JP5020847B2 - Staircase - Google Patents

Description

  The present invention relates to a staircase suitable for use in a small building such as a house.

  As for the stairs installed in a general house, the structure which supports the tread board which carries a passerby with the left and right side girders is prevailing widely. In this structure, since both ends of the tread are inserted into the side girders, the tread can be reliably supported, and the aesthetics are improved because the metal fittings are not exposed to the outside. Moreover, the tread board and side girders can be assembled simply by cutting the plate material into a predetermined shape and then machining the groove or the like, making it easy to manufacture and suppressing costs. If there is an open space between the upper and lower treads, an unexpected accident may occur, and in many cases, a soldering board is installed to block between adjacent treads.

Patent document 1 is mentioned as an example of the other staircase structure. In this staircase, a middle girder (climbing beam) is arranged so as to connect the top and bottom of the floor, and a tread board is attached to the upper surface thereof. This structure is open around the tread board, and is called a strip staircase or skeleton staircase. When used in an atrium, it creates a unique atmosphere around it. Patent Document 1 is not characterized in the basic structure of the staircase itself, but is characterized in that a rod-like member is provided between the upper and lower treads for the purpose of preventing the infant from falling.
JP 2007-321497 A

  In addition to the basic functions for comfortable daily life, the design of the interior and exterior of the house has a great influence on the satisfaction of residents. Therefore, the staircase is not a typical structure combining side girders and footboards, and there is a strong desire to introduce a novel design that sets it apart from the conventional one, and the strip staircase like the above-mentioned patent document is one of them. . However, the staircase needs to be strong enough to ensure the safety of the passerby, and various design restrictions are likely to occur.

  Even if a predetermined strength can be secured, sufficient consideration is required for workability. In particular, when newly installing stairs due to renovation, it is often impossible to use heavy equipment to carry in materials, and a structure that can be assembled on site by subdividing parts so that it can also be handled by human power is preferable. In renovation, staircases may be installed in places that are not expected at the time of new construction, so flexibility is required so that they can be installed in various places. In addition, renovation requires work to reduce work time as much as possible in order to proceed with work while maintaining the lives of the residents.

  The present invention was developed on the basis of such circumstances, and has an object of providing a staircase that is excellent in aesthetics, can be installed in any place, and is excellent in workability during construction.

  The invention according to claim 1 for solving the above-mentioned problem is that a plurality of footboards arranged obliquely at predetermined intervals, a support member for attaching the footboards, a lateral hole formed on a side surface of the footboard, and A shaft rod that passes through a holding hole formed in the support member, and a fastener that is driven from the upper surface or the lower surface of the foot plate in order to integrate the foot plate and the shaft rod. A plurality of fasteners are used, and one end side is provided with fastening means for integrating with the support member, and the other end side is formed with one or more rows of annular recesses for engaging the fasteners on the side circumferential surface. It is a staircase characterized by that.

  The present invention is a staircase having a structure in which a plurality of treads arranged in an oblique direction are received by a support member, and the tread is a rectangular plate that is long in the width direction, like a conventional staircase, and is made of wood including plywood. Assuming The supporting member is equivalent to a conventional side girder, etc., and has a function for attaching a footboard. The specific form of the supporting member is diagonally up and down like a general side girder. It is possible to use a wall with strength in addition to a bar to be connected to, and various things such as columns arranged at narrow intervals. In either case, however, it is necessary to have a strength that can withstand the load acting on the footboard and that the deformation is negligible.

  The shaft bar is a metal round bar that connects the tread plate and the support member, and has a function of receiving a load acting on the tread plate and transmitting it to the support member. In order to insert the shaft rod, a lateral hole is machined on the side surface of the tread plate, and a holding hole is machined on the extended line of the lateral hole in the supporting member. In principle, the horizontal hole is not penetrated to the opposite surface in consideration of aesthetics, but the holding hole may be penetrated. It should be noted that at least two shaft rods are used for one tread plate, and a horizontal hole and a holding hole are provided for each shaft rod. In addition, the horizontal hole to be machined into the tread plate is made larger in diameter than the shaft rod so as to absorb the shaft bar installation error so that the shaft rod can be inserted into the horizontal hole.

