Stepladder

Abstract

To provide a stepladder that can be provided with a latch mechanism regardless of its size, and that can be easily changed from a stepladder state to a closed state.SOLUTION: A stepladder 1, which includes a pair of ladder bodies 2 and 2, each having two pillars 3 and 3, a plurality of treads 4 spanned between the pillars 3 and 3, and a top plate 5 connecting one ends of the pillars 3 and 3, in which the pair of ladder bodies are connected at the one ends thereof for relative rotation so as to be changeable between a closed state where the ladder bodies 2 and 2 are close together and a stepladder state where the ladder bodies 2 and 2 are separated in a spaced-apart manner, which includes a latch mechanism 7 that regulates the relative displacement between the ladder bodies 2 and 2 in the stepladder state and the latch mechanism 7 is provided with a release member 92 for releasing the regulation of the relative displacement of the ladder bodies 2 and 2 in the stepladder state, and in which the release member 92 is assembled to either one of the ladder bodies 2 via a pair of brackets 91 and 91 formed by a plurality of members and provided on both sides of the concerned ladder body 2 respectively.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a stepladder, and more particularly to a structure for preventing a stepladder from opening. [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, the configuration in which a pair of ladder bodies are connected by an opening stop mechanism in this way is limited in the position where it can be installed on the stepladder. In other words, since the opening stop mechanism is placed near the user's hand, it may be difficult to adopt it for a relatively large stepladder.

[0007] 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 stepladder that can be equipped with an opening prevention mechanism regardless of its size and can be easily changed from the stepladder state to the closed state. [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 including 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 rotatable relative to each other, and the stepladder is provided with an opening prevention mechanism that regulates the relative displacement of the pair of ladder bodies in an open state in which the pair of ladder bodies are spaced apart at a predetermined distance, the stepladder comprising: a back plate and two side plates adjacent to the back plate and facing each other; and the opening prevention mechanism that regulates the relative displacement of the pair of ladder bodies in an open state in which the pair of ladder bodies are spaced apart at a predetermined distance, the stepladder comprising: a back plate and two side plates adjacent to the back plate and facing each other; The ladder structure comprises two sets of arm members, each of which has an arm body rotatably supported on a support pillar and has a tip end portion of the arm body connected to each other so as to be capable of rotating relative to each other, and a restriction release member which rotates one of the arm bodies upward to bend the two sets of arm members, and in an open state, the rotation connection portions of the arm bodies in the arm members are positioned below both ends of the arm body and are restricted from moving downward from said positions, and in an open state, the rotation connection portions are displaced upward to bend the arm members, thereby forming a ladder structure in which the pair of ladder bodies are connected to each other. The restriction release member is formed by combining a plurality of members, and is formed with an engagement portion located below and adjacent to the arm members in an open state, an operating portion arranged along the longitudinal direction of the step bar or the tabletop adjacent to the step bar or the tabletop, and a linking portion arranged along the longitudinal direction of the support pillar to link the engagement portion and the operating portion, the linking portions being provided on both ends of the operating portion, and the engagement portions being provided on both ends of the restriction release member so as to be able to bend the two sets of arm members, and the restriction release member is The ladder body is attached to the ladder body via a pair of brackets provided on both sides of the ladder body, and the brackets have a bracket main body portion that accommodates the connecting portion of the deregulation member and a clip portion, and are fixed to the support by clamping one of the side plates of the support between the bracket main body portion and the clip portion.When in the open state, by displacing the operating portion of the deregulation member upward, the engaging portion is displaced upward, and the engaging portion bends the arm member. Effect of the Invention

[0010] According to the stepladder of the present invention, an opening prevention mechanism can be provided regardless of the size of the stepladder, and it has the advantage that it can be easily changed from the stepladder state to the closed state. [Brief description of the drawings]

[0011] [Figure 1] FIG. [Diagram 2] FIG. [Diagram 3] Right side cross-sectional view showing the connection configuration of the ladder body. [Figure 4] FIG. 13 is a right side cross-sectional view showing a state in which the restriction of the opening prevention mechanism is released. [Diagram 5] FIG. [Figure 6] FIG. 4 is a diagram showing the structure of a restriction release unit. [Figure 7] FIG. [Figure 8] Cross-sectional view taken along line XX in Figure 6. [Figure 9] FIG. [Figure 10] FIG. [Figure 11] 1A to 1C are perspective views showing a bracket. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] A stepladder 1 according to one embodiment of the present invention will be described below with reference to Figs. 1 to 11. In this embodiment, the direction of the arrow shown in Fig. 1 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.

