FR3066516A1 - HEXAGONAL HELICOIDAL STAIRCASE STAIRCASE MODULE, TOGETHER WITH AT LEAST ONE SUCH MODULE AND STAIRCASE COMPRISING AT LEAST ONE SUCH ASSEMBLY - Google Patents

Abstract

The module (1) for a modular hexagonal spiral staircase, with six vertical corner uprights around a vertical central upright, comprises a vertical central post (2) and two horizontal triangular steps (3, 4), one of which is low and one high, secured to the central post (2), a stringer (7) and two corner posts (10, 11) parallel to the central post (2), and one of which said front corner post (10) ) is integral with the stringer (7) and the low step (3), and the other said rear corner post (11) is integral with the stringer (7) and the top step (4), the three poles (2, 10, 11) of the module each having a female end and a male end adapted to receive a male end and to be received in a female end of the identical module posts (1) to contribute with the latter to the constitution of the amount central and corner uprights of the stairs.

Description

STAIRCASE MODULE FOR HELICOID SECTIONAL STAIRCASE

HEXAGONAL, ASSEMBLY WITH AT LEAST ONE SUCH MODULE AND STAIRCASE COMPRISING AT LEAST ONE SUCH ASSEMBLY

The invention relates to the field of modular helical or rotating staircases, indoor or outdoor, allowing the movement of people between a low area and a high area of staircase installation, which is not of the integrated type. or associated with scaffolding, and, in general, does not constitute a work station, or is not associated with such a station, but only allows access from the ground, or a low level, to serve a single high level, or vice versa.

More particularly, the invention relates to a helical modular staircase of hexagonal horizontal cross section, which can be mounted, by non-professional people, from a set of modular elements, the set comprising in particular at least one module staircase with two steps, and preferably a plurality of such modules identical to each other, all the modular elements of the assembly allowing the construction of the staircase being light enough to be easily handled by non-specialized personnel for mounting a modular helical staircase with a simple and economical structure, by implementing a simple mounting process using repeated cycles.

The staircase according to the present invention does not have a bassinet or a typing key, as for most scaffolding, and its assembly does not require that the assembly personnel have undergone training, without this compromising safety, during assembly as when using the helical staircase, which is not a temporary staircase.

To this end, the invention provides a staircase module, for a modular helical staircase with a hexagonal horizontal cross section, delimited by six vertical corner posts around a vertical central post, said module comprising a central post with an axis. substantially vertical and two steps of substantially triangular shape, including a low step and a high step, extending in horizontal planes perpendicular to the axis of the central post and radially from said central post, to which the steps are each secured by an edge narrow internal radial end, and which is characterized in that said two steps are each secured by a wide edge of external radial end to a single stringer in the form of a substantially flat plate and parallel to the axis of the post central, the stringer having a lower part and an upper part secured to the edge of the wide edge respectively of the low step and the mar che high, and in that the module comprises two corner posts with axes parallel to the axis of the central post, so that the lower ends of the three posts of the module are in a transverse plane perpendicular to the axes of the three posts of the module, and of which one of the two corner posts, called the front corner post, is integral with the lower part of the stringer at the front end of the latter, from the nose of the low step to its external radial end, and the wide edge of the bottom step, at its front end, and the other corner post, said rear corner post is integral with the upper part of the stringer at the rear end of the latter, the rear edge from the high step at its outer radial end, and from the wide edge of the high step at its rear end, the central post and the two corner posts of the module each comprising a female end and a male end which are respectively suitable for receiving a male end the and to be received in a female end of analogous posts of identical modules with two steps, so as to contribute with said analogous posts to the constitution of said central upright and said staircase uprights.

Advantageously, in an embodiment which provides great resistance for a limited weight, and with great ease of assembly, the stair module is such that the central post and the two corner posts are three identical tubular posts, one to the other, secured to the two steps and to the common stringer, and the upper ends of which each extend by one respectively of three male end pieces, each in the form of a sleeve, retained partially fitted in a corresponding post and partially in protruding above said post, at the upper male end of said corresponding post.

In particular, to limit the weight while favoring a durable mounting of the staircase, the module is advantageously such that the three posts of said module are made of metal or light alloy and joined at least by welding to the steps and to the stringer which are in the same metal or alloy, each of the three male end pieces being a steel sleeve retained, by its lower end part, at least by screwing in a corresponding post, and having a projecting upper end part, above said corresponding post , and preferably pierced with radial screw holes, the lower end part of each post also being pierced with at least one radial screw hole.

Preferably, to facilitate mounting of the modules on each other and on the other modular elements of the staircase, it is advantageous for the male end piece of the front corner post to protrude above the upper end of the corresponding post over a greater height than the male end pieces of the rear corner post and the central post, which are identical and protrude by the same height above the corresponding posts. Thus, a partial engagement of a staircase module or other modular element on this male end piece of the front corner post of a module allows, on the one hand, by rotation about the axis of this post front angle, to pre-orient and preposition more easily another member which is to be mounted on the stair module considered, on the one hand, and, on the other hand, the male end piece of a greater height of the front corner post provides better substantially vertical support for other corner post posts, which are to be associated with the stair module according to the invention in the mounting of the helical staircase.

Advantageously also, to ensure good resistance to the staircase module without hindering a lateral exit or a lateral entry to a user at the top of the staircase, the stringer has a substantially rectangular lower part with lower and upper edges substantially parallel to the step. low, and a high part in the shape of a substantially inverted U, with an upper edge substantially parallel to the high step. This embodiment of the stringer also makes it possible to present, at the connection between the lower part of the stringer and the adjacent branch of the U turned over from the upper part of this stringer, a surface large enough for display, by any appropriate means (bonding, painting or other marking) of assembly instructions.

So that the helical staircase of hexagonal section occupies only a limited space, for example in a cylinder of circular section of diameter less than 2 meters, while allowing to stack identical modules on each other so that any of the three posts of a module can stack on any of the three posts of another module, and that, simultaneously, the two steps of each module have a comfortable support or support surface , the parallel axes of the three posts of the module each pass through one respectively of the three vertices of an equilateral triangle in a plane of transverse section of the module perpendicular to the axes of said posts, and each step has a plan shape substantially of right triangle .

The invention also relates, in a second step, to a set of modular elements, for producing the helical modular staircase of hexagonal horizontal cross section delimited by six vertical angle uprights around a vertical central upright, this set being characterized in that at least one modular element among said modular elements of the assembly is a staircase module with two steps as presented above, at least one second modular element among the modular elements of the assembly being a guard -body comprising two vertical tubular uprights of unequal length, braced, in the lower part, by a horizontal cross-member and in the upper part by at least one, but preferably two, inclined cross-member (s) forming a protective smooth (s) , each of the two railing uprights supporting, in lateral outward projection, a sleeve in the lower part and a pin projecting upwards in the upper part, which s have parallel to the railing upright, said sleeve being able to be fitted on the upper end of the rear corner post of a stair module or on a post of an angle post constituting another element modular of said assembly, said studs being able to be housed in lateral sleeves of the upright posts of the assembly. Such a railing thus mounted in a lateral face of the hexagonal staircase which is delimited by the rear corner post on which one of its two sleeves is mounted, and by the corner post on which the other of its sleeves is mounted, makes it possible to prevent a user from falling over the stringer which is positioned in this lateral face of the staircase, when a next staircase module has been mounted on the one whose rear corner post supports one of the railing sleeves.

The set of modular elements according to the invention advantageously further comprises a plurality of corner upright posts comprising:

a first post, of substantially the same structure and dimensions as the front corner post of the staircase module with two steps, and having female and male ends compatible respectively with the male and female ends of said posts of said module, but with, plus, an annular flange forming a stop limiting the fitting of a railing sleeve on said first post, and an external lateral protruding attachment, suitable for a removable connection with a free end of a heddle articulated by its other end to another corner post, a second post, of the same structure as the first corner post, but of double the height of said first corner post, a third post, of the same structure as the first corner post but three times the height of said first corner post, and at least a fourth post, also of the same structure as the first post of my so many angles, but four times the height of said first corner post, the second, third and fourth corner posts also having a smooth straight line, articulated by one end pivoting about an axis horizontal on said corner post, substantially the length of the first post from its upper end, and capable of being removably connected, by its other end, in an inclined spacer, to said fastener of a post 'neighboring angle delimiting the same face of the hexagonal staircase, and said at least one fourth post of angle post having, in lateral projection on either side of a portion of said post in its lower half, two sleeves, parallel to said fourth post, and each capable of receiving a railing tenon, so that said beam in inclined spacer of a fourth post of corner post is capable of acting as a safety rail ity additional adding to the or the two inclined rails of a railing previously mounted on the stairs.

