Lifting gear such as a crane and charge-inhibiting coating and / or impregnating agent for inhibiting static charges on the cable drive of such lifting gear

Abstract

The present invention relates to lifting gear, in particular a crane, having a high-strength fibre cable to which a load-receiving and / or load-holding means is attached, wherein a wetting device for wetting the surface of the fibre cable has a charge-inhibiting medium comprising a moistening means and / or a polyglycol, and additionally at least one cationic surfactant as an additive for wetting the fibre cable.

Description

[0001] Lifting equipment such as cranes, as well as antistatic coating and / or impregnating agent for inhibiting static charges on the rope drive of such lifting equipment.

[0002] The present invention relates to a lifting device, in particular in the form of a crane, with a high-strength fiber rope to which a load-bearing and / or holding device is attached, and a device for reducing static charges on such a lifting device.

[0003] For some time now, efforts have been underway in lifting technology, and especially in cranes, to replace the usual heavy steel cables used in rope drives with high-strength fiber ropes. These ropes are made of high-strength synthetic fibers such as aramid fibers, aramid / carbon fiber blends, high-modulus polyethylene fibers (HMPE), LCP, or PBO fibers, or at least contain fibers of this type. The weight savings compared to steel cables, of up to 80% while maintaining nearly the same breaking strength, allow for an increase in the load-bearing capacity or permissible lifting load, as the rope's own weight, which must be considered when calculating the load-bearing capacity, is significantly lower. Particularly in cranes with large lifting heights or in boom or mast adjustment systems with pulleys of high reeving ratios, considerable rope lengths and thus corresponding rope weights are required, making the weight reduction possible with high-strength fiber ropes highly advantageous.However, when using such high-strength fiber ropes, the problem arises that the rope drive or its attachments, such as a load hook or a tool attached to the rope, can become electrostatically charged, especially when it is warm and dry. This can cause the load hook rigger or tool operator to receive an electric shock when touching the load hook, tool, or attachment, because the rigger is at the "earth" potential and the load hook or tool has become electrostatically charged relative to this potential due to rope friction in pulleys and bearings.

[0004] Such static charges arise from the friction of different materials against plastics, as is known, for example, when pulling a synthetic sweater over the head or walking across a synthetic carpet. The human body, or other conductive objects such as metallic parts, accumulate a corresponding potential, which, upon contact with oppositely charged objects, can lead to a discharge or a spark. Depending on the potential and stored energy, this discharge through the human body can also result in potentially harmful electric currents.

[0005] This tendency to accumulate static charge is further increased in high-strength fiber ropes when the rope's sheath is coated with wax. Such a wax coating is sometimes applied to increase the service life of the fiber rope, but practical experience has shown that such wax-coated fiber ropes are more prone to electrostatic charging.

[0006] When using conventional steel cables, such electrostatic charges generally do not occur, or any charge can be dissipated into the crane structure or its steel frame via the steel cable and pulleys and / or attachment points, by means of which the cable is deflected or attached to the boom or tower, for example. Regarding the charging of crane cables and their dissipation, it is known to connect the crane's steel frame to the grounded railway or tramway tracks or another grounding potential via a grounding cable when operating the crane in the vicinity of overhead lines or power lines, and there is a risk of the crane hoist cable touching the overhead line.

[0007] However, when using high-strength fiber ropes, such self-discharge into the crane structure does not occur, so there is a risk of electric shock when handling the load hook or when touching an object attached to the fiber rope.

[0008] In German patent application DE 10 2020 108 990 A1, a wetting device is proposed to mitigate the aforementioned problems with static charges on fiber ropes in a crane. This device sprays the fiber rope with an electrically conductive medium. Specifically, water- and oil-based emulsions are to be applied to the fiber rope to increase its conductivity and thereby improve the dissipation of electrostatic charges via the crane structure. For this purpose, the high-strength fiber rope is electrically connected to the crane structure by a charge conductor.

[0009] However, it has been shown that such water- and oil-based emulsions wash off the fiber rope very quickly, especially in certain weather conditions. At the same time, the conductivity of such emulsions is currently rather poor, meaning that the problem of static electricity buildup has so far only been unsatisfactorily solved.

[0010] The present invention is based on the objective of creating an improved lifting device of the aforementioned type, which avoids disadvantages of the prior art and advantageously develops the latter further. In particular, reliable protection against electric shocks is to be achieved and the problem of electrostatic charging of the load-bearing and / or holding elements attached to the high-strength fiber rope is to be mitigated. According to the invention, this objective is achieved by a lifting device according to claim 1, a charge-inhibiting coating and / or impregnation agent according to claim 25, and the use of such a coating and / or impregnation agent according to claim 36. Preferred embodiments of the invention are the subject of the dependent claims.

[0011] It is therefore proposed to provide a wetting device for coating the surface of the fiber rope with a charge-inhibiting medium, which not only establishes and maintains very good conductivity of the fiber rope, but also has a long service life on the fiber rope under the often harsh operating conditions of rope construction in lifting equipment and is difficult or impossible to wash out. According to the invention, the charge-inhibiting medium with which the fiber rope is coated has a composition which, in addition to a wetting agent and / or a polyglycol, also includes at least one cationic surfactant as an additive. The addition of at least one surfactant to the polyglycol and / or the wetting agent not only results in very good conductivity, but also prevents or minimizes the washout of the charge-inhibiting medium.significantly reduced, even under harsh environmental conditions such as rain and harsh operating conditions such as a higher number of bending / alternating cycles, as occurs with roped lifting equipment on the deflection devices often present there.

