NZ624262B2 - Support metal structure for a false ceiling - Google Patents
Support metal structure for a false ceiling Download PDFInfo
- Publication number
- NZ624262B2 NZ624262B2 NZ624262A NZ62426212A NZ624262B2 NZ 624262 B2 NZ624262 B2 NZ 624262B2 NZ 624262 A NZ624262 A NZ 624262A NZ 62426212 A NZ62426212 A NZ 62426212A NZ 624262 B2 NZ624262 B2 NZ 624262B2
- Authority
- NZ
- New Zealand
- Prior art keywords
- section bar
- clip
- sheet metal
- steel
- shaped steel
- Prior art date
Links
- 229910052751 metal Inorganic materials 0.000 title claims description 90
- 239000002184 metal Substances 0.000 title claims description 90
- 229910000831 Steel Inorganic materials 0.000 claims abstract description 67
- 239000010959 steel Substances 0.000 claims abstract description 67
- 238000000034 method Methods 0.000 claims abstract description 15
- 239000000203 mixture Substances 0.000 claims abstract description 15
- 230000001808 coupling Effects 0.000 claims description 15
- 238000010168 coupling process Methods 0.000 claims description 15
- 238000005859 coupling reaction Methods 0.000 claims description 15
- 239000010935 stainless steel Substances 0.000 claims description 13
- 229910001220 stainless steel Inorganic materials 0.000 claims description 13
- 239000011248 coating agent Substances 0.000 claims description 10
- 238000000576 coating method Methods 0.000 claims description 10
- 238000003780 insertion Methods 0.000 claims description 5
- 229910001335 Galvanized steel Inorganic materials 0.000 claims description 4
- 239000008397 galvanized steel Substances 0.000 claims description 4
- 229910001297 Zn alloy Inorganic materials 0.000 claims description 3
- 239000000463 material Substances 0.000 description 24
- 238000004140 cleaning Methods 0.000 description 7
- 238000000137 annealing Methods 0.000 description 6
- 230000001603 reducing Effects 0.000 description 4
- HCHKCACWOHOZIP-UHFFFAOYSA-N zinc Chemical compound [Zn] HCHKCACWOHOZIP-UHFFFAOYSA-N 0.000 description 4
- 229910052725 zinc Inorganic materials 0.000 description 4
- 239000011701 zinc Substances 0.000 description 4
- 238000005246 galvanizing Methods 0.000 description 3
- 238000003754 machining Methods 0.000 description 3
- 238000004519 manufacturing process Methods 0.000 description 3
- 230000001590 oxidative Effects 0.000 description 3
- 238000003825 pressing Methods 0.000 description 3
- 229910052782 aluminium Inorganic materials 0.000 description 2
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminum Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 2
- 230000000875 corresponding Effects 0.000 description 2
- 238000011068 load Methods 0.000 description 2
- 239000000047 product Substances 0.000 description 2
- 239000010731 rolling oil Substances 0.000 description 2
- 238000009628 steelmaking Methods 0.000 description 2
- 238000005406 washing Methods 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- 229910000640 Fe alloy Inorganic materials 0.000 description 1
- IXCSERBJSXMMFS-UHFFFAOYSA-N HCl HCl Chemical compound Cl.Cl IXCSERBJSXMMFS-UHFFFAOYSA-N 0.000 description 1
- 238000007792 addition Methods 0.000 description 1
- 230000002730 additional Effects 0.000 description 1
- 230000001464 adherent Effects 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- QGZKDVFQNNGYKY-UHFFFAOYSA-N ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 1
- SHHIADHOJKLUIZ-UHFFFAOYSA-N azane;molecular hydrogen Chemical compound N.[H][H] SHHIADHOJKLUIZ-UHFFFAOYSA-N 0.000 description 1
- 239000000356 contaminant Substances 0.000 description 1
- 231100000078 corrosive Toxicity 0.000 description 1
- 231100001010 corrosive Toxicity 0.000 description 1
- 239000012043 crude product Substances 0.000 description 1
- 238000005238 degreasing Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000003517 fume Substances 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 239000003562 lightweight material Substances 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 238000005554 pickling Methods 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 230000001681 protective Effects 0.000 description 1
- 238000005096 rolling process Methods 0.000 description 1
Classifications
-
- E—FIXED CONSTRUCTIONS
- E04—BUILDING
- E04B—GENERAL BUILDING CONSTRUCTIONS; WALLS, e.g. PARTITIONS; ROOFS; FLOORS; CEILINGS; INSULATION OR OTHER PROTECTION OF BUILDINGS
- E04B9/00—Ceilings; Construction of ceilings, e.g. false ceilings; Ceiling construction with regard to insulation
- E04B9/06—Ceilings; Construction of ceilings, e.g. false ceilings; Ceiling construction with regard to insulation characterised by constructional features of the supporting construction, e.g. cross section or material of framework members
- E04B9/065—Ceilings; Construction of ceilings, e.g. false ceilings; Ceiling construction with regard to insulation characterised by constructional features of the supporting construction, e.g. cross section or material of framework members comprising supporting beams having a folded cross-section
