Description:

According to a first aspect, the present disclosure relates to an assembly comprising an elongate rail and a rail vehicle, wherein the rail vehicle is providable on the elongate rail such that the rail vehicle is movable along the elongate rail in a direction of extension of the elongate rail.

According to a second aspect, the present disclosure relates to a greenhouse for growing a crop, such as tomato plants or cucumber plants, in an interior of the greenhouse, provided with an assembly according to the first aspect of the present disclosure.

According to a third aspect, the present disclosure relates to a method of using the assembly according to the first aspect.

The assembly according to the present disclosure is provided with a construction comprising a positioning arrangement and arranged for being in a first position when the rail vehicle is provided on the elongate rail and at a distance from a free end of the elongate rail exceeding a first predetermined distance, wherein in the first position the construction is positioned, by the positioning arrangement, at the free end of the elongate rail and arranged for being moved from the first position into a second position, by the rail vehicle, when the rail vehicle is provided on the elongate rail and at a distance from the free end of the elongate rail shorter than a second predetermined distance, wherein in the second position the construction is free from the free end of the elongate rail.

The present disclosure relies at least partly on the insight that when a vehicle is used that may be provided on an elongate rail and that requires removal from the elongate rail via a free end of the elongate rail, a known buffer stop may not be used since the whole idea of the known buffer stop is to prevent railway vehicles from going past the end of a physical section of a track. It is noted that for instance in greenhouses vehicles are used that are provided on an elongate rail, and removed from the elongate rail, via a free end of the elongate rail, thereby allowing a single vehicle to be used between different rows of crops on another elongate rail in the greenhouse. This is beneficial for allowing a single rail vehicle to be used throughout the greenhouse.

Within the context of the present disclosure the free end of the elongate rail may understood as the physical end of the rail seen in the direction of extension of the elongate rail in which direction the rail vehicle is movable along the elongate rail.

In addition, the free end of the rail may also be an end face of an end part of the rail that extends in a direction different from the direction of extension of the elongate rail in which direction the rail vehicle is movable along the elongate rail. In other words, the end part of the rail may be a part of the rail that is provided such that the rail vehicle is not movable along the end part of the rail.

The construction may serve as a blocking arrangement for blocking persons or goods, or at least making it more difficult for persons, to be present along the elongate rail when the rail vehicle is provided on the elongate rail. This is beneficial for avoiding, or at least reducing the risk of injuring a person or damaging goods.

By providing the assembly with the positioning arrangement the rail vehicle itself may be used for providing the construction to the free end of the elongate rail. After the rail vehicle is provided onto the rail, via the free end of the rail, the rail vehicle may be moved away from the free end of the rail. When the rail vehicle is moved at a distance from the free end of the rail that is larger than the first predetermined distance the construction is positioned, by the positioning arrangement, at the free end of the elongate rail.

The positioning arrangement is further arranged such that when the rail vehicle is provided at a distance shorter than the second predetermined distance, the rail vehicle removes the construction from the free end of the elongate rail, thereby allowing the rail vehicle to be removed from the elongate rail via the free end thereof. Preferably, in the second position, the construction is connected to the rail vehicle, and wherein the construction is provided with a coupling arrangement arranged for coupling the construction to the rail vehicle upon movement of the construction from the first position to the second position. This allows the rail vehicle to carry the construction and moving the construction together with the rail vehicle when the rail vehicle is not provided on the elongate rail. This is beneficial for providing the construction on a free end of a further elongate rail after providing the rail vehicle on the further elongate rail, thereby avoiding the need for providing the construction for each elongate rail on which the rail vehicle may be provided.

In addition, by providing the coupling arrangement there is no longer a need for manually removing the construction and positioning the construction at the free end of the rail. This is beneficial for realizing relative low operating cost.

In this regard, it is beneficial if the construction is arranged for being pivoted about a virtual pivot axis extending substantially perpendicular, preferably perpendicular, to the extension of the elongate rail in a first pivoting direction when being moved in the first position from the second position and being pivoted about the virtual pivot axis in a second pivoting direction, opposite to the first pivoting direction, when being moved in the second position from the first position. This is beneficial for realising a relative reliable and practical positioning and removal of the construction onto and from the free end of the elongate rail.

