Step stool

Abstract

The objective is to provide a step stool that is height-adjustable and easy to manufacture. [Solution] The step stool 10 has a step stool body 11 that is square in plan view, and legs 40 that protrude downward from the four corners of the step stool body 11. The legs 40 are arranged and shaped so that when the lower surfaces of the step stool bodies 11 of two step stools 10 are placed facing each other and their planar shapes are superimposed, the multiple legs 40 can be placed between the upper surfaces (upper surfaces of the top plate portion 12) of the step stool bodies 11 without interfering with each other, resulting in a state where the lower surfaces face each other. Furthermore, the lower surface of the step stool body 11 has a lower surface engagement portion 30 that can receive the lower end of the legs 40 of the other step stool 10 when the lower surfaces face each other.

Description

Technical Field

[0001] The present disclosure relates to a step on which a user can ride.

Background Art

[0002] Conventionally, as this type of step, there is known one whose height can be changed (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

[0014] to

[0016] and FIGS. 1 and 3)

Summary of the Invention

Problems to be Solved by the Invention

[0004] The above-described conventional step has a configuration in which it is deformed to change the height of the step, and a plurality of parts need to be assembled to manufacture one step. In view of this, an object is to provide a step that can change its height and is easy to manufacture.

Means for Solving the Problems

[0005] One aspect of the invention is a step having a step body with a rotationally symmetric or circular planar shape and a plurality of downward protrusions protruding from the lower surface of the step body and abutting on an installation surface, wherein the lower surfaces of the step bodies of two steps are opposed to each other so that their planar shapes overlap, and in a state where the upper surfaces of the step bodies face each other and the plurality of downward protrusions are housed between them, the plurality of downward protrusions of the two steps are arranged with respect to the step body so as not to interfere with each other, and a plurality of first concavo-convex engaging portions that engage with each other in a concavo-convex manner in the state where the lower surfaces face each other are provided.

Effects of the Invention

[0006] According to one embodiment of the invention, a step stool has multiple first protruding and concave engaging parts that engage with each other when the bottom surfaces are facing each other. This allows a user to stand on the step stool when the bottom surfaces are facing each other, and the height of the step stool can be selected depending on whether the step stool is used alone or two step stools are used with the bottom surfaces facing each other. Furthermore, since the height can be adjusted by stacking step stools of the same shape, assembly work of parts is unnecessary during the manufacturing of the step stool, making manufacturing easier. In addition, the height adjustment work is simpler than deforming the step stool. [Brief explanation of the drawing]

[0007] [Figure 1] Figure 1 is a perspective view of the step stool according to the first embodiment. [Figure 2] Figure 2 is a cross-sectional perspective view of the stepping stool. [Figure 3] Figure 3 is a side perspective view of the underside of the step stool. [Figure 4] Figure 4 is a bottom view of the step stool. [Figure 5] Figure 5 is a perspective view of the area near the upper engagement portion. [Figure 6] Figure 6A is a plan cross-sectional view showing the upper step stool positioned in a locking position in a stacked configuration, and Figure 6B is a plan cross-sectional view showing the upper step stool positioned in a locking position in a stacked configuration. [Figure 7] Figure 7 is a side cross-sectional view showing the upper step stool positioned in a retaining position in a stacked configuration. [Figure 8] Figure 8 is a perspective view of the stacked state. [Figure 9] Figure 9 is a perspective view showing the upper step stool in the released position when the stacked stools are in place. [Figure 10] Figure 10A is a plan cross-sectional view showing the upper step stool in the released position in a stacked configuration, and Figure 10B is a plan cross-sectional view showing the upper step stool in the released position in a stacked configuration. [Figure 11] Figure 11 is a side cross-sectional view of the upper step stool in a stacked configuration, positioned in the release position. [Figure 12] Figure 12 is a perspective view of the bottom surface facing forward. [Figure 13] Figure 13 is a perspective view of the area near the lower engagement portion. [Figure 14] FIG. 14 is a plan sectional view of the state where the upper step is arranged at the retaining position in the state of facing the lower surface directly. [Figure 15] FIG. 15 is a side sectional view of the state where the upper step is arranged at the retaining position in the state of facing the lower surface directly. [Figure 16] FIG. 16 is a perspective view of the state where the upper step is arranged at the release position in the state of facing the lower surface directly. [Figure 17] FIG. 17 is a plan sectional view of the state where the upper step is arranged at the release position in the state of facing the lower surface directly. [Figure 18] FIG. 18 is a side sectional view of the state where the upper step is arranged at the release position in the state of facing the lower surface directly. [Figure 19] FIG. 19 is a perspective view of the state where three steps are overlapped at the release position. [Figure 20] FIG. 20 is a side sectional view near the upper surface engaging portion and the lower surface engaging portion of the central step in the state where three steps are overlapped. [Figure 21] FIG. 21 is a perspective view of the leg portion of the step according to the modified example. [Figure 22] FIG. 22 is a perspective view near the engaging protrusion of the step according to the modified example. [Figure 23] FIG. 23 is a perspective view near the upper surface engaging portion of the step according to the modified example. [Figure 24] [[ID=3l]]FIG. 24 is a side sectional view near the step body of the central step in the state where three steps according to the modified example are overlapped.

MODE FOR CARRYING OUT THE INVENTION

[0008] [First Embodiment] Referring to FIGS. 1 to 20, the step 10 of the first embodiment will be described. As shown in FIG. 1, the step 10 has a step body 11 having a square shape in plan view, and leg portions 40 protruding downward from the four corners of the step body 11. The step 10 of the present embodiment is made of synthetic resin (for example, polypropylene, polyethylene, etc.).

[0009] As shown in Figures 1 and 2, the step stool body 11 has a top plate 12, a plurality of vertical walls 15 hanging down from the top plate 12, a plurality of horizontal walls 16 projecting laterally from each vertical wall 15, and a plurality of ribs 20. The inner region 12B of the top plate 12 is lower by the thickness of 1 to 3 plates than the outer edge 12A. The upper surface of the inner region 12B of the top plate 12 is divided into a plurality of square regions 12C arranged diagonally, and each square region 12C has a plurality of protrusions 12D formed along one side of the square region 12C. In the plurality of square regions 12C, the direction in which the protrusions 12D extend differs for each adjacent square region 12C. This prevents slipping in two directions when the user steps onto the step stool 10. Furthermore, because the outer edge 12A of the top plate 12 is raised, it becomes easier to notice when a user shifts on the step stool 10 and reaches the outer edge 12A, making it less likely for the user to fall.

