Footstand

Abstract

To provide a step ladder that allows a user to work safely while ensuring a stable posture at the upper part of the step ladder. 【Solution means】The step ladder 1 has a step ladder main body 2, a first arm 3 rotatably provided in the vertical direction on the step ladder main body 2, and a first fixing means for fixing the first arm 3 rotated upward. The first arm 3 has a horizontal shaft portion 22 that extends horizontally and is rotatably and slidably held in the horizontal direction at the upper part of the step ladder main body 2, and a vertical shaft portion 23 that extends vertically from the end of the horizontal shaft portion 22. The first fixing means includes a hook 31 provided at the end on the horizontal shaft portion side in the longitudinal direction of the vertical shaft portion of the first arm, and protrusions 32a to 32c provided on the side surface of the step ladder main body 2 and capable of locking the hook 31 when the first arm 3 is rotated upward.

Description

Technical Field

[0001] The present invention relates to a stepladder.

Background Art

[0002] Conventionally, a stepladder has been proposed in which a pipe stored in a support column of a ladder section can be pulled upward and used as a handrail (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the conventional stepladder as described above, since the pipe is pulled out on the extension line of the support column, there is a problem that the pipe gets in the way when, for example, a user sits astride the top plate of the stepladder and works.

[0005] Therefore, the present invention has been made in view of the above problems, and an object thereof is to provide a stepladder that allows a user to work safely while securing a stable posture at the upper part of the stepladder.

Means for Solving the Problems

[0006] In order to solve the above problems, the present invention provides a stepladder body, a first arm rotatably provided in the vertical direction on the stepladder body, and first fixing means for fixing the first arm rotated upward. The first arm has a horizontal shaft portion that extends horizontally and is rotatably and slidably held in the horizontal direction at the upper part of the stepladder body, and a vertical shaft portion that extends vertically from an end of the horizontal shaft portion. The first fixing means is characterized by comprising a hook provided at an end portion on the horizontal axis portion side in the longitudinal direction of the vertical axis portion of the first arm, and a protrusion provided on the side surface of the step ladder main body and capable of locking the hook when the first arm is rotated upward, and provides a step ladder.

Effect of the Invention

[0007] According to the present invention, it is possible to provide a step ladder that allows a user to work safely while securing a stable posture at the upper part of the step ladder.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Embodiments for Carrying Out the Invention

[0009] The stools according to the embodiments of the present invention will be described based on the attached drawings. (First Embodiment) The stool 1 according to the first embodiment of the present invention shown in FIG. 1(a) includes a stool body 2 and first and second auxiliary arms 3 and 4 for assisting a user who climbs on the stool body 2 to perform work.

[0010] The stool body 2 has a basic configuration similar to that of a general stool, and has a pair of ladder parts 5a and 5b and a pair of hinge parts 6a and 6b that connect the ladder parts 5a and 5b in an openable and closable manner.

[0011] The ladder part 5a includes two column-shaped struts 7a and 7b arranged in a U shape, a plurality of, in this embodiment, two column-shaped rungs 8 and 8 that connect the struts 7a and 7b, and a rectangular plate-shaped top plate 9 that connects the upper ends of the struts 7a and 7b. Note that the configuration of the ladder part 5b is the same as that of the ladder part 5a.

[0012] The hinge part 6b includes a pair of plate-shaped members 11a and 11b in a substantially feather shape and a rotating shaft 12 that rotatably connects the plate-shaped members 11a and 11b. The plate-shaped member 11a is fixed to the side surface of the upper end of the strut 7a of the ladder part 5b, and the plate-shaped member 11b is fixed to the side surface of the upper end of the strut 7b of the ladder part 5a. Note that the configuration of the hinge part 6a is the same as that of the hinge part 6b. The ladder parts 5a and 5b can be opened and closed by the hinge parts 6a and 6b.

[0013] The stool body 2 can be in a stool state where the ladder parts 5a and 5b are opened in a U shape and can be used as a stool, a ladder state where the ladder parts 5a and 5b are opened 180 degrees and can be used as a ladder as shown in FIG. 4(b), and a non-use state where the ladder parts 5a and 5b are closed, which is convenient for carrying and storage.

[0014] On both side surfaces of the ladder portions 5a and 5b, a pair of first locking mechanisms 13a and 13b for fixing the ladder portions 5a and 5b in the stepladder state and a pair of second locking mechanisms 14a and 14b for fixing the ladder portions 5a and 5b in the ladder state are provided (see FIGS. 3(a) and 4(b)).

