ladder

Abstract

To provide a ladder that is easy to transport and assemble and that is also easy to rearrange for adaptation to a required length of the ladder.SOLUTION: A ladder, which is installed on a flat installation surface 101 in an oblique lean manner, includes a plurality of first ladder units 10 each having first support posts 22 in the form of a pair of elongated support posts 2, and a plurality of steps 3 installed between the pair of first support posts 22, in which the first support post 22 has coupling means 4 capable of coupling the first support post 22 and another support post 2 at an upper end and a lower end in a longitudinal direction thereof, and has an anti-slip portion 5 having an anti-slip surface 54 at a lower portion in the longitudinal direction thereof, and the anti-slip portion 5 can be shifted to a deployed state in which the anti-slip surface 54 is substantially parallel to the installation surface 101 below the first support post 22, and an avoidance state in which the anti-slip surface is substantially parallel to a side surface of the first support post 22 and is located beside the side surface.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a piece-shaped ladder that is easy to carry, easy to assemble and recombine, and can easily adapt to the use environment.

Background Art

[0002] 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 or the like, since the required length of the ladder varies depending on the location where the ladder is installed, a ladder that can freely change its length as in Patent Document 1 is suitable.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, the ladder described in Patent Document 1 is heavy in weight due to its structure, and the burden of transporting it to the place of use is large. In addition, since a long and heavy ladder has poor handling performance, for example, it is risky and dangerous to transport the ladder at a construction site before materials are placed on the surrounding ground and an appropriate walking route is secured, as there is a high risk of falling or damage to the surrounding environment.

[0005] The present invention has been made in view of the above circumstances, and an object thereof is to provide a ladder that is easy to transport and assemble and easy to recombine to adapt to the required length of the ladder.

Means for Solving the Problems

[0006] 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 diagonally, and includes a plurality of first ladder units having a pair of long columns, namely a first column, and a plurality of rungs installed between the pair of first columns. The first column has connecting means at the upper and lower ends in its longitudinal direction for connecting the first column and the other columns, and has a sliding prevention portion provided with a sliding prevention surface at the lower part in its longitudinal direction. The sliding prevention portion is shiftable between a deployed state in which the sliding prevention surface is substantially parallel to the installation surface below the first column and an avoidance state in which the sliding prevention surface is substantially parallel to the side surface of the first column and is located beside the side surface. The tread bar has substantially annular tread bar fixing portions at both ends thereof into which the columns are inserted, and has a tread bar fixing pin inside thereof that can expand and contract toward the columns inserted into the tread bar fixing portions. The columns have tread bar fixing holes on their side surfaces into which the tread bar fixing pins are inserted. By inserting the tread bar fixing pins into the tread bar fixing holes of the columns, the tread bar is fixed to the columns. It is characterized by this.

[0008] Furthermore, it includes one second ladder unit having a pair of second columns, which are the pair of columns, and a plurality of the rungs installed between the pair of second columns. The second column has the connecting means at the lower end in its longitudinal direction for connecting the second column and the other columns, and is characterized by having a long rod-shaped telescopic portion that can extend upward from the upper end of the second column inside the second column.

[0009] Furthermore, the telescopic portion has a plurality of telescopic portion length adjustment holes arranged at intervals along the longitudinal direction of the telescopic portion on its side surface. The telescopic portion is fixed to the column by inserting the rung fixing pin of the rung into the rung fixing hole of the column and any one of the telescopic portion length adjustment holes of the telescopic portion. The ladder according to claim 3 is characterized by this.

[0010] Furthermore, it includes a plurality of third ladder units having a pair of third columns, which are the pair of columns, and a plurality of the rungs installed between the pair of third columns. The third column has the connecting means at the upper and lower ends in its longitudinal direction for connecting the third column and the other columns, and does not have the sliding prevention portion and the telescopic portion. The third columns of each of the third columns are characterized by having different lengths.

