Stepladder and release member for opening prevention mechanism

Abstract

To provide a stepladder capable of being constituted by adding a regulation release member to a stepladder that includes a conventional open-stop mechanism, and a regulation release member of the open-stop mechanism.SOLUTION: A stepladder 1 includes an open-stop mechanism 7 that regulates the relative displacement of a pair of ladder bodies 2. The open-stop mechanism 7 includes a regulation release member 9 that flexes the two sets of arm members. The regulation release member 9 includes: a pair of swing parts 91 and 91 attached to each of struts 3 and 3 in a swingable manner; engagement parts 92 and 92 formed at a position near the lower side of the arm member in the open state in each swing part 91 and 91; and an operation part 93 connected to each of the pair of swing parts 91 and 91 and arranged along the longitudinal direction of a top plate close to the top plate 5. By swinging swing parts 91 and 91 via the operation part 93 in the regulation release member 9 when in the open state, the engagement part 92 is displaced upward, and the engagement part 92 bends the arm member.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a stepladder, and more particularly to a deregulating member in a stepladder's opening prevention mechanism. [Background technology]

[0002] Conventionally, a stepladder having a configuration in which the ends of a pair of ladder bodies are rotatably connected has been used (see, for example, Patent Document 1). In such a stepladder, an opening stop mechanism provided between the posts constituting the pair of ladder bodies is used to restrict the relative displacement of the ladder bodies in the stepladder state. In the case of the stepladder described in Patent Document 1, the restriction can be released by operating the opening stop mechanism in the stepladder state, and the stepladder can be folded into a closed state.

[0003] Meanwhile, there is a stepladder that can be folded and closed by operating an opening prevention mechanism provided between the ladder bodies that make up the stepladder (for example, see Patent Document 2). In such a stepladder, a user can bring a pair of ladder bodies close to each other and close the stepladder by lifting an operating part of the opening prevention mechanism between the ladder bodies. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2016-33305 A [Patent Document 2] JP 2013-119745 A Summary of the Invention [Problem to be solved by the invention]

[0005] According to the stepladder described in Patent Document 1, an opening prevention mechanism is connected to each of the two posts constituting one of the ladder bodies. Therefore, when changing from the stepladder state to the closed state, the user of the stepladder needs to operate the two opening prevention mechanisms with both hands or operate each opening prevention mechanism with one hand. Therefore, when the user is holding a tool or in a situation where it is difficult to use both hands, it is not easy to change from the stepladder state to the closed state.

[0006] On the other hand, according to the stepladder described in Patent Document 2, the user can change the stepladder from the stepladder state to the closed state simply by lifting the operating part with one hand. However, such a configuration in which a pair of ladder bodies are connected by an opening and closing mechanism cannot be retrofitted to a conventional stepladder such as the stepladder described in Patent Document 1.

[0007] The present invention has been made in consideration of the above-mentioned situation, and the problem that the present invention aims to solve is to provide a stepladder and a de-regulation member for the opening stop mechanism that can be constructed by retrofitting a de-regulation member to a stepladder equipped with a conventional opening stop mechanism. [Means for solving the problem]

[0008] Means for solving the above problems will be described below.

[0009] The stepladder according to the present invention is a stepladder comprising a pair of ladder bodies each comprising two support posts, one or more rungs stretched between the two support posts, and a top plate connecting the upper ends of the two support posts, the pair of ladder bodies being connected at their upper ends so as to be rotatable relative to each other, and a mechanism for preventing the pair of ladder bodies from moving relative to each other when the pair of ladder bodies are in an open state in which the pair of ladder bodies are spaced apart at a predetermined distance, the ... The ladder body is positioned below both ends of the ladder body and is restricted from moving downward beyond that position, and in the open state, the rotating connecting part is displaced upward and the arm member is bent, thereby bringing the pair of ladder bodies into a closed state in which they are close to each other, and the restriction release member comprises a pair of swinging parts which are swingably attached to each of the two supports that constitute one of the ladder bodies, an engaging part formed in each of the swinging parts at a position near the underside of the arm member in the open state, and an operating part which is connected to each of the pair of swinging parts and is positioned along the longitudinal direction of the top plate close to the top plate, and when in the open state, the swinging parts are swung via the operating parts of the restriction release member, thereby displacing the engaging parts upward and bending the arm members.

[0010] In addition, in the stepladder according to the present invention, it is preferable that the deregulation member is formed with a restricting portion that restricts a relative angle of the deregulation member with respect to the support pillar.

[0011] In addition, in the stepladder according to the present invention, it is preferable that the rocking portion of the deregulation member is rotatably attached to the support pillar via a pivot shaft.

[0012] In addition, in the stepladder of the present invention, it is preferable that the deregulation member has a fixed piece formed on the swaying portion, the fixed piece being fixed to the support, and the fixed piece being elastically deformed to enable the swaying portion to swing.

[0013] In addition, in the stepladder of the present invention, it is preferable that the deregulation member has an axis portion formed on the swinging portion, and the axis portion is rotatably assembled to the support pillar via a support member.

