Supporting device for tunnel construction

Abstract

The utility model discloses a supporting device for tunnel construction. The supporting device comprises a first connecting rod, a second connecting rod, a connecting plate, a long screw rod and a first nut. According to the supporting device for tunnel construction, the ends, close to each other, of second connecting rods are fixedly connected with connecting plates, a plurality of long screws jointly penetrate through the connecting plates, round holes allowing the long screws to penetrate through are formed in the connecting plates, and the two sides, corresponding to the connecting plates, of the long screws are in threaded connection with first nuts; the end, close to the first connecting rod, of the second connecting rod is further fixedly connected with an extension rod, the extension rod is inserted into the inner side of the end of the first connecting rod and slidably connected with the first connecting rod, and the first connecting rod and the second connecting rod are combined and connected through the extension rod and matched with a long screw connecting plate and a first nut to be combined and fixed. Therefore, the combined effective length of the first connecting rod and the second connecting rod can be conveniently controlled, the length of the connecting rod mechanism can be conveniently matched with the distance between the steel arches, and the problem that connection cannot be conducted due to the fact that the connecting rod mechanism is long or short is solved.

Description

Technical Field

[0001] The utility model relates to the technical field of tunnel support, in particular to a support device for tunnel construction. Background Technique

[0002] Tunnel lining is a permanent support structure built along the periphery of the tunnel body with materials such as reinforced concrete to prevent the surrounding rock from deforming or collapsing. Different lining forms can be adopted in different surrounding rocks. Commonly used lining forms include shotcrete lining, shotcrete with rockbolt lining, and composite lining. In the related technology, the support structure for tunnel lining construction includes a primary lining and a secondary lining, and the secondary lining includes steel arches arranged in the tunnel.

[0003] The patent document with the publication number of CN217538736U discloses a support structure for tunnel lining construction, including a primary lining and a secondary lining. The secondary lining includes a steel arch frame, and the steel arch frame includes: steel columns, provided with a number of first fixing grooves, a number of first through grooves, a number of second fixing grooves, and a number of second through grooves; the first fixing grooves are communicated with the first through grooves, and both the first fixing grooves and the first through grooves are distributed along the length direction of the steel columns; the second fixing grooves are communicated with the second through grooves, and both the second fixing grooves and the second through grooves are distributed along the length direction of the steel columns; connecting rods, arranged between adjacent steel columns, and are inserted and matched with the first through grooves and are inserted and matched with the second through grooves; connecting blocks, arranged at both ends of the connecting rods, and are inserted and matched with the first fixing grooves and are inserted and matched with the second fixing grooves; fixing components, connected with the steel columns, and used to block the connecting blocks in the first fixing grooves or the second fixing grooves. This application has the effect of facilitating the disassembly of the steel arch frame.

[0004] In the above-mentioned prior art, the steel arch frame is fixed on the concrete member through anchor bolts and nuts. During construction, there are problems with the deviation of the pouring spacing of the concrete member and the embedding spacing of the anchor bolts, resulting in the problem that the connecting rods between the steel columns are too long or too short to be connected when connecting, affecting the combined installation of adjacent steel arch frames. Therefore, a new support device for tunnel construction is proposed to optimize the above-mentioned prior art.

[0005] However, the traditional support devices for tunnel construction on the market at present have an unoptimized structure and an unreasonable design. Content of the Utility Model

[0006] The purpose of the utility model is to provide a support device for tunnel construction to solve the problems raised in the above background technique.

[0007] To achieve the above purpose, the utility model provides the following technical solutions:

[0008] A support device for tunnel construction, including a primary lining and a secondary lining. The secondary lining includes a steel arch frame, and the steel arch frame includes symmetrically arranged first arc-shaped members, symmetrically arranged second arc-shaped members and third arc-shaped members. T-shaped grooves are provided on the first arc-shaped members, the second arc-shaped members and the third arc-shaped members. A connecting rod mechanism is commonly connected in the corresponding T-shaped grooves. The connecting rod mechanism includes a first connecting rod and a second connecting rod. Clamping heads are fixedly connected to the mutually remote ends of the first connecting rod and the second connecting rod. The clamping heads correspond to and are adapted to the T-shaped grooves, and the clamping heads can be inserted into the T-shaped grooves. Connecting plates are fixedly connected to the mutually close ends of the second connecting rods. A plurality of long screw rods penetrate through the connecting plates together. Round holes for the long screw rods to penetrate are provided on the connecting plates. First nuts are threadedly connected to both sides of the connecting plates corresponding to the long screw rods. An extension rod is also fixedly connected to the end of the second connecting rod close to the first connecting rod. The extension rod is inserted into the inner side of the end of the first connecting rod and is slidably connected to the first connecting rod. A slot for the extension rod to be inserted and slidably connected is provided on the first connecting rod.

