Note: Descriptions are shown in the official language in which they were submitted.
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This invention relates to a formwork board having webs extending at
right angles to the formwork skin, in the edge areas, these webs forming end
faces and having points of attachment for secwring to an adjacent formwork board,
the formwork hoard consisting of parts which have obl:ique edges a.t least in
certain areas,to facilitate the removal of the forms, these parts fitting to-
gether to form a rectangle.
~ formwork board of this kind is known from German Patent 12 6~ 735.
In this patent, two wedge-type Eormwork boards are provided which, in the
operating position, together form a rectangle. Longitudinal displacement of a
wedge-type ormwork board of this kind loosens the formwork and especially
internal formwork, during the removal of the forms. However, this only operates
if there is enough space for this. longitudinal displacement of a wedge-type
formwork board in th~ longitudinal direction o the formwork. Furthe:rmore,
remo~al of the forms is dieficult ~n such a case, in spite Oe the wedge-type
construction, ~ince this longitudinal displacement has to be effected virtually
in the plane of concreting, with the result that corresponding forces of
adhesion between the concrete and the ~edge-type :Eormwork board may offer con-
siderable resistance.
The object Gf the inyention is therefore to provide a formwork board
of the kind referred to hereinbe~ore, which can be removed from the concrete
: without difficu;lty and which facilitates the removal of the forms, for example,
between two outgoing walls, in shafts or the like, without any need for
displacement in the plane ~f concreting.
~ccording to the invention there is provided a formwork board having
outer edge webs extending at right angles to a formwork skin in outer edge areas
of the board, these webs forming end faces and having points of attachment for
securing to an adjacent formwork board, the formwork board consisting of a
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plurality of parts which have oblique edges at least in certain areas, to
facilitate the removal of the forms, these parts fitting together, characterised
in that any separating line between parts of the formwork board is defined by
abutment webs, straps or the like which, in transverse cross seCtiQn, are
located in an oblique position relative to the formwork skin and the outer edge
webs and have attach~ent points for securing the parts together.
~ onsequently, thanks- to the overall inwardly tapered cross section
of one of the parts of the formwork board, during removal of the forms it is
easy to mo~e one of ~hese parts away from the concreted surface, thus making
room for the re~oval of the other formwork boards. A formwork board of this
kind can therefore facilitate the stripping of the forms even if a limitation,
such as a ceillng or the like, for example, is immediately adjacent to this
formwork board.
Advantageously, when the formwork skins of the parts of the formwork
board are in alignment, the securing points prov~ded on the abutment webs or the
like coincide and are ln the securing position. The abutment webs or the like
may contain holes for through-bolts or the like. ~ppropriately, the holes in
the abutment ~ebs or the like correspond in shape and size to those in the
outer edge webs of the ~ormwork ~oard.
Manufacture of the formwork hoard is made easier if the separating
lines extend parallel to the edges thereof. Certainly, it would be possible for
the separating line to extend diagonally, so that the formwork parts would not
only haYe an inwardly tapered cross section but would also have a tapered longi-
tudinal construction, but this is not necessar~, since the movement for detach-
ing the inwardly tapered part of the formwork board may occur outwardly away
from the concreted surface.
The parts for~ing the for~ork board may be of different widths and
the abutment web of one part ~ay define an obtuse angle with the formwork sk m
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adjoining its edge nearest the concrete. This ensures that the broader part
widens out, in cross section, away from the formwork skin, so that this broader
part is removed first from the formwork assembly. The form-removing gap thus
formed is correspondingly greater. It is particularly advantageous iE the
abutment web of one part of the formwork board defines an angle of 135 with the
form~ork skin, whilst the abutment ~eb of the other part of the formwork board
defines an angle of 45Q with its formwork skin. This produces, on the one hand,
a favourable taper for the formwork part which is to be removed first and also
makes production easier, since as a rule an angle of 45 is particularly easy
to measure out and produce. ~oreo~er, these webs are also made relatively
accessible or the securing members.
The abutment ~eb o the narrower part of the formwork board ~if there
is a narro~er part) may extend ~rom the formwork skin to the outer edge web.
~s a result, this formwork board part has a virtually triangular cross section,
so that the wider formwork part can make opt:imum use of the total width of the
fQrmwork board, so as to permlt the largest possible form-removing gap.
The overall width of the parts in the operating position may corres-
pond to a standard grid measurement used ln the building industry, preferably
about 25 cm. This will then enable the formwork boards to fit the standard
dimensions used in building.
The invention is hereinafter explained in more detail, with its
essential $eatures, with reference to the drawings, wherein:
Figure 1 is a 5chematic plan view of a formwork in the region of two
outgoing walls,
Figure 2 ls~ a cross section, on an enlarged scale, through a formwork
board according to the invention, which consists of two parts which have oblique
edges in certain areas to facilitate the remo~al of the forms,
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Figure 3, on the same sheet as Figure 1, is a schematic view of a ceil-
ing formwork, ~herein the form~ork board according to the inventio~ is provided
for forming a form-removing joint, and
Figure 4 is a representation corresponding to Figure 2 of an alter-
native embodiment.
During remDval of formwork 1 between two outgoing walls 2, in shafts
or the like, problems may arise in removing the forms, on account of the pres-
sures occurring during the concreting. Ln the first embodlment, therefore, a
formwork board 3 is provided inside the formwork 1, said formwork board 3 con-
sisting of two parts 4 and 5 which are partially inwardly tapered in construc-
tion and which fit together to form a formwork rectangle. This formwork board 3
is provided, on its edges, with webs 6 forming end faces and extending at right
angles to the surface which is to be c~ncretedt these ~ebs having points of
a~tachment for securing to the adjacent formwork boards 7. m is is cle æ ly
shGwn in Figure 2, ~1 which these points of attachment are in the form of holes
8 or through-bolts 9.
