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TITLE
End caps for structural members
DESCRIPTION
Field of the Invention
The invention relates to a method of constructing a multi-storey building from
modular panel components.
Background Art
In modular building construction it is known to assemble a building from factory-
formed modular building panels each fabricated from cold-formed structural steel.
The steel is cold-formed into various profiles to create the necessary rigidity. One
well documented profile is a so-called C-profile in which the sheet steel is folded
longitudinally to create a front face, two side faces each in a plane perpendicular to
the front face, and two inturned flange portions down the longitudinal edges of the
side faces remote from the front face. Cold-formed C-section structural steel
members can be assembled, generally by bolting together, into frameworks which
include some vertical members, some horizontal members and optionally one or more
diagonal cross-brace members. Z-section cold-formed structural steel members are
secured to the frameworks to provide offset support shoulders creating an edge rebate
into which solid shim panels can be secured.
One disadvantage of such a method of construction is that it is very limited in its
ability to support multiple storeys. As a generality, buildings made by the known
framework panel construction method can be three or at most four storeys high. For
higher buildings it is necessary to incorporate more rigid load-bearing vertical pillars
which may be of masonry, reinforced concrete or hot-rolled steel section such as I-
section girders.
This invention is based on the realisation, supported by structural analysis
calculations, that the known framework panel system as discussed above can be used
in the construction of buildings six, eight, ten or even twelve storeys high after only

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minor modification to strengthen the C-section structural members at the areas of
maximum potential weakness and to create a reliable and uniform transmission of the
vertical load of the building through mutually aligned C-section structural uprights.
The Invention
The invention provides the method of construction identified in claim 1 herein. When
the structural uprights have their end caps in direct contact with one another or
separated only by shim plates, the transmission of the vertical load of the building
directly from one structural upright to the next through abutting end caps and through
any associated shim plates enables the vertical load to be spread evenly throughout
the entire building in a manner and to an extent never before achieved. When the
structural uprights and their end caps slot into the internal recess of U-shaped
horizontal members spanning two or more of the structural uprights, the vertical load
is shared between adjacent C-section structural uprights and is thereby shared even
more evenly throughout the building.
The entire building shell is constructed from modular framework body panels before
any solid wall panel partitioning or cladding is added. Preferably the end cap at one
end of each structural upright, for example the top end, is provided with one or more
spigots which are received in one or more locating apertures in the end cap at the
adjacent end, for example the bottom end, of the aligned structural upright of the
framework body panel of the adjacent storey, for example the storey above. This
ensures rapid longitudinal alignment of the structural uprights of successive storeys.
The spigots are preferably held in place by swaging in apertures punched into the end
plate portions of the end caps during their initial manufacture. Preferably the spigots
are commercial fasteners sold under the Trade Mark AVDALE, which are intended to
create a recessed screw threaded anchor point in a metal plate. The method of
construction described above envisages those fasteners being inserted from the
underside of the end plate portion of each end cap, so that they project from the end
plate portion as a smooth-sided cylindrical steel spigot rather than depending from the
top face of the end plate portion to create an internally screw-threaded recess.

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Drawings
Figure 1 is a perspective view of a framework panel component of a modular building
constructed according to the invention;
Figure 2 is a perspective view of a top end of one of the cold-rolled C-section
structural uprights without its end cap;
Figure 3 is a perspective view of the end cap to be secured to the end of the structural
upright of Figure 2;
Figure 4 is a perspective view of the end cap of Figure 3 viewed from the direction of
the arrow A in Figure 3;
Figure 4A is a side elevation, taken in the direction of the arrow 4A of Figure 4, of the
end cap of Figure 4, but showing the joint between the side and end plate portions of
the end cap in greater detail. Figure 4A also shows, in phantom, the associated
structural upright and a U-shaped horizontal member which in use would span two or
more such structural uprights;
Figure 4B is an enlarged detail of one corner of the end cap of Figure 4A, but shown
in perspective view;
Figure 4C is a perspective view similar to that of Figure 3, but of a modification of the
end cap of Figure 3;
Figure 5 is a plan view of a flat piece of steel before it is bent and welded or brazed
into the end cap of Figures 3 and 4;
Figure 6 is a plan view of the structural upright of Figure 2 with the end cap secured
thereto, with the bottom end portion of an associated structural upright of the next
storey of the building being shown in phantom lines;
Figure 7 is a section through an AVDALE ™ fastener fitted as a spigot to the end
plate portion of an end cap; and
Figure 8 is a perspective view of a part of the framework of panel components of a
building during construction, before the addition of the solid wall panels to form the
internal partitioning of the building and cladding to form the outer walls of the
building.
The invention relates to a method of constructing a multi-storey building from
modular panel components. Figure 1 is a perspective view of one such modular panel

