Patent Publication Number: US-2023146867-A1

Title: Lifting device for the rail-guided transportation of a vehicle

Description:
BACKGROUND OF THE INVENTION 
     The invention relates to a lifting device for the transportation of a vehicle, in particular of a trailer and/or motor vehicle, comprising a support structure which is suitable for releasable or firm connection to the vehicle, in particular to a vehicle underbody of the vehicle, and comprising at least one lifting unit which is provided to lift the vehicle in a lifting direction from a lowered vehicle position, in which the vehicle rests on a ground surface, into a completely or partially lifted vehicle position. 
     The invention also relates to a vehicle, in particular to a motor vehicle or a trailer, having a lifting device according to the invention as well as to a method for the transportation of a vehicle by means of such a lifting device. 
     The term vehicle below is understood to mean all self-driven vehicles, in particular motor vehicles such as passenger cars, trucks, tracked vehicles or other commercial vehicles, but also to any designs of trailers which do not have a separate drive. 
     Vehicles, i.e., motor vehicles or trailers, are used not only in road traffic but also off-road, in open, sometimes rough terrains, for the transport of vehicle occupants and/or goods, but also for construction or rescue work and/or for surveying of the terrain. When driving off-road, it can happen that the wheels, chains or other drive means which are usually provided for the transportation of the vehicle, for example, on a muddy or sandy ground surface, but also on ice or snow, spin due to lack of traction and can no longer transport the vehicle. It is precisely in the case of sand or mud that it can moreover happen that the wheels of the vehicle dig in, which also results in transportation no longer being possible. Another challenge when driving off-road consists in overcoming obstacles, for example, an elevation or a ledge. Depending on the height of the obstacle, driving across the obstacle is not at all possible using the conventional wheel drive, or, when an attempt to drive across is made, the vehicle underbody may bottom out, whereby the vehicle becomes stuck on the obstacle and can no longer be transported. 
     For example, from DE 26 06 399 A1, an all-terrain vehicle is known, on the bottom underside of which, that is to say on the vehicle underbody, hydraulic cylinders designed as lifting cylinders are pivotably arranged, the bearing axles of which extend transversely to the vehicle longitudinal direction. By means of the hydraulic cylinders attached on the vehicle, transportation, supporting and lifting of the vehicle are to be enabled. The control of the lifting cylinder can take place automatically or manually from the vehicle interior. However, using the described device, an actual or complete lifting of the all-terrain vehicle is not possible, as a result of which it is impossible to overcome obstacles. For transportation, the wheels must still rest on the ground surface and actually roll. The lifting cylinder is used only for pushing the vehicle, as a result of which a lateral transportation can also not be implemented. 
     A supporting steering device and a walking device for a vehicle are known from CN 103 434 498. The supporting steering device comprises a hydraulic cylinder which is pivotably connected at its lower end to a bottom plate for resting on the ground surface and at its upper end to a rotating plate arranged on the motor vehicle. Thereby, the supporting steering device, if it is not in use, can be brought in contact with the vehicle underbody, and, if necessary, it can be pivoted out, wherein the motor vehicle is lifted into a lifted position in which all four wheels lose contact with the ground surface. Subsequently, the vehicle can be rotated 180° by means of the rotating plate, for example, to perform a “U-turn.” In addition, the motor vehicle is provided with a running device which includes four separate “feet” which are supposed to enable a running movement due to the pivoting of multiple plates and arms about respective pivot axles connecting said plates and arms to one another. On the one hand, such a “walking” transportation is complicated in terms of control technology and nearly impossible to perform on an uneven or slippery ground surface. In addition, such transportation also leads to intense rocking of the motor vehicle, which decreases the comfort for the vehicle occupants. 
     Overall, the devices disclosed in the prior art are often not very reliable in use or implemented in a complicated and expensive manner, whereby in particular the only limited existing installation space on the vehicle underbody is completely occupied and/or the ground clearance is considerably influenced. In addition, the described devices are also not suitable for the transportation of heavy motor vehicles having a total weight of more than several tons, such as, for example, trucks, since the movable components, in particular the deployable or pivotable components, are not suitable for accommodating the transverse forces and bending moments occurring here. 
     Therefore, the aim of the present invention is to eliminate the disadvantages from the prior art and to create a lifting device for the transportation of a vehicle, in particular of a trailer or of motor vehicle, which in particular makes it also possible to free a heavy vehicle, in particular a heavy trailer or a heavy motor vehicle having a weight of at least several tons, such as, for example, trucks, all-terrain vehicles, tracked vehicles or other commercial vehicles or trailers, from an immobilized state, to overcome obstacles and to further increase the maneuverability overall. 
     SUMMARY OF THE INVENTION 
     The aim is achieved by a lifting device according to claim  1 , by a vehicle having a lifting device according to claim  12 , and by a method according to claim  15 . 
     A lifting device according to the invention of the type described in further detail at the beginning is characterized in that the support structure comprises one or more guide rails as well as one or more guide rods which are guided linearly in the guide rails, wherein the guide rails are indirectly or directly connected to the vehicle and the guide rods are indirectly or directly connected to at least one lifting unit, so that, in the lifted vehicle position, the guide rails, together with the vehicle, can be moved linearly relative to the ground surface, in particular in the vehicle longitudinal direction x and/or in the vehicle longitudinal direction y, and, in the lowered vehicle position, the guide rods, together with the at least one lifting unit, can be moved linearly relative to the ground surface, in particular in the vehicle longitudinal direction x and/or in the vehicle transverse direction y. 
     However, alternatively, according to the invention, the guide rods can also be indirectly or directly connected to the vehicle, and the guide rails can be indirectly or directly connected to at least one lifting unit, so that, in the lifted vehicle position, the guide rods, together with a vehicle, can be moved linearly relative the ground surface, in particular in the vehicle longitudinal direction x and/or in the vehicle transverse direction y, and, in the lowered vehicle position, the guide rails, together with the at least one lifting unit, can be moved linearly relative to the ground surface, in particular in the vehicle longitudinal direction x and/or in the vehicle transverse direction y. 
     Thus, according to the invention, a lifting device is provided, which comprises at least one lifting unit and a support structure, wherein the support structure includes one or more guide rails and guide rods guided therein. Only the guide rails (or alternatively the guide rods) are connected to the vehicle itself, preferably to its underbody or to another supporting component of the vehicle. This connection can be implemented as firm or else releasable to enable subsequent retrofitting of a vehicle or, if necessary, assembly and disassembly also in the case of repair. Likewise, an indirect connection via adapter pieces is possible. 
