JP2024057643A - Connection structure, tread piece, spiral stairs, and assembly method for spiral stairs - Google Patents

Abstract

To provide a connection structure and a tread piece which facilitate connection work, and spiral stairs using the tread piece and an assembly method for spiral stairs.SOLUTION: A spiral stairs include a plurality of tread pieces 20 connected to each other. The tread piece 20 has a tread body 21, a fitting projection 25 extending in a first direction H1 from the tread body 21, a first engagement recess 26 which is opened to the side face of the fitting projection 25 and extends in a second direction H2 crossing the first direction H1, a fitting recess 31 to which the fitting projection 25 of the other tread piece 20 is fit, and an engagement hole 35 which extends in the second direction H2, and communicates with the first engagement recess 26 of the other tread piece 20 in a state where the fitting projection 25 of the other tread piece 20 is fit into the fitting recess 31. An engagement material is inserted into the engagement hole 35, and the first engagement recess 26 of the other tread piece 20 in the communication state.SELECTED DRAWING: Figure 2

Description

The present invention relates to a connection structure, a step piece, a spiral staircase, and a method for assembling a spiral staircase.

For example, Patent Document 1 describes a method for assembling stairs by fitting risers into cutouts formed in the upper rear surface of the treads. In this method, the treads and risers can be securely connected by connecting them using adhesives, nails, etc.

JP 2016-89355 A

However, connection work using adhesives, nails, etc. is prone to problems unless performed by experienced craftsmen. This is particularly true for special structures such as spiral staircases. For this reason, there is a demand for technology that allows even inexperienced people to easily assemble stairs.

The connection structure that solves the above problem is a connection structure that connects a first member and a second member, in which the first member has a mating protrusion extending in a first direction and an engagement recess that opens on a side of the mating protrusion and extends in a second direction intersecting the first direction, and the second member has a mating recess into which the mating protrusion fits and an engagement hole that extends in the second direction and can communicate with the engagement recess when the mating protrusion is engaged with the mating recess, and the first member and the second member are connected by an engagement material inserted into the engagement hole and the engagement recess that are in a communicating state.

According to the above configuration, the first and second members can be connected by simply fitting the mating convex portion of the first member into the mating concave portion of the second member and then inserting the mating material into the mating hole and mating concave portion that are in communication with each other.

In the above connection structure, the engagement recess is a first engagement recess, the engagement material is a first engagement material, the first engagement material has a first protrusion protruding from the insertion opening forming surface of the first engagement material, the second member has a second engagement recess opening at the insertion opening forming surface and extending in a third direction intersecting the second direction, and the connection structure may further include a second engagement material inserted into the second engagement recess and having a second protrusion protruding from the insertion opening forming surface, and a bonding material bonding the first protrusion and the second protrusion.

According to the above configuration, the second engaging member prevents the first engaging member from falling off, so that the connected state between the first member and the second member can be reliably maintained.
The step piece that solves the above problem is a step piece made of an FRP-based material that can be connected to each other, and has a step body, an interlocking protrusion extending from the step body in a first direction, an engagement recess that opens to a side of the interlocking protrusion and extends in a second direction intersecting the first direction, an interlocking recess into which the interlocking protrusion of another step piece fits, and an engagement hole that extends in the second direction and communicates with the engagement recess of the other step piece when the interlocking protrusion of the other step piece is engaged with the interlocking recess.

According to the above configuration, the step pieces can be connected to each other simply by fitting the mating convex portion having the mating recess into the mating recess of another step piece, and then inserting the mating material into the mating hole and mating recess that are in communication with each other.

The spiral staircase that solves the above problem is a spiral staircase having a plurality of step pieces configured as described above, and is equipped with an upper step step piece, a lower step step piece, and an engaging member that engages the upper step step piece and the lower step step piece, the upper step step piece having an upper step engaging convex portion that is the engaging convex portion and an upper step engaging concave portion that is the engaging concave portion, the lower step step piece having a lower step engaging concave portion that is the engaging concave portion and a lower step engaging hole that is the engaging hole, and the engaging member is inserted into the lower step engaging hole and the upper step engaging concave portion that are in a communicating state.

According to the above configuration, the upper step piece and the lower step piece can be connected by fitting the upper step fitting protrusion into the lower step fitting recess and then inserting the engaging material into the upper step engagement recess and the lower step engagement hole, which are in a connected state.

In the spiral staircase of the above configuration, the engaging member is a first engaging member, and the lower step piece may further include a second engaging recess that opens into the insertion opening surface of the first engaging member and extends in a third direction intersecting the second direction, and is inserted into the second engaging recess and joined to the first engaging member.

With the above configuration, the first engaging member is prevented from falling off by the second engaging member, and the second engaging member is prevented from falling off by the first engaging member, so that the upper step piece and the lower step piece can be reliably maintained in a connected state.

In the spiral staircase having the above configuration, it is preferable that the first engaging member and the second engaging member are pin-joined on the outside of the lower step engaging hole. With this configuration, the first engaging member and the second engaging member can be easily joined.