[0012] To make the fiber rope conductive and thus dissipative, and to prevent static charges, polar molecules are used for the coating. In particular, polar functional groups of the type (-OH) can bind to water molecules present in the ambient air via hydrogen bonds. For example, these functional groups (-OH) can be provided by the added polyglycol.

[0013] In particular, the anti-charging medium can comprise both a humectant and a polyglycol. Specifically, the anti-charging medium can comprise both a humectant and a cationic surfactant.

[0014] Glycerol can be advantageously added as a humectant. Glycerol, sometimes also called glycerin and characterized by the molecular formula C3H8O3, is a sugar alcohol that can be colorless and may have a lower viscosity than polyglycol. Glycerol is highly hygroscopic and can therefore attract and bind water or moisture in the form of vapor or mist from the ambient air, thereby significantly increasing the conductivity of the fiber rope.

[0015] In general, linear polyols with C2 to Ce or polyols with 2 to 6 hydroxy groups can be added as humectants, with a triol, particularly in the form of the triol glycerol, being advantageous.

[0016] By adding polyglycol, sometimes also called polyethylene glycol and characterized by the molecular formula C₂nH₄n+20n+i, the plastic fibers of the fiber ropes can be made more conductive, while at the same time, good lubrication is achieved due to the low coefficient of friction of polyglycols. Depending on the chain length, which is characterized by the coefficient n in the aforementioned molecular formula, polyglycols are either more liquid or more solid. This allows the consistency of the charge-inhibiting medium to be adjusted appropriately to ensure both sufficient impregnation of the fibers of the fiber rope and adequate penetration of the medium into the fiber rope, while simultaneously ensuring good adhesion to the fiber rope.

[0017] Advantageously, the viscosity of the charge-inhibiting medium can be reduced to a value in the range of 100 mm / s. 2 up to 1000 mm / s 2 or 200 mm / s 2 up to 750 mm / s2 or 400 mm / s 2 up to 700 mm / s 2 The viscosity should be adjusted, with a viscosity value in the range of 600 to 700 mm / s being used for good applicability and to increase adhesion. 2 This can be advantageous. The charge-inhibiting medium can form an impregnation of the fiber rope, influencing its electrophysical properties in order to prevent static charges or promote the dissipation of charges.

[0018] The polarization of plastics can be reduced by adding at least one cationic surfactant as an additive, since cationic surfactants have a positively charged functional group (-NR4). +Cationic surfactants possess multiple nonpolar hydrocarbon chains. The positively charged part is hydrophilic, meaning it attracts water, while the nonpolar parts are hydrophobic, meaning they repel water. At the same time, cationic surfactants have a high affinity for many fibers, which means that adding cationic surfactants can favorably influence the electrophysical properties of various fiber ropes.

[0019] Particularly in combination with the aforementioned humectant, for example in the form of glycerol and / or a polyglycol, the addition of cationic surfactants can achieve the desired very good drainage capacity and prevent or drastically reduce leaching.

[0020] A quaternary ammonium compound, in particular, can be used as a cationic surfactant.

[0021] R1 l + X' R 3 'R 4 are added, wherein the cationic surfactant can have the formula R, where R 1 , R2 , R 3 and R 4 alkyl groups can be, for example, stearyl, palmityl, methyl, benzyl and / or butyl groups, and x- is a counterion, for example, a halide.

[0022] In particular, the cationic surfactant that is added can have the following formula:

[0023] In an advantageous embodiment of the invention, at least one cationic surfactant can be added in an amount of 0.05 to 10.00 wt.%, or 0.1 to 7.5 wt.%, or 0.1 to 5.0 wt.%, or 0.5 to 5 wt.%, or 0.5 to 3 wt.%, or 2 to 3 wt.%, respectively, based on the total weight of the anti-static medium. If the proportion of cationic surfactants is too high, the washout resistance suffers, while if the surfactant content is too low, the conductivity is not increased to the desired extent. For example, surfactants in an amount of 0.5 to 2 wt.% may be advantageous.

[0024] The humectant, particularly in the form of glycol, can be present in a significantly larger proportion than the surfactants. The humectant content, especially the glycerol content, can range from 20 to 80 wt.%, 30 to 70 wt.%, 40 to 70 wt.%, or 40 to 60 wt.%, respectively, based on the total weight of the anti-static agent. To achieve low surface resistance and thus high conductivity, a high humectant content can be advantageous, for example, more than 40, 50, or even 60 wt.% based on the total weight of the anti-static agent. A reasonable range in this respect might be, for example, 50 to 70 wt.% based on the total weight of the anti-static agent. Increasing the humectant content can reduce the surface resistance and thus increase the conductivity.

[0025] Polyglycols can advantageously be added in a quantity of 5% to 90 wt% or 30 to 80 wt%, wherein polyethylene glycol can advantageously be added in a quantity of 60 to 90 wt% or 70 to 80 wt%, or polyalkylene glycol can be added in a quantity of 5 to 60 wt%, in each case based on the total weight of the charge-inhibiting medium.

[0026] In the aforementioned compositions of the charge-inhibiting medium, water can advantageously form the remainder.

