A roof telescopic climbing ladder and main battle fire fighting truck

Abstract

The utility model relates to fire fighting equipment technical field, more particularly, a kind of car roof telescopic climbing ladder and main battle fire engine are involved.Car roof telescopic climbing ladder includes front bracket, rear bracket, telescopic ladder stand, hydraulic actuator unit and cantilever support mechanism;Front bracket and rear bracket are located at the front and rear ends of roof, telescopic ladder stand is erected on front bracket and rear bracket, cantilever support mechanism is located at roof, and is hinged with telescopic ladder stand;Hydraulic actuator unit is fixed on roof, and is signal connected with cantilever support mechanism.The utility model realizes one-key lifting and telescoping, replaces manual carrying folding ladder, shortens rescue preparation time;Modular bracket is directly installed on roof, without modifying chassis, solve the problem that aerial ladder car volume is big, and it is difficult to adjust car, so as to give consideration to compactness, quick deployment and general adaptation three major technical effects.

Description

Technical Field

[0001] This utility model relates to the field of fire-fighting equipment technology, specifically to a roof-mounted telescopic ladder and a main battle fire truck. Background Technology

[0002] Currently, when main fire trucks need to conduct aerial rescue operations in multi-story buildings, they typically rely on folding ladders or independent aerial ladder trucks. However, folding ladders have limited length, require manual handling and setup, which is inefficient and physically demanding; while aerial ladder trucks are bulky, difficult to maneuver, and often cannot reach the work area in narrow streets or old residential areas. In addition, traditional roof-mounted ladders are rigid and cannot be retracted, resulting in high wind resistance and susceptibility to corrosion due to long-term exposure, and they also occupy overhead space, reducing vehicle maneuverability. Utility Model Content

[0003] The purpose of this utility model is to provide a roof-mounted telescopic ladder and a main fire truck, which can solve the above-mentioned technical problems.

[0004] In the first aspect, this utility model provides a retractable ladder for climbing on the roof of a main fire truck, which is installed on the roof of the main fire truck and includes a front bracket, a rear bracket, a retractable ladder frame, a hydraulic actuator and a cantilever support mechanism. The front bracket and the rear bracket are respectively installed at the front and rear ends of the vehicle roof, and the telescopic ladder is mounted on the front bracket and the rear bracket; The cantilever support mechanism is mounted on the roof of the vehicle, and its top end is hinged to the telescopic ladder frame. The hydraulic actuator is fixed to the roof of the vehicle and is signal-connected to the cantilever support mechanism.

[0005] In an optional embodiment, the front bracket includes a front base plate, a front side plate, and a crossbar; The two front side plates are respectively disposed at opposite ends on the upper side of the front bottom plate, and the two front side plates are fixed at both ends of the crossbar. The crossbar is at a set height from the front bottom plate.

[0006] In an optional embodiment, the front bracket is further provided with a reinforcing connecting rod, which is disposed between the front bottom plate and the crossbar, and the two ends of the reinforcing connecting rod are respectively connected to the two front side plates.

[0007] In an optional embodiment, the reinforcing connecting rod, the front floor plate, and the roof are fixedly connected by angle steel; The number of angle steels is two, and a positioning groove for positioning the hydraulic actuator is formed between the two angle steels.

[0008] In an optional embodiment, the rear bracket includes a rear base plate, a rear side plate, diagonal braces, and a connecting rotating shaft; The number of rear side plates is two, and the two rear side plates are respectively set at opposite ends of the rear bottom plate to form a groove structure; One end of the connecting rotating shaft is disposed on the rear side plate and inside the groove structure, and the other end of the connecting rotating shaft is connected to the end of the telescopic ladder frame, so that the telescopic ladder frame can rotate relative to the rear bracket. One end of the diagonal brace is fixedly connected to the rear bottom plate, and the other end of the diagonal brace is fixedly connected to the rear side plate.

[0009] In an optional embodiment, a transmission assembly is provided on the connecting rotating shaft, and the connecting rotating shaft is rotatably connected to the transmission assembly; The transmission assembly is slidably mounted on the side wall of the telescopic ladder.

