality, wherein a change in a section (16) of the surface quality is indicative of a state change of the cable. The invention also relates to a corresponding device (12), a press clamp (1) and a production method for a press clamp (1) of this type.

Description

[0001] Method and device for monitoring the condition of a rope and press clamping

[0002] Technical area

[0003] The present invention relates to a method and a device for monitoring the condition of a rope, in particular a wire rope, furthermore to a press clamp for a rope which enables condition monitoring, and to a manufacturing method for such a press clamp.

[0004] State of the art

[0005] Rope connections are used in a wide variety of applications, for example in mechanical engineering, the construction industry, or architecture, such as bridge construction, particularly for transmitting forces primarily in the direction of the rope. Steel wire ropes are often used to transmit large forces, such as in mechanical engineering or bridge construction.

[0006] In order to introduce forces into the rope at a given point, for example a rope end, it is known to apply a press clamp to the rope at that point. Press clamps are widely used throughout rope technology. For this purpose, the rope is usually threaded into a ferrule and this is then pressed onto the rope with a predetermined pressing force. The resulting (end) connection of the rope is permanent and essentially static. Slipping of the rope wires in the pressed-on ferrule is tantamount to failure of the crimp. Accordingly, slipping of the rope in or relative to the pressed-on ferrule must be ruled out in all applications.In other words, an overload situation for the press jam must be avoided or, if such an overload situation occurs, at least the press jam must be prevented or, if shortening the rope is not possible, the entire rope must be replaced.

[0007] EP 3485 998 A1 discloses providing a compression clamp with a bore that completely severs the cable contained within the compression clamp. If the cable slips relative to the ferrule, a depression forms on the previously cylindrical inner wall of the bore, the depth of which corresponds to the amount of cable slippage. If such a displacement of the cable end from the inner wall of the bore is detected, it can be concluded that the cable is no longer properly held in the ferrule, and therefore the compression clamp has failed.

[0008] Based on the known prior art, it is an object of the present invention to provide an improved method for monitoring the condition of a rope, in particular a wire rope, a corresponding device, a press clamp for a rope which enables condition monitoring, and a manufacturing method for such a press clamp.

[0009] The object is achieved by a method for monitoring the condition of a rope, in particular a wire rope, having the features of claim 1. Advantageous further developments emerge from the subclaims, the description, and the figures.

[0010] Accordingly, a method for monitoring the condition of a rope, in particular a wire rope, is proposed, comprising providing a reference surface condition of an end cross-section of a rope, in particular a wire rope, determining a current surface condition of the end cross-section, and determining a condition and / or a change in condition of the rope by comparing the reference surface condition and the currently determined surface condition, wherein a change in a partial area of ​​the surface condition is indicative of a change in condition of the rope.

[0011] This makes it possible to detect an overload case, in other words the occurrence of a (tensile) force above a specified limit, without the rope having already suffered safety-critical damage; the rope can therefore continue to provide or transmit the rope force required for the respective application. Because only a change in condition has occurred in a partial area of ​​the rope, the remaining area of ​​the rope, or the wires and strands of this remaining area of ​​the rope, are essentially still in their original position defining the reference surface and can continue to transmit forces correctly. In this way, the condition of the rope can be monitored and a critical load case, which is above a specified load level orThis allows for the determination of the rope's load condition without requiring a total failure of the rope as the cause—unlike conventional, technical methods. Consequently, an impermissible change in the rope's condition can be detected without compromising the safety of the structure surrounding the rope, as is the case with conventional methods. This is because the monitored rope can continue to absorb and transmit the required forces.

[0012] The proposed method also makes it possible, among other things, to dispense with a continuously operating sensor array, as is required with conventional, technical methods. Instead, monitoring the condition or change in condition can be carried out intermittently. Furthermore, the determination of the condition or a change in condition of the rope can also be performed retrospectively and / or repeated by comparing the determined surface condition with the reference surface condition.

[0013] The change in the surface texture, or the change in a sub-area of ​​the surface texture, is particularly permanent and irreversible within the rope. Accordingly, the change in the sub-area compared to the reference surface texture remains detectable even after the load that led to the change in the surface texture in the sub-area has been removed, as it is permanent and irreversible within the rope.

[0014] In the event that the change in the partial area is indicative of the occurrence of an overload in the rope, the overload can be detected retrospectively even after the overload has ceased to exist and thus subsequently verified. This overcomes the disadvantage inherent in conventional methods, which can be attributed to the technical background, namely that condition monitoring of the rope was previously directly linked to the operation of a sensor arrangement. If this sensor arrangement fails, is switched off, or is removed, the possibility of condition monitoring or the detection of an impermissible change in the rope's condition is also lost. Subsequent determination of any change in condition that has occurred is then only possible using the measured values ​​and data recorded by the sensor system, provided that these have been saved. However, these measured values ​​and data can be lost or deleted.Furthermore, the measured values ​​and data are inherently susceptible to manipulation. For example, the stored measured values ​​or data can be illegally altered, resulting in falsification, in order to illegally evade liability.

[0015] The proposed method therefore also enables subsequent detection of an overload in the rope. Since the change in the partial area is permanent and irreversible in the rope, it can also be detected retrospectively, for example, during damage assessment or legal investigations following an incident or accident. The change in condition is thus a hard fact directly present on the rope. The determination of the change in condition can therefore also be performed retrospectively directly on the rope and does not necessarily depend on data acquired during operation.Even the reference surface condition can be subsequently determined from the surface condition on the rope during the investigation if appropriately provided, whereby the reference surface condition in the partial area can be derived from the surface condition of at least one area of ​​the cross-section which is different from the partial area and in which no change was to be expected.

[0016] Consequently, the proposed method enables simplified evidence preservation, particularly independent of the rope's location of use, any sensor system installed at the location, and / or measured values ​​and data acquired by the sensor system. An expert opinion based on the proposed method is thus freed from the aforementioned disadvantages regarding the problem of subsequent verification and / or possible manipulation. While conventional, technical-related methods may no longer provide evidence of the occurrence of an overload on the rope, the proposed method can subsequently and repeatedly determine a change in condition that has occurred in the rope due to the permanent, permanent, and irreversible change in the sub-area of ​​the rope. This determination cannot be manipulated, for example, by interfering with stored measured values ​​or data.In this way, evidence of an overload event that has occurred cannot be determined in a manipulable and repeatable manner.

[0017] According to a preferred embodiment, the reference surface condition can be determined for the first time at least before delivery of the rope to a customer or before assembly or installation at the site of use, in particular in a facility or structure, preferably by a person or institution that is at least independent of the owner of the facility or structure, for example, a manufacturer of the rope. The reference surface condition is then generally available outside the sphere of influence of a liable party for (subsequent) determination of any change in condition that may have occurred.

[0018] In other words, a permanent, irreversible change in the condition of the rope can be determined by comparing the reference surface condition and the currently determined surface condition, whereby a permanent, irreversible change in a partial area of ​​the surface condition is indicative of the permanent, irreversible change in the condition of the rope.

[0019] According to a preferred embodiment of the method, providing the reference surface finish can comprise machining the end of the rope. This preferably comprises a removal process, particularly preferably cutting and / or grinding and / or eroding, of the end of the rope. Alternatively or additionally, a build-up process, preferably build-up welding, of the end of the rope can be provided. Furthermore, it is possible for the processing to alternatively or additionally comprise a cleaning process, preferably blowing out, wiping, rinsing, degreasing and / or drying the end of the rope. Furthermore, alternatively or additionally, providing the reference surface finish can comprise the initial determination of the reference surface finish.

[0020] According to a further embodiment, the change in the partial area of ​​the surface quality of the rope can occur by determining a relative movement, preferably an axial displacement, of at least one wire and / or at least one strand and / or at least one insert or core of the rope in the rope direction. Preferably, an axial displacement in the rope direction of 100 μm or more, preferably of 50 μm or more, particularly preferably of 10 μm or more, is indicative of a change in state. The relative movement, i.e. the movement performed by the at least one wire, the at least one strand and / or the insert or core of the rope relative to its or their position in the reference surface quality, makes it possible to determine in a simple and reliable manner that at least the relatively moved elements were exposed to a force that exceeded a predetermined limit value.The displacement of the at least one wire and / or the at least one strand and / or the at least one core or core of the rope in the rope direction is permanent and irreversible once it occurs. Accordingly, this displacement or the change in the partial area can be permanently detected.

[0021] Due to the structure of the rope, individual elements of the rope, such as wires or strands, cores or inserts, can have different critical tensile force limits. Accordingly, failure does not occur randomly within the rope as the rope force increases, but rather first in the less robust areas with lower limit force. In areas within the rope cross-section with different compression, for example within a compression clamp on the rope, displacement of an element of the rope as the rope force increases occurs first in the areas of lower compression, as the elements in these areas exert a lower holding force on one another. Accordingly, it is possible to detect when the specified limit force is exceeded without the entire rope orall areas of the rope were subjected to such a high force that slipping occurred in all areas and thus a failure of the rope strength of one or more elements occurred.

