spiral staircase and spiral stair treads

Abstract

To provide a spiral staircase and its treads that allow for easy partial replacement of the treads after construction, have high strength, and have a small number of components constituting the spiral staircase. [Solution] A spiral staircase is provided in which treads 1, each having a central column fitting hole 1h at the end on the staircase's central side, are arranged spirally adjacent to each other around an erected central column, characterized in that the tread 1 is divided along its short side at the position of the central column fitting hole 1h into two members 1a with an arc-shaped cross-section and a main body 1b with an arc-shaped notch at its end, and the divided holes 1ha and 1hb of the tread 1 are fitted into the central column and fixed in a detachable manner. Preferably, the tread 1 having the two divided holes 1ha and 1hb comprises a member 1a with an arc-shaped cross-section and a main body 1b with an arc-shaped notch at its end, and the member 1a with an arc-shaped cross-section and the main body 1b with an arc-shaped notch are joined to form a central column fitting hole 1h with a circular cross-section.

Description

Technical Field

[0001] The present invention relates to a spiral staircase and a tread used for the spiral staircase.

Background Art

[0002] Spiral staircases are installed inside or outside buildings and are used to ascend and descend between upper and lower floors such as the second floor or between large level differences. Spiral staircases are usually assembled by arranging treads spirally over a plurality of steps around a vertically installed central column, and are characterized by a small occupied area and a relatively small dead space.

[0003] As spiral staircases, lightweight spiral staircases with fewer types and numbers of components and easy assembly have been developed (see Patent Document 1).

[0004] Patent Document 1 describes, "A spiral staircase in which treads having holes for inserting a central column formed at the end on the staircase center side are arranged spirally around a vertically installed central column, and handrail column insertion holes are formed at the step nose portion and the step bottom portion at the end on the outer side of the staircase of the tread. Adjacent treads are supported by the central column, and the handrail column insertion hole formed at the step nose portion at the end on the outer side of the staircase of the upper tread and the handrail column insertion hole formed at the step bottom portion at the end on the outer side of the staircase of the lower tread are arranged so as to overlap, and the two adjacent treads are clamped and tightened by two nuts screwed onto the handrail column erected by inserting into the two overlapping handrail insertion holes." (Claim 1).

[0005] However, the above spiral staircase has a problem that the treads are inserted and stacked from above, and it is difficult to replace them after construction.

[0006] On the other hand, in a spiral staircase, it is also known to detachably fix the treads to the central column one by one (see Patent Documents 2 to 4).

[0007] Patent Document 2 describes a spiral staircase tread mounting structure in which an end plate is integrally provided at the end of the tread on the column side, and the end plate is detachably fixed to the side of the column by a fastener that penetrates the end plate... (Claim 1), and also states, "The end plate 9 has a plurality (four in Figure 2) of bolt insertion holes 12. These plurality of bolt insertion holes 12 and the plurality of pop nuts 7 described above are provided in correspondence. In Figure 3, two bolt insertion holes 12, 12 are arranged vertically, spaced apart in the circumferential direction of the column 3." (Paragraph

[0019] )

[0008] Patent Document 3 describes a spiral staircase in which protective members are provided on the outside of the support columns at predetermined intervals, stringer plates are arranged spirally, and a number of treads are sequentially fixed spirally between the support columns and the stringer plates, wherein the treads are planar fan-shaped formed and solidified from reinforced fiber concrete within a steel frame, one end of which is fixed to the support column with a mounting piece projecting radially and a bolt, and the other end is fixed to the stringer plate with a bolt. (Claim 1) It also states that "This invention has the advantage of making it easy to detachably fix the treads to the support columns and stringer plates, thus facilitating factory production of components and on-site assembly of the stairs, and eliminating the need for welding on site. Furthermore, since one end of the tread is fixed to the mounting piece of the support column with a bolt, there is no risk of weakening the strength of the support column, and it is possible to easily replace parts of the treads as needed." (Column 4, lines 23-29)