[0010] Multiple vertical walls 15 are positioned inward from the outer edge of the top plate portion 12 by a length of approximately 1 / 6 to 1 / 5 of the length of each side of the top plate portion 12, and extend approximately parallel to each side of the top plate portion 12. Each vertical wall 15 protrudes downward from a range opposite to approximately the central 1 / 3 of each side of the top plate portion 12. Opposing vertical walls 15 are connected by multiple connecting vertical ribs 20A included in multiple ribs 20. The multiple connecting vertical ribs 20A hang down from the top plate portion 12, and their lower ends are located above the lower ends of the multiple vertical walls 15.

[0011] As shown in Figures 2 and 3, the multiple horizontal walls 16 protrude outward from the lower end of each vertical wall 15. These horizontal walls 16 extend around the entire circumference of the step stool 10, excluding parts of each corner. Between the top plate 12 and the horizontal walls 16, horizontal ribs 21, which are part of the multiple ribs 20, are provided protruding from the vertical walls 15. The horizontal ribs 21 extend around the entire circumference of the step stool 10. The step stool body 11 also includes multiple vertical ribs 22, which connect the top plate 12, the horizontal ribs 21, and the horizontal walls 16, as multiple ribs 20. The end faces of the top plate 12, the horizontal walls 16, the horizontal ribs 21, and the vertical ribs 22 are flush with each other.

[0012] As shown in Figure 3, the leg portion 40 protrudes downward from the side wall 16 of the step stool body 11 and has a right-angled triangular shape in plan view. In detail, the leg portion 40 has a first leg portion side wall 41 that extends diagonally inward from the corner portion of the step stool body 11, and a second leg portion side wall 42 that extends parallel to one side of the step stool body 11 from near the inner end of the first leg portion side wall 41 to the outer edge of the square shape of the step stool body 11 in plan view. The corner between the first leg portion side wall 41 and the second leg portion side wall 42 is a curved portion 43.

[0013] The inner surfaces of the first leg side wall 41 and the second leg side wall 42 are connected by two triangular transverse ribs 44 parallel to the transverse wall 16. The transverse rib 21, the transverse wall 16, and the two triangular transverse ribs 44 are connected by a leg longitudinal rib 45 parallel to the second leg side wall 42. The outer end faces of the first leg side wall 41 and the second leg side wall 42, and the end faces of the two triangular transverse ribs 44 and the leg longitudinal rib 45 are flush and arranged in substantially the same plane as the outer end face of the top plate portion 12, and the outer surface 46 (corresponding to the "first side") which is one side of the leg portion 40 is formed from these end faces.

[0014] Figure 4 shows a view of the step stool 10 from below, with the hatched area representing the lowest end surface of the step stool 10. As shown in Figure 4, each leg 40 is arranged with 90-degree rotational symmetry. Furthermore, the first leg side wall 41 of each leg 40 is offset from the diagonal of the square planar shape of the step stool body 11 toward the second leg side wall 42. More specifically, the first leg side wall 41 of each leg 40 is located in a plane tilted 3.5° toward the second leg side wall 42 with the center of the step stool body 11 as the pivot point from the diagonal. As a result, all four legs 40 are positioned adjacent to each other in a counterclockwise direction in Figure 4, relative to the diagonal of the step stool body 11.

[0015] As shown in Figures 2 and 3, in the leg portion 40, below the lower triangular transverse rib 44, the portion on the outer surface 46 side is cut out to form a stepped portion 47. In addition, an engaging projection 50 is provided at the lower end of each leg portion 40, protruding from the outer surface of the second leg portion side wall 42. The engaging projection 50 has an open, roughly rectangular parallelepiped shape on the outer surface 46 side, and its upper surface is located below the lower triangular transverse rib 44. On the side of the upper surface of the engaging projection 50 opposite the second leg portion side wall 42, a locking projection 50T (see Figure 7) is provided that protrudes upward. Furthermore, as shown in Figures 3 and 10, a tapered portion 50B is formed on the inner portion of the projection side wall 50A of the engaging projection 50 that faces the second leg portion side wall 42.

[0016] Furthermore, as shown in Figures 3 and 4, a lower end recess 55 is formed at the lower end of the leg portion 40, opening into the first leg portion side wall 41 and the lower surface of the leg portion 40. The lower end recess 55 has a rectangular side opening 55A located in the center of the lower end of the first leg portion side wall 41, and a lower surface opening 55B located on the lower surface of the leg portion 40. The lower surface opening 55B has a shape that combines a roughly rectangular shape sharing one side with the lower side of the side opening 55A, and a roughly triangular shape sharing one side with the side of the roughly rectangular shape opposite to the first leg portion side wall 41. The lower surface opening 55B is slightly curved along an arc centered on the center of the step stool body 11, and correspondingly the inner surface of the lower end recess 55 is also curved. The bottom surface (top surface) of the lower end recess 55 is composed of a lower triangular transverse rib 44, and a plurality of ribs 55L are formed protruding from this bottom surface.

[0017] Furthermore, as shown in Figure 3, the horizontal wall 16 and the second leg side wall 42 are connected by a diagonally extending first reinforcing wall 60A, and the vertical wall 15 extends to the first reinforcing wall 60A. In addition, the leg portion 40 has a second reinforcing wall 60B that extends inward from the lower end of the first leg side wall 41, and a third reinforcing wall 60C that extends parallel to the second reinforcing wall 60B from the connection point between the second leg side wall 42 and the curved portion 43. The second reinforcing wall 60B and the third reinforcing wall 60C are connected to the lower surface of the top plate portion 12 and the connecting vertical rib 20A. Furthermore, the ends of the second reinforcing wall 60B and the third reinforcing wall 60C are connected by a curved rib 60D, and the connection point between the third reinforcing wall 60C and the curved rib 60D and the vertical wall 15 is connected by a connecting rib 60E.

[0018] As shown in Figure 1, an upper surface engagement portion 25 is provided on the upper surface of the step stool body 11 at a position above the multiple legs 40. The upper surface engagement portion 25 is a recess formed in the upper surface of the step stool body 11, and has a through hole 12K formed in the top plate portion 12 as an opening, with the upper surface of the horizontal rib 21 forming the bottom surface 25A of the upper surface engagement portion 25.

[0019] As shown in Figures 5 and 6, the planar shape of the upper engagement portion 25 is the area obtained by projecting the cross-sectional shape of the leg portion 40 directly upward and extending it toward the first leg portion side wall 41. More specifically, the planar shape of the upper engagement portion 25 is the portion of the area obtained by projecting the cross-sectional shape of the leg portion 40 directly upward that corresponds to the first leg portion side wall 41, rotated outward by approximately 5° to 10° (7° in this embodiment (3.5° from the diagonal of the step stool body 11). It may be greater than 10°, but 10° or less is preferable) with the center of the step stool body 11 as the pivot point. The upper engagement portion 25 has a first inner surface 25B that extends along the outer edge of the step stool body 11, a second inner surface 25C which is a portion rotated from the portion corresponding to the first leg side wall 41 described above, and a third inner surface 25D that extends from the inner end of the second inner surface 25C to a position corresponding to the inner end of the second leg side wall 42, which has the cross-sectional shape of the leg portion 40. In addition, a protruding wall 25E slightly protrudes from the end of the first inner surface 25B opposite to the second inner surface 25C toward the third inner surface 25D.

