JP7678972B2 - ladder - Google Patents

Description

The present invention relates to a ladder that is divided into pieces and is easy to transport, assemble and rearrange, and can be easily adapted to the environment in which it is used.

Conventionally, there is a ladder whose length can be freely changed, as described in Patent Document 1. For example, when using a ladder for construction work, the length required for the ladder varies depending on where the ladder is to be installed, so a ladder whose length can be freely changed, as described in Patent Document 1, is suitable.

JP 2015-227553 A

However, the ladder described in Patent Document 1 is heavy due to its structure, and transporting it to the location where it is to be used is a heavy burden. In addition, a heavy and long ladder is difficult to handle, so transporting the ladder at a construction site, for example, before materials have been placed on the surrounding ground and an appropriate walking route has been secured, poses a high risk of it falling over or damaging the surrounding environment, making it dangerous.

The present invention was made in consideration of the above circumstances, and aims to provide a ladder that is easy to transport and assemble, and can be easily rearranged to accommodate the required ladder length.

In order to solve the above problems, the ladder according to the present invention is a ladder that is installed on a flat installation surface and leaned at an angle, and includes a plurality of first ladder units each having a pair of long first posts and a plurality of rungs installed between the pair of first posts, and the first posts have connecting means at their upper and lower ends in the longitudinal direction for connecting the first posts to other posts, and a non-slip portion provided with a non-slip surface at the lower part in the longitudinal direction, and the non-slip surface is disposed below the first posts and approximately parallel to the installation surface. and an avoided state in which the first support pillar is positioned approximately parallel to a side surface of the first support pillar and is positioned to the side of the side surface , the tread has approximately ring-shaped tread fixing parts at both ends into which the support pillar is inserted, and has a tread fixing pin inside which is insertable and can be extended or retracted toward the support pillar and inserted into the tread fixing parts, the support pillar has a tread fixing hole on its side into which the tread fixing pin is inserted, and the tread is fixed to the support pillar by inserting the tread fixing pin into the tread fixing hole of the support pillar .

Furthermore, the ladder unit includes a pair of second posts, and a plurality of rungs that are installed between the pair of second posts. The second posts have the connecting means at their lower ends in the longitudinal direction that allows the second posts to be connected to other posts, and have a long rod-shaped extension section inside that can be extended and contracted upward from the upper end of the second posts.

The ladder of claim 3 further characterized in that the telescopic section has a plurality of telescopic section length adjustment holes spaced apart on its side along the longitudinal direction of the telescopic section, and the telescopic section is fixed to the support by inserting the tread fixing pin of the tread into the tread fixing hole of the support and into one of the telescopic section length adjustment holes of the telescopic section.

Furthermore, the ladder is provided with a plurality of third ladder units each having a pair of third supports and a plurality of rungs installed between the pair of third supports, and the third supports have the connecting means at their upper and lower ends in the longitudinal direction to connect the third supports to other supports, and do not have the anti-slip portion or the extendable portion, and the third supports of each third support have different lengths.

Furthermore, the connecting means at the upper end of the support is a rod-shaped protrusion that protrudes upward from the upper end of the support, and the connecting means at the lower end of the support is a recess into which the protrusion can be inserted from below to above the lower end of the support, and the protrusions and the protrusions each have through holes that overlap with each other when the protrusions are inserted into the recesses, and the supports are connected to each other by pin joints by inserting rod-shaped pins into the overlapping through holes.

Furthermore, the ladder is provided with a long, roughly rod-shaped rear support, the upper end of which has a rear support fixing part that can be detachably fixed to any of the rungs, and the lower end of which has a rear support anti-slip part with a rear support anti-slip surface that is roughly parallel to the installation surface, and the rear support supports the ladder from behind when the ladder is leaned against it.

Furthermore, the rear support includes a first rear support having a long cylindrical shape, a second rear support having a long cylindrical shape that is inserted inside the first rear support in a nested structure, and a third rear support having a long rod shape that is inserted inside the second rear support in a nested structure, the first rear support and the second rear support have a first length adjustment means that allows the length by which the second rear support protrudes from the lower end of the first rear support to be adjusted in stages, and the second rear support has a second length adjustment means that allows the length by which the third rear support protrudes from the lower end of the rear support to be continuously adjusted.

Furthermore, it is characterized by having handrails that can be attached and detached from the posts.

