FR2481989A1 - Staircase component prefabrication method - uses unitary concrete components each forming tread and riser moulded on table and separated by shuttering - Google Patents

Abstract

The staircase prefabrication method uses a number of separate one-piece components, these each consisting of two concrete portions at right angles, forming a tread and a riser. These components are moulded on a table, one of the portions being formed horizontally on the table and the other along its edge and vertically. The table can have horizontal (2) and vertical faces (4), while shuttering components (16, 17, 18) are mounted on it to form the moulds. The concrete is subsequently poured into the mould to form the unitary components.

Description

/ AND TOOLS /
PROCESS / PREFABRICATION OF MONOBLOCK ASSEMBLIES FOR
TO MAKE STAIRS AND MONOBLOCK ASSEMBLIES
PREFABRICATED
The invention relates to a pre-production method for making one-piece assemblies ready to be assembled on site to make a staircase.
It extends to prefabricated monoblock assemblies, to stairs made from them and to a tool specially designed for implementing the process.

 The invention relates to the prefabrication of one-piece assemblies of concrete or any other similar material capable of being molded 9 for the purpose of simplifying the terminology, this material will subsequently be designated by the term concrete, but it is understood that this covers any material capable of fulfilling the same function9 heavy concrete, light concrete with or without the addition of admixture, reinforced concrete, expanded clay concrete, moldable synthetic material capable of fulfilling the role of concrete ...

 The prefabrication of concrete stairs is currently a technique that is not widely used, in effect it requires expensive molds and only allows standardized types of stairs (straight or helical steps of identical shape), so that it lacks flexibility to meet existing needs which in most cases require the creation of stairs of specific type and size.

The present invention proposes to indicate a new prefabrication process requiring only inexpensive tools and benefiting from a great flexibility to adapt to each practical case.
An objective of the invention is in particular to allow, in each case, practical to prefabricate one-piece assemblies capable of authorizing the production of a staircase meeting the requirements of the case considered this staircase can be of any type and in particular of the type " balance "which is most often requested and requires the realization of markets of different shapes.

 Another objective is to prefabricate one-piece assemblies allowing, from these, a simple and easy assembly of the staircase.

Another objective is to produce low-weight monoblock assemblies which are easy to handle and to set up.

 To this end, the prefabricating process according to the invention which consists in making several separate monoblock assemblies, each composed of two concrete elements arranged at right angles to one another in order to constitute a step and a counter step, is characterized in that said one-piece assemblies are molded on a table, one of the elements in Breton being molded to extend horizontally on the table and the other being molded at the edge of the first and in continuity for extend approximately vertically.

Note that the terms defining a direction ("horizontal", "vertical" ...) must be interpreted broadly, as simply defining a general direction. Likewise, the expression "in square" aims at an orthogonal or secant orientation approaching orthogonality,
The concrete element produced in the horizontal direction on the table can be the riser or the step of the monobloc assembly; however, it will be seen below that this element is preferably walking, the riser being carried out vertically. In addition, it is possible to make the vertical element, by orienting it, either up above the table, or down below it. As will be seen below, this last case is advantageous because it corresponds to greater ease of implementation; in the first case, it is necessary to have a closure cap above the step molding volume, this cap having a lateral flank facing upwards which delimits the molding volume of the step.

According to a preferred embodiment which will be very advantageously used in practice, the monobloc assemblies are molded in concrete on a table provided with a substantially horizontal molding surface and at least one substantially vertical sidewall.
by placing on said table formwork elements of appropriate shapes to delimit molding volumes, corresponding to the steps
sets and extending horizontally to the edge of the table,
by positioning opposite one or more sides of the table one or more cheeks of suitable shapes to delimit molding volumes, corresponding to the risers of the assemblies and extending vertically at the edge of the aforementioned molding volumes,
by pouring the concrete inside said volumes so as to ensure continuity between steps and risers
by allowing the sets thus molded to harden, and then removing them from the mold after spacing out the days and removing the formwork elements.

Thus, the method of the invention leads to making stairs by means of prefabricated monoblock assemblies each comprising a step and a square riser. Firstly, it should be noted that the angled profile of these assemblies allows them to benefit from a high mechanical resistance, while having a moderate weight. Of course, in most cases, the concrete will be reinforced with metallic reinforcements at the time of pouring.