[0015] As shown in FIG. 3(a), the first locking mechanism 13b includes a shaft 15 provided at an intermediate position in the longitudinal direction of the support column 7b on the side surface of the support column 7b of the ladder portion 5a, a shaft 16 provided at an intermediate position in the longitudinal direction of the support column 7a on the side surface of the support column 7a of the ladder portion 5b, and an elongated square plate-like member 17 having one end rotatably attached to the shaft 16 and a groove 18 at the other end that can be fitted to the shaft 15. When the user opens the ladder portions 5a and 5b, the user can rotate the plate-like member 17 and fit the shaft 15 into the groove 18 of the plate-like member 17 to fix the ladder portions 5a and 5b in the stepladder state. The configuration of the first locking mechanism 13a is the same as that of the first locking mechanism 13b.

[0016] As shown in FIG. 3(a), the second locking mechanism 14b has the same configuration as the first locking mechanism 13b, and includes a shaft 15 provided on the plate-like member 11b of the hinge portion 6b, a shaft 16 provided on the plate-like member 11a of the hinge portion 6b, and a plate-like member 17 rotatably attached to the shaft 16. As shown in FIG. 4(b), the user can fix the ladder portions 5a and 5b in the ladder state by the second locking mechanism 14b. The configuration of the second locking mechanism 14a (not shown) is the same as that of the second locking mechanism 14b.

[0017] As shown in Fig. 2(a), the first auxiliary arm 3 is an elongated bar-shaped member generally in an L shape as a whole, and includes a cylindrical horizontal shaft portion 22 extending in the horizontal direction, a cylindrical vertical shaft portion 23 extending in the vertical direction from one end of the horizontal shaft portion 22, and a handle portion 24 extending horizontally inward from the tip of the vertical shaft portion 23. The handle portion 24 is composed of a cylindrical shaft portion 25 and a rice-bag-shaped grip portion 26 in order from the vertical shaft portion 23 side, and is shorter than the horizontal shaft portion 22 as a whole. Note that the shape of the grip portion 26 is not limited to the rice-bag shape and may be other shapes, such as a cylindrical shape. Also, the shape of the vertical shaft portion 23 is not limited to the cylindrical shape and may be other shapes, such as a prismatic shape.

[0018] At the upper parts of the columns 7a and 7b of the ladder portion 5a in the step ladder body 2, specifically at a position immediately below the top plate 9, circular through holes (not shown) are formed so as to penetrate the columns 7a and 7b in the horizontal direction. Also, circular through holes (not shown) are respectively formed in the plate-shaped members 11a of the hinge portion 6a and the plate-shaped members 11b of the hinge portion 6b so as to face the through holes of the columns 7a and 7b of the ladder portion 5a. The horizontal shaft portion 22 of the first auxiliary arm 3 is inserted into these through holes so as to be slidable and rotatable in the horizontal direction.

[0019] Note that in order to prevent the horizontal shaft portion 22 from falling out of the through holes of the columns 7a and 7b of the ladder portion 5a, the through holes of the plate-shaped member 11a of the hinge portion 6a, and the through holes of the plate-shaped member 11b of the hinge portion 6b, a screw groove (not shown) is formed at the end of the horizontal shaft portion 22 on the side opposite to the vertical shaft portion 23, and a nut 29 is detachably attached (see Fig. 2(a)).

[0020] With the above configuration, the first auxiliary arm 3 is slidable in the horizontal direction and rotatable in the vertical direction with respect to the step ladder body 2. Also, by removing the nut 29 from the horizontal shaft portion 22, the first auxiliary arm 3 can be removed from the step ladder body 2. Thereby, the user can remove the first auxiliary arm 3 from the step ladder body 2 according to the work content and use the step ladder 1, or can replace it with a new first auxiliary arm 3 when the first auxiliary arm 3 is damaged or the like.

[0021] At the end of the longitudinal axis portion 23 of the first auxiliary arm 3 on the side of the horizontal axis portion 22 in the longitudinal direction, as shown in Fig. 4(a), a substantially prismatic hook portion 31 extending outward in the longitudinal direction is integrally provided. A semi-circular groove 31a capable of engaging with the protrusions 32a to 32c of the hinge portion 6b described later is formed in the hook portion 31.