The ladder according to the present invention is used by connecting the posts of multiple first ladder units together, so that the ladder can be transported in units of first ladder units that have been disconnected, making it lighter in weight and smaller in size during transportation, and therefore highly convenient to carry, store, and transport. The length of the ladder can be adjusted by adjusting the number of first ladder units to be connected or by connecting first ladder units of different lengths. The first ladder unit is equipped with a non-slip part, but by putting the non-slip part in an avoided state, it is possible to connect other first ladder units to the lower end of the first ladder unit, and the first ladder unit located at the bottom of the ladder can easily function as a non-slip part by putting the non-slip part in an unfolded state. The non-slip part is always fixed to all first ladder units, so there is no risk of losing the non-slip part.

Furthermore, because the rungs are easily removable, for example, in an environment where the ladder is used, if the rung fixed at the bottom of the first ladder unit, which is located at the bottom of the ladder, gets in the way, the rung can be removed on the spot. Also, because it can be easily removed, it is easy to maintain.

Furthermore, by connecting the second ladder unit so that it is positioned at the very top of the ladder and extending the telescopic section of the second ladder unit, it is easy to ensure that the upper end of the ladder protrudes upward from the high position where the ladder is leaned against it and in contact with the ladder. Also, by shortening the telescopic section of the second ladder unit, the second ladder unit becomes easier to handle, making it convenient to carry, store and transport.

In addition, because the length of the telescopic section is adjusted using the tread fixing pin, there is no need for a special structure just for adjusting the length of the telescopic section, making it possible to reduce weight. Also, the length of the telescopic section can be easily adjusted.

Furthermore, the weight of the ladder can be reduced by connecting a third ladder unit that does not have an anti-slip portion or an extendable portion so that it is positioned between the first ladder unit and the second ladder unit.

In addition, the connecting means is pin joints, making it easy to assemble, rearrange and disassemble the installation ladder.

In addition, the installation ladder is equipped with a removable rear support, which can prevent the installation ladder from bending.

Furthermore, the rear support is equipped with a first length adjustment means and a second length adjustment means, and the first length adjustment means allows the length of the rear support to be changed in stages, while the second length adjustment function allows the length of the rear support to be changed continuously, so that the rear support can be adjusted to an appropriate length and can be used in any environment in which the ladder is leaned against it.

In addition, the installation ladder is equipped with a removable handrail to prevent the vehicle using the installation ladder from tipping over.

FIG. 2 shows a first ladder unit of one of the ladders in accordance with one embodiment of the present invention. A figure showing the other first ladder unit of a ladder in one embodiment of the present invention. FIG. 2 shows a second ladder unit of a ladder according to an embodiment of the present invention. A figure showing a third ladder unit on one side of a ladder in one embodiment of the present invention. A figure showing the other third ladder unit of the ladder in one embodiment of the present invention. FIG. 2 is a diagram showing the connection of ladders according to one embodiment of the present invention. FIG. 2 shows a ladder rung according to one embodiment of the present invention. A diagram showing how the extension section is fixed by the rungs of a ladder in one embodiment of the present invention. FIG. 2 shows the rear support of a ladder according to an embodiment of the present invention. A figure showing the second length adjustment means of the rear support of the ladder in one embodiment of the present invention. FIG. 2 shows a ladder according to an embodiment of the present invention leaned against a flat support surface. FIG. 2 is a diagram showing a ladder according to an embodiment of the present invention leaned against a floor.

The ladder according to the present invention will be described below with reference to the drawings. However, the following is merely an example of one embodiment of the present invention, and the scope of the present invention is not limited to the following embodiment, and can be modified as appropriate without departing from the concept of the present invention.

The ladder 1 according to one embodiment comprises two first ladder units 10 of different lengths, one second ladder unit 60, two third ladder units 70 of different lengths, a rear support 80, and two handrails 97, which are connected and assembled to form the ladder in its usable form.

As shown in Figs. 1 and 2, the first ladder unit 10 has a pair of long cylindrical supports 2, the first posts 22, and a number of approximately plate-shaped rungs 3. The pair of first posts 22 are parallel to each other with a gap between them, and the number of rungs 3 described below are fixed to the pair of first posts 22 so that they are suspended between the pair of first posts 22 at a predetermined interval (275 mm intervals in this embodiment). The first ladder unit 10 shown in Fig. 1 is one of the two first ladder units 10, the first ladder unit 10a, and the first ladder unit 10 shown in Fig. 2 is the other of the two first ladder units 10, the first ladder unit 10b.

