CABLE GUIDED ELEVATOR FOR WIND TURBINE

The invention refers to a wind turbine with a tower and a wire-guided lift comprising a cabin movable in a lift shaft of the tower from a lower platform to at least one higher platform.

Wind turbines usually comprise a wire-guided lift with a cab in, which lift is installed in the inner part of the tower. The lift comprises a cabin, which is movable in a lift shaft within the tower. The cabin is usually movable from a lower platform, usually ground floor, to at least one higher plat form, which is for example arranged in a nacelle, where the major equipment of the wind turbine like the generator etc. is arranged. The lift is wire-guided. The cabin is attached to respective wires, which run over one or more wheels for lifting and lowering the cabin. The cabin itself is guided along respective vertical rails arranged within the lift shaft for stabilizing the vertical movement.

As the lift is wire-guided, it is not possible to transport heavy cargo in the cabin. If heavy cargo is loaded in and out of the cabin, the cabin will significantly move vertically downwards due to the elongation of the steel wires, when the cargo is loaded in the lift, respectively move upwards due to the shortening of the wires when the cargo is unloaded from the cabin. Especially when the tower is higher, the elonga tion of the wires becomes very critical. Another problem is the gap between the cabin and the respective platform, which gap has a width of several centimetres. The gap itself pre vents the cargo to be rolled in and out of the cabin. There fore, only items with lower weight may be transported, which do not need a rolling transportation. This gap, especially in combination with the load related vertical movement of the cabin leading to a vertical displacement of the respective tower platform relative to the cabin platform, makes the loading of heavy cargo even more problematic. For these rea sons the transport of heavy cargo with such a wire-guided lift respectively cabin is prohibited. For loading these heavy cargo items usually external cranes are used.

It is an object of the invention to provide an improved wind turbine.

For addressing the object, the wind turbine as described above is characterized in that the cabin comprises several feet movable from a retracted position to an ex tended position, in which each foot rests on a support element arranged in or at the lift shaft or the respec tive platform, and a plate movable between a retracted position and an ex tended position providing a bridge from a cabin platform to the respective platform.

The inventive wind turbine comprises means for safely anchor ing the cabin in a rest position, when it has reached a load ing position relative to a lower or higher platform, and for allowing a safe roll in and out of the load, so that also heavy cargo may safely be loaded and transported.

For securely anchoring the cabin in the loading position the cabin comprises several feet, which are movable from a re tracted position, in which they allow a free vertical move ment of the cabin, to an extended position, in which each foot rests on a support element, which is arranged in or at the lift shaft or the respective platform. When the feet en gage with the respective support elements, the whole weight of the cabin rests on the feet respectively the support ele ments, so that no vertical movement occurs when the heavy load is loaded in or is unloaded from the cabin. The feet are, when the cabin is freely moving within the lift shaft, in a retracted position, in which they usually do not extend over the outer boundary of the cabin. When the cabin reaches the position close to a respective platform, the feet are moved from the retracted position to the extended position, so that, when the cabin is lowered for a final short dis tance, the feet are lowered on the support elements, on which they then finally rest, and which support elements bear the whole weight of the cabin and the load, which is either al ready in the cabin or is moved in the cabin. With this en gagement of the feet at the support elements, the cabin is safely anchored in this loading or unloading position, so that, no matter if the load is moved in or out of the cabin, the respective wires, especially when they are, after the feet finally rest on the support elements, released from any tension resting on the wires or cables, do not make the cabin move in a vertical direction, when the cabin is anchored.

Along with the safe anchoring of the cabin in the respective platform related position, the inventive wind turbine also provides means for a safe loading and unloading process, so that the heavy load may simply be rolled in and out of the cabin. The cabin comprises a plate, which is, just like the feet, movable from a retracted position, in which the cabin is movable in a vertical direction, to an extended position, in which the plate bridges the gap between the cabin platform and the fixed tower platform. The plate therefore provides a loading bridge, across which the heavy load may easily be rolled with a respective transporting means. As due to the safe anchoring of the cabin, the arrangement of both the cab in platform and the tower platform to each other is not changed throughout the whole loading or unloading process.

The plate, which is, when the cabin is anchored, moved to the extended position for bridging the gap, therefore remains in this usually horizontal position and allows for a simple rolling load process.