- E04B9/067—Ceilings; Construction of ceilings, e.g. false ceilings; Ceiling construction with regard to insulation characterised by constructional features of the supporting construction, e.g. cross section or material of framework members comprising supporting beams having a folded cross-section with inverted T-shaped cross-section
- E04B9/068—Ceilings; Construction of ceilings, e.g. false ceilings; Ceiling construction with regard to insulation characterised by constructional features of the supporting construction, e.g. cross section or material of framework members comprising supporting beams having a folded cross-section with inverted T-shaped cross-section with double web
-
- E—FIXED CONSTRUCTIONS
- E04—BUILDING
- E04B—GENERAL BUILDING CONSTRUCTIONS; WALLS, e.g. PARTITIONS; ROOFS; FLOORS; CEILINGS; INSULATION OR OTHER PROTECTION OF BUILDINGS
- E04B9/00—Ceilings; Construction of ceilings, e.g. false ceilings; Ceiling construction with regard to insulation
- E04B9/06—Ceilings; Construction of ceilings, e.g. false ceilings; Ceiling construction with regard to insulation characterised by constructional features of the supporting construction, e.g. cross section or material of framework members
- E04B9/10—Connections between parallel members of the supporting construction
-
- E—FIXED CONSTRUCTIONS
- E04—BUILDING
- E04B—GENERAL BUILDING CONSTRUCTIONS; WALLS, e.g. PARTITIONS; ROOFS; FLOORS; CEILINGS; INSULATION OR OTHER PROTECTION OF BUILDINGS
- E04B9/00—Ceilings; Construction of ceilings, e.g. false ceilings; Ceiling construction with regard to insulation
- E04B9/06—Ceilings; Construction of ceilings, e.g. false ceilings; Ceiling construction with regard to insulation characterised by constructional features of the supporting construction, e.g. cross section or material of framework members
- E04B9/12—Connections between non-parallel members of the supporting construction
- E04B9/122—Connections between non-parallel members of the supporting construction one member passing through the other member, both members laying at least partly in the same plane
-
- E—FIXED CONSTRUCTIONS
- E04—BUILDING
- E04B—GENERAL BUILDING CONSTRUCTIONS; WALLS, e.g. PARTITIONS; ROOFS; FLOORS; CEILINGS; INSULATION OR OTHER PROTECTION OF BUILDINGS
- E04B9/00—Ceilings; Construction of ceilings, e.g. false ceilings; Ceiling construction with regard to insulation
- E04B9/06—Ceilings; Construction of ceilings, e.g. false ceilings; Ceiling construction with regard to insulation characterised by constructional features of the supporting construction, e.g. cross section or material of framework members
- E04B9/12—Connections between non-parallel members of the supporting construction
- E04B9/127—Connections between non-parallel members of the supporting construction one member being discontinuous and abutting against the other member
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T29/00—Metal working
- Y10T29/49—Method of mechanical manufacture
- Y10T29/49616—Structural member making
- Y10T29/49623—Static structure, e.g., a building component
Abstract
steel support (2) for false ceilings or for supporting false ceilings and process for making. The support being made of a steel strip of 0.25mm or less. The support has the following combination of features: maximum tensile strength (Rm) greater than 500 N/mm and elongation of from 0% to 15%.
Description
SUPPORT METAL STRUCTURE FOR A FALSE CEILING
DESCRIPTION
The present disclosure generally refers to the field of support structures, or
load-bearing structures for false ceilings, i.e. support structures for plates or panels,
e.g. modular ones, placed underneath a regular ceiling, which are connected to the
ceiling by a so-called hanger, steel rods, a wire, section bars or other coupling
articles.
Support structures for false ceilings comprise a frame intended for supporting
or propping of panels or plates, in which the frame includes metal section bars fixed
and crossed by a special joint to ideally form a grid, the grid defining a support plane
for the panels or plates.
Even more specifically, the present disclosure relates to a steel article for a
false ceiling, like, for example, a metal section bar, and a process for the
manufacturing of the steel article.
It is known that a metal section bar for support structures of false ceilings is an
article of elongated shape having a T-shaped section, or other shape suitable for a
false ceiling, for instance a modular false ceiling, in which the section bar is obtained
by folding of a sheet metal or strip. The sheet metal is folded on itself to form an
overlap of two portions of sheet metal, such as to define adjacent and/or side-by-
side sheet metal portions.
In practice, the metal section bar includes at least two sheet metal portions, or
walls, side-by-side and/or overlapped along a longitudinal direction of the section
bar.