[0020] The upper engagement portion 25 is provided with recessed internal projections 26 that protrude from the bottom surface 25A and the second inner surface 25C. The recessed internal projections 26 are sized and shaped to fit perfectly into the lower end recess 55 of the leg portion 40. The recessed internal projections 26 have a pair of opposing side walls 26A that protrude from the second inner surface 25C, and a tip component wall 26B that extends from the tips of the pair of opposing side walls 26A, moving closer to each other. The pair of opposing side walls 26A are slightly curved along an arc centered on the center of the step stool body 11. Furthermore, the ends of the outer opposing side walls 26A and the position near the end of the inner opposing side walls 26A are connected by a connecting wall 26C, and a protruding ceiling wall 26D, to which the top plate portion 12 is extended, is provided on the upper surface of the portion partitioned by the second inner surface 25C, the pair of opposing side walls 26A, and the connecting wall 26C. The upper surface of the protruding ceiling wall 26D is flush with the upper end surfaces of the pair of opposing side walls 26A and the connecting wall 26C. Additionally, an extended projection 26E, which is an extension of the projection 12D of the top plate portion 12, is positioned on the upper surface of the protruding ceiling wall 26D. The extended projections 26E of each upper surface engaging portion 25 extend along their respective opposing side walls 26A. The height between the bottom surface 25A of the upper surface engaging portion 25 and the upper surface of the protruding ceiling wall 26D is approximately the same as the height between the lower end of the leg portion 40 and the bottom surface of the rib 55L of the bottom surface of the lower end recess 55.

[0021] As shown in Figures 5 and 6, the upper engagement portion 25 is provided with a lateral recess 27 that communicates laterally through a side opening 27K between the end of the third inner surface 25D and the protruding wall 25E. The lateral recess 27 is covered from above by the top plate portion 12. As shown in Figures 6 and 7, a locking projection 27A is provided within the lateral recess 27, protruding from the lower surface of the top plate portion 12. The locking projection 27A is positioned such that its distance from the side opening 27K is slightly shorter than the distance between the second leg side wall 42 of the leg portion 40 and the locking projection 50T of the engagement portion 50. Furthermore, the lower end of this locking projection 27A is located between the upper surface of the engagement portion 50 and the upper end of the locking projection 50T when the leg portion 40 of another step stool 10 is grounded on the bottom surface 25A of the upper engagement portion 25.

[0022] As shown in Figure 8, when the step stools 10 are stacked, each leg 40 of the upper step stool 10 engages with each upper engagement portion 25 of the lower step stool 10, stabilizing the stacked state. The method for stacking the step stools 10 will be described below.

[0023] Since the leg portion 40 is provided with an engaging projection 50 that protrudes from the second leg portion side wall 42, if the upper step 10 is lowered toward the lower step 10 with the planar shape of the upper step 10 aligned with the planar shape of the lower step 10, the engaging projection 50 interferes with the top plate portion 12 of the lower step 10, preventing the leg portion 40 of the upper step 10 from being received by the upper engaging portion 25 of the lower step 10. Therefore, first, as shown in Figure 9, the upper step 10 is rotated counterclockwise by about 5° to 10° (7° in this embodiment) in the horizontal plane relative to the lower step 10, and then the upper step 10 is lowered toward the lower step 10, allowing the leg portion 40 of the upper step 10 to be received by the upper engaging portion 25 of the lower step 10.

[0024] At this time, the second inner surface 25C of the upper engagement portion 25 is positioned so that the portion corresponding to the first leg side wall 41 in the area obtained by projecting the cross-sectional shape of the leg portion 40 directly upward is rotated outward by approximately 5° to 10° (7° in this embodiment) with the center of the step stool body 11 as the pivot point. By placing the first leg side wall 41 of the leg portion 40 of the upper step stool 10 against this second inner surface 25C, the leg portion 40 of the upper step stool 10 can be smoothly received by the upper engagement portion 25 of the lower step stool 10. Furthermore, since a tapered portion 50B is formed on the inner part of the projection side wall 50A of the engagement projection 50, interference between the engagement projection 50 and the top plate portion 12 is prevented. Hereafter, the position of the upper step stool 10 in this state will be referred to as the "release position".

[0025] Furthermore, when the first leg side wall 41 of the leg portion 40 of the upper step 10 is in surface contact with the second inner surface 25C of the upper engagement portion 25 of the lower step 10, the recessed internal projection 26 of the lower step 10 is received by the lower end recess 55 of the upper step 10. Moreover, as shown in Figures 10B and 11, the rib 55L of the lower end recess 55 of the upper step 10 comes into contact with the extended projection 26E of the projection ceiling wall 26D of the recessed internal projection 26, causing the lower end surface of the leg portion 40 to float above the bottom surface 25A of the upper engagement portion 25.

[0026] Next, the upper step stool 10 is rotated clockwise to align the planar shapes of the upper step stool 10 and the lower step stool 10 as shown in Figure 8. Then, the engaging projection 50 of the upper step stool 10 enters the lateral recess 27 through the side opening 27K. The locking projection 50T of the engaging projection 50 then overcomes the locking projection 27A in the lateral recess 27 and faces it from the outside, and the locking projections 27A and 50T lock together. Hereafter, the position of the upper step stool 10 in this state will be referred to as the "removal position".

[0027] When the upper step stool 10 is positioned in the locking position, the legs 40 of the upper step stool 10 are received by the upper engagement portion 25 of the lower step stool 10, restricting lateral movement. At the same time, the engagement projection 50 of the upper step stool 10 is received by the lateral recess 27 of the upper engagement portion 25, facing the top plate 12 and restricting vertical movement between the two step stools 10. Furthermore, the locking projections 27A and 50T engage with each other, preventing the upper step stool 10 from moving to the release position.

[0028] Furthermore, in the release position, the rib 55L in the lower end recess 55 of the upper step 10 abuts against the extension ridge 26E in the recessed projection 26 of the lower step 10, causing the lower end surface of the leg portion 40 to be lifted from the bottom surface 25A of the upper engagement portion 25. However, in the locking position, the upper step 10 lowers slightly so that the rib 55L abuts against the upper surface of the tip component wall 26B of the recessed projection 26, and the lower end surface of the leg portion 40 abuts against the bottom surface 25A of the upper engagement portion 25. Furthermore, in the locking position, the stepped portion 47 of the leg portion 40 of the upper step 10 abuts against the outer edge portion 12A of the top plate portion 12 of the lower step 10 (specifically, the opening edge of the through hole 12K), and the portion of the outer surface 46 of the leg portion 40 of the upper step 10 below the stepped portion 47 abuts against the first inner surface 25B of the upper engagement portion 25 of the lower step 10.