[0027] Alternatively, the remaining material can also contain a wetting agent. Such a wetting agent can contain or consist of natural or synthetic compounds that reduce the surface tension of water or other liquids. Surfactants are particularly suitable as wetting agents. With the help of wetting agents, water and other liquids can penetrate solid surfaces more effectively.

[0028] The wetting agent can advantageously be added in a proportion of 0.05 to 1.0 wt.% or of 0.05 to 0.5 wt.% or of 0.05 to 0.3 wt.%, based on the total weight of the charge-inhibiting medium.

[0029] By wetting the rope surface with the special medium as described, the insulating properties of the fiber rope can be overcome or its conductivity reduced, allowing electrostatic charges to be conducted to the charge collector via the applied medium. Simultaneously, the frictional contact with pulleys, guide clips, and the like is altered in such a way that the fiber rope no longer accumulates a charge in the usual manner.

[0030] An electrical discharge device can be connected to the fiber rope, which dissipates electrostatic charges by utilizing the conductivity of the fiber rope resulting from its impregnation. This allows a load-bearing and / or holding device attached to the fiber rope, such as a load hook, to be handled in the usual manner by a rigger or other person standing on the ground without receiving an electric shock. Advantageously, the discharge device can be designed to interact with the running or moving rope to enable discharge even during operation of the hoist. In particular, the discharge device can be in sliding contact and / or rolling engagement with the rope, so that the rope can move past the discharge device and still discharge itself, so to speak, as it passes by.

[0031] For example, the aforementioned discharge device can have a charge collector that contacts the rope surface in order to dissipate charges on the fiber rope. This charge collector can be connected to the steel structure or supporting structure of the hoist, or to another grounding potential, in order to dissipate the charge picked up from the surface of the fiber rope into the hoist structure or the aforementioned grounding potential.

[0032] The aforementioned charge arrester can include at least one rope contact element, which may be shaped to fit the rope surface and / or cross-section to provide sufficient contact area with the rope for charge dissipation. This contact element can engage in sliding contact with the fiber rope or form a frictional contact with the rope, allowing relative movement between the rope and the charge arrester. Alternatively or additionally, the contact element of the charge arrester can also engage in rolling contact with the fiber rope, allowing it to roll along the passing rope, thus also creating a sufficient contact area for charge dissipation.

[0033] Depending on the design of the hoist and the installation of the fiber rope, the charge arrester can also be in contact with the fiber rope in other ways. For example, if the fiber rope is installed in a boom and / or mast adjustment mechanism and attached to the boom and / or mast, the charge arrester can also be rigidly or immovably attached to the fiber rope, for example, by tightly gripping the fiber rope like a cuff. In particular, the aforementioned charge arrester can include a pulley over which the fiber rope runs or is deflected. Such a pulley can be made of steel or a conductive metal alloy and, for example, be electrically connected to the hoist's support structure by a metallic swivel bearing or another current-transmitting device in order to dissipate electrostatic charges into the hoist structure.

[0034] Regardless of such a deflection pulley, a contact element can also be a pure contact roller that does not actually deflect the rope but only rolls it on the rope, a contact brush, and / or a contact slide or another grinding or sliding contact.

[0035] The aforementioned wetting device can advantageously include a medium reservoir in which the electrically conductive medium to be applied to the rope can be stored. Such a reservoir can be, for example, a canister, a foil bag, or even a storage cylinder in which a supply of medium can be stored.

[0036] The aforementioned medium storage container can be located near the application point where the medium is applied to the fiber rope to minimize conveying and application distances. If, for example, the medium is to be applied to the load-bearing and / or holding device, the storage container can be attached to that device, such as a lifting hook.

[0037] Alternatively or additionally, a medium storage device can also be attached to a boom or a structural part of the hoist, from which the fiber rope runs or to which the fiber rope is attached, which could be, for example, a luffing boom or adjustable mast of the hoist.

[0038] Advantageously, the medium storage can be positioned above the application point in order to transport the medium to the application point by gravity or at least to support the conveyance of the medium to the application point by gravity.

[0039] Alternatively or additionally, a medium storage tank located at the same level or below the application point can be provided. In this case, a pump can be provided to transport the medium from the storage tank to the application point.

[0040] In order to apply the medium specifically to the surface of the fiber rope, the wetting device can have one or more application elements, each of which can have an application opening directed towards the rope.

[0041] Depending on the medium used, and especially its viscosity, various application elements can be provided. For example, if a fluid such as oil or water is to wet the rope, a spray nozzle can be used as the application element, directing a spray-like cloud and / or jet onto the rope.

[0042] Alternatively or additionally, a dropper can be provided as a delivery element for dripping or sprinkling the rope, wherein said dropper can be arranged above, and in particular vertically above, the rope to allow droplets to fall onto the rope. Preferably, such a dropper can be arranged in the immediate vicinity of the rope to prevent the droplets from being blown away, for example, in strong winds. Such a dropper can include a droplet generator that produces droplets of a suitable size, which can then drip onto the rope. For example, a droplet generator similar to those known from infusion sets in medical technology can be provided. Regardless of this, the droplet generator can be adjustable to produce droplets of different sizes and / or at different intervals.

[0043] Alternatively or in addition to a non-contact application element, the wetting device can also have a contact application element, for example in the form of a brush-like coating element that applies the medium to the surface of the fiber rope.

