JP2024048771A - Stairs - Google Patents

Abstract

[Problem] To provide a staircase with a structure that allows risers to be securely attached even when the treads are fixed. [Solution] The staircase 1 according to the present invention is a staircase with left and right beams (slat beams 2, 2) that are provided so as to extend at an incline in the vertical direction, and a plurality of treads 5 and risers 6 that are provided so as to be continuous in the vertical diagonal direction between the left and right beams, and is characterized in that it includes a riser lower end attachment portion 3 (riser lower end engagement groove 3A) provided on the upper surface 5a of the lower step 5, and a riser upper end attachment portion 4 attached to the left and right beams so as to be positioned lower than the lower surface 5b of the upper step 5, and the lower end 6e side of the riser 6 is attached to the riser lower end attachment portion 3, and the upper end 6t side of the riser 6 is attached to the riser upper end attachment portion 4. [Selected drawing] Fig. 5

Description

The present invention relates to a mounting structure for stair risers.

There is a known staircase that is configured with left and right beams (hereinafter referred to as "slat beams") that are arranged to extend at an incline in the vertical direction, steps that are arranged at a specified distance between the left and right beams along the vertical inclination direction, and a riser that is arranged between the upper surface of the rear end side of the lower step and the lower surface of the front end side of the upper step (see Patent Document 1).

JP 2003-41729 A

In the staircase disclosed in Patent Document 1, the treads are temporarily fixed with bolts or the like to the tread mounting portions provided on the left and right rafters, and the lower end of the riser plate is engaged with the lower end engagement groove provided on the upper surface of the rear end of the lower step, extending between the left and right ends of the rear end of the lower surface of the upper step, and the upper end of the riser plate is engaged with the upper end engagement groove provided on the lower surface of the rear end of the upper step, extending between the left and right ends of the rear end of the lower surface of the upper step.
However, with the above-mentioned staircase, if the risers are attached to the engagement grooves of the upper and lower step treads while the upper and lower step treads are temporarily secured to the tread mounting parts with bolts or the like, and then the upper and lower step treads are fully tightened and fixed to the tread mounting parts with bolts or the like, there will be no room for the riser to fit into the engagement groove, and the upper and lower ends of the riser will be prone to coming out of the engagement groove, making it difficult to install the riser.

To solve the above problems, the present invention provides a staircase with a structure that allows the riser to be securely attached even when the tread is fixed.

The staircase of the present invention is a staircase comprising left and right girders arranged to extend at an incline in the vertical direction, and a plurality of treads and risers arranged diagonally up and down between the left and right girders, and comprising a lower end mounting portion of the riser provided on the upper surface of the lower tread, and an upper end mounting portion of the riser attached to the left and right girders so as to be positioned lower than the underside of the upper tread, and the lower end of the riser is attached to the lower end mounting portion and the upper end of the riser is attached to the upper end mounting portion, thereby providing a staircase with a structure which allows the riser to be reliably attached even when the treads are fixed.
Further, a staircase having left and right girders that are arranged to extend at an angle in the vertical direction, and a plurality of treads and risers that are arranged diagonally up and down between the left and right girders, the staircase comprising a riser lower end mounting portion arranged on the upper surface of the lower tread, and a riser upper end mounting portion attached to the tread mounting portion arranged on the left and right girders so as to be positioned lower than the underside of the upper tread, the lower end of the riser being attached to the riser lower end mounting portion and the upper end of the riser being attached to the riser upper end mounting portion, it is possible to provide a staircase with a structure that allows the riser to be attached reliably even when the tread is fixed, and it is also possible to use a tread mounting portion that is long in the front-to-rear direction, making it possible to meet specifications that require the tread to be fixed to the tread mounting portion at least at two points, one at the front and one at the back, on the left and right sides of the tread.
The upper end mounting portion of the riser plate is arranged below the underside of the front end side of the underside of the upper tread plate, extending between the left and right girders, thereby ensuring reliable mounting of the upper end of the riser plate.
In addition, the upper end mounting portion of the riser plate is configured to function as a tread support portion that supports the underside of the front end of the upper tread plate, thereby improving quality and reducing costs.
In addition, the lower end mounting portion of the riser plate is formed so as to continue from the left and right ends at the rear edge side of the upper surface of the lower tread and is composed of an engagement groove into which the lower end side of the riser plate engages, making it possible to easily and reliably install the riser plate even when the tread is fixed.

