Element for a modular stair stringer

Abstract

The application relates to an element for a modular stair stringer, comprising a rectangular element (1), wherein the element (1) has a first side wall (2), a second side wall (3) opposite the first side wall, a base wall (4), and a top wall (5) opposite the base wall (4), and wherein the element (1) has an open front (6) and an open back (7). According to the invention, an insertion opening (8) for a tread (10) is arranged in the first side wall (2), wherein at least one flexible tab (9) for fastening the tread (10) is arranged on the side of the insertion opening (8) facing the base wall (4). The application further relates to steps, stair stringers, and stairs comprising at least one such element.

Description

[0001] The present invention relates to an element for a modular stair stringer.

[0002] Staircases are often offered as kits to enable cost-effective construction. A kit should also be relatively quick and easy to assemble at the desired location, even for experienced DIYers. It is important that the kit allows for easy adjustment of the staircase to the floor height and ensures stability along its entire height. Furthermore, the kit must allow for adjustment to the width of the existing ceiling opening. Since a staircase significantly influences the visual impact of a room, it is also important that the kit can be easily adapted to the design of the installation site and that assembly elements, such as screws and mounting holes, are as inconspicuous as possible.

[0003] Stringer stairs, where each tread is supported laterally by a stringer, are particularly stable. Various modular stringer stairs are known from current technology: DE 19523573 A1, for example, shows a stringer segment for a modular stringer staircase. Individual adaptation at the installation site is not possible with this system. DE 202011002694 U1 also shows a modular stringer staircase for the construction of industrial plants. The treads are placed on the stringer elements and screwed in laterally. A disadvantage of this system is that all screws are visible and individual customization of the staircase is not possible.

[0004] The object of the present invention is therefore to provide an element for a modular stair stringer that makes it possible to quickly and easily adapt and assemble a cost-effective staircase without visible mounting elements to the respective installation site.

[0005] This problem is solved in an element for a modular stair stringer, comprising a first side wall, a second side wall opposite the first side wall, a base wall arranged at a lower end of the side walls and a cover wall arranged at an upper end of the side walls and aligned parallel to the base wall, wherein the interior space of the element surrounded by the walls is hollow, by providing an insertion opening in the first side wall for inserting an end area of ​​a tread plate into the interior space, wherein at least one bendable tab for fastening the tread plate is provided at the insertion opening.

[0006] This element allows for individual adjustment of the stair width, as the steps can be cut to size. The cut is concealed within the element when the staircase is finished. The element can be used with a wide variety of treads, enabling customization to the spatial and aesthetic requirements of the installation site. All screws for connecting multiple elements to form a stringer can be concealed within the elements and are therefore not visible in the finished staircase.

[0007] The element according to the invention thus enables a quick and easy individual adaptation of a cost-effective staircase to the respective installation location.

[0008] Advantageous embodiments of the element are described in the dependent claims.

[0009] The element can be manufactured particularly cost-effectively if it is made from a rectangular hollow profile, open at each end. The tab and the insertion opening, as well as optionally further slots or holes, can be produced, for example, by milling.

[0010] The element is particularly stable when the first side wall and the second side wall are arranged parallel to each other, with the base wall and the top wall being arranged at right angles to the side walls, and in particular being aligned with each other.

[0011] The stability of the element is particularly high if at least the side walls, the base wall and the top wall are made of metal, especially if the element itself is made of metal.

[0012] An element is particularly easy to assemble and particularly stable if the insertion opening is at least partially aligned parallel to the top wall and the base wall.

[0013] Particularly cost-effective manufacturing is possible if the insertion opening is formed by a slot.A staircase is particularly stable if the slot has a straight central slot area, wherein a front slot area is arranged at a front end of the central slot area and a rear slot area is arranged at a rear end of the central slot area, wherein the central slot areas are converging or parallel to each other, and wherein a front slot end area is formed at the lower end of the front slot area, arranged parallel to the central slot area, with the front slot end area extending from the front slot area towards the rear of the element, and / or wherein a rear slot end area is formed at the lower end of the rear slot area, arranged parallel to the central slot area, with the rear slot end area extending from the rear slot area towards the front of the element.

[0014] The element is particularly stable and easy to adapt if the slot area is arranged parallel to the top wall and the front slot area and the rear slot area each extend towards the base wall and are preferably aligned parallel to each other.