[0011] Furthermore, the connecting means provided at the upper end of the column is a convex portion that is rod-shaped and protrudes upward from the upper end of the column. The connecting means provided at the lower end of the column is a concave portion into which the convex portion can be inserted from below upward at the lower end of the column. The convex portion and the convex portion each have a through-hole that overlaps with each other with the convex portion inserted into the concave portion, and the columns are connected by pin joining by inserting a rod-shaped pin into each of the overlapping through-holes.

[0012] Furthermore, it includes a long substantially rod-shaped rear column. The rear column has a rear column fixing portion at its upper end that can be detachably fixed to any of the crossbars, and a rear column anti-slip portion having a rear column anti-slip surface that is substantially parallel to the installation surface at its lower end. The rear column supports the ladder from behind when the ladder is leaned against.

[0013] Furthermore, the rear column includes a long cylindrical first rear column, a long cylindrical second rear column inserted into the first rear column in a nested structure, and a long rod-shaped third rear column inserted into the second rear column in a nested structure. The first rear column and the second rear column have first length adjusting means for enabling stepwise adjustment of the length of protruding the second rear column from the lower end of the first rear column. The second rear column has second length adjusting means for enabling continuous adjustment of the length of protruding the third rear column from the lower end of the second rear column.

[0014] Furthermore, it is characterized by including a handrail that is detachable from the column.

Advantages of the Invention

[0016] According to the ladder of the present invention, since it is a ladder used by connecting the columns of a plurality of first ladder units, by carrying it in units of the first ladder units with the connection of the ladders released, the weight during transportation is reduced and the size becomes smaller, so it is excellent in convenience for carrying, storing, and transporting. Further, by adjusting the number of the first ladder units to be connected or making the lengths of the first ladder units to be connected different lengths, the length of the ladder can be adjusted. Further, although the first ladder unit is provided with an anti-slip portion, by setting the anti-slip portion in an avoidance state, it is possible to connect another first ladder unit to the lower end of the first ladder unit, and the first ladder unit arranged at the lowermost position of the ladder can function as an anti-slip easily by deploying its anti-slip portion. Further, since the anti-slip portions are always fixed to all the first ladder units, there is no fear of losing the anti-slip portions.

[0017] Furthermore, since the treads can be easily removed, for example, in an environment where the ladder is used, when the tread fixed to the very bottom of the first ladder unit arranged at the very bottom of the ladder gets in the way, the tread can be removed on the spot. Also, since it can be easily removed, it has excellent maintainability.

[0018] Furthermore, by connecting the second ladder unit so as to be located at the uppermost position of the ladder and extending the telescopic portion of the second ladder unit, it is possible to easily secure the protrusion from the position where the ladder is leaned against and in contact with the ladder to above the upper end of the ladder. Also, by contracting the telescopic portion of the second ladder unit, the handling performance of the second ladder unit is improved, and it is excellent in convenience for carrying, storing, and transporting.

[0019] Furthermore, since the length adjustment of the telescopic portion is performed with the tread fixing pins, a special structure only for the length adjustment of the telescopic portion is not required, and weight reduction can be achieved. Also, the length of the telescopic portion can be easily adjusted.

[0020] Furthermore, by connecting a third ladder unit without an anti-slip portion and a telescopic portion so as to be arranged between the first ladder unit and the second ladder unit, weight reduction of the ladder can be achieved.

[0021] Furthermore, since the connecting means is a pin joint, the erection, recombination, and disassembly of the erection ladder are facilitated.

[0022] Furthermore, the erection ladder is provided with a detachable rear support column, which can suppress the deflection of the erection ladder.

[0023] Furthermore, the rear support column is provided with a first length adjustment means and a second length adjustment means. The first length adjustment means can stepwise change the length of the rear support column in the longitudinal direction, and the second length adjustment function can continuously change the length of the rear support column in the longitudinal direction. Therefore, the rear support column can be adjusted to an appropriate length, and the rear support column can be used regardless of the environment where the ladder is leaned against.

