JP6755083B2 - spiral staircase - Google Patents

Description

The present invention relates to a spiral staircase.

Spiral staircases are installed inside or outside the building and are used to move up and down between upper and lower floors such as two-story buildings and between large steps.
A spiral staircase is usually assembled by spirally arranging treads over a plurality of steps around an erected central pillar, and is characterized by a small occupied area and a relatively small dead space.

However, the conventional spiral staircase has a complicated structure because a tread plate is attached around the central pillar and is arranged in a spiral shape, and it is not easy to assemble.
For example, in the spiral staircase shown in FIG. 13, a receiving material 300 having a tread plate 200 as an arm is attached around a short columnar core pillar unit 100, and the core pillar unit to which the tread plate is attached is stacked in this way to form a spiral staircase. Is assembled. In this conventional example, a groove for fitting the receiving material must be formed on the upper surface and the lower surface of the tread plate 200, and a groove for fitting the inner edge of the receiving material 300 must be formed on the outer circumference of the core column unit 100. .. Then, in order to stack the core pillar unit 100, an insertion hole is formed in the core pillar unit 100, and a tightening bolt 400 is inserted into the insertion hole to be formed on the head of the tightening bolt inserted into the lower core pillar unit. The core pillar units are stacked by screwing them into the screw holes.

Further, Patent Document 1 shows a conventional example in which a receiving material is not used, unlike the conventional example shown in FIG. 13 (see FIGS. 1 and 3 of Patent Document 1). In this conventional spiral staircase, the inner end of each tread plate is sandwiched between two upper and lower core pillar units, and a tread plate positioning means for determining the separation angle around the core pillar of two adjacent tread plates is provided.
This positioning means requires a pin having a protrusion inserted into a hole provided in the inner wall of the hollow portion of the hollow columnar core column unit, a tread washer, and the like, and there are many types and points of parts constituting the spiral staircase. , The structure is complicated (see FIGS. 6 to 9 of Patent Document 1).

As described above, the conventional spiral staircase has a large number of parts and the number of parts, and the structure is complicated. Therefore, the assembly is not easy, takes a lot of time, and requires the involvement of a skilled worker. did not become. In addition, when the treads are made of heavy steel plates or concrete, large-scale construction was forced using a crane or the like.

Japanese Unexamined Patent Publication No. 2005-220656

The present invention has been made in view of the above-mentioned problems of the prior art, and an object of the present invention is a spiral staircase in which the types and numbers of parts constituting the spiral staircase are small and easy to assemble. Aims to provide a lightweight spiral staircase.

In order to solve the above problems, the present invention employs the following means.
[1] A spiral staircase in which treads having a hole for inserting a central pillar formed at the central end of the stairs are arranged in a spiral shape around the erected central pillar, and the nose of the outer end of the tread. A hole for inserting a handrail pillar is formed in the foot and the step tail, and the treads adjacent to each other are supported by the core pillar and the handrail pillar formed in the nose of the outer end of the stairs of the tread located on the upper side. The insertion hole and the handrail pillar insertion hole formed at the outer end of the stairs of the tread plate located on the lower side are arranged so as to overlap each other, and are inserted into the two overlapping handrail insertion holes to stand upright. A spiral staircase characterized in that it is fastened by sandwiching two tread plates adjacent to each other by two nuts screwed into the handrail pillar.
[2] The spiral staircase according to [1], wherein the tread plate is a foam made of a synthetic resin outer skin and a foam core material.
[3] The tread plate is characterized by comprising a plate-shaped portion, a rib portion arranged on the lower surface of the plate-shaped portion, and a peripheral wall of a hole for inserting a central pillar continuous with the rib portion [1]. Spiral staircase.
[4] The spiral staircase according to [3], wherein a plurality of air / drain holes are provided in the plate-shaped portion of the tread plate.