[0022] The magnitude of the displacement can be used as an indicator to determine the magnitude of the force causing this displacement. In other words, the magnitude of the force can be determined by determining the magnitude of the displacement in the rope direction.

[0023] The change in state can preferably be indicative of a predetermined overload of the rope and / or a compression jam of the rope, wherein the change in state is preferably indicative of an exceeding of a predetermined force applied to the rope, preferably a predetermined force in the rope direction. According to a further embodiment, the change in the partial area of ​​the surface condition, preferably a relative movement, particularly preferably an axial displacement, of at least one wire and / or at least one strand and / or at least one core or core of the rope in the rope direction, is determined in a predetermined monitoring area of ​​the cross-section. The predetermined monitoring area can preferably be an area in which a displacement of an element of this partial area is to be expected first, thus an area with a lower limit force than other areas of the rope.This reduces the measurement effort and simplifies the process. Furthermore, detection can be performed with a particularly short delay, since only a portion of the end cross-section needs to be monitored.

[0024] The predetermined, i.e., predefined monitoring area preferably comprises an inner area of ​​the end cross-section, for example, at least a portion of one or more core strands and / or a core of the rope, and / or an outer area of ​​the end cross-section, for example, at least one outer strand of the rope. The monitoring area preferably comprises a central core strand of the rope, which preferably runs centrally within the rope.

[0025] According to a further embodiment, the end cross-section is substantially planar. Alternatively or additionally, the end cross-section may comprise at least a first surface section and a second surface section, wherein the second surface section is preferably offset from the first surface section, such that the first and second surface sections are spaced apart from each other by a predetermined amount in the cable direction. Furthermore, alternatively or additionally, the second surface section may be oriented at an angle to the first surface section. The term "angle" is understood here to mean an angle enclosed by the planes defined as surface sections, in particular when viewed perpendicular to the (longitudinal) cable direction.

[0026] Alternatively or additionally, the end cross-section can preferably be oriented at an angle to the rope direction, particularly preferably at an angle between 10° and 90°, particularly preferably at 15°, 20°, 25°, 30°, 35°, 40°, 45°, 50°, 55°, 60°, 65°, 70°, 75°, 80° or 85°, and very particularly preferably substantially perpendicular to the rope direction.

[0027] Furthermore, the cross-section can alternatively or additionally at least partially have a curved surface, preferably with a constant curvature, wherein the cross-section is preferably a partial region of a bore side wall of a bore, preferably a cylindrical bore, introduced into a ferrule pressed onto the rope transversely to the axial rope direction. Further preferably, the bore diameter is larger than the outer diameter of the rope and / or the bore axis and the rope center axis intersect or are spaced from one another by a distance smaller than the difference between the bore diameter and the rope outer diameter in the region of the bore. This ensures that the cross-section extends across the entire rope transversely to the rope direction.

[0028] Alternatively, the diameter of the hole or a similar recess can be smaller than the rope diameter. The hole or recess then preferably only partially cuts through the rope, with the severed area or part of it being selected as the monitoring area. This allows safety-critical parts of the rope to remain completely in the compression clamp and continue to transmit forces with exceptional reliability.

[0029] According to a further embodiment, the end cross-section is arranged in the axial direction at the level of a ferrule, preferably a round ferrule, that is pressed onto the cable, with the end cross-section preferably being located at a free end of the ferrule or within the ferrule. This, on the one hand, provides a stable termination for the cable. On the other hand, it makes it possible to monitor both the cable itself and, in particular, the ferrule connection between the ferrule sleeve and the cable, and between the elements of the cable.

[0030] According to a further embodiment, the rope can comprise at least one predetermined region of high compression of elements of the rope, preferably of wires and / or strands of the rope, and at least one predetermined region of low compression of elements of the rope, preferably of wires and / or strands of the rope. Preferably, in the region of low compression, the compression of the elements, preferably of the wires and / or strands, relative to one another is less than in the region of high compression. It has proven advantageous if the region of low compression comprises a core strand of the rope and / or the region of high compression comprises at least one outer strand of the rope, preferably all outer strands of the rope.

[0031] Preferably, the predetermined monitoring area corresponds at least partially to the area of ​​low compression.

[0032] According to a further embodiment, the surface texture is preferably determined by determining a sensor data set, wherein the sensor data set is indicative of the surface texture of the cross-section. The surface texture is preferably determined mechanically and / or optically and / or inductively and / or magnetically, wherein the surface texture is preferably determined by a distance measurement, preferably a mechanical, optical and / or magnetic and / or inductive distance measurement, and / or the surface texture is determined by evaluating at least one recorded image of the cross-section.According to a further embodiment, the surface quality is determined optically, wherein preferably in an optical determination a light source emits a coherent light beam onto an end cross-section of the rope, in particular of the wire rope, at which the coherent light beam is reflected, wherein depending on the surface quality of the end cross-section speckle occurs and a recording device records images of occurring speckle patterns at a fixed distance from the end cross-section of the rope, in particular of the wire rope, and wherein a state and / or a change in state of the wire rope is determined based on an evaluation of the recorded images of the speckle patterns.

[0033] The optical determination of the surface condition of the rope, in particular of the wire rope, has proven to be extremely advantageous, whereby the optical determination is preferably carried out by taking images of speckle patterns.

[0034] By recording speckle patterns for condition monitoring of the end cross-section of the rope, especially a wire rope, it is advantageous to detect even the slightest surface changes. For example, changes in the displacement of wires and / or strands in the direction of the rope can be clearly detected in the speckle pattern of a wire rope, e.g., even in micrometer-scale displacements.

[0035] It is known that the wires or strands of a wire rope experience length changes of up to several tens of micrometers due to thermal expansion. Recording speckle patterns is advantageous for monitoring a rope, particularly a wire rope, in that expansion of the wires or strands due to a load in the rope direction can be distinguished from effects due to thermal expansion. This is particularly due to the fact that thermal expansion, which affects all components of the rope equally—for example, all wires and / or strands of a wire rope—and thus represents a common-mode change, can be compensated for by comparing speckle patterns for condition monitoring.

[0036] Furthermore, it is advantageous that the recording of speckle patterns for determining the surface condition of the rope, in particular wire rope, provides sufficient two-dimensional resolution to detect changes in length of the individual wires or strands. Furthermore, the recording of speckle patterns provides such a high resolution that displacements and / or changes in length in an axial third dimension orthogonal to the cross-sectional area can be determined with high precision. The inventors' discovery that optical condition monitoring by recording speckle patterns enables the monitoring of axial stress in the direction of the rope with high precision could not have been expected in view of known uses of speckle photography. In the prior art, speckle photography is used in particular to detect changes or structures in a plane.The inventors, however, recognized that changes in the condition of a wire rope associated with an axial displacement of a wire or strand lead to clearly detectable changes in the recorded speckle patterns due to a change in the shadow cast. Monitoring the end cross-section therefore advantageously allows for extremely early detection of even the slightest changes in condition using simple means.

[0037] Advantageously, the method for monitoring the condition of the rope, in particular the wire rope, according to the embodiment of recording speckle patterns allows for immediate detection without any time delay if a change in the surface condition has occurred. If the surface condition of the end cross-section of the rope, in particular the wire rope, changes, e.g., due to a shift of a wire in the rope direction, the recorded speckle pattern changes simultaneously. Thus, appropriate measures can be taken promptly to avoid hazards during use of the rope, in particular the wire rope, related to a possible tear and / or other types of functional impairment.

[0038] It is also advantageous that the embodiment allows for the acquisition and analysis of speckle patterns non-invasively over a long period of time. This advantageously enables continuous monitoring, which increases the reliability of the method.

[0039] Advantageously, the preferred components for implementing the speckle pattern recording method are also scalable. Thus, preferred components such as the light source and the recording device can be mounted at such distances from one another that large end cross-sections of ropes can be reliably monitored. Likewise, the preferred components can advantageously be positioned such that they can be integrated into a housing, thus advantageously providing a compact design. In preferred embodiments, the preferred components for optical monitoring are installed in a housing with a compression clamp for the rope, which is particularly advantageous for monitoring and fastening wire ropes.

[0040] Another advantage of condition monitoring using speckle patterns is that it is particularly cost-effective. The preferred components, such as a light source for emitting coherent light beams and a recording device, such as a CCD sensor, are inexpensive to purchase and can be easily and quickly installed and positioned for rope condition monitoring. Therefore, the preferred method is particularly suitable for monitoring the condition of ropes, especially wire ropes, in a particularly cost-effective manner.