In the spiral staircase having the above configuration, the first engaging member and the second engaging member may be pin-connected by a handrail support post that supports the handrail.
According to the above configuration, the first engaging material and the second engaging material are pin-joined at the handrail support post, so even if a handrail is installed on the spiral staircase, there is no need to provide a separate structure for supporting the handrail support post.

The spiral staircase that solves the above problem is a spiral staircase having a plurality of tread pieces of the above configuration, and comprises a top tread piece, an upper floor step piece, and an upper floor connection mechanism having an upper floor connection material that is connected to the top tread piece and the upper floor step piece, the upper floor step piece having an upper floor connection material connection part that is connected to the upper floor connection material, the upper floor connection material having an upper floor step piece connection part that is connected to the upper floor step piece, and a front connecting member that extends in the first direction and The upper floor connection mechanism has a top step connecting engagement protrusion that fits into the engagement recess of the top step step piece, and a connecting engagement recess that opens on the side of the top step connecting engagement protrusion and extends in the second direction, and communicates with the engagement hole of the top step step piece when the top step connecting engagement protrusion is engaged with the engagement recess of the top step step piece, and the upper floor connection mechanism has a top step engaging member that is inserted into the engagement hole of the top step step piece and the connecting engagement recess that are in a communicating state.

According to the above configuration, the upper floor connecting piece and the top step piece can be connected via the upper floor connecting mechanism by fitting the top step connecting convex portion into the connecting concave portion of the upper floor connecting material and the engaging hole of the top step piece, which are in a connected state, and then inserting the top step engaging material into the connecting engaging concave portion of the upper floor connecting material and the engaging hole of the top step piece.

It is preferable that the spiral staircase configured as described above has a connecting step which covers the upper floor connecting mechanism and is connected to the upper floor step piece and the top step step piece.
According to the above configuration, the upper floor connecting mechanism is covered by the connecting step, thereby improving the aesthetic appearance of the connecting portion between the upper floor step piece and the top step piece.

The spiral staircase that solves the above problem is a spiral staircase having a plurality of tread pieces of the above configuration, and includes a lowest tread piece, a lower floor step piece, and a lower floor connection mechanism having a lower floor connection material that connects the lowest tread piece and the lower floor step piece, the lower floor step piece having a lower floor connection material connection part that connects to the lower floor connection material, and the lower floor connection material having a lower floor step piece connection part that connects to the lower floor step piece and a lowest step connection fitting recess that extends in the first direction and into which the fitting protrusion of the lowest tread piece fits.

According to the above configuration, the lowest step piece can be easily installed on the lower floor piece by fitting the mating convex portion of the lowest step piece into the lowest step connecting mating concave portion of the lower floor connecting material.

The method of assembling a spiral staircase that solves the above problem is a method of assembling a spiral staircase having multiple tread pieces made of FRP material that can be connected to each other, in which the tread pieces have a tread body, a mating protrusion extending from the tread body in a first direction, an engagement recess that opens on the side of the mating protrusion and extends in a second direction intersecting the first direction, a mating recess into which the mating protrusion of another tread piece fits, and an engagement hole that extends in the second direction and communicates with the engagement recess of the other tread piece when the mating protrusion of the other tread piece is engaged with the mating recess, and the step of connecting the tread pieces includes the steps of mating the mating protrusion of the upper tread piece with the mating recess of the lower tread piece and inserting an engagement material into the engagement hole of the lower tread piece and the engagement recess of the upper tread piece.

According to the above configuration, the upper step piece and the lower step piece can be connected by fitting the mating convex portion of the upper step piece into the mating concave portion of the lower step piece, and then inserting an engaging member into the engaging concave portion of the upper step piece and the engaging hole of the lower step piece, which are in a connected state.

The method of assembling a spiral staircase with the above configuration preferably includes the steps of: connecting a lower step piece to a lower floor, the lower step piece having a lowest step connecting mating recess into which the mating protrusion of the lowest step piece fits; fitting the mating protrusion of the lowest step piece into the lowest step connecting mating recess; connecting the step pieces together; connecting the top step piece to an upper step piece having a top step connecting mating protrusion that fits into the mating recess of the top step piece; and connecting the upper step piece to the upper floor.

With the above configuration, a spiral staircase with tread pieces connected to each other can be installed between the lower floor and the upper floor.

FIG. 1 is a perspective view showing a schematic configuration of one embodiment of a spiral staircase. FIG. 2 is a perspective view showing a schematic configuration of one embodiment of a step piece. 13 is a perspective view showing a schematic view of the mating protrusion of an upper step piece being mated with the mating recess of a lower step piece; FIG. 13 is an oblique view showing the state in which the mating protrusion of the upper step piece is mated with the mating recess of the lower step piece. FIG. 1 is a perspective view showing a state in which a lower step piece and an upper step piece are connected to each other. FIG. 1 is an exploded perspective view showing the installation structure of the lowest step piece relative to the lower floor step piece. FIG. This is an oblique view showing the state in which the lowest step piece is installed on the lower floor floor piece. FIG. 2 is an exploded perspective view showing the connecting structure between the upper floor step piece and the top step tread piece. 1 is an exploded perspective view showing the upper floor step piece and the top step step piece connected together. FIG. FIG. 4 is an exploded perspective view showing the connection structure between the upper floor connecting material and the connecting tread. 13 is a perspective view showing the state in which a connecting step is connected to an upper floor connecting material. FIG. FIG. 11 is a perspective view showing a schematic configuration of a connection structure in a modified example.