The feet are, as mentioned, provided at the cabin, and are therefore movable with the cabin, while the respective sup port elements are stationary provided either in or at the lift shaft or the respective platform. Therefore, the feet also bridge the gap between the cabin and the lift shaft re- spectively the platform. The layout of the feet respectively their size and geometry and the layout of the support ele ments is chosen in view of a maximum load which is transport able with the lift, certainly with a certain safety factor. While at least three feet and support elements are sufficient to securely anchor the cabin and to avoid any tilting move ment during the loading process, it is preferable to provide at least four feet and support elements, which are distribut ed around the circumference of the cabin respectively the lift shaft or the platform.

As mentioned, the feet bridge the gap between the cabin and the support elements. They are preferably arranged in a hori zontal position when they are extended. Nevertheless, they may also be slightly tilted towards the vertical axis, with the inner end arranged at the cabin being higher than the outer end resting on the support element, so that each foot not only has a horizontal but also a vertical orientation.

Regarding the movement of the feet, several possibilities are conceivable. In a first alternative, the feet are movable in a linear direction, especially a horizontal direction between the retracted and the extended position. So, the feet are simply pushed or pulled for moving them. This linear movement is possible for both a horizontal or a tilted arrangement of the feet. According to a second alternative, the feet are pivotable between the retracted position, in which they are preferably vertical, and the extended position. According to this embodiment, each foot swings from a preferably vertical position to the horizontal or tilted position, in which it extends over the cabin boundary and is positioned with its end above respectively resting on the support element. Also, this pivot movement allows for a simple positioning of the respective foot in the retracted and the extended position.

The feet are preferably arranged at the bottom side of the cabin, so that they are moved towards the support elements from underneath the cabin. This arrangement is preferable for both the linear and the pivot movement. Especially regarding the pivotable foot arrangement it is also possible to arrange the feet at the side of the cabin allowing them to swing to wards the support element into the extended position.

While it is possible to manually move the feet, specially with a person being in the cabin, it is certainly preferable that the feet are automatically movable by drive means de pending on a control command given by a control means ar ranged in the cabin or at the respective platform. These drive means allow for an automatic foot movement, which is very comfortable and also safe, as with these drive means it may easily be ensured that each foot reaches its final re tracted or extended position, which may be sensed by a appro priated sensor means. Regarding the linear movement, such a drive means may for example be a spindle drive having a spin dle being rotated by an electric motor, on which spindle a screw nut is arranged, which is moved linearly when the spin dle rotates. This screw nut is coupled to the respective foot, which is then moved in the linear direction, depending on the direction of rotation of the spindle. Also a telescop ic cylinder may be used as a drive means, which is attached with one end to the cabin and with the other end to the lon gitudinal foot pushing and pulling the foot, which has pref erably in any of the discussed embodiments the form of a beam. Regarding the swivelling arrangement of the foot such a drive means may for example be a telescopic cylinder, which is arranged with one end at the cabin and with the other end at the movable foot, so that the foot is pivots from the re tracted to the extended position, when the telescopic cylin der is extended, and is moved from the extended to the re tracted position, when the telescopic cylinder is retracted or shortened. These drive means are only examples, also other drive means may be used.

The control of the drive means and therefore the control of the foot position is done by at least one control means, which is either arranged in the cabin or at the respective platform, while it is also certainly possible, that control means are both arranged in the cabin and at the platform, so that the foot position may be controlled from both sides.

Such control means may for example be a simple button or a button array, or for example a touch display with at least one touch field or touch button or a respective touch field array etc. So, the positioning control command for moving the feet for anchoring and disengaging the cabin is given manual ly according to this alternative. In an alternative it is al so possible, that the control command is given by one or more sensor means sensing the cabin position. In this embodiment one or preferably several sensing means like respective posi tion sensors or the like are arranged either at the cabin and/or at the platform or the lift shaft, which sensor means are adapted to sense the cabin position in order to monitor the cabin moving towards the platform and reaching at least one or several certain positions relative to the platform, according to which sensor information the positioning of the feet is automatically controlled.

As mentioned above, the feet rest on support elements when the cabin is in the anchored position. These support elements may directly be integrated in the lift shaft, i.e. the shaft wall in form of respective cut-outs arranged in the shaft wall, in which cut-outs the feet engage. In an alternative several beams or a complete frame comprising the respective support elements are or is arranged in the lift shaft or at the platform. According to this embodiment the support ele ments are provided at several beams preferably made of steel, or a whole frame extending around the lift shaft or the plat form, which frame is also made of several steel profiles.

