Middle-arranged and middle-driven type three-dimensional separate sowing equipment

Abstract

The utility model relates to the technical field of warehousing, and provides middle-mounted and middle-driven type three-dimensional separate sowing equipment which comprises a middle-mounted supporting track, a plurality of stand column assemblies and a cargo carrying platform. A bearing supporting piece is arranged in the middle area of the stand column assembly and connected with the middle supporting rail in a clamped mode. When the load-bearing supporting piece and the middle supporting rail are kept in a clamped connection state, the stand column assembly can drive the load-bearing supporting piece and the middle supporting rail to generate relative motion. A lifting rail is arranged on the stand column assembly, and the rail direction of the lifting rail and the rail direction of the middle supporting rail are arranged in a crossed mode. According to the technical scheme, the load-bearing supporting piece is arranged in the middle area of the stand column assembly, so that the upper end and the lower end of the stand column assembly are free, when the cargo carrying platform moves up and down, no extra resistance is generated on the load-bearing supporting piece, and in other words, movement of the load-bearing supporting piece on the middle supporting rail is not affected; therefore, extra power loss brought to the driving device is avoided, namely, the driving and operating efficiency of the stand column assembly is improved.

Description

Technical Field

[0001] The present application relates to the field of warehousing technology, and in particular to a centrally mounted, centrally driven stereoscopic broadcasting device. Background Art

[0002] In large multi-category warehouses, dedicated cargo sorting workstations need to be set up to sort cargo according to predetermined rules. In existing cargo sorting workstations, sorting work is mostly done manually. Workers need to take out target cargo from the shelves or cargo boxes transported by robots, and place the target cargo in the corresponding cargo baskets or shelf grids according to predetermined rules, thus realizing the distribution of cargo.

[0003] Due to the limitations of manual work capabilities, when the quantity of goods is large, manual labor is unable to handle a large number of orders at one time, and during the distribution of goods, it is very easy to put the goods in the wrong place. Utility Model Content

[0004] In order to avoid the problem that a large number of orders cannot be processed manually at one time and that goods are easily misplaced during the distribution process, an embodiment of the present application provides a centrally mounted, centrally driven, stereoscopic distribution device.

[0005] The embodiment of the present application provides a centrally mounted centrally driven stereoscopic broadcasting device, comprising: a centrally mounted support track, a plurality of column assemblies, and a cargo platform for carrying cargo;

[0006] A load-bearing support is provided in the middle area of ​​the column assembly, and the load-bearing support is clamped with the central support rail, so that the central support rail supports the column assembly and the support force point of the column assembly is located in the middle area of ​​the column assembly;

[0007] When the column assembly is driven by the driving device, the load-bearing support member and the middle support track can be driven to produce relative movement while the load-bearing support member and the middle support track are kept in a clamping state, so that the column assembly moves along the track line of the middle support track;

[0008] The column assembly is provided with a lifting track, and the track direction of the lifting track is arranged to intersect with the track direction of the middle support track;

[0009] The cargo platform can travel on the track line of the lifting track.

[0010] In one implementation, the middle region is the center of gravity of the column assembly;

[0011] or,

[0012] The middle area is the track length / position of the lifting track.

[0013] In one implementation, the driving device of the column assembly is a linear motor; the primary of the linear motor is arranged on the central support track, and the secondary of the linear motor is arranged in the middle area of ​​the column assembly.

[0014] In one implementation, the column assembly includes two lifting columns, the lifting track of the column assembly is arranged on the lifting columns, and the two lifting columns are respectively connected to two sides of the cargo platform.

[0015] In an implementation manner, the two lifting columns are arranged in parallel, and the distance between the two lifting columns is smaller than a first preset value.

[0016] In one implementation, the load-bearing support comprises: a suspension fixing bracket and a suspension wheel;

[0017] The suspension wheels arranged on the suspension fixing bracket are divided into two rows, and the central support rail is clamped between the two rows of suspension wheels;

[0018] The wheel center axes of the two rows of suspension wheels are arranged vertically so that the treads of the suspension wheels fit the track surface of the vertically arranged support track.

[0019] In one implementation, the number of suspension wheels in each column is two, the two suspension wheels are clamped side by side on the central support rail, and the distance between the two suspension wheels is less than a second preset value.