[0044] Advantageously, such a brush-like applicator can be supplied with medium via a supply channel or supply line from the medium storage, which can, for example, run into the brush bristles to be distributed by them on the rope.

[0045] Alternatively or additionally, the wetting device can also include an immersion bath or an immersion bath-like element, such as a tub or a mist chamber, through which the fiber rope to be wetted can pass. For example, a tub-shaped immersion bath container can be arranged in the area of ​​a rope pulley and / or a rope cylinder, in which the medium level is sufficiently high so that the rope can pass through the medium bath.

[0046] In a spray chamber, the medium can be atomized into a spray mist, which remains trapped in a preferably closed chamber to prevent excessive mist from escaping along the rope. Alternatively, a tray open at the top or bottom can be used to capture the spray mist sufficiently to prevent uncontrolled escape. The rope can pass through such a chamber, for example, by providing an opening on each of the opposing walls through which the rope can pass.

[0047] The rope does not necessarily have to pass through such an immersion bath or an immersion-bath-like dispensing device. If necessary, a stationary section of rope can also be immersed in the immersion basin and / or remain within the immersion-bath-like dispensing element and / or be positioned within it. Distribution of the medium can nevertheless be achieved, for example, through capillary action within the rope, which essentially absorbs the medium. Distribution of the medium along or within the rope via capillary action can also be combined with another dispensing method. For example, a section of rope can be continuously or repeatedly dripped, with the liquid then distributing itself within the rope or rope sheath through capillary action.

[0048] The application element(s) can be arranged at various points on the hoist to apply the medium to the fiber rope. For example, an application element can be provided on the load-bearing and / or holding device to wet a section of rope located on the load-bearing and / or holding device.

[0049] Alternatively or additionally, a delivery element can be attached to a rope deflection pulley.

[0050] Alternatively or additionally, a spray element can also be attached to a structural component of the hoist to wet a free section of rope. For example, a spray element can be attached to a boom to wet a section of rope extending along and / or running past the boom.

[0051] Alternatively or additionally, a spraying element can also be attached to or positioned adjacent to a cable drum in order to wet a section of cable located on the cable drum, for example, a cable turn wound around the cable drum. In particular, a section of cable running off or onto the cable drum can be wetted by a suitably attached spraying element.

[0052] Advantageously, at least one dispensing element is arranged directly on or near the medium storage unit to allow for a short connecting line or conveying channel to supply the medium. Depending on the available space on the respective lifting device, the dispensing element can also be positioned at a distance from the medium storage unit, in which case a conveying or pumping device may be provided to transport the medium from the storage unit to the dispensing element and / or to ensure sufficient pressure at the dispensing element.

[0053] Advantageously, a conveying and / or pumping device for conveying and / or pumping the electrically conductive medium can be coupled to a drive movement of the rope in order to derive a conveying effect from the rope movement and / or to match the conveying effect to the rope movement.

[0054] For example, the conveying and / or pumping device can be coupled to a pulley so that a rotational movement of the pulley generates a drive movement of the conveying and / or pumping device. For example, a pump can be coupled to a pulley on the load hook or the load-handling and / or holding device to provide a conveying effect when the load-handling device is lowered or raised.

[0055] The anti-charging medium can be liquid, or possibly also pasty or creamy. Liquid media can include water, oil, or light emulsions.

[0056] Advantageously, the wetting device can include an adjustable dosing device to control the amount of medium to be applied.

[0057] Such a metering device can, for example, include an adjustable valve that can open and close and / or enlarge or reduce the dispensing opening of the dispensing element or the front cross-section of the delivery line, whereby the valve can, for example, be opened and closed intermittently in order to dispense a targeted quantity per opening cycle.

[0058] For gravity-driven dispensing of the medium, an adjustable hose valve, similar to those used in medical dosing devices, can be employed. Alternatively or additionally, a tap-like valve can be installed in the delivery line.

[0059] Alternatively or additionally to such a metering valve, the metering device can also be part of the aforementioned conveying system, for example in the form of the pump, in order to control the actively conveyed delivery rate and thus the dose of the medium to be dispensed. For example, a piston pump can be used as a metering device, dispensing a specific quantity per stroke. Alternatively or additionally, a hydraulic cylinder, which can simultaneously serve as a medium reservoir, can include an adjustable piston, the movement of which by a specific distance dispenses a predetermined dose.

[0060] Advantageously, the aforementioned metering device can be driven and / or actuated by a motor. For example, an electromagnetic actuator can be used to open and close a metering valve, an electric motor to open and close a tap valve, a rack and pinion drive, and / or a hydraulic motor to actuate the metering cylinder. The metering device can also be coupled to a lifting cable movement, in particular a pulley or cable drum, to derive the metering from the cable movement.

[0061] A control device, which may be electronic and / or have a microprocessor and possibly a program memory, can control the wetting device and / or the dosing device depending on various operating and / or environmental parameters.

[0062] For example, the aforementioned control device can actuate the wetting device depending on a rope movement, whereby, for example, a rope speed and / or a rope adjustment distance traveled and / or a number of bending cycles can be taken into account for the control of the metering device, for example in such a way that a larger quantity of medium is dispensed at higher rope speeds and / or distances and / or numbers of bending cycles than at lower rope speeds and / or distances and / or numbers of bending cycles.