[0010] In an optional embodiment, the transmission assembly includes a central rotating wheel, a transmission base plate, a transmission shaft, and a transmission pulley; The central rotating wheel and the transmission shaft are respectively arranged on opposite sides of the transmission base plate; The central rotating wheel is located in the middle of the transmission base plate and is rotatably connected to the connecting rotating shaft; The number of drive shafts is two, and the two drive shafts are symmetrically arranged on both sides of the central rotating wheel; One end of the drive shaft is fixedly disposed in the middle of the drive base plate, and the other end of the drive shaft is rotatably connected to the drive pulley; The transmission pulley is installed in a sliding groove on the side wall of the telescopic ladder.

[0011] In an optional embodiment, the cantilever support mechanism includes a base frame, a support cantilever, and a support cylinder; The underframe is fixedly mounted on the roof of the vehicle; One end of the support cylinder is rotatably mounted on the base frame, and the other end of the support cylinder is rotatably mounted on the support cantilever. One end of the support cantilever is rotatably mounted on the base frame, and the other end of the support cantilever is rotatably connected to the telescopic ladder frame.

[0012] In an optional implementation, the number of supporting cantilever arms is at least two; The two support cantilever arms are connected by a synchronous shaft, and the other end of the support cylinder is rotatably connected to the synchronous shaft.

[0013] Secondly, this utility model provides a main battle fire truck, including the roof telescopic ladder described in any of the foregoing embodiments.

[0014] The beneficial effects of this utility model embodiment are: The telescopic ladder is supported when laid flat by the front and rear brackets, and when in use by the cantilever support mechanism. The hydraulically driven cantilever enables one-button lifting and extension, replacing manual handling of the folding ladder and shortening rescue preparation time. The modular bracket is directly installed on the roof of the vehicle without modifying the chassis, solving the problems of large size and difficult maneuvering of the ladder truck, thus achieving the three major technical effects of compactness, rapid deployment and universal adaptability. Attached Figure Description

[0015] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this utility model and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 A structural schematic diagram of the main battle fire truck provided in this embodiment of the utility model; Figure 2 This is a structural schematic diagram of the retractable roof-mounted ladder provided in an embodiment of the present utility model; Figure 3 A three-dimensional structural diagram of the retractable roof ladder provided for an embodiment of this utility model; Figure 4 for Figure 3 A magnified view of part A.

[0017] Icons: 1-Main battle fire truck; 2-Roof telescopic ladder; 2.1-Front bracket; 2.11-Front floor plate; 2.12-Front side plate; 2.13-Crossbar; 2.14-Reinforcing link; 2.15-Angle steel; 2.2-Hydraulic actuator; 2.3-Cantilever support mechanism; 2.31-Underframe; 2.32-Support cylinder; 2.33-Support cantilever; 2.34-Hinge seat; 2.35-Synchronous shaft; 2.4-Telescopic ladder frame; 2.41-Sliding groove; 2.5-Rear bracket; 2.51-Rear floor plate; 2.52-Rear side plate; 2.53-Reinforcing plate; 2.54-Diagonal brace; 2.55-Center wheel; 2.56-Transmission floor plate; 2.57-Transmission pulley. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. The components of the embodiments of this utility model described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0019] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0020] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0021] 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., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this utility model is in use. They 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. In addition, the terms "first," "second," and "third," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0022] Furthermore, terms such as "horizontal," "vertical," and "sag" do not imply that components must be absolutely horizontal or suspended, but rather that they can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal relative to "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0023] In the description of this utility model, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" 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.

[0024] The following is combined with Figures 1-4 The following describes some embodiments of the present invention in detail. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0025] In a first aspect, this utility model provides a retractable ladder for use on the roof of a main fire truck 1, comprising a front bracket 2.1, a rear bracket 2.5, a retractable ladder frame 2.4, a hydraulic actuator 2.2, and a cantilever support mechanism 2.3; the front bracket 2.1 and the rear bracket 2.5 are respectively located at the front and rear ends of the roof, and the retractable ladder frame 2.4 is mounted on the front bracket 2.1 and the rear bracket 2.5; the cantilever support mechanism 2.3 is located on the roof, and its top end is hinged to the retractable ladder frame 2.4; the hydraulic actuator 2.2 is fixed to the roof and is signal-connected to the cantilever support mechanism 2.3.

