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Description  |
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FIELD OF THE INVENTION
This invention relates to shuttering panels for use in formwork for
producing the upper floor of a cavity floor, which formwork has bearing
feet for supporting it spaced from the lower floor.
BACKGROUND OF THE INVENTION
To produce formwork for the upper floors of cavity floors, it is known to
use as expendable shuttering panel-like shuttering elements. Indeed, it is
also known to use a synthetic plastics shuttering film provided with
blocked-out portions which form the bearer feet by which the shuttering
foil is supported on a lower floor. Flowable flooring composition is
applied onto the shuttering film and flows into the upwardly-open bearer
feet shapes, where it hardens and forms the bearer feet (German
Offenlegungsschriften 31 03 632, 32 01 085, and 33 17 683). Such
shuttering films with integrally moulded bearer feet, to be filled with
flooring composition, are unstable to the extent that it is not possible
for anyone to walk on the structure during installation. Furthermore, a
variety of heights of cavity flooring cannot be produced with these
shuttering films.
It is also already known to use square shuttering sheets with downwardly
angled-over corners which fit into tubular bearer feet, the height of
which can be adjusted by means of setscrews (German Gebrauchsmuster 84 04
767.4). The shuttering sheets or panels are provided with upwardly-angled
edge parts at which they are clamped by means of special clamping
sections. The cost of production and installation of a cavity floor
produced by means of such shuttering sheets is relatively high.
Furthermore, at the corner zones of the panels there are a large number of
potential leakage points where the flooring composition can flow into the
cavity of the double floor. Adjustment of the carrier feet by means of
setscrews disposed at their bottom ends is difficult.
Finally, the state of the art also includes shuttering panels provided with
integrally moulded hollow studs which constitute the means of connecting
the vertically adjustable bearer feet (German Patent 34 34 872). The
pot-shaped bearer feet are fitted frictionally in telescopic fashion on
the hollow studs, with no holes on the bottom of the studs through which
the flooring composition might pass. Pouring the flooring composition into
the bearer feet is problematical since any enclosed air cannot escape.
Thus the stability of the upper floor is questionable.
SUMMARY OF THE INVENTION
The object of the invention is to provide, for the production of cavity
floors, a form shuttering panel of the type having connections for bearer
feet, which can be produced inexpensively while having a sufficiently
great structural strength and which can, if required, also permit
negotiation of the construction while the shuttering is being laid.
Desirably it should be adaptable so that cavity floors of variable height,
and/or where the bearer feet may be adapted to an uneven sub-floor, can be
produced without excessive installation costs.
According to the invention, this is achieved in connection members for the
bearer feet pass through holes in the shuttering board and in that the
shuttering board is provided with fittings which strengthen it in the area
around the holes. Preferably, the shuttering board is made from a
non-metallic material, most preferably, a pre-perforated mineral panel,
particularly a gypsum or fibrous cement panel or the like, while the
connection members, fittings and/or bearer feet are expediently metal
elements, steel tubes being advantageously used for the bearer feet. The
said reinforcing fittings may also be a constituent part of the connecting
members or of the bearer feet themselves.
A shutter panel or formwork embodying the invention may, without the boards
being excessively thick, be produced from comparatively inexpensive
materials of the aforesaid type. Adjustment of the height of the hollow or
cavity floor may be provided for by the length of the bearer feet which
can be connected to or fitted on the connecting members, or by the mode of
connection to the connection members. Reinforcement of the shuttering
panel in the area around its holes provides reliable connection of the
bearer feet to the shuttering panel and furthermore a secure absorption
and transmission of force to the sub-floor without the bearer feet first
having to acquire their supporting capacity by being filled with flooring
composition or some other flowable and hardenable compound. If filling of
the bearer feet is dispensed with, then there are no problems in
connection with the dispersal of any air trapped in the bearer feet. Thus,
it may be possible to achieve not inconsiderable savings in terms of the
relatively expensive flooring compound.
The said fittings preferably comprise or consist of support plates which
engage the panel surface around the through-holes, e.g. under the holes in
the panel. The support plates may consist of simple washers or the like
which are provided with apertures through which the bearer feet or their
connection members can pass. They may also consist of flanges on the
bearer feet or their connection members. If the plates are not flanges on
the bearer feet, it is advisable to connect the bracing plates to the
shuttering panel. This may be, for instance, by adhesion or by a
mechanical engagement e.g. claw attachment.
In one preferred aspect, the connection members comprise coupling studs
which pass through the holes in the shuttering board and project
downwardly from the holes, and onto which it is possible to fit hollow
bearer feet of whatever length is required, preferably with the bearer
feet butted against the periphery of the hole on the underside of the
shutter panel. This abutment may be e.g. via a flange of the bearer foot,
or against a washer as aforesaid which engages around the hole in the
panel. The coupling stud may be fitted loosely from above into the
relevant hole in the shuttering board. Expediently it has a head flange or
the like bearing on the panel upper surface, and a fixed connection of the
coupling stud to the panel may be provided, e.g. by adhesion, claw
attachment or by any other means, although it is not absolutely necessary.