[0024] Furthermore, the erection ladder is provided with a detachable handrail, which can prevent the erection ladder vehicle from tipping over.

Brief Description of the Drawings

[0026]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

MODE FOR CARRYING OUT THE INVENTION

[0027] The ladder which concerns on this invention is demonstrated below, referring drawings. However, the following is only an example of one Embodiment of this invention, The scope of this invention is not limited to the following Embodiment, It can change suitably in the range which does not deviate from the thought of this invention.

[0028] The ladder 1 which concerns on one Embodiment is a ladder which has two 1st ladder units 10 from which length differs, one 2nd ladder unit 60, two 3rd ladder units 70 from which length differs, a rear support | pillar 80, and two handrails 97, and forms the form at the time of use by connecting and assembling them.

[0029] As shown in FIG. 1 and FIG. 2, the 1st ladder unit 10 has a 1st support | pillar 22 which is a pair of long cylindrical support | pillars 2, and a some treads 3 which are substantially plate-shaped. A pair of 1st support | pillars 22 is in the state which has a clearance gap and is parallel, and a some treads 3 mentioned later are fixed to a pair of the said 1st support | pillars 22 so that it may be suspended at a predetermined space | interval (275mm space | interval in this Embodiment) between a pair of 1st support | pillars 22. In addition, the 1st ladder unit 10 shown in FIG. 1 is one 1st ladder unit 10a among two 1st ladder units 10, and the 1st ladder unit 10 shown in FIG. 2 is the other 1st ladder unit 10b among two 1st ladder units 10.

[0030] Fig. 7(a) is a rear view of the tread bar 3, and Fig. 7(b) is a plan view of the tread bar 3. As shown in Fig. 7, the tread bar 3 includes a tread bar main body portion 31 that is substantially plate-shaped and has an internal space, substantially annular tread bar fixing portions 21 that are fixed to both ends of the tread bar main body portion 31 and pass through the support columns 2, and a tread bar fixing pin 34 that is extendable and retractable from the internal space of the tread bar main body portion 31 through the tread bar fixing portion 33 toward the support column 2 for fixing the tread bar 3 to the support column 2.

[0031] Fig. 8 is a view showing how the tread bar 3 is fixed to the support column 2 by the tread bar fixing pin 34 and how the expansion and contraction portion 62 described later is fixed to the support column 2, and a part of it is shown as a cross-sectional view. As shown in Fig. 8, the tread bar fixing pin 34 is disposed through a first wall 32 provided in the internal space of the tread bar main body portion 31. Further, the tread bar fixing pin 34 has a second wall 35 that is fixed to the tread bar fixing pin 34 and abuts against the tread bar fixing portion 33, and a spring 36 that is disposed between the first wall 32 and the second wall 35 so as to wrap around the tread bar fixing pin 34. And normally, the tread bar fixing pin 34 protrudes toward the support column 2 passing through the tread bar fixing portion 33 by the force of the spring 36 as shown in Fig. 8(a). At this time, the tread bar 3 is fixed to the support column 2 by inserting the tread bar fixing pin 34 into a tread bar fixing hole 21 provided on the side surface of the support column 2.

[0032] Note that a string-like tension portion 37 is fixed to one end of the tread bar fixing pin 34 as shown in Fig. 7. As shown in Fig. 8(b), by pulling the tension portion 37, the tread bar fixing pin 34 contracts toward the inner side of the tread bar main body portion 31, and the fixation between the tread bar 3 and the support column 2 is released.

[0033] Further, as shown in FIGS. 1 and 2, the first support column 22 has connecting means 4 at each of its upper and lower ends. The connecting means 4 is means for connecting two different support columns 2 by pin joining. As shown in FIG. 6(b), the connecting means 4 provided at the upper end of the first support column 22 is a long rod-shaped convex portion 41 having an outer diameter substantially the same as the inner diameter of the support column, protruding upward from the upper end of the first support column 22 and arranged and fixed inside the first support column 22 in a nested structure. The connecting means 4 provided at the lower end of the first support column 22 is a concave portion 42 into which the convex portion 41, which is the connecting means 4 of the other support column 2, can be inserted from below upward, as shown in FIGS. 1 and 2.

