EP2404861A1 - Hoist device with position-detectable sensors - Google Patents

Abstract

The switch (22) has a reading and writing device (20) for reading and writing data, where operating condition of the switch is readable by the reading and writing device using a unit. The unit comprises two transponders (T1, T2) that convey the operating condition of the switch to the reading and writing device. The transponders are fastened to a movably guided carrier (23) and the reading and writing device comprises multiple reading and writing areas. The transponders are arranged depending upon the operating condition in the reading areas of the reading and writing device. An independent claim is also included for a lifting device comprising two different guidance units.

Description

The present invention relates to a hoisting limit switch for limiting the maximum permitted hoisting height of a hoist rope and further comprising a lifting device, in particular a crane or a crawler crane, with at least two different guide means for guiding at least one hoist rope, wherein at least one winch is provided for driving the at least one hoist rope.

Lifting devices, in particular cranes, mobile or crawler cranes or tower cranes or crawler cranes, can be configured in different setup variants. A load to be lifted is struck on the hoist rope of a crane or excavator and the hoist rope is guided by a guide means on the boom head up to the drive of the hoist rope in the form of a winch. At this point, there are numerous possible variations for guiding the hoist rope over the boom. Thus, for example, the hoisting rope can be guided on the roller head itself via the boom or via a boom end attached to the mast nose or at other different locations of a boom extension, such. B. one Folding tip, a rocking tip or a solid tip. At each of these points can thus be lifted a load including slings and hook bottle.

During the retraction of the hoisting rope by the respective cable winch must be ensured that the lifting height of the rope is limited so that a crane hook arranged on the hoist rope or a hook hook arranged is not drawn into the rope guide rollers of the guide means. Pulling the hoist rope beyond the maximum permissible lifting height would lead to damage to the rope guide rollers or even to the breakaway of the hoisting rope or hook block and consequently to the fall of the load.

In order to prevent the above-mentioned problem, the actual lifting height of the hoist rope or the load on the respective guide means must be continuously controlled and communicated to a provided for controlling the crane or excavator operation control unit. To make matters worse, that arranged on the crane or excavator different guide means should be designed to be used for the simultaneous lifting of one or more loads. Consequently, the safe operation of more than one winch must be monitored.

One method for monitoring the lifting height of the hoisting rope provides for the attachment of a so-called hoist limit switch to each individual guide means. The function of a known from the prior art Hubendschalters provides that a weight is longitudinally movably guided on a hoisting rope and is fastened via a connecting means on Hubendschalter. Approaching the lifting means of the hoisting rope inadmissible the boom or boom head, the weight is lifted by the stop means on the hoisting rope and relieves the connecting element of Hubendschalters, whereby the Hubendschalter is triggered and, for example, interrupts the drive of the hoisting rope. As a rule, the stroke limit switches known from the prior art are designed as reed limit switches, Hall switches, inductive switches or limit switches with mechanical contacts. The switches mentioned are largely based on magnetic principles of action and react sensitive to strong interference, as z. B. could occur in electroplating plants.

A disadvantage of the above-mentioned monitoring systems for lifting devices that a monitoring element in the form of a Hubendschalters must be fixed to each guide means always. However, in such lifting devices only as many guide means can actually be used as there are drives in the form of winches. Thus, in a lifting device with two winches and five guide means always three monitoring elements remain unused.

The control of the lifting device has the task to regulate the actuation of a control element in the form of a Hubendschalters the drives of the associated hoisting rope (winch). Although the control of the position of each Hubendschalters is clearly known, but the controller is no information about which hoist rope is actually guided by which winch at each Hubendschalter. This input must be made by the crane operator prior to crane operation and is therefore subject to error. Only when the crane operator consciously operates only one winch and drives it into the hoist limit switch does the controller know the assignment between winch, hoist rope and hoist limit switch. Current known from the prior art solutions provide that when triggering a Hubendschalters all winds must be stopped simultaneously, regardless of whether they have actually exceeded the maximum lift height of their driven hoist rope.

It is therefore an object of the present invention to provide the person skilled in the art with a lifting device which provides an improved monitoring system of the hoisting cable. Furthermore, it is an object of the present invention to provide a Hubendschalter that allows improved monitoring ability of the hoist and can be used in such a lifting device.

