JPH0960233A - Cut string for stairs - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cut string for stairs which has a strength comparative with the conventional value and which can be embodied in a lightweight construction. SOLUTION: An cut string 10 for stairs consists of a thick string body 11 installed in the middle part and an inner 12 and an outer plate 13 made from thin plate and joined with the inside and outside of the cut string body 11, wherein the string body 11 has an outer frame 14 formed from square rods and a core member 17 secured to the outer frame upon locating mounting holes 21 previously provided for the footboard in the specified mounting positions. The inner plate 12 is previously provided with mounting holes for the footboard and riser plate corresponding to the mounting holes 21.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a staircase girder for stairs used when constructing a wooden staircase provided with a footboard and a riser.

[0002]

2. Description of the Related Art Sasara girders used for wooden staircases for houses bear the load from footboards and risers, and are large and durable from the viewpoint of decorativeness. The mainstream is a laminated plywood having a plurality of laminated sheets or a single-ply laminated material (LVL) having a plurality of laminated single plates in parallel.

[0003]

However, these sasara girders are heavy and require labor for transportation and construction. The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a staircase girder for steps, which has a strength comparable to that of a conventional sasara girder and can achieve further weight reduction.

[0004]

A method according to the above-mentioned object.
The staircase girder for stairs described comprises a thick girder main body arranged in an intermediate portion and inner and outer plates made of a thin plate and joined to the inside and the outside of the girder main body, respectively. The main body of the sasara girder is an outer frame formed by framing a square bar, and mounting holes for the tread plate and the riser plate are machined in advance, and the attachment holes form the attachment positions of the tread plate and the riser plate. And a core member fixed to the outer frame in such a manner that the inner plate has mounting holes for the tread plate and the riser plate that match the mounting holes. Further, the staircase girder for stairs according to claim 2 is the stirrup girder for stairs according to claim 1, wherein a lightweight core material is filled between the outer frame body and the core material of the main body of the sasara girder. Here, the square bar material includes a single plate laminated material (LVL), an oriented wood piece molding plate (OSB), plywood, etc. As the lightweight core material, when the outer plate and the inner plate are thin, the dent is prevented. For this purpose, there is a honeycomb material such as aluminum or corrugated cardboard, or an insulation board having a specific gravity of 0.4 or less. The thin plates forming the inner plate and the outer plate are
It is preferable to use plywood or medium specific gravity fiberboard having a sufficient strength of about 2 to 5 mm, and a veneer or a decorative material such as decorative paper may be attached to the surface thereof. As the core material, a material having sufficient strength such as a single plate laminated material, an oriented wood piece molding plate or plywood is used.

[0005]

The staircase girder for stairs according to claims 1 and 2 uses a core material having sufficient strength in a portion that bears the load from the step plate and the riser plate, and the core material is a square bar material. Connected to the outer frame, inside and outside of the Sasara girder body,
Since the inner plate and the outer plate are joined to each other, these plates act as ribs and have sufficient strength like a conventional sasara girder. In addition, in this staircase girder for stairs, a strong material with a relatively large specific gravity is used only for the part that bears the strength, and the other parts are filled with space or lightweight core material, so the overall weight is light. Become. Particularly, in the staircase girder for stairs according to claim 2, since the lightweight core material is filled between the outer frame body and the core material of the body of the sasara girder, the load directly received by the inner plate and the outer plate is burdened. can do.

[0006]

Therefore, the staircase girders for stairs according to claims 1 and 2 are lighter in weight than the conventional integrated staircase girders for stairs, and can be made to have substantially the same strength. , The construction becomes easy. Particularly, in the staircase girder for stairs according to the second aspect, it is possible to reduce the thickness of the inner plate and the outer plate that are adhered by the lightweight core material, and thus it is possible to further reduce the weight.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Next, referring to the attached drawings, an embodiment in which the present invention is embodied will be described to provide an understanding of the present invention. Here, FIG. 1 is an exploded front view of a staircase girder for stairs according to an embodiment of the present invention, and FIG. 2 is a plan view thereof.

