Ladder body and climbing tools

Abstract

To provide a ladder body and a lifting tool which are configured such that the fixing strength of an end fixture to its associated post can be increased without increasing the number of components and without using a fixture such as a screw or rivet.SOLUTION: A stepladder 1 includes two pillars 3 and 3, one or more rungs 4 spanning between the two pillars 3 and 3, and an end fixture 8 provided at a lower end of each pillar 3, in which each pillar 3 has a back plate 31 and two side plates 32 and 32 adjacent to the back plate 31 and facing each other, a rung 4D spanning between the lowest ends of the two pillars 3 and 3 is supported from below by a reinforcement member 9 fixed to the back plate 31 of each of the pillars 3, a lower fixing section 93 of the reinforcement member 9 is positioned close to the lower end of the pillar 3, and the end fixture 8 is fixed to a lower part of the reinforcement member 9 with the lower end of the pillar 3 inserted inside.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a ladder body having end fittings, and to a climbing tool having this ladder body. [Background technology]

[0002] Conventionally, in a ladder body used in climbing tools such as a stepladder or scaffolding, a technique has been used in which an end fitting, which is a grounding device, is provided at the lower end of the ladder body's support pole (see, for example, Patent Document 1). Patent Document 1 describes a technique for fixing an end fitting to the stepladder support pole without using fasteners such as screws or rivets. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-70264 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the stepladder described in Patent Document 1, the end fittings are directly attached to the posts, so the fixing strength of the end fittings cannot be increased. On the other hand, a configuration in which a separate member for fixing the end fittings is provided is difficult to adopt because of the high cost due to the increase in the number of parts and labor.

[0005] The present invention has been made in consideration of the above-mentioned circumstances, and the problem that the present invention aims to solve is to provide a ladder body and climbing tool that makes it possible to increase the fixing strength of the end fittings to the supports without increasing the number of parts and without using fasteners such as screws or rivets. [Means for solving the problem]

[0006] Means for solving the above problems will be described below.

[0007] The ladder body according to the present invention comprises two posts, one or more rungs stretched between the two posts, and end fittings attached to the lower ends of the posts, the posts each having a back plate and two side plates adjacent to the back plate and facing each other, the rungs stretched across the lowermost part of the posts are supported from below by reinforcing members fixed to the back plate of each of the posts, the lower part of the reinforcing member is disposed adjacent to the lower ends of the posts, and the end fittings are fixed to the lower part of the reinforcing member with the lower ends of the posts inserted therein. An engaging portion is formed on the lower part of the reinforcing member, and an engaged portion that engages with the engaging portion is formed on the end tool, and the end tool is fixed to the lower part of the reinforcing member by engagement between the engaging portion and the engaged portion, the engaging portion being an engaging protrusion that protrudes in a direction perpendicular to the back plate, and the engaged portion being an engaged hole that is opened in the inner wall of the end tool that covers the inner surface of the back plate.

[0008] In addition, in the ladder body according to the present invention, it is preferable that the end fittings are fixed to the lower part of the reinforcing member with the lower part of the reinforcing member inserted inside.

[0009] In addition, in the ladder body of the present invention, it is preferable that the engaged hole is formed through the inner wall of the end tool, and the tip surface of the engaging protrusion is located on the same plane as the surface of the inner wall or protrudes from the surface of the inner wall.

[0010] In addition, in the ladder body of the present invention, it is preferable that an insertion surface is formed on the side of the lower end of the reinforcing member away from the back plate, the insertion surface being inclined with respect to the insertion direction into the end fitting.

[0011] In addition, in the ladder body of the present invention, it is preferable that the lower part of the reinforcing member is fixed to the back plate by a fixing device, and the end device covers the fixing device when fixed to the reinforcing member.

