Ladder fixing device and ladder with fixing device

Abstract

To provide a ladder fixing device which enables a ladder to be easily attached to and detached from a truck bed and can stably fix the ladder to the truck bed even if the height of the truck bed varies.SOLUTION: A ladder fixing device, which includes a left ladder fixing device and a right ladder fixing device 30 that are attached to a left support 11 and a right support 12 of a steel ladder 20 and fix the steel ladder to a truck bed 40, the ladder fixing device including fixing pieces 21, 31 that have a first longitudinal piece and are engaged with a frame of a tailgate of the truck bed 40, and frames 22, 32 that are connected to the first longitudinal piece and form an opening surface and a hollow section. The frames are provided with a first short hand piece and a second short hand piece that are connected to the first longitudinal piece, and a second longitudinal piece that is continuous to the first short hand piece and the second short hand piece, the fixing piece is in a horizontal state when the left support and the right support fitted in the hollow section are tilted by 40 to 75 degrees with respect to an installation surface GL, and the left support and the right support are in contact with the first short hand piece and the second short hand piece.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a ladder fixing device for fixing a ladder used when loading and unloading luggage and various materials (hereinafter referred to as "luggage, etc.") onto a truck bed, etc., and to a ladder with fixing device attached to this fixing device. [Background technology]

[0002] When loading and unloading cargo onto a truck bed, ladders are used to reduce the workload and ensure safety, and workers use ladders fixed to the truck bed to load and unload cargo. In this case, various proposals have been made from the standpoints of ease of fixing the ladder to the truck bed, ease of working using the ladder, safety, etc. For example, Patent Document 1 (JP 2005-313887 A) discloses a ladder for climbing only, which has a ladder body 10, a locking member 30 and a gate abutment leg 40, the ladder body 10 having a pair of support bars 11 and a plurality of step bars 12, the locking member 30 having a support body 33 and a hook portion 35 provided at its tip, which is connected and fixed to each of the pair of support bars 11 of the ladder body 10 and formed so as to protrude in a direction approximately perpendicular to the surface forming the step bar 12, the hook portion 35 being inserted into and locked in a gap 97 formed at the joint surface between the loading platform and the gate when the gate 70 is lowered, and the gate abutment leg 40 is connected to each of the pair of support bars 11 of the ladder body 10 and formed below the locking member 30 so as to protrude in a direction approximately perpendicular to the surface forming the step bar 12. However, in the ladder specifically for climbing up and down the truck bed of Patent Document 1, the locking member 30 is fixed to a pair of support bars 11 of the ladder body 10, so the distance (height) from the lower end 10a of the ladder body 10 to the locking member 30 is constant, which creates the problem that it cannot be used on trucks with different bed heights. In addition, the climbing ladder in Patent Document 1 is designed specifically for use on truck beds, and therefore cannot be used as ladders (stairs) as materials used to build scaffolding for construction work, resulting in a lack of versatility.

[0003] In this regard, Patent Document 2 (JP Patent Publication No. 2007-285054) discloses a truck climbing ladder A which is composed of a ladder main body 3 having step bars 2 horizontally suspended in multiple stages at required intervals on a pair of left and right side frames 1, 1, and hanging devices 4 which are provided on the upper end sides of each of the two side frames 1, 1 of the ladder main body 3 and are engaged with the leaning point of the truck bed, and a step member 5 which serves as a work platform and is wider than the step bar 2 is attached to the top of the step bar 2 on the top step side, each side frame 1 of the ladder main body 3 is formed in a U-shaped cross section, the hanging device 4 is composed of a hanging device main body 8 which is formed in an L-shape and a mounting bracket 9, the mounting bracket 9 is formed in a U-shape and the base end of the hanging device main body 8 is fixed to the upper end of the inner plate by welding, and the hanging device 4 is attached to the upper end side of each of the two side frames 1, 1 of the ladder main body 3 so that the installation height can be changed.

[0004] However, in the truck climbing ladder A of Patent Document 2, bolt insertion holes 25 are provided at regular intervals at multiple locations on the upper end side of the front and rear plate portions of each side frame 1, bolt insertion holes 26 are provided on the front and rear plate portions of the mounting bracket 9 so as to correspond to the bolt insertion holes 25 of the side frame 1, and the hanging device 4 is attached at a required height position on the upper end side of the side frame 1 by sliding the mounting bracket 9 fitted into the side frame 1 to the required position, and passing a bolt 28 through the required bolt insertion hole 25 in the front and rear plate portions of the side frame 1 through the bolt insertion hole 26 of the mounting bracket 9 and tightening it with a nut 27.Therefore, not only does it take a great deal of time and effort to attach the hanging device 4 to the side frame 1, but the attachment position of the hanging device 4 to each side frame 1 is limited to the position of the bolt insertion holes 25, 26, which creates the problem that the hanging device 4 cannot be attached at an arbitrary height. In addition, the truck climbing ladder A of Patent Document 2, like the climbing-specific ladder of Patent Document 1, is designed specifically for use on truck beds, and therefore cannot be used as a ladder (stairs) as a material for constructing scaffolding for construction work, resulting in a lack of versatility.

[0005] Incidentally, Patent Document 3 (JP 2010-48001 A) discloses a support rotation device 1 to be attached to the legs 3 of a ladder 2, which has two legs 3 (hollow, elongated rectangular bars) between which step plates 9 are attached at equal intervals in multiple stages, the support rotation device 1 comprising a base 4 (square pipe), a receiver 5 fixed to and protruding from the front of the upper end of the base 4, a block 6 attached to the side of the receiver 5, a thin plate-like support 7 with a roughly L-shaped planar shape placed on the block 6, and a handrail 8 erected on the support 7, the block 6 being rotatable relative to the receiver 5, the support 7 being rotatable relative to the block 6, a lower hook 21 provided at the tip of the receiver 5, a cylinder 42 slidably placed over the handrail 8, and an upper hook 41 attached to the tip of a plate-like spacing member 43 protruding from the cylinder 42. In Patent Document 3, the base 4 of the support rotator 1 is placed over the upper end of the leg 3 of the ladder 2, and the base 4 is adapted to rise and fall a certain distance along the leg 3, and the block 6 and support 7 can be rotated to point the handrail 8 upward or downward. When the tailgate 25 of the truck 22 is upright, the handrail 8 is stood vertically facing upward, the ladder 2 is placed against the side 23 of the body of the truck 22, the lower hook 21 is pressed against the side 23 of the body of the truck 22, and the upper hook 41 is placed over the upper edge of the tailgate 25 of the truck 22 and engaged (Figure 1 of Reference 3). When the tailgate 25 of the truck 22 is tilted downward, the handrail 8 is stood vertically facing upward, the ladder 2 is placed against the side 23 of the body of the truck 22, and the lower hook 21 of the support rotation device 1 is inserted into the gap 26 between the body of the truck 22 and the tilted down tailgate 25 to engage it (Figure 2 of Reference 3).

[0006] However, in the ladder 2 equipped with the support rotation device 1 of Patent Document 3, the base 4 slides (rises and falls) freely a certain distance along the leg 3, and the base 4 cannot be fixed to the leg 3 at a specific position. Therefore, when the ladder 2 is leaned against the side surface 23 of the vehicle body of the truck 22, the base 4 tends to move along the leg 3, resulting in the problem that the ladder 2 cannot be leaned stably. In addition, in Patent Document 3, when the support rotation device 1 is attached to the ladder 2, in order to regulate the ascending and descending positions of the base 4, the outer edge of a square plate-shaped stopper 15 is welded and fixed to the inside of the upper end of the leg 3, a round bar-shaped guide shaft 17 penetrates from below to above a hole 16 opened in the center of the stopper 15, the square pipe surface of the base 4 is blocked by a ceiling board 18, a flange 19 is provided at the lower end of the guide shaft 17, and the upper end of the guide shaft 17 is welded and fixed to the ceiling board 18, so that the base 4 cannot be easily removed from the leg 3, the support rotation device 1 cannot be removed from the ladder 2 and the ladder 2 cannot be used on its own, and there is a problem that it cannot be used as a ladder (stairs) that is a material used to construct scaffolding for construction work, and it is not versatile. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] JP 2005-313887 A [Patent Document 2] JP 2007-285054 A [Patent Document 3] JP 2010-48001 A Summary of the Invention [Problem to be solved by the invention]

[0008] To provide a ladder fixing device which allows a ladder that can be easily attached and detached and which can also be used to set up scaffolding on a truck bed, and which can stably fix the ladder to the truck bed even if the truck bed height is different, and a ladder with fixing device to which this ladder fixing device is attached. [Means for solving the problem]

[0009] The invention of claim 1 is a ladder fixing device that is attached to a ladder post to fix the ladder to a truck bed, comprising: a first long piece, a fixing piece having a hanging piece hanging from the first long piece and engaging with a frame of a sidegate of the truck bed, and a long frame body connected to the first long piece to form a rectangular opening surface and a rectangular parallelepiped hollow portion, the frame body comprising a first short piece and a second short piece arranged opposite to each other, extending in the short direction of the frame body and connected to the first long piece, and a second long piece arranged opposite to the first long piece, extending in the long direction of the frame body and continuing to the first short piece and the second short piece, the ratio of the long side to the short side of the opening surface is 1.6 to 4, and the ratio of the length of the hollow portion in the direction perpendicular to the opening surface to the length of the short side of the opening surface is 1.5 to 2. The above problem is solved by providing a ladder fixing device characterized in that the ratio is 0.5 to 1.5, and when the support is fitted into the hollow portion so that it is perpendicular to the opening surface, a longitudinal gap is created between the support and the first short piece and / or the second short piece, and a lateral gap is created between the support and the first long piece and / or the second long piece, the longitudinal gap being 1 / 5 to 1 / 2 the length of the long side of the opening surface, and the lateral gap being 1 / 5 or less of the length of the short side of the opening surface, and when the support fitted into the hollow portion is inclined at 40 degrees to 75 degrees with respect to the installation surface of the support, the fixing piece is in a horizontal position and the support abuts the first short piece and the second short piece.

[0010] The invention of claim 2 solves the above-mentioned problem by providing a ladder fixing device in which the fixing piece is formed from a single flat metal plate, the frame body is formed by bending a single flat metal plate, and the ends of the first short piece and the second long piece of the second short piece where the second long piece are not continuous are joined to the first long piece.