To also ensure user safety at the upper end of the spiral staircase, the set of modular elements for the construction of the staircase also includes an additional modular element arranged as a closing railing of the staircase, comprising two uprights of tubular railings, straight, parallel and of the same height, braced by at least two horizontal straight rails, rigidly connected, by each of their two ends, to one of the two uprights respectively , including an upper rail connecting the two upper ends of the two railing uprights, and at least one central rail, so as to form a rectangular open frame between the lower ends of these two uprights, said closing railing also comprising , in the lower part of the uprights and projecting laterally outwards, two collars each linked to one of the two uprights, and suitable s to be removably mounted one around the central upright and the other around a corner upright of the staircase, in the middle part of the uprights and in lateral projection outwards, two sleeves each linked to the one of the two uprights and an axis parallel to the latter, and capable of being removably mounted on the central and rear corner posts of another stair module of said assembly, and, preferably, in the upper part of the two uprights of the closing railing, two tenons projecting upwards and capable of being mounted in the sleeves of the upright posts of said modular assembly.

The other stair module on which the closing railing is mounted by its two sleeves is the last module with two steps of the staircase, in the direction of climb, that is to say the highest , the exit of the staircase or its entry, at the upper end of this staircase, being done over the stringer of this last staircase module.

To ensure good horizontal mounting of the steps, in particular the first stair modules which are mounted, and excellent rigidity of the staircase at its base, it is advantageous that the set of modular elements according to the invention also includes , as additional modular elements, two foot jacks, each of which is capable of adjusting the height of one respectively of the two corner posts of a first staircase module with two steps, as well as a substantially horizontal trapezoidal base, whose small base and the two inclined sides are of the same length corresponding to one side of the hexagonal section of the staircase, and produced by the assembly of straight tubular sections constituting at least the two bases and the two inclined sides of the trapezoidal base, which is fitted with a foot jack at each of its four vertices, and capable of adjusting the height of the angle upright posts delimiting three adjacent faces tes of the hexagonal horizontal cross section of the helical modular staircase, a fifth foot jack equipping the middle of the large base of the trapezoidal base for the height adjustment of the central post of said first staircase module with two steps.

The invention relates, in a third step, to a modular helical staircase of horizontal hexagonal cross section, delimited by six vertical uprights around a vertical central upright, and comprising a set of modular elements specific to the invention and as defined above, the modular elements of which are assembled together.

The invention relates, in a fourth step, to an advantageous method of mounting a modular helical staircase according to the invention, this method being characterized in that it comprises a succession of cycles each comprising three stages, the first of which is the arrangement of a staircase module with two steps on the ground or on an identical module and a corner post upright previously arranged, and such that the two corner posts of said staircase module define a face of the staircase of hexagonal horizontal cross section, the second step of which is the arrangement of a corner post, on the ground or on another identical module previously arranged, so that said corner post delimits with the rear corner post of said stair module to an adjacent face of the hexagonal staircase, the third step of which consists in mounting a railing, fitted by one of its two lower part sleeves on said corner post and the other of the two sleeves on said rear corner post of said stair module, so that the railing extends in said adjacent face of the hexagonal staircase.

The advantage of this process is that at each cycle, a protective railing is mounted even before the two-step module is mounted, the stringer of which is placed in the same side face of the staircase as the guard body considered.

When a trapezoidal base, as defined above, and two independent foot cylinders are used to ensure proper mounting of the base of the helical staircase, the method according to the invention is such that its first cycle consists in mounting , in its first stage, a first stair module by each of its corner posts on one respectively of the two independent foot cylinders, defining a first lateral face of the hexagonal staircase, and by its central post on a foot jack mounted in the middle of the large base of said trapezoidal base, then, in its second step, to mount a first corner post on the foot jack mounted on the end of the large base of the base in the direction of rotation of the staircase, then, in its third step, to mount a first railing by its sleeves on the rear corner post of said first stair module and on said first post of upright angle, which define a second side face of the hexagonal staircase, then to reproduce a second cycle, consisting, in its first step, of mounting a second staircase module on the first, by mounting the front corner post of the second module on the rear corner post of the first module, the central post of the second module on and in the extension of the central post of the first module, and the rear corner post of the second module on the first corner post, then, in its second step, to mount a second corner post, twice the height of the first corner post, on a foot jack mounted on the top of the small base of the trapezoidal base which is closest to the first corner post, and to connect the free end of its beam to said first corner post, so as to stiffen the assembly and delimit, by said first and second post d angle, a third lateral face of the hexagonal staircase, and then, in its third step, to mount a second railing in this third lateral face of the staircase, by fitting one of the sleeves of said second railing onto the second corner post and the other sleeve on the rear corner post of the second module, then to reproduce a third cycle, the first step of which is to mount a third stair module by mounting its front corner post on the rear corner post of the second module, its central post on and in the extension of the central post of the second module, and its rear corner post on the second corner post, then, in its second step, mounting a third corner post, of a height equal to three times the height of the first corner post, on a foot jack mounted on the other top of the small base of the trapezoidal base, and to connect the end tee free of its stringer at said second corner post, so as to stiffen the assembly and delimit a fourth lateral face of the hexagonal staircase by said second and third corner post, and to complete this third cycle by its third step, by mounting a third railing, one of the sleeves of which is fitted on the upper end of the third corner post, and the other sleeve on the rear corner post of the third module staircase, then to complete a fourth cycle, the first step of which is to mount a fourth staircase module by mounting its front corner post on the rear corner post of the third module, its central post on and in the extension of that of the third module, and its rear corner post on the upper end of the third corner post, then, in its second step, to mount a fourth corner post, of a high which is four times that of the first corner post, on a foot jack mounted on the second top of the large base of the trapezoidal base, and to connect its beam to the third corner post, so as to stiffen the assembly and delimit a fifth face of the hexagonal staircase, and to complete this fourth cycle by its third stage, by mounting a fourth railing, a sleeve of which is fitted on the upper end of the fourth post of corner post, and the other sleeve is fitted on the rear corner post of the third module, and so on until reaching the desired height of the staircase, each turn of which is made up of six modules staircase with two consecutive steps, reuse of six corner post and six railings.

Thus, in a preferred embodiment, the helical staircase comprises twelve modules with two steps, or twenty-four steps in all, and rises over a maximum height of approximately 5 meters.

The method of mounting such a staircase is such that from the fifth cycle, all of the corner upright posts mounted in the second stage of the cycles are identical to the fourth corner stud post, and each upright post angle is mounted on and in the extension of a front corner post of an underlying stair module.

Likewise, from the seventh cycle, the two lateral sleeves of each corner post are fitted on the vertical studs projecting from the side of two adjacent neighboring railings previously mounted, so as to stiffen the structure of the staircase.

Finally, from the seventh cycle, it is advantageous that the rail of each corner post is fixed by its free end on the corner post previously mounted in an inclined spacer substantially parallel to the beam (s) ) inclined (s) of an underlying railing previously mounted, so as to act as a third inclined rail.

