Construction panel for double floors in air conditioned rooms

A compound construction panel for double floors used in room air conditioning, comprising an external, tub-shaped sheath formed of a high tensile-strength and high Young's modulus material, a filler in the sheath formed of a low tensile strength and low Young's modulus material, and a rigid annular body disposed in an aperture in the bottom of the sheath and extending to the upper portion of the sheath. The annular body is anchored in the filler and is provided with a radially inwardly projecting annular flange at its lower portion which serves as a support for an air discharge nozzle, a dirt-catcher or the like.

BACKGROUND OF THE INVENTION 
The invention relates to an overhanging compound construction panel for 
double floors used in air conditioning applications to rooms, comprising 
an external tub-shaped sheath made from a high tensile-strength and high 
Young's modulus material, for instance, sheet metal or plate steel, and a 
hardened filler material positioned in the flowing or pourable state in 
this tub-shaped sheath and of a minor tensile-strength and minor Young's 
modulus, for instance, anhydrite. 
Such a compound panel is known from the German Pat. No. 2,004,101. This 
panel is especially characterized by high static strength at a relatively 
minor thickness, but furthermore it is also combustion-proof and 
acoustically very advantageous, so that it is especially suited to the 
manufacture of high-grade double floors. 
In recent times, double floors have been increasingly used in relation to 
room air conditioning, the conditioned air being directly introduced 
through the space between the double floor and a solid or raw ceiling or 
through ducts by means of apertures in several selected double-floor 
panels into the room to be air conditioned. Air-discharge means, so-called 
spin nozzles, together with a dirt-catching means or the like underneath 
each are integrated in these orifices in the double floors. To date, the 
mounting of these air discharge nozzles with associated dirt-catchers was 
implemented solely in double floors made of wood or steel. Where double 
floors made from compound panels as initially described are concerned, 
special steel plates have been used for room air conditioning purposes 
wherein are contained the air discharge nozzles with dirt-catchers. The 
integration of nozzles and dirt catchers in these compound panels presents 
some difficulties as these panels are of relatively low height and 
therefore one or more cut-outs in them will excessively reduce their 
mechanical strength. Account must be made in this respect that where such 
double floors are used, for instance, in offices or computer facilities, 
they are subjected to very substantial loads of several tons, even to 
point loading. On the other hand, the use of special steel plates in 
double floors is both uneconomical and acoustically disadvantageous. 
SUMMARY OF THE INVENTION 
It is therefore the object of the present invention to eliminate the above 
drawbacks and to so further develop a compound panel of the 
above-described kind that it can be equipped with one or more air 
discharge nozzles and associated dirt catchers without thereby degrading 
its mechanical strength and while retaining its previous highly economical 
production process, for the purpose of manufacturing double floors 
suitable for air conditioning which consist exclusively of compound panels 
of the above-described type. 
This object is obtained by an overhanging compound construction panel which 
is characterized by the invention by comprising at least one rigid annular 
body anchored in the filler means and mounted solidly in an orifice in the 
bottom of the tub-shaped sheath in a substantially sealed manner, and 
extending to the upper side of the compound panel and provided with 
radially inwardly projecting segments of an annular flange or with annular 
flange segments or similar projection means which can be reduced in height 
for adjusting to tolerance and which act as a support means for an air 
discharge nozzle and dirt catcher or the like known per se. This annular 
body advantageously can be fastened, prior to the introduction of the 
flowing or pourable filler materials, to the bottom of the tub-shaped 
sheath, e.g., by means of sheet metal screws and, as the annular body 
extends to the upper side of the compound panel, it will provide a space 
above the opening in the bottom of the tub-shaped sheath during the 
ensuing introduction of the filler material, the clear space then 
receiving the air discharge nozzle and the fastening flange for a dirt 
catcher. Once the filler material hardens, the annular body already fixed 
to the sheath will be solidly anchored within it, whereby the static 
parameters of the compound panel will practically correspond to those of a 
continuous compound panel of this design. Accordingly, the compound panel 
of this invention will withstand the highest point loads, as might occur 
for instance in computer facilities through the feet of the equipment. The 
required alignment of the upper edge of the annular body with the upper 
side of the hardened filler material is implemented in accordance with one 
variation of the invention in a simple manner by grinding the annular body 
simultaneously when grinding off the filler material, whereby the annular 
body shall always be flush with the upper side of the filler material. 
Even though the compound panels of the above-discussed type may vary 
slightly in height, i.e., thickness on account of manufacturing 
procedures, a projection of the air discharge nozzle can advantageously be 
avoided by correspondingly reducing its support means, for instance by 
turning or grinding, until the upper side of the air discharge nozzle is 
flush with that of the compound panel. This is especially significant when 
the walk-on covering of the compound panel consists of a material of small 
height and of relatively high density, for instance needle felt, or even 
when plastic plates, ceramic or stone are used for such coverings. Any 
high strength metal or plastic can practically be used as the annular body 
material; however, for reasons of easier workability, an aluminum alloy in 
conjunction with anhydrite is preferred, as the filler material thoroughly 
bonds with the outside of the annular body (the liquid anhydrite slightly 
etches the aluminum material). 
