Stage pedal and stage

Abstract

To provide a tread for stairs which is light and in which bent deflection hardly occurs, and to provide stairs including the same.SOLUTION: A tread 2 includes: a core material 10 comprising a rectangular plate-like body; frame materials 20, 20 provided on the front side and the rear side of the core material 10; and two surface materials 30, 30 fixed to an upper end surface and a lower end surface of the frame materials 20, 20 respectively. The core material 10 includes: a rectangular plate-like core 11 in which a plurality of holes 11a,...,11a extends in the thickness direction of the core material 10; and two sheets 12, 12 attached to an upper surface and a lower surface of the core 11. The upper surface material 30 is attached to the upper end surface of the frame material 20 and the upper sheet 12 constituting the upper surface of the core material 10, and the lower surface material 30 is attached to the lower sheet 12 constituting the lower end surface of the frame material 20 and the lower surface of the core material 10.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to a tread for stairs and a staircase provided with the same.

Background Art

[0002] Conventionally, as a tread for stairs used in buildings such as houses, a panel-shaped main body in which a honeycomb material is incorporated in a main body having surface plates disposed on both sides of a frame material has been proposed (for example, see Patent Document 1 below).

[0003] In the tread for stairs described in Patent Document 1, a rectangular frame composed of four frames, a reinforcing core material connecting the centers of the two long-side frames in the rectangular frame, and two surface materials fixed to the upper and lower surfaces of the rectangular frame to close the upper and lower surfaces are provided. A honeycomb material is incorporated in the main body. The honeycomb material is provided in the main body in a direction in which a plurality of holes extend in the thickness direction (front and back direction). Thus, in the conventional tread for stairs, by using a honeycomb material instead of using laminated wood or plywood as a core material, it can be manufactured lightweight and inexpensive, and also absorb the impact during ascending and descending.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the conventional tread for stairs, the two surface materials of the main body are fixed to the rectangular frame (four frames) and not fixed to the honeycomb material. Therefore, in the conventional tread for stairs, when a bending load acts, although the honeycomb material can support the load, there is a problem that it is likely to cause deflection deformation and bending deflection.

[0006] Furthermore, while it is conceivable to construct a frame for conventional stair treads using a thick, high-bending-strength material to create a structure that is less prone to bending and deflection, such a structure has the problem of not being able to achieve significant weight reduction.

[0007] The present invention has been made in view of these points, and its purpose is to provide a lightweight stair tread that is resistant to bending and deflection, and a staircase equipped with the same. [Means for solving the problem]

[0008] To achieve the above objective, this invention uses a rectangular plate-shaped core with multiple holes extending in the thickness direction and sheet-like material bonded to its upper and lower surfaces as the core material for a stair tread, and the two surface materials are bonded not only to the frame material but also to the core material.

[0009] Specifically, the first invention is a stair tread comprising a core material made of a rectangular plate-like body, frame members provided on at least the front and rear sides of the core material, and two surface materials fixed to the upper and lower end surfaces of the frame member, respectively, wherein the core material has a rectangular plate-shaped core with a plurality of holes extending in the thickness direction of the core material, and two sheet-like materials adhered to the upper and lower surfaces of the core, the upper surface material is adhered to the upper end surface of the frame member and the upper sheet-like material constituting the upper surface of the core material, and the lower surface material is adhered to the lower end surface of the frame member and the lower sheet-like material constituting the lower surface of the core material.

[0010] Here, "sheet-like material" includes paper, resin sheets, thin plates, etc., with a thickness of 0.01 mm or more and 10 mm or less.

[0011] In the first invention, the core material of the stair tread is made of a rectangular plate-shaped core with multiple holes extending in the thickness direction and sheet-like material bonded to the upper and lower surfaces, thus providing a lightweight stair tread with excellent bending strength. Furthermore, in the first invention, sheet-like material is bonded to the upper and lower surfaces of the core that constitutes the core material, and two surface materials are bonded not only to the frame material but also to the sheet-like material that constitutes the upper and lower surfaces of the core. Since the upper and lower surfaces of the core have multiple holes, if a thick surface material is directly bonded to the upper and lower surfaces of the core, the surface material is prone to peeling off. In the first invention, a sheet-like material thinner than the surface material is bonded to the upper and lower surfaces of the core, and then the thick surface material is bonded to the sheet-like material. When the sheet-like material thinner than the surface material is attached to the upper and lower surfaces of the core, it is less likely to peel off than when a thick surface material is attached. Furthermore, since the two thick surface materials are bonded in surface contact with the upper and lower surfaces (sheet-like material) of the core material, which has excellent bending strength, the peel strength is significantly higher (less likely to peel) compared to when they are directly attached to the upper and lower surfaces of the core. In this way, because the two surface materials are firmly bonded in surface contact with the core material, which has excellent bending strength, when a bending load is applied to the stair tread, deflection deformation is less likely to occur, and bending deflection is less likely to occur. Therefore, according to the first invention, it is possible to provide a lightweight stair tread that is less prone to bending deflection.