[0020] In one implementation, the number of the suspension fixing brackets is two;

[0021] The suspension wheels on the two suspension fixing brackets are arranged in parallel, and the distance between the two suspension fixing brackets is smaller than a third preset value.

[0022] In one implementation, the column assembly further includes: a lifting motor and a lifting transmission device;

[0023] The lifting motor is arranged at either end of the lifting track of the column assembly, and the lifting motor is connected to the cargo platform through a lifting transmission device to drive the cargo platform to move on the track line of the lifting track.

[0024] In one implementation, an equipment box is further provided on the column assembly, the equipment box and the cargo platform are respectively provided on both sides of the lifting track, and the equipment box is provided at a height higher than that of the middle area.

[0025] In one implementation, the central support rail includes rail components having lines of various shapes so as to deploy rail lines of different shapes.

[0026] In one implementation, the central support rail forms at least one section of a closed-loop rail line.

[0027] A centrally mounted, centrally driven stereoscopic broadcasting device provided in an embodiment of the present application comprises: a centrally mounted support rail, a plurality of column assemblies and a cargo platform for carrying cargo; a load-bearing support member is arranged in a central region of the column assembly, the load-bearing support member is clamped in the centrally mounted support rail, so that the centrally mounted support rail supports the column assembly, and the supporting force point of the column assembly is located in the central region of the column assembly; when the column assembly is driven by a driving device, the load-bearing support member and the centrally mounted support rail are kept in a clamped state, and the load-bearing support member and the centrally mounted support rail are driven to generate relative movement, so that the column assembly moves along the track line of the centrally mounted support rail; a lifting track is arranged on the column assembly, and the track direction of the lifting track is arranged to cross the track direction of the centrally mounted support rail; the cargo platform can move on the track line of the lifting track.

[0028] By applying the technical solution of the embodiment of the present application, the load-bearing support member is arranged in the middle area of ​​the column assembly. In this way, the upper and lower ends of the column assembly are free, and no additional resistance is generated to the load-bearing support member when the cargo platform moves up and down, that is, it will not affect the movement of the load-bearing support member on the central support rail, thereby avoiding additional power loss to the driving device, that is, improving the driving and operating efficiency of the column assembly. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solution of the present application, the drawings required for use in the embodiments are briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0030] Figure 1 A schematic diagram of the overall structure of a center-mounted, center-driven stereoscopic broadcasting device provided in an embodiment of the present application;

[0031] Figure 2 for Figure 1 Schematic diagram of the local structure;

[0032] Figure 3 A schematic diagram of the structure of a linear motor provided in an embodiment of the present application;

[0033] Figure 4 A schematic diagram of the structure of a column assembly provided in an embodiment of the present application;

[0034] Figure 5 for Figure 4 Schematic diagram of plane projection;

[0035] Figure 6 for Figure 4 Schematic diagram of the local structure.

[0036] In the figure: 1-central support rail, 2-column assembly, 21-load-bearing support, 211-fixed bracket, 212-suspension wheel, 22-lifting column, 23-lifting motor, 24-lifting transmission device, 3-cargo platform, 4-linear motor, 41-primary, 42-secondary, 5-equipment box. DETAILED DESCRIPTION

[0037] In order to avoid the problem that a large number of orders cannot be processed manually at one time and that goods are easily misplaced during the distribution process, an embodiment of the present application provides a centrally mounted, centrally driven, stereoscopic distribution device.

[0038] like Figure 1 As shown, an embodiment of the present application provides a centrally mounted, centrally driven stereoscopic broadcasting device, comprising: a centrally mounted support track 1, a plurality of column assemblies 2 and a cargo platform 3 for carrying cargo.

[0039] Among them, the central support track 1 is set in the site of the cargo sorting workstation through a column bracket. It should be noted that the central support track 1 is generally set as a horizontal track. Of course, in actual application, if the site conditions of the cargo sorting workstation are limited, it is impossible to set the central support track 1 as a complete horizontal track, the central support track 1 can also be set as a track with a slope change, but the value of the slope change needs to meet the design requirements.

[0040] like Figure 2 As shown, a load-bearing support member 21 is provided in the middle area of ​​the column assembly 2, and the load-bearing support member 21 is clamped to the central support rail 1, so that the central support rail 1 supports the column assembly 2 and can ensure that the supporting force point of the column assembly 2 is in the middle area of ​​the column assembly 2.