[0013] 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.

[0014] 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 columns 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. This allows the hinge 6 to connect the opposing columns 3 and 3 to be rotatable relative to each other. That is, the ladder bodies 2 and 2 are rotatable in the direction in which they move close to each other (the front-rear direction of the stepladder 1 in FIG. 1). In this embodiment, of the three rivets that fix the hinge 6 to the front column 3, the two rivets R and R (see FIG. 3 and FIG. 4) located on the rear side function as positioning members for a bracket 91, which will be described later.

[0015] 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 plate 3b and two side plates 3s,3s adjacent to the back plate 3b and facing each other so that the cross section perpendicular to the longitudinal direction has an approximately U-shaped shape (see FIG. 8). An end fitting 3a is fixed to the lower end of each support 3.

[0016] 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.

[0017] 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.

[0018] 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).

[0019] 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.

[0020] 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.

[0021] 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.

[0022] 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.

[0023] 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.

[0024] 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.

[0025] 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.

[0026] 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.

[0027] 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.

[0028] 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.

[0029] 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.

[0030] 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.

[0031] 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.

[0032] In the stepladder 1 according to this embodiment, the opening prevention mechanism 7 includes a restriction release part 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 to 4, in this embodiment, the restriction release part 9 is provided on the rear surface of the upper part of the front ladder body 2.

[0033] As shown in Figure 5, the deregulation section 9 comprises brackets 91, 91 (more specifically, a left bracket 91L provided on the left support 3 and a right bracket 91R provided on the right support 3 (see Figures 5 and 6)) provided on the rear side panels 3s of the left and right supports 3, 3 of the front ladder body 2, and a rod-shaped deregulation member 92, the left and right ends of which are supported by the left and right brackets 91, 91 and which is spanned between the brackets 91, 91. In this embodiment, the left bracket 91L and the right bracket 91R have the same configuration except that they are formed symmetrically, so the following will describe the left bracket 91L and a detailed description of the right bracket 91R will be omitted.

[0034] In this embodiment, the deregulation member 92 is formed by combining a plurality of members (three in this embodiment). Specifically, as shown in Fig. 10, the deregulation member 92 is formed by assembling two metal rod-shaped members bent into a crank shape to a resin columnar member. The columnar member may be made of metal such as an aluminum alloy.

[0035] The metal rod-shaped member has an outer end formed as an engagement portion 92a and an inner end formed as an insertion portion 92d. A linking portion 92c is formed between the engagement portion 92a and the insertion portion 92d, and is substantially perpendicular to the engagement portion 92a and the insertion portion 92d. The columnar member is formed in an isosceles trapezoid shape in a cross-sectional view perpendicular to the longitudinal direction, and is formed as an operation portion 92b.

[0036] Holes 92e are formed at both ends of the operating portion 92b. As shown in Fig. 10, by inserting the insertion portions 92d into the respective holes 92e, the restriction release member 92 is formed by combining a rod-shaped member and a columnar member. In this manner, the restriction release member 92 is formed by combining a pair of rod-shaped members, each having an engagement portion 92a and a linking portion 92c integrally formed at both ends, with the operating portion 92b provided in the center.

[0037] In the deregulation member 92, the hole 92e formed in the operating portion 92b is formed with a diameter slightly larger than that of the insertion portion 92d. Therefore, when forming the deregulation member 92, the insertion portion 92d is loosely fitted into the hole 92e (see Figs. 7 and 9). This allows the operating portion 92b and the rod-shaped members constituting the engaging portion 92a and the linking portion 92c to rotate relatively around an axis extending in the longitudinal direction of the operating portion 92b, and also to be relatively displaceable in the axial direction.

[0038] 9, in the restriction release member 92, a sliding surface 92f is formed on the front surface (surface corresponding to the base side of the isosceles trapezoid) of the operation portion 92b. In addition, in the restriction release member 92, an operation surface 92g is formed on the lower surface (surface corresponding to the lower side of the isosceles trapezoid) of the operation portion 92b.

