Ladder, and vehicle equipped with said ladder

Abstract

This ladder 3 has a ladder body 31 having a plurality of stages and that extends and contracts on a vehicle, wherein in the main ribs of the ladder body 31, an upper main rib 311 and a lower main rib 312have entirely the same cross-sectional shape, and the cross-sectional size of the upper main rib 311 or the lower main rib 312 on at least one stage is the same as the cross-sectional size of the upper main rib 311 or the lower main rib 312 on other stages. Consequently, there can be provided a vehicle ladder that is lighter and has a lower cost than a conventional ladder, and a vehicle provided with said ladder.

Description

Technical Field

[0001] The present invention relates to a ladder having a plurality of ladder sections that can be extended, retracted, etc. on a vehicle such as a fire truck, and a vehicle equipped with such a ladder.

Background Art

[0002] Ladders that can perform telescoping, undulating, or swiveling operations and are used on vehicles such as fire trucks and aerial work platforms are known. For example, in Patent Document 1, a ladder assembly composed of a plurality of ladder sections is configured such that each ladder is sequentially telescopically fitted together. The ladder has an upper main member, a lower main member, diagonal members connecting the two, cross bars connecting the lower main members, and cross bar diagonal members connecting the cross bars. Each member is connected by welding. The lower main member has a square tube and a bent plate sandwiched between them. The bent plate has a height higher than that of the square tube and protrudes upward from the square tube, and the bent plate is arranged so as not to protrude below the square tube. A fire ladder is disclosed.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Patent Document 1 provides a fire ladder that is low-cost, lightweight, and highly reliable in terms of strength. However, further weight reduction and cost reduction of ladders mounted on fire trucks, aerial work platforms, etc. are required. Therefore, an object of the present invention is to provide a ladder that is lighter and lower in cost than conventional ones, and a vehicle equipped with such a ladder.

Means for Solving the Problems

[0005] The ladder of the present invention as described in claim 1 is a ladder 3 that extends and retracts on a vehicle and has multiple ladder bodies 31, wherein the cross-sectional shapes of the upper ribs 311 and lower ribs 312 of the ladder body 31 are all the same, and the cross-sectional size of the upper rib 311 or lower rib 312 in at least one step is the same as the cross-sectional size of the upper rib 311 or lower rib 312 in the other steps. the law of nature, Most The lower rib 312 in the step above the lower step has an inner diameter larger than the outer diameter of the telescopic cylinder 33 used for extending and retracting the ladder 3, is arranged coaxially with the telescopic cylinder 33, and is characterized by housing the telescopic cylinder 33 when the ladder 3 is retracted. Claim 2 The present invention described herein is as claimed. 1 In the ladder described above, the lower rib 312 that houses the telescopic cylinder 33 is made of a single pipe, and a connecting member that connects the upper rib 311 and the lower rib 312 is attached to the single pipe. Claim 3 The present invention described herein is as claimed. 2 In the ladder described above, the connecting member is an oblique rib 314 provided at an angle to the main ribs, with one end connected to the upper main rib 311 via an oblique rib box 313 and the other end connected to the lower main rib 312 via an oblique rib box 313, and the width W of the oblique rib 314 is the same within each step. Claim 4 The present invention described herein is as claimed. 1 Claims 3 The ladder described in any one of the above paragraphs is characterized in that the ladder body 31 has 5 steps, the cross-sectional size of the upper rib 311 and lower rib 312 in the 1st step and the upper rib 311 in the 2nd step is the smallest among the ribs, the cross-sectional size of the lower rib 312 in the 2nd step and the upper rib 311 and lower rib 312 in the 3rd step is the second smallest among the ribs, the cross-sectional size of the upper rib 311 in the 4th step and the upper rib 311 in the 5th step is the third smallest among the ribs, the cross-sectional size of the lower rib 312 in the 5th step is the fourth smallest among the ribs, and the cross-sectional size of the lower rib 312 in the 4th step is the largest among the ribs. Claim 5 The present invention described herein is as claimed. 4The ladder described above is characterized in that the thickness of the lower rib 312 in the fourth step is smaller than the thickness of the lower rib 312 in the fifth step. Claim 6 The present invention described herein is as follows: 5 The ladder described in any one of the above paragraphs is characterized in that the cross-sectional shape of the upper rib 311 and the lower rib 312 is square. Claim 7 The present invention described herein is as claimed. 1 Claims 6 In the ladder described in any one of the above, the tube 332 of the telescopic cylinder 33 is provided with a tube pad 334 that contacts the inner surface of the lower rib 312 when it is housed in the lower rib 312, and the tube pad 334 consists of one pad 334a whose length is smaller than the inner diameter of the lower rib 312 that houses the tube 332, and the other pad 334b ​​whose length is equal to the inner diameter of the lower rib 312 that houses the tube 332, and the one pad 334a and the other pad 334b ​​are arranged to sandwich the tube 332, and piping or wiring is passed through the gap between the one pad 334a and the lower rib 312. Claim 8 The present invention described herein is as follows: 7 A ladder as described in any one of the paragraphs, comprising a lower roller 50 that rotates by contact with the lower surface of the lower rib 312 when the ladder 3 is extended or retracted, wherein the lower roller 50 consists of a first section 51 and a second section 52 adjacent to each other, each having a pair of rotating bodies 501 and 502, and wherein a first bracket 511 on one end side that supports one end of the pair of rotating bodies 501 of the first section 51 and a first bracket 512 on the other end side that supports the other end of the pair of rotating bodies 501 of the first section 51 are provided separately, and a second bracket 521 on one end side that supports one end of the pair of rotating bodies 502 of the second section 52 and a second bracket 522 on the other end side that supports the other end of the pair of rotating bodies 502 of the second section 52 are provided separately. Claim 9 The present invention described herein is as follows: 8In the ladder described in any one of the above, the lower rib 312 is provided with a swing suppression body 36 at its rear end to suppress swinging when the ladder 3 is extended or retracted, wherein the swing suppression body 36 has a first main body 361 provided between the guide rail 315 that guides the sliding of the ladder body 31 and the lower rib 312 in the same step of the ladder body 31, and a first sub-body 362 disposed in the gap between the guide rail 315 and the first main body 361, and in the gap between the lower rib 312 and the first main body 361. Claim 10 The present invention described herein is as claimed. 9 In the ladder described above, the swing suppressor 36 is characterized in that, on the same rung of the ladder body 31, it has a second main body with one end connected to the guide rail 315 and the other end connected to the lower rib 312, and a second sub-body positioned in the gap between the guide rail 315 provided on the ladder body 31 of the rung below and the second main body. Claim 11 The present invention described herein is as follows: 10 The ladder described in any one of the above paragraphs is characterized in that the tip of the ladder body 31 is provided with a bendable step 37 that can bend downward, the center of bending 37A of the bendable step 37 is located inside the ladder body 31 when the ladder 3 is retracted and stored, and the bending of the bendable step 37 is prevented when the center of bending 37A comes into contact with the ladder body 31. Claim 12 The present invention described herein is as claimed. 11 In the ladder described above, the bending step 37 has a protrusion 38 located behind the bending center 37A, the ladder body 31 has a receiving portion 39 corresponding to the protrusion 38, and when the ladder 3 is in the stored state, the protrusion 38 and the receiving portion 39 are close to or in contact with each other. Claim 13 The present invention described herein is as follows: 12 The ladder described in any one of the above paragraphs is characterized in that it comprises a ladder frame 32 that supports the rear of the ladder 3, and the ladder frame 32 is divided into a luffing center body 321 located at the rear end of the ladder 3 and having the center point when the ladder 3 is luffed, and a cylinder tip connector 322 located in front of the luffing center body 321 and to which the tip of the luffing cylinder 34 that raises and lowers the ladder 3 is connected. Claim 14 The vehicle of the present invention described is as described in claims 1 to 1.13 characterized in that the ladder 3 according to any one of the above is attached.