[0041] A lifting track is arranged on the column assembly 2, and the track direction of the lifting track is arranged to cross the track direction of the middle support track 1; the cargo platform 3 can move on the track line of the lifting track.

[0042] In actual application, the central support rail 1 is set horizontally and the lifting rail is set vertically. The load-bearing support member 21 can run along the track line of the central support rail 1 while maintaining the state of being engaged with the central support rail 1, that is, under the premise of ensuring that the column assembly 2 is provided with supporting force. Specifically, when the column assembly 2 is driven by the driving device, the driving force is transmitted to the load-bearing support member 21. When the load-bearing support member 21 and the central support rail 1 remain in the engaged state, the driving force drives the load-bearing support member 21 and the central support rail 1 to produce relative movement, that is, the column assembly 2 moves along the track line of the central support rail 1.

[0043] Compared with setting a central support track 1 in the middle area of ​​the column assembly 2, in the prior art, there is also a method of setting the support track at both ends of the column assembly 2. This upper and lower track fixing method is very likely to cause the column assembly 2 to generate unstable resistance during operation due to the inconsistent running positions of the upper and lower ends of the column assembly 2 in the vertical direction during the movement of the column assembly 2, thereby making the upper and lower ends of the column assembly 2 on the support track inconsistent. The instantaneous linear speed, thereby accelerating the wear of the load-bearing support 21 and increasing the energy consumption of the drive device. In particular, at the bends of the support track, which is a non-straight track, the upper and lower track fixing method is more likely to cause the column assembly 2 to encounter unstable resistance during operation.

[0044] It should be noted that the resistance brought about by this fixing method of the upper and lower tracks is unstable. On the one hand, this is because: the accuracy of the upper and lower tracks in maintaining parallelism is low, and there are up and down areas, which will bring operating resistance to the load-bearing support 21; on the other hand, this is because: when the cargo platform 3 moves up and down on the column assembly 2, the random swing of the column assembly 2 will also generate resistance, especially when the column assembly 2 runs on the bend of the support track. This unstable resistance will cause the drive device to consume more energy and bring about greater power consumption, and will increase the wear of the upper and lower load-bearing supports 21, which will cause the equipment to need to be shut down frequently to replace the load-bearing supports 21. At the same time, it will cause the operating speed of the column assembly 2 to be unable to be increased, resulting in low operating efficiency of the equipment.

[0045] The embodiment of the present application arranges the load-bearing support member 21 in the middle area of ​​the column assembly 2. In this way, the upper and lower ends of the column assembly 2 are free, and when the cargo platform 3 moves up and down, no additional resistance is generated to the load-bearing support member 21, that is, it will not affect the movement of the load-bearing support member 21 on the central support rail 1, thereby avoiding additional power loss to the driving device, that is, improving the driving and operating efficiency of the column assembly 2.

[0046] Specifically, in some embodiments of the present application, the middle area is the center of gravity of the column assembly 2; or, the middle area is the position of 1 / 2 of the track length of the lifting track. It should be noted that, since the column assembly 2 needs to carry the cargo platform 3, and in the actual operation process, the weight of the cargo carried on the cargo platform 3 each time is not a fixed value, when considering the center of gravity of the column assembly 2, the weight of the cargo platform 3 and other counterweight equipment can be ignored, and only the center of gravity of the column assembly 2 itself is used as a reference.

[0047] It should be noted that in actual application, the middle area is not a single precise coordinate point, that is, the center of gravity position or the 1 / 2 position is not a coordinate point, but refers to an area, the center point of which is the center of gravity position of the column assembly 2; or, the center point of the area is the 1 / 2 position of the track length of the lifting track.

[0048] like Figure 3 As shown, in the embodiment of the present application, the driving device of the column assembly 2 is a linear motor 4; the linear motor 4 includes a primary 41 and a secondary 42. Specifically, as shown in FIG. Figure 1 As shown, the primary 41 of the linear motor 4 is arranged on the central support track 1, as shown in FIG. Figure 4 and Figure 5 As shown, the secondary 42 of the linear motor 4 is arranged in the middle area of ​​the column assembly 2 .