[0041] For the preferred method of recording speckle patterns, a light source is preferably used that emits coherent light rays onto the end cross-section of the rope, in particular the wire rope. The coherent light rays are reflected at the end cross-section, resulting in speckle depending on the surface condition of the rope. Speckle, in the context of the invention, preferably refers to an interference phenomenon resulting from an inherently rough surface of the end cross-section of the rope, in particular the wire rope. Light rays emitted onto the end cross-section are initially reflected in different spatial directions from stochastically distributed scattering centers (roughnesses). At each point in space, light from multiple scattering centers interferes, resulting in a stochastically distributed intensity pattern.The resulting interference of the coherent light radiation causes constructive and destructive interference. This type of interference is also referred to as objective speckles.

[0042] If the surface is sharply imaged onto the image plane of a recording device (e.g. a sensor) by an optical system, a speckle pattern is created, which is now preferably referred to as a subjective speckle pattern. The difference compared to objective speckles is that with subjective speckles a spatial assignment between a point on the surface and a point on the sensor is possible. In this case, the term speckle pattern preferably refers to subjective speckles that are detectable on the recording device. The recording device preferably captures images of the occurring speckle patterns over several points in time. Based on an evaluation of the speckle patterns, a condition and / or a change in condition of the rope, in particular the wire rope, can be determined.

[0043] According to a further embodiment, the change in state of the rope, in particular of the wire rope, is determined by an axial displacement of a wire and / or a strand in the rope direction by a change in the speckle pattern in the recorded image, wherein the change in the speckle pattern can preferably be determined by means of a shadow cast due to the axial displacement of the wire and / or the strand in the rope direction.

[0044] The term "shadow casting" primarily refers to the appearance of a shadow when a wire and / or strand is displaced in the direction of the rope. The images captured of the speckle pattern are particularly sensitive to shadow casting, allowing early detection of any axial displacement of a wire and / or strand.

[0045] The inventors have recognized that ropes, especially wire ropes, can be monitored extremely reliably and efficiently by capturing images of speckle patterns. In the prior art, speckle photography is typically used to measure displacements perpendicular to the direction of observation, i.e., so-called in-plane displacements, i.e., displacements along a plane. However, it has been discovered that an out-of-plane displacement, i.e., a displacement outside the plane, can also be detected by capturing speckle patterns. Out-of-plane displacement preferably refers to an axial movement of a wire and / or strand in the direction of the rope.

[0046] According to a further embodiment, the axial displacement of a section of the rope, preferably of the wire rope, preferably of a wire and / or a strand in the rope direction can be measured from 100 pm, preferably from 50 pm, particularly preferably from 10 pm, most particularly preferably from 1 pm.

[0047] Advantageously, by recording speckle patterns, even the smallest displacements in the axial direction, ie in the direction of the rope, can be detected due to the change in the shadow.

[0048] According to a further embodiment, in order to determine a state and / or a change in state of the wire rope, images of speckle patterns are evaluated which were recorded at different times and are preferably compared with each other, wherein a comparison is particularly preferably carried out by a numerical difference of the recorded images of speckle patterns.

[0049] In this case, it may be preferable for the recording of images of speckle patterns at a first point in time to be used to determine a reference surface texture, while a recording at a later, second (current) point in time is used to determine a current surface texture. By comparing a reference surface texture (according to the recordings of speckle patterns at a first point in time) and a current surface texture (according to the recordings of speckle patterns at a later, second point in time), a condition and / or a change in condition of the wire rope can be determined.

[0050] The comparison therefore preferably refers to the determination of the difference between the reference surface texture and the current surface texture of the end cross-section of the rope, in particular the wire rope. In particular, if a change in condition occurs, e.g., if a wire and / or strand has been displaced in the direction of the rope, this can be detected by comparing the speckle pattern of the reference surface texture and the current surface texture. In the case of a displacement of a wire and / or strand, the corresponding displaced section of the rope can be identified in the speckle pattern in the current surface texture.

[0051] A comparison by forming a numerical difference can, for example, relate to the difference formation of the intensities of the speckle patterns of the reference surface quality and the current surface quality. For this purpose, it may be preferred for a computing unit to be configured to perform corresponding computing operations to compare the speckle pattern of the current surface quality and that of the reference surface quality and, for example, to form a difference between these two speckle patterns. The computing unit can, for example, be present as a component for carrying out the method, e.g., in a housing with the press clamp or even outside the press clamp. The method is not limited to specific computing methods for comparing the speckle patterns.Instead, in addition to a simple difference calculation, other metrics can also be used to determine a state and / or a change in state.

[0052] According to a further embodiment, the light source is a laser and / or an LED and / or the light source emits coherent light with a wavelength in a range from 400 nm to 3000 nm or from 450 nm to 3000 nm. Coherence preferably refers to a property of light according to which there is a fixed phase relationship between two wave trains. As a result of the fixed phase relationship between the two wave trains, spatially stable interference patterns can arise, which are used for speckle photography. The coherence length preferably refers to a maximum path length or travel time difference that two light beams have from a starting point, so that a (spatially and temporally) stable interference pattern is still created when they are superimposed.

[0053] The aforementioned light sources have proven reliable for emitting coherent light beams onto the end cross-section of the rope, especially wire rope, for speckle detection. Lasers can advantageously emit light beams with a comparatively high coherence length. LEDs have a shorter coherence length compared to lasers, but this is sufficient given the typical dimensions of the device, and LEDs are also easy to provide. Advantageously, the aforementioned light sources can be easily installed in a suitable structure.

[0054] According to a further embodiment, the coherent light beam strikes an end cross-section of the wire rope at an angle of incidence of 10° to 80°, preferably 20° to 70°, particularly preferably 30° to 60°. All intermediate values ​​from the aforementioned range can also be preferred, for example approximately 10°, 15°, 20°, 25°, 30°, 35°, 40°, 45°, 50°, 55°, 60°, 65°, 70°, 75° or approximately 80°. Terms such as substantially, approximately, about, etc. preferably describe a tolerance range of less than + 20%, preferably less than ± 10%, particularly preferably less than ± 5%, in particular less than + 1%, and always include the exact value.

[0055] The angle of incidence preferably characterizes the angle that the preferably coherent light rays form relative to the normal of the end cross-section of the rope, in particular a wire rope. An angle of incidence of 0° therefore preferably means a beam impinging perpendicularly on the end cross-section with the normal to the incidence. However, a different angle of incidence is preferred. The aforementioned angles of incidence lead to a particularly high sensitivity of the recorded speckle patterns with regard to shadows cast by axial displacement of a wire or strand, thus enabling particularly precise monitoring of a condition and / or a change in condition.

[0056] According to a further embodiment, one or more optical components for beam shaping, preferably a lens, particularly preferably a converging lens, are located between the light source and the end cross-section of the wire rope.

[0057] Optical components can advantageously be used to better focus the light rays emitted onto the end cross-section of the rope. This can advantageously increase the intensity of the recorded speckle pattern and thus also improve the resolution. Preferably, a lens, particularly a converging lens, is used, which has proven effective in enabling a special focusing of the light rays onto the end cross-section of the wire rope.

[0058] According to a further embodiment, the recording device is selected from a group comprising a digital camera and / or a CCD sensor, wherein the recording device preferably records at least 2, 3, 5, 10 or more images of speckle patterns per second.

[0059] The recording device preferably refers to any device capable of capturing images of speckle patterns. For example, a digital camera and / or a CCD sensor can be used cost-effectively to capture a plurality of images of speckle patterns within a time period, for example, at least 2, 3, 5, 10, or more images of speckle patterns per second. Capturing a plurality of images of speckle patterns increases reliability and ensures continuous monitoring.

[0060] According to a further embodiment, an aperture may be present between the recording device and the end cross-section so that a brightness and / or an image section of the recorded images of a speckle pattern can be regulated, wherein the aperture preferably has an aperture number between 1 and 20, preferably between 10 and 18.

[0061] Apertures primarily refer to openings that limit the expansion of the light beams. Apertures are often characterized by the f-number.

[0062] The aperture number preferably refers to the ratio of focal length to the diameter of the aperture or opening, so that the light intensity is inversely proportional to the square of the aperture number based on the cross-sectional area of ​​the opening. By selecting the aperture number, the depth of field of the speckle pattern can be regulated. The larger the aperture number (or the smaller the aperture opening), the greater the depth of field. The smaller the aperture number, the shallower the depth of field, because the larger the aperture opening. The preferred aperture numbers have proven particularly advantageous for achieving optimal depth of field while maintaining sufficient intensity (brightness).

[0063] The surface condition can also be measured volumetrically, for example, by introducing an incompressible fluid into a bore of a compression clamp that intersects at least the monitoring area of ​​the cable, with the introduced fluid volume being recorded. A change in the surface condition is reflected in a change in the fluid in the bore, so that a change in state can be inferred from the change in the measured fluid volume.

[0064] The above-mentioned object is further achieved by a device for monitoring the condition of a rope, in particular a wire rope, having the features of claim 18. Advantageous developments of the device emerge from the subclaims, the present description, and the accompanying figures.