[0012] The second invention is characterized in that, in the first invention, the frame material is provided only on the front and rear sides of the core material.

[0013] In the second invention, the frame members are provided only on the front and rear sides of the core material, and not on the left and right sides of the core material. In the above-mentioned stair tread, as described above, the two surface materials are firmly bonded in surface contact with the upper and lower surfaces of the core material, which has excellent bending strength. Therefore, as in conventional stair treads, it is not necessary to provide frame members around the four sides of the core material to fix the two surface materials, and it is sufficient to provide frame members to fix the risers to the front and rear sides of the core material. Furthermore, providing frame members around the four sides of the core material increases manual labor and labor costs, thus reducing manufacturing efficiency. However, according to the second invention, since the frame members are provided only on the two long sides (front and rear) of the core material, the frame members can be provided to the core material without changing the direction of the manufacturing line, making it possible to provide a stair tread that is easier to manufacture and lighter.

[0014] The third invention is characterized in that, in the first or second invention, the core is made of paper.

[0015] In the third invention, a lighter stair tread can be provided by using a paper core as the core material for the stair tread.

[0016] The fourth invention is characterized in that, in the third invention, the sheet-like material is paper.

[0017] In the fourth invention, a paper core with paper bonded to its upper and lower surfaces is used as the core material for a stair tread. The upper and lower surfaces of the core have multiple holes, making it difficult to bond sheet-like materials to them. However, by using paper for both the core and the sheet-like material, it becomes easier to bond the sheet-like material to the core. With such a core material, the sheet-like material can be firmly fixed (bonded) to the core, making it less likely for the stair tread to deflect when a bending load is applied. Therefore, according to the fourth invention, it is possible to provide a stair tread that is less prone to bending deflection.

[0018] The fifth invention is characterized in that, in the first or second invention, the surface material is made of medium-density fiberboard.

[0019] By the way, in recent years, due to wood shock and plywood shock, it has become difficult to obtain imported plywood, and replacement with other wood-based boards such as fiberboards has been attempted. Among them, medium-density fiberboard has high suitability as an interior material because its surface is relatively smooth and it has excellent water resistance (water repellency). On the other hand, because medium-density fiberboard has a high density, when it is used alone for the treads of stairs, it is heavy and lacks workability. Therefore, in the fifth invention, in the treads of stairs, the two surface materials are made of medium-density fiberboard, while the core material is made of a core with sheet-like materials adhered to the upper and lower surfaces. Thereby, it is possible to provide a lightweight stair tread that is difficult to cause bending deflection.

[0020] The sixth invention is characterized in that, in the first or second invention, the surface material is composed of a composite material in which a medium-density fiberboard and a veneer are laminated and adhered, and the medium-density fiberboard is fixed to the core material and the frame material, respectively, so as to be located on the surface side of the stair tread.

[0021] As described above, medium-density fiberboard has high suitability as an interior material because its surface is relatively smooth and it has excellent water resistance (water repellency) among wood-based boards, but it is inferior to veneer in terms of bending performance (bending strength, bending Young's modulus). Therefore, in the sixth invention, the surface material is made of a composite material in which a medium-density fiberboard and a veneer are laminated and adhered, and this composite material is fixed to the frame material and the core material so that the medium-density fiberboard with a smooth surface and excellent decorative properties is located on the surface side of the stair tread. Thereby, it is possible to provide a stair tread excellent in decorative properties (smoothness of the surface), water resistance (water repellency), and bending performance.

[0022] The seventh invention is a staircase provided with a plurality of stair treads, wherein the stair treads are the stair treads according to the first or second invention.

[0023] In the seventh invention, it is intended to use the above-mentioned lightweight stair tread that is difficult to cause bending deflection for the staircase. Therefore, it is possible to easily construct a staircase excellent in strength that is difficult to cause bending deflection.

Effects of the Invention

[0024] As described above, according to the present invention, a rectangular plate-shaped core in which a plurality of holes extend in the thickness direction and sheet-like materials are adhered to the upper and lower surfaces is used as the core material of the tread for the stairs, and two surface materials are adhered not only to the frame material but also to the core material. Therefore, it is possible to provide a lightweight stair tread that is difficult to bend.

Brief Description of the Drawings

[0025] [Figure 1] FIG. 1 is a perspective view showing a part of a staircase according to Embodiment 1. [Figure 2] FIG. 2 is a cross-sectional view showing a part of a staircase according to Embodiment 1. [Figure 3] FIG. 3 is an exploded perspective view of a stair tread. [Figure 4] FIG. 4 is a perspective view showing a part of a stair tread with a notch. [Figure 5] FIG. 5 is a cross-sectional view showing a part of a staircase according to Embodiment 2. [Figure 6] FIG. 6 is an enlarged view of part VI in FIG. 5.