[0039] 2 and 3, when the stepladder 1 is in the stepladder state, each of the engagement portions 92a-92a of the deregulation member 92 is disposed below the first arm body 7a or the second arm body 7b of each arm member provided on both the left and right sides of the ladder body 2. Specifically, as shown in Fig. 6, the engagement portion 92a extending to the left side of the stepladder 1 is disposed below the first arm body 7a of the opening prevention mechanism 7 provided on the left side. On the other hand, as shown in Fig. 6, the engagement portion 92a extending to the right side of the stepladder 1 is disposed below the second arm body 7b of the opening prevention mechanism 7 provided on the right side.

[0040] 3 and 6, when the stepladder 1 is in the stepladder state, the operating unit 92b is disposed on the underside close to the top board 5 along the longitudinal direction of the top board 5. The linking units 92c-92c are disposed along the longitudinal direction of the support posts 3 and link the engaging units 92a-92a and the operating unit 92b.

[0041] The deregulating member 92 is attached to the ladder body 2 via a pair of brackets 91, 91 provided on both sides of the front ladder body 2. As shown in Figures 5 and 6, the bracket 91 is a long member provided along the side plate 3s of the support 3.

[0042] 11(a) to (c), the bracket 91 includes a bracket main body 91a that houses the connecting portion 92c of the deregulation member 92, and a clip portion 91b. An opening 91c that opens in the horizontal direction is formed in the lower rear surface of the bracket main body 91a. The opening 91c is an insertion port for inserting the deregulation member 92 into the bracket 91 in a state where it is attached to the ladder body 2 (see FIG. 5).

[0043] As shown in Fig. 11, a sliding contact portion 91h is formed on the upper side of the front inner peripheral surface of the bracket main body 91a. A restricting wall 91f is formed on the side surface of the bracket main body 91a as a restricting portion that restricts the engaging portions 92a of the restricting member 92 from being displaced in a direction in which they approach each other. A bottom portion 91i that supports the engaging portions 92a of the restricting member 92 is formed on the lower end portion of the bracket main body 91a. A guide protrusion 91g that protrudes toward the inside of the bracket main body 91a is formed near the upper side of the opening 91c on the rear inner peripheral surface of the bracket main body 91a.

[0044] A slit 91j is formed between the bracket main body 91a and the clip portion 91b. Then, as shown in Fig. 8, the rear side plate 3s of the post 3 is inserted into the slit 91j and the side plate 3s is sandwiched between the bracket main body 91a and the clip portion 91b, whereby the bracket 91 is fixed to the post 3.

[0045] Specifically, the bracket main body 91a of the pair of brackets 91-91 is formed in a cylindrical shape with the opposing sides (the inner sides of the ladder body 2) open. A plurality of insertion protrusions 91k are formed protruding from the side of the bracket main body 91a facing the slit 91j. When the side plate 3s of the support 3 is inserted into the slit 91j, the insertion protrusions 91k are inserted into recesses formed in the side plate 3s, and the side plate 3s is clamped between the bracket main body 91a and the clip portion 91b.

[0046] At the tip of the clip portion 91b, a flange portion 91d is formed by bending the flange portion 91b at a substantially right angle along the longitudinal direction of the bracket 91. Two positioning portions 91e·91e are formed in a cut-out shape at a midpoint in the longitudinal direction of the flange portion 91d. When the bracket 91 is attached to the support 3, rivets R for fixing the hinges 6 are inserted into the positioning portions 91e (see Figs. 3 and 4). This determines the position of the bracket 91 relative to the ladder body 2.

[0047] In this manner, in this embodiment, the bracket 91 is configured to be easily positioned without the need for a separate positioning member. Note that when positioning the bracket 91, it is also possible to configure it to be positioned relative to the support post 3 by a fastener that fixes a member other than the hinge 6 to the support post 3 (for example, a rivet that fixes the tread 4 to the support post 3, or an axis member that rotatably supports the opening prevention mechanism 7 on the support post 3, etc.).

[0048] When assembling the brackets 91 and the deregulation member 92 constituting the deregulation section 9 to the ladder body 2, first, as shown in Fig. 5, the two brackets 91-91 (left bracket 91L and right bracket 91R) are fixed from the inside to the side plates 3s of the posts 3 on both the left and right sides. Then, the deregulation member 92 is inserted through the openings 91c-91c of the brackets 91-91. At this time, the upper side of the openings 91c on the rear surface of the bracket main body 91a is elastically deformed by the deregulation member 92.

[0049] 6, when the engaging portion 92a of the restriction release member 92 passes through the opening 91c, the engaging portion 92a and the linking portion 92c of the restriction release member 92 are housed inside the bracket 91. Inside the bracket 91, the restriction release member 92 is supported by a bottom portion 91i of the bracket 91.