[0009] As a further scheme of the utility model: Connecting pieces are fixedly connected to the top ends of the first arc-shaped members, the two ends of the second arc-shaped members and the two ends of the third arc-shaped members. A first bolt penetrates through the corresponding connecting pieces together. Round holes for the corresponding bolts to penetrate are symmetrically provided on the connecting pieces. After the first bolt penetrates through the two connecting pieces, a second nut is threadedly connected.

[0010] As a further scheme of the utility model: Clamping protrusions are provided at the top of the first arc-shaped member and at the two ends of the third arc-shaped member. Grooves adapted to the clamping protrusions are provided on the second arc-shaped member at the positions corresponding to the clamping protrusions. A second bolt penetrates through the clamping protrusion. A round hole for the second bolt to penetrate is provided on the clamping protrusion. The second bolt is inserted into the second arc-shaped member and is threadedly connected to the second arc-shaped member. A threaded hole for the second bolt to be inserted and threadedly connected is provided on the second arc-shaped member.

[0011] As a further scheme of the utility model: Covers adapted to the T-shaped grooves are provided on the outer sides of the T-shaped grooves. Third bolts penetrate through the four corners of the covers. Round holes for the third bolts to penetrate are provided at the four corners of the covers. The third bolts are inserted into the corresponding first arc-shaped member, second arc-shaped member or third arc-shaped member and are threadedly connected to the first arc-shaped member, the second arc-shaped member and the third arc-shaped member. Threaded holes for the third bolts to be inserted and threadedly connected are provided on the first arc-shaped member, the second arc-shaped member and the third arc-shaped member.

[0012] As a further scheme of the utility model: A first fixing plate is fixedly connected to the bottom end of the first arc-shaped member. An adjusting mechanism is connected to the bottom surface of the first fixing plate. The adjusting mechanism is installed on a concrete foundation.

[0013] As a further solution of the utility model: The adjusting mechanism includes a second fixing plate, a third fixing plate, an inner sleeve, an outer sleeve, a threaded rod, a threaded sleeve, a worm gear and a worm. Four corners of the second fixing plate and the first fixing plate are both penetrated by fourth bolts. Circular holes for the fourth bolts to penetrate are formed on the second fixing plate and the first fixing plate. After the fourth bolts penetrate the second fixing plate and the first fixing plate, they are threadedly connected with third nuts. Embedded bolts are pre-buried and fixed at the four corners of the concrete foundation corresponding to the third fixing plate. The top end of the embedded bolt penetrates the third fixing plate and is then threadedly connected with a fourth nut. Circular holes for the embedded bolts to penetrate are formed on the third fixing plate. The inner sleeve is fixedly connected to the top surface of the third fixing plate. The outer sleeve is fixedly connected to the bottom surface of the second fixing plate. The outer sleeve is slidably connected to the outside of the inner sleeve. The threaded rod and the threaded sleeve are arranged inside the inner sleeve and the outer sleeve. The threaded sleeve is fixedly connected to the third fixing plate. The threaded rod is rotatably connected to the bottom surface of the second fixing plate. The threaded rod is inserted into the threaded sleeve and is threadedly connected with the threaded sleeve. The worm gear is fixedly sleeved on the top end of the threaded rod. The worm is arranged on the outside of the worm gear and is in meshing transmission with the worm gear. The worm is rotatably installed with the outer sleeve. One end of the worm penetrates the outer sleeve and is then fixedly connected with a turning handle.