In the spiral staircase of the present invention, the upper and lower tread plates adjacent to each other can be attached to the upper and lower tread plates adjacent to each other with a handrail column and two nuts around the center column, so that the structure is not complicated and the spiral staircase is formed. Assembling is easy because the number of parts and the number of parts are small. Further, by making the tread plate a foam material, the spiral staircase can be made lightweight.

It is an overall front view of the spiral staircase which concerns on embodiment of this invention. It is external schematic of the spiral staircase main part which concerns on embodiment of this invention. It is a schematic plan view of the main part of the spiral staircase which concerns on embodiment of this invention. It is a plan view (a) and a front view (b) of the tread plate which concerns on embodiment of this invention. It is a figure which shows the means for erection of a central pillar. It is a figure which shows the handrail pillar erected on two tread plates located at the top and bottom. It is an external view of the spiral staircase of the present invention composed of four steps of treads. It is a figure which shows the handrail pillar erected on the 1st step or the uppermost step plate of a spiral staircase. It is a figure which shows the front view (a), the side view (b), and the side view (c) of a cap-shaped member of one Embodiment of a handrail attachment. It is a schematic diagram which shows the cross section of the foam which was integrally molded with the exodermis and the foam core material. A perspective view of different embodiments of the humiita is shown. 11 is a top view (a), a side view (b), a cross-sectional view (c), and a bottom view (d) of the tread plate shown in FIG. It is a schematic perspective view which shows the main part of the spiral staircase of a conventional example.

Hereinafter, embodiments of the present invention will be specifically described with reference to the drawings.
FIG. 1 shows an overall front view of the spiral staircase according to the embodiment of the present invention, FIG. 2 shows a schematic external view of the main part of the spiral staircase, and FIG. 3 shows a schematic plan view of the main part of the spiral staircase.
Here, 1 is a core pillar made of a hollow tubular body, 2 is a tread plate, 3 is a handrail pillar, and 4 is a handrail.
FIG. 2 shows a spiral staircase in which the handrail pillar 3 is erected but the handrail 4 is not erected on the handrail pillar.

4 (a) and 4 (b) show a plan view and a front view of one embodiment of the humiita.
A core pillar insertion hole (through hole) 23 is formed in the inner end portion 21 (the end portion on the center side of the spiral staircase) of the tread plate 2, and as can be seen from FIGS. 1 to 3, the core pillar insertion hole 23 is formed. A spiral staircase is formed by inserting the central pillar 1 and deploying a plurality of treads around the central pillar around the central pillar.
The tread plate 2 shown in FIG. 4 has a substantially fan shape that gradually widens from the vicinity of the inner end portion toward the outer end portion 22 (the outer end portion of the spiral staircase), and has a constant thickness. In the one shown in this figure, the inner end portion is made slightly thicker to provide the core column insertion hole 23, but the width may be gradually narrowed toward the inner end portion as in the tread plate shown in FIG. ..

As can be seen from FIG. 4, the handrail pillar insertion holes 24, 24 into which the handrail pillar 3 is inserted are formed at two positions, the nose portion and the step tail portion, at the outer end of the tread plate. The handrail pillar insertion holes 24, 24 penetrate the tread plate 2 in the thickness direction.
Here, the step nose portion and the step tail portion refer to a portion on the front side of the humiita and a portion on the back side of the humiita when climbing the stairs. FIG. 5, which shows a part of the spiral staircase that goes up clockwise, shows the step nose portion 25 and the step tail portion 26.

An example of the procedure for assembling the spiral staircase will be described below, and the structure of the spiral staircase will be shown.
First, the pillar 1 is erected.
As a means for erection of the central pillar, for example, as shown in FIG. 5, an anchor bolt (not shown) is attached to a disk-shaped seat plate 7 on which a hollow core body 8 having the same outer diameter as the inner diameter of the central pillar is erected. ) Is used to fix the spiral staircase to the ground or floor, and the hollow core body 8 can be erected by attaching the core pillar 1. It is desirable that the upper surface of the seat plate be at the same height as the upper surface of the ground or floor.
Further, in an installation place where a wall body or the like is provided around the wall body, the core pillar can be erected by supporting the upper end portion of the core pillar and the wall body with a laterally passing member.

