Self-retracting operation railway maintenance and treatment trolley

Abstract

The utility model discloses a kind of self-recovery and release operation trolley for operation railway maintenance and regulation, solve the problem that operation platform cannot be unfolded according to demand in prior art.The utility model includes the movable frame that can be moved along track, first operation platform being arranged on movable frame, second operation platform being slidably arranged on movable frame and being located on first operation platform, and respectively being arranged on the both sides of first operation platform and second operation platform climbing ladder.The utility model moves along track, and movable frame drives first operation platform and second operation platform to move synchronously, so as to facilitate adjusting the position of operation platform on track, in addition, first operation platform and second operation platform are all using storable structure, so that operation platform can be unfolded and stored according to the demand of tunnel maintenance, so as to facilitate overhauling, maintenance and construction to railway tunnel.

Description

Technical Field

[0001] This utility model belongs to the technical field of tunnel maintenance equipment, specifically relating to a self-retracting and extending work trolley for the maintenance and repair of operating railways. Background Technology

[0002] The railway system is an important infrastructure and transportation tool. my country's existing railway system is highly developed. Due to the large scale of my country's railway system and the high frequency of railway use, the daily inspection and maintenance of railway-related facilities has always been very important. In recent years, with the continuous advancement of railway construction, my country's railway tunnel industry has continued to develop, and it has now become the country with the largest scale of railway tunnels in operation in the world.

[0003] Chinese Patent (Application No.: CN202421131143.1) discloses a scaffold for tunnel maintenance, including a support unit, the support unit including two sets of support frame groups; a first lifting platform, the first lifting platform being disposed between the two support frame groups; and a second lifting platform, two of which are provided, the two second lifting platforms being slidably connected to the two support frame groups respectively and fixedly connected by connecting rods, wherein a lifting component is connected between one support frame group and the corresponding second lifting platform.

[0004] Although the height of the support frame group can be adjusted by the lifting components, the scaffolding is affected by the tunnel space during use, which makes it impossible to store and unfold the support frame group according to maintenance needs, thereby reducing the maintenance and repair efficiency of railway tunnels. Summary of the Invention

[0005] This utility model provides a self-retracting and extending work trolley for the maintenance and repair of operating railways, so as to at least solve some of the above-mentioned technical problems.

[0006] To achieve the above objectives, the technical solution adopted by this utility model is as follows:

[0007] A self-retracting work platform for railway maintenance and repair includes a movable frame that can move along a track, a first work platform mounted on the movable frame, a second work platform slidably mounted on the movable frame and located on the first work platform, and climbing ladders respectively mounted on both sides of the first and second work platforms; the first work platform includes a first fixed platform mounted at both ends of the movable frame, a first sliding plate and a second sliding plate slidably mounted on the first fixed platform, and a hydraulic push rod A mounted on the movable frame and connected to the first and second sliding plates respectively.

[0008] Furthermore, the first fixed platform and the movable frame are provided with a plurality of first guide mechanisms; the first guide mechanism includes a guide rod A provided on the first fixed platform and the movable frame, a limiting guide groove A opened on the guide rod A, a roller mounting seat A provided on the first sliding plate and the second sliding plate, and a roller A rotatably provided on the roller mounting seat A and located in the limiting guide groove A.

[0009] Furthermore, the movable frame is provided with a push rod mounting seat A, and the first sliding plate and the second sliding plate are provided with a push rod connecting seat A. The hydraulic push rod A is installed between the push rod mounting seat A and the push rod connecting seat A.

[0010] Furthermore, the second workbench includes a second fixed platform on a sliding frame, a third sliding plate and a fourth sliding plate slidably disposed on the second fixed platform, two hydraulic push rods B disposed on the second fixed platform and respectively connected to the third sliding plate and the fourth sliding plate, and two sets of drive mechanisms disposed on the frame for pushing the second fixed platform to move up and down.

[0011] Furthermore, the drive mechanism includes a clearance groove formed on the first sliding plate and the second sliding plate, and a hydraulic push rod C disposed on the movable frame and connected to the second fixed platform through the clearance groove.