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component. It is of standard room height and its length is preferably a standard length
so that multiples of the identical building panel can be made up into a variety of
building shapes and sizes, or possibly mixing together two similar building panels of
the same height but of different standardized lengths can provide more flexibility to
the designer. If a building length or width is desired that cannot be made up from
standardized length panels, then preferably a whole number of uniform standardized
length panels is used, with a single custom-made building panel constructed generally
as illustrated in Figure 1 being used to bring the array to the precise length specified
by the architect.
The modular panel of Figure 1 comprises a framework of cold-formed C-profile
structural steel members. These include vertical members 1 to 5, horizontal 6 and 7,
and diagonal cross-brace members 8 and 9. The framework is assembled in a factory
using an assembly jig which ensures that each panel can be made to precisely the
same dimensions, working to extremely low tolerances. The joints are all welded or
brazed.
The vertical members 1 and 5 form load-bearing structural uprights of the finished
building, and each is provided at its top and bottom ends with end caps 10. The
precise construction of which is explained with reference to Figures 2 to 5. The end
caps end at the top and bottom of the respective load-bearing structural uprights 1 and
5 are identical except for the addition of locating spigots 11 in the end caps 10 along
the top of the panel, cooperating with corresponding apertures in the end caps along
the bottom of the panel.
Each loading-bearing structural upright 1 and 5 extends the full height of the panel
component, emanating in a flat end (top or bottom) as illustrated in Figure 2. A
chamfer 12 is formed across the top and bottom ends of each intumed side flange
portion 13 of the C-profile of vertical member 1 or 5, as shown in Figure 2. The
purpose of this chamfer 12 is explained later.

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Each end cap 10 is formed by bending a metal blank that has been cut to the shape
shown in Figure 5. In Figure 5, the fold lines are shown in phantom. The blank is
formed from sheet steel and comprises a back plate portion 10a, a pair of wing
portions 10b and an upstanding portion 10c. The wing portions 10b are bent over by
90° from the back plate portion 10a to create side plate portions of the end cap as
shown in Figures 3 and 4, and the upstanding portion is bent over by 90° to create an
end plate portion, also as shown in Figures 3 and 4. The bending is a cold press
bending operation, and after the bending is complete the edges of the side plate
portions 10b are secured to edges of the end plate portion 10c by welding or by
brazing as indicated at 14 in Figures 3 and 4.
The formed end cap 10 is dimensioned to fit accurately and securely over the
respective upper or lower end of the structural upright 1 or 5. Because any end
formed by cold-bending a steel sheet is necessarily a small arc as opposed to a true
right angle, the internal bend line between the back plate portion 10a and the end plate
portion Kc is arcuate, and chamfer 12 is established on the structural uprights 1 and 5
to ensure that when fitted the end plate portion 10c lies completely flat in metal-to-
metal contact with the whole of the top or bottom of the structural upright 1 or 5.
The end caps 10 are secured to their associated structural uprights 1 and 5 by welding
or brazing. Preferably the back plate portion of the end cap is welded or brazed to
each of the mutually aligned edge portions of the oipen end of the associated C-
section structural upright 1 or 5. The side plate portions of each end cap may be
secured to the associated opposite sides of the structural upright 1 or 5 by screws or
by welding or brazing. In either case the weld or braze may be a spot weld or a plug
weld or braze. Thus the back plate portion 10a spans the gap between the intumed
slide flanges 13 of the structural uprights, so that when welded together the top and
bottom of each structural upright is formed as a complete channel member with metal
on all four side faces, as opposed to the remainder of the structural upright 1 or 5
which is open C-section.

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The end caps 10 which sit on the top of the panel framework are fitted with a pair of
protruding spigots 7 which protrude from apertures 15 cut from the end cap blank as
shown in Figure 5. The corresponding end caps of the bottom of the panel structure
have no such spigots 11 fitted, but are formed with corresponding apertures 15. Each
spigot is preferably a swaged anchor member such as those commercially available
under the Trade Mark AVDALE. One such spigot is shown in section in Figure 7. It
comprises a retaining flange portion 1 la, an internally screw threaded portion 1 lb and
an intermediate portion lie which is of a thinner wall thickness than that of lib so
that when the screw threaded portion 1 lb is pulled downwardly using an appropriate
setting tool, the intermediate portion lie swages over to lock the fastener to the
aperture 15 in the end plate portion 10c. The outer surface of the screw threaded
portion lib is cylindrical, so that the secured fastener act as a spigot extending
perpendicularly out from the end plate portion 10c. If all of the apertures 15 in the
end cap blanks are accurately positioned, as they can be if for example they are cut by
laser, then the spigots 11 protruding from the top of the framework are accurately
aligned with the corresponding apertures 15 in the end caps 10 of the bottom, so that
successive storeys of a building made by the method of the invention can be very
accurately positioned one over the other.
Figures 4A and 4B show in greater detail the preferred construction of the end plate
and side plate portions of the end cap and their precise inter-engagement. Outer side
edges 10c' of the end plate portions 10c abut but do not overlie top side edges 10b' of
the side plate portions 10b, so that there remains a recess or chamfer to accommodate
an internal form radius of an associated U-profile horizontal member 40 into which
the end cap can be located. This makes it possible for the end cap to establish face-to-
face contact with all three of the internal walls of the associated U-profile horizontal
member 40 as illustrated in Figure 4A in which the U-profile member 40 is shown in
phantom line together with the associated structural upright which is shown with the
reference number 42.
It will be noted that Figure 4A shows no spigots 11. Where the end cap is to be fitted
into a U-profile horizontal member spanning two or more structural uprights, it is