[0012] Further, a climbing tool according to the present invention includes at least one ladder body described above. Effect of the Invention

[0013] The ladder body and climbing tool of the present invention have the advantage that it is possible to increase the fixing strength of the end fittings to the support posts without increasing the number of parts and without using fasteners such as screws or rivets. [Brief description of the drawings]

[0014] [Figure 1] FIG. 1 is a perspective view showing a stepladder according to an embodiment of a climbing tool. [Diagram 2] FIG. 4 is an inner side view showing the connection configuration between the end fitting and the reinforcing member. [Diagram 3] Cross-sectional view taken along line AA in Figure 2. [Figure 4] 4A and 4B are top perspective views showing a reinforcing member. [Diagram 5] 11 is a bottom perspective view showing an assembly procedure of the reinforcing member. FIG. [Figure 6] FIG. [Figure 7] 4 is a cross-sectional view showing an assembly procedure of the end fittings. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] 1 to 7, a ladder combined with a stepladder (hereinafter, simply referred to as a "stepladder") 1, which is one embodiment of the climbing tool according to the present invention, will be described below. In this embodiment, the stepladder 1 will be described as one example of a climbing tool equipped with a ladder body 2. That is, the ladder body 2 can be used generally for other climbing tools equipped with at least one ladder body 2 with a step 4 stretched across a pair of posts 3, 3 to allow a user to climb up and down, such as a dedicated ladder, a dedicated stepladder, a step stool, a tripod, a scaffolding platform, etc., in addition to the ladder combined with a stepladder.

[0016] In this embodiment, the direction of the stepladder 1 in use is defined by the direction of the arrow shown in Fig. 1. That is, the direction in which the rungs 4 are installed in the stepladder 1 shown in Fig. 1 is defined as the left-right direction of the stepladder 1. In addition, the direction perpendicular to the left-right direction in the horizontal direction (the opening and closing direction of the ladder bodies 2-2) is defined as the front-rear direction of the stepladder 1, and the direction perpendicular to the left-right direction and the front-rear direction is defined as the up-down direction of the stepladder 1.

[0017] 1, a stepladder 1 according to this embodiment includes a pair of ladder bodies 2 and 2 having a common configuration. The ladder bodies 2 and 2 are arranged in a generally V-shaped configuration in side view with their lower ends spaced apart from each other, and their upper ends are rotatably connected by hinges 6 and 6.

[0018] The hinge 6 connects the opposing posts 3 and 3 of the ladder bodies 2 and 2 so that they can rotate relatively. That is, the ladder bodies 2 and 2 can rotate in directions in which they move toward and away from each other (the front-to-rear direction of the stepladder 1 in FIG. 1). In the stepladder 1 according to this embodiment, the posts 3, the rungs 4 and the top plate 5 are members made of light metal such as aluminum or an aluminum alloy.

[0019] Each ladder body 2 has a pair of long supports 3,3. The supports 3,3 are arranged so that the distance between them is greater at the bottom than at the top (approximately V-shaped when viewed from the front). The stepladder 1 according to this embodiment has four supports 3. Each support 3 is bent at two points along the longitudinal direction for the purpose of ensuring strength, etc. The support 3 is formed with a back plate 31 arranged on the outer side in the left-right direction and two side plates 32,32 adjacent to the back plate 31 and facing each other in the front-rear direction so that the cross-sectional shape perpendicular to the longitudinal direction is approximately U-shaped (see Figures 2 and 3). Note that in this embodiment, the support 3 is formed in an approximately U-shaped cross-section, but the support 3 can also be formed in a square tube shape.

[0020] A number of steps 4, 4..., which are hollow tubular members, are placed at a specified interval between a pair of posts 3, 3 in the ladder body 2. The steps 4 are formed by cutting a linear extrusion molded product with a specified cross-sectional shape to a specified length. As shown in Figures 2 and 3, each step 4 is formed with an upper surface portion 41 located on the upper side when in use, a lower surface portion 42 located on the lower side, an outer surface portion 43 located on the outer side in the front-to-rear direction, and an inner surface portion 44 located on the inner side in the front-to-rear direction.

[0021] Each step 4 is fixed between the opposing side plates 32, 32 of the support 3 by a rivet. Specifically, as shown in Fig. 5, an outer surface 43 and an inner surface 44 of the step 4 (the lowest step 4D in Fig. 5) are fixed to the side plates 32, 32 by a first rivet R1 and a second rivet R2. As the rivet in this embodiment, as shown in Fig. 5, a so-called blind rivet is used, in which the mandrel is pulled apart by an electric tool or the like to deform the inside of the cylindrical rivet and crimp it. Note that the step 4 can also be fixed to the support 3 by other fastening parts such as bolts, nuts, and screws.