  If the shaft rod is simply inserted into the holding hole formed in the support member, the shaft rod easily falls off, so that a fastening means for integrating the both is necessary. The fastening means is required to be able to transmit the load to the support member without dropping off the shaft rod no matter what load is applied to the shaft rod. However, if the fastening means is exposed, the aesthetics may be deteriorated, and it is preferable to bury the majority in the support member. Next, the concave portion is formed by forming an annular groove on the side peripheral surface of the shaft rod, and is provided on the tread plate side of the shaft rod, and has a function for engaging the fastener. If the recess is annular, the cross-sectional shape is free, but of course it must be large enough to insert the fastener into the recess.

  The fastener has a function of integrating the tread plate with the shaft rod by being driven in from the upper surface or the lower surface of the tread plate and sandwiched between the recesses of the shaft rod. This fastener is a rod-like member such as a metal pin or screw, and needs to be able to be fixed in a fixed state in the footboard in some form. Therefore, when a round bar-like pin is used, it is necessary to prevent the disconnection by a method such as increasing the extension. In addition, if it is a screw, it is only necessary to provide a locking hole in the tread board as needed and screw it in toward the shaft rod. However, if there is a risk of the screw falling off due to aging deformation, etc., a demon nut is interposed. Let

  As for the relationship between the fastener driven into the tread and the recess of the shaft rod, there is no problem in any state as long as the fastener cannot be removed from the recess, and the fastener crosses the tangential direction of the recess. In addition, the fastener may be configured such that the tip of the fastener presses the inner peripheral surface of the recess with the fastener directed toward the central axis of the shaft rod. In consideration of various errors, it is preferable to provide a slight gap between the fastener and the recess. In addition, since the fastener is arranged so as to be orthogonal to the shaft rod, it can inevitably be driven from both the upper and lower surfaces of the footboard, but from the viewpoint of aesthetics, in principle, it is driven from the lower surface and does not penetrate the upper surface. .

  By comprising in this way, each step board is integrated with a supporting member via a some shaft rod. Since the shaft rod is made of metal and has excellent strength, it is possible not only to receive the tread board but also to increase the strength of the tread board. Moreover, when a fastener using pins, wood screws, or the like is inserted into the recess of the shaft rod, the fastener is sandwiched in the recess and the installation of the footboard is completed. If there is no recess as in the present invention and the fastener is inserted through the shaft rod, of course, the shaft rod is provided with some hole, and the position and direction of this hole (when viewed from the cross section). (Direction) need to be adjusted. However, in the present invention, if the position is adjusted, the direction can be set freely, and the labor during operation is reduced.

  The invention described in claim 2 specifies the fastening means, and the fastening means is a spiral ridge formed on the side peripheral surface of the shaft rod. The ridge is the same as the lag screw which is one of the building materials, and the ridge that protrudes in the radial direction from the side peripheral surface is formed in a spiral shape, and this digs into the support member. The shaft rod is fixed by friction generated between the two.

  The invention according to claim 3 also specifies a fastening means, and the fastening means is driven from a side hole penetrating the side peripheral surface of the shaft rod and a pin hole formed in the support member and penetrates the side hole. And a drift pin. In this invention, a drift pin is driven to fix the shaft rod. In order to insert the drift pin in the side peripheral surface of the shaft rod, one or a plurality of side holes are provided, and the support member also has a drift. A pin hole for driving a pin is processed. At the time of construction, after inserting the shaft rod into the holding hole and aligning the side hole and the pin hole concentrically, the drift pin is driven through the pin hole. A plurality of drift pins are preferably used for one shaft rod.