In the above-mentioned field, it is also known the need to use sheet metals for
the manufacturing of metal section bars that be made of a material as light-weight
as possible and of reduced thickness, so as to least affect support structure weights
and cost.
However, the use of light-weight materials is incompatible with the possibility
of ensuring sufficient performances of mechanical strength and of stability of the
metal section bar once installed. In particular, a section bar having a thickness lower
than 0.25 mm does not ensure satisfactory strength for a connection with a clip. In
addition, the Inventor of the present disclosure has recognized that a double-wall
section bar, in which two thicknesses, for instance, of 0.25 mm or more, overlap,
does not have the same mechanical strength of a single-wall section bar having a
thickness equal to the sum of the two thicknesses, whose mechanical strength is
much higher. It follows that, up to now, the possibility and the perspective of further
reducing the thickness of the section bar, above all in a double-wall section bar, did
not appear successful.
Moreover, by the Inventor of the present patent application it has been
recognized that, below 0.25 mm of thickness, other problems of mechanical
resistance can occur; for instance, torques can be generated, as highlighted in the
International patent application , to the same holder of the
present patent application.
In addition, at the basis of the present disclosure there is the further
recognition by the Inventor that it is possible to reduce the thickness of the section
bar and, at the same time, obtain a sufficient mechanical performance, thanks to the
use of a specific steel material up to now never used, in the opinion of the Inventor
of the present disclosure, in the field of section bars for false ceilings.
Therefore, the present disclosure is based on the technical problem of how to
provide a steel article for false ceilings overcoming or ameliorating one of more of
the drawbacks mentioned above with reference to the known art, and/or attain
further advantages or features, in particular allowing to maintain reasonable costs
and weights.
Any discussion of documents, acts, materials, devices, articles or the like
which has been included in the present specification is not to be taken as an
admission that any or all of these matters form part of the prior art base or were
common general knowledge in the field relevant to the present disclosure as it
existed before the priority date of each claim of this application.
Throughout this specification the word "comprise", or variations such as
"comprises" or "comprising", will be understood to imply the inclusion of a stated
element, integer or step, or group of elements, integers or steps, but not the
exclusion of any other element, integer or step, or group of elements, integers or
steps.
Disclosed herein is a T-shaped steel section bar for a support structure for
false ceilings or for supporting false ceilings, wherein the T-shaped steel section bar
is made of a galvanized steel strip or sheet metal of thickness equal to or lower than
0.25 mm, wherein the steel presents the following combination of features:
- maximum tensile strength Rm of from 500 to 1000 N/mm ; and
- elongation from 2% to 8%.
Also disclosed herein is a process for making a T-shaped steel section bar for
supporting of false ceilings, wherein said T-shaped steel section bar is made from a
starting galvanized steel strip or sheet metal of thickness equal to or lower than 0.25
mm and the steel of said strip having the following combination of features
- maximum tensile strength of from 500 to 1000 N/mm ; and
- elongation of from 2% to 8%.
Also disclosed herein is a steel article for a false ceiling having a combination
of the following mechanical properties:
- maximum tensile strength Rm greater than 500 N/mm ; and
- elongation lower than or equal to 15%, i.e. ranging from 0 to 15%.
With reference to the above-reported features, it is specified that the meaning
conventionally recognized in the mechanical field should be attributed thereto. In
particular, the term “maximum tensile strength“ signifies maximum strength to point
of failure of a material. The term “elongation” signifies steel elongation to yield point
of a material. This data characterizes, in part, steel deformation ability.
On the basis of said features of reduced elongation ability and high maximum
strength, one or more embodiments of a steel article according to the present
disclosure has high abilities of elastic return.
In an embodiment of the present disclosure, the steel article according to the
present disclosure has a maximum tensile strength Rm of from 650 to 850 N/mm
and/or an elongation ranging from 1 to 12%.
In an embodiment of the present disclosure, the steel article according to the
present disclosure has an elongation ranging from 2 to 8%.
It is noted that in the steelmaking field it is possible to find plants adequate for
providing, on the basis of specific technical demands, a steel having said
mechanical features.
Even more specifically, the Inventor of the present patent application, on the
basis of knowledge in galvanization plants and related thermal cycles, has had the
intuition that, by using a steel having these features, it is possible to provide a
section bar for a false ceiling having a greatly reduced thickness, and at the same
time of high strength. In other words, the Inventor of the present patent application
has had the intuition that a steel section bar having the above-mentioned
mechanical features can have a reduced thickness, which does not nullify the
mechanical performances of a section bar.
In an embodiment of the present disclosure, the steel is a non-stainless steel, for
example comprising a zinc-based coating or a zinc alloy-based coating.
Alternatively, the steel can comprise an aluminum-based coating or a coating based
on aluminum-related alloys, or it can be a painted steel, or be differently coated.