For realizing the respective support elements, the beams or the frame may comprise several cut-outs, in which the feet engage, whereby the respective foot rests directly on the beam or frame being the support elements. In this embodiment, the feet are directly in contact with the steel beam or frame, with also the feet being in general made of metal re- spectively steel. In an alternative, respective support ele ments are arranged in the respective cut-outs. In this embod iment, specific support elements are arranged in the beam or frame cut-outs, on which support elements the feet rest.

These support elements may either be made of metal or, pref erably, of a polymer like POM or the like. Especially these polymer block support elements allow for a soft landing, as they have a certain elasticity unlike metal elements, so that the cabin can be lowered on them even more comfortably.

The drive means of the cabin for vertically moving the cabin is preferably PLC-controlled, so that the speed of the cabin can be controlled very precisely allowing for an easy and soft landing operation, which soft landing may even be im proved by using some softer support elements like the polymer support elements.

Another important device of the wind turbine respectively the cabin is the plate bridging the gap between the cabin plat form and the tower platform. As mentioned, this plate is also movable from a retracted position at the cabin to an extended bridging position allowing for a roll-over from one platform to the other. For moving the plate between these positions, the plate may either be pivotably connected to the cabin, or the plate may be linearly, especially horizontally movable arranged at the cabin. In the first alternative, the plate swings from the retracted position, in which it is for exam ple arranged vertical and parallel to a cabin wall, to the extended horizontal, lowered position. The plate is pivotally hinged to the cabin with its lower end, so that it is low ered, when it pivots from the retracted to the extended posi tion. In the second alternative, it is moved linearly, espe cially horizontally. It is for example arranged directly un derneath the cabin platform or within the cabin bottom and can be pushed from this retracted position to the extended position mainly in a horizontal linear movement. In the ex tended position it is safely supported with both ends at the cabin and at the tower platform respectively the lift shaft in each embodiment, so that also heavy load may roll over the plate.

Preferably, the cabin comprises a loading door, adjacent to which the plate is arranged. Usually, the cabin comprises four or more cabin walls, with at least one wall being equipped with or being a door, which may be opened or closed. The door is a loading door, through which the load is rolled in and out of the cabin. Therefore, the plate is ranged adja cent to this door.

In a further embodiment of this door-equipped cabin the plate may only be moved from the retracted position to the extended position when the loading door is opened. This is a safety arrangement, as the plate connection from the cabin to the platform may only be realized, when the door is opened, which is an unambiguous sign that a loading or unloading process is intended. The pivotable plate may for example be arranged within the cabin and being pivoted in an upright position in the retracted position, so that it may be moved when the door is opened. The plate and the door may be coupled by a fixa tion means, which is for example automatically opened, when the door reaches its final opened position. Certainly, the plate may also be arranged outside of the cabin directly in front of the door and may also be coupled with the door.

The plate itself may be manually movable, necessitating a manual interaction of the service personnel either in the cabin or outside the cabin at the tower platform. Preferably, the plate is, just like the feet, also automatically movable by means of an automatic actuator. Depending on the moving arrangement of the plate several actuators are conceivable. When the plate is hinged to the cabin the actuator may be a telescopic cylinder, which is coupled with one end to the cabin and with the other end to the plate, which plate is moved from the, for example, vertical retracted position to the extended horizontal position simply by extending the tel escopic cylinder and is moved backwards by retracting the telescopic cylinder. Also, a drive means may be directly ar ranged at the pivot axis for pivoting the plate. If the plate is linearly movable, also here a spindle drive comprising a rotating spindle driven by an electric motor with a nut run ning on the spindle, which nut is coupled to the plate, may be used. No matter which actuator respectively drive means is used, also this automatic drive means is controlled by con trol commands given by a control means, which is either ar ranged in the cabin or at the platform or, preferably, both in the cabin and at the platform. The arrangement of the con trol means for controlling the feet and the plate as well in the cabin as at the platform is advantageous, as this allows for a transport of the load with a person in the cabin or without a person in the cabin. If a person is in the cabin, all respective controls may be done by this person from with in the cabin, no additional person is needed at the respec tive platform. On the other hand, if a person is only at the platform, but not in the cabin, also this person may control all necessary functions.

