METHOD FOR RAISING AND/OR LOWERING A LOAD-HANDLING ELEMENT OF A LIFTING DEVICE, IN PARTICULAR OF A CRANE, AN DLIFTING DEVICE THEREFOR

Abstract

A crane lifting device, and method for raising and/or lowering a load-handling element of a crane lifting device, allows for operating the lifting device with a first velocity or with a second velocity greater than the first velocity, by means of a control unit. To achieve a reduction in impulses while raising the load-handling element, and to achieve an extended service life of the supporting means, an inclination sensor is used to determine an inclination angle of the load-handling element and/or a state sensor is used to determine a free or occupied state of the load-handling element. An evaluating unit interacts with the control unit in such a way that, depending on the determined inclination angle and/or the determined free or occupied state, the evaluation unit prevents or permits operation of the lifting device with the second velocity by means of the control unit.

Claims

1. A method for lifting or lowering a load handling means of a crane hoist, said method comprising: providing a flexible carrying means to which the load handling means is attached; operating the hoist at least at a first speed or a second speed with a control unit, for lifting or lowering the load handling means, wherein the first speed is lower than the second speed; determining either: (i) an inclination angle of the load handling means by an inclination sensor; or (ii) a free or occupied state of the load handling means by a state sensor, wherein the state sensor is configured to detect the presence or absence of an object, wherein the free state and also the occupied state can be recognised for the load handling means irrespective of its position or inclination, and irrespective of any lifting cable load forces; operating an evaluation unit in cooperation with the control unit to prevent or permit the hoist to operate at the second speed according to the determined inclination angle or the determined free or occupied state of the load handling means.

2. The method as claimed in claim 1, wherein the inclination angle is determined relative to a rest position of the load handling means suspended on a carrying means of the hoist.

3. The method as claimed in claim 1, wherein the hoist is prevented from operating at the second speed is for lifting or lowering of the load handling means when the inclination angle reaches or exceeds a limit value between 0 and 10 and the state sensor detects that the load handling means is occupied.

4. The method as claimed in claim 3, wherein the hoist is permitted to operate at the second speed after a delay following the inclination angle falling below the limit value in an uninterrupted manner.

5. The method as claimed in claim 3 wherein the hoist is prevented from operating at the second speed is for lifting when the inclination angle is less than the limit value and when a load force applied to the load handling means is less than a limit value of up to 500 N, and wherein the load force is determined by a load sensor.

6. The method as claimed in claim 3, wherein the hoist is permitted to operate at the second speed for lifting when the inclination angle is lower than the limit value and when a load force applied to the load handling means reaches or exceeds the limit value or falls below the limit value after a delay, and wherein the load force is determined by a load sensor.

7. The method as claimed in claim 1, wherein the hoist is permitted to operate at the second speed for lifting when the state sensor detects that the load handling means regardless of whether or not the inclination angle reaches or exceeds a limit value between 0 and 10.

8. The method of claim 5, further comprising at least one chosen from: (i) transmitting sensor signals from a signal transmitting module arranged on the load handling means to the evaluation unit arranged outside the load handling means, wherein the sensor signals correspond to the determined inclination angle or the determined state or the determined load force to prevent or permit, in dependence upon the sensor signals, operating the hoist at the second speed by means of the control unit; and (ii) transmitting enable signals or blocking signals for the second speed and generated by the evaluation unit arranged on the load handing means, from a signal transmitting module arranged on the load handling means to the control unit arranged outside the load handling means to prevent or permit, in dependence upon the enable signals or blocking signals operating the hoist at the second speed by means of the control unit.

9. The method as claimed in claim 8, wherein power for a sensor system including at least one chosen from the inclination sensor, the state sensor, the load sensor, and the signal transmitting module, is provided by a power supply unit arranged on the load handling means and having an energy store or an active power generating unit, wherein the power is generated by movement of the load handling means during lifting or lowering of the load handling means, and wherein the power is generated by an electrical generator of the active power generating unit.

