LOWER PART FOR AN INSTALLATION DUCT

PIECE INFERIEURE D'UN RAIL D'INSTALLATION

English Abstract

A lower part for an installation duct, in
particular a wall duct, is described which consists
of a sheet metal profile (1) having a C-shaped
cross-section on which an assembly rail (6)
extending over the length of the profile and
likewise having a C-shaped profile is mounted
for securing installation apparatus. This assembly
rail (6) has a novel structure in that it consists of
strip-shaped bars (7) which are cut out of the base
wall (2) in pairs arranged opposite each other in
sections and which are each shaped to form a leg
of the C-shaped profile of the assembly rail (6).

French Abstract

L'invention concerne la partie inférieure d'un conduit d'installation, notamment un conduit mural qui se présente sous forme de profilé en tôle (1) à section transversale en C, sur lequel est appliqué un rail de montage (6) s'étendant sur toute la longueur du profilé et présentant également un profil en C, qui sert à fixer les appareils d'installation. Ce rail de montage (6) présente un aspect novateur en ce sens qu'il se compose de barrettes (7) découpées sous forme de bandes dans la paroi du fond (2) du profilé, qui sont disposées de manière opposée par lots de deux paires et qui sont déformées pour constituer une branche du profil en C du rail de montage (6).

Claims

CLAIMS:
1. Lower part for an installation duct, particularly a wall
duct, which consists of a sheet metal profile 1 having a C-shaped
cross-section on which an assembly rail 6 extending over the
length of the profile and having a C-profile is mounted for
securing installation apparatuses on the interior side, of the
base wall 2, characterized in that the assembly rail 6 consists
of strip-shaped bars 7 which are situated opposite one another in
pairs and are cut in sections from the base wall and which are
shaped into a leg of the C-profile of the assembly rail 6.
2. Lower part according to Claim 1, characterized in that,
between the sections containing the bars 7, one reinforcing web 9
respectively is provided which extends transversely with respect
to the longitudinal sides of the bars and has a reinforcement 10.
3. Lower part according to Claim 2, characterized in that
the reinforcement is formed by a reinforcing rib 10 which is
formed by a straight cut 11 perpendicularly to the longitudinal
center axis 12 of the assembly rail 6 and by a scoop-type
deformation of the material area adjoining the cut 11.
4. Lower part according to Claims 1 to 3, characterized in
that the reinforcing rib 10 is constructed to be slightly longer
toward both sides of the longitudinal center axis 12 of the

assembly rail 6 than the width (b) of the openings 8 punched out
in the base wall 2 from which the material for the bars 7
originates.

Description

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PCT/EP95/00800 ENGLISH TRANSLATION
LOWER PART FOR AN INSTALLATION DUCT
The invention relates to a lower part for an installation
duct, particularly a wall duct, which consists of a sheet metal
profile having a C-shaped cross-section on which an assembly rail
extending over the length of the sheet metal profile and having a
C-profile is mounted for securing installation apparatuses on the
interior side.
Installation ducts with lower parts of this type are known,
for example, from Utility Model 87 04 502 or from Utility Model
87 08 607. In practice, the assembly rails provided there and
mounted on the base of the ducts are manufactured separately from
the groove-shaped sheet metal profile and are then welded,
riveted, glued or otherwise fastened to the base of the duct.
For manufacturing the duct profile, several operating cycles on
separate parts are therefore required which results in high
expenditures.
It is an object of the present invention to construct a
lower part for an installation duct of the initially mentioned
type in a more favorable manner with respect to manufacturing
techniques in order to limit the machining expenditures.