[0034] And, as shown in FIG. 6(a), the convex portion 41 and the concave portion 42 each have a through hole 43 that overlaps with each other with the convex portion 41 inserted into the concave portion 42. As shown in FIG. 6(a), it is possible to connect by pin joining by inserting a rod-shaped pin 44 into each of the overlapping through holes 43 with the convex portion 41 inserted into the concave portion 42. Note that the support column 2 of the present embodiment is cylindrical, and the cylindrical shape is used as the concave portion 42.

[0035] Furthermore, as shown in FIGS. 1 and 2, the first support column 22 has a slip prevention portion 5 at the lower part in its longitudinal direction. The slip prevention portion 5 includes a plate-shaped rotating portion 51 that bends into a U shape, a plate portion 53, and a slip prevention surface 54 having an uneven pattern formed on the lower surface of the plate portion 53. The plate portion 53 is fixed to the lower surface of the rotating portion 51, and the two side portions 52 of the rotating portion 51 are arranged so as to sandwich the lower end of the first support column 22. The two side portions 52 of the rotating portion 51 and the first support column 22 are fixed by a bolt and nut, which is a fixture 56, so that the slip prevention portion 5 can rotate.

[0036] Since the anti-slip part 5 is fixed to the first support column 22 so as to be rotatable, as shown in FIG. 1, it can easily transition between a deployed state in which the anti-slip surface 54 is substantially parallel to the installation surface 101 and an avoidance state in which the anti-slip surface 54 is substantially parallel to the side surface of the first support column 22 as shown in FIG. 2. By setting the anti-slip part 5 in the avoidance state, it becomes possible to connect the other support column 2 from below to the first support column 22 provided with the anti-slip part 5 without interference from the anti-slip part 5. By setting the anti-slip part 5 of the first ladder unit 10 arranged at the bottom of the ladder 1 in the deployed state, the anti-slip part 5 can function as an anti-slip device. Note that the installation surface 101 refers to a flat surface such as the ground on which the ladder 1 is erected.

[0037] Further, as shown in FIGS. 1 and 2, through holes 55 are provided in the plate part 53 and the anti-slip surface 54 of the anti-slip part 5. With the anti-slip part 5 of the first ladder unit 10 arranged at the bottom of the ladder 1 in the deployed state, the ladder 1 can be firmly fixed by driving a screw, which is a fixture not shown in the figure, into the installation surface 101 through the through hole 56. Note that when the fixture cannot be driven into the installation surface 101 depending on the usage environment of the ladder 1 or when the ladder 1 is used temporarily, etc., it is not necessary to fix the anti-slip part 5 to the installation surface 101 using the fixture.

[0038] As shown in FIG. 3, the second ladder unit 60 has a pair of cylindrical support columns 2, namely second support columns 61, and a plurality of substantially plate-shaped treads 3. Similar to the first ladder unit 10, the treads 3 are fixed to the pair of second support columns 61. And the second support column 61 has connecting means 4 at its lower end. Since the connecting means 4 at the lower end of the second support column 61 is the same as the connecting means 4 at the lower end of the first support column 10, the description thereof is omitted. Also, the second support column 61 has a long rod-shaped telescopic part 62 inside it that can extend and contract upward from the upper end of the second support column 61.

[0039] Further, as shown in FIG. 3, the telescopic part 62 is a long rod shape with an outer diameter substantially the same as the inner diameter of the support column 2, and has a substantially spherical protective part 64 at its upper end that is larger than the inner diameter of the support column 2. The telescopic part 62 is inserted into the inside of the second support column 61 in a nested structure from above.