The object is achieved by a Hubendschalter invention according to the features of claim 1. Accordingly, an inventive stroke limit switch to limit the maximum allowable lifting height of a hoist rope to a reading and writing device for reading and writing data, as well as a means from which the operating state of the Hubendschalters readable by the read and write device. Said means includes information characterizing the operating state of the hoist limit switch. Thus, the means may, for example, include information describing a permissible operating state of the hoist limit switch, which presupposes that a load applied to the hoist rope does not exceed a maximum permissible hoisting height. If the maximum permissible lifting height is reached or exceeded, which threatens a destruction of the guide means, the said means indicates an impermissible operating state. If an inadmissible operating state occurs, it is conceivable that certain safety measures are taken by the hoist limit switch.

In addition, the reading and writing device also offers the possibility of reading data that go beyond the content mentioned above, or to describe the means or other receiving elements with any data. More on the read and write device readable data can z. B. information about the location of the Hubendschalters include. It is also conceivable that during assembly of the stroke limit switch according to the invention by the reading and writing device, data can be written to a receiving device present at the site, which is a basic prerequisite for reliable functionality of the stroke limit switch.

Advantageously, the means comprises two transponders, which transmit the reading and writing device the respective operating state of the hoist limit switch. If the first transponder is positioned in the reading area of the reading and writing device, information is provided which characterizes the permissible operating state of the stroke limit switch. In contrast, a second transponder positioned in the read area of the read and write device causes an inadmissible operating state to be read out and predefined measures can be taken by the stroke limit switch according to the invention. Particularly preferred is either the first or the second transponder or both transponders in the reading area of the reading and writing device, so that a malfunction of the Hubendschalters can be detected as soon as no transponder is detected in the reading area of the reading and writing device. This is the case, for example, with a faulty reading and writing device. Thus, a failure of the reading and writing device is detectable. If both transponders are located in the reading and writing area of the reading and writing device, this symbolizes exactly the state of the transition between permissible and impermissible operating state. Thus, state transitions can be detected and measures taken at a very early stage. Only a solution with transponders, especially two transponders, can ensure the high level of security of the hoist limit switch.

Advantageously, the two transponders are mounted side by side on a movably guided carrier. The carrier is connected via suitable means with the hoisting rope at the place of use, so that via the hoisting rope a mechanical effect on the movably guided carrier can be transmitted, which leads to a displacement of the transponder. In the permissible operating state, the movably guided carrier is preferably positioned in such a way that the first transponder lies in the reading range of the reading and writing device. If the hoisting rope reaches an inadmissible maximum lifting height, the hoisting rope acts on the movably guided carrier in such a way that the carrier is displaced and the second transponder enters the reading area of the reading and writing device.

It may be provided that the reading and writing device is designed such that different transponders, which are arranged distributed in several directions, are recognizable and readable and / or writable. Consequently, the reading and writing device has at least two different read and write areas, in the region of which suitable means, in particular transponders, can be read out and written on.

It is particularly expedient that the Hubendschalter has a transponder, which is arranged externally in the immediate vicinity of the Hubendschalter and means the read and write device is readable and / or writable. It is conceivable that such an external transponder is already pre-assigned with data that can be read out or written to when the external transponder is introduced into the reading and writing area of the reading and writing device. For example, the external transponder is firmly fixed to a possible deployment position of the Hubendschalters. When mounting the Hubendschalters the externally arranged transponder is placed in the reading and writing area of the reading and writing device, whereby important data for the operation of the Hubendschalters from the externally arranged transponder can be read out.

Advantageously, a means for connection to a bus system for the transmission of data is provided on the stroke end switch. Consequently, the Hubendschalter can be used in a system consisting of several individual Hubendschaltern invention and the respective operating states of the individual Hubendschalter invention can be sent via the bus system to a central control unit. It is also conceivable that the individual Hubendschaltern information about the operation are supplied via the bus system.

It is also possible that information about the precise position of the Hubendschalters a lifting device are transferable.

In order to measure the permissible maximum lifting height of a hoisting rope, it is provided that the hoisting limit switch has a weight which can be longitudinally movably attached to a hoisting rope of a hoisting device and fastened or fastened by means of a connecting element on the hoisting limit switch. The use of a longitudinally guided weight on the hoist rope is known from the known from the prior art Hubendschalter. In the stroke limit switch according to the invention, the longitudinally movably guided weight on the hoisting cable acts on the means via the connecting means, in particular the two transponders, so that when the weight is relieved, an inadmissible operating state can be read out by the reading and writing device.