[0065] Accordingly, a device for monitoring the condition of a rope, in particular a wire rope, is proposed, comprising a sensor device which is configured to determine a surface condition of an end cross-section of a rope, in particular a wire rope, and an evaluation unit, preferably a computing unit, which is configured to determine a condition and / or a change in condition of the rope by comparing a reference surface condition of the end cross-section and a currently determined surface condition of the end cross-section, wherein the evaluation unit is configured to detect a change in condition of the rope based on a change in a partial area of ​​the surface condition.

[0066] In other words, the device can be configured to carry out the method described above.

[0067] The device enables the advantages and effects mentioned above to be achieved in an analogous manner. A person skilled in the art will recognize that technical features, definitions, and advantages of preferred embodiments disclosed for the method according to the invention apply equally to the device, and vice versa. Accordingly, a repetition of the disclosure is omitted here to avoid redundancies.

[0068] According to one embodiment, at least one sensor unit of the sensor device, preferably the sensor device, can be at least partially inserted into a recess, preferably a bore, formed transversely to the axial cable direction in a ferrule pressed onto the cable, wherein the sensor device is preferably configured to determine the surface quality when the sensor unit or sensor device is inserted into the bore. Accordingly, at least the part of the sensor unit or sensor device has external dimensions transversely to an insertion direction into the bore that are smaller than or equal to the dimensions of the recess or bore transversely to the insertion direction. As a rule, the insertion direction corresponds to a longitudinal extent of the recess or bore. In this way, the surface quality can be determined in a simple manner.Since the cross-section is present in the ferrule, it can also be assumed that, due to the pressed layer in the ferrule, it will remain stable over a long period of time even when in use, and therefore will not experience any changes such as fraying or unthreading of the elements of the rope at its end.

[0069] According to a further embodiment, the sensor device can comprise a probe, preferably a mechanical optical probe and / or an electrical and / or magnetic and / or inductive probe. Alternatively or additionally, the sensor device can comprise an optical sensor, preferably a recording device, particularly preferably a camera, and / or a light source for illuminating the cross-section. Accordingly, the device can have a robust design while simultaneously providing good measurement resolution and accuracy.

[0070] Alternatively, the sensor device may comprise a volumetric measuring sensor unit.

[0071] According to a further embodiment, the device comprises a light source and a recording device, wherein the light source is configured to emit a coherent light beam onto the end cross-section of the rope, in particular wire rope, such that the coherent light beam is reflected at the end cross-section of the rope, in particular wire rope, and speckle occurs depending on the surface condition of the end cross-section, and wherein the recording device is configured to record images of occurring speckle patterns at a fixed distance from the end cross-section of the wire rope, such that a state and / or a change in state of the wire rope can be determined based on an evaluation of the recorded images of the speckle patterns.

[0072] Such a device is designed in particular for a preferred optical determination of the surface quality of the rope on the basis of an image recording of speckle patterns, so that the above explanations regarding an advantageous use of the device and preferred embodiments apply analogously.

[0073] According to a further embodiment, the device comprises an evaluation unit, preferably a computing unit, which is configured to perform an evaluation of the recorded images of speckle patterns. Preferably, for the evaluation, images of speckle patterns recorded at different times are compared with one another. Particularly preferably, a comparison is carried out by means of a numerical difference between the recorded images of speckle patterns. By evaluating images of speckle patterns, the condition of the rope, in particular of the wire rope, can advantageously be monitored particularly reliably. In particular, a particularly precise comparison is made between the current surface condition and the reference surface condition of the end cross-section of the rope, in particular of the wire rope.

[0074] According to a further embodiment, the light source and the recording device are integrated in a housing, wherein the housing preferably has an evaluation unit, preferably a computing unit, wherein particularly preferably the evaluation unit, preferably the computing unit, is configured to carry out the comparison of recorded images of speckle patterns.

[0075] Advantageously, the device according to the last-mentioned embodiment is characterized by a particular compactness, so that even thin ropes, in particular wire ropes, can be monitored by means of the device.

[0076] A computing unit preferably refers to a data processing unit, which preferably comprises an integrated circuit (IC), an application-specific integrated circuit (ASIC), a programmable logic circuit (PLD), a field programmable gate array (FPGA), a microprocessor, a microcomputer, a programmable logic controller and / or another electronic, preferably programmable, circuit.

[0077] The computing unit can preferably also comprise a memory unit and / or communication unit. A memory unit allows for the backup and / or temporary storage of data. Non-limiting examples of memories, preferably semiconductor memories, are volatile memories, (RAM) memories, or non-volatile memories, such as ROM memories, EPROM memories, EEPROM memories, or flash memories, and / or other memory technologies.

[0078] The computing unit can, in particular, be a processor itself, a processor unit, or be formed by multiple processors. The computing unit is preferably designed to perform a comparison between a current surface quality and a reference surface quality. The comparison can, in particular, be performed by comparing recorded speckle patterns.

[0079] The expression that the evaluation unit, preferably the computing unit, is configured to perform certain steps preferably means that a computer program product is installed that includes instructions to perform such steps. For this purpose, it is preferred that software is installed on the computing unit that is configured or includes instructions to perform a comparison between the current surface condition and the reference surface condition. The comparison between the current surface condition and the reference surface condition of the end cross-section of the rope is preferably performed by comparing recorded images of speckle patterns.

[0080] The terms "software," "program," and "computer program" can be used synonymously. The software can be provided at least partially in the form of a cloud service or internet service, with the device transmitting data to an application in a cloud, for example, via the internet. In this case, too, the computing unit contains software configured to, or includes commands for, determining a state and / or a change in state of the rope, in particular a wire rope, by comparing a current surface condition with the reference surface condition of the end cross-section of the rope.

[0081] The software installed on the device's processing unit doesn't have to perform all steps independently. Instead, the data can be transmitted to an external data processing unit and / or a cloud, which performs at least a partial comparison between the current surface texture and the reference surface texture.

[0082] According to a further embodiment, the device comprises a communication unit, wherein the communication unit is configured to transmit a result of an evaluation of the recorded images of speckle patterns to an external data processing unit and / or the communication unit is configured to transmit the recorded images of speckle patterns to an external data processing unit, wherein preferably the external data processing unit is configured to carry out an evaluation of the recorded images of speckle patterns.

[0083] A communication unit preferably refers to a device for transmitting, in particular for sending and / or receiving, data. Transmission preferably occurs via directed or non-directed electromagnetic waves, whereby the frequency band used can vary from a few hertz (low frequency) to several hundred terahertz depending on the application and technology used. For example, the following data transmission methods can be used: Bluetooth, WLAN, ZigBee, NFC, Wibree, WiMAX, and / or cellular mobile networks such as GSM and UMTS in the radio frequency range, as well as IrDA and optical point-to-point radio (FSO) in the infrared or optical frequency range.

[0084] Advantageously, it is possible to evaluate the recorded data, in particular images of speckle patterns, directly on-site. Alternatively or additionally, raw data for evaluation of the results can advantageously be transmitted via the communication unit to an external data processing unit, which then performs the evaluation, for example, the comparison of speckle patterns. It is also advantageously possible for the result of the evaluation, preferably from the computing unit, to be transmitted via the communication unit to an external data processing unit, for example, to allow an additional assessment of the condition and / or change in condition of the rope.

[0085] For example, it is conceivable that an evaluation of the recorded images of the speckle patterns is transmitted to a control instance, preferably by the communication unit, which can initiate appropriate measures based on the determined condition.

[0086] The above-mentioned object is also achieved by a system according to claim 25 for monitoring the condition of a rope, in particular a wire rope, comprising a described device and a holder, preferably a press clamp, wherein the holder is configured to clamp a rope, in particular a wire rope, in such a way that an end cross-section of the rope can be emitted by a light source with a coherent light beam onto the end cross-section of the rope, in particular a wire rope, such that the coherent light beam is reflected at the end cross-section of the rope, in particular a wire rope, and depending on the surface quality of the end cross-section, speckle occurs, and wherein the recording device is configured to record images of occurring speckle patterns at a fixed distance from the end cross-section of the rope, in particular a wire rope.so that a condition and / or a change in condition of the rope, in particular wire rope, can be determined based on an evaluation of the recorded images of the speckle patterns.

[0087] The holder preferably refers to a component with which the rope can be fastened in such a way that an end cross-section is visible, preferably irradiated using a light source. The holder thus preferably offers sufficient mechanical stability as well as visual visibility of the end cross-section of the rope, in particular the wire rope. In preferred embodiments, the holder can be a ferrule or press clamp, as explained in more detail below.

[0088] The above-mentioned object is further achieved by a press clamp having the features of claim 26. Advantageous further developments emerge from the subclaims, the present description and the attached figures.