[0022] On the plate-like member 11b of the hinge portion 6b of the step ladder body 2, as shown in Figs. 3(a) and 4(a), at a position closer to the rotation axis 12 than the horizontal axis portion 22 of the first auxiliary arm 3, three protrusions 32a to 32c are provided side by side in the circumferential direction with the horizontal axis portion 22 as the center. As shown in Fig. 4(c), the protrusions 32a to 32c are composed of a disc-shaped head portion 33 and a columnar shaft portion 34 having a smaller diameter than the head portion 33. For example, a rivet-type metal fitting may be attached to the plate-like member 11b as the protrusions 32a to 32c. The protrusions 32a to 32c of such a hinge portion 6b and the hook portion 31 of the first auxiliary arm 3 constitute a fixing means for fixing the position of the first auxiliary arm 3 when the first auxiliary arm 3 is rotated upward with respect to the step ladder body 2 in the step ladder state.

[0023] The user of the step ladder 1 with the above-described configuration can climb onto the step ladder main body 2 with the ladder parts 5a and 5b opened to the step ladder state and sit astride the top plates 9, 9. Then, after the user slides the first auxiliary arm 3 outward in the horizontal direction (the right side in Fig. 1(a)), rotates it upward, and slides it inward in the horizontal direction (the left side in Fig. 1(a)), the hook part 31 of the first auxiliary arm 3 is locked to any one of the protrusions 32a to 32c of the hinge part 6b. Thereby, the user can put the first auxiliary arm 3 in the raised state (use state). Specifically, when the hook part 31 is locked to the protrusions 32a to 32c, the loads on the vertical shaft part 23 and the handle part 24 are applied from the hook part 31 to the protrusions 32a to 32c based on the lever principle with the rotation center of the horizontal shaft part 22 as the fulcrum. Therefore, the state where the hook part 31 is locked to the protrusions 32a to 32c, that is, the use state of the first auxiliary arm 3 can be maintained. In addition, the user can change the raised position of the first auxiliary arm 3, that is, the height position of the handle part 24, by changing the protrusions 32a to 32c of the hinge part 6b to which the hook part 31 of the first auxiliary arm 3 is locked (see Fig. 3(b)). Further, the user can lower the first auxiliary arm 3 and return it to the unused state by performing the above-described procedure in reverse.

[0024] Here, as shown in Fig. 4(a), on the plate-like member 11b of the hinge part 6b, a small plate-like stopper part 35 extending outward in the horizontal direction (the front side in the direction perpendicular to the paper surface of Fig. 4(a)) is integrally provided at the upper end side position of the support column 7b. With this configuration, when the first auxiliary arm 3 is rotated upward with respect to the step ladder main body 2, the vertical shaft part 23 abuts against the stopper part 35, so that it is possible to prevent the first auxiliary arm 3 from rotating excessively and rising too much.

[0025] In addition, in the use state of the first auxiliary arm 3, the horizontal movement of the hook part 31 is restricted by the heads 33 of the protrusions 32a to 32c (see Fig. 4(c)). With this configuration, since the first auxiliary arm 3 does not slide outward in the horizontal direction unintentionally and the hook part 31 does not come off from the protrusions 32a to 32c, it is possible to prevent the first auxiliary arm 3 from rotating and descending.

[0026] On the front surface of the column 7b of the ladder part 5a (the front surface in Fig. 1(b)), a groove part 36 extending in the horizontal direction is formed. With this configuration, when the first auxiliary arm 3 is rotated downward with respect to the step ladder body 2, that is, when the first auxiliary arm 3 is in a non-use state, the shaft part 25 of the handle part 24 can be housed in the groove part 36. Thereby, since the first auxiliary arm 3 does not protrude to the front side of the ladder part 5a, the first auxiliary arm 3 does not get in the way when the user climbs up and down the step ladder body 2 (see Fig. 1(a)).

[0027] As shown in Fig. 1(a), the length of the vertical shaft part 23 of the first auxiliary arm 3 is designed such that when the first auxiliary arm 3 is in a non-use state, the handle part 24 is positioned immediately below the uppermost rung 8 of the ladder part 5a in the step ladder body 2. Also, as described above, the horizontal shaft part 22 of the first auxiliary arm 3 is positioned immediately below the top plate 9 of the ladder part 5a in the step ladder body 2. With these configurations, the handle part 24 and the horizontal shaft part 22 of the first auxiliary arm 3 do not get in the way when the user climbs up and down the step ladder body 2.

[0028] Since the second auxiliary arm 4 has the same basic configuration as the first auxiliary arm 3, the same reference numerals are given to the same parts and the description thereof is omitted, and the different parts will be described. As shown in Fig. 2(b), the second auxiliary arm 4 is an overall rectangular slender rod-shaped member, and includes a horizontal shaft part 22, two vertical shaft parts 23, 23 extending parallel in the vertical direction from both ends of the horizontal shaft part 22, and a handle part 37 extending horizontally inward from the tip of one vertical shaft part 23 to reach the tip of the other vertical shaft part 23.

