UHPC-steel box composite beam intelligent hoisting equipment

Abstract

The utility model provides a kind of UHPC-steel box composite beam intelligent hoisting equipment, it is related to bridge engineering construction technical field, including: equipment main frame;Equipment main frame component, the equipment main frame is installed in the upside of equipment main frame component;Steel box girder hanger component, installation is in the upper portion of equipment main frame;UHPC beam hanger component, installation is in the bottom of equipment main frame.The utility model is deficient in view of prior art, develops a kind of UHPC-steel box composite beam intelligent hoisting equipment, the utility model is in view of the problems existing in traditional UHPC-steel box composite beam construction, to improve construction efficiency, reduce construction cost, shorten construction period, reduce manpower and material resources input, improve construction quality.

Description

Technical Field

[0001] This utility model relates to the field of bridge engineering construction technology, and in particular to a UHPC-steel box composite beam intelligent hoisting equipment. Background Technology

[0002] Currently, UHPC (Ultra-High-Pressure Polymer) steel box girder bridges are being used more and more widely in long-span bridge projects. However, there is currently no mature construction equipment for this type of bridge, making construction quite difficult. At present, construction mainly employs scaffolding for UHPC beams and cantilever assembly of steel beams.

[0003] The current construction methods have the following drawbacks:

[0004] 1. Construction requires the erection of large-scale scaffolding, resulting in high costs;

[0005] 2. The scaffolding erection needs to be carried out in water, and the scale of underwater construction is large, making the operation difficult;

[0006] 3. The construction process requires a large number of equipment and tools.

[0007] Therefore, in order to address the above problems, a UHPC-steel box composite beam intelligent hoisting equipment is proposed to solve these problems. Summary of the Invention

[0008] This invention addresses the shortcomings of existing technologies by developing an intelligent hoisting device for UHPC-steel box composite beams. This invention addresses the problems existing in the construction of traditional UHPC-steel box composite beams, aiming to improve construction efficiency, reduce construction costs, shorten the construction period, reduce the input of manpower and materials, and improve construction quality.

[0009] The technical solution to the technical problem solved by this utility model is as follows: This utility model provides a UHPC-steel box composite beam intelligent hoisting equipment, including: a main frame of the equipment; a main frame assembly of the equipment, wherein the main frame of the equipment is installed on the upper side of the main frame assembly of the equipment; a steel box beam hanger assembly, installed on the upper part of the main frame of the equipment; and a UHPC beam hanger assembly, installed at the bottom of the main frame of the equipment.

[0010] As an optimization, the main frame of the equipment includes two first diagonal braces, two second diagonal braces, and two vertical poles. The upper ends of the first diagonal braces, second diagonal braces, and vertical poles are respectively connected to an upper crossbeam, and the lower ends of the first diagonal braces, second diagonal braces, and vertical poles are respectively connected to a bottom beam. The vertical poles, first diagonal braces, bottom beams, and upper crossbeams are connected using bolts. The second diagonal braces are connected to the bottom beams and upper crossbeams using pins.

[0011] As an optimization, the two first diagonal braces and the two uprights are connected by connecting rods. Connecting rods are installed between the two uprights and the two first diagonal braces using pins, increasing the overall stability of the main frame. The bottom beam is a symmetrical structure, composed of two bottom beams on the left and right sides and a connecting rod in the middle, welded together.

[0012] As an optimization, the steel box girder hanger assembly includes a crane, which is mounted on the upper side of the upper crossbeam. A longitudinal movement cylinder for the crane is mounted on the upper crossbeam, and the piston rod of the cylinder is connected to the crane. A winch is mounted on the crane, and the winch's wire rope is connected to an electric rotating hoist. A pin is used to connect the electric rotating hoist to the steel box girder hanger below, and the steel box girder hanger is connected below, enabling the lifting, lowering, and 90° rotation of the steel box girder. The longitudinal movement cylinder is mounted on the upper crossbeam using a pin, driving the crane to move back and forth along the upper crossbeam. A limit block is installed at the front end of the upper crossbeam to ensure the safe operation of the crane.