[0022] Each step 4 has an uneven surface on both the upper and lower surfaces (see Figs. 2, 3, etc.). In this way, the stepladder 1 is configured to increase the frictional resistance of the upper surface of the step 4, making it less likely for the user's feet to slip, whether the stepladder 1 is in the upright position or in the ladder position.

[0023] Each ladder body 2 is provided at its upper end with a top plate 5 / 5 which is a hollow tubular member. The top plate 5 is formed by cutting a linear extrusion molding with a specified cross-sectional shape to a specified length. The top plate 5 is fixed between the opposing inner surfaces at the upper ends of the pillars 3 / 3 with rivets. In other words, the top plate 5 is provided in each ladder body 2 so as to connect the upper ends of the two pillars 3 / 3. It is also possible to fix the top plate 5 to the pillars 3 using other fastening parts such as bolts and nuts.

[0024] The stepladder 1 can be primarily in an in-use state or a closed state depending on the angle formed by the pair of ladder bodies 2 / 2 (more specifically, the angle formed by the supports 3 / 3, which move closer and farther apart as the ladder bodies 2 / 2 rotate relative to one another, in a side view; the same applies below).

[0025] When stepladder 1 is in use, it is supported by four posts 3 with the angle between ladder bodies 2 and 2 being approximately 30 degrees as shown in Figure 1. When in use, stepladder 1 is used in a state where it stands independently on the ground or floor. In the closed state, the angle between ladder bodies 2 and 2 is close to approximately 0 degrees. The closed state of stepladder 1 is mainly used when storing or transporting. Note that stepladder 1 can also be used in a ladder state by opening ladder bodies 2 and 2 to approximately 180 degrees.

[0026] The stepladder 1 is equipped with an opening prevention mechanism 7 that, when in use, determines the angle between the ladder bodies 2 and 2 and restricts their relative displacement (rotation) with respect to each other. Two sets of opening prevention mechanisms 7 are provided on both the left and right sides of the upper ends of the ladder bodies 2 and 2. The opening prevention mechanisms 7 connect the supports 3 that are located on the same side in the left-right direction and are spaced close to each other in a pair of ladder bodies 2 and 2 that are connected to each other.

[0027] In the stepladder 1 according to this embodiment, an end fitting 8 is fixed to the lower end of each of the posts 3. The end fitting 8 is a soft member made of synthetic resin such as polyvinyl chloride or elastomer, which is elastically deformable. In this embodiment, as shown in Figs. 2 to 7, the end fitting 8 provided on the right rear side of the stepladder 1 will be described. The other three end fittings 8 are configured similarly except that they are symmetrical in the front-rear and left-right directions, and detailed description thereof will be omitted.

[0028] 6, an insertion hole 81 is formed in a generally U-shape in plan view on the top surface of the end fitting 8, and the lower end of the post 3 is inserted into this insertion hole 81. An insertion groove 81a is formed in the inner peripheral surface of the insertion hole 81 in a portion covering the outer surface of the back plate 31 of the post 3 along the direction in which the post 3 is inserted. Furthermore, an inner wall 82 is formed in the portion covering the inner surface of the back plate 31 of the post 3. An engagement hole 83 that penetrates the inner wall 82 is opened in the inner wall 82.

[0029] 1 to 3, in the stepladder 1 according to this embodiment, reinforcing members 9 are fixed to the undersides of both left and right ends of the lowest step tread 4D disposed on the lowest step, and the lower ends of the reinforcing members 9 are fixed to the support posts 3. In this manner, the lowest step tread 4D spanning the lowest steps of the supports 3 and 3 is supported from below by the reinforcing members 9 fixed to the back panels 31 of the respective supports 3, thereby increasing its strength.

[0030] The reinforcing member 9 is a hard member integrally formed from synthetic resin such as nylon, polyacetal, ABS, etc. As shown in Figures 4(a) and (b), the reinforcing member 9 is formed in a triangular hollow shape. The reinforcing member 9 is composed of a support portion 91, an upper fixing portion 92, a lower fixing portion 93, an engagement portion 94, a support wall 95, a covering portion 96, etc.