Modes for Carrying Out the Invention

[0026] Hereinafter, embodiments of the present invention will be described in detail based on the drawings. The following embodiments are merely preferred examples in essence and are not intended to limit the scope of the present invention, its applications, or its uses.

[0027] 《Embodiment 1 of the Invention》 - Structure of the Staircase - As shown in FIGS. 1 and FIG. 2, the staircase S is, for example, a straight staircase that connects the upper and lower floors in a building such as a house without bending. In the following description, the front side toward the upward direction of the staircase S will be referred to as "front", the back side as "rear", the left side as "left", and the right side as "right".

[0028] The staircase S comprises, for example, a pair of stringers 1,1 arranged opposite each other in the left-right direction, a plurality of treads (stair treads) 2,...,2, and a plurality of risers 3,...,3 spanning between the front end of each tread 2 and the rear end of the tread 2 one step below. In this embodiment 1, an example is described in which the staircase S is a stringer staircase with a pair of stringers 1,1, but the staircase S may not have a pair of stringers 1,1, or it may have stringers 1 on only one side, left or right.

[0029] Each of the pair of side beams 1,1 is made of, for example, a long, narrow wooden board. The pair of side beams 1,1 are arranged parallel to each other and fixed to the floor, wall, etc., with a rearward slope where the height increases towards the rear in the front-to-back direction. The front ends of each of the pair of side beams 1,1 are cut vertically, and the lower ends are cut horizontally, contacting the floor surface F. Multiple tread grooves (not shown) into which the left and right ends of multiple treads 2,...,2 are fitted, and multiple riser grooves (not shown) into which the left and right ends of multiple risers 3,...,3 are fitted. The tread grooves are grooves that extend horizontally in the front-to-back direction, and the riser grooves are grooves that extend vertically. The tread grooves and riser grooves are formed to be alternately continuous on each of the opposing surfaces of the pair of side beams 1,1.

[0030] Multiple treads 2, ..., 2 are rectangular plate-like members that span between a pair of side girders 1, 1. The detailed configuration of the treads 2 will be described later. Multiple treads 2, ..., 2 are fixed to the pair of side girders 1, 1 with their left and right ends inserted into tread grooves formed on the opposing surfaces of the side girders 1, 1.

[0031] Multiple risers 3, ..., 3 are rectangular plate-like members that are thinner than the treads 2 (approximately 6 to 18 mm thick), and can be made of, for example, plywood, particleboard, medium-density fiberboard, composite plywood, laminated wood, etc. Multiple risers 3, ..., 3 are provided between each of the multiple treads 2, ..., 2 and between the lowest tread 2 and the floor surface F.

[0032] Multiple risers 3,…,3 are stretched between the front ends of each of the multiple treads 2,…,2 and the rear end of the tread 2 one step below or the floor surface F. Multiple risers 3,…,3 are also stretched between a pair of side beams 1,1. Multiple risers 3,…,3 are fixed to the pair of side beams 1,1 with adhesive, with their left and right ends inserted into riser grooves formed on the opposing surfaces of the side beams 1,1. In addition, each riser 3 stretched between each of the multiple treads 2,…,2 has its upper end inserted into a riser groove 2a, described later, formed on the front end of the upper tread 2, and its front lower end abuts against the rear end surface of the lower (one step below) tread 2, and is fixed to the upper and lower treads 2,2 with nail-like members 4,4 such as nails or screws. The lowest riser board 3 is fixed to the lowest step tread board 2 and the floor with nail-like members 4, 4, with its upper end inserted into a riser board groove 2a formed in the lowest step tread board 2, and its lower end in contact with the floor surface F or inserted into a riser board groove formed in the floor surface F.

[0033] <Detailed composition of the footboard> As shown in Figures 2-4, the step board 2 comprises a rectangular, flat, plate-shaped core material 10 in plan view, two frame materials 20, 20 provided on the front and rear sides of the core material 10, and two surface materials 30, 30 provided on the top and bottom of the core material 10. The step board 2 is formed to have a depth (length in the front-to-back direction) of approximately 180-300 mm, a width (length in the left-to-right direction) of approximately 750-1200 mm, and a thickness of approximately 25-40 mm. In this embodiment 1, the step board 2 is formed to have a depth of 260 mm, a width of 1000 mm, and a thickness of 36 mm.

[0034] The core material 10 has a predetermined thickness (height) and comprises a rectangular plate-shaped core 11 with multiple holes 11a extending in the thickness direction, and two sheets of paper (sheet-like material) 12, 12. In this embodiment 1, the core material 10 is formed to have dimensions of 180 mm in depth, 1000 mm in width, and 28 mm in thickness.