Effect of the Invention

[0006] According to the present invention, the weight and cost of the ladder mounted on the vehicle can be reduced.

Brief Description of the Drawings

[0007] [Figure 1] Left side view of a vehicle equipped with a ladder according to an embodiment of the present invention [Figure 2] Cross-sectional view of the same ladder body [Figure 3] Side view showing the state where the same ladder is reduced and the telescopic cylinder is housed in the lower parent bone [Figure 4] View showing the telescopic cylinder alone in the reduced state [Figure 5] Schematic cross-sectional view showing the telescopic cylinder housed in the lower parent bone [Figure 6] View showing the same lower roller [Figure 7] View showing the same swing suppressor [Figure 8] View showing the same swing suppressor [Figure 9] Side view showing up to the second stage from the bending stage of the same ladder [Figure 10] Detailed view regarding the storage of the same bending stage [Figure 11] Side view showing the rear part of the same ladder

Mode for Carrying Out the Invention

[0008] The ladder according to the first embodiment of the present invention is a ladder having a plurality of ladder bodies and telescoping on a vehicle, and the ladder body has the same cross-sectional shape for all of the upper parent bone and the lower parent bone, and the cross-sectional size of the upper parent bone or the lower parent bone in at least one stage is the same as the cross-sectional size of the upper parent bone or the lower parent bone in other stages. According to this embodiment, by standardizing the cross-sectional shape and size of the main ribs as much as possible, it becomes possible to use the same steel material for the main ribs, thereby reducing the number of types of steel material and lowering management effort and costs.

[0009] A second embodiment of the present invention is a ladder according to the first embodiment, wherein the lower rib of the step one step above the lowest step has an inner diameter larger than the outer diameter of the telescopic cylinder used to extend and retract the ladder, is arranged coaxially with the telescopic cylinder, and retracts when the ladder is retracted. According to this embodiment, the lower rib where the telescopic cylinder is housed can perform some of the functions, such as preventing buckling of the telescopic cylinder. This makes it possible to reduce the number of components and form a narrower ladder compared to when the telescopic cylinder is placed outside the lower rib, thereby reducing costs and weight.

[0010] A third embodiment of the present invention is a ladder according to the second embodiment, wherein the lower rib housing the telescopic cylinder is made of a single pipe, and a connecting member connecting the upper rib and the lower rib is attached to this single pipe. According to this embodiment, the lower main rib housing the telescopic cylinder can be constructed with fewer components and less processing effort than when the interior is divided into two steel materials, such as a pipe for housing the telescopic cylinder and a pipe for attaching the connecting material, thus reducing costs and weight.