10. A crane hoist comprising: a load handling means; a flexible carrying means to which the load handling means is attached for lifting; a control unit configured to operate the hoist at least at a first speed or at a second speed for lifting or lowering the load handling means, wherein the first speed is lower than the second speed; an inclination sensor for determining an inclination angle of the load handling means or a state sensor operable to determine a free state or an occupied state of the load handling means wherein the state sensor operable to detect the presence or the absence of an object to determine the free state or occupied state of the load handling means; and an evaluation unit in communication with the control unit such that operation of the hoist at the second speed is prevented or permitted by the evaluation unit based on the inclination angle or the state of the load handling means.

11. (canceled)

12. The hoist as claimed in claim 10, further comprising: a sensor module that includes a sensor system and the evaluation unit; a signal transmitting module for transmitting sensor signals, or enable signals or blocking signals; and a power supply unit; wherein the sensor module and the signal transmitting module are arranged on the load handling means, and wherein the power supply unit is configured to supply at least the sensor system of the sensor module with power.

13. The method as claimed in claim 2, wherein the hoist is prevented from operating at the second speed for lifting or lowering of the load handling means when (i) the inclination angle reaches or exceeds a limit value between 0 and 10 and (ii) the state sensor indicates that the load handling means is occupied.

14. The method as claimed in claim 2, wherein the hoist is permitted to operate at the second speed for lifting when (i) the state sensor detects that the load handling means is free and (ii) the inclination angle reaches or exceeds a limit value between 0 and 10.

15. The method as claimed in claim 3, wherein the hoist is permitted to operate at the second speed for lifting when the state sensor detects that the load handling means is free, regardless of whether or not the inclination angle reaches or exceeds a limit value between 0 and 10.

16. The method as claimed in claim 4, wherein the hoist is prevented from operating at the second speed for lifting when (i) the inclination angle is lower than the limit value and (ii) a load force applied to the load handling means is less than a limit value of up to 500 N, and wherein the load force is determined by a load sensor.

17. The method as claimed in claim 4, wherein the hoist is permitted to operate at the second speed for lifting when the inclination angle is lower than the limit value and when a load force applied to the load handling means (i) reaches or exceeds the limit value or (ii) falls below the limit value after the delay, and wherein the load force is determined by a load sensor.

18. The method as claimed in claim 5, wherein the hoist is permitted to operate at the second speed for lifting when the inclination angle is lower than the limit value and when a load force applied to the load handling means (i) reaches or exceeds the limit value or (ii) falls below the limit value after a delay, and wherein the load force is determined by a load sensor.

19. The method as claimed in claim 9, wherein the electrical generator of the active power generating unit is a dynamo.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0043] The invention will be explained in more detail hereinunder with the aid of exemplified embodiments illustrated in drawings. In the figures:

[0044] FIG. 1 shows a bridge crane formed as a single-girder crane;

[0045] FIG. 2 shows a side view of a load handling means of the bridge crane from FIG. 1 in an inclined position with a non-tightened, loose cable and a sensor module in accordance with the invention; and

[0046] FIG. 3 shows a side view of the load handling means from FIG. 2 in the vertical position, with a tightened cable and the sensor module.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0047] FIG. 1 shows a crane 1 designed as a single-girder bridge crane. The crane 1 includes a crane girder 2 formed as a lattice girder which extends with its longitudinal extent LE horizontally and transversely, in particular perpendicularly, to a crane travel direction F.

[0048] Of course, the crane 1 can also be formed as a single-girder gantry crane having a corresponding crane girder 2 supported by vertical gantry supports. Likewise, the crane 1 can be formed as a dual-girder bridge crane or as a dual-girder gantry crane and may include two crane girders 2 accordingly. The explanations given hereinafter using the crane 1 formed as a single-girder bridge crane are transferable accordingly.

[0049] With first and second running gear units 3, 4 attached to its mutually opposing ends, the crane girder 2 of the crane 1 forms a crane bridge which is substantially in a double T shape as seen in a plan view. The crane 1 can travel on rails, not illustrated, in the crane travel direction F via the running gear units 3, 4 driven by a motorised crane drive. The rails are typically disposed raised with respect to the ground 17 and for this purpose can be elevated, such as via a suitable support structure, or can be attached to mutually opposing building walls. In order to move the crane 1 or the crane girder 2 thereof, the first running gear unit 3 is driven by a first electric motor 3a of the crane drive and the second running gear unit 4 is driven by a second electric motor 4a of the crane drive.