[0026] In this embodiment, the front bracket 2.1 and the rear bracket 2.5 are fixedly installed at the front and rear ends of the vehicle roof, respectively. The rear end of the telescopic ladder 2.4 is rotatably connected to the rear bracket 2.5 and can slide relative to it. When not in use, the front end of the telescopic ladder 2.4 is placed on the front bracket 2.1 and supported by the front bracket 2.1 and the rear bracket 2.5 to ensure the stability of the telescopic ladder 2.4 on the vehicle roof.

[0027] Specifically, in this embodiment, the hydraulic actuator 2.2 is connected to the cantilever support mechanism 2.3 and the telescopic base frame 2.31 by signal connection, and can control the cantilever support mechanism 2.3 to support the telescopic ladder frame 2.4, and control the telescopic ladder frame 2.4 to extend and retract.

[0028] Specifically, in this embodiment, the bottom end of the cantilever support mechanism 2.3 is fixed to the roof of the vehicle, which effectively ensures the stability of the support when supporting the telescopic ladder frame 2.4. The fixing method can be bolt fixing connection, or welding, riveting, or other fixing connection methods, as long as the connection stability of the cantilever support mechanism 2.3 on the roof of the vehicle can be guaranteed.

[0029] In an optional embodiment, the front bracket 2.1 includes a front base plate 2.11, a front side plate 2.12, and a crossbar 2.13; the two front side plates 2.12 are respectively disposed at opposite ends on the upper side of the front base plate 2.11, and the two front side plates 2.12 are fixed at both ends of the crossbar 2.13, with a set height between the crossbar 2.13 and the front base plate 2.11.

[0030] In this embodiment, the front bottom plate 2.11 and the two front side plates 2.12 form a U-shaped load-bearing frame. The front bottom plate 2.11 is located below and serves to support the two front side plates 2.12. By fixing the front bottom plate 2.11 to the roof, the front side plates 2.12 can be fixed on the roof, thus achieving the fixation of the front side plates 2.12 and ensuring the stability of the front side plates 2.12 when fixed.

[0031] Specifically, in this embodiment, the front floor plate 2.11 can spread the vertical load from the ladder rollers to a larger area of ​​the roof, avoiding the roof from being dented due to single-point pressure on the front side plate 2.12; a flange is provided on the front floor plate 2.11, and the flange design increases the rigidity of the front floor plate 2.11 itself, making it less prone to bending under stress.

[0032] Specifically, in this embodiment, the two front side plates 2.12 can limit the left and right directions of the corresponding roof of the telescopic ladder frame 2.4, preventing the telescopic ladder frame 2.4 from sliding laterally and falling off the roof when the vehicle is turning or on a bumpy road.

[0033] In this embodiment, the crossbar 2.13 is horizontally positioned above the front floor plate 2.11, and its two ends are fixedly connected to the two front side plates 2.12 by welding or bolting, forming a support structure for the telescopic ladder 2.4 and preventing the telescopic ladder 2.4 from contacting the roof.

[0034] Specifically, in this embodiment, a flexible layer can be wrapped around the crossbar 2.13 to reduce the impact of friction and impact when the telescopic ladder 2.4 is on the crossbar 2.13.

[0035] In an optional embodiment, the front bracket 2.1 is also provided with a reinforcing connecting rod, which is located between the front bottom plate 2.11 and the crossbar 2.13, and the two ends of the reinforcing connecting rod are respectively connected to two front side plates 2.12.

[0036] In this embodiment, by strengthening the connecting rod 2.14, the stability between the two front side plates 2.12 can be increased.

[0037] Specifically, in this embodiment, there are at least two reinforcing links 2.14, which are respectively connected to the front and rear ends of the inner side of the front side plate 2.12.

[0038] In an optional embodiment, the reinforcing connecting rod, the front floor plate 2.11 and the roof are fixedly connected by angle steel 2.15; there are two angle steels 2.15, and a positioning groove for positioning the hydraulic actuator 2.2 is formed between the two angle steels 2.15.

[0039] In this embodiment, the reinforcing link 2.14, the front floor plate 2.11 and the roof are connected together by the angle steel 2.15, which can further increase the stability of the front bracket 2.1 on the roof.