[0009] Patent Document 4 describes "a spiral staircase characterized by comprising a ball, spacers arranged in a vertical line with a gap between the pole and step, and steps that are attached to the pole between each spacer in any direction within a 360-degree range of attachment directions." (Claims for Utility Model) It also states, "Furthermore, as shown in Figure 3, the pole (l) has a polygonal cross-section, and the step (4)' is split in two and a polygonal hole (7)' is formed therein that matches the polygon." Furthermore, by fitting the two-part step (4)'(4)' with its polygonal hole (7)'(7)' onto the pole (1), and integrating the step (4)'(4)' with appropriate connectors (12)(12), a spiral staircase can be obtained by sequentially changing the mounting direction of each upper and lower step (4)' within a 360-degree range. In this case, the polygon provides stable fixation and eliminates the risk of the step (4)' moving around. (Page 3, line 11 to Page 4, line 1) [Prior art documents] [Patent Documents]

[0010] [Patent Document 1] Patent No. 6755083 [Patent Document 2] Japanese Patent Publication No. 2006-316577 [Patent Document 3] Publication No. 4-12909 [Patent Document 4] Microfilm of Utility Model Application No. 48-80394 (Utility Model Publication No. 50-28519) [Overview of the Initiative] [Problems that the invention aims to solve]

[0011] The inventions described in Patent Documents 2 and 3 involve detachably fixing the treads to the central column in order to facilitate partial replacement of the treads. However, since one end of the tread is fixed to the side of the central column and the tread is not fitted into the central column, there was a problem in that the strength was insufficient. In contrast, Patent Document 4 describes a method in which a step (tread) is divided into two halves and holes are formed between them, and the holes in the divided step are fitted onto a pole (central column) and integrated with appropriate connectors. However, since the steps are not adjacent to each other, but rather spacers are provided between the steps, there is a problem in that the number of parts constituting the spiral staircase increases.

[0012] In view of the above-mentioned prior art, the present invention aims to provide a spiral staircase and its treads that allow for easy partial replacement of the treads after construction, have high strength, and have a small number of components constituting the spiral staircase. [Means for solving the problem]

[0013] To solve the above problems, the present invention employs the following means. (1) A spiral staircase in which treads, each having a hole for fitting into a central column at the end of the staircase center, are arranged spirally adjacent to each other around an erected central column, characterized in that the treads are divided into two along the short side at the position of the hole for fitting into the central column, and the divided holes of the treads are fitted into the central column and fixed in a detachable manner. (2) The spiral staircase of (1), wherein the tread having the two divided holes comprises a member having an arc-shaped cross-section and a main body having an arc-shaped notch at its end, and the member having an arc-shaped cross-section and the main body having an arc-shaped notch at its end are joined to form the central column fitting hole having a circular cross-section. (3) The spiral staircase of (1) or (2) above, wherein an additional part is attached to the outer circumference of the tread to expand the outer diameter of the tread. (4) Any of the spiral staircases described in (1) to (3) above, wherein handrail posts are attached to the outer periphery of the treads and erected, and a handrail is installed between the erected handrail posts. (5) Any of the spiral staircases described in (1) to (4) above, wherein the treads are made of synthetic resin. (6) A tread of a spiral staircase comprising a member with an arcuate cross-section and a main body having an arcuate notch at the end of the tread, wherein the member with an arcuate cross-section and the main body having an arcuate notch at the end of the tread are joined to form a hole for fitting a core column with a circular cross-section. (7) The tread of the spiral staircase according to (6), wherein an additional part is attached to the outer peripheral portion of the main body to expand the outer diameter of the tread. (8) The tread of the spiral staircase according to (6) or (7), which is made of synthetic resin.

Advantages of the Invention

[0014] With the spiral staircase and its tread of the present invention, it is possible to easily replace a part of the tread after construction, and a spiral staircase with high strength and a small number of components constituting the spiral staircase can be obtained.