Other advantages and characteristics of the invention will emerge from the description given below, without implied limitation, of an exemplary embodiment described with reference to the appended drawings in which:

FIG. 1 is a perspective view of a staircase module with two steps according to the invention,

- Figures 2 and 3 are plan views respectively of the low step and the high step of the module of Figure 1, ίο

FIG. 4a is a side elevation view of the module of FIG. 1, from the side of the stringer in the external face of this module, which corresponds to a lateral face of the helical staircase of hexagonal section according to the invention,

FIG. 4b is a view similar to FIG. 4a of a variant of the module of FIG. 1,

FIG. 5a is a side elevation view of each of the three posts without end piece of the module of FIGS. 1, 4a and 4b,

- Figure 5b is a side elevational view of a nozzle adapted to be fitted and retained in the upper end portion of a post according to Figure 5a, so that an upper end portion of the nozzle either projecting from the upper end of the post, shaped as a male end, for a male / female connection with other elements or modules of the staircase according to the invention,

FIGS. 6, 7 and 8 are three perspective views each representing one of the three stacking modes for storing two identical stair modules according to the invention,

- Figure 9 is a side elevational view of a railing, which is a modular element of a set of modular elements for making a helical staircase of hexagonal horizontal cross section delimited by six vertical angle posts around d '' a vertical central upright according to the invention,

- Figure 10 is a side elevational view of a first corner post of said set of modular elements according to the invention, this first corner post having substantially the same structure and the same dimensions as the '' at least one of the three posts of a staircase module with two steps, and in particular that the front corner post, secured to the low step and to the stringer of the staircase module, and in the variant of the module according to Figure 4b,

- Figure 11a is a view similar to Figure 10 for a second corner post which is a modular element of said assembly according to the invention, this second post being substantially the same structure as the first corner post of FIG. 10, but twice the height of that of said first corner post, and in addition to a hinge articulated by one end on the second post, substantially halfway up the latter,

- Figure 11b is a view similar to Figures 10 and 11a for a third corner post, the same structure as the second corner post of Figure 11a, but triple the height of said first post corner upright in Figure 10,

- Figure 11c is a view similar to Figures 10, 11a and 11b for a fourth corner post, belonging to the set of modular elements according to the invention, also of the same structure as the second and third posts of corner post of Figures 11a and 11b, but four times the height of the first post of the corner post of Figure 10, and in the lower part, with two sleeves projecting sideways on either side of the fourth post of an angle upright, these sleeves being parallel to this fourth post and capable of each receiving a railing lug, like those mounted in the upper part on the uprights of the railing of FIG. 9,

- Figure 12 is a view similar to Figure 9 for a closing railing, suitable for mounting at the upper end of a staircase according to the invention, at the rear edge of the top step of the last module mounted staircase, to border the exit or the upper entry of the staircase, over the stringer of said last mounted stair module,

FIG. 13 schematically represents in lateral elevation a foot jack, for supporting and adjusting in height one of the corner posts of the first stair module installed,

- Figure 14 is a perspective view of two independent foot cylinders according to Figure 13 associated with a trapezoidal base whose four vertices, at the ends of its small and large bases, as well as the middle of the large base, are equipped with five foot cylinders integral with said base,

- Figures 15a, 15b and 15c successively show three stages of a simple cycle of mounting a first stair module according to the invention, this cycle being repeated very substantially for all the stair modules used, except for the last, due to the mounting of the closing railing and the necessary adaptations to safely arrange the exit or high entry of the staircase over the stringer of the last assembled stair module,

FIGS. 16a, 16b and 16c represent the three successive stages of the assembly cycle of the second stair module,

FIGS. 17a, 17b and 17c are similar to FIGS. 16a, 16b and 16c for the three stages of the assembly cycle of the third stair module,

FIGS. 18a, 18b and 18c, 19a, 19b and 19c, and 20a, 20b and 20c show in a similar way the three stages of the successive assembly cycles of the fourth, fifth and sixth staircase modules respectively,

FIG. 21 is a figure similar to the previous ones and representing the staircase (during assembly) at the end of the second stage of the assembly cycle of the tenth staircase module, and

- Figure 22 is a figure similar to the previous and showing the staircase whose assembly is complete, in the last step of the last cycle during which the twelfth step module was mounted.

To make a helical modular staircase with a hexagonal horizontal cross section and delimited by six vertical angle uprights around a vertical central upright, the invention proposes a basic module 1, as shown in FIGS. 1 and 4a, three cylindrical tubular posts, with parallel axes, supporting two steps, the bearing surfaces of which extend in planes perpendicular to the axes of the posts, and a stringer bordering the steps on a side corresponding to one of the six external lateral faces of the staircase. One of the posts is called central post 2, because it participates in the constitution of the vertical central upright of a staircase by the vertical stacking and in the extension of each other of the central posts 2 of all the modules 1 used for the mounting a staircase, as described below with reference to Figures 15a to 22.

The two steps are a low step 3 and a high step 4, each in the shape of a right triangle, viewed in plan, as shown respectively in FIGS. 2 and 3, and each extending in one respectively of two parallel planes, radially with respect to the axis Z, vertical in the position of use, of the central post 2, to which each step 3, 4 is secured by its internal radial end at a narrow edge 5 in an arc corresponding to the external diameter of the central post 2. Each step 3, 4 is also secured by a wide edge 6, at its outer radial end, to the stringer 7, consisting of a flat plate parallel to the axis Z of the central post 2, and having a part low 8, substantially rectangular with lower and upper edges substantially parallel to the low step 3, and secured to the edge of the wide edge 6 of the low step 3, and a high part 9, in the shape of a substantially inverted U, with upper direction very parallel to the high step 4, and secured to the edge of the wide edge 6 of the high step 4.

The assembly consisting of the central post 2, the two steps 3 and 4 and the stringer 7 is also secured to the other two posts, which are corner posts, contributing to the constitution of the corner uprights of a hexagonal staircase, during the mounting of the plurality of modules 1 that this staircase comprises, as also described below with reference to FIGS. 15a to 22.

One of these two corner posts is called the front corner post 10, and the other rear corner post 11, because they are integral, the first 10 at the front of the step 3, the second 11 at the back of step 4, and both on the stringer

7. More specifically, the front corner post 10 is integral with the nose or front edge 12 of the bottom step 3 at its outer radial end as well as the wide edge 6 of this bottom step 3 at its front end, and this post d 'front angle 10 is also integral with the lower part 8 of the stringer 7, at the front end of the latter. The rear corner post 11 is secured to the rear edge 13 of the high step 4 at its outer radial end, as well as to the wide edge 6 of this high step 4 at its rear end, and this rear corner post 11 is also integral with the upper part 9 of the stringer 7 at the rear end of the latter, at the level of a small edge in an arc of circle which cuts the other non-right vertex of the corresponding right triangle in FIG. 2 for the low step 3 and in Figure 3 for high step 4.

The three posts 2, 10 and 11 of each module 1 comprise identical sections of cylindrical metal tube of circular section, for example 400 mm in length, with an external diameter of 48.6 mm and a thickness of 4 mm , the lower ends of which are situated in the same plane perpendicular to the axes of the posts 2, 10 and 11, this plane being horizontal in the position of use and, possibly, also of storage, of the module 1 (see FIG. 5a). The upper ends of the tube sections of the posts 2, 10 and 11 are also in the same plane perpendicular to the axes of these posts, and each section of the tube is extended upwards by a male end piece 14, having the shape of a sleeve. metallic cylindrical circular section, as shown in Figure 5b, whose dimensions are smaller than those of the tube sections (and are for example 200 mm long, with an external diameter of 39 mm and a thickness of 2 mm), so that each end piece 14 can be partially fitted by its lower part retained in the upper part of the corresponding section of tube, in which the end piece 14 is retained by a bolt or a screw 15 passing through holes 15a and 15b opposite in a post 2, 10 or 11 and a nozzle 14, so that a length of about 47 mm from the upper part of the nozzle 14 protrudes above the upper end of the tube section from pole 2, 10, 11 correspondent. Thus, each post 2, 10, 11 has a lower end arranged as a female end and an upper end arranged as a male end, which are respectively able to receive the upper male end and to be received in the lower female end of n ' any of the posts 2, 10 and 11 analogous to other modules 1.

To secure the interlocking of the posts 2, 10, 11 of different modules 1, and / or other modular elements, described below, for the production of a staircase, and in particular of the angle upright posts described in with reference to FIGS. 10 to 11c, the projecting upper end part of the male end pieces 14 is pierced with radial screw holes 16, and the lower end part of each post 2, 10, 11 is also pierced with a hole 17 radial screwing, which can cooperate with one of the holes 16 of the end piece 14 of a post 2, 10 or 11 of another module 1 to receive the same screw or the same connecting bolt.