[0063] Alternatively or additionally, the control device can actuate or control the wetting device or the metering device depending on the ambient humidity and / or the ambient temperature. For example, in rain or even just very high ambient humidity, the wetting device can be deactivated and / or the amount of medium applied can be reduced. As the weather becomes increasingly dry and / or the ambient humidity decreases, the wetting device can be actuated and / or the amount of medium applied can be increased.

[0064] The control device can be designed to take into account a weather signal, for example in the form of a rain signal and / or humidity signal, which can be provided, for example, by a weather station and / or a rain sensor and / or a humidity sensor.

[0065] Alternatively or additionally, the control device can also actuate or control the wetting device or the metering device depending on the ambient temperature and / or the rope temperature. Since static charge builds up more easily or intensely at increasing temperatures, the control device can be designed to deactivate the wetting device at low temperatures, for example, freezing temperatures, and / or reduce the metering quantity, and / or conversely, to actuate the device and / or increase the metering quantity as temperatures increase.

[0066] The control device can process a temperature signal provided by a weather station and / or a temperature sensor, wherein said temperature sensor can measure the ambient temperature and / or the rope temperature. The invention is explained in more detail below with reference to preferred embodiments and accompanying drawings. The drawings show:

[0067] Fig. 1 : a side view of a lifting device in the form of a tower crane, whose load-handling and / or holding device in the form of a load hook is attached to a hoist rope that runs from a trolley movable on the boom of the crane,

[0068] Fig. 2: a representation of a wetting device for wetting the lifting rope of the crane from the previous figure in the area of ​​the load hook, showing a medium reservoir and a dispensing element directed towards the fiber rope or its deflection pulley,

[0069] Fig. 3: a graphical representation of the different charges or stress values ​​on differently coated sections of a fiber rope after a test with 99 test strokes, and

[0070] Fig. 4: a graphical representation of the different charges or stress values ​​on differently coated rope sections of a fiber rope similar to Figure 3, but after a test with 165 test strokes.

[0071] As shown in Figure 1, the lifting device 1 can be designed as a crane, for example in the form of a tower crane, which includes a boom 3 sitting on a tower 2, wherein the tower 2 together with the boom 3 or the boom 3 can be rotated relative to the tower 2 about an upright axis 4.

[0072] A trolley 5 can be mounted on the boom 3, from which a load-bearing and / or holding device 7, for example in the form of a load hook, can be lowered and raised. The aforementioned load-bearing and / or holding device 7 is attached to a lifting rope 6, which can be designed as a high-strength fiber rope made of plastic fibers, as described above.

[0073] As an alternative to the tower crane shown in Figure 1, the lifting device can also be another type of crane, for example, a mobile crane, a telescopic jib crane, a luffing jib crane, a harbor crane, or a ship crane. However, the lifting device in question is not limited to cranes; it can also be other conveying and / or construction machinery such as cable excavators, freight or passenger elevators, or other personnel and / or freight transport systems such as cable cars or chairlifts.

[0074] The fiber rope need not be used as a lifting rope, but can also serve for the bracing and / or adjustment of a boom or mast, or be used as a moving, reciprocating conveying device. In particular, it is a moving, especially driven, rope that can, or would, become statically charged due to friction as a result of its movement if no countermeasures were taken.

[0075] To prevent such a build-up of charge on the rope 6 and, in particular, on the load-bearing and / or holding device 7 attached to it, a discharge device 8 is provided, which dissipates the electrical charge from the rope 6 and / or the load-bearing and / or holding device 7 into the supporting structure of the hoist or another grounding potential element. In particular, the discharge device 8 can electrically connect the rope 6 and / or the load-bearing and / or holding device 7 to the steel structure of the crane 1, preferably its boom 3 and / or its tower 2 and / or its superstructure and / or undercarriage. For example, the discharge device 8 can comprise a charge arrester 9, which has at least one contact element 10 for electrically contacting the moving rope 6. Such a contact element 10 can, for example, comprise a rope deflection pulley over which the rope 6 runs and is deflected.If necessary, a simple contact roller without a rope deflection effect could also be provided.

[0076] A wetting device 11 for wetting the surface of the fiber rope 6 can advantageously include a medium reservoir 12 in which the charge-inhibiting medium can be stored. The medium reservoir 12 can, for example, be in the form of a canister or other container, but a volume-variable reservoir can also be provided, for example in the form of a foil bag, a paste tube, or a storage cylinder with a movable piston, which could also be used to pressurize and / or dispense the medium.

[0077] The charge-inhibiting medium can advantageously be liquid or viscous, or for example slightly pasty like a paint.

[0078] Regardless of this, the charge-inhibiting medium may have a composition that includes at least one polyglycol to make the plastic fibers of the fiber rope 6 more conductive.

[0079] Alternatively or additionally, the medium comprises a humectant, in particular in the form of glycerol or, more generally, a linear polyol with C2 to C6, to bind moisture in the fiber rope or absorb it from the environment and thereby increase its conductivity. Generally, linear polyols with C2 to Ce or polyols with 2 to 6 hydroxyl groups can be added as humectants, preferably a triol.

[0080] In particular, glycerol can be added as a humectant. Glycerol, sometimes also called glycerin, has the molecular formula C3H8O3. Additionally, a cationic surfactant or several different cationic surfactants are advantageously added as an additive to reduce the polarization of the plastics.