[0014] The present invention also provides a restricting member for restricting the opening stop mechanism, which is provided on a stepladder in which a pair of ladder bodies, each of which comprises two posts, one or more rungs stretched between the two posts, and a top plate connecting the upper ends of the two posts, are connected at their upper ends so as to be rotatable relative to each other, and which is equipped with an opening stop mechanism for restricting the relative displacement of the pair of ladder bodies in an open state in which the pair of ladder bodies are spaced apart by a predetermined distance, the opening stop mechanism comprising two sets of arm bodies rotatably supported on the respective posts facing each other and spaced apart from each other on both sides of the pair of ladder bodies, and the arm bodies are connected at their tip ends so as to be rotatable relative to each other. The ladder has a member, and the deregulation member rotates one of the arm bodies upward to bend the two sets of arm members, and the ladder has a pair of swinging sections swingably attached to each of the two supports that constitute one of the ladder bodies, an engagement section formed in each of the swinging sections at a position near the lower side of the arm member in the open state, and an operating section connected to each of the pair of swinging sections and positioned along the longitudinal direction of the top plate close to the top plate, and when in the open state, the swinging sections are swung via the operating section of the deregulation member, causing the engaging sections to displace upward and bend the arm members. Effect of the Invention

[0015] The stepladder and the deregulation member for the opening stop mechanism according to the present invention have the advantage that they can be constructed by retrofitting the deregulation member to a stepladder equipped with a conventional opening stop mechanism. [Brief description of the drawings]

[0016] [Figure 1] FIG. [Diagram 2] FIG. [Diagram 3] 4A and 4B are perspective views showing a deregulation member and its assembly configuration. [Figure 4] A right side cross-sectional view showing the connection configuration of the ladder body. [Diagram 5] FIG. 13 is a right side cross-sectional view showing a state in which the restriction of the opening prevention mechanism is released. [Figure 6] 13A and 13B are perspective views showing a deregulation member according to a first modified example and its assembly configuration. [Figure 7] A right side cross-sectional view showing the connection configuration of the ladder body. [Figure 8] FIG. 13 is a right side cross-sectional view showing a state in which the restriction of the opening prevention mechanism is released. [Figure 9] 13A and 13B are perspective views showing a deregulation member according to a second modified example and its assembly configuration. [Figure 10] A right side cross-sectional view showing the connection configuration of the ladder body. [Figure 11] FIG. 13 is a right side cross-sectional view showing a state in which the restriction of the opening prevention mechanism is released. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] [Stepladder 1] A stepladder 1 according to one embodiment of the present invention will be described below with reference to Figs. 1 to 5. In this embodiment, the direction of the arrows shown in each figure defines the direction of the stepladder 1 in an open state (stepladder state) described below. That is, the axial direction (direction in which the rungs 4 are installed) of the rotation axis A (see the dashed line in Fig. 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.

[0018] 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 which are rotating fittings.

[0019] As shown in Fig. 2, the hinge 6 has a first hinge portion 6a and a second hinge portion 6b which are rotatably connected by a rotation support portion 6c. The first hinge portion 6a and the second hinge portion 6b are fixed to the upper ends of the pillars 3 and 3 on the same side in the left-right direction (facing and moving close to each other) via four rivets, which are fixing members. In this way, the hinge 6 connects the opposing pillars 3 and 3 so that they can rotate relatively. In other words, the ladder bodies 2 and 2 can rotate in directions in which they move close to each other and away from each other (the front-to-rear direction of the stepladder 1 in Fig. 1).

[0020] 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. Each support 3 is formed with a back panel 3b and two side panels 3s,3s adjacent to the back panel 3b and facing each other so that the cross section perpendicular to the longitudinal direction has an approximately U-shaped shape (see FIG. 3(b)). An end fitting 3a is fixed to the lower end of each support 3.

[0021] A plurality of steps 4, 4, . . . , which are hollow tubular members, are spanned 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 molding with a specified cross-sectional shape to a specified length. Each step 4 is fixed between the opposing inner surfaces of the posts 3 with rivets. In the stepladder 1 according to this embodiment, the posts 3, steps 4 and top plate 5 are members made of light metal such as aluminum or an aluminum alloy. The steps 4 can also be fixed to the posts 3 using other fastening parts such as bolts and nuts.

[0022] Each ladder body 2 is provided with a top plate 5 / 5, which is a hollow tubular member, at its upper end. 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 posts 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 posts 3 / 3. It is also possible to fix the top plate 5 to the post 3 using other fastening parts such as bolts and nuts. A gap is formed between the top plates 5 / 5 so that a user can insert his / her hands.

[0023] The stepladder 1 can be mainly in the following open or closed states, 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 due to the relative rotation of the ladder bodies 2 / 2, in a side view; the same applies below).