[0012] Furthermore, the second fixed platform is provided with several second guide mechanisms. The second guide mechanism includes a guide rod B provided on the second fixed platform, a limiting guide groove B opened on the guide rod B, a roller mounting seat B provided on the third sliding plate and the fourth sliding plate, and a roller B that is provided in the roller mounting seat B and located in the limiting guide groove B.

[0013] Furthermore, the mobile frame includes a base plate that slides on the track, four columns on the base plate, a crossbar between two adjacent columns, and a sliding column that slides inside the columns and is connected to the second work platform; a hydraulic push rod A is installed on the crossbar.

[0014] Furthermore, two sets of moving mechanisms are mirror-symmetrically arranged on the base plate. The moving mechanisms include mounting seats symmetrically arranged on the base plate and moving wheels rotatably arranged on the mounting seats and in contact with the track.

[0015] Furthermore, several reinforcing bars are installed between the uprights and the crossbars.

[0016] Furthermore, the sliding column is provided with reinforcing ribs that connect to the second worktable.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] This utility model has a simple structure, a scientific and reasonable design, and is easy to use. The mobile frame of this utility model moves along the track, and the mobile frame drives the first and second work platforms to move synchronously, thereby facilitating the adjustment of the position of the work platforms on the track. In addition, both the first and second work platforms adopt a retractable structure, so that the work platforms can be unfolded and retracted according to the needs of tunnel maintenance, thereby facilitating the inspection, maintenance and construction of railway tunnels. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of this utility model.

[0020] Figure 2 for Figure 1 Enlarged view of point A in the middle.

[0021] Figure 3 for Figure 1 Enlarged view of point B in the middle.

[0022] Figure 4 This is a schematic diagram of the mobile frame of this utility model.

[0023] Figure 5 This is a schematic diagram of the unfolded first workbench of this utility model.

[0024] Figure 6 This is a schematic diagram of the unfolded second workbench of this utility model.

[0025] Figure 7 This is a schematic diagram of hydraulic push rod A or hydraulic push rod B of this utility model.

[0026] The names corresponding to the reference numerals in the attached figures are as follows:

[0027] 1. Movable frame; 2. First work platform; 3. Second work platform; 4. Climbing ladder; 5. First fixed platform; 6. First sliding plate; 7. Second sliding plate; 8. Hydraulic push rod A; 9. Guide rod A; 10. Limiting guide groove A; 11. Roller mounting seat A; 12. Roller A; 13. Push rod mounting seat A; 14. Push rod connecting seat A; 15. Second fixed platform; 16. Third sliding plate; 17. Fourth sliding plate; 18. Hydraulic push rod B; 19. Clearance groove; 20. Hydraulic push rod C; 21. Guide rod B; 22. Limiting guide groove B; 23. Roller mounting seat B; 24. Roller B; 25. Base plate; 26. Column; 27. Horizontal bar; 28. Sliding column; 29. ​​Mounting seat; 30. Moving wheel; 31. Reinforcing rod; 32. Reinforcing rib plate; 33. Push rod mounting seat B; 34. Push rod connecting seat B. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this utility model, and not all of them. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0029] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0030] 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; of course, they can also refer to a mechanical connection or an electrical connection; furthermore, they can refer to a direct connection, an indirect connection through an intermediate medium, or a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances. Example

[0031] like Figure 1-7 As shown, the present invention provides a self-retracting and deploying work trolley for maintenance and repair of operating railways. It is characterized by comprising a movable frame 1 that can move along a track, a first work platform 2 mounted on the movable frame 1, a second work platform 3 slidably mounted on the movable frame 1 and located on the first work platform 2, and climbing ladders 4 respectively mounted on both sides of the first work platform 2 and the second work platform 3. The first work platform 2 includes a first fixed platform 5 mounted at both ends of the movable frame 1, a first sliding plate 6 and a second sliding plate 7 slidably mounted on the first fixed platform 5, and a hydraulic push rod A8 mounted on the movable frame 1 and connected to the first sliding plate 6 and the second sliding plate 7 respectively.