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For achieving this object, in the case of the lower part of
the initially mentioned type, the invention consists of the fact
that the assembly rail is composed of strip-shaped bars arranged
opposite one another in pairs and cut in sections out of the base
wall of the sheet metal profile, which bars are each shaped to
form a leg of the C-shaped profile of the assembly rail.
As a result of this development, the separate manufacturing
of the assembly rail and the related fastening expenditures will
no longer be required. The invention is based on the id~a that
it is not very important for the function of the assembly rail
whether the assembly rail is constructed in an uninterrupted
continuous manner or whether it is constructed of partial areas
which are disposed in sections behind one another and which are
still separated with respect to one another by base parts of the
of the wall duct. By means of the new further development, it
becomes possible to punch the lower part for the installation
duct, for example, from sheet metal in one working cycle and to
also shape on the assembly rail when shaping the sheet metal
profile into the duct shape. Additional operating expenditures
for the mounting of the assembly rail are superfluous.
As a further development of the invention, one reinforcing
web respectively, which extends transversely with respect to the
longitudinal sides of the bars, may be provided between the bars,
which reinforcing web keeps the remaining base of the lower part

2162605
on the whole sufficiently stiff irrespective of the bars punched
out in sections. In this case, this reinforcing web may be
formed in a simple manner by a straight cut perpendicularly to
the longitudinal center axis of the profile and by a scoop-type
deformation of the material area adjoining the cut. Thus, the
reinforcing webs can also be shaped-on directly, specifically by
means of relatively simple punching and pressing operations.
For reasons of stability, it is very advantageous in this
case for the reinforcing web to be constructed to be slightly
longer toward both sides of the longitudinal center axis of the
assembly rail than the openings punched out in the base of which
the bars are formed.
The invention is illustrated in the drawings by means of an
embodiment, which drawings are described in the following.
Figure 1 is a top view of the open side of a lower part for
a wall installation duct of which only the two end areas are
shown;
Figure 2 is a reduced view of the wall duct of Figure 1 from
the closed base side;
Figure 3 is a sectional view of the wall duct of Figure 1
along Line III-III in Figure 1;

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.
Figure 4 is the enlarged representation of the detail IV in
Figure 3; and
Figure 5 finally is the enlarged representation of the cut
along line V-V in Figure 1.
Figures 1 to 3 show the lower part of a wall installation
duct which consists of a sheet metal profile 1 with a C-shaped
cross-section whose base wall 2 merges into two side walls 3 from
which, in turn, end wall parts 4 extend in parallel to the base
wall 2, which end wall parts 4 are provided on their end edges
with grooves 5 for inserting a cover which is not shown.
On the interior side of the base wall 2, an assembly rail 6
is mounted which extends in parallel to the side walls 3 and
which has the purpose of receiving and holding the anchoring
parts of electric installation equipment. This assembly rail 6
consists of longitudinal bars 7 which are cut out of the material
of the base wall 2 and are bent upwards and inward by means of
their edges. In this case, Figure 4, but also Figure 1 shows the
rectangular openings 8 which were formed by the cutting-out and
bending-up of the bars 7.
Figures 1 and 2 also show that the bars 7 are cut out and
shaped only in sections and in that, between two pairs of bars
which follow one another in the longitudinal direction of the

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.
profile 1, respective connecting webs 9 exist between the base
parts remaining on both sides of the openings 8, which base parts
secure the required stability of the profile 1. In the case of
this embodiment, these connecting webs 9 are provided with an
additional reinforcement in the form of a stiffening rib 10 which
is ormed in that a separating cut (Figure 5) takes place
perpendicularly to the longitudinal edges of the bars 7 and
therefore also perpendicularly to the longitudinal edges of the
openings 8 at point 11, and in that the material area adjoining
this cut is bent open upwards toward the reinforcing rib 10 in
the manner of a scoop, which is open toward the cut 11. The
connecting web 9 will then merge in an aligned manner into base 2
of the profile 1. By means of this further development, a
reinforcement is achieved in the area of the remaining connecting
webs. Figure 1 shows in this case that, measured perpendicularly
from the longitudinal center axis 12 of the assembly rail 6, the
length of the reinforcing ribs 10 is slightly larger than the
width (b) of the outer edges of the openings 8 measured in the
same direction. The reinforcing ribs 10 therefore extend into
the area of the base 2 which is not weakened by cuts.
As demonstrated, the new lower part for a wall installation
duct can be manufactured in a very simple manner from a common
blank by punching, edging and bending as well as pressing if
suitable tools are provided. Therefore, without any additional
operating cycle, this profile can be shaped to the final shape
from one sheet metal strip.

Representative Drawing