[0015] To allow the element to be used with different tread plates, a bend can be formed between the front and rear ends of the slot to enlarge the insertion opening. In this case, the area surrounded by the slot can be bent outwards along the bend. The insertion opening then has a uniform height along its entire length, corresponding to the distance between the center of the slot and the front or rear end. This allows the element to be used with tread plates made of metal, wood, plastic, wood-plastic composite, grating, stone, and other materials.

[0016] To ensure particularly stable mounting of the footplate, a front tab can be formed adjacent to the front end of the slot, and / or a rear tab can be formed adjacent to the rear end of the slot. A particularly cost-effective and simple design is one in which the tab is formed by extending the slot of the insertion opening. In this case, the insertion opening and at least one tab are formed by a common slot. The mounting is especially stable when both a front and a rear tab are formed.

[0017] To enable a visually unobtrusive and simple installation, it is particularly advantageous if the tabs are arranged on the side of the insertion opening closer to the base wall.

[0018] Particularly cost-effective production of the element is possible if the element is made from a hollow profile that is open at each end.

[0019] To improve the overall visual appearance and prevent loose clothing or similar items from getting caught in the element when using the stairs, a front cover can be included to cover the front of the element and / or a back cover to cover the back. A particularly stable and simple way to attach the cover is to hold the front and / or back cover to the element using at least one magnetic retaining element.

[0020] To prevent the cover from slipping, corresponding projections and recesses can be formed on the cover and the front of the element or on the cover and the back of the element, wherein in particular at least two projections and two recesses are formed on the front and / or two projections and two recesses are formed on the back.

[0021] In order to make it particularly easy to connect the element to another element, the element can have at least one upper mounting hole, in particular several upper mounting holes, in the rear area of ​​the cover wall adjacent to the rear and at least one lower mounting hole, in particular several mounting holes, in the front area of ​​the base wall adjacent to the front.

[0022] To allow for individual adjustment of the stair tread depth, the upper mounting hole(s) or the lower mounting hole(s) can be designed as several, preferably partially overlapping, round bores. This allows for individual determination of how far the base wall of the upper element is positioned above the top wall of the lower element, or how far the elements are offset from each other.

[0023] To enable quick and easy railing assembly, the element can have an upper rear through-hole for attaching a baluster in the rear section of the cover wall adjacent to the back, an upper front through-hole in the front section of the cover wall adjacent to the front, and a lower through-hole opposite the upper front through-hole in the base wall. When the element is connected to another element to construct a stair stringer, the upper front and lower through-holes of the upper element and the upper rear through-hole of the lower element are aligned, and the baluster is inserted through the through-holes until it rests against the base wall of the lower element. Because the baluster is held in place at least at two points, it is secured against tipping without any further fastening.

[0024] To achieve a particularly stable fastening, the upper rear through-hole is preferably arranged between the upper mounting holes and the lower through-hole is preferably arranged between the lower mounting holes.

[0025] To allow for individual adjustment of the step depth, either the upper rear through-hole or the lower through-hole can be extended relative to the other of the two through-holes. The position of the upper element relative to the lower element can therefore be shifted within the limits of this extension.

[0026] The invention further relates to a step for a staircase. The step according to the invention comprises two elements described above, as well as a tread plate, wherein a left element is arranged to the left of the tread plate and a right element is arranged to the right of the tread plate, the first side wall of the right element being arranged symmetrically to the first side wall of the left element. The insertion openings of the elements are thus facing each other and are arranged opposite each other, the tread plate is inserted into the insertion openings and is attached to each element by means of at least one tab.

[0027] Furthermore, the invention also relates to a stair stringer. The stair stringer according to the invention comprises at least two elements as described above, wherein the elements are arranged offset one above the other, with the base wall of the upper element partially overlapping the top wall of the lower element. To create a particularly stable connection, the lower mounting holes of the upper element and the upper mounting holes of the lower element can be aligned with each other. Preferably, the upper element and the lower element are connected by fasteners passing through the mounting holes.

[0028] To make adjusting the stair pitch particularly easy, the stringer can have a spacer between the top wall of the lower element and the base wall of the upper element. A spacer designed according to patent AT 526,336 B1 is particularly advantageous. Such a spacer has a base body and at least one first spacer body, wherein the first spacer body is separated from the base body by a first gap extending over the entire wall thickness of the spacer and is connected to the base body by at least one web. In this case, the height of the spacer can be varied particularly easily by removing the spacer body.