In a practical embodiment, the first predetermined distance is equal to the second predetermined distance.

Preferably, the positioning arrangement comprises a receiving space arranged for receiving the free end of the elongate rail and an end wall partly delimiting the receiving space, wherein in the first position, the end wall is provided in an abutting manner against the free end of the elongate rail.

Preferably, the elongate rail comprises a magnetizable material such as steel and wherein the positioning arrangement comprises a magnet such as a permanent magnet or an electromagnet for releasably fixating the construction to the rail when the construction is in the first position. This is beneficial for realising a relative reliable releasable fixation of the construction to the rail when the construction is in the first position.

In this regard, it is beneficial if the magnet with a first contact surface thereof, in the first position of the construction, is provided on an upper side of the rail. This is beneficial for allowing the rail vehicle to move the construction from the first position to the second position.

Preferably, the rail vehicle comprises a section of a magnetizable material such as a steel section and wherein the coupling arrangement comprises a further magnet such as a permanent magnet or an electromagnet for coupling the construction to the section of the rail vehicle when the construction is moved by the rail vehicle from the first position into the second position. This is beneficial for realising a relative reliable releasable fixation of the construction to the rail vehicle when the construction is in the second position.

In this regard, it is beneficial if the further magnet with a second contact surface thereof, in the second position of the construction, is coupled to the section of the rail vehicle.

Preferably, the first contact surface extends in a first virtual plane and the second contact surface extends in a second virtual plane, wherein the first virtual plane and the second virtual plane enclose a sharp angle. This is beneficial for realizing the pivoting of the construction when moving the construction from the first position to the second position.

Preferably, the first virtual plane is parallel to the upper side of the rail when the construction is in the first position.

Preferably, the second virtual plane is inclined towards the rail vehicle when the construction is in the first position. This is beneficial for allowing the rail vehicle to remove the construction in a practical manner from the free end of the elongate rail, thereby allowing the rail vehicle to be removed from the elongate rail via the free end thereof.

Preferably, the second contact surface is provided at a larger distance from the rail, during use when the construction is in the first position, than the first contact surface.

In this regard, it is beneficial if a minimum distance of the second contact surface to the rail, when the construction is in the first position, is in the range of 0.1 m to 1.5 m. This is beneficial for allowing the construction to be moved from the first position to the second position using a relative moderate force, while allowing to realize a relative firm fixation of the construction to the rail, when the construction is in the first position.

In an embodiment, the first contact surface is provided such that, when the construction is in the first position, the first contact surface, in the direction of extension of the elongate rail is closer to the free end of the rail than the second contact surface. This is beneficial for allowing to move the construction from the first position into the second position while applying a relative low force.

In an embodiment, the first contact surface is provided such that, when the construction is in the first position, the first contact surface, in the direction of extension of the elongate rail is at a least partly at an identical distance to the free end of the rail than the second contact surface. This is beneficial for realising an assembly requiring a relative force to move the construction from the first position into the second position.

Preferably, the construction comprises an end stop arranged for abutting against the free end of the rail, wherein the end stop comprises and end stop wall that is substantially perpendicular, preferably perpendicular, to the first contact surface. This is beneficial for allowing the construction to be moved from the second position to the first position using a relative moderate force, while allowing to realize a relative firm fixation of the construction to the rail vehicle, when the construction is in the second position.

It is advantageous if the rail vehicle or the construction comprises a first holder provided with a first flexible connecting element such as a power cable.

In this regard, it is advantageous if the first holder comprises a first reel, wherein the first reel is designed to unwind the first flexible connecting element from the first reel when the rail vehicle is moving away from the construction and to wind up the first flexible connecting element onto the first reel when the rail vehicle is moving towards the construction.

In an embodiment, the rail vehicle is provided with the first holder and wherein the construction comprises a guiding organ for guiding the first flexible connecting element, via the construction, to the rail vehicle. Coupling a rail vehicle, via a flexible connecting element such as a power cable in order to energize the rail vehicle is known. During the movement of the rail vehicle along the elongate rail, the power cable is moved together with the rail vehicle.