[0011] A fourth embodiment of the present invention is a ladder according to the third embodiment, wherein the connecting member is an oblique bone provided at an angle to the main ribs, with one end connected to the upper main rib via an oblique bone box and the other end connected to the lower main rib via an oblique bone box, and the width of the oblique bone is the same within each rung. According to this embodiment, costs can be reduced by standardizing the size of multiple diagonal frame boxes within each stage. Furthermore, by standardizing the width of the diagonal frames within each stage, the number of diagonal frame types can be reduced, leading to a reduction in the number of verification steps compared to conventional methods and improving manufacturing efficiency.

[0012] A fifth embodiment of the present invention is a ladder according to any one of the second to fourth embodiments, wherein the ladder has five steps, the cross-sectional size of the upper and lower ribs in the first step and the upper rib in the second step is the smallest among the ribs, the cross-sectional size of the lower rib in the second step and the upper and lower ribs in the third step is the second smallest among the ribs, the cross-sectional size of the upper rib in the fourth step and the upper rib in the fifth step is the third smallest among the ribs, the cross-sectional size of the lower rib in the fifth step is the fourth smallest among the ribs, and the cross-sectional size of the lower rib in the fourth step is the largest among the ribs. According to this embodiment, since the total of 10 main ribs can be formed from five types of steel with different cross-sectional sizes, costs can be effectively reduced.

[0013] A sixth embodiment of the present invention is a ladder according to the fifth embodiment, wherein the thickness of the lower rib at the fourth step is smaller than the thickness of the lower rib at the fifth step. According to this embodiment, by reducing the thickness of the lower main rib, which has the largest cross-sectional size, it is possible to reduce the weight while still meeting the required strength as a main rib.

[0014] A seventh embodiment of the present invention is a ladder according to any one of the first to sixth embodiments, wherein the cross-sectional shape of the upper and lower ribs is square. According to this embodiment, the overall height of the vehicle, including the ladder, can be reduced when the ladder is stored, such as when the vehicle is in motion, and the width of the ladder body can be reduced to lower its weight.

[0015] An eighth embodiment of the present invention is a ladder according to any one of the second to seventh embodiments, wherein the tube of the telescopic cylinder is provided with a tube pad that contacts the inner surface of the lower rib when it is housed in the lower rib, and the tube pad consists of one pad whose length is smaller than the inner diameter of the lower rib that houses the tube, and the other pad whose length is equal to the inner diameter of the lower rib that houses the tube, and the one pad and the other pad are arranged to sandwich the tube, and piping or wiring is passed through the gap between the one pad and the lower rib. According to this embodiment, by effectively utilizing the limited space inside the lower rib that houses the telescopic cylinder to arrange piping and the like, the width of the ladder can be minimized and its weight reduced.

[0016] The ninth embodiment of the present invention is a ladder according to any one of the first to eighth embodiments, comprising a lower roller that rotates by contact with the lower surface of the lower ribs when the ladder is extended or retracted, wherein the lower roller consists of a first portion and a second portion adjacent to each other, each having a pair of rotating bodies, and a first bracket on one end side supporting one end of the pair of rotating bodies of the first portion and a first bracket on the other end side supporting the other end of the pair of rotating bodies of the first portion are provided separately, and a second bracket on one end side supporting one end of the pair of rotating bodies of the second portion and a second bracket on the other end side supporting the other end of the pair of rotating bodies of the second portion are provided separately. According to this embodiment, compared to the case where a bracket supporting one end of a rotating body and a bracket supporting the other end are directly connected with connecting parts, the number of connecting parts is reduced, thereby lowering costs such as material costs and processing costs, and improving work efficiency.

[0017] A tenth embodiment of the present invention is a ladder according to any one of the first to ninth embodiments, wherein the rear end of the lower rib is provided with a swing suppressor that suppresses swinging when the ladder is extended or retracted, and the swing suppressor has a first main body provided between the guide rail that guides the sliding of the ladder and the lower rib on the same rung of the ladder, and a first sub-body disposed in the gap between the guide rail and the first main body, and in the gap between the lower rib and the first main body. According to this embodiment, the swaying of the ladder during extension and retraction can be effectively suppressed by inserting the first sub-body into the gap between the first main body and other members to fill the gap. Furthermore, since the first sub-body can be formed according to the gap, manufacturing efficiency can be increased.

[0018] An eleventh embodiment of the present invention is a ladder according to the tenth embodiment, wherein the swing suppressor has a second main body on the same rung of the ladder, one end of which is connected to a guide rail and the other end of which is connected to a lower rib, and a second sub-body which is positioned in the gap between the guide rail on the rung below and the second main body. According to this embodiment, the swaying of the ladder during extension and retraction can be effectively suppressed by inserting a second sub-body into the gap between the second main body and other components to fill the gap. Furthermore, since the second sub-body can be formed according to the gap, manufacturing efficiency can be increased.

[0019] A twelfth embodiment of the present invention is a ladder according to any one of the first to eleventh embodiments, wherein the tip of the ladder body is provided with a downwardly foldable step, the center of the fold of the step is located inside the ladder body when the ladder is retracted for storage, and the bending of the step is prevented when the center of the fold comes into contact with the ladder body. According to this embodiment, the overall length of the ladder in its stored state can be reduced. Furthermore, there is no need to provide a separate mechanism to prevent bending, which can reduce costs and weight.