Each end piece 14 can be a steel sleeve while the tube sections of the posts 2, 10 and 11 are, like the stringer 7 and the steps 3 and 4, made of a metal or light alloy, for example aluminum, the posts 2, 10 and 11 being joined to the steps 3, 4 and to the stringer 5 at least by welding, the stringer 7 being for example an aluminum sheet 3 mm thick and the steps 3 and 4 being made of a sheet metal aluminum checkerboard with a thickness of 3 to 4.5 mm.

A basic module 1 thus produced can have a weight limited to 12 kg, easy to transport, handle and position for mounting the staircase.

FIG. 4b represents a preferred variant embodiment of module 1, which differs from the module in FIGS. 1 and 4a only in that the end piece 14 of the front corner post 10 is of greater length than the end pieces 14, which are identical, of the other two posts 2 and 11, and therefore protrudes above the upper end of the tube section of the post 10 over a height, for example of 145 mm, greater than on the male end pieces 14 of the central post 2 and the rear corner post 11, projecting by the same height above the latter posts. Thus, the module according to FIG. 4b facilitates the relative positioning of a module mounted on a module previously put in place by a partial engagement of the female part of a post of the newly installed module on the elongated end piece 14 of the post. front corner 10 of the module already installed, then, by pivoting around the axis of the elongated end piece, the newly installed module can be oriented in a horizontal plane to facilitate mounting, and, in addition, such an elongated end piece , fitted to the compatible ends of the corner post posts described below with reference to FIGS. 10 to 11c, allows better vertical support of these corner post posts when they are fitted onto such elongated end pieces, during the mounting the staircase as described below with reference to Figures 15b and following.

However, in the two embodiments of FIGS. 4a and 4b, the parallel axes of the three posts 2, 10, 11 of each module 1 each pass through one respectively of the three vertices of an equilateral triangle, in a section plane transverse of module 1, perpendicular to the axes of these posts 2, 10, 11. Thus, two or more of two modules 1 can be stored by being stacked one on the other, since the different modules 1 are identical and that thus any of the three posts 2, 10, 11 of a second module 1 can be fitted by its lower female end on the upper male end part with end piece 14 of any of the three posts 2, 10 and 11 of a first module 1 on which the second module is stacked.

Thus, it is possible to store two modules 1 superimposed according to one or other of the three positions represented in FIGS. 6, 7 and 8. In FIG. 6, the two central posts 2 of the two modules 1 are superimposed in the vertical extension of each other, as well as the two front corner posts 10 and the two rear corner posts 11. By rotating the upper module 1 120 ° around a vertical axis passing through the intersection of the perpendicular bisectors of the corresponding equilateral triangle, counterclockwise, we can bring the two modules in the stacked position of Figure 7, in which the central post 2 of the upper module is fitted on the rear corner post 11 of the lower module, the rear corner post 11 of the upper module being fitted onto the front corner post 10 of the lower module, and finally the front corner post of the upper module being fitted onto the central post 2 of the lower module, while an r 120 ° rotation of the upper module clockwise from the stack in Figure 6 provides the stack in Figure 8, in which the center post 2 of the upper module is fitted onto the corner post front 10 of the lower module, the front corner post 10 of the upper module is fitted onto the rear corner post 11 of the lower module, and finally the rear corner post of the upper module is fitted onto the central post 10 of the module lower (Figure 8).

The assembly according to the invention of modular elements for producing a helical modular staircase in accordance with the invention also comprises, in addition to the staircase modules 1 with two steps 3, 4, at least one, and in general a plurality, of railings as shown in Figure 9.

This railing 18 comprises two uprights 19a and 19b tubular and parallel, vertical in the position of use of the railing 18, with the same external and internal diameters, and therefore of the same thickness, for example with a thickness of 1.5 mm and an external diameter of 30 mm, the largest of which 19a is 1,905 mm in length and the smallest of which is 1,590 mm in length, the two uprights 19a and 19b being braced, in the lower part, by a cross member 20a perpendicular to the two uprights 19a and 19b, therefore horizontal in the position of use, the two uprights 19a and 19b having their lower end in the same plane perpendicular to these uprights. In the upper part, the two uprights 19a and 19b are braced by two crosspieces 20b and 20c inclined parallel to each other, from the longest upright 19a downwards and towards the other shortest upright 19b, the one of the crosspieces 20c connecting the upper ends of the two uprights 19a and 19b. The three crosspieces 20a, 20b, 20c are tubular, with the same dimensions of internal and external diameters and of thickness as the uprights. At a level slightly lower than that of the lower cross member 20a, each of the two uprights 19a and 19b supports, projecting laterally outwards, a cylindrical sleeve 21a, 21b of circular section, each obtained by cutting a section of 100 mm long in a tube, for example 60.3 mm in external diameter and 2.5 mm thick, each of the two sleeves 21a and 21b being connected by a plate 22a and 22b to the corresponding upright 19a or 19b, this flat having for example a length of 38 mm and a thickness of 5 mm, the axes of the sleeves 21a and 21b being parallel to the uprights 19a and 19b. In the upper part, near its upper end, each of the two uprights 19a, 19b also supports in lateral outward projection, a stud 23b, 23b, parallel to the uprights and protruding upward relative to a connecting plate from the lower end part of each stud to its respective amount.

As described below, in particular with reference to FIGS. 15c and following relating to the mounting of the staircase, each sleeve 21a, 21b is capable of fitting onto the upper end of the rear corner post 11 of a module 1 staircase or on an angle post, among those described below with reference to FIGS. 10 to 11c, while the studs 23a and 23b are able to be housed in lateral sleeves of some of the said studs angles described below.

The railing 18 is produced by assembling, for example by welding, its components which are all metallic, preferably made of a metal or light alloy.

The set of modular elements according to the invention also includes other modular elements which are angle post according to Figures 10 to 11c.

Among the plurality of corner post of the set of modular elements according to the invention, a first 24a, shown in Figure 10, is a straight tubular post, substantially the same structure and dimensions as the post front angle 10 of module 1 with two steps 3 and 4, and having a female lower end and a male upper end which are compatible with the male upper end and female lower end of the front corner post 10 of module 1 respectively , preferably in its variant according to FIG. 4b, in which the upper end piece 14 is a sleeve lengthened by approximately 150 mm relative to that of FIG. 4a. There is therefore a nozzle 14 in the form of a steel sleeve, for example approximately 350 mm long, pierced with screw holes 16 in its projecting upper end above the tubular body 25a of the post 24a, made of alloy aluminum or aluminum, and which has the same height as the tubular body of the front corner post 10, i.e. 400 mm for example, the end piece 14 being retained by screwing or bolting 15 of its lower end part in the tubular body 25a, the lower end portion of which is integral with a fastener 26a projecting from the lateral side on the tubular body 25a, and pierced with a hole 27a allowing a removable pivoting connection, about an axis perpendicular to the longitudinal axis of the post 24a, with the free end of a heald articulated by its other end on a second post of angle post 24b according to FIG.

Finally, the tubular body 25a of the first post 24a of the corner post comprises an annular flange 28a, which forms a peripheral abutment projecting radially outwards, to limit the fitting of a sleeve such as 21a or 21b d ' a railing 18 on this first post 24a of the corner post.

The second corner post 24b comprises, like the first corner post 24a, a tubular body 25b, the length of which is twice that of the first post 24a, therefore approximately 800 mm, the upper end of which male is equipped, in the same way, with a nozzle 14 retained by screwing or bolting 15 in the tubular body 25b of the second post 24b, which also has a lateral attachment 26b projecting in its median part, and pierced with a hole 27b for a link articulated around an axis perpendicular to the longitudinal axis of the second post 24b on a free end of a heald 31c articulated on the third post 24c of the upright of angle of FIG. 11b. The second corner post 24b also includes an annular flange 28b, similar to the annular flange 28a of the first post 24a, but, in addition comprises a heald 29b articulated by one end around an axis 30b perpendicular to the axis of the second post 24b on the latter, and whose free end 31b is capable of being hinged removably on the fastener 26a of the first post 24a.