  The invention according to claim 4 shows a specific configuration example of the present invention, and the support member is a row of climbing beams that cantilever the tread plate, and a side hole is formed on one side surface of the short side of the tread plate. A holding hole is formed on one side surface of the climbing beam. The invention according to claim 1 is characterized in that the tread plate is fixed through a shaft rod having a recess, and the specific shape of the staircase is not limited. However, in the present invention, a row of climbing beams is arranged in an oblique direction so as to connect the upper and lower sides of the floor, and a shaft bar is horizontally projected from one side thereof, and this shaft bar is inserted into a horizontal hole of the tread plate to constitute a staircase. is doing. Accordingly, the lateral hole is formed on one surface of the short side of the total four side surfaces of the tread board. In addition, although the tread plate is supported by the cantilever, restrictions on strength are increased, but a predetermined strength can be secured by increasing the thickness of the climbing beam and the length of the shaft rod.

  The invention according to claim 5 also shows a specific configuration example of the present invention, and the support member is a two-row climbing beam arranged below the tread, and a horizontal hole is formed on one side of the long side of the tread. And a holding hole is formed on the upper slope of the climbing beam. In the present invention, the climbing beam is arranged below the tread, and the shaft bar is projected horizontally from the upper slope of the climbing beam (the surface facing diagonally upward). It is inserted into the side of the long side located at the back in the line of sight when climbing. Since the climbing beams are arranged in two rows in parallel, and a single shaft rod is inserted into each, the footboard is supported by the two shaft rods.

  Since the steel plate is inserted into the tread plate by the structure in which the tread plate is supported by the shaft rod protruding from the support member as in the first aspect of the invention, the strength of the tread plate is improved and deformed. The amount can be suppressed. Therefore, the thickness of the footboard can be suppressed, and the degree of freedom in design can be increased. In the present invention, if the horizontal hole and the holding hole for inserting the shaft rod can be formed, the structure of the staircase itself is not limited, and various designs can be realized. In addition, since the shaft rod and the tread plate are fixed not in a form in which a pin or the like is passed through the shaft rod but in a form in which the fastener is engaged with one corner of an annular recess, the fastener does not depend on the orientation of the shaft rod. Can be typed. Therefore, when the shaft rod is embedded in the support member, there is no need to adjust the direction of the shaft rod, and labor and time can be reduced. Furthermore, the present invention is a form in which treads are carried one by one and attached locally, and can be transported by hand and can be adapted for renovation.

  As in the invention described in claim 2, by using a convex strip such as a lag screw as a fastening means between the shaft rod and the support member, friction is generated on the entire contact surface between the convex strip and the support member. The rod can be firmly fixed. In addition, since the aging of the support member can be restrained by the ridges, long-term reliability can be maintained. Next, as in the invention described in claim 3, in addition to using a drift pin as a fastening means, a side hole is provided in the shaft rod, and a pin hole is processed in the support member so that the pin hole is directed to the side hole. The shaft rod can be installed with a simple operation just by driving in the drift pin, saving labor and time. In addition, in the stage which attaches a shaft rod to a supporting member, since a shaft rod can be rotated easily, there is no difficulty in the operation | work which makes a side hole and a pin hole correspond.

  As in the invention described in claim 4, by attaching the tread board to the side surface of the climbing beam (support member) in a cantilever manner, it is possible to construct a staircase with a unique appearance such that the tread board protrudes into the space. It is possible to meet the demand for adoption. Moreover, if a single row of climbing beams can be installed, stairs can be constructed at any location, making it easy to accommodate renovations. In addition, if two rows of climbing beams can be installed as in the fifth aspect of the invention, a strip staircase with excellent aesthetics can be easily constructed.