[0031] The support part 91 is a diagonal member that receives a load in an oblique axial direction between the support 3 and the lowest step 4D. The upper fixing part 92 is formed at the upper end of the support part 91, and is fixed to the underside 42 of the lowest step 4D via a third rivet R3 as shown in Fig. 5. The lower fixing part 93 is formed at the lower end of the support part 91, and is fixed to the back plate 31 of the support 3 via a fourth rivet R4, which is a fastener, as shown in Fig. 5. In this case, the lower fixing part 93 of the reinforcing member 9 is disposed adjacent to the lower end of the support 3, as shown in Fig. 3.

[0032] It should be noted that a configuration may be adopted in which the upper fixing part 92 is fixed to the lowest step 4D without using a rivet. Specifically, a configuration may be adopted in which an insertion hole is opened in the lowest step 4D and the upper fixing part 92 is inserted into this insertion hole.

[0033] An engaging portion 94, which is an engaging protrusion that protrudes inward in the left-right direction (in a direction perpendicular to the back plate 31), is formed from the lower fixing portion 93 of the reinforcing member 9. The engaging portion 94 engages with an engaged hole 83 of the end tool 8, as described below. Furthermore, in the reinforcing member 9, a support wall 95 is formed along the back plate 31 in a portion facing the back plate 31 of the support 3. The outer end in the front-rear direction between the support portion 91 and the support wall 95 is covered by a covering portion 96.

[0034] In the stepladder 1 according to this embodiment, the end tool 8 is fixed to the lower part of the reinforcing member 9 with the lower end of the support 3 inserted inside. Specifically, as shown in Figures 6 and 7, the lower end of the support 3 is inserted into an insertion hole 81 formed in the end tool 8. At this time, the lower fixing part 93 and the engaging part 94 of the reinforcing member 9 are also inserted into the insertion hole 81, and the end tool 8 elastically deforms to match the shapes of the lower end of the support 3 and the lower fixing part 93 of the reinforcing member 9. Then, the engaging part 94 engages with the engaged hole 83, whereby the end tool 8 is fixed to the lower part of the reinforcing member 9.

[0035] In the stepladder 1 according to this embodiment, the end tool 8 is attached to the support 3 via the lower fixing portion 93 of the reinforcing member 9, so that the fixing strength of the end tool 8 to the support 3 can be increased. Specifically, the lower fixing portion 93 of the reinforcing member 9 can be made thicker than the back plate 31 of the support 3, so that the thickness that engages with the engaged hole 83 of the end tool 8 can be made larger. This allows the end tool 8 to be firmly attached to the support 3.

[0036] In addition, in the stepladder 1, the end fittings 8 are attached via the reinforcing members 9 that have been used conventionally, so the number of parts and the number of steps do not increase compared to a configuration in which a separate member is provided to fix the end fittings 8. In other words, the stepladder 1 according to this embodiment makes it possible to prevent an increase in costs.

[0037] In addition, in the stepladder 1, the end fitting 8 is fixed to the lower part of the reinforcing member 9 with the lower fixing part 93 of the reinforcing member 9 inserted inside. This allows the lower fixing part 93 to be covered with the inner wall 82 of the end fitting 8 as shown in Figures 2 and 3, thereby improving the design of the stepladder 1.

[0038] In addition, in the stepladder 1, the engaging portion 94 of the reinforcing member 9 engages with the engaged hole 83 of the end tool 8, thereby fixing the end tool 8 to the lower part of the reinforcing member 9. In this way, by eliminating the need for fasteners such as screws or rivets when attaching the end tool 8, the workability when attaching and detaching the end tool 8 to the support 3 can be improved.

[0039] In addition, the engaged hole 83 in the stepladder 1 is opened in the inner wall 82 that covers the inner surface of the back plate 31 in the end fitting 8. This allows the engaging portion between the lower fixing portion 93 of the reinforcing member 9 and the engaged hole 83 to be accommodated in the internal space (between the side plates 32, 32) of the post 3. Therefore, even if the engaging portion 94 in the reinforcing member 9 is formed large, the design of the stepladder 1 is not impaired, and the end fitting 8 can be firmly attached to the post 3.

[0040] 3, in the stepladder 1, the tip surface of the engaging portion 94 is positioned so as to protrude inward from the surface of the inner wall 82. This makes it possible to prevent dust and the like from accumulating in the engaged hole 83, and therefore makes it possible to keep the stepladder 1 clean. From the viewpoint of preventing dust and the like from accumulating in the engaged hole 83, it is acceptable to have the tip surface of the engaging portion 94 positioned on the same plane as the surface of the inner wall 82 (so that the tip surface of the engaging portion 94 and the surface of the inner wall 82 are positioned so as to be "flush").