Next, the tread plate 2, which is the first step of the spiral staircase, is attached to the tread plate 1 so that the tread plate 2 is inserted into the core pillar insertion hole 23 of the tread plate from the upper end of the erected core pillar 1. Subsequently, the second-stage humiita 2 is attached to the core column 1 in the same manner, and is stacked on the first-stage humiita.

Then, as shown in FIG. 5, it is formed in the handrail pillar insertion hole 24 formed in the step tail portion 26 at the outer end portion of the first step plate and the nose portion 25 at the outer end portion of the second step plate. The second step plate is arranged on the first step plate so as to overlap with the handrail pillar insertion hole 24.
Therefore, after the arrangement is completed in this way, as can be seen from FIG. 2, the upper surface of the step tail portion of the first step plate and the lower surface of the step nose portion of the second step come into contact with each other. In FIG. 2, when climbing a spiral staircase, the second step plate is rotated by a predetermined angle in the direction opposite to the movement of the clock hand around the central pillar with respect to the first step plate. It is arranged.

Then, the handrail pillar is inserted into the handrail pillar insertion hole 24 formed in the nose portion 25 of the second step plate, which overlaps with the handrail pillar insertion hole 24 formed in the step tail portion 26 of the first step plate. 3 is inserted and erected until it reaches the lower end of the handrail pillar insertion hole of the first step tread plate (see FIGS. 5 and 6). By doing so, the first-stage humiita and the second-stage humiita are arranged so as to form a predetermined angle around the central pillar.

As shown in FIG. 6, a threaded portion 31 of a male screw is formed at the lower end portion of the handrail column 3 so that the nut 6 can be screwed into the handrail column 3. Then, the tread plate (second step tread plate) located above and the tread plate (first step tread plate) located below it are sandwiched and tightened with two nuts.

By doing so, the two treads (that is, the first and second treads) are integrated and prevented from shifting from each other, and the handrail pillar 3 is prevented from coming out of the handrail pillar insertion hole 24. The pillar and the two treads are also integrated. Since the two tread plates are also supported by the core pillar 1 inserted into the core column insertion hole 23, the two tread plates are surely arranged spirally around the core column in a solid state around the core column. The first and second steps of the spiral staircase are formed in.

Similarly, the third-stage tread plate 2 is attached to the core column so that the core column is inserted into the core column insertion hole 23 of the tread plate from the upper end of the erected core column 1, and is attached to the second-stage tread plate. Stack up. Then, the handrail pillar insertion hole 24 formed in the step tail portion 26 at the outer end portion of the second step plate and the handrail pillar insertion hole 24 formed in the step nose portion 25 at the outer end portion of the third step plate. The third step plate is placed on the second step plate so as to overlap with each other, and then the handrail pillar 3 is inserted and erected until it reaches the lower end of the handrail pillar insertion hole of the second step plate. Then, the tread plate (third tread plate) located above and the tread plate (second tread plate) located below the tread plate (third tread plate) located above are sandwiched and tightened by two nuts screwed and fitted to the handrail pillar 3.

In this way, the two treads (that is, the second and third treads) are integrated to prevent them from shifting from each other, and the handrail pillars are prevented from coming out of the handrail pillar insertion holes. The two treads are integrated. Since the two tread plates are also supported by the core pillar 1 inserted through the core pillar insertion hole 23, the tread plates from the first step to the third step are surely in a firm state centered on the core pillar. Will be arranged in a spiral shape.