In a preferred embodiment of the stroke limit switch according to the invention, this has a quick-mounting device. This makes it possible to detachably and particularly flexibly fix the stroke limit switch to the desired site of use.

It is conceivable that the quick-mounting device is fixed at the place of use or is already integrated in the component at the place of use of a lifting device and the externally arranged transponder is integrated in this. It is conceivable that data are stored within the externally arranged transponder, which contain information about the precise location. In particular, the externally arranged transponder is located within the quick mounting device when mounting the Hubendschalters in the read and write area of the reading and writing device. The fixation of the quick assembly device at the site offers a constructive way to convert existing cranes to the solution of the invention. Preferably, the quick assembly device is already integrated in the component of a corresponding crane.

The present invention further relates to a lifting device, in particular a crane or a crawler crane, with at least two different guide means for at least one hoist rope for lifting a load, wherein at least one winch is provided for driving the at least one hoist rope. According to the invention, the lifting device has at least one sensor device in the immediate vicinity of one of the at least two guide means, each sensor independently recognizing its mounting position. During crane work, a load is preferably struck on one side at the end of the hoisting rope or, preferably, the hoisting rope is guided around a diverting pulley on a hooked bottle and fastened to the boom with a lock or the like at the end. The Hubseilantrieb via a winch, the hoist rope is optionally performed on one of the guide means on the boom. Conceivable are crane configurations with several winches that drive various guided over each different guide means hoisting ropes.

The sensors used monitor at the respective guide means the operating state of the lifting device. The automatic detection of a sensor of its mounting position ensures that a reliable and automatic assignment of the sensor to the respective guide means takes place. Lifting devices known from the prior art, on the contrary, assume that the sensor and guide means are assigned manually by the operator of the lifting device. However, this carries a risk potential which is difficult to estimate, which is efficiently solved by the present invention.

Particularly preferably, the sensors are releasably attachable or attached to the respective mounting position. This offers the advantage that sensors need only be attached to these guide means, which are actually needed during crane operation. Due to the automatic detection of the own position, the sensor can be selectively positioned on one of the existing guide means of the lifting device, wherein the assignment to the guide means is independent due to the position detection of the sensor. This inventive variant of the lifting device, the correct assignment of winch, hoist rope and sensor is much easier. Significant risks that can result from a faulty configuration of the sensors can be kept to a minimum.

It is expedient that the sensors are designed such that they detect the Hubseilposition, in particular the exceeding of the maximum lift height of the hoisting rope, on the guide means by measurement. Thus, the maximum allowable lifting height of a hoisting rope of the lifting device according to the invention can be monitored and it can optionally be taken at exceeding this height definable measures. Furthermore, it can be detected separately for each individual guide means whether the corresponding guided hoisting rope of the individual guide means has reached a critical maximum lifting height.

In a particularly advantageous embodiment of the invention, a control unit is provided in the lifting device, with at least one or all sensors connectable or connected. As a result, all or part of the metrologically recorded data of the sensors can be transmitted to the central control unit and evaluated by the latter. According to the control unit is known, which sensors are positioned on which guide means and are responsible for the monitoring of these.

It is conceivable that the control unit of at least one sensor data such as the serial number of the Hebeborrichtungsbauteils on which the sensor is arranged and / or the current Hubseilposition and / or an attachment position assigned address and / or geometric data of the lifting device component, such as mass and geometric data of the component or the coordinates of the center of gravity, receives.

It is also possible that the control unit transmits data to the sensors. This data can be z. B. concern the load collective.

It is expedient that at least one of the sensors comprises a stroke end switch according to one of claims 1 to 12. The reading and writing device of the Hubendschalters according to one of claims 1 to 12 is thus in constant communication with said control unit of the lifting device. On the one hand, the reading and writing device pursues the task of reading out the current operating state of the stroke limit switch and transmitting it to the control unit. On the other falls in the scope of the Hubendschalters to determine the current mounting position of the Hubendschalters and data, such as the serial number of the steel component is attached to the Hubendschalter, the coordinates of the center of gravity, mass and geometric data of the component and a unique assigned to the Hubendschalter address to transmit the control unit, whereby an exact assignment of the Hubendschalters to the guide means, the hoist rope guided over it and the hoist rope driving winch is possible. Furthermore, there is the possibility that data can be written to during the use of the crane in the externally arranged transponder by means of the reading and writing device.