[0032] The mobile frame 1 of this utility model moves along the track, and the mobile frame 1 drives the first work platform 2 and the second work platform 3 to move synchronously, thereby facilitating the adjustment of the position of the work platform on the track. In addition, the first work platform 2 and the second work platform 3 both adopt a retractable structure, so that the work platform can be unfolded and retracted according to the needs of tunnel maintenance, thereby facilitating the inspection, maintenance and construction of railway tunnels.

[0033] In this invention, two hydraulic push rods A8 are respectively connected to the first sliding plate 6 and the second sliding plate 7. That is, the output end of one hydraulic push rod A8 is connected to the first sliding plate 6, and the output end of the other hydraulic push rod A8 is connected to the second sliding plate 7. When unfolding, one hydraulic push rod A8 pushes the first sliding plate 6 to the left, and the other hydraulic push rod A8 pushes the second sliding plate 7 to the right, thereby unfolding the first sliding plate 6 and the second sliding plate 7, thus increasing the area of ​​the first work platform 2 and facilitating the maintenance of the tunnel by the workers. Similarly, when folding up, one hydraulic push rod A8 pushes the first sliding plate 6 to the right, and the other hydraulic push rod A8 pushes the second sliding plate 7 to the left, so that the first sliding plate 6 and the second sliding plate 7 come into contact, thereby facilitating the folding up of the first sliding plate 6 and the second sliding plate 7.

[0034] In this invention, the climbing ladder 4 is installed on the first fixed platform 5, and the two climbing ladders 4 are staggered with each other.

[0035] In one embodiment, a more detailed structure of the first fixed platform 5 and the movable frame 1 is provided; the first fixed platform 5 and the movable frame 1 are provided with a plurality of first guide mechanisms; the first guide mechanism includes a guide rod A9 provided on the first fixed platform 5 and the movable frame 1, a limiting guide groove A10 opened on the guide rod A9, a roller mounting seat A11 provided on the first sliding plate 6 and the second sliding plate 7, and a roller A12 rotatably provided on the roller mounting seat A11 and located in the limiting guide groove A10.

[0036] In this utility model, the first guide mechanism can easily restrict the movement direction of the first sliding plate 6 and the second sliding plate 7. In use, when the first sliding plate 6 and the second sliding plate 7 are moving, the roller A12 moves synchronously in the limiting guide groove A10. The roller A12 can effectively reduce the friction of the first sliding plate 6 and the second sliding plate 7 when they are moving.

[0037] In one embodiment, a more detailed structure of the movable frame 1 is provided; the movable frame 1 is provided with a push rod mounting seat A13, and the first sliding plate 6 and the second sliding plate 7 are provided with a push rod connecting seat A14, and the hydraulic push rod A8 is installed between the push rod mounting seat A13 and the push rod connecting seat A14.

[0038] In this utility model, the push rod mounting seat A13 is mounted on the crossbar 27, and the push rod connecting seat A14 is located at the bottom of the first sliding plate 6 and the second sliding plate 7. Specifically, one end of the hydraulic push rod A8 is mounted on the push rod mounting seat A13, and its output end is mounted in the push rod connecting seat A14 at the bottom of the first sliding plate 6 or the second sliding plate 7. The push rod mounting seat A13 and the push rod connecting seat A14 facilitate the installation of the hydraulic push rod A8.

[0039] In one embodiment, a more detailed structure of the second workbench 3 is provided; the second workbench 3 includes a second fixed platform 15 on a sliding frame 1, a third sliding plate 16 and a fourth sliding plate 17 slidably disposed on the second fixed platform 15, two hydraulic push rods B18 disposed on the second fixed platform 15 and respectively connected to the third sliding plate 16 and the fourth sliding plate 17, and two sets of drive mechanisms disposed on the moving frame 1 for pushing the second fixed platform 15 to move up and down.