[0050] A crane trolley 5 having a hoist 6 is arranged on the crane girder 2 and can travel, by means of its running gear unit driven by a motorised crane drive, together with the hoist 6 along the longitudinal extent LE of the crane girder 2 and thus transversely to the crane travel direction F. Moreover, a control unit 15 and control switch 16, connected thereto in a control technology and in particular signal-transmitting manner, are arranged on the crane 1 or its crane girder 2, whereby the electric motors 3a, 4a of the crane drive and at least one electric motor of the trolley drive and a motorised lifting drive of a lifting mechanism 7 of the hoist 6 can each be actuated and operated separately from one another. In all of the present embodiments, the control unit 15 can be divided such that one part 15a of the control unit 15 used for actuating the lifting drive and in particular also the trolley drive is arranged on the crane trolley 5 as a lifting or trolley controller and one part 15b of the control unit 15 used to actuate the crane drive is arranged as a crane controller outside the crane trolley 5 on the crane girder 2 or at least one of the running gear units 3, 4. The control switch 16 is formed as a pendant control switch connected by cables, but can also be formed as a wireless remote control unit.

[0051] A carrying means 8 formed, for example, as a cable and a load handling means 9 having, optionally, a load L attached to the load handling means 9 (see FIG. 2) can be lifted or lowered via the lifting mechanism 7 of the hoist 6 driven in a motorised manner. The hoist 6, in particular its lifting mechanism 7, can be operated at least at two speeds (v1) and (v2) in order to be able to lift the load handling means 9 alone or with an attached load L, i.e. a load attached to the load handling means 9. The first speed v1 is lower than, or slower than, the second quicker speed v2. For example, the first speed v1 can be in the range of approximately 1-2 m/min and the v1/v2 ratio can be 1/6 or 1/4. More than two speeds are also feasible, wherein the speeds can then be continuously adjustable in particular including the speeds v1 and v2 and the v1/v2 ratio can be considerably higher, e.g. 1/100. The desired speed, in particular the speed v1 or v2, can be triggered by an operator by actuating the control switch 16 accordingly. A corresponding control command is then transmitted in terms of a speed desired value from the control switch 16 to the control unit 15 or the part 15a thereof. The hoist 6, in particular the lifting drive of its lifting mechanism 7, can then be actuated by the control unit 15 and thus can be operated by means of the control unit 15 at the first speed v1 or at the second speed v2 in order to effect corresponding lifting or lowering movement at the desired speed.

[0052] The flexible carrying means 8 can, in addition to the exemplified embodiment as a cable, also be designed as a chain or the like and so the hoist 6 is then not formed as a cable winch but as a chain hoist. The load handling means 9 includes by way of example a load hook 9a and is suspended on the carrying means 8 in particular via its lower block 9b with one or more deflection rollers (not illustrated) for the carrying means 8. Accordingly, the cable can be reeved once or multiple times forming a corresponding number of cable strands and thus can be formed as a pulley block. Alternatively, the load handling means 9 can also be attached to the carrying means 8 without deflection rollers or reeving, in particular if the hoist 6 is formed as a chain hoist.

[0053] Depending upon the type of load L to be lifted by means of the hoist 6, the load L can be attached to the load handling means 9 directly or by means of a lifting accessory 8a. The lifting accessory 8a for attaching a load L to the load handling means 9 may be, for example, chains, cables or belts which can each form a sling, in particular a round sling. Corresponding slings are generally flexible.

[0054] FIG. 2 shows a schematic illustration of the load handling means 9 suspended on the carrying means 8 and in particular its load hook 9a and lower block 9b. A load L is attached to the load handling means 9 by means of a lifting accessory 9a, which is formed as a sling, for example, and is received by the hook jaw of the load hook 9a, the sling being looped around the load. The load handling means 9 is illustrated in an inclined position in which the carrying means 8 and also the lifting accessory 8a are not tightened but are loose. The load handling means 9 includes a sensor module 10 for lifting and/or lowering the load handling means 9, in accordance with the invention, with a load optionally attached thereto, such as the load L. The sensor module 10 isas illustratedarranged on the load handling means 9 and can be arranged in particular on the lower block 9b and/or on the load hook 9a. The sensor module 10 schematically illustrated additionally as a detailed view in FIG. 2 in addition to the load handling means 9 includes a sensor system 11 and in the present case also an electronic evaluation unit 12 connected to the sensor system 11 in a signal-transmitting manner. The evaluation unit 12 can alternatively also be arranged outside the load handling means 9, and thus also outside the sensor module 10, and can be arranged on the crane girder 2, for example, and in particular can be integrated in the control unit 15 or at least connected thereto in a signal-transmitting manner.