  FIG. 1 shows a configuration example of a staircase according to the present invention. The staircase in this figure has a cantilever structure in which one climbing beam 31 extending in an oblique direction is disposed as a support member, and the side surface of the tread plate 41 is attached to this one side surface. In the figure, only one footboard 41 and the climbing beam 31 in the vicinity thereof are depicted, but the climbing beam 31 is arranged in an oblique direction so as to connect the upper and lower floors, and the footboard 41 is vertically moved at a predetermined interval. Are lined up. Next, the shaft rod 11 is made of a steel round bar, and a ridge 12 having a side circumferential surface projecting in the radial direction is spirally formed near the right end. The ridge 12 functions as a fastening means with the climbing beam 31 in the same form as a general-purpose lag screw. In addition, a double-sided width portion 13 is formed in the middle portion of the shaft 11 by cutting away the opposing side circumferential surfaces for applying a tool such as a spanner. Further, near the left end, a concave portion 14 is formed by scraping the side peripheral surface into an annular shape. The cross section of the recess 14 (the cut surface in the axial direction of the shaft 11) is semicircular throughout.

  In the climbing beam 31, a holding hole 33 for inserting the shaft 11 is formed at a predetermined position. The holding hole 33 is equal to the diameter of the shaft 11 excluding the ridges 12. When embedding the shaft 11, the tip is inserted into the holding hole 33, and then a tool is applied to the two-sided width portion 13 to rotate it, and the ridge 12 is bitten into the wood portion. When the ridges 12 bite in to some extent, a propulsive force is naturally generated, so that the shaft rod 11 is buried to a predetermined depth only by applying rotation. In this figure, two shaft bars 11 are used for one tread plate 41.

  The tread 41 is made of wood including plywood, is cut to a length that matches the width of the stairs, one side of the short side faces the climbing beam 31, and two rows of horizontal holes 42 are horizontally disposed on this surface. It is formed in the direction. The horizontal hole 42 has a function for inserting the shaft rod 11, but the two shaft rods 11 protruding from the climbing beam 31 may not be arranged in parallel due to an error. Therefore, the diameter of the lateral hole 42 is slightly larger than that of the shaft rod 11. Since the tread plate 41 cannot be fixed simply by inserting the shaft rod 11 into the horizontal hole 42, a locking hole 43 aligned with the center of the horizontal hole 42 is formed on the lower surface of the tread plate 41, and functions as a fastener therein. A set screw 21 is screwed in. The set screw 21 has a shape like a wood screw on the side peripheral surface and a structure in which a hexagon wrench can be inserted into one end surface. Therefore, when the tip is inserted into the locking hole 43 and then rotated, It enters the recess 14 of the shaft 11.

  FIG. 2 shows a state where the footboard 41 is attached to the climbing beam 31 after FIG. The side surfaces of the climbing beam 31 and the tread plate 41 are in close contact with each other, and the shaft rod 11 is inserted so as to penetrate the boundary between both. Since the shaft rod 11 has the spiral ridges 12 bite into the climbing beam 31, the shaft rod 11 is firmly integrated with the climbing beam 31, and is less likely to loosen over time. Further, the recess 14 of the shaft rod 11 is positioned immediately above the locking hole 43 formed in the tread plate 41, and when the set screw 21 is screwed into the locking hole 43, the tip of the recess is in the recess 14. The tread board 41 cannot be detached from the shaft 11 by entering. Since the set screw 21 has a structure similar to that of the wood screw on the side peripheral surface, it is not necessary to form a female screw in the locking hole 43.

  As shown in the figure, a plurality of footboards 41 are arranged on the side surface of the climbing beam 31 at equal intervals, and the shaft rod 11 is inserted into each footboard 41. Accordingly, since the load acting on the tread 41 is immediately transmitted to the shaft 11, the thickness of the tread 41 can be suppressed. When the tread plate 41 is supported in a cantilever manner, the mechanical conditions become severe, and therefore it is preferable to increase the rigidity by taking measures such as increasing the length and number of the shaft rods 11. In addition, although the holding hole 33 of this figure has penetrated the side surface of the climbing beam 31, when there is a problem with aesthetics etc., it is good also as a bottom without making it penetrate.