Brief Description of the Drawings

[0015] [Figure 1] It is a schematic view of a spiral staircase according to an embodiment of the present invention. [Figure 2] It is a schematic view of a tread of a spiral staircase according to an embodiment of the present invention. [Figure 3] It is a schematic view of a spiral staircase with an additional part attached to a tread according to another embodiment of the present invention. [Figure 4] It is a schematic view of a tread of a spiral staircase with an additional part attached according to another embodiment of the present invention. <unk>0000088< / unk>

Modes for Carrying Out the Invention

[0016] Hereinafter, embodiments of the present invention will be specifically described with reference to the drawings. FIG. <unk>00|000|095< / unk> is a schematic view of a spiral staircase according to an embodiment of the present invention (hereinafter referred to as "this embodiment"), and FIG. 2 is a schematic view of a tread of the spiral staircase according to this embodiment. It seems there is an issue with tag and in the original text where they are not properly formatted. I've translated them as best as possible while keeping the tags intact. If these are meant to be something specific, the translation might need adjustment based on the correct understanding of those tags.The spiral staircase according to this embodiment is a spiral staircase in which treads 1 having core column fitting holes 1h at the end portions on the staircase center side are arranged spirally adjacent to each other around a vertically erected core column 2. The tread 1 is divided at the position of the core column fitting hole 1h into two members 1a with arc-shaped cross sections along the short side and a main body 1b having an arc-shaped notch at the end, and the divided holes 1ha and 1hb of the tread 1 are fitted to the core column 2 and detachably fixed.

[0017] The tread of the spiral staircase according to this embodiment is such that the tread 1 having two divided holes 1ha and 1hb includes a member 1a with an arc-shaped cross section and a main body 1b having an arc-shaped notch at the end. It is preferable that the member 1a with an arc-shaped cross section forming one semi-circular portion 1ha of the hole 1h and the main body 1b having an arc-shaped notch at the end forming the other semi-circular portion 1hb of the hole 1h are joined to form a core column fitting hole 1h with a circular cross section.

[0018] The means for joining the member 1a with an arc-shaped cross section and the main body 1b having an arc-shaped notch at the end is not limited. For example, as shown in FIG. 2, bolt holes are provided at the left and right end portions of the member 1a with an arc-shaped cross section, bolts are passed through the left and right holes provided at the end of the main body 1b, and a nut (not shown) can be screwed and joined.

[0019] FIG. 3 shows a schematic view of a spiral staircase according to another embodiment of the present invention (hereinafter referred to as the "expanded embodiment"). In the spiral staircase according to the expanded embodiment, as shown in FIG. 3, the outer peripheral diameter of the tread 1 is expanded by attaching an additional part 1c to the outer peripheral portion of the tread 1. The means for attaching the additional part 1c is not limited. For example, a plurality of convex portions of the additional part 1c can be fitted into a plurality of concave portions provided on the outer peripheral portion of the main body 1b of the tread 1 and attached with bolts (not shown). There is an effect that it is not necessary to make a mold for a large diameter, and a large-diameter tread can be manufactured using a relatively small mold for the additional part. Also, by giving an inclination to the additional part, another function can be provided.

[0020] Figure 4 shows a schematic diagram of the treads of a spiral staircase according to an extended embodiment. The above-described tread is the same as the tread of the spiral staircase according to this embodiment in that it is a tread 1 in which a member 1a with an arc-shaped cross-section and a main body 1b having an arc-shaped notch at its end are joined to form a central column fitting hole 1h with a circular cross-section. However, an additional part 1c is attached to the outer circumference of the tread 1 to expand its outer diameter. As an example of the additional part 1c, a plurality of recesses are provided on the outer circumference of the main body 1b, and a plurality of protrusions are provided on the additional part 1c, and the additional part 1c is attached by fitting the protrusions into the recesses.

[0021] As shown in Figures 1 to 4, the tread 1 is divided along its short side at the position of the central column fitting hole 1h at the end of the staircase center, into two members 1a and a main body 1b. The two divided holes in members 1a and the main body 1b of the tread 1 are fitted into the central column 2 and fixed in a detachable manner. In this way, multiple treads 1 are arranged around the central column 2 to form a spiral staircase.

