Wooden skeleton staircase and construction method thereof

Abstract

To provide a wooden skeleton staircase which can be easily constructed by a small number of processes, can save labor for field work, and can shorten a construction period, and a construction method thereof.SOLUTION: A wooden skeleton staircase has two wooden open strings 2 arranged in parallel at a fixed interval, a plurality of wooden treads 3, a lower side fixing member, and an upper side fixing member. In the open string 2, mortises 22, 28 and are respectively formed on a contact surface 21 of a lower end part and a contact surface 27 of an upper end part. The treads 3 are respectively placed on terraced horizontal surfaces of the open strings 2 and fixed by lock means. The lower fixing member is fixed to a position for fixing the lower end parts of the open strings 2, and the upper fixing member is fixed to a position for fixing the upper end parts of the open strings 2, the lower end part and the upper end part of the open string 2 are respectively fixed in a state of fitting the lower side fixing member in the mortise 22 of the lower end part of the open string and in a state of fitting the upper side fixing member in the mortise 28 of the upper end part of the open string 2.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a skeleton staircase consisting of wooden stringers and treads, and a construction method thereof. [Background technology]

[0002] Traditional wooden stairs installed in two-story wooden buildings, etc., have many components, require many steps during construction, and can require difficult on-site work. For example, even if the components are installed in the positions specified in the design drawings, the actual physical positions may not match, resulting in misalignment. When such misalignment occurs, on-site work is required to properly address the issue, but such on-site work requires skilled techniques. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2018-016964 Summary of the Invention [Problem to be solved by the invention]

[0004] In recent years, due to reasons such as a shortage of skilled workers capable of constructing wooden buildings, it has become difficult to secure the necessary personnel, which has affected construction schedules. For this reason, there is a demand for wooden stairs that can be constructed more easily and do not require skilled techniques.

[0005] The present invention is intended to solve the problems of the prior art, and aims to provide a wooden skeleton staircase and a construction method thereof that can be constructed easily with a small number of steps, saves on-site work, and shortens the construction period. [Means for solving the problem]

[0006] The wooden skeleton staircase of the present invention comprises two wooden stringers arranged parallel to each other at a fixed distance, a plurality of wooden treads, a lower fixing member, and an upper fixing member. The stringers have mortises formed on the contact surfaces of their lower and upper ends, respectively. The treads are placed on the tiered horizontal surfaces of the stringers and secured by locking means. The lower fixing member is secured in a position to secure the lower ends of the stringers, and the upper fixing member is secured in a position to secure the upper ends of the stringers. The lower and upper ends of the stringers are secured with the lower fixing member fitted into the mortise at the lower end of the stringers, and the upper fixing member is fitted into the mortise at the upper end of the stringers. The width of the lower fixing member is set smaller than the width of the mortise at the lower end of the stringers, with a play range of 5 to 15 mm.

[0007] It is also preferable that the length of the lower fixing member is set smaller than the length of the mortise at the lower end of the stringer, with the play being set within the range of 5 to 15 mm, and it is further preferable that the width of the upper fixing member is set smaller than the width of the mortise at the upper end of the stringer, with the play being set within the range of 5 to 15 mm.

[0008] It is also preferable that the locking means be composed of a connector placed in a mating recess on the underside of each of the tiered horizontal surfaces of the stringer, and a connecting bolt attached so as to protrude downward from the underside of the tread, so that when the tread is placed on the tiered horizontal surfaces of the stringer, the lower end of the connecting bolt can be inserted into the connector, and by rotating the connector in a predetermined direction with the lower end of the connecting bolt inserted, the upward movement of the connecting bolt can be restricted and the tread can be fixed to the stringer.

[0009] Furthermore, the connecting bolt has a small-diameter portion between its lower end and the main body, the small-diameter portion having a diameter or width smaller than that of the lower end, and the connector has a hollow portion formed inside it large enough to receive the lower end of the connecting bolt, and the outer surface of the connector has a through-hole formed therein which has a diameter larger than that of the lower end of the connecting bolt and which communicates with the hollow portion, and a notch having a width larger than the diameter of the small-diameter portion of the connecting bolt and smaller than the diameter of the lower end of the connecting bolt is formed circumferentially offset from the through-hole on the outer surface of the connector so as to be continuous with the through-hole, and when the connecting bolt of the footboard is inserted into the vertical hole of the side panel with the through-hole in an upwardly opening position, the lower end of the connecting bolt passes through the through-hole and enters the hollow portion, and when the connector is rotated in a predetermined direction in this state, the notch moves above the lower end of the connecting bolt, trapping the lower end of the connecting bolt within the hollow portion of the connector.