Similarly, for the treads from the fourth step to the uppermost step, the treads can be spirally assembled around the central pillar around the central pillar by the same procedure.
Therefore, in the spiral staircase of the present invention, the lower nth step (n is an integer) tread and the upper (n + 1) step tread, which are adjacent to each other, are the upper (n + 1) steps. The handrail pillar insertion hole formed in the nose of the outer end of the step plate of the eye and the handrail pillar insertion hole formed in the step tail of the outer end of the nth step plate located below overlap. The n-th and (n + 1) -th step treads adjacent to each other are connected by two nuts that are screwed and fitted into the handrail pillar that is erected through the two overlapping handrail pillar insertion holes. It is pinched and tightened.

FIG. 7 shows a spiral staircase in which the fourth step plate is spirally arranged, and the step plates 2 from the first step to the fourth step are spirally arranged using three handrail columns 3. Has been done. A nut (not shown) is attached to each handrail column to tighten the two sets of treads, so that the operator can go up to the fourth step.
In addition, in FIG. 7, the handrail pillar is also erected in the handrail pillar insertion hole formed in the nose portion of the outer end of the first step plate, which will be described later.

When the two tread plates are sandwiched between the two nuts inserted into the handrail pillar and tightened between the second to upper tread plates, the form shown in FIG. 6A may be used, but as can be seen from FIG. 2, 2 Since a space is formed below the lower surface of the tread plate on the step tail side after the step, the form shown in FIG. 6 (b) may be used in which the lower nut and the lower end of the handrail pillar are projected.

That is, while FIG. 6A shows an embodiment in which the lower end of the handrail column is arranged so as to be embedded in the tread plate on the lower surface of the tread plate without protruding from the lower surface of the tread plate. 6 (b) shows an embodiment in which the lower end of the handrail pillar protrudes from the lower surface of the tread plate, and the nut at the lower portion also protrudes from the lower surface of the tread plate.
As can be seen from FIGS. 6 (a) and 6 (b), the length of the threaded portion 31 formed at the lower end of the handrail pillar 3 inserted into the handrail pillar insertion hole 24 at the outer end of the two overlapping tread plates. Since the two treads are sandwiched between nuts, they are slightly longer than the thickness of the two treads.

On the other hand, when the handrail pillar is erected in the hole for inserting the handrail pillar formed in the nose portion at the outer end of the first step plate and the step tail portion at the outer end portion of the uppermost step plate, it can be seen from FIG. As described above, since the handrail pillar is erected by inserting the handrail pillar into the handrail pillar insertion hole of one tread plate, as shown in FIGS. 8A and 8B, the handrail pillar is more than the handrail pillar shown in FIG. The length is shorter by the thickness of one tread plate, and the threaded portion 31 at the lower end is slightly longer than the thickness of one tread plate. Using a handrail column, the upper surface and the lower surface of one tread plate are two nuts. Tighten it by sandwiching it with, and integrate the handrail pillar and one tread plate so that the handrail pillar does not come out from the hole for inserting the handrail pillar.

Since the lower surface of the first step plate is in contact with the ground or the floor and there is a space under the lower surface of the step tail portion of the uppermost step plate, the former first step nose portion has the form of FIG. 8 (a). It is desirable to adopt. The latter uppermost step tail portion may have any of the forms shown in FIGS. 8A and 8B.

The tread plate 2 is attached by inserting the core pillar into the core pillar insertion hole 23 at the inner end of the tread plate at the upper end of the erected core pillar 1. However, if the core pillar is high, the tread plate attachment work is required. It can be difficult. In the spiral staircase of the four-step tread plate shown in FIG. 7, the height of the central pillar is not so high, but as the number of tread plate steps increases, the central pillar also becomes higher.
In such a case, the central pillar can be divided instead of one.
If it is a split type, a predetermined number of treads are attached to the shinbashira, a spiral staircase for a predetermined number of treads is constructed as described above, and then this spiral staircase is climbed and the split type shinbashira is added. Further, a predetermined number of tread plates may be attached.
To add a split-type shinbashira, either form a threaded portion that fits into each connection port and screw-join it, or insert a hollow core body for connection into each connection port and insert an embedded pin. By inserting it, it is possible to connect it and add a split type core column.

