Rope gripper and method for operating a rope gripper

Abstract

The invention relates to a rope gripper comprising a gripper frame, at least two gripper blades which are adjustably mounted at a lower end of the gripper frame between a closed and an open position, a retaining rope for holding the rope gripper, and an actuating device with an actuating rope for actuating the gripper blades. According to the invention, an energy conversion device is arranged on the rope gripper, with which kinetic energy, which can be transmitted in particular from the retaining rope and / or the actuating rope, can be converted into pressure energy and / or electrical energy.

Description

[0001] The invention relates to a rope grab with a grab frame, at least two grab blades which are adjustable at a lower end of the grab frame between a closed position and an open position, a retaining rope for holding the rope grab and an actuating device with an actuating rope for actuating the grab blades, according to the preamble of claim 1.

[0002] The invention further relates to a method for operating a rope grab or a grab device, according to the preamble of claim 12.

[0003] Grab devices are used in specialist foundation engineering to create trenches in the ground. Diaphragm walls can then be constructed within these trenches to support and / or seal excavation pits.

[0004] Grab devices essentially comprise a grab with grab buckets, the grab suspended from a carrier device, typically a boom crane, by a tether cable. The tether cable allows the grab to be lowered into the ground. By closing the grab buckets, soil material can be excavated and scooped into the grab. The grab is then pulled back out of the ground by the tether cable and swung by the carrier device to a discharge position, where the grab buckets are opened to release the soil material. The grab is then swung back into its working position and inserted into the trench in the ground for another grab operation.

[0005] There are two different types of grippers used on such gripping devices: hydraulic grippers and cable grippers. A so-called hydraulic gripper is known, for example, from EP 3 798 367 A1. In a hydraulic gripper, the movement for opening and closing the gripper blades is generated by a hydraulic cylinder located on the gripper frame.

[0006] These types of hydraulic grippers are relatively easy to operate and control thanks to the hydraulic system. Due to the existing hydraulic supply, extendable control flaps can be incorporated into the gripper frame, which are hydraulically actuated.

[0007] However, hydraulic lines are required for the supply and return of hydraulic fluid, running parallel to the support cable. The carrier unit must be equipped with appropriate hose reels for the hydraulic lines, along with corresponding winch drives and a suitably designed hydraulic system. This increases the size and cost of the gripper device.

[0008] In contrast, so-called cable grabs offer a significantly simplified design. Such a generic cable grab is known, for example, from EP 4 134 489 A1 or EP 4 134 490 A1. In a cable grab, the opening and closing movement of the grab buckets is effected by an actuating cable. The actuating cable runs essentially parallel to the retaining cable from the actuating device of the grab buckets to the carrier device. By means of a separate winch for the actuating cable, the grab buckets can be opened or closed by unwinding or winding the actuating cable onto the winch.

[0009] With a cable grab, the complex hydraulic lines leading to the grab are eliminated. Only an additional operating cable with a corresponding winch is required. Such an operating cable also requires significantly less maintenance than hydraulic lines and a corresponding hydraulic system.

[0010] However, operating and controlling the position of a rope grab is not as straightforward as with a hydraulic grab and requires an experienced machine operator. In particular, the lack of a hydraulic supply to the grab prevents the use of hydraulically controlled control flaps. A degree of change, and thus control, of the rope grab's position can be achieved by the operator adjusting the suspension point of the support rope, for example, by moving the boom crane. This can exert certain tilting moments on the rope grab, thereby altering its position and / or orientation within the slot. Such position control, however, demands considerable skill and experience from the operator and does not provide the same level of precise control as with control flaps.

[0011] Because of the desired simple design of a rope grab, which is basically only connected to a carrier device via carrying and operating ropes, practically no sensors with data acquisition or other electrical components can be used on the rope grab, especially when used in the ground, because there is no power supply.

[0012] The invention is based on the Task The basis is to specify a rope grab and a method for operating the rope grab, in which a simple design and in particular a simple suspension of the rope grab are given and at the same time an improved operating and application possibility is achieved.

[0013] The problem is solved, firstly, by a rope gripper with the features of claim 1 and, secondly, by a method with the features of claim 12. Preferred embodiments of the invention are specified in the respective dependent claims.

[0014] The rope gripper according to the invention is characterized in that an energy converter device is arranged on the rope gripper, which is capable of converting kinetic energy, which can be transmitted in particular from the holding rope and / or the actuating rope, into pressure energy and / or electrical energy.

