Modular support for staircase steps

Abstract: A modular support for staircase steps comprising a vertical cylindrical body (3) having, at its top, a rigidly coupled horizontal supporting plate (4) for a corresponding step. The cylindrical body (3) is provided with two walls (8) which protrude in a vertically parallel fashion from the cylindrical body (3), below the supporting plate (4). A coupling element (12) is associable with the cylindrical body (3) and forms a sleeve constituted by a vertical cylindrical portion, suitable to duplicate the outer surface of the cylindrical body and from which two vertically parallel wings (14) protrude which are suitable to respectively couple to the walls (8) and to be crossed by screw means (16) for the vise-like clamping of the vertical cylindrical body (3) of an adjacent support.

Description: The present invention relates to a modular support for staircase steps. Staircases of the so-called "independent-structure" type are known whose flights are constituted by a supporting base on which the steps rest. The base is rigidly coupled, at its ends, to the levels to be connected and is preferably provided in a modular manner by a plurality of supports for the individual steps. Said supports in fact allow to vary the orientation of the axis of the flight as desired and to adjust the rise of the steps. A conventional modular support has, for example, a body which forms, in an upward region, a horizontal supporting surface for a corresponding step and two vertical cylindrical elements arranged at different elevations and suitable to couple to complementarily shaped cylindrical elements of the adjacent supports. Said supports are mutually locked in the chosen angular position with suitable screw means. The mutual axial position of the supports, i.e., the so-called rise of the steps of the staircase, is usually adjusted by inserting suitable spacer means. However, the mutual longitudinal position of the steps, i.e., the breadth of the tread, must also be appropriately adjustable so as to optimize the modularity characteristics of the staircase. Obvious aesthetic reasons also generally require the screw means for the mutual locking of the supports to be externally not visible. This requirement, however, makes it difficult to position and lock conventional modular supports, and therefore the installation of the staircase is complicated and expensive. The aim of the present invention is to solve the above problem by providing a modular support for staircase steps which allows to continuously vary the breadth of the tread and the distance between the horizontal surfaces of the steps, without resorting to spacers and the like. Within the scope of this aim, an object of the present invention is to provide a modular support for staircase steps which is simple in concept, easy to manufacture and to assemble, versatile in use and safely reliable. This aim, this object and others which will become apparent hereinafter are achieved, according to the present invention, as defined in claim 1. Further characteristics and advantages of the present invention will become apparent from the following detailed description of a preferred embodiment of the modular support for staircase steps, illustrated only by way of non-limitative example in the accompanying drawings, wherein: Figure 1 is a partially sectional plan view, taken along a horizontal plane, of a portion of a flight of steps provided by the modular supports according to the invention; Figure 2 is a corresponding partially sectional elevation view, taken along the vertical plane II-II of Figure 1; Figure 3 is an enlarged-scale sectional view, taken along the plane III-III of Figure 2, of a portion of the modular support according to the invention. With particular reference to the above figures, the reference numeral 1 generally designates the modular support according to the present invention, meant to support a single step 2 of a flight of steps having an independent structure. The support 1 is constituted by a vertical cylindrical body 3 having a tubular shape and preferably made of metal plate. A horizontal supporting plate 4, also made of metal plate, is rigidly coupled to the top of the cylindrical body 3; said supporting plate 4 has a plurality of ribs 5 running substantially radially to the cylindrical body 3 and holes 6 for the passage of screw means for fixing a corresponding step 2. The cylindrical body 3 is closed in a downward region, in the active configuration, by means of a respective plug 7, preferably made of plastics such as polyethylene. The plug 7 fits snugly in the cylindrical body 3 by pushing and is retained elastically by a plurality of annular ribs 7a. Two vertically parallel walls 8, also made of metal plate and joined to said cylindrical body 3 by welding, extend from the cylindrical body 3 below the supporting plate 4. The walls 8 are substantially tangent to the cylindrical body 3, in diametrically opposite positions which are symmetrical to a median vertical plane of the supporting plate 4. The walls 8 have a respective portion 8a spaced from the cylindrical body 3 and wider than the median vertical plane of the plate 4. A plurality of longitudinal slots 9, three in Figure 2, vertically aligned at different heights, and two suitably spaced square holes 10, are provided on the wider portion 8a. More particularly, the intermediate