The present disclosure further relies at least partly on the insight that a flexible connecting element, such as a power cable, may partly be pulled in a direction of movement of the rail vehicle that is directed away from the free end of the rail. In particular when the rail vehicle subsequently moves towards the free end of the rail or is removed, via the free end of the rail, from the rail, it may occur that the rail vehicle runs over the flexible connecting element or, that the flexible connecting element entangles with parts of the rail vehicle. By providing the construction with the guiding organ, the risk of the rail vehicle running over the flexible connecting element or the flexible connecting element entangling with parts of the rail vehicle is avoided, or at least significantly reduced.

Preferably, the construction comprises a second holder provided with a second flexible connecting element such as a further power cable. Providing the second holder allows to further reduce the risk of the rail vehicle running over the flexible connecting element or the flexible connecting element entangling with parts of the rail vehicle is avoided, or at least significantly reduced.

The first flexible connecting element may be provided between the rail vehicle and the construction and the second connecting element may be provided between the construction and an external connector such as a wall socket, control unit and/or a fluid supply.

In this regard it is advantageous if the second holder comprises a second reel, wherein the second reel is designed to unwind the second flexible connecting element from the second reel when the second holder is moving away from a free end of the second flexible connecting element and to wind up the second flexible connecting element onto the second reel when the second holder is moving towards the free end of the second flexible connecting element. By providing the second reel, the risk of the rail vehicle running over the flexible connecting element or the flexible connecting element entangling with parts of the rail vehicle is avoided, or at least significantly reduced.

Preferably, the first flexible connecting element and/or the second flexible connecting element comprise at least one of: a data cable for controlling the rail vehicle; a hose for supplying a fluid to the rail vehicle; and a power cable for supplying electrical energy to the rail vehicle.

The data cable, the power cable, and any other cables are preferably combined to form a cable bundle so that the risk of the rail vehicle running over the flexible connecting element or the flexible connecting element entangling with parts of the rail vehicle is avoided, or at least significantly reduced.

Preferably, an axis of rotation of the first reel and/or the second reel is provided so as to be substantially perpendicular, preferably perpendicular, to the extension of the elongate rail. An advantage of this is that such an embodiment allows a relative efficient winding up and unwinding of the first flexible connecting element and/or the second flexible connecting element.

Preferably, the first reel comprises a first drive mechanism for winding up and unwinding the first flexible connecting element and/or the second reel comprises a second drive mechanism for winding up and unwinding the second flexible connecting element. An advantage of such an embodiment is that the first and/or second drive mechanism represents a simple and efficient way of ensuring that the first and/or second flexible connecting element is wound up and unwound in accordance with the movement of the rail vehicle along the elongate rail. The unwinding of the first and/or second flexible connecting element by means of the first and/or second drive mechanism is favourable for the prevention, or at least the reduction, of a relatively great force being exerted on the flexible connecting element. A relatively low force is advantageous for preventing, or at least reducing, relatively rapid degradation of the flexible connecting element.

Preferably, the first drive mechanism and/or the second drive mechanism comprise a stepper motor so that the movement and/or speed of the first reel and/or the second reel can be adjusted in a precise manner.

The assembly preferably comprises a control unit for controlling the assembly. The control unit is preferably designed to control the rail vehicle in order to move the rail vehicle along the elongate rail.

The control unit is preferably further designed to control the first drive mechanism of the first reel and/or to control the second drive mechanism of the second reel in order to wind up and/or unwind the first reel and/or the second reel in accordance with the movement in a first and/or second direction of movement of the rail vehicle along the elongate rail.

Preferably, the construction is provided with a safety arrangement arranged to provide a visual and/or an audible signal to a person when said construction is in the first position. In this regard, the construction may comprise a light source arranged for emitting electromagnetic radiation that is visible to the human eye.

In this regard, the construction may comprise a sound generator arranged for emitting sound waves that audible by a person in the vicinity of the construction.

Preferably, the assembly is provided with a track section of a railway track for allowing the rail vehicle to drive along it, the track section comprising the elongate rail and a further elongate rail that are spaced-apart elongate rails which extend parallel to each other.