[0029] According to the invention, a stair stringer, in particular a stair stringer as previously described, further comprises at least a first side wall, a second side wall opposite the first side wall, a base wall arranged at a lower end of the side walls, and a cover wall arranged at an upper end of the side walls, wherein the interior space enclosed by the walls is hollow, and wherein an insertion opening for inserting an end portion of a tread plate into the interior space is arranged in the first side wall, and wherein a through-opening for inserting a baluster is formed in the cover wall, the through-opening being arranged above the insertion opening. In such a stair stringer, a baluster can be fixed without additional screws if it is inserted through the through-opening and clamped by a tread plate inserted into and secured in the insertion opening.

[0030] A baluster can be attached particularly securely if the stair stringer comprises an upper element and a lower element as previously described, wherein each element has an upper, rear through-hole in the top wall for inserting a baluster and an upper, front through-hole for inserting a baluster, the upper front through-hole being located above the insertion opening, and wherein a lower through-hole opposite the upper, front through-hole is formed in the base wall, the elements being arranged offset one above the other, the base wall of the upper element being partially aligned with and connected to the top wall of the lower element, and the upper, front through-hole and the lower through-hole of the upper element being aligned with the upper, rear through-hole of the lower element.

[0031] According to the invention, a staircase further comprises at least two previously described steps, wherein the steps are arranged offset one above the other, wherein the staircase has a left stringer as previously described, the left stringer comprising the left element of the lower step and the left element of the upper step, and wherein the staircase has a right stringer as previously described, the right stringer comprising the right element of the lower step and the right element of the upper step. Such a staircase can be customized particularly easily. The treads can be cut quickly and easily, since the end areas of the treads are not visible after insertion into the slots, so that an imprecise cut does not impair either the stability or the overall visual appearance of the staircase. In addition, the rise and tread of the staircase can be adjusted quickly and easily.

[0032] To improve safety, the staircase can include at least one baluster. To enable quick and easy assembly, the baluster can be inserted through the upper front through-hole of the upper element, through the lower through-hole of the upper element, and through the upper rear through-hole of the lower element. The baluster has a lateral fixing slot, and the tread is inserted into the fixing slot of the lower element through the insertion opening to secure the baluster. The baluster is thus stable without any further fixings.

[0033] To ensure optimal adaptation of the staircase to its installation location, it can include a landing. This makes the assembly and adjustment of a quarter-turn or half-turn staircase quick and easy.

[0034] Preferably, the platform comprises at least two previously described elements as platform elements, wherein a left platform element is arranged offset above the left element of the step below and a right platform element is arranged offset above the right element of the step below, and wherein a tread plate with its lateral tread plate end regions is inserted into the insertion opening of the left platform element and the right platform element and connected to the platform elements via the tab.

[0035] To facilitate easy size adjustment of the platform, the platform element can have plug-in connectors on its front for connecting to other platform elements. These connectors correspond to plug-in connectors located on the back of the platform element. If the platform is composed of several left and several right platform elements, the platform elements on one side can be connected to each other, with the front of one platform element adjacent to the back of the next, and the platform elements connected via the corresponding plug-in connectors. Additionally or alternatively, the platform element can have at least one lateral mounting hole in at least one side wall for attaching a reinforcement element.In this case, the platform elements on one side can be connected along their side walls by a reinforcing element, such as a flat band. This makes assembling and adapting the platform to its installation site particularly easy.

[0036] To avoid gaps between the platform treads, the insertion opening of the platform element can extend almost the entire length of the element, with a front stabilizing rib adjacent to the front and a rear stabilizing rib adjacent to the back. In this case, the distance between the treads of two adjacent platform elements corresponds to the width of the front and rear stabilizing ribs. A particularly simple staircase construction is possible if the length of the insertion opening of the platform element matches the length of the insertion opening of the element itself. This allows the treads to be used for both the platform and the steps.