The coupling stud may instead comprise a (preferably slotted) clamping
sleeve which fits with a clamping action in the hole in the shutter panel
so that its clamping effect secures it into the panel. Preferably, the
coupling stud is a hollow stud closed at the bottom.
In a particularly preferred feature, the holes in the panel have a diameter
such that the bearer feet can be passed through them from above. This
makes it possible when laying the panels to pass the bearer feet through
them from above and to fix them in the appropriate position, which means a
substantial simplification of the installation work and which may also
make it possible for the height of the bearer feet e.g. in the case of an
uneven sub-floor, to be adjusted subsequently from the top of the
shuttering. Particularly when this feature is used it is preferred to
dispose in the holes coupling sleeves or the like which serve to connect
the bearer feet and which at the same time may comprise a bracing flange
which forms the support plate. Such sleeve-like coupling members can be
used to secure the bearer feet in various ways preferably with variability
of height. For example, in one preferred version the coupling sleeves are
provided with a screwthread for an adjusting nut which carries the
vertically adjustable bearer foot and to which the bearer foot is
advantageously connected by means of a rotary connection. The adjusting
nut expediently has an upwardly-open internal polygonal aperture into
which it is possible to fit a key to actuate the adjusting nut.
In an alternative arrangement using a coupling sleeve, the bearer foot is
fitted into the sleeve mounted on the panel and is fixed therein, for
instance by a simple crimped connection, by spot welding, by bolting or
the like.
It is preferred, after laying the panels to provide a formwork, to cover
them with a synthetic plastics film onto which then the flooring
composition or some other flowable and hardenable compound is applied. The
synthetic plastics film prevents the flooring composition penetrating the
joints between the panels and potentially passing into the bearer feet or
their connection means. That is, it forms a cover for the formwork.
The invention will be explained in greater detail hereinafter by reference
to preferred embodiments shown in the accompanying drawings, in which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a vertical section through a cavity floor showing a shuttering
panel embodying the invention in a detail in the region of one of its
bearer feet, and
FIGS. 2 and 3 show in a sectional view as in FIG. 1 respectively two
further advantageous developments of the shuttering board embodying the
invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The cavity floor shown in FIG. 1 consists of an upper floor 1 supported by
prefabricated bearer feet 2 on a lower floor 3 forming for example, the
crude concrete floor of a building. The cavity 4 may be used e.g. as an
installation space for laying pipes and cables, for the installation of
underfloor heating or for air conditioning. The upper floor or cavity
floor 1 is produced by the use of an expendable shuttering or lost
formwork consisting of individual preferably rectangular or square
shuttering panels 5 which are spaced apart from the lower floor 3 by means
of bearer feet 2. Then, a flowable and hardenable composition, generally a
flooring composition 6, is to be applied onto the resulting shuttered
formwork as shown.
The individual shutter panels 5 are, for example, 1000.times.1000 mm in
size. Preferably they consist of plaster board panel elements. Each has a
plurality of rows of holes 7, the distance between the holes within each
row and the gap between the rows being, for example, 250 mm. At each hole
7 the panel 5 is provided with a connection member 8 for a bearer foot 2.
Furthermore, in the region of the holes 7, the shuttering board 5
comprises reinforcement parts or fittings 9.
In the case of embodiment shown in FIG. 1, the fitting 9 consists of a
support plate in the form of a washer which engages the under-surface of
the panel 5 in the region of the respective hole and has an aperture to
accommodate the top of the tubular steel bearer foot 2. The washer 9 is
ideally rigidly connected, for example by glueing and/or claw attachment,
to the panel 5; this is not shown in detail in FIG. 1. With a claw
attachment, the washer 9 is provided with suitable claws which are pressed
or driven into the panel under-surface.
In the case of the embodiment shown in FIG. 1, the connection member 8 for
the bearer foot 2 consists of a hollow cylindrical coupling stud which
extends through the hole 7, projecting downwardly by a relatively
considerable distance from the hole 7. The coupling stud 8 has, bearing
from above against the shuttering board 5, a head flange 10 which likewise
constitutes a marginal reinforcement of the panel element 5 in the region
of the hole. The tubular bearer foot 2 is fitted onto the coupling stud 8
from below, being centred by this latter and supported in a transverse
sense. The bearer foot 2 has its upper end 11 abutting against the washer
9.