[0015] A fundamental aspect of the invention is to provide the rope gripper itself with its own independent power supply. However, while it is possible to attach a simple energy storage device, such as an electric battery, to the rope gripper, this would hardly be sufficient for practical gripper operation. If the energy storage device is kept compact, insufficient energy is available for efficient gripper operation. Frequent and time-consuming recharging of the energy storage device would be necessary. Conversely, if an energy storage device with a sufficient energy capacity for economical operation were provided, this would significantly increase the dimensions of the rope gripper, making it practically unmanageable and unusable.

[0016] The invention provides energy for the gripper by arranging an energy converter device on the rope gripper, which can convert the kinetic energy available at the rope gripper into pressure energy and / or electrical energy. This energy converter device can be configured in any way that allows the kinetic energy available at the rope gripper to be converted in the desired manner. In particular, the energy converter device can be configured to convert a movement of the holding rope and / or the actuating rope and / or an associated movement of the positioning carriage, a rotary movement on pulleys, or a vertical movement of the rope gripper into the required or desired pressure energy, in particular hydraulic or pneumatic energy, or into electrical energy.

[0017] In this way, according to the invention, a readily usable form of energy, in particular pressure energy and / or electrical energy, is available in sufficient quantity at a rope gripper without the need for complex external supply lines from a carrier device. Sufficient energy supply directly at the rope gripper makes it possible to arrange and use a wide variety of additional actuators, drives, sensors, or electronic control elements and components in virtually any configuration, which can simplify or even enable operation, control, and / or data acquisition.

[0018] In principle, the energy generated by the energy conversion device can be supplied directly to corresponding consumers on the rope grab. According to a preferred embodiment of the invention, it is advantageous that an energy storage device is arranged on the rope grab, which preferably comprises a pressure vessel, a spring accumulator, and / or an electric current accumulator, and with which the converted energy can be stored on the rope grab. Thus, the energy generated by the energy conversion device can be temporarily stored in the energy storage device. This ensures a continuous energy supply to the rope grab, even if energy conversion on the rope grab is not constant, but only occurs in certain operating situations, such as when the grab buckets are closed and opened and / or when lifting or lowering.

[0019] In the generation of electrical energy, one or more accumulators can be installed. Appropriate electrical circuitry for storage can be installed, for example, with rectifiers, inverters, and / or transformers. Generated pressure energy can be supplied to a pressure accumulator, in particular a pressure vessel, for example, via a suitable pipe arrangement with control valves. Alternatively or additionally, energy can also be temporarily stored in a spring accumulator, for example, with a torsion spring, which can drive, for example, a generator to produce electricity or a hydraulic pump when needed.

[0020] According to a further development of the invention, it is preferred that the energy conversion device has at least one pump cylinder with which a pressure fluid can be pressurized. In particular, the piston of a pump cylinder could be moved axially via one of the cables on the cable gripper, thus generating a pumping action. A pressure fluid provided in one or more corresponding containers on the cable gripper can thus be pressurized. The pressure fluid can be supplied directly to a consumer, such as an actuator cylinder, or temporarily stored in a pressure accumulator.

[0021] In a further development of the invention, it is particularly preferred that the pressure fluid is a liquid, especially hydraulic oil, or a gas, especially compressed air. Hydraulic oil is particularly suitable for pressure transmission. However, other liquids, especially water, can also be used. The use of water as the pressure fluid can be particularly advantageous when the gripper is used in sensitive environments, such as in a groundwater protection area. The same applies to the use of ambient air as compressed air.

[0022] A particularly advantageous embodiment of the rope gripper, according to one version of the invention, is characterized by the arrangement of an adjusting carriage on the rope gripper, which is adjustable relative to the gripper frame by means of the actuating rope; the arrangement of a transmission device with which a relative positioning movement between the gripper frame and the adjusting carriage can be converted into a movement for opening or closing the gripper blades; and the connection between the adjusting carriage and / or the gripper frame and the energy conversion device for supplying kinetic energy. Such an adjusting carriage can often be present on a rope gripper for actuating the gripper blades. Thus, the energy conversion device can be implemented relatively easily in existing rope grippers or based on existing designs.In principle, a positioning slide can also be arranged on the rope gripper, which is designed exclusively for actuating the energy converter device, in particular for actuating one or more pump cylinders.