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possible that the spigots 11 may be omitted. Alternatively they may be included as
already described, in which case they interfit with holes drilled through the horizontal
web of the U-profile horizontal member 40.
An alternative end cap to that of Figures 3, 4A and 4B is shown in Figure 4C. As
with the end cap of Figures 3, 4A and 4B, it is made with a back plate portion 10a,
two side plae portions 10b and an end plate portion 10c formed by bending from a
single cut metal blank similar to that of Figure 5. However with the end cap of Figure
4C there are shown holes 43 in the back plate portion 10a, being the holes through
which the plug braze or plug weld joins are made to connect the end cap to the
aligned sides of the open face of the C-profile structural upright (not shown) to which
it is joined. The holes 43 may be arranged in any suitable pattern. A slot 45 is made
down each of the side plate portions 10b. The two slots are identical, although only
one is visible in Figure 4C. In use the end cap at the end of a structural vertical
upright is pushed into an inverted U-profile channel section wall plate , and if that
channel section has been formed with internally directed dimples in its parallel side
faces, those dimples can slide down the slot 45 to locate the end cap longitudinally of
the U-profile wall plate. By forming that wall plate accurately to size and locating the
dimples accurately in the factory using numerically controlled machinery, the location
of the end cap along the wall plate can be both positive and accurate even when the
building is being erected under site conditions. The slot 45 and the dimples in the U-
profile wall plate provide an inexpensive alternative to the use of the AVDALE ™
spigot location means discussed earlier.
The end caps 10 are preferably secured to the corresponding structural uprights 1 and
5 by plug welding or by plug brazing, using holes (not shown) which are pre-formed
in the blanks for the end caps 10. In addition, bolt holes 16 are formed, to enable the
assembled wall panels to be pulled together and secured fast one to the other during
construction.
When erecting a multi-storey building by the method of the invention, a first storey is
first erected, by bolting and/or welding an appropriate number of panel frameworks

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one to the other. To build the next higher storey, similar building panels are used,
with the structural uprights (1 and 5) both the higher of the two storeys being placed
directly over the corresponding structural uprights of the storey just completed. Metal
shims (one of which is shown as 17 in Figure 6) are placed over the tops of the end
caps 10 of the structural uprights of the floor just completed, and the number and
thickness of the shims 17 is adjusted until the new storey being built is exactly
horizontal. The spigots 11 pass through holes cut in the shims. They continue on to
engage in the apertures 15 cut in the end caps at the bottom of the structural uprights
of the next higher storey, and the metal-to-metal contact between the top edge of the
structural uprights and the peripheral internal edge of the end plate portion of each
end cap means that there is a continuous longitudinal run of metal through all such
structural uprights running from the lowest to the highest storey of the building. That
enables a significantly higher building to be constructed than if the building load were
transmitted generally along the whole of the top and bottom faces of the horizontal
members 6 and 7.
i
Figure 8 illustrates just how versatile the method of construction of the invention can
be. The end caps can be used whenever the structural uprights meet horizontal
members of the framework in an L-configuration as shown at 20, a T-configuration as
shown at 21, a 3-way mutually perpendicular junction as shown at 22, a 4-way
mutually perpendicular junction (not illustrated) or a 5-way mutually perpendicular
junction as illustrated at 23. All of those junctions more advanced than the simple re-
shaped junction 20 can be created by bolting together two, three or four panel
components, each of which is constructed as previously described.
Once the building framework has been constructed from the modular panel
components as described above, floors ceilings and wall cladding can be added.
Preferably individual panel components contain the necessary anchorages for the
doors and windows, so the final finishing of the building can be carried out rapidly
according to conventional methods.