The formwork elements which are placed on the molding table to delimit the steps or possibly the counter-steps) can be constituted by simple metal profiles with rectangular or U-shaped section, arranged according to the desired shapes.

These elements are very inexpensive, and it is possible to provide an appropriate assortment for performing all forms of walking, both for the manufacture of straight and helical stairs as for the manufacture of balanced stairs. In particular, the straight steps are achievable in all dimensions, simply by moving certain formwork elements in the manner of sliders to assign them appropriate positions.

 The visible face of the storytelling of each monobloc assembly may or may not be produced with a nose, by adapting the shape of the cheeks which are arranged opposite the vertical sides of the table and are used for molding this face.

 During the assembly of the staircase, the monoblock assemblies thus prefabricated are superimposed so that the riser of an assembly rests on the step of the lower neighboring assembly The step can be adjusted according to the dimensions of the cage staircase, which allows the same group of monoblock assemblies corresponding to a given type of staircase, to provide the assembly with multiple possibilities for adapting to cages of different dimensions.

 We can see the flexibility of the process of the invention which, in practice, proves capable of meeting most of the needs with very limited investments.

It is possible by this method to design a sampling of staircases of various shapes and dimensions in order to cover almost all of the needs, the manufacturer's investment being limited to the production of the various formwork elements corresponding to these staircases.

 Preferably, the formwork elements corresponding to the monoblock assemblies of a given staircase will be stored together and referenced, so that it is easy for molding a staircase requires selecting the corresponding formwork elements in order to arrange them on the molding table: the method of the invention thus makes it possible, at each molding, to produce in a very practical manner various monoblock assemblies corresponding to the desired staircase.

To facilitate the choice of customers, the manufacturer may publish a brochure giving all the parameters of the stairs with their reference, this reference transferred to the formwork elements allowing the
manufacturer to instantly select the necessary elements according to the customer's choice, in order to undertake prefabrication on demand. Of course, the monoblock assemblies corresponding to the most common staircases can be stored in order to be quickly available.

Furthermore, according to another characteristic of the invention tending to facilitate the fitting of the cheeks during the prefabrication of the mono-block assemblies, each of these is preferably articulated below the molding table so as to be able to tilt towards the side of said table or, on the contrary, in the opposite direction for demolding; before pouring the concrete, it is thus easy to block each cheek in the appropriate position by means of blocking members9 in the buttocks by means of blocking wedges introduced at the back of the cheeks in necklaces.

In addition, according to another characteristic of the invention, the molding table and its cheek or cheeks are vibrated during the pouring of the concrete in order to distribute and homogenize it.

 The invention extends to a tool for implementing the process described; according to the invention, this tool essentially comprises a table provided with a substantially horizontal molding surface and at least one substantially vertical flank, at least one cheek adapted to come opposite said one or more flanks, means for finishing said cheek, and formwork elements adapted to rest on the molding surface and constitute a formwork at the edge of the stair treads.

 The molding table is advantageously of elongated rectangular shape9 carried by several uprights, comprising along its long sides two continuous flanks extending from one end to the other 9 a cheek extends so continues, opposite each sidewall9 and is articulated on the table uprights and associated with collars and locking corners. In addition, the molding table is preferably associated with vibrating means.

 The invention extends to monoblock assemblies for staircases, produced by implementing the method described and each consisting of a step and a right angle step. It covers each single block assembly separately as well as the superimposed assemblies to form a staircase.

The invention having been explained in its general form, other characteristics, aims and advantages will emerge from the description which follows, with reference to the appended drawings, which illustrate, by way of non-limiting examples of the embodiments of the method of the invention and an embodiment of tooling; on these drawings which form an integral part of the description
- Figure 1 is a schematic view of a one-piece assembly according to the invention; in this figure has been symbolized in broken lines another assembly in order to illustrate the assembly on site,
FIG. 2 is a practical perspective view, intended to illustrate the prefabrication process of the invention and representing a tool for implementation in use,
FIG. 3 is a section through a vertical transverse plane AA of this tool,
FIG. 4 is a partial section thereof of a tamil by a transverse plane B offset relative to the plane AA,
FIG. 5 is a partial profile view of the arrow V with partial section of a tool member,
FIG. 6 is a schematic perspective view of a formwork element,
- Figure 7 illustrates another embodiment of the method of the invention.