Such a steel is very different from a steel currently used in the field, usually called
DX51D steel, or from other forming-specific steel, which has the following features:
- maximum tensile strength Rm of 270 to 500 N/mm , and more specifically
usually ranging from 350 to 380 N/mm ; and
- elongation greater than 22%, and more specifically usually ranging from 25 to
%.
In fact, it is observed that the steel according to one or more embodiments of the
present disclosure has a maximum tensile strength almost twice that well-known
material to be applied in the field of section bars for false ceilings. In this connection,
it should be noted that the material subject-matter of the present disclosure is so
different from that normally used up to now in the field of false ceilings, that
adequate sheet metal forming and pressing equipment had to be used in order to
obtain the section bars for false ceilings according to the present disclosure. The
need for a change in equipment is mainly due to the fact that the material subject-
matter of one or more embodiments of the present disclosure has a greatly reduced
elongation ability.
Moreover, as disclosed above, it is observed that, with respect to the possibility
of having modest deformations of the section bar (reduced elongation) with
increased strength, for the section bar it is possible to use a material having a
thinner thickness, though maintaining system performances which are the same, or
with superior properties.
In particular, to ensure the obtainment of a section bar, for instance a double-wall
one, or of a similar article for false ceilings, of a thickness reduced even of the order
of 0.10 mm-0.20 mm, the Inventor of the present disclosure has discovered the
need for the steel mill to avail itself of a plant with an adequate thermal and cleaning
cycle, prior to a galvanization step.
In particular, a starting article, as for instance a strip, is subjected to a specific
treatment, which envisages a cold cleaning and a subsequent low-temperature
annealing treatment, for instance at 450°C to 520°C.
Moreover, with regard to double-wall section bars, in order to overcome torque
increase caused, as disclosed above, by thickness decrease, it is adopted the
technical solution described and claimed in the above-mentioned International
patent application , to the same holder of the present patent
application, and incorporated herein by reference.
According to some further embodiments of the present disclosure, taking into
account the above-reported mechanical properties of a section bar for false ceilings,
the Inventor of the present disclosure has discovered the expediency or possibility of
associating the section bar to a clip or connection article which may be deformed in
order to make the connection with the section bar. In particular, the inventor has
discovered the expediency of using a clip having elongation ability greater than the
section bar. In particular, according to these further embodiments of the present
disclosure, the clip has a deformed sheet metal portion, for example deep-drawn,
that surrounds at least partially a hole intended for the connection to the metal
section bar, wherein said deep-drawn sheet metal portion is adapted to be riveted
after having been inserted in a corresponding hole of the metal section bar.
Said clip can be made from a material with good elongation property (therefore
that can be deep-drawn) and high strength and tensile strength (therefore with a
spring effect necessary for the coupling function in the slit of another clip or of
another section bar).
In an embodiment, a suitable material for the clip was found to be the stainless
steel that combines both advantages.
In other exemplary embodiments, other materials having the above-mentioned
features of good elongation property (therefore that can be deep-drawn) and high
strength and high tensile strength have been used for making the clip.
It may be noted that the deformed or deep-drawn sheet metal portion of the clip,
intended to be riveted on the section bar, is part of the clip itself. It follows that, after
the riveting on the section bar, the major load due to the connection with the section
bar weighs on the clip, and is carried by the latter, so as not to burden the section
bar. It further follows that, in some embodiments, the connection article or clip can
be fixed to a metal section bar being of reduced thickness but of high tensile
strength, (in fact, the section bar does not need to be deformed or deep-drawn), and
then, the material being equal, of reduced weight. For example, there is the
possibility of reducing the thickness of the material used to produce the section bar,
for instance saving 20% or more material, with respect to a known-art section bar.
In this respect it is found that, in the opinion of the author of the present
disclosure, in the field of articles for false ceilings the combination of a stainless
steel clip with a non-stainless steel section bar being of a hardness/tensile strength
greater than or similar/comparable to that of the clip, and of reduced elongation, is
totally new.
It follows that, in case a clip is made of stainless steel, which, as is known, is a
valuable material, a possible cost of this valuable material is far compensated by the
saved thickness of the material used for the section bar. It further follows that it is
possible to have a combination of a stainless steel clip with a non-stainless steel
section bar having a weight remarkably reduced with respect to the known art.
It is also to be noted that, in relation to the production, a further advantage lies in
the fact of not necessarily having to replace moulds and punches to vary the
thickness of the various types of section bar produced, since the thickness of the
clip, which is the part to be deformed, i.e., the material “to be machined”, can remain
unchanged.
According to some further embodiments of the present disclosure, the use of a
material for the section bar with a high elastic return solves, if necessary, a possible
problem of having to apply on the section bar a clip with elastic properties (and
therefore, for instance, a stainless steel clip). Said performance is necessary for a
connection of the clip in the slit of another section bar, as for instance described in
the International patent application to the same holder of the
present patent application, and incorporated herein by reference.
