Background of the invention Elevated floor assemblies are commonly used in commercial applications and office buildings, where a substantial number of cables, pipes and ducts are required and where it is desirable to maintain accessibility to the latter for ease of installation, change or removal. An elevated floor assembly basically consists of floor panels supported above the base floor by pedestals. The pedestals are normally located so as to provide support at panel corners. Cables, pipes or even air conditioning services are thus installed in a chamber formed between the base floor and the elevated floor and are easily accessible by simply removing the floor panels where needed.

The pedestals generally comprise a column having a lower end and an upper end, wherein the lower end is connected to a base plate for resting on the base floor and the upper end is connected to a support plate for receiving the floor panels thereon.

The design of the support plate is often very complicated, especially if stringer members, which are generally used to reinforce the elevated floor assembly, are to be connected to the support plates. Such support plates are e. g. shown in GB 2 226 060, wherein the support plate has radial tabs for the coupling of corresponding ends of stringer members. The pedestals are often designed so that the height of the elevated floor above the base floor can be adjusted. Such adjustment is often necessary due to irregularities in the surface of the base floor. Often, the pedestal comprises two members, connected together via a threaded connection. By rotating one member with respect to the other, fine height adjustment of the pedestal is achieved. This design does however generally not allow for a more substantial height adjustment.

It will also be appreciated that the manufacture of pedestals having complicated support plates is rather expensive. In addition, the greater the size of the support plate, the further the load discharge will be shifted to the outer part of the pedestal, consequently moving the load further from its axis and creating a deflection load on the pedestal itself.

Object of the invention It is an object of this invention to provide an elevated floor assembly that does not have the above-mentioned disadvantages. This problem is solved by an elevated floor assembly as claimed in claim 1.

Summary of the invention The invention proposes an elevated floor assembly comprising floor panels having an upper surface, an opposite lower surface and side faces, two adjoining side faces meeting in corner portions of the floor panel. The elevated floor assembly further comprises pedestals for supporting the floor panels at their corner portions above a base ftoor. wherein the pedestals comprise a <BR> <BR> <BR> shaft having a lower end being connected to a base plate for resting on the base floor and an upper end being connected to a supporting column for supporting the corner portions of the ftoor panets. According to an important aspect of the invention, the floor panels comprise lugs on the lower surface in the region of the corner portions, the lugs extending ina dlrection that is substantial perpendicular to the lower surface and away from the floor panel : and the supporting column comprises a receiving end for receiving the lugs therein.

Unlike pedestals of prior art assemblies, the pedestals used in the present elevated floor assembly are easy to manufacture. There is no need to provide a complicated support plate, as in prior art assemblies, thereby notably reducing manufacturing costs. All that is necessary is that the lug is received in the receiving end of the supporting column. The installation of the elevated floor assembly is also simplified ; the floor panels are simply placed with their corner

portion over the pedestal so that the lug engages the receiving end of the supporting column. This leads to a simpler and speedier installation of the elevated floor assembly, and hence reduces labour costs. Furthermore, by cutting the receiving end to size, the height of the pedestal can easily be reduced on site. Also, due to the fact that there is no support plate, deflection load on the pedestal is reduced.

Preferably, the tug comprises a first lug portion and an adjoining second lug portion the first tug portion being in a plane essentially parallel to a plane of a first side face of the floor panel, the second lug portion being in a plane essentially parallel to a, plane of a second side face of the floor panel, the second side face adjoining the first side face. The first and second lug portions are therefore arranged at an angle to each other, thereby reinforcing the structure of the lug. Preferably, the first and second lug portions are arranged in the same plane as the first and second side faces of the floor panel. The lug is hence located right at the edge of the corner portion of the floor panel. It is however not excluded to place the lug slightly in retreat of the edge of the corner portion.

The lug can comprise a taper in a direction away from the fioor pane !. The taper allows easier installation of the floor panel by guiding the lug into the receiving end of the supporting column.

The receiving end is advantageously a generally cylindrical hoitow member. The cross-section of the cylindrical hollow member can be circular, square, hexagonal or of any other convenient shape. Such a cylindrical hollow member provides a further important advantage of the invention. If the height of the pedestal needs to be reduced, this can be achieved by cutting off a top portion of the receiving end. The resulting receiving end will still be a cylindrical hollow member being able to receive the lugs of the floor panels therein. The height of the pedestal can therefore very easily be reduced on site during installation. There is no need to provide pedestals of different heights for the installation of the elevated floor assembly. An accurate survey of the installation site is no longer needed and savings in transport, handling and storage costs

can be made.

The receiving end is preferably dimensioned so as to receive the lugs of all the corner portions meeting over one pedestal.