The coupling stud 8 may also have its head flange 10 fixed to the
shuttering board 5, for example by glueing and/or claw attachment,
although this is not absolutely necessary. It may be constructed so that
it can serve as a clamping sleeve and fit with a certain wedging or
interference effect in the hole 7 in the shutter panel. In this respect,
it is possible to construct the coupling stud 8 as a longitudinally
slotted clamping sleeve. Such a longitudinal slot is indicated at 12 in
FIG. 1.
The coupling stud 8 is closed at its bottom end 13. After the individual
panels 5 have been laid, it is a good idea to place over the finished
shuttering a synthetic plastics film 14 which covers the joints between
the shuttering boards 5 and also the connection areas of the bearer feet 2
so that the flooring composition 6 which is subsequently applied does not
flow into the joints or into the coupling studs 8 and the bearer feet 2.
It will be appreciated that the length(s) of the bearer feet 2 will depend
on the height(s) of the cavity 4, so the shuttering panels 5 may be fitted
with bearer feet 2 of different lengths. For the bearer feet 2, it is
ideal to use steel tubes. The connection members 8 and the reinforcing
fitting parts 9 are also expediently made from metal e.g. steel.
It is evident that in this embodiment the load resting on the panels of the
formwork or on the cavity floor is, via the washers 9, spread over a
relatively large area onto the bearer feet 2 and thence to the underfloor
3. Instead of the washers 9, the bearer feet 2 may carry at their upper
ends integrally-formed flange plates which are applied against the
underside of the shuttering 5, supporting substantial areas of the panel
element around the holes 7.
FIGS. 2 and 3 show two further conformations of panels and formwork
embodying the invention, in which the holes 7 in the plaster panel 5 have
in each case an inside diameter such that the bearer feet 2 can be passed
through these holes from above. At the same time, it is possible to fit
into each hole 7 in the shuttering panel 5 a sleeve e.g. coupling sleeve
15 which has as a fitting a support flange 16 engaging around the panel 5
in the area of the hole periphery and which performs the same function as
the washer 9 in FIG. 1. The coupling sleeve 15 is rotationally rigid on
the panel 5. This can be achieved, for example, by glueing and/or by claw
attachment. FIG. 2 shows, disposed on the flange 16, claws 17 which are
driven into the panel 5. The sleeve-like collar 18 of the coupling sleeve
15 which engages through the hole 7 comprises an internal screwthread into
which a plug-like adjusting nut 21 can be screwed by engagement with an
external screw-thread 20 thereof. The bearer foot 2 is connected to this
nut 21. The connection is expediently performed by a rotary joint, e.g. in
that, as FIG. 2 shows, the upper end 22 of the tubular bearer foot 2 is
flanged-over into an annular groove 23 of the adjusting nut 21 so that the
two parts can rotate relative to one another. The adjusting nut 21
comprises a blind square hole 24 into which it is possible to fit a key
from above, so that the adjusting nut 21 can be screwed into or out of the
coupling sleeve 15. By means of the adjusting nut 21, it is also possible
to set the height of and adjust the supporting foot 2, e.g. for an uneven
subfloor 3. The adjusting nut 21 also seals the hole 7 when the flooring
composition 6 is subsequently poured into it.
In the embodiment shown in FIG. 3, adjustment of the height and fixing of
the bearer foot 2 by means of an adjusting nut is dispensed with. The
tubular bearer foot 2 fits directly into the coupling sleeve 15 fixed in
the panel 5, and is fixed therein at the desired height. This can be
achieved, for instance, by a crimped joint in which the neck piece 18 of
the coupling sleeve, as indicated schematically by arrows at 25 in FIG. 3,
is pressed or crimped inwardly so that the bearer foot 2 is rigidly
clamped. Alternatively or additionally, fixing may be achieved at 25 by
spot welding or by bolting, e.g. a bolt indicated schematically in FIG. 3
by the dotted line 26 is passed through aligned bolt holes in the coupling
sleeve and bearer foot 2 and then secured.
Particularly in the embodiment according to FIG. 3 it may be advisable to
close off the top ends of the tubular bearer feet 2 in order to avoid
flooring composition flowing into them. This can be done by fitting a plug
or the like. The bearer feet 2 may also if desired be closed at their
bottom ends, for example by means of a plug.
In the case of the embodiment shown in FIG. 2, the bearer feet 2 may
instead be rigidly connected to the adjusting nuts 20, for example by a
welded connection. The skilled man will appreciate that numerous
variations on the illustrated embodiments are possible.
In any case, the shuttering panel element should consist of a hard layer
material, preferably a plaster panel as aforesaid. In the version shown in
FIGS. 2 and 3, the joints may be sealed by a synthetic plastic film being
placed over the shuttering panels 5 and this may if desired be provided
with apertures or blocked-out configurations at the connecting members for
the bearer feet 2.
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