[0011] The invention of claim 3 is a ladder fixing device that is attached to a ladder post and fixes the ladder to a truck bed, comprising: a movable piece having a first long piece and an inclined piece inclined from the first long piece and engaging with a frame of a side panel of the truck bed; and a long frame body that holds the movable piece and forms a rectangular opening surface and a rectangular parallelepiped hollow portion, the frame body comprises a first short piece and a second short piece that are arranged opposite to each other and extend in the short direction of the frame body to hold the first long piece, and a second long piece that is arranged opposite to the first long piece, extends in the long direction of the frame body and is continuous with the first short piece and the second short piece, the first short piece and the second short piece are provided with slits through which the first long piece is inserted and holds the first long piece so that it can move opposite to the second long piece, and the first long piece has a slit that can be inserted into the slit. The above problem is solved by providing a ladder fixing device in which a slip-prevention means is provided to prevent the first long piece from slipping off the first short piece and the second short piece, and when the support is fitted into the hollow portion, a longitudinal gap is created between the support and the first short piece and / or the second short piece, and a lateral gap is created between the support and the long piece and / or the movable piece, the longitudinal gap being 1 / 4 or less of the length of the long side of the opening surface, and the lateral gap being 1 / 5 or less of the length of the short side of the opening surface, and when the support fitted into the hollow portion is tilted at 40 degrees to 75 degrees with respect to the installation surface of the support, the movable piece is in a horizontal position, the first long piece abuts the surface that forms the slit, and the support abuts the first short piece and the second short piece.

[0012] The invention of claim 4 solves the above problem by providing a ladder fixing device in which the movable piece is formed from a single flat metal plate, and the first short piece, the second short piece and the second long piece are formed by bending a single flat metal plate.

[0013] The invention of claim 5 solves the above-mentioned problem by providing a ladder fixing device in which the anti-slip means includes a bolt hole provided in the first longitudinal piece, a bolt inserted into the bolt hole, and a nut screwed onto the threaded portion of the bolt.

[0014] The invention of claim 6 solves the above-mentioned problem by providing a ladder fixing device in which the support consists of a left support located on the left side and a right support located on the right side, the ladder fixing device consists of a left ladder fixing device attached to the left support and a right ladder fixing device attached to the right support, and the left ladder fixing device and the right ladder fixing device have a symmetrical structure.

[0015] The invention of claim 7 relates to a ladder with a fixing device, comprising a ladder having a support and a ladder fixing device attached to the support to fix the ladder to a truck bed, the ladder fixing device comprising a first long piece and a fixing piece having a hanging piece hanging from the first long piece and engaging with a frame of a side panel of the truck bed, and a long frame body connected to the first long piece to form a rectangular opening surface and a rectangular parallelepiped hollow portion, the frame body comprising a first short piece and a second short piece arranged opposite to each other, extending in the short direction of the frame body and connected to the first long piece, and a second long piece arranged opposite to the first long piece, extending in the long direction of the frame body and continuing to the first short piece and the second short piece, the ratio of the long side to the short side of the opening surface is 1.6 to 4, and a front of the hollow portion is provided. The above problem is solved by providing a ladder with fixing devices in which the ratio of the length perpendicular to the opening surface to the length of the short side of the opening surface is 0.5 to 1.5, and when the support is fitted into the hollow portion so that it is perpendicular to the opening surface, a longitudinal gap is created between the support and the first short piece and / or the second short piece, and a lateral gap is created between the support and the first long piece and / or the second long piece, the longitudinal gap being 1 / 5 to 1 / 2 the length of the long side of the opening surface, and the lateral gap being 1 / 5 or less of the length of the short side of the opening surface, and the support fitted into the hollow portion abuts against the first short piece and the second short piece when inclined at 40 degrees to 75 degrees with respect to the installation surface of the support.

[0016] The invention of claim 8 relates to a ladder with a fixing device, comprising a ladder having a support and a ladder fixing device attached to the support to fix the ladder to a truck bed, the ladder fixing device comprising a movable piece having a first long piece and an inclined piece inclined from the first long piece and engaging with a frame of a side panel of the truck bed, and a long frame body that holds the movable piece and forms a rectangular opening surface and a rectangular parallelepiped hollow portion, the frame body comprises a first short piece and a second short piece that are arranged opposite to each other and extend in the short direction of the frame body to hold the first long piece, and a second long piece that is arranged opposite to the first long piece, extends in the long direction of the frame body and is continuous with the first short piece and the second short piece, the first short piece and the second short piece are provided with slits through which the first long piece is inserted and holds the first long piece so that it can move opposite to the second long piece, and the first long piece The above-mentioned problem is solved by providing a ladder with fixing devices in which the first long piece inserted into the slit is prevented from coming off the first short piece and the second short piece, and when the support is fitted into the hollow portion, a longitudinal gap is created between the support and the first short piece and / or the second short piece, and a lateral gap is created between the support and the long piece and / or the movable piece, the longitudinal gap being 1 / 4 or less of the length of the long side of the opening surface, and the lateral gap being 1 / 5 or less of the length of the short side of the opening surface, and when the support fitted into the hollow portion is inclined at 40 degrees to 75 degrees with respect to the installation surface of the support, the movable piece is in a horizontal position, the first long piece abuts the surface that forms the slit, and the support abuts the first short piece and the second short piece.

[0017] The invention of claim 9 solves the above problem by providing a ladder with fixing devices, which is a ladder having a hook portion that can be attached to a horizontal member of a scaffold and is used as a step of the scaffold. Effect of the Invention

[0018] In the ladder fixing device of the invention described in claim 1, an opening surface and a hollow portion are formed by the fixing piece and the frame body, and when the ladder post is fitted into the hollow portion so as to be perpendicular to the opening surface, a longitudinal gap is generated between the post and the first short piece and / or the second short piece, and a lateral gap is generated between the post and the first long piece and / or the second long piece, and when the post fitted into the hollow portion is inclined at an angle of 40 degrees to 75 degrees with respect to the installation surface of the post, the fixing piece is in a horizontal state, and the post Because the ladder fixing device abuts against the first short piece and the second short piece, the ladder fixing device can be easily attached to the ladder by simply fitting the support pillar into the hollow portion, and the ladder fixing part can be removed from the ladder.Even if the height of the truck bed is different, the fixing piece can be easily engaged with the side gate frame to fix the ladder to the truck bed, and the ladder is prevented from slipping off the truck bed when a worker climbs up or down the ladder, allowing the worker to safely climb up and down the ladder to load and unload luggage, etc.

[0019] In the ladder fixing device of the invention described in claim 2, further, since the fixing piece is formed from a single flat metal plate and the frame body is formed by bending a single flat metal plate, the fixing piece and the frame body can be easily manufactured, and since the end portions of the first short piece and the second long piece of the second short piece where they are not continuous are joined to the first long piece, the fixing piece can be easily connected to the frame body.

[0020] In the ladder fixing device of the invention described in claim 3, a first long piece of a movable piece is inserted into a slit provided in a first short piece and a second short piece of a frame body to form an opening surface and a hollow portion, and when a ladder support pole is fitted into the hollow portion so as to be perpendicular to the opening surface, a longitudinal gap is generated between the support pole and the first short piece and / or the second short piece, and a lateral gap is generated between the support pole and the first long piece and / or the second long piece, and when the support pole fitted into the hollow portion is inclined at an angle of 40 degrees to 75 degrees with respect to the installation surface of the support pole, the movable piece is in a horizontal state, and Since the first long piece abuts the surface forming the slit and the support pillar abuts the first short piece and the second short piece, the ladder fixing device can be easily attached to the ladder by simply fitting the support pillar into the hollow portion, and the ladder fixing part can be removed from the ladder.Even if the height of the truck bed is different, the fixing piece can be easily engaged with the frame of the tailgate to fix the ladder to the truck bed, and the ladder is prevented from slipping off the truck bed when a worker ascends or descends the ladder, allowing the worker to safely ascend and descend the ladder to load and unload luggage, etc.

[0021] In the ladder fixing device of the invention described in claim 4, the movable piece is further formed from a single flat metal plate, and the first short piece, the second short piece and the second long piece are formed by bending a single flat metal plate, thereby achieving the effect that the movable piece and the frame body can be easily manufactured.

[0022] The ladder fixing device of the invention recited in claim 5 has a further effect that the anti-detachment means provided on the first long piece can be made to have a simple structure.

[0023] The ladder fixing device of the invention described in claim 6 further comprises a left ladder fixing device and a right ladder fixing device which have a symmetrical structure, so that the fixing force of the left ladder fixing device and the fixing force of the right ladder fixing device to the truck bed are the same, thereby achieving the effect of allowing the ladder to be stably fixed to the truck bed.

[0024] In the ladder with fixing device of the invention described in claim 7, the opening surface and hollow portion of the ladder fixing device are formed by the fixing piece and the frame body, and when the ladder support pole is fitted into the hollow portion so as to be perpendicular to the opening surface, a longitudinal gap is generated between the support pole and the first short piece and / or the second short piece, and a lateral gap is generated between the support pole and the first long piece and / or the second long piece, and when the support pole fitted into the hollow portion is inclined at an angle of 40 degrees to 75 degrees with respect to the installation surface of the support pole, the fixing piece is in a horizontal state, Since the support pillar abuts the first short piece and the second short piece, the ladder fixing device can be easily attached to the ladder by simply fitting the support pillar into the hollow portion, and the ladder fixing part can be removed from the ladder.Even if the height of the truck bed is different, the fixing piece can be easily engaged with the side gate frame to fix the ladder to the truck bed, and the ladder is prevented from slipping off the truck bed when a worker climbs up or down the ladder, allowing the worker to safely climb up and down the ladder to load and unload luggage, etc.

[0025] In the ladder with fixing device of the invention described in claim 8, a first long piece of the movable piece is inserted into a slit provided in a first short piece and a second short piece of the frame body to form an opening surface and a hollow portion of the ladder fixing device, and when a ladder post is fitted into the hollow portion so as to be perpendicular to the opening surface, a longitudinal gap is generated between the post and the first short piece and / or the second short piece, and a lateral gap is generated between the post and the first long piece and / or the second long piece, and when the post fitted into the hollow portion is inclined at an angle of 40 degrees to 75 degrees with respect to the installation surface of the post, the movable piece is in a horizontal state. Since the first long piece abuts against the surface forming the slit and the support pillar abuts against the first short piece and the second short piece, the ladder fixing device can be easily attached to the ladder by simply fitting the support pillar into the hollow portion, and the ladder fixing part can be removed from the ladder.Even if the height of the truck bed is different, the fixing piece can be easily engaged with the frame of the tailgate to fix the ladder to the truck bed, and the ladder is prevented from slipping off the truck bed when a worker ascends or descends the ladder, allowing the worker to safely ascend and descend the ladder to load and unload luggage, etc.