In this respect, according to said further embodiments of the present disclosure,
in order to exploit the elastic properties already present in the material of the section
bar, the clip or connection article is an integral part of the section bar, to define an
integral coupling element. In other words, the connection article is formed integrally
or in one piece with the section bar, and therefore it is not applied. It follows that the
integral coupling element is formed from the same above-described material of the
section bar, and exploits its elastic properties.
Other features and the operation modes of the subject-matter of the present
disclosure will be made evident from the following detailed description of
embodiments thereof, given by way of a non-limiting example.
It is also to be understood that all possible combinations of embodiments
described with reference to the following detailed description fall within the scope of
the present disclosure.
Reference will be made to the figures of the annexed drawings, wherein:
- Figures 1 and 2 schematically show a perspective view of a support structure for
false ceilings;
- Figures 3 and 4 show perspective views of a further support structure for false
ceilings;
- Figure 5 shows a perspective view of a connection article associated to a section
bar according to the present disclosure;
- Figure 6 shows a side view of a connection article associated to a section bar
according to the present disclosure;
- Figure 7 shows a sectional view along line III-III of Figure 6;
- Figure 8 shows a detail IV of Figure 7;
- Figures 9 and 10 show a perspective view of a support structure for false ceilings
according to an embodiment of the present disclosure;
- Figures 11 and 12 show a perspective view of a support structure for false
ceilings according to an embodiment of the present disclosure.
With reference to the annexed figures, a metal section bar according to the
present disclosure is denoted by number 2. The metal section bar 2 is connected to
a clip 1 or connection article (Figures 1-8, 11-12), or includes an integral coupling
element 101 (Figures 9-10), to define a propping frame of a support structure for a
false ceiling according to the present disclosure.
The clip 1, which will be described more specifically in the following, is fixed to
one end of the metal section bar 2. As shown in Figures 1-4, the clip 1 can be used
for the connection to another clip, which is in turn fixed to a metal section bar, or it
can be inserted in a slit of a further metal section bar 2’ (Figures 3 and 4), to form a
support or propping structure for a false ceiling.
Alternatively, in an embodiment shown by way of example in Figures 9 and 10,
and Figures 11 and 12, in said slit of the metal section bar 2’, two clips 1 or two
integral coupling elements 101 are inserted from opposite sides, the two clips or the
two coupling articles being in turn associated to the respective section bar 2 to form
a crosswise structure.
The metal section bar 2 has, in the example, a T-shaped section, and is obtained
by folding a sheet metal, in order to obtain an overlap of at least two sheet metal
portions 5, 6 (Figures 7 and 8). The metal section bar 2 can be different from the
one illustrated, for instance of different section, but anyhow suitable for the false
ceiling field.
In particular, according to an embodiment of the present disclosure like the one
illustrated in the figures, the metal section bar 2 includes at least two sheet metal
portions 5, 6, or walls, side-by side and/or overlapped, as shown for instance in
Figures 7 and 8. The two sheet metal portions 5, 6 can be adherent the one on the
other.
The metal section bar 2 extends along a prevalent direction, also called
longitudinal direction. In other words, the metal section bar is an elongated body in
which there can be seen a long side, extended in said longitudinal direction, and a
short side, extended transversally with respect to the long side.
According to an aspect of the present disclosure, the metal section bar 2 has the
following mechanical features:
- maximum tensile strength Rm greater than 500 N/mm , more specifically 500
N/mm to 1000 N/mm ; and
- elongation of from 0% to 15%.
In practice, the metal section bar has high hardness and low elongation. In an
embodiment of the present disclosure, the metal section bar 2 has the following
mechanical features:
- maximum tensile strength Rm: 650 to 850 N/mm ; and
- elongation of from 1% to 12%, or elongation of from 2% to 8%.
wherein said mechanical features proved capable of attaining the best results. It
is therefore a steel section bar having a reduced elongation and high strength, with
a consequent high elastic return.
The steel can be zinc-coated (galvanized) steel, non-stainless steel, or painted
steel, or differently coated steel. In embodiments, for productions of lower grade and
cost, the steel is not coated.
Thanks to the fact that the metal section bar has said mechanical features of high
mechanical strength and low elongation, it is possible to use a metal section bar of
greatly reduced thickness, as will be explained in the following, which is suitable for
undergoing machining, like deforming or deep-drawings carried out with specific
equipment, without nullifying the mechanical performances of the installed section
bar when mounted in a false ceiling.
In particular, according to a further aspect of the present disclosure and
according to some embodiments of the present disclosure, like the ones shown in
Figures 1-8, 11-12, the deforming and deep-drawing machining are mainly carried
out on the clip 1, which has greater elongation ability than the section bar 2. The clip
1 can be of stainless steel, and is then coupled to a non-stainless steel section bar.