 The method of the invention proposes to prefabricate at low cost and with reduced investments one-piece assemblies such as l (fig. 1) intended for the production of stairs on site.

 Each set is constituted by a step la of various shape, depending on the type of staircase, and by a counter-step lb in a square.

on site by installing several monoblock assemblies 1 so that the counter step of an assembly rests on the step of the lower assembly, the assemblies being positioned relative to each other to adjust the fold of each step to the desired value according to the dimensions of the stairwell to be trimmed.

It should be noted that the monoblock assemblies could be produced in a reverse manner, each monobloc assembly being constituted by a step and by the riser situated above.

The monoblock assemblies 1 are prefabricated on a molding table (FIGS. 2, 3, 4 and 5) comprising a horizontal molding surface 2 of elongated rectangular shape, carried by several uprights such as 3; this table includes along its long sides two continuous flanks such as 4, formed by plates fixed on the uprights.

In addition, opposite each side 4, the table comprises a movable cheek 5 formed by a plate 5a of direction close to the vertical and by a return 5b of direction close to the horizontal, intended to come into abutment against the side 4 of the table.

 Each cheek 5 is continuous and extends over the entire length of the table opposite the corresponding flank 4; it is carried by supports 6 distributed along the table opposite the uprights 3 which support it.

These supports 6 are articulated on the uprights 3 by yokes 6a which extend them, so that each cheek 5 can be brought to pivot towards the table or in the opposite direction
Locking members are provided at each support 6 to block the cheeks in the closed position; for example, each of these members may be constituted by a collar 7 which is fixed to the upright 3 and allows the establishment of a blocking wedge 8, in particular made of wood.

The cheeks 5 can thus be very quickly blocked in the closed position or released for demolding and this, under very safe operating conditions since the system is devoid of screw or similar members which, in the presence of cement or similar products, tend to get stuck.

Furthermore, the molding table is associated with vibrating means, comprising in the example three separate vibrating assemblies, one 9 disposed below the molding surface 2 in the middle position, w another 10 associated with one cheek 5 and the third ll associated with the other cheek 5.

 Each vibrating assembly 9, -10 or 11 comprises a motor 12 which drives by means of pulleys and belt 13 a shaft 14; this shaft 14 is formed by rigid sections 14a and - by coupling sleeves 14ben of an elastic material, for example of rubberized rubber (fig. 5).

 Each rigid section of the shaft passes through a body 15 secured to the corresponding movable cheek 5 & comprising support bearings and eccentric counterweights for vibrating; these means are known in themselves and will not be described in more detail.

 The prefabrication tool is supplemented by an assortment of formwork elements such as 16, which are called upon to rest on the molding surface 2 to delimit the periphery of each step. These elements can very simply be constituted by metal profiles with a square or rectangular section or with a U-shaped section.

In the parts corresponding to demouldable tread portions (without undercut) several sections of sections can be welded one after the other to obtain the required shape (part 16a shown in Figure -6); in the undercut parts (16b), a section of profile formed in the example by a plate is fixed by screws and bolts so that it can be removed during demolding.

 It is understood that these formwork elements are extremely inexpensive and that it is possible to produce a complete assortment thereof with a reduced investment.

Note that, for straight steps, it is possible to provide a straight profile such as 17 extending over the entire length of the table and transverse sliders such as 18 to separate the assemblies.

The essential characteristics of the tooling according to the invention having been set out, the implementation process will be described below.

 Thanks to a brochure giving the various characteristics of a set of staircases that meet existing needs, the customer chooses the one that meets his requirements and provides the manufacturer with the reference.

This one selects the corresponding formwork elements 16, 17 or 18 which bear this reference and arranges them on the surface of; oulage 2 of the table
It also has vertical formwork elements such as wooden blocks 199 at the edge of each riser between the cheek 5 and the flank 4 of the table in order to limit on its edges the molding volume of each counter -market. These elements may be independent or else may be integral with the horizontal elements 16 or 18. For example, for straight steps, these vertical elements may be integral with the sliders 18 which will therefore be square.