[0023] Alternatively or additionally, energy conversion can also be achieved using at least one pulley on the rope grab, which is set in motion when the grab buckets open and close. The resulting rotation of the pulley can then drive, for example, an electric generator or a pump impeller (e.g., of a gear pump) to convert kinetic energy into electrical energy or pressure energy.

[0024] In general, the positioning carriage and the gripper frame can be coupled to each other in any suitable manner. According to one embodiment of the invention, it is particularly advantageous that the gripper frame and the positioning carriage are mounted so as to be displaceable relative to each other in a longitudinal direction. In particular, the positioning carriage can be arranged centrally on the rope gripper, so that no or only minimal lateral forces act on the rope gripper during operation. This has a positive effect on the directional stability of the rope gripper. The retaining rope can be attached to the gripper frame or, preferably, to the positioning carriage, with the actuating rope effecting a relative displacement between the gripper frame and the positioning carriage.

[0025] According to a further embodiment of the invention, it is advantageous that at least one energy-driven consumer, in particular an actuator, a control unit, and / or a data acquisition device, is arranged on the rope gripper, which can be operated by energy converted by the energy converter. The at least one actuator can be electrically driven or driven by a pressure fluid. This applies to both linear actuators, in particular actuator cylinders, and rotary actuators. The control and / or data acquisition devices can preferably be electrically operated. The data acquisition devices can comprise a wide variety of sensors, with the acquired data either being transmitted to a carrier device via a suitable transmitter or temporarily stored in a data storage device arranged on the rope gripper.

[0026] A preferred embodiment of the invention further comprises the fact that the pump cylinder can additionally be operated actively as an actuator cylinder, wherein pressurized fluid from a pressure vessel can be supplied to the pump cylinder. If required, this can be done via a suitable switching device, so that the pump cylinder is actively operated as an actuator cylinder, for example to support an opening or closing movement of the gripper blades.

[0027] For data transmission, a wireless or wired transmitter can preferably be arranged, which, with suitable design, can utilize at least one cable of the grab to the carrier device. Typically, the tethering cable and the operating cable are steel cables with metallic strands, which are generally suitable for transmitting electrical, electromagnetic, or acoustic signals. A radio transmitter, for example, can be used as the transmitter, which, depending on its transmission power, can send signals from a trench in the ground to the ground surface, or, if the grab is outside the trench (e.g., for emptying the filled grab buckets), to the carrier device, at least to a certain depth.

[0028] According to a further development of the invention, it is particularly advantageous that the at least one actuator is designed as an electric drive, in particular as an electric linear drive or as an electric motor, or as a drive operated with a pressure fluid, in particular a hydraulic motor or a hydraulic cylinder. The individual drives can perform independent functions on the cable gripper and / or serve, for example, to support the closing and / or opening movement of the gripper blades effected by the actuating cable.

[0029] A particularly advantageous embodiment of the invention lies in the fact that the at least one actuator for adjusting an actuating element, in particular a control flap or a control frame, for position control of the rope grab in a slot in the ground is designed. Such control flaps are known and frequently used in conventional hydraulic grabs. By extending or retracting control flaps on the grab frame, the position and orientation of the grab frame relative to the vertical in the slot in the ground can be influenced and preferably precisely adjusted. With the energy converter device according to the invention, this function can now also be implemented in rope grabs, thereby significantly simplifying and improving the functionality of a rope grab and, in particular, its position control in the ground. The actuating element of the at least one can be controlled, for example, from the carrier device or by a control unit on the rope grab itself.The control unit on the rope gripper can preferably be connected to one or more sensors for detecting the position of the rope gripper, for example at least one tilt sensor.

[0030] Another advantage is the ability to measure the depth of the rope grab using a sensor. This can be achieved, for example, with a pressure sensor mounted on the rope grab. Depending on the measured position data, the control unit on the rope grab can autonomously actuate at least one actuator according to a predefined control logic (control program) to achieve the desired position and / or orientation.

[0031] The invention further comprises a gripping device with a carrier unit, each having a winch assembly for a holding cable and an actuating cable. The gripping device is further developed according to the invention in that a cable gripper according to the invention is arranged on the carrier unit and held by the holding cable. By using the cable gripper according to the invention, as described above, the advantages outlined above for using such a gripping device can be achieved.

[0032] The grab device is preferably further developed by making the carrier device movable, in particular by having a crawler chassis. A superstructure can preferably be rotatably mounted on the crawler chassis. The cable grab can be lowered and raised via a mast or a boom arm, wherein a winch device for the holding cable and the operating cable are arranged on the carrier device, in particular the superstructure, in a generally known manner.