Like the cabin, also each platform may comprise a loading door adjacent to the cabin loading door when the cabin is in the rest position. This door which closes the platform area to the lift shaft, also needs to be opened for loading any items. Also, this door, which is, just like the cabin loading door, preferably automatically movable, may only open when the cabin is in the secured rest position, so that for safety reasons, any uncontrolled opening of this platform door, just like the cabin loading door, is prevented. The safe and an chored rest position of the cabin may be monitored by means of at least one sensor means, as already described above.

When this sensor information is provided to the overall lift control means, any of the door may then be opened, either manually or automatically.

The invention furthermore relates to a method for operating a lift for a wind turbine as described above comprising at least one control means for controlling a drive means for moving the cabin and respective drive means for moving the feet, with the following steps: moving the cabin into a certain position relative to the respective platform, providing a control command for bringing the cabin into a final loading position, lifting the cabin for a certain distance, moving the feet from the retracted to the extended posi tion, lowering the cabin until the feet rest on the respective support elements, opening the cabin loading door and/or the platform door, moving the plate from the retracted to the extended po sition.

According to the inventive method at least one control means, preferably only one overall lift control means, controls the respective drive means for vertically moving the cabin and the drive means of the feet. When the cabin moves vertically it is preferably PLC-controlled by the control means, so that it may be very precisely positioned relative to the respec tive platform, where a loading process is intended. Having reached this position, the control means provides a control command for bringing the cabin into a final load position. This control command is given by a respective control ar ranged either in the cabin or at the platform, e.g. by manual interaction of a person in the cabin or at the platform. When this control command is provided, the control means is noti fied that a loading process shall be performed, and that the respective anchoring of the cabin is necessary. Having re ceived this control command, the control means controls the drive means for moving the cabin to lift the cabin for a cer tain distance, e.g. 10 - 20 cm, and to bring it into a cer tain position above the support elements. Having reached this position, the feet are moved from the retracted position to the extended position, whereupon the cabin is again slowly lowered, until the feet rest on the respective support ele ments. As now the anchored position is finally reached, the cabin loading door and/or the platform door is opened and the plate is moved from the retracted position to the extended position, bridging from the cabin platform to the tower plat form.

It is advantageous to request a certain control command ei ther from a control in the cabin or at the platform for hav ing the control means control the feet movement, i.e. the an choring of the cabin. This anchoring is only necessary, when heavy loads are transported. Therefore, when only smaller loads or only persons are transported, the cabin anchoring is not needed It is only needed when heavy loads are transported resulting in the problems mentioned above, i.e. the extension of the wires leading to a certain unwanted vertical movement of the cabin and the given gap between the cabin and the lift shaft preventing the load to be rolled in out of the cabin etc.

Preferably, also a drive means for moving the plate is pro vided, wherein this drive means is also controlled by the control means for automatically moving the plate. So, not on ly the drive means for the feet are automatically controlled, but also the drive means of the plate is automatically con trolled, so that, when the overall control command is given, the whole anchoring and plate bridging process is completely automatic and no manual or personal interference is needed, except for giving the control command.

This control command is preferably given by pressing a but ton, which is provided or realized at the control in the cab in or the platform, which may either be a stand-alone button or be realized by a touch screen or the like. Preferably, this button needs to be pressed until the feet rest on the support elements and/or the plate has reached its final ex tended position. This means, that the interaction of the per son is permanently necessary from the beginning until the fi nal end of this automatic anchoring and, if given, the auto- matic plate bridging process for safely guarding the respec tive automatic actions.

In another embodiment of the inventive method the drive means for moving the cabin are controlled after the feet finally rest on the support elements for releasing tension resting on the cables to which the cabin is attached. After the cabin is secured and anchored, the control means controls the cabin drive means winding and unwinding the wires, to which the cabin is attached, to release tension from the wires, meaning that the wires are unwound slightly and are loose to a cer tain extent, so that the wires are no longer tensioned. This avoids any unwanted lifting of the cabin even for a short distance, which might occur when the heavy load is unloaded from the cabin and the wires shorten a bit due to the reduced weight, when the feet are only resting on the support ele ments preventing any downward movement but not also secured for preventing any upward movement.

If a platform loading door is provided, this platform loading door is finally opened after the cabin loading door is opened.