[0040] In this invention, the second fixed platform 15 is mounted on the sliding column 28. Two hydraulic push rods B18 are respectively connected to the third sliding plate 16 and the fourth sliding plate 17. That is, the output end of one hydraulic push rod B18 is connected to the third sliding plate 16, and the output end of the other hydraulic push rod B18 is connected to the fourth sliding plate 17. In use, two sets of drive mechanisms drive the second fixed platform 15 to move up and down on the movable frame 1, thereby adjusting the height of the second fixed platform 15. In addition, when it is necessary to unfold the third sliding plate 16 and the fourth sliding plate 17, the hydraulic push rods B18 are activated, one of which... Hydraulic push rod B18 pushes the third sliding plate 16 to the left, and another hydraulic push rod B18 pushes the fourth sliding plate 17 to the right, thereby unfolding the third sliding plate 16 and the fourth sliding plate 17, thus increasing the usable area of ​​the second fixed platform 15. Similarly, when storing, hydraulic push rods B18 are activated, one hydraulic push rod B18 pushes the third sliding plate 16 to the right, and the other hydraulic push rod B18 pushes the fourth sliding plate 17 to the left, so that the third sliding plate 16 and the fourth sliding plate 17 come into contact, thereby completing the storage of the second workbench 3, which facilitates the improvement of the workbench's usable range.

[0041] In this utility model, the second fixed platform 15 is provided with a push rod mounting seat B33, the third sliding plate 16 and the fourth sliding plate 17 are provided with push rod connecting seats B34, and the hydraulic push rod B18 is installed between the push rod mounting seat B33 and the push rod connecting seat B34.

[0042] In this utility model, the climbing ladder 4 is installed on the second fixed platform 15, and the two climbing ladders 4 are staggered with each other.

[0043] In one embodiment, a more detailed structure of the drive mechanism is provided; the drive mechanism includes a clearance groove 19 formed on the first sliding plate 6 and the second sliding plate 7, and a hydraulic push rod C20 disposed on the movable frame 1 and passing through the clearance groove 19 to connect with the second fixed platform 15.

[0044] In this invention, a clearance groove 19 is provided on the first sliding plate 6 and the second sliding plate 7, and the clearance groove 19 on the first sliding plate 6 and the second sliding plate 7 can be spliced ​​into a rectangle. A hydraulic push rod C20 is installed on the movable frame 1, and the output end of the hydraulic push rod C20 passes through the clearance groove 19 and is connected to the bottom of the second fixed platform 15. When in use, the hydraulic push rod C20 is activated, and the hydraulic push rod C20 pushes the second fixed platform 15 to move up and down on the movable frame 1, thereby adjusting the height of the second fixed platform 15.

[0045] In one embodiment, a more detailed structure of the second fixed platform 15 is provided; the second fixed platform 15 is provided with a plurality of second guide mechanisms, the second guide mechanism including a guide rod B21 provided on the second fixed platform 15, a limiting guide groove B22 opened on the guide rod B21, a roller mounting seat B23 provided on the third sliding plate 16 and the fourth sliding plate 17, and a roller B24 rotatably provided in the roller mounting seat B23 and located in the limiting guide groove B22.

[0046] In this invention, the second guiding mechanism facilitates the guidance of the third sliding plate 16 and the fourth sliding plate 17. During use, when the third sliding plate 16 and the fourth sliding plate 17 are moving, the rollers B24 on the third sliding plate 16 and the fourth sliding plate 17 rotate within the limiting guide groove B22 as the third sliding plate 16 and the fourth sliding plate 17 move. The rollers B24 can effectively reduce the friction caused by the movement of the third sliding plate 16 and the fourth sliding plate 17.

[0047] In one embodiment, a more detailed structure of the second fixed platform 15 is provided; the mobile frame 1 includes a base plate 25 slidably mounted on a track, four columns 26 mounted on the base plate 25, a crossbar 27 mounted between two adjacent columns 26, and a sliding column 28 slidably mounted in the columns 26 and connected to the second workbench 3; a hydraulic push rod A8 is mounted on the crossbar 27.

[0048] In this utility model, the column 26 is a hollow rectangular structure, and the sliding column 28 is slidably installed inside the column 26. When in use, when the second fixed platform 15 moves up and down, the sliding column 28 moves synchronously with the second fixed platform 15, so that the second fixed platform 15 can be limited and guided by the sliding column 28.