[0022] An example of the assembly procedure for a spiral staircase is described below. First, the central column 2 is erected. One way to erect the central column 2 is, for example, as shown in Figure 5 of Patent Document 1, to fix a disc-shaped base plate 7 on which a hollow core body 8 having the same outer diameter as the inner diameter of the central column is erected, to the ground or floor surface of the spiral staircase installation site, and then to attach the central column 2 to this hollow core body 8 and erect it. It is desirable that the upper surface of the base plate be at the same height as the upper surface of the ground or floor. Furthermore, in installation locations where walls or other structures are provided around the structure, the central column 2 can be erected by supporting it with a member that spans horizontally between the upper end of the central column and the wall.

[0023] Next, as shown in Figures 1 and 3, the divided members 1a and main body 1b, which will form the first step of the spiral staircase, are sandwiched between the erected central column 2 and fitted together to form the tread 1, and attached using fastening means such as bolts and nuts. Subsequently, the divided members 1a and main body 1b, which will form the second step, are similarly fitted to the central column 2 to form the tread 1, attached using fastening means, and stacked on top of the first step's tread. Furthermore, the third step's tread 1 is attached to the central column 2 in the same manner and stacked on top of the second step's tread. The steps from the fourth step onward are then stacked in the same manner. Compared to conventional spiral staircases, where the treads from the second step onward had to be attached to the central column 2 by inserting the central column into the central column insertion hole in the tread 1 from the upper end of the central column 2, this design simplifies construction.

[0024] Even when the divided treads 1 are fitted onto the erected central column 2 and attached using connecting means, if the central column 2 is tall, the installation of the treads may become difficult. In such cases, the central column 2 can be made into a divided type instead of a single piece to address this issue. If it's designed in sections, you can attach a predetermined number of treads to the central column, construct a spiral staircase for that number of treads, then climb this spiral staircase, add more sections to the central column, and attach yet another predetermined number of treads. To add sections to a split central column, threaded sections can be formed at each connection point to fit together and then joined by screwing, or by inserting a hollow core for connection into each connection point and then inserting an embedded pin.

[0025] As shown in Figure 1, the handrail posts 3 are fitted into recesses provided on the outer circumference of the main body 1b of the tread 1 on the spiral staircase assembled as described above, and attached using bolts or other fastening means to erect the handrail posts 3. Handrails 4 are then installed between the erected handrail posts. The handrail 4 can also be installed with a length corresponding to the distance between adjacent handrail posts, via a connecting device (not shown) that connects the handrail posts 3 and the handrail 4. In this case, the connecting device is attached to the upper end of the handrail post 3 and has two handrail insertion openings.

[0026] In the spiral staircase of the present invention, if one of the treads 1 is damaged for any reason after construction as described above, even if the damaged tread 1 is located at the bottom, it can be easily replaced with a new tread 1 by removing the connecting means such as bolts and nuts attached to the central column 2. In conventional spiral staircases, if a damaged tread 1 is located below it, all the treads above it must be removed, and a new tread 1 must be inserted from above the central column 2. Therefore, the spiral staircase of the present invention is exceptionally efficient.

[0027] The stepping board 1 can be made of metal such as steel or aluminum, but it is preferable to make it out of synthetic resin in order to reduce weight. The member 1a with an arc-shaped cross-section and the main body 1b having an arc-shaped notch at its end, as shown in Figures 2 and 4, are preferably made of high-strength fiber-reinforced plastic (FRP). Fibers such as glass fibers and carbon fibers can be used, and plastics such as polyester can be used. The stepping board 1 can be manufactured using known FRP manufacturing techniques such as hand lay-up or vacuum impregnation, but for mass production, the vacuum impregnation method is preferred. The vacuum impregnation method is a molding method in which a fiber-reinforced substrate (such as a fabric of glass fibers or carbon fibers) laminated on a mold is sealed in a plastic film or the like, vacuum-suctioned, and then liquid resin is injected and impregnated to harden it. Even a box-shaped stepping board 1 made of FRP with a thickness of about 6 mm and molded by this method can have sufficient strength.