     The at least one lifting unit, which is driven, for example, via one or more linear actuator(s) such as hydraulic or pneumatic cylinders, electrically deployable actuators or other linear actuator principles known from the prior art, makes it possible for the vehicle to be lifted from its lowered position with its wheels, chains or other drive means on the ground surface into a completely lifted vehicle position (also operating position) in which the wheels, chains or other drive means are not in contact with the ground surface or into a partially lifted vehicle position in which a portion of the wheels, chains or other drive means is not in contact with the ground surface and for the vehicle to be put down again. For the transportation of the vehicle, the at least one lifting unit is connected to one or more guide rods (or alternatively guide rails) of the support structure. The guide rods are guided in the guide rails and, together with the at least one lifting unit, can be moved relative to the guide rails and consequently also relative the vehicle. Depending on the orientation of the support structure, a linear displacement of the lifting unit relative to the vehicle in a direction in a plane parallel to the underbody, in particular in the vehicle longitudinal direction x and/or the vehicle transverse direction y, is enabled. 
     According to the invention, in the lifted vehicle position, a relative movement between guide rail and guide rod leads to a displacement of the guide rail with the vehicle attached thereto with respect to the ground surface, while the lifting unit supported on the ground surface as well as the guide rod itself remain stationary in their original position. Vice versa, in the lowered vehicle position, in which the vehicle rests on the ground surface, a relative movement between guide rail and guide rod leads to a displacement of the guide rod, together with the lifting unit attached thereto, with respect to the ground surface, while the vehicle, together with the guide rail, remains stationary in its original position. 
     In this way, a vehicle can be transported by repeated lifting, displacement, lowering, without the need to use the separate drive of the vehicle. Advantageously, the vehicle can thus be freed from an “immobilized” position and/or moved over obstacles. Likewise advantageously, the implementation of the lifting device by guide rods guided in guide rails enables a particularly stable design, whereby the absorption of high transverse forces and/or high bending moments is enabled, so that particularly heavy vehicles having a weight of at least several tons, such as, for example, trucks, all-terrain vehicles, tracked vehicles or other commercial vehicles or trailers, can also be lifted and transported. 
     Advantageous embodiments are claimed in the dependent claims and explained in further detail below. 
     Thus, the lifting device can comprise one or more guide rails and one or guide rods which are oriented parallel to the vehicle longitudinal direction x and/or parallel to the vehicle transverse direction y, so that the guide rods are guided in the guide rails linearly in the vehicle longitudinal direction x and/or linearly in the vehicle transverse direction y. 
     Preferably, multiple, in particular two, guide rails with guide rods guided therein are indirectly or directly connected to the vehicle parallel to the vehicle longitudinal direction x and parallel to one another, so that it is possible to transport the vehicle in the vehicle longitudinal direction x, forward or backward as desired. Additionally or alternatively, multiple, in particular two, guide rails with guide rods guided therein can be indirectly or directly connected to the vehicle parallel to the vehicle transverse direction y and parallel to one another, in order to be able to laterally transport the vehicle in the vehicle transverse direction y. 
     In order to further increase the stability, it is also advantageous if, according to an embodiment, the support structure comprises at least two guide rails oriented parallel to one another with respective guide rods guided therein, wherein the guide rails are connected to one another via a rail connection piece and the guide rods are connected to one another via a rod connection piece to form a linearly extendible frame structure, and wherein the rail connection piece can be moved relative to the rod connection piece. 
     Due to the fact that two guide rails and two guide rods guided therein are each connected to one another via a rail connection piece or a rod connection piece in the manner of a frame, the ability of the support structure to absorb transverse forces and/or bending moments is further increased. The guide rods connected to one another via the rod connection piece can be deployed “in the manner of drawers” by means of linear actuators preferably located in between, which are designed, for example, as hydraulic or pneumatic cylinders, or are electrically driven. 
     Furthermore, it is advantageous for the operation if the guide rods are arranged within the guide rails and if at least two inner walls of the guide rails are designed as supporting or sliding surfaces on which the guide rods are supported when subjected to corresponding forces. 
     For example, the guide rods can be designed as completely closed or partially open pipes or supports having a rectangular, round or other suitable cross section. The guide rods guided in the interior of the guide rails have a complementary cross section and, depending on the direction of the acting forces and/or moments, they are supported on the corresponding inner walls of the guide rails. To the extent that the support structure, for example, in the lowered vehicle position, “hangs” under the vehicle, the weight of the lifting unit acts in the direction of the ground surface, while, in the lifted vehicle position, the weight of the vehicle itself acts in the direction of the ground surface. The guide rods can be supported on the upper and lower inner walls of the guide rails. The inner walls of the guide rails, which in the operating position of the vehicle are temporarily oriented, specifically parallel to the vehicle vertical axis z, laterally support the guide rods and thus prevent a tilting of the guide rods in the guide rails. At the same time, the inner walls of the guide rails are also used as sliding surfaces on which the guide rods slide when deployed or retracted. 
     As a rule, the at least one lifting unit is arranged under the support structure with respect to the vehicle vertical axis z. However, to save ground clearance, an advantageous embodiment provides that, with respect to the vehicle longitudinal direction x, at least one lifting unit is oriented longitudinally with respect to the vehicle support structure and is connected to one or more guide rods in such a way that the support structure and the at least one lifting unit are arranged in a common plane, wherein the lifting unit extends either between mutually adjacent guide rails or is arranged longitudinally with respect to one or more guide rods. 
     Due to the fact that the lifting units are arranged in a plane with the support structure, before or after or in between or next to the support structure, the overall extension of the lifting device in the vehicle vertical axis z can be reduced, for example, in order to enable an attachment on vehicles with only little ground clearance. 
     It is possible that one or more lifting units are arranged exclusively on a vehicle longitudinal side or vehicle transverse side, wherein the vehicle can then be moved along the lifting direction h from the lowered vehicle position into an only partially lifted vehicle position. 
     Due to the fact that only a portion of the vehicle is lifted and the other portion, in particular the front or rear wheels, chains or other drive means, continue to rest on the ground surface, the vehicle can be transported in the manner of a wheelbarrow by deployment of the guide rods, wherein the lifting unit is supported on one vehicle side on the ground surface, and, on the respective other vehicle side, the rails, chains or other drive means resting on the ground surface roll or slide on the ground surface. With this embodiment variant, heavier loads can be lifted and/or transported, since both the support structure and also the lifting unit support only a portion of the vehicle weight. 
     Precisely in combination with the above-described embodiment variant, the connection of the at least one lifting unit to one or more guide rods or to one or more guide rails is advantageously designed to be fixed, so that the lifting direction h is always oriented substantially parallel to the vehicle vertical axis z. 
     When the vehicle is lifted on only one vehicle longitudinal side, for example, the front or rear vehicle longitudinal side, a rotation or a pivoting of the vehicle about a transverse axis arranged on the opposite vehicle longitudinal side takes place, and the vehicle is set up at a slant or tilted. By a rigid or fixed connection of the lifting unit to the support structure, more precisely to the guide rods, the lifting direction h which is directed orthogonally to the ground surface at the beginning also “rotates” and always extends parallel to the vehicle vertical axis z, and the vehicle is lifted by translation. Such a design further increases the stability of the overall system. 
