Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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FORMWORK FOR PRISMATIC COLUMNS
DESCRIPTION
OBJECT OF THE INVENTION
This invention pertains to a formwork of the type used in construction for
producing prismatic columns, preferably of quadrangular section, although
applicable to
the production of columns with any polygonal section and with or without
truncated
vertices, a single-use formwork that can be eliminated at the time of
stripping.
The object of the invention is to provide an extremely light, foldable
formwork
that is supplied in totally finished form, meaning that there is no need for
specialized
labor to assemble it or for additional materials such as adhesive tape and the
like. Nor is
there a need for intermediate assembly stages, so that final on-site assembly
is
extremely simple, with an equiangular distribution between the vertical faces
of the
prism corresponding to the column or pillar to be produced, as well as
facilitating
stabilization of the device in its emplacement and perfectly positioning the
vertices of
each column according to the desired orientation.
BACKGROUND OF THE INVENTION
Numerous types of formworks for prismatic columns are known, based on a
cylindrical, tubular surround of sufficient stiffness, with a core that is
also tubular,
externally cylindrical in correspondence with said surround, and internally
prismatic in
correspondence with the column to be produced. The inner surface has a lining
made
from a plastic laminate or similar material, one adequate in any event to
prevent the
moisture in the column's constituent materials from damaging the formwork's
structure
while it is fulfilling its function.
The outer surround is generally made from cardboard, plastic, and aluminum,
while the inner tubular core is made from four cylindrical segments of high-
density
expanded polystyrene, duly lined, either directly joined by their edges or
with their
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edges discernibly distanced in order to produce bevels corresponding to the
column
edges.
As can be deduced from the structure described, the formwork leaves the
factory
with a cylindrical configuration of slightly greater diameter than the
diagonal of the
column to be produced. In other words, the formwork's volume is exactly the
same
when in storage or transport as it is when in use.
In an attempt to get round this storage and transport problem, formworks of
the
type mentioned above are known in which both the outer surround and the
tubular core
are cut along their generatrices, allowing independent storage and transport
of both parts
and permitting nested storage of multiple surrounds, minimizing occupation of
space,
and also allowing to some extent the dovetailing of their inner cores, also to
save space.
However, this solution presents a problem of great importance, the fact that a
fonnwork
structured in this way cannot be directly used by the building contractor, but
requires an
intermediate operational stage that generally has to be performed by a company
working
with the manufacturer and involves locking the tubular core onto itself,
using, for
example, an adhesive strip that is applied to the marginal area of the edges
of the plastic
laminate interior to said core at the same time that it is externally
stabilized using a
second adhesive tape, generally applied helicoidally.
This results in a notable increase in costs, a loss of time that delays
delivery of
the formworks, and above all, a loss of the formwork's internal surface
continuity,
which will have subsequent negative repercussions for the column's aesthetics.
Aiming to solve these problems, the applicant is the holder of invention
patent
PCT/ES2004/000235, which describes a fonnwork of the type discussed above, but
with the difference that the tubular core is foldable at the storage and
transportation
stages, with a notable reduction in volume, the outer cover having at least
one cut along
one of its generatrices, allowing it to be mounted and dismounted on the
tubular core at
the time the formwork is used, with the aid of straps or locking elements that
keep the
tubular cover immobile in its working position or position for the pouring of
concrete.
Said locking elements can take the form of straps or metal rings that encircle
the
formwork externally. The fundamental problem presented by this kind of
formwork is
the complexity of assembly of said locking elements when they are in the form
of metal
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rings, given that said rings' inner diameter must be equal to the outer
diameter of the
tubular core's outer cover, in order to avoid gaps when assembled. This
renders the
insertion of said rings over the surround of the tubular core much more
difficult, an
operation that must be carried out by qualified personnel, resulting in loss
of time and
higher costs.
Likewise, it should be emphasized that when said locking elements take the
form of straps provided with tightening elements or the like, said elements'
lack of
stiffness is an obstacle to ensuring the formwork's correct positioning and
setup,
allowing the internal walls or the walls corresponding to the prismatic column
to lack
the correct parallelism or equiangularity between faces.