FIG. 2 is an exploded perspective view showing the configuration of a staircase (first embodiment). FIG. FIG. 4 is a perspective view showing the mounting portion at the upper end of the riser plate (first embodiment). FIG. 1 is a front view of a staircase (first embodiment). FIG. 5 is a cross-sectional view taken along line AA of FIG. 4 (first embodiment). FIG. 11 is an exploded perspective view showing the configuration of a staircase (second embodiment). FIG. 13 is a perspective view showing the mounting portion at the upper end of the riser plate (embodiment 2). FIG. 4 is a front view of the stairs (embodiment 2). FIG. 9 is a cross-sectional view taken along line AA in FIG. 8 (second embodiment).

EMBODIMENT 1
As shown in FIG. 1 to FIG. 5, the staircase 1 according to the first embodiment is a staircase having left and right girders 2, 2 that are provided so as to extend at an incline in the vertical direction, and a plurality of treads 5 and risers 6 that are provided so as to be continuous in the vertical diagonal direction between the left and right girders 2, 2. That is,
The staircase is constructed by installing treads 5, 5... at each step at a predetermined interval between the left and right rafters 2, 2 along the vertical inclination direction, and installing a riser 6 between the upper and lower treads 5, 5.
The staircase 1 of embodiment 1 comprises a lower end attachment portion 3 of a riser plate provided on the upper surface of the lower tread 5, and an upper end attachment portion 4 of a riser plate attached to the left and right rafters 2, 2 so as to be positioned lower than the underside of the upper tread 5, and the lower end 6e side of the riser plate 6 is attached to the lower end attachment portion 3, and the upper end 6t side of the riser plate 6 is attached to the upper end attachment portion 4.
The staircase 1 is, for example, an outdoor staircase.
In this specification, the terms up, down, left, right, front, and rear are defined as directions shown in the drawings.
5 is a cross-sectional view taken along line AA of FIG. 4, but hatching of the cross-sectional portion is omitted.

As shown in Figure 1, the sash 2 is composed of a side panel 2a that rises vertically from a foundation not shown in the figure and then extends at an upward incline, a front panel 2b that extends laterally from the front edge of the side panel 2a, and a rear panel 2c that extends laterally from the rear edge of the side panel 2a.
The left sash beam 2 is formed so that the front panel 2b and the rear panel 2c extend in the leftward direction, and the right sash beam 2 is formed so that the front panel 2b and the rear panel 2c extend in the rightward direction.

For each step, it is preferable to use a structure in which the treads 5, 5... are configured such that a plurality of hollow sections 52 are provided at predetermined intervals along the front-to-rear direction of a rectangular molded cement board 51, the hollow sections 52 extending from the left and right end faces of the molded cement board 51, as shown in FIG. 2, for example.

The riser plate 6 is made of a rectangular steel plate or other plate material formed to a size that corresponds to the rectangular opening space surrounded by the upper surface 5a of the lower tread 5, the lower surface 5b of the upper tread 5, and the inner surfaces 2u, 2u of the left and right rafters 2, 2.

The lower end attachment portion 3 of the riser plate is formed by a lower end engagement groove 3A of the riser plate that is provided so as to extend continuously between the left and right ends of the riser plate 5 on the rear end edge 5r side of the upper surface 5a of the riser plate 5, as shown in FIG. 2, for example, and the lower end 6e side of the riser plate 6 is attached so as to engage with the lower end engagement groove 3A of the riser plate.