[0035] Furthermore, in this embodiment 1, a paper core 11 is used, which is formed by bonding paper together with an adhesive. Any type of paper can be used for the paper core 11, but from the viewpoint of forming a core 11 with excellent bending strength at low cost, corrugated cardboard is preferred. In addition, in this embodiment 1, a water-resistant core 11 is used, which is formed by bonding paper coated with a water-resistant agent with a water-resistant adhesive. Note that the method of making the paper water-resistant is not limited to coating with a water-resistant agent; instead, a resin may be coated, or the paper may be impregnated with a water-resistant agent or resin.

[0036] In this embodiment 1, a decorative sheet is not attached to the outer periphery (end grain), and a core 11 with the outermost holes 11a exposed is used. If the paper constituting the core 11 is not water-resistant or has low water resistance, it is preferable to apply or impregnate the outer periphery of the core 11 with a water-resistant agent or resin. Alternatively, the core 11 may have a decorative sheet attached to its outer periphery. The decorative sheet attached to the outer periphery of the core 11 is preferably made of a water-resistant material, or is made water-resistant by applying or impregnating it with a water-resistant agent or resin.

[0037] The material of the core 11 does not have to be paper, and any material is acceptable as long as the density of the core material 10 is lower than the density of the surface materials 30, 30, preferably half or less of the density of the surface materials 30, 30, and more preferably one-tenth or less of the density of the surface materials 30, 30. The thickness of the core 11 used for the core material 10 of the stair tread 2 is preferably 10 mm to 40 mm. In this embodiment 1, the density is 0.05 g / cm³. 3 A core 11 with a thickness of 26 mm is used. In this embodiment 1, the upper and lower surfaces of the core 11 are made rough (fuzzy) using a file or the like.

[0038] The paper sheets 12, 12 bonded to the upper and lower surfaces of the core 11 can be made of any material and thickness, as long as they are thinner than the surface material 30, have good adhesion to the core 11, and have sufficient strength to prevent tearing when a bending load is applied to the tread 2. In this embodiment 1, cardboard with a thickness of 1 mm is used. The paper sheets 12, 12 are formed to cover the entire upper or lower surface of the core 11, and are the same shape (same rectangular shape) as the core 11 in a plan view. The paper sheets 12, 12 are bonded to the entire upper and lower surfaces of the core 11. Any adhesive that can bond the paper sheets 12, 12 to the core 11 can be used, but it is preferable to use a water-resistant adhesive.

[0039] In this embodiment 1, the core 11 is made of paper, and the sheet-like material 12 attached to the upper and lower surfaces of the core 11 is also made of paper 12. In other words, the core 11 and the sheet-like material 12 are made of the same material. Therefore, although the upper and lower surfaces of the core 11 have multiple holes 11a, making it difficult to adhere the sheet-like material 12, using paper for both the core 11 and the sheet-like material 12 makes it easier to adhere the sheet-like material 12 to the core 11. In addition, in this embodiment 1, the upper and lower surfaces of the core 11 are made rough (fuzzy), and this configuration also makes it easier to adhere the paper sheet-like material 12.

[0040] The frame material 20 is made up of wooden rod-shaped members (square timbers) with a rectangular cross-section. The frame material 20 is made up to have a thickness equal to the thickness of the core material 10 (the sum of the thickness of the core 11 and the thickness of the two sheets of paper 12, 12) and a width equal to the width (length in the left-right direction) of the core material 10. In this embodiment 1, the frame material 20 is made of laminated veneer lumber with a depth of 40 mm, a width of 1000 mm, and a thickness of 28 mm. Note that the frame material 20 may be made of a material other than laminated veneer lumber as long as it has sufficient strength to hold the nail-shaped members 4, 4 for fixing the kick plate 3, and plywood or sawn lumber can be used.

[0041] Of the two frame members 20, 20, the frame member 20 provided in front of the core member 10 has a rectangular groove formed on its underside, which will serve as the riser board groove 2a. The groove is formed to a width (length in the front-to-back direction) that the upper end of the riser board 3 fits into. The groove is formed to extend from the left end to the right end of the underside of the frame member 20. The groove of the frame member 20, together with the linear holes of the surface material 30 (described later) which will be bonded to the underside of the frame member 20, constitutes the riser board groove 2a. The groove of the frame member 20 is formed simultaneously with the linear holes of the surface material 30 by cutting after the surface material 30 has been bonded to the underside of the frame member 20.