[0055] In order to determine, preferably continuously, an inclination angle N of the load handling means 9, the sensor system 11 includes at least one inclination sensor 11a in accordance with a first embodiment. The inclination angle N can relate, for example, to a rest position of the load handling means 9 in which the load handling means 9 is free, i.e. in particular without contact with the ground 17 on the tightened carrying means 8 and suspended therefrom. The rest position thus corresponds to a swinging-free equilibrium position of the freely suspended load handling means 9 in which a longitudinal axis LA of the load handling means 9, which can be used as a reference line, coincides with a perpendicular S corresponding to the direction of gravitational force (see FIG. 3). In the inclined position of the load handling means 9 shown in FIG. 2, the load handling means 9 is inclined with respect to the rest position or the perpendicular S by the inclination angle N owing to the flexible and non-tightened carrying means 8, wherein it lies on the load L lying on the ground 17. Load forces emanating from the load L are not introduced into the carrying means 8 in this position of the load handling means 9 because the carrying means and the lifting accessory 8a are not sufficiently tightened for this purpose. The inclination angle N determined by the inclination sensor 11a is made available to the evaluation unit 12 in particular in the form of corresponding sensor signals and for this purpose are transmitted from the sensor system 11 to the evaluation unit 12.

[0056] The evaluation unit 12 evaluates, in accordance with the first embodiment, the sensor signals from the inclination sensor 11a corresponding to the determined inclination angle N and cooperates with the control unit 15 such that the evaluation unit 12, in dependence upon the determined inclination angle N, prevents or permits the hoist 6 from being operated or being able to be operated by means of the control unit 15 at the second, greater, speed v2, in order to lift and/or lower the load handling means 9.

[0057] The speed v2 is hereby prevented when the determined inclination angle N of the load handling means 9 deviates from the rest position or the perpendicular S of zero and reaches or exceeds a predetermined limit value, i.e. the load handling means 9 is inclined too much, and is permitted at the earliest when the inclination angle N is less than the predetermined limit value, i.e. the load handling means 9 is inclined to a sufficiently small extent. As the limit value for the inclination angle N, an angle in the range between 0 and 4 is preferably predetermined, and is set, for example, in the evaluation unit 12.

[0058] Preventing the hoist 6 from being operated or being able to be operated by the control unit 15 at the speed v2 means in the context of this embodiment and all other embodiments described below that the speed v2 in particular cannot be triggered or executed by the control unit 15 despite an operator actuating the control switch 16 accordingly. In other words, the speed v2 can be blocked in the control unit 15 by the evaluation unit 12 in dependence upon the determined inclination angle N in terms of control technology in the sense of a speed limitation, i.e. a limitation of speed desired values which can be executed by means of the control unit 15.

[0059] In this context, provision can be made that the evaluation unit 12 has to actively generate an enable signal for the speed v2 which then has to be transmitted to the control unit 15 and has to be received by the control unit 15 in order to permit the control unit 15 to effect or execute the speed v2 in the case of a corresponding control command. The lack of the enable signal then corresponds to preventing the speed v2 and ensures that the control unit 15 cannot effect or execute the speed v2. Then, for example only the speed v1 can be effected or executed.

[0060] Alternatively, it is also feasible that the evaluation unit 12 has to actively generate a blocking signal in relation to the quicker, second speed v2, which signal then has to be transmitted to the control unit 15 and has to be received by the control unit 15 in order to prevent the speed v2 and thus ensure that the control unit 15 cannot effect or execute the second speed v2 in the case of a corresponding control command. The lack of the blocking signal then corresponds to permitting the speed v2 and ensures that the control unit 15 cannot effect or execute the speed v2.