[0040] And as shown in FIG. 8, the telescopic part 62 has a plurality of telescopic part length adjustment holes 63 spaced along the longitudinal direction of the telescopic part 62 on its side surface. The tread bar fixing pin 34 of the tread bar 3 disposed at the uppermost position of the second ladder unit 60 is inserted into any one of the telescopic part length adjustment holes 63 overlapping the tread bar fixing hole 21 of the second support column 61. Thus, the tread bar 3 is fixed to the second support column 61 and at the same time the telescopic part 62 is fixed to the second support column 61. That is, by selecting the telescopic part length adjustment hole 63 into which the tread bar fixing pin 34 of the tread bar 3 disposed at the uppermost position of the second ladder unit 60 is inserted, it is possible to adjust the length by which the telescopic part 62 protrudes upward from the upper end of the second ladder unit 60.

[0041] As shown in FIGS. 4 and 5, the third ladder unit 70 has a pair of long cylindrical support columns 2, i.e., third support columns 71, and a plurality of substantially plate-shaped tread bars 3. Similar to the first ladder unit 10, the tread bars 3 are fixed to the pair of third support columns 71. And as shown in FIGS. 4 and 5, the third support columns 71 have connecting means 4 at their upper and lower ends and do not have the anti-slip part 5 and the telescopic part 62. Since the connecting means 4 at the upper end of the third support column 71 is the same as the connecting means 4 at the upper end of the first support column 22 and the connecting means 4 at the lower end of the third support column 71 is the same as the connecting means 4 at the lower end of the first support column 22, the description thereof is omitted. Note that the third ladder unit 70 shown in FIG. 4 is one of the two third ladder units 70a, and the third ladder unit 70 shown in FIG. 5 is the other third ladder unit 70b of the two third ladder units 70.

[0042] As shown in FIG. 9, the rear support column 80 has a long cylindrical first rear support column 81, a long cylindrical second rear support column 82 having an outer diameter substantially the same as the inner diameter of the first rear support column 81 and inserted into the first rear support column 81, and a long cylindrical third rear support column 83 having an outer diameter substantially the same as the inner diameter of the second rear support column 82 and inserted into the second rear support column 82.

[0043] The first rear support column 81 and the second rear support column 82 have first length adjustment means 84 for fixing the first rear support column 81 and the second rear support column 82 in a state where the second rear support column 82 protrudes downward from the lower end of the first rear support column 81 by an arbitrary length. The first length adjustment means 84 provided on the first rear support column 81 are a plurality of through holes 85 provided at predetermined intervals along the longitudinal direction of the first rear support column 81 on the side surface of the first rear support column 81. The first length adjustment means 84 provided on the second rear support column 82 is a lock pin 86 that normally protrudes outward from the side surface near the upper end of the second rear support column 82 and can be pushed into the inside of the second rear support column 82.

[0044] Then, with the lock pin 86 pushed into the inside of the second rear support column 82, the second rear support column 82 is inserted into the first rear support column 81 from below. When the lock pin 86 overlaps with any one of the through holes 85 of the first rear support column 81, the lock pin 86 protrudes outward from the side surface of the second rear support column 82 and fits into the through hole 85 of the first rear support column 81, thereby fixing the first rear support column 81 and the second rear support column 82 to each other. That is, by selecting the through hole 85 of the first rear support column 81 into which the lock pin 86 is fitted, the length of the second rear support column 82 protruding from the first rear support column 81 can be adjusted step by step as shown in FIG. 9(b).

[0045] The second rear support column 82 has second length adjustment means 87 for fixing the second rear support column 82 and the third rear support column 83 in a state where the third rear support column 83 protrudes downward from the lower end of the second rear support column 82 by an arbitrary length. The second length adjustment means 87 provided on the second rear support column 82 includes a second length adjustment means fixing portion 88 fixed so as to cover the outer periphery of the lower end of the second rear support column 82, a fulcrum portion 89 fixed to the second length adjustment means fixing portion 88 at a position away from the second rear support column 82 and extending downward, a plate-shaped engaging portion 90 having an engaging hole 91 with a diameter larger than the outer diameter of the third rear support column 83 and rotatably fixed below the fulcrum portion 89, and a contraction portion 93 which is a spring fixed to the second length adjustment means fixing portion 88 and the engaging portion 90 and pulls the engaging portion 90 toward the second length adjustment means fixing portion 88 side.