[0013] As an optimization, the UHPC beam hanger assembly includes two UHPC hoisting device main beams. Two UHPC hoisting device main beams are respectively installed above the bottom beam. Multiple main beams are horizontally connected between the two main beams to form a whole. Two transverse sliding seats are respectively installed above the two UHPC hoisting device main beams. Two transverse sliding cylinders are respectively installed above the two UHPC hoisting device main beams. The piston rod of each transverse sliding cylinder is connected to a corresponding transverse sliding seat. Each transverse sliding seat is equipped with a longitudinal sliding beam. Each longitudinal sliding beam is connected to a longitudinal sliding beam cylinder. Each longitudinal sliding beam cylinder is connected to a corresponding transverse sliding seat. A winch is installed on each longitudinal sliding beam. The wire rope of the winch is connected to the UHPC beam hanger. The transverse sliding cylinders drive the transverse sliding seats to move left and right along the UHPC hoisting device main beams. Limiting blocks are set on both sides of the main beams. The hydraulic cylinder of the longitudinal beam is connected to the lateral moving seat on the rear side, driving the longitudinal beam to move back and forth along the lateral moving seat. The lateral moving seat on the front side is equipped with a limit block to limit the longitudinal travel. The lateral moving seat and the longitudinal beam work together to complete fine adjustments in the lateral and longitudinal directions. The winch uses a wire rope to connect to the UHPC beam hanger, and the UHPC beam hanger connects to the UHPC beam to realize lifting and lowering actions.

[0014] As an optimization, the transverse sliding seat includes a transverse sliding seat body. A lower limit pressure plate is installed below the transverse sliding seat body using bolts to lock the upper flange of the main beam in place, ensuring the safe operation of the transverse sliding seat. An upper limit pressure plate is installed above the transverse sliding seat body using the same bolts to lock the lower flange of the longitudinal sliding beam in place, ensuring the safe operation of the longitudinal sliding beam.

[0015] As an optimization, two main beam support cylinders are symmetrically installed below the positions of the two main beams of the UHPC hoisting device corresponding to the web plates of the steel box girder.

[0016] As an optimization, the main frame assembly of the equipment includes two tracks, each nested with a second main frame support slide and a first main frame support slide. The second and first main frame support slides are respectively connected to the bottom beam. Each track is connected to a set of fixed lugs welded to the steel box girder, fixing it to the steel box girder. Each track is connected to a reaction seat, and the two reaction seats are connected to main frame longitudinal movement cylinders. The piston rods of the two main frame longitudinal movement cylinders are connected to the corresponding first main frame support slides. The main frame longitudinal movement cylinders drive the main frame of the equipment to move back and forth along the tracks. The first main frame support slide is bolted to the bottom of the corresponding upright of the bottom beam, and the second main frame support slide is installed at the front end of the bottom beam. One track is installed below each of the two bottom posts of the bottom beam.

[0017] As an optimization, a reverse buckle wheel is installed below the bottom beam corresponding to the installation position of the second diagonal bar. The reverse buckle wheel locks the upper flange of the track in it and can slide back and forth along the track to prevent the main frame from overturning when moving. A rear anchor device is installed behind the bottom beam corresponding to the reverse buckle wheel. When the equipment is fixed, one end of the rear anchor device is connected to the bottom beam and the other end is connected to the corresponding fixing lug to provide rear anchor force for the equipment and fix the equipment to prevent overturning.

[0018] The effects provided in the utility model description are merely those of the embodiments, and not all the effects of the utility model. The above technical solution has the following advantages or beneficial effects:

[0019] (1) The equipment combines the hoisting functions of steel box girder and UHPC beam into one device, which can realize the hoisting of steel box girder and UHPC beam of bridge. The equipment has a high degree of integration, diverse functions, and low manufacturing and use costs.

[0020] (2) The UHPC hoisting device is equipped with a transverse shift seat and a longitudinal shift beam, which can realize the position adjustment in both the transverse and longitudinal directions, and can also perform fine-tuning positioning to ensure the installation accuracy of the UHPC beam.

[0021] (3) The main beam of the UHPC hoisting device is equipped with four support cylinders. When the UHPC beam is installed, the support cylinders are supported on the bridge deck, which reduces the cantilever length of the main beam and reduces the stress on the main frame of the equipment.