Figure 7(a) is a rear view of the tread 3, and Figure 7(b) is a plan view of the tread 3. As shown in Figure 7, the tread 3 has a roughly plate-shaped tread body 31 with an internal space, roughly ring-shaped tread fixing parts 21 fixed to both ends of the tread body 31 and through which the support post 2 passes, and a tread fixing pin 34 that can be extended and retracted from the internal space of the tread body 31 toward the support post 2 through the tread fixing part 33 to fix the tread 3 to the support post 2.

Figure 8 shows how the tread 3 is fixed to the support 2 by the tread fixing pin 34 and how the expandable part 62 described later is fixed to the support 2, with a part of the figure shown as a cross section. As shown in Figure 8, the tread fixing pin 34 is arranged through the first wall 32 provided in the internal space of the tread main body part 31. The tread fixing pin 34 also has a second wall 35 fixed to the tread fixing pin 34 and abutting the tread fixing part 33, and a spring 36 arranged between the first wall 32 and the second wall 35 so as to wrap around the tread fixing pin 34. Under normal conditions, the tread fixing pin 34 protrudes toward the support 2 passing through the tread fixing part 33 by the force of the spring 36, as shown in Figure 8 (a). At this time, the tread fixing pin 34 is inserted into the tread fixing hole 21 provided on the side of the support 2, and the tread 3 is fixed to the support 2.

As shown in FIG. 7, a string-like tension part 37 is fixed to one end of the tread fixing pin 34. As shown in FIG. 8(b), by pulling the tension part 37, the tread fixing pin 34 shrinks toward the inside of the tread main body part 31, and the fixation between the tread 3 and the support post 2 is released.

The first support 22 has a connecting means 4 at each of its upper and lower ends, as shown in Figures 1 and 2. The connecting means 4 is a means for connecting two different supports 2 by pin joints, as shown in Figure 6(b). The connecting means 4 at the upper end of the first support 22 is a long rod-like protrusion 41 whose outer diameter is approximately the same as the inner diameter of the support, protruding upward from the upper end of the first support 22 and fixed inside the first support 22 in a nested structure, as shown in Figures 1 and 2. The connecting means 4 at the lower end of the first support 22 is a recess 42 into which the protrusion 41, which is the connecting means 4 of another support 2, can be inserted from below to above, as shown in Figures 1 and 2.

The protruding portion 41 and the recessed portion 42 each have a through hole 43 that overlaps with each other when the protruding portion 41 is inserted into the recessed portion 42, as shown in FIG. 6(a), and can be connected by pin joints by inserting rod-shaped pins 44 into the through holes 43 that overlap when the protruding portion 41 is inserted into the recessed portion 42, as shown in FIG. 6(a). Note that the support 2 in this embodiment is cylindrical, and the cylindrical shape is used as the recessed portion 42.

Furthermore, the first support 22 has an anti-slip portion 5 at its lower part in the longitudinal direction, as shown in Figs. 1 and 2. As shown in Figs. 1 and 2, the anti-slip portion 5 is composed of a plate-shaped rotating portion 51 that is bent into a U-shape, a plate-shaped plate portion 53, and an anti-slip surface 54 with an uneven pattern formed on the underside of the plate portion 53. The plate portion 53 is fixed to the underside of the rotating portion 51, and the two side portions 52 of the rotating portion 51 are arranged to sandwich the lower end of the first support 22, and the two side portions 52 of the rotating portion 51 and the first support 22 are fixed by bolts and nuts as fasteners 56 so that the anti-slip portion 5 can rotate.

The anti-slip portion 5 is fixed to the first support 22 so that it can rotate, and can easily be switched between an expanded state in which the anti-slip surface 54 is approximately parallel to the installation surface 101 as shown in FIG. 1, and an avoided state in which the anti-slip surface 54 is approximately parallel to the side of the first support 22 as shown in FIG. 2. By setting the anti-slip portion 5 in the avoided state, it is possible to connect other supports 2 from below to the first support 22 equipped with the anti-slip portion 5 without interference from the anti-slip portion 5. By setting the anti-slip portion 5 of the first ladder unit 10, which is located at the bottom of the ladder 1, in the expanded state, it is possible to make the anti-slip portion 5 function as an anti-slip. The installation surface 101 refers to a flat surface such as the ground on which the ladder 1 is set up.