[0049] In one embodiment, a more detailed structure of the base plate 25 is provided; two sets of moving mechanisms are mirror-symmetrically arranged on the base plate 25, each moving mechanism including a mounting base 29 symmetrically arranged on the base plate 25, and a moving wheel 30 rotatably arranged on the mounting base 29 and in contact with the track.

[0050] In this utility model, the moving mechanism facilitates the movement of the base plate 25 on the track. Specifically, when the base plate 25 moves, the moving wheel 30 rotates on the track along with the movement of the base plate 25, thereby reducing the friction caused by the movement of the base plate 25.

[0051] In one embodiment, a more detailed connection structure is provided between the column 26 and the crossbar 27; a number of reinforcing rods 31 are provided between the column 26 and the crossbar 27.

[0052] In this invention, the reinforcing rod 31 can enhance the structural strength of the movable frame 1.

[0053] Example 10.

[0054] In one embodiment, a more detailed connection structure is provided for the column 26 and the crossbar 27; the sliding column 28 is provided with a reinforcing rib 32 that is connected to the second workbench 3.

[0055] In this invention, the reinforcing rib 32 can enhance the structural strength of the sliding column 28 and the second fixed platform 15.

[0056] Working principle.

[0057] In use, the base plate 25 is pushed to move it to the desired position. When the first work platform 2 needs to be unfolded, the hydraulic push rods A8 are activated. One hydraulic push rod A8 pushes the first sliding plate 6 to the left, and the other hydraulic push rod A8 pushes the second sliding plate 7 to the right, thereby unfolding the first sliding plate 6 and the second sliding plate 7, which facilitates the maintenance of the tunnel by the workers on the first work platform 2. Similarly, when folding, one hydraulic push rod A8 pushes the first sliding plate 6 to the right, and the other hydraulic push rod A8 pushes the second sliding plate 7 to the left, so that the first sliding plate 6 and the second sliding plate 7 come into contact, which facilitates the folding of the first sliding plate 6 and the second sliding plate 7.

[0058] When the second workbench 3 needs to be unfolded, hydraulic push rods B18 are activated. One hydraulic push rod B18 pushes the third sliding plate 16 to the left, and the other hydraulic push rod B18 pushes the fourth sliding plate 17 to the right, thereby unfolding the third sliding plate 16 and the fourth sliding plate 17, thus increasing the usable area of ​​the second fixed platform 15. Similarly, when folding it up, hydraulic push rods B18 are activated. One hydraulic push rod B18 pushes the third sliding plate 16 to the right, and the other hydraulic push rod B18 pushes the fourth sliding plate 17 to the left, so that the third sliding plate 16 and the fourth sliding plate 17 come into contact, thereby completing the folding up of the second workbench 3 and facilitating the expansion of the workbench's usable range.

[0059] When it is necessary to adjust the height of the second work platform 3, the hydraulic push rod C20 is activated. The hydraulic push rod C20 pushes the second fixed platform 15 to move up and down. At the same time, the sliding column 28 moves synchronously with the sliding column 28, thereby guiding the movement direction of the second work platform 3, so as to facilitate the maintenance of the tunnel by the staff.

[0060] Workers can use the climbing ladder 4 to climb to the first working platform 2 or the second working platform 3 to maintain, inspect, and carry out construction on the railway tunnel.

[0061] The hydraulic push rods A8, B18, and C20 used in this invention are existing technologies and can be purchased and used directly on the market. Therefore, the structure, principle, and circuit of the hydraulic push rods A8, B18, and C20 will not be described in detail here.

[0062] Finally, it should be noted that the above embodiments are merely preferred embodiments of this utility model used to illustrate the technical solutions of this utility model, and are not intended to limit it, nor are they intended to limit the patent scope of this utility model. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model. That is to say, any changes or refinements made to the main design concept and spirit of this utility model that are not of substantial significance, but whose technical problems are still consistent with those of this utility model, should be included within the protection scope of this utility model. In addition, the direct or indirect application of the technical solutions of this utility model to other related technical fields are similarly included within the patent protection scope of this utility model.