[0026] The ladder with fixing devices of the invention described in claim 9 further has the advantage that a ladder that is also used for assembling scaffolding can also be used as a ladder to be attached to a truck bed. [Brief description of the drawings]

[0027] [Figure 1] FIG. 1 is a perspective view of a ladder with fixing devices according to a first embodiment of the present invention. [Diagram 2] FIG. 2 is a plan view of the ladder with fasteners shown in FIG. 1. [Diagram 3] FIG. 2 is a front view of the ladder with fasteners shown in FIG. 1. [Figure 4] FIG. 2 is a left side view of the ladder with fasteners shown in FIG. 1. [Diagram 5] 2 is a perspective view, a plan view, a left side view, and a front view of the left ladder fixing device shown in FIG. 1. [Figure 6] 2 is a perspective view, a plan view, a left side view, and a front view of the right ladder fixing device shown in FIG. 1. [Figure 7] This is a plan view and left side view of the left ladder fixture 20 positioned at an angle so that the top surface of the frame body 22 is horizontal. [Figure 8] This is a plan view and a left side view of the left ladder fixing device 20 shown in Figure 7, with the left support 11 fitted into the hollow portion 20h so that it is perpendicular to the opening surface 20k. [Figure 9] This is a left side view of the area near the left ladder fixture 20 with the steel ladder 10 fixed to the truck bed 40 by the left ladder fixture 20 and the right ladder fixture 30. [Figure 10] FIG. 11 is a perspective view of a ladder with fixing devices according to a second embodiment of the present invention. [Figure 11] FIG. 11 is a plan view of the ladder with fasteners shown in FIG. [Figure 12] FIG. 11 is a front view of the ladder with fasteners shown in FIG. [Figure 13] FIG. 11 is a left side view of the ladder with fasteners shown in FIG. [Figure 14] 11 is a perspective view, a plan view, a left side view, a front view, and a right side view of the left ladder fixing device shown in FIG. [Figure 15]11 is a perspective view, a plan view, a left side view, a front view, and a right side view of the right ladder fixing device shown in FIG. [Figure 16] This is a plan view and a left side view of the left ladder fixing device 60 positioned at an angle so that the top surfaces of the second long side piece 62a and the second short side piece 62b2 of the frame body 62 are horizontal. [Figure 17] This is a plan view and a left side view of the left ladder fixing device 60 shown in Figure 16, with the left support 51 fitted into the hollow portion 60h so that it is perpendicular to the opening surface 60k. [Figure 18] This is a left side view of the area near the left ladder fixing device 70 when the aluminum ladder 50 is fixed to the truck bed 40 by the left ladder fixing device 60 and the right ladder fixing device 70. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0028] [Overall configuration of the ladder with fixing device of the first embodiment] Figure 1 is an oblique view of a ladder with fixing devices of the first embodiment of the present invention, Figure 2 is a plan view of the ladder with fixing devices shown in Figure 1, Figure 3 is a front view of the ladder with fixing devices shown in Figure 1, Figure 4 is a left side view of the ladder with fixing devices shown in Figure 1, Figures 5(a) to (d) are respectively an oblique view, plan view, left side view and front view of the left ladder fixing device shown in Figure 1, and Figures 6(a) to (d) are respectively an oblique view, plan view, left side view and front view of the right ladder fixing device shown in Figure 1. In the figure, 1 is a ladder with a fixing device, 10 is a steel ladder, 11 is a left support, 12 is a right support, 13 and 14 are hook parts, 13a and 14a are hook bodies, 13b and 14b are clamps, 15 and 16 are base parts, 15a and 16a are base plates, 15b1, 15b2, 16b1 and 16b2 are clamping plates, 15c1 and 16c1 are bolts, 15c2 and 16c2 are nuts, 17, 18 and 19 are treads, 20 is a left ladder fixing device, 20k is an opening surface, 20h is a hollow part, 21 is a fixing piece, 21a is a first longitudinal piece, 21b is a hanging piece, 2 Reference numeral 2 is the frame body, 22a is the second long side, 22b1 is the first short side, 22b2 is the second short side, 30 is the right ladder fixing device, 30k is the opening surface, 30h is the hollow section, 31 is the fixed piece, 31a is the first long side, 31b is the hanging piece, 32 is the frame body, 32a is the second long side, 32b1 is the first short side, 32b2 is the second short side, 40 is the truck bed, 41 is the floor, 42 is the tailgate and GL is the installation surface, and in each drawing, X is the left-right direction, Y is the front-back direction and Z is the up-down direction, and the floor 41, tailgate 42 and installation surface GL are indicated by dashed dotted lines. As shown in the figure, the ladder with fixing devices 1 of the first embodiment is composed of a steel ladder 10, a left ladder fixing device 20 and a right ladder fixing device 30, and is attached to a truck bed 40.

[0029] [Steel ladder] The steel ladder 10 is a steel ladder (stairs) for scaffolding, and includes a left support 11, a right support 12, base portions 15 and 16, and treads 17, 18 and 19. Steel ladders 10 come in a variety of types, including Type A, which is approximately 2,500 mm long and 400 mm wide, and Type A half-step, which is roughly half the length, at approximately 1,200 mm, and 400 mm wide. The steel ladder 10 shown in Figure 1 etc. is a half-step Type A. The left support pillar 11 and the right support pillar 12 are made of square lumber such as steel pipes, and have hook portions 13, 14 attached to their upper ends and base portions 15, 16 attached to their lower ends. The hook portions 13, 14 include hook bodies 13a, 14a and clamps 13b, 14b, etc., and the bases of the hook bodies 13a, 14a are fixed to the upper ends of the left support 11 and the right support 12 by bolts and nuts (not shown) or the like. The base portion 15 includes a base plate 15a and a pair of substantially semicircular clamping plates 15b1 and 15b2 fixed onto the base plate 15a. The clamping plates 15b1 and 15b2 are provided with bolt insertion holes. The lower end of the left support 11, which has a bolt insertion hole, is clamped between these clamping plates 15b1, 15b, and a bolt 15c1 is inserted through the clamping plates 15b1, 15b and the bolt insertion hole in the lower end of the left support 11. A nut 15c2 is screwed onto the bolt 15c1, and the lower end of the left support 11 is attached to the base portion 15. Similarly, the base portion 16 comprises a base plate 16a and a pair of approximately semicircular clamping plates 16b1, 16b2 fixed onto it, with bolt insertion holes provided in the clamping plates 16b1, 16b2, and the lower end of the right support 12, which also has a bolt insertion hole, is clamped between the clamping plates 16b1, 16b. A bolt 16c1 is inserted through the clamping plates 16b1, 16b and the bolt insertion hole at the lower end of the right support 12, and a nut 16c2 is screwed onto the bolt 16c1, so that the lower end of the right support 12 is attached to the base portion 16. The treads 17, 18, and 19 are the upper, middle, and lower steps of a ladder (stairs), and each is made of a rectangular steel plate surrounded by ribs protruding from the underside, with numerous holes formed in the plate.

[0030] The steel ladder 10 has the above-mentioned structure and is used as a step for scaffolding. Specifically, in a scaffold consisting of vertical members of a building site, horizontal members such as arms, cloth, handrails, middle members, diagonal members, treads, etc., the horizontal members of the scaffold are gripped by the curved parts of hook bodies 13a, 14a and clamps 13b, 14b respectively, and base plates 15a, 16a are placed on a mounting surface such as the ground so that the angles of the left support pillar 11 and right support pillar 12 to the horizontal plane are 40 to 60 degrees, and bolts 15c1, 16c1 and nuts 15c2, 16c2 are tightened, whereby steel ladder 10 is assembled to the scaffold. In the first embodiment of the present invention, the steel ladder 10 thus incorporated into scaffolding is attached to the bed of a truck via a ladder fixture and used as a ladder for the bed of the truck. The ladder of the first embodiment of the present invention is not limited to the steel ladder described above, but may be an aluminum ladder (steps) used as steps on a scaffold, or a ladder that is used by leaning it against a building, a wall, etc.

[0031] [Ladder fixture] The ladder fixing device of the first embodiment of the present invention consists of a left ladder fixing device 20 and a right ladder fixing device 30, and the left ladder fixing device 20 consists of a fixing piece 21 and a frame body 22 as shown in Figure 5. The fixed piece 21 is formed from a single flat metal plate made of steel or the like, and is composed of a first long side piece 21a and a hanging piece 21b hanging down from one end of the first long side piece 21a, and has an overall L-shape. The frame body 22 is a longitudinal frame long in the Y direction and composed of a second long side piece 22a, a first short side piece 22b1 and a second short side piece 22b2, and is formed by bending a single flat metal plate made of steel or the like into a U-shape. In the frame body 22, the first short side piece 22b1 and the second short side piece 22b2 are arranged opposite each other and extend in the short direction (X direction), the second long side piece 22a is arranged opposite the first long side piece 21a and extends in the long direction (Y direction), the first short side piece 22b1, the second long side piece 22a, and the second short side piece 22b2 are arranged consecutively in this order, and the bent portion when a single metal flat plate is bent into a U shape forms the boundary between the first short side piece 22b1, the second long side piece 22a, and the second short side piece 22b2. The ends of the first short side piece 22b1 and the second short side piece 22b2 that are not continuous with the second long side piece 22a are connected to the first long side piece 21a of the fixing piece 21 by welding or the like to form a rectangular opening surface 20k and a rectangular parallelepiped hollow portion 20h.