[0042] The two surface materials 30,30 have a density (g / cm³). 3 The material is made of medium-density fiberboard with a density of 0.6 to less than 1.00 and a thickness of approximately 2 to 20 mm. In this embodiment 1, the two surface materials 30, 30 have a density of 0.7 g / cm³. 3 It is made of a medium-density fiberboard with a thickness of 4 mm. From the viewpoint of suppressing warping, it is preferable to make the thickness of the two surface materials 30, 30 provided above and below the core material 10 the same, however the thickness of the two surface materials 30, 30 provided above and below the core material 10 may be different.

[0043] The medium-density fiberboards that make up the two surface materials 30, 30 preferably contain an adhesive with excellent water resistance. In this embodiment 1, the two surface materials 30, 30 are made of medium-density fiberboard containing a urea-melamine co-condensation resin adhesive. The adhesive used for the medium-density fiberboard is not limited to a urea-melamine co-condensation resin adhesive, and may also contain diphenylmethane diisocyanate or phenolic resin, and if a decorative sheet is attached to the outermost layer, a medium-density fiberboard containing an adhesive with low water resistance, such as urea resin, may be used.

[0044] The two surface materials 30, 30 are formed to be large enough to cover the top surface of the core material 10 (the upper paper 12 glued to the top surface of the core 11) and the top surfaces of the two frame materials 20, 20, or the bottom surface of the core material 10 (the lower paper 12 glued to the bottom surface of the core 11) and the bottom surfaces of the two frame materials 20, 20. In this embodiment 1, the two surface materials 30, 30 are each formed to have a depth of 260 mm, a width of 1000 mm, and a thickness of 4 mm.

[0045] The two surface materials 30, 30 are bonded to the two frame materials 20, 20 and the core material 10, respectively. Specifically, the upper surface material 30 is bonded to the entire upper end surfaces of the two frame materials 20, 20 and the entire upper surface of the upper paper 12 that constitutes the upper surface of the core material 10, while the lower surface material 30 is bonded to the entire lower end surfaces of the two frame materials 20, 20 and the entire lower surface of the lower paper 12 that constitutes the lower surface of the core material 10. Any adhesive that can bond the two surface materials 30, 30 to the frame materials 20 and core material 10 may be used, but it is preferable to use a water-resistant adhesive.

[0046] The tread 2 is a sandwich panel in which a core material 10, consisting of a core 11 with paper (sheet material) 12 attached to its upper and lower surfaces, is sandwiched between two surface materials 30, 30 made of medium-density fiberboard, and bonded together with a water-resistant adhesive. By making the tread 2 a three-layer structure in this way, and by composing the core material 10 with a core 11 that is significantly lower in density and lighter than the medium-density fiberboard used for the surface material 30, and two sheets of paper 12, 12, the weight of the tread 2 can be reduced.

[0047] In this embodiment 1, as shown in Figure 2, decorative materials 5 such as decorative sheets or veneers are attached to the exposed surfaces (top surface, front surface, and front end of the bottom surface) of the treads 2 that are exposed after the construction of the stairs S.

[0048] Furthermore, in the tread 2, the core material 10 is not simply made of a core 11, but rather paper (sheet material) 12, 12 is attached to the upper and lower surfaces of the core 11. By attaching paper (sheet material) 12, 12, which is thinner and less likely to peel off than the surface material 30, to the upper and lower surfaces (paper 12) of the core material 10 and the surface material 30, 30 can be firmly bonded in a surface contact state.

[0049] -Effects of Embodiment 1- In this embodiment 1, the core material 10 of the tread 2 is made of a rectangular plate-shaped core 11 with multiple holes 11a extending in the thickness direction and paper (sheet-like material) 12,12 bonded to its upper and lower surfaces, thus providing a lightweight tread 2 with excellent bending strength. In addition, in this embodiment 1, paper 12,12 is bonded to the upper and lower surfaces of the core 11 that constitutes the core material 10, and two surface materials 30,30 are bonded not only to the frame materials 20,20 but also to the paper 12,12 that constitutes the upper and lower surfaces of the core material 10. Since the upper and lower surfaces of the core 11 have multiple holes 11a, if the thick surface material 30,30 is directly bonded to the upper and lower surfaces of the core 11, the surface material 30,30 will easily peel off. In this embodiment 1, however, thinner paper (sheet material) 12,12 than the surface material 30,30 is bonded to the upper and lower surfaces of the core 11, and then the thick surface material 30,30 is bonded to the paper 12,12. The paper (sheet material) 12,12, which is thinner than the surface material 30,30, is less likely to peel off when attached to the upper and lower surfaces of the core 11 than when the thick surface material 30,30 is bonded. Furthermore, since the two thick surface materials 30,30 are bonded in a surface contact state to the upper and lower surfaces (paper 12) of the core material 10, which has excellent bending strength, the peel strength is significantly higher (less likely to peel off) compared to when they are directly bonded to the upper and lower surfaces of the core 11. In this way, the two surface materials 30, 30 are firmly bonded to the core material 10, which has excellent bending strength, so that when a bending load is applied to the tread 2, deflection deformation is less likely to occur, and bending deflection is less likely to occur. Therefore, according to this embodiment 1, it is possible to provide a lightweight tread 2 that is resistant to bending deflection.