[0020] A thirteenth embodiment of the present invention is a ladder according to the twelfth embodiment, wherein the bending step has a protrusion behind the bending center, the ladder body has a receiving portion corresponding to the protrusion, and when the ladder is in the retracted state, the protrusion and the receiving portion are close to or in contact with each other. According to this embodiment, the refraction of the refraction stage in the retracted state can be prevented more reliably.

[0021] A fourteenth embodiment of the present invention is a ladder according to any one of the first to thirteenth embodiments, wherein the ladder is provided with a ladder frame that supports the rear of the ladder, and the ladder frame is divided into a luffing center body located at the rear end of the ladder and having the center point when the ladder is luffed, and a cylinder tip connector located in front of the luffing center body and to which the tip of the luffing cylinder that raises and lowers the ladder is connected. According to this embodiment, the amount of steel used can be reduced compared to conventional ladder frames where the rear end of the ladder body is integrally connected to the point where the tip of the luffing cylinder is connected, thereby reducing weight and cost.

[0022] A vehicle according to the 15th embodiment of the present invention is equipped with a ladder according to any one of the first to 14th embodiments. According to this embodiment, it is possible to reduce the weight and cost of the vehicle. [Examples]

[0023] The following describes a ladder according to one embodiment of the present invention, and a vehicle equipped with said ladder. Figure 1 is a left side view of a vehicle equipped with a ladder according to this embodiment. The vehicle (fire ladder truck) comprises a cabin 1 located at the front of the vehicle and having a driver's seat, a body 2 located behind the cabin 1, a ladder 3 stored in a prone position above the cabin 1 and body 2, a gyro turntable 4 located at the rear of the body 2, a support frame 5 located on the gyro turntable 4 and supporting the rear end of the ladder 3, a support device 6 located close to the rear of the cabin 1 that supports the ladder 3 from below, a basket 7 attached to the tip of the ladder 3, and outriggers 8. The ladder 3 has a multi-stage ladder body 31 and is connected to the vehicle body 2 via a ladder body frame 32, a support frame 5, and a gyro turntable 4. The ladder 3 is also equipped with an extension cylinder 33 used for extending and retracting the ladder 3, a luffing cylinder 34 used for raising and lowering the ladder 3, and a bending cylinder 35 used for adjusting the bending angle of the bending steps 37.

[0024] Figure 2 is a cross-sectional view of the ladder. Note that since the ladder is symmetrical, only one side is shown in Figure 2. Figure 3 is a side view showing the ladder scaled down with the telescopic cylinder stored inside the lower ribs. The ladder 3 in this embodiment has a five-step structure in which the ladder body 31 has five steps, from the first to the fifth step, and extends and retracts by sliding the ladder body 31 with the telescopic cylinder 33. The first step is the uppermost step of the five steps when retracted, and the fifth step is the lowermost step of the five steps when retracted. Each step of the ladder body 31 includes an upper main rib 311 located above, a lower main rib 312 located below, a diagonal rib 314 connecting the upper main rib 311 and the lower main rib 312 via a diagonal rib box 313, and a guide rail 315 positioned above the lower main rib 312 to guide the sliding of the ladder body 31. The upper and lower ribs 311 and 312 are formed from steel materials such as metal pipes, and their cross-sectional shapes are all identical, regardless of whether they are on the same or different steps. Furthermore, the cross-sectional size of the upper or lower rib 311 or 312 on at least one step is the same as the cross-sectional size of the upper or lower rib 311 or 312 on other steps. In a ladder 3 consisting of multiple steps, the required strength differs from step to step. Conventionally, the cross-sectional shape and size of the steel materials varied depending on which step they were used on, or whether they were for the upper or lower rib 311. However, by unifying the cross-sectional shape and size of the ribs as much as possible while meeting the required strength, as in this embodiment, it becomes possible to use the same steel material for the ribs, reducing the types of steel materials and thus lowering management effort and costs. For example, if multiple types of steel materials with the same shape but different cross-sectional sizes are stored, when manufacturing ladder 3, even if the steps are different, for the main ribs that share the same cross-sectional size, one type of steel material from the stored materials can be cut to the required length and used. Furthermore, if the cross-sectional shape of the main ribs is the same even between vehicles with different ladder sizes and number of steps, it becomes possible to use steel materials in common across many vehicles, regardless of the model. In this case, for example, a steel material with a cross-sectional size used as the upper main rib 311 of the third step for one vehicle can be used as the lower main rib 312 of the second step for another vehicle, thereby broadening the scope of common use and further reducing costs. Furthermore, when we say that the cross-sectional size of the main ribs is the same, it means that the outer diameter and inner diameter are the same, and if the cross-sectional shape is elliptical or rectangular, the major axis and minor axis are also the same.

[0025] The lower main rib 312 in the fourth section has an inner diameter larger than the outer diameter of the telescopic cylinder 33, is hollow inside, and has an open bottom surface. The fourth lower rib 312 and the telescopic cylinder 33 are arranged approximately coaxially, and as shown in Figure 3, when the ladder 3 is retracted, the telescopic cylinder 33 is housed inside the fourth lower rib 312. As a result, the fourth lower rib 312, where the cylinder is housed, can perform some of the functions, such as preventing buckling of the telescopic cylinder 33. This makes it possible to reduce the number of components and make the ladder 3 narrower compared to when the telescopic cylinder 33 is located outside the lower rib 312, thereby reducing costs and weight. Furthermore, even if the ladder 3 has four steps or fewer, or six steps or more, the telescopic cylinder 33 is stored in the lower rib 312 of the step one step above the bottom step.