[0029] The handle part 37 is composed of, in order from the side of the one vertical shaft part 23 described above, a cylindrical shaft part 38, a cylindrical grip part 39 thinner than the shaft part 38, and a cylindrical shaft part 40 having the same diameter as the shaft part 38. The grip part 39 is not limited to a cylindrical shape and may be other shapes, such as a cylindrical shape, a bag shape, a prismatic shape, etc. Note that a hook part 31 is integrally provided on the other vertical shaft part 23 described above in the same manner as the vertical shaft part 23 of the first auxiliary arm 3.

[0030] On the upper parts of the columns 7a and 7b of the ladder part 5b in the stool body 2, through holes (not shown) are formed in the same manner as the columns 7a and 7b of the ladder part 5a. Further, through holes (not shown) are also formed in the plate-like members 11b of the hinge part 6a and the plate-like members 11a of the hinge part 6b so as to face the through holes of the columns 7a and 7b of the ladder part 5b. The horizontal shaft part 22 of the second auxiliary arm 4 is inserted into these through holes so as to be slidable and rotatable in the horizontal direction. With such a configuration, the second auxiliary arm 4 can slide in the horizontal direction and rotate in the vertical direction with respect to the stool body 2.

[0031] Note that the plate-like member 11b of the hinge part 6a of the stool body 2 is provided with three protrusion parts 32a to 32c and a stopper part 35 (both not shown) in the same manner as the plate-like member 11b of the hinge part 6b. As shown in FIG. 2(b), groove parts 36, 36 are provided on the front side surfaces of the columns 7a and 7b of the ladder part 5b in the same manner as the column 7b of the ladder part 5a.

[0032] Here, an annular part (not shown) is integrally provided at the tip on the horizontal shaft part 22 side in the longitudinal direction of the vertical shaft part 23 on the other side (the left side in FIG. 2(b)) of the second auxiliary arm 4 described above. Further, a screw groove (not shown) is formed at the end of the horizontal shaft part 22 on the vertical shaft part 23 side of the other side. The annular part of the vertical shaft part 23 is externally fitted to the end of the horizontal shaft part 22 having the screw groove, and a nut 29 is detachably attached. With this configuration, the second auxiliary arm 4 can be removed from the stool body 2 by removing the nut 29 from the horizontal shaft part 22.

[0033] With the above configuration, the user can set the stool body 2 in the stool state and set the second auxiliary arm 4 in the use state by the same procedure as the first auxiliary arm 3. The second auxiliary arm 4 can exhibit the same effects as the first auxiliary arm 3 described above.

[0034] According to the step ladder 1 according to this embodiment, when the user climbs onto the step ladder main body 2 in the step ladder state and sits across the top plates 9, 9 to perform work, the user can adjust the first and second auxiliary arms 3, 4 to a desired height, for example, a height at which the respective handle portions 24, 37 are positioned near the user's knees (400 to 500 mm above the top plates 9, 9). By doing so, the user can grasp the handle portions 24, 37 and the vertical shaft portions 23 of the first and second auxiliary arms 3, 4 to adjust their body postures. Further, since the user can hang tools, equipment, materials, safety belts, etc. on the handle portions 24, 37 of the first and second auxiliary arms 3, 4, the user can free both hands to prepare for work or adjust their body posture. Then, the user can perform work with a stable body posture while grasping the handle portions 24, 37 and the vertical shaft portions 23 of the first and second auxiliary arms 3, 4, ensuring safety.

[0035] In addition, when the user needs to stand on the top plates 9, 9 of the step ladder main body 2 in the step ladder state to perform work, by using the first auxiliary arm 3 or the second auxiliary arm 4 in the used state and grasping it, the user can get on and off the top plates 9, 9 more safely while maintaining the balance of the body posture.

[0036] When the user climbs up and down with the step ladder main body 2 in the ladder state or climbs up and down with the step ladder main body 2 in the step ladder state, by setting the first and second auxiliary arms 3, 4 to the unused state, the first and second auxiliary arms 3, 4 will not get in the way.