As shown in Figures 1 and 2, the plate portion 53 and the anti-slip surface 54 of the anti-slip portion 5 are provided with through holes 55, and when the anti-slip portion 5 of the first ladder unit 10 arranged at the bottom of the ladder 1 is in the deployed state, the ladder 1 can be firmly fixed by driving a screw (not shown) as a fixing device into the installation surface 101 through the through hole 56. Note that in cases where the environment in which the ladder 1 is used makes it impossible to drive a fixing device into the installation surface 101 or when the ladder 1 is used temporarily, it is not necessary to fix the anti-slip portion 5 to the installation surface 101 using a fixing device.

As shown in FIG. 3, the second ladder unit 60 has a pair of cylindrical posts 2, called second posts 61, and a number of roughly plate-shaped rungs 3, and similarly to the first ladder unit 10, the rungs 3 are fixed to the pair of second posts 61. The second posts 61 have a connecting means 4 at their lower ends. The connecting means 4 at the lower end of the second posts 61 is the same as the connecting means 4 at the lower end of the first posts 10, so a description thereof will be omitted. The second posts 61 also have a long rod-shaped telescopic section 62 inside that can telescope upward from the upper end of the second posts 61.

As shown in FIG. 3, the telescopic section 62 is a long rod-like member with an outer diameter that is approximately the same as the inner diameter of the support 2, and has an approximately spherical protective section 64 at the upper end of the telescopic section 62 that is larger than the inner diameter of the support 2, and the telescopic section 62 is inserted from above into the inside of the second support 61 in a nested structure.

As shown in FIG. 8, the telescopic section 62 has a plurality of telescopic section length adjustment holes 63 spaced apart along the longitudinal direction of the telescopic section 62 on its side, and the tread fixing pin 34 of the topmost tread 3 of the second ladder unit 60 is inserted into one of the telescopic section length adjustment holes 63 that overlaps with the tread fixing hole 21 of the second support 61, so that the tread 3 is fixed to the second support 61 and the telescopic section 62 is fixed to the second support 61 at the same time. In other words, by selecting the telescopic section length adjustment hole 63 into which the tread fixing pin 34 of the topmost tread 3 of the second ladder unit 60 is inserted, it is possible to adjust the length by which the telescopic section 62 protrudes upward from the top end of the second ladder unit 60.

As shown in Figures 4 and 5, the third ladder unit 70 has a pair of long cylindrical pillars 2, the third support posts 71, and a number of approximately plate-shaped rungs 3. As with the first ladder unit 10, the rungs 3 are fixed to the pair of third support posts 71. As shown in Figures 4 and 5, the third support post 71 has a connecting means 4 at its upper and lower ends, and does not have a non-slip portion 5 or an expandable portion 62. The connecting means 4 at the upper end of the third support post 71 is the same as the connecting means 4 at the upper end of the first support post 22, and the connecting means 4 at the lower end of the third support post 71 is the same as the connecting means 4 at the lower end of the first support post 22, so a description is omitted. The third ladder unit 70 shown in Figure 4 is one third ladder unit 70a of the two third ladder units 70, and the third ladder unit 70 shown in Figure 5 is the other third ladder unit 70b of the two third ladder units 70.

As shown in FIG. 9, the rear support 80 has a first rear support 81 that is a long cylindrical column, a second rear support 82 that is a long cylindrical column whose outer diameter is approximately the same as the inner diameter of the first rear support 81 and is inserted inside the first rear support 81, and a third rear support 83 that is a long cylindrical column whose outer diameter is approximately the same as the inner diameter of the second rear support 82 and is inserted inside the second rear support 82.

The first rear support 81 and the second rear support 82 have a first length adjustment means 84 for fixing the first rear support 81 and the second rear support 82 in a state in which the first rear support 81 protrudes downward by an arbitrary length from the lower end of the first rear support 81. The first length adjustment means 84 of the first rear support 81 is a plurality of through holes 85 provided at a predetermined interval along the longitudinal direction of the first rear support 81 on the side surface of the first rear support 81, and the first length adjustment means 84 of the second rear support 82 is a lock pin 86 that normally protrudes outward from the side surface near the upper end of the second rear support 82 and can be pushed inward of the second rear support 82.