[0050] When the restriction release member 92 is attached to the brackets 91-91 as described above, a sliding surface 92f of the operating portion 92b and a sliding contact portion 91h, which is the inner peripheral surface of the bracket main body 91a, come into sliding contact with each other as shown in Fig. 9. This restricts the rotation of the operating portion 92b relative to the bracket 91. When the stepladder 1 is in the open state, the operating portion 92b is disposed in a position in which the operating surface 92g is horizontally facing downward.

[0051] In the stepladder 1 according to this embodiment, the stepladder 1 can be put into the closed state by operating the restriction release member 92 in the stepladder state. Specifically, as shown in Fig. 4, a user inserts his / her hand below the top board 5 and pushes up the operation surface 92g of the restriction release member 92, displacing the operation portion 92b upward. This displaces the linkage portions 92c·92c and the engagement portions 92a·92a upward. Then, the engagement portions 92a·92a rotate the first arm body 7a and the second arm body 7b upward to bend the arm members.

[0052] That is, by displacing the engaging portion 92a 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 supports the top board 5 from below, the ladder bodies 2·2 move closer to each other due to their own weight, the relative angle between them becomes approximately 0 degrees, and the stepladder 1 enters the closed state.

[0053] In this embodiment, the engaging portions 92a-92a are configured to bend the arm member consisting of the first arm body 7a and the second arm body 7b when the vertical position of at least a part of the operating surface 92g of the operating portion 92b approaches the underside of the tabletop 5 located directly above the restriction release member 92. This makes it possible to transform the stepladder 1 from the open state to the closed state even when the user pushes up either the left or right end of the operating surface 92g.

[0054] In this way, when the stepladder 1 is in the stepladder state, the user can operate the operation unit 92b to place the stepladder 1 in the closed state. Also, the user can lift the top board 5 immediately after operating the operation unit 92b upward. That is, the user of the stepladder 1 can perform the operation of changing the stepladder state from the stepladder state to the closed state and the operation of lifting the stepladder 1 in the closed state almost simultaneously with one touch.

[0055] In this embodiment, the operation portion 92b is formed of a resin columnar member, thereby increasing the rigidity of the operation portion 92b in the longitudinal direction. Therefore, even if the user lifts the table top 5 immediately after operating the operation portion 92b, bending or deformation of the operation portion 92b can be suppressed.

[0056] When stepladder 1 is in the stepladder state, the operating part of the restriction release member can be operated to pivotally displace the linking part, thereby rotating first arm body 7a and second arm body 7b relative to each other. This configuration also releases the angle restriction of ladder bodies 2 and 2, and stepladder 1 can be put into the closed state.

[0057] In the stepladder 1 according to this embodiment, when the ladder body 2 on which the deregulating unit 9 is provided is on the upper side in the ladder state, the deregulating member 92 is located downward due to its own weight. Therefore, the operating unit 92b is located lower than the upper end surface of the adjacent top board 5 (upside down state in FIG. 4). This ensures that even when the user uses the stepladder 1 in the ladder state, the operating unit 92b is located above the back surface 5R of the top board 5 and does not become an obstacle to use.

[0058] On the other hand, when the stepladder 1 is in the ladder state in which the ladder body 2 on which the deregulation unit 9 is provided is on the lower side, the operating unit 92b is located lower than the adjacent top board 5 as shown in Fig. 3. That is, even in this case, the operating unit 92b does not impede the use of the top board 5.

[0059] As described above, in the stepladder 1 according to this embodiment, the restriction release member 92 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 92 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.

[0060] Furthermore, according to the stepladder 1 of this embodiment, the operating part 92b of the deregulation unit 9 is configured to be located near the top board 5, but by changing the shapes of the bracket 91 and the linking part 92c, it is also possible to configure the operating part 92b to be located near the step 4. In this case, since the operating part 92b can be operated near the step 4, operability is not impaired even when the stepladder 1 is relatively long and the top board 5 is positioned high.

[0061] As described above, when the operating part 92b is disposed near the step 4, the engaging parts 92a-92a are configured to bend the arm member consisting of the first arm body 7a and the second arm body 7b when the vertical position of at least a part of the operating surface 92g of the operating part 92b approaches the underside of the step 4 located directly above the restriction release member 92. This makes it possible to transform the stepladder 1 from the open state to the closed state even when the user pushes upward either the left or right end of the operating surface 92g.