As shown in FIG. 1 and FIG. 2, a staircase girder main body 11 according to an embodiment of the present invention is a staircase girder main body 11.
And an inner plate 12 and an outer plate 13 attached to both sides thereof. These will be described in detail below.

The Sasara girder main body 11 has an outer frame body 14 framed around by a square bar material having a quadrangular cross section made of a single plate laminated material, an oriented wood piece molding plate, or a plywood as described above,
Vertical and horizontal core members 16 and 17 each having a mounting hole 15 (shown by hatching in FIG. 1) of a predetermined depth formed in a portion where the footboard and the riser plate are mounted, and a lightweight core material 18 filled in the gap between them. And have. In the frame of the outer frame body 14, a square bar material is cut at a predetermined length and a predetermined angle, an end portion is appropriately meshed (cut), and fixed by an adhesive. And the core material 16,
17 is also made of the same material as the above-mentioned square bar material, and is joined to the outer frame body 14 by an adhesive material. In addition, in joining the outer frame 14 and the core members 16 and 17, nails, screws or the like may be used in addition to the adhesive.

The mounting holes 15 formed in the core members 16 and 17 are provided with a step plate 19 and a riser plate 2 to be mounted.
0 (see FIG. 2) is a width that fits with a small gap, and the depth thereof is about 1/3 to 1/2 of that of the core materials 16 and 17. The lightweight core material 18 is formed by the inner plates 12 on both sides.
In order to reduce the weight, the specific gravity is small (0.
4 or less) Insulation board is used.

The inner plate 12 has a length of 2 to 5 m as described above.
It consists of a thin plate of about m, and a decorative sheet is attached to the surface. A mounting hole 21 is formed through which the footboard 19 and the riser plate 20 are mounted, and the mounting hole 21 is formed so as to match the mounting hole 15. On the other hand, the outer plate 13 is made of a thin plate of the same quality as the inner plate 12, but the whole plate is made of a single plate and is not provided with cutouts or holes. The inner plate 12 and the outer plate 13 are joined to the front and back of the sasara girder body 11 with a strong adhesive.

Since the staircase girder 10 for stairs is constructed as described above, the weight can be reduced as compared with the conventional staircase girder for steps. Moreover, the outer frame 1 is on the outside.
4, only the inner plate 12 and the outer plate 13 are exposed, so that it looks like a single plate. In the above-mentioned embodiment, the inner lightweight core material 18 may be omitted to make the inside an air core, but in this case, a slightly thicker plate (4 to 6) is used as the inner plate and the outer plate.
mm) is preferably used.

[Brief description of drawings]

FIG. 1 is an exploded front view of a staircase girder for stairs according to an embodiment of the present invention.

FIG. 2 is a plan view of the same.

[Explanation of symbols]

10 Sasara girder for stairs 11 Sasara girder main body 12 Inner plate 13 Outer plate 14 Outer frame body 15 Mounting hole 16 Core material 17 Core material 18 Light weight core material 19 Footboard 20 Raised plate 21 Mounting hole

Claims (2)

[Claims] 1. A staircase girder for stairs, comprising a thick sasara girder main body arranged in an intermediate portion, and an inner plate and an outer plate made of a thin plate and joined to the inside and the outside of the sasara girder main body, respectively. The Sasara girder main body has an outer frame body formed by framing a square bar material, and mounting holes for a step plate and a riser plate are processed in advance,
A core member fixed to the outer frame body such that the mounting hole is at a mounting position of the step plate and the riser plate, and the inner plate has the step plate and the riser corresponding to the mount hole. A girder for stairs, characterized in that mounting holes for the plate are preformed. 2. The staircase girder for stairs according to claim 1, wherein a lightweight core material is filled between the outer frame body and the core material of the sasara girder body.