[0061] If the speed v2 is prevented in the above sense by the lack of an enable signal or by a blocking signal, control commands of the control switch 16, which in the sense of speed desired values are directed to effecting operation of the hoist 6 at the speed v2 and are triggered by actuating the control switch 16 accordingly, are processed by the control unit 15 only such that the hoist 6 does not execute any lifting or lowering movement at all or is operated only at a speed lower than the speed v2, such as the speed v1. If the speed v2 is permitted by an enable signal or the lack of a blocking signal, the above-mentioned control commands of the control switch 16 can be, in contrast, processed by the control unit 15 such that the hoist 6 is operated at the speed v2.

[0062] Permitting the second speed occurs, as already described above, at the earliest when the value falls below the predetermined limit value for the inclination angle N, but preferably with a time-dependent and/or displacement-dependent delay after the value falls below the predetermined limit value.

[0063] Owing to the above-described cooperation of the inclination sensor 11a, the evaluation unit 12 and the control unit 15, critical impulses can thus be avoided, which result from situations in which the hoist 6 is operated at the speed v2 although the carrying means 8 and any flexible lifting accessory 8a are not sufficiently tightened as shown in FIG. 2 and accordingly no load forces emanating from the load L into the carrying means 8 are absorbed by the not sufficiently tightened carrying means 8. The above-described risk of contact of the load handling means 9 and/or carrying means 8 with the ground can also be avoided. Such situations can be recognised by corresponding inclination angles N of the load handling means 9 which reach and/or exceed the limit value. Even in the case of a determined inclination angle N of the load handling means 9 which do not reach the limit value, there can still be a risk of a critical impulse during the lifting operation when the lifting accessory 8a is not yet sufficiently tightened. In this case, the speed v2 may then be permitted with a corresponding delay. However, this is not applicable for lowering operation.

[0064] A second embodiment differs from the first embodiment in that the sensor system 11 additionally includes a state sensor 11b. The state sensor 11b can be used to continuously determine whether the load handling means 9 is free or occupied as a state of the load handling means 9. The load handling means 9 has the state occupied when a load L or a lifting accessory 8 for attaching a load L to the load handling means 9 is attached directly to the load handling means 9. If the load handling means 9 is formed as a load hook 9a, a corresponding state sensor 11b is also referred to as a hook jaw sensor which can then determine whether the state is occupied and accordingly in particular whether or not part of a load L or a lifting accessory 8a is arranged in the hook jaw of the load hook 9a, in particular is lying there. If not, the state is free. The respective state of occupied or free is recognised by the state sensor 11b, which can be, for instance, a sensor operating according to the optical or capacitive principle, in particular a proximity sensor.

[0065] The states occupied or free determined by the state sensor 11b are made available to the evaluation unit 12 in particular in the form of corresponding sensor signals and for this purpose are transmitted from the sensor system 11 to the evaluation unit 12. The evaluation unit 12 evaluates the sensor signals from the inclination sensor 11a corresponding to the determined inclination angle N and the sensor signals from the state sensor 11b corresponding to the state of the load handling means 9 and cooperates with the control unit 15 such that the evaluation unit 12, in dependence upon the determined inclination angle N and/or the determined state, prevents or permits the hoist 6 from being operated or being able to be operated by means of the control unit 15 at the second speed v2, in order to lift and/or lower the load handling means 9.

[0066] The speed v2 is permitted by the evaluation unit 12 in the above-described sense when the state sensor 11b recognises that the load handling means 9 is free. This also applies, with the exception of the lowering operation of the hoist 6, in particular when the determined inclination angle N reaches or exceeds the predetermined limit value. The speed v2 is thus permitted in the lifting operation solely in dependence upon the state determined by the state sensor 11b and independently of the determined inclination angle N or the corresponding sensor signals from the inclination sensor 11a when the state of the load handling means 9 is free. When the state of the load handling means 9 is occupied, the speed v2 is permitted, optionally with the above-described delay, or prevented during lifting and/or lowering in dependence upon the state determined by the state sensor 11b and additionally, as per the first embodiment, in dependence upon the inclination angle N.