     During travel, in order not to affect the normal vehicle operation, according to an alternative design of the invention, the connection of the at least one lifting unit to one or more guide rods or to one or more guide rails can be implemented by means of an articulation, so that the at least one lifting unit can be pivoted and/or rotated between a transport position and an operating position. 
     In this design, the at least one lifting unit and the guide rods or the guide rails can additionally be connected to one another via one or more pivot cylinders. By actuation of the pivot cylinders, the at least one lifting unit can be pivoted out of the transport position, in which the at least one lifting unit is arranged, for example, in the interior, in the storage space and/or on a loading surface of the vehicle, into the operating position, in which the at least one lifting unit is oriented for lifting and lowering the vehicle, or said lifting unit can be pivoted out of the operating position into the transport position. Depending on the predetermined space conditions, it can be advantageous that the articulation axis extends along or parallel to the guide rails or guide rods or is oriented transversely or orthogonally thereto. 
     A particularly compact or space-saving transport position, whereby, for example, the arrangement of the lifting device during normal vehicle operation in a passenger car trunk space is enabled, can be implemented according to an optional variant of the invention, in that one or more components of the at least one lifting unit and/or of the support structure, in particular lifting cylinders, lifting guides, guide rails, guide rods, linear rail actuators and/or pivot cylinders, are telescopically designed, so that the at least one lifting unit can be moved linearly between the transport position and an operating position and/or the vehicle in the lifted vehicle position can be moved linearly relative to the ground surface. 
     Thus, in particular a telescopic design of the guide rails and/or of the guide rods contributes not only to the facilitated transport of the lifting device but also to the transportation of the vehicle. By a telescopic design of the lifting units, additional space can be saved in the transport position. In combination with a design in which the at least one lifting unit is connected to one or more guide rods or to one or more guide rails by means of an articulation, the at least one lifting unit can thus be first linearly deployed, for example, from a transport position, and subsequently pivoted about the articulation axis into the operating position. 
     According to an advantageous variant of the invention, in order to achieve additional stability, the at least one lifting unit comprises a stopping means which stops the at least one lifting unit in a retracted, completely deployed or partially deployed position. 
     In the case of particularly heavy loads, when the vehicle is displaced by means of the support structure, very high forces act on the completely or partially deployed lifting unit. To be able to reduce the load on the lifting unit, said lifting unit can be designed with a stopping means, for example, a toothing, which, if necessary, stops the lifting unit in the desired deployed position. 
     Finally, it is also advantageous if the support structure is designed for indirect or direct attachment to one or more longitudinal and/or cross members of the vehicle underbody of the vehicle, wherein at least one wall of the longitudinal and/or cross member connected to the support structure is designed as supporting or sliding surface on which the guide rods of the support structure are supported when subjected to corresponding forces. 
     In this design, the load-bearing capacity of the vehicle underbody, in particular of the longitudinal and/or cross members there, of the vehicle to be transported itself is to be used. For this purpose, a wall of a longitudinal and/or cross member oriented downward with respect to the vehicle vertical axis z, in the direction of the ground surface, can replace an inner wall of a guide rail as supporting and/or sliding surface. In this case, the guide rail is partially open, designed, for example, as a U-profile. In particular, this embodiment variant is suitable for forming the device with a lower overall weight, in order not to exceed, for example, acceptable loads of the vehicle. 
     The invention therefore also relates to a vehicle, in particular to a motor vehicle or to a trailer, having a lifting device according to one of the above-described embodiment variants, wherein the one or more guide rails of the support structure are indirectly or directly connected firmly or releasably to the vehicle, wherein an attachment on the vehicle underbody and/or on the vehicle roof and/or to a vehicle loading surface and/or on the vehicle frame and/or on the vehicle body takes place. 
     Preferably, the lifting device is connected firmly or releasably to supporting components of the vehicle, although it can nonetheless be positioned in the desired position, in particular under the vehicle. Individual components of the device, in particular drive elements and/or fuel tanks but also an associated open-loop and/or closed-loop control device can also be accommodated within a storage space, a passenger compartment or on a loading surface of the vehicle. 
     In an advantageous embodiment, the one or more guide rails of the support structure are attached to one or more longitudinal members and/or cross members of the vehicle underbody of the vehicle, wherein at least one wall of the longitudinal member and/or cross member connected to the support structure is designed as supporting or sliding surface on which the guide rods of the support structure are supported when subjected to corresponding forces. 
     In the case in which the longitudinal members and/or cross members do not comprise a flat extending sliding surface along which the guide rods can slide, an adapter structure can advantageously be provided, which is arranged between the longitudinal members and/or cross members and the guide rods or the guide rails. The side of the adapter structure facing the guide rods or the guide rails preferably comprises a straight and flat sliding surface; the remaining sides can be supported on the longitudinal members and/or cross members and are advantageously designed to be complementary to their course. 
     In order not to affect the normal vehicle operation, it is advantageous that the at least one lifting unit in a transport position is arranged in a storage space and/or on a loading surface and/or on the roof and/or on the engine hood and/or on the trunk lid of the vehicle and/or on the vehicle front and/or on the vehicle rear and/or laterally on the vehicle. 
     In a development, the at least one lifting unit can be moved and/or pivoted by means of the support structure between the transport position and an operating position for the transportation of the vehicle, wherein one or more components of the at least one lifting unit and/or of the support structure are telescopically designed and/or the at least one lifting unit is pivotably or rotatably connected via an articulation to the support structure. In an arrangement of the at least one lifting unit on the vehicle front and/or on the vehicle rear, the articulation makes it possible to pivot the at least one lifting unit in in the transport position in order to avoid obstruction of the view. 
     Finally, the aim of the invention formulated at the beginning is also achieved by a method for the transportation of a vehicle, in particular of a motor vehicle or trailer, by means of a lifting device according to one of the above-described embodiments. 
     Here, the vehicle is lifted by means of at least one lifting unit of the lifting device in a lifting direction from a lowered vehicle position, in which the vehicle rests on the ground surface, into a completely or partially lifted vehicle position, is displaced in the lifted vehicle position relative to the ground surface by means of mutually movable guide rails and guide rods of a support structure of the lifting device, and is lowered from the completely or partially lifted vehicle position into the lowered vehicle position by means of the at least one lifting unit of the lifting device. 
     Optionally, the at least one lifting unit can be deployed by means of the support structure from a transport position into an operating position and/or be pivoted out of the transport position into the operating position by means of an articulation connecting the at least one lifting unit and the support structure. After the transportation of the vehicle has taken place, the at least one lifting unit can naturally be correspondingly pivoted in and/or retracted from the operating position into the transport position. 