[0010] In addition, the construction method for wooden skeleton staircases according to the present invention involves fixing a lower fixing member in a position where the lower ends of the stringers will be fixed, and fixing an upper fixing member in a position where the upper ends of the stringers will be fixed, positioning two stringers so that the lower fixing member fits into the mortise at the lower ends of the stringers and the upper fixing member fits into the mortise at the upper ends of the stringers, attaching the second, third or fourth step from the bottom and the second, third or fourth step from the top to the two stringers, inserting the connecting bolts attached to the undersides of the treads into the connectors, and while maintaining this position, driving screws from above the horizontal surfaces of the lowest and highest stringers to secure the lower and upper ends of the two stringers, respectively, and then attaching and securing the remaining treads to the respective horizontal surfaces of the stringers. [Effects of the Invention]

[0011] The wooden skeleton staircase of the present invention can be constructed using fewer parts than conventional techniques and can be easily constructed with fewer steps, thereby reducing on-site work and shortening construction time. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a perspective view of a wooden skeleton staircase 1 according to a first embodiment of the present invention. [Figure 2] FIG. 2 is a perspective view of the lower and upper ends of the stringer 2 shown in FIG. [Figure 3] FIG. 3 is an explanatory diagram of a method for fixing the lower end of the stringer 2 shown in FIG. [Figure 4] FIG. 4 is an explanatory diagram of a method for fixing the upper end of the stringer 2 shown in FIG. [Figure 5] FIG. 5 is a cross-sectional view showing a state in which a lower fixing member 41 is fitted into the mortise 22 at the lower end of the stringer 2 shown in FIG. [Figure 6] FIG. 6 is a perspective view showing the lower surface 32 of the tread 3 shown in FIG. [Figure 7] FIG. 7 is a perspective view of the lower half of the connecting bolt 6 shown in FIG. 6 and the connector 5 shown in FIGS. [Figure 8] FIG. 8 is a plan view of connector 5 showing a state in which lower end portion 61 shown in FIG. [Figure 9] FIG. 9 is a plan view of connector 5 showing a state in which lower end portion 61 shown in FIG. [Figure 10] FIG. 10 is an explanatory diagram of a method for fixing the lower end of the stringer 2 shown in FIG. [Figure 11] FIG. 11 is an explanatory diagram of a method for fixing the upper end of the stringer 2 shown in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0013] The present invention can be implemented as a "wooden skeleton staircase" and also as a "construction method for a wooden skeleton staircase." Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

[0014] 1 is a perspective view of a wooden skeleton staircase 1 according to a first embodiment of the present invention. As shown in the figure, the staircase 1 is basically composed of two wooden stringers 2 and a plurality of wooden treads 3.

[0015] The two stringers 2 are arranged parallel to each other at a fixed distance, with their lower ends fixed to the horizontal surface of the floor below (the surface of the floorboards or the upper surface of the underfloor structural material) via lower fixing members (not shown), and their upper ends fixed to the vertical surface of the floor above (the surface of the beam or other structural material below the upper step frame 7) via upper fixing members (not shown). The treads 3 are each placed on the stepped horizontal surface of the stringers 2 and secured by locking means (not shown).

[0016] Figure 2 is a perspective view of the lower and upper ends of the stringer 2 shown in Figure 1. A mortise 22 is formed in contact surface 21 (the downward-facing horizontal surface that contacts the object to be fixed) of the lower end of the stringer 2, and a mortise 28 is also formed in contact surface 27 (the outward-facing vertical surface that contacts the object to be fixed) of the upper end.

[0017] 3 is an explanatory diagram of a method for fixing the lower end of the stringer 2. A lower fixing member 41 is first fixed (with screws) to the position where the lower end of the stringer 2 will be fixed (the surface of the floorboard or the upper surface of the underfloor structural material), and the lower end of the stringer 2 is then placed over it so that the lower fixing member 41 fits into the mortise 22.

