DOUBLE BOTTOM WITH MODULE BASE PLATES

1. Field of the Invention

This invention relates to a raised floor made up of modular slabs mounted on vertical supports which are separated from each other and which rest on the ground.

2. Discussion of Background and Relevant Information

Raised floors known today are constituted of modular, usually square, slabs which are attached to one another in a horizontal plane and whose tops rest on horizontal supporting plates made up of the upper horizontal heads of vertical supports separated from each other. Each of these supports comprises a lower base fixed to the ground and a vertical bonding element, of fixed or adjustable length, between the lower base fixed to the ground and the upper support head of the slabs.

Up to the present time, slab tops have usually been placed quite simply on the upper support head of each support, their position on said head being determined by upwardly projecting elements held by the upper head of the support. These projecting elements are generally constituted of splinters which, in the case of square or rectangular slabs, are placed at regular intervals at right angles to each other around the vertical support axis, on which said axis the tops of four adjacent slabs merge. The splinters are inserted loosely in demarcated intervals between the lower parts of the slab edges in such a way that the assembly of the adjacent slabs on the support is relatively loose and the resulting floor is therefore not perfectly stabilized.

Another type of known raised floor assembly consists of supports whose heads possess slots into which the edges of the modular slabs are fitted, but the assembly of the adjacent slabs on the support obtained according to this process is also relatively loose, because a certain amount of play needs to be maintained for the purpose of fitting the edges of the slabs into the slots of the supports in order to facilitate assembly and to compensate for any expansion of the slabs. A known example of such an assembly is given in the context of U.S. Pat. No. 5,052,157 filed under the name of DUCROUX et al; another example is constituted by the floor described in German Patent Publication No. 2,107,898 filed under the name of CENTRAL FLOORING LTD. in which the support heads possess a protuberance against which the truncated tops of the slabs rest. Although the amount of play may be reduced in such an assembly, it cannot be completely eliminated for fear of raising the slabs in the event of expansion.

This invention aims to remedy the disadvantages described above by providing a slab assembly device ensuring a firm hold on these slabs once they are fixed on the upper heads of their supports. For this purpose, the raised floor, whose surface consists exclusively of modular slabs 1 in the shape of a regular polygon, presenting along their sides vertical edges 6 perpendicular to the plate 7 forming the base surface of said slabs 1, sustained at their tops by vertical supports 2 resting on the ground, is characterized in that the upper head 5 of the vertical supports 2 is fitted with radial slots 4 which are usually rectangular and which terminate in the periphery of said upper head 5, the width of said radial slots 4 being so determined as to cause a tightening through vertical fitting into a radial slot 4 of the vertical edges 6, facing each other, said vertical edges 6 belonging to two adjacent slabs 1.

The assembly device represented in FIGS. 1 to 3 is designed to ensure the maintenance of horizontal modular slabs 1, square or rectangular, of a raised floor on vertical supports 2 resting on the ground on which the raised floor is to be mounted. These vertical supports 2 are separated from each other by a distance corresponding to the dimensions of the modular slabs 1. Each vertical support 2, of fixed or adjustable height, comprises, on its lower part, a ground support base, not represented in the drawing, and, on its upper end, a horizontal support head 5 on which the tops of modular slabs 1 rest. In FIG. 1, only two slabs are partially represented, but it is clear that each vertical support 2 serves to support four square or rectangular slabs 1. These four slabs 1 are attached to each other, that is to say that their vertical edges 6 are fixed against each other, and the tops of the four adjacent slabs are merged together, as seen from a plan view in point O through which the vertical axis zz' of the support 2 passes.

According to the invention, the width of the rectangular slots 4, fitted on the upper head 5 of vertical supports 2 and terminating in its periphery, is so determined as to cause a tightening of vertical edges 6, facing each other, when said vertical edges 6, belonging to two adjacent slabs 1 are fitted vertically into a radial slot 4.

FIGS. 3 and 4 represent a variant of square-shaped modular slabs according to which the edge 6 of said slab spreads horizontally over a length which is less than that of a side of the slab, being centered on the middle of the side.