In an attempt to work around these problems, the applicant is also the holder
of
invention patent 200602568/6, in which is described a formwork of similar
structural
characteristics, but with the difference that the formwork's outer surround is
complemented by at least one semi-rigid ring with an inner diameter that
matches the
outer diameter of the surround. The ring fits tightly to the surround and has
hinging
regions along its generatrices that, in their storage or transport position,
fit together with
the hinging regions of the outer surround, while in the formwork's assembled
position
they are dephased from one another by turning the ring to a particular angle.
Even though this solution fulfils the function for which it was designed, in
practice it presents assembly problems, to which must be added the positioning
of the
formwork, and more specifically that of the vertices of the column or pillar
to be
produced, by means of external markings on said formwork.
DESCRIPTION OF THE INVENTION
The formwork for prismatic columns proposed by the invention provides a
completely satisfactory solution to the problems described above, in each of
the aspects
commented on.
For this purpose, and based on the configuration described above, in which
there
is a foldable inner tubular core, constituted on the basis of four or more
cylindrical
segments made of light, thermally formed products, in accordance with the
polygonal
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prismatic configuration to be given to the column or pillar to be produced,
which
cylindrical segments are externally attached by their curved faces to a
likewise outer
surround made of a sufficiently strong and flexible material, for example
raffia, Kraft
paper, etc., of cylindrical configuration, capable of adopting a flattened
configuration
thanks to the joined edges of the cylindrical segments attached to said
surround, these
segments having at least one Ieaktight lining on their inner faces in order to
conveniently seal the chamber or receptacle in which the column will be
shaped, which
column may or may not have beveled edges, the invention is characterized by
the fact
that said formwork is supplied together with a laminate, annular piece of a
configuration
in accordance with the geometry of the column or pillar to be produced, made
of
cardboard, wood, plastic, or another material of suitable stiffness for said
element, with
an inner section having dimensions in accord with those of the column to be
produced,
and with appropriate external dimensions to enable stabilization of the
formwork once
assembled, as will be seen below.
As a complement to the structure described, the formwork's inner faces extend
into folding tabs, so that when the formwork is unfolded, said tabs are
introduced into
the cavity of the annular piece, in such a way that for said coupling to be
effected
properly, the formwork must present the exact assembly configuration for
pouring the
concrete or mixture in question, ensuring a perfect coplanarity between the
opposed
faces of the column's constituent prism.
Therefore, the formwork will be supplied with two annular pieces, to which the
tabs that emerge from both ends of the formwork will be internally coupled.
For greater
stabilization, said fins fold outward onto said annular piece, being attached
to it by any
conventional means, such as clamps, nails, adhesives, etc.
Once the fins have been attached to the annular pieces, the formwork can be
attached to the floor or immobilized via said annular pieces, preventing the
formwork
from moving during the production of the column in question, by bracing with
planks or
any conventional means.
In accord with another of the invention's characteristics, said annular pieces
have markings on their surfaces indicating the exact positioning of each of
the column
or pillar vertices, in order to enable exact positioning and alignment of the
formwork
during setup, ensuring parallelism between contiguous pillars.
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DESCRIPTION OF THE DRAWINGS
To complement this description and for the better comprehension of the
invention's characteristics, in accordance with a preferred embodiment of the
same, a
5 set of illustrations accompany said description as an integral part thereof.
In these, by
way of illustration and not of limitation, are represented the following:
Figure 1.- Shows a perspective view of a formwork for prismatic columns made
in accord with the object of the invention, in its transport and storage mode.
Figure 2.- Shows a perspective view of the device in an initial stage of
assembly.
Figure 3.- Shows a view similar to the previous figure, corresponding to an
intermediate stage of assembly.
Figure 4.- Shows a view similar to the previous figure, corresponding to the
final
stage of assembly.
Figure 5.- Shows a perspective detail of the device's mounting position in
place
for use.
Figure 6.- Shows several plane views of an invention variant in which the
annular bodies are subdivided into two elements attachable to one another in
different
positions, like those shown in the figure, in order to enable application to
formworks of
different sizes.