The movable cheeks 5 are then folded down to be applied against the ends of the formwork elements 6 and against the vertical elements in order to form the molding volumes of the risers; they are locked in this position by means of the corners 8.

Wedging pieces such as wooden spacers 20 are then placed in the middle part of the table between the formwork elements of the two series of assemblies called to be molded simulates simultaneously (a series on one side of the table, the other on the other side). These parts are blocked by small blows of mallet.

 The table is then set in vibration by operating the motors 12 of the vibrating assemblies 9, 10 and 11. The concrete is poured in the horizontal molding volumes (steps) and vertical (risers) until it is flush with the upper surface of the formwork elements 16.

 Reinforcement reinforcements are, if necessary, placed in the heart of the concrete.

 When the latter is correctly distributed and homogenized, the vibrating assemblies are stopped.

 The visible face of each molded monobloc assembly, called c 'constituting the upper face of the step la of the assembly, is then treated by smoothing and anti-slip bush hammering before hardening of the concrete.

Once the concrete has hardened, demoulding is carried out by removing the spacers 20, by removing the cheeks 5, and if necessary, by dismantling the undercut parts 16b of the formwork elements 16.

Note that the portions 5a of the cheeks 5 can be slightly inclined relative to the vertical, as shown in Figure 3, to facilitate demolding.

 The various monobloc sets of the staircase are finished and ready to be delivered for assembly on site.

 Furthermore, Figure 7 illustrates another embodiment of the method of the invention ~ and another embodiment of the tool. The tooling is similar to the previous one with certain modifications described below.

 The continuous flanks referenced in 4 ′ are arranged above the molding surface 2 ′ of the table and integral with the latter.

 The monoblock assemblies are then molded with their riser facing upwards. The molding volumes of the step are demarcated, as before, by formwork elements 16 'arranged in a similar manner. In this mode of implementation, these molding volumes are closed above by caps 21 which have facing flanks 4 'of the cheeks referenced in 5'. Each cap 21 can be sorted simply by means of two square plates with gussets between lss, a plate forming the vertical cheek 5 'and the @ @ hor * óntaleX resting on the formwork elements 16 and closing the volume molding of the steps.

 The molding is carried out first by filling the molding volume of the steps with concrete, then by placing the caps 21 with their cheeks 5 ′ which delimit the molding volumes of the risers, finally by filling these latter molding volumes .

 It should be noted that, in this case, the visible faces of the step and the riser are both molded, which eliminates the finishing operations.

 Of course, the invention is not limited to the terms of the preceding description, but includes all variants thereof.

Claims (18)

