Title of Invention

FORMWORK SUPPORT

Abstract A formwork support (1) having a top chord (2) and a bottom chord (4) and a web (6) which connects the two chords, the chords and the web all being made essentially of wood, wherein said web (6) and/or at least one of said chords (2,4) comprises at least one recess (8) in at least one end region (1') of said support, said recess, if located in a chord (2,4), being located at least in the region of an overlap (0) of said web (6) and adjacent to said web (6), said at least one recess (8) being provided with a filling material (10) that has shock-absorbing properties.
Full Text Formwork Support
Technical Field
The present invention relates to a formwork support that comprises a top chord and a
bottom chord and a web which connects the two chords, the aforementioned all being
made essentially of wood, and the invention further relates to a method of producing such
a formwork support.
Prior Art
The aforementioned type of formwork support is widely used in construction engineering.
The formwork supports in use on building sites are exposed, inter alia, to pronounced
mechanical loads, in particular shock-type and impact-type stress, such as arises for
instance whenever the supports fall down from scaffolding or the like. There is the risk
that the formwork supports are damaged to such an extent that they no longer exhibit
sufficient dimensional stability or even load-bearing capacity.
To remedy this situation, various protective configurations for formwork supports, in
which the support ends are usually provided with caps or the like, are known in the prior
art. For example, DE 43 04 438 A1 thus discloses a wooden chord support in which a top
chord is connected to a bottom chord by means of a latticework type or solid-wall type
web, the chord ends are protected by a cap and at least two edges are at an angle at the end
face of the chords. Furthermore, AT 403 305 B discloses a formwork support comprising
a top chord and a bottom chord and at least one connecting web, with an end-face
protector being provided at the end face on the top chord and on the bottom chord, this
protector being composed of a castable or injectable plastic that is moulded directly on the
top chord or bottom chord by means of integral casting or injection moulding.
These protective devices have by all means proved themselves to be suitable to protect the
formwork support from shock-type and impact-type stress that acts upon the free support
end (i.e. in the support's longitudinal direction. In practice, however, the most common
shock-type or impact-type stress arises essentially transverse to or at an angle to the
longitudinal axis of the support, especially when the support falls down from scaffolding
or the like. In the event of this type of stress transverse to or at an angle to the longitudinal

direction, the impact generally occurs at an outer edge of the chord. The normally I-
shaped support cross-section within the chord end gives rise to particularly critical
stresses transverse to the fibre direction in the form of a massive deformation and/or this
cross-section causes the chords to split open. Further high and hence critical
concentrations of stress are therefore produced, caused by the geometry of the support
and the anisotropy of the wood, in the region of the web/chord joint, especially if the
chord and the web exhibit different material properties. The impact almost always causes
the support to lose its usefulness since it no longer has an adequate load-bearing capacity,
though at the very least it no longer has sufficient dimensional stability.
It must be remembered here that if a formwork support falls down from scaffolding or the
like, both support ends are always subjected to stress, with the last support end to make
impact continuing to accelerate as the first support end makes impact, whereupon the last
support end hits the ground with even greater momentum. Very high stresses in the
support's transverse direction arise here.
One way to protect the formwork support from this kind of stress as well was, for
example, to reinforce the support of means of screwed-in or riveted steel pins or steel
bolts in order to increase the support's strength in this way (EP 0 255 110 Bl). This
approach resulted in a certain degree of improvement to the support's load-bearing
capacity in the event of shock-type stress in a transverse or diagonal direction, but was
often unable to prevent effectively damage to the formwork support during normal
construction-site activity.
Summary of the Invention
It is the object of the present invention to provide a formwork support in accordance with
the class designation, the load-bearing capacity or resistance of which is improved in the
event of shock-type stress, particularly in the support's transverse or diagonal direction.