Thus, the first and second posts 24a and 24b of the corner post have the same structure and the same dimensions except that the second 24b is twice the length of the first 24a, the fastener 26b of the second post 24b is substantially at middle of its length, and not in its lower part as for the first post 24a, and finally the second post 24b further comprises the heald 29b, of tubular structure, articulated around the axis 30b on the tubular body 25b, substantially at level of the fastener 26b but on the opposite side of the body 25b, and the free end 3 lb of which is capable of being removably connected to the fastener 26a of the first post 24a of the corner upright.

FIG. 1 lb shows a third post 24c for an angle post, the structure and dimensions of which are substantially the same as for the second post 24b for an angle post, except that the length of the third post 24c is three times that of of the first post 24a, that its attachment 26c is at the same distance from the upper end of the end piece 14 as on the first and second posts 24a and 24b, so that the various elements and components of the third post 24c are marked on Figure 11b by references identical to those identifying the same elements or components in Figures 10 and 11a or assigned an index c to distinguish them from similar elements and components identified by references assigned an index a in Figure 10 for the first post 24a and of index b for the post 24b in FIG.

FIG. 11c represents a fourth post 24d of an angle upright, the elements and components of which are identical or analogous to those of the three posts previously described are identified by the same references assigned an index d, the length of the fourth post 24d being the quadruple that of the first post 24a, and this fourth post 24d having the particularity of comprising in addition, relative to the other three, two sleeves 32d, projecting laterally on either side of the tubular body 25d in its lower half, and parallel to the axis of the tubular body 25d, these sleeves 32d being able to each receive a railing lug, such as a lug 23a or 23b of the railing 18 of FIG. 9, as described below for the mounting the staircase, and so that the rail 29d of the fourth post 24d of the corner post can function, when it is mounted in an inclined spacer between two posts of the corner post, of a top safety bar additional adding to the two stringers 20b and 20c of a railing 18 mounted on the staircase prior to the fourth post 24d of the angle post considered, as described below.

The set of modular elements for the construction of a staircase according to the invention also comprises a closing railing, as shown in FIG. 12, to prevent the passage of the last module beyond the top step. 'staircase with two steps mounted at the upper end of the staircase, the exit of which then takes place laterally, over the stringer of said last module with two steps.

The closing railing 33 of FIG. 12 comprises two upright tubular uprights 34 parallel and of the same length, vertical in the position of use of the railing 33, and such that their lower ends are in the same horizontal plane, both uprights 34 being braced by three straight rails 35, tubular and perpendicular to the two uprights 34, and rigidly linked, by each of their two ends to one respectively of the two uprights 34, an upper smooth 35 connecting the two upper ends of the two uprights 34, a central rail 35 connecting the two uprights 34 substantially to two thirds of their height, and the third bottom rail 35 connecting the two uprights substantially to one third of their height, from their lower ends. The railing 33 thus has the shape of a rectangular frame open between the lower ends of the two uprights 34. In the middle part of the two uprights 34, between the two middle and bottom crosspieces, the railing 33 also has two projecting sleeves 36 lateral to the outside, each on one of the two uprights 34 respectively, to which the sleeve 36 is connected by a plate 37 welded to the upright, the axes of the two sleeves 36 being parallel to the longitudinal axes of the two uprights 34. These sleeves 36 are able to be removably fitted onto the central 1 and rear corner 11 posts of the last module 1 at two steps from the stairs. In the lower part of each of the two uprights 34, and in lateral projection towards the outside and towards the rear, like the plates 37 supporting the sleeves 36, each upright 34 supports a collar 38, of the type with two pivoting jaws one relative to each other around an axis substantially parallel to the axis of the corresponding upright 34, the two jaws being able to close against each other by screwing, so that the collar 38 is able to be removably mounted one around the central upright and the other around a corner upright of the staircase, or around a fourth post 24d of the upright corner mounted on a rear corner post 11 and in the extension vertical of the latter on a module 1 of stairs. In addition, in the upper part of the two uprights 34 of this railing 33, two studs 39, projecting towards the upper end of the uprights 34, are each supported by one of the two uprights 34 projecting laterally outwards and towards the rear of the frame of the railing 33, these two studs 39 being able to be mounted in sleeves 32d of fourth posts 24d of the upright, at the end of assembly of the upper end part of the 'staircase.

The set of modular elements according to the invention also comprises, as shown in FIG. 14, two independent foot cylinders 40, such as that of FIG. 13, as well as a substantially horizontal trapezoidal base 41, each of which ends of the large base 42 as of the small base 43 of the base 41, as well as the middle of the large base 42 are equipped with one respectively of five similar foot cylinders 40, the structure of a foot cylinder being schematically shown in Figure 13. Each foot cylinder 40, of a well known structure, comprises a plate 44 for supporting the ground, supporting a vertical threaded rod 45, on which is screwed a nut 46 with wings 47, with a breakpoint 48 on the rod 45 which limits the height adjustment range of the nut 46 upwards, on the fins 47 from which the female lower ends of the front corner posts 10 and rear 11 can come to bear from module 1 to d them steps or the female lower ends of the first, second, third and fourth angle post poles 24a, 24b, 24c and 24d previously described, in order to compensate for a defect in the flatness and / or horizontality of the ground surface where a staircase according to the invention must be fitted. On the base 41, the small base 43 and the two inclined sides 49, which connect the small base 43 to the large base 42, are each of the same length which corresponds to the length of one side of the hexagonal section of the staircase. The base 41 is produced by assembling, for example by welding, rectilinear tubular sections which constitute, in this example, not only the two bases 42 and 43 and the two inclined sides 49 of the trapezoidal base 41, but also two spacers 50 each of which connects one respectively of the two ends of the small base 43 to the center of the large base 42.

The method of mounting a staircase is described below with reference to FIGS. 15a to 22.

The first three-step cycle is shown in Figures 15a, 15b and 15c. In the first step (FIG. 15a), a module 1 with two steps is mounted by its central post 2 on the foot jack 40 in the middle of the large base 42 of the horizontal base 41, and the two front corner posts 10 and rear 11 of module 1 are each mounted on one of two independent foot cylinders 40 respectively, thereby defining the first of the six faces of the staircase of hexagonal horizontal cross section to be mounted. In the second step (FIG. 15b), the first post 24a of the corner upright is mounted vertically by fitting on the foot jack 40 at the end of the large base 42 of the base 41 towards which the module 1 of the the staircase turns upwards, and so that the first post 24a of the corner post delimits with the rear corner post 11 of the staircase module 1 the second face of the hexagonal staircase. In the third step of this first cycle, a railing 18 is mounted in this second face of the staircase by fitting one of its sleeves 21b on the upper male end of the rear corner post 11 of the module 1 , and by the other sleeve 21a on the male upper end of the first corner post 24a, as shown in FIG. 15c, which shows that the height of the male upper ends of the first corner post 24a as of the rear corner post 11 of the step module 1 is greater than the height of the sleeves 21a and 21b of the railing 18, so that the upper end parts of the end pieces 14 (FIGS. 1, 4a and 4b) protrude at above the sleeves 21a and 21b.

At the first stage of the second stair mounting cycle, a second module 1 of steps is mounted by fitting its central post 2 onto that of the first module 1 (see FIG. 16a), its front corner post 10 on the part of the male upper end of the rear corner post 11 of the first module 1 which protrudes above the sleeve 21b of the railing 18, and its rear corner post 11 on the part of the male upper end of the first corner post 24a which protrudes above the other sleeve 21a of the railing 18. At the second stage of the second cycle, the second corner post 24b is fitted on the foot jack 40 to the end closest to the small base 43 of the base 41, and the articulated heald 29b of this second post 24b is fixed in a spacer between this second post 24b and the first 24a by connection of this heald 29b with the fastener 26a of the first corner post 24a, in the third f ace of the hexagonal staircase. At the third stage of this second cycle, a railing 18 is mounted in this third face of the staircase by fitting its sleeve 21b on the upper male end of the rear corner post 11 of the second step module 1 and of its second sleeve 21a on the upper male end of the second post 24b of the corner upright (FIG. 16c).