[0081] A quaternary ammonium compound, in particular, can be used as a cationic surfactant.

[0082] R1 l + X' R 3 'R 4 are added, wherein the cationic surfactant can have the formula R, where R 1 , R 2 , R 3 and R 4 Alkyl groups can be, for example, stearyl, palmityl, methyl, benzyl and / or butyl groups, and x- is a counterion, for example, a halide.

[0083] In particular, the cationic surfactant that is added can have the following formula:

[0084] In an advantageous embodiment of the invention, at least one cationic surfactant can be added in an amount of 0.05 to 10.00 wt.% or 0.1 to 7.5 wt.% or 0.1 to 5.0 wt.% or 0.5 to 3 wt.% or 1 to 3 wt.% or 2 to 3 wt.%, each based on the total weight of the charge-inhibiting medium.

[0085] The humectant, particularly in the form of glycol, can be present in a significantly larger proportion than the surfactants, with the humectant content, especially the glycerol content, ranging from 20 to 80 wt.%, 30 to 80 wt.%, 30 to 70 wt.%, 40 to 70 wt.%, or 40 to 60 wt.%, respectively, based on the total weight of the anti-charge agent.

[0086] Mediums.

[0087] To achieve low surface resistance and thus high conductivity, a high proportion of dampening agent can be advantageous, for example more than 40 or more than 50 or even more than 60 wt.% based on the total weight of the charge-inhibiting medium, whereby a sensible range in this respect may be, for example, 50 to 70 wt.% based on the total weight of the charge-inhibiting medium.

[0088] Polyglycols can advantageously be added in a quantity of 5% to 90% or 30 to 70 wt.%, wherein polyethylene glycol can advantageously be added in a quantity of 60 to 90 wt.% or 70 to 80 wt.% or polyalkylene glycol in a quantity of 5 to 60 wt.%, in each case based on the total weight of the charge-inhibiting medium.

[0089] For example, the fiber rope 6 can be provided with one or more coatings made of one or more of the following media:

[0090] Advantageously, the viscosity of the charge-inhibiting medium can be reduced to a value in the range of 100 mm / s. 2 up to 1000 mm / s 2 or 200 mm / s 2 up to 750 mm / s 2 or 400 mm / s 2 up to 700 mm / s 2 The viscosity should be adjusted, with a viscosity value in the range of 600 to 700 mm / s being used for good applicability and to increase adhesion. 2 This can be advantageous. Using the coatings mentioned above, the coated rope was subjected to bending cycles on a rope test rig by deflecting it around pulleys, simulating a defined temperature and humidity profile as environmental conditions.

[0091] The different coatings used in the experiments can be found in the following table:

[0092] As the following table shows, the electrical charging could be significantly inhibited or reduced, in particular, when the coating contained a combination of a cationic surfactant and a humectant, especially in the form of a linear polyol C2-C6, preferably glycerol, the compositions of which can be identified by the laboratory number given in the following table and the coating examples given above:

[0093] The significant inhibition of static charging for the combination of the cationic surfactant 1 with the humectant or of the cationic surfactant 2 with the humectant glycerol is particularly evident from Figures 3 and 4, where Figure 3 shows the set of measurement results after 99 strokes and a corresponding number of bending cycles on the test bench and Figure 4 shows the set of measurement results after 165 strokes and a corresponding number of bending cycles.

[0094] For targeted application of the medium onto the rope 6, the wetting device 11 can advantageously comprise at least one application element 13, which can include an application opening directed towards the rope 6, cf. Fig. 2.

[0095] For example, the aforementioned dispensing element 13 can include a spray nozzle that directs a directed jet and / or a directed mist cloud onto the rope 6.

[0096] Alternatively or additionally, a dispensing element 13 in the form of a drip valve or a drip element can also be provided, which forms the medium to be dispensed into droplets that can drip onto the rope 6.

[0097] Alternatively or additionally, the application element 13 can also be provided for, for example in the form of a brush or a fluffy material roller or fabric material roller, with which the medium can be spread or rolled onto the surface of the rope 6.

[0098] As shown in Figures 2 to 5, the wetting device 11 can be assigned to the rope section that is to be wetted with the medium. In particular, the medium reservoir 12 can be arranged above the rope section to be wetted, with the dispensing element 13 directed towards the rope 6 being arranged directly on the rope and connected to the medium reservoir 12 by a front line 14.

[0099] As shown in Fig. 2, for example, a section of rope located on the load-bearing and / or holding device 7 can be wetted, and the wetting device 11 can be arranged on said load-bearing and / or holding device 7. The dispensing element 13 can discharge the medium directly onto said section of rope on the load-bearing and / or holding device 7 and / or onto a deflection pulley around which the rope 6 on the load-bearing and / or holding device 7 runs. For example, the medium reservoir 12 can be mounted on the load-bearing and / or holding device 7 and move with the movements of the load-bearing and / or holding device 7.

[0100] A control device 19 can control the wetting device 11 and / or the metering device 18 depending on various operating and / or environmental parameters. For example, the control device 19 can actuate the wetting device depending on a rope movement, whereby, for example, a rope speed and / or a rope travel distance can be taken into account for controlling the metering device 18, such that at higher rope speeds and / or travel distances a larger quantity of medium is dispensed than at lower rope speeds and / or travel distances.

