U.S. patent application number 10/537932 was filed with the patent office on 2006-06-29 for structural building element.
This patent application is currently assigned to Henley Consultants Limited. Invention is credited to John Window.
Application Number | 20060137284 10/537932 |
Document ID | / |
Family ID | 9948983 |
Filed Date | 2006-06-29 |
United States Patent
Application |
20060137284 |
Kind Code |
A1 |
Window; John |
June 29, 2006 |
Structural building element
Abstract
The invention provides a structural building element formed from
cold-rolled lightweight sheet steel. The building element may be
used as a structural upright or as a beam, and is based generally
on building elements with a known C-shaped profile. The profile of
the building element of the invention is however based on a
continuous curve. Each of a pair of front wall portions extends in
a wholly or substantially smooth arc from a central slot opening
onto the corresponding lateral side. The rear portion is
sinusoidal, comprising a pair of convex wall portions each
extending in a wholly or substantially smooth arc from a concave
arcuate or substantially arcuate rear central wall portion onto a
respective one of the lateral sides.
Inventors: |
Window; John; (Market
Harborough, GB) |
Correspondence
Address: |
PIETRAGALLO, BOSICK & GORDON
ONE OXFORD CENTRE, 38TH FLOOR
301 GRANT STREET
PITTSBURGH
PA
15219-6404
US
|
Assignee: |
Henley Consultants Limited
7 Hill Street
Douglas, Isle of Man
GB
|
Family ID: |
9948983 |
Appl. No.: |
10/537932 |
Filed: |
December 3, 2003 |
PCT Filed: |
December 3, 2003 |
PCT NO: |
PCT/GB03/05257 |
371 Date: |
November 3, 2005 |
Current U.S.
Class: |
52/656.9 |
Current CPC
Class: |
E04C 2003/0495 20130101;
E04C 2003/0447 20130101; E04C 3/09 20130101; E04C 2003/0434
20130101; E04C 2003/0413 20130101; E04C 2003/0452 20130101; E04B
2001/5875 20130101; E04C 2003/043 20130101; E04C 2003/0473
20130101; E04C 2003/0421 20130101; E04C 3/07 20130101 |
Class at
Publication: |
052/656.9 |
International
Class: |
E04C 2/38 20060101
E04C002/38 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 3, 2002 |
GB |
0228171.5 |
Claims
1. A structural building element formed from cold-rolled
lightweight sheet steel, with a generally C-shaped profile having a
front comprising a pair of front wall portions extending outwardly
from a central slot opening to a pair of lateral sides of the
building element, and a rear wall portion joining together the
lateral sides, wherein each of the pair of front wall portions
extends in a substantially smooth arc from the central slot opening
onto the corresponding lateral side, and the rear wall portion
comprises a central concave portion bounded by a pair of convex
wall portions each extending from a concave arcuate portion of the
central concave portion in a smooth arc to a respective one of the
lateral sides.
2. A structural building element according to claim 1, wherein the
cold-rolled sheet steel has a thickness of 0.5 mm to 2 mm.
3. A structural building element according to claim 1, wherein the
cold-rolled sheet steel has a thickness of about 0.8 mm.
4. A structural building element according to claim 1, wherein the
lateral sides each have a flat portion centrally thereon, and the
front portions join the flat portions tangentially.
5. A structural building element according to claim 1, wherein the
concave portion of the rear central wall portion comprises a flat
portion bounded by two concave substantially arcuate wall portions
from which the pair of convex wall portions of the rear wall
portion extend.
6. A connector for connecting together two structural building
elements of claim 1 in a T- or L-configuration, comprising a pair
of side portions each formed as a substantially arcuate jaw element
shaped to conform to a lateral side or a front portion or a convex
arcuate portion of a rear of one of the structural building
elements to be connected together, and a leg portion extending from
the jaw element, whereby when the jaw elements are secured to
opposite faces of the said one of the structural elements with the
leg portions mutually aligned, the leg portions cooperate to form a
profiled spur extending laterally from the said one of the
structural elements, with a profile corresponding to that of the
other of the structural elements to be connected together, for
sleeving the said other of the structural elements onto or into the
profile of the spur.