     Additional details, features, (sub) combinations of features, advantages and effects on the basis of the invention result from the following description of preferred embodiment examples of the invention and the drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
         FIG.  1    is a diagrammatic perspective representation of a first exemplary embodiment of the lifting device according to the invention with two guide rails, two guide rods and two lifting units in a completely retracted position, 
         FIG.  2    is a diagrammatic perspective representation of the first embodiment of  FIG.  1    with the guide rails and guide rods as well as the lifting units in a completely deployed position, 
         FIG.  2   a    is a diagrammatic perspective representation of an exemplary stopping means which is provided as optional component of the lifting unit according to  FIGS.  1  and  2   , 
         FIG.  2   b    is a diagrammatic perspective representation of an enlarged detail of the stopping means of  FIG.  2     a,    
         FIG.  3    is a diagrammatic sketch of an exemplary movement course of the lifting device for the transportation of a vehicle, 
         FIG.  4    is a diagrammatic perspective representation of a second exemplary embodiment of the lifting device according to the invention, wherein the lifting unit is arranged between every two adjacent guide rails, 
         FIG.  5    is a diagrammatic perspective representation of a third exemplary embodiment of the lifting device according to the invention for the transportation of a vehicle in a vehicle longitudinal direction and in a vehicle transverse direction, 
         FIG.  6    is a diagrammatic perspective representation of a fourth exemplary embodiment of the lifting device according to the invention having a total of four lifting units for completely lifting a vehicle as well as for the transportation of the vehicle in a vehicle longitudinal direction and in a vehicle transverse direction, 
         FIG.  7    is a diagrammatic perspective representation of a fifth exemplary embodiment of the lifting device according to the invention, wherein the support structure is attached to transverse and longitudinal members of the vehicle, 
         FIG.  7   a    is a diagrammatic partial section of an exemplary embodiment of an adapter piece, 
         FIG.  8    is a diagrammatic perspective representation of a sixth exemplary embodiment of the lifting device according to the invention, which is attached to a trailer, 
         FIG.  9    is a diagrammatic perspective representation of a first embodiment of a traction foot on a lower section of a lifting unit, 
         FIG.  10    is a diagrammatic perspective representation of a second embodiment of a traction foot on a lower section of a lifting unit, 
         FIG.  11    is a diagrammatic perspective representation of a third embodiment of a traction foot on a lower section of a lifting unit, 
         FIG.  12    is a diagrammatic perspective representation of a seventh exemplary embodiment of the lifting device according to the invention with two vertical lifting units, 
         FIG.  13    a is diagrammatic perspective representation of an eighth exemplary embodiment of the lifting device according to the invention with two vertical lifting units which can be pivoted and/or rotated about respective articulation axes, 
         FIG.  14    is a diagrammatic perspective representation of a ninth exemplary embodiment of the lifting device according to the invention with two pivotable and/or rotatable vertical lifting units, wherein respective articulation axes are oriented parallel to the support structure, and in 
         FIG.  15    is a diagrammatic perspective representation of a tenth exemplary embodiment of the lifting device according to the invention in a transport position. 
     
    
    
     The figures are merely exemplary in nature and used only for the understanding of the invention. Identical elements are always provided with identical reference numerals, and for this reason, as a rule, they are also described only once. The represented embodiment variants are mostly symmetrical with respect to their longitudinal axis and partially symmetrical with respect to their transverse axis. For clarity, elements which are mirrored on these axes in the figures are always marked only once with a reference numeral. 
     DETAILED DESCRIPTION OF THE INVENTION 
     In  FIG.  1   , a diagrammatic perspective representation of a first exemplary embodiment of the lifting device  10  according to the invention, having a support structure  100  and two lifting units  200 , is shown. The representation shows the lifting device  10  from below, i.e., looking from the ground surface  400  in the direction of the vehicle underbody. The two lifting units  200  are here associated with the same vehicle longitudinal side. Both the support structure  100  and also the lifting units  200  are in a completely retracted position. The support structure  100  comprises two guide rails  110  running parallel, which are connected to one another at a mutual distance to one another via a rail connection piece  130 . In the guide rails  110 , designed here as rectangular pipes, in each case a guide rod  120  comprising a complementary cross section and here also rectangular cross section is movably mounted. The guide rods  120  are connected to one another at a mutual distance in the region of a connection section  121  (also in the completely retracted position) protruding from the guide rails  110  via a rod connection piece  140 , so that the support structure  100  overall is designed in the manner of a frame. Preferably, the guide rails  110  are oriented in the vehicle longitudinal direction x of the vehicle  500  and attached to the vehicle  500 , in particular to its underbody and/or preferably to a supporting component of the vehicle  500 , so that the connection sites between guide rails  110  and vehicle  500  can support the portion of the vehicle weight taken up by the guide rails  110 . If no supporting component of the vehicle  500  is available at the connection sites of the guide rails  110 , the guide rails  110  can be connected to a support adapter (not represented) which is part of the lifting device  10 . 
     Between the guide rails  110  and oriented parallel thereto at least one linear rail actuator is provided, in the exemplary embodiment variant three linear rail actuators  150  being provided, one end of which is supported on the rail connection piece  130  and the other end of which is supported on the rod connection piece  140 . The linear rail actuators  150  can be designed, for example, as hydraulic cylinders, pneumatic cylinders, electrolinear units, etc., and they are preferably actuated by the operator or by an open-loop and/or closed-loop control unit in order to move the support structure  100  from the completely retracted position shown here into a partially or completely deployed position (see  FIG.  2   ). 
     On the respective connection section  121  of the guide rods  120 , in each case a lifting unit  200  is arranged, which is provided for lifting and lowering the vehicle  500  from a lowered vehicle position into a lifted vehicle position and vice versa. The lifting unit  200  substantially includes a lifting support  211  which is arranged on an upper section  210  of the lifting unit  200 , which faces the vehicle  500 , as well as a pivotable articulated traction foot  300  which is arranged on a lower section  220  of the lifting unit  200 , which faces the ground surface  400 . For deploying the lifting unit  200 , one or more linear actuators  230  are supported on the lifting support  211  and on the traction foot  300 . In the representation shown here, in each case two external linear actuators  230  are pivotably attached to the two longitudinal-side ends of the lifting support  211  and they are guided in each case by a linear guide  231  lying in between. The linear guides  231  are used for absorbing transverse forces and/or bending moments which could and can damage the linear actuators  230 , and, like the guide rails  110  as well, can have different cross-sectional shapes, in particular a rectangular, circular, oval, T-shaped, U-shaped, double T-shaped, cross-sectional shape, etc. In the lower section  220  of the lifting unit  200 , the traction foot  300  is pivotably articulated to the linear actuators  230 , in order to be able to compensate for irregularities and/or gradients of the ground surface  400 . In order to increase the friction between ground surface  400  and traction foot  300 , the latter has a traction profile  310 . In the completely retracted position of the lifting unit  200  shown here, lifting support  211 , linear actuators  230  as well as traction foot  300  are oriented parallel to the guide rails  110  and to the guide rods  120  of the support structure  100 , whereby the necessary installation space is reduced, in particular under the vehicle  500 . 