[0032] The right ladder fixing device 30 consists of a fixing piece 31 and a frame body 32, as shown in FIG. The fixed piece 31 has the same shape and size as the fixed piece 21, and is formed from the same flat metal plate as the fixed piece 21, such as a sheet of steel. Similar to the fixed piece 21, the fixed piece 31 is made up of a first long piece 31a and a hanging piece 31b hanging down from one end of the first long piece 31a, and has an overall L-shape. Frame body 32 has the same shape and size as frame body 22, and is a longitudinal frame that is long in the Y direction and consists of a second long side piece 32a, a first short side piece 32b1 and a second short side piece 32b2, and is formed by bending a single flat metal plate made of steel or the like, like frame body 22, into a U-shape. In frame body 32, similarly to frame body 22, first short side piece 32b1 and second short side piece 32b2 are arranged opposite each other and extend in the short direction (X direction), second long side piece 32a is arranged opposite first long side piece 31a and extends in the long direction (Y direction), first short side piece 32b1, second long side piece 32a, and second short side piece 32b2 are arranged consecutively in this order, and the bent portion when a single metal flat plate is bent into a U shape forms the boundary between first short side piece 321b, second long side piece 32a, and second short side piece 32b2. The ends of the first short side piece 32b1 and the second short side piece 32b2 that are not continuous with the second long side piece 32a are connected to the first long side piece 31a of the fixing piece 31 by welding or the like, forming a rectangular opening surface 30k and a rectangular parallelepiped hollow portion 30h. As described above, the fixing piece 21 and frame body 22 of the left ladder fixing device 20 and the fixing piece 31 and frame body 32 of the right ladder fixing device 30 have the same shape and size, and in the left ladder fixing device 20, the frame body 22 is positioned to the right of the fixing piece 21 (first long piece 21a), while in the right ladder fixing device 30, the frame body 32 is positioned to the left of the fixing piece 31 (first long piece 31a), so that the left ladder fixing device 20 and the right ladder fixing device 30 have a symmetrical structure.

[0033] [Attaching the ladder fixing device to the ladder, and fixing the ladder to the truck bed] In the ladder with fixing devices 1, as shown in Figures 1 to 4, the base portions 15, 16 (base plates 15a, 16a) of the steel ladder 10 are placed on the installation surface GL, and the left ladder fixing device 20 is attached to the left support 11 by fitting the portion above the tread 17 of the left support 11 into the hollow portion 20h of the left ladder fixing device 20, and the right ladder fixing device 30 is attached to the right support 12 by fitting the portion above the tread 17 of the right support 12 into the hollow portion 30h of the right ladder fixing device 30. The truck bed 40 has a floor 41 and tailgates 42 (side tailgates, rear tailgates) surrounding the floor 41, and the tailgates 42 are kept in a folded down position. Then, the left ladder fixing device 20 and the right ladder fixing device 30 are moved in the axial direction of the left support 11 and the right support 12, respectively, and the hanging piece 21b of the left ladder fixing device 20 and the hanging piece 31b of the right ladder fixing device 30 are inserted into the gap formed between the floor 41 and the gate 42, and the fixing pieces 21, 31 are engaged with the frame of the gate 42. At the same time, the base portions 15, 16 are moved along the installation surface GL to tilt the steel ladder 10, so that the back and front of the left support 11 abut against the first short piece 22b1 and the second short piece 22b2 of the left ladder fixing device 20, respectively, and the back and front of the right support 31 abut against the first short piece 32b1 and the second short piece 32b2 of the right ladder fixing device 30, respectively. As a result, the first long sides 21a, 31a of the fixing pieces 21, 31 are horizontal (inclined less than 10 degrees from the horizontal plane), the steel ladder 10 (left support 11 and right support 12) are inclined at an inclination angle θ1 from the installation surface GL, and the steel ladder 10 is fixed to the truck bed 40 by the left ladder fixing device 20 and the right ladder fixing device 30. In this case, the inclination angle θ1 is 40 degrees to 75 degrees, and it is preferable that the inclination angle θ1 is 45 degrees to 60 degrees. In this case, gaps (longitudinal gap, shortitudinal gap) described below are created in the hollow portion 20h of the left ladder fixing device 20 into which the left support 11 is fitted, and in the hollow portion 30h of the right ladder fixing device 30 into which the right support 12 is fitted, allowing the left ladder fixing device 20 and the right ladder fixing device 30 to move freely in the axial direction of the left support 11 and the right support 12, respectively.Even if the height of the truck bed 40 is different, the fixing pieces 21, 31 can be easily engaged with the frame of the tailgate 42, and the left support 11 and right support 12 can be abutted against the left ladder fixing device 20 and the right ladder fixing device 30.

[0034] [Opening surface and hollow dimensions of ladder fixture] Figure 7 shows a plan view (Figure 7(a)) and a left side view (Figure 7(b)) of the left ladder fixing device 20 positioned at an angle so that the top surface of the frame body 22 is horizontal.In the figure, the fixing piece 21 is represented by a dotted line, and the opening surface 20k and hollow portion 20h are represented in gray. The dimensions of the opening surface 20k and hollow portion 20h of the left ladder fixing device 20 will be explained below with reference to the drawings. In the left ladder fixing device 20, an opening surface 20k and a hollow portion 20h are formed by the frame body 22 and the fixing piece 21 (first long side piece 21a). However, since most of the space facing the second long side piece 22a of the frame body 22 is blocked by the first long side piece 21a, as shown in Figure 7, the rectangular space inside the U-shaped frame body 22 becomes the hollow portion 20h, and the upper surface of the hollow portion 20h becomes the rectangular opening surface 20k. Now, assuming that the length of the long side of opening surface 20k is L1 and the length of the short side of opening surface 20k is W1, L1 = 50 to 80 mm, W1 = 15 to 30 mm, and the ratio of L1 to W1 (L1 / W1) is 1.6 to 4, but it is preferable that the ratio of L1 to W1 (L1 / W1) is 2 to 3. Furthermore, if the height of hollow portion 20h (the length perpendicular to opening surface 20k) is H1, then H1=15 to 40 mm, and H1 / W1=0.5 to 1.5. Furthermore, the dimensions of the opening surface 30k and hollow portion 30h of the right ladder fixing device 30 are the same as the dimensions of the opening surface 20k and hollow portion 20h of the left ladder fixing device 20 described above.

[0035] [Opening surface of ladder fixture, dimensional relationship between hollow part and ladder support, etc.] Figure 8 is a plan view (Figure 8(a)) and a left side view (Figure 8(b)) of the left ladder fixing device 20 shown in Figure 7, in which the left support 11 is fitted into the hollow portion 20h of the left ladder fixing device 20 so that it is perpendicular to the opening surface 20k. As in Figure 7, the fixing piece 21 is represented by a dotted line, and the opening surface 20k and hollow portion 20h are represented in gray. The dimensional relationship between the opening surface 20k and hollow portion 20h of the left ladder fixing device 20 and the left support 11 will be explained below based on the drawings. Now, let us assume that the left support 11 is made of a square pipe with a rectangular cross-sectional outline, and if the length of the long side of the rectangular cross-section is PL1 and the length of the short side is PW1, then PL1 = 40 to 64 mm and PW1 = 13 to 28 mm. Furthermore, since the cross section of the left support 11 (square pipe) is smaller than the cross section of the hollow portion 20h, L1>PL1 and W1>PW1. A gap δ1 is generated between the inner surface of the frame body 22 and the fixed piece 21 (first long side piece 21a) and the left support 11. If the gap (longitudinal gap) generated between the first short side piece 22b1, the second short side piece 22b2 and the left support 11 within the gap δ1 is defined as δL1, and the gap (short side gap) generated between the first long side piece 21a, the second long side piece 22a and the left support 11 within the gap δ is defined as δW1, then δL1=L1-PL1 and δW1=W1-PW1, where δL1 / L1=1 / 5 to 1 / 2, δW1 / W1=<1 / 5, and it is preferable that δW1 / W1=0.5 to 2 mm. Furthermore, the dimensional relationship between the opening surface 30k, hollow portion 30h and right support 12 of the right ladder fixing device 30 is the same as the dimensional relationship between the opening surface 20k, hollow portion 20h and left support 11 of the left ladder fixing device 20 described above.

[0036] Figure 9 is a left side view of the vicinity of the left ladder fixture 20 with the steel ladder 10 fixed to the truck bed 40 by the left ladder fixture 20 and the right ladder fixture 30. In the figure, P1 is the abutment point between the left support 11 and the first short piece 22b1, and P2 is the abutment point between the left support 11 and the second short piece 22b2. As in Figure 7, the fixed piece 21 is represented by a dotted line, and the opening surface 20k and hollow portion 20h are represented in gray. As shown in Figure 9, when the steel ladder 10 is fixed to the truck bed 40 by the left ladder fixing device 20 and the right ladder fixing device 30, the inclination angle of the support 11 with respect to the installation surface GL is θ1, and in the left ladder fixing device 20, the first long piece 21a of the fixing piece 21 is horizontal (inclination with respect to the horizontal plane is 10 degrees or less), the back surface of the left support 11 abuts the inner upper end of the first short piece 22b1 at P1, and the front surface of the left support 11 abuts the inner lower end of the second short piece 22b2 at P2. In this case, the dimensions (L1, H1) of the opening surface 20k (30k) and hollow portion 20h (30h) and the dimension (PL1) of the left pillar 11 (right pillar 12) are selected so that the fixed piece 21 is horizontal and the inclination angle θ1 of the steel ladder 10 is 40 degrees to 75 degrees, preferably 45 degrees to 60 degrees. When a worker stands on the treads 17, 18, and 19 of the steel ladder 10, the worker's weight increases the contact force between the left support 11 and the first short piece 22b1 and the second short piece 22b2 at P1 and P2, preventing the left support 11 from shifting in the axial direction (longitudinal direction) of the left support 11 relative to the left ladder fixing device 20. In addition, since the short-side gap δW1 between the left support 11, the frame body 22, and the fixing piece 21 (first long side piece 21a) is extremely small, being less than 1 / 5 of the length W1 of the short side of the opening surface 20k, the left support 11 is prevented from shifting perpendicular to the axial direction (longitudinal direction) of the left support 11 relative to the left ladder fixing device 20. Similarly, the right support 12 is prevented from shifting relative to the right ladder fixture 30 in the axial direction (longitudinal direction) of the right support 12 and in the direction perpendicular thereto. This prevents the steel ladder 10 from slipping off the truck bed 40 when a worker ascends or descends the steel ladder 10, allowing the worker to safely ascend or descend the steel ladder 10 to load or unload luggage, etc.