7. A connector according to claim 6, wherein each of the jaw
elements of the side portions is pre-punched with a hole located to
correspond to a respective one of a pair of pre-punched holes in
the said one of the structural building elements to be connected
together, for receiving a fixing element to define the angle made
by the spur to the profile of the said one of the structural
elements.
8. A connector for connecting together three structural building
elements of claim 1 in a cross configuration, comprising a pair of
side portions each formed as a generally convex jaw element shaped
to conform to a front or rear portion of one of the structural
building elements to be connected together, and two co-linear leg
portions extending one from each side from the jaw element, whereby
when the jaw elements are secured to opposite front and rear faces
of the said one of the structural elements with the pairs of leg
portions of the jaw elements mutually aligned, each pair of
mutually aligned leg portions cooperates to form a profiled spur
extending laterally from the said one of the structural elements,
each spur having a profile corresponding to that of one of the
others of the structural elements to be connected together, for
sleeving the said others of the structural elements onto or into
the profiles of the spurs.
9. A connector for connecting together three structural elements of
claim 1 in a K-configuration, comprising two mating halves each
press-formed from sheet steel, which together define three tubular
cavities in a K-configuration for receiving a central portion and
two end portions respectively of the three structural building
elements of claim 1.
10. A connector according to claim 9, wherein the sheet steel of
the two connector halves is deep-drawn to an extent such that the
mating halves have zones of mutual contact, and the connector
halves are welded together in the zones.
11. A connector according to claim 6, wherein the leg portion joins
the jaw elements along an arcuate edge of the material from which
the connector is made.
12. A connector according to claim 11, wherein the material from
which the connector is made is lightweight sheet steel.
13. A connector according to claim 12, which is press-formed.
Description
[0001] The invention relates to structural building elements formed
from cold-rolled lightweight sheet steel. Such building elements,
made to a constant profile, are known lightweight alternatives to
hot-rolled steel girders and may be built up into structures with a
high strength-to-weight ratio.
[0002] Lightweight sheet steel can be cold-rolled into a variety of
different useful profiles. C-shaped profiles are very useful, as
they can be joined together in a variety of ways to make up
structures that have a good resistance to bending and excellent
strength-to-weight ratios. A typical C-section profile would
comprise two front wall portions extending outwardly from a central
slot opening; a pair of lateral sides; and a rear portion joining
together the lateral sides. If desired, a swage may be provided in
the rear portion and optionally in the lateral sides, which
increases the strength appreciably without increasing the weight.
If desired, the front wall portions may be inturned along the line
of the central slot opening, which further increases the strength
and rigidity of the profile. Such profiles are made by
cold-rolling, which creates a radiussed fold or bend between the
generally flat front walls and the flat lateral sides and between
the lateral sides and the flat rear portion, but as a generality
the practice has been to keep the radii of those bends as small as
possible, to create building elements that are generally
rectangular in overall section.
[0003] It is an object of the invention to increase further the
strength of such structural building elements, without adding to
the overall weight.
The Invention
[0004] The invention provides a structural building element as
defined in claim 1 herein. The building element of the invention
uses curves wherever possible in place of the flat faces of known
C-shaped profile building elements. The overall profile of the
building elements according to the invention is preferably a
continuous arcuate curve, without any creases or sharp bends, from
the inner edge of one of the front wall portions, out in an arcuate
path embracing the whole of the associated lateral side and joining
the concave arcuate or substantially arcuate rear central wall
portion, before continuing symmetrically around to the inner edge
of the other wall portion on the opposite side of the central slot
opening. In such a building element the depth of the element from
front to back is equal to the diameter of the arc shared between
the front wall portions, the lateral sides and the mutually outer
extremities of the rear portion. As an alternative, however, each
of the lateral sides may have a flat portion centrally thereon, the
front portions joining the flat portions tangentially. That gives
the building element a greater depth than the diameter of the arcs
of the opposite sides. If desired, the concave arcuate or
substantially arcuate rear central wall section may be formed with
a central flat portion, merging tangentially with arcuate concave
portions on either side of that flat portion. That gives the
building element a potentially greater width than one with a
totally arcuate formation throughout.
