JP-7856245-B2 - stepladder

JP7856245B2JP 7856245 B2JP7856245 B2JP 7856245B2JP-7856245-B2

Inventors

泉幸治

Assignees

長谷川工業株式会社

Dates

Publication Date: 20260511
Application Date: 20250205

Claims (2)

A stepladder comprising a pair of ladder bodies each having two support posts, one or more rungs spanning 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 equipped with an opening mechanism that restricts the relative displacement of the pair of ladder bodies when they are in an open state separated by a predetermined distance , The opening stopper mechanism comprises two sets of arm members, each arm rotatably supported on opposite and spaced-together support columns on both sides of the pair of ladder bodies, with the ends of the arm members connected to each other so as to be rotatable relative to each other; and a release member that rotates one of the arm members upward to bend the two sets of arm members . The restriction release member comprises an engaging portion that engages with the arm member when in the open state, and an operating portion arranged along the longitudinal direction of the rung or the top plate. When in the open state, displacing the operating portion of the restriction release member causes the engaging portion to be displaced, the arm member to bend, and the pair of ladder bodies are brought into a closed state in close proximity. A stepladder having a sliding contact surface formed on the operating section that moves substantially parallel to the support column .
The stepladder according to claim 1, wherein an operating surface is formed on the operating section, and the operating section is provided such that the operating surface is horizontal and facing downwards when the section is in the open position.

Description

This invention relates to a stepladder, and more particularly, to a mechanism for preventing the stepladder from opening. Conventionally, stepladders have been used in which the ends of a pair of ladder sections are rotatably connected (see, for example, Patent Document 1). In such stepladders, a mechanism is used to restrict the relative displacement of the ladder sections when the stepladder is in use, by providing an opening-stopping mechanism between the support columns constituting the pair of ladder sections. In the case of the stepladder described in Patent Document 1, the restriction can be released by operating the opening-stopping mechanism when the stepladder is in use, allowing the stepladder to be folded into a closed state. On the other hand, stepladders are used that can be folded into a closed state by operating an opening-locking mechanism provided between the ladder sections (see, for example, Patent Document 2). In such stepladders, the user can lift the operating part of the opening-locking mechanism between the ladder sections to bring the pair of ladder sections closer together and close the stepladder. Japanese Patent Publication No. 2016-33305Japanese Patent Publication No. 2013-119745 A perspective view showing a step ladder in a step-ladder configuration.A left side view showing the connection configuration of the ladder body.A right-side cross-sectional view showing the connection configuration of the ladder body.A cross-sectional view of the right side showing the state with the opening restraint mechanism released.An exploded view showing the assembly structure of the de-regulation section.A diagram showing the structure of the de-regulation section.A cross-sectional view showing the internal structure of the bracket.Cross-sectional view along line X-X in Figure 6.Right side view showing the bracket.Exploded perspective view of the de-regulation component.(a) through (c) are perspective views showing the brackets. The following describes a stepladder 1 according to one embodiment of the present invention, using Figures 1 to 11. In this embodiment, the direction of the stepladder 1 in the open state (stepladder state), described later, is defined by the direction of the arrows shown in Figure 1. That is, the axial direction of the pivot axis A (see the dashed line in Figure 1) (the direction in which the rungs 4 are erected) is defined as the left-right direction of the stepladder 1. Furthermore, the direction perpendicular to the left-right direction in the horizontal direction (the opening and closing direction of the ladder bodies 2 and 2) is defined as the front-back direction of the stepladder 1, and the direction perpendicular to both the left-right and front-back directions is defined as the up-down direction of the stepladder 1. As shown in Figure 1, the stepladder 1 according to this embodiment comprises a pair of ladder bodies 2 and 2 having common components. The ladder bodies 2 and 2 are arranged so that their lower ends are spaced apart from each other in a roughly V-shape when viewed from the side, and their upper ends are rotatably connected by hinges 6 and 6, which are rotating fittings. As shown in Figure 2, the hinge 6 is rotatably connected to a first hinge portion 6a and a second hinge portion 6b by a pivot support portion 6c. The first hinge portion 6a and the second hinge portion 6b are fixed to the upper ends of the two support columns 3 and 3, which are on the same side in the left-right direction (facing each other and moving closer together and further apart), via four rivets, which are fixing members. This allows the hinge 6 to rotatably connect the opposing support columns 3 and 3 relative to each other. That is, the ladder bodies 2 and 2 are rotatable in the direction of moving closer together and further apart (the front-to-back direction of the stepladder 1 in Figure 1). In this embodiment, of the three rivets that fix the hinge 6 to the front support column 3, the two rivets R and R located on the rear side (see Figures 3 and 4) function as positioning members for the bracket 91, which will be described later. Each ladder body 2 is equipped with a pair of elongated support columns 3, 3. The support columns 3, 3 are arranged so that the distance between them increases from the top to the bottom (in a roughly V-shape when viewed from the front). The stepladder 1 according to this embodiment is equipped with four support columns 3. Each support column 3 is bent at two points along its longitudinal direction for purposes such as ensuring strength. Furthermore, the support column 3 is formed with a back plate 3b and two side plates 3s, 3s adjacent to and facing each other, so that the cross-sectional shape perpendicular to the longitudinal direction is roughly U-shaped (see Figure 8). In addition, end fittings 3a are fixed to the lower ends of each support column 3. Between the pair of support columns 3, 3 in the ladder body 2, a plurality of hollow cyl