[0028] The central column 2 is a long, hollow cylindrical material. While steel or aluminum alloy can be used, it is preferable to use a synthetic resin material to further reduce weight, and fiber-reinforced plastic is suitable in terms of strength. Since synthetic resin materials do not corrode with rust, they also have water resistance. However, for central columns 2 exceeding 10m in length, it is preferable for strength reasons to use stainless steel.

[0029] Handrail posts 3 and handrails 4, like the central post, are hollow, elongated cylindrical materials. While steel or aluminum alloy materials can be used, it is preferable to use synthetic resin materials to further reduce weight, and fiber-reinforced plastic is suitable in terms of strength. Synthetic resin materials do not corrode with rust, and therefore also have water resistance.

[0030] Incidentally, spiral staircases can also be installed underwater, such as at the bottom of a water tank, and used to ascend and descend between the bottom surface of the tank and its outer edge. In water, buoyancy acts on a spiral staircase submerged in the water. As shown in Figures 2 and 4, the treads 2 have a uniform thickness throughout, and their volume is relatively large. Furthermore, if the treads are made of foam, their weight is relatively light, resulting in a large buoyant force. Therefore, a large force constantly acts on the treads in the direction of floating. As the number of steps in the water increases, the buoyant force also increases, so in some cases, it may be necessary to provide a means to suppress the floating of the treads. By using a resin with a density greater than that of water, such as a thermosetting resin or fiber-reinforced plastic with a density of 1.5 g / cc, as the outer material for the footboard, the buoyancy force of the footboard in water can be kept low. Furthermore, as a means to prevent the treads from floating, the treads can be provided with ribs, air / water drainage holes, etc., as described in Patent Document 1. [Industrial applicability]

[0031] The spiral staircase of the present invention has high industrial applicability because it allows for easy partial replacement of treads after construction, has high strength, and consists of fewer components. [Explanation of Symbols]

[0032] 1. Stepping board 1a A member with a circular arc-shaped cross-section for the tread. 1b Main body having a circular arc-shaped notch at the end of the tread 1c Additional parts for the footboard 1h Hole for fitting the central post of the tread One semicircular portion of the hole 1h formed by member 1a, which has an arc-shaped cross-section. 1hb The other semicircular portion of the hole 1h formed by the arc-shaped notch in the cross-section of the main body 1b 2 Shinbashira 3 handrail pillar 4 Handrail

Claims

1. A spiral staircase comprising treads having holes for fitting a central column at the ends on the central side of the staircase, arranged spirally adjacent to each other around an erected central column, characterized in that the treads are divided into two along the short side at the position of the holes for fitting the central column, and the divided holes of the treads are fitted into the central column and fixed in a detachable manner.

2. The spiral staircase according to claim 1, wherein the tread having the two divided holes comprises a member having an arc-shaped cross-section and a main body having an arc-shaped notch at its end, and the member having an arc-shaped cross-section and the main body having an arc-shaped notch at its end are joined to form the central column fitting hole having a circular cross-section.

3. The spiral staircase according to claim 1, wherein an additional part is attached to the outer circumference of the tread to expand the outer diameter of the tread.

4. The spiral staircase according to claim 1, wherein handrail posts are attached to the outer periphery of the aforementioned treads and erected, and a handrail is installed between the erected handrail posts.

5. The spiral staircase according to any one of claims 1 to 4, wherein the treads are made of synthetic resin.

6. A spiral stair tread comprising a member with an arc-shaped cross-section and a main body having an arc-shaped notch at the end of the tread, wherein the member with an arc-shaped cross-section and the main body having an arc-shaped notch at the end of the tread are joined to form a central column fitting hole with a circular cross-section.

7. A tread for a spiral staircase according to claim 6, wherein an additional part is attached to the outer circumference of the main body to expand the outer diameter of the tread.

8. A spiral stair tread made of synthetic resin, according to claim 6 or 7.

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