In this regard, it is beneficial if the elongate rail and the further elongate rail are mutually connected via end parts of the elongate rail and the further elongate rail.

Preferably, the end parts of the elongate rail and the further elongate rail at least partly extend in a direction different from the direction of extension of the elongate rail in which direction the rail vehicle is movable along the elongate rail. In other words, the end part of the rail may be a part of the rail that is provided such that the rail vehicle is not movable along the end part of the rail.

Preferably, the rail vehicle is one of: a leaf-stripping device arranged for stripping leafs from a crop, such as tomato plants or cucumber plants, provided in a greenhouse; and a crane arranged for lifting a person to a predetermined height above a ground surface.

According to the second aspect, the present disclosure relates to a greenhouse for growing a crop, such as tomato plants or cucumber plants, in an interior of the greenhouse, provided with an assembly according to the first aspect of the present disclosure, wherein the elongate rail of the assembly is provided between two rows of the crop. Embodiments of the assembly according to the first aspect correspond to or are similar to embodiments of the greenhouse according to the second aspect of the present disclosure.

Effects of the assembly according to the first aspect correspond to or are similar to effects of the greenhouse according to the second aspect of the present disclosure.

According to the third aspect, the present disclosure relates to a method of using the assembly according to the first aspect, the method comprising the steps of: providing the rail vehicle on the elongate rail such that the rail vehicle is movable along the elongate rail in a direction of extension of the elongate rail and wherein the distance between the rail vehicle and the free end of the rail is exceeding the first predetermined distance; moving the rail vehicle, along the elongate rail, towards the free end of the rail such that the distance between the rail vehicle and the free end of the rail is shorter than the second predetermined distance; and moving the construction, by the rail vehicle, from the first position to the second position during the step of moving the rail vehicle.

Embodiments of the assembly according to the first aspect and the greenhouse according to the second aspect correspond to or are similar to embodiments of the method according to the third aspect of the present disclosure.

Effects of the assembly according to the first aspect and the greenhouse according to the second aspect correspond to or are similar to effects of the method according to the third aspect of the present disclosure.

Preferably, the method comprises the steps of: further providing the rail vehicle on the elongate rail such that the rail vehicle is movable along the elongate rail in a direction of extension of the elongate rail and wherein the distance between the rail vehicle and the free end of the rail is shorter than the second first predetermined distance; further moving the rail vehicle, along the elongate rail, away from the free end of the rail such that the distance between the rail vehicle and the free end of the rail exceeds the first predetermined distance; and further moving the construction, by the rail vehicle, from the second position to the first position during the step of further moving the rail vehicle.

Preferably, the first predetermined distance is equal to the second predetermined distance.

The present disclosure will now be explained by means of a description of an embodiment of an assembly in accordance to the first aspect, a greenhouse according to the second aspect and a method according to the third aspect, in which reference is made to the following schematic figures, in which:

Fig. 1 shows schematically a side view of an embodiment of the assembly according to the first aspect of the present disclosure, wherein the construction is in the first position;

Fig. 2 shows schematically a side view of the assembly of Fig. 1 , wherein the construction is in the second position;

Fig. 3 shows schematically a front view of elements of the assembly of Fig. 1 ;

Fig. 4 shows schematically a side view of another embodiment of the assembly according to the first aspect of the present disclosure;

Fig. 5 shows schematically a back view of an embodiment of the construction according to the first aspect of the present disclosure;

Fig. 6 shows schematically a back view of another embodiment of the construction according to the first aspect of the present disclosure;

Fig. 7 shows schematically an embodiment of the greenhouse according to the second aspect of the present disclosure, wherein two rail vehicles are each provided on a track section;

Fig. 8 shows schematically another embodiment of the greenhouse according to the second aspect of the present disclosure, wherein a rail vehicle is moving between two track sections;

Fig. 9 shows schematically an embodiment of the method according to the third aspect of the present disclosure. The assembly 1 comprises an elongate rail 3, a rail vehicle 5 and a construction 7. The assembly 1 is provided with a track section 39A, 39B of a railway track for allowing the rail vehicle 5 to drive along it. The track section 39A, 39B comprises the elongate rail 3 and a further elongate rail 3 that are spaced-apart elongate rails which extend parallel to each other. For the track section 39A, the outer ends of the elongate rails 3 and the further elongate rail 3 are open, as indicated in figure 7. For the track section 39B, the outer ends of the elongate rails 3 and the further elongate rail 3 are connected by a further track section 38, as indicated in figure 8. Within the context of the present disclosure the further tract section 38 may also be referred to a an end part of the elongate rail and/or the further elongate rail.