[0024] In the open state, as shown in FIG. 1, the ladder bodies 2 and 2 form an angle of approximately 30 degrees, and the stepladder 1 is supported by four posts 3. In the rest of this specification, the open state will be referred to as the "stepladder state." In the stepladder state, the stepladder 1 is used in a state in which it stands independently on the ground or a floor. In the closed state, the angle between the ladder bodies 2 and 2 is close to approximately 0 degrees. The closed state of the stepladder 1 is mainly used when storing or transporting.

[0025] As a third form, the stepladder 1 can be in a ladder state in which the angle between the ladder bodies 2 and 2 is approximately 180 degrees and the stepladder 1 is supported by two supports 3 on one side. That is, the stepladder 1 according to this embodiment is configured as a stepladder combined with a ladder. Note that the present invention is not limited to being applied to stepladders combined with ladders, but can be applied to all stepladders of other configurations, including dedicated stepladders.

[0026] The stepladder 1 is equipped with an opening prevention mechanism 7 that determines the angle between the ladder bodies 2 and 2 and restricts their relative displacement (rotation) when in the stepladder state. A total of two 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 posts 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] More specifically, the opening prevention mechanism 7 is rotatably supported on one of the supports 3 and 3 (the left support 3 in FIG. 2) that face each other and are spaced apart from each other on the ladder bodies 2 and 2. The opening prevention mechanism 7 is engageable with the other of the supports 3 and 3 (the right support 3 in FIG. 2) when the stepladder 1 is in the stepladder state. Since each opening prevention mechanism 7 has the same configuration, the opening prevention mechanism 7 on the left side will be mainly described in this embodiment.

[0028] As shown in Fig. 2, the opening prevention mechanism 7 is an arm member formed by connecting a first arm body 7a and a second arm body 7b. In the opening prevention mechanism 7 provided on the left side of the stepladder 1, the base end (the left end in Fig. 2) of the first arm body 7a is rotatably supported by a rotating shaft 7c at the upper part of the rear support 3. The tip end of the second arm body 7b is rotatably connected to the tip end of the first arm body 7a by a rotating connector 7d. It should be noted that in the opening prevention mechanism 7 provided on the right side of the stepladder 1, the base end of the first arm body 7a is rotatably supported by a rotating shaft 7c at the upper part of the front support 3.

[0029] An engagement end 7e is formed at the base end of the second arm body 7b. The engagement end 7e includes an engagement member 7f biased by a torsion spring 7h and an engagement hole 7g that can be expanded or contracted by the displacement of the engagement member 7f. The engagement member 7f is biased by the torsion spring 7h in a direction that contracts (closes) the engagement hole 7g. When the stepladder 1 is in the stepladder state, as shown in FIG. 1, the angle between the ladder bodies 2 and 2 is opened to about 30 degrees, and the engagement end 7e is engaged with a first lock pin P1 formed on the other support 3. At this time, the first lock pin P1 is inserted into the engagement hole 7g, and the engagement member 7f is biased by the torsion spring 7h, so that the engagement state between the engagement end 7e and the first lock pin P1 is maintained. The configuration of the engagement end formed on the second arm body 7b is not limited to this embodiment, and it is also possible to engage with the first lock pin P1 (as well as the second lock pin P2) with other configurations.

[0030] In this manner, in the stepladder 1, the base end of the first arm body 7a is rotatably supported on one of the support pillars 3, and the tip end of the second arm body 7b is rotatably connected to the tip end of the first arm body 7a and the base end is engageable with the other support pillar 3. In other words, in the opening prevention mechanism 7, the base ends of the first arm body 7a and the second arm body 7b are rotatably supported on the respective support pillars 3, 3 that face each other and are spaced apart from each other, and the tips of the first arm body 7a and the second arm body 7b are connected to each other so as to be rotatable relative to each other. In this embodiment, the rotation shaft 7c formed on one support pillar 3 and the first lock pin P1 formed on the other support pillar 3 are formed at the same vertical position.

[0031] The second arm body 7b has an angular range restricted relative to the first arm body 7a by a stopper (not shown). Specifically, the second arm body 7b can rotate about the rotary coupling part 7d from a state close to the first arm body 7a to a state where the angle is opened to about 185 degrees in the counterclockwise direction. In the stepladder 1 in the stepladder state, the rotary coupling part 7d of the first arm body 7a and the second arm body 7b is located downward due to their own weight in the natural state, so that the relative angle is about 185 degrees as shown in FIG. 2. As a result, the rotary coupling part 7d is located lower than both ends (the rotary shaft 7c and the first lock pin P1) of the first arm body 7a and the second arm body 7b, and downward displacement from this position is restricted.

[0032] In this way, when the stepladder 1 is in the stepladder state, the angle between the ladder bodies 2 and 2 is fixed at approximately 30 degrees by connecting the supports 3 and 3 with the opening stop mechanism 7. At this time, even if a force is applied to the ladder bodies 2 and 2 in a rotational direction that brings the ladder bodies 2 and 2 closer to each other, the ladder bodies 2 and 2 will not rotate relative to each other because the rotating connector 7d is located below both ends of the first arm body 7a and the second arm body 7b and downward displacement of the rotating connector 7d below this position is restricted.