[0026] As shown in Figure 2, in this embodiment, the cross-sectional size of the upper rib 311 and lower rib 312 in the first stage and the upper rib 311 in the second stage are made the same, and its cross-sectional size is made the smallest among the ribs. Furthermore, the cross-sectional size of the lower rib 312 in the second row and the upper rib 311 and lower rib 312 in the third row are made the same, and their cross-sectional size is made the second smallest among the ribs. Furthermore, the cross-sectional size of the upper rib 311 in the fourth row and the upper rib 311 in the fifth row are made the same, and their cross-sectional size is made the third smallest among the ribs. Furthermore, the cross-sectional size of the lower main rib 312 in the fifth tier is set to be the fourth smallest among the main ribs. Furthermore, the cross-sectional size of the lower rib 312 in the fourth stage, which houses the telescopic cylinder 33, is made the largest among the ribs. This allows the 10 main ribs to be formed from five different types of steel with varying cross-sectional sizes, effectively reducing costs.

[0027] The cross-sectional shapes of the upper rib 311 and the lower rib 312 are square. This allows for a larger gap between the lower surface of the upper rib 311 and the upper surface of the lower rib 312, even if the distance from the top surface of the upper rib 311 to the bottom surface of the lower rib 312 is the same, compared to the case where the cross-sectional shapes of the upper rib 311 and the lower rib 312 are rectangular and elongated vertically. This makes it easier to secure space for installing pipes, wires, etc., between the upper rib 311 and the lower rib 312. As a result, the distance from the top surface of the upper rib 311 to the bottom surface of the lower rib 312 can be made smaller than in the case where the cross-section is rectangular and elongated vertically, thereby reducing the overall height of the vehicle, including the ladder 3, when the ladder 3 is stored, such as when the vehicle is in motion. Furthermore, by making the cross-sectional shape of the upper rib 311 and the lower rib 312 square, the ladder sections 31 can be brought closer together than if the cross-sectional shape were a rectangle that is long in the left-right direction. As a result, the width of the ladder section 31 can be made smaller, and the weight can be reduced.

[0028] The thickness of the lower rib 312 in the fourth section is smaller than the thickness of the lower rib 312 in the fifth section. By making the thickness of the lower rib 312 in the fourth section, which has the largest cross-sectional size, smaller than that of the lower rib 312 in the fifth section, it is possible to reduce the weight while still meeting the necessary strength as a rib. Furthermore, the thickness of the main ribs in the first to third rows is the same, and this thickness is smaller than the thickness of the lower main rib 312 in the fourth row. Also, the thickness of the upper main rib 311 in the fourth row and the upper main rib 311 in the fifth row are the same, and this thickness is the same as the thickness of the lower main rib 312 in the fourth row.

[0029] As shown in Figure 3, the oblique rib 314 is one of the connecting members that connect the upper main rib 311 and the lower main rib 312. It is provided at an angle to the main rib, with one end connected to the upper main rib 311 via an upper oblique rib box 313 provided on the lower surface of the upper main rib 311, and the other end connected to the lower main rib 312 via a lower oblique rib box 313 provided on the lower main rib 312. Multiple oblique ribs 314 are provided so as to weave between the upper main rib 311 and the lower main rib 312, but the width W of the oblique rib 314 (see Figure 2) is the same within each section. In this way, by unifying the width W of the diagonal frame 314 for each row, the size of the multiple diagonal frame boxes 313 used to connect the diagonal frames 314 can be unified for each row, thereby reducing costs. Furthermore, even within the same row, the size of the diagonal frame 314 differs depending on the mounting position, so it is necessary to proceed with the work while checking the size to avoid mistakes in the manufacturing process. However, in this embodiment, by unifying the width W of the diagonal frame 314 within each row, the number of types of diagonal frame 314 sizes can be reduced, thus reducing the time required for the size verification process and improving manufacturing efficiency.

[0030] Furthermore, each main rib, including the fourth lower rib 312 which houses the telescopic cylinder 33, is made from a single pipe, and the diagonal rib 314 is attached to that single pipe. By making the fourth lower rib 312, which houses the telescopic cylinder 33, a single pipe, the number of components can be reduced and the processing time reduced compared to constructing the lower rib 312 that houses the telescopic cylinder 33 by dividing the interior with two steel materials, such as the pipe that houses the telescopic cylinder 33 and the pipe to which the diagonal rib 314 is attached. This reduces costs and weight.

[0031] Figure 4 shows the telescopic cylinder in its retracted state. As described above, the telescopic cylinder 33 is entirely stored in the lower rib 312 of the fourth section when the ladder 3 is retracted, such as when the vehicle is in motion. When the rod 331 of the telescopic cylinder 33 is extended from that state to start extending the ladder 3, the ladder body 31 gradually slides toward the tip, and the tube 332 of the telescopic cylinder 33, which was housed in the lower rib 312 of the fourth step, is exposed to the outside. The rod 331 remains housed inside the lower rib 312 of the fourth step. Furthermore, when the ladder 3 is retracted from its extended state by shortening the rod 331 of the telescopic cylinder 33, the ladder body 31 gradually slides toward the rear end, and the tube 332 of the telescopic cylinder 33 becomes covered by the lower rib 312 of the fourth step.