[0067] Owing to this cooperation of the inclination sensor 11a, the state sensor 11b, the evaluation unit 12 and the control unit 15, it can be avoidedin cases where the load handling means 9 is freethat the speed b2 is prevented because the limit value for the inclination angle N is reached and/or exceeded even though there is no risk of critical impulse owing to the fact that the load handling means 9 is free. Therefore, in these cases the speed v2 can be permitted in particular independently of the inclination angle N and thus from the outset, i.e. immediately at the start of a lifting process for lifting the load handling means 9 and without a delay.

[0068] A third embodiment, as an alternative to the second embodiment, differs from the first embodiment in that the sensor system 11 includes a load sensor 11c in addition to the inclination sensor 11a. The load sensor 11c is used to determine a load force applied to the load handling means 9, the force emanating from a load L attached to the load handling means 9. By determining the load force multiple times and in particular continuously by means of the load sensor 11c, an increase in the load force can also be determined. The load forces determined by the load sensor 11c are made available to the evaluation unit 12 in particular in the form of corresponding sensor signals and for this purpose are transmitted from the sensor system 11 to the evaluation unit 12. The evaluation unit 12 evaluates the sensor signals from the inclination sensor 11a corresponding to the determined inclination angle N and the sensor signals from the load sensor 11c corresponding to the determined load forces and cooperates with the control unit 15 such that the evaluation unit 12, in dependence upon the determined inclination angle N and the determined load force, prevents or permits the hoist 6 from being operated or being able to be operated by means of the control unit 15 at the second, greater, speed v2, in order to lift the load handling means 9.

[0069] In contrast to the first embodiment, a lifting operation of the hoist 6 at the speed b2 can thus also be prevented in the above sense when the determined inclination angle N is less than the predetermined limit value and in particular has already reached a value of zero but when in addition the load force determined by the load sensor 11c is less than a predetermined limit value, which is, for example, up to 500 N. Likewise, in contrast to the first embodiment, it is possible to permit the speed v2 for a lifting operation in the above sense at the earliest when the determined inclination angle N is less than the predetermined limit value and when in addition the load force determined by the load sensor 11c reaches and/or exceeds the predetermined limit value or, as already described above, is still less than the limit value even after the end of a predetermined time-dependent or displacement-dependent delay.

[0070] Owing to this cooperation of the inclination sensor 11a, load sensor 11c, evaluation unit 12 and control unit 15, it can be avoided that that the speed v2 is permitted solely owing to the fact that the value is less than the limit value for the inclination angle N. In particular in the cases already mentioned above, in which a flexible lifting accessory 8a is used, a critical impulse as a result of a not yet sufficiently tightened lifting accessory 8a can be avoided in that the speed v2 is only permitted with a corresponding delay.

[0071] A particularly preferred fourth embodiment is achieved by combining the second and third embodiments. Accordingly, the sensor system 11 includes the inclination sensor 11a and the state sensor 11b of the second embodiment and the load sensor 11c of the third embodiment. The evaluation unit 12 evaluates the sensor signals from all three sensors 11a, 11b, 11c and cooperates with the control unit 15 such that the evaluation unit 12, in dependence upon the state determined by the state sensor 11b and/or in dependence upon the inclination angle N determined by the inclination sensor 11a and the load force determined by the load sensor 11c, prevents or permits the hoist 6 from being operated or being able to be operated by means of the control unit 15 at the second, greater, speed v2, in order to lift and/or lower the load handling means 9.

[0072] The speed v2 is then permitted by the evaluation unit 12 in the above described sense in the lifting operation of the hoist 6 as per the second embodiment solely in dependence upon the state determined by the state sensor 1b when the state sensor 11b recognises that the load handling means 9 is free. In contrast, when the state of the load handling means 9 is occupied, the speed v2 is permitted, optionally with the above-described delay, or prevented during lifting and/or lowering in dependence upon the state determined by the state sensor 11b and additionally, as per the third embodiment, in dependence upon the determined inclination angle N and the determined load force.