[0033] Even if a force is applied to the ladder bodies 2·2 in a rotational direction that moves the ladder bodies 2·2 apart, the ladder bodies 2·2 will not rotate relative to each other because the posts 3·3 are connected by the opening stop mechanism 7. As a result, the angle between the ladder bodies 2·2 remains at approximately 30 degrees, and the stepladder 1 maintains the stepladder state. To release the engagement between the engagement end 7e and the first lock pin P1, the user can disengage the engagement end 7e from the first lock pin P1 by displacing the engagement member 7f against the biasing force of the torsion spring 7h.

[0034] When the stepladder 1 is closed, the first arm body 7a or the second arm body 7b is rotated so that the angle formed on the lower side between the first arm body 7a and the second arm body 7b is 180 degrees or less, with the engagement end 7e of the opening prevention mechanism 7 engaged with the first lock pin P1. Specifically, a force is applied to the rotating connector 7d from below, and the first arm body 7a and the second arm body 7b are rotated relative to each other so that the rotating connector 7d is displaced upward. This releases the angle restriction of the ladder bodies 2·2, and the ladder bodies 2·2 can be rotated so that the angle formed by the ladder bodies 2·2 is smaller than about 30 degrees. Then, the stepladder 1 is closed by making the angle formed by the ladder bodies 2·2 about 0 degrees. In this way, when the stepladder is in the stepladder state, the rotating connector 7d is displaced upward to bend the arm member consisting of the first arm body 7a and the second arm body 7b, and the stepladder 1 is in the closed state in which the ladder bodies 2·2 are close to each other.

[0035] When the stepladder 1 is put into the ladder state, the engagement end 7e of the opening prevention mechanism 7 is released from the first lock pin P1, and the angle between the ladder bodies 2 and 2 is opened to about 180 degrees, and the engagement end 7e is engaged with the second lock pin P2 formed on the upper end of the support 3. In this way, by connecting the support 3 and 3 with the opening prevention mechanism 7, the angle between the ladder bodies 2 and 2 is fixed at about 180 degrees. At this time, even if a force is applied to the ladder bodies 2 and 2 in a direction that changes the angle between the ladder bodies 2 and 2, the first arm body 7a and the second arm body 7b do not rotate relative to each other because the rotating shaft 7c, the rotating connector 7d, and the engagement end 7e are arranged on a straight line. Therefore, the angle between the ladder bodies 2 and 2 remains at about 180 degrees, and the stepladder 1 maintains the ladder state.

[0036] As described above, since the stepladder 1 according to this embodiment is configured as a stepladder that can also be used as a ladder, an engagement end 7e is provided at the base end of the second arm body 7b in the opening prevention mechanism 7, making the second arm body 7b detachable from the first lock pin P1 and the second lock pin P2 of the support 3. However, when the stepladder 1 is configured as a dedicated stepladder, it is also possible to configure the base end of the second arm body 7b to be rotatably and non-detachably connected to the position of the first lock pin P1 on the support 3.

[0037] [Deregulation material 9] In the stepladder 1 according to this embodiment, the opening prevention mechanism 7 includes a restriction release member 9 that releases the restriction on the relative displacement between the ladder bodies 2 and 2 when the stepladder 1 is in the stepladder state. As shown in Figures 2, 4, and 5, in this embodiment, the restriction release member 9 is provided on the upper part of the front ladder body 2.

[0038] As shown in Fig. 3, the restriction release member 9 in this embodiment is integrally formed with a pair of swinging portions 91, engagement portions 92 formed on each of the swinging portions 91, and an operation portion 93 connected to each of the swinging portions 91. In this embodiment, the restriction release member 9 is made of a resin member. Note that in this embodiment and in the modified examples described below, the restriction release member can also be formed by combining a plurality of members. In this case, it is also possible to form the restriction release member using other materials, such as metal members, other than resin materials.

[0039] In the restricting member 9 of this embodiment, the swinging portion 91 is formed in a boomerang shape ("L" shape) with the vertical center portion protruding forward in a side view. As shown in Figures 2 and 4, the swinging portions 91-91 are attached to each of the two posts 3-3 constituting the front ladder body 2 near the arm members constituting the opening prevention mechanism 7 (more specifically, between the top board 5 and the top step 4).

[0040] 3(b), the central portions of the swinging parts 91·91 are rotatably attached via pivot shafts 91a formed with screw members to the back plates 3b·3b of the two posts 3·3 that constitute the front ladder body 2. In this way, the swinging parts 91·91 are swingably attached to the two posts 3·3, respectively.