[0005] The building elements according to the invention may be made
from sheet steel of thickness 2 mm or less down even to 0.05 mm.
Preferably they are made from sheet steel of thickness about 0.8
mm.
[0006] It will be appreciated that because the structural building
elements of the invention have not flat faces, or alternatively if
their only flat faces are the flat portions centrally on the
lateral or back sides, then conventional joining techniques for
securing together such building elements to a grid-like framework
become very difficult. The invention therefore further provides a
range of connectors for connecting together the structural building
elements according to the invention. Two such building elements can
be connected together in a T- or L-configuration using a connector
as specified in claim 6 herein. Alternatively three such elements
can be connected together in a cross or a K-configuration, using a
connector as specified in claim 8 herein. Any of the connectors can
be made from lightweight sheet steel, preferably by press-forming.
Preferably the leg portions join the jaw elements along an arcuate
edge of the material from which the connector is made. That is to
say, if the connector is first stamped out from sheet steel as a
flat blank, that blank will be generally T-shaped or L-shaped,
X-shaped or K-shaped but whatever the shape the internal angles
would be cut not as abrupt angular changes in direction of the edge
of the material from which the connector is made, but would be
rounded to create a smooth transition in the line of the edges of
the portion of the blank to be pressed into the jaw elements, and
the portions to be pressed into the leg portions. During pressing,
this arcuate gusset of sheet metal is cold-stretched to form the
junction between two curved sections extending in mutually
perpendicular directions (namely the jaw element and the associated
leg portion) each of which has been press-shaped to its own
profile. In some cases this cold-stretching may be sufficient to
bring the material of the two side portions into contact with one
another, in which case they may be spot-welded at their zone of
contact. This adds very considerably to the overall strength and
rigidity of the joint formed by a connector according to the
invention between two or more structural building elements
according to the invention.
[0007] The structural building elements of the invention can be
used, together with the connectors of the invention which join them
together, in the construction of modular buildings, mobile homes,
commercial racking, building joists, lattice beams, partition
walls, floors, ceilings, roofs, mezzanine floors, staircases, steel
framed furniture, workbenches, masts, pylons, gantries, stage
lighting frameworks and scaffolding. Many other uses will become
apparent from the true potential is explored of the ability to join
together linear struts at angles other than 90.degree..
DRAWINGS
[0008] FIG. 1 is a perspective view of a structural building
element according to the invention;
[0009] FIG. 2 is a cross section through the structural building
element of FIG. 1;
[0010] FIG. 3 is a cross section through a slightly altered profile
of a structural building element according to the invention;
[0011] FIG. 4 is a cross section through another slightly altered
profile of a structural building element according to the
invention;
[0012] FIG. 5 is a cross section through yet another slightly
altered profile of a structural building element according to the
invention;
[0013] FIG. 6 is a perspective view of an upright structural
building element according to the invention with a pair of profiled
spurs formed from structural building elements according to the
invention connected to the structural upright at a high level and
in the main plane of the structural upright and with a similar
profiled spur connected to the structural upright at a low level
and perpendicular to the main plane of the structural upright;
[0014] FIGS. 7a, 7b and 7c are respectively a plan view from above,
a front elevation and an end elevation of one half of the connector
used to join the pair of profiled spurs of FIG. 6 in the main plane
of the structural upright; and
[0015] FIGS. 8a, 8b and 8c are respectively a plan view from above,
a front elevation and an end elevation of a strengthening strap
shown in FIG. 6;
[0016] FIGS. 9a, 9b and 9c are respectively a plan view from above,
a front elevation and an end elevation of the connector used to
join the profiled spur of FIG. 6 perpendicular to the main plane of
the structural upright;
[0017] FIG. 10 is a perspective view of a structural upright formed
from a structural building element as shown in FIG. 5 with profiled
spurs extending perpendicularly therefrom at high and low
levels;
[0018] FIG. 11 is a plan view from above of a structural building
element of FIG. 1 with a spur extending therefrom at an angle of
45.degree. to the main plane of the structural building
element;
[0019] FIG. 12 is a perspective view of one side portion of the
asymmetric connector shown in FIG. 11;
[0020] FIG. 13 is a side elevation of a lattice beam made from
structural building elements according to the invention;
[0021] FIG. 14 is a perspective view of one connector used to make
the lattice beam of FIG. 13;
[0022] FIG. 15 is a plan view from above of two structural building
elements according to FIG. 5 made up into a rectangular section
column; and
[0023] FIG. 16 is a horizontal section through a triangular pylon
structure that may be made from three upright structural elements
according to FIG. 1.