[0037] The invention is shown schematically in the drawings below with reference to particularly advantageous, but not limiting, embodiments and is described by way of example with reference to the drawings: Fig. 1a shows an example element. Fig. 1b shows the element from Fig. 1a with bent tabs. Fig. Figure 2 shows another embodiment of the element with a front cover. Fig. Figure 3 shows a section of an example staircase from below. Fig. Figure 4 shows a section of an exemplary staircase in an oblique view from above. Fig. Figure 5 shows the section of the staircase. Fig. 4 from the outside. Fig. Figure 6 shows a section of an exemplary staircase with a landing in an oblique view from above.

[0038] Fig. Figure 1a shows an exemplary element 1. Element 1 has a first side wall 2 and a second side wall 3 parallel to the first side wall 2 and opposite it. At the lower end of the side walls 2 and 3, a base wall 4 is arranged, oriented at right angles to the side walls 2 and 3. At the upper end of the side walls 2 and 3, element 1 has a top wall 5 parallel to the base wall 4 and opposite it. The interior of element 1, enclosed by walls 2, 3, 4, and 5, is hollow. Element 1 is open at the front 6 and the back 7. The front 6 is bounded laterally by the front edges of walls 2, 3, 4, and 5, and the back 7 is bounded laterally by the rear edges of walls 2, 3, 4, and 5.

[0039] The first side wall 2 and the second side wall 3 have the same height, which corresponds to the height of element 1. In the illustrated embodiment, side walls 2 and 3 are each 160 mm high. The base wall 4 and the top wall 5 have the same width, which corresponds to the width of element 1. In the illustrated embodiment, the base wall 4 and the top wall 5 are each 60 mm wide. In the illustrated embodiment, all walls 2, 3, 4, and 5 have a uniform length of 381 mm, which corresponds to the length of element 1. The height of side walls 2 and 3 is greater than the width of the base wall 4 and the top wall 5. The walls 2, 3, 4, and 5 have a substantially uniform material thickness.

[0040] In the illustrated embodiment, element 1 consists of metal and is made from a hollow profile that is open at each end.

[0041] In the rear section of the cover wall 5, adjacent to the back, four upper mounting holes 17 are arranged, each formed in the illustrated embodiment as several overlapping circular bores. Between the upper mounting holes 17 is an upper rear through-hole 14 into which a railing post 13 can be inserted. An upper front through-hole 15 is arranged in the front end section of the cover wall 5. In the illustrated embodiment, the upper rear through-hole 14 has a greater length than the upper front through-hole 15; its extent along the length of the element 1 is therefore greater.

[0042] The first side wall 2 has an insertion opening 8 for inserting the lateral end section of a footplate 10. The insertion opening 8 is formed by a slot. In the illustrated embodiment, the slot has a thickness of 3 mm. This thickness allows the insertion of a metal footplate 10.

[0043] In Fig. Figure 1b shows that the slot has a straight central slot region 27, which is arranged parallel to the top wall 5. At the front end of the central slot region 27, which is closest to the front wall 6, a front slot region 28 is arranged, extending towards the base wall 4. Parallel to the front slot region 28, at the rear end of the central slot region 27, which is closer to the rear wall 7, a rear slot region 29 is arranged, also extending towards the base wall 4. At the lower end of the front slot region 28, a front slot end region 30 is formed, arranged parallel to the central slot region 27. At the lower end of the rear slot region 29, a rear slot end region 31 is formed, arranged parallel to the central slot region 27.

[0044] In the illustrated embodiment, the insertion opening 8 has a length of 241 mm, which corresponds to the length of the slot center section 27. The height of the insertion opening 8, which corresponds to the distance between the slot center section 27 and the front slot end section 30 or the rear slot end section 31, is 37.7 mm in the illustrated embodiment.

[0045] In the illustrated embodiment, the insertion opening 8 is located in the front upper region of the first side wall 2. In the illustrated embodiment, the insertion opening 8 is 7 mm away from the front 6 and 7 mm away from the top wall 5.

[0046] In the illustrated embodiment, two tabs 9 are formed for attaching a footplate 10. The tabs 9 are formed by extending the slot through which the insertion opening 8 is formed. The insertion opening 8 and the tabs 9 are thus formed by a single slot. The front slot end region 30 adjoins the front tab 9, and the rear slot end region 31 adjoins the rear tab 9. In the illustrated embodiment, two tabs 9 are thus formed, which are arranged on the side of the insertion opening 8 facing the base wall 4.

[0047] In Fig. 1 b the tabs 9 are bent outwards to make it easy to attach the footplate 10 to the element 1.