As shown in Figure 5, the tread mounting portion 50 to which the tread 5 is attached is installed on the inner surfaces 2u, 2u of the truss 2, which are the opposing surfaces of the side panels 2a, 2a of the left and right truss beams 2, 2, and is fixed to the side panels 2a, 2a by fixing means F1 such as bolts and nuts.
The tread mounting portion 50 is a member installed so as to extend in the front-to-rear direction on the inner surface 2u of the stringer 2, and is, for example, composed of a so-called angle material with an L-shaped cross section, having a vertical plate 50a installed on the inner surface 2u of the stringer 2 and fixed to the side panel 2a of the stringer 2 by fixing means F1, and a horizontal plate 50b on which the tread 5 is placed and fixed.
That is, the tread mounting portion 50 is configured so that the vertical plate 50a is fixed to the side plate 2a of the stringer 2 by a fixing means F1, and the upper plate surface of the horizontal plate 50b extending from the upper end of the vertical plate 50a forms a horizontal tread mounting surface extending in the fore-and-aft direction perpendicular to the inner surface 2u of the stringer 2.

The upper end mounting portion 4 of the riser plate is a member configured to extend continuously between the left and right girders 2, 2 so as to be positioned below the lower surface 5b of the upper tread 5, as shown in Figure 4, for example.
As shown in FIG. 3, the riser plate upper end mounting portion 4 includes a long portion 4A and mounting portions 4B provided on the left and right ends of the long portion 4A.
The long section 4A is composed of a so-called angle material, which is a long material with an L-shaped cross section, consisting of a horizontal plate 41 formed to a length corresponding to the length between the left and right trusses 2, 2 and a vertical plate 42 extending downward from the front edge of the horizontal plate 41.
The mounting portion 4B is composed of mounting plates 43, 43 that are provided on both the left and right ends of the angle iron that constitutes the long portion 4A and have surfaces that face the inner surfaces 2u, 2u of the left and right girders 2, 2.
The mounting plate 43 is formed, for example, of a square flat plate that is installed on the inner surface 2u of the stringer 2 and fixed to the side panel 2a of the stringer 2 by fixing means F3 such as bolts and nuts (see Figures 4 and 5).
The mounting plate 43 is formed with a through hole Bh for passing the fixing means F3 therethrough.

The riser upper end side mounting portion 4 is arranged such that the mounting plate 43 is positioned forward of the tread mounting portion 50 .
The upper end mounting portion 4 of the riser plate is configured so that the mounting plate 43 is fixed to the rafter 2 by the fixing means F3, and the upper plate surface of the horizontal plate 41 of the upper end mounting portion 4 of the riser plate is perpendicular to the inner surface 2u of the rafter 2, so that the upper plate surface of the horizontal plate 41 of the upper end mounting portion 4 of the riser plate and the upper plate surface of the horizontal plate 50b of the tread mounting portion 50 are positioned on the same horizontal plane to form a horizontal tread placement surface, and the front plate surface 42f of the vertical plate 42 of the upper end mounting portion 4 of the riser plate and the rear groove edge of the riser plate lower end engagement groove 3A of the lower tread 5 are positioned on the same vertical plane.
In other words, the front panel surface 42f of the vertical plate 42 is formed into a vertical surface, and the vertical plate 42 is configured to function as an attachment plate for attaching the upper end 6t side of the riser plate 6 using fixing means F4 such as a drill screw.
It is preferable that pilot holes h be formed in the riser plate 6 and the vertical plate 42 for passing the fixing means F4 therethrough.

As shown in Figure 5, the underside 5b of the tread 5 is placed on a horizontal tread placement surface formed by the upper surface of the horizontal plate 50b of the tread mounting portion 50 and the upper surface of the horizontal plate 41 of the upper end side mounting portion 4 of the riser plate, via a buffer plate such as a gasket P, and is fixed to the horizontal plate 50b of the tread mounting portion 50 by fixing means F2.
The fixing means F2 is composed, for example, of a plate nut 53 installed in one or more of the hollow portions 52 formed in the molded cement plate 51, a bolt 54 screwed into the plate nut 53 by passing through a bolt hole formed in a buffer plate such as a gasket P laid on the upper surface of the horizontal plate 50b of the tread mounting portion 50 and the horizontal plate 50b, and a bolt hole formed to reach the lower surface of the cement plate 51 and the hollow portion 52.
In other words, the bolt 54 is inserted into the bolt hole from the underside of the horizontal plate 50b of the tread mounting portion 50 attached to the side panel 2a of the slat 2, and screwed into the plate nut 53, thereby fixing the tread 5 to the horizontal plate 50b of the tread mounting portion 50.