 1 / - Method for prefabrication of stairs, consisting of making several separate monoblock assemblies (1), each composed of two concrete elements (la, lb) arranged at right angles to one another in order to constitute a step and a counter step, characterized in that said one-piece assemblies are molded on a table, one of the concrete elements (la) being molded to extend horizontally on the table and the other (lb) being molded at the edge of the first and in continuity to extend approximately vertically. 2 / - A method of prefabrication of stairs according to claim 1, consisting of making several separate monoblock assemblies (l), each composed by a step (la) and by a square step (lb), characterized in that said monoblock assemblies (1) are molded in concrete on a table provided with a substantially horizontal molding surface (2) and at least one substantially vertical sidewall (4) . by arranging on said table formwork elements (16, 17, 18) of shapes suitable for delimiting molding volumes, corresponding to the steps (la) of the assemblies and extending horizontally to the edge of the table,  by positioning opposite one or more sides (4) of the table one or more cheeks (5) of suitable shapes to delimit molding volumes, corresponding to the risers (lb) of the assemblies and extending vertically at the edge of the vdumes aforementioned molding, by pouring the concrete inside said volumes so as to ensure continuity between steps (la) and counter steps (lb),  . by allowing the assemblies (1) thus molded to harden and then removing them from the mold after the cheeks (5) have been moved apart and the formwork elements (16, 17, 18) have been removed.  3 / - Method according to claim 2, characterized in that a longiform table is used, comprising two sides (4) extending along its two long sides, the monoblock assemblies (1) being molded in two series, the one on one side of the table with the risers (lb) of the molded assemblies between a side of the table (4) and a cheek (5), the other on the other side with the risers (lb) molded between the 'another side (4) and another cheek (5).  4 / - Method according to claim 3, characterized in that the formwork elements (16, 17) arranged on the table for molding the two series of monoblock assemblies (l) are locked against the corresponding cheeks (5) by pieces wedging (20) placed in the middle of the table between the formwork elements (16, 17) of the two series  5 / - Method according to one of claims 2, 3 or 4 characterized in that vertical coforming elements (19) are arranged at the edge of each step (lb) between the corresponding cheek (5) and the side of the table (d) in order to limit on its edges the molding volume of each riser  6 / - Method according to claims 4 and 5 taken together, characterized in that each cheek (5) is articulated below the table to be able to tilt towards it or in the opposite direction, said cheek (5) being blocked in the appropriate position by applying it by means of locking members (7, 8) against the ends of the formwork elements (16, 18) and against the above-mentioned vertical elements (19). 7 / - Method according to one of claims 1, 2, 3, 4, 5 or 6 characterized in that the visible horizontal face of each monobloc assembly (1) is called upon to constitute the upper face of the step (la) and is treated before hardening of the concrete by smoothing and anti-slip bush hammering.  8 / - Method according to one of claims 2, 3, 4 or 5, characterized in that the vertical flank (s) (4 ') of the table are arranged above the molding surface (2') thereof, the cheeks (5 ') being integral with closure caps (21) adapted to be positioned above the formwork elements (16') in order to close the mold volumes corresponding to the steps.  9 / - Method according to one of claims 1, 2, 3, 4, 5, 6, 7 or 8, characterized in that the table and its or its whips are vibrated during the pouring of the concrete in order to distribute and homogenize it.  10 / - Method according to one of claims 1, 2, 3, 4, S, 6, 7 or 8, characterized in that one realizes, ci 'each molding, one-piece assemblies (1) suitable for the construction of a staircase of predetermined type, the formwork elements (16, 17, 18) arranged on the table being adapted to allow the molding of the various forms of steps (la) of said staircase. 11 / - Tools for the prefabrication of monoblock sets of stairs in accordance with the method according to one of claims 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10, characterized in that it comprises a table provided with a substantially horizontal molding surface (2) and at least one substantially vertical sidewall (4), at least one cheek (5) adapted to come opposite said side (s), fixing means (7, 8 ) of said cheek, and formwork elements (16, 17, 18) adapted to rest on the molding surface (2) and constitute a formwork border of the stair treads (la).  12 / - Tooling according to claim 11, characterized in that the table is of elongated rectangular shape, carried by several uprights (3), and comprises along its long sides two continuous sides (4), a cheek (5) which extends continuously opposite each side (4), being articulated on the uprights (3) of the table and associated with collars (7) and wedges of block cage (8).  13 / - Tooling according to claim il, characterized in that the table is of elongated rectangular shape and comprises along its long sides and above the molding surface (2t) two continuous flanks (4 '), closure caps (21) being provided to be arranged above the shuttering elements (16 ') and each comprising a cheek (5') intended to come opposite a side (4 ') of the table. 14 / - Tooling according to one of claims 11, 12 or 13, characterized in that the shuttering elements (16, 17, 18) are constituted by metal sections arranged to delimit the periphery of each step (la) to be produced .  15 / - Tooling according to one of claims 11, 12, 13 or 14, characterized in that the table is associated with means for vibrating (92 10, 11). 16 / - Tooling according to claims 12 and 15 taken together, characterized in that the vibrating means comprise three vibrating assemblies, one (9) disposed below the molding surface of the table, another ( 10) associated with one cheek and the third (11) associated with the other cheek.  17 / - Monoblock assemblies for esca vers, characterized in that they are produced by implementing the method according to one of claims 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10, and are each consisting of a step (la) and a counter step (lb)  18 / - One-piece assemblies according to claim 17, characterized in that they are superimposed to make a staircase so that the counter step (lb) of a one-piece assembly rests on the step (la) of the lower one-piece assembly.