At the first stage of the third cycle (FIG. 17a), a third module 1 of steps is mounted by fitting its central post 2 onto that of the second module 1, its front corner post 10 on the part of the male upper end of the rear corner post 11 of the second module 2 which protrudes above the sleeve 21b of the second railing 18, and its rear corner post 11 is fitted on the part of the male upper end of the second post 24b of the upright angle which protrudes above the sleeve 21a of the second railing 18.

Thus, at the first stage of the third cycle (FIG. 17a), the third module 1 of steps is mounted on the second as the second was on the first, by vertical stacking of its central post 2 on that of the second module 1 , its rear corner post 11 on the part of the upper male end of the second post 24b of the corner post which protrudes above the sleeve 21a of the second railing 18, and the front corner post 10 on the part of the male upper end of the rear corner post 11 of the second module 1 which protrudes above the other sleeve 21b of the second railing 18. At the second stage of this third cycle (FIG. 17b), the third post 24c of the corner post of the figure

11b is mounted on the foot jack 40 at the other end of the small base 43 of the base 41, and the hinged bar 29c of this third post 24c of the corner post is mounted as a spacer between the second and third posts 24b and 24c of the corner post by fixing its free end to the fastener 26b of the second post 24b of the corner post (see FIG. 11a). At the third stage of the third cycle (FIG. 17c), a third railing 18 is mounted in the fourth lateral face of the staircase delimited by the second and third posts 24b, 24c of the upright, by fitting its sleeve 21b on the upper male end of the rear corner post 11 of the third step module 1 and its other sleeve 21a on the upper male end of the third post 24c of the corner post.

At the first stage of the fourth cycle (FIG. 18a), a fourth module 1 of steps is installed, as the third was on the second, by fitting its central post 2 onto that of the third module 1, and fitting its rear corner post 11 on the part of the male upper end of the third post 24c of the corner post which protrudes above the sleeve 21a of the third railing 18 and fitting of its front corner post 10 on the part of the upper male end of the rear corner post 11 of the third module 1 which protrudes above the sleeve 21b of the third railing 18. At the second stage of this fourth cycle, a fourth post 24d of amount of angle according to FIG. 11c is mounted on the foot jack 40 at the second end of the large base 42 of the base 41, and its articulated heald 29d is mounted in an inclined spacer between the two posts 24c and 24d of the angle upright , delimiting the ci nth side face of the staircase, by fixing the free end 31d (see FIG. 1c) of this rail 29d on the fastener 26c of the third post 24c of the corner post. This fourth cycle ends, in the third step, by the mounting of a fourth railing 18 (see FIG. 18c), the sleeve 21a of which is fitted on the male upper end of the fourth post 24d of the corner post and whose the other sleeve 21b is fitted on the upper male end of the rear corner post 11 of the fourth step module 1.

The three stages of the fifth cycle are shown in Figures 19a,

19b and 19c. At the first stage, a fifth module 1 of steps is mounted like the previous ones, by fitting its central post 2 in the vertical extension of those of the other modules 1 to constitute the central upright of the staircase, and by fitting its post rear corner 11 on the part of the upper male end of the fourth post 24d of the corner post which protrudes above the sleeve 21a of the last railing 18 mounted, and by fitting the front corner post 10 of the fifth module 1 on the upper male end part of the rear corner post 11 of the fourth module 1 which protrudes above the second sleeve 21b of the fourth railing 18. At the second stage of the fifth cycle, another fourth post 24d corner post is mounted on and in the vertical extension of the front corner post 10 of the first module 1 of the staircase, and its hinged rail 29d is attached to the fastener 26d of the pre post previously mounted, namely a first fourth post 24d. Indeed, from the angle post 24d mounted in the second step of the fourth cycle, all the corner post which are used are identical to the fourth post 24d of the corner post according to FIG. 11c. At the third stage of this fifth cycle, a fifth railing 18 is installed, like the previous ones, by fitting one of its sleeves 21a on the upper male end of the last post 24d of the corner post mounted at the second step of this cycle, and fitting of the other sleeve 21b on the rear corner post 11 of the fifth module 1 mounted in the first step of this same cycle. The fifth railing 18 is thus arranged in the sixth face of the hexagonal staircase, above an entry opening giving access to the base of the staircase, between the two posts 24d of the angle upright and below the rail 29d mounted in an inclined spacer between these two posts 24d.

The first stage of the sixth cycle consists in mounting a sixth module 1 of steps, like the previous ones, which comes to be placed above the entrance to the staircase, which then comprises a complete turn (see Figure 20a). The central post 2 of this sixth module 1 is fitted in the vertical extension of the central posts 2 of the five modules 1 previously mounted, and its front corner posts 10 and rear 11 fit respectively on the parts which protrude above the sleeves 21b and 21a of the fifth railing 18 of the rear corner post 11 of the previous module 1 and of the last post 24d of the corner post installed. The second step of the sixth cycle (see FIG. 20b) consists in mounting a new post 24d with an angle post identical to the fourth post in FIG. 11c on the front corner post 10 of the second module 1 installed, and in fixing the boom 29d of the last post 24d and mounted on an inclined beam bracing the last two posts 24d installed. In addition, one of the sleeves 32d of the last post 24d installed is engaged on the stud 23b of the short post 19b of the first railing 18 (Figure 9) installed in the third step of the first cycle. At the third stage of this sixth cycle, as at the end of each preceding cycle, a sixth railing 18 is mounted (see FIG. 20c) by fitting its sleeve 21a onto the post 24d of the angle post which comes from be installed and by fitting the other sleeve 21b on the rear corner post 11 of the step module 1 installed at the first stage of this same cycle.

After the sixth cycle and up to the tenth, possibly even up to the eleventh, each cycle is a repetition of the sixth cycle, with a level shift corresponding to the module 1 of steps added to each cycle, to make a second round of the staircase, plumb above the first tower, the new corner post posts incorporated in the assembly being all identical to the fourth post 24d of FIG. 11c. The first stage of each of these cycles always concerns the installation of an additional module 1 of steps, the second stage relates to the installation of a fourth post 24d of additional amount of angle, and the last stage of each cycle always corresponds to the installation of an additional railing 18, except at the third stage of the eleventh cycle, to allow the exit of the staircase at the level of the twelfth and last module 1 of steps, in this example, where the spiral staircase is limited to two towers.

In these assembly cycles, from the fifth cycle, not only are all of the angle post posts mounted in the second step of each cycle identical to the fourth corner post 24d, but each of them is mounted on a front corner post 10 of an underlying staircase module 1, and in the vertical extension of the front corner post 10 of this module 1.

In addition, from the seventh assembly cycle, the two lateral sleeves 32d of each post 24d of the corner post are fitted onto the vertical studs 23a and 23b projecting from the side of two neighboring and underlying railings 18, previously assembled. Similarly, from the seventh assembly cycle, the rail 29d of each post 24d of the corner post is fixed by its free end 31d on the post 24d of the corner post previously mounted in an inclined spacer substantially parallel to the two inclined posts 20b and 20c of a previously mounted and underlying guardrail 18, thus acting as a third inclined rail, reinforcing safety for users in the second turn of the staircase.

These latter characteristics are visible in FIG. 21, which represents the second stage of the tenth cycle, during which a new post 24d is mounted on the front corner post 10 of the sixth module 1, and its smooth 29d fixed inclined on the post 24d previously mounted, after the installation of the tenth step module 1, mounted so that its rear corner post 11 is fitted onto the upper end of a post 24d of an upright, the two sleeves 32d of which are fitted one on the post 23a of the railing 18 previously mounted and below that which borders the tenth module 1 of steps, while the other sleeve 32d of the post 24d of the corner post is fitted on the post 23b d a bodyguard 18 previously mounted, just after the bodyguard 18 having the other tenon 23a, these two underlying bodyguards 18 being adjacent by their tenons 23a and 23b.

It will be recalled that, during the first step of a new assembly cycle, the front corner post 10 of a step module 1 is mounted on the rear corner post 11 of module 1 mounted in the first step of the previous cycle, with the interposition of a lateral sleeve 21b of the railing 18 mounted in the third step of the previous cycle on this rear corner post 11.