[0073] Owing to this cooperation of the inclination sensor 11a, the state sensor 11b, the load sensor 11c, the evaluation unit 12 and the control unit 15, it can be avoidedin cases where the load handling means 9 is freethat the speed v2 is prevented because the limit value for the inclination angle N is reached and/or exceeded or the limit value for the load force is not reached, even though there is no risk of critical impulse owing to the fact that the load handling means 9 is free. Therefore, in these cases the speed v2 can be permitted in particular independently of the inclination angle N and the load force and thus from the outset, i.e. immediately at the start of a lifting process for lifting the load handling means 9 and without a delay. In cases where the load handling means 9 is occupied, it can be avoidedin particular owing to the delayed permission of the speed v2that the speed v2 is permitted solely owing to the limit value for the inclination angle N not being reached and that then a critical impulse is caused owing to a not yet sufficiently tightened carrying means 8 or lifting accessory 8a. The above statements also apply accordingly when permitting or preventing the speed v2, when lowering, in dependence upon the situation.

[0074] FIG. 3 shows a schematic illustration of the load handling means 9 suspended on the carrying means 8 and in particular its load hook 9a and lower block 9b as well as the sensor module 10 with the load L being raised, the load being attached to the load handling means 9 by means of the lifting accessory 8a. The load handling means 9 is in a perpendicular position which corresponds to the above-defined rest position. The inclination angle N is accordingly zero and the longitudinal axis LA of the load handling means 9 used as a reference line coincides with the perpendicular S. The carrying means 8 and also the lifting accessory 8a are tightened and so load forces emanating from the load L are introduced into the carrying means 8 and are absorbed thereby. As soon as the lifting forces introduced by the lifting mechanism 7 of the hoist 6 into the carrying means 8 exceed the load forces, the load L is raised, as has already occurred in FIG. 3.

[0075] Because the load handling means 9 can move together with its sensor module 10 relative to the control unit 15 and in particular also relative to the crane girder 2 and/or crane trolley 5, particular provisions should be made when implementing the sensor module 10 on the load handling means 9 in terms of the power supply and signal transmission, i.e. the transmission of sensor signals or enable signals and blocking signals, between the sensor module 10, in particular its sensor system 11, the evaluation unit 12 and the control unit 15. Preferably, the power supply and signal transmission are thus implemented in all embodiments without cabling leading away from the load handling means 9 and in particular without cabling between the load handling means 9 or the sensor module 10 at that location and the control unit 15.

[0076] For the signal transmission, accordingly free of cables, to the control unit 15 arranged outside the load handling means 9, a corresponding signal transmitting module 13 such as in the form of a radio module is used. If the evaluation unit 12 is arranged on the load handling means 9, the above-described enable signals or blocking signals are transmitted if need be from the signal transmitting module 13 to the control unit 15. If the evaluation unit 12 is arranged outside the load handling means 9, the sensor signals determined by the sensor system 11 are transmitted to the evaluation unit 12 via the signal transmitting module 13 and are made available thereto. Any generation of corresponding enable signals or blocking signals by the evaluation unit 12 and the transmission thereof to the control unit 15 then takes place if need be outside the load handling means 9.

[0077] The power supply, free of cables, of the sensor module 10, in particular the sensor system 11, evaluation unit 12 and the signal transmitting module 13 is effected locally via a power supply unit 14 arranged on the load handling means 9 and having an energy store, which may include, for example, one or more batteries, rechargeable batteries, capacitors, and/or having an active power generating unit. In a preferred embodiment, as an alternative to or in addition to an energy store, an electrical generator, such as in the form of a dynamo, as an active power generating unit is used as an essential component of the power supply unit 14. It is readily possible to use the rotation of any deflection roller for generating power. As soon as the deflection roller rotates by lifting or lowering the load handling means 9, the generator is driven thereby and the sensor module 10 is supplied with power or any energy store is charged. The functions, in accordance with the invention, of the sensor module 10 arranged on the load handling means 9, in particular the sensor system 11 and the evaluation unit 12 arranged if need be on the load handling means 9, the signal transmitting module 13 or its respective cooperation with the control unit 15 can thus be implemented.

[0078] Changes and modifications in the specifically-described embodiments may be carried out without departing from the principles of the present invention, which is intended to be limited only by the scope of the appended claims as interpreted according to the principles of patent law including the doctrine of equivalents.