[0014] Compared with the prior art, the beneficial effects of the utility model are as follows:

[0015] 1. In the utility model, the first connecting rod and the second connecting rod are combined and connected through an extension rod, and are combined and fixed with the long screw connecting plate and the first nut, so that the combined effective length of the first connecting rod and the second connecting rod can be conveniently controlled, so that the length of the connecting rod mechanism can be adapted to the distance between the steel arch frames, and the problem that the length is too long or too short to be connected can be avoided.

[0016] 2. In the utility model, the first arc-shaped member, the second arc-shaped member and the third arc-shaped member are combined and assembled to form a steel arch frame. During combination, positioning can be carried out through the cooperation of the clamping protrusion and the groove, and locking and fixing are carried out through the second bolt. At the same time, connection and reinforcement can be carried out through the connecting piece, the first bolt and the second nut, so that the first arc-shaped member, the second arc-shaped member and the third arc-shaped member are combined into a stable whole. The steel arch frame is a combined assembly design, which is convenient for on-site assembly and disassembly.

[0017] 3. In the utility model, the cover plate is fixed through the third bolt, so that the Y-shaped groove is shielded by the cover plate, effectively preventing the chuck from falling out of the T-shaped groove, and improving the connection stability between the connecting rod mechanism and the steel arch frame.

[0018] 4. In the utility model, the steel arch frame is installed on the concrete foundation through the adjusting mechanism. The adjusting mechanism can drive the inner sleeve and the outer sleeve to slide relative to each other by rotating the turning handle, so as to control the distance between the second fixing plate and the third fixing plate, and thus control the support height of the steel arch frame. Description of the Drawings

[0019] Figure 1 It is a structural schematic diagram of a support device for tunnel construction.

[0020] Figure 2 It is a display diagram of the steel arch in a support device for tunnel construction.

[0021] Figure 3 It is a display diagram of the linkage mechanism in a support device for tunnel construction.

[0022] Figure 4 It is a cross-sectional view of the adjusting mechanism in a support device for tunnel construction.

[0023] Figure 5 It is a display diagram of the connection between the clamping projection and the groove in a support device for tunnel construction.

[0024] Figure 6 It is a display diagram of the connection between the steel arch and the concrete foundation in a support device for tunnel construction.

[0025] In the figure: 1. Steel arch; 2. First arc-shaped member; 3. Second arc-shaped member; 4. Third arc-shaped member; 5. T-shaped groove; 6. Linkage mechanism; 7. First connecting rod; 8. Second connecting rod; 9. Chuck; 10. Connecting plate; 11. Long screw; 12. First nut; 13. Extension rod; 14. Connecting piece; 15. First bolt; 16. Second nut; 17. Clamping projection; 18. Groove; 19. Second bolt; 20. Cover plate; 21. Third bolt; 22. First fixing plate; 23. Adjusting mechanism; 24. Concrete foundation; 25. Second fixing plate; 26. Third fixing plate; 27. Inner sleeve; 28. Outer sleeve; 29. Threaded rod; 30. Threaded sleeve; 31. Worm gear; 32. Worm; 33. Fourth bolt; 34. Third nut; 35. Embedded bolt; 36. Fourth nut; 37. Rotating handle. Specific embodiments

[0026] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0027] Please refer to Figures 1 to 6, in the embodiment of the present utility model, a support device for tunnel construction includes a primary lining and a secondary lining. The secondary lining includes a steel arch frame 1, and the steel arch frame 1 includes symmetrically arranged first arc-shaped members 2, symmetrically arranged second arc-shaped members 3 and third arc-shaped members 4. T-shaped grooves 5 are provided on the first arc-shaped members 2, second arc-shaped members 3 and third arc-shaped members 4, and a connecting rod mechanism 6 is commonly connected in the corresponding T-shaped grooves 5. The connecting rod mechanism 6 includes a first connecting rod 7 and a second connecting rod 8. Clamping heads 9 are fixedly connected to the mutually remote ends of the first connecting rod 7 and the second connecting rod 8. The clamping heads 9 correspond to and are adapted to the T-shaped grooves 5, and the clamping heads 9 can be inserted into the T-shaped grooves 5. Connecting plates 10 are fixedly connected to the mutually close ends of the second connecting rods 8. A plurality of long screw rods 11 penetrate through the connecting plates 10 together. Circular holes for the long screw rods 11 to penetrate are provided on the connecting plates 10. First nuts 12 are threadedly connected to both sides of the connecting plates 10 corresponding to the long screw rods 11. An extension rod 13 is also fixedly connected to the end of the second connecting rod 8 close to the first connecting rod 7. The extension rod 13 is inserted into the inner side of the end of the first connecting rod 7 and is slidably connected to the first connecting rod 7. A slot for the extension rod 13 to be inserted into and slidably connected is provided on the first connecting rod 7.