[0037] In addition, since the handle portion 24 of the first auxiliary arm 3 is designed to be shorter than the horizontal shaft portion 22 as described above, the user can also climb up and down the step ladder main body 2 in the step ladder state while keeping the first auxiliary arm 3 in the used state. As described above, the columns 7b of the ladder part 5a, and the columns 7a and 7b of the ladder part 5b are each provided with the groove part 36, but they may not be provided. In this case, when the user climbs up and down the step ladder body 2 in the step ladder state or the ladder state with the first and second auxiliary arms 3 and 4 not in use, although the handle parts 24 and 37 of the first and second auxiliary arms 3 and 4 slightly protrude from the front side of the ladder parts 5a and 5b respectively, since the handle parts 24 and 37 are located just below the treads 8 and 8, they are not likely to get in the way.

[0038] (Second Embodiment) Regarding the step ladder 41 according to the second embodiment of the present invention shown in FIGS. 5(a) and 5(b), the same components as those in the first embodiment are denoted by the same reference numerals and the description thereof is omitted, and the different components will be described.

[0039] The first auxiliary arm 42 of the step ladder 41 according to the present embodiment includes a horizontal shaft part 43 having a cylindrical shape extending in the horizontal direction, a vertical shaft part 44 that is separate from the horizontal shaft part 43 and extends in the vertical direction from one end of the horizontal shaft part 43, and a handle part 45 that extends horizontally inward from the tip of the vertical shaft part 44. The handle part 45 is composed of only the rice-bag-shaped grip part 26.

[0040] As shown in FIG. 6(a), screw grooves are provided at both ends of the horizontal shaft part 43, and a hook part 46 is integrally provided at a position opposite to the vertical shaft part 44 in the longitudinal direction. The hook part 46 has the same configuration as the hook part 31 of the vertical shaft part 23 of the first auxiliary arm 3 in the first embodiment. Further, L-shaped parts 47 and 47 are integrally provided at positions that trisect the horizontal shaft part 43 in the longitudinal direction. The L-shaped parts 47 and 47 are composed of L-shaped plate members having through holes 47a at their tips.

[0041] A first extension step 48 for expanding the area of the top plate 9 of the ladder part 5a when the step ladder body 2 is in the step ladder state is attached to the horizontal shaft part 43. As shown in Fig. 6(a), the first extension step 48 consists of a rectangular plate portion 49 and two projecting portions 50, 50 integrally provided on the back surface of the plate portion 49. The projecting portion 50 has a rectangular plate shape with a through hole 50a at its tip, and is fixed to the L-shaped portion 47 of the first auxiliary arm 42 by attaching nuts 52 to bolts 51 inserted into the respective through holes 47a, 50a. When attaching the nut 52 to the bolt 51, two washers 53, 53 are arranged so as to sandwich the projecting portion 50 and the L-shaped portion 47.

[0042] Specifically, in the non-use state of the first auxiliary arm 42, the first extension step 48 is housed in the lower space of the top plate 9 of the ladder portion 5a, and in the use state of the first auxiliary arm 42, the mounting angle of the first extension step 48 with respect to the first auxiliary arm 42, that is, the angle formed by the L-shaped portions 47, 47 and the projecting portions 50, 50, is set so as to be located directly beside the top plate 9 of the ladder portion 5a. More specifically, when the user locks the hook portion 31 of the vertical shaft portion 44 to the lowermost protruding portion 32a of the hinge portion 6b in the use state of the first auxiliary arm 42, the top plate 9 of the ladder portion 5a and the plate portion 49 of the first extension step 48 are positioned on the same plane (see Fig. 7(b)).

[0043] The user can adjust the mounting angle of the first extension step 48 with respect to the first auxiliary arm 42 by loosening the aforementioned bolts 51 and nuts 52. Further, the user can also remove the first extension step 48 from the first auxiliary arm 42 according to the user's work by removing the nut 52 from the bolt 51 and use the step ladder 41.

[0044] As shown in Fig. 6(a), the vertical shaft portion 44 is composed of an elongated rectangular thin plate member. A circular through-hole 44a is formed at the end on the horizontal shaft portion 43 side in the longitudinal direction, which faces the above-mentioned through-hole (not shown) of the support column 7b of the ladder portion 5a. At the end of the vertical shaft portion 44 on the handle portion 45 side in the longitudinal direction, a bent portion 65 that is bent in a U-shape inward in the horizontal direction is integrally provided, and the handle portion 45 is provided near the tip of the bent portion 65. With this configuration, when the first auxiliary arm 42 is in a non-use state, the bent portion 65 can rotate inward in the horizontal direction around the support column 7b of the ladder portion 5a, and the handle portion 45 can be stored directly below the rung 8. Therefore, when the user climbs up and down the step ladder body 2, the handle portion 45 of the first auxiliary arm 42 will not get in the way.

