Note: Descriptions are shown in the official language in which they were submitted.
CA 03165222 2022-06-17
PCT/EP2021/068684
Anchor rail and method for producing an anchor rail
The present invention relates to an anchor rail for fixing fastening means,
hav-
ing a first rail part and a second rail part, which are connected to one
another,
and on each of which anchor webs are formed, wherein a channel-shaped re-
ceptacle for a head section of a fastening means is formed between a first
wall
of the first rail part and a second wall of the second rail part, and an
inwardly
projecting web is provided on the first wall and an inwardly projecting web is
provided on the second wall, and the inwardly projecting webs cover the chan-
nel-shaped receptacle at the edge, and a method for producing an anchor rail.
EP 1 764 448 A2 discloses an anchor rail in which anchor webs are formed on
a first rail part, which is connected to a second C-shaped rail part in a
bottom
area. This connection point between the two rail parts forms a weak point that
can fail when fastening means are inserted into the second rail part and high
forces are applied.
In addition, anchor rails in which the anchor rail is made from two rail parts
are
known (DE 10 2008 029 838 Al, DE 10 2018 003 160 Al), wherein each rail
part comprises anchor webs and forms a wall which surrounds a channel for re-
ceiving fastening means. A bent-over, inwardly projecting web is formed on
each wall which can be engaged behind by a head section of a fastening
means. This allows tensile forces through the fastening means to be introduced
directly into the anchor webs via each rail section, resulting in high holding
forces. Such anchor rails have generally proven themselves, but bending high-
strength steel sheets is problematic, especially if they are to be produced
with
somewhat greater thickness. In the area of the channel-shaped receptacle, an
inwardly projecting web on a wall section is bent almost at right angles,
which
limits the strength and thickness of the steel sheet and thus also the maximum
holding forces permitted by the anchor rail.
It is therefore the object of the present invention to provide an anchor rail
and a
method for manufacturing an anchor rail that can absorb particularly high hold-
ing forces and can be manufactured effectively.
This object is solved with an anchor rail having the features of claim 1 and a
method having the features of claim 12.
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2
In the anchor rail according to the invention, a channel-shaped receptacle for
a
head section of a fastening means is formed between a first wall and a second
wall, wherein an inwardly projecting web is provided on each wall, which
covers
the channel-shaped receptacle at the edge, and an outwardly projecting sup-
port web protrudes at least in sections on the first and/or second wall
opposite
the inwardly projecting web. As a result, after the anchor rail has been cast
in
concrete or another casting material, the outwardly projecting support web can
be used to stabilize the inwardly projecting web. When a tensile load is
applied
by a fastening means, the inwardly projecting web is pivoted slightly in a
direc-
tion away from the anchor rail, wherein deformation is limited by the
outwardly
projecting support web, which forms an abutment. The outwardly projecting
support web is supported on the cast material and can thus counteract defor-
mation at the inwardly projecting web. This also prevents deformation of the
wall, which acts as a kind of bending bearing. The attachment of at least one
support web thus increases the strength of the anchor rail in this area,
resulting
in the provision of higher holding forces.
Preferably, a support web is provided on both the first and the second wall,
in
particular a continuous support web, which extends over substantially the same
length as the inwardly projecting web. This allows support to be provided over
the entire length of the anchor rail. Alternatively, several sections of
support
webs can be fixed to one wall each.
The first wall, the inwardly projecting web and the outwardly projecting
support
web are preferably designed T-shaped in cross-section, so that the first wall
is
aligned essentially at right angles to the inwardly projecting web and the sup-
port web. The same applies to the second wall, which is preferably also ar-
ranged at right angles to the inwardly projecting web and support web attached
thereto.
For effective manufacturing, the support web can be welded to the first or sec-
ond wall, for example by a laser welding process. Preferably, the support web
is integrally formed with the inwardly projecting web so that they can be
fixed to
the first or second wall with high accuracy. Tests have shown that a
sufficiently
stable connection between webs and the wall aligned at an angle to them can
be produced by a welded connection, in particular by laser welding.
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3
In a preferred design, the support web and the inwardly projecting web are
made of a metal sheet, in particular a steel sheet, which is thicker than the
first
and second rail parts, which are preferably also made of a metal sheet, in par-
ticular a steel sheet. As a result, the inwardly projecting web, against which
a
head section of a fastening means rests, can be of particularly stable design.
The inwardly projecting web is preferably at least 20% thicker, for example at
least 1 mm thicker, than one of the two rail parts forming the walls.