[0041] Each of the engagement portions 92 is formed to extend outward in the left-right direction from the lower end of the swinging portion 91. When the deregulation member 9 is attached to the ladder body 2, the engagement portions 92 are formed to protrude from a position near the lower side of the first arm body 7a or the second arm body 7b of the arm member in the open state, as shown in Figures 2 and 4. More specifically, the engagement portion 92 formed on the left side of the deregulation member 9 is disposed below the first arm body 7a of the opening prevention mechanism 7 provided on the left side. Meanwhile, the engagement portion 92 formed on the right side of the deregulation member 9 is disposed below the second arm body 7b of the opening prevention mechanism 7 provided on the right side.

[0042] 3(a), both ends of the operating unit 93 are connected to the upper ends of the pair of swinging units 91. The operating unit 93 is disposed close to the tabletop 5 along the longitudinal direction (left-right direction) of the tabletop 5. It is also possible to form operating units extending from the upper ends of each of the swinging units 91 toward the center, and to configure the operating units to overlap each other in the left-right direction between the swinging units 91.

[0043] In the stepladder 1 according to this embodiment, as shown in Fig. 3(b), the deregulation member 9 is inserted between the posts 3 and 3, and the swinging parts 91 are attached to the back plates 3b and 3b of the posts 3 and 3 by a screw member which serves as a pivot shaft 91a. In this manner, the deregulation member 9 can be attached to the ladder body 2 without using a separate assembly member such as a bracket. In other words, since the deregulation member 9 can be attached to the ladder body 2 with a simple structure, it is possible to reduce material costs and simplify the manufacturing process.

[0044] In the stepladder 1 according to this embodiment, the stepladder 1 can be put into a closed state by operating the restriction release member 9 in the stepladder state. Specifically, as shown by the imaginary line in Fig. 5, a user inserts his / her hand from under the top board 5 and pulls the operating portion 93 of the restriction release member 9 toward the top board 5 to swing the swinging portions 91·91. As a result, the engaging portions 92·92 are displaced upward as shown in Fig. 5, and the engaging portions 92·92 rotate the first arm body 7a and the second arm body 7b upward to bend the arm members.

[0045] As described above, by displacing the engaging portion 92 upward, the first arm body 7a and the second arm body 7b are rotated relative to each other so that the rotating connector 7d is displaced upward. This releases the restriction on the angle of the ladder bodies 2·2, and the ladder bodies 2·2 can be rotated so that the angle they form becomes smaller than approximately 30 degrees. Then, when the user lifts the top board 5, the ladder bodies 2·2 approach each other due to their own weight, the relative angle between them becomes approximately 0 degrees, and the stepladder 1 enters the closed state.

[0046] In this manner, in the stepladder 1 according to this embodiment, when the stepladder 1 is in the open state, the operating part 93 of the deregulation member 9 is displaced toward the top board 5 to swing the swinging parts 91-91, thereby displacing the engagement parts 92-92 upward to bend the arm members and place the stepladder 1 in the closed state. In addition, the user can lift the top board 5 immediately after pulling the operating part 93 in. In other words, the user of the stepladder 1 can perform the operation of changing the stepladder state to the closed state and the operation of lifting the stepladder 1 in the closed state almost simultaneously with one touch. The user of the stepladder 1 can also insert his / her hand between the top boards 5-5 to operate the operating part 93 from above the top board 5.

[0047] Moreover, the stepladder 1 according to this embodiment can be constructed by retrofitting the restriction release member 9 to a stepladder equipped with a conventional opening prevention mechanism. That is, since the restriction release member 9 can be attached to the ladder body 2 afterwards, it is possible to construct the stepladder 1 according to this embodiment by attaching the restriction release member 9 to a stepladder that does not have a restriction release member.

[0048] In the stepladder 1 according to this embodiment, when the ladder body 2 on which the deregulation member 9 is provided is placed on the upper side in the ladder state, the deregulation member 9 is displaced downwards by its own weight. For this reason, the operating unit 93 is positioned lower than the upper end surface of the adjacent top board 5 (upside down state in FIG. 5). This ensures that even when the user uses the stepladder 1 in the ladder state, the operating unit 93 is located above the top board 5 and does not become an obstacle to use.

[0049] On the other hand, when the stepladder 1 is in the ladder state in which the ladder body 2 to which the deregulating member 9 is attached is on the lower side, the operating part 93 is located lower than the adjacent top board 5 as shown in Fig. 4. That is, even in this case, the operating part 93 does not hinder the use of the top board 5.

[0050] As described above, in the stepladder 1 according to this embodiment, the restriction release member 9 provided in the opening prevention mechanism 7 releases the restriction on the relative displacement between the ladder bodies 2 and 2 when the stepladder 1 is in the stepladder state. This allows the user to transform the stepladder 1 from the stepladder state to the closed state simply by operating the restriction release member 9 with one hand. In other words, even in a situation where it is difficult for the user to use both hands, such as when the user is holding a tool, the stepladder 1 can easily transform from the stepladder state to the closed state.

[0051] The engaging portion 92 of the deregulation member 9 can be configured to be disposed below either the first arm body 7a or the second arm body 7b. In other words, as long as the engaging portion 92 is configured to be displaced upward to bend the arm member, the engaging portion 92 may be configured to be disposed below either the first arm body 7a or the second arm body 7b.