[0029] When disassembling the two step stools 10, the upper step stool 10 is rotated counterclockwise, retracting the engaging projection 50 from the lateral recess 27, which allows the upper step stool 10 to be lifted from the lower step stool 10.

[0030] Now, in this embodiment, as described above, all the legs 40 of the step stool 10 are positioned adjacent to each other in a counterclockwise direction with respect to the diagonal of the step stool body 11. Therefore, as shown in Figure 12, when the lower surfaces of the step stool bodies 11 of two step stools 10 are placed facing each other and their planar shapes are superimposed, it is possible to fit multiple legs 40 between the upper surfaces (upper surfaces of the top plate portion 12) of the step stool bodies 11 without interfering with each other. Hereafter, the state shown in Figure 12 will be referred to as the "underside facing state". The underside of the step stool body 11 has an underside engaging portion 30 (see Figure 13) that can receive the lower end of the leg 40 of the other step stool 10 in the underside facing state.

[0031] As shown in Figures 4 and 13, the lower engagement portion 30 is formed by an upward recess in the portion of the lower surface (including the side wall 16) of the step stool body 11 adjacent to each leg portion 40, and the lower surface of the transverse rib 21 constitutes the bottom surface 30A (top surface). As shown in Figure 14, the planar shape of the lower engagement portion 30 is such that the region overlapping with the leg portion 40 of the inverted step stool 10 is extended to the first leg portion side wall 41 of the leg portion 40, and is substantially the same as the planar shape of the upper engagement portion 25. The lower engagement portion 30 has a first inner surface 30B that extends along the outer edge of the step stool body 11, and a second inner surface 30C which is formed by the upward extension of the first leg portion side wall 41. In addition, a protruding wall 30E slightly protrudes inward from the end of the first inner surface 30B opposite to the second inner surface 30C.

[0032] As a result, the arrangement and shape of the four legs 40, the lower engagement portion 30, and the upper engagement portion 25 of the step stool 10 are rotationally symmetrical by 90 degrees. Furthermore, the arrangement and shape of the lower engagement portion 30 and the upper engagement portion 25 are asymmetrical in the horizontal direction along the outer edge of the step stool body 11.

[0033] As shown in Figures 13 and 14, the lower engagement portion 30, like the upper engagement portion 25, is provided with a recessed projection 35 and a lateral recess 32. The recessed projection 35 protrudes inward from the second inner surface 30C of the lower engagement portion 30 and has substantially the same outer shape as the recessed projection 26 of the upper engagement portion 25, so as to fit perfectly into the lower end recess 55 of the leg portion 40. The recessed projection 35 has a pair of opposing side walls 35A protruding from the second inner surface 30C, and a tip-forming wall 35B extending from the tips of the pair of opposing side walls 35A while moving closer to each other. The positions of the pair of opposing side walls 35A near the tip-forming wall 35B are connected by a connecting wall 35C. The recessed projection 35 of the lower engagement portion 30 is open downward, and the lower ends of the opposing side walls 35A and the tip-forming wall 35B are located substantially in the same plane as the lower surface of the side wall 16. Furthermore, the lower end of the connecting wall 35C is located above the lower ends of the opposing side wall 35A and the tip component wall 35B. The height between the bottom surface 30A of the lower engagement portion 30 and the lower ends of the opposing side wall 35A and the tip component wall 35B is approximately the same as the height between the lower end of the leg portion 40 and the lower surface of the rib 55L on the bottom surface of the lower end recess 55.

[0034] Furthermore, the vertical wall 15 and horizontal wall 16 of the step stool body 11 are located on the opposite side of the leg portion 40, with the lower engagement portion 30 in between. The lower engagement portion 30 is provided with a lateral recess 32 that communicates laterally through a side opening 32K between the protruding wall 30E and the vertical wall 15. The lateral recess 32 is covered from below by the horizontal wall 16. As shown in Figures 14 and 15, a locking projection 32A protruding from the upper surface of the horizontal wall 16 is provided inside the lateral recess 32.

[0035] To position the two step stools 10 facing each other from below, first, one step stool 10 (hereinafter referred to as the lower step stool 10) is inverted and placed on the ground or floor. Then, as shown in Figure 16, the other step stool 10 (hereinafter referred to as the upper step stool) is rotated counterclockwise by approximately 5° to 10° (7° in this embodiment) in the horizontal plane relative to the lower step stool 10, and the upper step stool 10 is lowered toward the lower step stool 10, with the legs 40 of the upper step stool 10 being received by the underside engaging portion 30 of the lower step stool 10. At this time, the legs 40 of the lower step stool 10 are also received by the underside engaging portion 30 of the upper step stool 10.

[0036] At this time, as shown in Figures 16 and 17, by aligning the first leg side wall 41 of the leg 40 of the upper step 10 with the first leg side wall 41 of the leg 40 of the lower step 10 and the second inner surface 30C of the lower engagement portion 30, the leg 40 of the upper step 10 can be smoothly received by the lower engagement portion 30 of the lower step 10. The tapered portion 50B prevents the engagement projection 50 from interfering with the side wall 16. Hereafter, the position of the upper step 10 in this state will be referred to as the "release position".

[0037] Furthermore, as shown in Figure 17, when the first leg side wall 41 of the leg portion 40 of the upper step 10 is in surface contact with the second inner surface 30C of the lower surface engaging portion 30 of the lower step 10, the recessed inner projection 35 of the lower step 10 is received by the lower end recess 55 of the upper step 10. In addition, in this state, as shown in Figure 18, the rib 55L of the lower end recess 55 of the upper step 10 abuts against the upper end surface of the recessed inner projection 35, and the lower end surface of the leg portion 40 abuts against the bottom surface 30A of the lower surface engaging portion 30. The leg portion 40 of the lower step 10 and the lower surface engaging portion 30 of the upper step 10 are in the same state.

[0038] Next, the upper step stool 10 is rotated clockwise to align the planar shapes of the upper step stool 10 and the lower step stool 10 as shown in Figure 12. As a result, the engaging projection 50 of the upper step stool 10 enters the lateral recess 32 of the lower step stool, and the engaging projection 50 of the lower step stool 10 enters the lateral recess 32 of the upper step stool. Then, the locking projection 50T of the engaging projection 50 overcomes the locking projection 32A in the lateral recess 32 and faces it from the outside, and the locking projections 32A and 50T lock together. Hereafter, the position of the upper step stool 10 in this state will be called the "locking position".

