spiral staircase and spiral stair treads

Abstract

The present invention provides a spiral staircase and its treads that can be expanded in outer diameter. [Solution] A spiral staircase characterized by having treads 1 having a hole 1h for inserting a central column or a hole for fitting a central column at the end of the staircase center, arranged spirally around an erected central column 2, and having an additional part 1p attached to the outer circumference of the treads 1 to expand the outer diameter of the spiral staircase, and a tread for a spiral staircase characterized by having an additional part 1p attached to the outer circumference of the treads 1 to expand the outer diameter.

Description

Technical Field

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

Background Art

[0002] Spiral staircases are installed inside or outside buildings, and are used to move up and down between upper and lower floors such as two-story buildings, or between large level differences. A spiral staircase is usually assembled by arranging a plurality of tiers of tread boards in a spiral around an erected newel post, and is characterized by a small occupied area and relatively small dead space.

[0003] As spiral staircases, lightweight spiral staircases with few types of constituent parts and a small number of parts, which are easy to assemble, have been developed (see Patent Document 1).

[0004] Patent Document 1 describes: "A spiral staircase in which tread boards each having a newel post insertion hole formed at the staircase center side end portion are arranged in a spiral around an erected newel post, wherein handrail post insertion holes are formed in the nosing portion and the back edge portion of the staircase outer side end portion of each tread board, adjacent tread boards are supported by the newel post, and the handrail post insertion hole formed in the nosing portion of the staircase outer side end portion of the upper tread board and the handrail post insertion hole formed in the back edge portion of the staircase outer side end portion of the lower tread board are arranged to overlap, and the two adjacent tread boards are clamped between two nuts screwed onto a handrail post that is inserted into the two overlapping handrail insertion holes and erected, the spiral staircase being characterized thereby." (Claim 1) is recorded therein.

[0005] However, the spiral staircase described in the above Patent Document 1 has a problem that when the tread boards are to be changed to those with a larger outer peripheral diameter, a new mold corresponding to the tread boards with the larger outer peripheral diameter must be prepared.

[0006] On the other hand, Patent Document 2 describes a spiral staircase with a structure similar to that of the spiral staircase described in Patent Document 1, in which a plurality of treads (corresponding to the "treads" mentioned above) are arranged spirally around a central column that extends vertically, wherein a tread support member having a horizontally extending tread support surface is provided on the lower side of the tread (a plate-shaped portion having a plate-like structure that intersects with the central column) (see Claim 1). [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Patent No. 6755083 [Patent Document 2] Japanese Patent Publication No. 2024-5596 [Overview of the Initiative] [Problems that the invention aims to solve]

[0008] The tread support member provided on the tread of the spiral staircase described in Patent Document 2 has a tread support surface that extends horizontally, but it does not expand the outer diameter of the spiral staircase, and its function is to increase the mechanical strength of the spiral staircase.

[0009] In view of the above-mentioned prior art, the object of the present invention is to provide a spiral staircase and its treads that can expand the outer diameter. [Means for solving the problem]

[0010] 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 column or a hole for fitting a central column at the end of the staircase on the central side are arranged spirally around an erected central column, characterized in that the outer diameter of the spiral staircase is expanded by attaching additional parts to the outer circumference of the treads. (2) The spiral staircase of (1) with the additional parts having an incline. (3) The spiral staircase according to (1) or (2), wherein handrail posts are attached to the outer periphery of the treads and erected, and a handrail is installed between the erected handrail posts. (4) Any of the spiral staircases described in (1) to (3) above, wherein the treads are made of synthetic resin. (5) A spiral stair tread, characterized in that an additional part is attached to the outer circumference of the tread to expand its outer diameter. (6) The treads of the spiral staircase of (5), with the additional parts having an incline. (7) A tread for the spiral staircase of (5) or (6) above, made of synthetic resin. [Effects of the Invention]

[0011] The spiral staircase and its treads of the present invention have the effect of being able to expand the outer diameter of the spiral staircase. [Brief explanation of the drawing]

[0012] [Figure 1] This is a schematic diagram of a spiral staircase relating to one embodiment of the present invention. [Figure 2] This is a schematic diagram of the treads of a spiral staircase according to one embodiment of the present invention. [Figure 3] This is a schematic diagram showing an example of a conventional spiral staircase. [Figure 4] This is a schematic diagram of a spiral stair tread according to another embodiment of the present invention. [Figure 5] This is a schematic diagram of a spiral staircase according to another embodiment of the present invention. [Modes for carrying out the invention]

[0013] The embodiments of the present invention will be specifically described below with reference to the drawings. Figure 1 is a schematic diagram of a spiral staircase according to one embodiment of the present invention (hereinafter referred to as "this embodiment"), and Figure 2 is a schematic diagram of the treads of the spiral staircase according to this embodiment. The spiral staircase shown in Figure 1 according to the present embodiment is a spiral staircase in which treads 1 each having a newel post insertion hole 1h at the center-side end of the staircase are arranged in a spiral around an erected newel post 2, wherein an additional part 1p is attached to the outer peripheral portion of each tread 1 to expand the outer peripheral diameter of the spiral staircase.

[0014] The means for attaching the additional part 1p is not limited, but as shown in Figure 2, for example, a plurality of protrusions 1b of the additional part 1p can be fitted into a plurality of recesses 1a provided on the outer peripheral portion of the tread 1, and the additional part can be attached using bolts (not shown). This eliminates the need to create a mold for a large diameter, and has the effect that a tread with a large diameter can be manufactured using a relatively small mold for the additional part.