[0033] Finally, the invention further comprises a method for operating a rope gripper or gripper device according to the invention, wherein the method provides that an energy conversion device is arranged on the rope gripper, which converts kinetic energy, which is transferred in particular from the holding rope and / or the actuating rope to the rope gripper, into pressure energy and / or electrical energy. In this way, kinetic energy can be converted into a readily usable form of energy, which can be used directly to drive or operate components on the rope gripper.

[0034] According to a preferred embodiment of the method according to the invention, an energy storage device is arranged on the rope gripper, which preferably comprises a pressure vessel, a spring accumulator and / or an accumulator for electric current and which stores the converted energy on the rope gripper. Thus, even in the case of uneven energy conversion, for example, only under certain operating conditions, a uniform energy supply to the rope gripper for corresponding energy-driven components can be ensured.

[0035] According to a further embodiment of the invention, it is advantageous that at least one actuator on the rope grab is operated by the converted energy, wherein, in particular, the at least one actuator is actuated via a control unit, which is preferably arranged on the rope grab or a carrier device, and the position of the rope grab in the slot in the ground is controlled. Thus, a rope grab can be controlled for positional alignment in a similar manner to a hydraulic grab by means of controllable actuators, without, however, having to run complex hydraulic lines to the rope grab and store large cable reels on the carrier device. The control unit for actuating the at least one actuator can be arranged on the rope grab itself or remotely on the ground surface, preferably on a carrier device.

[0036] If the control unit is located directly on the rope gripper, it can be connected to position sensors and, depending on a stored control program, automatically actuate at least one actuator to achieve a desired target position of the gripper. If the control unit is located remotely from the rope gripper, a corresponding transmitter and receiver can be provided for communication between the rope gripper and the remote control unit. Operation via the external control unit can also be carried out directly by a machine operator and / or by an automated control program.

[0037] Finally, a preferred embodiment of the method according to the invention consists in creating a slot in the ground with the cable grab and, in particular, forming a foundation element in the ground therein. The foundation element can, in particular, be a cutoff wall segment for a cutoff wall or a retaining wall segment for a retaining wall.

[0038] According to the invention, a hybrid gripper can be created, so to speak, which combines the advantages of the simple construction and suspension of a rope gripper with the advantages of a hydraulic gripper, for example with regard to the possibility of targeted position control by means of adjustable control flaps.

[0039] The invention is further described below with reference to a preferred embodiment. The drawings show: Fig. 1 a perspective view of the basic structure of a gripper device according to the invention; Fig. 2 a front view of the rope gripper of the gripper device. Fig. 1 with closed grab buckets; Fig. 3 a front view of the rope grab accordingly Fig. 2 with open grab buckets; Fig. 4 a schematic front view of a rope grab according to the invention; and Fig. 5 a schematic representation of an energy converter device.

[0040] A gripper device 10 according to the invention Fig. 1 The mobile carrier unit 12 has a crawler chassis as its undercarriage 14. A superstructure 16 with an operator cabin 17 is rotatably mounted on the undercarriage 14 about a vertical axis of rotation. A control unit, including an input device for a machine operator, can be located inside the operator cabin 17.

[0041] A boom arm 18 is pivotally mounted on the superstructure 16 about a horizontal axis. A retaining cable 24 is guided on a head 20 of the boom arm 18, which has pulleys. A cable grab 30 with a grab frame 32 and lower grab buckets 34 is attached to the end of the cable. The retaining cable 24 can be actuated to raise and lower the cable grab 30 via a first winch 21 on the carrier unit 12. A second winch 22 is also located on the carrier unit 12 for an actuating cable 44, which is guided via the head 20 to the cable grab 30 for actuating the grab buckets 34 at the lower end of the grab frame 32.

[0042] The functioning of the gripper device 10 according to the invention is described below in connection with the Figures 2 and 3 explained in more detail.

[0043] In a central area of ​​the gripper frame 32, an adjusting carriage 42 of an actuating device 40 for actuating the gripper buckets 34 is mounted so as to be displaceable in a vertical longitudinal direction. The end of the retaining cable 24 is attached to the upper end of the adjusting carriage 42, so that the cable gripper 30 is held by the adjusting carriage 42.