The central control unit of the lifting device according to the invention, which receives the data of the sensors connected to it, is designed such that the at least one winch can be controlled as a function of the data transmitted to the control unit. Thus, for example, the operation of the winch can be deactivated if the sensors detect an exceeding of the maximum permissible lifting height of a hoist rope.

It is particularly expedient that the control unit is designed in such a way that several winches can be activated separately if necessary. Thus, due to the inventive assignment of the sensors to the respective guide means in case of need, that is, when exceeding the maximum allowable height of the hoist rope of a guide means, exactly one winch can be switched off, which is responsible for the operation of said hoist rope. In contrast to the known from the prior art embodiments of a lifting device not all winds in this case need to be turned off when needed, but it is deliberately exactly one winch off.

In order to achieve even greater safety, it is expedient that the control unit is designed such that before starting the crane operation by the controller, the individual approach of each occupied and ready-to-use sensor is controllable. This ensures that the control unit is uniquely known which wind meets at which point of a lifting task. This simplifies in particular the separate control of the winches in case of need by the control unit.

Since the individual sensors are in two-way data exchange with the control unit in connection, it is conceivable that a possible defect of a sensor is detectable by the control unit. For example, if a sensor sends erroneous or no information regarding its mounting position, the control unit concludes that the sensor is defective.

It is also possible that the lifting device according to the invention, in particular the sensors for monitoring the guide means, as well as for assembly purposes Lifting work performed by the lifting device according to the invention can be used. As an example, the assembly of a lattice boom with the SA-Bock or the derrick boom may be mentioned.

Figur 1:

eine Detailansicht einer Hebevorrichtung mit einem daran angeordneten erfindungsgemäßen Hubendschalter,

Figur 2:

eine schematische Darstellung des erfindungsgemäßen Hubendschalters im zulässigen Betriebszustand,

Figur 3:

eine schematische Darstellung des erfindungsgemäßen Hubendschalters im unzulässigen Betriebszustand,

Figur 4:

eine Seitenansicht des erfindungsgemäßen Hubendschalters,

Figur 5:

eine Schnellwechselhalterung für den erfindungsgemäßen Hubendschalter aus Figur 4 und

Figur 6:

eine erfindungsgemäße Hebevorrichtung in Form eines Mobilkrans.

The present invention will now be explained in more detail with reference to drawings. Show it:

FIG. 1:

a detailed view of a lifting device with an end stop according to the invention arranged thereon,

FIG. 2:

a schematic representation of the Hubendschalters invention in the permitted operating condition,

FIG. 3:

a schematic representation of the invention Hubendschalters in impermissible operating condition,

FIG. 4:

a side view of the Hubendschalters invention,

FIG. 5:

a quick-change holder for the Hubendschalter invention FIG. 4 and

FIG. 6:

a lifting device according to the invention in the form of a mobile crane.

FIG. 1 shows the schematic representation of a guide means 31 which is rotatably mounted on the boom 32 of a lifting device. The illustration also shows a hoist rope 30 which is guided over the guide means 31 and is guided over the deflection roller of a hook block, not shown, back to the boom and is secured thereto by means of a lock or the like. When pulling the hoist rope 30, the guide means 31 rotates counterclockwise, so that the attached to the hoist rope hook hook and a load hanging thereon is raised. It is important to ensure that the load or the hoist rope 31 arranged hook or the like is not drawn into the guide means 31, which could lead to damage of the guide means 31 or even to the demolition of the hoist rope 30 or the hook bottle. To avoid these risks, an inventive limit switch 22 is arranged in the immediate vicinity of the guide means 31, which is to ensure that the drive of the hoisting cable 30 is stopped when reaching or exceeding a maximum allowable stroke position of the load or the hook block.

In the following should be briefly based on FIG. 1 on the operation of the Hubendschalters 22 of the invention will be discussed. The stroke limit switch 22 is arranged within a housing 26. A connecting element 21 is connected via the cable 27 hanging with the Hubendschalter 22. On the connecting element 21 itself, a weight 25 is mounted. The weight 25 completely encloses the hoist rope 30, so that it is longitudinally movably guided on the hoist rope 30. During operation, the weight of the weight 25 acts steadily on the Hubendschalter 22 a. If a load or hook block approaches the weight 25 guided on the hoist rope 30 and raises it upward against its weight force, the weight force acting on the hoisting limit switch 22 is relieved or reduced. The changed state is detected by the Hubendschalter 22 according to the invention and optionally forwarded via a bus system to the control unit of the lifting device.