[0028] The first connecting rod 7 and the second connecting rod 8 are combined and connected through the extension rod 13, and are combined and fixed with the connecting plates 10 and the first nuts 12 by means of the long screw rods 11, so that the combined effective length of the first connecting rod 7 and the second connecting rod 8 can be conveniently controlled, so that the length of the connecting rod mechanism 6 can be adapted to the spacing of the steel arch frame 1, avoiding the problem that the length is too long or too short and cannot be connected.

[0029] Connecting pieces 14 are fixedly connected to the top ends of the first arc-shaped members 2, both ends of the second arc-shaped members 3 and both ends of the third arc-shaped members 4. First bolts 15 penetrate through the corresponding connecting pieces 14 together. Circular holes for the corresponding bolts 15 to penetrate are symmetrically provided on the connecting pieces 14. After the first bolts 15 penetrate through the two connecting pieces 14 at the same time, second nuts 16 are threadedly connected.

[0030] Clamping protrusions 17 are provided at the tops of the first arc-shaped members 2 and both ends of the third arc-shaped members 4. Grooves 18 adapted to the clamping protrusions 17 are provided on the second arc-shaped members 3 at positions corresponding to the clamping protrusions 17. Second bolts 19 penetrate through the clamping protrusions 17. Circular holes for the second bolts 19 to penetrate are provided on the clamping protrusions 17. The second bolts 19 are inserted into the second arc-shaped members 3 and are threadedly connected to the second arc-shaped members 3. Threaded holes for the second bolts 19 to be inserted into and threadedly connected are provided on the second arc-shaped members 3.

[0031] The first arc-shaped member 2, the second arc-shaped member 3 and the third arc-shaped member 4 are assembled together to form the steel arch frame 1. During the assembly, positioning can be carried out through the cooperation of the clamping projection 17 and the groove 18, and locking and fixing are carried out through the second bolt 19. At the same time, connection and reinforcement can be carried out through the connecting piece 14, the first bolt 15 and the second nut 16, so that the first arc-shaped member 2, the second arc-shaped member 3 and the third arc-shaped member 4 are combined into a stable whole. The steel arch frame 1 is designed as an assembled combination, which is convenient for on-site assembly and disassembly.

[0032] Cover plates 20 adapted to the T-shaped grooves 5 are provided on the outer sides of the T-shaped grooves 5. The third bolts 21 penetrate through the four corners of the cover plates 20. Circular holes for the third bolts 21 to penetrate are opened at the four corners of the cover plates 20. The third bolts 21 are inserted into the corresponding first arc-shaped member 2, second arc-shaped member 3 or third arc-shaped member 4 and are threadedly connected to the first arc-shaped member 2, second arc-shaped member 3 and third arc-shaped member 4. Threaded holes for the third bolts 21 to be inserted and threadedly connected are opened on the first arc-shaped member 2, second arc-shaped member 3 and third arc-shaped member 4.

[0033] The cover plate 20 is fixed by the third bolt 21, so as to shield the Y-shaped groove 5 through the cover plate 20, effectively preventing the chuck 9 from falling out of the T-shaped groove 5, and improving the connection stability between the link mechanism 6 and the steel arch frame 1.

[0034] The bottom end of the first arc-shaped member 2 is fixedly connected with a first fixing plate 22, and an adjusting mechanism 23 is connected to the bottom surface of the first fixing plate 22. The adjusting mechanism 23 is installed on the concrete foundation 24.