The procedure for assembling the spiral staircase of the present invention is not limited to that described above. For example, it is possible to assemble a spiral staircase by inserting a tread plate constituting the spiral staircase with the shinbashira lying down into the shinbashira and then erecting the shinbashira.

As described above, in the spiral staircase of the present invention, since the tread plate inserted into the core pillar can be assembled with the handrail pillar and the nut, the number of parts and the types of parts constituting the spiral staircase are smaller than those of the conventional ones. I'm done. Moreover, since the structure is not complicated, the spiral staircase can be easily assembled even by a non-skilled worker.
Further, it is used in a conventional spiral staircase because the overlapping width of the upper and lower tread plates adjacent to each other can be changed only by changing the position of the handrail column insertion hole 24 in the direction along the outer peripheral edge of the outer end portion of the tread plate. The turning angle of the spiral staircase can be easily adjusted without the need for special means such as the positioning means for the tread plate.

As shown in FIG. 1, a handrail 4 is erected between the erected handrail pillars.
The handrail 4 may have a length corresponding to that between adjacent handrail columns, and may be erected via a connecting tool (not shown in FIG. 1) that connects the handrail columns 3 and the handrail 4. In this case, the connector is attached to the upper end of the handrail column 3 and has two handrail insertion ports.

A handrail having a length corresponding to the distance between adjacent handrail pillars can be used, but as shown in FIG. 7, a long handrail 4 having a length longer than the length corresponding to the distance between the adjacent handrail pillars can also be used. ..
When erection of a long handrail between the handrail pillars, as can be seen from FIG. 7, a handrail attachment 5 provided with a ring is used, and the long handrail 4 is inserted through the ring to insert the long handrail 4 between the handrail pillars. Can be erected.
An example of the fitting 5 is shown in FIGS. 9A to 9C. In this figure, the handrail mounting tool 5 includes a ring 51 through which the handrail 4 is inserted and a cap-shaped member 52 attached to the upper end of the handrail column, and the ring 51 is pivotally supported by a shaft 53 at the upper end of the cap-shaped member 52. , Can swivel around the axis. As can be seen from this figure, the ring 51 has a tongue piece member having a hole through which the shaft passes (no drawing number), and the cap-shaped member 52 has two protrusions that support the shaft by sandwiching the tongue piece member. Each has a shape (without drawing number). FIG. 9B also shows a state in which the ring 51 is turned to the right.

The handrail 4 is made of a long and flexible material, and the handrail 4 is sequentially inserted into the ring 51 of the fitting 5 fitted to the upper end of the handrail pillar 3 and erected spirally to form a spiral. Handrails for the entire staircase can be erected. Since the ring 51 is pivotally supported by the cap-shaped member 52 and can be swiveled in the fitting 5, the ring 51 swivels when the long handrail 4 is inserted, so that the long handrail 4 can be easily inserted into the ring. Therefore, the handrail can be erected between the handrail pillars.
The long handrail can also be made into a long handrail by connecting a short handrail. For the connection of the handrail, a means such as inserting a core material for connection into each connection port of the short handrail and connecting the handrail may be adopted.

As can be seen from FIGS. 4 and 5, the tread plate 2 of the present invention has a center column insertion hole 23 formed at the central end of the spiral staircase, and is formed at the nose and tail of the outer end of the spiral staircase. A hole 24 for inserting a handrail column is formed.
The tread plate 2 can be made of a metal such as steel or aluminum, but can also be made of a foam made of an exodermis and a foam core material in order to reduce the weight. A schematic cross-sectional view of the footboard 2 made of this foam is shown in FIG.
The foam 9 is a foam core material 91 whose inside is made of foamed resin, and the outer skin 92 covers the foam core material 91. The outer skin and the foam core material are integrated by using a blow molding method or a vacuum impregnation method. Can be made into a product.
A foamable polystyrene resin, a plant-derived polylactic acid-based foamable resin, or the like is used as the foam core material. Further, although a synthetic resin such as polyethylene or polypropylene can be used for the outer skin, a fiber reinforced plastic material having high strength is preferable.
The foam 9 has low strength only with the foam core material 91, but the strength is dramatically improved by integrating the foam core material 91 with the outer skin 92, and the load resistance, durability, and water resistance are improved. Is excellent. Moreover, since the foam core material occupies most of the volume, it is lightweight. Therefore, the spiral staircase can be made lightweight.