Then, with the lock pin 86 pressed into the inside of the second rear support 82, the second rear support 82 is inserted into the first rear support 81 from below, and when the lock pin 86 overlaps with one of the through holes 85 of the first rear support 81, the lock pin 86 protrudes outward from the side of the second rear support 82 and fits into the through hole 85 of the first rear support 81, thereby fixing the first rear support 81 and the second rear support 82 to each other. In other words, by selecting the through hole 85 of the first rear support 81 into which the lock pin 86 fits, the length of the second rear support 82 protruding from the first rear support 81 can be adjusted in stages as shown in FIG. 9(b).

The second rear support 82 has a second length adjustment means 87 for fixing the second rear support 82 and the third rear support 83 in a state where it protrudes downward by an arbitrary length from the lower end of the second rear support 82. As shown in FIG. 10, the second length adjustment means 87 of the second rear support 82 is composed of a second length adjustment means fixing part 88 fixed so as to cover the outer periphery of the lower end of the second rear support 82, a fulcrum part 89 fixed to the second length adjustment means fixing part 88 at a position away from the second rear support 82 and extending downward, a plate-shaped engagement part 90 rotatably fixed below the fulcrum part 89 and having an engagement hole 91 with a diameter larger than the outer diameter of the third rear support 83, and a contraction part 93 which is a spring fixed to the second length adjustment means fixing part 88 and the engagement part 90 and pulls the engagement part 90 toward the second length adjustment means fixing part 88.

Then, as shown in FIG. 10(a), the tip of the engaging portion 90 is grasped and the engaging portion is held perpendicular to the longitudinal direction of the second rear support 82, and the third rear support 83 is inserted into the second rear support 82 from below so as to pass through the engaging hole 91. By releasing the engaging portion 90, the engaging portion 90 is pulled toward the second length adjustment means fixing portion 88 by the contracting portion 93 as shown in FIG. 10(b), and the engaging portion 90 jumps up obliquely with the position 110 where the engaging portion 90 is fixed to the fulcrum portion 89 as the fulcrum. At this time, the edge 92 of the engaging hole 91 of the engaging portion 90 in the tilted position engages with the side of the third rear support 83, and the second rear support 82 and the third rear support 83 are fixed to each other. In other words, the length of the third rear support 83 protruding from the second rear support 82 can be continuously adjusted as shown in FIG. 9(b) by the position of the side of the third rear support 83 that engages the edge 92 of the engaging hole 91 of the engaging portion 90.

As shown in FIG. 9, the first rear support 81 has a rear support fixing part 94 at its upper end, and the third rear support 81 has a rear support anti-slip part 95 at its lower end that functions as an anti-slip part against the installation surface 101. As shown in FIG. 9(b), the rear support fixing part 94 can be detachably fixed to the underside of any tread 3 by a bolt, which is a fixing device not shown, and is rotatably fixed to the first rear support 81 in the same way that the anti-slip part 5 can rotate relative to the first support 22. The rear support anti-slip part 95 is composed of an anti-slip surface 96 with an uneven pattern formed thereon that is attached to its underside.

As shown in Figures 11 and 12, the handrail 97 is formed in a roughly U-shape by a pair of long, rod-shaped parent posts 98 and a long, rod-shaped handrail section 99 fixed to each end of the pair of parent posts 98. A connecting clamp 100 for a single pipe is fixed to the other end of each of the pair of parent posts 98, and the handrail 97 can be detachably attached to the ladder 1 by fixing the connecting clamp 100 to the parent posts 98 at any position on the support 2 of the ladder 1. The handrail 97 can be attached symmetrically to the ladder 1 or only on one side of the ladder 1, or otherwise freely depending on the installation environment of the ladder 1.

Next, a method of using the ladder 1 according to this embodiment will be described. In the construction work of a building in which a floor structure is constructed on a horizontally extending support plane 102 to form a first floor floor 103, the ladder 1 is used by leaning against a beam 104 hanging from the first floor ceiling at a specified leaning angle 106, with the support plane 102 as the installation surface 101 as shown in FIG. 11 and the first floor floor 103 as the installation surface 101 as shown in FIG. 12, in order for a worker to move from the first floor to the second floor height. Note that the specified leaning angle 106 is an angle determined at the work site where the ladder 1 of the present invention is used, and in this embodiment it is 65 degrees as shown in the figure, but depending on the work site it is specified in the range of 45 degrees to 90 degrees.