[0050] Furthermore, in the tread 2 of this embodiment 1, the frame members 20, 20 are provided only on the front and rear sides of the core material 10, and not on the left and right sides of the core material 10. In the tread 2, as described above, the two surface materials 30, 30 are firmly bonded in surface contact with the upper and lower surfaces of the core material 10, which has excellent bending strength. Therefore, unlike conventional stair treads, it is not necessary to provide frame members around the four sides of the core material to fix the two surface materials, and it is sufficient to provide frame members 20 to fix the risers 3, 3 on the front and rear sides of the core material 10. Moreover, if frame members are provided around the four sides of the core material, the amount of manual work increases, the amount of labor increases, and the manufacturing efficiency decreases. However, according to this embodiment 1, since the frame members 20 are provided only on the two long sides (front and rear) of the core material 10, the frame members 20, 20 can be provided on the core material 10 without changing the direction of the manufacturing line, making it easier to manufacture and providing a lighter tread 2.

[0051] Furthermore, in this embodiment 1, since a paper core 11 is used as the core material 10 of the tread 2, a lighter tread 2 can be provided.

[0052] Furthermore, in this embodiment 1, a paper core 11 with paper sheets 12, 12 bonded to its upper and lower surfaces is used as the core material 10 of the tread 2. The upper and lower surfaces of the core 11 have multiple holes 11a, making it difficult to bond sheet-like materials. However, by using paper materials for both the core 11 and the sheet-like material (paper core 11 and paper sheets 12, 12), it becomes easier to bond the sheet-like material to the core 11. With such a core material 10, the sheet-like material can be firmly fixed (bonded) to the core 11, making it less likely for the tread 2 to deform when a bending load is applied. Therefore, according to this embodiment 1, it is possible to provide a tread 2 that is less prone to bending deformation.

[0053] Furthermore, in this embodiment 1, while medium-density fiberboard has a high density and therefore increases weight and impairs workability when used for the tread 2, in the tread 2, the two surface materials 30, 30 are made of medium-density fiberboard, while the core material 10 is made of a core 11 with sheet-like material (paper 12, 12) bonded to its upper and lower surfaces, thereby providing a lightweight tread 2 that is less prone to bending and flexing.

[0054] Furthermore, in this embodiment 1, the stairs S are constructed using the lightweight treads 2 described above, which are resistant to bending and deflection. Therefore, the stairs S, which are strong and resistant to bending and deflection, can be easily constructed.

[0055] Embodiment 2 of the Invention Embodiment 2 is a modification of Embodiment 1 in which the configuration of the tread plate 2 is changed.

[0056] As shown in Figures 5 and 6, in Embodiment 2 as well, the tread 2 comprises a rectangular, flat, plate-shaped core material 10 in plan view, two frame materials 20, 20 provided on the front and rear sides of the core material 10, and two surface materials 30, 30 provided above and below the core material 10, however, the thickness of the core material 10 and the configuration of the surface materials 30 differ from those in Embodiment 1.

[0057] In Embodiment 2, the core material 10 also has a rectangular plate-shaped core 11 and two sheets of paper (sheet-like material) 12, 12. In Embodiment 2, the core material 10 has the same planar dimensions as Embodiment 1 (depth 180 mm, width 1000 mm), but is thinner than Embodiment 1, and is formed to a size of 23 mm (28 mm in Embodiment 1). The other components of the core material 10 are the same as in Embodiment 1.

[0058] In Embodiment 2, the surface material 30 is made of a composite material formed by laminating and bonding together first and second rectangular, flattened plate materials 31 and 32 with an adhesive. The surface material 30 is fixed to the core material 10 and the frame material 20, respectively, such that the first plate material 31 is located on the surface side of the tread 2 and the second plate material 32 is located on the core material 10 side. The first and second plate materials 31 and 32 constituting the surface material 30 are formed to a size (in Embodiment 2, 260 mm in depth and 1000 mm in width) that can cover the upper surface of the core material 10 (the upper paper 12 bonded to the upper surface of the core 11) and the upper surfaces of the two frame materials 20, 20, or the lower surface of the core material 10 (the lower paper 12 bonded to the lower surface of the core 11) and the lower surfaces of the two frame materials 20, 20.