[0032] Multiple rod pads 333 are attached to the rod 331 of the telescopic cylinder 33 at intervals along its longitudinal direction. The rod pads 333 are approximately tetrahedrons, and the rod 331 passes through a hole located in the center of each rod pad 333. The rod pad 333 serves to prevent buckling of the rod 331. Furthermore, the rod pad 333 is sized to contact the inner surface of the fourth lower rib 312, where the rod 331 is housed, and thus also serves to guide the rod 331 to prevent it from coming into contact with the lower rib 312.

[0033] Multiple tube pads 334 are attached to the tube 332 of the telescopic cylinder 33 at intervals along its longitudinal direction. The tube pads 334 serve to prevent buckling of the tube 332. In addition, the tube pads 334 are positioned to protrude from the outer surface of the tube 332 and come into contact with the inner surface of the lower rib 312 when the tube 332 is retracted into the fourth lower rib 312, thus guiding the tube 332 to prevent it from coming into contact with the lower rib 312.

[0034] Figure 5 is a schematic cross-sectional view showing the telescopic cylinder housed in the lower rib. Near the tube 332, two hydraulic pipes 40 are arranged along the tube 332, carrying oil used to operate the telescopic cylinder 33. The hydraulic pipes 40 are attached to the tube 332 with fasteners at intervals along the longitudinal direction, and are housed together with the telescopic cylinder 33 within the lower rib 312 when the ladder body 31 is retracted. The tube pad 334 consists of one pad 334a positioned on the upper surface of the tube 332 and the other pad 334b ​​positioned on the lower surface of the tube 332. The two pads 334a and 334b ​​are positioned on either side of the tube 332, with their positions being approximately 180 degrees apart. One pad 334a has a lateral length smaller than the inner diameter of the fourth lower rib 312 and the outer diameter of the tube 332. The hydraulic piping 40, which is provided in parallel with the telescopic cylinder 33, passes through the resulting gap between the pad 334a and the lower rib 312. In this way, by effectively utilizing the limited space inside the fourth lower rib 312 to arrange the piping, the width of the ladder 3 can be minimized, thereby reducing its weight. Alternatively, other pipes or wiring can be passed through the gap between the pad 334a and the lower rib 312, either together with or in place of the hydraulic piping 40. Furthermore, the height of one pad 334a is such that when the tube 332 is housed in the fourth lower rib 312, the upper surface of one pad 334a contacts the upper inner surface of the lower rib 312. The length of the other pad 334b ​​in the horizontal direction is approximately equal to the inner diameter of the fourth lower rib 312 that houses the tube 332, and the height is such that when the tube 332 is housed in the fourth lower rib 312, the lower surface of the other pad 334b ​​contacts the lower inner surface of the lower rib 312. As a result, when the tube 332 is housed in the fourth lower rib 312, one pad 334a and the other pad 334b ​​contact the inner surface of the fourth lower rib 312, thus reliably preventing the tube 332 from coming into contact with the lower rib 312.

[0035] Figure 6 shows the bottom roller, with Figure 6(a) being a side view and Figure 6(b) being a cross-sectional view in the expansion / contraction direction of one step. The second to fifth steps of the ladder 31 are each provided with a bottom roller 50 that rotates when the ladder 3 is extended or retracted, by contact with the lower surface of the lower rib 312. The bottom roller 50 consists of a first part 51 having a pair of rotating bodies 501 and a second part 52 having a pair of rotating bodies 502, which are adjacent to each other. The axes of rotation of the rotating bodies 501 and 502 are oriented in the width direction of the lower rib 312. One end of the pair of rotating bodies 501 of the first section 51 is supported by a balance-shaped (approximately inverted triangular) first bracket 511 on one end side, and the other end of the pair of rotating bodies 501 of the first section 51 is supported by a balance-shaped (approximately inverted triangular) first bracket 512 on the other end side. In addition, one end of the pair of rotating bodies 502 of the second section 52 is supported by a balance-shaped (approximately inverted triangular) second bracket 521 on one end side, and the other end of the pair of rotating bodies 502 of the second section 52 is supported by a balance-shaped (approximately inverted triangular) second bracket 522 on the other end side. In this way, by providing the first bracket 511 on one end and the first bracket 512 on the other end separately without directly connecting them, and by providing the second bracket 521 on one end and the second bracket 522 on the other end separately without directly connecting them, the number of connecting parts is reduced compared to the case where the bracket supporting one end of the rotating body 501 or rotating body 502 and the bracket supporting the other end are directly connected with connecting parts, etc., thereby reducing costs such as material costs and processing costs, and improving work efficiency. The first bracket 511 on one end, the first bracket 512 on the other end, the second bracket 521 on one end, and the second bracket 522 on the other end are attached to the roller frame. The roller frame comprises a central suspension section 531 suspended in the width direction between a first section 51 and a second section 52, a first suspension section 532 suspended in the width direction between a pair of rotating bodies 501 of the first section 51, a second suspension section 533 suspended in the width direction between a pair of rotating bodies 502 of the second section 52, a one-end support section 534 that supports one end of the central suspension section 531, the first suspension section 532, and the second suspension section 533, and a one-end support section 535 that supports the other end of the central suspension section 531, the first suspension section 532, and the second suspension section 533. One end of the first bracket 511 engages with one end of the first suspension section 532, the other end of the first bracket 512 engages with the other end of the first suspension section 532, one end of the second bracket 521 engages with one end of the second suspension section 533, and the other end of the second bracket 522 engages with the other end of the second suspension section 533.