Claims

1. A self-retracting and extending work trolley for railway maintenance and repair, characterized in that, It includes a movable frame (1) that can move along a track, a first work platform (2) on the movable frame (1), a second work platform (3) that is slidably disposed on the movable frame (1) and located on the first work platform (2), and climbing ladders (4) respectively disposed on both sides of the first work platform (2) and the second work platform (3); the first work platform (2) includes a first fixed platform (5) disposed at both ends of the movable frame (1), a first sliding plate (6) and a second sliding plate (7) slidably disposed on the first fixed platform (5), and a hydraulic push rod A (8) disposed on the movable frame (1) and connected to the first sliding plate (6) and the second sliding plate (7) respectively.

2. The self-retracting and extending work trolley for maintenance and repair of operating railways according to claim 1, characterized in that, The first fixed platform (5) and the movable frame (1) are provided with a plurality of first guide mechanisms; the first guide mechanism includes a guide rod A (9) provided on the first fixed platform (5) and the movable frame (1), a limiting guide groove A (10) opened on the guide rod A (9), a roller mounting seat A (11) provided on the first sliding plate (6) and the second sliding plate (7), and a roller A (12) rotatably provided on the roller mounting seat A (11) and located in the limiting guide groove A (10).

3. The self-retracting and extending work trolley for maintenance and repair of operating railways according to claim 1, characterized in that, The movable frame (1) is provided with a push rod mounting seat A (13), and the first sliding plate (6) and the second sliding plate (7) are provided with a push rod connecting seat A (14). The hydraulic push rod A (8) is installed between the push rod mounting seat A (13) and the push rod connecting seat A (14).

4. The self-retracting and extending work trolley for maintenance and repair of operating railways according to claim 1, characterized in that, The second workbench (3) includes a second fixed platform (15) on a sliding frame (1), a third sliding plate (16) and a fourth sliding plate (17) slidably disposed on the second fixed platform (15), two hydraulic push rods B (18) disposed on the second fixed platform (15) and respectively connected to the third sliding plate (16) and the fourth sliding plate (17), and two sets of drive mechanisms disposed on the moving frame (1) for pushing the second fixed platform (15) to move up and down.

5. A self-retracting and extending work trolley for maintenance and repair of operating railways according to claim 4, characterized in that, The drive mechanism includes a clearance groove (19) formed on the first sliding plate (6) and the second sliding plate (7), and a hydraulic push rod C (20) provided on the movable frame (1) and connected to the second fixed platform (15) through the clearance groove (19).

6. A self-retracting and extending work trolley for maintenance and repair of operating railways according to claim 4, characterized in that, The second fixed platform (15) is provided with several second guide mechanisms. The second guide mechanism includes a guide rod B (21) provided on the second fixed platform (15), a limiting guide groove B (22) opened on the guide rod B (21), a roller mounting seat B (23) provided on the third sliding plate (16) and the fourth sliding plate (17), and a roller B (24) provided in the roller mounting seat B (23) and located in the limiting guide groove B (22) for rotation.

7. A self-retracting and extending work trolley for maintenance and repair of operating railways according to claim 1, characterized in that, The mobile frame (1) includes a base plate (25) that slides on the track, four columns (26) on the base plate (25), a crossbar (27) between two adjacent columns (26), and a sliding column (28) that slides in the columns (26) and is connected to the second worktable (3); the hydraulic push rod A (8) is installed on the crossbar (27).

8. A self-retracting and extending work trolley for maintenance and repair of operating railways according to claim 7, characterized in that, Two sets of moving mechanisms are mirror-symmetrically arranged on the base plate (25). The moving mechanisms include mounting seats (29) symmetrically arranged on the base plate (25) and moving wheels (30) rotatably arranged on the mounting seats (29) and in contact with the track.

9. A self-retracting and extending work trolley for maintenance and repair of operating railways according to claim 7, characterized in that, Several reinforcing bars (31) are provided between the column (26) and the crossbar (27).

10. A self-retracting and extending work trolley for maintenance and repair of operating railways according to claim 7, characterized in that, The sliding column (28) is provided with a reinforcing rib (32) that is connected to the second worktable (3).

Images