In particular, the clip 1 includes a plate sheet metal body 3 formed by a first clip
portion 11, including a slit intended for connection through retainers and fins with
another clip, or with said slit or slot of the section bar 2’, or with another connection
article (not illustrated) and a second portion 21 intended for connection and fixing to
the section bar 2.
The present disclosure relates in particular to the second portion 21 for
connection with the metal section bar 2; it follows that, in the following description
the first portion 11 will not be described, it being understood that it can be made with
slits, retainers, fins or other types of connection elements according to the needs for
connection with another clip or another section bar.
The second portion 21 comprises at least one hole 23, in the example two
through holes 23, for the connection with the section bar 2. The metal section bar 2
includes in turn two through holes 32.
In the exemplary embodiment the holes 23, 32 are circular. It should be
understood that they can be of any other shape and size.
The two through holes 23 of the clip 1 are identical to each other. The two
through holes 32 of the metal section bar 2 are also identical to each other.
Therefore in the following, reference will be made to only one hole 23 of each clip 1
and only one hole 32 of the metal section bar 2, it being understood that such
description is valid for all through holes 23 of the clip 1 and through holes 32 of the
metal section bar 2.
In particular, according to an aspect of the present disclosure and according to
some embodiments of the present disclosure like the ones shown in Figures 1-8, 11-
12, the clip 1 includes a deformed sheet metal portion, in the illustrated example
deep-drawn 24, that surrounds the hole 23 and that protrudes with respect to one
face 33 of the plate sheet metal body 3. Said deep-drawn sheet metal portion 24
defines a projection with respect to the face 33 of the plate sheet metal body 3 of the
clip 1. The deep-drawn sheet metal portion 24 is intended to be inserted in a
corresponding through hole 32 of the section bar 2, and therein riveted against the
section bar 2.
When fixed to the metal section bar 2, the deep-drawn sheet metal portion 24,
has an insertion clip portion 26 received in the through hole 32 of the section bar 2,
and a riveted clip portion 27 that protrudes radially with respect to the insertion
portion 26.
More specifically, in the embodiment illustrated in Figures 5-8, the section bar
2 has a piece of flat sheet metal 37 adjacent to the hole 32; it follows that, after the
connection, the riveted clip portion 27 overcomes and exerts a stable pressing
contact on the flat piece of sheet metal 37 of the section bar 2, ensuring a stabile
connection.
Moreover, in the exemplary embodiment of Figures 5-8, the deep-drawn sheet
metal portion 24 of the clip 1 has substantially the shape of a collar or a cylindrical
shape. It follows that, after the riveting, the riveted clip portion 27 has the shape of a
crown.
In other embodiments not illustrated, the deep-drawn sheet metal portion 24
can have a different shape from the cylindrical shape, for instance it may consist of
separate blades, or similar fins, intended to be riveted.
According to some alternative embodiments of the present disclosure, as for
instance the embodiment illustrated in Figures 9-10, in place of the connection
article 1 or clip, it is provided an integral coupling element 101, which is an integral
part formed as one piece with the section bar 2. It follows that the integral coupling
element 101 includes all above-reported mechanical features and properties of the
section bar 2, i.e. reduced elongation, and high strength and high elastic return. The
integral coupling element 101 can be suitable for a connection to the section bar 2’
as described in the above-mentioned International patent application
According to another aspect of the present disclosure a process for fixing a
clip 1 or connection article to a metal section bar of a support structure for a false
ceiling, having the above-mentioned mechanical features is described.
Said process provides a preliminary step for preparing the metal section bar.
Said preliminary step includes a step of providing a steel article, as for instance a
steel strip, having the following features:
- maximum tensile strength Rm greater than 500 N/ mm , for instance 500 to
1000 N/mm , even more specifically 650 to 850 N/mm ;
- elongation lower than 15%, i.e., from 0% to 15%, even more specifically from
1% to 12%, or from 2% to 8%.
In accordance with said properties, the steel strip can have a greatly reduced
thickness, of the order of 0.10-0.20 mm, which is suitable for the field of section bars
for false ceilings.
In other embodiments, the strip is coated, e.g., zinc-coated (galvanized). In
particular, prior to galvanizing the steel strip undergoes a specific thermal cycle.
Even more specifically, the steel strip undergoes a thermal cycle including a
maintenance cycle (at 450 °C) and/or a modest annealing (520°C) to obtain a crude
or little-annealed strip.
By way of information it is observed that the thermal cycle is based on a process
referred to as “Sendzimir-type galvanizing” in the field, still currently in use, in honor
of first prototypes of continuous galvanization plants created in the 1930s by T.K.