The shaft preferably comprises a thread and a nut with a corresponding internal thread. wherein the supporting cotumn is designed so as to engage the shaft and rest on the nut. If a height adjustment of the pedestal is necessary, the nut can be rotated about the shaft, thereby moving the nut up or down the shaft. As the supporting column is designed to rest on the nut, its position is also modified, thereby adjusting the height of the pedestal. The height adjustment by means of the nut is preferably used for fine adjusting the height, e. g. to compensate for small irregularities in the base floor. The lower end of the supporting column can be tapered in order to provide engagement with the shaft. Alternatively, a plastic or metal buckle shape can be fixed inside the lower end of the supporting column for the same purpose.

In order to reinforce the'ioor pane !, the latter can comprise a meta ! plate on the lower surface.

According to a preferred embodiment of the invention, the floor panel cornprises stiffener elements, the stiffener elements being arranged on the lower surface of the floor pane ! along the side faces and extending in a generally perpendicular direction away from the floor panel. Such stiffener elements provide a structural reinforcement along the sides of the floor panels.

The structural reinforcement provides additional stiffness to the floor panels and increased stability to the floor assembly. In prior art assemblies, stringer members are connected to the pedestals before installation of the floor panels to provide the structural reinforcement. The Installation of such stringer members is rather time consuming. The need for such stringer members is eliminated by the stiffener elements. In the present assembly, the stiffener elements are connected to the floor panel, so that the structural reinforcement is provided with the installation of the floor panel. It will be appreciated that installation time and costs of the elevated floor assembly is substantially reduced with respect to prior art assemblies.

The stiffener elements can have generally rectangular or triangular cross- section. Other shapes are however not excluded.

The stiffener elements can be arranged on the edge of the floor panel or slightly in retreat of the edge of the floor panel. By placing the stiffener elements slightly in retreat of the edge of the floor panel, it can be ensured that the stiffener elements do not hinder the introduction of the lugs into the receiving ends of the supporting columns of the pedestals.

The stiffener eìements and/or the lugs are preferably formed in one piece with the metal support. Alternatively, the stiffener elements and/or the lugs can be welded or otherwise fixed to the metal support. By connecting the stiffener elements and/or the lugs to the metal support, a reinforced structure can be achieved.

According to an embodiment of the invention, the metal support comprises at ! east one btocking tab for receiving an edge of the stiffener element in engagement between the at least one blocking tab and the metal plate.

Preferably, the at least one blocking tab is formed in one piece with the metal plate. Advantageously, the edge of the stiffener element is engaged in a plurality of blocking tabs.

Brief description of the drawings The present invention will now be described, by way of example, with reference to the accompanying drawings, in which: Fig. 1 : is a perspective view of a floor panel and a pedestal of an elevated floor assembly in accordance with the present invention; Fig. 2: is an enlarged view of the corner portion of the floor panel of FIG. 1; Fig. 3: is a perspective view of a floor panel received on a supporting column of a pedestal ; Fig. 4: is a perspective view of three floor panels received on a supporting column of a pedestal ;

Fig. 5: is a section view through an edge portion of a floor panel according to a first embodiment; Fig. 6: is a section view through an edge portion of a floor panel according to a second embodiment; Fig. 7: is a section view through an edge portion of a floor panel according to a third embodiment; Fig. 8: is a section view through an edge portion of a floor panel according to a fourth embodiment; and Fig. 9: is a bottom view of the edge portion of the floor panel of Fig. 8.

Detailed description of a prerferred embodiment A floor panel and a pedestal of an elevated floor assembly in accordance with the present invention are shown in Fig. 1. Such an elevated floor assembly consists of individual floor panels 10, only one of which is shown in Fig. 1, supported above a base floor by means of pedestals 12 so as to define a chamber between the base floor and the elevated floor in which cables, pipes or even air conditioning services may be installed. The floor panels 10 are generally of square or rectangular shape and have an upper surface 14, an opposite lower surface 16 and side faces 18,18', the latter meeting in corner portions 20 of the floor panels 10. The pedestals are designed to provide support to the floor panels 10 at their corner portions 20. Four corner portions 20 of four individual floor panels 10 meet above one pedestal.

The pedestal 12 comprises a shaft 22 with an upper end 24 and a lower end 26. The lower end 26 of the shaft 22 is rigidly connected to a base plate 28 for resting on the base floor. The upper end 24 of the shaft 22 is designed to receive a supporting column 30 thereon for supporting the corner portions 20 of the floor panels 10. The lower end 32 of the supporting column 30 engages the upper end 24 of the shaft 22. The receiving end 34 of the supporting column 30 supports the corner portion 20 of the floor panel 10.

The floor panel 10 comprises, on the lower surface 16 of the corner portion 20, a lug 36 designed to engage in the receiving end 34 of the supporting column 30. The receiving end 34 is preferably designed as a hollow cylinder for receiving the lug 36 therein. It will be understood that the cross- section of the cylindrical receiving end can be circular, square, hexagonal or of any other convenient shape.