An embodiment of a connecting structure, a tread piece, a spiral staircase, and a method for assembling a spiral staircase will be described with reference to Figures 1 to 11 .
(Outline of the spiral staircase)
As shown in Figure 1, a spiral staircase 10 has a stair section 11 and a handrail 12. The stair section 11 is formed in a spiral shape. In the following, when viewed from above, the direction approaching the central axis of the stair section 11 is referred to as the inner diameter direction, and the direction away from the central axis of the stair section 11 is referred to as the outer diameter direction.

The handrail 12 is arranged along the end of the staircase section 11 in the inner diameter direction when viewed from above. The handrail 12 is supported by handrail support posts 14 connected to the staircase section 11. The staircase section 11 is made up of multiple step pieces 20 connected to each other. The step pieces 20 are made of, for example, CFRP (Carbon Fiber Reinforced Plastics), a type of FRP (Fiber Reinforced Plastics) material, commonly known as carbon fiber reinforced plastic material.

Of the step pieces 20 that are connected to each other, the step piece 20 located on the lower level is called the lower step piece, and the step piece 20 located on the upper level is called the upper step piece. In addition, the step piece 20 located on the lowest level is called the lowest step piece, and the step piece 20 located on the highest level is called the highest step piece.

(Step piece)
As shown in Fig. 2, the step piece 20 has a step body 21. The step body 21 has a narrow inner diameter portion 22 and a wide outer diameter portion 23. A lower surface 22b of the inner diameter portion 22 is a supported surface that is supported by a lower step piece.

The tread body 21 has a tread surface 21a and a kick-up surface 21b. The tread surface 21a is formed in a fan shape by the upper surface of the inner diameter portion 22 and the upper surface of the outer diameter portion 23. The kick-up surface 21b is formed by the side surface of the inner diameter portion 22 and the side surface of the outer diameter portion 23. The side surface of the inner diameter portion 22 is formed in a substantially rectangular shape. The side surface of the inner diameter portion 22 is formed in a substantially triangular shape with the lower end approaching the tread surface 21a as it approaches the outer diameter side.

The step piece 20 has a mating protrusion 25. The mating protrusion 25 is integrally connected to the inner diameter portion 22. The mating protrusion 25 extends in the first direction H1 so as to protrude downward from the lower surface 22b of the inner diameter portion 22. The mating protrusion 25 has a first engagement recess 26 formed therein. The first engagement recess 26 opens on the side of the mating protrusion 25. More specifically, the first engagement recess 26 opens across the side of the mating protrusion 25 on the inner diameter side and the side connected to the kick-up surface 21b. The first engagement recess 26 extends in a second direction H2 that intersects with the first direction H1. The second direction H2 is a direction in which the horizontal component is larger than the vertical component. It is preferable that the second direction H2 is composed only of a horizontal component. The first engagement recess 26 is a portion into which the first engagement member 40 described later is inserted.

The step piece 20 has a fitting recess forming portion 30. The fitting recess forming portion 30 is integrally connected to the inner diameter portion 22 and the inner portion of the outer diameter portion 23 of the step body 21. The fitting recess forming portion 30 protrudes from the step body 21 on the side opposite the kick-up surface 21b. The fitting recess forming portion 30 has a fitting recess 31 formed therein into which the fitting protrusion 25 of the upper step piece fits.

The fitting recess 31 is recessed in the first direction H1 from the upper surface 30a of the fitting recess forming portion 30. The upper surface 30a of the fitting recess forming portion 30 is located slightly below the tread surface 21a. This upper surface 30a is a support surface that supports the lower surface 22b of the inner diameter portion 22 of the upper step piece when the fitting protrusion 25 of the upper step piece is fitted into the fitting recess 31.

The step body 21 is also formed with an engagement hole 35 and a second engagement recess 36. The engagement hole 35 and the second engagement recess 36 open into the insertion port forming surface 21s, which is the side surface of the step body 21 in the inner diameter direction. The engagement hole 35 and the second engagement recess 36 are formed so that the ends on the insertion port forming surface 21s side, including the opening portion, are connected and the opening portions are aligned in the vertical direction.

The engagement hole 35 is a through hole that extends from the insertion opening forming surface 21s in the second direction H2 and opens to the side surface of the engagement recess 31. When the engagement protrusion 25 of the upper step piece is engaged with the engagement recess 31, the engagement hole 35 communicates with the first engagement recess 26 formed in the engagement protrusion 25 of the upper step piece. A first engagement member 40, described later, is inserted into the first engagement recess 26 and engagement hole 35 that are in communication.