[0037] As described above, the ladder with fixing devices 1 comprises a steel ladder 10 having a left support 11 and a right support 12, a left ladder fixing device 20 attached to the left support 11, and a right ladder fixing device 30 attached to the right support 12. The left ladder fixing device 20 and the right ladder fixing device 30 each have fixing pieces 21, 31 and longitudinal frame bodies 22, 32, and the fixing pieces 21, 31 each have a first longitudinal piece 21a, 31a and a hanging piece 21b, 31b, respectively, and engage with the side panel 42 of the truck bed 40. The frame bodies 22, 32 each have a first short piece 22b1, 32b1, a second short piece 22b2, 32b2, and a second long piece 22b3. a, 32a, the first short side pieces 22b1, 32b1 and the second short side pieces 22b2, 32b2 are arranged opposite to each other and connected to the first long side pieces 21a, 31a, the second long side pieces 22a, 32a are arranged opposite to the first long side pieces 21a, 31a, respectively, and are continuous with the first short side pieces 22b1, 32b1 and the second short side pieces 22b2, 32b2, the first long side pieces 21a, 31a and the frames 22, 32 form rectangular opening surfaces 20k, 30k and rectangular parallelepiped hollow portions 20h, 30h, and the ratio of the long side length L1 to the short side length W1 of the opening surfaces 20k, 30k is 1.6 to 4. The ratio of the length H1 and W1 of the hollows 20h and 30h in the direction perpendicular to the opening faces 20k and 30k is 0.5 to 1.5. When the left support 11 and the right support 12 are fitted into the hollows 20h and 30h so as to be perpendicular to the opening faces 20k and 30k, a gap δ1 is generated between the frame bodies 22 and 32 and the inner surfaces of the first long pieces 21a and 31a and the left support 11 and the right support 12. Of the gap δ1, a longitudinal gap δL1 generated between the first short pieces 22b1 and 32b1 and the second short pieces 22b2 and 32b2 and the left support 11 and the right support 12 is 1 / 5 to 1 / 2 of the length L1 of the long side of the opening faces 20k and 30k. / 2, and of the gap δ1, the short-side gap δW1 occurring between the first long side pieces 21a, 31a and the second long side pieces 22a, 32a and the left pillar 11 and the right pillar 12 is 1 / 5 or less of the length W1 of the short side of the opening faces 20k, 30k. When the inclination angle θ1 of the left pillar 11 and the right pillar 12 with respect to the installation surface GL is 40 degrees to 75 degrees, the fixing pieces 21, 31 are in a horizontal state, the back faces of the left pillar 11 and the right pillar 12 abut against the inner upper ends of the first short side pieces 22b1, 32b1, and the front faces of the left pillar 11 and the right pillar 12 abut against the inner lower ends of the second short side pieces 22b2, 32b2.

[0038] Therefore, in the ladder with fixing devices 1, the left ladder fixing device 20 and the right ladder fixing device 30 can be easily installed by simply fitting them into the left support 11 and right support 12 of the steel ladder 10, and the left ladder fixing device 20 and the right ladder fixing device 30 fitted into the left support 11 and right support 12 can be easily removed.Furthermore, even if the height of the truck bed 40 is different, the fixing pieces 21, 31 can be easily engaged with the frame of the side panel 42, and the left support 11 and right support 12 can be abutted against the first short pieces 22b1, 32b1 and the second short pieces 22b2, 32b2, to fix the steel ladder 10 to the truck bed 40. Furthermore, when the inclination angle θ1 of the left support 11 and the right support 12 with respect to the installation surface GL is 40 degrees to 75 degrees, the fixed pieces 21, 31 are in a horizontal position, the back surfaces of the left support 11 and the right support 12 abut against the inner upper ends of the first short pieces 22b1, 32b1, and the front surfaces of the left support 11 and the right support 12 abut against the inner lower ends of the second short pieces 22b2, 32b2.This prevents the steel ladder 10 from slipping off the truck bed 40 when a worker ascends or descends the steel ladder 10, and allows the worker to safely ascend and descend the steel ladder 10 to load and unload luggage, etc.

[0039] [Overall configuration of the ladder with fixing device of the second embodiment] Figure 10 is an oblique view of a ladder with fixing devices of the second embodiment of the present invention, Figure 11 is a plan view of the ladder with fixing devices shown in Figure 10, Figure 12 is a front view of the ladder with fixing devices shown in Figure 10, Figure 13 is a left side view of the ladder with fixing devices shown in Figure 10, Figures 14(a) to (e) are respectively an oblique view, plan view, left side view, front view and right side view of the left ladder fixing device shown in Figure 10, and Figures 15(a) to (e) are respectively an oblique view, plan view, left side view, front view and right side view of the right ladder fixing device shown in Figure 10. In the figure, 2 is a ladder with a fixing device, 50 is an aluminum ladder, 51 is a left support, 52 is a right support, 53 and 54 are hook parts, 53a and 54a are hook bodies, 53b and 54b are clamps, 57, 58 and 59 are treads, 60 is a left ladder fixing device, 60k is an opening surface, 60h is a hollow part, 61 is a movable piece, 61a is a first long piece, 61b is an inclined piece, 62 is a frame body, 62a is a second long piece, 62b1 is a first short piece, 62b2 is a second short piece, 62s1 is a first slit, 62s2 is a second slit, 63 and 64 are stoppers, 63a and 64a are bolts, 63b and 64b are nuts, Reference numeral 70 denotes the right ladder fixing device, 70k denotes the opening surface, 70h denotes the hollow portion, 71 denotes the movable piece, 71a denotes the first long piece, 71b denotes the inclined piece, 72 denotes the frame body, 72a denotes the second long piece, 72b1 denotes the first short piece, 72b2 denotes the second short piece, 72s1 denotes the first slit, 72s2 denotes the second slit, 73 and 74 denote stoppers, 73a and 74a denote bolts, and 73b and 74b denote nuts. The same symbols are used for the same parts as those shown in Figures 1 to 4, and in each figure, X denotes the left-right direction, Y denotes the front-back direction, Z denotes the up-down direction, and the floor 41, the gate 42, and the installation surface GL are indicated by dashed double-dashed lines. As shown in the figure, the ladder with fixing devices 2 of the second embodiment is composed of an aluminum ladder 50, a left ladder fixing device 60 and a right ladder fixing device 70, and is attached to the truck bed 40.

[0040] [Aluminum ladder] The aluminum ladder 50 is an aluminum ladder (step) for scaffolding, and includes a left support 51, a right support 52, treads 57, 58, 59, etc. The size of the aluminum ladder 50 is about 1200 mm long and 400 mm wide, and the aluminum ladder 50 shown in Fig. 10 is an aluminum ladder with seven steps, about 2500 mm long and 400 mm wide, with upper and lower hooks, cut in the middle. The underside of the aluminum ladder 50 is made of the aluminum ladder support pole. The left support pillar 51 and the right support pillar 52 are made of square material such as an aluminum channel or an aluminum pipe, and hook portions 53 and 54 are attached to the upper ends thereof. The hook portions 53, 54 include hook bodies 53a, 54a and clamps 53b, 54b, etc., and the bases of the hook bodies 53a, 54a are fixed to the upper ends of the left and right supports 51, 52 by bolts, nuts, etc. The lower end surfaces of the left support 51 and the right support 52 (the lower surface of the aluminum ladder 50) are cut surfaces obtained by cutting the above-mentioned square timber. Treads 57, 58, 59 are the upper, middle and lower steps of a ladder (stairs), and each is made of a rectangular aluminum plate surrounded by ribs protruding from the underside, with multiple grooves formed in the plate.

[0041] The aluminum ladder 50 has the configuration described above, and before being cut into the aluminum ladder 50, the aluminum ladder has a lower hook in addition to an upper hook (hook portions 53, 54) and is used as a scaffolding step in the same way as the steel ladder 10. Specifically, in a scaffold consisting of vertical members of a building site, arms, cloth, handrails, horizontal members such as middle beams, diagonal members, treads, etc., the upper hook is attached to the horizontal member of the scaffold (the horizontal member of the scaffold is gripped by the curved parts of hook bodies 53a, 54a and clamps 53b, 54b respectively) and the lower hook is placed on the ground so that the angle of the left support 51 and right support 52 to the horizontal plane is 40 to 60 degrees, or the upper hook is attached to the upper (middle) horizontal member and the lower hook is attached to the middle (lower) horizontal member, and the aluminum ladder is assembled to the scaffold. In the second embodiment of the present invention, an aluminum ladder 50 cut from an aluminum ladder that is incorporated into scaffolding and used in this manner is attached to the bed of a truck via a ladder fixing device and used as a ladder for the bed of the truck. The ladder in the second embodiment of the present invention is not limited to a cut-off aluminum ladder as described above, but may also be a steel ladder used as a step on a scaffold, or a ladder that can be leaned against a building or wall.

[0042] [Ladder fixture] The ladder fixing device of the second embodiment of the present invention consists of a left ladder fixing device 60 and a right ladder fixing device 70. As shown in Figure 14, the left ladder fixing device 60 consists of a movable piece 61, a frame body 62, and stoppers 63 and 64, and differs from the left ladder fixing device 20 in that it has a movable piece 61 instead of the fixed piece 21 of the left ladder fixing device 20 of the first embodiment, and has stoppers 63 and 64 which are not present in the left ladder fixing device 20. The movable piece 61 is formed from a single flat metal plate such as steel, and consists of a first long side piece 61a and an inclined piece 61b inclined from one end of the first long side piece 61a, and has an overall U-shape, with the angle between the first long side piece 61a and the inclined piece 61b being 70 to 87 degrees. The frame body 62 is a longitudinal frame that is long in the Y direction and consists of a second long piece 62a, a first short piece 62b1 and a second short piece 62b2, and is formed by bending a flat metal plate such as steel into a U-shape, with the second long piece 62a being rectangular, the first short piece 62b1 being shaped like a rectangle with a small rectangular portion at the top right corner cut out, and the second short piece 62b2 being shaped like a rectangle with a small rectangular portion at the bottom right corner cut out. In the frame body 62, the first short side piece 62b1 and the second short side piece 62b2 are arranged opposite each other and extend in the short direction (X direction), the second long side piece 62a is arranged between the right end of the first short side piece 62b1 and the right end of the second short side piece 62b2 and extends in the long side direction (Y direction), the first short side piece 62b, the second long side piece 62a, and the second short side piece 62b2 are arranged consecutively in this order, and the bent portion when a single flat metal plate is bent into a U shape forms the boundary between the first short side piece 62b1, the second long side piece 62a, and the second short side piece 62b2.