The rail vehicle 5 is providable on the elongate rail 3 such that the rail vehicle 3 is movable along the elongate rail 3 in a direction D of extension of the elongate rail 3. When the rail vehicle 5 is moving in the direction D, the distance d between the rail vehicle 5 and the free end of the elongate rail 3 is increasing. When the rail vehicle 5 is moving opposite to the direction D, the distance d between the rail vehicle 5 and the free end of the elongate rail 3 is decreasing.

The construction 7 comprises a positioning arrangement 9 and a coupling arrangement 11 , both connected to a frame 8. The construction 7 is arranged for being in a first position, as indicated in figure 1 and 3, and in a second position, as indicated in figure 2.

In the first position, the construction 7 is fixated to a free end of the elongate rail 3 via the positioning arrangement 9 and free from the rail vehicle 5. The positioning arrangement 9 comprises two magnets 9 such as permanent magnets or electromagnets, wherein the rail 3 is made of a magnetizable material such as steel. When the construction 7 is in the first position, the construction 7 is releasably fixated to an upper side of the free end of the elongate rail 3, via two first contact surfaces 10 of the two magnets 9.

In the second position, the construction 7 is coupled to the rail vehicle 5 via the coupling arrangement 11 and free from the elongate rail 3. The coupling arrangement 11 comprises two further magnets 11 such as permanent magnets or electromagnets, wherein at least a section 17 of the real vehicle 5 is made of a magnetizable material such as steel. When the construction 7 is in the second position, the construction 7 is releasably coupled to the section 17 of the rail vehicle 5, via two second contact surfaces 12 of the two further magnets 11.

The first contact surface 10 extends in a first virtual plane 14 and the second contact 12 surface extends in a second virtual plane 16, wherein the first virtual plane 14 and the second virtual plane 16 enclose a sharp angle a. The first virtual plane 14 is parallel to the upper side of the rail 3 when the construction 7 is in the first position. For sake of clarity, the first virtual plane 14 and the second virtual plane 16 are shown in Fig. 1 only with respect to their orientation and not in their absolute position. The second virtual plane 16 is inclined towards the rail vehicle 5 when the construction 7 is in the first position. In the first position, the second contact surface 12 is provided at a larger distance from the rail 3 than the first contact surface 10, which is abutting the rail 3. A minimum distance of the second contact surface 12 to the rail 3 is in the range of 0.1 m to 1.5 m, when the construction 7 is in the first position.

The construction 7 furthermore comprises an end stop 18 arranged for abutting against the free end of the rail 3. In case of track section 39A, the end stop 18 abuts against one or both of the outer ends of the elongate rails 3. In case of track section 39B, the end stop 18 abuts against the outer end, also referred to as end face of the end part within the present disclosure, of the further track section 38. The end stop 18 comprises and end stop wall 20 that is perpendicular to the first contact surface 10.

The assembly 1 is arranged for releasably coupling the construction 7 to the section 17 of the rail vehicle 5 upon moving the construction 7 by the rail vehicle 5 from the first position into the second position. This is done as follows, wherein the starting point is the situation as indicated in figure 1 , in which the construction 7 is in the first position and the rail vehicle 5 is provided on the elongate rail 3. When the rail vehicle 5 is moving opposite to the direction D, the distance d between the rail vehicle 5 and the free end of the elongate rail 3 is decreasing. When the distance d is equal to a second predetermined distance d2, the section 17 of the rail vehicle 5 contacts the two further magnets 11 of the construction 7.