[0052] Furthermore, according to the stepladder 1 of this embodiment, the restriction release member 9 is integrally formed with the swinging portions 91-91, the engagement portions 92-92, and the operation portion 93. This allows the user of the stepladder 1 to release the restrictions of the opening prevention mechanisms 7 on both the left and right sides by simply operating the operation portion 93 once. In other words, the user can change the stepladder state from the closed state by simply operating the restriction release member 9 with one hand, making it easier to change the stepladder 1 from the stepladder state to the closed state.

[0053] 3, in the restriction release member 9 according to this embodiment, a restricting portion 91b that restricts the relative angle of the restriction release member 9 with respect to the support pillar 3 is formed on the swinging portion 91 and protrudes outward in the left-right direction. As shown in FIG. 5, when a user rotates the restriction release member 9, the restricting portion 91b abuts against a side plate 3s of the support pillar 3. This restricts the relative rotation angle of the restriction release member 9 with respect to the support pillar 3.

[0054] According to the stepladder 1 of this embodiment, the restriction release member 9 is provided only on one of the ladder bodies 2, but it is also possible to provide the restriction release member 9 on both of the ladder bodies 2. In this case, the restriction release member 9 can be operated on either the front or rear ladder body 2.

[0055] In addition, according to the stepladder 1 of this embodiment, the user can directly operate the opening prevention mechanism 7 to change the stepladder 1 from the stepladder state to the closed state without operating the restriction release member 9. Specifically, the user applies a force from below to the rotating connector 7d with his / her own hand, and rotates the first arm body 7a and the second arm body 7b relative to each other so that the rotating connector 7d is displaced upward. This releases the angle restriction of the ladder bodies 2·2, and the ladder bodies 2·2 can be rotated so that the angle formed by the ladder bodies 2·2 becomes smaller than about 30 degrees, and the stepladder 1 is in the closed state. In this way, the user of the stepladder 1 of this embodiment can change the stepladder 1 from the stepladder state to the closed state regardless of whether he / she operates the restriction release member 9 or the opening prevention mechanism 7.

[0056] [Restriction release member 19 (first modified example)] Next, a deregulating member 19 according to a first modified example that can be used in place of the deregulating member 9 in the stepladder 1 according to the embodiment will be described with reference to Figures 6 to 8. In each of the modified examples described after this modified example, the same components as those in the embodiment will be denoted by the same reference numerals and detailed description thereof will be omitted.

[0057] 6 to 8, the restriction release member 19 in this modified example is integrally formed with a pair of swinging portions 191, engagement portions 192 formed on each of the swinging portions 191, and an operating portion 193 connected to each of the swinging portions 191. In this modified example, the restriction release member 19 is made of an elastically deformable resin member.

[0058] In the restrictor release member 19 of this embodiment, the swinging portion 191 is formed in a boomerang shape ("L" shape) with the vertical center protruding forward in side view. As shown in Figures 6 to 8, the swinging portions 191 are attached to each of the two posts 3 that constitute the front ladder body 2 near the arm members that constitute the opening prevention mechanism 7 (more specifically, between the top board 5 and the top step 4).

[0059] As shown in Fig. 6(b), fixed pieces 191a are formed in the center of the swinging parts 191, and the fixed pieces 191a are fixed to the side plates 3s of the support pillars 3. In this modified example, the lower parts of the fixed pieces 191a are configured to be elastically deformable, as shown in Fig. 8. The elastic deformation of the lower parts of the fixed pieces 191a allows the swinging parts 191 to be swingably attached to the two support pillars 3, respectively.

[0060] Each of the engagement portions 192 is formed to extend outward in the left-right direction from the lower end of the swinging portion 191. Furthermore, the operation portion 193 is connected to each of the upper ends of the pair of swinging portions 191, 191. The configurations of the engagement portions 192 and operation portion 193 in this modified example are similar to the configurations of the engagement portions 92 and operation portion 93 in the above embodiment.

[0061] In this modified example, the stepladder can be put into the closed state by operating the restriction release member 19 in the stepladder state. Specifically, as shown by the imaginary line in Fig. 8, the user inserts his / her hand from under the top board 5 and pulls the operating portion 193 of the restriction release member 19 toward the top board 5. This causes the lower portions of the fixed pieces 191a to elastically deform, causing the swinging portions 191 to swing. Furthermore, as shown in Fig. 8, the engaging portions 192 are displaced upward, so that the engaging portions 192 rotate the first arm body 7a and the second arm body 7b upward to bend the arm members.

[0062] As described above, by displacing the engaging portion 192 upward, the first arm body 7a and the second arm body 7b are rotated relative to each other so that the rotating connector 7d is displaced upward. This releases the restriction on the angle of the ladder bodies 2·2, and the ladder bodies 2·2 can be rotated so that the angle they form becomes smaller than approximately 30 degrees. Then, when the user lifts the top board 5, the ladder bodies 2·2 approach each other due to their own weight, the relative angle between them becomes approximately 0 degrees, and the stepladder is in the closed state.