[0044] At a lower end of the positioning carriage 42, a transmission device 45 with a linkage mechanism 46 and connecting rods 47 is arranged. The connecting rods 47 are pivotally connected at one end to the positioning carriage 42 and at the other end to one of the gripper blades 34. The gripper blades 34 are themselves pivotally mounted at the lower end of the gripper frame 32 via pivot bearings 35. By a relative displacement of the positioning carriage 42 with respect to the gripper frame 32, the gripper blades 34 can be opened and closed. By a relative displacement of the positioning carriage 42 upwards, the connecting rods 47 are pulled upwards, whereby the gripper blade 34 is pivoted about its pivot axes 35 into its open position, which is illustrated in Fig. 3 is shown.

[0045] Below the adjusting carriage 42, a pulley system 50 is provided for the actuating cable 44. The pulley system 50 has at least one upper pulley 52, which is rotatably mounted on the adjusting carriage 42, and at least one lower pulley 54, which is rotatably mounted on a lower portion of the gripper frame 32. The pulleys 52 and 54 are encircled by the actuating cable 44, which is supplied from above, forming loops 56 or pulleys. The lower end of the actuating cable 44 can be fixedly connected to the gripper frame 32. Alternatively, the lower end of the actuating cable 44 can also be fixedly connected to the adjusting carriage 42. The adjusting carriage 42 can thus be connected or coupled to the gripper frame 32 via the actuating cable 44 in a relatively adjustable manner.

[0046] Starting from the opening position according to Fig. 3By pulling the actuating cable 44 upwards, the second winch 22 pulls the adjusting slide 42 downwards relative to the gripper frame 32 via the pulley system 50. During this action, the connecting rods 47 press the gripper blades 34 downwards with an increased closing force, causing the gripper blades 34 to pivot about their pivot bearings 35 into the closed position. Fig. 2 be swerved.

[0047] When used in a slot in the ground, soil material can be gripped and enclosed between the grab buckets 34 by means of a closing force increased compared to the pulling force on the actuating rope 44.

[0048] After the cable grab 30 is pulled out of a slot in the floor and moved to an emptying position, the pulling force on the actuating cable 44 can be reduced. In this way, the grab frame 32 shifts downwards relative to the positioning carriage 42 due to its weight, so that the grab buckets 34 are swung back into their open position via the linkage rods 47, as shown in Fig. 3 is shown.

[0049] The described arrangement is only an example. In principle, other pulley systems with different rope linkages and linkage mechanisms can be chosen to enable comparable grab bucket operation.

[0050] According to Fig. 4A rope grab 30 according to the invention with an energy converter device 60 is shown in detail. The energy converter device 60 comprises a pump cylinder 62 with a cylinder housing 64, which is preferably fixedly attached to the grab frame 32. A pump piston 66 projecting from the cylinder housing 64 is slidably mounted and can be connected at its free end to an adjusting slide 42.

[0051] The positioning carriage 42 and the gripper frame can, as previously described, preferably be moved relative to each other along the gripper frame 32 by means of the actuating cable 44, in order to open and close the gripper blades 34 via a transmission device with a linkage mechanism 46. By moving the positioning carriage 42 relative to the gripper frame 32 by means of the actuating cable 44, the attached pump piston 66 is also axially adjusted, whereby the pump cylinder 62 can convert the kinetic energy of the positioning carriage 42 into pressure energy.

[0052] The rope gripper 30 can be fitted with one or more actuating elements 80, each with at least one in Fig. 4 The actuator (not shown) can be operated. This allows, in particular, one or more control flaps 84 to be controlled for aligning the cable grab 30 in the ground.

[0053] A possible and preferred design of an energy converter device 60 is shown schematically in Fig. 5 depicted accordingly. Fig. 4 The energy converter device 60 can have a pump cylinder 62 with a cylinder housing 64 and a pump piston 66 slidably mounted therein. In this embodiment, the pump cylinder 62 is designed as a double-acting pump cylinder 62, which can discharge pressurized fluid, in particular hydraulic oil, to a pressure line 65 both during an extension movement and during a retraction movement of the pump piston 66 from or into the cylinder housing 64.

[0054] The pressurized fluid can be used in various ways, depending on the control provided by a control unit (not shown) via controllable valve units 69. For example, the pressurized fluid can be supplied to an energy storage device 70 with a pressure vessel 72, in which pressurized fluid can be stored. This fluid can then be released again as needed via a suitable switching device, for example, to actively operate the pump cylinder 62 as an actuator, such as to assist the opening or closing movement of the gripper blades 34.