[0089] Accordingly, a press clamp on a rope, in particular a wire rope, is proposed, comprising a rope, in particular a wire rope, and a ferrule pressed onto the rope. The press clamp is characterized in that, in the region of the compression with the ferrule, the rope comprises at least one predetermined region of high compression of elements of the rope, preferably of wires and / or strands of the rope, and at least one predetermined region of low compression of elements of the rope, preferably of wires and / or strands of the rope, in which the compression of the elements, preferably of the wires and / or strands, of the rope relative to one another is less than in the region of high compression.

[0090] By providing at least one area of ​​high compression and at least one area of ​​low compression, it can be achieved that when a limit force in the compression clamp is exceeded, a relative movement of an element of the rope initially only occurs in the area of ​​low compression, while the area of ​​high compression remains fully functional. In other words, it can be achieved that parts of the rope that are not safety-critical experience a controlled relative movement when the predetermined limit force is exceeded. The areas designated as safety-critical, on the other hand, do not experience an overload at the limit force, so that they can continue to transmit the rope force, and the rope and the compression clamp as a whole are therefore not subject to failure. The compression clamp is therefore suitable for monitoring the condition of the rope.

[0091] The terms "ferrule" and "ferrule sleeve" refer to the identical component (the ferrule). For clarity, the term "ferrule sleeve" refers to its condition before crimping, and the term "ferrule" refers to its condition after crimping with the rope. However, they can also be used interchangeably as synonyms.

[0092] According to one embodiment, at least part of the low compression region can provide a predetermined monitoring region, wherein the low compression region is preferably designed such that when a predetermined force, which can be referred to as a limit value force, is applied to the press clamp, preferably when a force acting between the rope and the ferrule is applied in the rope direction, a relative movement, preferably an axial displacement, of at least one wire and / or at least one strand and / or at least one insert or core of the low compression region in the rope direction is brought about. When the predetermined force is applied and / or exceeded, the axial displacement in the rope direction is preferably at least 1 μm, preferably at least 10 μm, particularly preferably at least 50 μm, very particularly preferably at least 100 μm. Accordingly, only the predetermined orto monitor a predetermined monitoring area in order to monitor the integrity of the press clamp and in particular the rope.

[0093] It has proven advantageous if the low compression region comprises a core strand of the rope and / or the high compression region comprises at least one outer strand of the rope, preferably all outer strands of the rope. According to a further embodiment, the high compression region can be designed such that, upon application of the predetermined force, there is essentially no relative movement, preferably no axial displacement, of the elements, preferably the wires and / or strands, of the high compression region.

[0094] According to a further embodiment, a foreign substance can be arranged between the inner side of the ferrule and the radial outer side of the rope to increase the friction between the rope and the ferrule, preferably between the outer wires of the rope and the ferrule, and / or a foreign substance can be arranged between the wires of at least one outer strand of the rope, preferably between the wires of each outer strand, to increase the friction between the wires of the at least one outer strand, and / or a foreign substance can be arranged between at least two outer strands, preferably between all outer strands, to increase the friction between the outer wires of the outer strands. As a result, a region of high compression can be provided in the region where the foreign substance is introduced, which region has a higher compression between its elements than other regions of the compression clamp that do not have a friction-increasing filler.

[0095] The above-mentioned object is further achieved by a manufacturing method for a press clamp according to one of the preceding embodiments with the features of claim 30. Advantageous further developments of the method emerge from the two subclaims as well as the present description and the figures.

[0096] Accordingly, a manufacturing method for a press clamp according to one of the preceding embodiments is proposed, comprising inserting a rope, preferably a wire rope, into a rope receiving opening of a ferrule, and pressing the ferrule and the rope inserted into the ferrule.

[0097] The pressing is carried out in such a way that the rope in the area of ​​the press clamping receives at least one predetermined area of ​​high pressing and at least one predetermined area of ​​low pressing, in which the pressing of the wires and / or strands of the rope to one another is less than in the area of ​​high pressing.

[0098] The manufacturing process allows the advantages and effects described with regard to press clamping to be achieved in an analogous manner.

[0099] According to one embodiment, the pressing can comprise a plurality of successive pressing processes, wherein at least two pressing processes have differently oriented pressing directions, and / or that prior to the pressing a foreign substance is introduced to increase the friction between the inside of the ferrule sleeve and the radial outside of the rope, preferably between the outer wires of the rope and the ferrule, and / or between the wires of at least one outer strand of the rope, preferably between the wires of each outer strand, and / or between at least two outer strands, preferably between all outer strands.

[0100] Short description of the characters

[0101] Preferred further embodiments of the invention are explained in more detail in the following description of the figures. In the figures:

[0102] Figure 1 schematically shows a perspective view of an end face of a press clamp with an end cross-section of a rope pressed into the press clamp;

[0103] Figure 2 shows schematically a sectional view through the press clamp of Figure 1 with a device for monitoring the condition of a rope;

[0104] Figure 3 shows schematically a further sectional view of the press clamp from Figure 1;

[0105] Figures 4 and 5 schematically show the sectional views from Figures 2 and 3, with a device for monitoring the condition of a rope according to a further embodiment;

[0106] Figures 6A-6H each show schematically a sectional view of different designs of a press clamp for monitoring the condition of the cable pressed therein;

[0107] Figure 7 schematically shows a further sectional view of the press clamp of Figure 6C with a device for monitoring the condition of the cable of the press clamp; and

[0108] Figure 8 schematically shows a perspective view of an end face of another press clamp with an end cross-section of a rope pressed into the press clamp.

[0109] Figure 9 shows a schematic view of a press clamp and a device for monitoring an end cross-section of a rope.

[0110] Figure 10 schematically illustrates a schematic view of an arrangement of components for capturing images of speckle patterns.

[0111] Figure 11 shows exemplary images of speckle patterns for determining a condition and / or a change in condition of the end cross-section of a rope.

[0112] Detailed description of preferred embodiments

[0113] Preferred embodiments are described below with reference to the figures. Identical, similar, or equivalent elements in the different figures are provided with identical reference numerals, and a repeated description of these elements is partially omitted to avoid redundancies.

[0114] Figure 1 schematically shows a perspective view of an end face of a compression clamp 1 with an end cross-section 3 of a rope 2 pressed into the compression clamp. The compression clamp 1 comprises the rope 2 and a ferrule 4 pressed onto the rope 2. The rope 2 is in the form of a wire rope. It comprises a central core strand 5 and a plurality of outer strands 6 arranged around the core strand in the circumferential direction relative to an axial (longitudinal) direction 8 of the rope 2. All strands 5, 6 of the rope 2 each comprise a plurality of wires 8, which are shown schematically in one of the outer strands 6 in Figure 1, but are not shown for the remaining strands 5, 6 for reasons of clarity.

[0115] In the area of ​​compression with the ferrule 4, the rope 2 comprises a predetermined area of ​​high compression 9 of elements of the rope 2, here the outer strands 6 of the rope 2, and a predetermined area of ​​low compression 10 of elements of the rope 2, here the core strand 5 of the rope 2, in which the compression of the wires 7 to one another is less pronounced compared to the area of ​​high compression 9.

[0116] The low compression area 10, which essentially corresponds to the cross-sectional area of ​​the core strand 5, represents a predetermined monitoring area 11 in the compression clamp 1 for monitoring the condition of the rope 2.

[0117] The low compression region 10 is designed such that when a predetermined force is applied to the compression clamp 1 in the rope direction 8, a relative movement in the form of a substantially axial displacement of at least one wire 7 of the core strand 5 in the rope direction 8 is brought about, wherein the axial displacement in the rope direction 8 upon application and / or exceeding of the predetermined force is optionally at least 50 pm.

[0118] To create the high compression area 9, a foreign substance was introduced during the manufacture of the compression clamp 1 between the inside of the ferrule 4 and the radial outside of the rope 2 to increase the friction between the rope and the ferrule, and also partially between the outer strands of the rope. Furthermore, a number of consecutive compression processes were used during the compression process, with the orientation of the compression direction varying between the individual compression processes.

[0119] Figure 2 schematically shows a sectional view through the compression clamp 1 from Figure 1 with a device 12 for monitoring the condition of a rope 2. The core strand 5 can be seen, which is predetermined as a low compression area 10 and monitoring area 11. The device 12 comprises a sensor device 13 configured to determine the surface condition of the end cross-section 3 of the rope 2, here the surface condition of the predetermined monitoring area 11. The sensor unit 13 can determine the surface condition within a sensor area 15.

[0120] The device 12 further comprises an evaluation unit 14, here comprising a computing unit 14, which is configured to determine a state and / or a change in state of the rope 2 by comparing a reference surface quality of the end cross-section 3 and a currently determined surface quality of the end cross-section 3. The evaluation unit 14 is configured to detect a change in the state of the rope 2 based on a change in a partial area of ​​the surface quality. The surface quality of the monitoring area 11, as shown in Figure 2, represents the reference.