[0101] Alternatively or additionally, the control device 19 can actuate or control the wetting device 11 or the metering device 18 depending on the ambient humidity and / or the ambient temperature. For example, in the event of rain or even just very high ambient humidity, the wetting device 11 can be deactivated and / or the amount of medium to be applied can be reduced. In increasingly dry weather and / or decreasing ambient humidity, the wetting device can be actuated and / or the amount of medium to be applied can be increased.

[0102] The control device 19 can be configured to take into account a weather signal, for example in the form of a rain signal and / or humidity signal, which can be provided, for example, by a weather station and / or a rain sensor and / or a humidity sensor.

[0103] Alternatively or additionally, the control device 19 can also actuate or control the wetting device 11 or the metering device 18 depending on the ambient temperature and / or the rope temperature. Since static electricity builds up more easily or more strongly at increasing temperatures, the control device 19 can be configured to deactivate the wetting device 11 at low temperatures, for example, freezing temperatures, and / or reduce the metering quantity, and / or conversely, to actuate the operating device 11 and / or increase the metering quantity at increasing temperatures.

[0104] To significantly reduce the surface resistance of the coated rope and thereby achieve higher conductivity and simultaneously a longer service life of the coating, it can be advantageous to increase the proportion of the dampening agent, preferably well above 30 percent by weight, for example to the range of 50 to 70 or 60 to 70 percent by weight, based on the total weight of the charge-inhibiting medium, as shown in examples -09 to -14 in the table below: Comparing, for example, test sample -09, which has a dampening agent content of 30% by weight and was used in test series 0.1, with test sample -13, which contains 68.95% by weight dampening agent and was used in test series V13, a significantly lower surface resistance and, consequently, a significantly increased conductivity are observed. At the same time, the coating exhibits high durability, even after more than 50 hours of rain at 25 liters / m². 2 withstands, as the following diagrams show in comparison to each other:

[0105] Surface SoLITE 22 resistance

[0106] Coating 240272-09

[0107] [Ohm] ■ 0.1 irrigation 25 l / m 2 l,0E+10

[0108] 1.0E+09 l,0E+08

[0109] 1.0E+07

[0110] 0 6 12 18 24 30 36 42 48 54 60 66 72

[0111] Time [h]

[0112]

[0113] In the diagrams above, the surface resistance corresponds to 1 x 10 10 the 1% limit of the permitted static charge.

Claims

Patent claims 1. Lifting device, in particular crane (1) with a high-strength fiber rope (6) to which a load-bearing and / or holding device (7) is attached, characterized in that a wetting device (11) for wetting the surface of the fiber rope (6) comprises a charge-inhibiting medium comprising a dampening agent and / or a polyglycol, as well as additionally at least one cationic surfactant as an additive for wetting the fiber rope (6).

2. Lifting device according to the preceding claim, wherein the charge-inhibiting medium comprises both a dampening agent and a polyglycol.

3. Lifting device according to one of the preceding claims, wherein the charge-inhibiting medium comprises both a dampening agent and the cationic surfactant.

4. Lifting device according to one of the preceding claims, wherein the dampening agent comprises a linear polyol with two to six hydroxy groups, preferably in the form of a triol.

5. Lifting device according to the preceding claim, wherein the dampening agent comprises glycerol.

6. Lifting device according to one of the preceding claims, wherein the dampening agent is present in a larger proportion than the cationic surfactant in the charge-inhibiting medium.

7. Lifting device according to the preceding claim, wherein the dampening agent content, in particular the glycerol content, is in the range of 20 to 80 wt.% or 30 to 70 wt.% or 40 to 70 wt.% or 40 to 60 wt.% or 50 to 70 wt.% or 60 to 70 wt.%.

8. Lifting device according to one of the preceding claims, wherein the cationic surfactant comprises a quaternary ammonium compound.

9. Lifting device according to the preceding claim, wherein the cationic ten- R 1 sid the formula possesses, where R1, R2, R3 and R4 can be alkyl groups, for example stearyl, palmityl, methyl, benzyl and / or butyl groups, and x- is a counterion, for example a halide.

10. Lifting device according to the preceding claim, wherein the cationic surfactant has the following formula:

11. Lifting device according to one of the preceding claims, wherein the cationic surfactant is present in a proportion of 0.05 to 10 wt.% or of 0.1 to 7.5 wt.% or of 0.1 to 5 wt.% or of 0.5 to 2 wt.% in the charge-inhibiting medium.

12. Lifting device according to any of the preceding claims, wherein the polyglycol is added in a quantity of 5% to 90% or of 25% to 90 wt.% or of 60 to 90 wt.% or 70 to 80 wt.% or of 30 to 70 wt.%.

13. Lifting device according to one of the preceding claims, wherein the charge-inhibiting medium has a viscosity in the range of 100 to 1000 mm / s 2or 400 to 700 mm / s 2 owns.

14. Lifting device according to one of the preceding claims, wherein said wetting device (11) has a medium storage unit (12) and at least one dispensing element connected to the medium storage unit (12) for dispensing the medium onto the fiber rope (6).

15. Lifting device according to the two preceding claims, wherein the at least one dispensing element (13) has at least one spray nozzle for spraying the fiber rope (6) with the medium and / or a droplet generator for generating medium droplets and sprinkling the fiber rope (6).