Then, after the lower end 6e of the kick plate 6 is inserted into the lower end engagement groove 3A of the kick plate, the rear plate surface 6r of the upper end 6t of the kick plate 6 and the front plate surface 42f of the vertical plate 42 of the upper end mounting portion 4 of the kick plate are in contact with each other, and the upper end 6t of the kick plate 6 is attached to the vertical plate 42 by fixing means F4 such as a drill screw, thereby completing the installation of the kick plate 6.
In this way, the lower end 6e side of the riser plate 6 is inserted into the lower end side engagement groove 3A of the riser plate to position the lower end side, and then the upper end 6t side of the riser plate 6 is attached to the vertical plate 42, so that the riser plate 6 can be attached easily and reliably even when the tread 5 is fixed.
In addition, the upper end mounting portion 4 of the riser plate is arranged to extend between the left and right girders 2, 2 below the underside 5b of the front end 5f of the upper tread 5, thereby ensuring reliable mounting of the upper end of the riser plate 6.
In addition, Figure 1 shows a form in which only the left and right ends of the upper end 6t of the riser plate 6 are attached to the vertical plate 42 by the fixing means F4, but since the upper end mounting portion 4 of the riser plate is arranged to extend between the left and right girders 2, 2, it is possible to configure the central side of the upper end 6t of the riser plate 6 to be also attached to the vertical plate 42 by the fixing means F4, thereby ensuring reliable attachment of the upper end 6t of the riser plate 6.

In addition, the underside 5b of the front end 5f of the tread 5 is placed on the tread support surface formed by the upper plate surface of the horizontal plate 41 of the upper end mounting portion 4 of the riser plate via a buffer plate such as a gasket P, so that the upper end mounting portion 4 of the riser plate, which has an L-shaped cross section and includes a horizontal plate 41 and a vertical plate 42 arranged to extend between the left and right girders 2, 2, is configured to function as a tread reinforcement plate that supports the underside 5b of the front end 5f of the upper tread 5 and reinforces the tread 5.
Conventionally, when constructing a tread made from a molded cement board, the strength of the tread 5 was sometimes reinforced by installing a reinforcing material such as a steel pipe in one or more hollow portions 52 (see Patent Document 1).
However, when a tread is constructed using a reinforcing material such as a steel pipe, there are problems such as deterioration in quality due to rust generation from the steel pipe and increased cost of the tread 5.
According to embodiment 1, by using the riser plate upper end mounting portion 4 which functions as a tread reinforcing plate supporting the underside 5b of the front end 5f side of the upper tread 5, it is possible to reinforce the tread 5 without having to install a reinforcing material such as a steel pipe in the hollow portion 52 to reinforce the tread 5. This simplifies the configuration and eliminates the problem of rust occurring when using reinforcing materials such as steel pipes, thereby improving quality and reducing costs.

The construction of the staircase 1 according to the first embodiment is carried out, for example, in the following manner.
(1) The upper ends of the left and right girders 2, 2 are attached to the girders of a landing, corridor, etc. that have been previously constructed (not shown in the figure), and the lower ends of the left and right girders 2, 2 are fixed to the foundation concrete, etc. (not shown in the figure) using anchor bolts, etc. (not shown in the figure).
(2) The step mounting portions 50, 50... for mounting the steps 5, 5... of each step are attached to the left and right girders 2, 2 with fixing means F1, and the riser upper end mounting portions 4, 4... are respectively positioned on the front side of the step mounting portions 50 of each step, and the riser upper end mounting portions 4, 4... are fixed to the girders 2, 2 with fixing means F3.
(3) The underside surfaces 5b on the left and right sides of the tread 5 are placed on the tread support surface of the horizontal plate 50b of the tread mounting portion 50 via a gasket P or the like, and the underside surface 5b of the front side of the tread 5 is placed on the tread support surface of the horizontal plate 41 of the upper end side mounting portion 4 of the riser plate via a gasket P or the like, and the tread 5 and the horizontal plate 50b of the tread mounting portion 50 are fixed together with the fixing means F2.
(4) The lower end 6e of the kick plate 6 is inserted into the lower end engagement groove 3A formed between the left and right ends on the upper surface 5a of the rear edge 5r of the lower tread 5, and the upper end 6t of the kick plate 6 is fixed to the vertical plate 42 of the upper end mounting portion 4 with the rear plate surface 6r of the upper end 6t of the kick plate 6 brought into contact with the front plate surface 42f of the vertical plate 42 of the upper end mounting portion 4 of the kick plate using fixing means F4.