According to the invention, the separating line 10 between the two
parts 4 and 5 of the form~ork board is defined by abutment webs 12 which, in
cross section, are located in an inclined position relative to the formwork skin
11 and to the outer edge webs 6~ me abutment webs 12 may be for~ed from sheet
metal. In the e~bodiment shcwn, at least the abutment web 12 of the part 4 of
the form~ark board is continuous over its entire length. Advantageously, this
is also true of the abutment web 12 of the other part 5 of the form~ork board.
~ever, for connecting the two parts 4 and S, it ~y also be suficient to pro-
vide only web portions, i.e. individual straps or the likel in certain areas, so
as to make room for a point of attachment 13. When the formwork skin 11 of the
bwo parts 4 and 5 is in alignment, -the points of attachment 13 on the abutment
webs 12 adjoining the separating line 10 coincide with one another and are
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in the securing position, the points of attachment 13 in the emhodiment
consis.ting of holes for through-bolts ~. The holes in the abutment webs 12
correspond in shape and size to those provided in the edge webs 6, so that
the through-bolts 9 can be the same for both methods of securing. This makes
storage easier.
Since t.he removal of the forms starts by reLeasing the appropriate
connections and then removing the part 4 in the direction of the arrow Pf 1
(~igures 2 and 3~, to facilitate the removal of the forms it is sufficient if
the separating l~ne 10 of the form~ork board 3 extends parallel to the edges and
edge webs 6 thereo$.
The abutment ~ebs 12, like the edge webs 6, may be pro~ided with
keyhole-shaped holes 8 and 13, respectively, for the securing bolts 9, whilst
these bolts ~ may be provided, on the one hand, with cross-pins 14 and, on the
other hand, with a counter-s-top 15 for holding together the abutment webs or
edge webs coming into contact, these bolts being capable of being rotated into
the securing position shown, aEter being inserted. Thus, here again, the
securing bolts ~ already available for use ~ith numerous formworks of this kind
may also be used for assembling the $ormwork board 3 and also for securing the
t~o parts 4 and 5 to each other.
The two parts 4 and 5 constituting the formwork board 3 are of dif-
ferent widths in the embodiment and the abutment web 12 of the wider part 4
defines-an ~btuse angle ~ith the form~ork skin 11 adjoining its edge 16 nearest
the concrete. In the embodiment shown, this angle is 135. The abutment web
12 of the narro~er part 5 of the formwork board thus deines an angle of 45 with
its form~ork skin part, so that the two webs 12 abut each other in the operating
position and form the re~uired abutment whilst simultaneously reinforcing the
two-part formwork board. Conversely, the part 4 of the formwork board which is
to he removed first, with the abutment ~eb 12 mounted at an obtuse angle, may
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also he -the same width as or narrower than the other part 5 of the formwork
board.
Figures 2 and 3 also clearly show that the abutment web 12 of the part
5 of the formwork board extends from the formwork skin 11 sub~tantially to the
outer edge 17 of the associated edge web 6, with the result that the part 5 of
the formwork board is virtually triangular in cross section. As a result, this
part is made relatively rigid, so that its additional reinforcement will at
least partially compensate for any weakening of the ~ormwork board 3 caused by
the separating line lQ, and in addition the wider part 4 of the formwork board
is thus made as wide as possible, resulting in a correspondingly large form-
remoYing gap after it has been removed.
In the embodiment illustrated, the formwork skin 11 of the two parts
4 and 5 consists of sheet me~al. As a result, ths abutment webs 12 can be
securely attached, e.g. by welding.
~igures 1 and 2 show that the formwork tie rods 18 each may extend in
the region of the edge webs 6 of the formwork board 3, so that the wing nuts 19
partly engage over the formwork board 3. On removal of the forms, first these
wing nuts 1~ are released, followed hy all the connecting bolts 9 along the
inclined separating line 10. The thro~gh-bolts 9 on the edge webs 6 of the widerpart 4 of the formwork board are then removed. This formwork part 4 can then
be removed in the direction of t~e arrow ~f 1, i.e. in a slightly oblique
d~rection relatiYe to the concreted surface, this movement being made easier by
its tapering shape in this cross sectional direction. After this part has been
remoYed ~cf. the illustration shown in broken lines in ~igure 2), a sufficientlylarge form-removing gap is formed which ena~les the remainder of the formwork 1
to be removed without any difficulty. Longitudinal displacement along the
concreted surface is avoided.
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The emhodiment according to ~igure 2 shows a formwork board -
as described - consisting of two parts 4 and 5 which are detachably
connected at the inclined separating line 10 in the position of use.
Figure 4 illustrates an alternative embodiment. For a better overview,
identical parts, even with a slight alteration, have been provided with
the same reference numerals as in Figure 2.
In this embodiment the formwork board 3 consists of parts 4, 5
- and 5a c~nd has two separating lines 10 inclined from the formwork skin 11
in cToss-section and extending away from one another for the detachable
connection of the three parts 4, 5 and 5a. The two separating lines 10 in
the embodiment are symmetrically disposed relative to the centre line M
extending at right angles to the formwork skin. In this way the removal
of the forms can occur almost exactly at right angles to the concreted
surface in the direction of the arrow Pf 2.
Substantial advantages of this arrangement with a middle formwork
board part 4, which in cross-section corresponds approximately to an equal-
sided trapezoid, result above all for shaft formworks if the tension points
are not disposed symmetrically at the edge webs 6, viewed in the longitudinal
direction of the formwork board.
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