[0049] Among them, the primary 41 of the linear motor 4 is fixed to the middle position of the central support rail 1 through a fixed bracket, which helps the smooth operation of the column assembly 2; the secondary 42 is fixed to the inner side of the middle area of ​​the column assembly 2 and maintains a certain gap with the primary 41, that is, a central drive method is adopted, and the drive method of the linear motor 4 is adopted to realize contactless electromagnetic drive, thereby reducing friction resistance and improving the driving efficiency of the column assembly 2. The driving component is arranged in the middle area of ​​the column assembly 2, thereby ensuring the operating stability of each column assembly 2.

[0050] It should be noted that, in actual application, for distribution lines of different lengths and shapes (track lines of the central support track 1), the number of stators can be appropriately increased to improve the ability of rotational drive. Of course, in actual application, it is not limited to the linear motor 4 as a driving device, and the traditional rotational drive method can also be used. For example, a high-power rotating motor is set at the center of the central support track 1, and then transmitted to the column assembly 2 through mechanical transmission. The linear motor 4 used in the embodiment of the present application can reduce the driving friction resistance, thereby reducing the noise during the operation of the equipment, and can also improve the accuracy of rotation control, reduce the difficulty of control, and make the stereoscopic distribution equipment more flexible, and can flexibly design the length and rotation path; can effectively reduce the cost of the stereoscopic distribution equipment and the energy consumption during operation; and also bring convenience to the deployment of the stereoscopic distribution equipment.

[0051] like Figure 4 As shown, the column assembly 2 includes two lifting columns 22 , the lifting track of the column assembly 2 is arranged on the lifting columns 22 , and the two lifting columns 22 are respectively connected to two sides of the cargo platform 3 .

[0052] By independently deploying two lifting columns 22 on the cargo platform 3 and fixing the guide rails on the lifting columns 22, the two lifting columns 22 are deployed separately, which can effectively suppress the horizontal swing of the column assembly 2, especially the swing of the column assembly 2 after the column assembly 2 completes the curve, thereby improving the stability of the column assembly operation.

[0053] It should be noted that, in actual application, the two lifting columns 22 are arranged in parallel, and the distance between the two lifting columns 22 is less than the first preset value. In this way, it is avoided that the distance between the two lifting columns 22 is too large, which causes the two lifting columns 22 to get stuck at the bend of the central support track 1, thereby improving the operating stability of the column assembly 2.

[0054] like Figure 5 As shown, in some embodiments of the present application, the load-bearing support member 21 includes: a suspension fixing bracket 211 and a suspension wheel 212; wherein, the number of the suspension wheels 212 is multiple and distributed in two rows, and the central support rail 1 is clamped between the two rows of suspension wheels; wherein, the suspension wheels 212 are placed horizontally, that is, the wheel center axes of the two rows of suspension wheels 212 are arranged vertically, and correspondingly, the track surface for walking on the support rail 1 is arranged so that the tread of the suspension wheel 212 fits the track surface of the vertically arranged support rail 1.

[0055] In actual application, the number of suspension wheels 212 in each column can be set to multiple, such as Figure 6 As shown, in the embodiment of the present application, the number of suspension wheels 212 in each row is two, and the two suspension wheels 212 are clamped side by side on the central support rail 1, and the distance between the two suspension wheels 212 is less than the second preset value, wherein the second threshold value is less than the first threshold value. In this way, it is avoided that the distance between the two suspension wheels 212 is too large, causing the two suspension wheels 212 to get stuck at the curve of the central support rail 1, thereby improving the running stability of the column assembly 2.

[0056] In order to ensure that the column assembly 2 can operate stably, Figure 5 As shown, in the embodiment of the present application, the number of the suspension fixing brackets 211 is two, correspondingly, as shown in FIG. Figure 2 As shown, the central support track 1 is provided with two tracks, corresponding to two suspension fixing brackets 211 respectively. Specifically, the suspension wheels 212 on the two suspension fixing brackets 211 are arranged in parallel, and the distance between the two suspension fixing brackets 211 is less than the third preset value. By setting the distance between the two suspension fixing brackets 211 to the third preset value, the distance between the suspension wheels 212 on the two suspension fixing brackets 211 is limited, thereby avoiding uneven force on the suspension wheels 212 on the two suspension fixing brackets 211.