[0046] Then, as shown in Fig. 10(a), while grasping the tip of the engaging portion 90 and making the engaging portion perpendicular to the longitudinal direction of the second rear support column 82, the third rear support column 83 is inserted into the second rear support column 82 from below so as to pass through the engaging hole 91. By releasing the engaging portion 90, as shown in Fig. 10(b), the engaging portion 90 is pulled toward the second length adjusting means fixing portion 88 by the contracting portion 93, and it bounces obliquely upward 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 inclined engaging portion 90 engages with the side surface of the third rear support column 83, whereby the second rear support column 82 and the third rear support column 83 are fixed to each other. That is, the length of the third rear support column 83 protruding from the second rear support column 82 can be continuously adjusted as shown in Fig. 9(b) according to the position of the side surface of the third rear support column 83 where the edge 92 of the engaging hole 91 of the engaging portion 90 is engaged.

[0047] Also, as shown in Fig. 9, the first rear support column 81 has a rear support column fixing portion 94 at its upper end, and the third rear support column 81 has a rear support column anti-slip portion 95 that functions as an anti-slip for the installation surface 101 at its lower end. The rear support column fixing portion 94 can be detachably fixed to the lower surface of an arbitrary crossbar 3 by a bolt, which is a fixing tool not shown, as shown in Fig. 9(b), and is rotatably fixed to the first rear support column 81 in the same manner as the anti-slip portion 5 is rotatable with respect to the first support column 22. And the rear support column anti-slip portion 95 is composed of an anti-slip surface 96 on which an uneven pattern is formed and is attached to the lower surface thereof.

[0048] As shown in Figs. 11 and 12, the handrail 97 is formed in a substantially U shape by a pair of long bar-shaped main columns 98 and long bar-shaped handrail portions 99 fixed so as to span the respective ends of the pair of main columns 98. A single-pipe connecting clamp 100 is fixed to the other end of each of the pair of main columns 98, and by fixing the connecting clamp 100 to an arbitrary position of the support column 2 of the ladder 1, the handrail 97 can be detachably attached to the ladder 1. Incidentally, the handrail 97 can be freely attached in consideration of the installation environment of the ladder 1, such as being attached symmetrically to the left and right of the ladder 1 or being attached only to one side of the ladder 1.

[0049] Next, the usage method of the ladder 1 according to this embodiment will be described. In the construction work of a building where a floor structure is assembled on a support plane 102 that extends horizontally to form a first-floor floor 103, as shown in FIG. 11, the support plane 102 is used as the installation surface 101 for the worker to move from the first floor to the second-floor height. Also, as shown in FIG. 12, with the first-floor floor 103 as the installation surface 101, the ladder 1 is leaned against the beam 104 spanning the first-floor ceiling at a specified leaning angle 106 and used. Note that the specified leaning angle 106 is the angle determined at the work site where the ladder 1 of the present invention is used. In this embodiment, it is 65 degrees as shown in the figure, and depending on the work site where it is used, it is defined in the range of 45 degrees to 90 degrees.

[0050] Here, the length 105 of the first support column 22 of one of the first ladder units 10a will be described. The length 105 of the first support column 22 of one of the first ladder units 10a shown in FIG. 1 is, as shown in FIG. 12, 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.

[0051] First, the case of using the support plane 102 as the installation surface 101 will be described. The ladder 1 is carried into the work site in a disassembled state into the first ladder unit 10, the second ladder unit 60, the third ladder unit 70, the rear support column 80, and the handrail 97 respectively. Then, as shown in FIG. 11, one of the third ladder units 70a is connected under the second ladder unit 60, the other first ladder unit 10b is connected under the third ladder unit 70, one of the first ladder units 10a is connected under the other third ladder unit 10b, and the rear support column 80 and the handrail 97 are attached at appropriate positions.