Any height tolerance adjustment required when installing an air discharge 
nozzle and a dirt catcher in the annular body will be facilitated if, in 
conformity with an embodiment of the invention, an upper part of the 
annular flange or annular flange segments acting as a support is or are 
separated by an annular groove or annular groove segments, respectively, 
from a cylindrical inside wall of that annular body. Such an annular 
groove or annular groove segments simplify the tool adjustment or guidance 
for removing the material from the annular flange or annular flange 
segments. A further embodiment of the invention also helps in this 
respect, by means of which the inside cross-section of the annular groove 
or annular groove segments may flare inward and upwardly in a trapezoidal 
manner. 
In yet another embodiment of this invention, the annular body anchored in 
the filler is provided with at least one outwardly radially projecting 
annular flange or several annular flange segments or similar projecting 
means.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
FIG. 1 shows an overhung compound construction panel 10 comprising an 
external, tub-shaped, high-tensile strength sheath 11, for instance, of 
galvanized steel, and a filler means 12, for instance, of anhydrite, that 
is introduced in flowable or pourable condition into the tub-shaped sheath 
11, where it hardens. Compound panels of this design are propped at their 
corners on feet (not shown) and butt against one another by their edges, 
so as to form a double floor. Each compound panel 10, furthermore, is 
provided on its upper side with a walk-on covering, for instance, 
carpeting or plastic, stone or ceramic plates. The joints between the 
individual compound panels can be sealed in any known manner. 
In order to integrate double floors made from such compound panels into air 
conditioning, several selected panels must be provided with passages 
through which the conditioned air can flow from the space below the double 
floor into the room to be conditioned. A compound panel with such a 
passage means is shown in partial section in FIG. 1. To that end, a 
circular orifice 14 is provided, for instance, by stamping the bottom 13 
of the tub-shaped sheath 11, and an annular body 16 of a high-strength 
material such as an aluminum alloy, and comprising an annular collar 15, 
is seated in a tight-fitting manner in the aperture 14. Several radially 
outwardly extending fastening eyes 17 with bores are provided at the lower 
or upper sides of the annular body 16, through which pass the sheet metal 
screws 18 by means of which the annular body 16 is fixed to the bottom 13 
of the tub-shaped sheathing 13. The filler 12, for instance, anhydrite, is 
introduced in the liquid state into the tub-shaped sheath 11 after the 
annular body 16 is solidly and essentially hermetically joined to the 
bottom 13 of the sheath 11. 
Four radially projecting annular flange segments 19 located in 
substantially the same plane are provided in the annular body 16 to anchor 
it in the filler 12 in this embodiment. 
The annular body 16 further comprises, for instance, an annular flange 20 
acting as support for the air discharge nozzle 21, for instance, a spin 
nozzle, and a dirt catcher 22, also indicated by dot-dash lines and 
fastened to the annular flange 20 below the air discharge nozzle 21, for 
instance, by a rim bent around radially outwardly. 
Referring to FIG. 3, an upper part 23 of the annular flange 20 is separated 
from the cylindrical inside wall 25 of the annular body 16 by an annular 
groove 24. This annular groove 24 has an inside cross-section which flares 
trapezoidally inwardly and upwardly from the bottom of the groove. The 
upper part 23 of the annular flange 20 can be machined off mechanically to 
various elevations for the purpose of meeting tolerances, as indicated by 
the illustrative dash-dot lines 26. In this way, there is assurance that, 
regardless of minor fluctuations in the height of the compound panels, the 
air discharge nozzle 21 shall not project at its upper side beyond that of 
the panel, which would result in an undesirable tripping edge. Any 
required removal of the upper part 23 of the annular flange 20 by means of 
a lathe means or a grinding tool is facilitated by the annular groove 24. 
This annular groove 24 does prevent formation of any annular projections, 
for instance, on the cylindrical inside wall 25 that might then become 
support means for an erroneous air discharge nozzle emplacement. 
FIG. 4 illustrates the bottom of the tub-shaped sheath 11 of the compound 
panel 10. In this case, it contains only one aperture 14 for seating an 
annular body 16. In the present embodiment, four holes 27 are provided 
around the aperture 14 into which can be mounted the sheet metal screws 18 
which fasten the annular body 16. 
FIG. 5 illustrates schematically four sheaths 11 for compound panels, with 
apertures 14 for seating annular bodies 16 that may be present, for 
instance, in different numbers and arrangements. By using the annular body 
16 and embedding it in the filler 12, i.e., fixing it to the bottom 13 of 
the sheath 11, the static parameters of the finished compound panels are 
assured to be practically the same as in another such panel without these 
apertures.