According to the staircase 1 of the first embodiment, it is possible to provide a staircase having a structure that allows the riser 6 to be securely attached even when the tread 5 is fixed.
In addition, since the riser plate 6 can be attached and detached by attaching and detaching the fixing means F4, the work of installing the riser plate 6 and the work of attaching and detaching the riser plate 6 when replacing it can be easily performed.
Furthermore, when steel pipes are used as reinforcing material for the tread 5, since the steel pipes are arranged inside the tread, there are problems such as the inability to perform maintenance such as replacing the steel pipes, and the inability to confirm whether the steel pipes need replacing due to rust occurring in the steel pipes.
On the other hand, according to the staircase 1 of embodiment 1, by using the upper end mounting portion 4 of the riser plate which is configured to function as a tread reinforcing plate that supports and reinforces the underside 5b of the front end 5f side of the upper tread 5, it is possible to reinforce the tread 5 without using reinforcing materials such as steel pipes, thereby eliminating the above-mentioned problems that arise when steel pipes are used, and also improving quality and reducing costs.

EMBODIMENT 2
The staircase according to the second embodiment will be described with reference to FIGS.
6 to 9, the same parts as those in the first embodiment shown in FIGS. 1 to 5 are designated by the same reference numerals, and detailed description thereof will be omitted.
9 is a cross-sectional view taken along line AA of FIG. 8, but hatching of the cross-sectional portion is omitted.
In embodiment 1, an example was given of the use of a riser plate upper end mounting portion 4 attached to the left and right rafters 2, 2. However, in embodiment 2, as shown in Figures 6 to 9, the left and right mounting portions 43, 43 use a riser plate upper end mounting portion 4X attached to tread mounting portions 50A, 50A provided on the left and right rafters 2, 2.
That is, in embodiment 2, rather than a configuration in which the left and right mounting portions 43, 43 are attached to the left and right girders 2, 2, the left and right mounting portions 43X, 43X use a riser plate upper end mounting portion 4X that is configured to be attached to the left and right girders 2, 2 via left and right tread mounting portions 50A, 50A attached to the left and right girders 2, 2.

As shown in Figure 6, the tread mounting portion 50A is a member installed so as to extend in the front-to-rear direction on the inner surface 2u of the slat 2, and is configured, for example, as a so-called angle material with an L-shaped cross section comprising a vertical plate 50a fixed to the side panel 2a of the slat 2 by fixing means F1, and a horizontal plate 50b on which the tread 5 is placed and fixed, and is provided with a mounting plate 50c as a mounting portion for mounting the mounting portion 43X of the upper end mounting portion 4X of the riser plate.
That is, in the second embodiment, a mounting plate 50c serving as a mounting portion to which the mounting portion 43X of the riser plate upper end mounting portion 4X is attached is provided on the step plate mounting portion 50A.
The mounting plate 50c is formed of a vertical plate having a plate surface perpendicular to the plate surface of the vertical plate 50a from the front end side of the vertical plate 50a.
The tread mounting portion 50A is configured such that the vertical plate 50a is fixed to the side plate 2a of the stringer 2 by a fixing means F1, and, for example, the upper plate surface of the horizontal plate 50b forms a horizontal tread mounting surface extending in the fore-and-aft direction perpendicular to the inner surface 2u of the stringer 2, and the front plate surface of the mounting plate 50c forms a vertical mounting surface.