[0045] On the upper part of the support column 7a of the ladder portion 5a, a reinforcing portion 54 formed by bending a rectangular thin plate member in a U-shape is attached so as to cover the inner side surface in the horizontal direction of the support column 7a. A circular through-hole 54a is formed in the reinforcing portion 54 so as to face the above-mentioned through-hole (not shown) of the support column 7a. Further, as shown in Fig. 6(c), the reinforcing portion 54 is provided with protrusion portions 55a to 55c similar to the plate member 11b of the hinge portion 6b.

[0046] One end of the horizontal shaft portion 43 is sequentially inserted into the through-holes (not shown) of the support column 7b of the ladder portion 5a and the plate member 11b of the hinge portion 6b, the through-hole 44a of the vertical shaft portion 44, and the washer 57, and the nut 58 is removably attached. The other end of the horizontal shaft portion 43 is sequentially inserted into the through-hole 54a of the reinforcing portion 54, the through-holes (not shown) of the support column 7a of the ladder portion 5a and the plate member 11a of the hinge portion 6a, the washer 59, the spring 60, and the washer 61, and the nut 62 is removably attached. With such a configuration, the vertical shaft portion 44 is fixed to the horizontal shaft portion 43 and integrated, and the first auxiliary arm 42 can slide in the horizontal direction and rotate in the vertical direction with respect to the step ladder body 2. Note that the first auxiliary arm 42 is biased by the spring 60 toward the vertical shaft portion 44 side in the longitudinal direction of the horizontal shaft portion 43.

[0047] When the user sets the first auxiliary arm 42 to the use state, by locking the hook portion 31 of the vertical axis portion 44 to any one of the protruding portions 32a to 32c of the hinge portion 6b, the hook portion 46 of the horizontal axis portion 43 can be locked to the protruding portions 55a to 55c of the corresponding reinforcing portion 54. Therefore, the use state of the first auxiliary arm 42 can be maintained more firmly. Note that the reinforcing portion 54 may not be provided on the support column 7a of the ladder portion 5a, and the protruding portions 55a to 55c may be directly provided on the inner side surface in the horizontal direction of the support column 7a.

[0048] The first auxiliary arm 42 having the above configuration can achieve the same effects as the first auxiliary arm 3 in the first embodiment. Further, when the first auxiliary arm 42 is set to the use state with the stepladder body 2 in the stepladder state, the first extension step 48 also rotates together with the horizontal axis portion 43 and rises to the side of the top plate 9 of the ladder portion 5a, and the area of the top plate 9 can be expanded. Thereby, the user can sit and work on the top plates 9, 9 in a more stable state. Also, even when the user needs to stand and work on the top plates 9, 9, the user can work more safely while maintaining the balance of the body posture.

[0049] The second auxiliary arm 63 has basically the same configuration as the first auxiliary arm 42. The same parts are denoted by the same reference numerals and the description thereof is omitted, and the different parts will be described. As shown in FIGS. 5(b) and 6(b), the second auxiliary arm 63 is a quadrangular frame-shaped member as a whole, and includes a horizontal axis portion 43, two vertical axis portions 44, 44 extending vertically in parallel from both ends of the horizontal axis portion 43, and a handle portion 45 extending horizontally inward from the bent portion 65 of one vertical axis portion 44 and reaching the bent portion 65 of the other vertical axis portion 44. The handle portion 45 is composed of only the elongated cylindrical grip portion 39. The hook portion 31 is provided only on one (the right side in FIGS. 5(b) and 6(b)) vertical axis portion 44. A second extension step 64 similar to the first extension step 48 is attached to the horizontal axis portion 43 of the second auxiliary arm 63. A reinforcing portion 54 is attached to the upper part of the support column 7a of the ladder portion 5b.

[0050] Similar to the first auxiliary arm 42, such a second auxiliary arm 63 can be switched between a used state and a non-used state, and can achieve the same effects as the first auxiliary arm 42 and the second auxiliary arm 4 in the first embodiment. In particular, when the step ladder body 2 is in the step ladder state and both the first auxiliary arm 42 and the second auxiliary arm 63 are in the used state, the areas of the top plates 9, 9 can be maximally expanded, specifically, expanded by 1.5 to 2 times, by the first and second extension steps 48, 64. Therefore, the user can perform both the work of sitting on the top plates 9, 9 and the work of standing on the top plates 9, 9 more stably and safely.