This object is achieved by a formwork support having a top chord and a bottom chord and
a web which connects the two chords, the chords and the web all being made essentially
of wood, wherein said web and/or at least one of said chords comprises at least one
recess in at least one end region of said support, said recess, if located in a chord, being
located at least in the region of an overlap of said web and adjacent to said web, said at
least one recess being provided with a filling material that has shock-absorbing
properties.
The present invention is based on the idea of protecting the formwork support not only by
means of outer impact members, but of selectively designing the inner structure in such a
way that the support's defonnability and hence load-bearing capacity are considerably
increased. For this purpose, the invention envisages that the web and/or at least one of
the chords comprises at least one recess in at least one end region of the support, this
recess being provided with a filling material that has shock-absorbing properties.

By designing the formwork support in accordance with the invention, especially as a
result of the shock-absorbing filling material, the formwork support can, by means of
deformation, avoid excessive stress peaks in the event of high loads. In this way, the load-
bearing capacity of the formwork support can be boosted to a surprising degree in the
event of shock-type stress, especially in the transverse or diagonal direction. At the same
time, the support still has a simple structural design, because a well-known support in
accordance with the class designation can be easily modified in keeping with the
invention.
In accordance with an embodiment of the present invention, the at least one recess within
the web is located adjacent to the top chord and/or the bottom chord. In this way, the
critical transition region between the web and the chord can be protected particularly
effectively, thereby especially enabling the chord to be effectively prevented from
splitting as a result of the compressive force that is introduced by the web.
In the light of this situation, according to a further aspect of the present invention the at
least one recess in the top chord and/or bottom chord is adjacent to the web. At the same
time, this relieves the web of stress, since the web as a whole is subjected to stress in a
uniform manner and without any stress peaks, which increases its load-bearing capacity.
In addition, particularly advantageous load-bearing characteristics are obtained if the two
aforementioned aspects are combined such that the at least one recess extends from the
web into the top chord and/or bottom chord. As a result, stress peaks in the transition
region between the web and the chords can be eliminated completely, which considerably
relieves both the chords and the web of stress, with the result that, overall, the load-
bearing capacity is greatly boosted with respect to shock-type stress.
Particularly effective damping characteristics are achieved in accordance with an
embodiment of the present invention in that the filling material essentially fills up the at
least one recess.
In accordance with a further aspect of the present invention, the recesses as defined by the
invention can, moreover, be very advantageously combined with an end-face protector
that covers at least sectionally a formwork-support end face located in the end region.
This particularly benefits the load-bearing capacity of the formwork support in the event
of shock-type stress both in the transverse direction and in the longitudinal direction of the
support.
in accordance with the invention, it is particularly preferred for the end-face protector to
encompass the formwork support's end region at least partially in order thereby to
contribute to the support's load-bearing capacity in its transverse or diagonal direction,
too. At the same time, as a result of encompassing the formwork support, especially the
chords, the support is reliably prevented from splitting or splintering whenever nails are
hammered in or screws and bolts are screwed in.
To achieve simple production of the formwork support in accordance with the invention
and to avoid joints in the support, it is preferred, in accordance with an embodiment of the
present invention, for the end-face protector to be formed integrally with the filling
material of at least one recess.
It has proved particularly beneficial for the filling material and/or end-face protector to be
formed by a plastic material that is preferably sprayed or cast on. The use of a plastic
material permits, on the one hand, advantageous damping properties and, on the other
hand, a simple, rapid and cost-effective method of producing the formwork support in
accordance with the invention.
Particular preference is given to a plastic material such as PUR, especially a polyether-
based or polyester-based PUR casting resin. These materials can be processed using high-
pressure or low-pressure techniques and are consequently, furthermore, ideal for casting
on in the event of relatively low pressures. In addition, they have also proved to be
beneficial on account of their excellent damping characteristics. Moreover, the PUR can
be advantageously filled with additives such as fibre glass, talcum, etc.
Further preferred materials include rubber, especially EPDM rubber, and thermoplastic
elastomers (TPE). Due to their excellent damping properties, TPE-S (based on styrene-
ethylene-butadiene-styrene), TPE-V (based on EDM/polypropylene) and TPE-U (based
on polyurethane), in particular, have turned out to be advantageous.
Nevertheless, it should be borne in mind that the filling material and/or the end-face
protector can, moreover, each be applied individually or integrally as a semi-finished part
(or parts), for instance by means of an adhesive or the like.
In accordance with a further aspect, the present invention envisages the end-face protector
and/or the filling material to comprise at least one reinforcing member which is preferably
made of steel, aluminium or fibre-reinforced plastic. In this way, the formwork support
defined by the invention can be lent additional strength without impairing the
advantageous deformation properties, thereby enabling the support's load-bearing