       FIG.  2    shows a diagrammatic perspective representation of the first embodiment of  FIG.  1   , viewed from the top, i.e., from the direction of the vehicle  500  in the direction of the ground surface  400 . Both the support structure  100  and also the two lifting units  200  are here shown in a completely deployed position. Since in this embodiment the two lifting units  200  are provided on only one vehicle longitudinal side, the vehicle  500 , which is not represented, is in a partially lifted vehicle position, i.e., in particular the wheels, chains or other drive means of the vehicle  500  arranged on one longitudinal side “hang in the air,” while the wheels, chains or other drive means of the vehicle  500  arranged on the other longitudinal side, continue to rest on the ground surface  400 . The lifting direction h itself extends orthogonally with respect to the lifting support  211  and parallel to the vehicle vertical axis z. 
       FIGS.  2   a  and  2   b    each show a diagrammatic perspective representation of an exemplary stopping means  260  which is provided as optional component of the lifting unit  200  according to  FIGS.  1  and  2   , wherein  FIG.  2   b    represents an enlarged detail of  FIG.  2     a.    
     In order to completely stop the lifting unit  200  in a completely or partially deployed position, the linear guide  231  arranged between the linear actuators  230  can be designed with a stopping means  260 . The stopping means  260  is designed here, for example, as toothing  261  which extends along a guide rod of the linear guide  231 . A tooth anchor  262  having a counter-toothing designed to complementarily fit the toothing  261  is connected to the guide rail of the linear guide  231 . In order to move the tooth anchor  262  into a position engaging in the toothing  261  and thus be able to stop the lifting unit  200  in the desired deployed position, if necessary, an actuator  263  or an electromagnet is connected to the tooth anchor  262  in order to pivot and/or to perform linear movements. Alternatively, the toothing  261  on the linear guide  231  and/or the counter-toothing on the tooth anchor  262  can be dispensed with, and a locking of the lifting unit alone can be implemented via static friction. In this case, it is also conceivable to attach the tooth anchor  262  alternatively or additionally to one or more linear actuators  230 . 
     An exemplary movement course for the transportation of the vehicle  500 , if said vehicle has become stuck, for example, on an unpaved ground surface, is diagrammatically sketched in  FIG.  3   . First, the lifting units  200 , more precisely the linear actuators  230  thereof, are activated, whereby the traction feet  300  are moved by translation in the direction of the ground surface  400 . Here, the two traction feet  300  can either be deployed at the same speed, or else each traction foot  300  can be individually actuated by the operator or a connected open-loop and/or closed-loop control device with stored control electronics, in order to adjust the respective lifting path to the constitution of the ground surface  400 . The vehicle  500  is in the lowered vehicle position and rests completely on the ground surface  400  (position  3   a ). The lifting unit  200  with the linear actuators  230  arranged between the lifting support  211  and the traction foot  300  is here indicated purely diagrammatically and it can be designed in any embodiment, in particular in any embodiment described above or below. As soon as the traction feet  300  rest on the ground surface  400  and the lifting units  200  are deployed further, they start to lift the vehicle  500  in a lifting direction h via the guide rods  120  which are supported on the inner walls or contact and/or sliding surfaces of the guide rails  110  into unilateral or partially lifted vehicle position. The lifting direction h here always extends translationally and parallel to the vehicle vertical axis z (position  3   b ). During the lifting, it can be advantageous to retain the vehicle  500  in a horizontal orientation with respect to the vehicle transverse direction y in order to reduce the risk of tipping over. For this reason, the linear actuators  230  which are part of the two traction feet  300  can be separately actuated by the operator. Alternatively, a sensor system can also be provided as component of the lifting device  10 , which automatically orients the vehicle  500  via a control electronics during the lifting. After the vehicle  500  has been lifted, the support device  100  is deployed, in that the linear rail actuators  150  are activated by the operator or the open-loop and/or closed-loop control device, whereby the guide rods  120  are shifted out of the guide rails  110 . Due to the traction profile  310 , sufficient friction is present between the ground surface  400  and the traction feet  300 , so that the latter cannot be moved relative to the ground surface  400 . Instead, the vehicle  500  is moved in a transportation direction f by a desired length corresponding to the length by which the guide rods  120  are deployed out of the guide rails  110  (position  3   c ,  FIG.  2   ). Preferably, the wheels, chains and other drive means of the vehicle  500  still resting on the ground surface  400  roll on said ground surface, whereby the force expenditure for the transportation of the vehicle  500  decreases. Finally, the vehicle  500  is first lowered again by retracting the lifting unit  200  (position  3   d ), and the lifting device  10  is transferred into its completely retracted position ( FIG.  1   ) by retraction of the support structure  100  by means of the linear rail actuators  150 . 
     The described process can be repeated as many times as desired in order to negotiate the desired distance. By reversing the movement course, the transportation direction f can also be reversed. Alternatively, it is also conceivable to design the vehicle with lifting units on both longitudinal sides or transverse sides, whereby said vehicle can be transferred into a completely lifted vehicle position. In order to establish maximum friction between traction foot  300  and ground surface  400 , it is appropriate to position the lifting units  200  in the vicinity of or as much as possible under the center of gravity of the vehicle. 
       FIG.  4    shows a diagrammatic perspective representation of a second exemplary embodiment of the lifting device  10  according to the invention, in which in each case one lifting unit  200  is arranged between every two adjacent guide rails  110 . Compared to the embodiment described in  FIGS.  1  and  2   , the variant shown here consequently differs in that the lifting device  10  overall comprises four guide rails  110  oriented parallel to one another each having guide rods  120  guided therein. The lifting unit  200  arranged between two adjacent guide rails  110  is indirectly connected via a flat U-shaped connection piece  160  to the guide rods  120 , more precisely to the connection section  121  thereof. The U-shaped connection piece  160  is preferably attached on the side of the guide rods  120  facing the vehicle bottom, in order to make room for the accommodation of the lifting unit  200  under the guide rods  120 . The overall extension of the U-shaped connection piece  160 , which extends in vehicle vertical direction z, and of the lifting unit  200  attached thereto, should not exceed the overall extension of the support structure  100 , so that this embodiment variant has a particularly low ground clearance requirement. In order to stabilize the guide rails  110  and the guide rods  120 , the rail connection piece  130  and/or the rod connection piece  140  alternatively can also connect (differently from the way it is shown here) all the guide rails  110  and/or all the guide rods  120  to one another. Furthermore, in an alternative variant not shown here, the U-shaped connection piece  160  can also be connected to a longitudinal side of the two guide rods  120  according to the first embodiment according to  FIG.  1    and extend the guide rods  120  in the manner of a fork. The two lifting units  200  are then each arranged inside the “fork” and in a plane with the support structure  100 . 