[0036] Figures 7 and 8 show the oscillation suppressor, with Figures 7(a) and 8(a) being side views and Figures 7(b) and 8(b) being cross-sectional views. At the rear end of each of the four ladder sections 31, a swing suppressor 36 is provided to suppress the swinging of the ladder 3 in the vertical direction and other directions when it is extended or retracted. The oscillation suppressor 36 comprises a U-shaped member 361 as the first main body, an upper rear end pad 362 and a lower rear end pad 363 as the first sub-body, and a J-shaped member 364 as the second main body, and a lateral rear end pad 365 as the second sub-body. The material of the U-shaped member 361 and the J-shaped member 364 is, for example, SUS, and the material of the upper rear end pad 362, the lower rear end pad 363, and the lateral rear end pad 365 is, for example, nylon. The U-shaped member 361 is positioned with a gap between the lower rib 312 and the guide rail 315 and is bolted in place. The outer surface of the U-shaped member 361 is in contact with the outer surface of the lower rib 312 of the row above it. The upper rear end pad 362 is positioned to fill the gap between the upper surface of the U-shaped member 361 and the lower surface of the guide rail 315. The lower rear end pad 363 is positioned to fill the gap between the lower surface of the U-shaped member 361 and the upper surface of the lower rib 312. The J-shaped member 364 is bolted to the outer surface of the guide rail 315 at one end and to the upper surface of the lower rib 312 at the other end. The lateral rear end pad 365 is positioned to fill the gap between the guide rail 315 of the next lower level and the J-shaped member. By inserting the first sub-parts 362, 363, and second sub-part 365 into the gaps between the first main body 361 or the second main body 364 and other components to fill the gaps, the swaying of the ladder 3 during extension and retraction can be effectively suppressed. Furthermore, since the first sub-part 362 or the second sub-part 365 can be formed according to the gap, manufacturing efficiency can be increased.

[0037] Figure 9 is a side view showing the ladder from the bent section to the second step, with Figure 9(a) showing the ladder in its retracted state and Figure 9(b) showing it in its extended state. The tip of the ladder body 31 is provided with a bendable step 37 that can bend downwards. Although not shown in Figure 9, a basket 7 is connected to the tip of the bendable step 37. The center of articulation 37A, which is the point at which the articulated step 37 bends, is located inside the ladder body 31, inward of the tip 31A of the second step, when the ladder 3 is retracted for storage. By pulling the center of articulation 37A of the articulated step 37 inward of the tip 31A of the second step of the ladder body 31, the overall length of the ladder 3 in the stored state can be shortened. Furthermore, since the bending of the articulated section 37 in the stored state is prevented by contact with the second section of the ladder body 31, there is no need to provide a separate mechanism to prevent bending, thus reducing costs and weight.

[0038] Figure 10 is a detailed diagram of the retraction of the step; Figure 10(a) shows the protrusion, Figure 10(b) shows the receiving part, and Figure 10(c) shows the engagement state between the protrusion and the receiving part when the ladder is in the retracted state. Note that the lower diagrams in Figures 10(a) and (b) are enlarged views of the parts circled in the upper diagram. At the bending step 37, a convex portion 38 is provided behind the bending center 37A, and at the second step of the ladder body 31, a receiving portion 39 corresponding to the convex portion 38 is provided behind the tip 31A. When the ladder 3 is retracted and stored, as shown in Figure 10(c), the convex portion 38 is positioned close to or in contact with the receiving portion 39. The length of the receiving portion 39 is greater than the length of the convex portion 38. As a result, the downward bending motion of the bending step 37 is prevented by the convex portion 38 contacting the receiving portion 39, thus more reliably preventing the bending of the bending step 37.

[0039] Figure 11 is a side view showing the rear of the ladder. The ladder frame 32, which supports the rear of the ladder 3, is divided into a luffing center body 321, which has the center point when the ladder 3 is luffed, and a cylinder tip connector 322 to which the tip of the luffing cylinder 34 that luffs the ladder 3 is connected. The luffing center body 321 is located at the rear end of the ladder 3, and the cylinder tip connector 322 is located in front of the luffing center body 321, and both are bolted to the ladder frame 31. A frame connector 323, which is connected to the support frame 5, extends downward from the central luffing body 321, and the rear end of the luffing cylinder 34 is attached to the frame connector 323. By dividing the contact points between the ladder frame 32 and the ladder 31 into two parts, the luffing center body 321 and the cylinder tip connector 322, the amount of steel used can be reduced compared to conventional ladder frames where the rear end of the ladder 31 is connected integrally to the point where the tip of the luffing cylinder 34 is connected, thereby reducing weight and cost. [Industrial applicability]

[0040] By incorporating the ladder of the present invention, it is possible to reduce the weight and cost of firefighting ladder trucks, aerial work platforms, and other similar vehicles. [Explanation of symbols]