[0063] In this manner, in this modified example, when the stepladder is in the open state, the operating portion 193 of the deregulating member 19 is displaced toward the top board 5 to cause the swinging portions 191-191 to swing, thereby displacing the engaging portions 192-192 upward to bend the arm members and place the stepladder in the closed state. Also, the user can lift the top board 5 immediately after pulling the operating portion 193 in. That is, the user of the stepladder can perform the action of changing the stepladder state to the closed state and the action of lifting the stepladder in the closed state almost simultaneously with one touch. The user of the stepladder can also insert his / her hand between the top boards 5-5 and operate the operating portion 193 from above the top board 5.

[0064] In addition, the stepladder according to this modification can be constructed by retrofitting the restriction release member 19 to a stepladder equipped with a conventional opening prevention mechanism. That is, since the restriction release member 19 can be retrofitted to the ladder body 2, it is possible to construct the stepladder according to this embodiment by attaching the restriction release member 19 to a stepladder that does not have a restriction release member.

[0065] [Restriction release member 29 (second modified example)] Next, a restriction release member 29 according to a second modified example will be described with reference to Figures 9 to 11. As shown in Figures 9 to 11, restriction release member 29 in this modified example is formed by bending a single metal rod-shaped member, and is integrally and continuously formed with a pair of swinging portions 291, engagement portions 292 formed on each of the swinging portions 291, and an operating portion 293 connected to each of the swinging portions 291.

[0066] As shown in Fig. 9(a), in the restriction release member 29, the swinging portions 291 are formed so that the upper sides thereof are slightly inclined rearward. The upper ends of the swinging portions 291 are connected by an operating portion 293 arranged along the left-right direction. The lower ends of the swinging portions 291 are formed with shaft portions 291a extending outward in the left-right direction. The outer ends of the shaft portions 291a are formed with restricting portions 291b extending rearward. The rear ends of the restricting portions 291b are formed with engaging portions 292 extending outward in the left-right direction.

[0067] 9(b), the deregulation member 29 is attached to the pillars 3 and 3 via support members 294. Specifically, shaft portions 291a and 291a of the deregulation member 29 are rotatably attached to the side plate 3s of the pillar 3 via support members 294 and 294. In this manner, the swing portions 291 and 291 are made rotatable about the shaft portions 291a and 291a, so that the deregulation member 29 is swingably attached to each of the two pillars 3 and 3.

[0068] A support portion 294a extending rearward is formed on the support member 294. The restriction release member 29 is restricted from rotating rearward (falling over) by placing the restriction portion 291b on the upper surface of the support portion 294a.

[0069] When the deregulation member 29 is attached to the ladder body 2, the engagement portion 292 is formed to protrude from a position near the underside of the first arm body 7a or the second arm body 7b of the arm member in the open state, as shown in Fig. 10. More specifically, the engagement portion 292 formed on the left side of the deregulation member 29 is disposed below the first arm body 7a of the opening prevention mechanism 7 provided on the left side. On the other hand, the engagement portion 92 formed on the right side of the deregulation member 29 is disposed below the second arm body 7b of the opening prevention mechanism 7 provided on the right side.

[0070] 10, the operation unit 293 is disposed adjacent to the tabletop 5 along the longitudinal direction (left-right direction) of the tabletop 5. In this modification, the operation unit 293 is disposed so as to be located between the two tabletops 5.

[0071] In this modified example, the stepladder can be put into the closed state by operating the restriction release member 29 in the stepladder state. Specifically, as shown by the imaginary line in Fig. 11, the user inserts his / her hand from under the top board 5 and pulls the operating portion 293 of the restriction release member 29 toward the top board 5 to swing the swinging portions 291-291. As a result, the engaging portions 292-292 are displaced upward as shown in Fig. 11, and the engaging portions 292-292 rotate the first arm body 7a and the second arm body 7b upward to bend the arm members.

[0072] As described above, by displacing the engaging portion 292 upward, the first arm body 7a and the second arm body 7b are rotated relative to each other so that the rotating connector 7d is displaced upward. This releases the restriction on the angle of the ladder bodies 2·2, and the ladder bodies 2·2 can be rotated so that the angle they form becomes smaller than approximately 30 degrees. Then, when the user lifts the top board 5, the ladder bodies 2·2 approach each other due to their own weight, the relative angle between them becomes approximately 0 degrees, and the stepladder is in the closed state.

[0073] In this manner, in this modified example, when the stepladder is in the open state, the operating portion 293 of the deregulation member 29 is displaced toward the top board 5 to swing the swinging portions 291-291, thereby displacing the engagement portions 292-292 upward to bend the arm members and place the stepladder in the closed state. Also, the user can lift the top board 5 immediately after pulling the operating portion 293 in. That is, the user of the stepladder can perform the action of changing the stepladder state to the closed state and the action of lifting the stepladder in the closed state almost simultaneously with one touch. The user of the stepladder can also insert his / her hand between the top boards 5-5 and operate the operating portion 293 from above the top board 5.