[0062] In this way, in the stepladder 1 according to this embodiment, the degree of freedom in arranging the operating unit 92b can be increased by changing the shape of the restriction release member 92. That is, in a stepladder 1 of a relatively large size, even if the opening stop mechanism 7 is at a height that is difficult for the user to reach, the operating unit 92b can be arranged near the user's hand. That is, according to the stepladder 1 according to this embodiment, it is possible to provide the opening stop mechanism 7 and the restriction release unit 9 regardless of the size of the stepladder 1.

[0063] The engaging portion 92a of the deregulation member 92 may be arranged below either the first arm body 7a or the second arm body 7b. In other words, as long as the engaging portion 92a is displaced upward to bend the arm member, the engaging portion 92a may be arranged below either the first arm body 7a or the second arm body 7b.

[0064] Furthermore, according to the stepladder 1 of this embodiment, in the restriction release member 92, the linking portions 92c are provided on both ends of the operating portion 92b, and the engaging portions 92a are provided on both ends of the restriction release member 92 so that the two sets of arm members can be bent. This allows the user of the stepladder 1 to release the restrictions of the opening stop mechanisms 7 on both the left and right sides by simply operating the operating portion 92b once. In other words, the user can change the stepladder 1 from the stepladder state to the closed state by simply operating the restriction release member 92 with one hand, making it easier to change the stepladder 1 from the stepladder state to the closed state.

[0065] In addition, according to the stepladder 1 of this embodiment, the deregulating unit 9 is provided only on one of the ladder bodies 2, but it is also possible to provide the deregulating unit 9 on both of the ladder bodies 2. In this case, the operating unit 92b can be operated in the vicinity of either the front or rear top board 5.

[0066] Furthermore, 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 92. 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 92 or the opening prevention mechanism 7.

[0067] As described above, in the stepladder 1 according to this embodiment, the deregulation member 92 is formed by combining two rod-shaped members bent into a crank shape to form the engagement portion 92a and the linking portion 92c, and a columnar member to form the operation portion 92b. This makes it easy to adjust the shape, such as aligning the rod-shaped members with the columnar member, when forming the deregulation member 92. Therefore, compared to forming the deregulation member from a single member (for example, forming the member by bending a single rod-shaped member), the dimensional accuracy of each part can be set low. That is, the deregulation member 92 can be formed with high accuracy with a simple configuration.

[0068] In addition, the deregulation member 92 in this embodiment is formed by loosely fitting one end (insertion portion 92d) of a rod-shaped member constituting the engagement portion 92a and the linkage portion 92c into a hole portion 92e formed at both ends of the operation portion 92b. As a result, even if an external force is applied to the deregulation member 92 and the engagement portion 92a or the linkage portion 92c is deformed relative to the operation portion 92b, the rod-shaped member and the columnar member are allowed to move relative to each other, so that the deregulation member 92 can return to its original shape. In other words, the degree of freedom of the shape of the deregulation member 92 can be increased, so that the deregulation member 92 can be prevented from being stuck inside the bracket 91 and becoming difficult to displace up and down while maintaining the deformed state.

[0069] In the present embodiment, the rod-shaped members constituting the engaging portion 92a and the linking portion 92c and the operating portion 92b are relatively rotatable about an axis in the longitudinal direction (left-right direction) of the operating portion 92b and relatively displaceable in the axial direction. This allows the degree of freedom of the shape of the restriction release member 92 to be increased, allowing the restriction release member 92 to be displaced more smoothly inside the bracket 91.

[0070] In the restriction release member 92 of this embodiment, a sliding surface 92f is formed on the operating portion 92b. When the restriction release member 92 is attached to the bracket 91, the sliding surface 92f comes into sliding contact with a sliding contact portion 91h, which is the inner peripheral surface of the bracket main body 91a, thereby restricting the rotation of the operating portion 92b relative to the bracket 91. This makes it possible to always keep the attitude of the operating portion 92b relative to the bracket 91 constant and to stably position the operating portion 92b.

[0071] In the restrictor release member 92 of this embodiment, an operation surface 92g is formed on the operation portion 92b, and the operation portion 92b is provided such that the operation surface 92g faces downward and is horizontal when in the open state as shown in Fig. 9. This allows the user to always touch the operation surface 92g when operating the operation portion 92b, thereby improving the user's operation feel.