[0039] When positioned in the locking position, the legs 40 of the upper step 10 are received by the recessed projection 35 of the lower step 10, preventing lateral movement. At the same time, the engaging projections 50 of each step 10 are received by the lateral recesses 32 of the lower engaging portion 30 of the other step 10, facing the top plate 12 and preventing the steps 10 from unintentionally moving vertically. Furthermore, the locking projections 32A and 50T engage with each other, preventing the upper step 10 from unintentionally moving to the release position. In addition, the portion of the opening edge of the lower engaging portion 30 corresponding to the outer edge of the step body 11 is an outer edge projection 30T that protrudes downward from the side wall 16, and in the locking position, the stepped portion 47 of the legs 40 of each step 10 abuts against the outer edge projection 30T of the other step 10.

[0040] When disassembling the two step stools 10, the upper step stool 10 is rotated counterclockwise, retracting the engaging projection 50 from the lateral recess 32, which allows the upper step stool 10 to be lifted from the lower step stool 10.

[0041] Thus, the way the step stools 10 are moved (direction of rotation and amount of rotation) when the two step stools 10 are facing each other from below and when they are separated from that position is approximately the same as the way the upper step stool 10 is moved when the stacked step stools are assembled and when they are separated from that position.

[0042] Furthermore, the 25C side portion of the upper engagement portion 25 and the second inner surface 30C side portion of the lower engagement portion 30 are aligned vertically. As shown in Figures 19 and 20, when one step stool 10 (hereinafter referred to as the central step stool 10) is stacked on top of another step stool 10 (referred to as the upper step stool 10) in a stacked manner, and another step stool 10 (referred to as the lower step stool 10) is stacked below it with its bottom surface facing directly forward, and both are positioned in the release position, the legs 40 of the upper step stool 10 and the legs 40 of the lower step stool 10 overlap in a plan view. When one of the upper or lower step stools 10 is rotated to the locking position from this state, the legs 40 of the upper step stool 10 and the legs 40 of the lower step stool 10 no longer overlap in a plan view. In other words, the portion of the upper engagement portion 25 that receives the leg portion 40 at the locking position and the lower engagement portion 30 do not overlap in a plan view, and the portion of the lower engagement portion 30 that receives the leg portion 40 at the locking position and the upper engagement portion 25 do not overlap in a plan view. Furthermore, since the rotation direction for locking and releasing is the same in the downward facing state and the stacked state, when stacking three step stools 10 as shown in Figure 19, rotating the upper step stool 10 relative to the middle step stool 10 and then rotating the upper step stool 10 will cause the middle step stool 10 to rotate relative to the lower step stool 10. In other words, the locking and releasing of the three step stools 10 can be switched by rotating only the upper step stool 10.

[0043] Next, the effects and advantages of the step stool 10 of this embodiment will be described. The step stool 10 of this embodiment allows the height of the step stool to be selected depending on whether it is used as a single step stool, with its bottom facing forward, or in a stacked configuration. Furthermore, it is possible to stack more step stools 10 on top of the one in the bottom-facing or stacked configuration, so the step stool can be adjusted to the required height. In addition, when not using multiple step stools 10, they can be stored compactly by placing them in the bottom-facing configuration.

[0044] In this way, the height of the step stool 10 can be changed by stacking multiple step stools 10, eliminating the need for assembly work of parts required when manufacturing a deformable step stool, thus simplifying manufacturing. Also, since the height can be changed by stacking identical step stools 10, the height adjustment work is simpler than when deforming the step stool.

[0045] Furthermore, since the step stool 10 has legs 40, upper engagement portion 25, and lower engagement portion 30 arranged in a 90° rotational symmetry, the step stool 10 can be stacked or positioned facing downwards at any of the 90° rotational positions, making it easy to align the step stools with each other.

[0046] Furthermore, in the step stool 10, each leg 40 is positioned at one of the four corners of the step stool body 11, close to one side of the diagonal. This allows the step stools to engage with each other when facing each other from below, while also providing greater stability when standing on the step stool 10 compared to when the legs 40 are positioned at the four corners of the step stool body 11 and inside the step stool body 11.

[0047] Furthermore, in both the downward-facing and stacked configurations, at the locking position, the lower end of the leg portion 40 of the upper step stool 10 abuts against the bottom surface 30A, 25A of the lower surface engaging portion 30 or upper surface engaging portion 25 of the lower step stool 10. As a result, the load received by the step stool body 11 of the upper step stool 10 is transmitted to the lower step stool 10 via the leg portion 40, making it less likely for the load to concentrate on the leg portion 40 and preventing damage to the step stool 10. In addition, the load-bearing capacity is also improved by the contact between the rib 55L in the lower end recess 55 of the upper step stool 10 and the upper end surface of the recessed internal projection 26.

[0048] Furthermore, when stacking the step stools 10, the rib 55L of the upper step stool 10 contacts the extended projection 26E of the recessed internal projection 26 of the lower step stool 10, and the lower end surface of the leg portion 40 is lifted off the bottom surface 25A of the upper engagement portion 25. As the upper step stool 10 is rotated from the release position to the locking position, friction is reduced compared to when the leg portion 40 of the upper step stool 10 is in full contact with the bottom surface 25A of the upper engagement portion 25, making the rotation easier. In addition, the opposing side walls 26A, 35A of the recessed internal projections 26, 35 and the inner wall of the lower end recess 55 are curved, which acts as a guide for rotation and improves workability.

[0049] Incidentally, it is also conceivable to configure the upper and lower retaining mechanisms for the step stools 10 to be sized to just receive the lower engaging portion 30 or upper engaging portion 25, so that the leg portion 40 and the lower engaging portion 30 or upper engaging portion 25 engage by friction. However, if friction engagement is used, there is a concern that the leg portion 40 of the upper step stool 10 may get stuck when inserting it into the lower engaging portion 30 or upper engaging portion 25, preventing it from being pushed in all the way. In contrast, according to this embodiment, the upper and lower retaining mechanisms are achieved by abutting the upper step stool 10 against the lower step stool 10 and then rotating it in the horizontal plane, making it easier to abut the step stools 10 against each other and making it easier to transfer the load on the upper step stool 10 to the lower step stool 10.

[0050] Furthermore, the upper engagement portion 25 is provided with a recessed internal projection 26, and the opening of the upper engagement portion 25 is made smaller, making it difficult for the user's foot to get caught in the upper engagement portion 25, allowing for stable footing on the step stool 10.

[0051] [Other embodiments] In the above embodiment, the planar shape of the step stool 10 was a square, but it may be a rectangle, another rotationally symmetric shape such as a regular polygon, or a circle.