[0121] Figure 3 shows a schematic further sectional view of the compression clamp 1 from Figure 1, corresponding to Figure 2. Compared to Figure 2, two of the wires 7' of the core strand 5 have been displaced in the rope direction 8 because the rope 2 experienced a force above a predetermined force and below a maximum force, at which the areas of high compression 9 would also be damaged. Since the maximum force was not exceeded, the strands 7 of the outer strands 6 are essentially unchanged from their position in Figure 2. Accordingly, the surface quality of the end cross-section 3 has only changed in a partial area 16, which is determined by the displaced wires 7'. This change can be detected by determining the current surface quality of the monitoring area 11 and comparing the current surface quality with the previously recorded reference surface quality (cf.Figure 2) can be detected, and a change in the state of the rope 2 can be inferred from this. The displacement of the wires 7' is permanent and irreversible, even after the force above the predetermined force in the rope has been removed. The change in the surface condition in partial area 16 is therefore also permanent and irreversible.

[0122] According to this embodiment, the surface quality is determined in each case by the device 12 determining a sensor data set which is indicative of the surface quality of the cross-section 3, here specifically of the monitoring area 11.

[0123] In this case, the sensor device is designed to detect the surface texture optically. Alternatively or additionally, it can also be designed to determine the surface texture mechanically and / or inductively and / or magnetically.

[0124] Figures 4 and 5 show schematically the sectional views from Figures 2 and 3, with a device 12 for monitoring the condition of a rope 2 according to a further embodiment. The device 12 differs from the device 12 in Figures 2 and 3 in the installed sensor device 13. While the sensor device 13 of the embodiment according to Figures 2 and 3 is designed to detect the entire monitoring area 11, in the sensor device 13 of Figures 4 and 5 only a part of the monitoring area 11 lies within the sensor area 15. Accordingly, the device 12 is designed to move the sensor device 13 essentially parallel to the end face of the press clamp, thus essentially perpendicular to the rope direction 8, in the present case in a plane parallel to the end face of the press clamp 1 orparallel to a plane defined by the end cross-section 3, in order to successively cover the entire monitoring area 11 and to determine the surface condition therefrom.

[0125] Figures 6A-6H each schematically show a sectional view of different designs of a press clamp 1 for the purpose of monitoring the condition of the cable 2 pressed therein.

[0126] The embodiments according to Figures 6B to 6C and 6F each have a recess 17 extending through the press clamp 1 perpendicular to the cable direction 8, which recess completely intersects the cable 2 present in the press clamp 1 and thus an inner wall of the recess 17 forms the end cross-section 3. In the embodiment according to Figure 6A, the recess 17 has the shape of a cross, which is oriented such that the inner end cross-section 3 comprises a first surface section 18 and a second surface section 19, wherein the second surface section 19 is offset from the first surface section 18 in the cable direction 8 by a predetermined amount. In the embodiment according to Figure 6B, the recess 17 has a rectangular cross-section, which is oriented such that the end cross-section 3 is essentially planar.In the embodiments according to Figures 6C and 6F, the recess 17 is designed in the form of a bore. Accordingly, the end cross-section 3 has a curvature of constant magnitude.

[0127] In the embodiments according to Figures 6D and 6E, the end cross-section 3 is located at a free front end of the press clamp 1, corresponding to Figures 1 to 5.

[0128] The press clamp 1 according to Figure 6G comprises a free end in the shape of a spherical end. Accordingly, the cross-section 3 at the frontal free end of the press clamp 1 is designed in the shape of a spherical segment. The surface of the end-side cross-section 3 is thus curved in two mutually orthogonal directions.

[0129] The press clamp 7 from Figure 6H essentially corresponds to that from Figures 1 to 5 and 6D, wherein a coating 20 has been applied to the free end face of the press clamp 1, in this case via build-up welding, in order to provide the reference surface quality of the end cross-section 3 and at the same time seal the cable end against environmental influences, such as the penetration of moisture. Figure 7 schematically shows a further sectional view of the press clamp 1 from Figure 6C rotated 90° to this, with a device 12 for monitoring the condition of the cable 2 of the press clamp 1. As can be seen therefrom, the device 12 is designed to be insertable into the recess 18 in the form of the through-bore in an insertion direction 12 that corresponds to the longitudinal axis of the bore. Accordingly, the device 12, as can be seen from Figure 7, has dimensions perpendicular to the insertion direction 12 which are smaller than the bore diameter 22.

[0130] Figure 8 shows a schematic perspective view of an end face of another compression clamp 1 with an end cross-section 3 of a cable 2 compressed in the compression clamp 1. This embodiment essentially corresponds to that of Figure 1.

[0131] Where applicable, all individual features presented in the embodiments may be combined and / or exchanged without departing from the scope of the invention.

[0132] Fig. 9 shows a schematic view of the rope 2, which is attached to a holder, preferably a press clamp 1. The device 12 is located within the holder such that the end cross-section 3 of the rope 2 can be illuminated by a light source of the device 12, so that, for example, images of speckle patterns can be recorded in order to monitor the condition of the rope 2. Furthermore, the device 12 comprises a communication unit (not shown) that can transmit data to an external data processing unit 23. The communication unit can be configured to transmit a result of the evaluation of the recorded images of speckle patterns to the external data processing unit 23. Likewise, the

[0133] Communication unit may be configured to transmit the recorded images of the speckle patterns to the external data processing unit 23, wherein the external

[0134] Data processing unit 23 can be configured to evaluate the recorded images.

[0135] Fig. 10A schematically illustrates an arrangement of components for capturing images of speckle patterns 26. A light source 24 emits coherent light rays onto the end cross-section 3 of the rope 2. The coherent light rays are reflected at the end cross-section 3. Depending on the surface condition of the end cross-section 3, speckle occurs, allowing a recording device 25, in this case a digital camera, to capture images of the speckle pattern.

[0136] Fig. 10B shows a speckle pattern 26 measured using the arrangement of Fig. 10A. Fig. 11 shows exemplary images of speckle patterns 26 for determining a condition and / or a change in condition of the end cross-section of a rope. The left figure shows a speckle pattern without load, while the middle figure shows a speckle pattern with a load in the rope direction. The right figure shows the numerical difference between the two speckle patterns, clearly showing a difference in the cross-section at different times (no load on the left, load on the right).

[0137] Advantages of the invention

[0138] Overall, a method according to the invention allows for continuous and time-unlimited (i.e., not just punctual) monitoring of the rope at its end cross-section. The method according to the invention is thus not limited to a punctual representation of the rope condition at a selected time compared to a reference condition with the aim of observing deviations at this selected time. In particular, the claimed method is characterized by continuous, rather than punctual, observation of the rope condition.

[0139] A method according to the invention is preferably based on observing any changes in the rope structure when the direction of movement of at least one wire and / or at least one strand and / or at least one core or core of the rope (as elements of the rope) is in the rope direction, i.e., as a result of the force acting on the rope in the rope direction, as it acts on the rope in the tensile direction (z-direction), particularly during use. Accordingly, under such a force, the aforementioned elements of the rope, e.g., the wires of the rope as wire bundles, can be "pulled" into the rope, possibly indicating rope damage. A method according to the invention that can detect such changes in the rope structure in the tensile direction as rope damage must be distinguished in particular from methods used, for example, in connection with the manufacture of ropes, such as in the case of stripping sheathed ropes.Such methods known in the prior art detect, in particular, rope structural changes, particularly during the manufacturing process, along other directions due to external force input, e.g., a device. Such external force input must be distinguished from force input due to a load during rope use; for example, such methods known in the prior art detect whether wires as rope elements protrude from the rope as a result of an external force input, i.e., forces have acted in the opposite direction to the rope direction, and / or whether wires protrude from the rope, i.e., forces have acted with a force vector directed perpendicular to the rope. In such cases, methods known in the prior art are generally methods for quality control during the manufacturing process, rather than for the detection of manufacturing defects.In contrast, according to the invention, in particular exclusively the rope condition before a use-related force is applied and the rope condition during a use-related force is applied in the rope direction, as mentioned, in particular continuously and in real time. Accordingly, in particular exclusively the retraction of rope elements, e.g. wires, in particular due to the load acting on the rope during use, is observed according to a method of the invention. Overall, a method according to the invention is thus suitable for use during the use of the rope, even over its entire life cycle, and is not limited to application as a test method under narrowly defined laboratory conditions. Furthermore, a method according to the invention typically does not relate to the observation of any manufacturing defects during the rope production process, but rather to the observation of use-related changes in condition due to load influences.Real-time observations during use ensure maximum occupational safety. Any observed safety-relevant structural change in the rope can immediately trigger a cessation of rope use.

[0140] A rope observed by the present method typically has a machined end face. Minor material removal occurs in the radial direction by machining the end face of such a rope. In contrast, the rope observed by the method according to the invention is not machined by removing material from its outer surface or circumferential surface, e.g., by removing the outer surface of the rope or wire bundle.