The second engagement recess 36 extends in a third direction H3 that intersects with the second direction H2. The third direction H3 has a greater horizontal component than a vertical component. The third direction H3 is preferably perpendicular to the second direction H2. A second engagement member 45, which will be described later, is inserted into the second engagement recess 36.

(How to connect the step pieces)
A method of connecting the lower step piece 20A and the upper step piece 20B will be described with reference to Figures 3 to 5. In Figures 3 to 5, the lead lines of the symbols for the upper step piece 20B are shown with two-dot chain lines. The upper step piece 20B corresponds to the first member, and the lower step piece 20A corresponds to the second member.

As shown in FIG. 3, when connecting the step pieces 20, first, the fitting convex portion 25 (upper fitting convex portion) of the upper step piece 20B is fitted into the fitting recess 31 (lower fitting recess) of the lower step piece 20A. When these are fitted, the lower surface 22b of the inner diameter portion 22 of the upper step piece 20B abuts against the upper surface 30a of the fitting recess forming portion 30 of the lower step piece 20A, thereby supporting the upper step piece 20B on the lower step piece 20A. In addition, the engagement hole 35 (lower engagement hole) of the lower step piece 20A communicates with the first engagement recess 26 (upper engagement recess) of the upper step piece 20B.

Next, as shown in FIG. 4, the first engaging member 40 is inserted from the insertion opening forming surface 21s of the lower step piece 20A into the engaging hole 35 of the lower step piece 20A and the first engaging recess 26 of the upper step piece 20B, which are in a connected state. By inserting the first engaging member 40, the lower step piece 20A and the upper step piece 20B are connected in a state in which relative movement in the vertical direction is restricted.

The first engaging member 40 has a shape that forms a gap between the engaging hole 35 of the lower step piece 20A and the first engaging recess 26 of the upper step piece 20B that allows insertion and removal while suppressing rattling. The first engaging member 40 has a first protruding portion 41 that protrudes from the insertion opening forming surface 21s when inserted into the engaging hole 35 of the lower step piece 20A and the first engaging recess 26 of the upper step piece 20B. The first protruding portion 41 has a first joining hole 42 that penetrates the first protruding portion 41 in the vertical direction.

The second engaging member 45 is inserted into the second engaging recess 36 of the lower step piece 20A from the insertion opening forming surface 21s. The second engaging member 45 has a shape that forms a gap between the second engaging recess 36 and the second engaging member 45 that allows insertion and removal while suppressing rattling. The second engaging member 45 has a second protruding portion 46 that protrudes from the insertion opening forming surface 21s when inserted into the second engaging recess 36. The second protruding portion 46 is arranged to be aligned with the first protruding portion 41 in the vertical direction. The second protruding portion 46 has a second joint hole 47 that penetrates the second protruding portion 46 in the vertical direction. The second joint hole 47 communicates with the first joint hole 42 when the first engaging member 40 and the second engaging member 45 are inserted.

Next, as shown in FIG. 5, a pin 49, which is a joining material, is inserted into the first joining hole 42 and the second joining hole 47, so that the first engaging material 40 and the second engaging material 45 are pin-joined outside the engaging hole 35 (lower engaging hole 35) of the lower step piece 20A. This prevents the first engaging material 40 from falling out by the second engaging material 45, and prevents the second engaging material 45 from falling out by the first engaging material 40. In other words, the lower step piece 20A and the upper step piece 20B are maintained in a connected state.

In this way, the staircase section 11 is formed by connecting the step pieces 20 in order from the lowest step piece to the highest step piece. Note that a portion of the first engaging member 40 and the second engaging member 45 are pin-joined by the handrail support post 14.

(How to install the bottom step piece)
As shown in Figure 6, the spiral staircase 10 has a lower floor step piece 50 and a lower floor connecting mechanism 51. The lowest step piece 20C is installed on the lower floor via the lower floor step piece 50 and the lower floor connecting mechanism 51.

The lower floor step piece 50 is a member fixed to the lower floor or a part of the lower floor. The lower floor connection mechanism 51 has a lower floor connection member 52 and a fastening member 53 that connects the lower floor connection member 52 to the lower floor step piece 50.

The lower floor step piece 50 has a lower floor connecting material storage section 55 that stores the lower floor connecting material 52. The lower floor connecting material storage section 55 has a lower floor connecting material connection section 56 to which the lower floor connecting material 52 is connected. The lower floor connecting material connection section 56 is fastened with a fastening material 53 that connects the lower floor step piece 50 and the lower floor connecting material 52.

The lower floor connecting material 52 has a lower floor step piece connecting portion 58 that is connected to the lower floor step piece 50. The lower floor step piece connecting portion 58 accommodates the head of the fastening material 53 and forms a seat surface for the fastening material 53 at the bottom of the lower floor connecting material 52. After the lower floor connecting material 52 is accommodated in the lower floor connecting material accommodation portion 55 of the lower floor step piece 50, the fastening material 53 is fastened to the lower floor connecting material connecting portion 56, thereby connecting the lower floor step piece 50.