[0015] An example of the assembly procedure for the spiral staircase shown in Figure 1 is described below. First, the newel post 2 is erected. The means for erecting the newel post 2 is, for example, as shown in Figure 5 of Patent Document 1, such that a disc-shaped base plate 7 on which a hollow core body 8 having an outer diameter equal to the inner diameter of the newel post is erected is fixed to the ground or floor surface at the installation site of the spiral staircase, and the newel post 2 is fitted onto the hollow core body 8 to be erected. 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 surface. In addition, at an installation site where a wall body or the like is provided in the surroundings, the newel post 2 can also be erected by supporting the space between the upper end portion of the newel post and the wall body with a horizontally spanning member.

[0016] Next, as shown in Figure 2, the tread 1 fitted with the additional part 1p to serve as the first step of the spiral staircase is attached to the erected newel post 2 such that the newel post 2 is inserted into the newel post insertion hole 1h of the tread 1 from the upper end of the newel post 2. Subsequently, the tread 1 fitted with the additional part 1p to serve as the second step is similarly attached to the newel post 2 and stacked on the first-step tread 1.

[0017] In Figures 1 and 2, 11 is a hole for inserting a handrail post. As shown in Patent Document 1, the handrail post insertion hole formed in the nosing of the outer end of the upper step and the handrail post insertion hole formed in the toe of the outer end of the lower step are arranged to overlap. The handrail post is inserted into these two overlapping holes and erected, and then tightened between the two adjacent steps by two nuts screwed onto the handrail post. However, when additional part 1p is attached, 12 becomes the handrail post insertion hole, and it is tightened in the same manner.

[0018] On the other hand, as an example of a conventional spiral staircase, there is a spiral staircase in which, instead of providing handrail post insertion holes 11 inside the treads as shown in Figures 1 and 2, the handrail posts 3 are fitted into recesses 1a provided on the outer circumference of the treads 1, as shown in Figure 3, the handrail posts 3 are erected using fastening means such as bolts, and a handrail 4 is installed between the erected handrail posts 3.

[0019] To expand the outer diameter of the spiral staircase shown in Figure 3, the handrail 4 and handrail posts 3 can be removed, and as shown in Figure 4, the multiple protrusions 1b of the additional part 1p can be fitted into the multiple recesses 1a provided on the outer circumference of the tread 1 to which the handrail posts 3 were fitted, and then attached with bolts (not shown). By attaching the additional parts 1p in order from the bottom, the spiral staircase shown in Figure 5 is formed. The handrail posts 3 can be fitted into the multiple recesses 1a' provided on the outer circumference of the additional part 1p.

[0020] Figures 1 to 5 show a spiral staircase in which a tread 1 has a central column insertion hole 1h at the end of the staircase center and the tread 1 is arranged spirally around an erected central column 2. However, a tread with a central column fitting hole can also be used instead of the central column insertion hole 1h.

[0021] By dividing the tread 1 into two parts at the position of the central column fitting hole and fitting the divided holes into the central column 2, the tread 1 with the additional part 1p attached can be installed. Compared to inserting the central column 2 into the central column insertion hole 1h of the tread 1 from the upper end of the erected central column 2, this method allows for installation without difficulty and has the advantage of allowing for easy removal of each part individually.

[0022] 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.

[0023] The stepping board 1 can be made of metal such as steel or aluminum, but it is preferable to make it of synthetic resin to reduce weight. Fiber-reinforced plastic (FRP), which has high strength, is even more preferable. Glass fiber, carbon fiber, etc. can be used as the fiber, and polyester, etc. can be used as the plastic. 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.

[0024] 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.

[0025] 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.

[0026] 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 1 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 1 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 1. 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 1, the buoyant force of the footboard 1 in water can be kept low. Furthermore, as a means to prevent the tread plate 1 from floating, the tread plate 1 can be provided with ribs, air / water drainage holes, etc., as shown in Figure 2. [Industrial applicability]

[0027] The spiral staircase of the present invention has high industrial applicability because it eliminates the need to create molds for large diameters, and allows the production of large diameter treads using molds for relatively small additional parts. [Explanation of Symbols]

[0028] 1. Stepping board 1a Multiple recesses provided on the outer periphery of the tread plate 1 1a' Multiple recesses into which the handrail post 3 is fitted. 1b Additional part 1p Multiple protrusions 1h Hole for inserting the central pillar in tread 1 1p Additional part for step board 1 2 Shinbashira 3 handrail pillar 4 Handrail 11 Holes for inserting handrail posts 12 Holes for inserting handrail posts

Claims

1. A spiral staircase in which treads, each having a hole for inserting or fitting a central column at the end of the staircase center, are arranged spirally around an erected central column, characterized in that additional parts are attached to the outer circumference of the treads to expand the outer diameter of the spiral staircase.

2. The spiral staircase according to claim 1, wherein the aforementioned additional part is given an incline.

3. 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.

4. The spiral staircase according to any one of claims 1 to 3, wherein the treads are made of synthetic resin.

5. A spiral stair tread, characterized in that an additional part is attached to the outer circumference of the tread to expand its outer diameter.

6. The tread of the spiral staircase according to claim 5, wherein the aforementioned additional part is inclined.

7. A spiral stair tread according to claim 5 or 6, made of synthetic resin.

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