[0141] According to the invention, the condition of the rope itself before use serves as a reference condition against which changes in the subsequent observation period are compared. Therefore, an external evaluation of the reference condition using reference variables is not required according to the invention.

[0142] A method according to the invention allows the condition of the rope to be assessed by observing its cross-section. This access to the rope makes it possible to observe changes in the elements located inside the rope; for example, it can be determined whether a wire located inside the rope has been pulled in by a load acting in the direction of the rope. Thus, the method according to the invention is not limited to observing changes in the rope structure or its elements occurring on the sheath surface.

[0143] A method according to the invention preferably allows the observation of the condition of a rope whose elements, in particular wires and strands, are not stabilized in the ferrule by means of corresponding agents that increase the coefficient of friction, e.g., by adhesives or bonding agents. Furthermore, the ropes observed according to the invention preferably do not have special rope-stabilizing ferrule shapes, e.g., conical ones. Rather, a method according to the invention is preferred if it is suitable for observing structural changes in ropes whose rope sections, in particular in the ferrule, are not stabilized or statically secured by a special design, as previously mentioned, for example. Ropes observed by a method according to the invention preferably have regions, in particular in the radial direction, within the ferrule with different coefficients of friction.

[0144] In the case of optical determination of the condition of the rope on its end face, e.g., using speckle photography, the evaluation unit is suitable for detecting the difference between the reference condition (i.e., the initial condition before use) and the current condition during use, e.g., the difference between speckle images. Therefore, a direct geometric evaluation of the measurement object is typically not required according to the invention.

[0145] According to the invention, an optical determination of the condition of the rope on its end face does not require a straight light or beam path. Although this can be designed to be straight, it can be designed within a technically acceptable angular range, i.e., from 0° to 80°C, preferably from 10° to 80°. The method according to the invention also does not require a telecentric beam path to ensure largely distortion-free projections. This applies in particular to the use of speckle patterns, which allow changes in the rope condition to be detected from the difference between speckle images, for example, in the case of wire or strand displacements.

[0146] An advantageous embodiment of the present invention is a method and device using speckle photography. Speckle photography allows the detection of changes in the potentially insensitive z-direction, i.e., the tensile direction, as shown below. The typically locally occurring changes in the z-direction (as a result of, for example, material fatigue in the rope) to be detected are converted, in the case of speckle photography, by shadowing or overexposure into laterally clearly recognizable, and thus easily detectable, xy-displacements. Thus, speckle photography essentially only detects those changes, namely those in the z-direction, that it is intended to detect, e.g., in the case of material fatigue. In this way, according to the invention, local wire or strand displacements are distinguished from overall surface displacements, such as those that can occur due to thermal expansion, etc.ichenl iste.