From the unfinished staircase of Figure 21, one arrives at the completed staircase of Figure 22 by mounting a tenth and last railing 18 shown in Figure 22, mounted in the same manner as the others , in the third step of the tenth cycle, which then allows the safe mounting of an eleventh module 1, in the first step of the eleventh cycle, then the mounting of a new post 24d of angle post allowing direct mounting of the twelfth and last module 1 of steps, without the prior assembly of another railing. Thus, the front corner 10 and rear corner posts 11 of the last module 1 are fitted directly and respectively on the rear corner post 11 of the eleventh module 1 and on the new corner post 24d of corner post, without interposition of sleeves. bodyguard. The closing railing 33 of FIG. 12 is mounted behind the high step 4 of the last module 1 and along the rear edge of this high step 4, and fitted by its sleeves 37 on the upper ends of the central posts 2 and d 'rear corner 11 of the last module 1, and retained by one of its collars 38 around the central post 2 of the penultimate module 1 and by the other collar 38 around the post 24d of the upright supporting the rear corner post 11 of the last module 1.

In addition, the studs 39 of the closing railing 33 are engaged in sleeves 32d of two posts 24d of a corner upright mounted along the sides of the closing railing 33 and fitted on the upper ends of the central posts 2 and rear corner 11 of the last module 1. In addition, four other 5 posts 24d of the upright are mounted vertically along the sides of the last three railings 18 and between them, by fitting on the upper male ends front 10 and rear 11 corner posts of the eleventh, tenth and ninth modules 1, the beams 29d of these four posts 24d being fixed inclined between these posts 24d, to secure the access of the stairs to these last three modules 1 10 of steps, and the studs 23a and 23b of the railings 18 are engaged in sleeves 32d of these posts 24d to stiffen the upper part of the staircase with lateral exit over the stringer 7 of the last module 1 of my rch.

Claims (16)