Other objects and features of the present invention will be come apparent from the following detailed description consid ered in conjunction with the accompanying drawings. The draw ings, however, are only principle sketches designed solely for the purpose of illustration and do not limit the inven tion. The drawings show:

Fig. 1 A principle sketch of a wind turbine with a wire- guided lift movable within a tower,

Fig. 2 a principle drawing of the cabin arranged in the lift shaft before reaching the final anchored rest position, Fig. 3 the arrangement of fig. 2 with the cabin being an chored,

Fig. 4 the cabin of fig. 3 in a 90-degree view with the plate bridging to the platform being in the extend ed position,

Fig. 5 a top view of the cabin arranged in the lift shaft, with the feet being in the extended position,

Fig. 6 a top view of the beam or frame arrangement provid ed in the lift shaft respectively at the platform with the respective support elements,

Fig. 7 a partial, perspective view of a beam with the sup port element of a first embodiment,

Fig. 8 a partial, perspective view of a beam with the sup port element of a second embodiment with a foot resting on the support element,

Fig. 9 a second embodiment of a cabin having feet and a plate arrangement of a second alternative, and

Fig. 10 a flow chart showing the respective steps of the inventive method.

Fig. 1 shows a principle illustration of a wind turbine 1 comprising a tower 2 and a nacelle 3 arranged on top of the tower, which nacelle 3 comprises a hub 4 to which several, usually three blades 5 are attached. When the blades 5 inter act with blowing wind the hub rotates and drives a generator arranged in the nacelle for providing power, as commonly known.

The tower 2 has a hollow inner 6, in which a lift 7 compris ing a cabin 8, which is wire-guided, can be moved in a verti cal direction along a lift path 9, for example realized by one or more rails guiding the cabin 8. The cabin 8 can be po sitioned to several platforms. The embodiment shows a first lower platform 10 at the bottom, and three further platforms 11, 12, 13 arranged in different heights of the tower. At each platform the cabin 8 may be precisely positioned, for which a respective control means controlling a hoist prefera bly arranged at the cabin 8, interacting with the one or the several wires to which the cabin 8 is attached for lifting and lowering the cabin 8. The cabin 8 is therefore wire- guided movable in a lift shaft 14 and can precisely stop at the respective platforms 10-13. By means of this wire-guided lift 7 personnel and/or material may be transported within the tower 2. The inventive wind turbine 1 comprises a lift 7, which is adapted to be anchored in the respective position at a platform 10-13 allowing for also transporting very heavy loads and also allowing for rolling the load in and out of the cabin 8. The exact positioning in the respective platform area respectively the vertical movement is, as mentioned, controlled by a control means, which comprises a PLC means (PLC = Programmable Logic Controller) for driving with dif ferent speed to first lift the respective personnel or items quickly and to secondly allow for an exact and ease landing operation.

Fig. 2 shows a principle illustration of the cabin 8, with a hoist 15 arranged on top of the cabin 8, which hoist 15 in teracts with the wire 16 for moving the cabin 8 vertically, as shown by the arrow PI. The cabin 8 comprises a respective cabin housing 17 having several wall elements, with several side elements 18, a roof 22 and a bottom 23. At least one side element 18 comprises a cabin loading door 19 having for example two door wings 20, 21 for opening and closing the in ner of the cabin 8.

The lift shaft 14 is shown together with a platform, for ex ample the platform 10 arranged at the bottom of the tower 2. When heavy loads shall be transported, it is necessary to se curely anchor the cabin 8 in the loading position in order to avoid any vertical movement of the cabin 8 when the heavy load is transported in or out of the cabin 8. For securing the cabin 8 in the respective position underneath the bottom 23 several feet 24 are mounted to the bottom 23. Each foot 24 is arranged in a linear guiding means 25 and connected to a drive means 26, for example a spindle drive with a spindle driven by an electric motor, on which spindle a nut is ar ranged, which is connected to the respective foot 24. This allows for horizontally moving the respective foot 24, as shown by the arrows P2. This movement is controlled by a re spective control means 27, which may be an overall control means 27 arranged in a control area of the tower 2, or which may be arranged directly at the cabin 8, as shown with the control means 27, which is arranged in the cabin 8. Another control means 27 is arranged at the platform 10 outside of the cabin 8, so that the respective movement control of the feet 24 can be performed from within the cabin 8 and from outside of the cabin 8.

The lift shaft 14 comprises one or several beams 28 arranged in the area of the platform 10 or directly at the platform 10, which beams 28 are tightly fixed as illustrated in fig.

2. Each beam 28 comprises a support element 29 here in form of a block element, which is preferably made of a polymer to show a certain elasticity.