slot 9a is provided along an expansion 8b of the respective wall 8. Furthermore, the walls 8 have, along their upper and lower margins, edges 11 folded horizontally towards the inside of the support; the edges 11 are suitably shaped like a circular arc at their ends. An element for coupling to an adjacent support 1, generally designated by the reference numeral 12, is associable with the cylindrical body 3 at the walls 8. The coupling element 12 forms a sleeve 13 which is constituted by a vertical cylindrical portion, whose height approximates that of the walls 8 and which is suitable to duplicate the outer surface of the cylindrical body 3; the cylindrical portion substantially covers an arc equal to half a circumference. Two vertically parallel wings 14 protrude from the sleeve 13 along the vertical borders and are suitable to couple respectively to said walls 8 at a respective cambered portion 14a. A plurality of holes 15, three in Figure 2, is provided on said cambered portion 14a. The holes are aligned vertically at different heights so as to match, in assembly position, the slots 9 of the walls 8; more particularly, the intermediate hole 15 which is indicated by 15a is provided on an expansion 14b of the respective wing 14. The slots 9, 9a and the corresponding holes 15, 15a are suitable to be crossed by screw elements 16, 16a constituted in practice by conventional bolts; the first screw element is meant to produce the vise-like clamping of the vertical cylindrical body 3 of an adjacent support and the second screw element is meant to fasten the coupling element 12 to the walls 8. Furthermore, the wings 14 of the coupling element 12 have, along their upper and lower borders, edges 17 folded horizontally towards the inside of the support; the edges 17 are coupled, in assembly position, to the corresponding edges 11 of the walls 8, as shown in detail in Figure 3. The region where the walls 8 are joined to the wings 14 is affected externally by the slots 9 and by the nuts for locking the bolts 16, 16a lying outside said walls 8 and has a concave lateral cover 18 applied thereto; said cover is preferably made of plastics such as polypropylene. The lateral cover 18 has, along a vertical side, a hook-like edge 18a meant to engage the end border of the corresponding wall 8, and also has, on the concave side, two protruding hooks 19 meant to engage said square holes 10 of said wall 8. Finally, the support 1 is closed in a downward region, at the compartment formed between the walls 8 and the wings 14 of the coupling element 12, by a first cover 20 and by a second cover 21 which are partially superimposed and slideable with respect to each other and equally made of plastics such as polypropylene. The first lower cover 20 is substantially applied at the region formed by the wider portion 8a of the walls 8, by means of two hooks 22 which protrude symmetrically on the inner side. The hooks 22 are suitable to engage, in an upward region, the folded edge 17 of the corresponding wing 14 of the coupling element 12, so as to keep a shoulder 20a of said cover 20 in contact with the folded edge 11 of the corresponding wall 8 (Figure 3). The second lower cover 21, slideable over the first cover 20, is applied at the region that is adjacent to the cylindrical body 3, between the walls 8, by means of a corresponding pair of hooks 23 protruding symmetrically from the inner side and suitable to engage in an upward region the folded edge 11 of the corresponding wall 8. The coupling element 12 allows to quickly and easily mutually join the modular supports 1 to form the chosen flight of steps. For this purpose, the cylindrical body 3 of each modular support 1 is axially inserted in the sleeve 13 formed by the coupling element 12 of the underlying support and is then clamped in a vise-like fashion by means of the wings 14 of said coupling element 12, which are stably coupled in the position for assembly to the corresponding walls 8. It is possible to continuously adjust the breadth of the tread, i.e., the longitudinal distance between one step and the next, by means of the slots 9, 9a which allow the mutual sliding of the wings 14 of the supporting element 12 with respect to the walls 8 that are coupled thereto, before locking by means of the screw elements 16a and, indirectly, 16. It should be noted that during the sliding of the wings 14 of the supporting element 12 with respect to the walls 8 that are coupled thereto, the second lower cover 21 in turn slides above the first cover 20, keeping closed the compartment formed between said walls 8. Preferably, in order to allow a greater possibility to adjust the breadth of the tread, the walls 8 to be welded to the cylindrical body 3 are provided in two different longitudinal dimensions to be used alternatively according to the type of flight of steps to be obtained. In this case, the second lower cover 21, produced with the larger longitudinal dimension, has, in a median position, a transverse fracture line 24 which allows to reduce said cover 21 to the smaller longitudinal dimension in relation to the dimensions of the walls 8 that are used. The fact is stressed that the mutual locking of said adjacent modular supports 1 is achieved simply by means of the two screw elements 16, constituted in practice by conventional bolts, which can be easily inserted through the slots 9 and the holes 15 of said