[0018] 4 is an explanatory diagram of a method for fixing the upper end of stringer 2. An upper fixing member 42 is first fixed (with screws) to the position where the upper end of stringer 2 will be fixed (to the surface of the beam or other structural material below upper stile 7), and the upper end of stringer 2 is then placed over it so that upper fixing member 42 fits into mortise hole 28. In this embodiment, wooden timbers cut to a predetermined length are used as fixing members 41 and 42.

[0019] 5 is a cross-sectional view showing the state in which the lower fixing member 41 is fitted into the mortise 22 at the lower end of the stringer 2. As shown in the figure, the width and length of the lower fixing member 41 are set smaller than the width and length of the mortise 22 of the stringer 2. In other words, there is a "play" in both the width and length directions between the mortise 22 at the lower end of the stringer 2 and the lower fixing member 41. More specifically, the width of the lower fixing member 41 is set 10 mm (preferably 5 to 15 mm) smaller than the width of the mortise 22, and the length of the lower fixing member 41 is set 10 mm (preferably 5 to 15 mm) smaller than the length of the mortise 22.

[0020] Also, a width of play of 10 mm (preferably 5 to 15 mm) is provided in the width direction between the mortise 28 at the upper end of the stringer 2 and the upper fixing member 42 (see FIG. 4).

[0021] The reason for providing such play in the width and length directions of the lower fixing member 41 and the width direction of the upper fixing member 42 is that in the case of wooden buildings, even if the fixing members 41, 42 are fixed in the positions according to the design drawings, the actual physical positional relationship may not match, and there is a possibility that misalignment may occur in the width and length directions of the fixing members 41, 42.By providing such play, errors can be accommodated and the stringer 2 can be installed without any problems.

[0022] The lower and upper ends of the stringer 2 are placed over the fixing members 41, 42, and then finally fixed to the floorboards, beams, etc. by driving screws 23 from above, as shown in Figures 10 and 11; this will be described later.

[0023] FIG. 6 is a perspective view showing the underside 32 of the step 3 shown in FIG. 1. As shown in the figure, two connecting bolts 6 are attached to the underside 32 of the step 3 so as to protrude downward from the underside 32. These connecting bolts 6 are configured to be engageable with the connectors 5 shown in FIGS. 3 and 4 and, together with these connectors 5, function as a locking means for the step 3. As shown in FIGS. 3 and 4, the connectors 5 are located in mating recesses (open to the horizontal surfaces 29 and side surfaces of the stringers 2) on the underside of each of the tiered horizontal surfaces 29 (the surfaces on which the steps 3 are placed) of the stringers 2. The two connecting bolts 6 are attached in positions that allow them to engage with the connectors 5 located on the two stringers 2 when the two stringers 2 are spaced apart as designed.

[0024] 7 is a perspective view of the lower half of the connecting bolt 6 and the connector 5. The connecting bolt 6 has a lower end 61 formed in a hemispherical shape at the bottom end of the body, and a small-diameter portion 62 between the lower end 61 and the body, the small-diameter portion 62 having a smaller diameter (or width dimension) than the lower end 61. The outer peripheral surface of the upper half of the connecting bolt 6 is formed with a screw thread (not shown), and the upper half can be fixed to the tread 3 by screwing it into a pilot hole formed in the lower surface 32 of the tread 3 shown in FIG.

[0025] Connector 5 is formed in a cylindrical shape, and one end 54 is formed with a cross-shaped groove 55 that can engage with the tip of a Phillips head screwdriver. A hollow portion 51 large enough to receive a lower end portion 61 of connecting bolt 6 is formed inside connector 5. Furthermore, a through hole 52 that communicates with hollow portion 51 is formed in the outer circumferential surface of connector 5, and a notch 53 having a width dimension smaller than the diameter of through hole 52 is formed at a position offset from this through hole 52 in the circumferential direction (direction around the central axis) of the outer circumferential surface of connector 5 so as to be continuous with through hole 52.

[0026] The through-hole 52 has a diameter larger than the lower end 61 of the connecting bolt 6, allowing the lower end 61 of the connecting bolt 6 to pass through and enter the hollow portion 51. The width of the cutout 53 is set to be larger than the diameter of the small-diameter portion 62 of the connecting bolt 6, but smaller than the diameter of the lower end 61 of the connecting bolt 6.