  FIG. 3 shows a form in which a footboard 41 is disposed above two parallel climbing beams 32. This structure is substantially the same as a general skeleton staircase, and climbing beams 32 are arranged near the center of the staircase, and a footboard 41 is arranged on the climbing beam 32. In this figure, only one tread board 41 is drawn, and the climbing beam 32 also shows only a small part of the middle part. As in FIG. 1, the shaft rod 11 has a spiral ridge 12 formed on one end side and an annular recess 14 formed on the other end side, but a hexagonal portion 15 is formed on the end face instead of the two-surface width portion 13. Is formed. The hexagonal portion 15 is literally a hexagonal cross section and can be rotated by inserting a tool around it. The holding hole 33 for inserting the shaft rod 11 is formed in the horizontal direction with the upper slope of the climbing beam 32 as a base point. Therefore, the upper slope of the climbing beam 32 and the holding hole 33 are not orthogonal to each other, and have an intersection angle corresponding to the inclination of the climbing beam 32.

As with the tread plate 41, a horizontal hole 42 is formed on the side surface as in FIG. 1, and a locking hole 43 that intersects the horizontal hole 42 is provided to attach the set screw 21. However, since the positional relationship between the climbing beam 32 and the tread board 41 is significantly different from that in FIG. 1, the lateral holes 42 are formed on the four sides of the tread board 41 on the back surface with reference to the line of sight when going up the stairs. In this figure, since one shaft rod 11 is embedded in each climbing beam 32, it is difficult to arrange both shaft rods 11 in parallel, and the diameter of the lateral hole 42 is larger than the shaft rod 11, Care is taken to absorb errors.

  FIG. 4 shows a state in which the footboard 41 is attached to the climbing beam 32 after FIG. 3. The shaft 11 is embedded in the horizontal direction and has an angle of intersection with the upper slope of the climbing beam 32. In this configuration, it is impossible to bring the upper slope of the climbing beam 32 into contact with the tread plate 41. The climbing beam 32 and the tread plate 41 are not in contact with each other. It is supported. Therefore, it is inevitable that the shaft bar 11 is exposed between the climbing beam 32 and the tread plate 41. However, in order to improve aesthetics and ensure safety, the ridges 12 of the shaft rod 11 are entirely connected to the climbing beam 32. Screwed inside.

  FIG. 5 shows a form in which the step board 41 is disposed above the two parallel climbing beams 32 as in FIG. 3, but the configuration of the shaft rod 11 is different. In this figure, a cutout portion 34 is provided by partially cutting off the upper slope of the climbing beam 32 so that the climbing beam 32 and the footboard 41 can be in surface contact with each other. A holding hole 33 for embedding is formed in the horizontal direction. Therefore, the load acting on the footboard 41 can be directly transmitted to the climbing beam 32, and the step between the upper surface of the footboard 41 and the upper slope of the climbing beam 32 can be eliminated, improving the aesthetics. Moreover, since the back surface of the footboard 41 contacts the climbing beam 32, the shaft bar 11 is not exposed to the outside.

  In addition, as for the shaft rod 11, the drift pin 18 is used as a fastening means with the climbing beam 32. Therefore, the side hole 16 is formed in the side peripheral surface of the shaft 11, and the pin hole 35 penetrating the side surface is also formed in the climbing beam 32. When attaching the shaft rod 11, the tip end portion is inserted into the holding hole 33, the pin hole 35 and the side hole 16 are aligned, and the drift pin 18 is driven through the pin hole 35 and inserted into the side hole 16. Then, the shaft 11 is integrated with the climbing beam 32. By fixing the shaft 11 using the drift pin 18 in this way, the work can be simplified and time and labor can be reduced, and the lower surface of the tread plate 41 can be placed directly on the climbing beam 32. The acting load can be reduced. In addition, the shaft rod 11 in this figure has two rows of recesses 14 into which a set screw 21 is screwed.