capacity to be increased even further in the event of shock-type stress. In this respect, it is
preferred by the invention for the reinforcing members to be formed by rings that
encompass in particular the top chord and/or the bottom chord. In this way, the chords
are reliably protected from splitting if a load is applied transversely or at an angle.
In addition, the present invention provides a method of producing a formwork support,
said method comprising the steps of:
producing a secure connection between said web and said top chord and said bottom
chord to make a formwork support,
inserting at least one recess within said web and/or within at least one of said chords into
an end region of said formwork support, and
introducing a filling material that has shock-absorbing properties into said at least one
recess.
The method defined by the invention makes it possible to manufacture a novel formwork
support in an industrially feasible and hence economical manner, this formwork support
exhibiting a considerably improved load-bearing capacity whenever shock-type stress
occurs, especially in the support's transverse or diagonal direction.
If the method is to be performed comparatively simply and if a simple apparatus is to be
used to perform this method, there is an advantage to casting on the filling material rather
than spraying it on, in that lower pressures are used. This simplifies sealing between a
casting mould or an injection mould and the outer contour of the support end.
In an embodiment of the method according to the invention, the web is securely
connected to the top and bottom chords before the at least one recess is introduced. This
means that the manufacture of the support can, per se, be separate from the introduction
of the recesses, with the result that any support can be provided subsequently with those
recesses which are necessary and beneficial in relation to individual applications.

In accordance with the invention, particular preference is given to sawing or milling in
the at least one recess from an end face of the web and/or of the at least one chord. It is
due to this measure that the at least one recess can be effected with particular ease and
that, in particular, this recess can be easily introduced on supports that have already been
finished.
Furthermore, in accordance with another aspect, the method involves applying an end-
face protector that covers at least sectionally a formwork-support end face located in the
end region, with particular preference being given to the fact that the filling material
and/or the end-face protector is applied by spraying or casting on a plastic material,
particularly in an integral manner. Alternatively, however, it is of course possible to
apply the filling material and/or the end-face protector individually or integrally in each
case as a semi-finished part (or parts), for example by means of an adhesive or the like.
Short Description of the Accompanying Drawings
Fig. 1 shows a schematic perspective view of a first embodiment of the formwork
support according to the invention ;
Fig. 2a) shows a schematic side view of the embodiment depicted in Fig. 1 ;
Fig. 2b) shows a schematic sectional view of the first embodiment of the formwork
support according to the invention, with the section being made along the
line A-A in Fig. 2a) ;
Fig. 2c) shows a schematic sectional view of the first embodiment of the formwork
support according to the invention, with the section being made along the
line B-B in Fig. 2a) ; and

Fig. 3 shows a schematic exploded view of a second embodiment of the
formwork support according to the invention.
Detailed Description of Preferred Embodiments
Preferred embodiments of the formwork support according to the invention will now be
described in detail with reference to the accompanying drawings.
Figs. 1 and 2 show schematically a first embodiment of a formwork support 1 in
accordance with the invention. The formwork support 1 comprises a top chord 2, a
bottom chord 4 and a web 6 that connects the two chores, the aforementioned all being
made essentially of wood. The web 6 may be a solid-wall web or, for example, a
trelliswork or latticework structure or the like. In the present embodiment example, the
chords 2, 4 each comprise a recess 8 in an end region 1' of the support 1, this recess
extending from the end face 1" of the formwork support 1 into the chords 2, 4. In the
present embodiment, furthermore, the recesses 8 are arranged such that they are each
located adjacent to the web 6, i.e. they adjoin same. In accordance with the invention,
however, it is, moreover, possible for the recesses 8 to pass into the web 6 or just for
them to be provided within the web 6, in which case an arrangement of recesses adjacent
to the chords 2, 4 is preferred.
The recesses 8 each comprise a filling material 10 which has shock-absorbing properties
and in the present embodiment example essentially fills up the recesses 8. Although it is
preferable to fill up the recesses 8 to a large extent, embodiments with cavities or gaps in
the filling material 10 are possible, too. In addition, the invention envisages the filling
material 10 having in the web's transverse direction at least a width of the cover (U)
between the web 6 and the chords 2, 4.