When the rail vehicle 5 is further moving, thereby further decreasing the distance d to a value shorter than the second predetermined distance d2, the magnetic forces of the two further magnets 11 force the construction 7 to the final situation as indicated in figure 2, wherein two second contact surfaces 12 of the two further magnets 11 are aligned with a contact surface 22 of the section 7 of the rail vehicle 5. When the construction 7 is moved from the first position into the second position, the construction is pivoted in a first pivoting direction P1 , about a virtual pivot axis P extending perpendicular to the extension of the elongate rail 3. During pivoting of the construction 7, the end stop 18 enables controlled moving of the construction 7 towards the rail vehicle 3, as the end stop wall 20 is abutting the outer end of the elongate rail 3 of track section 39A or the further track section 38 of track section 39B, while the rail vehicle 5 is moving towards the free end of the rail 3.

With the construction 7 coupled to the rail vehicle 5, the rail vehicle 5 can be moved from the track section 39A, 39B. The rail vehicle further comprises a moving arrangement (not shown) for moving the rail vehicle 3 in between rails sections 39A, 39B on a ground surface 103, free from the rail 3.

The assembly 1 is further arranged for releasably fixating the construction 7 to the free end of the elongate rail 3 upon moving the construction 7 by the rail vehicle 5 from the second position into the first position. This is done as follows, wherein the starting point is the situation as indicated in figure 2, in which the construction 7 is in the second position and the rail vehicle 5 is provided on the elongate rail 3. When the rail vehicle 5 is moving in the direction D, the distance d between the rail vehicle 5 and the free end of the elongate rail 3 is increasing. When the distance d is equal to a first predetermined distance d1 , further moving of the construction 7 is limited by the end stop 18 of the construction 7, as the end stop wall 20 is abutting an outer end of one or both of the elongate rails 3 of rail section 39A or as the end stop 20 is abutting an outer end of the further tack section 38 of rail section 39B. The first predetermined distance d1 is equal to the second predetermined distance d2, equal to a predetermined distance Ad.

When the rail vehicle 5 is further moving, thereby further increasing the distance d to a value exceeding the predetermined distance Ad, the gravitational force and the magnetic forces of the two magnets 9 force the construction 7 to the final situation as indicated in figure 1 , wherein two first contact surfaces 10 of the two magnets 9 are aligned with the upper side of the free end of the elongate rail 3. When the construction 7 is moved from the second position into the first position, the construction is pivoted in a second pivoting direction P2, about the virtual pivot axis P. During pivoting of the construction 7, the moving of the rail vehicle 5 and the end stop 18 enable controlled moving of the construction 7.

The rail vehicle 5 comprises a first holder 19, as indicated in figure 4. The first holder 19 comprises a first reel 23 provided with a first flexible connecting element 21 , wherein the first flexible connecting element 21 is for example a data cable for controlling the rail vehicle 5, a hose for supplying a fluid to the rail vehicle 5, or a power cable for supplying electrical energy to the rail vehicle 5. The data cable, the power cable, and any other cables are preferably combined to form a cable bundle.

The first reel 23 comprises a first drive mechanism 33 for winding up the first flexible connecting element 21 onto the first reel 23 when the rail vehicle 5 is moving towards the construction 7 in the opposite direction of D, and for unwinding the first flexible connecting element 21 from the first reel 23 when the rail vehicle 5 is moving away from the construction 7 in the direction D. The construction 7 comprises a guiding organ 25, as indicated in figures 4, 7 and 8, for guiding the first flexible connecting element 21 , via the construction 7, to the rail vehicle 5.

Furthermore, the construction 7 can comprise a second holder 27, as indicated in figure 5. The second holder 27 comprises a second reel 31 provided with a second flexible connecting element 29, wherein the second flexible connecting element 29 is for example a data cable for controlling the rail vehicle 5, a hose for supplying a fluid to the rail vehicle 5, or a power cable for supplying electrical energy to the rail vehicle 5. The data cable, the power cable, and any other cables are preferably combined to form a cable bundle.

The second flexible connecting element 29 can be connected to the rail vehicle 5 via the first flexible connecting element 21. The first flexible connecting element 21 may be provided between the rail vehicle 5 and the construction 7 and the second connecting element 29 may be provided between the construction 7 and an fixed external connector 24 such as a wall socket, control unit and/or a fluid supply. In another example, the second flexible connecting element 29 can be connected directly to rail vehicle 5. In a yet further example, the first flexible connecting element 21 can be directly connected to the fixed external connector 24.