[0059] The first plate material 31 has a density (g / cm³). 3 The material is made of medium-density fiberboard with a density of 0.6 to less than 1.00 and a thickness of approximately 1 to 9 mm. In Embodiment 2, the first plate material 31 has a density of 0.7 g / cm³. 3 It is made of a medium-density fiberboard with a thickness of 2.5 mm. Similar to the medium-density fiberboard that constitutes the surface material 30 of Embodiment 1, the first board material 31 preferably contains an adhesive with excellent water resistance, and in Embodiment 2, it is made of a medium-density fiberboard containing a urea-melamine co-condensation resin adhesive. Note that the adhesive used for the medium-density fiberboard is not limited to a urea-melamine co-condensation resin adhesive, and may also contain diphenylmethane diisocyanate or phenolic resin, and if a decorative sheet is attached to the outermost layer, a medium-density fiberboard containing an adhesive with low water resistance, such as urea resin, may be used.

[0060] The second board material 32 is made of a veneer with a thickness of about 1 to 6 mm. In Embodiment 2, the second board material 32 is made of a veneer with a thickness of 4 mm. Any type of wood can be used for the veneer used as the second board material 32, but it is preferable to use one with high bending performance (bending strength and bending Young's modulus).

[0061] Any adhesive capable of bonding the first and second plate materials 31 and 32 can be used, but it is preferable to use a water-resistant adhesive. For example, vinyl acetate resin-based, aqueous vinyl urethane resin-based, urea melamine resin-based, melamine resin-based, phenol resin-based, resorcinol resin-based, urethane resin-based, epoxy resin-based, and acrylic resin-based adhesives can be used.

[0062] In Embodiment 2, the two surface materials 30, 30 are bonded to the two frame materials 20, 20 and the core material 10, respectively. Specifically, with the upper surface material 30 positioned with the first board material 31 on top (the surface side of the tread 2) and the second board material 32 on the bottom, the lower surface of the lower second board material 32 is bonded to the entire upper end surfaces of the two frame materials 20, 20 and the entire upper surface of the upper paper 12 that constitutes the upper surface of the core material 10. With the lower surface material 30 positioned with the first board material 31 on the bottom (the surface side of the tread 2) and the second board material 32 on top, the upper surface of the upper second board material 32 is bonded to the entire lower end surfaces of the two frame materials 20, 20 and the entire lower surface of the lower paper 12 that constitutes the lower surface of the core material 10. Any adhesive capable of bonding the two surface materials 30, 30 to the frame material 20 and core material 10 may be used, but it is preferable to use a water-resistant adhesive. For example, the adhesive used for bonding the first and second plate materials 31, 32 can be used.

[0063] Similar to Embodiment 1, the tread 2 is a sandwich panel in which a core material 10, consisting of a core 11 with paper (sheet material) 12 attached to its upper and lower surfaces, is sandwiched between two surface materials 30, 30 and bonded together with a water-resistant adhesive. By making the tread 2 a three-layer structure in this way, and by composing the core material 10 with a core 11 and two sheets of paper 12, 12, which have significantly lower density and lighter weight compared to the medium-density fiberboard (first board material 31) and single sheet (second board material 32) used for the surface material 30, the weight of the tread 2 can be reduced.

[0064] In this second embodiment, as shown in Figures 5 and 6, decorative materials 5 such as decorative sheets or veneers are attached to the exposed surfaces (top surface, front surface, and front end of the bottom surface) of the treads 2 that are exposed after the construction of the stairs S.

[0065] With the above configuration, Embodiment 2 can achieve the same effects as Embodiment 1.

[0066] Furthermore, in Embodiment 1, the surface material 30 was made solely of medium-density fiberboard. While medium-density fiberboard has a relatively smooth surface and excellent water resistance (water repellency) among wood-based boards, making it highly suitable as an interior material, it is inferior to veneer in terms of bending performance (bending strength, bending Young's modulus). Therefore, in Embodiment 2, the surface material 30 is made of a composite material formed by laminating and bonding a first board material 31 made of medium-density fiberboard and a second board material 32 made of veneer, and the first board material 31 is fixed to the core material 10 and the frame material 20, respectively, so that it is located on the surface side of the tread 2. Accordingly, Embodiment 2 provides a tread 2 with excellent decorative properties (surface smoothness), water resistance (water repellency), and bending performance.

[0067] Other embodiments In the treads 2 of the embodiments 1 and 2 described above, the frame members 20, 20 are provided only on the front and rear sides of the core material 10, and not on the left and right sides of the core material 10. However, in the stair tread according to the present invention, the frame members 20, 20 may be provided not only on the front and rear sides of the core material 10, but also on the left and right sides, that is, the core material 10 may be surrounded on all four sides by four frame members 20, ..., 20. In a tread 2 with frame members 20 provided on all four sides of the core material 10, the core material 10 is not exposed, so it can be used, for example, as a tread 2 for an open staircase that does not use stringers 1, 1.

[0068] Furthermore, in the treads 2 of embodiments 1 and 2 described above, a paper core 11 was used for the core material 10, but the core material 10 may also be made of a material other than paper. For example, a resin or metal core 11 may be used.