[0022] (4) Limiting blocks are installed at the front end of the crossbeam on the main frame of the equipment, on both sides of the main beam of the UHPC hoisting device, and at the bottom of the longitudinal beam. Limiting pressure plates are installed on the upper and lower sides of the transverse seat to prevent the hoisting devices from slipping and to improve the safety of the hoisting devices during operation. Attached Figure Description

[0023] The accompanying drawings are provided to further understand the present invention and form part of the specification. They are used together with the embodiments of the present invention to explain the present invention and do not constitute a limitation thereof.

[0024] Figure 1 This is a side view of the hoisting equipment of this utility model.

[0025] Figure 2 This is a front view of the hoisting equipment of this utility model.

[0026] Figure 3 This is a side view of the UHPC hoisting device of this utility model.

[0027] Figure 4 This is a partial view of the transverse sliding seat of this utility model.

[0028] Figure 5 This is a schematic diagram of the steel box girder lifting method of this utility model.

[0029] Figure 6 This is a schematic diagram of the steel box girder of this utility model rotated 90 degrees.

[0030] Figure 7 This is a schematic diagram of the installation of the steel box girder of this utility model.

[0031] Figure 8 This is a schematic diagram of the installation of the UHPC beam of this utility model.

[0032] Figure 9 This is a schematic diagram showing the completed installation of the UHPC beam of this utility model.

[0033] In the diagram: 1. Main frame of the equipment; 1-1. First diagonal brace; 1-2. Upper crossbeam; 1-3. Vertical pole; 1-4. Second diagonal brace; 1-5. Bottom beam; 1-6. Connecting rod; 2. Overhead crane; 3. Winch; 4. Overhead crane longitudinal movement cylinder; 5. Electric rotating hoist; 6. Steel box girder hanger; 7. Second main frame support slide; 8. First main frame support slide; 9. Track; 10. Main frame longitudinal movement cylinder; 11. Reaction force. 12. Fixed ear plate; 13. Reverse buckle wheel; 14. Rear anchor device; 15. Horizontal moving seat; 15-1. Upper limit pressure plate; 15-2. Horizontal moving seat body; 15-3. Bolt; 15-4. Lower limit pressure plate; 16. Horizontal moving seat cylinder; 17. Main beam support cylinder; 18. UHPC hoisting device main beam; 19. Longitudinal moving beam; 20. Longitudinal moving beam cylinder; 21. Main beam transverse brace; 22. UHPC beam hanger. Detailed Implementation

[0034] To clearly illustrate the technical features of this solution, the present invention will be described in detail below through specific embodiments and in conjunction with the accompanying drawings. The following disclosure provides many different embodiments or examples for implementing different structures of the present invention. To simplify the disclosure of the present invention, the components and arrangements of specific examples are described below. Furthermore, the present invention may repeat reference numerals and / or letters in different examples. This repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. It should be noted that the components illustrated in the drawings are not necessarily drawn to scale. The present invention omits descriptions of well-known components and processing techniques and processes to avoid unnecessarily limiting the present invention. The terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate orientation or positional relationships based on the orientation or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0035] like Figures 1 to 9 As shown in Embodiment 1: A UHPC-steel box composite beam intelligent hoisting equipment includes: a main frame 1; a main frame assembly, wherein the main frame 1 is installed on the upper side of the main frame assembly; a steel box beam hanger assembly, installed on the upper part of the main frame 1; and a UHPC beam hanger assembly, installed at the bottom of the main frame 1.

[0036] The main frame 1 of the equipment includes two first diagonal braces 1-1, two second diagonal braces 1-4, and two uprights 1-3. The upper ends of the first diagonal braces 1-1, the second diagonal braces 1-4, and the uprights 1-3 are respectively connected to the upper crossbeam 1-2, and the lower ends of the first diagonal braces 1-1, the second diagonal braces 1-4, and the uprights 1-3 are respectively connected to the bottom beam 1-5. The uprights 1-3, the first diagonal braces 1-1, the bottom beam 1-5, and the upper crossbeam 1-2 are connected using bolts. The second diagonal braces 1-4 are connected to the bottom beam 1-5 and the upper crossbeam 1-2 using pins.