[0051] In addition, it is more preferable that the step ladder 41 according to the present embodiment has a locking mechanism for fixing the first and second extension steps 48, 64 when the first and second auxiliary arms 42, 63 are in the used state in the step ladder body 2 in the step ladder state. For example, a locking mechanism similar to the second locking mechanism 14a described above may be provided on the upper surface of the top plate 9 of the ladder part 5a and the surface of the plate-like part 49 of the first extension step 48, and on the upper surface of the top plate 9 of the ladder part 5b and the surface of the plate-like part 49 of the second extension step 64, respectively. Thereby, even when the user's weight is applied to the first and second extension steps 48, 64, it can be more stably supported.

[0052] According to each of the above embodiments, it is possible to realize the user-friendly step ladders 1, 41 that are simple in configuration and low in cost, and that allow the user to work safely while ensuring a stable posture at the upper part of the step ladder. In addition, it is preferable that the components constituting the step ladders 1, 41 according to each embodiment are all made of metal from the viewpoint of strength, and particularly preferably made of aluminum which is lightweight, high-strength, and rust-resistant.

[0053] The step ladders 1 and 41 according to each embodiment include both the first auxiliary arms 3 and 42 and the second auxiliary arms 4 and 63, but are not limited thereto, and may be configured to include only one of them. Further, the step ladders 1 and 41 may be configured to include the first auxiliary arms 3 and 42 instead of the second auxiliary arms 4 and 63, that is, a configuration including two first auxiliary arms 3 and 42, or may be configured to include the second auxiliary arms 4 and 63 instead of the first auxiliary arms 3 and 42, that is, a configuration including two second auxiliary arms 4 and 63.

[0054] Each embodiment shows a 3-foot step ladder 1 and 41 as an example, but the present invention is not limited thereto and may be applied to step ladders of 3 feet or more. For example, if the present invention is applied to a 7-foot or 8-foot step ladder for performing high-altitude work, the effects of the present invention will be maximally useful. In each embodiment, the hinge portions 6a and 6b and the reinforcing portion 54 are configured to include three protrusions 32a to 32c and 55a to 55c as described above, but the number of protrusions is not limited thereto, and may be configured to include 1, 2, or 4 or more protrusions.

[0055] It is also possible to replace or combine the configurations of the step ladders 1 and 41 according to each embodiment with each other. For example, the first and second extension steps 48 and 64 and the hook portions 46 and the reinforcing portion 54 of the first and second auxiliary arms 42 and 63 in the second embodiment may be applied to the step ladder 1 according to the first embodiment. Further, for example, the vertical shaft portions 44 of the first and second auxiliary arms 42 and 63 in the second embodiment may be replaced with the vertical shaft portions 23 of the first and second auxiliary arms 3 and 4 in the first embodiment.

[0056] For example, regarding the first and second auxiliary arms 3 and 4 of the first embodiment, each vertical shaft portion 23 may be made shorter than the horizontal shaft portion 22 to omit the handle portions 24 and 37, and further, a configuration including the first and second extension steps 48 and 64 of the second embodiment may be adopted. Thereby, without using the first and second auxiliary arms for assisting the user's work, each vertical shaft portion 23 can be used as a lever for moving the first and second extension steps 48 and 64 up and down. The first and second auxiliary arms having such a configuration are particularly useful when applied to a three-foot or four-foot step ladder for working at a relatively low position, for example. In the step ladder 1 according to the first embodiment, the first and second auxiliary arms having such a configuration and the first and second auxiliary arms 3 and 4 described above may be removed and exchanged according to the work content for use.

Explanation of Reference Numerals

[0057] 1, 41 Step ladder 2 Step ladder body 3, 42 First auxiliary arm 4, 63 Second auxiliary arm 5a, 5b Ladder portion 6a, 6b Hinge portion 7a, 7b Support column 8 Rung 11a, 11b Plate-like member 12 Rotation axis 13a, 13b First locking mechanism 14a, 14b Second locking mechanism 22, 43 Horizontal shaft portion 23, 44 Vertical shaft portion 24, 37, 45 Handle portion 31, 46 Hook portion 32a~32c Protrusion 48 First extension step 54 Reinforcement portion 64 Second extension step 65 Bending portion

Claims

1. a footstool body, a first arm rotatably provided in the vertical direction on the footstool body, and first fixing means for fixing the first arm rotated upward, wherein the first arm has a horizontal axis portion extending horizontally and rotatably and slidably held in the horizontal direction at the upper part of the footstool body, and a vertical axis portion extending vertically from an end of the horizontal axis portion, wherein the first fixing means includes a hook provided at an end portion on the horizontal axis side in the longitudinal direction of the vertical axis portion of the first arm, and a protrusion provided on a side surface of the footstool body and capable of locking the hook when the first arm is rotated upward. The footstool is characterized by this.