When for example the cabin 8 is lowered and has a heavy load inside, which shall be unloaded, the lift is lowered by con trolling the hoist 15, until the cabin 8 reaches a first po sition relative to the platform 10, which position may be sensed by a sensor means for example arranged at the cabin 8 or at the lift shaft 14 or the platform 10. In this position, in which the cabin 8 stops, a person either in the cabin 8 or at the platform 10 needs to press a certain button or control field at the control means 27 for initiating the final "land ing process". Preferably, the person needs to hold the button pressed until the final end of this landing process. When pressing the button, a control command is given to the hoist 15 to again lift the cabin 8 for a certain distance, for ex ample for about 15 cm, so that it is positioned slightly above the first position with the feet 24 being slightly higher than the support elements 29. When this slight lifting is finished, the feet 24 are extended by a linear horizontal movement along the arrows P2 by means of the drive means 26. When the feet 24, of which for example four are arranged around the circumference of the cabin 8, reach their extended position, the hoist 15 again lowers the cabin 8 until the feet 24 are lowered on top of the support elements 29. When they rest on the support elements 29 with the whole cabin weight comprising the weight of the cabin itself and the load weight, the hoist 15 unwinds the wire 16 a little bit in or der to release the wire tension, so that the cabin 8 rests with the whole weight of the cabin itself and the load on the support elements 29. In this position the cabin platform 30 is flush with the platform 10. The cabin 8 is securely an chored in this position, as it cannot move vertically down ward, as it is blocked by the support elements 29, while it is also not possible that the cabin 8 moves upwards, as the wire 16 is not under tension.

In this final anchored rest position as shown in fig. 3 now, after releasing the button, the door wings 20, 21 may be opened as shown by the arrows P3, opening the cabin 8. Now, as shown in fig. 4, a plate 31, which is arranged in the in ner of the cabin 8 close to the door 19, and which is during the transport in a retracted upright position parallel to the door 19, as shown by the dotted line in fig. 4, can now be brought in an extended position as shown in fig. 4. In this position it bridges the gap 32 between the cabin 8 respec tively the respective side element 18 with the cabin loading door 19, which door 19 is shown by the dashed line, and the platform 10. This allows for also transporting heavy loads by rolling it from the cabin platform 30 to the tower platform 10 and vice versa. The plate 31 in this embodiment is pivotable, it can be swiv elled around a hinge 33 as shown by the arrow P4 in fig. 4. The arrangement is preferably such that the plate 31 may only be moved when the door 19 of the cabin 8 is open.

In the shown embodiment also the lift shaft 14 comprises a platform door 34, which in this illustration is already opened, so that the plate 31 may pivot from the vertical po sition to the almost horizontal position.

This movement may be performed manually, but preferably a drive means 35 is provided to automatically move the plate 31, which may also be referred to as a kick-plate. This plate movement may also be controlled by the control means 27.

The same is certainly also true for the movement of the cabin door 19 and/or the movement of the platform door 34, which may also be opened and closed automatically simply by con trolling it via the respective control means 27.

In this position the loading process may be accomplished by simply rolling the load in or out of the cabin 8, as the gap 32 is bridged by the plate 31, so that a roller transport means may be used, so that also very heavy loads may be transported. Furthermore, due to the secure anchoring of the cabin 8, the cabin 8 will not move in the vertical direction, neither downwards nor upwards, due to the respective fixation on the support elements 29 via the feet 24, which anchoring is also shown in fig. 4, and the relaxation of the wire ten sion.

Fig. 5 shows a top view of the cabin 8, which in this embodi ment has a pentagonal cross-section. It shows a top view of the roof 22 with the hoist 15. Also shown is the lift shaft 14 respectively the shaft shielding together with two beams 28 arranged at the lift shaft respectively below the respec tive platform. The lift shaft 14 respectively the shielding has certain cut-outs 36, in the area of which the respective support element 29 is arranged.

The feet 24 are shown in their extended resting position, they rest on the respective support elements 29. The resting area of a foot 24 on a support element 29 should be for exam ple 50x50 mm to transport loads of about 1000 kg having a re spective safety factor. This respective resting area may also be larger in case of higher loads needing to be transported, while also more than four feet 24 and respective support ele ments 29 may be provided.

The inner line between the cabin 8 and the lift shaft 14 de notes the inner end of the platform 10. The lift shaft 14 re spectively its shielding provides a hollow space, in which the cabin 8 moves or into which it moves when it is lowered from above or lifted from below.

As shown, the lift shaft 14 comprises the platform door 34, which is shown in the closed state in fig. 5.