[0048] Fig. Figure 2 shows an alternative embodiment of an exemplary element 1 with a front cover 11. The element 1 has a projection 22 at the front end of the cover wall 5 and at the front end of the base wall 4 for positioning the cover 11, and the cover 11 has recesses 23 corresponding to the projections 22. In the illustrated embodiment, the element 1 includes magnetic retaining elements 12 for securing the front cover 11. In the illustrated embodiment, the cover 11 and the element 1 are made of metal. The magnetic retaining elements 12 are inserted inside the element 1 between the cover and the element and fix the cover 11 to the element 1.

[0049] The in Fig. The embodiment of element 1 shown in Figure 2 differs from the one shown in Figure 2. Fig. 1a and Fig. In the embodiment shown in 1b, this is due to the shape of the insertion opening 8 and the tabs 9. In the embodiment shown in Fig. In the embodiment shown in Figure 2, the slot between the front slot area 28 and the front tab 9 is widened, as is the slot between the rear slot area 29 and the rear tab 9. A fold line is formed between the front slot end area 30 and the rear slot end area 31. The area between the tabs 9 and the slot center area 27 can be bent outwards along this fold line. In this case, the insertion opening 8 is suitable for both thin tread plates, for example made of metal plates, and thicker tread plates, for example made of metal mesh, wood, or other materials.

[0050] Fig. Figure 3 shows a section of an exemplary staircase from below. The staircase has two exemplary elements 1, which are connected to each other via a spacer 19. The elements 1 are arranged one above the other, offset from each other, with the base wall 4 of the upper element 1 partially aligned with the top wall 5 of the lower element 1. To connect the elements 1, four lower mounting holes 18 are formed in the front area of ​​the base wall 4. The lower mounting holes 18 of the upper element 1 are aligned with the four upper mounting holes 17 of the lower element 1. The elements 1 are connected by screws. To simplify the fastening of the screws, four mounting holes 32 are formed in the base wall 4 opposite the upper mounting holes 17.

[0051] A tread plate 10 is inserted into each of the insertion openings 8 of the first side wall 2 of the elements 1. In the illustrated embodiment, the tread plates 10 are made of metal. The tread surface of the tread plate 10 is arranged in the central slot area 27.

[0052] Fig. 4 shows a section of a staircase, which in addition to the Fig. The railing post 13 has the features described in section 3. The railing post 13 is inserted through the upper front through-hole 15 and the lower through-hole 16 of the upper element 1 and the upper rear through-hole 14 of the lower element 1.

[0053] Fig. Figure 5 shows that the railing post 13 has a lateral mounting slot 21 and the footplate 10 is inserted into the mounting slot 21. The railing post 13 is therefore clamped and fixed by the footplate 10.

[0054] Fig. Figure 5 further shows that the spacer 19 in the illustrated embodiment has a base body and several spacer bodies, wherein the first spacer body is separated from the base body by a first gap 20 extending over the entire wall thickness of the spacer 19 and is connected to the base body by at least one web.

[0055] Fig. Figure 6 shows a section of an exemplary staircase with a landing. The landing comprises treads 10 and landing elements 24. The landing elements 24 have a first side wall, a second side wall parallel to the first side wall, a base wall arranged at the lower end of the side walls, and a top wall arranged at the upper end of the side walls, wherein the interior space of the landing elements 24 enclosed by the walls is hollow. In the illustrated embodiment, the landing elements 24 are made of hollow profiles that are open at each end and consist of metal.

[0056] The platform elements 24 have insertion openings 8 into which the tread plates 10 are inserted. Flexible tabs are arranged in the lower area of ​​the insertion openings 8, which are located in the Fig. 6 are not recognizable. The footplates 10 are attached to the platform elements 24 via the tabs. In the illustrated embodiment, the insertion openings 8 of the platform elements 24 extend almost over the entire length of the platform elements 24, with a front stabilizing rib forming adjacent to the front of each platform element 24 and a rear stabilizing rib forming adjacent to each rear of the platform elements 24, so that there is only a small gap between the individual footplates 10, corresponding to the combined width of a front and a rear stabilizing rib.