16. Lifting device according to one of the preceding claims, wherein the wetting device (11) is for wetting a load-bearing and / or The holding means (7) is designed in the rope section located and / or in the rope section circulating around a deflection pulley (15), wherein the wetting device (11) is designed in particular to wet a free rope section of the fiber rope (6).

17. Lifting device according to one of the preceding claims, wherein the wetting device (11) has an adjustable metering device (18) for variably adjusting a dose of the medium to be applied, wherein the metering device (18) preferably has a motor-operated metering valve and / or a delivery device controllable with respect to the delivery rate, in particular a pump (17).

18. Lifting device according to one of the preceding claims, wherein a control device (19) for controlling the wetting device (11) depending on at least one environmental and / or operating parameter of the lifting device.

19. Lifting device according to the preceding claim, wherein the control device (19) is configured to actuate the wetting device (11) depending on a rope movement of the fiber rope (6), in particular to increase the dispensing quantity of the medium with increasing rope speed and / or increasing rope movement distance.

20. Lifting device according to one of the two preceding claims, wherein the control device (19) is configured to actuate the wetting device (11) depending on an ambient humidity signal and / or rain signal, in particular to reduce the application rate of the medium with increasing ambient humidity and / or in the event of rain and / or to increase the application rate of the medium with decreasing ambient humidity and / or in the event of no rain, and / or is configured to actuate the wetting device (11) depending on an ambient temperature and / or a rope temperature, in particular with increasing Ambient and / or rope temperature can increase the application rate of the medium.

21. Lifting device according to one of the preceding claims, wherein a discharge device (8) for dissipating electrostatic charges on the fiber rope (6) and / or on the load-bearing and / or holding means (7) comprises a charge arrester (9) contacting the fiber rope (6) and connected to a support structure (2, 3) of the lifting device and / or another grounding potential element.

22. Lifting device according to the preceding claim, wherein the charge arrester (9) has at least one contact element (10) movable relative to the fiber rope (6) which is in contact with an outer circumferential surface of the fiber rope (6), wherein the contact element (10) is in rolling engagement with the fiber rope (6) and comprises a contact roller and / or is in sliding engagement with the fiber rope (6) and comprises a contact slide and / or a contact brush.

23. Lifting device according to one of the preceding claims, wherein the fiber rope (6) forms a lifting rope and is provided with a hoist drive for hauling in and lowering the lifting rope.

24. Lifting device according to one of claims 1 to 22, wherein the fiber rope (6) forms a guying and / or adjusting rope of a guying and / or adjusting rope system for guying and / or adjusting a boom (3) and / or mast and / or tower (2).

25. Charging-inhibiting coating and / or impregnating agent for inhibiting static charges on rope drives of lifting equipment, comprising a composition including a dampening agent and / or a polyglycol, wherein the coating and / or impregnating agent additionally includes at least one cationic surfactant as an additive.

26. Charging-inhibiting coating and / or impregnating agent according to the preceding claim, wherein the composition comprises both a humectant and a polyglycol.

27. Charging-inhibiting coating and / or impregnating agent according to one of the two preceding claims, wherein the composition comprises both a humectant and the cationic surfactant.

28. Charging-inhibiting coating and / or impregnating agent according to one of claims 25 - 27, wherein the dampening agent comprises a linear polyol with two to six hydroxy groups, preferably in the form of a triol.

29. Charging-inhibiting coating and / or impregnating agent according to the preceding claim, wherein the humectant comprises glycerol.

30. Anti-charging coating and / or impregnating agent according to one of claims 25 - 29, wherein the dampening agent is present in a larger proportion than the cationic surfactant in the anti-charging medium.

31. Charging-inhibiting coating and / or impregnating agent according to the preceding claim, wherein the dampening agent content, in particular the glycerol content, is in the range of 20 to 80 wt.% or 30 to 70 wt.% or 40 to 70 wt.%.

32. Charging-inhibiting coating and / or impregnating agent according to one of claims 25-31, wherein the cationic surfactant is a quaternary Am- R 1 h - R3 NI . R 4 x has a mono-compound which has the formula R 2 possesses, where R1, R2, R3 and R4 can be alkyl groups, for example stearyl, palmityl, Me- thyl, benzyl and / or butyl residues are, and x- is a counterion, for example a halide.

33. Charging-inhibiting coating and / or impregnating agent according to one of claims 25-32, wherein the cationic surfactant has the following formula:

34. Anti-charging coating and / or impregnating agent according to any one of claims 25-33, wherein the cationic surfactant is present in a proportion of 0.05 to 10 wt.% or 0.1 to 7.5 wt.% or 0.1 to 5 wt.% or 0.5 to 2 wt.% in the anti-charging medium, and the polyglycol is added in a proportion of 5% to 90% or 30 to 90 wt.% or 60 to 90 wt.% or 60 to 80 wt.%.

35. Charging-inhibiting coating and / or impregnating agent according to one of claims 25-34, wherein the coating and / or impregnating agent has a viscosity in the range of 100 to 1000 mm / s 2 or 400 to 700 mm / s 2 owns.

36. Use of a charge-inhibiting coating and / or impregnating agent designed according to one of claims 25 to 35 for impregnating the fiber rope (6) of a lifting device, in particular a crane (1).

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