[0052] In the above embodiment, an engaging projection 50 protrudes from the leg portion 40, and lateral recesses 27 and 32 are formed in the upper engaging portion 25 and the lower engaging portion 30. However, the upper engaging portion 25 and the lower engaging portion 30 may be provided with projections, and the leg portion 40 may be provided with recesses that engage with these projections in the vertical direction.

[0053] In the above embodiment, the legs 40 were configured to engage with the lower surface of the step stool body 11 when facing downwards. However, for example, protrusions and recesses may be provided on the sides of the legs 40 so that the sides of the legs 40 engage with each other in a concave-concave-concave manner.

[0054] In the above embodiment, one of the steps 10 was rotated to prevent it from coming off, but it may also be configured to move in a straight line.

[0055] In the above embodiment, the detachment of the steps 10 was prevented by rotating one step 10 to engage the protrusions and recesses. However, the leg portion 40 of one step 10 may be inserted from above and engage by friction. Alternatively, an elastic piece may be provided on one of the leg portion 40 and the upper engaging portion 25 or lower engaging portion 30, while an engaging portion that engages with the elastic piece may be provided on the other, so that when the leg portion 40 is inserted from above, they engage with each other. Furthermore, magnets or the like may be fixed and detachment may be prevented by magnetic force. Similarly, in the above embodiment, the rotation of the steps 10 was restricted by the locking of the locking protrusions 27A and 50T, but it may also be restricted by friction, elastic pieces, or magnetic force.

[0056] In the above embodiment, the upper engaging portion 25 and the lower engaging portion 30 were recessed, but for example, the step stool body 11 may be configured with a hood portion on the upper or lower surface that can receive the engaging projection 50 from the side.

[0057] As shown in Figure 21, the engaging projection 50 may be located not at the lower end of the leg portion 40, but in the middle portion (preferably closer to the lower end).

[0058] Furthermore, as shown in Figures 21 and 22, a tapered portion 50K may be formed on the lower surface of the engaging projection 50. In this case, when the leg portion 40 of the upper step 10 is received by the upper engaging portion 25 or lower engaging portion 30 of the lower step 10, even if the leg portion 40 is displaced from the release position, the tapered portion 50K will contact the opening edge of the upper engaging portion 25 or lower engaging portion 30, guiding the leg portion 40 to the release position. In the examples shown in Figures 21 and 22, the inclination angle of the tapered portion 50K gradually increases from the outside to the inside, making it easier for the outer portion of the tapered portion 50K to contact first and then be guided to rotate toward the release position.

[0059] As shown in Figures 23 and 24, the portion of the transverse rib 21 where the upper engaging portion 25 and the lower engaging portion 30 overlap may be passed through, so that the bottom surface 30A of the lower engaging portion 30 is positioned above the bottom surface 25A of the upper engaging portion 25. In this case, when stacking the three steps 10 as shown in Figure 19, the legs 40 of one step 10 (the lower step 10 in the example shown in Figure 24) are placed in the locking position, and then the legs 40 of the other step 10 (the upper step 10 in the example shown in Figure 24) are received in the release position and rotated, thereby allowing the three steps 10 to overlap without the legs 40 of both steps interfering with each other.

[0060] In the above embodiment, when two step stools 10 are stacked, the stacked state is higher than the state where the bottom surfaces face forward. However, the dimensions of the legs 40, upper engagement portion 25, and lower engagement portion 30 may be designed so that the stacked state is lower. Since multiple step stools 10 can be stacked in the stacked state, the height can be finely adjusted depending on the number of step stools 10 by lowering the height of the stacked state.

[0061] Engaging parts that can engage the upper surfaces of the step stool 10 may be provided. For example, it is conceivable to provide multiple hood parts that protrude upward from the top plate 12 and multiple engaging claw parts that engage with the hood parts. By positioning the engaging claw parts so that they do not protrude from the upper surface of the top plate 12, it is possible to suppress contact between the mounting surface and the engaging claw parts.

[0062] Multiple recessed projections 26 may be made thinner and installed, and multiple lower end recesses 55 may also be installed corresponding to the recessed projections 26. Alternatively, the recessed projections 26 may be extended toward the protruding wall 25E to cross the upper engagement portion 25, and the lower end recess 55 may also be extended to separate the lower end of the leg portion 40. In these cases, it becomes more difficult for the user's foot to get caught in the upper engagement portion 25.

[0063] In the above embodiment, a projection (extension ridge 26E) was provided only on the projection 26 inside the recess of the upper engagement portion 25. However, a projection may also be provided on the projection 35 inside the recess of the lower engagement portion 30, so that when facing downwards, in the release position, the rib 55L in the lower end recess 55 of the step stool 10 abuts against the projection of the opposing step stool 10, causing the lower end surface of the leg portion 40 to be lifted from the bottom surface 30A of the lower engagement portion 30.

[0064] An anti-slip member may be installed on the lower end surface of the leg portion 40. In this case, the extension ridge 26E or the aforementioned protrusion will cause the lower end surface of the leg portion 40 to be lifted from the bottom surfaces 25A and 30A of the upper engaging portion 25 and lower engaging portion 30 when in the released position, thereby preventing obstruction of rotation and suppressing wear of the anti-slip member.

[0065] In the above embodiment, the upper engagement portion 25 was designed to be just the right size to accommodate the leg portion 40, but it may be made larger than the leg portion 40, or a tapered guide portion may be provided on the upper edge.

[0066] The depth of the upper engagement portion 25 and the thickness of the engagement projection 50 of the leg portion 40 may be reduced. A shallower upper engagement portion 25 further prevents the user's foot from getting caught.

[0067] In the above embodiment, the step stool 10 was made of synthetic resin (for example, polypropylene, polyethylene, etc.), but it may be made of a different material such as metal, or manufactured by combining parts made of different materials. For example, the engaging projection 50 and the hood part may be made of metal and attached to the step stool made of synthetic resin.

[0068] <Note> The following describes the features extracted from the above embodiment, explaining their effects and other aspects as needed. For ease of understanding, corresponding configurations in the above embodiment will be indicated in parentheses as appropriate, but these features are not limited to the specific configurations indicated in parentheses.

[0069] [Feature 1] A step stool (10) having a step stool body (11) with a rotationally symmetric or circular planar shape, and a plurality of downward projections (40) that protrude from the lower surface of the step stool body (11) and abut against the installation surface, The lower surfaces of the two step stools (10) are facing each other, their planar shapes overlapping, and the multiple downward projections (40) are positioned so that they do not interfere with each other when the lower surfaces are facing each other, with the multiple downward projections (40) of the two step stools (10). A step stool (10) is provided with a plurality of first recessed and recessed engaging parts (40, 30) that engage with each other in a recessed and recessed manner when the lower surfaces are facing each other.