Sendzimir. This process initially consisted in the preliminary burning of a cold-rolled
strip in an oxidizing free-flame furnace to volatilize rolling oil residues and produce a
thin surface oxide layer. Subsequently, annealing at about 900° was carried out
under a highly aggressive reducing Nitrogen-Hydrogen atmosphere obtained from
pyrolyzed ammonia that pickled, thanks to the high temperatures, the oxide present
on the strip.
Therefore, it was not possible to successfully galvanize crude strips without
annealing them.
Around the 1970s a new type of furnace departs from Sendzimir principles by
making use of special non-oxidizing burners for direct-flame cleaning of the strip. A
further improvement is obtained with non-oxidizing vertical furnaces for surface
preparation. With this type of furnace it is attained a good flexibility in temperatures
required by the various thermal cycles, enabling annealing from 520° to 850° or
more, and therefore it is possible to obtain crude and half-crude products, however
still not in the thicknesses of interest as indicated in some embodiments of the
present disclosure. In fact, the need to obtain crude or little-annealed galvanized
products of extra-thin thickness (0.10-0.20mm), impossible to obtain with traditional
furnaces only, is relatively recent.
It was important to understand, for the application field (false ceilings) of the present
disclosure, that the first part of strip cleaning represents a critical part of the process,
since cold reduction is contaminated by rolling oils and oxide layers. It is of vital
importance, for the correct interstitial forming of the Iron/Zinc alloy, that these
contaminants be removed from the strip, as it is crucial to present a perfectly
cleaned surface to the molten bath to obtain acceptable adherence in the zinc-
coating step.
In order to make steel strips suitable for articles for false ceilings, as for instance
section bars according to the present disclosure, specific steelmaking plants have
been selected which obtain the cleaning with a cold process prior to the inletting in
the galvanization plant. Thus, direct-flame heating for the cleaning is definitely
facilitated, and on these thicknesses the plant can run at lower temperatures, as is
technically convenient for thicknesses so reduced. The various steps comprise an
electrolytic or ultrasonic degreasing in special hot-bath solutions, with subsequent
washing and rinsing in hot water. Here, all oily fractions from rolling are removed.
Subsequently, to remove surface oxides the strip transits in a pickling of diluted and
hot hydrochloric acid (HCl) in a suitable vat, hermetically sealed to suck up and
abate corrosive HCL fumes. A last washing in hot water at compensated PH ends
the preparing of the strip, which is ready to be zinc-coated (galvanized). It is
possible to also carry out a bland annealing to obtain a minimum deformability of the
product according to the end use.
After having obtained the galvanized strip of reduced thickness and having the
above-mentioned mechanical features, the strip is subjected to a forming or
pressing with specific plants, to obtain a section bar ready for use.
In an embodiment of the present disclosure, like the one shown in Figures 1 to 8, it
is further provided a step wherein a part of the clip is deformed around a through
hole 23 of the clip 1 intended for connection with the metal section bar 2, to
determine, for instance, a deep-drawn sheet metal portion 24.
It has to be noted that thanks to the properties of hardness and strength of the
material of the section bar 2, when a punch is operated for deep-drawing the clip 1
against section bar 2, the latter undergoes no deformation.
The deep-drawn sheet metal portion 24 has for instance substantially a cylindrical
shape or the shape of a collar.
In a first exemplary embodiment, the clip 1 is connected to a section bar 2 having a
flat piece of sheet metal 37, as shown in Figure 8. It follows that after insertion, the
deep-drawn sheet metal portion 24 is riveted to the section bar 2 to obtain a
connection like the one illustrated in Figure 8, without, as mentioned, creating
deformations.
Subsequently, a free end edge of the deep-drawn sheet metal portion 24 of the clip
1 is riveted on the other side of the metal section bar 2, to form a riveted clip portion
27.
The riveted clip portion 27 overcomes and surmounts the respective section bar
portion 2.
A very stable connection is obtained by riveting the deep-drawn sheet metal portion
24 of the clip 1. It may be observed that such connection is independent from the
thickness S of the section bar 2, which can be greatly reduced, for instance lower
than or equal to 0.25 mm or less, up to 0.10 mm. The clip 1 may have a higher
thickness S’, which can be of 0.4 mm for instance.
It is to be noted that thanks to the use of reduced thickness S, if necessary or
required, for the clip 1 more valuable materials having features of higher hardness
and yield strength can be used, without affecting significantly the costs of the metal
section bar.
In an embodiment of the present disclosure, as illustrated in Figures 9 and 10, in
place of the clip 1 applied to the section bar 2, an integral coupling element 101 is
provided, integrally formed as one piece with the section bar 2 at forming, from a
single strip according to the above-described galvanizing process. Accordingly,
being the integral coupling element 101 one piece with the section bar 2, no
machining on a separate clip is required. The integral coupling element 101 of this
alternative embodiment has the same features of elastic return of the section bar 2
and can be connected to the section bar 2’ by exploiting said elastic properties.