Furthermore, fig. 5 shows the cabin door 19, which is also closed. Furthermore, the plate 31, which in this embodiment, as both doors 19, 34 are closed, would be in a vertical posi tion arranged at the inside or the outside of the cabin door 19, is shown in its extended position by the dashed line. It obviously bridges the gap 32 between the platform 10 and the cabin platform 30. When now both doors 19, 34 are opened, the load may be transported in the cabin 8 or may be unloaded from the cabin 8 by rolling it over the plate 31.

Fig. 6 shows a principle sketch of the lift shaft 14 with the respective beams 28 and with the respective support elements 29, on which finally the feet 28 rest. According to the per spective view shown in fig. 7, each beam 28 comprises respec tive cut-outs 37, in which the respective support element 29 here in the form of a respective block element preferably made of a polymer like POM is arranged and fixed. The respec- tive foot 28 is lowered from above, when the cabin 8 is low ered, and rests on the upper surface of the support element 29.

Another embodiment of such a "landing zone" is shown in fig. 8. It again shows the lift shaft 14 with one beam 28, which engages the respective cut-out 36 as already show in fig. 5.

A support element 29 is arranged at the beam 28 at its inner side and provides together with the part of the beam 28 ex tending in the cut-out 36 an enlarged resting area, on which the foot 24 rests.

Finally, fig. 9 shows another embodiment of a cabin 8, the setup of which is the same as described above, only the foot arrangement differs. In the embodiment shown in fig. 9 both feet 24 are arranged in a vertical position when they are in a retracted position. They are hinged to a respective support 38 arranged underneath the bottom 23 of the cabin 8, so that they can be swivelled around a horizontal axis 39. For this movement again a respective drive means 40 is provided, with each foot 24 having its own drive means 40. When it is neces sary to bring the feet 24 from the vertical retracted posi tion to the extended position, which is shown by the dashed lines in fig. 9, the respective drive means 40 pivots the re spective foot 24 around the respective axis 39, so that they swing to the side and may be lowered on the respective sup port element 29, on which they then rest as shown in fig. 9. The drive means 40 may again be an electric motor or a tele scopic cylinder or the like. The foot movement around the re spective axis 39 is shown by the respective arrows P5.

Furthermore, the plate 31 is shown in the retracted position and by the dashed line in the extended position bridging the gap 32 to the platform, for example the platform 10. In this embodiment, the plate 31 is arranged within the hollow bottom 23 and is movable in a linear movement as shown by the arrow P6. An actuator 41, again for example a spindle drive or a telescopic cylinder, is provided to push the plate 31 from the retracted position to the extended position as shown in fig. 9 and to pull it back when the transport process is fin ished.

Fig. 10 finally shows a diagram showing the respective steps of the inventive method. In step SI the cabin is vertically moved in the regular operation mode. It is either lifted or lowered, until it reaches the platform, where the loading process shall be performed in step S2. This position may be detected by respective sensor elements.

In step S3, the person in the cabin 8 or at the platform needs to press a respective button for example at the control means 27 for initiating the load landing process. This button preferably needs to be pressed throughout the whole process until its final end.

After initiating this process, the control means controls the lifting means respectively the hoist 15 to lift the cabin 8 for a certain distance, for example 10-20 cm from its first sensed position, see step S4. Also, this lifting position may be sensed, if not otherwise taken from any parameter of the hoist drive.

Next, in step S5, the feet 24 are moved from their retracted position to the extended position, which may be done manually or, preferably, automatically by the respective drive means, as shown in the previously described embodiments.

When the feet 24 reach their extended position, the control means 27 controls the hoist 15 to slowly lower the cabin 8 until the feet 24 rest on the respective support elements 29, see step S6. The hoist 15 still moves the wire 16 a little bit in order to release the wire tension completely.

In step S7 the button is released, as the cabin 8 reaches its final anchored resting position. The cabin door 19 is now opened in step S8 and also the platform door 30 is opened. Then, in step S9 the plate 31, which as mentioned may also be named as a kick-plate, is moved from the retracted position to the extended position, bridging the respective gap 32 be- tween the cabin 8 and the respective platform, so that, fi nally, in step S10 the cargo may be loaded in the cabin or from the cabin by transferring respectively rollings it over the plate 31. Although the present invention has been described in detail with reference to the preferred embodiment, the present in vention is not limited by the disclosed examples from which the skilled person is able to derive other variations without departing from the scope of the invention.