Based on FIG. 2 Let now briefly the schematic structure of the Hubendschalters 22 according to the invention will be described in more detail. Within the housing 26 of the Hubendschalters 22 according to the invention is a read and write device 20 having a plurality of read and write areas, which point in different directions. A first read and write area of the reading and writing device 20 points in the direction of the movable carrier 23 lying laterally to the left of the reading and writing device 20. On the movably guided carrier 23, the two transponders T1 and T2 are arranged in the vertical direction with one another the transponder T1 is located above the transponder T2. By movement of the movable carrier 23 along a vertical axis is either the transponder T1 or the transponder T2 in the reading and writing area of the reading and writing device 20. At the lower end of the carrier 23, the cable 27 is arranged, at the free end, the connecting element 21 is attached to receive the weight 25 hanging. If the weight force of the weight 25 acts on the stroke limit switch 22 via the connecting element 21, the carrier 22 is moved downwards along a vertical axis so that the transponder T1 is located in the reading and writing area of the reading and writing device 20. The data stored on the transponder T1 are read out by the device 20. The data stored on the transponder T1 characterize the permissible operating state of the Hubendschalters 22, in which the load fixed to the hoist rope 30 has not yet reached the maximum lift height. Is according to the in FIG. 1 explained operating principle, the weight 25 relieved by the load or hook bottle of the hoist rope 30, the preferably spring-loaded carrier 23 moves due to the spring restoring force in the vertical direction upwards.

FIG. 3 shows the state of the Hubendschalter 22 with the unloaded weight 25. In this case, the transponder T2 is in the reading area of the reading and writing device 20. Consequently, the data is read out by the reading and writing device 20 from the transponder T2 and interpreted such that a Inadmissible operating state of Hubendschalters 22 is detected.

In the Figures 2 and 3 is shown with the item number 40 every component on which previously the Hubendschalter were firmly attached to a lifting device. These components are, for example, parts of the boom system of the lifting device and will later be based on the FIG. 6 be explained in more detail. At these points now external transponder T3 are attached. These transponders T3 are assigned data that unambiguously define the component 40. For example, these data include information about the serial number of the steel component 40, coordinates of the center of gravity or mass, and geometric data of the component. Likewise, a unique address may be stored on the transponder T3, whereby the transponder T3 is uniquely identifiable.

According to the invention, the read and write device 20 has the further task of reading the transponder T3 in the reception area. To facilitate this, the reader and writer 20 has a plurality of read and write areas directed in different directions. If the stroke limit switch 22 according to the invention is mounted in the immediate vicinity of the transponder T3 on the component 40, whereby the transponder T3 is in a second read and write area, preferably laterally to the right of the stroke limit switch, the read and write device 20, then the transponder T3 is detected and read out. The reading of the transponder T3 at the mounting location of the Hubendschalters 22 allows automatic position detection of the Hubendschalters 22. The self-identified position provides the basis for each Hubendschalter 22 uniquely assigned to be checked a guide means, a hoisting rope or a drive winch of the lifting device.

In contrast to the well-known from the prior art Hubendschaltern the assignment of Hubendschalters 22 must not be manually identified by the operator, but is detected automatically and error-free by Hubendschalter 22 itself.

In FIG. 4 is a further detail view of Hubendschalters 22 of the invention shown. At the lower end of the Hubendschalters 22 is a arranged at the free end of the rope 27 loop-shaped connecting element 21 for fixing a weight 25. In order to transfer the collected data of the reading and writing device 20 to a central control unit, the Hubendschalter 22 has a bus connection 24th on. Thus, the limit switch 22 can be connected to a central bus system, which accomplishes the communication between the individual Hubendschaltern 22 within a system or with a control unit. In order to mount the Hubendschalter 22 quickly and safely, a quick assembly device 50 is given, which are firmly fixed in the immediate vicinity of the guide means on the lifting device.