[0040] Specifically, in this embodiment, the opening directions of the two angle steels 2.15 are set opposite to each other, so that a groove structure is formed between the two angle steels 2.15. This groove structure allows the hydraulic actuator 2.2 to be placed, thereby realizing the positioning of the hydraulic actuator 2.2. The distance between the two angle steels 2.15 is the same as the width of the hydraulic actuator 2.2, thereby improving the positioning stability of the hydraulic actuator 2.2.

[0041] In this embodiment, the hydraulic actuator 2.2 placed in the positioning groove can also be fixedly connected to the angle steel 2.15 by bolts, thereby further ensuring the stability of the hydraulic actuator 2.2 and reducing the impact of vehicle vibration, turning and other factors.

[0042] In an optional embodiment, the rear bracket 2.5 includes a rear base plate 2.51, a rear side plate 2.52, a diagonal brace 2.54, and a connecting rotating shaft; there are two rear side plates 2.52, which are respectively disposed at opposite ends of the rear base plate 2.51 to form a groove structure; one end of the connecting rotating shaft is disposed on the rear side plate 2.52 and is disposed inside the groove structure, and the other end of the connecting rotating shaft is connected to the end of the telescopic ladder frame 2.4, so that the telescopic ladder frame 2.4 can rotate relative to the rear bracket 2.5; one end of the diagonal brace 2.54 is fixedly connected to the rear base plate 2.51, and the other end of the diagonal brace 2.54 is fixedly connected to the rear side plate 2.52.

[0043] In this embodiment, the rear bracket 2.5 consists of a rear base plate 2.51, two rear side plates 2.52, diagonal braces 2.54, and a connecting rotating shaft. The rear base plate 2.51 is a rectangular steel plate with flanged edges to increase rigidity and is connected to the roof longitudinal beam by bolts. The two rear side plates 2.52 are vertically welded to both ends of the base plate, forming a "U"-shaped groove. The space inside the groove is used to accommodate the end of the ladder frame. The connecting rotating shaft is a solid shaft, installed on the inner side of the rear side plates 2.52 by copper sleeves or rolling bearings, and a retaining plate is provided at the shaft end to prevent axial movement. The diagonal braces 2.54 are flat steel bars, with one end welded to the rear base plate 2.51 and the other end welded to the midpoint or slightly above the inner side of the rear side plates 2.52, forming a triangular support. After the overall welding is completed, stress relief and anti-corrosion treatment are performed.

[0044] Specifically, in this embodiment, the rear bracket 2.5 serves as the rotating hinge support for the telescopic ladder 2.4, allowing the telescopic ladder 2.4 to pitch around the connecting rotation axis; it also bears the vertical and horizontal reaction forces generated by the telescopic ladder 2.4 during operation and transmits these forces to the overall frame of the roof through the rear bottom plate 2.51. The diagonal brace 2.54 connects the rear side plate 2.52 and the rear bottom plate 2.51 into a triangle, preventing the rear side plate 2.52 from opening outwards under heavy load and ensuring that the connecting rotation axis always remains on the designed axis.

[0045] In this embodiment, a reinforcing plate 2.53 is also provided on the rear side plate 2.52 near the front side plate 2.12. The upright end of the reinforcing plate 2.53 is fixedly connected to the rear side plate 2.52, and the bottom edge is fixedly connected to the rear bottom plate 2.51. The reinforcing plate 2.53 and the rear side plate 2.52 are on the same plane.

[0046] In an optional embodiment, a transmission component is provided on the connecting rotating shaft, and the connecting rotating shaft is rotatably connected to the transmission component; the transmission component is slidably disposed on the side wall of the telescopic ladder frame 2.4.

[0047] In this embodiment, a sliding groove 2.41 is provided on the side wall of the telescopic ladder frame 2.4. One end of the transmission component can slide in the sliding groove 2.41, and the other end can rotate around the connecting rotating shaft, so that the telescopic ladder frame 2.4 can both rotate relative to the rear bracket 2.5 and slide relative to the rear bracket 2.5.

[0048] In an optional embodiment, the transmission assembly includes a central rotating wheel 2.55, a transmission base plate 2.56, a transmission shaft, and a transmission pulley 2.57. The central rotating wheel 2.55 and the transmission shaft are respectively disposed on opposite sides of the transmission base plate 2.56. The central rotating wheel 2.55 is disposed in the middle of the transmission base plate 2.56 and is rotatably connected to the connecting rotating shaft. There are two transmission shafts, which are symmetrically disposed on both sides of the central rotating wheel 2.55. One end of the transmission shaft is fixedly disposed in the middle of the transmission base plate 2.56, and the other end of the transmission shaft is rotatably connected to the transmission pulley 2.57. The transmission pulley 2.57 is disposed in a sliding groove 2.41 on the side wall of the telescopic ladder frame 2.4.