[0043] In addition, a first slit 62s1 having a vertically elongated rectangular shape is provided on the left end side of the first short side piece 62b1, and a second slit 62s2 having a vertically elongated rectangular shape is provided on the left end side of the second short side piece 62b2.The first long side piece 61a of the movable piece 61 is inserted into the first slit 62s1 and the second slit 62s2, thereby holding the movable piece 61 in the frame body 62, and the first long side piece 61a is positioned opposite the second long side piece 62a. The movable piece 61 is held by the frame 62, so that a rectangular opening surface 60k and a rectangular parallelepiped hollow portion 60h are formed. In this case, the length of the short sides (length in the X direction) of the first slit 62s1 and the second slit 62s2 is slightly (about 0.5 to 2 mm) larger than the thickness (length in the X direction) of the first long side piece 61a, and the length of the long sides of the first slit 62s1 and the second slit 62s2 is larger than the length of the first long side piece 61a in the thickness direction and perpendicular direction, so that the movable piece 61 can move in the longitudinal direction along the first slit 62s1 and the second slit 62s2. Furthermore, the first long side piece 61a is provided with a stopper 63 at a position adjacent to the left side of the first slit 62s1, and a stopper 64 at a position adjacent to the right side of the second slit 62s2. The stoppers 63, 64 serve as the anti-disengagement means of the present invention, and are made up of bolts 63a, 64a inserted through the first long piece 61a and nuts 63b, 64b screwed into the bolts. The stoppers 63 and 64 prevent the movable piece 61 from coming off the frame body 62 .

[0044] As shown in Figure 15, the right ladder fixing device 60 consists of a movable piece 71, a frame body 72, and stoppers 73 and 74, and differs from the right ladder fixing device 30 in that it has a movable piece 71 instead of the fixed piece 31 of the right ladder fixing device 30 of the first embodiment, and has stoppers 73 and 74 which are not present in the right ladder fixing device 30. The movable piece 71 has the same shape and size as the movable piece 61, and is formed from the same flat metal plate as the movable piece 61, such as a sheet of steel. Similar to the movable piece 61, the movable piece 71 consists of a first long side piece 71a and an inclined piece 71b inclined from one end of the first long side piece 71a, and has an overall V shape, with the angle between the first long side piece 71a and the inclined piece 71b being 70 to 87 degrees. The frame body 72 is a longitudinal frame that is long in the Y direction and consists of a second long piece 72a, a first short piece 72b1, and a second short piece 72b2, and is formed by bending a flat metal plate such as steel into a U-shape, with the second long piece 72a being rectangular, the first short piece 72b1 being shaped like a rectangle with a small rectangular portion at the upper left cut out, and the second short piece 72b2 being shaped like a rectangle with a small rectangular portion at the lower left cut out. In the frame body 72, the first short side piece 72b1 and the second short side piece 72b2 are arranged opposite each other and extend in the short direction (X direction), the second long side piece 72a is arranged between the left end of the first short side piece 72b1 and the left end of the second short side piece 72b2 and extends in the long side direction (Y direction), the first short side piece 72b, the second long side piece 72a, and the second short side piece 72b2 are arranged consecutively in this order, and the bent portion when a single flat metal plate is bent into a U shape forms the boundary between the first short side piece 72b1, the second long side piece 72a, and the second short side piece 72b2.

[0045] In addition, a first slit 72s1 having a vertically elongated rectangular shape is provided on the right end side of the first short side piece 72b1, and a second slit 72s2 having a vertically elongated rectangular shape is provided on the right end side of the second short side piece 72b2.The first long side piece 71a of the movable piece 71 is inserted into the first slit 72s1 and the second slit 72s2, thereby holding the movable piece 71 in the frame body 72 and positioning the first long side piece 71a opposite the second long side piece 72a. The movable piece 71 is held by the frame 72, whereby a rectangular opening surface 70k and a rectangular parallelepiped hollow portion 70h are formed. In this case, the length of the short sides (length in the X direction) of the first slit 72s1 and the second slit 72s2 is slightly (about 0.5 to 2 mm) larger than the thickness (length in the X direction) of the first long side piece 71a, and the length of the long sides of the first slit 72s1 and the second slit 72s2 is larger than the length of the first long side piece 71a in the thickness direction and perpendicular direction, so that the movable piece 71 can move in the longitudinal direction along the first slit 72s1 and the second slit 72s2. Furthermore, the first long piece 71a is provided with a stopper 73 at a position adjacent to the left side of the first slit 72s1, and a stopper 74 at a position adjacent to the right side of the second slit 72s2. The stoppers 73, 74 serve as the removal prevention means of the present invention, and are made up of bolts 73a, 74a inserted through the first long piece 71a and nuts 73b, 74b screwed onto the bolts. The stoppers 73 and 74 prevent the movable piece 61 from coming off the frame body 62 . Here, comparing the structures of the left ladder fixing device 60 and the right ladder fixing device 70, the movable pieces 61 and 71 have the same shape and size, the frame bodies 62 and 72 have bilaterally symmetrical shapes, the mounting positions of the stoppers 63, 64 and the stoppers 73, 74 are the same, and the left ladder fixing device 60 and the right ladder fixing device 70 have bilaterally symmetrical structures.

[0046] [Attaching the ladder fixing device to the ladder, and fixing the ladder to the truck bed] In the ladder with fixing devices 2, as shown in Figures 10 to 13, the underside of the aluminum ladder 50 (left support 51 and right support 52) ​​is placed on the installation surface GL, and the part above the tread 57 of the left support 51 is fitted into the hollow portion 60h of the left ladder fixing device 60 to attach the left ladder fixing device 60 to the left support 51, and the part above the tread 57 of the right support 52 is fitted into the hollow portion 70h of the right ladder fixing device 70 to attach the right ladder fixing device 70 to the right support 52. The truck bed 40 has a floor 41 and tailgates 42 (side tailgates, rear tailgates) surrounding the floor 41, and the tailgates 42 are kept in a folded down position. Then, the left ladder fixing device 60 and the right ladder fixing device 70 are moved in the axial direction of the left support 51 and the right support 52, respectively, and the movable pieces 61, 71 are inserted into the first slits 62s1, 72s1, the inclined piece 61b of the left ladder fixing device 60 and the inclined piece 71b of the right ladder fixing device 70 into the gap formed between the floor 41 and the gate 42, and the movable pieces 61, 71 are engaged with the frame of the gate 42. At the same time, the underside of the aluminum ladder 50 is moved along the installation surface GL to tilt the aluminum ladder 50, so that the back and front of the left support 61 abut against the first short piece 62b1 and the second short piece 62b2 of the left ladder fixing device 60, respectively, the back and front of the right support 71 abut against the first short piece 72b1 and the second short piece 72b2 of the right ladder fixing device 70, respectively, and further, the upper and lower surfaces of the movable piece 61 (first long piece 61a) abut against the first slit 62s1 and the second slit 62s2 of the frame body 62, and the upper and lower surfaces of the movable piece 71 (first long piece 71a) abut against the first slit 72s1 and the second slit 72s2 of the frame body 72. As a result, the first long pieces 61a, 71a of the movable pieces 61, 71 are in a horizontal position (inclined less than 10 degrees from the horizontal plane), the aluminum ladder 50 (left support 51 and right support 52) ​​are inclined at an inclination angle θ2 from the installation surface GL, and the aluminum ladder 50 is fixed to the truck bed 40 by the left ladder fixing device 60 and the right ladder fixing device 70. In this case, the inclination angle θ2 is 40 degrees to 75 degrees, and it is preferable that the inclination angle θ2 is 45 degrees to 60 degrees. In this case, gaps (longitudinal gap, transverse gap) described below are created in the hollow portion 20h of the left ladder fixing device 20 into which the left support 11 is fitted, and in the hollow portion 30h of the right ladder fixing device 30 into which the right support 12 is fitted, allowing the left ladder fixing device 20 and the right ladder fixing device 30 to move freely in the axial direction of the left support 11 and the right support 12, respectively.In addition, the movable pieces 61 and 71 also move freely through the first slits 62s1, 72s1 and the second slit The movable pieces 61, 71 can be freely moved along the slits 62s2, 72s2, and even if the height of the truck bed 40 is different, the movable pieces 61, 71 can be easily engaged with the frame of the tailgate 42, the movable pieces 61, 71 (first long pieces 61a, 71a) can be abutted against the first slits 62s172s1 and the second slits 62s2, 72s2, and the left support 51 and right support 52 can be abutted against the left ladder fixing device 60 and the right ladder fixing device 70.

[0047] [Opening surface and hollow dimensions of ladder fixture] Figure 16 shows a plan view (a), a left side view (b), and a longitudinal cross-sectional view (c) passing through the longitudinal axis of the first long piece 61a, in which the left ladder fixing device 60 is positioned at an angle so that the upper surfaces of the second long piece 62a and the second short piece 62b2 of the frame body 62 are horizontal. In figures (a) and (b), the movable piece 61 is represented by a dotted line, and the opening surface 60k and hollow portion 60h are represented in grey. The dimensions of the opening surface 60k and hollow portion 60h of the left ladder fixing device 60, and the angle of the movable piece 61 (first long piece 61a) will be described below with reference to the drawings. In the left ladder fixing device 60, an opening surface 60k and a hollow portion 60h are formed by the frame body 62 and the movable piece 61 (first long piece 61a), but since more than half of the space formed by a plane passing through the upper and lower surfaces of the frame body 62 and the second long piece 62a is blocked by the first long piece 21a, as shown in Figures 16(a) and (b), the rectangular space formed by the plane passing through the frame body 62 and the upper and lower surfaces of the second long piece 62a and the plane passing through the surface of the first long piece 21a facing the second long piece 62a becomes the hollow portion 60h, and the upper surface of the hollow portion 60h becomes a rectangular opening surface 60k. Now, assuming that the length of the long side of opening surface 60k is L2 and the length of the short side of opening surface 60k is W2, L2 = 70 to 100 mm, W2 = 20 to 45 mm, and the ratio of L2 to W2 (L1 / W1) is 1.6 to 5, but it is preferable that the ratio of L5 to W5 (L5 / W5) is 2 to 3. Furthermore, if the height of hollow portion 60h (the length in the direction perpendicular to opening surface 60k) is H2, then H2=15 to 40 mm, and H2 / W2=1 / 3 to 2. Furthermore, the dimensions of the opening surface 70k and hollow portion 70h of the right ladder fixing device 70 are the same as the dimensions of the opening surface 60k and hollow portion 60h of the left ladder fixing device 60 described above.