[0037] The two first diagonal braces 1-1 and the two uprights 1-3 are connected by connecting rods 1-6. Connecting rods 1-6 are installed between the two uprights 1-3 and the two first diagonal braces 1-1 using pins, increasing the overall stability of the main frame. The bottom beam 1-5 is a symmetrical structure, composed of two bottom rods on the left and right sides and a connecting rod in the middle, welded together.

[0038] The steel box girder suspension assembly includes a crane 2, which is mounted on the upper side of the upper crossbeam 1-2. A crane longitudinal movement cylinder 4 is installed on the upper crossbeam 1-2, and the piston rod of the cylinder 4 is connected to the crane 2. A winch 3 is mounted on the crane 2, and the wire rope of the winch 3 is connected to an electric rotating hoist 5. A steel box girder suspension frame 6 is connected to the lower part of the electric rotating hoist 5 via a pin, and the steel box girder is connected to the lower part of the suspension frame 6, enabling the lifting, lowering, and 90° rotation of the steel box girder. The crane longitudinal movement cylinder 4 is mounted on the upper crossbeam 1-2 via a pin, driving the crane 2 to move back and forth along the upper crossbeam 1-2. A limit block is installed at the front end of the upper crossbeam 1-2 to ensure the safe operation of the crane 2.

[0039] The UHPC beam hanger assembly includes two UHPC hoisting device main beams 18. Two UHPC hoisting device main beams 18 are respectively installed above the bottom beams 1-5. Multiple main beam cross bracing 21 are installed between the two main beams to form a whole. Two transverse sliding seats 15 are respectively installed above the two UHPC hoisting device main beams 18. Two transverse sliding cylinders 16 are respectively installed above the two UHPC hoisting device main beams 18. The piston rod of each transverse sliding cylinder 16 is connected to the corresponding transverse sliding seat 15. Each transverse sliding seat 15 is equipped with a longitudinal sliding beam 19. Each longitudinal sliding beam 19 is connected to a longitudinal sliding beam cylinder 20. Each longitudinal sliding beam cylinder 20 is connected to the corresponding transverse sliding seat 15. Each longitudinal sliding beam 19 is equipped with a winch 3. The wire rope of the winch 3 is connected to the UHPC beam hanger 22. The transverse cylinder 16 drives the transverse seat 15 to move left and right along the main beam 18 of the UHPC hoisting device. Limiting blocks are set on both sides of the main beam. The longitudinal beam cylinder 20 is connected to the rear transverse seat 15, driving the longitudinal beam 19 to move back and forth along the transverse seat 15. Limiting blocks are set on the front transverse seat 15 to limit the longitudinal travel. The transverse seat 15 and the longitudinal beam 19 work together to complete the fine adjustment in the transverse and longitudinal directions. The winch 3 is connected to the UHPC beam hanger 22 with a wire rope. The UHPC beam hanger 22 is connected to the UHPC beam to realize the lifting and lowering actions.

[0040] The main frame assembly of the equipment includes two rails 9, which respectively nest a second main frame support slide 7 and a first main frame support slide 8. The second main frame support slide 7 and the first main frame support slide 8 are respectively connected to the bottom beam 1-5. Each rail 9 is connected to a set of fixed lugs 12 welded to the steel box girder, fixing it to the steel box girder. Each rail 9 is connected to a reaction seat 11, and the two reaction seats 11 are connected to main frame longitudinal movement cylinders 10. The piston rods of the two main frame longitudinal movement cylinders 10 are connected to the corresponding first main frame support slide 8. The main frame longitudinal movement cylinders 10 drive the main frame 1 of the equipment to move back and forth along the rails 9. The first main frame support slide 8 is bolted to the bottom beam 1-5 below the corresponding upright 1-3, and the second main frame support slide 7 is installed at the front end of the bottom beam 1-5. One rail 9 is installed below each of the two bottom rods of the bottom beam 1-5.

[0041] The workflow of this embodiment is as follows:

[0042] During installation, the steel box girder is hoisted first, then the equipment travels a suitable length to hoist the corresponding UHPC beam below. This process is repeated until all the corresponding UHPC beams below a section of steel box girder are installed. Then the lower steel box girder is installed, and so on.