The subject-matter of the present disclosure has hereto been described with
reference to preferred embodiments thereof. It is understood that there may be other
embodiments referable to the same inventive concept, all falling within the protective
scope of the claims set forth hereinafter.
Claims (21)
1. T-shaped steel section bar for a support structure for false ceilings or for supporting false ceilings, wherein the T-shaped steel section bar is made of a galvanized steel strip or sheet metal of thickness equal to or lower than 0.25 mm, 5 wherein the steel presents the following combination of features: - maximum tensile strength Rm of from 500 to 1000 N/mm ; and - elongation from 2% to 8%.
2. T-shaped steel section bar according to claim 1, wherein said article has maximum tensile strength Rm of from 650 to 850 N/mm . 10
3. T-shaped steel section bar according to any one of the preceding claims, wherein the steel is non-stainless steel.
4. T-shaped steel section bar according to any one of the preceding claims, wherein the steel is steel comprising a coating.
5. T-shaped steel section bar according to claim 4, wherein the coating is a zinc- 15 based coating or a zinc alloy-based coating.
6. T-shaped steel section bar according to any one of the preceding claims, wherein the section bar is able to be directly joined to another metal section bar via an integral coupling element integrally formed as one piece with the T-shaped section bar. 20
7. T-shaped steel section bar according to any one of the preceding claims 1 to 5, wherein the section bar is able to be indirectly joined to another metal section bar via a clip, or connection article, said clip or connection article being an element separate from the section bar and having elongation ability greater than the section bar. 25
8. T-shaped steel section bar according to claim 6 or claim 7, wherein said section bar is of shape elongated along a longitudinal direction and includes at least two sheet metal or strip portions side-by-side, or overlapped, the one with the other in said longitudinal direction.
9. T-shaped steel section bar according to claim 8, wherein the section bar 30 comprises a single sheet metal folded on itself to define an overlap of walls, wherein said two sheet metal portions are said walls of said sheet metal, and are set in contact the one with the other.
10. Combination of a T-shaped steel section bar according to any one of the preceding claims 6 to 9, with said clip, or connection article, said clip being an 35 element separate from the section bar and having elongation ability greater than the section bar.
11. Combination according to claim 10, wherein said clip is of stainless steel.
12. Combination according to claim 10 or 11, wherein said clip is suitable for being fixed to said section bar and includes a plate sheet metal body having at least one through hole, said plate sheet metal body comprising at least one deformed sheet metal portion, said deformed sheet metal portion being protruding from one 5 face of said plate sheet metal body and surrounding at least partially said through hole of the clip, wherein said section bar has at least one through hole intended to be aligned to the through hole of the clip, wherein said deformed sheet metal portion of the clip is inserted in the through hole of the section bar and wherein the deformed sheet metal portion has an insertion clip portion received in the 10 through hole of the section bar, and a riveted clip portion that protrudes radially with respect to the insertion portion of the clip.
13. Combination according to claim 12, wherein said deformed sheet metal portion is a deep-drawn sheet metal portion.
14. Combination according to any one of the claims 10 to 13, wherein said clip has a 15 thickness greater than a thickness of the section bar.
15. Support structure for a false ceiling including a combination according to any one of the claims 10 to 14, or including a T-shaped steel section bar as set forth in any one of claims 1 to 9.
16. Process for making a T-shaped steel section bar for supporting of false ceilings, 20 wherein said T-shaped steel section bar is made from a starting galvanized steel strip or sheet metal of thickness equal to or lower than 0.25 mm and the steel of said strip having the following combination of features - maximum tensile strength of from 500 to 1000 N/mm ; and - elongation of from 2% to 8%. 25
17. Process according to claim 16, wherein said starting steel article has maximum tensile strength Rm of from 650 to 850 N/mm .
18. Process according to any one of the preceding claims 16 or 17, wherein said starting steel article is a strip that is subject to a zinc-coating step.
19. Process according to any one of the preceding claims 16 to 18, wherein the 30 same steel strip is used to make a T-shaped section bar able to be directly joined to another metal section bar via an integral coupling element.
20. Process according to any one of the preceding claims 16 to 18, wherein the same steel strip is used to make a T-shaped section bar able to be indirectly joined to another metal section bar via a clip, or connection article, said clip being 35 an element separate from the section bar and having elongation ability greater than the section bar.
21. T-shaped steel section bar substantially as described herein with reference to
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
IB2011055051 | 2011-11-11 | ||
PCT/IB2012/056221 WO2013068937A2 (en) | 2011-11-11 | 2012-11-07 | Support metal structure for a false ceiling |
Publications (2)
Publication Number | Publication Date |
---|---|
NZ624262A NZ624262A (en) | 2016-04-29 |
NZ624262B2 true NZ624262B2 (en) | 2016-08-02 |
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