[0057] In the illustrated embodiment, the platform comprises four platform elements 24 on each side of the staircase. These four platform elements 24 are connected by corresponding plug-in elements formed on the front and back of the platform elements. Additionally, the platform elements are connected to each other by a flat band 25 screwed onto the outer side walls of the platform elements 24.

[0058] The size of the platform can be adjusted via the number of platform elements (24) and the length of the stepping stones (10).

[0059] In the illustrated embodiment, the last step below the landing is arranged at a right angle to the first step above the landing, so that the direction changes by 90° when ascending the stairs. In the illustrated embodiment, the staircase is thus designed as a quarter-turn staircase.

[0060] The platform elements 24 adjoining the last step below the platform, or their base walls, are in the illustrated embodiment partially overlapping a part of the cover wall 5 of the elements 1 of the lower step and are connected to the cover wall 5 by screws.

[0061] The elements 1 of the first stage, arranged directly above the platform, are positioned transversely to the platform elements 24. The front portion of the base wall 4 of the elements 1 is aligned with a portion of the top wall of the respective platform element 24 below and, in the illustrated embodiment, rests on the platform element 24 below. The elements 1 arranged directly above the platform are additionally fastened to the side walls of the respective platform elements 24 below by means of an angle iron 26 and are thereby stabilized.

[0062] The elements shown thus allow for the quick and easy construction of a cost-effective staircase that can be individually adapted to the installation site. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] DE 19523573 A1

[0003] DE 202011002694 U1

[0003] AT 526.336 B1

[0028]