[0043] During the installation of the steel box girder: A transport vehicle is used to transport the steel box girder to the designated location. The steel box girder hanger 6 is lowered and connected to the corresponding lifting points on the steel box girder. After a reliable connection, the winch 3 is controlled to lift the steel box girder to the designated height. Then, the electric rotating hoist 5 is used to rotate the steel box girder 90 degrees, and then the lifting continues to the appropriate height. The gantry crane's longitudinal movement cylinder 4 retracts, causing the gantry crane 2 to move backward, which in turn moves the steel box girder backward to align with the previously installed box girder. Finally, the two box girder sections are welded to complete the installation. Figure 5 , 6 As shown in Figures 7 and 8.

[0044] When the equipment is moving: at this time, the track 9 is fixed to the steel box girder; the main frame longitudinal movement cylinder 10 extends, driving the equipment to move forward a certain length along the track 9; the reaction seat 11 is unlocked from the track 9, the main frame longitudinal movement cylinder 10 retracts, driving the reaction seat 11 to move forward a certain length along the track 9, and the above process is repeated to move the equipment to the appropriate position.

[0045] During UHPC beam installation: A transport vehicle is used to move the UHPC beam to the designated location. The UHPC beam hangers 22 on both sides are lowered and connected to the lifting points of the UHPC beam. After a secure connection, the UHPC beam is raised to the designated height. Then, the horizontal sliding seat cylinder 16 is controlled to extend and retract, causing the horizontal sliding seat 15 to move left and right along the main beam 18 of the UHPC lifting device, which in turn causes the longitudinal sliding beam 19 to move left and right, aligning the UHPC beam laterally with the already installed beam block. The longitudinal sliding beam cylinder 20 is then controlled to retract, causing the longitudinal sliding beam 19 to move backward, completing the docking installation with the previous UHPC beam section. For example... Figure 8 , 9 As shown.

[0046] Example 2: This example further elaborates on Example 1. A reverse-locking wheel 13 is installed below the installation position of the second diagonal bar 1-4 on the bottom beam 1-5. The reverse-locking wheel 13 engages the upper flange of the track 9 and can slide back and forth along the track 9 to prevent the main frame from overturning during movement. A rear anchoring device 14 is installed behind the bottom beam 1-5 corresponding to the reverse-locking wheel 13. When the equipment is fixed, one end of the rear anchoring device 14 is connected to the bottom beam 1-5, and the other end is connected to the corresponding fixing lug 12, providing rear anchoring force to fix the equipment and prevent overturning.

[0047] During the installation of the steel box girder: First, ensure that the equipment rear anchoring device 14 is reliably anchored to the steel bridge.

[0048] When the equipment is moving: Before the equipment moves, first unlock the anchorage of the rear anchor device 14 to the steel box girder.

[0049] Example 3: This example is a further elaboration based on Example 1 or 2. The transverse shift seat 15 includes a transverse shift seat body 15-2. A lower limit pressure plate 15-4 is installed below the transverse shift seat body 15-2 using bolts 15-3 to lock the upper flange of the main beam in it, ensuring the safe operation of the transverse shift seat 15. An upper limit pressure plate 15-1 is installed above the transverse shift seat body 15-2 using the same bolts 15-3 to lock the lower flange of the longitudinal shift beam in it, ensuring the safe operation of the longitudinal shift beam.

[0050] During UHPC beam installation: First, ensure that the equipment's rear anchoring device 14 is reliably anchored to the steel bridge.

[0051] Example 4: This example is a further elaboration based on Example 1, 2 or 3. Two main beam support cylinders 17 are symmetrically installed below the positions of the two main beams 18 of the UHPC hoisting device corresponding to the web of the steel box girder.

[0052] The workflow of this embodiment is as follows:

[0053] When the equipment is moving, the main beam support cylinder 17 is retracted and disengaged from the bridge deck. After the equipment has finished moving, the main beam support cylinder 17 is retracted and re-engaged from the bridge deck.