     In  FIG.  5   , a diagrammatic perspective representation of a third exemplary embodiment of the lifting device  10  according to the invention is shown. This embodiment enables a transportation of the vehicle  500  not only in the vehicle longitudinal direction x but also in the vehicle transverse direction y. The support structure  100 , as also in the previously described designs, is connected to the vehicle  500  via the longitudinal guide rails  110   a  oriented in the vehicle longitudinal direction x. In the longitudinal guide rails  110 , longitudinal guide rods  120   a  are mounted and connected to with a rod connection piece  140 . In addition, on the rod connection piece  140 , a subsystem for the transverse movement  170  is articulated by means of a pivot bearing  171  which can rotate in an x-y plane. On the rotatable side of the pivot bearing  171 , one or more transverse guide rails  110   b  are attached, in which a respective individual transverse guide rod  120   b  is mounted, which can be deployed or retracted from both sides of the transverse guide rail  110   b . In this variant, two lifting units  200  are attached to the transverse guide rod  120   b  and oriented in the vehicle longitudinal direction x. 
     For the lateral deployment, i.e., in the vehicle transverse direction y, of the transverse guide rod  120   b  out of the transverse guide rails  110   b , one or more transverse linear actuators  172  are supported with one end thereof on the transverse guide rail  110   b  and with the other end thereof on the transverse guide rod  120   b  and are designed, for example, as hydraulic cylinders, pneumatic cylinders, electrolinear units or according to another linear drive principle. By positioning of all the components necessary for deployment or retraction of the transverse guide rod  120   b  in the vehicle transverse direction y, any states of the longitudinal-side deployment can be combined independently of one another with any states of the transverse-side deployment. In the lifted vehicle position, during the transverse-side displacement of the vehicle  500 , the subsystem for the transverse movement  170  must be rotatable with respect to the longitudinal guide rails  110   a , in order to avoid material stresses which otherwise occur and which could lead possibly to destruction of components. In order to ensure that a rotation angle of the support structure  100  with respect to the subsystem for the transverse movement  170  returns to its starting state after the vehicle  500  has been transported, it is possible, for example, to provide pivoting linear actuators  173  and/or pivot springs  174  designed as traction-thrust springs and/or a pivot motor  175  indirectly or directly connected as rotating motor to the pivot bearing  171 . In the representation, all three variants are shown purely as examples, wherein, in the practical implementation, only one of the variants should be used. In the embodiment shown according to  FIG.  5   , the subsystem for the transverse movement  170  is indirectly connected via the support structure  100  to the vehicle  500 . However, it is also conceivable to connect the subsystem for the transverse movement  170  directly to the vehicle  500  and to connect the support structure  100  indirectly via the subsystem for the transverse movement  170  (as represented in  FIG.  6   ). 
       FIG.  6    shows a diagrammatic perspective representation of a fourth exemplary embodiment of the lifting device  10  according to the invention, having a total of four lifting units  200  which are distributed for the complete lifting of the vehicle  500  over the two longitudinal sides of the vehicle  500 . In addition, on the two longitudinal sides of the vehicle  500 , a respective subsystem for the transverse movement  170  is also provided, so that the vehicle  500 , in a completely lifted vehicle position, can be moved both in a vehicle longitudinal direction x and also in a vehicle transverse direction y. In principle, a lateral transportation occurs, i.e., in vehicle transverse direction y according to the embodiment variant described previously based on  FIG.  5   . However, based on the fact that the vehicle  500  is in a completely lifted vehicle position, an angle compensation between the support structure  100  and the subsystem for the transverse movement  170  is not necessary, and therefore the corresponding components such as pivot bearing  171 , etc., can be dispensed with. 
     A diagrammatic perspective representation of a fifth exemplary embodiment of the lifting device  10  according to the invention can be obtained from  FIG.  7   . Here, the support structure  100  is attached to longitudinal members  510  and cross members  520  of the vehicle  500  itself, whereby the carrying capacity of the vehicle itself is exploited, so that the support structure  100  can correspondingly be designed to be smaller and lighter. For example, the cross-sectional area of both the guide rails  110  and also of the guide rods  120  can be selected to be smaller. For example, from the representation, a support structure can be obtained, as is used in some vehicle types such as, for example, trucks or all-terrain vehicles. In this embodiment, for example, the guide rails  110  are directly connected to the support structure, in particular to the cross members  520  of the vehicle  500 . Two lifting units  200  are each arranged laterally, parallel to the guide rails  110 , wherein the respective lifting supports  211  thereof are connected via L-shaped connection pieces  180  to the guide rods  120  guided in the guide rails  110 . Via sliding elements  190 , the lifting units  200  slide during the deployment or retraction of the support structure  100 , each in contact along the longitudinal members  510  of the vehicle  500 , and they are supported on said longitudinal members, whereby the weight of the vehicle  500  in the lifted vehicle position rests on the support structure itself of the vehicle. The side of the longitudinal member  510  facing the ground surface is thus used as supporting and/or sliding surface, here indirectly via the lifting support  211  of the lifting units  200 , for the guide rods  120 . The sliding elements  190  include a material which, in combination with its friction partner, has a low friction and wear value. Advantageously, on the longitudinal members  510  and/or cross members  520  of the vehicle  500 , an adapter structure  191  can be attached (see  FIG.  7   a   ), of which the side facing the sliding elements  190  has a straight and flat sliding surface, and the other sides of which are supported on the structure of the vehicle underbody and/or its supporting structure. Naturally, it is also conceivable to connect the sliding elements  190  firmly to the longitudinal members  510  and/or any adapter structure  191 . 
     Since the supporting structure of the vehicle  500  almost completely absorbs forces and moments transmitted by the lifting units  200 , the guide rails  110  and the guide rods  120 , in the case of identical deployment path or displacement of the vehicle  500 , can be designed to be shorter than in the previously described embodiments. However, in order to prevent, in the deployed state of the guide rods  120  out of the guide rails  110  and with simultaneously lowered vehicle  500  resting on the ground surface  400 , the guide rods  120  from tipping over laterally in transverse direction y and/or downward in the direction of the ground surface  400 , the guide rods  120  each comprise rail extensions  111  which are open upward in the direction of the vehicle underbody. The upper side of the rail extensions  111 , directed in the direction of the vehicle underbody, has no guiding and/or supporting function; instead the lifting supports  211  are supported on the lower sides of the longitudinal member  510  of the vehicle  500 , which face the ground surface  400 . 
     From  FIG.  7   a    a diagrammatic partial section of an embodiment variant of an adapter structure  191  can be obtained. The adapter structure  191  is here arranged, in an example, between the longitudinal members  510  and/or cross members  520  of the vehicle  500  and between the guide rails  110  and/or the guide rods  120 . The side of the adapter structure  191  associated with the vehicle  500  advantageously has a design which is complementary (in the present example step-like) to the longitudinal members  510  and/or cross members  520 . Optionally, as already previously described, sliding elements  190  (see  FIG.  7   ) can be provided in order to reduce the friction coefficients. 