[0057] When the central support track 1 is provided with two tracks, the driving component of the column assembly 2 is arranged between the two tracks to ensure the stable operation of each column assembly 2. For example, if the driving component is a linear motor 4, the primary 41 of the linear motor 4 is arranged between the two tracks.

[0058] like Figure 4As shown, the column assembly 2 also includes: a lifting motor 23 and a lifting transmission device 24; the lifting motor 23 is arranged at either end of the lifting track of the column assembly 2, and the lifting motor 23 is connected to the cargo platform 3 through the lifting transmission device 24 to drive the cargo platform 3 to move on the track line of the lifting track. Specifically, the lifting transmission device 24 can adopt a synchronous belt or a chain, and the lifting motor 23 is arranged at the top or bottom of the column assembly 2, and in the case of using two lifting columns 22, the two lifting columns 22 are deployed separately, which can effectively suppress the horizontal swinging track direction of the two lifting columns 22 after turning, thereby improving the stability of the column assembly 2.

[0059] In the embodiment of the present application, a cargo platform 3 for carrying goods needs to be provided on the column assembly 2, and an equipment box 5 needs to be provided for placing electrical equipment and cables, etc. On this basis, in order to improve the dynamic balance of the column assembly 2, the equipment box 5 and the cargo platform 3 are respectively arranged on both sides of the lifting track, and the height of the equipment box 5 is set higher than the height of the middle area, that is, the equipment box 5 is set on the side close to the central support track 1, and the cargo platform 3 is set on the side away from the central support track 1, so that the equipment box 5 plays the role of a counterweight, thereby improving the dynamic balance of the column assembly 2 and improving the operating stability of the column assembly 2.

[0060] In an embodiment of the present application, the central support rail 1 includes rail components with lines in various shapes, for example, straight rail components, arc-shaped rail components or rail components in other curved forms, so that different shapes of track lines can be deployed by utilizing different forms of rail components, and various forms of distribution paths can be quickly deployed.

[0061] In the embodiment of the present application, the central support track 1 forms at least one track line arranged in a closed loop. For example, the deployed distribution path is circular or approximately circular, similar to the shape of the letter O, or the shape of the letter E, or a track line with more strip loops.

[0062] It should be noted that the centrally mounted centrally driven stereoscopic broadcasting device provided in the embodiment of the present application can select different cargo platforms 3 according to the actual needs of the cargo, wherein the cargo platform 3 includes but is not limited to a conveying mechanism such as a roller motor or a belt, and a laser sensor can be provided on the cargo platform 3 to detect the occurrence of the bagging and unpacking actions of the sorted goods. In addition, in order to facilitate the replacement of different cargo platforms 3, the cargo platform is fixed to the guide rail slider of the column assembly 2 by bolts.

[0063] A centrally mounted centrally driven stereoscopic broadcasting device provided in an embodiment of the present application comprises: a centrally mounted support rail 1, a plurality of column assemblies 2 and a cargo platform 3 for carrying cargo; a load-bearing support member 21 is provided in the central region of the column assembly 2, and the load-bearing support member 21 is clamped in the centrally mounted support rail 1, so that the centrally mounted support rail 1 supports the column assembly 2, and the supporting force point of the column assembly 2 is located in the central region of the column assembly 2; when the column assembly 2 is driven by a driving device, the load-bearing support member 21 and the centrally mounted support rail 1 are kept in a clamped state, and the load-bearing support member 21 and the centrally mounted support rail 1 are driven to generate relative movement, so that the column assembly 2 moves along the track line of the centrally mounted support rail 1; a lifting track is provided on the column assembly 2, and the track direction of the lifting track is cross-set with the track direction of the centrally mounted support rail 1; the cargo platform 3 can move on the track line of the lifting track.

[0064] By applying the technical solution of the embodiment of the present application, the load-bearing support member 21 is arranged in the middle area of ​​the column assembly 2. In this way, the upper and lower ends of the column assembly 2 are free, and when the cargo platform 3 moves up and down, no additional resistance is generated to the load-bearing support member 21, that is, it will not affect the movement of the load-bearing support member 21 on the central support rail 1, thereby avoiding additional power loss to the driving device, that is, improving the driving and operating efficiency of the column assembly 2.