[0048] Next, in the left ladder fixing device 60, the first longitudinal piece 61a of the movable piece 61 is capable of moving in its longitudinal direction along the first slit 62s1 and the second slit 62s2, so that the angle formed between the first longitudinal piece 61a and a plane perpendicular to the opening surface 60k changes. In this case, as shown in Figure 16 (c), when the upper surface of the first long side piece 61a abuts against the upper surface of the first slit 62s1 at Q1 and the lower surface of the first long side piece 61a abuts against the lower surface of the second slit 62s2 at Q2, the angle between the first long side piece 61a and a plane perpendicular to the opening surface 60k becomes maximum, and this maximum angle is defined as φ1. Now, if the distance from the opening surface 60k to the upper surface (Q1) of the first slit 62s1 is t1, the distance from the opening surface 60k to the lower surface (Q2) of the second slit 62s2 is t2, the horizontal distance from Q1 to Q2 (the distance in the direction of the opening surface 60k) is L2', and the length of the short side of the first long side piece 61a is D, then the maximum angle φ1 is uniquely determined by the distance t1, the distance t2, the height H2 of the hollow portion 60h, the horizontal distance L2', and the length D, and the horizontal distance L2' is the length L2 of the long side of the opening surface 60k plus the thicknesses (a fixed value) of the first short side piece 62b1 and the second short side piece 62b2, so that the maximum angle φ1 is uniquely determined by the distance t1, the distance t2, the height H2, the length L2, and the length D.

[0049] [Opening surface of ladder fixture, dimensional relationship between hollow part and ladder support, etc.] Figure 17 shows a plan view (Figure 17(a)) and a left side view (Figure 17(b)) of the left support 51 inserted into the hollow portion 60h of the left ladder fixing device 60 shown in Figure 16 so that it is perpendicular to the opening surface 60k. As in Figures 16(a) and (b), the movable piece 61 is represented by a dotted line, and the opening surface 60k and hollow portion 60h are represented in gray. The dimensional relationship between the opening surface 60k and hollow portion 60h of the left ladder fixing device 60 and the left support 51 will be explained below with reference to the drawings. Now, let us assume that the left support 51 is made of an aluminum channel having a U-shaped cross section, the length of the long side of the cross section being PL2 and the length of the short side being PW2, then PL2 = 68 to 98 mm and PW1 = 18 to 43 mm. Furthermore, since the cross section of the left support 51 (aluminum channel) is smaller than the cross section of the hollow portion 60h, L2>PL2 and W2>PW2. A gap δ2 is generated between the inner surface of the movable piece 61 (first long side piece 61a) of the frame body 62 and the left support 51. If the gap (longitudinal gap) generated between the first short side piece 62b1, the second short side piece 62b2 and the left support 11 within the gap δ2 is defined as δL2, and the gap (short side gap) generated between the first long side piece 61a, the second long side piece 62a and the left support 51 within the gap δ2 is defined as δW2, then δL2=L2-PL2 and δW2=W2-PW2, and therefore δL2 / L2=<1 / 4, δW2 / W2=<1 / 5, and it is preferable that δW2 / W2=0.5 to 2 mm. The dimensional relationship between the opening surface 70k, hollow portion 70h and right support 52 of the right ladder fixing device 70 is the same as the dimensional relationship between the opening surface 60k, hollow portion 60h and left support 51 of the left ladder fixing device 60 described above.

[0050] FIG. 18 is a left side view of the vicinity of the left ladder fixing device 70 with the aluminum ladder 50 fixed to the truck bed 40 by the left ladder fixing device 60 and the right ladder fixing device 70. In the figure, R1 is the contact point between the left support pillar 51 and the first short piece 62b1, and R2 is the contact point between the left support pillar 51 and the second short piece 62b2. As in Figure 17, the movable piece 61 is represented by a dotted line, and the opening surface 60k and hollow portion 60h are represented in gray. As shown in Figure 18, when the aluminum ladder 50 is fixed to the truck bed 40 by the left ladder fixing device 60 and the right ladder fixing device 60, the inclination angle of the support 51 with respect to the ground is θ2, and in the left ladder fixing device 60, the first long piece 61a of the movable piece 61 is horizontal, the upper surface of the first long piece 61a abuts the upper surface of the first slit 62s1 at Q1, the lower surface of the first long piece 61a abuts the lower surface of the second slit 62s2 at Q2, and further, the back surface of the left support 61 abuts the inner upper end of the first short piece 62b1 at R1, and the front surface of the left support 51 abuts the inner lower end of the second short piece 62b2 at R2. Now, if the angle between the left support 61 and a plane perpendicular to the opening surface 60k is φ2, then the inclination angle θ2 of the aluminum ladder 50 is θ2 = φ1 + φ2, where φ2 is uniquely determined from the distance between R1 and R2 in the direction perpendicular to the opening surface 60k, the length PL2 of the long side of the left support 51, and the length L2 of the long side of the opening surface 60k. In this case, the dimensions (L2, H2) of the opening surface 60k (70k), hollow portion 60h (70h), dimension (PL2) of the left pillar 51 (right pillar 52), dimensions of the first short piece 62b1, second short piece 62b2, dimensions (t1, t2) of the first slit 62s1, second slit 62s2, etc. are selected so that the movable piece 61 is in a horizontal state (inclined at 10 degrees or less with respect to the horizontal plane) and the inclination angle θ2 of the aluminum ladder 50 is 40 degrees to 75 degrees, preferably 45 degrees to 60 degrees. When a worker stands on the treads 57, 58, 59 of the aluminum ladder 50, the worker's weight increases the contact force between the first long piece 61a and the upper surface of the first slit 62s1 and the lower surface of the second slit 62s2 at Q1 and Q2, and increases the contact force between the left support 51 and the first short piece 62b1 and the second short piece 62b2 at R1 and R2, preventing the left support 51 from shifting in the axial direction (longitudinal direction) of the left support 51 relative to the left ladder fixing device 60. In addition, since the short-side gap δW2 between the left support 51, the frame body 62, and the fixing piece 61 (first long side piece 61a) is extremely small, being less than 1 / 5 of the length W2 of the short side of the opening surface 60k, the left support 51 is prevented from shifting perpendicular to the axial direction (longitudinal direction) of the left support 51 relative to the left ladder fixing device 60. Similarly, the right support 52 is prevented from shifting relative to the right ladder fixture 70 in the axial direction (longitudinal direction) of the right support 52 and in the direction perpendicular thereto. This prevents the aluminum ladder 50 from slipping off the truck bed 40 when a worker ascends or descends the aluminum ladder 50, allowing the worker to safely ascend or descend the aluminum ladder 50 to load or unload luggage, etc.

[0051] As described above, the ladder with fixing devices 2 comprises an aluminum ladder 50 having a left support 51 and a right support 52, a left ladder fixing device 60 attached to the left support 51, and a right ladder fixing device 70 attached to the right support 52. The left ladder fixing device 60 and the right ladder fixing device 70 each have movable pieces 61, 71 and long frame bodies 62, 72, and the movable pieces 61, 71 each have a first long piece 61a, 71a and an inclined piece 61b, 71b, and engage with the side panel 42 of the truck bed 40. The frame bodies 62, 72 each have a first short piece 62b1, 72b1, a second short piece 62b2, 72b2, and a second long piece 62a, 72. a, the first short side pieces 62b1, 72b1 and the second short side pieces 62b2, 77b2 are arranged opposite to each other, the second long side pieces 62a, 72a are continuous with the first short side pieces 62b1, 72b1 and the second short side pieces 62b2, 72b2, the first short side piece 62b1 and the second short side piece 62b2 are respectively provided with a first slit 62s1 and a second slit 62s2, and the first long side pieces 61a, 71a are inserted into the first slit 62s1 and the second slit 62s2, respectively, so that the first long side pieces 61a, 71a are arranged opposite to the second long side pieces 62a, 72a, and the first short side pieces 62b1, 72a are connected to the first short side pieces 62b1, 72b1 and the second short side pieces 62b2. 2b1 and the second short pieces 62b2 and 77b2, stoppers 63 and 64 are provided on the first long piece 61a, and stoppers 73 and 74 are provided on the first long piece 71a. The first long pieces 61a and 71a and the frames 62 and 72 form rectangular opening faces 60k and 70k and rectangular parallelepiped hollow portions 60h and 70h. When the left support 51 and the right support 52 are fitted into the hollow portions 60h and 70h so as to be perpendicular to the opening faces 60k and 70k, a gap δ2 is generated between the frames 62 and 72 and the inner surfaces of the first long pieces 61a and 71a and the left support 51 and the right support 52. The gap δ A longitudinal gap δL2 occurring between the first short pieces 62b1, 72b1 and the second short pieces 62b2, 72b2 of the gap δ2 and the left support 51 and the right support 52 is ¼ or less of the length L3 of the long side of the opening surface 60k, 70k, and a transverse gap δW2 occurring between the first long pieces 61a, 71a and the second long pieces 62a, 72a of the gap δ2 and the left support 51 and the right support 52 is ⅕ or less of the length W2 of the short side of the opening surface 60k, 70k. When the inclination angle θ2 of the left support 51 and the right support 52 with respect to the installation surface GL is 40 degrees to 75 degrees, the movable pieces 61, 71 are in a horizontal state, and the first long pieces 61a,The upper surface of 71a abuts against the upper surface of the first slit 62s1, 72s1, the lower surface of the first long pieces 61a, 71a abuts against the lower surface of the second slit 62s2, 72s1, the back surfaces of the left support 51 and the right support 52 abut against the inner upper ends of the first short pieces 62b1, 72b1, and the front surfaces of the left support 51 and the right support 52 abut against the inner lower ends of the second short pieces 62b2, 72b2.