The upper end mounting portion 4X of the riser plate is composed of a so-called angle material, which is a long material with an L-shaped cross section, consisting of a vertical plate 42X formed to a continuous length spanning the rafters 2, 2 and a horizontal plate 41X extending rearward from the upper edge of the vertical plate 42X.
Furthermore, the upper end side mounting portion 4X of the riser plate is formed in a removed portion d, with both left and right ends of the vertical plate 42 functioning as mounting portions 43X, 43X, and the portion of the horizontal plate 41X extending rearward from the upper edge of the mounting portion 43X being removed.
In other words, when the lower plate surfaces on the left and right end sides of the horizontal plate 41X of the upper end side mounting portion 4X of the riser plate are placed on the upper edge 50d of the mounting plate 50c so that the rear plate surface of the mounting portion 43X comes into contact with the front plate surface of the mounting plate 50c, the horizontal plate 50b of the tread mounting portion 50A fits into the removal portion d and the upper plate surface of the horizontal plate 41X is positioned on the same horizontal plane as the upper plate surface of the horizontal plate 50b of the tread mounting portion 50A.

For example, in the case of a semi-fireproof specification, the fixing form of the step 5 requires that at least two points, one at the front and one at the back, on the left and right sides of the step 5, be fixed to the horizontal plate 50b of the step mounting portion 50A by the above-mentioned fixing means F2.
In this case, if a riser plate upper end mounting portion 4 is used that is fixed to the left and right girders 2, 2 as in embodiment 1, the front end side of the vertical plate 50a of the tread mounting portion 50A will be positioned at the position where the mounting portions 43, 43 of the riser plate upper end mounting portion 4 are to be installed, making it difficult to mount the mounting portions 43, 43 of the riser plate upper end mounting portion 4 to the girders 2, 2.
Therefore, in embodiment 2, a step mounting portion 50A is used which is formed with a long dimension in the front-to-rear direction, so that at least two points on the left and right sides of the step 5, one at the front and one at the rear, can be fixed to the side plate 50b of the step mounting portion 50A.
Furthermore, by providing an attachment plate 50c as an attachment portion to which the attachment portion 43X of the upper end attachment portion 4X of the riser plate is attached on the tread attachment portion 50A, the attachment portion 43X of the upper end attachment portion 4X of the riser plate is attached to the attachment plate 50c with a fixing means F4X such as a screw.

In the second embodiment, after the step mounting parts 50A, 50A... for mounting the step 5 of each step are mounted on the left and right girders 2, 2, the lower surfaces of the left and right sides of the step 5 are placed on the upper plate surface of the horizontal plate 50b of the step mounting part 50 via a packing P or the like, and the step 5 and the horizontal plate 50b of the step mounting part 50 are fixed together with the fixing means F2. In this case, as shown in Fig. 9, the step 5 and the step mounting part 50 are fixed together at two points, front and rear, by the fixing means F2.
Next, the riser upper end mounting portions 4X, 4X . . . are installed on the front side of the tread mounting portion 50 of each step (see FIG. 9).
That is, the horizontal plate 41X of the upper end mounting portion 4X of the riser plate is inserted between the underside 5b of the tread 5 attached to the tread plate mounting portion 50A and the upper edges 50d, 50d of the left and right mounting plates 50c, and set so that the rear plate surface of the mounting portion 43X comes into contact with the front plate surface of the mounting plate 50c, so that the horizontal plate 50b of the tread plate mounting portion 50A fits into the removal portion d and the upper plate surface of the horizontal plate 41X and the upper plate surface of the horizontal plate 50b of the tread plate mounting portion 50A are positioned on the same horizontal plane. In this case, it is preferable to attach a packing P or the like to the upper plate surface of the horizontal plate 41X beforehand.
Then, the lower end 6e of the kick plate 6 is inserted into the kick plate lower end engagement groove 3A formed between the left and right ends on the upper surface 5a of the rear edge 5r of the lower tread 5, and the rear plate surface of the upper end 6t of the kick plate 6 is set in contact with the front plate surface of the vertical plate 42X of the kick plate upper end mounting portion 4X, and the upper end 6t of the kick plate 6, the vertical plate 42X of the kick plate upper end mounting portion 4X and the mounting plate 50c of the tread mounting portion 50 are fixed together with the fixing means F4.

In addition, after the vertical plate 42X of the upper end mounting portion 4X of the riser plate is attached to the mounting plate 50c of the tread mounting portion 50 with a screw or the like, the upper end 6t side of the riser plate 6 may be fixed to the vertical plate 42X of the upper end mounting portion 4X of the riser plate with a fixing means F4 such as a screw.