     In  FIG.  8   , a diagrammatic perspective representation of a sixth exemplary embodiment of the lifting device  10  according to the invention, which is attached to a vehicle  500 , here a tractor/trailer combination, is represented. Naturally, all the other previously described embodiments can be connected without change to a trailer on its own. In principle, a trailer, due to the additional weight and since the trailer does not have a separate drive axle, decreases the maneuverability of a vehicle  500  which in the present case is designed as a combination of a tractor and one or more trailers. However, the embodiment shown in this representation exploits some peculiarities of the trailer. Thus, the drawbar  530  of the trailer, as support structure  100 , can be designed to be extendible and correspondingly comprises one or more guide rails  110  (in the present representation, one guide rail), with guide rods  120  mounted therein. The connection section  121  of the guide rod  120  is indirectly connected to the traction vehicle via the trailer coupling  540  and/or it is itself designed as trailer coupling  540 . The guide rail  110  is connected to the trailer itself, so that a relative movement caused by one or more linear actuators  150 , in this case two linear actuators, between guide rail  110  and guide rod  120  leads to a lengthening of the drawbar  530 . Two lifting units  200  oriented parallel to the vehicle longitudinal direction x, according to the previously described embodiment variants, are directly and firmly attached to the trailer, preferably in the vicinity of its center of gravity, i.e., the lifting units are indirectly connected via the trailer to the guide rail  110  and can be deployed together with the trailer via the extendible drawbar  530  relative to the tractor in the vehicle longitudinal direction x. An additional lifting unit  200 , oriented parallel to the vehicle transverse direction y, is arranged on the connection section  121  of the guide rod  120  still before the trailer coupling  540 . The transversely oriented lifting unit  200  is designed as vertical lifting unit  201  with a lifting linear actuator  240  which is preferably arranged orthogonally to the guide rods  120  and held by or supported on a corresponding recess  250  in the connection section  121  of the guide rod  120 . The lifting linear actuator  240  can be designed, for example, as a hydraulic cylinder or pneumatic cylinder or electrolifting unit, etc., and it lifts the connection section  121  of the guide rod  120  in its deployment direction. In other words, the lifting linear actuator  240  itself is always oriented along the lifting direction h. 
     In order to transfer a self-driving traction vehicle back into a position allowing maneuverability, according to the sixth embodiment in  FIG.  8   , the trailer is first lifted by means of the longitudinally oriented lifting units  200 . Subsequently, via the linear actuators  150 , the guide rod  120 , connected to the tractor via the trailer coupling, is moved out of the guide rail  110 , wherein the tractor is moved in the vehicle longitudinal direction x, while the trailer in the lifted state remains fixed relative to the ground surface  400 . After the tractor has been displaced in the vehicle longitudinal direction x, the trailer is lowered again by retraction of the lifting units  200 , and the guide rod  110  is reinserted into the guide rail  120 , whereby, in the ideal case, the trailer is pulled at the same time in the direction of the tractor. If the trailer itself is stuck immobilized in the ground surface  400 , the transversely oriented lifting unit  200  can additionally be activated, whereby its traction foot  300  is supported on the ground surface  400 , so that the stability of the tractor is increased while the trailer is pulled. 
     The lifting units  200  described in the different embodiments can each also be designed as a more simply constructed vertical lifting unit, if the installation space available allows this. The use of other lifting units  200  known from the prior art, such as, for example, a scissor-type jack, is naturally also conceivable. In the following paragraphs, different exemplary designs of a traction foot  300  are explained in greater detail. Each of the explained designs can be combined both with a lifting unit  200  according to one of embodiment examples 1 to 5 and also with a lifting unit  200 , designed as a vertical lifting unit according to embodiment example 6 or even with another lifting unit  200  known from the prior art, such as, for example, a scissor-type jack. 
     A diagrammatic perspective representation of a first exemplary embodiment of a traction foot  300 , which is articulated to a lower section  220  of a lifting unit  200  designed as vertical lifting unit, can be obtained from  FIG.  9   . Thus, the traction foot  300  can be designed with one or more ground drills, here two ground drills  320 , which are driven via connected drill motors  321 . The drill motors  321  in turn are attached to a holding device  322  and connected thereby to one another. The holding device  322  is attached on an end of a contact pressure actuator  323  which can be designed as hydraulic cylinder, pneumatic cylinder or electrolifting unit, etc. The other end of the contact pressure actuator  323  is supported on holding elements  324  which in turn are connected to the traction foot  300 . Via the contact pressure actuator  323 , the required contact pressure is generated during the rotation of the ground drills  320 , so that, for the purpose of maximizing the traction between traction foot  300  and ground surface  400 , said ground drills are drilled into the latter. The traction foot  300  comprises a passage opening  325  for the passage of the ground drill  320 . By a combination of ground drills  320  and traction profile  310 , a particularly high stability of the lifting unit  200  on almost any ground surface  400  can be achieved. 
     A second exemplary embodiment of a traction foot  300  is shown in  FIG.  10    in a diagrammatic perspective representation. In principle, the second embodiment of the traction foot  300  is constructed similarly to the previously described first embodiment. However, instead of the ground drill  320 , hammering traction plates  330  are here attached to the holding device  322 . Preferably, the hammering traction plates  330  are driven by hammering actuators  331 . The hammering actuators  331  act in the manner of electrohammers or hydraulic hammers or pressurized air hammers known from the prior art and drive the traction plates  330  out into the ground surface  400  in order to increase the traction of the traction foot  300  via the action of the traction profile  310 . 
     Finally, from  FIG.  11   , a diagrammatic perspective representation of a third exemplary embodiment of a traction foot  300  on a lower section  220  of a lifting unit  200  can be obtained. The embodiment shown here is particularly suitable for soft ground surfaces  400 , in that a traction foot  300  is designed with so-called cryonozzles  340 , the outlet openings of which are provided on the side of the traction foot  300  facing the ground surface  400 . If desired, if the traction foot  300  rests on the ground surface  400 , the outflow of the cryogen from the outlet openings can be started by the operator. Due to the penetration of the cryogen into the soft ground surface  400 , the latter is solidified or even frozen, whereby the traction foot  300  has a better foothold. The cryogen can be stored in a cryotank  341  attached to the traction foot  300  or can be supplied from another reservoir via pipe and/or hose connection to the cryonozzles  340 . As cryogen, for example, cold and/or liquefied air, other cold and/or liquefied gases, solid carbon dioxide as well as other cryogens known from the prior art are suitable. 
     From  FIGS.  12  to  15   , respective diagrammatic perspective representations of different exemplary designs of the lifting device  10  can be obtained, in which the lifting units  200  are each designed as vertical lifting units  201  oriented orthogonally or nearly orthogonally to the support structure  100  and pointing in the operating position in the direction of the ground surface  400 . 