[0072] Furthermore, in the stepladder 1 according to this embodiment, the bracket main body 91a of the bracket 91 is formed with an opening 91c into which the deregulation member 92 can be inserted when the bracket 91 is attached to the ladder body 2. In this manner, in this embodiment, it is not necessary to assemble the bracket 91 and the deregulation member 92 to the ladder body 2 at the same time, and the bracket 91 and the deregulation member 92 can be assembled to the ladder body 2 in stages. In other words, since the deregulation portion 9 can be easily assembled to the ladder body 2, the assembly of the stepladder 1 can be easily performed.

[0073] In the stepladder 1 according to this embodiment, the opening 91c formed in the bracket main body 91a is formed on the surface of the bracket main body 91a opposite to the clip portion 91b (the rear surface in this embodiment). This makes it possible to insert the deregulating member 92 from the opening 91c in a state in which the bracket 91 is attached to the ladder body 2 via the clip portion 91b.

[0074] In the stepladder 1 according to this embodiment, a bottom portion 91i is formed at the lower end of the bracket main body portion 91a, which supports the engaging portion 92a of the restriction release member 92. By supporting the engaging portion 92a with this bottom portion 91i, it becomes possible for the bracket 91 to stably hold the restriction release member 92.

[0075] Furthermore, in the stepladder 1 according to this embodiment, the bracket main body 91a is formed with a restricting wall 91f as a restricting portion that restricts the engaging portions 92a from moving inward toward each other when the restricting release member 92 is positioned at the bottom inside the bracket 91. This prevents the engaging portions 92a from moving inward, resulting in insufficient engagement between the engaging portions 92a and the first arm body 7a and the second arm body 7b and preventing the arm members from bending.

[0076] In this embodiment, the restricting wall 91f of the bracket main body 91a is formed below the opening 91c, thereby allowing elastic deformation of the upper side of the opening 91c in the bracket main body 91a when the restricting member 92 is inserted into the opening 91c.

[0077] It is also possible to form a restricting protrusion on the inner surface of the bracket main body 91a as a restricting portion that restricts the engaging portions 92a of the restricting member 92 from moving inward so as to approach each other.

[0078] In the stepladder 1 according to this embodiment, as shown in Figures 8, 9, and 11, a guide protrusion 91g is formed on the inner surface of the bracket main body 91a above the opening 91c to restrict deformation of the engagement portions 92a of the deregulation member 92 in a direction in which they approach each other. As a result, when the deregulation member 92 is inserted into the opening 91c, the guide protrusion 91g engages with the linking portion 92c of the deregulation member 92. This makes it possible to prevent the deregulation member 92 from being deformed by the elastic force of the bracket main body 91a so that the engagement portions 92a approach each other, and makes it possible to smoothly accommodate the deregulation member 92 inside the bracket 91. [Explanation of symbols]

[0079] 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. Deregulation Department 91 Bracket 91L Left Bracket 91R Right bracket 91a Bracket body 91b Clip part 91c Opening 91d flange 91e positioning part 91f Restriction wall (restriction part) 91g Guide protrusion 91h Sliding contact part 91i Bottom part 91j slit 91k insertion protrusion 92 Restriction release member 92a Engagement portion 92b Operation section 92c Linking section 92d Insertion part 92e Hole part 92f Sliding surface 92g Operation surface A Rotating shaft P1 First lock pin P2 Second lock pin R rivet

Claims

[Claim 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 support pillar includes a back plate and two side plates adjacent to the back plate and facing each other, 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 deregulation member is formed by combining a plurality of members, and is formed with an engagement portion located below and adjacent to the arm member when in an open state, an operation portion arranged along the longitudinal direction of the step or the tabletop adjacent to the step or the tabletop, and a linking portion arranged along the longitudinal direction of the support pillar to link the engagement portion and the operation portion, the linking portions being provided on both ends of the operation portion, and the engagement portions being provided on both ends of the deregulation member so as to be able to bend the two sets of arm members, The deregulating member is attached to the ladder body via a pair of brackets provided on both sides of one of the ladder bodies, The bracket includes a bracket main body portion that houses the linking portion of the deregulation member, and a clip portion, and is fixed to the support by clamping one of the side plates of the support between the bracket main body portion and the clip portion, When the stepladder is in an open state, the operating portion of the deregulation member is displaced upward, causing the engagement portion to displace upward and bend the arm member.

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