FIGS. 5 and 6 represent a slab assembly device according to another variant. In FIGS. 5 and 6, each edge 6 of a square or rectangular-shaped slab 1 is formed by a lateral rim, folded at right angles towards the bottom of the upper plate or plate portion 7 of slab 1. This edge 6 extends over a part of the length of the side of the slab, terminates at a distance from the top O of the slab and is extended towards this top for a short distance by a vertical joining edge of lesser height constituting a locking element of the slab 1 on the upper horizontal head 5 of a vertical support 2. For this purpose, the head 5 possesses four rectangular radial slots 4, terminating in the periphery of the circular or polygonal head 5, converging towards the center O and distributed regularly at right angles to each other around the vertical axis zz' of the support 2. Each locking slot 4 is rectangular in shape and its width e is equal, in the case of edges without bosses, to twice the thickness of a joining edge 3 of reduced height. The radial depths, and according to axis zz' of each slot 4, are sufficient to receive the whole of the joining edge 3, thereby allowing the corner of the slab 1 to rest on the central part of head 5 without there being contact between the vertical slices 8 of the parts 3 of the edges 6 ensuring the joining of slabs 1 and the vertical bottom 9 of the slots 4.

As may be seen from a study of FIG. 6, the adjacent slabs 1 are firmly secured on the head 5 of the support 2 by their joining edges 6 which are inserted tightly in their locking slots 4 and are held close to each other due to the fact that the thickness e of each slot 4 is equal to twice the thickness of the edges 6.

FIG. 7 is a side-face view of the slabs represented in FIGS. 5 and 6.

FIGS. 8, 9 and 10 illustrate a variant embodiment of the slabs according to the invention in which the end 3 of the edge 6 ensuring the fastening of each slab 1 in a radial slot 4 is made up of an elastic strip 10 which is obtained by means of a vertical cut 11 or horizontal cut 12 in the edge 6. In these same figures, a boss 13, shown in greater detail in FIG. 11a, is represented on half of the elastic strips, this boss corresponding to another embodiment of the slabs. According to this variant, one elastic strip in two is fitted with a boss 13 according to the distribution illustrated in FIGS. 11 and 12. These figures represent, in the case of square slabs, the two possible distributions of the bosses allowing the assembly of the slabs according to the invention. It is obvious that the shape of the slabs is not limitative and that the same results would be achieved with triangular or hexagonal slabs. The purpose of the elastic strips 10 is to make it possible to fix the slabs on the supports, this fixture presenting a certain elasticity, due to the strips, whilst at the same time maintaining a tight assembly of said strips 10 in the slots 4 provided on the heads 5 of the supports. Moreover, the addition of a boss on one of the two strips facing towards the interior of a slot 4 makes it possible to create a certain play between the surfaces 7 of the corresponding adjacent slabs. This illustrates how elastic strips fitted with bosses preserve play between the surfaces of the slabs which may therefore expand, for example as the result of heat, without this expansion causing the slabs to rise, even if the expansion of one or more slabs is greater than the play between the same slabs, the elasticity of the assembly allowing a relative movement of the slabs with regard to their support in the horizontal plane without causing upheaval phenomena. In addition, the slabs 1 will firmly fit onto their support 2 by means of the tight assembly of the strips in the slots 4. The result is a floor on which the two kinds of play have been disassociated. The play concerning the slots is eliminated thereby allowing a firm assembly of the edges 6 of the slabs 1 in the radial slots 4. The play between the base plates 7 of the slabs 1 is preserved and even accentuated by the elasticity of the bonding between the slabs and their supports, thus making it possible to offset all the problems of expansion. Obviously, the play between the base surfaces 7 of the adjacent slabs 1 obtained by adding a boss on the elastic strips 10 could equally well be achieved with another device, for example through folding the strips 10, but in this case, a regular distribution of the play between the base surfaces 7 would be harder to achieve than with bosses.

FIG. 13 shows a raised floor according to the invention consisting of a set of horizontal modular slabs 1, which are attached to each other and are of the same size and the same equilateral triangle shape. The tops of the individual slabs 1 are merged in points O constituting the nodes of a mesh network with triangular meshes formed by the set of slabs 1.