[0035] The adjusting mechanism 23 includes a second fixing plate 25, a third fixing plate 26, an inner sleeve 27, an outer sleeve 28, a threaded rod 29, a threaded sleeve 30, a worm gear 31 and a worm 32. The four corners of the second fixing plate 25 and the first fixing plate 22 are both penetrated by fourth bolts 33. Circular holes for the fourth bolts 33 to penetrate are provided on the second fixing plate 25 and the first fixing plate 22. After the fourth bolts 33 penetrate the second fixing plate 25 and the first fixing plate 22, they are threadedly connected with third nuts 34. Embedded bolts 35 are pre-buried and fixed at the four corners of the concrete foundation 24 corresponding to the third fixing plate 26. The top end of the embedded bolt 35 penetrates the third fixing plate 26 and is then threadedly connected with a fourth nut 36. Circular holes for the embedded bolts 35 to penetrate are provided on the third fixing plate 26. The inner sleeve 27 is fixedly connected to the top surface of the third fixing plate 26. The outer sleeve 28 is fixedly connected to the bottom surface of the second fixing plate 25. The outer sleeve 28 is slidably connected to the outside of the inner sleeve 27. The threaded rod 29 and the threaded sleeve 30 are arranged inside the inner sleeve 27 and the outer sleeve 28. The threaded sleeve 30 is fixedly connected to the third fixing plate 26. The threaded rod 29 is rotatably connected to the bottom surface of the second fixing plate 25. The threaded rod 29 is inserted into the threaded sleeve 30 and is threadedly connected with the threaded sleeve 30. The worm gear 31 is fixedly sleeved on the top end of the threaded rod 29. The worm 32 is arranged outside the worm gear 31 and is in meshing transmission with the worm gear 31. The worm 32 is rotatably installed with the outer sleeve 28. One end of the worm 32 penetrates the outer sleeve 28 and is then fixedly connected with a turning handle 37.

[0036] The steel arch 1 is installed on the concrete foundation 24 through the adjusting mechanism 23. The adjusting mechanism 23 can drive the inner sleeve 27 and the outer sleeve 28 to slide relative to each other by rotating the turning handle 27, so as to control the distance between the second fixing plate 25 and the third fixing plate 26, and thus control the support height of the steel arch 1.

[0037] The working principle of the present utility model is:

[0038] In use, the adjusting mechanism 23 is fixedly installed on the concrete foundation 24 through the third fixing plate 26, cooperating with the embedded bolts 35 and the fourth nuts 36. Rotate the handle 37 to drive the worm gear 31 through the worm 32, so that the threaded rod 29 rotates. The threaded rod 29 cooperates with the threaded sleeve 30 to drive the inner sleeve 27 and the outer sleeve 28 to separate and extend telescopically, adjusting the height of the second fixing plate 25. Positioning is carried out through the cooperation of the clamping protrusion 17 and the groove 18, and locking and fixing are carried out through the second bolt 19. At the same time, connection and reinforcement can be carried out through the connecting piece 14, the first bolt 15 and the second nut 16, so that the first arc-shaped member 2, the second arc-shaped member 3 and the third arc-shaped member 4 are combined into a stable whole, and the steel arch 1 is fixed through the first fixing plate 22 cooperating with the second fixing plate 25. When combining, the link mechanism 6 is installed and fixed corresponding to the T-shaped groove 5, and the T-shaped groove 5 is closed through the cover plate 20 cooperating with the third bolt 21. When installing the link mechanism 6, the first link 7 and the second link 8 are combined and connected through the extension rod 13, and combined and fixed with the long screw 11, the connecting plate 10 and the first nut 12. Adjust the position of the first nut 12 on the long screw 11, so as to conveniently control the combined effective length of the first link 7 and the second link 8, so as to conveniently adapt the length of the link mechanism 6 to the spacing of the steel arch 1, thus completing the assembly of the overall support structure and forming a support effect.