Furthermore, the formwork support 1 is provided with an end-face protector 12 that is
formed integrally with the filling material 10, as can be best identified in Fig. 2b). The
end-face protector 12 covers at least sectionally an end face 1" that is located in the end
region 1' of the formwork support 1. The end-face protector 12 may also cove completely
the end face 1" of the formwork support 1. Moreover, in the present embodiment, the
end-face protector 12 also encompasses the lateral faces of the top chord 2 and of the
bottom chord 4.
The filling material 10 and the end-face protector 12 are each made of a shock-absorbing
material, particularly a thermoplastic elastomer (TPE), preferably TPE-S (based on
styrene-ethylene-butadiene-styrene), TPE-V (based on EDM/polypropylene) or TPE-U
(based on polyurethane), a rubber, preferably an EPDM rubber, or a polyurethane,
preferably a polyether-bascd or polyester-based polyurethane casting resin.
Based on the embodiment of the formwork support 1 with the shock-absorbing material
10 in the recesses 8, as specified by the invention, the formwork support 1 is lent an
excellent load-bearing capacity in the event of shock-type or impact-type stress, which
load-bearing capacity is considerably enhanced compared to conventional supports,
particularly in the support's transverse or diagonal direction. One way in which this
improvement is brought about is in that, thanks to the shock-absorbing filling material, an
internal resilience of the support is, to an extent, achieved, so that the support can, by
means of deformation, avoid excessive stress peaks in the event of shock-type or impact-
type stress. Yet the support still has a simple structural design and in particular does not
require any intricate reinforcements such as steel bolts, steel caps or the like.
The formwork support 1 described above can be produced for example in the following
way. First, a top chord 2, a bottom chord 4 and a web 6, which are all essentially made of
wood, are joined together to form a formwork support. Alternatively, moreover, you can
immediately start out with a commercially available formwork support that has a top