[0147] 1 press clamp

[0148] 2 rope

[0149] 3 Cross section

[0150] 4 press clamp

[0151] 5 core strands

[0152] 6 outer strands

[0153] 7 wire

[0154] 8 Rope direction

[0155] 9 Area of ​​high compression

[0156] 10 Low compression area

[0157] 11 Predetermined surveillance area

[0158] 12 Device

[0159] 13 Sensor device

[0160] 14 Computing unit

[0161] 15 Sensor area

[0162] 16 sub-area

[0163] 17 Recess

[0164] 18 First surface section

[0165] 19 Second surface section

[0166] 20 Coating

[0167] 21 Insertion direction

[0168] 22 bore diameters

[0169] 23 External data processing unit

[0170] 24 light source

[0171] 25 Mounting device

[0172] 26 speckle patterns

Claims

Claims: A method for monitoring the condition of a rope (2), in particular a wire rope, comprising: Providing a reference surface finish of an end cross-section (3) of a rope (2), in particular a wire rope, Determining the current surface condition of the end cross-section (3), Determining a state and / or a change of state of the rope (2) by comparing the reference surface condition and the currently determined surface condition, wherein a change in a sub-area (16) of the surface condition is indicative of a change of state of the rope (2).The method according to claim 1, characterized in that providing the reference surface finish comprises processing the end of the rope (2), preferably a subtractive process, particularly preferably a cutting and / or grinding process and / or EDM, of the end of the rope (2), and / or a subtractive process, particularly preferably welding, of the end of the rope, and / or a cleaning process, particularly preferably blowing, wiping, rinsing, degreasing and / or drying, and / or providing the reference surface finish comprises the initial determination of the reference surface finish.The method of claim 1 or 2, characterized in that the change of the partial area (16) of the surface condition of the rope (2) is effected by determining a relative movement, preferably an axial displacement, of at least one wire (7, 7') and / or at least one strand (5, 6) and / or at least one core or liner of the rope (2) in the rope direction (8), wherein preferably an axial displacement in the rope direction (8) from 100 pm, more preferably from 50 pm, more preferably from 10 pm, most preferably from 1 pm is indicative of a change of state, and / or the change of state is indicative of a predetermined overload case of the rope (2) and / or a press clamping (1 ) of the rope (2), wherein preferably the change of state is indicative of exceeding a predetermined force applied to the rope (2), more preferably a predetermined force in the rope direction (8). Method according to one of claims 1 to 3, characterized in that the change of the partial area (16) of the surface finish, preferably a relative movement, particularly preferably an axial displacement, of at least one wire (7, 7') and / or at least one strand (5, 6) and / or at least one core or core of the rope (2) in the rope direction (8) is determined in a predetermined monitoring area (11) of the cross-section (3), wherein the monitoring area (11) preferably comprises an inner area of ​​the end cross-section (3) and / or an outer area of ​​the end cross-section (3), wherein the monitoring area preferably comprises a core strand of the rope.Method according to one of the preceding claims, characterized in that the end-side cross-section (3) is at least partially substantially planar and / or the end-side cross-section (3) comprises at least a first surface section (18) and a second surface section (19), wherein the second surface section (19) is preferably set off from the first surface section (18) and / or is oriented at an angle to the first surface section (18), and / or the end-side cross-section^) is preferably oriented at an angle to the rope direction (8), particularly preferably at an angle between 10° and 90°, and most preferably substantially perpendicular to the rope direction (8).Method according to one of the preceding claims, characterized in that the cross-section (3) has at least partially a curved surface, preferably with constant curvature, wherein preferably the cross-section (3) is a partial region of a bore side wall of a bore, preferably a cylindrical bore, provided in a press clamp (4) pressed onto the rope (2) transversely to the axial rope direction (8), wherein preferably the bore diameter (22) is larger than the outer diameter of the rope (2) and / or the bore axis and the rope center axis (8) intersect or have a distance from each other that is smaller than the difference between the bore diameter (22) and the rope outer diameter in the region of the bore.Method according to one of the preceding claims, characterized in that the end cross-section (3) is arranged in the axial direction at the level of a crimp clamp (4) pressed with the rope (2), preferably a round clamp, wherein preferably the end cross-section (3) is located at a free end of the crimp clamp (4) or in the crimp clamp (4), preferably the one located in the crimp clamp (4). The end cross-section (3) is formed by a machining operation in the crimp clamp (4), particularly preferably by a bore, a milling and / or a cutout in or through the crimp clamp (4). A method according to one of the preceding claims, characterized in that the rope (2) comprises at least a predetermined area of ​​high crimping (9) of elements of the rope (2), preferably of wires (7, 7') and / or strands (5, 6) of the rope (2), and at least a predetermined area of ​​low crimping (10) of elements of the rope (2), preferably of wires (7, 7') and / or strands (5, 6) of the rope (2), wherein in the area of ​​low crimping (10) the crimping of the elements, preferably of the wires (7, 7') and / or strands (5, 6), is less pronounced compared to the area of ​​high crimping (9).wherein the low-pressure area (10) preferably comprises a core strand (5) of the rope (2) and / or the high-pressure area (9) comprises at least one outer strand (6) of the rope (2), preferably all outer strands (6) of the rope (2), wherein the predetermined monitoring area (11) preferably corresponds at least partially to the low-pressure area (10). Method according to one of the preceding claims, characterized in that the determination of the surface texture is carried out by determining a sensor data set, wherein the sensor data set is indicative of the surface texture of the cross-section (3), and / or wherein the surface texture is determined mechanically and / or optically and / or inductively and / or magnetically, wherein the surface texture is preferably determined by a distance measurement, preferably a mechanical, optical and / or magnetic and / or inductive distance measurement.a method according to one of the preceding claims characterized in that the surface texture is determined optically, wherein a light source (24) emits a coherent light beam onto an end cross-section (3) of the rope (2), at which the coherent light beam is reflected, wherein, depending on the surface texture of the end cross-section (3), speckle occurs, and a recording device (25) at a fixed distance from the end cross-section (3) of the rope (2) records images of occurring speckle patterns (26), and wherein, based on an evaluation of the recorded images of the speckle patterns (26), a state and / or a change of state of the rope (2), in particular wire rope, is determined. A method according to the preceding claim, characterized in that the change in state of the rope (2), in particular the wire rope, caused by an axial displacement of a wire (7) and / or a strand (5, 6) in the rope direction is determined by a change in the speckle pattern (26) in the recorded image, wherein preferably the change in the speckle pattern (26) can be determined by means of a shadow cast due to the axial displacement of the wire (7) and / or the strand (5, 6) in the rope direction. A method according to one of the preceding claims 10 or 11, characterized in that, to determine a state and / or a change in state of the rope, in particular wire rope, images of speckle patterns (26) are evaluated which were recorded at different times and are preferably compared with each other, wherein a comparison is particularly preferably carried out by a numerical difference of the recorded images of speckle patterns.A method according to any one of claims 10-12, characterized in that the light source (24) is a laser and / or an LED and / or the light source emits coherent light with a wavelength in the range of 400 nm to 3000 nm or of 450 nm to 3000 nm. A method according to any one of claims 10-13, characterized in that one or more optical components for beam shaping are located between the light source (24) and the end cross-section of the rope (2), in particular wire rope, preferably a lens, and more preferably a converging lens. A method according to any one of the preceding claims, characterized in that the recording device (25) is selected from the group comprising a digital camera and / or a CCD sensor, wherein the recording device preferably records at least 2, 3, 5, 10 or more images of speckle patterns per second.A method according to one of the preceding claims, characterized in that an aperture is provided between the recording device and the end cross-section, so that the brightness and / or the image section of the recorded images of a speckle pattern can be regulated, wherein the aperture preferably has an aperture number between 1 and 20, more preferably between 10 and 18. A device (12) for monitoring the condition of a rope (12), in particular a wire rope, comprising a sensor device (13) configured to determine the surface condition of an end cross-section (3) of a rope (2), in particular a wire rope, and an evaluation unit (14), preferably a computing unit, configured to determine the state and / or change of state of the rope (2) by comparing a reference surface condition of the end cross-section (3) and a currently determined surface condition of the end cross-section (3), wherein the evaluation unit (14) is configured to detect a change of state of the rope (2) based on a change in a partial area (16) of the surface condition.Device (12) according to the preceding claim, characterized in that at least one sensor unit of the sensor device (13), preferably the sensor device (13), can be inserted at least partially into a recess (17), preferably a bore, provided transversely to the rope direction (8) in a crimp clamp (1) pressed onto the rope (2), wherein the sensor device (13) is preferably configured to determine the surface condition in the state of the sensor unit or the sensor device (13) when inserted into the recess (17), preferably the bore. Device (12) according to one of the two preceding claims, characterized in that the sensor device (13) comprises a sensor, preferably a mechanical optical sensor and / or an electrical and / or magnetic and / or inductive sensor.Device (12) according to any one of the preceding claims 17 to 19, characterized in that the sensor device (13) comprises an optical sensor, preferably a recording device, particularly preferably a camera, and / or a light source for illuminating the cross-section (3). Device (12) according to any one of the preceding claims 17 to 20, characterized in that the device (12) comprises a light source (24) and a recording device (25), wherein the light source (24) is configured to emit a coherent beam of light onto the end cross-section (3) of the rope (2), in particular wire rope, such that the coherent beam of light is reflected at the end cross-section (3) of the rope (2), and speckle occurs depending on the surface properties of the end cross-section (3), and wherein the recording device is configured to be at a fixed distance from the end cross-section (3). The device (12) is characterized in that it comprises an evaluation unit, preferably a processing unit (14), which is configured to perform an evaluation of the recorded images of speckle patterns (26), wherein preferably images of speckle patterns (26) recorded at different times are compared with each other, and wherein a comparison is particularly preferably carried out by a numerical difference of the recorded images of speckle patterns.A device (12) according to one of the preceding claims 21 or 22, characterized in that the light source (24) and the recording device are integrated in a housing, the housing preferably comprising a processing unit (14), the processing unit (14) being particularly preferably configured to perform a comparison of recorded images of speckle patterns (26). A device (12) according to one of the preceding claims 21-23, characterized in that the device (12) comprises a communication unit, the communication unit being configured to transmit a result of an evaluation of the recorded images of speckle patterns (26) to an external to transmit the recorded images of speckle patterns (26) to an external data processing unit (23) and / or the communication unit is set up to transmit the recorded images of speckle patterns (26) to an external data processing unit (23), wherein preferably the external data processing unit (23) is configured to perform an evaluation of the recorded images of speckle patterns (26).System for monitoring the condition of a rope (2), in particular a wire rope, comprising a device according to one of the preceding claims 17-24 and a holder, preferably a press clamp (1), wherein the holder is configured to clamp a rope (2), in particular a wire rope, such that an end cross-section (3) of the rope (2) can be illuminated by a light source (24) with a coherent light beam onto the end cross-section (3) of the rope (2), in particular a wire rope, such that the coherent light beam is reflected at the end cross-section (3) of the rope (2), in particular a wire rope, and its condition is monitored depending on the... The surface condition of the end cross-section (3) leads to the occurrence of speckle, and the recording device (25) is configured to record images of occurring speckle patterns (26) at a fixed distance from the end cross-section of the rope (2), in particular wire rope, so that a condition and / or a change of condition of the rope (2), in particular wire rope, can be determined by evaluating the recorded images of the speckle patterns (26).Press clamp (1) on a rope (2), in particular wire rope, comprising a rope (2), in particular wire rope, and a press clamp (4) pressed with the rope (2), characterized in that the rope (2) in the area of ​​the press clamp with the press clamp (4) comprises at least a predetermined area of ​​high press clamping (9) of elements of the rope (2), preferably of wires (7) and / or strands (5, 6) of the rope (2), and at least a predetermined area of ​​low press clamping (10) of elements of the rope (2), preferably of wires (7, 7') and / or strands (5, 6) of the rope (2), in which the press clamping of the elements, preferably of the wires (7, 7') and / or strands (5, 6), of the rope (2) to each other is less pronounced compared to the area of ​​high press clamping (9).Press clamp (1) according to the preceding claim, characterized in that at least a part of the low crimp area (10) forms a predetermined monitoring area (11), wherein the low crimp area (10) is preferably designed such that when a predetermined force is applied to the press clamp (1), preferably when a force acting between rope (2) and press clamp (4) in the rope direction (8), a relative movement, preferably an axial displacement, of at least one wire (7') and / or at least one strand (5, 6) and / or at least one core or liner of the low crimp area (10) in the rope direction (8) is caused, wherein the axial displacement in the rope direction (8) when the predetermined force is applied and / or exceeded is preferably at least 1 pm, preferably at least 10 pm, particularly preferably at least 50 pm, and most preferably at least 100 pm.Press clamp (1) according to one of the two preceding claims, characterized in that the low crimping area (10) comprises a core strand (5) of the rope (2) and / or the high crimping area (9) comprises at least one outer strand (6) of the rope (2), preferably all outer strands (6) of the rope (2), and / or that the high crimping area (9) is designed such that when the. The specified force results in essentially no relative movement, preferably no axial displacement, of the elements, preferably the wires (7) and / or strands (5, 6), of the area of ​​high compression (9). Press clamp (1) according to one of claims 25 to 27, characterized in that an impurity for increasing the friction between the rope (2) and the press clamp (4), preferably between the outer wires of the rope (2) and the radial outer side of the rope (2), is arranged between the inside of the press clamp (4) and the radial outside of the rope (2), and / or that an impurity for increasing the friction between the wires (7) of at least one outer strand (6) of the rope (2), preferably between the wires (7) of each outer strand (6), is arranged between the wires (7) of the at least one outer strand (6), and / or an impurity for increasing the friction between the outer wires of the outer strands (6) is arranged between at least two outer strands (6), preferably between all outer strands (6).Manufacturing method for a press clamp (1 ) according to claims 25 to 28, comprising:. Inserting a rope (2), preferably a wire rope, into a rope receiving opening of a crimp sleeve 4), and Crimping of the crimp sleeve (4) and the rope (2) inserted into the crimp sleeve (4), characterized in that the crimping is carried out such that the rope (2) in the area of ​​the crimp clamp (1) receives at least one predetermined area of ​​high crimping (9) and at least one predetermined area of ​​low crimping (10), in which the crimping of the wires (7) and / or strands (5, 6) of the rope (2) to each other is less pronounced compared to the area of ​​high crimping (9). Manufacturing method according to the preceding claim, characterized in that the crimping comprises a plurality of successive crimping operations, wherein at least two crimping operations have differently oriented crimping directions.Manufacturing method according to one of claims 18 or 19, characterized in that, prior to crimping, a foreign substance is added to increase the friction between the inside of the crimp sleeve (4) and the radial outside of the rope (2), preferably between the outer wires of the rope (2) and the crimp sleeve (4). and / or at least one outer strand of the rope (2), preferably between the wires (7) of each outer strand (6), and / or between at least two outer strands (6), preferably between all outer strands (6), is inserted between the wires (7) of each outer strand (6).

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