[0039] Although the present invention has been described in detail with reference to the foregoing embodiments, for those skilled in the art, they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A support device for tunnel construction, comprising a primary lining and a secondary lining, wherein the secondary lining comprises a steel arch (1), characterized in that: The steel arch frame (1) comprises a symmetrically arranged first arc-shaped member (2), a symmetrically arranged second arc-shaped member (3) and a third arc-shaped member (4); the first arc-shaped member (2), the second arc-shaped member (3) and the third arc-shaped member (4) are all provided with T-shaped grooves (5); corresponding T-shaped grooves (5) are commonly connected with a connecting rod mechanism (6); the connecting rod mechanism (6) comprises a first connecting rod (7) and a second connecting rod (8); the ends of the first connecting rod (7) and the second connecting rod (8) which are away from each other are fixedly connected with a clamp (9); the clamp (9) corresponds to and fits with the T-shaped groove (5); The ends of the second connecting rods (8) close to each other are fixedly connected to a connecting plate (10), and a plurality of long screws (11) are passed through the connecting plate (10). The long screws (11) are threadedly connected to first nuts (12) on both sides of the connecting plate (10). The end of the second connecting rod (8) close to the first connecting rod (7) is also fixedly connected to an extension rod (13). The extension rod (13) is inserted into the inner side of the end of the first connecting rod (7) and is slidably connected to the first connecting rod (7). The first connecting rod (7) is provided with a slot for the extension rod (13) to be inserted and slidably connected.

2. A tunnel construction support device according to claim 1, characterized in that: The top end of the first arc-shaped member (2), the two ends of the second arc-shaped member (3) and the two ends of the third arc-shaped member (4) are all fixedly connected with connecting plates (14), and the corresponding connecting plates (14) are penetrated by a first bolt (15), and the first bolt (15) penetrates the two connecting plates (14) at the same time and is then threadedly connected with a second nut (16).

3. A tunnel construction support device according to claim 1, characterized in that: A clamping protrusion (17) is provided at the top of the first arc-shaped member (2) and at both ends of the third arc-shaped member (4); a groove (18) matching the clamping protrusion (17) is provided on the second arc-shaped member (3) at a position corresponding to the clamping protrusion (17); a second bolt (19) passes through the clamping protrusion (17); the second bolt (19) is inserted into the second arc-shaped member (3) and is threadedly connected to the second arc-shaped member (3).

4. A tunnel construction support device according to claim 1, characterized in that: The outer sides of the T-shaped slots (5) are provided with cover plates (20) adapted thereto, and the four corners of the cover plates (20) are penetrated by third bolts (21), and the third bolts (21) are inserted into the corresponding first arc-shaped member (2), the second arc-shaped member (3) or the third arc-shaped member (4) and are threadedly connected to the first arc-shaped member (2), the second arc-shaped member (3) and the third arc-shaped member (4).

5. A tunnel construction support device according to claim 1, characterized in that: The bottom end of the first arc-shaped member (2) is fixedly connected to a first fixing plate (22), the bottom surface of the first fixing plate (22) is connected to an adjustment mechanism (23), and the adjustment mechanism (23) is installed on a concrete foundation (24).

6. A tunnel construction support device according to claim 5, characterized in that: The adjusting mechanism (23) comprises a second fixing plate (25), a third fixing plate (26), an inner sleeve (27), an outer sleeve (28), a threaded rod (29), a threaded sleeve (30), a worm wheel (31) and a worm (32); the fourth bolts (33) are passed through the four corners of the second fixing plate (25) and the first fixing plate (22); the fourth bolts (33) pass through the second fixing plate (25) and the first fixing plate (22) and are then threadedly connected to the third nuts (34); the concrete foundation (24) is pre-embedded with embedded bolts (35) at the four corners corresponding to the third fixing plate (26); the top ends of the embedded bolts (35) pass through the third fixing plate (26) and are then threadedly connected to the fourth nuts (36); the inner sleeve (27) is fixedly connected to the top surface of the third fixing plate (26); the outer sleeve ( The outer sleeve (28) is fixedly connected to the bottom surface of the second fixed plate (25), the outer sleeve (28) is slidably connected to the outer side of the inner sleeve (27), the threaded rod (29) and the threaded sleeve (30) are arranged on the inner sides of the inner sleeve (27) and the outer sleeve (28), the threaded sleeve (30) is fixedly connected to the third fixed plate (26), the threaded rod (29) is rotatably connected to the bottom surface of the second fixed plate (25), the threaded rod (29) is inserted into the threaded sleeve (30) and is threadedly connected to the threaded sleeve (30), the worm gear (31) is fixedly sleeved on the top end of the threaded rod (29), the worm (32) is arranged on the outer side of the worm gear (31) and is meshed with the worm gear (31) for transmission, the worm (32) is rotatably installed with the outer sleeve (28), and one end of the worm (32) passes through the outer sleeve (28) and is fixedly connected to a rotating handle (37).

Images