[0052] The difference between one of the third ladder units 70a and the other third ladder unit 70b is the length in its longitudinal direction. In this embodiment, one of the third ladder units 70a is used. Note that depending on the required length of the ladder 1, it is possible to select to use the other third ladder unit 70b, to use both third ladder units 70, or to use neither of the third ladder units 70.

[0053] Then, as shown in FIG. 11, the ladder 1 is leaned against the beam 104 spanning the first-floor ceiling with the support plane 102 as the installation surface 101 at a specified leaning angle 106. The rear support column 80 is angled at 108 so that the ladder 1 does not bend backward and extended to the support plane 102. The telescopic part 62 of the second ladder unit 60 is extended upward so that the length 109 by which the ladder 1 protrudes upward from the upper surface of the beam 104 is approximately 60 cm, and the ladder 1 is used. Note that the angle 108 of the rear support column 80 in this embodiment is adjusted to be 75 degrees from the installation surface 101.

[0054] Next, when moving the ladder 1 and using the first-floor floor 103 as the installation surface 101, the connection between one first ladder unit 10a disposed and connected at the lowermost part of the already assembled ladder 1 and the other first ladder unit 10b is released. One first ladder unit 10a is removed, and with the anti-slip part 5 of the other first ladder unit 10b in the deployed state, as shown in FIG. 12, it is leaned against the beam 104 from the first-floor floor 103 at the specified leaning angle 106, and it is only necessary to adjust the length of the rear support column 80 so that the rear support column anti-slip part 95 touches the first-floor floor 103.

[0055] As already described, since the length 105 of the first support column 22 of one first ladder unit 10a is the length from the support plane 102 to the upper surface of the floor 103 at the specified leaning angle 106 at which the ladder 1 is leaned, depending on whether one first ladder unit 10a is connected to the lowermost part of the ladder 1 or not, the ladder 1 can be easily changed between the length with the support plane 102 as the installation surface 101 and the length with the first-floor floor 103 as the installation surface 101.

[0056] Also, when the ladder 1 is installed at the same location for a long time, if necessary, a screw, which is a fixture not shown in the figure, can be driven into the installation surface 101 through the through-hole 55 of the anti-slip part 5 of the first ladder unit 10 disposed at the lowermost part of the ladder 1 to fix the lower end of the ladder 1.

[0057] When the ladder 1 is removed, the ladder 1 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, respectively, and each is carried out from the use site and stored in a storage location.

[0058] In addition, the ladder 1 according to one embodiment includes two first ladder units 10, two third ladder units 70, and two handrails 97. However, the present invention is not limited thereto, and by providing a larger number, the combination patterns of the ladder 1 increase, enabling it to cope with various heights.

[0059] Also, the ladder 1 according to one embodiment is used by being hung on a beam 104 spanning from the first floor to the ceiling of the first floor. However, the present invention is not limited thereto, and regardless of the floor where it is used, the ladder 1 may be hung on other than the beam 104.

Explanation of Reference Numerals

[0060] 1 Ladder 10 First ladder unit 2 Support 21 Rung fixing hole 22 First support 3 Rung 33 Rung fixing part 34 Rung fixing pin 4 Connecting means 41 Protrusion 42 Recess 43 Through hole 44 Pin 5 Anti-slip part 54 Anti-slip surface 60 Second ladder unit 61 Second support 62 Telescopic part 63 Telescopic part 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 strut fixing part 95 Rear strut anti-slip part 96 Rear strut anti-slip surface 97 Handrail 101 Installation surface 102 Support plane 103 Floor 105 Length of one of the first struts 106 Specified leaning angle 107 Length from the support plane to the floor at the specified leaning angle

Claims

1. 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.

2. 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.

3. 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.

4. 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.

5. 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.

6. 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.

7. 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. 8. The ladder of claim 7, further comprising handrails detachable from the posts.

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