[0070] With the step stool of Feature 1, multiple first interlocking parts engage with each other when the bottom surfaces are facing each other, allowing a user to stand on the step stool when the bottom surfaces are facing each other. The height of the step stool can be selected depending on whether it is used alone or two step stools are used facing each other from below. In addition, since the height can be adjusted by stacking step stools of the same shape, assembly work of parts is unnecessary during the manufacturing of the step stool, making manufacturing easier. Furthermore, the height adjustment work is simpler than deforming the step stool.

[0071] [Feature 2] The plurality of downward projections (40) are a plurality of legs (40) extending downward from the step stool body (11), The step stool (10) according to Feature 1, wherein the plurality of first recessed and recessed engaging portions (40, 30) include a plurality of leg lower end engaging portions (40) provided at the lower end of the leg portion (40) and a plurality of body lower surface engaging portions (30) provided on the lower surface of the step stool body (11).

[0072] According to the step stool of Feature 2, when facing directly downwards, the load received by the step stool body of the upper step stool is transmitted to the step stool body of the lower step stool via the legs, thus reducing the concentration of load on the legs and preventing damage to the step stool. Note that "lower end" includes not only the very bottom but also positions close to the lower end.

[0073] [Feature 3] The step stool (10) according to feature 2, wherein the plurality of first recessed and recessed engaging portions (40, 30) are structured to prevent them from coming loose in the vertical direction when facing the lower surface.

[0074] According to the step stool of Feature 3, multiple first interlocking parts are secured in the vertical direction, preventing unintended disengagement when using it with the bottom surface facing directly forward.

[0075] [Feature 4] The step stool (10) according to feature 3, wherein the plurality of first protruding and recessed engaging portions (40, 30) are prevented from coming off in the vertical direction by abutting the plurality of downward projections (40) against each other on the step stool body (11) and then shifting them horizontally.

[0076] [Feature 5] One of the leg lower end engaging portion (40) and the main body lower surface engaging portion (30) is provided with a lateral projection (50) that protrudes laterally. The step stool (10) according to feature 4, wherein the other of the leg lower end engaging portion (40) and the main body lower surface engaging portion (30) is capable of receiving the lateral projection (50) from the side, and the step stool (10) is provided with a lateral open receiving portion (32) that engages with the lateral projection (50) in an indented and concave direction in the vertical direction by abutting the plurality of downward projections (40) against each other on the step stool body (11) and then shifting them horizontally.

[0077] The first interlocking part can be prevented from coming loose by, for example, a configuration in which a downward projection inserted from above and below into a recess provided in the step stool body engages by friction. However, in this case, the downward projection may get stuck halfway within the recess. In contrast, with the step stools of features 4 and 5, the first interlocking part is prevented from coming loose by butting the step stools together and then shifting them horizontally. This makes it easier to bring the step stools together than in the former case, and allows the load on the upper step stool to be transferred to the lower step stool.

[0078] [Feature 6] The step stool (10) according to feature 4 or 5, wherein the plurality of first protruding and recessed engaging parts (40, 30) are locked together and have locking parts (50T, 32A) that restrict relative movement from a locking position where they are prevented from coming out in the vertical direction to a release position where they are released.

[0079] With the step stool of Feature 6, the first grooved engagement part is prevented from unintentionally moving from the locking position to the release position.

[0080] [Feature 7] The plurality of downward projections (40) are a plurality of legs (40) extending downward from the step stool body (11), The plurality of first recessed and recessed engaging portions (40, 30) include a plurality of leg lower end engaging portions (40) provided at the lower end of the leg portion (40) and a plurality of body lower surface engaging portions (30) provided on the lower surface of the step stool body (11). On the upper surface of the step stool body (11), a plurality of upper body engagement portions (25) are provided above the plurality of legs (40), and a plurality of second concave and convex engagement portions (40, 25) are provided, including the plurality of upper body engagement portions (25) and the plurality of lower leg end engagement portions (40). A step stool (10) according to any one of the features 1 to 5, wherein, in a stacked state of two step stools (10), the plurality of lower leg end engaging parts (40) of the upper step stool (10) and the plurality of upper body engaging parts (25) of the lower step stool (10) engage with each other in a concave-concave manner.

[0081] According to Feature 7 of the step stool, the height of the step stool can be selected from three stages: the step stool alone, the position facing directly downwards, and the stacked position. Note that "lower end" includes not only the very bottom but also positions close to the lower end.

[0082] [Feature 8] The step stool (10) according to feature 7, wherein the plurality of first interlocking parts (40, 30) or the plurality of second interlocking parts (40, 25) are structured such that they are interlocked vertically by interlocking the first interlocking parts (40, 30) or the second interlocking parts (40, 25) vertically and then sliding them horizontally to prevent them from coming apart vertically.

[0083] [Feature 9] The aforementioned upper surface engagement portion (25) is recessed into the upper surface of the step stool body (11) and is configured to receive the lower end engagement portion (40) of the leg of the upper step stool (10) in the stacked state. The recessed internal projection (26) protrudes upward from the bottom surface of the main body upper engagement portion (25), A step stool (10) according to feature 7 or 8, comprising a lower end receiving portion (55) formed at the lower end of the lower end engaging portion (40) of the leg portion and capable of receiving the internal projection of the recess.

[0084] According to the step stool of Feature 9, a recessed internal projection is provided within the upper surface engagement portion formed in the upper surface of the step stool body, making it difficult for the foot to get caught in the upper surface engagement portion and allowing the user to stand on the step stool stably.

[0085] [Feature 10] The aforementioned step stool body (11) has a rectangular shape, The step stool (10) according to any one of features 2 to 9, wherein the planar shape and arrangement of the multiple downward projections (40) and the main body lower surface engagement portion (30) are asymmetrical in the first horizontal direction and the second horizontal direction along the outer edge of the step stool body (11).

[0086] [Feature 11] The step stool (10) according to feature 10, wherein the shape and arrangement of the multiple downward projections (40) and the main body bottom surface engagement portion (30) are rotationally symmetrical.

[0087] According to the step stool of Feature 10, two step stools can be positioned facing each other from below at multiple rotational positions, making it easy to align the step stools.

[0088] [Feature 12] The aforementioned step stool body (11) has a rectangular shape, The step stool (10) according to feature 11, wherein the plurality of downward projections (40) are arranged at the four corners of the step stool body (11), and each has a first side surface (46) extending along one side from the corner of the step stool body (11) and a second side surface (41) extending diagonally inward from that corner, and are arranged in a rotationally symmetric manner.

[0089] [Feature 13] The step stool body (11) is square in shape, The multiple downward projections are arranged at the four corners of the step stool body (11), and each has a first side surface (46) extending along one side from the corner of the step stool body, and a second side surface (41) extending diagonally inward from that corner, closer to the first side surface (46) than the diagonal of the step stool body (11), and are arranged rotationally symmetrically. The step stool (10) according to feature 6, wherein in the release position, the second sides (41) of the two step stools (10) can come into contact with each other, and in the restricted position, the outer shapes of the step stool bodies (11) of the two step stools (10) overlap when viewed from above.