[0027] As shown in Figures 3 and 4, the connector 5 is positioned so that a portion of its outer surface is exposed on the horizontal surface 29 of the stringer 2 (it is accessible from above the horizontal surface 29) and its end 54 is exposed on the vertical side of the stringer 2 (in a mating recess below the horizontal surface 29).When placing the step 3 on the horizontal surface 29 of the stringer 2, the lower end 61 of the connecting bolt 6 is inserted into the connector 5, and in this state the connector 5 is rotated in a predetermined direction to secure the step 3 to the stringer 2.

[0028] More specifically, when the through hole 52 of the connector 5 is open upward as shown in Figure 7, and the connecting bolt 6 is inserted into the connector 5, the hemispherical lower end 61 passes through the through hole 52 and enters the hollow portion 51 as shown in Figure 8 (a plan view of the connector 5 showing the state in which the lower end 61 has entered the hollow portion 51).

[0029] In this state, when connector 5 is rotated clockwise by approximately 90° using a Phillips head screwdriver, notch 53, which has a width smaller than the diameter of lower end 61, moves upward (to a position on the outer periphery of small diameter portion 62) as shown in Figure 9 (a plan view of connector 5 showing lower end 61 trapped within hollow portion 51). As a result, lower end 61 is trapped within hollow portion 51, restricting the upward movement of connecting bolt 6 (see Figures 6 and 7), and tread 3 is fixed to stringer 2.

[0030] Furthermore, in order for the two connecting bolts 6 (see Figure 6) of one tread 3 to enter the two connectors 5 attached to each horizontal surface 29 of the two stringers 2, the spacing between the two stringers 2 must be the appropriate dimension (the designed dimension). However, as mentioned above, there is play between the mortises 22, 28 of the stringer 2 and the fixing members 41, 42. Therefore, when the lower and upper ends of the stringer 2 are placed over the fixing members 41, 42 and fitted into the mortises 22, 28, the spacing between the two stringers 2 may differ from the designed dimension (become smaller or larger than the designed dimension).

[0031] Therefore, as shown in Figure 10 (an explanatory diagram of a method for fastening the lower end of the stringer 2 shown in Figure 1) and Figure 11 (an explanatory diagram of a method for fastening the upper end of the stringer 2 shown in Figure 1), first, the second-lowest (or third or fourth) step 3 and the second-highest (or third or fourth) step 4 are attached to the two stringers 2. At this time, one of the two connecting bolts 6 attached to the underside 32 of the step 3 is inserted into the connector 5 of one of the stringers 2, and in this state, the distance between the two stringers 2 is adjusted appropriately within the play width, and the other connecting bolt 6 is inserted into the connector 5 of the other stringer 2.

[0032] In this way, by properly attaching the second-lowest and second-highest treads 3 to the two stringers 2, the distance between the two stringers 2 can be set to the designed dimension. While maintaining this state (with the two treads 3 attached to the stringers 2), screws 23 are driven into the lower fixing member 41 and the upper fixing member 42 from above the horizontal surfaces 29 of the lowest and highest stringers 2, respectively, as shown in Figures 10 and 11, to secure the lower and upper ends of the stringers 2.

[0033] The remaining treads 3 are then attached to each horizontal surface 29 of the stringers 2, and the connectors 5 are rotated in the specified direction to secure all of the treads 3 to the stringers 2. In this way, compared to conventional techniques, the wooden skeleton staircase 1 of this embodiment can be constructed with fewer parts and can be easily constructed with fewer steps, thereby reducing on-site labor and significantly shortening the construction period.

[0034] In the above embodiment, an example was described in which the wooden skeleton staircase according to the present invention is configured as a straight staircase (a staircase that connects the lower floor and the upper floor in a straight line), but the application of the present invention is not limited to straight staircases, and it can also be applied to a return staircase with a landing in the middle.