[0065] The above specific implementation methods further illustrate the purpose, technical solutions and beneficial effects of the present application in detail. It should be understood that the above are only specific implementation methods of the present application and are not used to limit the protection scope of the present application. Any modifications, equivalent substitutions, improvements, etc. made on the basis of the technical solutions of the present application should be included in the protection scope of the present application.

Claims

1. A central-center-drive stereoscopic broadcasting device, characterized in that: include: A central support rail (1), a plurality of column assemblies (2) and a cargo platform (3) for carrying cargo; A load-bearing support member (21) is provided in the middle region of the column assembly (2), and the load-bearing support member (21) is clamped to the central support rail (1), so that the central support rail (1) supports the column assembly (2), and the support force point of the column assembly (2) is located in the middle region of the column assembly (2); When the column assembly (2) is driven by the driving device, the load-bearing support member (21) and the central support track (1) can be kept in a clamped state, driving the load-bearing support member (21) and the central support track (1) to produce relative movement, so that the column assembly (2) moves along the track line of the central support track (1); The column assembly (2) is provided with a lifting track, and the track direction of the lifting track is arranged to intersect with the track direction of the middle support track (1); The cargo platform (3) can travel on the track line of the lifting track.

2. A center-center-drive type stereoscopic broadcasting device according to claim 1, characterized in that: The middle area is the center of gravity of the column assembly (2); or, The middle area is the 1 / 2 position of the track length of the lifting track.

3. A center-center-drive type stereoscopic broadcasting device according to claim 1 or 2, characterized in that: The driving device of the column assembly (2) is a linear motor (4); The primary (41) of the linear motor (4) is arranged on the central support track (1), and the secondary (42) of the linear motor (4) is arranged in the middle area of ​​the column assembly (2).

4. The central-center-drive type stereoscopic broadcasting device according to claim 1, characterized in that: The column assembly (2) comprises two lifting columns (22), the lifting track of the column assembly (2) is arranged on the lifting columns (22), and the two lifting columns (22) are respectively connected to two sides of the cargo platform (3).

5. The center-center-drive type stereoscopic broadcasting device according to claim 4, characterized in that: The two lifting columns (22) are arranged in parallel, and the distance between the two lifting columns (22) is less than a first preset value.

6. A center-center-drive type stereoscopic broadcasting device according to claim 1 or 4, characterized in that: The load-bearing support member (21) comprises: a suspension fixing bracket (211) and a suspension wheel (212); The suspension wheels (212) arranged on the suspension fixing bracket (211) are divided into two rows, and the central support rail (1) is clamped between the two rows of suspension wheels; The wheel center axes of the two rows of suspension wheels (212) are arranged vertically so that the treads of the suspension wheels (212) fit the track surface of the vertically arranged support track (1).

7. The center-center-drive type stereoscopic broadcasting device according to claim 6, characterized in that: The number of suspension wheels (212) in each row is two, the two suspension wheels (212) are clamped side by side on the central support rail (1), and the distance between the two suspension wheels (212) is less than a second preset value.

8. The center-center-drive type stereoscopic broadcasting device according to claim 6, characterized in that: The number of the suspension fixing brackets (211) is two; The suspension wheels (212) on the two suspension fixing brackets (211) are arranged in parallel, and the distance between the two suspension fixing brackets (211) is less than a third preset value.

9. A center-center-drive type stereoscopic broadcasting device according to claim 1 or 4, characterized in that: The column assembly (2) further comprises: a lifting motor (23) and a lifting transmission device (24); The lifting motor (23) is arranged at either end of the lifting track of the column assembly (2), and the lifting motor (23) is connected to the cargo platform (3) through a lifting transmission device (24) to drive the cargo platform (3) to move on the track line of the lifting track.

10. The center-center-drive type stereoscopic broadcasting device according to claim 1, characterized in that: The column assembly (2) is also provided with an equipment box (5), the equipment box (5) and the cargo platform (3) are respectively arranged on both sides of the lifting track, and the height of the equipment box (5) is higher than the height of the middle area.

11. The center-center-drive type stereoscopic broadcasting device according to claim 1, characterized in that: The central support rail (1) comprises rail components with lines in various shapes, so as to deploy rail lines of different shapes.

12. A center-center-drive type stereoscopic broadcasting device according to claim 1 or 11, characterized in that: The central support track (1) forms at least one track line in a closed loop arrangement.

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