[0024] Referring first to FIG. 1, a structural building element 1
is shown which has been formed from cold-rolled lightweight sheet
steel and has a generally C-shaped profile. The profile is constant
along the length of the building element 1 which may be made much
longer than that shown in FIG. 1. The building element has,
generally speaking, a pair of front wall portions 2a and 2b; a pair
of lateral sides 3a and 3b; and a rear portion 4. The front wall
portions 2a and 2b extend laterally outwardly from a central slot
opening 5, and each follows the arc of a circle from its inturned
inner edge 6a or 6b, around onto and over the lateral side 3a or 3b
to the rear portion 4. The rear portion 4 is a sinusoidal wall in
which the convex arcs just described merge with a concave arcuate
central rear wall portion 7.
[0025] The same section is shown in greater detail in FIG. 2 which
illustrates how the circles (shown in broken line) which the
arcuate front and side walls follow touch but do not overlap. One
possible variation of the shape is shown in FIG. 3, where it can be
seen that the lateral sides 3a and 3b include flat sections, with
the front portions joining the flat sections tangentially and the
convex elements of the sinusoidal rear portion also joining the
flat sections tangentially. Two other possible variations of the
sectional shape are shown in FIGS. 4 and 5, where it can be seen
that the rear wall portion 7 includes a flat section, with the
concave portions one on each side of the central flat section
joining the flat section tangentially. The flat section of the rear
wall portion can be of variable width, as illustrated in FIGS. 4
and 5. Alternatively the flat sections of FIGS. 3 to 5 may be
formed not completely flat but as continuous curves of larger
radius than the circles shown in FIG. 2 in broken line.
[0026] The curves of the structural building elements according to
the invention provide a very much stronger and more versatile
building element than the conventional flat-faced C-section
profiles. The building elements may be used as structural uprights
or as joists or beams, and their advantages are numerous. They may
be joined together in lattice frameworks using pressed steel
connectors according to the invention, with a far greater potential
strength and a vastly greater flexibility of design than
conventional C-section cold rolled lightweight steel structural
building elements which have a generally rectangular box-like
section with a central slot opening along one side.
[0027] To create T- or L- or X- or K-connections between structural
building elements according to the invention, individual connectors
are provided. FIG. 6 shows one X-configuration junction and one
L-configuration junction. The X-configuration junction, at the
upper half of FIG. 6, shows how two structural building elements 1a
and 1b according to FIG. 1 are connected to extend laterally one
from each side of a third structural building element 1c according
to FIG. 1 positioned as a structural upright. The elements 1a and
1b are in the main plane of the element 1c, aligned with a plane
passing centrally through both of the side walls 3a and 3b of FIG.
1. The L-configuration junction, at the lower half of FIG. 6, shows
how a fourth structural building element 1d is connected to extend
perpendicularly from the main plane of the element 1c.