2. The footstool according to claim 1, wherein the first arm includes the horizontal axis portion, the vertical axis portion, and a handle portion provided at a tip of the vertical axis portion, extending horizontally, and shorter than the horizontal axis portion.

3. The first fixing means has a plurality of the protrusions, and the height of the first arm can be changed by changing the protrusion for locking the hook. The footstool according to claim 1 is characterized by this.

4. a first step that rotates together with the first arm is provided on the horizontal axis portion of the first arm, wherein when the first arm is rotated upward, the first step is arranged laterally of a top plate of the footstool body to expand the area of the top plate, and when the first arm is rotated downward, the first step is housed below the top plate. The footstool according to claim 1 is characterized by this.

5. The footstool according to claim 2, wherein a groove portion for housing the handle portion is formed in the footstool body when the first arm is rotated downward.

6. The vertical axis portion of the first arm is plate-shaped and has a bent portion bent in a U-shape horizontally inward along the footstool body at an end portion on the handle portion side in the longitudinal direction, and the handle portion is provided on the bent portion. The footstool according to claim 2 is characterized by this.

7. a hook is provided on the horizontal axis portion of the first arm on the side opposite to the vertical axis portion in the longitudinal direction, the footstool body has a reinforcing portion covering a part of the footstool body, and the reinforcing portion is provided with a protrusion capable of locking the hook of the horizontal axis portion when the first arm is rotated upward. The footstool according to claim 1 is characterized by this.

8. The first arm consists of the horizontal axis part and the vertical axis part. The horizontal axis part of the first arm is provided with a first step that rotates together with the first arm. The first step is arranged on the side of the top plate of the step stool body when the first arm is rotated upward to expand the area of the top plate, and is housed below the top plate when the first arm is rotated downward. The step stool according to claim 1, characterized in that.

9. A second arm rotatably provided in the vertical direction on the opposite side of the first arm in the step stool body, And second fixing means for fixing the second arm rotated upward. The second arm has a horizontal axis part extending in the horizontal direction and rotatably and slidably held in the horizontal direction at the upper part of the step stool body, and a vertical axis part extending in the vertical direction from the end of the horizontal axis part. The second fixing means includes a hook provided at the end on the horizontal axis side in the longitudinal direction of the vertical axis part of the second arm, and a protrusion provided on the side surface of the step stool body and capable of locking the hook when the second arm is rotated upward. The step stool according to claim 1, characterized in that.

10. The second arm consists of the horizontal axis part, the vertical axis part, a vertical axis part extending in the vertical direction from the other end of the horizontal axis part, and a handle part extending in the horizontal direction connecting the tips of the two vertical axis parts. The step stool according to claim 9, characterized in that.

11. The second fixing means has a plurality of the protrusions. The step stool according to claim 9, characterized in that the height of the second arm can be changed by changing the protrusion for locking the hook.

12. The horizontal axis part of the second arm is provided with a second step that rotates together with the second arm. The second step is arranged on the side of the top plate of the step stool body when the second arm is rotated upward to expand the area of the top plate, and is housed below the top plate when the second arm is rotated downward. The step stool according to claim 9, characterized in that.

13. The step stool according to claim 10, characterized in that a groove part for housing the handle part is formed in the step stool body when the second arm is rotated downward.

14. The two vertical shaft portions of the second arm each have a bent portion that is plate-shaped and bent in a U-shape inward in the horizontal direction along the step body at the end on the handle portion side in the longitudinal direction. The step according to claim 10, wherein the handle portion of the second arm connects the bent portions of the two vertical shaft portions.

15. A hook is provided on the horizontal shaft portion of the second arm on the other end side. The step body has a reinforcing portion that covers a part of the step body. The step according to claim 10, wherein the reinforcing portion is provided with a protrusion capable of locking the hook of the horizontal shaft portion when the second arm is rotated upward.

16. The second arm is composed of the horizontal shaft portion and the vertical shaft portion. A second step that rotates together with the second arm is provided on the horizontal shaft portion of the second arm. The step according to claim 9, wherein the second step is arranged on the side of the top plate of the step body when the second arm is rotated upward to expand the area of the top plate, and is housed below the top plate when the second arm is rotated downward.

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