The lower floor connecting member 52 is also formed with a fitting recess 59 for the lowest step connection. The fitting recess 59 for the lowest step connection is a recess into which the fitting protrusion 25 of the lowest step tread piece 20C fits. The fitting recess 59 for the lowest step connection is formed in the same shape as the fitting recess 31 formed in the tread piece 20.

As shown in FIG. 7, the lowest step piece 20C is installed on the lower floor via the lower floor step piece 50 and the lower floor connecting mechanism 51 by fitting the fitting protrusion 25 into the lowest step connecting fitting recess 59 of the lower floor connecting material 52 connected to the lower floor step piece 50.

(How to connect the top step pieces)
As shown in Figure 8, the spiral staircase 10 has an upper floor step piece 60 and an upper floor connecting mechanism 61. The top step piece 20D is connected to the upper floor via the upper floor step piece 60 and the upper floor connecting mechanism 61. Although omitted in Figure 8 and Figures 9 to 11 described below, the top step piece 20D is connected to other step pieces 20 that constitute the stair section 11 so as to continue to the bottom step piece 20C.

The upper floor step piece 60 is a member fixed to the upper floor or a part of the upper floor. The upper floor connection mechanism 61 has an upper floor connection material 62 and a fastening material 63 that connects the upper floor connection material 62 to the upper floor step piece 60.

The upper floor step piece 60 has an upper floor connecting member connection part 66 to which the upper floor connecting member 62 is connected. The upper floor connecting member connection part 66 has a fastening member 63 fastened thereto, which connects the upper floor step piece 60 and the upper floor connecting member 62.

The upper floor connecting material 62 has an upper floor connecting material main body 67 and a top stage connecting fitting protrusion 68.
The upper floor connecting material body 67 has a stepped shape that covers part of the upper surface and part of the side of the upper floor step piece 60. The upper floor connecting material body 67 has an upper floor step piece connecting part 69 that is connected to the upper floor step piece 60 in a part that is arranged facing the upper surface of the upper floor step piece 60. The upper floor step piece connecting part 69 accommodates the head of the fastening material 63 and forms a seat surface for the fastening material 63 at the bottom of the upper floor connecting material body 67.

The upper floor connecting material body 67 also has a connecting step fitting portion 70 and a connecting step connection portion 71 in a portion disposed opposite the side surface of the upper floor step piece 60. The connecting step fitting portion 70 is a portion into which a portion of the connecting step 80 described below is fitted. The connecting step fitting portion 70 is disposed so as to fill the step between the tread surface 21a of the top step piece 20D and the upper surface 30a of the fitting recess forming portion 30. The connecting step connection portion 71 is a portion to which the connecting step 80 is connected.

The top step connecting fitting protrusion 68 is a protrusion that has a shape similar to the fitting protrusion 25 formed on the step piece 20 and fits into the fitting recess 31 of the top step piece 20D. Specifically, the top step connecting fitting protrusion 68 extends in the first direction H1 so as to protrude downward from a portion of the upper floor connecting material main body 67 that is arranged opposite the side surface of the upper floor step piece 60. The top step connecting fitting protrusion 68 has a connecting engagement recess 73 formed therein. The connecting engagement recess 73 opens on the side surface of the top step connecting fitting protrusion 68 and extends in the second direction H2. The connecting engagement recess 73 communicates with the engagement hole 35 of the top step piece 20D when the top step connecting fitting protrusion 68 is fitted into the fitting recess 31 of the top step piece 20D.

The upper floor connecting mechanism 61 also has a top-most first engaging member 75 and a top-most second engaging member 76. The top-most first engaging member 75 is the same member as the first engaging member 40 described above. The top-most first engaging member 75 is inserted into the engaging hole 35 and the connecting engaging recess 73 of the top-most step piece 20D, which are in a communicating state, from the insertion opening forming surface 21s of the top-most step piece 20D. The top-most second engaging member 76 is the same member as the second engaging member 45 described above. The top-most second engaging member 76 is inserted into the second engaging recess 36 of the top-most step piece 20D. The top-most first engaging member 75 and the top-most second engaging member 76 are pin-joined outside the engaging hole 35 of the top-most step piece 20D.

When connecting the top step piece 20D and the upper floor step piece 60 using the upper floor connecting mechanism 61, first, the upper floor connecting member 62 is positioned so that the top step connecting fitting protrusion 68 fits into the fitting recess 31 of the top step piece 20D, and so that the upper floor connecting member connecting portion 66 of the upper floor step piece 60 and the upper floor step piece connecting portion 69 of the upper floor connecting member 62 are aligned. Then, the upper floor step piece 60 and the upper floor connecting member 62 are fastened together with the fastening member 63. This connects the upper floor step piece 60 and the upper floor connecting member 62.

Then, as shown in FIG. 9, the top step first engaging member 75 is inserted into the engaging hole 35 and the connecting engaging recess 73 of the top step piece 20D, which are in a connected state, and the top step second engaging member 76 is inserted into the second engaging recess 36 of the top step piece 20D. After that, the top step first engaging member 75 and the top step second engaging member 76 are pin-joined. This connects the top step piece 20D and the upper floor step piece 60 with the upper floor connecting mechanism 61.