supports. Before fully tightening the screw elements 16 and 16a, the angular position of the steps 2 is adjusted in the chosen manner by angularly rotating the corresponding cylindrical body 3 as shown by the dashed line 4a in Figure 1 with reference to the position of the supporting plate 4 of a corresponding step, and the distance between the horizontal surfaces of the steps 2, i.e., the rise, is also adjusted by axially moving the cylindrical body 3 with respect to the sleeve 13 of the underlying coupling element 12. The modular support for steps of staircases allows, in summary, to continuously vary the breadth of the tread and the distance between the horizontal surfaces of the steps, as well as their angular position, without resorting to spacers and the like. The modular support according to the present invention has a very simple structure both from the constructive and from the functional point of view, with proportionally reduced production and assembly costs. Moreover, the application of the lateral covers 18 and of the lower covers 20 and 21, as well as of the plug 7 for closing the cylindrical body 3, allows to conceal all the coupling elements. In the practical embodiment of the present invention, the materials employed, as well as the shapes and the dimensions, may be any according to requirements. Where technical features mentioned in any claim are followed by reference signs, those reference signs have been included for the sole purpose of increasing the intelligibility of the claims and accordingly, such reference signs do not have any limiting effect on the interpretation of each element identified by way of example by such reference signs.

Claims: A modular support for staircase steps, characterized in that it comprises a vertical cylindrical body (3) which has, at its top, a rigidly coupled horizontal supporting plate (4) for a corresponding step and is provided with two walls (8) which protrude in a vertically parallel fashion from said cylindrical body (3), below said supporting plate (4); and a coupling element (12) which forms a sleeve constituted by a vertical cylindrical portion, suitable to duplicate the outer surface of said cylindrical body and from which two vertically parallel wings (14) protrude which are suitable to respectively couple to said walls (8) and to be crossed by screw means (16) for the vise-like clamping of the vertical cylindrical body (3) of an adjacent support, and in that said walls (8) have a plurality of longitudinal slots (9) provided therein, said slots (9) being vertically aligned at different heights, at respective holes (15) provided on said wings (14) of said coupling element, and being meant to be crossed in an adjustable position by said locking screw means (16). The support according to claim 1, characterized in that said slots (9) are formed on a portion of said walls (8) spaced from said cylindrical body (3) and wider with respect to a median vertical plane. The support according to claim 1, characterized in that said walls (8) have, along their upper and lower borders, edges (11) folded horizontally inward and shaped at the ends so as to form an arc-like concavity. The support according to claim 1, characterized in that said wings (14) of said coupling element have, along their upper and lower borders, edges (11) which are folded horizontally inward and are suitable to be coupled in the assembly position to corresponding folded edges of said walls. The support according to claim 1, characterized in that a concave lateral cover (18) made of plastics is suitable to be applied to said walls (8) at a region where joining to said wings (14) occurs. The support according to claim 5, characterized in that said lateral cover has (18), along one side, a hook-like edge (18a) meant to engage the end border of said corresponding wall (8) and having, on the side of the concavity, two protruding hooks (19) meant to engage corresponding holes (10) formed in said wall (8). The support according to claim 1, characterized in that it has a first lower cover (20) applied at a region formed by a wider portion (8a) of said walls (8) which is spaced from said cylindrical body (3) and is coupled to said wings (14) of said coupling element, and a second lower cover (21) slideable over said first cover and applied at a region which is adjacent to said cylindrical body (3) between said walls (8). The support according to claim 7, characterized in that said first lower cover (20) has two hooks (22) which protrude symmetrically from the inner side and are suitable to engage, in an upward region, a folded edge (17) of said wings (14) of said coupling element (12). The support according to claim 7, characterized in that said second lower cover (21) has two hooks (23) which protrude symmetrically from the inner side and are suitable to engage, in an upward region, a folded edge (11) of said corresponding wall (8). The support according to claim 1, characterized in that said cylindrical body (3) is closed in a downward region, in the active configuration, by means of a plug (7) which is made of plastics and fits snugly by pushing in said cylindrical body and is retained elastically by means of a plurality of annular ribs (7a).

Inventors: DENICOLO' PIERO, DENICOLO', PIERO
Applicants: ALBINI & FONTANOT SPA, ALBINI & FONTANOT S.P.A.
Application year: 1998
Main classification: E04F11
IPC codes: E04F11