[0090] With the step stools of features 11 and 12, it is possible to engage the step stools with each other in a face-to-face position, and since the protrusions on the bottom surface are located at the four corners of the step stool body, it is possible to stand on the step stool more stably than when the protrusions on the bottom surface are located on the inside. Furthermore, with the step stool of feature 12, the second side surface can be used as a guide when lowering the upper step stool toward the lower step stool.

[0091] [Feature 14] A step stool (10) having a rectangular step stool body (11) and four downward protrusions (40) protruding from the lower surface of the step stool body (11), The four downward protrusions (40) are all positioned adjacent to the diagonal of the step stool body (11) in either a clockwise or counterclockwise direction, on the step stool (10).

[0092] According to Feature 14, the bottom surfaces of the two step stools can be placed facing each other, with their planar shapes perfectly aligned, and the lower protrusions of the two step stools positioned diagonally apart. This allows the two step stools to be used as step stools of different heights when facing each other, and when not in use, multiple step stools can be compactly stored in this facing-each-each-each-each position.

[0093] [Feature 15] The step stool (10) according to feature 14, wherein on the lower surface of the step stool body (11), at positions adjacent to the plurality of downward projections (40) across the diagonal, a plurality of lower surface engagement portions (30) are provided that engage with the plurality of downward projections (40) of the opposing step stool (10) in a face-to-face state where the lower surfaces of the step stool bodies (11) of the two step stools (10) are facing each other and their planar shapes are exactly overlapping.

[0094] [Feature 16] A step stool (10) having a step stool body (11) and a plurality of downward projections (40) that protrude from the lower surface of the step stool body (11) and abut against the installation surface, On the upper surface of the step stool body (11), a plurality of upper body engagement portions (25) are provided at a position above the plurality of downward projections (40), The above-mentioned multiple upper body engagement portions (25) and multiple lower leg end engagement portions (40) provided at the lower end of the lower projection (40) are provided, and a plurality of second recessed engagement portions (40, 25) are provided that engage in a recessed and recessed manner when stacked. The step stool (10) has a structure in which the plurality of second protrusions and recesses (40, 25) are prevented from coming off in the vertical direction by abutting the plurality of downward protrusions (40) against the step stool body (11) of the lower step stool and then sliding it horizontally.

[0095] According to the step stool described in Feature 16, the stacked step stools are secured in the vertical direction, allowing for stable footing on the stacked step stools.

[0096] While this specification and drawings disclose specific examples of the technology included in the claims, the technology described in the claims is not limited to these specific examples, but also includes various modifications and changes to these examples, as well as parts of the examples taken individually. [Explanation of symbols]

[0097] 10 Step stool 11 Step stool body 12 Top panel 25 Top surface engagement part (main body top surface engagement part, second uneven engagement part) 25A bottom 26 Recessed internal protrusion 27 Lateral recess 27A Locking protrusion 30 Lower surface engaging portion (main body lower surface engaging portion, first uneven engaging portion) 30A Bottom 32 Lateral recess (lateral open receiving section) 32A Locking protrusion (locking part) 35 Recessed internal protrusion 40 Leg portion (first uneven engagement portion, second uneven engagement portion, downward protrusion, leg lower end engagement portion) 50 Engaging projection (lateral projection) 50T Locking protrusion (locking part) 55 Lower end recess (lower end receiving portion)

Claims

1. A step stool having a step stool body with a rotationally symmetrical or circular planar shape, and a plurality of downward projections that protrude from the lower surface of the step stool body and abut against the installation surface, The lower surfaces of the two step stool bodies are facing each other, their planar shapes overlapping, and the multiple downward protrusions are housed between the upper surfaces of the step stool bodies in a face-to-face lower surface configuration, such that the multiple downward protrusions of the two step stool bodies do not interfere with each other. A step stool provided with a plurality of first protruding and concave engaging parts that engage with each other in a concave and concave manner when the lower surfaces are facing each other.

2. The aforementioned multiple downward projections are multiple legs extending downward from the step stool body, The step stool according to claim 1, wherein the plurality of first recessed engagement portions include a plurality of leg lower end engagement portions provided at the lower end of the leg portion and a plurality of body lower surface engagement portions provided on the lower surface of the step stool body.

3. The step stool according to claim 2, wherein the plurality of first protrusions and recesses engaging portions are structured to prevent them from coming loose in the vertical direction when facing the lower surface.

4. The step stool according to claim 3, wherein the plurality of first protrusions and recesses engaging portions are structured to prevent them from coming off in the vertical direction by abutting the plurality of downward protrusions against each other and then shifting them horizontally.

5. The step stool according to claim 4, wherein the plurality of first protrusions and recesses engage with each other, and the locking portion restricts relative movement from a locking position where it is prevented from coming out in the vertical direction to a release position where the locking is released.

6. The aforementioned multiple downward projections are multiple legs extending downward from the step stool body, The plurality of first protruding engagement portions include a plurality of leg lower end engagement portions provided at the lower end of the leg portion and a plurality of body lower surface engagement portions provided on the lower surface of the step stool body, The upper surface of the step stool body is provided with a plurality of upper body engagement portions located above the plurality of legs, and a plurality of second recessed engagement portions are provided, including the plurality of upper body engagement portions and the plurality of lower end engagement portions of the legs. A step stool according to any one of claims 1 to 5, wherein, in a stacked configuration of two step stools, the plurality of lower leg end engagement portions of the upper step stool and the plurality of upper body engagement portions of the lower step stool engage in a concave-concave-convex

7. The aforementioned upper surface engagement portion of the main body is recessed into the upper surface of the step stool body and is configured to receive the lower end engagement portion of the leg of the upper step stool in the stacked state. The recessed internal projection protrudes upward from the bottom surface of the engagement portion on the upper surface of the main body, The step stool according to claim 6, further comprising a lower end receiving portion formed at the lower end of the lower end engaging portion of the leg portion and capable of receiving the internal projection of the recess.

8. A step stool having a step stool body and a plurality of downward projections that protrude from the lower surface of the step stool body and abut against the installation surface, Multiple body top surface engaging portions are provided on the upper surface of the step stool body, positioned above the multiple downward protrusions. The above-mentioned multiple upper body engagement portions and multiple lower end engagement portions provided at the lower end of the lower projection are provided, and a plurality of second recessed engagement portions are provided that engage in a recessed manner when stacked. The aforementioned plurality of second protrusions and recesses are structured to prevent them from coming off in the vertical direction by abutting the plurality of downward protrusions against the step stool body of the lower step stool and then sliding them horizontally.

Images