[0041] 3 ladder 31 Ladder 37 Bending section 37A Center of Refraction 311 Upper rib 312 Lower rib 313 Oblique box 314 Oblique bone 315 Guide Rail 32 Ladder Frames 321 undulating centrosome 322 Tip connector 33 Telescopic cylinder 332 Tubes 334 Tube Pads 334a One pad 334b The other pad 34. Relief cylinder 36. Oscillation suppressor 361 First main body (U-shaped member) 362, 363 First sub-body (upper rear end pad, lower rear end pad) 364 Second main body (J-shaped member) 365 Second auxiliary body (lateral rear end pad) 38 Convex part 39 Receiving part 50 Bottom roller 51 First part 52 Second part 501, 502 Rotating bodies 511 First bracket 521 Second bracket W Oblique width

Claims

1. A ladder having multiple sections that extends and retracts on a vehicle, The aforementioned ladder body has identical cross-sectional shapes for both the upper and lower ribs. The cross-sectional size of the upper or lower rib in at least one section is the same as the cross-sectional size of the upper or lower rib in other sections. The lower rib of the step one step above the lowest step has an inner diameter larger than the outer diameter of the telescopic cylinder used to extend and retract the ladder, is arranged coaxially with the telescopic cylinder, and is characterized in that it stores the telescopic cylinder when the ladder is retracted.

2. The ladder according to claim 1, characterized in that the lower rib housing the telescopic cylinder is made of a single pipe, and a connecting member connecting the upper rib and the lower rib is attached to the single pipe.

3. The connecting member is an oblique bone provided at an angle to the main bone, with one end connected to the upper main bone via an oblique bone box and the other end connected to the lower main bone via the oblique bone box. The ladder according to claim 2, characterized in that the width of the diagonal bones is the same within each step.

4. The aforementioned ladder has five sections. The cross-sectional size of the upper and lower main ribs in the first stage and the upper main rib in the second stage is the smallest among the main ribs. The cross-sectional size of the lower main rib in the second stage and the upper main rib and lower main rib in the third stage is the second smallest among the main ribs. The cross-sectional size of the upper rib in the fourth and fifth stages is the third smallest among the ribs. The cross-sectional size of the lower main rib in the fifth stage is the fourth smallest among the main ribs. The ladder according to any one of claims 1 to 3, characterized in that the cross-sectional size of the lower main rib in the fourth step is the largest among the main ribs.

5. The ladder according to claim 4, characterized in that the thickness of the lower rib in the fourth step is smaller than the thickness of the lower rib in the fifth step.

6. The ladder according to any one of claims 1 to 5, characterized in that the cross-sectional shape of the upper rib and the lower rib is square.

7. The tube of the telescopic cylinder is equipped with a tube pad that contacts the inner surface of the lower rib when it is housed in the lower rib, The tube pad consists of one pad whose length is smaller than the inner diameter of the lower rib that houses the tube, and the other pad whose length is equal to the inner diameter of the lower rib that houses the tube, and the one pad and the other pad are positioned to sandwich the tube. The ladder according to any one of claims 1 to 6, characterized in that a pipe or wiring is passed through the gap between the one pad and the lower rib.

8. The ladder is equipped with a lower roller that rotates by contact with the lower surface of the lower rib when the ladder is extended or retracted, The aforementioned lower roller consists of a first portion and a second portion adjacent to each other, each having a pair of rotating bodies. A first bracket on one end of the first portion that supports one end of the pair of rotating bodies, and a first bracket on the other end that supports the other end of the pair of rotating bodies of the first portion are provided separately. The ladder according to any one of claims 1 to 7, characterized in that a second bracket on one end side that supports one end of the pair of rotating bodies of the second part and a second bracket on the other end side that supports the other end of the pair of rotating bodies of the second part are provided separately.

9. The rear end of the lower main rib is provided with a swing suppressor that suppresses swinging when the ladder is extended or retracted, The swing suppressor comprises a first main body provided between the guide rail that guides the sliding of the ladder and the lower rib in the same stage of the ladder, A ladder according to any one of claims 1 to 8, characterized in that it has a gap between the guide rail and the first main body, and a first sub-body disposed in the gap between the lower rib and the first main body.

10. The ladder according to claim 9, characterized in that the swing suppressor has a second main body in the same step of the ladder, one end of which is connected to the guide rail and the other end of which is connected to the lower rib, and a second sub-body which is positioned in the gap between the guide rail and the second main body on the ladder of the step below.

11. The ladder body is provided with a downwardly flexible step at its tip, The center of the bending step is located inside the ladder when the ladder is retracted and stored. The ladder according to any one of claims 1 to 10, characterized in that the bending of the bending step is prevented by the bending center coming into contact with the ladder body.

12. The aforementioned refraction step has a protrusion behind the center of refraction, The ladder body has a receiving portion corresponding to the protrusion, The ladder according to claim 11, characterized in that when the ladder is in the stored state, the protrusion and the receiving portion are close to or in contact with each other.

13. The ladder includes a ladder frame that supports the rear of the ladder, The ladder according to any one of claims 1 to 12, characterized in that the ladder frame is divided into a luffing center body located at the rear end of the ladder and having the center point when the ladder is luffed, and a cylinder tip connecting body located in front of the luffing center body and to which the tip of the luffing cylinder that luffs the ladder is connected.

14. A vehicle characterized by having a ladder as described in any one of claims 1 to 13 attached to it.

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