  FIG. 6 shows a state in which the footboard 41 is attached to the climbing beam 32 after FIG. 5. In the configuration of this figure, the back side surface of the tread plate 41 is in surface contact with the cutout portion 34 of the climbing beam 32, and the side hole 42 and the holding hole 33 are in contact with each other. Not exposed to In addition, the size of the notch 34 is adjusted to eliminate the step between the upper surface of the tread plate 41 and the upper slope of the climbing beam 32, giving the impression that the tread plate 41 is integrated with the climbing beam 32. Since the drift pin 18 is driven in the horizontal direction and has a length equivalent to the thickness of the climbing beam 32, sufficient friction is ensured and does not fall off over time.

  Each form shown in FIGS. 1 to 6 is merely an example of the present invention, and the positional relationship between the support members 31 and 32 and the tread plate 41 and the fastening means between the support members 31 and 32 and the shaft 11 are various. Combinations are possible. For example, as shown in FIG. 1, the drift pin 18 as shown in FIG. 5 can also be used as a fastening means for the climbing beam 31 and the shaft rod 11 even in the form of supporting the tread plate 41 in a cantilever manner. Further, as shown in FIG. 5, even when the climbing beam 32 is provided with the notch 34, the shaft bar 11 having the ridges 12 as shown in FIG. 1 can also be used. In addition, instead of the climbing beams 31 and 32 as support members, columns and wall surfaces can be used as long as a predetermined strength can be secured.

  FIG. 7 shows the relationship between the fastener and the recess 14 in a cross-section. FIG. 7A uses a set screw 21 as the fastener, and FIG. 7B shows the set screw 21 as the fastener. In addition to the use, measures are taken to prevent it from falling out. FIG. 7C uses a fixing pin 22 as a fastener. 7A, 7B, and 7C are assumed to have a tread plate 41 that is cantilevered by a single climbing beam 31, as shown in FIG. Is a cross section along the longitudinal direction of the shaft 11, and the left side is a cross section of the recess 14. As shown in FIG. 7A, the lateral hole 42 formed in the tread plate 41 is slightly larger in diameter than the shaft 11 and absorbs dimensional errors during construction. Further, a locking hole 43 is formed at a predetermined position on the lower surface of the tread plate 41 so that the set screw 21 is inserted. After the tread plate 41 is temporarily placed, the set screw 21 is screwed into the locking hole 43. When the tip of the set screw 21 reaches the inside of the recess 14, the set screw 21 is restrained by the recess 14, and the tread plate 41 is fixed to the shaft rod 11.

  FIG. 7B basically has the same configuration as FIG. 7A, but uses a so-called demon nut 23 at the entrance of the locking hole 43. As shown in FIG. 7A, if the set screw 21 is simply screwed into the locking hole 43 and the length of the set screw 21 and the protruding amount of the thread are insufficient, the set screw 21 is not fixed sufficiently. Sometimes it falls off. Therefore, the demon nut 23 is driven concentrically with the locking hole 43, and the set screw 21 is fixed thereby, so that the drop-off can be prevented.

  FIG. 7C uses a fixing pin 22 as a fastener. The fixing pin 22 is a metal round bar and the side peripheral surface is smooth, and there is no effect that the screw thread bites into the tread plate 41 like the set screw 21 in FIG. Therefore, when the fixing pin 22 is used, it is necessary to sufficiently secure the contact length with the tread plate 41 to increase the friction, and the locking hole 43 reaches the vicinity of the upper surface of the tread plate. For this reason, it is necessary to prevent interference between the shaft 11 and the fixing pin 22, and the locking hole 43 is formed at a position where the fixing pin 22 can pass through the side of the shaft 11. Even when the fixing pin 22 is used as a fastener, as long as sufficient friction can be ensured, it can be driven directly under the shaft 11 as shown in FIG. Even when it is used, it is possible to pass the side of the shaft rod 11 as shown in FIG.