PREFERRED EMBODIMENT OF THE INVENTION
Looking at the figures, it can be seen how the proposed formwork starts with
the
basic structure of the formworks previously described, constituted on the
basis of a
tubular core (1) internally defining a prismatic housing (2), quadrangular in
the chosen
embodiment, but adaptable to any other polygonal configuration. The core (1)
is
externally cylindrical, constituted on the basis of cylindrical segments of
expanded
polyurethane or a similar light material, with a leaktight inner lining (3) in
order to
conveniently seal the chamber or housing (2), said core being housed and
stabilized in
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the cavity of a surround (4) made of a sufficiently strong material, such as
paper, plastic,
or aluminum, without this enumeration being in any way limiting, and having
hinging
regions corresponding to the edges (5) of the prismatic column for folding the
formwork
for storage or transport, allowing minimal occupation of space.
Based on the structure described above, the invention is characterized by the
fact
that the inner surround (3), which determines each of the prismatic column's
faces,
extends beyond the formwork's lower and upper bases in the form of fins (6).
In the
chosen embodiment these have an isosceles trapezoidal configuration, but a
rectangular
configuration could equally be used, without affecting the essence of the
invention.
Complementing the described structure, the formwork has a pair of annular
bodies (7), in this case quadrangular, and in all cases with geometry in
accord with the
section of the column to be produced, these laminate, annular bodies (7) being
made
from cardboard, plastic, wood, or another material of suitable stiffness, the
internal
dimensions whereof will be appropriate for the dimensions of said column and
the
thickness whereof will be sufficient to determine the means of stabilizing the
formwork,
in. such a way that the length of said fins will be appropriate for said
thickness of the
annular body (7).
More specifically, and as can be seen in the sequence of figures 1 to 5, once
the
formwork has been unfolded, pressure is exerted on it in such a way that the
fins (6)
adopt a disposition in which they face one another in pairs, forming
orthogonal planes
between the contiguous fins, as shown in figure 2, so that in this position,
said annular
body (7) can be fitted over said fins at both the upper and lower ends of the
formwork,
said body being supported on the ends or bases of the core (1), so that once
each body
(7) has been mounted, equiangularity is guaranteed between the formwork's
internal
faces, which determine the column to be produced.
Thereafter, as shown in figure 4, the fins are folded onto the surface of each
side
of the annular body (7), being attached to it by means of adhesive, clamps,
nails, or any
other conventional means.
Once this process has been completed for both ends of the formwork, it can be
stabilized at its place of use by supporting it on said annular body (7),
which acts as a
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supporting base that can be attached to the floor by bracing with planks or
any other
conventional means.
To enable easy and precise identification of where the determining vertices of
the column or pillar edges will be positioned, said annular bodies (7) will
have markings
(8) on their surfaces in the form of an extension of the internal edges of
said ring and
which will extend out to the external edge of the same, aiding said
identification.
It should equally be emphasized that, as is conventional with this type of
formwork, it may or may not be supplied with means for scoring it for
elimination when
the column is completely finished.
In accord with a second embodiment of the invention, shown in figure 6, in
order to reduce manufacturing costs, the annular body (7) can be divided into
two L-
shaped elements, attachable to one another using any conventional means (9),
both at
their ends and along their lengths, in different positions, as for example
those shown in
said figure 6, in order that said assembly can be adapted to different-sized
formworks.
This is done in such a way that, in any case, attaching said elements in an L
will
produce an annular frame of appropriate section for the formwork in question,
onto
which the formwork's fins (6) can be likewise folded and attached.
CLAIMS
1. - Formwork for prismatic columns, of the type constituted on the basis of a
tubular core (1) internally defining a prismatic housing (2), which core (1)
is externally
cylindrical, made up of cylindrical segments of a heat-formed product or other
similar
light material, with a leaktight inner lining (3), said core being housed and
stabilized in
the cavity of a surround (4) made of a sufficiently strong material and
provided with
hinging regions corresponding to the edges or bevels, as appropriate, of the
prismatic
column, so that the formwork can be folded to reduce space requirements when
stored
or transported, characterized in that the inner surround extends, with respect
to both the
upper and the lower base of the formwork, in as many fins (6) as the column or
pillar is
to have faces, over which fins, when the formwork is assembled, there fits
externally an