In the tread plate made of the foam 9, an outer skin can be formed on the inner peripheral surfaces of the core column insertion hole and the handrail column insertion hole, but the length of the tread plate is long when the foam core material 91 and the outer skin 92 are integrated. A sleeve with the same inner diameter as the outer diameter of the pillar and the handrail pillar is placed in advance at the center pillar insertion hole and the handrail pillar insertion hole, respectively, and the exodermis and foam core are arranged together with the sleeve. The materials can also be integrated. By doing so, each of the core column insertion hole 23 and the handrail column insertion hole 24 can be formed into a foam with high accuracy in the dimensions of the outer diameters of the core column and the handrail column. In this case, since the sleeve is attached to the inner peripheral surfaces of the core column insertion hole and the handrail column insertion hole, the foam core material is not exposed.
As an example of the dimensions of the tread plate made of the foam 9 having a constant thickness shown in FIG. 4, the thickness (that is, the height of the tread plate) is 200 mm, the length of the edge of the outer end is 565 mm, and the inner end is The width (outer diameter) of the cylindrical portion is 300 mm, the diameter of the core column insertion hole 23 is 200 mm, the diameter of the handrail column insertion hole is 36 mm, and the thickness of the outer skin is about 6 mm. A humiita with a weight of about 12 kg can be manufactured if the size is about this level.

The core pillar 1 is a hollow long tubular material, and a steel material, an aluminum alloy material, or the like can be used, but it is desirable to use a synthetic resin material in order to further reduce the weight. , Fiber reinforced plastic material is also suitable for strength. Since synthetic resin products do not corrode due to rust, they also have water resistance.

Like the core pillar, the handrail pillar 3 is also a hollow long tubular material, and a steel material, an aluminum alloy material, or the like can be used, but the handrail pillar 3 is made of synthetic resin in order to further reduce the weight. It is desirable to use fiber reinforced plastic material, which is also suitable for strength. Since synthetic resin products do not corrode due to rust, they also have water resistance.
Similarly, it is desirable to use a plastic material such as fiber reinforced plastic for the nut attached to the threaded portion of the handrail column for water resistance and weight reduction.

As the handrail, a hollow steel material or an aluminum alloy material can be used, but it is desirable to use a handrail made of synthetic resin for further weight reduction and corrosion resistance.
When using a handrail mounter equipped with a ring-shaped member and inserting a long handrail through the ring-shaped member to erection the handrail between the handrail columns, use a flexible hollow synthetic resin handrail. However, fiber reinforced plastic materials are also suitable for strength.

By the way, the spiral staircase can be installed in water such as the bottom of the water tank and used for going up and down between the bottom of the water tank and the outer peripheral edge of the water tank.
Underwater, buoyancy acts on the spiral staircase that is submerged. When the tread plate 2 shown in FIGS. 2, 4, 5 and 10 has a constant thickness over the entire surface, the volume of the tread plate is relatively large, and the tread plate is made of foam 9, the weight is relatively light. The buoyancy that acts is great. For this reason, a large force is constantly exerted on the humiita in the ascending direction. As the number of steps of the humiita in the water increases, the ascending force also increases. Therefore, in some cases, it is necessary to provide a means for suppressing the ascent of the humiita. In addition, since buoyancy constantly acts on the tread plate, it is not easy to submerge it in water, and the workability of assembling and installing the spiral staircase is poor.