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CLAIMS
1. A method of constructing a multi-storey building from modular panel
components wherein:
each panel component comprises a framework of cold-formed C-profile or U-
profile structural steel members including vertical members and horizontal members
of which at least some of the vertical members are C-profile members forming load-
bearing structural uprights of the finished building;
each of the said load-bearing structural uprights is provided at each of its top
and bottom ends with an end cap which is connected to the load-bearing structural
upright by welding or by brazing, and which comprises a back plate portion secured
across the open side of the C-profile of the associated structural upright, two side
plate portions secured to opposite sides of the associated structural upright, and an end
plate portion which lies across the otherwise open end of the associated structural
upright, the end plate portion being in continuous metal-to-metal contact with the
associated end of the load-bearing structural upright; and
in the finished building the end cap at the top of each of the load-bearing
structural uprights of one storey is in contact, either directly or via one or more metal
shim plates, with the internal walls of a U-profile horizontal member spanning two or
more of the structural uprights or with an end cap at the bottom end of one of the
load-bearing structural uprights of the next higher storey so as to transmit the vertical
load of the building directly through the end caps down through the associated load-
bearing structural uprights.
2. A method according to claim 1, wherein the end caps are formed by cold-
bending a steel sheet so that two wing portions are bent over by 90° from the back
plate portion to create the side plate portions and an upstanding portion is bent over
by 90° from the back plate portion to create the end plate portion, and edges of the
side plate portions are secured to edges of the end plate portion by welding or by
brazing.
3. A method according to claim 2, wherein the end caps are made to establish
face-to-face contact with all three internal walls of an associated U-profile horizontal

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member spanning two or more of the structural uprights, by forming the outer side
edges of the end plate portion of the end cap to abut but not completely to overlie the
associated edges of the side plate portion thereof and by connecting together the
abutting edges by a seam weld or braze so as to define therebetween a recess or
chamfer to accommodate an internal form radius of the associated U-profile member.
4. A method according to any preceding claim, wherein one of the pair of end
caps secured to each of the load-bearing structural uprights is provided with one or
more spigots projecting longitudinally from the end cap and the other of the pair of
end caps secured to the same structural upright is provided with one or more apertures
in its end plate portion, so that in the finished building each of the spigots projecting
from the structural uprights of one storey is located in a corresponding one of the
apertures to locate the structural uprights of adjacent storeys in longitudinal alignment
one with another.
5. A method according to claim 4, wherein the spigots are secured to their
associated end caps by passing each one through an aperture in the end plate portion
of the end cap and securing it in position by swaging.
6. A method according to claim 5, wherein the spigots axe AVDALE ™
fasteners.
7. A method according to any preceding claim, wherein the back plate portion of
the end cap is welded or brazed to each of the mutually aligned edge portions of the
open end of the assocoated C-profile structural upright so as to create, at the said top
or bottom end of the C-section structural upright a complete box section profile.
8. A method according to claim 7, wherein each weld or braze between the back
plate portion of the end cap and the mutually aligned edge portions of the open end of
the associated C-profile structural uprights is a spot weld or a plug weld or plug braze.

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9. A method according to claim 7, wherein the side plate portions of each end
cap are secured to the oipposite sides of the associated C-profile structural uprights by
screws or by welding or brazing.
10. A method according to any preceding claim wherein the framework of each
panel includes at least one diagonal cross-brace member which is also a cold-formed
C-profile structural steel member.

The invention provides a method of constructing a multi-storey building from modular panel components. Each
panel component comprises a framework of cold- formed C-profile structural steel members including vertical members (1 to 5)
horizontal members (6 and 7) and optional diagonal cross-brace members (8 and 9). The vertical members include some load-bearing
structural uprights of the finished building, each of which is provided with an end cap (10) on each of its top and bottom ends,
connected to the corresponding load-bearing structural upright by welding or by brazing. Each end cap comprises a back plate
portion (10a) secured across the open side of the C-profile of the associated structural upright (1 or 5), to side plate portions (10b)
secured to opposite sides of the associated structural upright (1 or 5) and an end plate portion which lies across the otherwise open
end of the associated structural upright (1 or 5). The end plate portion is in continuous metal -to-metal contact with the associated
load-bearing structural upright, so that in the finished building the end caps (10) at the top ends of the load-bearing structural uprights
(1 or 5) of one storey are in contact, either directly or via one or more metal shim plates (17), with the interior faces of a C-profile
horizontal structural member spanning two or more structural uprights or with the end caps at the bottom ends of the load-bearing
structural uprights (1 or 5) to the next higher storey. This construction, relying as it does on continuous metal-to-metal contact,
enables the building of higher structures than would otherwise be possible using cold-formed C-profile structural steel members.