The mentioned quick-mounting device 50 is described in detail in FIG FIG. 5 given. In the illustrated embodiment of the quick-mounting device 50, the externally arranged transponder T3 is firmly integrated into the quick-mounting device 50. If the hoisting limit switch 22 is correctly inserted into the quick-mounting device 50, the transponder T3 is located in the reading and writing area of the reading and writing device 20 of the hoisting limit switch 22 and the data stored on the transponder T3 are read out by the hoisting limit switch 22 and via the bus connection 24 communicated to the central control unit. Similarly, a writing procedure on the transponder T3 is possible to write data during crane operation on the transponder T3. Conceivable here are z. B. all data concerning the load collective. If the transponder T3 is fixed in the quick-mounting device 50 FIG. 5 integrated, it must be ensured that the quick-mounting device 50 is fixedly mounted in the required position of a lifting device, so that the data stored on the transponder T3 with respect to the component 40 match.

FIG. 6 schematically shows an illustration of a lifting device according to the invention in the form of a mobile crane, which has an inventive arrangement of sensor devices in the form of the above-described Hubendschalter 22 in the immediate vicinity of the three different guide means on the mobile crane. In the embodiment FIG. 6 The mobile crane has three different guide means for guiding a hoist rope 30. The mobile crane consists of a telekopierbaren main boom 7 with a roller head arranged at the top 3. To extend the main boom 7, the boom extension 6 is used with a tiltable tipping tip 5. The rocking tip 5 has the two guide means 1 and 2, via a hoisting rope 30 is feasible. In order to accomplish the monitoring of the hoist rope 30 on the guide means 1, 2 and 3, sensors are arranged in the immediate vicinity of the guide means 1, 2, 3. At the same time, the mobile crane provides a bus system which transmits the signals of the individual sensors arranged to a central controller 4. According to the invention, the individual sensors independently recognize their position on the boom system of the mobile crane and communicate it to the central crane control during crane operation.

In order to minimize the safety risks, the single start-up of each occupied sensor can be requested by the control unit 4 before the start of the crane work. Thus, the controller is clearly known, which winds 8 at which point or guide means 1, 2, 3 complies with a lifting task. Thus, if necessary, the control unit 4 only has to stop the winch 8 responsible for the lifting task. The targeted start of the Hubendschalter 22 is possible and brings beneficial results, however, it is also a separate step, which could also be dispensed with when setting up the crane. If this step is required, then it is efficiently performed directly when erecting the boom 7, since then only a small distance from the respective hoist rope 30 is to be covered until the Hubendschalter 22 switches. Alternatively, it would be possible for the crane to be equipped without this requirement. During crane operation, the control 4 then monitors, as before, each limit switch 22. If a Hubendschalter 22 is actuated, then checks the controller 4, whether the crane movement is clearly attributable to a winch 8, for example, if only one winch 8 is driven. In this case, the controller also switches off only this one winch 8 and remembers the assignment winch 8 to guide means 31 and end limit switch 22. Thus, the crane learns casually in operation its configuration with a very high degree of security.

Furthermore, the mobile crane according to the invention offers the possibility that the sensors are also used in places where lifting work has to be carried out for assembly purposes of the mobile crane. As an example, the assembly of the lattice boom with the SA-Bock or the derrick boom may be mentioned.

Claims (6)

Lifting device, in particular crane or crawler crane, with at least two different guide means (1,2,3) for at least one hoist rope (30) for lifting a load, at least one winch (8) being provided for driving the at least one hoist rope (30),
characterized,
in that at least one sensor device in the immediate vicinity of one of the at least two guide means (1, 2, 3) is arranged on the lifting device, each sensor independently recognizing its mounting position. Lifting device according to claim 1, characterized in that the sensors are releasably attachable to the mounting position, wherein the sensors are preferably designed such that they detect the hoist position on the guide means (1,2,3) by measurement. Lifting device according to one of claims 1 or 2, characterized in that the lifting device provides a control unit (4) which is connectable or connected to at least one or all sensors, wherein the control unit (4) preferably receives data from at least one sensor, in particular, the serial number of the lifting device component (40) on which the sensor is arranged and / or the hoisting rope position and / or address and / or geometric data of the hoisting device component (40) assigned to the sensor by the mounting position. Lifting device according to one of claims 1 to 3, characterized in that at least one of the sensors comprises a Hubendschalter (22) according to one of claims 1 to 12. Lifting device according to claim 3 or 4, characterized in that the control unit (4) depending on the transmitted data of the sensors, the at least one winch (8) drives, wherein the control unit (4) is preferably designed such that a plurality of winches (8) in If necessary, can be controlled separately. Lifting device according to one of the preceding claims, characterized in that the control unit (4) is designed such that all fixed sensors are approached before the start of operation of the crane, wherein preferably from the control unit (4) a defective sensor is detectable.

Images