[0055] Additionally or alternatively, the generated pressure fluid can also be used to drive a drive motor 67, in particular a hydraulic drive motor 67. A generator 68 can be operated via the drive motor 67 to generate electricity. The electricity generated in this way can be supplied directly to a consumer or to an accumulator 74 as part of an energy storage device 70. Electricity can be drawn from the accumulator 74 as needed.

[0056] Furthermore, one or more actuating elements can be operated via the pressurized fluid, alternatively or additionally, in particular by means of actuators 82 designed as hydraulic cylinders. The actuators 82 can preferably be used to control the control flaps 84 for controlling a basic orientation of the rope grab 30 in a slot in the ground.

Claims

1. Cable grab with - a grab frame (32), - at least two grab buckets (34) which are adjustable at a lower end of the grab frame (32) between a closed position and an open position, - a retaining cable (24) for holding the cable grab (30) and - an actuating device (40) with an actuating cable (44) for actuating the grab buckets (34), characterized by - that An energy converter device (60) is arranged on the rope gripper (30), with which a kinetic energy, which can be transmitted in particular from the holding rope (24) and / or the actuating rope (44), can be converted into pressure energy and / or electrical energy.

2. Rope gripper according to claim 1, characterized by thatAn energy storage device (70) is arranged on the rope gripper (30), which preferably has a pressure vessel (72), a spring storage device and / or an accumulator for electric current and with which the converted energy can be stored on the rope gripper (30).

3. Rope gripper according to claim 1 or 2, characterized by that the energy converter device (60) has at least one pump cylinder (62) with which a pressure fluid can be pressurized.

4. Rope gripper according to claim 3, characterized by that the pressure fluid is a liquid, in particular hydraulic oil, or a gas, in particular compressed air.

5. Rope gripper according to one of claims 1 to 4, characterized by that a positioning slide (42) is arranged which is adjustable relative to the gripper frame (32) by means of the actuating cable (44), thata transmission device (45) is arranged with which a relative positioning movement between the gripper frame (32) and the positioning slide (42) can be transmitted into a movement for opening or closing the gripper blades (34), and that the positioning carriage (42) and / or the gripper frame (32) is connected to the energy converter device (60) for supplying kinetic energy.

6. Rope gripper according to claim 5, characterized by that the gripper frame (32) and the positioning slide (42) are mounted so as to be displaceable relative to each other in a longitudinal direction.

7. Rope gripper according to one of claims 1 to 6, characterized by that On the rope gripper (30) at least one energy-operated consumer, in particular an actuator (82, 61), a control unit and / or a data acquisition device, are arranged, which can be operated by converted energy from the energy converter device (60).

8. Rope gripper according to claim 7, characterized by that the at least one actuator (82, 61) is designed as an electric drive, in particular an electric linear drive or an electric motor, or as a drive operated with a pressure fluid, in particular a hydraulic motor or a hydraulic cylinder.

9. Rope gripper according to claim 7 or 8, characterized by that which is formed by at least one actuator (82) for adjusting an actuating element (80), in particular a control flap (84) or a control frame, for position control of the rope grab (30) in a slot in the floor.

10. Gripper device with a carrier device (12) with a winch device for a holding rope (24) and an operating rope (44), characterized by that a rope gripper (30) according to one of claims 1 to 9 is arranged on the carrier device (12) and is held by the retaining rope (24).

11. Gripper device according to claim 10, characterized by that the carrier device (12) is movable, in particular has a crawler chassis.

12. Method for operating a rope grab (30) according to one of claims 1 to 9 or a grab device (10) according to claim 10 or 11, characterized by that An energy converter device (60) is arranged on the rope gripper (30), which converts kinetic energy, which is transmitted in particular by the holding rope (24) and / or the actuating rope (44), into pressure energy and / or electrical energy.

13. Method according to claim 12, characterized by that An energy storage device (70) is arranged on the rope gripper (30), which preferably has a pressure vessel (72), a spring storage device and / or an accumulator (74) for electric current and which stores the converted energy on the rope gripper (30).

14. Method according to claim 12 or 13, characterized by thatat least one actuator (82, 61) on the rope grab (30) is operated by the converted energy, wherein in particular the at least one actuating element (80, 62) is actuated via a control unit, which is in particular arranged on the rope grab (30) or a carrier device (12), and a position of the rope grab (30) in a slot in the ground is controlled.

15. Method according to any one of claims 12 to 14, characterized by that A slot is created in the ground using the cable grab (30), and in particular a foundation element is formed in the ground therein.

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