Alternatively or in addition to the thickness design, the support web and the
in-
wardly projecting web may be formed from a material of higher strength than
the first and second rail parts. By using a high-strength steel sheet to
produce a
strip-shaped blank for the support web and the inwardly projecting web, the
area subjected to forces by fastening means can be made more stable even
with the same thickness as the rail part by selecting a suitable material.
The support web and the inwardly projecting web are preferably made from a
flat steel sheet, in particular by a strip-shaped blank, wherein this blank is
con-
nected to the first or second wall in a central region by a welded butt seam.
The
inwardly projecting web and the support web can project from the respective
wall by, for example, 1 mm to 20 mm, in particular 3 mm to 12 mm. The thick-
ness of the strip-shaped blank for producing the two webs can be, for example,
between 2 mm to 10 mm, in particular 3 mm to 8 mm.
Each rail part is preferably made of a bent steel sheet. The anchor webs are
preferably aligned at an angle to the respective wall on the rail part. The
first
and second rail parts can be connected to each other by welded connecting
webs, as disclosed for example in DE 10 2020 103 568. Optionally, the two rail
parts can also be integrally formed with each other and manufactured from a
single blank.
In a further design, the inwardly projecting webs each have a toothing in
order
to be able to fix the fastening means in the longitudinal direction of the
anchor
rail. To fix the fastening means in the longitudinal direction, a retaining
plate
with teeth at the edge can be provided, as disclosed in DE 10 2020 102 977.
In the method for producing an anchor rail according to the invention, two
blanks for a first and a second rail part with anchor webs are made from a
steel
sheet and strip-shaped blanks are made from a steel sheet. A first strip-
shaped
blank is welded to a first wall of a first rail part and a second strip-shaped
blank
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is welded to a second wall of the second rail part. Furthermore, the two rail
parts are joined to one another, in particular by welding, before or after the
strip-shaped blanks are welded together, wherein a channel-shaped receptacle
for a head section of a fastening means is formed between the first wall and
the
second wall, and each strip-shaped blank forms an inwardly projecting web on
the first or second wall, which covers the receptacle at the edge, and an out-
wardly projecting support web. Thus, in the method according to the invention,
instead of bending two rail parts and then joining them, an additional compo-
nent is produced by the strip-shaped blank, which is welded to a wall of a
rail
part. As a result, the loaded area of the anchor rail can be made particularly
stable by selecting the strip-shaped blank in accordance with the mechanical
requirements. In addition, the outwardly projecting support web can limit
defor-
mation of the inwardly projecting web, since the support web is supported on
the cast body in the cast state.
Preferably, the welding of the first and second strip-shaped blanks is
performed
by laser welding, in which the material in the contact area between the strip-
shaped blank and an end face of a wall of a rail part is melted without
welding
additions. This allows the inwardly projecting web to be positioned on the
first
or second rail part with a high degree of accuracy.
Preferably, a strip-shaped blank is welded to an end face of each of the first
or
second walls in a central region via a butt seam so that the strip-shaped
blank
protrudes from the respective wall on opposite sides.
The invention is explained in more detail below by means of an exemplary em-
bodiment with reference to the accompanying drawings, wherein:
Figs. 1A and 1B show two views of an anchor rail according to the
inven-
tion;
Fig. 2 shows a sectional view through the anchor rail of
Fig. 1,
and
Fig. 3 shows a sectional view through the anchor rail of Fig. 1
with a fastening means.
An anchor rail 1 comprises two rail parts 2a and 2b which are made of a metal
sheet, in particular a steel sheet. Integrally formed anchor webs 3 are
provided
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on each rail part 2a and 2b, which have a widened foot section 4 and are later
immersed in a cast body, in particular one of concrete.
A recess 5 is provided at least on one part of the anchor webs 3 in order to
use
5 the web-shaped material punched out on three sides at the recess 5 to
produce
a connecting web 6a or 6b. The connecting webs 6a and 6b are of stepped de-
sign at their facing end so that the two rail parts 2a and 2b can be fixed at
a
predefined distance. The connecting webs 6a and 6b are preferably welded to-
gether as described in DE 10 2020 103 568.
As shown in particular in Fig. 2, there is a wall 8a on the first rail part
2a, and
spaced from the first wall 8a a second wall 8b formed integrally with the
second
rail part 2b. A channel-shaped receptacle 13 for inserting a head section of a
fastening means is formed between the two walls 8a and 8b. The channel-
shaped receptacle 13 is bounded by the connecting webs 6a and 6b, which are
fixed to each other.