chord 2, a bottom chord 4 and a web 6. In the present embodiment example, the recesses
8 are then sawed or milled into the web 6 from the end face 1" of the formwork support 1.
Next, the filling material 10 is introduced into each of the recesses 8.
It has proved particularly advantageous for the filling material 10 and, where appropriate,
an additional end-face protector 12 to be integrally applied as a result of spraying or
casting a plastic material onto the formwork support 1. This achieves a rapid and
economical production process, whereby a particularly good bond between the filling
material 10 — and the end-face protector 12 — and the formwork support 1 is obtained by
spraying or casting on the plastic material, because the plastic material is able to penetrate
the pores of the wood.
Fig. 3 shows schematically a second preferred embodiment of the formwork support 1 in
accordance with the invention. Identical or corresponding components are each provided
with the same reference numbers in Figs. 2 and 3, thus making it unnecessary to repeat
the description of these components. First of all, the embodiment shown in Fig. 3 differs
from the first embodiment in that the end-face protector 12 is not designed as a single
component as such, but has two sections each assigned to the chords, these sections each
being integral with the filling material 10 of the recesses 8, and it also has a middle
section 12' assigned to the web. This arrangement has the advantage that in the region of
the chords 2, 4 and of the web 6, material that is precisely tailored to the specific
requirements that in each case be used as an end-face protector. It is thus conceivable, for
example, for the highly stressed chord ends to each be provided with a top-quality
damping material as end-face protector 12, whereas in the region of the web, use is made
of a middle section 12' that does indeed exhibit sufficient damping and sealing properties,
but which can otherwise be customized in terms of the design and recognition value of
the formwork support.
In addition, the end-face protector in the present embodiment, to be more precise, the
sections 12 assigned to the chords 2, 4, each comprise a reinforcing member 14 that
extends into the reinforcing material 10 provided within the recesses 8. In the present
embodiment, the reinforcing members 14 are formed by rings which each enclose the free
end portions of the chords 2, 4. In this way, the formwork support 1 in accordance with
the invention is lent further improved strength in addition to its excellence damping
properties, thereby effectively preventing the chord ends from detrimentally splitting
open.
The reinforcing members 14 may in principle be arranged at any point within the end-face
protector 12 and/or the filling material 10. With regard to a particularly good efficacy of
the reinforcing members 14, however, it is advantageous for the reinforcing members or
reinforcing rings 14 to directly enclose the free ends of the chords 2, 4, i.e. to be directly
adjacent thereto, and to be outwardly surrounded, in a shock-absorbing manner, by the
filling material 10 and/or the end-face protector 12.
The reinforcing members 14 are preferably made of steel, aluminium or fibre-reinforced
plastic. Equally, other reinforcing members can be used instead of rings, for instance
wooden strips, wood materials, metal, plastic or fibre materials which are arranged such as
to reinforce the chord wood transverse to or at an angle to the fibre direction in the region
of the chord ends.
The manner of producing the second embodiment of the formwork support 1 according to
the invention, as shown in Fig. 3, likewise corresponds in principle to that of the first
embodiment. It must be remembered that the reinforcing members 14 are preferably fitted
onto the ends of the chords 2, 4 after the recesses 8 have been introduced, in order then to
integrally or gradually spray or cast the plastic material for the filling material 10 and end-
face protector 12. This dispenses with any separate attachment of the reinforcing members
14 to the chord ends, because the securing members are enclosed and connected to the
chord ends while the plastic material is being sprayed or cast on.
Although the present embodiments have described a technique to spray or cast on the
filling material 10 and the end-face protector 12, it is, of course, equally possible to
perform a different manner of attaching these members to the formwork support 1
according to the invention without impairing the advantageous effects of the present
invention, particularly the excellent damping properties and the correspondingly improved
load-bearing capacity in the event of shock-type stress. In particular, the invention also
provides for the filling material 10 and/or the end-face protector 12, which may each be
multi-component versions as well, to be joined to the formwork support 1 by bonding or
by comparable techniques.
WE CLAIM :
1. A formwork support (1) having a top chord (2) and a bottom chord (4) and a web
(6) which connects the two chords, the chords and the web all being made essentially of
wood, wherein said web (6) and/or at least one of said chords (2,4) comprise at least one
recess (8) in at least one end region (T) of said support, said recess, if located in a chord
(2,4), being located at least in the region of an overlap (U) of said web (6) and adjacent to
said web (6), said at least one recess (8) being provided with a filling material (10) that
has shock-absorbing properties.
2. A formwork support as claimed in claim 1, wherein said at least one recess (8)
within said web (6) is located adjacent to said top chord (2) and/or said bottom chord (4).
3. A formwork support as claimed in claim 1 or 2, wherein said at least one recess
(8) extends from said web into said top chord (2) and/or said bottom chord (2).
4. A formwork support as claimed in any one of the preceding claims, wherein said
filling material (10) essentially fills up said at least one recess (8).
5. A formwork support as claimed in any one of the preceding claims, wherein said
formwork support also comprises an end-face protector (12) that coves at least sectionally
an end face (1") of said formwork support (1), said end face being located in said end
region (1').
6. A formwork support as claimed in any one of the preceding claims, wherein said
end-face protector (12) is integrally formed with said filling material (10) of at least one
recess (8).