[0035] Furthermore, in the above embodiment, the two connecting bolts 6 attached to the underside 32 of the tread 3 are positioned so that an imaginary line passing through their centers is parallel to the longitudinal direction of the tread 3 (i.e., at positions equidistant from the longitudinal edges of the tread 3). However, it is also possible to position the imaginary line so that it is inclined relative to the longitudinal direction of the tread 3 (for example, at an angle of 10° or more (for example, on the diagonal of the tread 3)), with the connectors 5 shown in Figures 3 and 4 also positioned in a corresponding position. In this case, even if one tread 3 is fixed to one point on each side of the left and right stringers 2, rattling and flapping of the tread 3 can be suppressed. [Explanation of symbols]

[0036] 1: Wooden skeleton stairs, 2: Stringers, 21: Contact surface, 22: Mortise, 23: Bis, 27: Contact surface, 28: Mortise, 29: horizontal plane, 3:Treadboard, 32: Lower side, 41: Lower fixing member, 42: Upper fixing member, 5: Connector, 51: Hollow part, 52: through hole, 53: Notch, 54: end, 55: cruciform groove, 6: Connecting bolt, 61: Bottom end, 62: Small diameter part, 7: Upper stile,

Claims

1. The structure comprises two wooden stringers arranged parallel to each other at a fixed interval, a plurality of wooden treads, a lower fixing member, and an upper fixing member; The stringer has a mortise formed on the contact surface at the lower end and the contact surface at the upper end, The treads are respectively placed on the stepped horizontal surfaces of the stringers and secured by locking means; The lower fixing member is fixed in a position to fix the lower end of the stringer; the upper fixing member is fixed in a position to fix the upper end of the stringer; The lower and upper ends of the stringer are fixed in place with the lower fixing member fitted into the mortise at the lower end of the stringer and the upper fixing member fitted into the mortise at the upper end of the stringer, respectively; This wooden skeleton staircase is characterized in that the width dimension of the lower fixing member is set smaller than the width dimension of the mortise hole at the lower end of the stringer, and the play width is set within the range of 5 to 15 mm.

2. The wooden skeleton staircase according to claim 1, characterized in that the length of the lower fixing member is set to be smaller than the length of the mortise at the lower end of the stringer, and the play width is set within the range of 5 to 15 mm.

3. The wooden skeleton staircase according to claim 1, characterized in that the width dimension of the upper fixing member is set smaller than the width dimension of the mortise hole at the upper end of the stringer, and the play width is set within the range of 5 to 15 mm.

4. the locking means is comprised of a connector disposed in a mating recess on the underside of each horizontal tiered surface of the stringer and a connecting bolt attached so as to protrude downward from the underside of the tread; 2. The wooden skeleton staircase of claim 1, characterized in that, when placing a tread on the tiered horizontal surface of the stringers, the lower end of the connecting bolt can be inserted into the connector, and by rotating the connector in a predetermined direction with the lower end of the connecting bolt inserted, the upward movement of the connecting bolt can be restricted, thereby fixing the tread to the stringers.

5. The connecting bolt has a small diameter portion between the lower end portion and the body, the small diameter portion having a diameter or width dimension smaller than that of the lower end portion, A hollow portion having a size capable of receiving the lower end of the connecting bolt is formed inside the connector, a through hole having a diameter larger than that of the lower end of the connecting bolt and communicating with the hollow portion is formed on the outer peripheral surface of the connector; a notch having a width dimension larger than the diameter of the small diameter portion of the connecting bolt and smaller than the diameter of the lower end portion of the connecting bolt is formed at a position circumferentially offset from the through hole on the outer circumferential surface of the connector so as to be continuous with the through hole; 5. The wooden skeleton staircase according to claim 4, characterized in that when the connecting bolt of the tread is inserted into the vertical hole of the side panel with the through hole of the connector open upward, the lower end of the connecting bolt passes through the through hole and enters the hollow part, and when the connector is rotated in a predetermined direction in this state, the notch moves above the lower end of the connecting bolt, so that the lower end of the connecting bolt is trapped within the hollow part of the connector.

6. A method for constructing the wooden skeleton staircase according to claim 4, a lower fixing member is fixed at a position where the lower end of the stringer is fixed, and an upper fixing member is fixed at a position where the upper end of the stringer is fixed; Positioning two stringers such that a lower fixing member fits within a mortise at the lower end of the stringer and an upper fixing member fits within a mortise at the upper end of the stringer; The second, third or fourth step from the bottom and the second, third or fourth step from the top are attached to the two stringers, and the connecting bolts attached to the undersides of the steps are inserted into the connectors. While maintaining this state, drive screws into the lowermost and uppermost horizontal surfaces of the tiered horizontal surfaces of the stringers to fix the lower and upper ends of the two stringers, respectively. A construction method for wooden skeleton stairs characterized by attaching and fixing the remaining treads to each horizontal surface of the stringers.

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