As shown in FIG. 10, the spiral staircase 10 has a connecting step 80. The connecting step 80 is connected to the upper floor step piece 60 and the top step piece 20D via the upper floor connecting member 62. The connecting step 80 is connected to the upper floor connecting member 62 by a fastening member 81 so as to cover and hide the upper floor connecting member 62 of the upper floor connecting mechanism 61.

The connecting step 80 has a connecting step main body 82 that covers a part of the upper floor step piece 60 and the upper floor connecting material 62 from above, and a connecting step side portion 83 that covers the upper floor connecting material 62 from the tread surface 21a side of the top step piece 20D.

The connecting step body 82 is formed with an upper floor connecting material storage section (not shown) that stores the portion of the upper floor connecting material 62 that is located above the upper floor step piece 60. By forming the upper floor connecting material storage section, the connecting step body 82 is positioned so that it abuts against the upper surface of the upper floor step piece 60.

The connecting tread side portion 83 is formed with an insertion recess 84 and an upper floor connecting material side connection portion 85. The insertion recess 84 is the portion that is inserted into the connecting tread insertion portion 70 of the upper floor connecting material 62 when placing the connecting tread 80. The upper floor connecting material side connection portion 85 accommodates the head of the fastening material 81 and forms a seat surface for the fastening material 81 at the back of the connecting tread side portion 83.

As shown in FIG. 11, when connecting the connecting step 80 to the upper floor connecting member 62, the connecting step 80 is positioned so that the upper floor connecting member 62 is accommodated in the upper floor connecting member accommodation portion, and so that the fitting recess 84 fits into the connecting step fitting portion 70 of the upper floor connecting member 62. Then, the connecting step 80 is connected to the upper floor connecting member 62 by fastening the upper floor connecting member side connection portion 85 and the connecting step connection portion 71 of the upper floor connecting member 62 with fastening material 81.

(How to assemble a spiral staircase)
When assembling the above-mentioned spiral staircase 10, first, the lower floor connecting member 52 is connected to the lower floor step piece 50, and then the lowest step piece 20C is installed. Next, the step pieces 20 are connected in order from the lowest step piece 20C to the highest step piece 20D. Then, the highest step piece 20D and the upper floor step piece 60 are connected with the upper floor connecting mechanism 61, and then the connecting step 80 is connected to the upper floor connecting member 62.

The operation and effects of this embodiment will be described.
(1) According to the above embodiment, the mating convex portion 25 of the upper step piece 20B is mated with the mating concave portion 31 of the lower step piece 20A. The first engaging member 40 is then inserted into the engaging hole 35 of the lower step piece 20A and the first engaging concave portion 26 of the upper step piece 20B, thereby connecting the step pieces 20 together. This allows the step pieces 20 to be connected together with a simple connecting operation.

(2) Since the step pieces 20 are made of FRP-based materials, the weight of the step pieces 20 and therefore the weight of the stair section 11 can be reduced.
(3) The first engaging member 40 is joined to the second engaging member 45 that is inserted into the second engaging recess 36. This prevents the first engaging member 40 from falling off by the second engaging member 45, and prevents the second engaging member 45 from falling off by the first engaging member 40. As a result, the connected state between the lower step piece 20A and the upper step piece 20B can be reliably maintained.

(4) Since the first engaging member 40 and the second engaging member 45 are pin-joined outside the engaging hole 35, the first engaging member 40 and the second engaging member 45 can be easily joined.
(5) The first engaging member 40 and the second engaging member 45 are pin-connected by the handrail support column 14. This means that even if the handrail 12 is provided on the spiral staircase 10, there is no need to provide a separate structure for supporting the handrail support column 14 on the staircase section 11. As a result, it is possible to suppress an increase in the number of parts required for installing the handrail 12.

(6) In the topmost portion, the topmost connecting engagement convex portion 68 is engaged with the engagement recess 31 of the topmost step piece 20D, and the topmost first engaging member 75 is inserted into the connecting engagement recess 73 of the upper floor connecting member 62, which is in a communicating state, and the engagement hole 35 of the topmost step piece 20D. This makes it easy to connect the upper floor step piece 60 and the topmost step piece 20D via the upper floor connecting mechanism 61.

(7) The upper floor connection mechanism 61 is covered by a connecting step 80 that is connected to the upper floor step piece 60 and the top step step piece 20D. This improves the aesthetics of the connection between the upper floor step piece 60 and the top step step piece 20D.

(8) The lower floor connecting member 52 is connected to the lower floor step piece 50 while being accommodated in the lower floor connecting member accommodation section 55. The lowermost step tread piece 20C is installed on the lower floor step piece 50 by fitting the mating protrusion 25 of the lowermost step tread piece 20C into the lowermost step connecting mating recess 59 of the lower floor connecting member 52. This allows the lowermost step tread piece 20C to be installed in a simple manner while improving the aesthetic appearance of the lowest step of the spiral staircase 10.