1. Staircase module (1) for a helical modular staircase of horizontal hexagonal cross section, delimited by six vertical angle uprights around a vertical central upright, said module (1) comprising a central post (2) of substantially vertical axis (Z) and two steps (3, 4) of substantially triangular shape, including a low step (3) and a high step (4), extending in horizontal planes perpendicular to the axis (Z) of the central post (2) and radially from said central post (2), to which the steps (3, 4) are each joined by a narrow edge (5) of internal radial end, characterized in that said two steps (3, 4 ) are each secured by a wide edge (6) of radial end external to a single stringer (7) in the form of a substantially planar plate and parallel to the axis (Z) of the central post (2), the stringer (7) having a bottom part (8) and a top part (9) secured to the edge of the wide edge (6) respectively of the low step (3) and the high step (4), and in that the module comprises two corner posts (10, 11) with axes parallel to the axis (Z) of the post central (2), so that the lower ends of the three posts (2, 10, 11) of the module are in a transverse plane perpendicular to the axes of the three posts (2, 10, 11) of the module, and one of the two corner posts, called front corner post (10), is integral with the lower part (8) of the stringer (7) at the front end of the latter, of the nose (12) of the low step (3 ) at its outer radial end, and the wide edge (6) of the bottom step (3), at its front end, and of which the other corner post, called rear corner post (11) is integral with the upper part (9) of the stringer (7) at the rear end of the latter, from the rear edge (13) of the high step (4) to its external radial end, and from the wide edge (6) of the high step ( 4) at its rear end, the central post (2) and the two corner posts (10, 11) of the module (1) each comprising a female end and a male end which are adapted respectively to receive a male end and to be received in a female end of similar posts of modules (1) identical to two steps, so as to contribute with said posts analogous to the constitution of said central upright and of said corner uprights of the staircase. 2. Staircase module (1) according to claim 1, characterized in that the central post (2) and the two corner posts (10, 11) are three tubular posts identical to one another, secured the two steps (3, 4) and the common stringer (5), and the upper ends of which are each extended by one respectively of three male end pieces (14), each in the form of a sleeve, retained partially fitted in a corresponding post and partially projecting above said post (2, 10, 11), at the male upper end of said corresponding post. 3. Staircase module (1) according to claim 2, characterized in that the three posts (2, 10, 11) of said module are made of metal or light alloy and joined at least by welding to the steps (3, 4) and the stringer (5) which are made of the same metal or alloy, each of the three male end pieces (14) being a steel sleeve retained, by its lower end part, at least by screwing (15) in a corresponding post, and having a projecting upper end part, above said corresponding post, and preferably pierced with radial screw holes (16), the lower end part of each post (2, 10, 11) also being pierced with at least one radial screw hole (17). 4. Staircase module (1) according to claim 3, characterized in that the male end piece (14) of the front corner post (10) protrudes above the upper end of the corresponding post on a plus great height than the male end pieces (14) of the rear corner post (11) and of the central post (2), which are identical and protrude by the same height above the corresponding posts. 5. Module according to any one of claims 1 to 4, characterized in that the stringer (7) has a lower part (8) substantially rectangular with lower and upper edges substantially parallel to the bottom step (3), and a part high (9) substantially in the form of an inverted U, with an upper edge substantially parallel to the high step (4). 6. Module (1) according to any one of claims 1 to 5, characterized in that the parallel axes of the three posts (2, 10, 11) of the module each pass through one respectively of the three vertices of a triangle equilateral in a cross-sectional plane of the module (1) perpendicular to the axes of said posts (2, 10, 11), and each step (3, 4) has a plan shape substantially of a right triangle. 7. Set of modular elements, to produce a helical modular staircase of horizontal hexagonal cross section delimited by six vertical angle uprights around a vertical central upright, characterized in that at least one modular element among said modular elements of the assembly is a two-step staircase module (1) (3, 4) according to any one of the preceding claims, at least one second modular element among the modular elements of the assembly being a railing (18 ) comprising two vertical tubular uprights (19a, 19b) of unequal length, braced, at the bottom, by a horizontal crosspiece (20a) and at the top by at least one, but preferably two, crosspiece (s) (20b, 20c ) inclined (s) forming smooth (s) of protection, each of the two uprights (19a, 19b) of railing supporting, in lateral projection outward, a sleeve (21a, 21b) in the lower part and a tenon ( 23a, 23b) protruding upwards in the upper part, which are parallel to the railing upright (19a, 19b), said sleeve (21b, 21a) being capable of fitting onto the upper end of the rear corner post (11) d '' a staircase module (1) or on a post (24a, 24b, 24c, 24d) of a corner post constituting another modular element of said assembly, said studs (23a, 23b) being able to be housed in lateral sleeves (32d) of posts (24d) of the corner post of the assembly. 8. A set of modular elements according to claim 7, characterized in that it further comprises a plurality of angle upright posts comprising: a first post (24a), of substantially the same structure and dimensions as the front corner post (10) of the two-step staircase module (1), and having female and male ends compatible with the male and female ends respectively said posts (2, 10, 11) of said module (1), but with, in addition, an annular collar (28a) forming a stop limiting the fitting of a sleeve (21a, 21b) of railing (18) on said first post (24a), and an attachment (26a) projecting from the lateral side, suitable for a removable connection with a free end (31b) of a heald (29b) articulated by its other end to a second post (24b) of corner post, said second post (24b) being substantially of the same structure as the first post (24a) of corner post, but twice the height of said first post (24a) of corner post, a third post (23 c), of substantially the same structure as the first post (24a) of a corner post but of high ur triple that of said first post (24a) of angle post, and at least a fourth post (24d), also substantially of the same structure as the first post (24a) of post of angle, but of height four times that said first corner post (24a), the second (24b), third (24c) and fourth (24d) corner posts also having a straight (29b, 29c, 29d) rail, articulated by a end pivoted about a horizontal axis (30b, 3Oc, 30d) on said corner post (24b, 24c, 24d), substantially the length of the first corner post (24a) from the upper end of said post (24b, 24c, 24d), and capable of being removably connected, by its other end (31b, 31c, 31d), in inclined spacer, to said fastener (26a, 26b, 26c, 26d) d '' a neighboring corner post delimiting the same face of the hexagonal staircase, and said at least one fourth post (24d) aya post nt moreover, in lateral projection on either side of a portion of said post (24d) in its lower half, two sleeves (32d), parallel to said fourth post (24d), and each capable of receiving a stud (23a , 23b) of railing (18), so that said beam (29d) in inclined spacer of a fourth post (24d) of the upright is able to act as an additional security beam adding to the or to the two heddles (29a, 29b) inclined with a railing (18) previously mounted on the staircase. 9. A set of modular elements according to claim 7 or 8, characterized in that it also comprises an additional modular element arranged in railing (33) for closing the staircase, comprising two uprights (34) of tubular railings , rectilinear, parallel and of the same height, braced by at least two horizontal straight bars (35), rigidly connected, by each of their two ends, to one respectively of the two uprights (34) of railing (33), including an upper rail (35) connecting the two upper ends of the two railing uprights (34), and at least one middle or lower rail (35), so as to form a rectangular open frame between the lower ends of these two uprights (34), said closing railing (33) also comprising, in the lower part of the uprights (34) and projecting laterally outwards, two collars (38) each linked to one of the two uprights (34 ), and able to be m have removably one around the central upright and the other around a corner upright of the staircase, in the middle part of the uprights (34) and in lateral projection towards the outside, two sleeves (36) each linked to one of the two uprights (34) and of axis parallel to the latter, and capable of being removably mounted on the central posts (2) and rear corner (11) of a last stair module of said assembly, and preferably in the upper part of the two uprights (34) of the closing railing (33), two tenons (39) projecting upwards and capable of being mounted in post sleeves (32d) (24d) of the corner upright of said modular assembly. 10. Set of modular elements according to any one of claims 7 to 9, characterized in that it also comprises, as additional modular elements, two independent foot cylinders (40), each of which is capable of adjusting the height l '' respectively one of the two corner posts (10, 11) of a first module (1) of staircase with two steps, as well as a substantially horizontal trapezoidal base (41), including the small base (43) and the two inclined sides (49) are of the same length corresponding to one side of the hexagonal section of the staircase, and produced by the assembly of straight tubular sections constituting at least the two bases (42, 43) and the two sides inclined (49) of the trapezoidal base (41), which is equipped with a foot jack (40) at each of its four vertices, and capable of adjusting the height of the posts (24a, 24b, 24c, 24d) of corner post delimiting three adjacent faces of the horizontal cross section hexagonal of the helical modular staircase, a fifth foot jack (40) equipping the middle of the large base (42) of the trapezoidal base (41) for the height adjustment of the central post (2) of said first module (1 ) staircase with two steps. 11. Modular helical staircase of horizontal hexagonal cross section, delimited by six vertical angle uprights around a vertical central upright, characterized in that it comprises a set of modular elements according to any one of claims 7 to 10 . 12. A method of mounting a modular helical staircase according to claim 11, characterized in that it comprises a succession of cycles each comprising three stages, the first of which is the arrangement of a staircase module (1) for two steps on the ground or on an identical module (1) and a post (24a, 24b, 24c, 24d) of angle post previously arranged, and such that the two corner posts (10, 11) of said module (1 ) of stairs define a face of the staircase of hexagonal horizontal cross-section, the second stage of which is the provision of a post (24a, 24b, 24c, 24d) of amount of angle, on the ground or on another identical module (1) previously arranged, so that said post (24a, 24b, 24c, 24d) of 33 corner post defines with the rear corner post (11) of said stair module (1) an adjacent face of the hexagonal staircase, and the third step of which is to mount a railing (18), fitted by one (21a) of its two lower part sleeves on said post (24a, 24b, 24c, 24d) of the corner post and by the other (21b) of the two sleeves on said rear corner post ( 11) of said staircase module (1), so that the railing (18) extends in said adjacent face of the hexagonal staircase. 13. A method of mounting a helical modular staircase according to claim 12, characterized in that the first cycle consists in mounting, in its first step, a first stair module (1) by each of its corner posts ( 10, 11) on one respectively of two independent foot jacks (40), defining a first lateral face of the hexagonal staircase, and by its central post (2) on a foot jack (40) mounted in the middle of the large base (42) of a trapezoidal base (41) according to claim 10, then, in its second step, to mount a first post (24a) of the angle upright on the foot jack (40) mounted on the end of the large base (42) of the base (41) in the direction of rotation of the staircase, then, in its third step, to mount a first railing (18) by its sleeves (21a, 21b) on the rear corner post (11) of said first stair module (1) and on said first corner post (24a), which defines ssent a second side face of the hexagonal staircase, then to reproduce a second cycle, consisting, in its first step, of mounting a second staircase module (1) on the first, by mounting the front corner post (10 ) of the second module (1) on the rear corner post (11) of the first module (1), the central post (2) of the second module (1) on and in the extension of the central post (2) of the first module (1), and the rear corner post (11) of the second module (1) on the first post (24a) of the corner post, then, in its second step, to mount a second post (24b) of the post angle, double the height of the first post (24a) of the angle post, on a foot jack (40) mounted on the top of the small base (43) of the base (41) trapezoidal which is closest to the first post (24a) of the corner post, and to connect the free end (31b) of its beam (29b) to said first post (24a) of the corner post, so as to stiffen er the assembly and delimit, by said first and second posts (24a, 24b) of the corner upright, a third lateral face of the hexagonal staircase, and then, in its third step, to mount a second railing ( 18) in this third lateral face of the staircase, fitting one (21a) of the sleeves of said second bodyguard (18) onto the second post (24b) of the upright and the other sleeve (21b) onto the rear corner post (11) of the second module (1), then to reproduce a third cycle, the first step of which is to mount a third stair module (1) by mounting its front corner post (10) on the rear corner post (11) of the second module (1), its central post (2) on and in the extension of the central post (2) of the second module (1), and its rear corner post (11 ) on the second corner post (24b), then, in its second step, to mount a third post (24c) for the corner post, height equal to three times the height of the first corner post (24a), on a foot jack (40) mounted on the other top of the small base (43) of the trapezoidal base (41), and connect the free end (31c) of its heddle (29c) to said second post (24b) of an upright, so as to stiffen the assembly and delimit a fourth lateral face of the hexagonal staircase by said second and third posts (24b, 24c) of the corner post, and to complete this third cycle by its third step, by mounting a third railing (18), one of which (21a) of the sleeves is fitted on the upper end of the third corner post (24c), and the other sleeve (21b) on the rear corner post (11) of the third stair module (1), then to complete a fourth cycle, the first step of which consists in mounting a fourth staircase module (1) by mounting its front corner post (10) on the rear corner post (11) of the third e module (1), its central post (2) on and in the extension of that of the third module (1), and its rear corner post (11) on the upper end of the third post (24c) of amount d angle, then, in its second step, to mount a fourth post (24d) of the corner post, of a height which is four times that of the first post (24a) of the corner post, on a foot jack (40) mounted on the second top of the large base (42) of the trapezoidal base (41), and to connect its heald (29d) to the third post (24c) of the angle upright, so as to stiffen the assembling and delimiting a fifth face of the hexagonal staircase, and finishing this fourth cycle with its third step, by mounting a fourth railing (18), of which a sleeve (21a) is fitted on the upper end of the fourth post (24d) corner post, and the other sleeve (21b) is fitted on the rear corner post (11) of the third module (1), and so continuation until reaching the desired height of the staircase, each turn of which is made up of six modules (1) of staircase with two consecutive steps, the use of six posts of angle post and six railings (18). 14. A method of mounting a modular staircase according to claim 13, characterized in that from the fifth cycle, all the posts of angle post mounted in the second stage of the cycles are identical to the fourth post (24d) of corner post, and each corner post (24d) is mounted on and in the 5 extension of a front corner post (10) of an underlying staircase module (1). 15. A method of mounting a modular staircase according to any one of claims 12 to 14, characterized in that from the seventh cycle, the two lateral sleeves (32d) of each pole (24d) of the upright fit on the vertical studs (23a, 23b) projecting from the side of two neighboring railings (18) 10 underlying components previously assembled. 16. A method of mounting a modular staircase according to any one of claims 12 to 15, characterized in that from the seventh cycle, the rail (29d) of each post (24d) of the amount of angle is fixed by its free end (3 ld) on the post (24d) of the angle upright previously mounted in inclined spacer 15 substantially parallel to the inclined rail (s) (29b, 29c) of an underlying railing (18) previously mounted, so as to act as a third inclined rail.