[0052] Therefore, in the ladder with fixing devices 2, the left ladder fixing device 60 and the right ladder fixing device 70 can be easily attached by simply fitting them into the left support 51 and the right support 52 of the aluminum ladder 50, and the left ladder fixing device 60 and the right ladder fixing device 70 fitted into the left support 51 and the right support 52 can be easily removed. Furthermore, even if the height of the truck bed 40 is different, the movable pieces 61, 71 can be easily engaged with the frame of the side panel 42, the movable pieces 61, 71 (first long pieces 61a, 71a) can be abutted against the first slits 62s1, 72s1 and the second slits 62s2, 72s2, and the left support 51 and the right support 52 can be abutted against the first short pieces 62b1, 72b1 and the second short pieces 62b2, 72b2, to fix the aluminum ladder 50 to the truck bed 40. Furthermore, When the inclination angle θ2 of the left and right support pillars 51 and 52 relative to the installation surface GL is 40 degrees to 75 degrees, the movable pieces 61 and 71 are in a horizontal position, the upper surfaces of the first long pieces 61a and 71a abut against the upper surfaces of the first slits 62s1 and 72s1, the lower surfaces of the first long pieces 61a and 71a abut against the lower surfaces of the second slits 62s2 and 72s1, the back surfaces of the left and right support pillars 51 and 52 abut against the inner upper ends of the first short pieces 62b1 and 72b1, and the front surfaces of the left and right support pillars 51 and 52 abut against the inner lower ends of the second short pieces 62b2 and 72b2.This prevents the aluminum ladder 50 from slipping off the truck bed 40 when a worker ascends or descends the aluminum ladder 50, and allows the worker to safely ascend and descend the aluminum ladder 50 to load and unload luggage, etc. [Industrial Applicability]

[0053] The ladder fixing device of the present invention can easily attach and remove ladders that can also be used to set up scaffolding on a truck bed, and can stably fix the ladder to the truck bed even if the truck bed height is different.It can be used for steel ladders or aluminum ladders used as scaffolding steps, and ladders that are used by leaning them against buildings, walls, etc. [Explanation of symbols]

[0054] 1 Ladder with fixings 2 Ladder with fixings 10 steel ladder, 11 Left pillar 12 Right Support 13, 14 Hook part 13a, 14a Hook body 13b, 14b Clamp 15, 16 Base part 15a, 16a Base plate 15b1, 15b2, 16b1, 16b2 holding plate 15c1, 16c1 bolts 15c2, 16c2 Nuts 17, 18, 19 Tread 20 Left ladder fixture 20k aperture surface 20h Hollow part 21 Fixed piece 21a 1st long piece 21b hanging piece 22 Frame 22a 2nd long piece 22b1 1st short hand 22b2 2nd short hand 30 Right ladder fixture 30k aperture surface 30h Hollow part 31 Fixed piece 31a 1st Long Side 31b hanging piece 32 Frame 32a 2nd long piece 32b1 1st short hand 32b2 2nd short hand 40 Truck Bed 41 Beds 42 Aori 50 Aluminum ladder 51 Left pillar 52 Right Support 53, 54 Hook part 53a, 54a Hook body 53b, 54b clamp 57, 58, 59 Tread 60 Left ladder fixture 60k aperture 60h Hollow part 61 Movable piece 61a 1st Long Side 61b Inclined piece 62 Frame 62a 2nd Long Side 62b1 1st short hand 62b2 2nd short hand 62s1 First slit 62s2 2nd slit 63, 64 Stopper 63a, 64a bolts 63b, 64b Nut 70 Right ladder fixture 70k aperture 70h Hollow part 71 Movable piece 71a 1st Long Side 71b Inclined piece 72 Frame 72a 2nd Long Side 72b1 1st short hand 72b2 2nd short hand 72s1 First slit 72s2 2nd slit 73, 74 Stopper 73a, 74a Bolts 73b, 74b Nut GL installation surface

Claims

1. A ladder fastener for attaching to a ladder post and fastening the ladder to a truck bed, comprising: a fixed piece having a first longitudinal piece and a hanging piece hanging from the first longitudinal piece and engaging with a frame of a side panel of the truck bed; and a longitudinal frame body connected to the first longitudinal piece to form a rectangular opening surface and a rectangular parallelepiped hollow portion, The frame body includes a first short piece and a second short piece that are arranged opposite to each other, extend in a short direction of the frame body, and are connected to the first long piece, and a second long piece that is arranged opposite to the first long piece, extends in the long direction of the frame body, and is continuous with the first short piece and the second short piece, a ratio of a long side to a short side of the opening surface is 1.6 to 4, and a ratio of a length of the hollow portion in a direction perpendicular to the opening surface to a length of a short side of the opening surface is 0.5 to 1.5; When the support is fitted into the hollow portion so as to be perpendicular to the opening surface, a longitudinal gap is generated between the support and the first short piece and / or the second short piece, and a lateral gap is generated between the support and the first long piece and / or the second long piece, The longitudinal gap is 1 / 5 to 1 / 2 of the length of the long side of the opening surface, The short-side gap is 1 / 5 or less of the length of the short side of the opening surface, This ladder fixing device is characterized in that when the support inserted into the hollow portion is tilted at an angle of 40 degrees to 75 degrees relative to the installation surface of the support, the fixing piece is in a horizontal position and the support abuts against the first short piece and the second short piece.

2. A ladder fixing device as described in claim 1, characterized in that the fixing piece is formed from a single flat metal plate, the frame body is formed by bending a single flat metal plate, and the ends of the first short piece and the second long piece of the second short piece where the second long piece are not continuous are joined to the first long piece.

3. A ladder fastener for attaching to a ladder post and fastening the ladder to a truck bed, comprising: a movable piece having a first longitudinal piece and an inclined piece inclined from the first longitudinal piece and adapted to engage with a frame of the side panel of the truck bed; and a longitudinal frame body that holds the movable piece and forms a rectangular opening surface and a rectangular parallelepiped hollow portion, The frame body includes a first short piece and a second short piece that are arranged opposite to each other, extend in a short direction of the frame body, and hold the first long piece, and a second long piece that is arranged opposite to the first long piece, extends in the long direction of the frame body, and is continuous with the first short piece and the second short piece, The first short piece and the second short piece are provided with a slit through which the first long piece is inserted and which holds the first long piece so as to be movable opposite to the second long piece, The first long piece is provided with a stopper means for preventing the first long piece inserted into the slit from coming off the first short piece and the second short piece, When the support is fitted into the hollow portion, a longitudinal gap is generated between the support and the first short piece and / or the second short piece, and a lateral gap is generated between the support and the long piece and / or the movable piece, The longitudinal gap is equal to or less than ¼ of the length of the long side of the opening surface, The short-side gap is 1 / 5 or less of the length of the short side of the opening surface, This ladder fixing device is characterized in that when the support inserted into the hollow portion is inclined at 40 degrees to 75 degrees relative to the support installation surface, the movable piece is in a horizontal position, the first long piece abuts against the surface forming the slit, and the support abuts against the first short piece and the second short piece.

4. A ladder fixing device as described in claim 3, characterized in that the movable piece is formed from a single flat metal plate, and the first short piece, the second short piece and the second long piece are formed by bending a single flat metal plate.

5. A ladder fixing device as described in claim 3, characterized in that the anti-slip means comprises a bolt hole provided in the first longitudinal piece, a bolt inserted into the bolt hole, and a nut screwed onto the threaded portion of the bolt.

6. A ladder fixing device as described in claim 1 or claim 3, characterized in that the support pillars consist of a left support pillar located on the left side and a right support pillar located on the right side, the ladder fixing device consists of a left ladder fixing device attached to the left support pillar and a right ladder fixing device attached to the right support pillar, and the left ladder fixing device and the right ladder fixing device have a symmetrical structure.

7. A ladder with supports; A ladder fixture attached to the post to secure the ladder to the truck bed A ladder with a fixture comprising: The ladder fixing device includes a first longitudinal piece and a fixing piece having a hanging piece hanging from the first longitudinal piece and engaging with a frame of the side panel of the truck bed, and a longitudinal frame body connected to the first longitudinal piece to form a rectangular opening surface and a rectangular parallelepiped hollow portion, The frame body includes a first short piece and a second short piece that are arranged opposite to each other, extend in a short direction of the frame body, and are connected to the first long piece, and a second long piece that is arranged opposite to the first long piece, extends in the long direction of the frame body, and is continuous with the first short piece and the second short piece, a ratio of a long side to a short side of the opening surface is 1.6 to 4, and a ratio of a length of the hollow portion in a direction perpendicular to the opening surface to a length of a short side of the opening surface is 0.5 to 1.5; When the support is fitted into the hollow portion so as to be perpendicular to the opening surface, a longitudinal gap is generated between the support and the first short piece and / or the second short piece, and a lateral gap is generated between the support and the first long piece and / or the second long piece, The longitudinal gap is 1 / 5 to 1 / 2 of the length of the long side of the opening surface, The short-side gap is 1 / 5 or less of the length of the short side of the opening surface, A ladder with fixing devices, characterized in that the support pillar inserted into the hollow portion abuts against the first short piece and the second short piece when inclined at 40 degrees to 75 degrees relative to the installation surface of the support pillar.

8. A ladder with supports; A ladder fixture attached to the post to secure the ladder to the truck bed A ladder with a fixture comprising: The ladder fixing device includes a movable piece having a first longitudinal piece and an inclined piece inclined from the first longitudinal piece and engaging with a frame of the side panel of the truck bed, and a longitudinal frame body that holds the movable piece and forms a rectangular opening surface and a rectangular parallelepiped hollow portion, The frame body includes a first short piece and a second short piece that are arranged opposite to each other, extend in a short direction of the frame body, and hold the first long piece, and a second long piece that is arranged opposite to the first long piece, extends in the long direction of the frame body, and is continuous with the first short piece and the second short piece, The first short piece and the second short piece are provided with a slit through which the first long piece is inserted and which holds the first long piece so as to be movable opposite to the second long piece, The first long piece is provided with a stopper means for preventing the first long piece inserted into the slit from coming off the first short piece and the second short piece, When the support is fitted into the hollow portion, a longitudinal gap is generated between the support and the first short piece and / or the second short piece, and a lateral gap is generated between the support and the long piece and / or the movable piece, The longitudinal gap is equal to or less than ¼ of the length of the long side of the opening surface, The short-side gap is 1 / 5 or less of the length of the short side of the opening surface, This ladder with fixing device is characterized in that when the support inserted into the hollow portion is tilted at an angle of 40 degrees to 75 degrees relative to the installation surface of the support, the movable piece is in a horizontal position, the first long piece abuts against the surface forming the slit, and the support abuts against the first short piece and the second short piece.

9. A ladder with fixing devices as described in claim 7 or claim 8, characterized in that the ladder is provided with a hook portion that can be attached to a horizontal member of the scaffold and is used as a step of the scaffold.

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