(9) The first engaging members 40, 75 and the second engaging members 45, 76 are configured to be removable. This makes it easy to dismantle the stepped portion 11.
This embodiment can be modified as follows: This embodiment and the following modifications can be combined with each other to the extent that there is no technical contradiction.

- In the above embodiment, the lowest step piece 20C is installed on the lower floor step piece 50 via the lower floor connection mechanism 51. This is not limited to the above, and the lowest step piece 20C may be installed directly on the lower floor step piece 50 by providing a lowest step connection fitting recess in the lower floor step piece 50.

In the above embodiment, a connecting step 80 is provided to cover the upper floor connecting mechanism 61, but the connecting step 80 is not a required component.
In the above embodiment, the top step connecting fitting convex portion 68 of the upper floor connecting material 62 is fitted into the fitting concave portion 31 of the top step step piece 20D, and the top step first engaging member 75 and the top step second engaging member 76 are used to connect the top step step piece 20D and the upper floor connecting material 62. Without being limited to this, the top step step piece 20D and the upper floor connecting material 62 may be connected by fastening using a fastening material, for example.

- In the above embodiment, the step pieces 20 are connected to each other using the first engaging material 40 and the second engaging material 45. This is not limited to the above, and the step pieces 20 may be connected to each other using only the first engaging material 40. In this configuration, it is preferable that the first engaging material 40 is pressed into the engaging hole 35 and the first engaging recess 26 so that the first engaging material 40 is less likely to fall off. In addition, the method of joining the first engaging material 40 and the second engaging material 45 is not limited to pin joining, and they may be joined using, for example, an adhesive or the like.

The spiral staircase 10 only needs to have the stair section 11, and the handrail 12 and the handrail support posts 14 are not essential components.
In the above embodiment, the spiral staircase 10 is constructed using the tread pieces 20 that are connected to each other. However, the present invention is not limited to this, and stairs of other shapes, such as straight stairs, may be constructed using tread pieces that are connectable to each other by a similar connection structure.

The connection structure of the above embodiment is not limited to connection of the step piece 20, but may be applied to connection of a first member and a second member that are different from each other.
For example, as shown in FIG. 12, the first member 110 has a first body 111, a fitting protrusion 112, and an engagement recess 113. The fitting protrusion 112 extends from the first body 111 in a first direction H1. The engagement recess 113 opens on a side surface of the fitting protrusion 112 and extends in a second direction H2 intersecting the first direction H1. The second member 120 has a second body 121, a fitting recess 122, and an engagement hole 123. The fitting recess 122 is a recess that has an opening in the second body 121 and extends in the first direction H1, and is a recess into which the fitting protrusion 112 fits. The engagement hole 123 is a hole that extends in the second direction H2 and is capable of communicating with the engagement recess 113 when the fitting protrusion 112 is fitted into the fitting recess 122. The first member 110 and the second member 120 are connected by fitting the mating protrusion 112 into the mating recess 122 and then inserting the engaging member 130 into the engaging hole 123 and the engaging recess 113 .

H1: first direction, H2: second direction, H3: third direction, 10: spiral staircase, 11: staircase section, 12: handrail, 14: handrail support column, 20: step piece, 20A: lower step piece, 20B ...Upper step piece, 20C...Lowest step piece, 20D...Top step piece, 21...Step body, 21a...Tread surface, 21b...Kick-up surface, 21s...Insertion port forming surface, 22...Inner diameter portion, 22b...Lower surface , 23... outer diameter portion, 25... fitting protrusion portion, 26... first engagement recess portion, 30... fitting recess forming portion, 30a... upper surface, 31... fitting recess portion, 35... engagement hole, 36... second Engagement recess, 40...first engagement member, 41...first protrusion, 42...first joining hole, 45...second engagement member, 46...second protrusion, 47...second joining hole, 49... Pin, 50... Lower floor step piece, 51... Lower floor connecting mechanism, 52... Lower floor connecting material, 53... Fastening Connecting material, 55...Lower floor connecting material storage section, 56...Lower floor connecting material connection section, 58...Lower floor step piece connection section, 59...Lowest step connection fitting recess, 60...Upper floor step piece, 61 ...upper floor connecting mechanism, 62...upper floor connecting material, 63...fastening material, 66...upper floor connecting material connecting portion, 67...upper floor connecting material main body, 68...top stage connecting fitting protrusion, 69...upper floor Floor step piece connecting portion, 70...connecting step fitting portion, 71...connecting step connecting portion Connection portion, 73...connecting engagement recess, 75...top-most first engagement member, 76...top-most second engagement member, 80...connecting step, 81...fastening member, 82...connecting step body, 83... Connecting step side portion, 84... fitting recess, 110... first member, 111... first body, 112... fitting protrusion, 113... engagement recess, 120... second member, 121... second body, 122... Fitting recess, 123...engagement hole, 130...engagement material.