  FIG. 8 shows an example of the structure of the shaft 11, FIG. 8 (A) is the overall shape, FIG. 8 (B) is a cross-sectional view with the components divided, and FIG. It is sectional drawing of the state which carried out. The shaft rod 11 shown in the drawings so far has the fastening means and the recess 14 integrally formed, but in this figure, it is divided into a main body 25 and an attachment portion 26 and is integrated by a bolt 27. It has a structure. A concave portion 14 having a semicircular cross section is formed at the boundary between the main body 25 and the attachment portion 26.

It is a perspective view which shows the structural example of the staircase by this invention. It is a perspective view which shows the state which attached the tread board to the climbing beam after FIG. It is a perspective view which shows the form which has arrange | positioned the step board above two parallel climbing beams. It is a perspective view which shows the state which attached the tread board to the climbing beam after FIG. It is a perspective view which shows the form which has arrange | positioned the tread board above the parallel two-line climbing beam similarly to FIG. It is a perspective view which shows the state which attached the tread board to the climbing beam after FIG. The relationship between the fastener and the recess is shown in cross section, (A) uses a set screw as the fastener, (B) uses a set screw as the fastener, and takes measures to prevent it from coming off , (C) uses a fixing pin as a fastener. The structural example of the shaft bar is shown, (A) is a perspective view showing the overall shape, (B) is a sectional view in a state where the constituent elements are divided, and (C) is a sectional view in an integrated state. .

Explanation of symbols

11 Shaft bar 12 Convex strip (fastening means)
13 Width across flats 14 Recess 15 Hexagon 16 Side hole (fastening means)
18 Drift pin (fastening means)
21 Set screw (fastener)
22 Fixing pin (fastener)
23 Onim nut 25 Main body 26 Attached part 27 Bolt 31 Climbing beam (support member: arranged in a row)
32 Climbing beam (support member: two rows)
33 Holding hole 34 Notch 35 Pin hole 41 Tread plate 42 Horizontal hole 43 Locking hole

Claims (5)

A plurality of footboards (41) arranged obliquely at a predetermined interval;
A support member (31 or 32) for attaching the tread plate (41);
A shaft rod (11) penetrating a horizontal hole (42) formed in the side surface of the tread plate (41) and a holding hole (33) formed in the support member (31 or 32);
In order to integrate the tread plate (41) and the shaft rod (11), a fastener (21 or 22) driven from the upper surface or the lower surface of the tread plate (41);
Consisting of
A plurality of the shaft rods (11) are used for one footboard (41), and one end side is provided with fastening means (12 or 16 and 18) for integrating with the support member (31 or 32), A staircase characterized in that an annular recess (14) for engaging the fastener (21 or 22) is formed on the side peripheral surface in one or more rows on the other end side.   The staircase according to claim 1, wherein the fastening means is a spiral ridge (12) formed on a side peripheral surface of the shaft rod (11).   The fastening means is driven from a side hole (16) penetrating the side peripheral surface of the shaft rod (11) and a pin hole (35) formed in the support member (31 or 32). A staircase according to claim 1, characterized in that it comprises a drift pin (18) penetrating through.   The support member is a row of climbing beams (31) that cantileverly support the tread plate (41), a lateral hole (42) is formed on one side of the short side of the tread plate (41), and the climbing beam (31 The staircase according to claim 1, 2 or 3, wherein a holding hole (33) is formed on one side surface. The supporting members are two rows of climbing beams (32) disposed below the footboard (41), a lateral hole (42) is formed on one side of the long side of the footboard (41), and the climbing beam ( The staircase according to claim 1, 2, or 3, wherein a holding hole (33) is formed in the upper slope of 32).

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