[0028] FIGS. 7a to 7c illustrate the shape of the connector used to
create the X-configuration junction of FIG. 6. The connector is
made in two identical halves 10, only one of which is shown in
FIGS. 7a to 7c. It is formed from cold pressed steel, which may be
the same gauge steel as that of the elements 1a to 1c or of a
heavier gauge metal. Each half 10 of the connector may be spot-,
plug- or seam-welded to the structural upright 1c in a jig, for
example, and then the side elements 1a and 1b simply inserted
between the pairs of spurs which extend laterally from the upright
1c, and welded into place.
[0029] FIGS. 9a to 9c similarly illustrate the shape of the
connector used to create the L-configuration junction of FIG. 6.
The connector is made in two identical halves 11, only one of which
is shown in FIGS. 9a to 9c. It is formed from cold pressed steel,
like that of FIGS. 7a to 7c, but is preferably welded to the side
element 1d in a jig before the assembly of the element 1d and the
connector halves 11 is offered up to the structural upright 1c and
welded to that upright. The opposite sides of the connector formed
by the two halves 11 lap around the side walls of the structural
upright 1c by preferably more than 180.degree., so that the union
can be self-supporting prior to welding.
[0030] FIG. 6 also shows a strap 12 which can be welded across the
front of the structural building element according to the
invention. The shape of the strap 12 is illustrated in FIGS. 8a to
8c. The provision of a number of such straps along the length of
the structural building elements according to the invention greatly
increases the strength. In particular, one such strap immediately
above and one immediately below a junction such as that shown in
the lower half of FIG. 6 greatly enhances the strength of the
junction, as the two halves 11 of the connector are effectively
held together by the strap 12.
[0031] FIG. 10 illustrates other variants of the connectors 11 and
straps 12 that are possible. The connector 11a at a high level of
FIG. 10 has jaws which pass around the curved front and inside arc
of one arcuate portion of a structural upright building element 1
and around the curved arcuate outer wall of the same arcuate
portion, as opposed to straddling opposite outer side walls as in
FIG. 6. The connector 11b at a low level of FIG. 10 has jaws which
straddle opposite outer side walls as in FIG. 6, but the laterally
extending spurs which support the horizontally extending structural
element 1 by contacting the outer side walls of that horizontal
element 1 as opposed to the front and rear faces as in FIG. 6.
[0032] FIG. 10 also shows how an extended strap 12a can straddle
two parallel structural building elements 1; how a strap 12b can be
formed with a central stamped-out inturned flange 25 which is
spot-welded to a flat rear mid-portion of a structural building
element 1 shaped as shown in FIG. 4 or FIG. 5; and how a strap 12c
can be formed with a deep-drawn dimpled portion 26 which is deep
enough to contact an inside of the rear wall 7 of a structural
building element 1 according to FIG. 2 (not shown) or a similar
dimpled portion 26 of another strap 12 (not shown). Where the
dimpled portion 26 contacts the rear wall 7 or another dimpled
portion 26 the contacting zones are spot-welded together for
greater rigidity.
[0033] FIG. 10 also shows how a strengthening member 30 can be
inserted longitudinally down the centre of any arcuate curved wall
of any structural building element 1 according to the invention.
The strengthening member 30 can be a rod or tube, to enhance both
tensile strength and compression resistance in the axial direction,
or it may be a wire or cable under tension to enhance tensile
strength alone. If the structural building elements of the
invention are made to create a building module to be built up into
a framework for example as disclosed in W068004 then such a
strengthening member 30 can be inserted in selected structural
uprights of the building module, and preferably is provided with a
screw-threaded protruding portion 31 as shown in FIG. 10, so that
each strengthening member can be screw-connected to that
immediately above. Thus vertical reinforcement can be provided,
extending the whole height of the building and effectively locking
successive storeys together. Similar bracing or reinforcement can
be provided in the horizontal plane, by passing strengthening
members 30 through the arcuate curved walls of horizontally
disposed elements 1.
[0034] FIGS. 6 and 10 show how the connection between the
structural upright 1c and the side members can be in the main plane
of the structural upright or perpendicular to that main plane.