7. A formwork support as claimed in claim 5 or 6, wherein said end-face protector
(12) at least partially encompasses said end region.
8. A formwork support as claimed in any one of the preceding claims, wherein said
filling material (10) and/or said end-face protector (12) is formed by a plastic material
which is preferably sprayed or cast on.
9. A formwork support as claimed in any one of the preceding claims, wherein said
filling material (10) and/or said end-face protector (12) comprises a rubber material, a
thermoplastic elastomer or a polyurethane.
10. A formwork support as claimed in any one of the preceding claims, wherein said
filling material (10) and/or said end-face protector (12) comprises at least one reinforcing
member (14) that is preferably made of steel, aluminium or fibre-reinforced plastic.
11. A formwork support as claimed in claim 10, wherein said at least one reinforcing
member (14) is formed by a ring which preferably encompasses said top chord (2) and/or
said bottom chord (4).
12. A method of producing a formwork support (1) as claimed in any of the preceding
claims, said method comprising the steps of:
producing a secure connection between said web (6) and said top chord (2) and said
bottom chord (4) to make a formwork support (1),
inserting at least one recess (8) within said web (6) and/or within at least one of said
chords (2,4) into an end region (1) of said formwork support (1), and
introducing a filling material (10) that has shock-absorbing properties into said at least
one recess (8).

13. A method as claimed in claim 12, wherein said web (6) is securely connected to
said top and bottom chords (2,4) before said at least one recess (8) is inserted.
14. A method as claimed in claim 12 or 13, wherein said at least one recess (8) is
sawn or milled in from an end face of said web (6) and/or said at least one chord (2, 4).
15. A method as claimed in any of claims 12 to 14, wherein an end-face protector (12)
is also applied, said end-face protector covering at least sectionally an end face (1") of
said fo mi work support (1), said end face being located in said end region (1').
16. A method as claimed in any of claims 12 to 15, wherein said filling material (10)
and/or said end-face protector (12) is applied as a result of spraying or casting on a plastic
material.


A formwork support (1) having a top chord (2) and a bottom chord (4) and a web
(6) which connects the two chords, the chords and the web all being made essentially of
wood, wherein said web (6) and/or at least one of said chords (2,4) comprises at least one
recess (8) in at least one end region (1') of said support, said recess, if located in a chord
(2,4), being located at least in the region of an overlap (0) of said web (6) and adjacent to
said web (6), said at least one recess (8) being provided with a filling material (10) that
has shock-absorbing properties.

Documents:

01510-kolnp-2005-abstract.pdf

01510-kolnp-2005-claims.pdf

01510-kolnp-2005-description complete.pdf

01510-kolnp-2005-drawings.pdf

01510-kolnp-2005-form 1.pdf

01510-kolnp-2005-form 3.pdf

01510-kolnp-2005-form 5.pdf

01510-kolnp-2005-international publication.pdf

1510-kolnp-2005-assignment.pdf

1510-kolnp-2005-correspondence.pdf

1510-kolnp-2005-examination report.pdf

1510-kolnp-2005-form 13.pdf

1510-kolnp-2005-form 18.pdf

1510-KOLNP-2005-FORM 27.pdf

1510-kolnp-2005-form 3.pdf

1510-kolnp-2005-form 5.pdf

1510-KOLNP-2005-FORM-27.pdf

1510-kolnp-2005-gpa.pdf

1510-kolnp-2005-granted-abstract.pdf

1510-kolnp-2005-granted-claims.pdf

1510-kolnp-2005-granted-description (complete).pdf

1510-kolnp-2005-granted-drawings.pdf

1510-kolnp-2005-granted-form 1.pdf

1510-kolnp-2005-granted-form 2.pdf

1510-kolnp-2005-granted-specification.pdf

1510-kolnp-2005-reply to examination report.pdf

abstract-01510-kolnp-2005.jpg


Patent Number 243397
Indian Patent Application Number 1510/KOLNP/2005
PG Journal Number 42/2010
Publication Date 15-Oct-2010
Grant Date 13-Oct-2010
Date of Filing 01-Aug-2005
Name of Patentee DOKA INDUSTRIE GMBH
Applicant Address REICHSTRASSE 23, A-3300 AMSTETTEN
Inventors:
# Inventor's Name Inventor's Address
1 PENEDER, JOHANN TRUCKENSTETTEN 7, A-3325 FERSHNITZ
PCT International Classification Number E04C 3/14
PCT International Application Number PCT/EP2004/000621
PCT International Filing date 2004-01-26
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 103 05 613.0 2003-02-11 Germany