[0049] In this embodiment, the transmission base plate 2.56 is a rectangular plate, which is mounted on the connecting rotating shaft via bearings or directly sleeved on it, allowing it to rotate relative to the connecting rotating shaft. The central rotating wheel 2.55 is located on one side of the transmission base plate 2.56 and is mounted on the connecting rotating shaft via bearings. Transmission shafts are respectively provided at both ends on the other side of the transmission base plate 2.56. The two transmission shafts are symmetrically arranged relative to the connecting rotating shaft, and the axes of the two transmission shafts are on the same plane as the axis of the connecting rotating shaft, thereby ensuring the uniformity of force distribution. The transmission pulley 2.57 is rotatably mounted on the transmission shaft and rollably mounted in the sliding groove 2.41 of the telescopic ladder frame 2.4.

[0050] In this embodiment, the two ends of the sliding groove 2.41 have limiting structures to prevent the transmission pulley 2.57 from disengaging from the sliding groove 2.41.

[0051] In an optional embodiment, the cantilever support mechanism 2.3 includes a base frame 2.31, a support cantilever 2.33, and a support cylinder 2.32; the base frame 2.31 is fixedly mounted on the roof of the vehicle; one end of the support cylinder 2.32 is rotatably mounted on the base frame 2.31, and the other end of the support cylinder 2.32 is rotatably mounted on the support cantilever 2.33; one end of the support cantilever 2.33 is rotatably mounted on the base frame 2.31, and the other end of the support cantilever 2.33 is rotatably connected to the telescopic ladder frame 2.4.

[0052] In this embodiment, the base frame 2.31 is fixedly mounted on the roof by means of bolts or welding. The lower end of the support cylinder 2.32 is hinged to the upper part of the base frame 2.31, and the upper end of the support cylinder 2.32 is hinged to the support cantilever 2.33. The lower end of the support cantilever 2.33 is hinged to the base frame 2.31 through the hinge seat 2.34, and the upper end of the support cantilever 2.33 is hinged to the telescopic ladder frame 2.4.

[0053] In this embodiment, the hinge seat 2.34 is fixedly mounted on the base frame 2.31.

[0054] When in use, the extension and retraction of the support cylinder 2.32 can change the angle between the support cantilever 2.33 and the base frame 2.31, thereby changing the pitch angle of the telescopic ladder 2.4 and raising the telescopic ladder 2.4 to facilitate high-altitude rescue.

[0055] In an optional embodiment, the number of support cantilever 2.33 is at least two; the two support cantilever 2.33 are connected by a synchronous shaft 2.35, and the other end of the support cylinder 2.32 is rotatably connected to the synchronous shaft 2.35.

[0056] In this embodiment, there are at least two supporting cantilever arms 2.33, which can effectively ensure the balance of the telescopic ladder 2.4 when supporting it.

[0057] In this embodiment, the supporting cantilever 2.33 is connected by a synchronous shaft 2.35, which can ensure both the balance when supporting the telescopic ladder 2.4 and the support strength of the telescopic ladder 2.4.

[0058] In this embodiment, the number of support cylinders 2.32 and support cantilever 2.33 are in one-to-one correspondence, that is, the lower end of each support cylinder 2.32 is connected to the base frame 2.31, and the upper end is connected to a support cantilever 2.33.

[0059] The support cylinder 2.32 can also be connected to the base frame 2.31 at the lower end and to the synchronous shaft 2.35 at the upper end, thereby reducing the number of support cylinders 2.32.

[0060] Secondly, this utility model provides a main battle fire truck 1, which includes a roof telescopic ladder 2 of any of the aforementioned embodiments.