The second reel 31 comprises a second drive mechanism 35 for unwinding the second flexible connecting element 29 from the second reel 31 when the construction 7 is moving away from a free end of the second flexible connecting element 29 and for winding up the second flexible connecting element 29 onto the second reel 31 when the construction 7 is moving towards the free end of the second flexible connecting element 29. An axis of rotation R of the first reel 23 and/or the second reel 31 is provided so as to be perpendicular to the extension of the elongate rail 3, when the construction 7 is in the first position.

Provision of the construction 7 according to the present disclosure in accordance with any of the embodiments described above, enables automated and controlled guiding of the first flexible connecting element 21 , such that the rail vehicle 5 can freely move via the rail sections 39A, 39B and via the ground surface 103. This enables a fixed connection of an outer end of the first flexible connecting element 21 or the second flexible connecting element 29 to the fixed external connector 24 while the rail vehicle 5 is moving, thereby ensuring that the rail vehicle 5 does not cross or run over the first flexible connecting element 21 or the second flexible connecting element 29. In another embodiment, as shown in figure 6, the construction 7 is provided with a safety arrangement 37. The safety arrangement 37 provides a visual and/or an audible signal to a person when the construction 7 is in the first position.

Figures 7 and 8 show a greenhouse 100 with the ground surface 103, for growing a crop 101 , such as tomato plants or cucumber plants, in an interior of the greenhouse 100. The greenhouse is provided with one or more assembly 1 as described above. The elongate rail 3 of the assembly 1 is provided between two rows of the crop 101 .

Figure 7 shows a leaf-stripping device 5' provided on a rail section 39A and a crane 5” provided on another rail section 39A in the greenhouse 100. The leafstripping device 5' is arranged for stripping leafs from the crop 101 , and is provided with a construction 7’ provided with a guiding organ 25 for guiding the first flexible connecting element 21. The crane 5” is provided with a battery for powering the crane 5” and is arranged for lifting a person 41 to a predetermined height above the ground surface 103. The crane 5” is provided with a construction 7” provided with a safety arrangement 37 for providing a visual signal to a person.

Figure 8 shows the greenhouse 100 in which the leaf-stripping device 5' is moving in between rail sections 39B via the ground surface 103.

Figure 9 shows a method 201 of using the assembly 1 as described above. The method 201 comprises the following steps.

Providing 203 the rail vehicle 5 on the elongate rail 3 such that the rail vehicle 5 is movable along the elongate rail 3 in a direction D of extension of the elongate rail 3 and wherein the distance d between the rail vehicle 5 and the free end of the rail 3 is exceeding the predetermined distance Ad. During this step, the construction 7 is in the first position as indicated by figure 1 , wherein the construction 7 is positioned, by the positioning arrangement 9, at the free end of the elongate rail 3 and the construction 7 is free from the rail vehicle 5. Moving 205 the rail vehicle 5, along the elongate rail 3, towards the free end of the rail 3 such that the distance d between the rail vehicle 5 and the free end of the rail 3 is shorter than the predetermined distance Ad.

Moving 207 the construction 7, by the rail vehicle 5, from the first position to the second position during the step of moving 205 the rail vehicle. In the second position, as indicated in figure 2, the construction 7 is coupled to the rail vehicle 5 and free from the elongate rail 3 and the rail vehicle 5 can be moved via the ground surface 103 in between rail sections 39A, 39B.

Providing 209 the rail vehicle 5 on the elongate rail 3 such that the rail vehicle 5 is movable along the elongate rail 3 in a direction of extension of the elongate rail 3 and wherein the distance d between the rail vehicle 5 and the free end of the rail 3 is shorter than the predetermined distance Ad.

Further moving 211 the rail vehicle 5, along the elongate rail 3, away from the free end of the rail 3 such that the distance d between the rail vehicle 5 and the free end of the rail 3 exceeds the predetermined distance Ad.

Further moving 213 the construction 7, by the rail vehicle 5, from the second position to the first position during the step of further moving 211 the rail vehicle 211.