[0054] Although the specific embodiments of the utility model have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of the utility model. Based on the technical solution of the utility model, various modifications or variations that can be made by those skilled in the art without creative effort are still within the scope of protection of the utility model.

Claims

1. A UHPC-steel box composite beam intelligent hoisting equipment, characterized in that, include: Equipment main frame (1); The main frame assembly of the equipment, wherein the main frame (1) is mounted on the upper side of the main frame assembly of the equipment; The steel box girder hanger assembly is installed on the upper part of the main frame (1) of the equipment; The UHPC beam hanger assembly is installed at the bottom of the main frame (1) of the equipment.

2. The UHPC-steel box composite beam intelligent hoisting equipment according to claim 1, characterized in that: The main frame (1) of the equipment includes two first diagonal braces (1-1), two second diagonal braces (1-4) and two uprights (1-3). The upper ends of the first diagonal braces (1-1), the second diagonal braces (1-4) and the uprights (1-3) are respectively connected to the upper crossbeam (1-2), and the lower ends of the first diagonal braces (1-1), the second diagonal braces (1-4) and the uprights (1-3) are respectively connected to the bottom beam (1-5).

3. The UHPC-steel box composite beam intelligent hoisting equipment according to claim 2, characterized in that: The two first diagonal bars (1-1) and the two upright bars (1-3) are connected by connecting rods (1-6).

4. The UHPC-steel box composite beam intelligent hoisting equipment according to claim 2, characterized in that: The steel box girder hanger assembly includes a crane (2), which is installed on the upper side of the upper crossbeam (1-2). The upper crossbeam (1-2) is equipped with a crane longitudinal movement cylinder (4), the piston rod of which is connected to the crane (2). A winch (3) is installed on the crane (2), and the wire rope of the winch (3) is connected to an electric rotating hoist (5). The steel box girder hanger (6) is connected to the electric rotating hoist (5) by a pin shaft.

5. The UHPC-steel box composite beam intelligent hoisting equipment according to claim 2, characterized in that: The UHPC beam hanger assembly includes two UHPC hoisting device main beams (18). Two UHPC hoisting device main beams (18) are installed above the bottom beam (1-5). Two transverse seats (15) are installed above the two UHPC hoisting device main beams (18). Two transverse cylinders (16) are installed above the two UHPC hoisting device main beams (18). The piston rod of each transverse cylinder (16) is connected to the corresponding transverse seat (15). Each transverse seat (15) is equipped with a longitudinal beam (19). Each longitudinal beam (19) is connected to a longitudinal beam cylinder (20). Each longitudinal beam cylinder (20) is connected to the corresponding transverse seat (15). Each longitudinal beam (19) is equipped with a winch (3). The wire rope of the winch (3) is connected to the UHPC beam hanger (22).

6. The UHPC-steel box composite beam intelligent hoisting equipment according to claim 5, characterized in that: The transverse shift seat (15) includes a transverse shift seat body (15-2), a lower limit pressure plate (15-4) is installed below the transverse shift seat body (15-2) using bolts (15-3), and an upper limit pressure plate (15-1) is installed above the transverse shift seat body (15-2) using the same bolts (15-3).

7. The UHPC-steel box composite beam intelligent hoisting equipment according to claim 5, characterized in that: Two main beam support cylinders (17) are symmetrically installed on the two main beams (18) of the UHPC hoisting device.

8. The UHPC-steel box composite beam intelligent hoisting equipment according to claim 2, characterized in that: The main frame assembly of the equipment includes two rails (9), which are nested in a second main frame support slide (7) and a first main frame support slide (8). The second main frame support slide (7) and the first main frame support slide (8) are respectively connected to the bottom beam (1-5). The two rails (9) are respectively connected to the reaction seats (11). The two reaction seats (11) are connected to the main frame longitudinal movement cylinders (10). The piston rods of the two main frame longitudinal movement cylinders (10) are connected to the corresponding first main frame support slides (8).

9. The UHPC-steel box composite beam intelligent hoisting equipment according to claim 8, characterized in that: The bottom beam (1-5) is equipped with a reverse-locking wheel (13), which locks the upper flange of the track (9) in place; The bottom beam (1-5) is equipped with a rear anchor device (14).

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