[0041] In addition, in the stepladder 1, an insertion surface 94a is formed on the side of the lower end of the reinforcing member 9 farther from the back plate 31, which is inclined with respect to the insertion direction into the end tool 8. In this way, by reducing the thickness of the lower end of the reinforcing member 9, it is possible to easily insert the lower end of the support 3 and the reinforcing member 9 into the insertion hole 81 of the end tool 8. In addition, in the end tool 8 of the stepladder 1 according to this embodiment, an insertion surface 82a is formed on the upper end of the inner wall 82, which is inclined in the same direction as the insertion surface 94a. In this way, by enlarging the opening of the upper end of the insertion hole 81, it is possible to easily insert the lower end of the support 3 and the reinforcing member 9 into the insertion hole 81 of the end tool 8.

[0042] In addition, in the stepladder 1, the end tool 8 covers the fourth rivet R4, which is a fastener for fastening the lower fixing portion 93 of the reinforcing member 9 to the back plate. Specifically, as shown in Fig. 3 and Fig. 7, when the lower end portions of the support 3 and the reinforcing member 9 are inserted into the insertion hole 81 of the end tool 8, the head of the fourth rivet R4 is inserted into the insertion groove portion 81a formed on the inner peripheral surface of the end tool 8. As a result, the fourth rivet R4 is covered by the end tool 8. In this way, in the stepladder 1 according to this embodiment, the design of the stepladder 1 can be improved by covering the fourth rivet R4, which is a fastener for fastening the reinforcing member 9, with the end tool 8. [Explanation of symbols]

[0043] 1 Stepladder 2 Ladder body 3 Posts 4 Steps 4D Bottom step 5 Top plate 6 Hinge 7 Opening prevention mechanism 8 End fittings 9 Reinforcing members 31 Back plate 32 Side plate 41 Top part 42 Bottom part 43 External part 44 Inner part 81 Insertion hole 81a Insertion groove portion 82 Inner wall 82a Insertion surface 83 Engaged hole 91 Support part 92 Upper fixing part 93 Lower fixing part 94 Engagement part 94a Insertion surface 95 Support wall 96 Covering part R1 First rivet R2 Second rivet R3 Third rivet R4 Fourth rivet (fixture)

Claims

1. A ladder body comprising two posts, one or more rungs stretched between the two posts, and end fittings provided at the lower ends of the posts, The support pillar includes a back plate and two side plates adjacent to the back plate and facing each other, The tread bar that is bridged across the bottom of the support pillar is supported from below by a reinforcing member fixed to the back plate of each of the support pillars, The lower portion of the reinforcing member is disposed adjacent to the lower end of the support column, The end fitting is fixed to the lower part of the reinforcing member with the lower end of the support inserted therein, An engagement portion is formed at a lower portion of the reinforcing member, The end tool is formed with an engaged portion that engages with the engaging portion, The engaging portion and the engaged portion are engaged with each other, whereby the end tool is fixed to the lower portion of the reinforcing member, The engagement portion is an engagement protrusion that protrudes in a direction perpendicular to the back plate, A ladder body, wherein the engaged portion is an engaged hole opened in an inner wall covering the inner surface of the back plate at the end fitting.

2. The ladder body according to claim 1 , wherein the end fitting is fixed to the lower part of the reinforcing member with the lower part of the reinforcing member inserted therein.

3. The engaged hole is formed through the inner wall of the end tool, 3. A ladder body as described in claim 1 or claim 2, wherein the tip surface of the engagement projection is located flush with the surface of the inner wall or protrudes from the surface of the inner wall.

4. A ladder body as described in any one of claims 1 to 3, wherein the lower end of the reinforcing member has an insertion surface on the side farther from the back plate that is inclined with respect to the insertion direction into the end fitting.

5. A lower portion of the reinforcing member is fixed to the back plate by a fastener, A ladder body as claimed in any one of claims 1 to 4, wherein the end fittings cover the fasteners when fixed to the reinforcing members.

6. A climbing tool having at least one ladder body described in any one of claims 1 to 5.

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