FIG. 11 shows a perspective view of the footboard 2 suitable for a spiral staircase used underwater, and FIG. 12 shows a top view, a side view, a cross-sectional view, and a bottom view thereof.
As can be seen from FIGS. 11 and 12, the tread plate 2 includes a substantially fan-shaped plate-shaped portion 27 and a rib portion 28 arranged on the back surface of the plate-shaped portion, and the plate-shaped portion 27 is an upper surface portion of the tread plate. The rib portion 28 is arranged on the lower surface (back surface) of the plate-shaped portion 27 at a right angle to the surface, and the height of the tread plate 2 is formed by the thickness of the plate-shaped portion and the height of the rib portion. Has been done.
Air / drain holes 29 having a diameter of about 15 mm are provided in several places of the plate-shaped portion 27. Since air and water escape through this hole, the footboard can be submerged in a short time when assembling the spiral staircase in water or submerging the spiral staircase in water.

Since the rib portion is arranged on the lower surface of the plate-shaped portion to form the tread plate, the volume can be significantly reduced as compared with the tread plate shown in FIG. By doing so, the buoyancy acting on the tread plate immersed in water can be remarkably reduced.
Further, by stretching the rib portion on the lower surface of the plate-shaped portion, the strength as a tread plate can be maintained.

In the ones shown in FIGS. 11 and 12, the rib portion 28 is formed on the center line of the substantially fan-shaped plate-shaped portion 27 from the inner end portion 21 of the tread plate to the outer end portion 22 of the core column insertion hole described later. It extends linearly from the peripheral wall near the outer end to a point about 1/2 the length of the plate-shaped part, then branches at this point and extends in an arc shape to the nose and tail of the tread, and then there. It extends from the outer end portion 22 toward the center line of the plate-shaped portion to form a substantially triangular shape [see FIG. 12 (d)].

At the inner end 21 of the plate-shaped portion, a cylindrical peripheral wall of the core column insertion hole 23 is formed downward from the upper surface of the tread plate, and a portion of the peripheral wall near the tread plate outer side is a rib portion 28 on the tread plate center line. The height of the peripheral wall is equal to the height of the tread plate 2.
Further, also in the outer end portion 22 of the tread plate, a rib portion 28 is arranged on the lower surface (back surface) of the plate-shaped portion to form a peripheral surface of the outer end portion of the tread plate. Both ends [left and right in FIG. 12D] of the rib portion on the peripheral surface of the outer end portion are thickened, and a handrail column insertion hole 24 is formed. By doing so, as shown in FIGS. 6 and 8, the handrail pillar 3 can be erected on the tread plate 2. Further, the rib portion on the peripheral surface of the outer end portion is continuous with the rib portion forming the substantially triangular shape on the center line of the plate-shaped portion.

Similar to that shown in FIG. 10, a tread plate having a plate-shaped portion and a rib portion as shown in FIG. 11 is also foamed by using a blow molding method or a vacuum impregnation method to integrate an exodermis and a foam core material. Can be made from the body. FIG. 12 (c) shows a plate-shaped portion and a rib portion containing a foam core material (the portion where the lines intersect is the foam core material). In the tread plate shown in FIG. 11, the peripheral wall of the core column insertion hole 23 does not have a foam core material and is formed only from the material of the exodermis.

As the material of the exodermis of the tread plate, a resin having a density higher than that of water, for example, a thermosetting resin having a density of 1.5 g / cc or a fiber reinforced plastic is used to keep the tread plate floating force in water low. You can also. Further, as the material of the foam core material, foamable polystyrene resin, plant-derived polylactic acid-based foamable resin, or the like can be used as in the case of the tread plate shown in FIG.

As an example of the dimensions of the tread plate shown in FIG. 11, the thickness of the plate-shaped portion is 25 mm, the thickness of the exodermis is 7 mm, the height of the rib portion is 17.5 mm (hence, the height of the tread plate is 19.5 mm), and the core column. The thickness of the peripheral wall of the hole 23 is 10 mm. With this size, the total volume is about 20000 cc, and when a resin with a density of 1.5 g / cc is used for the exodermis, the weight can be about 20 kg. In this way, by making the specific gravity of the tread plate substantially the same as the specific gravity of water, it is possible to easily install and assemble the spiral staircase in water.