However the system of the invention is sufficiently flexible that
all other angles may be accommodated. FIG. 11 shows a junction in
which a side element 1e extends from a structural building element
1c of the invention at an angle of 45.degree. to the main plane X-X
of the element 1c. The joint is created using a connector made in
two portions, 13a and 13b. The two portions are not symmetrical, as
each comprises a jaw portion 14 partially to surround the outside
side wall of the structural element 1c, and a spur portion 15 to
encase a front or rear side of the side element 1e. The arcuate
extents of the jaw portions 15 are different as between the
portions 13a and 13b. FIG. 12 illustrates the shape of one of the
two portions. Both portions of the connector can be simply pressed
from sheet steel, and preferably a location hole 16 is punched into
each of the connector portions 13a and 13b during pressing, or
during stamping out of the blank for pressing, with another such
hole accurately positioned in the structural upright element 1c so
that assembly of the junction at the accurate angle is simply
assured by aligning the holes, inserting a rivet into the aligned
holes to obtain a temporary securing of the two connector halves
13a and 13b to the upright element 1c, and then welding the
connector firmly into position before sleeving the cross-element 1e
between the spur portions 15 and welding that in place.
Alternatively the connector portions 13a and 13b can be welded to
the side element 1e in a jig before being presented up to the
upright element 1c, when optionally holes such as the hole 16 can
be used to provide a temporary fixing by rivet before welding up
the junction.
[0035] The structural building elements according to the invention
can be made up into lattice beams such as that shown in FIG. 13
using K-configuration connectors which create a junction of less
than 90.degree. between the axis of the main structural building
element and the axis of each of two side elements. One such
connector is illustrated in FIG. 14. It is made in two halves 17a
and 17b, each pressed from lightweight sheet steel. The halves 17a
and 17b when placed together define three tubular cavities, 18, 19
and 20. The cavity 18 is a continuous tubular cavity extending from
one end to the other of the connector, and in use surrounds one
arcuate side of a structural building element 1 as shown in FIG. 5
for example. The structural element 1 of FIG. 14 is shown as
passing only half way through the connector but that is for
illustrative purposes only. In practice the connector would be
positioned mid-way along the length of an element 1. The cavities
19 and 20 are blind cavities each inclined at 45.degree. to the
axis of the cavity 18 and of the element 1. The cavities 19 and 20
receive respective arcuate sides of two further structural building
elements 1 (not shown) of identical size and shape to the element 1
shown in FIG. 15. If desired for additional strength another such
connector can be used to connect together the other arcuate sides
of the three structural building elements 1, to build up the
lattice beam of FIG. 13. Advantageously the sheet steel of the
connector halves is deep-drawn to an extent such that the mating
halves contact each other, as shown at 21, and the two halves are
spot-welded together in those zones of contact for increased
strength.
[0036] FIG. 15 shows how two straps 12 similar to those of FIGS. 6
and 8a to 8c but with a longer length can be used to join together
two structural building elements 1 into a rectangular
configuration. This creates a strong pillar for a building, and its
strength may be reinforced if necessary against compressive loads
by forming the structure around a pre-cast and optionally
reinforced concrete core 22.
[0037] FIG. 16 shows a triangular pylon structure that may be made
from three upright structural building elements 1 according to FIG.
1, connected together by cross-braces 1 which are also of the same
cross-sectional form as the uprights and. which are connected to
the uprights by connectors as shown in FIGS. 9a to 9c or as shown
in FIG. 14. If desired, braces 12 (shown in chain-dotted line) can
be added to the outside for added strength. The upright elements 1
may be truly vertical and mutually parallel, or may be mutually
inclined to one another to create an upwardly tapering pylon. FIG.
16 illustrates the flexibility of the structural building elements
of the invention when used in association with the connectors as
illustrated. The angles between the connectors and the main plane
of the structural elements can be varied at will, and the angles
between the axes of the connected structural elements can be varied
by varying the angle shown in FIG. 14 as 45.degree.. This gives the
designer the flexibility of a free choice of angle in all three
axes when constructing each joint in a lattice system.
* * * * *