[0074] In addition, the stepladder according to this modification can be constructed by retrofitting the restriction release member 29 to a stepladder equipped with a conventional opening prevention mechanism. That is, since the restriction release member 29 can be attached to the ladder body 2 afterward, it is possible to construct the stepladder according to this embodiment by attaching the restriction release member 29 to a stepladder that does not have a restriction release member. [Explanation of symbols]

[0075] 1 Stepladder 2 Ladder body 3 Post 3a End fitting 3b Back plate 3s Side plate 4 Stepping rail 5 Top plate 6 Hinge (rotating metal fitting) 6a First hinge part 6b Second hinge portion 6c Rotation support portion 7 Opening prevention mechanism 7a First arm body 7b Second arm body 7c Rotation axis 7d Rotating connection part 7e Engagement end part 7f Engagement member 7g Engagement hole 7h Torsion spring 9 Restriction release member 19. Deregulation member (first modified example) 29 Restriction release member (second modified example) 91 Swinging part 91a Rotating shaft 91b Regulating portion 92 Engagement portion 93 Operation section 191 Swinging part 191a Fixed piece 192 Engagement part 193 Operation part 291 Swinging part 291a Shaft part 291b Regulating portion 292 Engagement portion 293 Operating unit 294 Support member 294a Support part A Rotating axis P1 First lock pin P2 Second lock pin

Claims

1. A stepladder comprising a pair of ladder bodies each having two posts, one or more rungs stretched between the two posts, and a top plate connecting the upper ends of the two posts, the ladder bodies being connected at their upper ends so as to be capable of relative rotation, and the stepladder body is provided with an opening prevention mechanism for restricting relative displacement of the pair of ladder bodies when the pair of ladder bodies are in an open state in which they are spaced apart by a predetermined distance, The opening prevention mechanism includes two sets of arm members, each set of arm bodies being rotatably supported on one of the posts facing each other and spaced apart from each other on both sides of the pair of ladder bodies, and the arm bodies are connected at their respective tip ends so as to be rotatable relative to each other, and a restriction release member that rotates one of the arm bodies upward to bend the two sets of arm members, In an open state, a rotation connection portion of the arm body of the arm member is located below both ends of the arm body and is restricted from being displaced downward from the position, In the open state, the rotary connecting portion is displaced upward and the arm member is bent, so that the pair of ladder bodies are brought into a closed state in which they are close to each other, The restriction release member includes a pair of swinging parts that are swingably attached to each of the two posts that constitute one of the ladder bodies, an engagement part formed in each of the swinging parts at a position near the lower side of the arm member in the open state, and an operating part that is connected to each of the pair of swinging parts and is arranged along the longitudinal direction of the tabletop close to the tabletop, When the stepladder is in an open state, the swinging portion is swung via the operating portion of the deregulation member, whereby the engagement portion is displaced upward and bends the arm member.

2. The stepladder according to claim 1 , wherein the deregulation member is formed with a restricting portion that restricts a relative angle of the deregulation member with respect to the support pole.

3. The stepladder according to claim 1 or 2, wherein the deregulating member is assembled such that the swinging portion is rotatably mounted to the support via a pivot shaft.

4. The stepladder according to claim 1 or 2, wherein the deregulation member has a fixed piece formed on the swinging portion, the fixed piece being fixed to the support, and the swinging portion is made swingable by elastic deformation of the fixed piece.

5. The stepladder according to claim 1 or 2, wherein the deregulating member has an axis portion formed on the swinging portion, and the axis portion is rotatably attached to the support post via a support member.

6. A deregulating member for an opening prevention mechanism is provided on a stepladder, in which a pair of ladder bodies each having two posts, one or more rungs stretched between the two posts, and a top plate connecting the upper ends of the two posts are connected to each other at their upper ends so as to be capable of relative rotation, and the stepladder body is provided with an opening prevention mechanism that regulates the relative displacement of the pair of ladder bodies when the pair of ladder bodies are in an open state in which they are spaced apart by a predetermined distance, The opening prevention mechanism includes two sets of arm members, each set of arm bodies being rotatably supported on the respective support columns that face each other and are spaced apart from each other, and the distal ends of the arm bodies are connected to each other so as to be capable of rotating relative to each other, and the restriction release member rotates one of the arm bodies upward to bend the two sets of arm members, a pair of swinging parts that are swingably attached to each of the two posts that constitute one of the ladder bodies, an engagement part formed in each of the swinging parts at a position near the lower side of the arm member in the open state, and an operating part that is connected to each of the pair of swinging parts and is arranged along the longitudinal direction of the tabletop close to the tabletop, A restricting member for an opening prevention mechanism, in which when in an open state, the swinging portion is swung via the operating portion in the restricting member, thereby displacing the engaging portion upward and bending the arm member.

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