Each node O of the network constitutes the common top of six triangular slabs 1 distributed regularly around a vertical axis passing through the node O and constituting at the same time a regular hexagon. A subjacent support 2 is associated to each node O, which said subjacent support will be described in detail below. The support may consist of an independent element, for example such as one of the element 16, 21, 25, 29, or 31 illustrated in FIGS. 21 to 27. At its lower end, the support 2 rests on the ground on which the raised floor is mounted. From the preceding description it may therefore be seen that each triangular slab 1 rests on the floor at the three points O formed by the three tops of the equilateral triangle constituted by said slab.

The triangular-shaped modular slabs 1 are only used if the length L of the surface to be covered by the raised floor is equal to a multiple of the height h of each triangular slab 1.

However, as may be required in exceptional circumstances, provision is made, again according to the invention, to complete the assembly of the raised floor, in the neighborhood of the walls, by means of supplementary end slabs 14 , each in the form of an isosceles trapezium corresponding to three attached standard main triangular slabs 1. In other words, the small base of each end slab 14 is equal in length to the side of the triangular slab 1, the length of its large base is equal to twice the length of the side of a triangular slab 1, and the height of an end trapezoid slab 14 is equal to the height h of a triangular slab 1. The median area of the large base of each end slab 14 is arranged so as to be capable of receiving a standard support or a standard jack, as will be seen below.

The end slabs 14 ensure good floor stability along the walls, once adjusting cuts have been made. FIG. 14 shows various scenarios explaining this necessity.

The section carried out in the direction of arrow a reveals that the triangular main slabs 1 give satisfactory results, that is to say an adequate support along length a1. Lengths a2 and a3 show three other adjustment possibilities by means of end slabs 14 which are truncated in order to obtain improved results.

The section carried out in the direction of arrow b shows that the small surfaces x of the triangular slabs 1, remaining after cutting and indicated by section lining, are inadequate and unequal to the task of providing satisfactory support along length b1. In contrast, end slabs 14 are used along length b2, and the parts remaining after cutting, represented in section lining, have a sufficient surface to provide a satisfactory support.

The section carried out in the direction of arrow c shows that satisfactory stability is obtained, along length c1, using the end slabs 14, but in this case triangular slabs 1 could also have been used.

The section carried out in the direction of arrow d reveals that satisfactory stability along length d1 is obtained using cut end slabs 14, whereas the triangular slabs 1 would involve small cuts x which would be impossible to fix.

In the angles, the sectional intersections--in directions a and c, on the one hand, and in directions b and d, on the other hand--are made using end slabs 14.

FIGS. 14, 15, 16, 17 and 18 represent the triangular-shaped slabs corresponding to the variant of the invention under consideration. The characteristics are the same as for modular slabs of any regular polygonal shape. The subjacent support 2 comprises an upper support face 5 in which six converging radial slots are bored, these slots being distributed at regular intervals and at an angle of 60.degree. to each other, on a circle of center O where the tops of six adjacent triangular slabs 1 are merged, as shown in FIG. 16. If the support face 5 is circular, it may be seen that each corner of a triangular slab 1 rests on a sector at an angle of 60.degree. of the circular support face 5. Parts 3 of edges 6, folded downwards, are inserted in the converging radial slots 4. As the width e of each slot 4 is chosen equal to twice the thickness of the parts 3 of the edges 6, said edges 6 of two adjacent triangular slabs 1 are packed and blocked against each other in the same slot 4, as may be seen from a study of FIGS. 17 and 18, thereby ensuring a firm fixture of the slabs 1 on the support 2. The converging forms of the slots 4 provide the horizontal hold of the slabs 1, while the three-point support for each slab 1 gives perfect stability, thus eliminating any risk of vertical movement which might lead to disassembly, but at the same time ensuring easy, fast and effortless dismantling. Moreover, each support 2 is particularly stable since it is simultaneously retained by six adjacent triangular slabs 1.