Claims

[1] Element (1) for a modular stair stringer, comprising a first side wall (2), a second side wall (3) opposite the first side wall (2), a base wall (4) arranged at a lower end of the side walls (2,3) and a top wall (5) arranged at an upper end of the side walls (2,3) and aligned parallel to the base wall (4), wherein the interior space of the element (1) surrounded by the walls (2,3,4,5) is hollow, characterized by , that in the first side wall (2) an insertion opening (8) for inserting an end area of ​​a footplate (10) into the interior is arranged, wherein at least one flexible tab (9) for fastening the footplate (10) is arranged at the insertion opening (8). [2] Element (1) according to claim 1, wherein the insertion opening (8) is formed by a slot having a straight slot center region (27), wherein a front slot region (28) is arranged at a front end of the slot center region (27) and a rear slot region (29) is arranged at a rear end of the slot center region (27), wherein the slot center regions (28, 29) are converging or parallel to each other, and wherein a front slot end region (30) arranged parallel to the slot center region (27) is formed at the lower end of the front slot region (28), the front slot end region (30) extending from the front slot region (28) towards the rear (7) of the element (1), and / or wherein a rear slot end region (31) arranged parallel to the slot center region (27) is formed at the lower end of the rear slot region (29),wherein the rear slot end region (31) extends from the rear slot region (29) towards the front (6) of the element (1), wherein in particular it is provided that a kink line is formed between the front slot end region (30) and the rear slot end region (31) to enlarge the insertion opening (8). [3] Element (1) according to claim 2, wherein a front tab (9) is formed adjacent to the front slot end region (30), and / or wherein a rear tab (9) is formed adjacent to the rear slot end region (31). [4] Element (1) according to one of claims 1 to 3, wherein the element is made from a hollow profile open at each end face, wherein it is particularly provided that a front cover (11) for covering the front (6) and / or a rear cover for covering the back (7) of the element (1) is included, wherein it is preferably provided that the front cover (11) and / or the rear cover is held on the element (1) by means of at least one magnetic retaining element (12). [5] Element (1) according to one of claims 1 to 4, wherein the element (1) has an upper, rear through-hole (14) in the rear area of ​​the cover wall (5) adjoining the rear (7) for fastening a railing bar (13), an upper, rear through-hole (14) in the front area of ​​the cover wall (5) adjoining the front (6), an upper, front through-hole (15) and a lower through-hole (16) opposite the upper, front through-hole (15) in the base wall (4). [6] Element (1) according to one of claims 1 to 5, wherein the element (1) for connecting with further identically designed elements (1) has at least one upper mounting hole (17), in particular several upper mounting holes (17), in the rear area of ​​the cover wall (5) adjoining the rear (7), and has at least one lower mounting hole (18), in particular several mounting holes (18), in the front area of ​​the base wall (4) adjoining the front (6), wherein it is particularly provided that the upper mounting hole (17) or the lower mounting hole (18) is designed in the form of several, preferably overlapping, round bores. [7] Step comprising two elements (1) according to one of claims 1 to 6, and a tread plate (10), wherein a left element (1) is arranged to the left of the tread plate (10) and a right element (1) is arranged to the right of the tread plate, wherein the first side wall (2) of the right element (1) is arranged in a mirror-symmetrical manner to the first side wall (2) of the left element (1), wherein the insertion openings (8) of the elements are facing each other and are arranged opposite each other, and wherein the tread plate (10) is inserted into the insertion openings (8) and is attached to the element (1) via the at least one tab (9). [8] Stair stringer comprising at least two elements according to any one of claims 1 to 7, wherein the elements (1) are arranged offset one above the other, wherein the base wall (4) of the upper element (1) is partially aligned with the top wall (5) of the lower element (1), wherein it is particularly provided that the lower fastening holes (18) of the upper element (1) and the upper fastening holes (17) of the lower element (1) are aligned with each other, wherein it is preferably provided that the upper element (1) and the lower element (1) are connected by fastening elements guided through the fastening holes (17, 18). [9] Stair stringer according to claim 8, wherein a spacer (19) is arranged between the top wall (5) of the lower element (1) and the base wall (4) of the upper element (1). [10] Stair stringer, in particular according to claim 8 or 9, comprising at least a first side wall (2), a second side wall (3) opposite the first side wall (2), a base wall (4) arranged at a lower end of the side walls (2, 3) and a cover wall (5) arranged at an upper end of the side walls (2, 3), wherein the interior space (1) surrounded by the walls (2, 3, 4, 5) is hollow, and wherein an insertion opening (8) for inserting an end portion of a tread plate (10) into the interior space is arranged in the first side wall (2), and wherein a through-hole (15) for inserting a baluster (13) is formed in the cover wall (5), wherein the through-hole (15) is arranged above the insertion opening (8). [11] Stair stringer according to one of claims 8 to 10, comprising an upper element (1) and a lower element (1), wherein the elements (1) each have in the cover wall (5) an upper, rear through-hole (14) for inserting a baluster (13) and an upper, front through-hole (15) for inserting a baluster (13), wherein the upper front through-hole is arranged above the insertion opening (8), and wherein a lower through-hole (16) opposite the upper, front through-hole (15) is formed in the base wall (4), wherein the elements (1) are arranged offset one above the other, wherein the base wall (14) of the upper element (1) is arranged partially in alignment with and connected to the cover wall (5) of the lower element (1), wherein the upper, front through-hole (15) and the lower through-hole (16) of the upper element (1) are arranged in alignment with the upper,are arranged in the rear through-hole (14) of the lower element (1). [12] Staircase comprising at least two steps according to claim 7, wherein the steps are arranged offset above one another, wherein the staircase has a left stringer according to any one of claims 8 to 11, wherein the left stringer comprises the left element (1) of the lower step and the left element (1) of the upper step, and wherein the staircase has a right stringer according to any one of claims 8 to 11, wherein the right stringer comprises the right element (1) of the lower step and the right element (1) of the upper step. [13] Staircase according to claim 12, comprising at least one baluster (13), wherein the baluster (13) is inserted through the upper, front through-hole (15) of the upper element (1), through the lower through-hole (16) of the upper element (1) and through the upper, rear through-hole (14) of the lower element (1), wherein the baluster (13) has a lateral fixing slot, and wherein the tread plate (10) is inserted through the insertion opening (8) of the lower element (1) into the fixing slot for fixing the baluster (13). [14] Staircase according to one of claims 12 or 13, wherein the staircase comprises a landing, wherein it is particularly provided that the landing comprises at least one element according to one of claims 1 to 5 as a landing element (24), wherein it is preferably provided that the landing element (24) has plug-in elements on its front (6) for connecting with further landing elements (24), which are designed corresponding to plug-in elements arranged on the rear (7) of the landing element (24), and / or wherein the landing element (24) has at least one lateral fastening hole in at least one side wall for fastening a reinforcement element for connecting with further landing elements (24). [15] Staircase according to claim 14, wherein the insertion opening (8) of the platform element (24) extends over almost the entire length of the platform element (24), wherein a front stabilizing rib is formed adjacent to the front (6) and a rear stabilizing rib is formed adjacent to the rear (7).

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