The staircase 1 according to the second embodiment has the same effect as the first embodiment, and since it is possible to use a tread mounting portion 50A that is long in the front-to-rear direction, it can accommodate specifications (such as specifications known as semi-fireproof specifications) that require the tread 5 to be fixed to the tread mounting portion 50A at least at two points on the left and right sides (front and back).

EMBODIMENT 3
In each of the above-described embodiments, an example has been given of the upper end mounting portion of the riser plate that is configured to function as a tread support portion that supports the underside 5b of the upper tread plate 5 and reinforces the tread plate 5, but as long as it functions as an mounting portion to which the upper end of the riser plate is attached, it does not have to function as a tread support portion.

EMBODIMENT 4
In each of the above-mentioned embodiments, an example is given of an upper end mounting portion of a riser plate that is arranged to extend between the left and right stringers 2, 2, but the upper end mounting portion of a riser plate according to the present invention may also be composed of left and right upper end mounting portions of risers that are separately attached to the left and right stringers 2, 2, respectively.

In other words, in the staircase of the present invention, the upper end mounting portion of the riser plate may be configured to extend between the left and right trusses 2, 2 and function as a mounting portion, or may be configured with left and right upper end mounting portions of the riser plate that are provided separately on the left and right trusses 2, 2 and function as mounting portions.
In other words, the staircase of the present invention only needs to be a staircase equipped with a structure that allows the riser plate 6 to be reliably attached even when the tread plate 5 is fixed to the tread plate mounting portion, and therefore the upper end mounting portion of the riser plate must be attached to the left and right rafters so as to be positioned lower than the underside 5b of the upper tread plate 5, or attached to the tread plate mounting portions 50A provided on the left and right rafters 2, 2 so as to be positioned lower than the underside 5b of the upper tread plate 5, providing a mounting portion to which at least the upper end 6t of the riser plate 6 is attached.

In addition, in the above example, the lower end attachment portion 3 of the riser plate is formed by the lower end engagement groove 3A of the riser plate, but the lower end attachment portion 3 of the riser plate may be a lower end attachment portion of the riser plate provided so as to protrude from the upper surface 5a of the lower tread 5.

In addition, in the present invention, there are no particular limitations on the configuration, materials, etc. of the treads and risers.

1. Stairs 2. Sash beams
3 Lower end side mounting portion of riser plate 3A Lower end side engagement groove of riser plate 4 Upper end side mounting portion of riser plate 5 Step 5a Upper surface of step 5b Lower surface of step 6 Rise plate 6e Lower end of riser plate 6t Upper end of riser plate 50A Step mounting portion

Claims (5)

A staircase having left and right beams that are extended at an incline in the vertical direction, and a plurality of treads and risers that are continuously provided between the left and right beams in the vertical diagonal direction,
A lower end side mounting portion of the riser plate provided on the upper surface of the lower tread plate;
a riser upper end side mounting portion attached to the left and right beams so as to be located below the lower surface of the upper step,
A staircase characterized in that the lower end side of the riser is attached to the lower end side mounting portion of the riser, and the upper end side of the riser is attached to the upper end side mounting portion of the riser. A staircase having left and right beams that are extended at an incline in the vertical direction, and a plurality of treads and risers that are continuously provided between the left and right beams in the vertical diagonal direction,
A lower end side mounting portion of the riser plate provided on the upper surface of the lower tread plate;
a riser upper end side mounting portion attached to the step mounting portion provided on the left and right girders so as to be located below the lower surface of the upper step,
A staircase characterized in that the lower end side of the riser is attached to the lower end side mounting portion of the riser, and the upper end side of the riser is attached to the upper end side mounting portion of the riser. The staircase according to claim 1 or 2, characterized in that the upper end mounting portion of the riser is provided below the lower surface of the front end side of the upper step tread, extending between the left and right girders. The staircase described in claim 3, characterized in that the upper end mounting portion of the riser is configured to function as a tread support portion that supports the underside of the front end side of the tread of the upper step. The staircase described in claim 4, characterized in that the lower end mounting portion of the riser plate is formed so as to be continuous from the left and right ends at the rear end edge side of the upper surface of the lower step tread, and is constituted by a lower end engagement groove in which the lower end side of the riser plate engages.

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