[0069] Furthermore, in the footboard 2 of embodiments 1 and 2 described above, paper 12, 12 was used as the sheet-like material attached to the upper and lower surfaces of the core 11 with adhesive. However, the sheet-like material is not limited to paper 12, 12. For example, a resin sheet or a thin metal plate may be attached to the upper and lower surfaces of the core 11 as the sheet-like material. The material of the sheet-like material can be anything, but it is preferable to use the same material as the core 11, as this eliminates the need to select an adhesive for attaching the sheet-like material to the core 11 and allows for easy adhesion.

[0070] Furthermore, in the treads 2 of embodiments 1 and 2 described above, the frame members 20, 20 were made of wooden rod-shaped members (square timbers), but the material of the frame members 20, 20 is not limited to those described above. The frame members 20, 20 may be made of resin square timbers or metal square timbers, as long as they have sufficient strength to hold the nail-shaped members 4, 4 for fixing the riser board 3.

[0071] Furthermore, in the first embodiment of the tread 2, the two surface materials 30, 30 were made of medium-density fiberboard, and in the second embodiment of the tread 2, the two surface materials 30, 30 were made of a composite material formed by laminating and bonding a first plate material 31 made of medium-density fiberboard and a second plate material 32 made of veneer. However, the materials of the two surface materials 30, 30 are not limited to those described above. Any material can be used for the two surface materials 30, 30 as long as its bending strength is equal to or greater than that of medium-density fiberboard. For example, thin plywood or hardboard can be used.

[0072] Furthermore, in embodiments 1 and 2 described above, an example was given in which a honeycomb core with a hexagonal cross-sectional shape for each hole 11a is used as the core 11. However, the core 11 only needs to have a plurality of holes 11a, ..., 11a extending in the thickness direction that are adjacent to each other in a plan view, and the cross-sectional shape of each hole 11a is not limited to a hexagon. The cross-sectional shape of each hole 11a of the core 11 may be triangular, square, trapezoidal, circular, wave-shaped, semicircular, etc.

[0073] Furthermore, in embodiments 1 and 2 described above, the treads 2 were applied to a staircase S consisting of a straight staircase, but the staircase S to which the treads 2 can be applied is not limited to a straight staircase. [Industrial applicability]

[0074] This invention is useful for stair treads and stairs equipped with them. [Explanation of symbols]

[0075] 2 Treads (treads for stairs) 10 Core material 11 cores 11a hole 12. Paper (sheet material) 20 Frame material 30 Surface material 31. First type of board material (medium-density fiberboard) 32. Second board material (veneer) S stairs

Claims

1. A stair tread comprising a core material made of a rectangular plate-like body, frame members provided on at least the front and rear sides of the core material, and two surface members fixed to the upper and lower end surfaces of the frame members, respectively, The core material described above comprises a rectangular plate-shaped core with multiple holes extending in the thickness direction of the core, and two sheet-like materials bonded to the upper and lower surfaces of the core. The upper surface material is bonded to the upper end surface of the frame material and to the upper sheet-like material that constitutes the upper surface of the core material. The lower surface material is bonded to the lower end surface of the frame material and to the lower sheet-like material that constitutes the lower surface of the core material. The above frame material is provided only on the front and rear sides of the above core material. The above core is made of paper, and its top and bottom surfaces are made rough. The above-mentioned sheet-like material is paper that is thinner than the above-mentioned surface material, and is adhered to the entire upper and lower surfaces of the core. The above surface material is made of medium-density fiberboard. A stair tread characterized by the following features.

2. A stair tread comprising a core material made of a rectangular plate-like body, frame members provided on at least the front and rear sides of the core material, and two surface members fixed to the upper and lower end surfaces of the frame members, respectively, The core material described above comprises a rectangular plate-shaped core with multiple holes extending in the thickness direction of the core, and two sheet-like materials bonded to the upper and lower surfaces of the core. The upper surface material is bonded to the upper end surface of the frame material and to the upper sheet-like material that constitutes the upper surface of the core material. The lower surface material is bonded to the lower end surface of the frame material and to the lower sheet-like material that constitutes the lower surface of the core material. The above frame material is provided only on the front and rear sides of the above core material. The above core is made of paper, and its top and bottom surfaces are made rough. The above-mentioned sheet-like material is paper that is thinner than the above-mentioned surface material, and is adhered to the entire upper and lower surfaces of the core. The surface material described above is composed of a composite material in which medium-density fiberboard and veneer are laminated and bonded together, and the medium-density fiberboard is fixed to the core material and the frame material respectively so that it is located on the surface side of the stair tread. A stair tread characterized by the following features.

3. A staircase equipped with multiple stair treads, The above-mentioned stair tread is the stair tread described in claim 1 or 2. A staircase characterized by the following features.

Images