Here, we will explain the length 105 of the first support 22 of one of the first ladder units 10a. The length 105 of the first support 22 of one of the first ladder units 10a shown in Figure 1 is the length from the support plane 10 to the upper surface of the floor 103 at the specified leaning angle 106 at which the ladder 1 is leaned, as shown in Figure 12.

First, a case where the support plane 102 is used as the installation surface 101 will be described. The ladder 1 is transported to the work site disassembled into the first ladder unit 10, the second ladder unit 60, the third ladder unit 70, the rear support 80 and the handrail 97. Then, as shown in FIG. 11, one of the third ladder units 70a is connected below the second ladder unit 60, the other first ladder unit 10b is connected below the third ladder unit 70, one of the first ladder units 10a is connected below the other third ladder unit 10b, and the rear support 80 and the handrail 97 are attached in appropriate positions.

The difference between one third ladder unit 70a and the other third ladder unit 70b is their longitudinal length, and in this embodiment, one third ladder unit 70a is used. Depending on the required length of the ladder 1, it is possible to choose to use the other third ladder unit 70b, to use both third ladder units 70, or to use neither third ladder unit 70.

As shown in FIG. 11, the ladder 1 is leaned against a beam 104 hanging from the first floor ceiling at a specified leaning angle 106 with the support plane 102 as the installation surface 101, the rear support 80 is extended to the support plane 102 at an angle 108 so that the ladder 1 does not bend backward, the telescopic section 62 of the second ladder unit 60 is extended upward so that the length 109 by which the ladder 1 protrudes upward from the top surface of the beam 104 is approximately 60 cm, and the ladder 1 is then used. Note that the angle 108 of the rear support 80 in this embodiment is adjusted to 75 degrees from the installation surface 101.

Next, when moving the ladder 1 to use the first floor 103 as the installation surface 101, the first ladder unit 10a, which is connected and positioned at the lowest position of the already assembled ladder 1, is disconnected from the other first ladder unit 10b, one first ladder unit 10a is removed, and the anti-slip portion 5 of the other first ladder unit 10b is placed in an unfolded state, and then it is leaned against the beam 104 at the specified leaning angle 106 from the first floor 103 as shown in Figure 12, and the length of the rear support 80 is adjusted so that the support anti-slip portion 95 is then in contact with the first floor 103.

As already explained, the length 105 of the first support 22 of one of the first ladder units 10a is the length from the support plane 102 to the top surface of the floor 103 at the specified leaning angle 106 at which the ladder 1 is leaned, so depending on whether or not the one of the first ladder units 10a is connected to the bottom of the ladder 1, the length of the ladder 1 can be easily changed between a length in which the support plane 102 is the installation surface 101 and a length in which the first floor floor 103 is the installation surface 101.

In addition, if the ladder 1 is installed in the same location for a long period of time, the lower end of the ladder 1 can be fixed, if necessary, by driving a screw (not shown) into the installation surface 101 through the through hole 55 of the anti-slip portion 5 of the first ladder unit 10 located at the bottom of the ladder 1.

When the ladder 1 is to be removed, it is disassembled into the first ladder unit 10, the second ladder unit 60, the third ladder unit 70, the rear support 80 and the handrail 97, and each of these is transported from the site of use and stored in a storage location.

In one embodiment, the ladder 1 includes two first ladder units 10, two third ladder units 70, and two handrails 97, but the present invention is not limited to this. By including a greater number of units, the number of combinations of the ladder 1 increases, making it possible to accommodate a variety of heights.

In addition, the ladder 1 in one embodiment is used by hanging it from a beam 104 that spans the ceiling from the first floor to the first floor, but the present invention is not limited to this, and the ladder 1 may be hung on something other than the beam 104 regardless of the floor on which it is used.