Claims (12)

A connection structure for connecting a first member and a second member,
The first member is
A fitting protrusion extending in a first direction;
an engagement recess that opens on a side surface of the fitting protrusion and extends in a second direction intersecting the first direction,
The second member is
a fitting recess into which the fitting protrusion fits;
an engagement hole extending in the second direction and capable of communicating with the engagement recess when the fitting protrusion is fitted into the fitting recess,
A connection structure in which the first member and the second member are connected by an engaging member inserted into the engaging hole and the engaging recess, which are in a communicating state. The engagement recess is a first engagement recess,
The engaging material is a first engaging material,
The first engaging member has a first protruding portion protruding from an insertion opening forming surface of the first engaging member,
the second member has a second engagement recess that opens to the insertion opening surface and extends in a third direction intersecting the second direction,
The connection structure includes:
a second engaging member that is inserted into the second engaging recess and has a second protruding portion that protrudes from the insertion opening forming surface;
The connection structure according to claim 1 , further comprising a bonding material that bonds the first protrusion and the second protrusion. A step piece made of FRP material that can be connected to each other,
A tread body,
A fitting protrusion extending in a first direction from the step body;
an engagement recess that opens on a side surface of the fitting protrusion and extends in a second direction intersecting the first direction;
a fitting recess into which a fitting protrusion of another step piece fits;
a step piece having an engagement hole extending in the second direction and communicating with the engagement recess of the other step piece when the engagement protrusion of the other step piece is engaged with the engagement recess. A spiral staircase having a plurality of step pieces according to claim 3,
An upper step piece;
A lower step piece;
and an engaging member that engages the upper step piece and the lower step piece,
The upper step piece has an upper step fitting convex portion which is the fitting convex portion and an upper step engaging concave portion which is the engaging concave portion,
The lower step piece has a lower step fitting recess which is the fitting recess and a lower step engagement hole which is the engagement hole,
A spiral staircase, wherein the engaging member is inserted into the lower step engaging hole and the upper step engaging recess, which are in a communicating state. The engaging material is a first engaging material,
The lower step piece has a second engagement recess that opens into an insertion opening forming surface of the first engagement member and extends in a third direction intersecting the second direction,
The spiral staircase according to claim 4, further comprising a second engaging member inserted into the second engaging recess and joined to the first engaging member. The spiral staircase according to claim 5, wherein the first engaging member and the second engaging member are pin-joined outside the lower step engaging hole. The spiral staircase according to claim 6, wherein the first engaging member and the second engaging member are pin-connected by a handrail support post that supports the handrail. A spiral staircase having a plurality of step pieces according to claim 3,
A top step piece;
Upper floor step pieces,
and an upper floor connecting mechanism having an upper floor connecting member connected to the top step piece and the upper floor step piece,
The upper floor step piece is
The upper floor connecting member has an upper floor connecting member connection part that is connected to the upper floor connecting member,
The upper floor connecting material is
An upper floor step piece connecting portion connected to the upper floor step piece;
a top step connecting fitting protrusion extending in the first direction and fitting into a fitting recess of the top step step piece;
a connecting engagement recess that opens on a side surface of the top step connecting fitting protrusion, extends in the second direction, and communicates with an engagement hole of the top step step piece when the top step connecting fitting protrusion is fitted into the fitting recess of the top step step piece,
The upper floor connecting mechanism is
A spiral staircase having a top step engaging member that is inserted into the engaging hole of the top step piece and the connecting engaging recess, which are in a communicating state. 9. The spiral staircase according to claim 8, further comprising a connecting step covering the upper floor connecting mechanism and connected to the upper floor step piece and the top step step piece. A spiral staircase having a plurality of step pieces according to claim 3,
A bottom step piece;
Lower floor step pieces,
A lower floor connecting mechanism having a lower floor connecting member connected to the lowest step piece and the lower floor step piece,
The lower floor step piece is
A lower floor connecting member connection part that is connected to the lower floor connecting member,
The lower floor connecting material is
A lower floor piece connecting portion connected to the lower floor piece;
a lowest step connecting fitting recess extending in the first direction into which the fitting protrusion of the lowest step piece fits. A method for assembling a spiral staircase having a plurality of connectable FRP tread pieces, comprising:
The step piece is
A tread body,
A fitting protrusion extending in a first direction from the step body;
an engagement recess that opens on a side surface of the fitting protrusion and extends in a second direction intersecting the first direction;
a fitting recess into which a fitting protrusion of another step piece fits;
an engagement hole extending in the second direction and communicating with the engagement recess of the other step board piece when the engagement protrusion of the other step board piece is engaged with the engagement recess,
The step of connecting the step pieces together includes:
A step of fitting a fitting protrusion of the upper step piece into a fitting recess of the lower step piece;
and inserting an engaging member into the engaging hole of the lower step piece and the engaging recess of the upper step piece. A step of connecting a lower floor step piece to the lower floor, the lower floor step piece having a lowest step connecting fitting recess into which the fitting protrusion of the lowest step step piece fits;
a step of fitting a fitting protrusion of the lowest step board piece into the lowest step connection fitting recess;
connecting the step pieces together;
A step of connecting a top step piece to an upper floor step piece having a top step connecting fitting protrusion that fits into a fitting recess of the top step piece;
The method for assembling a spiral staircase according to claim 11, further comprising the step of: connecting the upper floor step pieces to an upper floor.

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