     Thus,  FIG.  12    shows a lifting device  10  having two vertical lifting units  201  each comprising a lifting cylinder  202  which is flanked by two lifting guides  203  extending parallel thereto. The lifting guides  203 , together with the lifting cylinder  202 , can deploy preferably perpendicularly opposite the lifting direction h in the direction of the ground surface  400  and absorb the bending moments occurring during the lifting and displacement of the vehicle  500 . The vertical lifting units  201  are each indirectly or directly connected via the first end thereof to the support structure  100 , for example, the guide rods  120 , and, at the second end thereof, they comprise a respective traction foot  300  supported on the ground surface  400 . Between the two vertical lifting units  201  and/or between a respective vertical lifting unit  201  and the support structure  100 , stiffening struts  204 , here running diagonally, can be arranged, in order to absorb the forces occurring during the transportation of the vehicle  500 . The positioning of the stiffening struts  204  is represented here as an example; depending on the concrete design of the lifting device  10 , the stiffening struts  204  can also be provided in any other positions for optimal force absorption. As desired, the support structure  100  can be attached on the underbody, on the loading surface, on the vehicle roof, on the engine hood, in the storage space or in other suitable positions of a vehicle  500 , which is not represented here. The vertical lifting units  201  are preferably arranged on the rear, on the front or laterally on the vehicle  500 . 
     The lifting device  10  represented in  FIG.  13    substantially corresponds to the previously described embodiment according to  FIG.  12   . In addition, between a respective vertical lifting unit  201  and the support structure  100  or the guide rods  120 , a respective articulation  270  is arranged. By means of respective pivot cylinders  271 , the first end of which is attached indirectly or directly to the support structure  100 , in particular to the guide rods  120 , and the second end of which is indirectly or directly connected to the vertical lifting unit  201 , the vertical lifting units can be pivoted or rotated about the respective articulation axis between a transport position and the operating position shown here. The articulation axis is here directed orthogonally to the course of the guide rods  120  and the guide rails  110 , so that the vertical lifting units  201  in the transport position are oriented parallel thereto and in the operating position orthogonally thereto. 
     An alternative embodiment of the lifting device  10 , in which the articulation axes of two articulations  270  are oriented parallel and the pivoting cylinders  271  are oriented orthogonally to the guide rods  120  and the guide rails  110 , can be obtained from  FIG.  14    in a pivoted out operating position. So that the vertical lifting units  201  do not collide with one another during the pivoting in or during the rotation about the articulation axes, it is advantageous to design one vertical lifting unit or both vertical lifting units  201  with an extension  205  accommodating the respective articulation  270 . When one extension  205  is used for each vertical lifting unit  201 , said extensions should have mutually differing lengths. In the pivoted-in transport position, not shown here, the vertical lifting units  201  are then arranged correspondingly one above the other. Alternatively, it is also conceivable to arrange the vertical lifting units  201  mutually offset in the longitudinal direction of the guide rods  120 . For the absorption of bending moments, the vertical lifting units  201  can have a respective stiffener  206  which is then connected to the support structure  100  via its own second articulation  272 , arranged in alignment with the articulation  270 , so that pivoting and/or rotation about the same articulation axis is/are possible. 
     Alternatively, but not represented in the figures, an additional embodiment is conceivable, in which the respective vertical lifting units  201  are mounted so that they can be pivoted and/or rotated about an articulation axis of respective articulations  270 , which is oriented orthogonally to the guide rods  120  and which protrudes from a plane predetermined by the support structure  100  or “stands” perpendicularly on the guide rods  120 . 
     In all the previously described embodiments of the lifting device  10 , it can be advantageous to telescopically design one or more components of the lifting units  200 , of the vertical lifting units  201  and/or of the support structure  100 , so that the lifting device  10 , in particular the lifting units  200  and/or the vertical lifting units  201  can (also) be linearly moved between a compact or space-saving transport position and an operating position. 
     Such an exemplary embodiment, in which the lifting device  10  is shown in a pivoted-in and retracted transport position, can be obtained from  FIG.  15   . The here single vertical lifting unit  201  is pivotably and/or rotatably connected via articulations  270  to the guide rods  120  of the support structure  100 . The lifting cylinder  202  and the lifting guides  203  of the vertical lifting unit  201  as well as the guide rods  120 , the guide rails  110  and the linear rail actuators  150  of the support structure  100  are moreover telescopically designed, i.e., they can be coaxially retracted or deployed, whereby, for example, the guide rods  120  at the same time also can perform the function of a guide rail  110 . If necessary, the pivoting cylinders  271  can also be telescopically designed. The embodiment shown enables a particularly space-saving arrangement of the lifting device  10  in the transport position shown, in order to arrange or install the lifting device  10  also in particularly tight installation spaces, for example, in the trunk space of a passenger car. In principle, for all the previously described embodiments, the embodiment-specific features can be combined with one another if technically feasible. For example, each of the described embodiments can be implemented with two or four or another desired number of lifting units  200 ,  201 . The different design of the exemplary traction feet  300  or lifting units  200 ,  201  can be combined with any embodiments. Advantageously, the positioning of the lifting units  200 ,  201  with respect to the support structure  100  and/or the attachment of the support structure  100  on the vehicle  500  can be adapted to the respective space specifications of the vehicle  500 . 
     LIST OF REFERENCE NUMERALS 
     
         
         
           
               10  Lifting device 
               100  Support structure 
               110  Guide rail 
               110   a  Longitudinal guide rail 
               110   b  Transverse guide rail 
               111  Rail extensions 
               120  Guide rod 
               121  Connection section of the guide rods 
               120   a  Longitudinal guide rod 
               120   b  Transverse guide rod 
               130  Rail connection piece 
               140  Rod connection piece 
               150  Linear rail actuator 
               160  U-shaped connection piece 
               170  Subsystem for transverse movement 
               171  Pivot bearing 
               172  Transverse linear actuators 
               173  Pivoting linear actuators 
               174  Pivot springs 
               175  Pivot motor 
               180  L-shaped connection piece 
               190  Sliding element 
               191  Adapter structure 
               200  Lifting unit 
               201  Vertical lifting unit 
               202  Lifting cylinder 
               203  Lifting guide 
               204  Stiffening struts 
               205  Extension 
               206  Stiffener 
               210  Upper section of the lifting unit 
               211  Lifting support 
               220  Lower section of the lifting unit 
               230  Linear actuator 
               231  Linear guide 
               240  Lifting linear actuator 
               250  Recess 
               260  Stopping means 
               261  Toothing 
               262  Tooth anchor 
               263  Actuator 
               270  Articulation 
               271  Pivot cylinder 
               272  Second articulation 
               300  Traction foot 
               310  Traction profile 
               320  Ground drill 
               321  Drill motor 
               322  Holding device 
               323  Contact pressure actuator 
               324  Holding element 
               325  Passage opening 
               330  Hammering traction plates 
               331  Hammering actuator 
               340  Cryonozzles 
               341  Cryotank 
               400  Ground surface 
               500  Vehicle 
               510  Longitudinal member 
               520  Cross member 
               530  Drawbar 
               540  Trailer coupling 
             f Transportation direction 
             h Lifting direction 
             x Vehicle longitudinal direction 
             y Vehicle transverse direction 
             z Vehicle vertical axis