LIST OF SYMBOLS 1 Ladder 10 First ladder unit 2 Support 21 Rung fixing hole 22 First support 3 Rung 33 Rung fixing portion 34 Rung fixing pin 4 Connecting means 41 Convex portion 42 Concave portion 43 Through hole 44 Pin 5 Anti-slip portion 54 Anti-slip surface 60 Second ladder unit 61 Second support 62 Telescopic portion 63 Telescopic portion length adjustment hole 70 Third ladder unit 71 Third support 80 Rear support 81 First rear support 82 Second rear support 83 Third rear support 84 First length adjustment means 87 Second length adjustment means 94 Rear support fixing portion 95 Rear support anti-slip portion 96 Rear support anti-slip surface 97 Handrail 101 Installation surface 102 Support plane 103 Floor 105 Length of one of the first supports 106 Specified leaning angle 107 Length from the support plane to the floor at the specified leaning angle

Claims (8)

A ladder that can be installed on a flat surface and leaned against an angle,
The ladder includes a plurality of first ladder units each having a pair of first posts which are long posts, and a plurality of rungs installed between the pair of first posts,
The first support has a connecting means at its upper end and lower end in the longitudinal direction, which can connect the first support to another support, and has a non-slip portion provided with a non-slip surface at its lower end in the longitudinal direction,
the anti-slip portion is capable of transitioning between an unfolded state in which the anti-slip surface is substantially parallel to the installation surface below the first support and an avoided state in which the anti-slip surface is substantially parallel to a side surface of the first support and is positioned to the side of the side surface ,
The tread has a substantially ring-shaped tread fixing portion at both ends into which the support pole is inserted, and has a tread fixing pin therein that is extendable and retractable toward the support pole inserted into the tread fixing portion,
The support pillar has a tread bar fixing hole on a side surface thereof into which the tread bar fixing pin is inserted,
A ladder characterized in that the step is fixed to the support by inserting the step fixing pin into the step fixing hole of the support . A second ladder unit having a pair of second posts that are the above-mentioned supports and a plurality of the above-mentioned rungs installed between the pair of the second posts,
A ladder as described in claim 1, characterized in that the second support has a connecting means at its lower end in the longitudinal direction, which enables the second support to be connected to other supports, and has a long, rod-shaped telescopic section inside it, which can be extended and contracted upward from the upper end of the second support. The stretchable portion has a plurality of stretchable portion length adjustment holes arranged at intervals along the longitudinal direction of the stretchable portion on a side surface thereof,
A ladder as described in claim 2, characterized in that the telescopic section is fixed to the support by inserting the tread fixing pin of the tread into the tread fixing hole of the support and into one of the telescopic section length adjustment holes of the telescopic section. A third ladder unit having a pair of third posts that are the above-mentioned supports and a plurality of the above-mentioned rungs installed between the pair of the third posts,
the third support has the connecting means at its upper end and lower end in the longitudinal direction, which enables the third support to be connected to another support, and does not have the anti-slip portion and the expandable portion;
4. The ladder of claim 3 , wherein the third posts of each of the third posts are of different lengths. the connecting means at the upper end of the support is a rod-shaped protrusion protruding upward from the upper end of the support,
the connecting means at the lower end of the support is a recess into which the protrusion can be inserted from below toward above the lower end of the support,
A ladder as described in claim 4, characterized in that the convex portion and the concave portion each have a through hole that overlaps with each other when the convex portion is inserted into the concave portion, and the posts are connected to each other by pin joints by inserting rod-shaped connecting pins into each of the overlapping through holes. Further, a long, substantially rod-shaped rear support is provided,
The rear support has a rear support fixing part at its upper end that can be detachably fixed to any of the treads, and a rear support anti-slip part at its lower end that has a rear support anti-slip surface that is approximately parallel to the installation surface,
6. The ladder according to claim 5 , wherein the rear support supports the ladder from behind when the ladder is leaning against something. the rear support pillars include a first rear support pillar having a long cylindrical shape, a second rear support pillar having a long cylindrical shape inserted into the inside of the first rear support pillar in a nested structure, and a third rear support pillar having a long rod shape inserted into the inside of the second rear support pillar in a nested structure,
the first rear support and the second rear support have a first length adjustment means that makes it possible to adjust in a stepwise manner a length by which the second rear support protrudes from a lower end of the first rear support,
A ladder as described in claim 6 , characterized in that the second rear support has a second length adjustment means for continuously adjusting the length by which the third rear support protrudes from the lower end of the second rear support. 8. The ladder of claim 7 , further comprising handrails detachable from the posts.

Images