[0061] The beneficial effects of this utility model embodiment are: The telescopic ladder frame 2.4 is supported when laid flat by the front bracket 2.1 and the rear bracket 2.5, and is supported when in use by the cantilever support mechanism 2.3. The hydraulically driven cantilever enables one-button lifting and telescopic movement, replacing manual handling of the folding ladder and shortening rescue preparation time. The modular bracket is directly installed on the roof of the vehicle without modifying the chassis, solving the problems of large size and difficult maneuvering of the ladder truck, thus achieving the three major technical effects of compactness, rapid deployment and universal adaptability.

[0062] The above are merely preferred embodiments of this utility model and are not intended to limit the scope of this utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A retractable ladder for climbing on the roof of a main fire truck, characterized in that, It includes a front bracket, a rear bracket, a telescopic ladder, a hydraulic actuator, and a cantilever support mechanism; The front bracket and the rear bracket are respectively installed at the front and rear ends of the vehicle roof, and the telescopic ladder is mounted on the front bracket and the rear bracket; The cantilever support mechanism is mounted on the roof of the vehicle, and its top end is hinged to the telescopic ladder frame. The hydraulic actuator is fixed to the roof of the vehicle and is signal-connected to the cantilever support mechanism.

2. The retractable roof-mounted ladder according to claim 1, characterized in that, The front bracket includes a front base plate, a front side plate, and a crossbar; The two front side plates are respectively disposed at opposite ends on the upper side of the front bottom plate, and the two front side plates are fixed at both ends of the crossbar. The crossbar is at a set height from the front bottom plate.

3. The retractable roof-mounted ladder according to claim 2, characterized in that, The front bracket is also provided with a reinforcing connecting rod, which is located between the front bottom plate and the crossbar, and the two ends of the reinforcing connecting rod are respectively connected to the two front side plates.

4. The retractable roof ladder according to claim 3, characterized in that, The reinforcing connecting rod, the front floor plate, and the roof are fixedly connected by angle steel. The number of angle steels is two, and a positioning groove for positioning the hydraulic actuator is formed between the two angle steels.

5. The retractable roof-mounted ladder according to claim 1, characterized in that, The rear bracket includes a rear base plate, a rear side plate, diagonal braces, and a connecting rotating shaft; The number of rear side plates is two, and the two rear side plates are respectively set at opposite ends of the rear bottom plate to form a groove structure; One end of the connecting rotating shaft is disposed on the rear side plate and inside the groove structure, and the other end of the connecting rotating shaft is connected to the end of the telescopic ladder frame, so that the telescopic ladder frame can rotate relative to the rear bracket. One end of the diagonal brace is fixedly connected to the rear bottom plate, and the other end of the diagonal brace is fixedly connected to the rear side plate.

6. The retractable roof-mounted ladder according to claim 5, characterized in that, A transmission component is provided on the connecting rotating shaft, and the connecting rotating shaft is rotatably connected to the transmission component; The transmission assembly is slidably mounted on the side wall of the telescopic ladder.

7. The retractable roof ladder according to claim 6, characterized in that, The transmission assembly includes a central rotating wheel, a transmission base plate, a transmission shaft, and a transmission pulley; The central rotating wheel and the transmission shaft are respectively arranged on opposite sides of the transmission base plate; The central rotating wheel is located in the middle of the transmission base plate and is rotatably connected to the connecting rotating shaft; The number of drive shafts is two, and the two drive shafts are symmetrically arranged on both sides of the central rotating wheel; One end of the drive shaft is fixedly disposed in the middle of the drive base plate, and the other end of the drive shaft is rotatably connected to the drive pulley; The transmission pulley is disposed in a sliding groove on the side wall of the telescopic ladder.

8. The retractable roof ladder according to claim 1, characterized in that, The cantilever support mechanism includes a base frame, a support cantilever, and a support cylinder; The underframe is fixedly mounted on the roof of the vehicle; One end of the support cylinder is rotatably mounted on the base frame, and the other end of the support cylinder is rotatably mounted on the support cantilever. One end of the support cantilever is rotatably mounted on the base frame, and the other end of the support cantilever is rotatably connected to the telescopic ladder frame.

9. The retractable roof ladder according to claim 8, characterized in that, The number of supporting cantilever arms is at least two; The two support cantilever arms are connected by a synchronous shaft, and the other end of the support cylinder is rotatably connected to the synchronous shaft.

10. A main battle fire truck, characterized in that, Including the retractable roof ladder as described in any one of claims 1-9.

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