In the tread plate provided with a plate-shaped portion and a rib portion, a core pillar insertion hole 23 is formed at the central end of the spiral staircase, and a handrail pillar insertion hole 24 is formed at the nose and tail of the outer end of the spiral staircase. However, the shape and the like of the rib portion 28 are not limited to those shown in FIGS. 11 and 12, as long as the plate-shaped portion 27 can be reinforced to secure the strength as a tread plate. Good. Further, although the treads shown in FIGS. 11 and 12 have a foam core material wrapped in an outer skin, a solid tread plate (plate-shaped part, rib part, and core column insertion) is made only of the outer skin material without using the foam core material. It can also be formed on the peripheral wall of the hole). In this case, the dimensions of the plate-shaped portion, the rib portion, and the peripheral wall of the core column insertion hole may be appropriately adjusted.

In this way, the tread plate is composed of the plate upper portion 27 and the rib portion 28, and the volume of the tread plate can be significantly reduced while maintaining the strength as the tread plate, and the buoyancy in water can be significantly reduced. .. Further, by providing the air / drainage hole 29 in the plate-shaped portion of the tread plate, the workability at the time of assembling the spiral staircase can be further improved.

The above-mentioned tread plate having a plate-shaped portion and a rib portion can also be used for a spiral staircase installed in a place other than underwater. In this case, it is not necessary to provide the air / drain hole. Further, it is not always necessary to provide a foam core material on the plate-shaped portion and the rib portion. A solid humiita in which the foam core material is not provided on the humiita can be manufactured by injection molding or the like.

Since the spiral staircase of the present invention has fewer parts and the number of parts than the conventional one, and the structure is not complicated, not only is it easy to assemble the spiral staircase even by a skilled worker, but also the manufacturing cost is high. I'm sorry. In addition, since the tread plate using the foam core material is lightweight, it is easy to transport and transport.

1: Core pillar 2: Tread plate 21: Inner end 22: Outer end 23: Center pillar insertion hole 24: Handrail pillar insertion hole 25: Tread plate nose 26: Tread plate tail 27: Plate-shaped part 28 : Rib 29: Air / drain hole 3: Handrail pillar 31: Handrail pillar threaded portion 4: Handrail 5: Handrail mounting tool 51: Ring 52: Cap-shaped member 53: Shaft 6: Nut 7: Seat plate 8: Hollow core (attached to the seat plate) 9: Foam 91: Foam core 92: Outer skin 100: Shinbashira unit 200: Tread 300: Receiving material

Claims (4)

It is a spiral staircase in which treads with holes for inserting the core pillars are arranged spirally around the erected core pillars at the end on the center side of the stairs. A hole for inserting a handrail column is formed in the portion, and the tread plates adjacent to each other are supported by the core column , and a hole for inserting the handrail column is formed in the nose of the outer end of the stairs of the tread plate located on the upper side. And the handrail column insertion hole formed in the step tail of the staircase outer end of the tread plate located on the lower side are arranged so as to overlap each other, and the handrail is erected by being inserted into the two overlapping handrail insertion holes. A spiral staircase characterized in that it is fastened by sandwiching two tread plates adjacent to each other by two nuts screwed into a pillar. The spiral staircase according to claim 1, wherein the tread plate is a foam made of a synthetic resin outer skin and a foam core material. The spiral staircase according to claim 1, wherein the tread plate is composed of a plate-shaped portion, a rib portion arranged on the lower surface of the plate-shaped portion, and a peripheral wall of a core column insertion hole continuous with the rib portion. .. The spiral staircase according to claim 3, wherein a plurality of air / drain holes are provided in the plate-shaped portion of the tread plate.