With a view to making the representation as clear as possible, in FIGS. 14, 15, 16, 17 and 18 the edges 6 are shown in their simplest form, that is to say without height reduction at their extremities, without strips and without bosses. It is clear that all these different variants may be applied to triangular-shaped slabs. In particular, in the presence of bosses 13 on the elastic strips 10, the width of the radial slots 4 will be equal to twice the thickness of the strips 10 plus once the thickness of the boss 13.

The view from below represented in FIG. 18 gives a good illustration of the way in which the edges 6 of triangular slabs 1 are attached to each other, thereby establishing the continuity of the floor. However, due to the fact that there is a separation plane between two adjacent slabs 1, the floor displays good acoustic performance since the separation planes between the slabs break horizontal sound transmission, particularly in the case of the variant in which parts 3 of edges 6 are in the shape of elastic strips fitted with bosses, because in this case the base plates 7 of the slabs are separated from each other by a play corresponding to the thickness of the boss. Moreover, given that the triangular slabs 1 are small in size, they mitigate the membrane effect obtained with larger surfaces.

FIGS. 19 and 20 represent an arrangement of a trapezoid end slab 14. This end slab may also, like the triangular slab 1, be made up of sheet metal cut and folded so as to form a trapezoid base plate 35 which presents, on its sides, rims folded at right angles in the same direction and culminating at a same distance from the tops of the base plate 35. The two inclined sides and the small base of the trapezoid slab 35 each comprise two distinct edges 15 which are obtained by creating a recess 34 centered on the edge of the large base. This recess 34 between the two edges 15 of the large base is needed to attach the end slab 14 to the subjacent supports.

With reference to FIGS. 21 to 27, a description will now be given of various non limitative embodiments of the floor supports. These supports, which are constituted by independent elements designed to receive, according to a preferred variant of the considered invention, on their upper faces, the triangular slabs 1 and the trapezoid end slabs 14 and to keep them assembled, determine the height of the plenum obtained, that is to say, of the empty space under the floor which is equal to their own height. Each support comprises a horizontal upper face 5 in which are formed the six converging radial slots 4 distributed, at an angle of 60.degree. in relation to each other, around the center O of the upper face 5.

The support 16 represented in FIG. 21, is made in a single steel piece, in a general upwardly converging tapered shape, terminated at its lower part by an external flange 17 constituting a support base on the ground. The upper face of the upper horizontal wall 18 of the support 16 constitutes in itself the planar support and fastening face 5 of the slabs. The radial slots 4 are bored both in the upper wall 18 and in the upper part of the tapered lateral wall.

In the variant represented in FIG. 22, the support 16 comprises a full upper wall 20 onto which is fastened, for example by welding, an added circular plate 19 in which the radial slots 4 are formed.

In the variant represented in FIG. 23, the support 21 is made up of three parts, assembled together by welding or otherwise, namely a lower horizontal base 22, an upper horizontal head 23 in which the radial slots 4 are bored in order to fasten the slabs, and an intermediate vertical body 24 stretching between the base 22 and the head 23, all these elements being preferably fabricated in steel.

In the variant represented in FIG. 24, the support 25 comprises a lower block 26, of tapered shape and possibly made of matter which is inert to fire such as resin, plastic matter, plaster, cement, anhydrites, calcium silicate, conglomerate wood, etc. An upper circular steel plate 27 is fixed on the upper face of block 26, in which said plate 27 are cut the radial slots 4 which lie above corresponding radial grooves 28 formed on the upper part of block 26.

In the variant represented in FIG. 25, the support 29 is made up of a molded block, with a grooved structure, and fabricated of light alloy, plastic material, compressed wood, resin, etc. The support 29, of a general taper shape, possesses in its upper horizontal wall six molded radial grooves 30 placed at an angle of 60.degree. in relation to each other as described in the previous embodiments.

FIGS. 26 and 27 show a variant in which the support 31 is made up of a hexagonal shape in molded material hollowed out by six radial slots 32 and equipped with six reinforcement grooves 33 shifted by 30.degree. compared to the radial slots, these reinforcement slots 33 making it possible both to increase the ground support surface and the slab support surface.