The anchor webs 3 are aligned at an angle to the wall 8a or 8b, preferably by
an angle a, which can lie in a range between 5 and 300. A kink 9 is provided
between the anchor bars 3 and the wall 8a or 8b.
An inwardly projecting web 10 is provided on opposite sides of the channel-
shaped receptacle 13. The two inwardly projecting webs 10 cover the edge of
the channel-shaped receptacle 13 and leave a slot through which the fastening
means with the head section can be inserted into the channel-shaped recepta-
cle 13. A toothing 11 is formed on the inwardly projecting webs 10 in order to
be able to fix the fastening means in the longitudinal direction of the anchor
rail
1.
The inwardly projecting webs 10 are not integrally formed with one of the rail
parts 2a or 2b, but are made from a strip-shaped blank which also forms an
outwardly projecting support web 12. This flat blank is preferably made of a
steel sheet which is connected in a central region to an end face of the first
wall
8a or the second wall 8b by a welded butt seam 14. The inwardly projecting
web 10 and the support web 12 thus protrude from the respective wall 8a or 8b
on opposite sides.
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In Fig. 3, the anchor rail 1 is shown with a fastening means 20 in the form of
a
hammerhead screw. A head section 21 of the fastening means 20 has been in-
serted into the channel-shaped receptacle 13 and rotated so that the head sec-
tion 21 engages behind the two inwardly projecting webs 10. A threaded sec-
tion 22 protrudes from the head section 21 from the anchor rail 1, to which
fur-
ther components can be attached.
In order to fix the anchor rail 1 precisely in a casting, in particular a
concrete
body, a retaining bracket 30 is provided, which has a projecting flange 31 on
opposite sides in each case, which can be fixed to a formwork component by
means of fastening means, for example nails. A bracket-shaped section 32
thereby embraces the channel-shaped receptacle 13, which is surrounded by
the walls 8a and 8b and the connecting webs 6a and 6b. The retaining bracket
30 may be designed as described in DE 10 2019 124 308.
To manufacture the anchor rail 1, two blanks are made from a steel sheet, from
which the first and second rail parts with the anchor webs are formed. In addi-
tion, strip-shaped blanks are produced from a steel sheet which later form the
inner webs 10 and the support webs 12. The steel sheet for the strip-shaped
blank can be thicker and/or of higher strength than the steel sheet for the
rail
parts. For example, the thickness of the strip-shaped blanks may be 20%
greater than the thickness of the blanks made of the steel sheet for the rail
parts. In particular, the thickness can be more than 0.5 mm, in particular
more
than 1 mm. Alternatively or additionally, a steel sheet can be selected for
the
strip-shaped blank which has a higher strength than the steel sheet for produc-
ing the rail parts.
After the blanks have been produced, a first blank is welded to a first wall
8a of
the first rail part 2a and a second strip-shaped blank is welded to a second
wall
8b of the second rail part 2b. The welding is preferably carried out using a
laser
welding process, in which the material on the wall 8a or 8b is melted in the
area
of the contact surface to the strip-shaped blank with or without welding addi-
tions. The strip-shaped blank is welded in a central area via a butt seam 14.
Temporally independent of this welding, the two rail parts 2a and 2b can be
welded to each other via the connecting webs 6a and 6b, wherein preferably
the rail parts 2a and 2b are manufactured individually with the welded-on
blanks, since these can be manufactured identically. After the weld has been
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produced, the rail parts 2a and 2b can then be welded together via the connect-
ing webs 6a and 6b.
In the illustrated exemplary embodiment, the connecting webs 6a and 6b are
made of material provided by making a recess 5 on the anchor webs 3. It is ob-
viously also possible to connect the rail parts 2a and 2b by connecting webs
made from the blank for the rail parts 2a and 2b at a different position. In
addi-
tion, separate connecting webs made of a different material can also be used
to
connect the two rail parts 2a and 2b. In a further alternative, the rail parts
2a
and 2b can also be manufactured in one piece.
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List of reference signs
1 Anchor rail
2a, 2b Rail part
3 Anchor web
4 Foot section
5 Recess
6a, 6b Connecting web
8a, 8b Wall
9 Kink
10 Web
11 Toothing
12 Support web
13 Channel-shaped receptacle
14 Butt seam
20 Fastening means
21 Head section
22 Threaded section
30 Retaining bracket
31 Flange
32 Bracket-shaped section
a Angle
Date Recue/Date Received 2022-06-17