The lug 36 can be more clearly seen in Fig. 2, which is an enlarged view of the corner portion 20 of the floor panel 10 of Fig. 1. The lug 36 can e. g. comprise a first lug portion 38, being essentially in the same plane as the side face 18, and a second lug portion 38', being essentially in the same plane as the side face 18'. In the case of square or rectangular floor panels 10, the two lug portions 38,38'are then at right angles to one another. In order to facilitate engagement of the lug 36 in the receiving end 34 of the supporting column 30, the lug portions 38,38'comprise a taper in a direction away from the lower surface 16 of the floor panel 10. Alternatively, the lug 36 can also be differently shaped in order to provide an engagement of the lug 36 in the receiving end 34.

In Fig. 3, the lug 36 is shown in engagement with the cylinder shaped receiving end 34 of the supporting column 30. The receiving end 34 is designed so as to receive the lugs of all the corner portions meeting over one pedestal. In Fig. 4, e. g. , the corner portions of three floor panels 10,10', 10"are shown with their lugs 36,36', 36"engaged in the receiving end 34 of the supporting column 30.

Referring back to Fig. 3, the mounting of the supporting column 30 on the shaft 22 can be explained. The shaft 22 comprises a thread and a nut 40 with a corresponding internal thread. The lower end 32 of the supporting column 30 is designed so as to engage the upper end 24 of the shaft 22. The lower end 32 can e. g. comprise an internal thread corresponding to the thread of the shaft 22. When in engagement, a lower surface 42 of the lower end 32 of the supporting column 30 rests on an upper surface 44 of the nut 40. By adjusting the position of the nut 40 on the shaft 22, through rotation of the nut 40, the height of the pedestal 12 can be adjusted. Height adjustment by means of the

nut 40 can be made especially for fine-tuning. If a more substantial height reduction is necessary, e. g. if the pedestal rests on a raised portion on the base floor, the receiving end 34 of the supporting column 30 can be shortened. An upper portion of the receiving end 34 can simply be cut off, for example along cutting line 45 as indicated in Fig. 3. This can easily be carried out on site, thereby simplifying the installation of the elevated floor assembly, as there is no need to provide pedestals of different sizes.

If further support for the floor panels 10 is needed, which would previously have been provided by stringer members connected between neighbouring pedestals, stiffener elements 46,46'can be connected to the lower surface 16 of the floor panels 10. The stiffener elements 46,46'extend along the side faces 18, 18'of the floor panel 10 so as to structurally reinforce the floor panel 10.

As shown in Figs 5 to 8, the stiffener elements 46, 46'can be connected to a metal plate 48 attached to the lower surface 16 of the floor panel 10.

Preferably, the stiffener element 46 is formed in one piece with the metal plate 48. A marginal region 50 of the metal plate 48 can be folded so as to form the stiffener element 46. The edge 52 of the marginal region 50 can be welded to the lower surface 54 of the metal plate 48 facing away from the floor panel 10.

The stiffener element 46 can be arranged right at the edge of the floor panel 10 as shown in Fig. 5 or 8, or slightly in retreat as shown in Figs 6 and 7.

Alternatively, the stiffener elements 46,46'can be separate elements welded to the metal plate 48.

The stiffener element can be formed so as to have a generally triangular cross-section as shown in Figs 5,6 or 8, or a generally rectangular cross- section as shown in Fig. 7. It will be understood that many other configurations are possible.

It will be appreciated that the lugs 36 are preferably also connected to the metal plate 48, either formed in one piece therewith or welded thereon. This will increase the strength of the assembly.

The metal plate 48 can comprise one or more blocking tabs 56 for receiving the edge 52 of the stiffener element 46 in engagement between the blocking tabs 56 and the metal plate 48. Such blocking tabs 56 can be seen on Figs 8 and 9. Preferably, the blocking tabs 56 are formed in one piece with the metal plate 48.

It remains to be noted that, as shown in the figures, a floor panel for an elevated floor assembly commonly has a square shape. However it is not excluded to design the elevated floor assembly with floor panels having any other polygonal shape.

Reference numerals 10 10'10"floor panels 12 pedestal 14 upper surface of floor panels 16 lower surface of floor panels 18 18'side faces of floor panels 20 corner portions of floor panels 22 shaft 24 upper end of shaft 26 lower end of shaft 28 base plate 30 supporting column 32 lower end of supporting column 34 receiving end of supporting column 36,36', 36"lugs 38, 38'lug portions 40 nut

42 lower surface of lower end of supporting column 44 upper surface of nut 45 cutting line 46 46'stiffener elements 48 metal plate 50 marginal region of metal plate 52 edge of marginal region 54 lower surface of metal plate 56 blocking tab